2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
55 struct ktermios *old_termios);
56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
57 static void uart_change_pm(struct uart_state *state,
58 enum uart_pm_state pm_state);
60 static void uart_port_shutdown(struct tty_port *port);
62 static int uart_dcd_enabled(struct uart_port *uport)
64 return !!(uport->status & UPSTAT_DCD_ENABLE);
68 * This routine is used by the interrupt handler to schedule processing in
69 * the software interrupt portion of the driver.
71 void uart_write_wakeup(struct uart_port *port)
73 struct uart_state *state = port->state;
75 * This means you called this function _after_ the port was
76 * closed. No cookie for you.
79 tty_wakeup(state->port.tty);
82 static void uart_stop(struct tty_struct *tty)
84 struct uart_state *state = tty->driver_data;
85 struct uart_port *port = state->uart_port;
88 spin_lock_irqsave(&port->lock, flags);
89 port->ops->stop_tx(port);
90 spin_unlock_irqrestore(&port->lock, flags);
93 static void __uart_start(struct tty_struct *tty)
95 struct uart_state *state = tty->driver_data;
96 struct uart_port *port = state->uart_port;
98 if (!uart_tx_stopped(port))
99 port->ops->start_tx(port);
102 static void uart_start(struct tty_struct *tty)
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->uart_port;
108 spin_lock_irqsave(&port->lock, flags);
110 spin_unlock_irqrestore(&port->lock, flags);
114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119 spin_lock_irqsave(&port->lock, flags);
121 port->mctrl = (old & ~clear) | set;
122 if (old != port->mctrl)
123 port->ops->set_mctrl(port, port->mctrl);
124 spin_unlock_irqrestore(&port->lock, flags);
127 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
128 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
131 * Startup the port. This will be called once per open. All calls
132 * will be serialised by the per-port mutex.
134 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
137 struct uart_port *uport = state->uart_port;
141 if (uport->type == PORT_UNKNOWN)
145 * Make sure the device is in D0 state.
147 uart_change_pm(state, UART_PM_STATE_ON);
150 * Initialise and allocate the transmit and temporary
153 if (!state->xmit.buf) {
154 /* This is protected by the per port mutex */
155 page = get_zeroed_page(GFP_KERNEL);
159 state->xmit.buf = (unsigned char *) page;
160 uart_circ_clear(&state->xmit);
163 retval = uport->ops->startup(uport);
165 if (uart_console(uport) && uport->cons->cflag) {
166 tty->termios.c_cflag = uport->cons->cflag;
167 uport->cons->cflag = 0;
170 * Initialise the hardware port settings.
172 uart_change_speed(tty, state, NULL);
176 * Setup the RTS and DTR signals once the
177 * port is open and ready to respond.
179 if (tty->termios.c_cflag & CBAUD)
180 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
183 spin_lock_irq(&uport->lock);
184 if (uart_cts_enabled(uport) &&
185 !(uport->ops->get_mctrl(uport) & TIOCM_CTS))
186 uport->hw_stopped = 1;
188 uport->hw_stopped = 0;
189 spin_unlock_irq(&uport->lock);
193 * This is to allow setserial on this port. People may want to set
194 * port/irq/type and then reconfigure the port properly if it failed
197 if (retval && capable(CAP_SYS_ADMIN))
203 static int uart_startup(struct tty_struct *tty, struct uart_state *state,
206 struct tty_port *port = &state->port;
209 if (port->flags & ASYNC_INITIALIZED)
213 * Set the TTY IO error marker - we will only clear this
214 * once we have successfully opened the port.
216 set_bit(TTY_IO_ERROR, &tty->flags);
218 retval = uart_port_startup(tty, state, init_hw);
220 set_bit(ASYNCB_INITIALIZED, &port->flags);
221 clear_bit(TTY_IO_ERROR, &tty->flags);
222 } else if (retval > 0)
229 * This routine will shutdown a serial port; interrupts are disabled, and
230 * DTR is dropped if the hangup on close termio flag is on. Calls to
231 * uart_shutdown are serialised by the per-port semaphore.
233 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
235 struct uart_port *uport = state->uart_port;
236 struct tty_port *port = &state->port;
239 * Set the TTY IO error marker
242 set_bit(TTY_IO_ERROR, &tty->flags);
244 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
246 * Turn off DTR and RTS early.
248 if (uart_console(uport) && tty)
249 uport->cons->cflag = tty->termios.c_cflag;
251 if (!tty || (tty->termios.c_cflag & HUPCL))
252 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
254 uart_port_shutdown(port);
258 * It's possible for shutdown to be called after suspend if we get
259 * a DCD drop (hangup) at just the right time. Clear suspended bit so
260 * we don't try to resume a port that has been shutdown.
262 clear_bit(ASYNCB_SUSPENDED, &port->flags);
265 * Free the transmit buffer page.
267 if (state->xmit.buf) {
268 free_page((unsigned long)state->xmit.buf);
269 state->xmit.buf = NULL;
274 * uart_update_timeout - update per-port FIFO timeout.
275 * @port: uart_port structure describing the port
276 * @cflag: termios cflag value
277 * @baud: speed of the port
279 * Set the port FIFO timeout value. The @cflag value should
280 * reflect the actual hardware settings.
283 uart_update_timeout(struct uart_port *port, unsigned int cflag,
288 /* byte size and parity */
289 switch (cflag & CSIZE) {
310 * The total number of bits to be transmitted in the fifo.
312 bits = bits * port->fifosize;
315 * Figure the timeout to send the above number of bits.
316 * Add .02 seconds of slop
318 port->timeout = (HZ * bits) / baud + HZ/50;
321 EXPORT_SYMBOL(uart_update_timeout);
324 * uart_get_baud_rate - return baud rate for a particular port
325 * @port: uart_port structure describing the port in question.
326 * @termios: desired termios settings.
327 * @old: old termios (or NULL)
328 * @min: minimum acceptable baud rate
329 * @max: maximum acceptable baud rate
331 * Decode the termios structure into a numeric baud rate,
332 * taking account of the magic 38400 baud rate (with spd_*
333 * flags), and mapping the %B0 rate to 9600 baud.
335 * If the new baud rate is invalid, try the old termios setting.
336 * If it's still invalid, we try 9600 baud.
338 * Update the @termios structure to reflect the baud rate
339 * we're actually going to be using. Don't do this for the case
340 * where B0 is requested ("hang up").
343 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
344 struct ktermios *old, unsigned int min, unsigned int max)
346 unsigned int try, baud, altbaud = 38400;
348 upf_t flags = port->flags & UPF_SPD_MASK;
350 if (flags == UPF_SPD_HI)
352 else if (flags == UPF_SPD_VHI)
354 else if (flags == UPF_SPD_SHI)
356 else if (flags == UPF_SPD_WARP)
359 for (try = 0; try < 2; try++) {
360 baud = tty_termios_baud_rate(termios);
363 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
366 if (try == 0 && baud == 38400)
370 * Special case: B0 rate.
377 if (baud >= min && baud <= max)
381 * Oops, the quotient was zero. Try again with
382 * the old baud rate if possible.
384 termios->c_cflag &= ~CBAUD;
386 baud = tty_termios_baud_rate(old);
388 tty_termios_encode_baud_rate(termios,
395 * As a last resort, if the range cannot be met then clip to
396 * the nearest chip supported rate.
400 tty_termios_encode_baud_rate(termios,
403 tty_termios_encode_baud_rate(termios,
407 /* Should never happen */
412 EXPORT_SYMBOL(uart_get_baud_rate);
415 * uart_get_divisor - return uart clock divisor
416 * @port: uart_port structure describing the port.
417 * @baud: desired baud rate
419 * Calculate the uart clock divisor for the port.
422 uart_get_divisor(struct uart_port *port, unsigned int baud)
427 * Old custom speed handling.
429 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
430 quot = port->custom_divisor;
432 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
437 EXPORT_SYMBOL(uart_get_divisor);
439 /* Caller holds port mutex */
440 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
441 struct ktermios *old_termios)
443 struct uart_port *uport = state->uart_port;
444 struct ktermios *termios;
447 * If we have no tty, termios, or the port does not exist,
448 * then we can't set the parameters for this port.
450 if (!tty || uport->type == PORT_UNKNOWN)
453 termios = &tty->termios;
454 uport->ops->set_termios(uport, termios, old_termios);
457 * Set modem status enables based on termios cflag
459 spin_lock_irq(&uport->lock);
460 if (termios->c_cflag & CRTSCTS)
461 uport->status |= UPSTAT_CTS_ENABLE;
463 uport->status &= ~UPSTAT_CTS_ENABLE;
465 if (termios->c_cflag & CLOCAL)
466 uport->status &= ~UPSTAT_DCD_ENABLE;
468 uport->status |= UPSTAT_DCD_ENABLE;
469 spin_unlock_irq(&uport->lock);
472 static inline int __uart_put_char(struct uart_port *port,
473 struct circ_buf *circ, unsigned char c)
481 spin_lock_irqsave(&port->lock, flags);
482 if (uart_circ_chars_free(circ) != 0) {
483 circ->buf[circ->head] = c;
484 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
487 spin_unlock_irqrestore(&port->lock, flags);
491 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
493 struct uart_state *state = tty->driver_data;
495 return __uart_put_char(state->uart_port, &state->xmit, ch);
498 static void uart_flush_chars(struct tty_struct *tty)
503 static int uart_write(struct tty_struct *tty,
504 const unsigned char *buf, int count)
506 struct uart_state *state = tty->driver_data;
507 struct uart_port *port;
508 struct circ_buf *circ;
513 * This means you called this function _after_ the port was
514 * closed. No cookie for you.
521 port = state->uart_port;
527 spin_lock_irqsave(&port->lock, flags);
529 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
534 memcpy(circ->buf + circ->head, buf, c);
535 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
542 spin_unlock_irqrestore(&port->lock, flags);
547 static int uart_write_room(struct tty_struct *tty)
549 struct uart_state *state = tty->driver_data;
553 spin_lock_irqsave(&state->uart_port->lock, flags);
554 ret = uart_circ_chars_free(&state->xmit);
555 spin_unlock_irqrestore(&state->uart_port->lock, flags);
559 static int uart_chars_in_buffer(struct tty_struct *tty)
561 struct uart_state *state = tty->driver_data;
565 spin_lock_irqsave(&state->uart_port->lock, flags);
566 ret = uart_circ_chars_pending(&state->xmit);
567 spin_unlock_irqrestore(&state->uart_port->lock, flags);
571 static void uart_flush_buffer(struct tty_struct *tty)
573 struct uart_state *state = tty->driver_data;
574 struct uart_port *port;
578 * This means you called this function _after_ the port was
579 * closed. No cookie for you.
586 port = state->uart_port;
587 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
589 spin_lock_irqsave(&port->lock, flags);
590 uart_circ_clear(&state->xmit);
591 if (port->ops->flush_buffer)
592 port->ops->flush_buffer(port);
593 spin_unlock_irqrestore(&port->lock, flags);
598 * This function is used to send a high-priority XON/XOFF character to
601 static void uart_send_xchar(struct tty_struct *tty, char ch)
603 struct uart_state *state = tty->driver_data;
604 struct uart_port *port = state->uart_port;
607 if (port->ops->send_xchar)
608 port->ops->send_xchar(port, ch);
610 spin_lock_irqsave(&port->lock, flags);
613 port->ops->start_tx(port);
614 spin_unlock_irqrestore(&port->lock, flags);
618 static void uart_throttle(struct tty_struct *tty)
620 struct uart_state *state = tty->driver_data;
621 struct uart_port *port = state->uart_port;
625 mask |= UPF_SOFT_FLOW;
626 if (tty->termios.c_cflag & CRTSCTS)
627 mask |= UPF_HARD_FLOW;
629 if (port->flags & mask) {
630 port->ops->throttle(port);
631 mask &= ~port->flags;
634 if (mask & UPF_SOFT_FLOW)
635 uart_send_xchar(tty, STOP_CHAR(tty));
637 if (mask & UPF_HARD_FLOW)
638 uart_clear_mctrl(port, TIOCM_RTS);
641 static void uart_unthrottle(struct tty_struct *tty)
643 struct uart_state *state = tty->driver_data;
644 struct uart_port *port = state->uart_port;
648 mask |= UPF_SOFT_FLOW;
649 if (tty->termios.c_cflag & CRTSCTS)
650 mask |= UPF_HARD_FLOW;
652 if (port->flags & mask) {
653 port->ops->unthrottle(port);
654 mask &= ~port->flags;
657 if (mask & UPF_SOFT_FLOW)
658 uart_send_xchar(tty, START_CHAR(tty));
660 if (mask & UPF_HARD_FLOW)
661 uart_set_mctrl(port, TIOCM_RTS);
664 static void do_uart_get_info(struct tty_port *port,
665 struct serial_struct *retinfo)
667 struct uart_state *state = container_of(port, struct uart_state, port);
668 struct uart_port *uport = state->uart_port;
670 memset(retinfo, 0, sizeof(*retinfo));
672 retinfo->type = uport->type;
673 retinfo->line = uport->line;
674 retinfo->port = uport->iobase;
675 if (HIGH_BITS_OFFSET)
676 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
677 retinfo->irq = uport->irq;
678 retinfo->flags = uport->flags;
679 retinfo->xmit_fifo_size = uport->fifosize;
680 retinfo->baud_base = uport->uartclk / 16;
681 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10;
682 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
683 ASYNC_CLOSING_WAIT_NONE :
684 jiffies_to_msecs(port->closing_wait) / 10;
685 retinfo->custom_divisor = uport->custom_divisor;
686 retinfo->hub6 = uport->hub6;
687 retinfo->io_type = uport->iotype;
688 retinfo->iomem_reg_shift = uport->regshift;
689 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase;
692 static void uart_get_info(struct tty_port *port,
693 struct serial_struct *retinfo)
695 /* Ensure the state we copy is consistent and no hardware changes
697 mutex_lock(&port->mutex);
698 do_uart_get_info(port, retinfo);
699 mutex_unlock(&port->mutex);
702 static int uart_get_info_user(struct tty_port *port,
703 struct serial_struct __user *retinfo)
705 struct serial_struct tmp;
706 uart_get_info(port, &tmp);
708 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
713 static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
714 struct uart_state *state,
715 struct serial_struct *new_info)
717 struct uart_port *uport = state->uart_port;
718 unsigned long new_port;
719 unsigned int change_irq, change_port, closing_wait;
720 unsigned int old_custom_divisor, close_delay;
721 upf_t old_flags, new_flags;
724 new_port = new_info->port;
725 if (HIGH_BITS_OFFSET)
726 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
728 new_info->irq = irq_canonicalize(new_info->irq);
729 close_delay = msecs_to_jiffies(new_info->close_delay * 10);
730 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
731 ASYNC_CLOSING_WAIT_NONE :
732 msecs_to_jiffies(new_info->closing_wait * 10);
735 change_irq = !(uport->flags & UPF_FIXED_PORT)
736 && new_info->irq != uport->irq;
739 * Since changing the 'type' of the port changes its resource
740 * allocations, we should treat type changes the same as
743 change_port = !(uport->flags & UPF_FIXED_PORT)
744 && (new_port != uport->iobase ||
745 (unsigned long)new_info->iomem_base != uport->mapbase ||
746 new_info->hub6 != uport->hub6 ||
747 new_info->io_type != uport->iotype ||
748 new_info->iomem_reg_shift != uport->regshift ||
749 new_info->type != uport->type);
751 old_flags = uport->flags;
752 new_flags = new_info->flags;
753 old_custom_divisor = uport->custom_divisor;
755 if (!capable(CAP_SYS_ADMIN)) {
757 if (change_irq || change_port ||
758 (new_info->baud_base != uport->uartclk / 16) ||
759 (close_delay != port->close_delay) ||
760 (closing_wait != port->closing_wait) ||
761 (new_info->xmit_fifo_size &&
762 new_info->xmit_fifo_size != uport->fifosize) ||
763 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
765 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
766 (new_flags & UPF_USR_MASK));
767 uport->custom_divisor = new_info->custom_divisor;
772 * Ask the low level driver to verify the settings.
774 if (uport->ops->verify_port)
775 retval = uport->ops->verify_port(uport, new_info);
777 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
778 (new_info->baud_base < 9600))
784 if (change_port || change_irq) {
788 * Make sure that we are the sole user of this port.
790 if (tty_port_users(port) > 1)
794 * We need to shutdown the serial port at the old
795 * port/type/irq combination.
797 uart_shutdown(tty, state);
801 unsigned long old_iobase, old_mapbase;
802 unsigned int old_type, old_iotype, old_hub6, old_shift;
804 old_iobase = uport->iobase;
805 old_mapbase = uport->mapbase;
806 old_type = uport->type;
807 old_hub6 = uport->hub6;
808 old_iotype = uport->iotype;
809 old_shift = uport->regshift;
812 * Free and release old regions
814 if (old_type != PORT_UNKNOWN)
815 uport->ops->release_port(uport);
817 uport->iobase = new_port;
818 uport->type = new_info->type;
819 uport->hub6 = new_info->hub6;
820 uport->iotype = new_info->io_type;
821 uport->regshift = new_info->iomem_reg_shift;
822 uport->mapbase = (unsigned long)new_info->iomem_base;
825 * Claim and map the new regions
827 if (uport->type != PORT_UNKNOWN) {
828 retval = uport->ops->request_port(uport);
830 /* Always success - Jean II */
835 * If we fail to request resources for the
836 * new port, try to restore the old settings.
839 uport->iobase = old_iobase;
840 uport->type = old_type;
841 uport->hub6 = old_hub6;
842 uport->iotype = old_iotype;
843 uport->regshift = old_shift;
844 uport->mapbase = old_mapbase;
846 if (old_type != PORT_UNKNOWN) {
847 retval = uport->ops->request_port(uport);
849 * If we failed to restore the old settings,
853 uport->type = PORT_UNKNOWN;
861 /* Added to return the correct error -Ram Gupta */
867 uport->irq = new_info->irq;
868 if (!(uport->flags & UPF_FIXED_PORT))
869 uport->uartclk = new_info->baud_base * 16;
870 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
871 (new_flags & UPF_CHANGE_MASK);
872 uport->custom_divisor = new_info->custom_divisor;
873 port->close_delay = close_delay;
874 port->closing_wait = closing_wait;
875 if (new_info->xmit_fifo_size)
876 uport->fifosize = new_info->xmit_fifo_size;
877 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
881 if (uport->type == PORT_UNKNOWN)
883 if (port->flags & ASYNC_INITIALIZED) {
884 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
885 old_custom_divisor != uport->custom_divisor) {
887 * If they're setting up a custom divisor or speed,
888 * instead of clearing it, then bitch about it. No
889 * need to rate-limit; it's CAP_SYS_ADMIN only.
891 if (uport->flags & UPF_SPD_MASK) {
894 dev_notice(uport->dev,
895 "%s sets custom speed on %s. This is deprecated.\n",
897 tty_name(port->tty, buf));
899 uart_change_speed(tty, state, NULL);
902 retval = uart_startup(tty, state, 1);
907 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
908 struct serial_struct __user *newinfo)
910 struct serial_struct new_serial;
911 struct tty_port *port = &state->port;
914 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
918 * This semaphore protects port->count. It is also
919 * very useful to prevent opens. Also, take the
920 * port configuration semaphore to make sure that a
921 * module insertion/removal doesn't change anything
924 mutex_lock(&port->mutex);
925 retval = uart_set_info(tty, port, state, &new_serial);
926 mutex_unlock(&port->mutex);
931 * uart_get_lsr_info - get line status register info
932 * @tty: tty associated with the UART
933 * @state: UART being queried
934 * @value: returned modem value
936 * Note: uart_ioctl protects us against hangups.
938 static int uart_get_lsr_info(struct tty_struct *tty,
939 struct uart_state *state, unsigned int __user *value)
941 struct uart_port *uport = state->uart_port;
944 result = uport->ops->tx_empty(uport);
947 * If we're about to load something into the transmit
948 * register, we'll pretend the transmitter isn't empty to
949 * avoid a race condition (depending on when the transmit
950 * interrupt happens).
953 ((uart_circ_chars_pending(&state->xmit) > 0) &&
954 !uart_tx_stopped(uport)))
955 result &= ~TIOCSER_TEMT;
957 return put_user(result, value);
960 static int uart_tiocmget(struct tty_struct *tty)
962 struct uart_state *state = tty->driver_data;
963 struct tty_port *port = &state->port;
964 struct uart_port *uport = state->uart_port;
967 mutex_lock(&port->mutex);
968 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
969 result = uport->mctrl;
970 spin_lock_irq(&uport->lock);
971 result |= uport->ops->get_mctrl(uport);
972 spin_unlock_irq(&uport->lock);
974 mutex_unlock(&port->mutex);
980 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
982 struct uart_state *state = tty->driver_data;
983 struct uart_port *uport = state->uart_port;
984 struct tty_port *port = &state->port;
987 mutex_lock(&port->mutex);
988 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
989 uart_update_mctrl(uport, set, clear);
992 mutex_unlock(&port->mutex);
996 static int uart_break_ctl(struct tty_struct *tty, int break_state)
998 struct uart_state *state = tty->driver_data;
999 struct tty_port *port = &state->port;
1000 struct uart_port *uport = state->uart_port;
1002 mutex_lock(&port->mutex);
1004 if (uport->type != PORT_UNKNOWN)
1005 uport->ops->break_ctl(uport, break_state);
1007 mutex_unlock(&port->mutex);
1011 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1013 struct uart_port *uport = state->uart_port;
1014 struct tty_port *port = &state->port;
1017 if (!capable(CAP_SYS_ADMIN))
1021 * Take the per-port semaphore. This prevents count from
1022 * changing, and hence any extra opens of the port while
1023 * we're auto-configuring.
1025 if (mutex_lock_interruptible(&port->mutex))
1026 return -ERESTARTSYS;
1029 if (tty_port_users(port) == 1) {
1030 uart_shutdown(tty, state);
1033 * If we already have a port type configured,
1034 * we must release its resources.
1036 if (uport->type != PORT_UNKNOWN)
1037 uport->ops->release_port(uport);
1039 flags = UART_CONFIG_TYPE;
1040 if (uport->flags & UPF_AUTO_IRQ)
1041 flags |= UART_CONFIG_IRQ;
1044 * This will claim the ports resources if
1047 uport->ops->config_port(uport, flags);
1049 ret = uart_startup(tty, state, 1);
1051 mutex_unlock(&port->mutex);
1055 static void uart_enable_ms(struct uart_port *uport)
1058 * Force modem status interrupts on
1060 if (uport->ops->enable_ms)
1061 uport->ops->enable_ms(uport);
1065 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1066 * - mask passed in arg for lines of interest
1067 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1068 * Caller should use TIOCGICOUNT to see which one it was
1070 * FIXME: This wants extracting into a common all driver implementation
1071 * of TIOCMWAIT using tty_port.
1074 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1076 struct uart_port *uport = state->uart_port;
1077 struct tty_port *port = &state->port;
1078 DECLARE_WAITQUEUE(wait, current);
1079 struct uart_icount cprev, cnow;
1083 * note the counters on entry
1085 spin_lock_irq(&uport->lock);
1086 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1087 uart_enable_ms(uport);
1088 spin_unlock_irq(&uport->lock);
1090 add_wait_queue(&port->delta_msr_wait, &wait);
1092 spin_lock_irq(&uport->lock);
1093 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1094 spin_unlock_irq(&uport->lock);
1096 set_current_state(TASK_INTERRUPTIBLE);
1098 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1099 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1100 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1101 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1108 /* see if a signal did it */
1109 if (signal_pending(current)) {
1117 current->state = TASK_RUNNING;
1118 remove_wait_queue(&port->delta_msr_wait, &wait);
1124 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1125 * Return: write counters to the user passed counter struct
1126 * NB: both 1->0 and 0->1 transitions are counted except for
1127 * RI where only 0->1 is counted.
1129 static int uart_get_icount(struct tty_struct *tty,
1130 struct serial_icounter_struct *icount)
1132 struct uart_state *state = tty->driver_data;
1133 struct uart_icount cnow;
1134 struct uart_port *uport = state->uart_port;
1136 spin_lock_irq(&uport->lock);
1137 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1138 spin_unlock_irq(&uport->lock);
1140 icount->cts = cnow.cts;
1141 icount->dsr = cnow.dsr;
1142 icount->rng = cnow.rng;
1143 icount->dcd = cnow.dcd;
1144 icount->rx = cnow.rx;
1145 icount->tx = cnow.tx;
1146 icount->frame = cnow.frame;
1147 icount->overrun = cnow.overrun;
1148 icount->parity = cnow.parity;
1149 icount->brk = cnow.brk;
1150 icount->buf_overrun = cnow.buf_overrun;
1155 static int uart_get_rs485_config(struct uart_port *port,
1156 struct serial_rs485 __user *rs485)
1158 unsigned long flags;
1159 struct serial_rs485 aux;
1161 spin_lock_irqsave(&port->lock, flags);
1163 spin_unlock_irqrestore(&port->lock, flags);
1165 if (copy_to_user(rs485, &aux, sizeof(aux)))
1171 static int uart_set_rs485_config(struct uart_port *port,
1172 struct serial_rs485 __user *rs485_user)
1174 struct serial_rs485 rs485;
1176 unsigned long flags;
1178 if (!port->rs485_config)
1179 return -ENOIOCTLCMD;
1181 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1184 spin_lock_irqsave(&port->lock, flags);
1185 ret = port->rs485_config(port, &rs485);
1186 spin_unlock_irqrestore(&port->lock, flags);
1190 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1197 * Called via sys_ioctl. We can use spin_lock_irq() here.
1200 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1203 struct uart_state *state = tty->driver_data;
1204 struct tty_port *port = &state->port;
1205 void __user *uarg = (void __user *)arg;
1206 int ret = -ENOIOCTLCMD;
1210 * These ioctls don't rely on the hardware to be present.
1214 ret = uart_get_info_user(port, uarg);
1218 down_write(&tty->termios_rwsem);
1219 ret = uart_set_info_user(tty, state, uarg);
1220 up_write(&tty->termios_rwsem);
1224 down_write(&tty->termios_rwsem);
1225 ret = uart_do_autoconfig(tty, state);
1226 up_write(&tty->termios_rwsem);
1229 case TIOCSERGWILD: /* obsolete */
1230 case TIOCSERSWILD: /* obsolete */
1235 if (ret != -ENOIOCTLCMD)
1238 if (tty->flags & (1 << TTY_IO_ERROR)) {
1244 * The following should only be used when hardware is present.
1248 ret = uart_wait_modem_status(state, arg);
1252 if (ret != -ENOIOCTLCMD)
1255 mutex_lock(&port->mutex);
1257 if (tty->flags & (1 << TTY_IO_ERROR)) {
1263 * All these rely on hardware being present and need to be
1264 * protected against the tty being hung up.
1268 case TIOCSERGETLSR: /* Get line status register */
1269 ret = uart_get_lsr_info(tty, state, uarg);
1273 ret = uart_get_rs485_config(state->uart_port, uarg);
1277 ret = uart_set_rs485_config(state->uart_port, uarg);
1280 struct uart_port *uport = state->uart_port;
1281 if (uport->ops->ioctl)
1282 ret = uport->ops->ioctl(uport, cmd, arg);
1287 mutex_unlock(&port->mutex);
1292 static void uart_set_ldisc(struct tty_struct *tty)
1294 struct uart_state *state = tty->driver_data;
1295 struct uart_port *uport = state->uart_port;
1297 if (uport->ops->set_ldisc) {
1298 mutex_lock(&state->port.mutex);
1299 uport->ops->set_ldisc(uport, &tty->termios);
1300 mutex_unlock(&state->port.mutex);
1304 static void uart_set_termios(struct tty_struct *tty,
1305 struct ktermios *old_termios)
1307 struct uart_state *state = tty->driver_data;
1308 struct uart_port *uport = state->uart_port;
1309 unsigned int cflag = tty->termios.c_cflag;
1310 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1311 bool sw_changed = false;
1314 * Drivers doing software flow control also need to know
1315 * about changes to these input settings.
1317 if (uport->flags & UPF_SOFT_FLOW) {
1318 iflag_mask |= IXANY|IXON|IXOFF;
1320 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1321 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1325 * These are the bits that are used to setup various
1326 * flags in the low level driver. We can ignore the Bfoo
1327 * bits in c_cflag; c_[io]speed will always be set
1328 * appropriately by set_termios() in tty_ioctl.c
1330 if ((cflag ^ old_termios->c_cflag) == 0 &&
1331 tty->termios.c_ospeed == old_termios->c_ospeed &&
1332 tty->termios.c_ispeed == old_termios->c_ispeed &&
1333 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1338 mutex_lock(&state->port.mutex);
1339 uart_change_speed(tty, state, old_termios);
1340 mutex_unlock(&state->port.mutex);
1341 /* reload cflag from termios; port driver may have overriden flags */
1342 cflag = tty->termios.c_cflag;
1344 /* Handle transition to B0 status */
1345 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1346 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1347 /* Handle transition away from B0 status */
1348 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1349 unsigned int mask = TIOCM_DTR;
1350 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1352 uart_set_mctrl(uport, mask);
1356 * If the port is doing h/w assisted flow control, do nothing.
1357 * We assume that port->hw_stopped has never been set.
1359 if (uport->flags & UPF_HARD_FLOW)
1362 /* Handle turning off CRTSCTS */
1363 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1364 spin_lock_irq(&uport->lock);
1365 uport->hw_stopped = 0;
1367 spin_unlock_irq(&uport->lock);
1369 /* Handle turning on CRTSCTS */
1370 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1371 spin_lock_irq(&uport->lock);
1372 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1373 uport->hw_stopped = 1;
1374 uport->ops->stop_tx(uport);
1376 spin_unlock_irq(&uport->lock);
1381 * Calls to uart_close() are serialised via the tty_lock in
1382 * drivers/tty/tty_io.c:tty_release()
1383 * drivers/tty/tty_io.c:do_tty_hangup()
1384 * This runs from a workqueue and can sleep for a _short_ time only.
1386 static void uart_close(struct tty_struct *tty, struct file *filp)
1388 struct uart_state *state = tty->driver_data;
1389 struct tty_port *port;
1390 struct uart_port *uport;
1391 unsigned long flags;
1394 struct uart_driver *drv = tty->driver->driver_state;
1396 state = drv->state + tty->index;
1397 port = &state->port;
1398 spin_lock_irq(&port->lock);
1400 spin_unlock_irq(&port->lock);
1404 uport = state->uart_port;
1405 port = &state->port;
1407 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1409 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1413 * At this point, we stop accepting input. To do this, we
1414 * disable the receive line status interrupts.
1416 if (port->flags & ASYNC_INITIALIZED) {
1417 unsigned long flags;
1418 spin_lock_irqsave(&uport->lock, flags);
1419 uport->ops->stop_rx(uport);
1420 spin_unlock_irqrestore(&uport->lock, flags);
1422 * Before we drop DTR, make sure the UART transmitter
1423 * has completely drained; this is especially
1424 * important if there is a transmit FIFO!
1426 uart_wait_until_sent(tty, uport->timeout);
1429 mutex_lock(&port->mutex);
1430 uart_shutdown(tty, state);
1431 tty_port_tty_set(port, NULL);
1433 spin_lock_irqsave(&port->lock, flags);
1435 if (port->blocked_open) {
1436 spin_unlock_irqrestore(&port->lock, flags);
1437 if (port->close_delay)
1438 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1439 spin_lock_irqsave(&port->lock, flags);
1440 } else if (!uart_console(uport)) {
1441 spin_unlock_irqrestore(&port->lock, flags);
1442 uart_change_pm(state, UART_PM_STATE_OFF);
1443 spin_lock_irqsave(&port->lock, flags);
1447 * Wake up anyone trying to open this port.
1449 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1450 clear_bit(ASYNCB_CLOSING, &port->flags);
1451 spin_unlock_irqrestore(&port->lock, flags);
1452 wake_up_interruptible(&port->open_wait);
1453 wake_up_interruptible(&port->close_wait);
1455 mutex_unlock(&port->mutex);
1457 tty_ldisc_flush(tty);
1460 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1462 struct uart_state *state = tty->driver_data;
1463 struct uart_port *port = state->uart_port;
1464 unsigned long char_time, expire;
1466 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1470 * Set the check interval to be 1/5 of the estimated time to
1471 * send a single character, and make it at least 1. The check
1472 * interval should also be less than the timeout.
1474 * Note: we have to use pretty tight timings here to satisfy
1477 char_time = (port->timeout - HZ/50) / port->fifosize;
1478 char_time = char_time / 5;
1481 if (timeout && timeout < char_time)
1482 char_time = timeout;
1485 * If the transmitter hasn't cleared in twice the approximate
1486 * amount of time to send the entire FIFO, it probably won't
1487 * ever clear. This assumes the UART isn't doing flow
1488 * control, which is currently the case. Hence, if it ever
1489 * takes longer than port->timeout, this is probably due to a
1490 * UART bug of some kind. So, we clamp the timeout parameter at
1493 if (timeout == 0 || timeout > 2 * port->timeout)
1494 timeout = 2 * port->timeout;
1496 expire = jiffies + timeout;
1498 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1499 port->line, jiffies, expire);
1502 * Check whether the transmitter is empty every 'char_time'.
1503 * 'timeout' / 'expire' give us the maximum amount of time
1506 while (!port->ops->tx_empty(port)) {
1507 msleep_interruptible(jiffies_to_msecs(char_time));
1508 if (signal_pending(current))
1510 if (time_after(jiffies, expire))
1516 * Calls to uart_hangup() are serialised by the tty_lock in
1517 * drivers/tty/tty_io.c:do_tty_hangup()
1518 * This runs from a workqueue and can sleep for a _short_ time only.
1520 static void uart_hangup(struct tty_struct *tty)
1522 struct uart_state *state = tty->driver_data;
1523 struct tty_port *port = &state->port;
1524 unsigned long flags;
1526 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1528 mutex_lock(&port->mutex);
1529 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1530 uart_flush_buffer(tty);
1531 uart_shutdown(tty, state);
1532 spin_lock_irqsave(&port->lock, flags);
1534 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1535 spin_unlock_irqrestore(&port->lock, flags);
1536 tty_port_tty_set(port, NULL);
1537 if (!uart_console(state->uart_port))
1538 uart_change_pm(state, UART_PM_STATE_OFF);
1539 wake_up_interruptible(&port->open_wait);
1540 wake_up_interruptible(&port->delta_msr_wait);
1542 mutex_unlock(&port->mutex);
1545 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1550 static void uart_port_shutdown(struct tty_port *port)
1552 struct uart_state *state = container_of(port, struct uart_state, port);
1553 struct uart_port *uport = state->uart_port;
1556 * clear delta_msr_wait queue to avoid mem leaks: we may free
1557 * the irq here so the queue might never be woken up. Note
1558 * that we won't end up waiting on delta_msr_wait again since
1559 * any outstanding file descriptors should be pointing at
1560 * hung_up_tty_fops now.
1562 wake_up_interruptible(&port->delta_msr_wait);
1565 * Free the IRQ and disable the port.
1567 uport->ops->shutdown(uport);
1570 * Ensure that the IRQ handler isn't running on another CPU.
1572 synchronize_irq(uport->irq);
1575 static int uart_carrier_raised(struct tty_port *port)
1577 struct uart_state *state = container_of(port, struct uart_state, port);
1578 struct uart_port *uport = state->uart_port;
1580 spin_lock_irq(&uport->lock);
1581 uart_enable_ms(uport);
1582 mctrl = uport->ops->get_mctrl(uport);
1583 spin_unlock_irq(&uport->lock);
1584 if (mctrl & TIOCM_CAR)
1589 static void uart_dtr_rts(struct tty_port *port, int onoff)
1591 struct uart_state *state = container_of(port, struct uart_state, port);
1592 struct uart_port *uport = state->uart_port;
1595 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1597 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1601 * Calls to uart_open are serialised by the tty_lock in
1602 * drivers/tty/tty_io.c:tty_open()
1603 * Note that if this fails, then uart_close() _will_ be called.
1605 * In time, we want to scrap the "opening nonpresent ports"
1606 * behaviour and implement an alternative way for setserial
1607 * to set base addresses/ports/types. This will allow us to
1608 * get rid of a certain amount of extra tests.
1610 static int uart_open(struct tty_struct *tty, struct file *filp)
1612 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1613 int retval, line = tty->index;
1614 struct uart_state *state = drv->state + line;
1615 struct tty_port *port = &state->port;
1617 pr_debug("uart_open(%d) called\n", line);
1619 spin_lock_irq(&port->lock);
1621 spin_unlock_irq(&port->lock);
1624 * We take the semaphore here to guarantee that we won't be re-entered
1625 * while allocating the state structure, or while we request any IRQs
1626 * that the driver may need. This also has the nice side-effect that
1627 * it delays the action of uart_hangup, so we can guarantee that
1628 * state->port.tty will always contain something reasonable.
1630 if (mutex_lock_interruptible(&port->mutex)) {
1631 retval = -ERESTARTSYS;
1635 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1640 tty->driver_data = state;
1641 state->uart_port->state = state;
1642 state->port.low_latency =
1643 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1644 tty_port_tty_set(port, tty);
1647 * Start up the serial port.
1649 retval = uart_startup(tty, state, 0);
1652 * If we succeeded, wait until the port is ready.
1654 mutex_unlock(&port->mutex);
1656 retval = tty_port_block_til_ready(port, tty, filp);
1661 mutex_unlock(&port->mutex);
1665 static const char *uart_type(struct uart_port *port)
1667 const char *str = NULL;
1669 if (port->ops->type)
1670 str = port->ops->type(port);
1678 #ifdef CONFIG_PROC_FS
1680 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1682 struct uart_state *state = drv->state + i;
1683 struct tty_port *port = &state->port;
1684 enum uart_pm_state pm_state;
1685 struct uart_port *uport = state->uart_port;
1687 unsigned int status;
1693 mmio = uport->iotype >= UPIO_MEM;
1694 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1695 uport->line, uart_type(uport),
1696 mmio ? "mmio:0x" : "port:",
1697 mmio ? (unsigned long long)uport->mapbase
1698 : (unsigned long long)uport->iobase,
1701 if (uport->type == PORT_UNKNOWN) {
1706 if (capable(CAP_SYS_ADMIN)) {
1707 mutex_lock(&port->mutex);
1708 pm_state = state->pm_state;
1709 if (pm_state != UART_PM_STATE_ON)
1710 uart_change_pm(state, UART_PM_STATE_ON);
1711 spin_lock_irq(&uport->lock);
1712 status = uport->ops->get_mctrl(uport);
1713 spin_unlock_irq(&uport->lock);
1714 if (pm_state != UART_PM_STATE_ON)
1715 uart_change_pm(state, pm_state);
1716 mutex_unlock(&port->mutex);
1718 seq_printf(m, " tx:%d rx:%d",
1719 uport->icount.tx, uport->icount.rx);
1720 if (uport->icount.frame)
1721 seq_printf(m, " fe:%d",
1722 uport->icount.frame);
1723 if (uport->icount.parity)
1724 seq_printf(m, " pe:%d",
1725 uport->icount.parity);
1726 if (uport->icount.brk)
1727 seq_printf(m, " brk:%d",
1729 if (uport->icount.overrun)
1730 seq_printf(m, " oe:%d",
1731 uport->icount.overrun);
1733 #define INFOBIT(bit, str) \
1734 if (uport->mctrl & (bit)) \
1735 strncat(stat_buf, (str), sizeof(stat_buf) - \
1736 strlen(stat_buf) - 2)
1737 #define STATBIT(bit, str) \
1738 if (status & (bit)) \
1739 strncat(stat_buf, (str), sizeof(stat_buf) - \
1740 strlen(stat_buf) - 2)
1744 INFOBIT(TIOCM_RTS, "|RTS");
1745 STATBIT(TIOCM_CTS, "|CTS");
1746 INFOBIT(TIOCM_DTR, "|DTR");
1747 STATBIT(TIOCM_DSR, "|DSR");
1748 STATBIT(TIOCM_CAR, "|CD");
1749 STATBIT(TIOCM_RNG, "|RI");
1753 seq_puts(m, stat_buf);
1760 static int uart_proc_show(struct seq_file *m, void *v)
1762 struct tty_driver *ttydrv = m->private;
1763 struct uart_driver *drv = ttydrv->driver_state;
1766 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1768 for (i = 0; i < drv->nr; i++)
1769 uart_line_info(m, drv, i);
1773 static int uart_proc_open(struct inode *inode, struct file *file)
1775 return single_open(file, uart_proc_show, PDE_DATA(inode));
1778 static const struct file_operations uart_proc_fops = {
1779 .owner = THIS_MODULE,
1780 .open = uart_proc_open,
1782 .llseek = seq_lseek,
1783 .release = single_release,
1787 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1789 * uart_console_write - write a console message to a serial port
1790 * @port: the port to write the message
1791 * @s: array of characters
1792 * @count: number of characters in string to write
1793 * @write: function to write character to port
1795 void uart_console_write(struct uart_port *port, const char *s,
1797 void (*putchar)(struct uart_port *, int))
1801 for (i = 0; i < count; i++, s++) {
1803 putchar(port, '\r');
1807 EXPORT_SYMBOL_GPL(uart_console_write);
1810 * Check whether an invalid uart number has been specified, and
1811 * if so, search for the first available port that does have
1814 struct uart_port * __init
1815 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1817 int idx = co->index;
1819 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1820 ports[idx].membase == NULL))
1821 for (idx = 0; idx < nr; idx++)
1822 if (ports[idx].iobase != 0 ||
1823 ports[idx].membase != NULL)
1832 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1833 * @options: pointer to option string
1834 * @baud: pointer to an 'int' variable for the baud rate.
1835 * @parity: pointer to an 'int' variable for the parity.
1836 * @bits: pointer to an 'int' variable for the number of data bits.
1837 * @flow: pointer to an 'int' variable for the flow control character.
1839 * uart_parse_options decodes a string containing the serial console
1840 * options. The format of the string is <baud><parity><bits><flow>,
1844 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1848 *baud = simple_strtoul(s, NULL, 10);
1849 while (*s >= '0' && *s <= '9')
1858 EXPORT_SYMBOL_GPL(uart_parse_options);
1865 static const struct baud_rates baud_rates[] = {
1866 { 921600, B921600 },
1867 { 460800, B460800 },
1868 { 230400, B230400 },
1869 { 115200, B115200 },
1881 * uart_set_options - setup the serial console parameters
1882 * @port: pointer to the serial ports uart_port structure
1883 * @co: console pointer
1885 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1886 * @bits: number of data bits
1887 * @flow: flow control character - 'r' (rts)
1890 uart_set_options(struct uart_port *port, struct console *co,
1891 int baud, int parity, int bits, int flow)
1893 struct ktermios termios;
1894 static struct ktermios dummy;
1898 * Ensure that the serial console lock is initialised
1900 * If this port is a console, then the spinlock is already
1903 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1904 spin_lock_init(&port->lock);
1905 lockdep_set_class(&port->lock, &port_lock_key);
1908 memset(&termios, 0, sizeof(struct ktermios));
1910 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1913 * Construct a cflag setting.
1915 for (i = 0; baud_rates[i].rate; i++)
1916 if (baud_rates[i].rate <= baud)
1919 termios.c_cflag |= baud_rates[i].cflag;
1922 termios.c_cflag |= CS7;
1924 termios.c_cflag |= CS8;
1928 termios.c_cflag |= PARODD;
1931 termios.c_cflag |= PARENB;
1936 termios.c_cflag |= CRTSCTS;
1939 * some uarts on other side don't support no flow control.
1940 * So we set * DTR in host uart to make them happy
1942 port->mctrl |= TIOCM_DTR;
1944 port->ops->set_termios(port, &termios, &dummy);
1946 * Allow the setting of the UART parameters with a NULL console
1950 co->cflag = termios.c_cflag;
1954 EXPORT_SYMBOL_GPL(uart_set_options);
1955 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1958 * uart_change_pm - set power state of the port
1960 * @state: port descriptor
1961 * @pm_state: new state
1963 * Locking: port->mutex has to be held
1965 static void uart_change_pm(struct uart_state *state,
1966 enum uart_pm_state pm_state)
1968 struct uart_port *port = state->uart_port;
1970 if (state->pm_state != pm_state) {
1972 port->ops->pm(port, pm_state, state->pm_state);
1973 state->pm_state = pm_state;
1978 struct uart_port *port;
1979 struct uart_driver *driver;
1982 static int serial_match_port(struct device *dev, void *data)
1984 struct uart_match *match = data;
1985 struct tty_driver *tty_drv = match->driver->tty_driver;
1986 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1989 return dev->devt == devt; /* Actually, only one tty per port */
1992 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1994 struct uart_state *state = drv->state + uport->line;
1995 struct tty_port *port = &state->port;
1996 struct device *tty_dev;
1997 struct uart_match match = {uport, drv};
1999 mutex_lock(&port->mutex);
2001 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2002 if (device_may_wakeup(tty_dev)) {
2003 if (!enable_irq_wake(uport->irq))
2004 uport->irq_wake = 1;
2005 put_device(tty_dev);
2006 mutex_unlock(&port->mutex);
2009 put_device(tty_dev);
2011 if (console_suspend_enabled || !uart_console(uport))
2012 uport->suspended = 1;
2014 if (port->flags & ASYNC_INITIALIZED) {
2015 const struct uart_ops *ops = uport->ops;
2018 if (console_suspend_enabled || !uart_console(uport)) {
2019 set_bit(ASYNCB_SUSPENDED, &port->flags);
2020 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2022 spin_lock_irq(&uport->lock);
2023 ops->stop_tx(uport);
2024 ops->set_mctrl(uport, 0);
2025 ops->stop_rx(uport);
2026 spin_unlock_irq(&uport->lock);
2030 * Wait for the transmitter to empty.
2032 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2035 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2037 drv->tty_driver->name_base + uport->line);
2039 if (console_suspend_enabled || !uart_console(uport))
2040 ops->shutdown(uport);
2044 * Disable the console device before suspending.
2046 if (console_suspend_enabled && uart_console(uport))
2047 console_stop(uport->cons);
2049 if (console_suspend_enabled || !uart_console(uport))
2050 uart_change_pm(state, UART_PM_STATE_OFF);
2052 mutex_unlock(&port->mutex);
2057 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2059 struct uart_state *state = drv->state + uport->line;
2060 struct tty_port *port = &state->port;
2061 struct device *tty_dev;
2062 struct uart_match match = {uport, drv};
2063 struct ktermios termios;
2065 mutex_lock(&port->mutex);
2067 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2068 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2069 if (uport->irq_wake) {
2070 disable_irq_wake(uport->irq);
2071 uport->irq_wake = 0;
2073 put_device(tty_dev);
2074 mutex_unlock(&port->mutex);
2077 put_device(tty_dev);
2078 uport->suspended = 0;
2081 * Re-enable the console device after suspending.
2083 if (uart_console(uport)) {
2085 * First try to use the console cflag setting.
2087 memset(&termios, 0, sizeof(struct ktermios));
2088 termios.c_cflag = uport->cons->cflag;
2091 * If that's unset, use the tty termios setting.
2093 if (port->tty && termios.c_cflag == 0)
2094 termios = port->tty->termios;
2096 if (console_suspend_enabled)
2097 uart_change_pm(state, UART_PM_STATE_ON);
2098 uport->ops->set_termios(uport, &termios, NULL);
2099 if (console_suspend_enabled)
2100 console_start(uport->cons);
2103 if (port->flags & ASYNC_SUSPENDED) {
2104 const struct uart_ops *ops = uport->ops;
2107 uart_change_pm(state, UART_PM_STATE_ON);
2108 spin_lock_irq(&uport->lock);
2109 ops->set_mctrl(uport, 0);
2110 spin_unlock_irq(&uport->lock);
2111 if (console_suspend_enabled || !uart_console(uport)) {
2112 /* Protected by port mutex for now */
2113 struct tty_struct *tty = port->tty;
2114 ret = ops->startup(uport);
2117 uart_change_speed(tty, state, NULL);
2118 spin_lock_irq(&uport->lock);
2119 ops->set_mctrl(uport, uport->mctrl);
2120 ops->start_tx(uport);
2121 spin_unlock_irq(&uport->lock);
2122 set_bit(ASYNCB_INITIALIZED, &port->flags);
2125 * Failed to resume - maybe hardware went away?
2126 * Clear the "initialized" flag so we won't try
2127 * to call the low level drivers shutdown method.
2129 uart_shutdown(tty, state);
2133 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2136 mutex_unlock(&port->mutex);
2142 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2146 switch (port->iotype) {
2148 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2151 snprintf(address, sizeof(address),
2152 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2159 snprintf(address, sizeof(address),
2160 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2163 strlcpy(address, "*unknown*", sizeof(address));
2167 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2169 drv->tty_driver->name_base + port->line,
2170 address, port->irq, port->uartclk / 16, uart_type(port));
2174 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2175 struct uart_port *port)
2180 * If there isn't a port here, don't do anything further.
2182 if (!port->iobase && !port->mapbase && !port->membase)
2186 * Now do the auto configuration stuff. Note that config_port
2187 * is expected to claim the resources and map the port for us.
2190 if (port->flags & UPF_AUTO_IRQ)
2191 flags |= UART_CONFIG_IRQ;
2192 if (port->flags & UPF_BOOT_AUTOCONF) {
2193 if (!(port->flags & UPF_FIXED_TYPE)) {
2194 port->type = PORT_UNKNOWN;
2195 flags |= UART_CONFIG_TYPE;
2197 port->ops->config_port(port, flags);
2200 if (port->type != PORT_UNKNOWN) {
2201 unsigned long flags;
2203 uart_report_port(drv, port);
2205 /* Power up port for set_mctrl() */
2206 uart_change_pm(state, UART_PM_STATE_ON);
2209 * Ensure that the modem control lines are de-activated.
2210 * keep the DTR setting that is set in uart_set_options()
2211 * We probably don't need a spinlock around this, but
2213 spin_lock_irqsave(&port->lock, flags);
2214 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2215 spin_unlock_irqrestore(&port->lock, flags);
2218 * If this driver supports console, and it hasn't been
2219 * successfully registered yet, try to re-register it.
2220 * It may be that the port was not available.
2222 if (port->cons && !(port->cons->flags & CON_ENABLED))
2223 register_console(port->cons);
2226 * Power down all ports by default, except the
2227 * console if we have one.
2229 if (!uart_console(port))
2230 uart_change_pm(state, UART_PM_STATE_OFF);
2234 #ifdef CONFIG_CONSOLE_POLL
2236 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2238 struct uart_driver *drv = driver->driver_state;
2239 struct uart_state *state = drv->state + line;
2240 struct uart_port *port;
2247 if (!state || !state->uart_port)
2250 port = state->uart_port;
2251 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2254 if (port->ops->poll_init) {
2255 struct tty_port *tport = &state->port;
2258 mutex_lock(&tport->mutex);
2260 * We don't set ASYNCB_INITIALIZED as we only initialized the
2261 * hw, e.g. state->xmit is still uninitialized.
2263 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2264 ret = port->ops->poll_init(port);
2265 mutex_unlock(&tport->mutex);
2271 uart_parse_options(options, &baud, &parity, &bits, &flow);
2272 return uart_set_options(port, NULL, baud, parity, bits, flow);
2278 static int uart_poll_get_char(struct tty_driver *driver, int line)
2280 struct uart_driver *drv = driver->driver_state;
2281 struct uart_state *state = drv->state + line;
2282 struct uart_port *port;
2284 if (!state || !state->uart_port)
2287 port = state->uart_port;
2288 return port->ops->poll_get_char(port);
2291 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2293 struct uart_driver *drv = driver->driver_state;
2294 struct uart_state *state = drv->state + line;
2295 struct uart_port *port;
2297 if (!state || !state->uart_port)
2300 port = state->uart_port;
2303 port->ops->poll_put_char(port, '\r');
2304 port->ops->poll_put_char(port, ch);
2308 static const struct tty_operations uart_ops = {
2310 .close = uart_close,
2311 .write = uart_write,
2312 .put_char = uart_put_char,
2313 .flush_chars = uart_flush_chars,
2314 .write_room = uart_write_room,
2315 .chars_in_buffer= uart_chars_in_buffer,
2316 .flush_buffer = uart_flush_buffer,
2317 .ioctl = uart_ioctl,
2318 .throttle = uart_throttle,
2319 .unthrottle = uart_unthrottle,
2320 .send_xchar = uart_send_xchar,
2321 .set_termios = uart_set_termios,
2322 .set_ldisc = uart_set_ldisc,
2324 .start = uart_start,
2325 .hangup = uart_hangup,
2326 .break_ctl = uart_break_ctl,
2327 .wait_until_sent= uart_wait_until_sent,
2328 #ifdef CONFIG_PROC_FS
2329 .proc_fops = &uart_proc_fops,
2331 .tiocmget = uart_tiocmget,
2332 .tiocmset = uart_tiocmset,
2333 .get_icount = uart_get_icount,
2334 #ifdef CONFIG_CONSOLE_POLL
2335 .poll_init = uart_poll_init,
2336 .poll_get_char = uart_poll_get_char,
2337 .poll_put_char = uart_poll_put_char,
2341 static const struct tty_port_operations uart_port_ops = {
2342 .activate = uart_port_activate,
2343 .shutdown = uart_port_shutdown,
2344 .carrier_raised = uart_carrier_raised,
2345 .dtr_rts = uart_dtr_rts,
2349 * uart_register_driver - register a driver with the uart core layer
2350 * @drv: low level driver structure
2352 * Register a uart driver with the core driver. We in turn register
2353 * with the tty layer, and initialise the core driver per-port state.
2355 * We have a proc file in /proc/tty/driver which is named after the
2358 * drv->port should be NULL, and the per-port structures should be
2359 * registered using uart_add_one_port after this call has succeeded.
2361 int uart_register_driver(struct uart_driver *drv)
2363 struct tty_driver *normal;
2369 * Maybe we should be using a slab cache for this, especially if
2370 * we have a large number of ports to handle.
2372 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2376 normal = alloc_tty_driver(drv->nr);
2380 drv->tty_driver = normal;
2382 normal->driver_name = drv->driver_name;
2383 normal->name = drv->dev_name;
2384 normal->major = drv->major;
2385 normal->minor_start = drv->minor;
2386 normal->type = TTY_DRIVER_TYPE_SERIAL;
2387 normal->subtype = SERIAL_TYPE_NORMAL;
2388 normal->init_termios = tty_std_termios;
2389 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2390 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2391 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2392 normal->driver_state = drv;
2393 tty_set_operations(normal, &uart_ops);
2396 * Initialise the UART state(s).
2398 for (i = 0; i < drv->nr; i++) {
2399 struct uart_state *state = drv->state + i;
2400 struct tty_port *port = &state->port;
2402 tty_port_init(port);
2403 port->ops = &uart_port_ops;
2406 retval = tty_register_driver(normal);
2410 for (i = 0; i < drv->nr; i++)
2411 tty_port_destroy(&drv->state[i].port);
2412 put_tty_driver(normal);
2420 * uart_unregister_driver - remove a driver from the uart core layer
2421 * @drv: low level driver structure
2423 * Remove all references to a driver from the core driver. The low
2424 * level driver must have removed all its ports via the
2425 * uart_remove_one_port() if it registered them with uart_add_one_port().
2426 * (ie, drv->port == NULL)
2428 void uart_unregister_driver(struct uart_driver *drv)
2430 struct tty_driver *p = drv->tty_driver;
2433 tty_unregister_driver(p);
2435 for (i = 0; i < drv->nr; i++)
2436 tty_port_destroy(&drv->state[i].port);
2439 drv->tty_driver = NULL;
2442 struct tty_driver *uart_console_device(struct console *co, int *index)
2444 struct uart_driver *p = co->data;
2446 return p->tty_driver;
2449 static ssize_t uart_get_attr_uartclk(struct device *dev,
2450 struct device_attribute *attr, char *buf)
2452 struct serial_struct tmp;
2453 struct tty_port *port = dev_get_drvdata(dev);
2455 uart_get_info(port, &tmp);
2456 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2459 static ssize_t uart_get_attr_type(struct device *dev,
2460 struct device_attribute *attr, char *buf)
2462 struct serial_struct tmp;
2463 struct tty_port *port = dev_get_drvdata(dev);
2465 uart_get_info(port, &tmp);
2466 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2468 static ssize_t uart_get_attr_line(struct device *dev,
2469 struct device_attribute *attr, char *buf)
2471 struct serial_struct tmp;
2472 struct tty_port *port = dev_get_drvdata(dev);
2474 uart_get_info(port, &tmp);
2475 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2478 static ssize_t uart_get_attr_port(struct device *dev,
2479 struct device_attribute *attr, char *buf)
2481 struct serial_struct tmp;
2482 struct tty_port *port = dev_get_drvdata(dev);
2483 unsigned long ioaddr;
2485 uart_get_info(port, &tmp);
2487 if (HIGH_BITS_OFFSET)
2488 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2489 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2492 static ssize_t uart_get_attr_irq(struct device *dev,
2493 struct device_attribute *attr, char *buf)
2495 struct serial_struct tmp;
2496 struct tty_port *port = dev_get_drvdata(dev);
2498 uart_get_info(port, &tmp);
2499 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2502 static ssize_t uart_get_attr_flags(struct device *dev,
2503 struct device_attribute *attr, char *buf)
2505 struct serial_struct tmp;
2506 struct tty_port *port = dev_get_drvdata(dev);
2508 uart_get_info(port, &tmp);
2509 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2512 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2513 struct device_attribute *attr, char *buf)
2515 struct serial_struct tmp;
2516 struct tty_port *port = dev_get_drvdata(dev);
2518 uart_get_info(port, &tmp);
2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2523 static ssize_t uart_get_attr_close_delay(struct device *dev,
2524 struct device_attribute *attr, char *buf)
2526 struct serial_struct tmp;
2527 struct tty_port *port = dev_get_drvdata(dev);
2529 uart_get_info(port, &tmp);
2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2534 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2535 struct device_attribute *attr, char *buf)
2537 struct serial_struct tmp;
2538 struct tty_port *port = dev_get_drvdata(dev);
2540 uart_get_info(port, &tmp);
2541 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2544 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2545 struct device_attribute *attr, char *buf)
2547 struct serial_struct tmp;
2548 struct tty_port *port = dev_get_drvdata(dev);
2550 uart_get_info(port, &tmp);
2551 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2554 static ssize_t uart_get_attr_io_type(struct device *dev,
2555 struct device_attribute *attr, char *buf)
2557 struct serial_struct tmp;
2558 struct tty_port *port = dev_get_drvdata(dev);
2560 uart_get_info(port, &tmp);
2561 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2564 static ssize_t uart_get_attr_iomem_base(struct device *dev,
2565 struct device_attribute *attr, char *buf)
2567 struct serial_struct tmp;
2568 struct tty_port *port = dev_get_drvdata(dev);
2570 uart_get_info(port, &tmp);
2571 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2574 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2575 struct device_attribute *attr, char *buf)
2577 struct serial_struct tmp;
2578 struct tty_port *port = dev_get_drvdata(dev);
2580 uart_get_info(port, &tmp);
2581 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2584 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2585 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2586 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2587 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2588 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2589 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2590 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2591 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2592 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2593 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2594 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2595 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2596 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2598 static struct attribute *tty_dev_attrs[] = {
2599 &dev_attr_type.attr,
2600 &dev_attr_line.attr,
2601 &dev_attr_port.attr,
2603 &dev_attr_flags.attr,
2604 &dev_attr_xmit_fifo_size.attr,
2605 &dev_attr_uartclk.attr,
2606 &dev_attr_close_delay.attr,
2607 &dev_attr_closing_wait.attr,
2608 &dev_attr_custom_divisor.attr,
2609 &dev_attr_io_type.attr,
2610 &dev_attr_iomem_base.attr,
2611 &dev_attr_iomem_reg_shift.attr,
2615 static const struct attribute_group tty_dev_attr_group = {
2616 .attrs = tty_dev_attrs,
2620 * uart_add_one_port - attach a driver-defined port structure
2621 * @drv: pointer to the uart low level driver structure for this port
2622 * @uport: uart port structure to use for this port.
2624 * This allows the driver to register its own uart_port structure
2625 * with the core driver. The main purpose is to allow the low
2626 * level uart drivers to expand uart_port, rather than having yet
2627 * more levels of structures.
2629 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2631 struct uart_state *state;
2632 struct tty_port *port;
2634 struct device *tty_dev;
2637 BUG_ON(in_interrupt());
2639 if (uport->line >= drv->nr)
2642 state = drv->state + uport->line;
2643 port = &state->port;
2645 mutex_lock(&port_mutex);
2646 mutex_lock(&port->mutex);
2647 if (state->uart_port) {
2652 /* Link the port to the driver state table and vice versa */
2653 state->uart_port = uport;
2654 uport->state = state;
2656 state->pm_state = UART_PM_STATE_UNDEFINED;
2657 uport->cons = drv->cons;
2660 * If this port is a console, then the spinlock is already
2663 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2664 spin_lock_init(&uport->lock);
2665 lockdep_set_class(&uport->lock, &port_lock_key);
2667 if (uport->cons && uport->dev)
2668 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2670 uart_configure_port(drv, state, uport);
2673 if (uport->attr_group)
2676 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2678 if (!uport->tty_groups) {
2682 uport->tty_groups[0] = &tty_dev_attr_group;
2683 if (uport->attr_group)
2684 uport->tty_groups[1] = uport->attr_group;
2687 * Register the port whether it's detected or not. This allows
2688 * setserial to be used to alter this port's parameters.
2690 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2691 uport->line, uport->dev, port, uport->tty_groups);
2692 if (likely(!IS_ERR(tty_dev))) {
2693 device_set_wakeup_capable(tty_dev, 1);
2695 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2700 * Ensure UPF_DEAD is not set.
2702 uport->flags &= ~UPF_DEAD;
2705 mutex_unlock(&port->mutex);
2706 mutex_unlock(&port_mutex);
2712 * uart_remove_one_port - detach a driver defined port structure
2713 * @drv: pointer to the uart low level driver structure for this port
2714 * @uport: uart port structure for this port
2716 * This unhooks (and hangs up) the specified port structure from the
2717 * core driver. No further calls will be made to the low-level code
2720 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2722 struct uart_state *state = drv->state + uport->line;
2723 struct tty_port *port = &state->port;
2724 struct tty_struct *tty;
2727 BUG_ON(in_interrupt());
2729 if (state->uart_port != uport)
2730 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2731 state->uart_port, uport);
2733 mutex_lock(&port_mutex);
2736 * Mark the port "dead" - this prevents any opens from
2737 * succeeding while we shut down the port.
2739 mutex_lock(&port->mutex);
2740 if (!state->uart_port) {
2741 mutex_unlock(&port->mutex);
2745 uport->flags |= UPF_DEAD;
2746 mutex_unlock(&port->mutex);
2749 * Remove the devices from the tty layer
2751 tty_unregister_device(drv->tty_driver, uport->line);
2753 tty = tty_port_tty_get(port);
2755 tty_vhangup(port->tty);
2760 * If the port is used as a console, unregister it
2762 if (uart_console(uport))
2763 unregister_console(uport->cons);
2766 * Free the port IO and memory resources, if any.
2768 if (uport->type != PORT_UNKNOWN)
2769 uport->ops->release_port(uport);
2770 kfree(uport->tty_groups);
2773 * Indicate that there isn't a port here anymore.
2775 uport->type = PORT_UNKNOWN;
2777 state->uart_port = NULL;
2779 mutex_unlock(&port_mutex);
2785 * Are the two ports equivalent?
2787 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2789 if (port1->iotype != port2->iotype)
2792 switch (port1->iotype) {
2794 return (port1->iobase == port2->iobase);
2796 return (port1->iobase == port2->iobase) &&
2797 (port1->hub6 == port2->hub6);
2803 return (port1->mapbase == port2->mapbase);
2807 EXPORT_SYMBOL(uart_match_port);
2810 * uart_handle_dcd_change - handle a change of carrier detect state
2811 * @uport: uart_port structure for the open port
2812 * @status: new carrier detect status, nonzero if active
2814 * Caller must hold uport->lock
2816 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2818 struct tty_port *port = &uport->state->port;
2819 struct tty_struct *tty = port->tty;
2820 struct tty_ldisc *ld;
2822 lockdep_assert_held_once(&uport->lock);
2825 ld = tty_ldisc_ref(tty);
2827 if (ld->ops->dcd_change)
2828 ld->ops->dcd_change(tty, status);
2829 tty_ldisc_deref(ld);
2833 uport->icount.dcd++;
2835 if (uart_dcd_enabled(uport)) {
2837 wake_up_interruptible(&port->open_wait);
2842 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2845 * uart_handle_cts_change - handle a change of clear-to-send state
2846 * @uport: uart_port structure for the open port
2847 * @status: new clear to send status, nonzero if active
2849 * Caller must hold uport->lock
2851 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2853 lockdep_assert_held_once(&uport->lock);
2855 uport->icount.cts++;
2857 if (uart_cts_enabled(uport)) {
2858 if (uport->hw_stopped) {
2860 uport->hw_stopped = 0;
2861 uport->ops->start_tx(uport);
2862 uart_write_wakeup(uport);
2866 uport->hw_stopped = 1;
2867 uport->ops->stop_tx(uport);
2872 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2875 * uart_insert_char - push a char to the uart layer
2877 * User is responsible to call tty_flip_buffer_push when they are done with
2880 * @port: corresponding port
2881 * @status: state of the serial port RX buffer (LSR for 8250)
2882 * @overrun: mask of overrun bits in @status
2883 * @ch: character to push
2884 * @flag: flag for the character (see TTY_NORMAL and friends)
2886 void uart_insert_char(struct uart_port *port, unsigned int status,
2887 unsigned int overrun, unsigned int ch, unsigned int flag)
2889 struct tty_port *tport = &port->state->port;
2891 if ((status & port->ignore_status_mask & ~overrun) == 0)
2892 if (tty_insert_flip_char(tport, ch, flag) == 0)
2893 ++port->icount.buf_overrun;
2896 * Overrun is special. Since it's reported immediately,
2897 * it doesn't affect the current character.
2899 if (status & ~port->ignore_status_mask & overrun)
2900 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2901 ++port->icount.buf_overrun;
2903 EXPORT_SYMBOL_GPL(uart_insert_char);
2905 EXPORT_SYMBOL(uart_write_wakeup);
2906 EXPORT_SYMBOL(uart_register_driver);
2907 EXPORT_SYMBOL(uart_unregister_driver);
2908 EXPORT_SYMBOL(uart_suspend_port);
2909 EXPORT_SYMBOL(uart_resume_port);
2910 EXPORT_SYMBOL(uart_add_one_port);
2911 EXPORT_SYMBOL(uart_remove_one_port);
2913 MODULE_DESCRIPTION("Serial driver core");
2914 MODULE_LICENSE("GPL");