2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57 static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
60 static void uart_port_shutdown(struct tty_port *port);
62 static int uart_dcd_enabled(struct uart_port *uport)
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
71 void uart_write_wakeup(struct uart_port *port)
73 struct uart_state *state = port->state;
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
79 tty_wakeup(state->port.tty);
82 static void uart_stop(struct tty_struct *tty)
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
93 static void __uart_start(struct tty_struct *tty)
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
98 if (port->ops->wake_peer)
99 port->ops->wake_peer(port);
101 if (!uart_tx_stopped(port))
102 port->ops->start_tx(port);
105 static void uart_start(struct tty_struct *tty)
107 struct uart_state *state = tty->driver_data;
108 struct uart_port *port = state->uart_port;
111 spin_lock_irqsave(&port->lock, flags);
113 spin_unlock_irqrestore(&port->lock, flags);
117 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
122 spin_lock_irqsave(&port->lock, flags);
124 port->mctrl = (old & ~clear) | set;
125 if (old != port->mctrl)
126 port->ops->set_mctrl(port, port->mctrl);
127 spin_unlock_irqrestore(&port->lock, flags);
130 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
131 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
134 * Startup the port. This will be called once per open. All calls
135 * will be serialised by the per-port mutex.
137 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
140 struct uart_port *uport = state->uart_port;
144 if (uport->type == PORT_UNKNOWN)
148 * Make sure the device is in D0 state.
150 uart_change_pm(state, UART_PM_STATE_ON);
153 * Initialise and allocate the transmit and temporary
156 if (!state->xmit.buf) {
157 /* This is protected by the per port mutex */
158 page = get_zeroed_page(GFP_KERNEL);
162 state->xmit.buf = (unsigned char *) page;
163 uart_circ_clear(&state->xmit);
166 retval = uport->ops->startup(uport);
168 if (uart_console(uport) && uport->cons->cflag) {
169 tty->termios.c_cflag = uport->cons->cflag;
170 uport->cons->cflag = 0;
173 * Initialise the hardware port settings.
175 uart_change_speed(tty, state, NULL);
179 * Setup the RTS and DTR signals once the
180 * port is open and ready to respond.
182 if (tty->termios.c_cflag & CBAUD)
183 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
188 * This is to allow setserial on this port. People may want to set
189 * port/irq/type and then reconfigure the port properly if it failed
192 if (retval && capable(CAP_SYS_ADMIN))
198 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
201 struct tty_port *port = &state->port;
204 if (port->flags & ASYNC_INITIALIZED)
208 * Set the TTY IO error marker - we will only clear this
209 * once we have successfully opened the port.
211 set_bit(TTY_IO_ERROR, &tty->flags);
213 retval = uart_port_startup(tty, state, init_hw);
215 set_bit(ASYNCB_INITIALIZED, &port->flags);
216 clear_bit(TTY_IO_ERROR, &tty->flags);
217 } else if (retval > 0)
224 * This routine will shutdown a serial port; interrupts are disabled, and
225 * DTR is dropped if the hangup on close termio flag is on. Calls to
226 * uart_shutdown are serialised by the per-port semaphore.
228 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
230 struct uart_port *uport = state->uart_port;
231 struct tty_port *port = &state->port;
234 * Set the TTY IO error marker
237 set_bit(TTY_IO_ERROR, &tty->flags);
239 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
241 * Turn off DTR and RTS early.
243 if (uart_console(uport) && tty)
244 uport->cons->cflag = tty->termios.c_cflag;
246 if (!tty || (tty->termios.c_cflag & HUPCL))
247 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
249 uart_port_shutdown(port);
253 * It's possible for shutdown to be called after suspend if we get
254 * a DCD drop (hangup) at just the right time. Clear suspended bit so
255 * we don't try to resume a port that has been shutdown.
257 clear_bit(ASYNCB_SUSPENDED, &port->flags);
260 * Free the transmit buffer page.
262 if (state->xmit.buf) {
263 free_page((unsigned long)state->xmit.buf);
264 state->xmit.buf = NULL;
269 * uart_update_timeout - update per-port FIFO timeout.
270 * @port: uart_port structure describing the port
271 * @cflag: termios cflag value
272 * @baud: speed of the port
274 * Set the port FIFO timeout value. The @cflag value should
275 * reflect the actual hardware settings.
278 uart_update_timeout(struct uart_port *port, unsigned int cflag,
283 /* byte size and parity */
284 switch (cflag & CSIZE) {
305 * The total number of bits to be transmitted in the fifo.
307 bits = bits * port->fifosize;
310 * Figure the timeout to send the above number of bits.
311 * Add .02 seconds of slop
313 port->timeout = (HZ * bits) / baud + HZ/50;
316 EXPORT_SYMBOL(uart_update_timeout);
319 * uart_get_baud_rate - return baud rate for a particular port
320 * @port: uart_port structure describing the port in question.
321 * @termios: desired termios settings.
322 * @old: old termios (or NULL)
323 * @min: minimum acceptable baud rate
324 * @max: maximum acceptable baud rate
326 * Decode the termios structure into a numeric baud rate,
327 * taking account of the magic 38400 baud rate (with spd_*
328 * flags), and mapping the %B0 rate to 9600 baud.
330 * If the new baud rate is invalid, try the old termios setting.
331 * If it's still invalid, we try 9600 baud.
333 * Update the @termios structure to reflect the baud rate
334 * we're actually going to be using. Don't do this for the case
335 * where B0 is requested ("hang up").
338 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
339 struct ktermios *old, unsigned int min, unsigned int max)
343 unsigned int altbaud;
345 upf_t flags = port->flags & UPF_SPD_MASK;
365 for (try = 0; try < 2; try++) {
366 baud = tty_termios_baud_rate(termios);
369 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
372 if (try == 0 && baud == 38400)
376 * Special case: B0 rate.
383 if (baud >= min && baud <= max)
387 * Oops, the quotient was zero. Try again with
388 * the old baud rate if possible.
390 termios->c_cflag &= ~CBAUD;
392 baud = tty_termios_baud_rate(old);
394 tty_termios_encode_baud_rate(termios,
401 * As a last resort, if the range cannot be met then clip to
402 * the nearest chip supported rate.
406 tty_termios_encode_baud_rate(termios,
409 tty_termios_encode_baud_rate(termios,
413 /* Should never happen */
418 EXPORT_SYMBOL(uart_get_baud_rate);
421 * uart_get_divisor - return uart clock divisor
422 * @port: uart_port structure describing the port.
423 * @baud: desired baud rate
425 * Calculate the uart clock divisor for the port.
428 uart_get_divisor(struct uart_port *port, unsigned int baud)
433 * Old custom speed handling.
435 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
436 quot = port->custom_divisor;
438 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
443 EXPORT_SYMBOL(uart_get_divisor);
445 /* Caller holds port mutex */
446 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
447 struct ktermios *old_termios)
449 struct uart_port *uport = state->uart_port;
450 struct ktermios *termios;
454 * If we have no tty, termios, or the port does not exist,
455 * then we can't set the parameters for this port.
457 if (!tty || uport->type == PORT_UNKNOWN)
460 termios = &tty->termios;
461 uport->ops->set_termios(uport, termios, old_termios);
464 * Set modem status enables based on termios cflag
466 spin_lock_irq(&uport->lock);
467 if (termios->c_cflag & CRTSCTS)
468 uport->status |= UPSTAT_CTS_ENABLE;
470 uport->status &= ~UPSTAT_CTS_ENABLE;
472 if (termios->c_cflag & CLOCAL)
473 uport->status &= ~UPSTAT_DCD_ENABLE;
475 uport->status |= UPSTAT_DCD_ENABLE;
477 /* reset sw-assisted CTS flow control based on (possibly) new mode */
478 hw_stopped = uport->hw_stopped;
479 uport->hw_stopped = uart_softcts_mode(uport) &&
480 !(uport->ops->get_mctrl(uport) & TIOCM_CTS);
481 if (uport->hw_stopped) {
483 uport->ops->stop_tx(uport);
488 spin_unlock_irq(&uport->lock);
491 static inline int __uart_put_char(struct uart_port *port,
492 struct circ_buf *circ, unsigned char c)
500 spin_lock_irqsave(&port->lock, flags);
501 if (uart_circ_chars_free(circ) != 0) {
502 circ->buf[circ->head] = c;
503 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
506 spin_unlock_irqrestore(&port->lock, flags);
510 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
512 struct uart_state *state = tty->driver_data;
514 return __uart_put_char(state->uart_port, &state->xmit, ch);
517 static void uart_flush_chars(struct tty_struct *tty)
522 static int uart_write(struct tty_struct *tty,
523 const unsigned char *buf, int count)
525 struct uart_state *state = tty->driver_data;
526 struct uart_port *port;
527 struct circ_buf *circ;
532 * This means you called this function _after_ the port was
533 * closed. No cookie for you.
540 port = state->uart_port;
546 spin_lock_irqsave(&port->lock, flags);
548 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
553 memcpy(circ->buf + circ->head, buf, c);
554 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
561 spin_unlock_irqrestore(&port->lock, flags);
566 static int uart_write_room(struct tty_struct *tty)
568 struct uart_state *state = tty->driver_data;
572 spin_lock_irqsave(&state->uart_port->lock, flags);
573 ret = uart_circ_chars_free(&state->xmit);
574 spin_unlock_irqrestore(&state->uart_port->lock, flags);
578 static int uart_chars_in_buffer(struct tty_struct *tty)
580 struct uart_state *state = tty->driver_data;
584 spin_lock_irqsave(&state->uart_port->lock, flags);
585 ret = uart_circ_chars_pending(&state->xmit);
586 spin_unlock_irqrestore(&state->uart_port->lock, flags);
590 static void uart_flush_buffer(struct tty_struct *tty)
592 struct uart_state *state = tty->driver_data;
593 struct uart_port *port;
597 * This means you called this function _after_ the port was
598 * closed. No cookie for you.
605 port = state->uart_port;
606 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
608 spin_lock_irqsave(&port->lock, flags);
609 uart_circ_clear(&state->xmit);
610 if (port->ops->flush_buffer)
611 port->ops->flush_buffer(port);
612 spin_unlock_irqrestore(&port->lock, flags);
617 * This function is used to send a high-priority XON/XOFF character to
620 static void uart_send_xchar(struct tty_struct *tty, char ch)
622 struct uart_state *state = tty->driver_data;
623 struct uart_port *port = state->uart_port;
626 if (port->ops->send_xchar)
627 port->ops->send_xchar(port, ch);
629 spin_lock_irqsave(&port->lock, flags);
632 port->ops->start_tx(port);
633 spin_unlock_irqrestore(&port->lock, flags);
637 static void uart_throttle(struct tty_struct *tty)
639 struct uart_state *state = tty->driver_data;
640 struct uart_port *port = state->uart_port;
644 mask |= UPSTAT_AUTOXOFF;
645 if (tty->termios.c_cflag & CRTSCTS)
646 mask |= UPSTAT_AUTORTS;
648 if (port->status & mask) {
649 port->ops->throttle(port);
650 mask &= ~port->status;
653 if (mask & UPSTAT_AUTOXOFF)
654 uart_send_xchar(tty, STOP_CHAR(tty));
656 if (mask & UPSTAT_AUTORTS)
657 uart_clear_mctrl(port, TIOCM_RTS);
660 static void uart_unthrottle(struct tty_struct *tty)
662 struct uart_state *state = tty->driver_data;
663 struct uart_port *port = state->uart_port;
667 mask |= UPSTAT_AUTOXOFF;
668 if (tty->termios.c_cflag & CRTSCTS)
669 mask |= UPSTAT_AUTORTS;
671 if (port->status & mask) {
672 port->ops->unthrottle(port);
673 mask &= ~port->status;
676 if (mask & UPSTAT_AUTOXOFF)
677 uart_send_xchar(tty, START_CHAR(tty));
679 if (mask & UPSTAT_AUTORTS)
680 uart_set_mctrl(port, TIOCM_RTS);
683 static void do_uart_get_info(struct tty_port *port,
684 struct serial_struct *retinfo)
686 struct uart_state *state = container_of(port, struct uart_state, port);
687 struct uart_port *uport = state->uart_port;
689 memset(retinfo, 0, sizeof(*retinfo));
691 retinfo->type = uport->type;
692 retinfo->line = uport->line;
693 retinfo->port = uport->iobase;
694 if (HIGH_BITS_OFFSET)
695 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
696 retinfo->irq = uport->irq;
697 retinfo->flags = uport->flags;
698 retinfo->xmit_fifo_size = uport->fifosize;
699 retinfo->baud_base = uport->uartclk / 16;
700 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
701 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
702 ASYNC_CLOSING_WAIT_NONE :
703 jiffies_to_msecs(port->closing_wait) / 10;
704 retinfo->custom_divisor = uport->custom_divisor;
705 retinfo->hub6 = uport->hub6;
706 retinfo->io_type = uport->iotype;
707 retinfo->iomem_reg_shift = uport->regshift;
708 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
711 static void uart_get_info(struct tty_port *port,
712 struct serial_struct *retinfo)
714 /* Ensure the state we copy is consistent and no hardware changes
716 mutex_lock(&port->mutex);
717 do_uart_get_info(port, retinfo);
718 mutex_unlock(&port->mutex);
721 static int uart_get_info_user(struct tty_port *port,
722 struct serial_struct __user *retinfo)
724 struct serial_struct tmp;
725 uart_get_info(port, &tmp);
727 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
732 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
733 struct uart_state *state,
734 struct serial_struct *new_info)
736 struct uart_port *uport = state->uart_port;
737 unsigned long new_port;
738 unsigned int change_irq, change_port, closing_wait;
739 unsigned int old_custom_divisor, close_delay;
740 upf_t old_flags, new_flags;
743 new_port = new_info->port;
744 if (HIGH_BITS_OFFSET)
745 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
747 new_info->irq = irq_canonicalize(new_info->irq);
748 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
749 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
750 ASYNC_CLOSING_WAIT_NONE :
751 msecs_to_jiffies(new_info->closing_wait * 10);
754 change_irq = !(uport->flags & UPF_FIXED_PORT)
755 && new_info->irq != uport->irq;
758 * Since changing the 'type' of the port changes its resource
759 * allocations, we should treat type changes the same as
762 change_port = !(uport->flags & UPF_FIXED_PORT)
763 && (new_port != uport->iobase ||
764 (unsigned long)new_info->iomem_base != uport->mapbase ||
765 new_info->hub6 != uport->hub6 ||
766 new_info->io_type != uport->iotype ||
767 new_info->iomem_reg_shift != uport->regshift ||
768 new_info->type != uport->type);
770 old_flags = uport->flags;
771 new_flags = new_info->flags;
772 old_custom_divisor = uport->custom_divisor;
774 if (!capable(CAP_SYS_ADMIN)) {
776 if (change_irq || change_port ||
777 (new_info->baud_base != uport->uartclk / 16) ||
778 (close_delay != port->close_delay) ||
779 (closing_wait != port->closing_wait) ||
780 (new_info->xmit_fifo_size &&
781 new_info->xmit_fifo_size != uport->fifosize) ||
782 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
784 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
785 (new_flags & UPF_USR_MASK));
786 uport->custom_divisor = new_info->custom_divisor;
791 * Ask the low level driver to verify the settings.
793 if (uport->ops->verify_port)
794 retval = uport->ops->verify_port(uport, new_info);
796 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
797 (new_info->baud_base < 9600))
803 if (change_port || change_irq) {
807 * Make sure that we are the sole user of this port.
809 if (tty_port_users(port) > 1)
813 * We need to shutdown the serial port at the old
814 * port/type/irq combination.
816 uart_shutdown(tty, state);
820 unsigned long old_iobase, old_mapbase;
821 unsigned int old_type, old_iotype, old_hub6, old_shift;
823 old_iobase = uport->iobase;
824 old_mapbase = uport->mapbase;
825 old_type = uport->type;
826 old_hub6 = uport->hub6;
827 old_iotype = uport->iotype;
828 old_shift = uport->regshift;
831 * Free and release old regions
833 if (old_type != PORT_UNKNOWN)
834 uport->ops->release_port(uport);
836 uport->iobase = new_port;
837 uport->type = new_info->type;
838 uport->hub6 = new_info->hub6;
839 uport->iotype = new_info->io_type;
840 uport->regshift = new_info->iomem_reg_shift;
841 uport->mapbase = (unsigned long)new_info->iomem_base;
844 * Claim and map the new regions
846 if (uport->type != PORT_UNKNOWN) {
847 retval = uport->ops->request_port(uport);
849 /* Always success - Jean II */
854 * If we fail to request resources for the
855 * new port, try to restore the old settings.
858 uport->iobase = old_iobase;
859 uport->type = old_type;
860 uport->hub6 = old_hub6;
861 uport->iotype = old_iotype;
862 uport->regshift = old_shift;
863 uport->mapbase = old_mapbase;
865 if (old_type != PORT_UNKNOWN) {
866 retval = uport->ops->request_port(uport);
868 * If we failed to restore the old settings,
872 uport->type = PORT_UNKNOWN;
880 /* Added to return the correct error -Ram Gupta */
886 uport->irq = new_info->irq;
887 if (!(uport->flags & UPF_FIXED_PORT))
888 uport->uartclk = new_info->baud_base * 16;
889 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
890 (new_flags & UPF_CHANGE_MASK);
891 uport->custom_divisor = new_info->custom_divisor;
892 port->close_delay = close_delay;
893 port->closing_wait = closing_wait;
894 if (new_info->xmit_fifo_size)
895 uport->fifosize = new_info->xmit_fifo_size;
896 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
900 if (uport->type == PORT_UNKNOWN)
902 if (port->flags & ASYNC_INITIALIZED) {
903 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
904 old_custom_divisor != uport->custom_divisor) {
906 * If they're setting up a custom divisor or speed,
907 * instead of clearing it, then bitch about it. No
908 * need to rate-limit; it's CAP_SYS_ADMIN only.
910 if (uport->flags & UPF_SPD_MASK) {
911 dev_notice(uport->dev,
912 "%s sets custom speed on %s. This is deprecated.\n",
914 tty_name(port->tty));
916 uart_change_speed(tty, state, NULL);
919 retval = uart_startup(tty, state, 1);
924 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
925 struct serial_struct __user *newinfo)
927 struct serial_struct new_serial;
928 struct tty_port *port = &state->port;
931 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
935 * This semaphore protects port->count. It is also
936 * very useful to prevent opens. Also, take the
937 * port configuration semaphore to make sure that a
938 * module insertion/removal doesn't change anything
941 mutex_lock(&port->mutex);
942 retval = uart_set_info(tty, port, state, &new_serial);
943 mutex_unlock(&port->mutex);
948 * uart_get_lsr_info - get line status register info
949 * @tty: tty associated with the UART
950 * @state: UART being queried
951 * @value: returned modem value
953 * Note: uart_ioctl protects us against hangups.
955 static int uart_get_lsr_info(struct tty_struct *tty,
956 struct uart_state *state, unsigned int __user *value)
958 struct uart_port *uport = state->uart_port;
961 result = uport->ops->tx_empty(uport);
964 * If we're about to load something into the transmit
965 * register, we'll pretend the transmitter isn't empty to
966 * avoid a race condition (depending on when the transmit
967 * interrupt happens).
970 ((uart_circ_chars_pending(&state->xmit) > 0) &&
971 !uart_tx_stopped(uport)))
972 result &= ~TIOCSER_TEMT;
974 return put_user(result, value);
977 static int uart_tiocmget(struct tty_struct *tty)
979 struct uart_state *state = tty->driver_data;
980 struct tty_port *port = &state->port;
981 struct uart_port *uport = state->uart_port;
984 mutex_lock(&port->mutex);
985 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
986 result = uport->mctrl;
987 spin_lock_irq(&uport->lock);
988 result |= uport->ops->get_mctrl(uport);
989 spin_unlock_irq(&uport->lock);
991 mutex_unlock(&port->mutex);
997 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
999 struct uart_state *state = tty->driver_data;
1000 struct uart_port *uport = state->uart_port;
1001 struct tty_port *port = &state->port;
1004 mutex_lock(&port->mutex);
1005 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1006 uart_update_mctrl(uport, set, clear);
1009 mutex_unlock(&port->mutex);
1013 static int uart_break_ctl(struct tty_struct *tty, int break_state)
1015 struct uart_state *state = tty->driver_data;
1016 struct tty_port *port = &state->port;
1017 struct uart_port *uport = state->uart_port;
1019 mutex_lock(&port->mutex);
1021 if (uport->type != PORT_UNKNOWN)
1022 uport->ops->break_ctl(uport, break_state);
1024 mutex_unlock(&port->mutex);
1028 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1030 struct uart_port *uport = state->uart_port;
1031 struct tty_port *port = &state->port;
1034 if (!capable(CAP_SYS_ADMIN))
1038 * Take the per-port semaphore. This prevents count from
1039 * changing, and hence any extra opens of the port while
1040 * we're auto-configuring.
1042 if (mutex_lock_interruptible(&port->mutex))
1043 return -ERESTARTSYS;
1046 if (tty_port_users(port) == 1) {
1047 uart_shutdown(tty, state);
1050 * If we already have a port type configured,
1051 * we must release its resources.
1053 if (uport->type != PORT_UNKNOWN)
1054 uport->ops->release_port(uport);
1056 flags = UART_CONFIG_TYPE;
1057 if (uport->flags & UPF_AUTO_IRQ)
1058 flags |= UART_CONFIG_IRQ;
1061 * This will claim the ports resources if
1064 uport->ops->config_port(uport, flags);
1066 ret = uart_startup(tty, state, 1);
1068 mutex_unlock(&port->mutex);
1072 static void uart_enable_ms(struct uart_port *uport)
1075 * Force modem status interrupts on
1077 if (uport->ops->enable_ms)
1078 uport->ops->enable_ms(uport);
1082 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1083 * - mask passed in arg for lines of interest
1084 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1085 * Caller should use TIOCGICOUNT to see which one it was
1087 * FIXME: This wants extracting into a common all driver implementation
1088 * of TIOCMWAIT using tty_port.
1091 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1093 struct uart_port *uport = state->uart_port;
1094 struct tty_port *port = &state->port;
1095 DECLARE_WAITQUEUE(wait, current);
1096 struct uart_icount cprev, cnow;
1100 * note the counters on entry
1102 spin_lock_irq(&uport->lock);
1103 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1104 uart_enable_ms(uport);
1105 spin_unlock_irq(&uport->lock);
1107 add_wait_queue(&port->delta_msr_wait, &wait);
1109 spin_lock_irq(&uport->lock);
1110 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1111 spin_unlock_irq(&uport->lock);
1113 set_current_state(TASK_INTERRUPTIBLE);
1115 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1116 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1117 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1118 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1125 /* see if a signal did it */
1126 if (signal_pending(current)) {
1133 __set_current_state(TASK_RUNNING);
1134 remove_wait_queue(&port->delta_msr_wait, &wait);
1140 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1141 * Return: write counters to the user passed counter struct
1142 * NB: both 1->0 and 0->1 transitions are counted except for
1143 * RI where only 0->1 is counted.
1145 static int uart_get_icount(struct tty_struct *tty,
1146 struct serial_icounter_struct *icount)
1148 struct uart_state *state = tty->driver_data;
1149 struct uart_icount cnow;
1150 struct uart_port *uport = state->uart_port;
1152 spin_lock_irq(&uport->lock);
1153 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1154 spin_unlock_irq(&uport->lock);
1156 icount->cts = cnow.cts;
1157 icount->dsr = cnow.dsr;
1158 icount->rng = cnow.rng;
1159 icount->dcd = cnow.dcd;
1160 icount->rx = cnow.rx;
1161 icount->tx = cnow.tx;
1162 icount->frame = cnow.frame;
1163 icount->overrun = cnow.overrun;
1164 icount->parity = cnow.parity;
1165 icount->brk = cnow.brk;
1166 icount->buf_overrun = cnow.buf_overrun;
1171 static int uart_get_rs485_config(struct uart_port *port,
1172 struct serial_rs485 __user *rs485)
1174 unsigned long flags;
1175 struct serial_rs485 aux;
1177 spin_lock_irqsave(&port->lock, flags);
1179 spin_unlock_irqrestore(&port->lock, flags);
1181 if (copy_to_user(rs485, &aux, sizeof(aux)))
1187 static int uart_set_rs485_config(struct uart_port *port,
1188 struct serial_rs485 __user *rs485_user)
1190 struct serial_rs485 rs485;
1192 unsigned long flags;
1194 if (!port->rs485_config)
1195 return -ENOIOCTLCMD;
1197 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1200 spin_lock_irqsave(&port->lock, flags);
1201 ret = port->rs485_config(port, &rs485);
1202 spin_unlock_irqrestore(&port->lock, flags);
1206 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1213 * Called via sys_ioctl. We can use spin_lock_irq() here.
1216 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1219 struct uart_state *state = tty->driver_data;
1220 struct tty_port *port = &state->port;
1221 void __user *uarg = (void __user *)arg;
1222 int ret = -ENOIOCTLCMD;
1226 * These ioctls don't rely on the hardware to be present.
1230 ret = uart_get_info_user(port, uarg);
1234 down_write(&tty->termios_rwsem);
1235 ret = uart_set_info_user(tty, state, uarg);
1236 up_write(&tty->termios_rwsem);
1240 down_write(&tty->termios_rwsem);
1241 ret = uart_do_autoconfig(tty, state);
1242 up_write(&tty->termios_rwsem);
1245 case TIOCSERGWILD: /* obsolete */
1246 case TIOCSERSWILD: /* obsolete */
1251 if (ret != -ENOIOCTLCMD)
1254 if (tty->flags & (1 << TTY_IO_ERROR)) {
1260 * The following should only be used when hardware is present.
1264 ret = uart_wait_modem_status(state, arg);
1268 if (ret != -ENOIOCTLCMD)
1271 mutex_lock(&port->mutex);
1273 if (tty->flags & (1 << TTY_IO_ERROR)) {
1279 * All these rely on hardware being present and need to be
1280 * protected against the tty being hung up.
1284 case TIOCSERGETLSR: /* Get line status register */
1285 ret = uart_get_lsr_info(tty, state, uarg);
1289 ret = uart_get_rs485_config(state->uart_port, uarg);
1293 ret = uart_set_rs485_config(state->uart_port, uarg);
1296 struct uart_port *uport = state->uart_port;
1297 if (uport->ops->ioctl)
1298 ret = uport->ops->ioctl(uport, cmd, arg);
1303 mutex_unlock(&port->mutex);
1308 static void uart_set_ldisc(struct tty_struct *tty)
1310 struct uart_state *state = tty->driver_data;
1311 struct uart_port *uport = state->uart_port;
1313 if (uport->ops->set_ldisc) {
1314 mutex_lock(&state->port.mutex);
1315 uport->ops->set_ldisc(uport, &tty->termios);
1316 mutex_unlock(&state->port.mutex);
1320 static void uart_set_termios(struct tty_struct *tty,
1321 struct ktermios *old_termios)
1323 struct uart_state *state = tty->driver_data;
1324 struct uart_port *uport = state->uart_port;
1325 unsigned int cflag = tty->termios.c_cflag;
1326 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1327 bool sw_changed = false;
1330 * Drivers doing software flow control also need to know
1331 * about changes to these input settings.
1333 if (uport->flags & UPF_SOFT_FLOW) {
1334 iflag_mask |= IXANY|IXON|IXOFF;
1336 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1337 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1341 * These are the bits that are used to setup various
1342 * flags in the low level driver. We can ignore the Bfoo
1343 * bits in c_cflag; c_[io]speed will always be set
1344 * appropriately by set_termios() in tty_ioctl.c
1346 if ((cflag ^ old_termios->c_cflag) == 0 &&
1347 tty->termios.c_ospeed == old_termios->c_ospeed &&
1348 tty->termios.c_ispeed == old_termios->c_ispeed &&
1349 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1354 mutex_lock(&state->port.mutex);
1355 uart_change_speed(tty, state, old_termios);
1356 mutex_unlock(&state->port.mutex);
1357 /* reload cflag from termios; port driver may have overriden flags */
1358 cflag = tty->termios.c_cflag;
1360 /* Handle transition to B0 status */
1361 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1362 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1363 /* Handle transition away from B0 status */
1364 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1365 unsigned int mask = TIOCM_DTR;
1366 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1368 uart_set_mctrl(uport, mask);
1373 * Calls to uart_close() are serialised via the tty_lock in
1374 * drivers/tty/tty_io.c:tty_release()
1375 * drivers/tty/tty_io.c:do_tty_hangup()
1376 * This runs from a workqueue and can sleep for a _short_ time only.
1378 static void uart_close(struct tty_struct *tty, struct file *filp)
1380 struct uart_state *state = tty->driver_data;
1381 struct tty_port *port;
1382 struct uart_port *uport;
1385 struct uart_driver *drv = tty->driver->driver_state;
1387 state = drv->state + tty->index;
1388 port = &state->port;
1389 spin_lock_irq(&port->lock);
1391 spin_unlock_irq(&port->lock);
1395 uport = state->uart_port;
1396 port = &state->port;
1398 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1400 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1404 * At this point, we stop accepting input. To do this, we
1405 * disable the receive line status interrupts.
1407 if (port->flags & ASYNC_INITIALIZED) {
1408 spin_lock_irq(&uport->lock);
1409 uport->ops->stop_rx(uport);
1410 spin_unlock_irq(&uport->lock);
1412 * Before we drop DTR, make sure the UART transmitter
1413 * has completely drained; this is especially
1414 * important if there is a transmit FIFO!
1416 uart_wait_until_sent(tty, uport->timeout);
1419 mutex_lock(&port->mutex);
1420 uart_shutdown(tty, state);
1421 tty_port_tty_set(port, NULL);
1423 spin_lock_irq(&port->lock);
1425 if (port->blocked_open) {
1426 spin_unlock_irq(&port->lock);
1427 if (port->close_delay)
1428 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1429 spin_lock_irq(&port->lock);
1430 } else if (!uart_console(uport)) {
1431 spin_unlock_irq(&port->lock);
1432 uart_change_pm(state, UART_PM_STATE_OFF);
1433 spin_lock_irq(&port->lock);
1437 * Wake up anyone trying to open this port.
1439 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1440 clear_bit(ASYNCB_CLOSING, &port->flags);
1441 spin_unlock_irq(&port->lock);
1442 wake_up_interruptible(&port->open_wait);
1444 mutex_unlock(&port->mutex);
1446 tty_ldisc_flush(tty);
1450 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1452 struct uart_state *state = tty->driver_data;
1453 struct uart_port *port = state->uart_port;
1454 unsigned long char_time, expire;
1456 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1460 * Set the check interval to be 1/5 of the estimated time to
1461 * send a single character, and make it at least 1. The check
1462 * interval should also be less than the timeout.
1464 * Note: we have to use pretty tight timings here to satisfy
1467 char_time = (port->timeout - HZ/50) / port->fifosize;
1468 char_time = char_time / 5;
1471 if (timeout && timeout < char_time)
1472 char_time = timeout;
1475 * If the transmitter hasn't cleared in twice the approximate
1476 * amount of time to send the entire FIFO, it probably won't
1477 * ever clear. This assumes the UART isn't doing flow
1478 * control, which is currently the case. Hence, if it ever
1479 * takes longer than port->timeout, this is probably due to a
1480 * UART bug of some kind. So, we clamp the timeout parameter at
1483 if (timeout == 0 || timeout > 2 * port->timeout)
1484 timeout = 2 * port->timeout;
1486 expire = jiffies + timeout;
1488 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1489 port->line, jiffies, expire);
1492 * Check whether the transmitter is empty every 'char_time'.
1493 * 'timeout' / 'expire' give us the maximum amount of time
1496 while (!port->ops->tx_empty(port)) {
1497 msleep_interruptible(jiffies_to_msecs(char_time));
1498 if (signal_pending(current))
1500 if (time_after(jiffies, expire))
1506 * Calls to uart_hangup() are serialised by the tty_lock in
1507 * drivers/tty/tty_io.c:do_tty_hangup()
1508 * This runs from a workqueue and can sleep for a _short_ time only.
1510 static void uart_hangup(struct tty_struct *tty)
1512 struct uart_state *state = tty->driver_data;
1513 struct tty_port *port = &state->port;
1514 unsigned long flags;
1516 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1518 mutex_lock(&port->mutex);
1519 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1520 uart_flush_buffer(tty);
1521 uart_shutdown(tty, state);
1522 spin_lock_irqsave(&port->lock, flags);
1524 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1525 spin_unlock_irqrestore(&port->lock, flags);
1526 tty_port_tty_set(port, NULL);
1527 if (!uart_console(state->uart_port))
1528 uart_change_pm(state, UART_PM_STATE_OFF);
1529 wake_up_interruptible(&port->open_wait);
1530 wake_up_interruptible(&port->delta_msr_wait);
1532 mutex_unlock(&port->mutex);
1535 static void uart_port_shutdown(struct tty_port *port)
1537 struct uart_state *state = container_of(port, struct uart_state, port);
1538 struct uart_port *uport = state->uart_port;
1541 * clear delta_msr_wait queue to avoid mem leaks: we may free
1542 * the irq here so the queue might never be woken up. Note
1543 * that we won't end up waiting on delta_msr_wait again since
1544 * any outstanding file descriptors should be pointing at
1545 * hung_up_tty_fops now.
1547 wake_up_interruptible(&port->delta_msr_wait);
1550 * Free the IRQ and disable the port.
1552 uport->ops->shutdown(uport);
1555 * Ensure that the IRQ handler isn't running on another CPU.
1557 synchronize_irq(uport->irq);
1560 static int uart_carrier_raised(struct tty_port *port)
1562 struct uart_state *state = container_of(port, struct uart_state, port);
1563 struct uart_port *uport = state->uart_port;
1565 spin_lock_irq(&uport->lock);
1566 uart_enable_ms(uport);
1567 mctrl = uport->ops->get_mctrl(uport);
1568 spin_unlock_irq(&uport->lock);
1569 if (mctrl & TIOCM_CAR)
1574 static void uart_dtr_rts(struct tty_port *port, int onoff)
1576 struct uart_state *state = container_of(port, struct uart_state, port);
1577 struct uart_port *uport = state->uart_port;
1580 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1582 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1586 * Calls to uart_open are serialised by the tty_lock in
1587 * drivers/tty/tty_io.c:tty_open()
1588 * Note that if this fails, then uart_close() _will_ be called.
1590 * In time, we want to scrap the "opening nonpresent ports"
1591 * behaviour and implement an alternative way for setserial
1592 * to set base addresses/ports/types. This will allow us to
1593 * get rid of a certain amount of extra tests.
1595 static int uart_open(struct tty_struct *tty, struct file *filp)
1597 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1598 int retval, line = tty->index;
1599 struct uart_state *state = drv->state + line;
1600 struct tty_port *port = &state->port;
1602 pr_debug("uart_open(%d) called\n", line);
1604 spin_lock_irq(&port->lock);
1606 spin_unlock_irq(&port->lock);
1609 * We take the semaphore here to guarantee that we won't be re-entered
1610 * while allocating the state structure, or while we request any IRQs
1611 * that the driver may need. This also has the nice side-effect that
1612 * it delays the action of uart_hangup, so we can guarantee that
1613 * state->port.tty will always contain something reasonable.
1615 if (mutex_lock_interruptible(&port->mutex)) {
1616 retval = -ERESTARTSYS;
1620 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1625 tty->driver_data = state;
1626 state->uart_port->state = state;
1627 state->port.low_latency =
1628 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1629 tty_port_tty_set(port, tty);
1632 * Start up the serial port.
1634 retval = uart_startup(tty, state, 0);
1637 * If we succeeded, wait until the port is ready.
1639 mutex_unlock(&port->mutex);
1641 retval = tty_port_block_til_ready(port, tty, filp);
1646 mutex_unlock(&port->mutex);
1650 static const char *uart_type(struct uart_port *port)
1652 const char *str = NULL;
1654 if (port->ops->type)
1655 str = port->ops->type(port);
1663 #ifdef CONFIG_PROC_FS
1665 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1667 struct uart_state *state = drv->state + i;
1668 struct tty_port *port = &state->port;
1669 enum uart_pm_state pm_state;
1670 struct uart_port *uport = state->uart_port;
1672 unsigned int status;
1678 mmio = uport->iotype >= UPIO_MEM;
1679 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1680 uport->line, uart_type(uport),
1681 mmio ? "mmio:0x" : "port:",
1682 mmio ? (unsigned long long)uport->mapbase
1683 : (unsigned long long)uport->iobase,
1686 if (uport->type == PORT_UNKNOWN) {
1691 if (capable(CAP_SYS_ADMIN)) {
1692 mutex_lock(&port->mutex);
1693 pm_state = state->pm_state;
1694 if (pm_state != UART_PM_STATE_ON)
1695 uart_change_pm(state, UART_PM_STATE_ON);
1696 spin_lock_irq(&uport->lock);
1697 status = uport->ops->get_mctrl(uport);
1698 spin_unlock_irq(&uport->lock);
1699 if (pm_state != UART_PM_STATE_ON)
1700 uart_change_pm(state, pm_state);
1701 mutex_unlock(&port->mutex);
1703 seq_printf(m, " tx:%d rx:%d",
1704 uport->icount.tx, uport->icount.rx);
1705 if (uport->icount.frame)
1706 seq_printf(m, " fe:%d",
1707 uport->icount.frame);
1708 if (uport->icount.parity)
1709 seq_printf(m, " pe:%d",
1710 uport->icount.parity);
1711 if (uport->icount.brk)
1712 seq_printf(m, " brk:%d",
1714 if (uport->icount.overrun)
1715 seq_printf(m, " oe:%d",
1716 uport->icount.overrun);
1718 #define INFOBIT(bit, str) \
1719 if (uport->mctrl & (bit)) \
1720 strncat(stat_buf, (str), sizeof(stat_buf) - \
1721 strlen(stat_buf) - 2)
1722 #define STATBIT(bit, str) \
1723 if (status & (bit)) \
1724 strncat(stat_buf, (str), sizeof(stat_buf) - \
1725 strlen(stat_buf) - 2)
1729 INFOBIT(TIOCM_RTS, "|RTS");
1730 STATBIT(TIOCM_CTS, "|CTS");
1731 INFOBIT(TIOCM_DTR, "|DTR");
1732 STATBIT(TIOCM_DSR, "|DSR");
1733 STATBIT(TIOCM_CAR, "|CD");
1734 STATBIT(TIOCM_RNG, "|RI");
1738 seq_puts(m, stat_buf);
1745 static int uart_proc_show(struct seq_file *m, void *v)
1747 struct tty_driver *ttydrv = m->private;
1748 struct uart_driver *drv = ttydrv->driver_state;
1751 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1753 for (i = 0; i < drv->nr; i++)
1754 uart_line_info(m, drv, i);
1758 static int uart_proc_open(struct inode *inode, struct file *file)
1760 return single_open(file, uart_proc_show, PDE_DATA(inode));
1763 static const struct file_operations uart_proc_fops = {
1764 .owner = THIS_MODULE,
1765 .open = uart_proc_open,
1767 .llseek = seq_lseek,
1768 .release = single_release,
1772 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1774 * uart_console_write - write a console message to a serial port
1775 * @port: the port to write the message
1776 * @s: array of characters
1777 * @count: number of characters in string to write
1778 * @putchar: function to write character to port
1780 void uart_console_write(struct uart_port *port, const char *s,
1782 void (*putchar)(struct uart_port *, int))
1786 for (i = 0; i < count; i++, s++) {
1788 putchar(port, '\r');
1792 EXPORT_SYMBOL_GPL(uart_console_write);
1795 * Check whether an invalid uart number has been specified, and
1796 * if so, search for the first available port that does have
1799 struct uart_port * __init
1800 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1802 int idx = co->index;
1804 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1805 ports[idx].membase == NULL))
1806 for (idx = 0; idx < nr; idx++)
1807 if (ports[idx].iobase != 0 ||
1808 ports[idx].membase != NULL)
1817 * uart_parse_earlycon - Parse earlycon options
1818 * @p: ptr to 2nd field (ie., just beyond '<name>,')
1819 * @iotype: ptr for decoded iotype (out)
1820 * @addr: ptr for decoded mapbase/iobase (out)
1821 * @options: ptr for <options> field; NULL if not present (out)
1823 * Decodes earlycon kernel command line parameters of the form
1824 * earlycon=<name>,io|mmio|mmio32|mmio32be|mmio32native,<addr>,<options>
1825 * console=<name>,io|mmio|mmio32|mmio32be|mmio32native,<addr>,<options>
1828 * earlycon=<name>,0x<addr>,<options>
1829 * console=<name>,0x<addr>,<options>
1830 * is also accepted; the returned @iotype will be UPIO_MEM.
1832 * Returns 0 on success or -EINVAL on failure
1834 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1837 if (strncmp(p, "mmio,", 5) == 0) {
1840 } else if (strncmp(p, "mmio32,", 7) == 0) {
1841 *iotype = UPIO_MEM32;
1843 } else if (strncmp(p, "mmio32be,", 9) == 0) {
1844 *iotype = UPIO_MEM32BE;
1846 } else if (strncmp(p, "mmio32native,", 13) == 0) {
1847 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1848 UPIO_MEM32BE : UPIO_MEM32;
1850 } else if (strncmp(p, "io,", 3) == 0) {
1851 *iotype = UPIO_PORT;
1853 } else if (strncmp(p, "0x", 2) == 0) {
1859 *addr = simple_strtoul(p, NULL, 0);
1867 EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1870 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1871 * @options: pointer to option string
1872 * @baud: pointer to an 'int' variable for the baud rate.
1873 * @parity: pointer to an 'int' variable for the parity.
1874 * @bits: pointer to an 'int' variable for the number of data bits.
1875 * @flow: pointer to an 'int' variable for the flow control character.
1877 * uart_parse_options decodes a string containing the serial console
1878 * options. The format of the string is <baud><parity><bits><flow>,
1882 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1886 *baud = simple_strtoul(s, NULL, 10);
1887 while (*s >= '0' && *s <= '9')
1896 EXPORT_SYMBOL_GPL(uart_parse_options);
1899 * uart_set_options - setup the serial console parameters
1900 * @port: pointer to the serial ports uart_port structure
1901 * @co: console pointer
1903 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1904 * @bits: number of data bits
1905 * @flow: flow control character - 'r' (rts)
1908 uart_set_options(struct uart_port *port, struct console *co,
1909 int baud, int parity, int bits, int flow)
1911 struct ktermios termios;
1912 static struct ktermios dummy;
1915 * Ensure that the serial console lock is initialised
1917 * If this port is a console, then the spinlock is already
1920 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1921 spin_lock_init(&port->lock);
1922 lockdep_set_class(&port->lock, &port_lock_key);
1925 memset(&termios, 0, sizeof(struct ktermios));
1927 termios.c_cflag |= CREAD | HUPCL | CLOCAL;
1928 tty_termios_encode_baud_rate(&termios, baud, baud);
1931 termios.c_cflag |= CS7;
1933 termios.c_cflag |= CS8;
1937 termios.c_cflag |= PARODD;
1940 termios.c_cflag |= PARENB;
1945 termios.c_cflag |= CRTSCTS;
1948 * some uarts on other side don't support no flow control.
1949 * So we set * DTR in host uart to make them happy
1951 port->mctrl |= TIOCM_DTR;
1953 port->ops->set_termios(port, &termios, &dummy);
1955 * Allow the setting of the UART parameters with a NULL console
1959 co->cflag = termios.c_cflag;
1963 EXPORT_SYMBOL_GPL(uart_set_options);
1964 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1967 * uart_change_pm - set power state of the port
1969 * @state: port descriptor
1970 * @pm_state: new state
1972 * Locking: port->mutex has to be held
1974 static void uart_change_pm(struct uart_state *state,
1975 enum uart_pm_state pm_state)
1977 struct uart_port *port = state->uart_port;
1979 if (state->pm_state != pm_state) {
1981 port->ops->pm(port, pm_state, state->pm_state);
1982 state->pm_state = pm_state;
1987 struct uart_port *port;
1988 struct uart_driver *driver;
1991 static int serial_match_port(struct device *dev, void *data)
1993 struct uart_match *match = data;
1994 struct tty_driver *tty_drv = match->driver->tty_driver;
1995 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1998 return dev->devt == devt; /* Actually, only one tty per port */
2001 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2003 struct uart_state *state = drv->state + uport->line;
2004 struct tty_port *port = &state->port;
2005 struct device *tty_dev;
2006 struct uart_match match = {uport, drv};
2008 mutex_lock(&port->mutex);
2010 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2011 if (device_may_wakeup(tty_dev)) {
2012 if (!enable_irq_wake(uport->irq))
2013 uport->irq_wake = 1;
2014 put_device(tty_dev);
2015 mutex_unlock(&port->mutex);
2018 put_device(tty_dev);
2020 /* Nothing to do if the console is not suspending */
2021 if (!console_suspend_enabled && uart_console(uport))
2024 uport->suspended = 1;
2026 if (port->flags & ASYNC_INITIALIZED) {
2027 const struct uart_ops *ops = uport->ops;
2030 set_bit(ASYNCB_SUSPENDED, &port->flags);
2031 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2033 spin_lock_irq(&uport->lock);
2034 ops->stop_tx(uport);
2035 ops->set_mctrl(uport, 0);
2036 ops->stop_rx(uport);
2037 spin_unlock_irq(&uport->lock);
2040 * Wait for the transmitter to empty.
2042 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2045 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2047 drv->tty_driver->name_base + uport->line);
2049 ops->shutdown(uport);
2053 * Disable the console device before suspending.
2055 if (uart_console(uport))
2056 console_stop(uport->cons);
2058 uart_change_pm(state, UART_PM_STATE_OFF);
2060 mutex_unlock(&port->mutex);
2065 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2067 struct uart_state *state = drv->state + uport->line;
2068 struct tty_port *port = &state->port;
2069 struct device *tty_dev;
2070 struct uart_match match = {uport, drv};
2071 struct ktermios termios;
2073 mutex_lock(&port->mutex);
2075 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2076 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2077 if (uport->irq_wake) {
2078 disable_irq_wake(uport->irq);
2079 uport->irq_wake = 0;
2081 put_device(tty_dev);
2082 mutex_unlock(&port->mutex);
2085 put_device(tty_dev);
2086 uport->suspended = 0;
2089 * Re-enable the console device after suspending.
2091 if (uart_console(uport)) {
2093 * First try to use the console cflag setting.
2095 memset(&termios, 0, sizeof(struct ktermios));
2096 termios.c_cflag = uport->cons->cflag;
2099 * If that's unset, use the tty termios setting.
2101 if (port->tty && termios.c_cflag == 0)
2102 termios = port->tty->termios;
2104 if (console_suspend_enabled)
2105 uart_change_pm(state, UART_PM_STATE_ON);
2106 uport->ops->set_termios(uport, &termios, NULL);
2107 if (console_suspend_enabled)
2108 console_start(uport->cons);
2111 if (port->flags & ASYNC_SUSPENDED) {
2112 const struct uart_ops *ops = uport->ops;
2115 uart_change_pm(state, UART_PM_STATE_ON);
2116 spin_lock_irq(&uport->lock);
2117 ops->set_mctrl(uport, 0);
2118 spin_unlock_irq(&uport->lock);
2119 if (console_suspend_enabled || !uart_console(uport)) {
2120 /* Protected by port mutex for now */
2121 struct tty_struct *tty = port->tty;
2122 ret = ops->startup(uport);
2125 uart_change_speed(tty, state, NULL);
2126 spin_lock_irq(&uport->lock);
2127 ops->set_mctrl(uport, uport->mctrl);
2128 ops->start_tx(uport);
2129 spin_unlock_irq(&uport->lock);
2130 set_bit(ASYNCB_INITIALIZED, &port->flags);
2133 * Failed to resume - maybe hardware went away?
2134 * Clear the "initialized" flag so we won't try
2135 * to call the low level drivers shutdown method.
2137 uart_shutdown(tty, state);
2141 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2144 mutex_unlock(&port->mutex);
2150 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2154 switch (port->iotype) {
2156 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2159 snprintf(address, sizeof(address),
2160 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2167 snprintf(address, sizeof(address),
2168 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2171 strlcpy(address, "*unknown*", sizeof(address));
2175 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2176 port->dev ? dev_name(port->dev) : "",
2177 port->dev ? ": " : "",
2179 drv->tty_driver->name_base + port->line,
2180 address, port->irq, port->uartclk / 16, uart_type(port));
2184 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2185 struct uart_port *port)
2190 * If there isn't a port here, don't do anything further.
2192 if (!port->iobase && !port->mapbase && !port->membase)
2196 * Now do the auto configuration stuff. Note that config_port
2197 * is expected to claim the resources and map the port for us.
2200 if (port->flags & UPF_AUTO_IRQ)
2201 flags |= UART_CONFIG_IRQ;
2202 if (port->flags & UPF_BOOT_AUTOCONF) {
2203 if (!(port->flags & UPF_FIXED_TYPE)) {
2204 port->type = PORT_UNKNOWN;
2205 flags |= UART_CONFIG_TYPE;
2207 port->ops->config_port(port, flags);
2210 if (port->type != PORT_UNKNOWN) {
2211 unsigned long flags;
2213 uart_report_port(drv, port);
2215 /* Power up port for set_mctrl() */
2216 uart_change_pm(state, UART_PM_STATE_ON);
2219 * Ensure that the modem control lines are de-activated.
2220 * keep the DTR setting that is set in uart_set_options()
2221 * We probably don't need a spinlock around this, but
2223 spin_lock_irqsave(&port->lock, flags);
2224 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2225 spin_unlock_irqrestore(&port->lock, flags);
2228 * If this driver supports console, and it hasn't been
2229 * successfully registered yet, try to re-register it.
2230 * It may be that the port was not available.
2232 if (port->cons && !(port->cons->flags & CON_ENABLED))
2233 register_console(port->cons);
2236 * Power down all ports by default, except the
2237 * console if we have one.
2239 if (!uart_console(port))
2240 uart_change_pm(state, UART_PM_STATE_OFF);
2244 #ifdef CONFIG_CONSOLE_POLL
2246 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2248 struct uart_driver *drv = driver->driver_state;
2249 struct uart_state *state = drv->state + line;
2250 struct uart_port *port;
2257 if (!state || !state->uart_port)
2260 port = state->uart_port;
2261 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2264 if (port->ops->poll_init) {
2265 struct tty_port *tport = &state->port;
2268 mutex_lock(&tport->mutex);
2270 * We don't set ASYNCB_INITIALIZED as we only initialized the
2271 * hw, e.g. state->xmit is still uninitialized.
2273 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2274 ret = port->ops->poll_init(port);
2275 mutex_unlock(&tport->mutex);
2281 uart_parse_options(options, &baud, &parity, &bits, &flow);
2282 return uart_set_options(port, NULL, baud, parity, bits, flow);
2288 static int uart_poll_get_char(struct tty_driver *driver, int line)
2290 struct uart_driver *drv = driver->driver_state;
2291 struct uart_state *state = drv->state + line;
2292 struct uart_port *port;
2294 if (!state || !state->uart_port)
2297 port = state->uart_port;
2298 return port->ops->poll_get_char(port);
2301 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2303 struct uart_driver *drv = driver->driver_state;
2304 struct uart_state *state = drv->state + line;
2305 struct uart_port *port;
2307 if (!state || !state->uart_port)
2310 port = state->uart_port;
2313 port->ops->poll_put_char(port, '\r');
2314 port->ops->poll_put_char(port, ch);
2318 static const struct tty_operations uart_ops = {
2320 .close = uart_close,
2321 .write = uart_write,
2322 .put_char = uart_put_char,
2323 .flush_chars = uart_flush_chars,
2324 .write_room = uart_write_room,
2325 .chars_in_buffer= uart_chars_in_buffer,
2326 .flush_buffer = uart_flush_buffer,
2327 .ioctl = uart_ioctl,
2328 .throttle = uart_throttle,
2329 .unthrottle = uart_unthrottle,
2330 .send_xchar = uart_send_xchar,
2331 .set_termios = uart_set_termios,
2332 .set_ldisc = uart_set_ldisc,
2334 .start = uart_start,
2335 .hangup = uart_hangup,
2336 .break_ctl = uart_break_ctl,
2337 .wait_until_sent= uart_wait_until_sent,
2338 #ifdef CONFIG_PROC_FS
2339 .proc_fops = &uart_proc_fops,
2341 .tiocmget = uart_tiocmget,
2342 .tiocmset = uart_tiocmset,
2343 .get_icount = uart_get_icount,
2344 #ifdef CONFIG_CONSOLE_POLL
2345 .poll_init = uart_poll_init,
2346 .poll_get_char = uart_poll_get_char,
2347 .poll_put_char = uart_poll_put_char,
2351 static const struct tty_port_operations uart_port_ops = {
2352 .carrier_raised = uart_carrier_raised,
2353 .dtr_rts = uart_dtr_rts,
2357 * uart_register_driver - register a driver with the uart core layer
2358 * @drv: low level driver structure
2360 * Register a uart driver with the core driver. We in turn register
2361 * with the tty layer, and initialise the core driver per-port state.
2363 * We have a proc file in /proc/tty/driver which is named after the
2366 * drv->port should be NULL, and the per-port structures should be
2367 * registered using uart_add_one_port after this call has succeeded.
2369 int uart_register_driver(struct uart_driver *drv)
2371 struct tty_driver *normal;
2377 * Maybe we should be using a slab cache for this, especially if
2378 * we have a large number of ports to handle.
2380 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2384 normal = alloc_tty_driver(drv->nr);
2388 drv->tty_driver = normal;
2390 normal->driver_name = drv->driver_name;
2391 normal->name = drv->dev_name;
2392 normal->major = drv->major;
2393 normal->minor_start = drv->minor;
2394 normal->type = TTY_DRIVER_TYPE_SERIAL;
2395 normal->subtype = SERIAL_TYPE_NORMAL;
2396 normal->init_termios = tty_std_termios;
2397 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2398 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2399 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2400 normal->driver_state = drv;
2401 tty_set_operations(normal, &uart_ops);
2404 * Initialise the UART state(s).
2406 for (i = 0; i < drv->nr; i++) {
2407 struct uart_state *state = drv->state + i;
2408 struct tty_port *port = &state->port;
2410 tty_port_init(port);
2411 port->ops = &uart_port_ops;
2414 retval = tty_register_driver(normal);
2418 for (i = 0; i < drv->nr; i++)
2419 tty_port_destroy(&drv->state[i].port);
2420 put_tty_driver(normal);
2428 * uart_unregister_driver - remove a driver from the uart core layer
2429 * @drv: low level driver structure
2431 * Remove all references to a driver from the core driver. The low
2432 * level driver must have removed all its ports via the
2433 * uart_remove_one_port() if it registered them with uart_add_one_port().
2434 * (ie, drv->port == NULL)
2436 void uart_unregister_driver(struct uart_driver *drv)
2438 struct tty_driver *p = drv->tty_driver;
2441 tty_unregister_driver(p);
2443 for (i = 0; i < drv->nr; i++)
2444 tty_port_destroy(&drv->state[i].port);
2447 drv->tty_driver = NULL;
2450 struct tty_driver *uart_console_device(struct console *co, int *index)
2452 struct uart_driver *p = co->data;
2454 return p->tty_driver;
2457 static ssize_t uart_get_attr_uartclk(struct device *dev,
2458 struct device_attribute *attr, char *buf)
2460 struct serial_struct tmp;
2461 struct tty_port *port = dev_get_drvdata(dev);
2463 uart_get_info(port, &tmp);
2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2467 static ssize_t uart_get_attr_type(struct device *dev,
2468 struct device_attribute *attr, char *buf)
2470 struct serial_struct tmp;
2471 struct tty_port *port = dev_get_drvdata(dev);
2473 uart_get_info(port, &tmp);
2474 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2476 static ssize_t uart_get_attr_line(struct device *dev,
2477 struct device_attribute *attr, char *buf)
2479 struct serial_struct tmp;
2480 struct tty_port *port = dev_get_drvdata(dev);
2482 uart_get_info(port, &tmp);
2483 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2486 static ssize_t uart_get_attr_port(struct device *dev,
2487 struct device_attribute *attr, char *buf)
2489 struct serial_struct tmp;
2490 struct tty_port *port = dev_get_drvdata(dev);
2491 unsigned long ioaddr;
2493 uart_get_info(port, &tmp);
2495 if (HIGH_BITS_OFFSET)
2496 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2497 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2500 static ssize_t uart_get_attr_irq(struct device *dev,
2501 struct device_attribute *attr, char *buf)
2503 struct serial_struct tmp;
2504 struct tty_port *port = dev_get_drvdata(dev);
2506 uart_get_info(port, &tmp);
2507 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2510 static ssize_t uart_get_attr_flags(struct device *dev,
2511 struct device_attribute *attr, char *buf)
2513 struct serial_struct tmp;
2514 struct tty_port *port = dev_get_drvdata(dev);
2516 uart_get_info(port, &tmp);
2517 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2520 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2521 struct device_attribute *attr, char *buf)
2523 struct serial_struct tmp;
2524 struct tty_port *port = dev_get_drvdata(dev);
2526 uart_get_info(port, &tmp);
2527 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2531 static ssize_t uart_get_attr_close_delay(struct device *dev,
2532 struct device_attribute *attr, char *buf)
2534 struct serial_struct tmp;
2535 struct tty_port *port = dev_get_drvdata(dev);
2537 uart_get_info(port, &tmp);
2538 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2542 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2543 struct device_attribute *attr, char *buf)
2545 struct serial_struct tmp;
2546 struct tty_port *port = dev_get_drvdata(dev);
2548 uart_get_info(port, &tmp);
2549 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2552 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2553 struct device_attribute *attr, char *buf)
2555 struct serial_struct tmp;
2556 struct tty_port *port = dev_get_drvdata(dev);
2558 uart_get_info(port, &tmp);
2559 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2562 static ssize_t uart_get_attr_io_type(struct device *dev,
2563 struct device_attribute *attr, char *buf)
2565 struct serial_struct tmp;
2566 struct tty_port *port = dev_get_drvdata(dev);
2568 uart_get_info(port, &tmp);
2569 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2572 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2573 struct device_attribute *attr, char *buf)
2575 struct serial_struct tmp;
2576 struct tty_port *port = dev_get_drvdata(dev);
2578 uart_get_info(port, &tmp);
2579 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2582 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2583 struct device_attribute *attr, char *buf)
2585 struct serial_struct tmp;
2586 struct tty_port *port = dev_get_drvdata(dev);
2588 uart_get_info(port, &tmp);
2589 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2592 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2593 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2594 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2595 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2596 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2597 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2598 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2599 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2600 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2601 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2602 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2603 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2604 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2606 static struct attribute *tty_dev_attrs[] = {
2607 &dev_attr_type.attr,
2608 &dev_attr_line.attr,
2609 &dev_attr_port.attr,
2611 &dev_attr_flags.attr,
2612 &dev_attr_xmit_fifo_size.attr,
2613 &dev_attr_uartclk.attr,
2614 &dev_attr_close_delay.attr,
2615 &dev_attr_closing_wait.attr,
2616 &dev_attr_custom_divisor.attr,
2617 &dev_attr_io_type.attr,
2618 &dev_attr_iomem_base.attr,
2619 &dev_attr_iomem_reg_shift.attr,
2623 static const struct attribute_group tty_dev_attr_group = {
2624 .attrs = tty_dev_attrs,
2628 * uart_add_one_port - attach a driver-defined port structure
2629 * @drv: pointer to the uart low level driver structure for this port
2630 * @uport: uart port structure to use for this port.
2632 * This allows the driver to register its own uart_port structure
2633 * with the core driver. The main purpose is to allow the low
2634 * level uart drivers to expand uart_port, rather than having yet
2635 * more levels of structures.
2637 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2639 struct uart_state *state;
2640 struct tty_port *port;
2642 struct device *tty_dev;
2645 BUG_ON(in_interrupt());
2647 if (uport->line >= drv->nr)
2650 state = drv->state + uport->line;
2651 port = &state->port;
2653 mutex_lock(&port_mutex);
2654 mutex_lock(&port->mutex);
2655 if (state->uart_port) {
2660 /* Link the port to the driver state table and vice versa */
2661 state->uart_port = uport;
2662 uport->state = state;
2664 state->pm_state = UART_PM_STATE_UNDEFINED;
2665 uport->cons = drv->cons;
2666 uport->minor = drv->tty_driver->minor_start + uport->line;
2669 * If this port is a console, then the spinlock is already
2672 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2673 spin_lock_init(&uport->lock);
2674 lockdep_set_class(&uport->lock, &port_lock_key);
2676 if (uport->cons && uport->dev)
2677 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2679 uart_configure_port(drv, state, uport);
2682 if (uport->attr_group)
2685 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2687 if (!uport->tty_groups) {
2691 uport->tty_groups[0] = &tty_dev_attr_group;
2692 if (uport->attr_group)
2693 uport->tty_groups[1] = uport->attr_group;
2696 * Register the port whether it's detected or not. This allows
2697 * setserial to be used to alter this port's parameters.
2699 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2700 uport->line, uport->dev, port, uport->tty_groups);
2701 if (likely(!IS_ERR(tty_dev))) {
2702 device_set_wakeup_capable(tty_dev, 1);
2704 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2709 * Ensure UPF_DEAD is not set.
2711 uport->flags &= ~UPF_DEAD;
2714 mutex_unlock(&port->mutex);
2715 mutex_unlock(&port_mutex);
2721 * uart_remove_one_port - detach a driver defined port structure
2722 * @drv: pointer to the uart low level driver structure for this port
2723 * @uport: uart port structure for this port
2725 * This unhooks (and hangs up) the specified port structure from the
2726 * core driver. No further calls will be made to the low-level code
2729 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2731 struct uart_state *state = drv->state + uport->line;
2732 struct tty_port *port = &state->port;
2733 struct tty_struct *tty;
2736 BUG_ON(in_interrupt());
2738 if (state->uart_port != uport)
2739 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2740 state->uart_port, uport);
2742 mutex_lock(&port_mutex);
2745 * Mark the port "dead" - this prevents any opens from
2746 * succeeding while we shut down the port.
2748 mutex_lock(&port->mutex);
2749 if (!state->uart_port) {
2750 mutex_unlock(&port->mutex);
2754 uport->flags |= UPF_DEAD;
2755 mutex_unlock(&port->mutex);
2758 * Remove the devices from the tty layer
2760 tty_unregister_device(drv->tty_driver, uport->line);
2762 tty = tty_port_tty_get(port);
2764 tty_vhangup(port->tty);
2769 * If the port is used as a console, unregister it
2771 if (uart_console(uport))
2772 unregister_console(uport->cons);
2775 * Free the port IO and memory resources, if any.
2777 if (uport->type != PORT_UNKNOWN)
2778 uport->ops->release_port(uport);
2779 kfree(uport->tty_groups);
2782 * Indicate that there isn't a port here anymore.
2784 uport->type = PORT_UNKNOWN;
2786 state->uart_port = NULL;
2788 mutex_unlock(&port_mutex);
2794 * Are the two ports equivalent?
2796 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2798 if (port1->iotype != port2->iotype)
2801 switch (port1->iotype) {
2803 return (port1->iobase == port2->iobase);
2805 return (port1->iobase == port2->iobase) &&
2806 (port1->hub6 == port2->hub6);
2812 return (port1->mapbase == port2->mapbase);
2816 EXPORT_SYMBOL(uart_match_port);
2819 * uart_handle_dcd_change - handle a change of carrier detect state
2820 * @uport: uart_port structure for the open port
2821 * @status: new carrier detect status, nonzero if active
2823 * Caller must hold uport->lock
2825 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2827 struct tty_port *port = &uport->state->port;
2828 struct tty_struct *tty = port->tty;
2829 struct tty_ldisc *ld;
2831 lockdep_assert_held_once(&uport->lock);
2834 ld = tty_ldisc_ref(tty);
2836 if (ld->ops->dcd_change)
2837 ld->ops->dcd_change(tty, status);
2838 tty_ldisc_deref(ld);
2842 uport->icount.dcd++;
2844 if (uart_dcd_enabled(uport)) {
2846 wake_up_interruptible(&port->open_wait);
2851 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2854 * uart_handle_cts_change - handle a change of clear-to-send state
2855 * @uport: uart_port structure for the open port
2856 * @status: new clear to send status, nonzero if active
2858 * Caller must hold uport->lock
2860 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2862 lockdep_assert_held_once(&uport->lock);
2864 uport->icount.cts++;
2866 if (uart_softcts_mode(uport)) {
2867 if (uport->hw_stopped) {
2869 uport->hw_stopped = 0;
2870 uport->ops->start_tx(uport);
2871 uart_write_wakeup(uport);
2875 uport->hw_stopped = 1;
2876 uport->ops->stop_tx(uport);
2882 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2885 * uart_insert_char - push a char to the uart layer
2887 * User is responsible to call tty_flip_buffer_push when they are done with
2890 * @port: corresponding port
2891 * @status: state of the serial port RX buffer (LSR for 8250)
2892 * @overrun: mask of overrun bits in @status
2893 * @ch: character to push
2894 * @flag: flag for the character (see TTY_NORMAL and friends)
2896 void uart_insert_char(struct uart_port *port, unsigned int status,
2897 unsigned int overrun, unsigned int ch, unsigned int flag)
2899 struct tty_port *tport = &port->state->port;
2901 if ((status & port->ignore_status_mask & ~overrun) == 0)
2902 if (tty_insert_flip_char(tport, ch, flag) == 0)
2903 ++port->icount.buf_overrun;
2906 * Overrun is special. Since it's reported immediately,
2907 * it doesn't affect the current character.
2909 if (status & ~port->ignore_status_mask & overrun)
2910 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2911 ++port->icount.buf_overrun;
2913 EXPORT_SYMBOL_GPL(uart_insert_char);
2915 EXPORT_SYMBOL(uart_write_wakeup);
2916 EXPORT_SYMBOL(uart_register_driver);
2917 EXPORT_SYMBOL(uart_unregister_driver);
2918 EXPORT_SYMBOL(uart_suspend_port);
2919 EXPORT_SYMBOL(uart_resume_port);
2920 EXPORT_SYMBOL(uart_add_one_port);
2921 EXPORT_SYMBOL(uart_remove_one_port);
2923 MODULE_DESCRIPTION("Serial driver core");
2924 MODULE_LICENSE("GPL");