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 if (copy_to_user(rs485, &port->rs485, sizeof(port->rs485)))
1163 static int uart_set_rs485_config(struct uart_port *port,
1164 struct serial_rs485 __user *rs485_user)
1166 struct serial_rs485 rs485;
1169 if (!port->rs485_config)
1170 return -ENOIOCTLCMD;
1172 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1175 ret = port->rs485_config(port, &rs485);
1179 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1186 * Called via sys_ioctl. We can use spin_lock_irq() here.
1189 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1192 struct uart_state *state = tty->driver_data;
1193 struct tty_port *port = &state->port;
1194 void __user *uarg = (void __user *)arg;
1195 int ret = -ENOIOCTLCMD;
1199 * These ioctls don't rely on the hardware to be present.
1203 ret = uart_get_info_user(port, uarg);
1207 down_write(&tty->termios_rwsem);
1208 ret = uart_set_info_user(tty, state, uarg);
1209 up_write(&tty->termios_rwsem);
1213 down_write(&tty->termios_rwsem);
1214 ret = uart_do_autoconfig(tty, state);
1215 up_write(&tty->termios_rwsem);
1218 case TIOCSERGWILD: /* obsolete */
1219 case TIOCSERSWILD: /* obsolete */
1224 if (ret != -ENOIOCTLCMD)
1227 if (tty->flags & (1 << TTY_IO_ERROR)) {
1233 * The following should only be used when hardware is present.
1237 ret = uart_wait_modem_status(state, arg);
1241 if (ret != -ENOIOCTLCMD)
1244 mutex_lock(&port->mutex);
1246 if (tty->flags & (1 << TTY_IO_ERROR)) {
1252 * All these rely on hardware being present and need to be
1253 * protected against the tty being hung up.
1257 case TIOCSERGETLSR: /* Get line status register */
1258 ret = uart_get_lsr_info(tty, state, uarg);
1262 ret = uart_get_rs485_config(state->uart_port, uarg);
1266 ret = uart_set_rs485_config(state->uart_port, uarg);
1269 struct uart_port *uport = state->uart_port;
1270 if (uport->ops->ioctl)
1271 ret = uport->ops->ioctl(uport, cmd, arg);
1276 mutex_unlock(&port->mutex);
1281 static void uart_set_ldisc(struct tty_struct *tty)
1283 struct uart_state *state = tty->driver_data;
1284 struct uart_port *uport = state->uart_port;
1286 if (uport->ops->set_ldisc) {
1287 mutex_lock(&state->port.mutex);
1288 uport->ops->set_ldisc(uport, &tty->termios);
1289 mutex_unlock(&state->port.mutex);
1293 static void uart_set_termios(struct tty_struct *tty,
1294 struct ktermios *old_termios)
1296 struct uart_state *state = tty->driver_data;
1297 struct uart_port *uport = state->uart_port;
1298 unsigned int cflag = tty->termios.c_cflag;
1299 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1300 bool sw_changed = false;
1303 * Drivers doing software flow control also need to know
1304 * about changes to these input settings.
1306 if (uport->flags & UPF_SOFT_FLOW) {
1307 iflag_mask |= IXANY|IXON|IXOFF;
1309 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1310 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1314 * These are the bits that are used to setup various
1315 * flags in the low level driver. We can ignore the Bfoo
1316 * bits in c_cflag; c_[io]speed will always be set
1317 * appropriately by set_termios() in tty_ioctl.c
1319 if ((cflag ^ old_termios->c_cflag) == 0 &&
1320 tty->termios.c_ospeed == old_termios->c_ospeed &&
1321 tty->termios.c_ispeed == old_termios->c_ispeed &&
1322 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1327 mutex_lock(&state->port.mutex);
1328 uart_change_speed(tty, state, old_termios);
1329 mutex_unlock(&state->port.mutex);
1330 /* reload cflag from termios; port driver may have overriden flags */
1331 cflag = tty->termios.c_cflag;
1333 /* Handle transition to B0 status */
1334 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1335 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1336 /* Handle transition away from B0 status */
1337 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1338 unsigned int mask = TIOCM_DTR;
1339 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
1341 uart_set_mctrl(uport, mask);
1345 * If the port is doing h/w assisted flow control, do nothing.
1346 * We assume that port->hw_stopped has never been set.
1348 if (uport->flags & UPF_HARD_FLOW)
1351 /* Handle turning off CRTSCTS */
1352 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1353 spin_lock_irq(&uport->lock);
1354 uport->hw_stopped = 0;
1356 spin_unlock_irq(&uport->lock);
1358 /* Handle turning on CRTSCTS */
1359 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1360 spin_lock_irq(&uport->lock);
1361 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
1362 uport->hw_stopped = 1;
1363 uport->ops->stop_tx(uport);
1365 spin_unlock_irq(&uport->lock);
1370 * Calls to uart_close() are serialised via the tty_lock in
1371 * drivers/tty/tty_io.c:tty_release()
1372 * drivers/tty/tty_io.c:do_tty_hangup()
1373 * This runs from a workqueue and can sleep for a _short_ time only.
1375 static void uart_close(struct tty_struct *tty, struct file *filp)
1377 struct uart_state *state = tty->driver_data;
1378 struct tty_port *port;
1379 struct uart_port *uport;
1380 unsigned long flags;
1383 struct uart_driver *drv = tty->driver->driver_state;
1385 state = drv->state + tty->index;
1386 port = &state->port;
1387 spin_lock_irq(&port->lock);
1389 spin_unlock_irq(&port->lock);
1393 uport = state->uart_port;
1394 port = &state->port;
1396 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
1398 if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1402 * At this point, we stop accepting input. To do this, we
1403 * disable the receive line status interrupts.
1405 if (port->flags & ASYNC_INITIALIZED) {
1406 unsigned long flags;
1407 spin_lock_irqsave(&uport->lock, flags);
1408 uport->ops->stop_rx(uport);
1409 spin_unlock_irqrestore(&uport->lock, flags);
1411 * Before we drop DTR, make sure the UART transmitter
1412 * has completely drained; this is especially
1413 * important if there is a transmit FIFO!
1415 uart_wait_until_sent(tty, uport->timeout);
1418 mutex_lock(&port->mutex);
1419 uart_shutdown(tty, state);
1420 tty_port_tty_set(port, NULL);
1422 spin_lock_irqsave(&port->lock, flags);
1424 if (port->blocked_open) {
1425 spin_unlock_irqrestore(&port->lock, flags);
1426 if (port->close_delay)
1427 msleep_interruptible(jiffies_to_msecs(port->close_delay));
1428 spin_lock_irqsave(&port->lock, flags);
1429 } else if (!uart_console(uport)) {
1430 spin_unlock_irqrestore(&port->lock, flags);
1431 uart_change_pm(state, UART_PM_STATE_OFF);
1432 spin_lock_irqsave(&port->lock, flags);
1436 * Wake up anyone trying to open this port.
1438 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1439 clear_bit(ASYNCB_CLOSING, &port->flags);
1440 spin_unlock_irqrestore(&port->lock, flags);
1441 wake_up_interruptible(&port->open_wait);
1442 wake_up_interruptible(&port->close_wait);
1444 mutex_unlock(&port->mutex);
1446 tty_ldisc_flush(tty);
1449 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1451 struct uart_state *state = tty->driver_data;
1452 struct uart_port *port = state->uart_port;
1453 unsigned long char_time, expire;
1455 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1459 * Set the check interval to be 1/5 of the estimated time to
1460 * send a single character, and make it at least 1. The check
1461 * interval should also be less than the timeout.
1463 * Note: we have to use pretty tight timings here to satisfy
1466 char_time = (port->timeout - HZ/50) / port->fifosize;
1467 char_time = char_time / 5;
1470 if (timeout && timeout < char_time)
1471 char_time = timeout;
1474 * If the transmitter hasn't cleared in twice the approximate
1475 * amount of time to send the entire FIFO, it probably won't
1476 * ever clear. This assumes the UART isn't doing flow
1477 * control, which is currently the case. Hence, if it ever
1478 * takes longer than port->timeout, this is probably due to a
1479 * UART bug of some kind. So, we clamp the timeout parameter at
1482 if (timeout == 0 || timeout > 2 * port->timeout)
1483 timeout = 2 * port->timeout;
1485 expire = jiffies + timeout;
1487 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1488 port->line, jiffies, expire);
1491 * Check whether the transmitter is empty every 'char_time'.
1492 * 'timeout' / 'expire' give us the maximum amount of time
1495 while (!port->ops->tx_empty(port)) {
1496 msleep_interruptible(jiffies_to_msecs(char_time));
1497 if (signal_pending(current))
1499 if (time_after(jiffies, expire))
1505 * Calls to uart_hangup() are serialised by the tty_lock in
1506 * drivers/tty/tty_io.c:do_tty_hangup()
1507 * This runs from a workqueue and can sleep for a _short_ time only.
1509 static void uart_hangup(struct tty_struct *tty)
1511 struct uart_state *state = tty->driver_data;
1512 struct tty_port *port = &state->port;
1513 unsigned long flags;
1515 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1517 mutex_lock(&port->mutex);
1518 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1519 uart_flush_buffer(tty);
1520 uart_shutdown(tty, state);
1521 spin_lock_irqsave(&port->lock, flags);
1523 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1524 spin_unlock_irqrestore(&port->lock, flags);
1525 tty_port_tty_set(port, NULL);
1526 if (!uart_console(state->uart_port))
1527 uart_change_pm(state, UART_PM_STATE_OFF);
1528 wake_up_interruptible(&port->open_wait);
1529 wake_up_interruptible(&port->delta_msr_wait);
1531 mutex_unlock(&port->mutex);
1534 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1539 static void uart_port_shutdown(struct tty_port *port)
1541 struct uart_state *state = container_of(port, struct uart_state, port);
1542 struct uart_port *uport = state->uart_port;
1545 * clear delta_msr_wait queue to avoid mem leaks: we may free
1546 * the irq here so the queue might never be woken up. Note
1547 * that we won't end up waiting on delta_msr_wait again since
1548 * any outstanding file descriptors should be pointing at
1549 * hung_up_tty_fops now.
1551 wake_up_interruptible(&port->delta_msr_wait);
1554 * Free the IRQ and disable the port.
1556 uport->ops->shutdown(uport);
1559 * Ensure that the IRQ handler isn't running on another CPU.
1561 synchronize_irq(uport->irq);
1564 static int uart_carrier_raised(struct tty_port *port)
1566 struct uart_state *state = container_of(port, struct uart_state, port);
1567 struct uart_port *uport = state->uart_port;
1569 spin_lock_irq(&uport->lock);
1570 uart_enable_ms(uport);
1571 mctrl = uport->ops->get_mctrl(uport);
1572 spin_unlock_irq(&uport->lock);
1573 if (mctrl & TIOCM_CAR)
1578 static void uart_dtr_rts(struct tty_port *port, int onoff)
1580 struct uart_state *state = container_of(port, struct uart_state, port);
1581 struct uart_port *uport = state->uart_port;
1584 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1586 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1590 * Calls to uart_open are serialised by the tty_lock in
1591 * drivers/tty/tty_io.c:tty_open()
1592 * Note that if this fails, then uart_close() _will_ be called.
1594 * In time, we want to scrap the "opening nonpresent ports"
1595 * behaviour and implement an alternative way for setserial
1596 * to set base addresses/ports/types. This will allow us to
1597 * get rid of a certain amount of extra tests.
1599 static int uart_open(struct tty_struct *tty, struct file *filp)
1601 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1602 int retval, line = tty->index;
1603 struct uart_state *state = drv->state + line;
1604 struct tty_port *port = &state->port;
1606 pr_debug("uart_open(%d) called\n", line);
1608 spin_lock_irq(&port->lock);
1610 spin_unlock_irq(&port->lock);
1613 * We take the semaphore here to guarantee that we won't be re-entered
1614 * while allocating the state structure, or while we request any IRQs
1615 * that the driver may need. This also has the nice side-effect that
1616 * it delays the action of uart_hangup, so we can guarantee that
1617 * state->port.tty will always contain something reasonable.
1619 if (mutex_lock_interruptible(&port->mutex)) {
1620 retval = -ERESTARTSYS;
1624 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1629 tty->driver_data = state;
1630 state->uart_port->state = state;
1631 state->port.low_latency =
1632 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1633 tty_port_tty_set(port, tty);
1636 * Start up the serial port.
1638 retval = uart_startup(tty, state, 0);
1641 * If we succeeded, wait until the port is ready.
1643 mutex_unlock(&port->mutex);
1645 retval = tty_port_block_til_ready(port, tty, filp);
1650 mutex_unlock(&port->mutex);
1654 static const char *uart_type(struct uart_port *port)
1656 const char *str = NULL;
1658 if (port->ops->type)
1659 str = port->ops->type(port);
1667 #ifdef CONFIG_PROC_FS
1669 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1671 struct uart_state *state = drv->state + i;
1672 struct tty_port *port = &state->port;
1673 enum uart_pm_state pm_state;
1674 struct uart_port *uport = state->uart_port;
1676 unsigned int status;
1682 mmio = uport->iotype >= UPIO_MEM;
1683 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1684 uport->line, uart_type(uport),
1685 mmio ? "mmio:0x" : "port:",
1686 mmio ? (unsigned long long)uport->mapbase
1687 : (unsigned long long)uport->iobase,
1690 if (uport->type == PORT_UNKNOWN) {
1695 if (capable(CAP_SYS_ADMIN)) {
1696 mutex_lock(&port->mutex);
1697 pm_state = state->pm_state;
1698 if (pm_state != UART_PM_STATE_ON)
1699 uart_change_pm(state, UART_PM_STATE_ON);
1700 spin_lock_irq(&uport->lock);
1701 status = uport->ops->get_mctrl(uport);
1702 spin_unlock_irq(&uport->lock);
1703 if (pm_state != UART_PM_STATE_ON)
1704 uart_change_pm(state, pm_state);
1705 mutex_unlock(&port->mutex);
1707 seq_printf(m, " tx:%d rx:%d",
1708 uport->icount.tx, uport->icount.rx);
1709 if (uport->icount.frame)
1710 seq_printf(m, " fe:%d",
1711 uport->icount.frame);
1712 if (uport->icount.parity)
1713 seq_printf(m, " pe:%d",
1714 uport->icount.parity);
1715 if (uport->icount.brk)
1716 seq_printf(m, " brk:%d",
1718 if (uport->icount.overrun)
1719 seq_printf(m, " oe:%d",
1720 uport->icount.overrun);
1722 #define INFOBIT(bit, str) \
1723 if (uport->mctrl & (bit)) \
1724 strncat(stat_buf, (str), sizeof(stat_buf) - \
1725 strlen(stat_buf) - 2)
1726 #define STATBIT(bit, str) \
1727 if (status & (bit)) \
1728 strncat(stat_buf, (str), sizeof(stat_buf) - \
1729 strlen(stat_buf) - 2)
1733 INFOBIT(TIOCM_RTS, "|RTS");
1734 STATBIT(TIOCM_CTS, "|CTS");
1735 INFOBIT(TIOCM_DTR, "|DTR");
1736 STATBIT(TIOCM_DSR, "|DSR");
1737 STATBIT(TIOCM_CAR, "|CD");
1738 STATBIT(TIOCM_RNG, "|RI");
1742 seq_puts(m, stat_buf);
1749 static int uart_proc_show(struct seq_file *m, void *v)
1751 struct tty_driver *ttydrv = m->private;
1752 struct uart_driver *drv = ttydrv->driver_state;
1755 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1757 for (i = 0; i < drv->nr; i++)
1758 uart_line_info(m, drv, i);
1762 static int uart_proc_open(struct inode *inode, struct file *file)
1764 return single_open(file, uart_proc_show, PDE_DATA(inode));
1767 static const struct file_operations uart_proc_fops = {
1768 .owner = THIS_MODULE,
1769 .open = uart_proc_open,
1771 .llseek = seq_lseek,
1772 .release = single_release,
1776 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1778 * uart_console_write - write a console message to a serial port
1779 * @port: the port to write the message
1780 * @s: array of characters
1781 * @count: number of characters in string to write
1782 * @write: function to write character to port
1784 void uart_console_write(struct uart_port *port, const char *s,
1786 void (*putchar)(struct uart_port *, int))
1790 for (i = 0; i < count; i++, s++) {
1792 putchar(port, '\r');
1796 EXPORT_SYMBOL_GPL(uart_console_write);
1799 * Check whether an invalid uart number has been specified, and
1800 * if so, search for the first available port that does have
1803 struct uart_port * __init
1804 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1806 int idx = co->index;
1808 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1809 ports[idx].membase == NULL))
1810 for (idx = 0; idx < nr; idx++)
1811 if (ports[idx].iobase != 0 ||
1812 ports[idx].membase != NULL)
1821 * uart_parse_options - Parse serial port baud/parity/bits/flow control.
1822 * @options: pointer to option string
1823 * @baud: pointer to an 'int' variable for the baud rate.
1824 * @parity: pointer to an 'int' variable for the parity.
1825 * @bits: pointer to an 'int' variable for the number of data bits.
1826 * @flow: pointer to an 'int' variable for the flow control character.
1828 * uart_parse_options decodes a string containing the serial console
1829 * options. The format of the string is <baud><parity><bits><flow>,
1833 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1837 *baud = simple_strtoul(s, NULL, 10);
1838 while (*s >= '0' && *s <= '9')
1847 EXPORT_SYMBOL_GPL(uart_parse_options);
1854 static const struct baud_rates baud_rates[] = {
1855 { 921600, B921600 },
1856 { 460800, B460800 },
1857 { 230400, B230400 },
1858 { 115200, B115200 },
1870 * uart_set_options - setup the serial console parameters
1871 * @port: pointer to the serial ports uart_port structure
1872 * @co: console pointer
1874 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1875 * @bits: number of data bits
1876 * @flow: flow control character - 'r' (rts)
1879 uart_set_options(struct uart_port *port, struct console *co,
1880 int baud, int parity, int bits, int flow)
1882 struct ktermios termios;
1883 static struct ktermios dummy;
1887 * Ensure that the serial console lock is initialised
1889 * If this port is a console, then the spinlock is already
1892 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1893 spin_lock_init(&port->lock);
1894 lockdep_set_class(&port->lock, &port_lock_key);
1897 memset(&termios, 0, sizeof(struct ktermios));
1899 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1902 * Construct a cflag setting.
1904 for (i = 0; baud_rates[i].rate; i++)
1905 if (baud_rates[i].rate <= baud)
1908 termios.c_cflag |= baud_rates[i].cflag;
1911 termios.c_cflag |= CS7;
1913 termios.c_cflag |= CS8;
1917 termios.c_cflag |= PARODD;
1920 termios.c_cflag |= PARENB;
1925 termios.c_cflag |= CRTSCTS;
1928 * some uarts on other side don't support no flow control.
1929 * So we set * DTR in host uart to make them happy
1931 port->mctrl |= TIOCM_DTR;
1933 port->ops->set_termios(port, &termios, &dummy);
1935 * Allow the setting of the UART parameters with a NULL console
1939 co->cflag = termios.c_cflag;
1943 EXPORT_SYMBOL_GPL(uart_set_options);
1944 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1947 * uart_change_pm - set power state of the port
1949 * @state: port descriptor
1950 * @pm_state: new state
1952 * Locking: port->mutex has to be held
1954 static void uart_change_pm(struct uart_state *state,
1955 enum uart_pm_state pm_state)
1957 struct uart_port *port = state->uart_port;
1959 if (state->pm_state != pm_state) {
1961 port->ops->pm(port, pm_state, state->pm_state);
1962 state->pm_state = pm_state;
1967 struct uart_port *port;
1968 struct uart_driver *driver;
1971 static int serial_match_port(struct device *dev, void *data)
1973 struct uart_match *match = data;
1974 struct tty_driver *tty_drv = match->driver->tty_driver;
1975 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1978 return dev->devt == devt; /* Actually, only one tty per port */
1981 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1983 struct uart_state *state = drv->state + uport->line;
1984 struct tty_port *port = &state->port;
1985 struct device *tty_dev;
1986 struct uart_match match = {uport, drv};
1988 mutex_lock(&port->mutex);
1990 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1991 if (device_may_wakeup(tty_dev)) {
1992 if (!enable_irq_wake(uport->irq))
1993 uport->irq_wake = 1;
1994 put_device(tty_dev);
1995 mutex_unlock(&port->mutex);
1998 put_device(tty_dev);
2000 if (console_suspend_enabled || !uart_console(uport))
2001 uport->suspended = 1;
2003 if (port->flags & ASYNC_INITIALIZED) {
2004 const struct uart_ops *ops = uport->ops;
2007 if (console_suspend_enabled || !uart_console(uport)) {
2008 set_bit(ASYNCB_SUSPENDED, &port->flags);
2009 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2011 spin_lock_irq(&uport->lock);
2012 ops->stop_tx(uport);
2013 ops->set_mctrl(uport, 0);
2014 ops->stop_rx(uport);
2015 spin_unlock_irq(&uport->lock);
2019 * Wait for the transmitter to empty.
2021 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2024 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2026 drv->tty_driver->name_base + uport->line);
2028 if (console_suspend_enabled || !uart_console(uport))
2029 ops->shutdown(uport);
2033 * Disable the console device before suspending.
2035 if (console_suspend_enabled && uart_console(uport))
2036 console_stop(uport->cons);
2038 if (console_suspend_enabled || !uart_console(uport))
2039 uart_change_pm(state, UART_PM_STATE_OFF);
2041 mutex_unlock(&port->mutex);
2046 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2048 struct uart_state *state = drv->state + uport->line;
2049 struct tty_port *port = &state->port;
2050 struct device *tty_dev;
2051 struct uart_match match = {uport, drv};
2052 struct ktermios termios;
2054 mutex_lock(&port->mutex);
2056 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2057 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2058 if (uport->irq_wake) {
2059 disable_irq_wake(uport->irq);
2060 uport->irq_wake = 0;
2062 put_device(tty_dev);
2063 mutex_unlock(&port->mutex);
2066 put_device(tty_dev);
2067 uport->suspended = 0;
2070 * Re-enable the console device after suspending.
2072 if (uart_console(uport)) {
2074 * First try to use the console cflag setting.
2076 memset(&termios, 0, sizeof(struct ktermios));
2077 termios.c_cflag = uport->cons->cflag;
2080 * If that's unset, use the tty termios setting.
2082 if (port->tty && termios.c_cflag == 0)
2083 termios = port->tty->termios;
2085 if (console_suspend_enabled)
2086 uart_change_pm(state, UART_PM_STATE_ON);
2087 uport->ops->set_termios(uport, &termios, NULL);
2088 if (console_suspend_enabled)
2089 console_start(uport->cons);
2092 if (port->flags & ASYNC_SUSPENDED) {
2093 const struct uart_ops *ops = uport->ops;
2096 uart_change_pm(state, UART_PM_STATE_ON);
2097 spin_lock_irq(&uport->lock);
2098 ops->set_mctrl(uport, 0);
2099 spin_unlock_irq(&uport->lock);
2100 if (console_suspend_enabled || !uart_console(uport)) {
2101 /* Protected by port mutex for now */
2102 struct tty_struct *tty = port->tty;
2103 ret = ops->startup(uport);
2106 uart_change_speed(tty, state, NULL);
2107 spin_lock_irq(&uport->lock);
2108 ops->set_mctrl(uport, uport->mctrl);
2109 ops->start_tx(uport);
2110 spin_unlock_irq(&uport->lock);
2111 set_bit(ASYNCB_INITIALIZED, &port->flags);
2114 * Failed to resume - maybe hardware went away?
2115 * Clear the "initialized" flag so we won't try
2116 * to call the low level drivers shutdown method.
2118 uart_shutdown(tty, state);
2122 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2125 mutex_unlock(&port->mutex);
2131 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2135 switch (port->iotype) {
2137 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2140 snprintf(address, sizeof(address),
2141 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2147 snprintf(address, sizeof(address),
2148 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2151 strlcpy(address, "*unknown*", sizeof(address));
2155 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2157 drv->tty_driver->name_base + port->line,
2158 address, port->irq, port->uartclk / 16, uart_type(port));
2162 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2163 struct uart_port *port)
2168 * If there isn't a port here, don't do anything further.
2170 if (!port->iobase && !port->mapbase && !port->membase)
2174 * Now do the auto configuration stuff. Note that config_port
2175 * is expected to claim the resources and map the port for us.
2178 if (port->flags & UPF_AUTO_IRQ)
2179 flags |= UART_CONFIG_IRQ;
2180 if (port->flags & UPF_BOOT_AUTOCONF) {
2181 if (!(port->flags & UPF_FIXED_TYPE)) {
2182 port->type = PORT_UNKNOWN;
2183 flags |= UART_CONFIG_TYPE;
2185 port->ops->config_port(port, flags);
2188 if (port->type != PORT_UNKNOWN) {
2189 unsigned long flags;
2191 uart_report_port(drv, port);
2193 /* Power up port for set_mctrl() */
2194 uart_change_pm(state, UART_PM_STATE_ON);
2197 * Ensure that the modem control lines are de-activated.
2198 * keep the DTR setting that is set in uart_set_options()
2199 * We probably don't need a spinlock around this, but
2201 spin_lock_irqsave(&port->lock, flags);
2202 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2203 spin_unlock_irqrestore(&port->lock, flags);
2206 * If this driver supports console, and it hasn't been
2207 * successfully registered yet, try to re-register it.
2208 * It may be that the port was not available.
2210 if (port->cons && !(port->cons->flags & CON_ENABLED))
2211 register_console(port->cons);
2214 * Power down all ports by default, except the
2215 * console if we have one.
2217 if (!uart_console(port))
2218 uart_change_pm(state, UART_PM_STATE_OFF);
2222 #ifdef CONFIG_CONSOLE_POLL
2224 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2226 struct uart_driver *drv = driver->driver_state;
2227 struct uart_state *state = drv->state + line;
2228 struct uart_port *port;
2235 if (!state || !state->uart_port)
2238 port = state->uart_port;
2239 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2242 if (port->ops->poll_init) {
2243 struct tty_port *tport = &state->port;
2246 mutex_lock(&tport->mutex);
2248 * We don't set ASYNCB_INITIALIZED as we only initialized the
2249 * hw, e.g. state->xmit is still uninitialized.
2251 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2252 ret = port->ops->poll_init(port);
2253 mutex_unlock(&tport->mutex);
2259 uart_parse_options(options, &baud, &parity, &bits, &flow);
2260 return uart_set_options(port, NULL, baud, parity, bits, flow);
2266 static int uart_poll_get_char(struct tty_driver *driver, int line)
2268 struct uart_driver *drv = driver->driver_state;
2269 struct uart_state *state = drv->state + line;
2270 struct uart_port *port;
2272 if (!state || !state->uart_port)
2275 port = state->uart_port;
2276 return port->ops->poll_get_char(port);
2279 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2281 struct uart_driver *drv = driver->driver_state;
2282 struct uart_state *state = drv->state + line;
2283 struct uart_port *port;
2285 if (!state || !state->uart_port)
2288 port = state->uart_port;
2291 port->ops->poll_put_char(port, '\r');
2292 port->ops->poll_put_char(port, ch);
2296 static const struct tty_operations uart_ops = {
2298 .close = uart_close,
2299 .write = uart_write,
2300 .put_char = uart_put_char,
2301 .flush_chars = uart_flush_chars,
2302 .write_room = uart_write_room,
2303 .chars_in_buffer= uart_chars_in_buffer,
2304 .flush_buffer = uart_flush_buffer,
2305 .ioctl = uart_ioctl,
2306 .throttle = uart_throttle,
2307 .unthrottle = uart_unthrottle,
2308 .send_xchar = uart_send_xchar,
2309 .set_termios = uart_set_termios,
2310 .set_ldisc = uart_set_ldisc,
2312 .start = uart_start,
2313 .hangup = uart_hangup,
2314 .break_ctl = uart_break_ctl,
2315 .wait_until_sent= uart_wait_until_sent,
2316 #ifdef CONFIG_PROC_FS
2317 .proc_fops = &uart_proc_fops,
2319 .tiocmget = uart_tiocmget,
2320 .tiocmset = uart_tiocmset,
2321 .get_icount = uart_get_icount,
2322 #ifdef CONFIG_CONSOLE_POLL
2323 .poll_init = uart_poll_init,
2324 .poll_get_char = uart_poll_get_char,
2325 .poll_put_char = uart_poll_put_char,
2329 static const struct tty_port_operations uart_port_ops = {
2330 .activate = uart_port_activate,
2331 .shutdown = uart_port_shutdown,
2332 .carrier_raised = uart_carrier_raised,
2333 .dtr_rts = uart_dtr_rts,
2337 * uart_register_driver - register a driver with the uart core layer
2338 * @drv: low level driver structure
2340 * Register a uart driver with the core driver. We in turn register
2341 * with the tty layer, and initialise the core driver per-port state.
2343 * We have a proc file in /proc/tty/driver which is named after the
2346 * drv->port should be NULL, and the per-port structures should be
2347 * registered using uart_add_one_port after this call has succeeded.
2349 int uart_register_driver(struct uart_driver *drv)
2351 struct tty_driver *normal;
2357 * Maybe we should be using a slab cache for this, especially if
2358 * we have a large number of ports to handle.
2360 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2364 normal = alloc_tty_driver(drv->nr);
2368 drv->tty_driver = normal;
2370 normal->driver_name = drv->driver_name;
2371 normal->name = drv->dev_name;
2372 normal->major = drv->major;
2373 normal->minor_start = drv->minor;
2374 normal->type = TTY_DRIVER_TYPE_SERIAL;
2375 normal->subtype = SERIAL_TYPE_NORMAL;
2376 normal->init_termios = tty_std_termios;
2377 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2378 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2379 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2380 normal->driver_state = drv;
2381 tty_set_operations(normal, &uart_ops);
2384 * Initialise the UART state(s).
2386 for (i = 0; i < drv->nr; i++) {
2387 struct uart_state *state = drv->state + i;
2388 struct tty_port *port = &state->port;
2390 tty_port_init(port);
2391 port->ops = &uart_port_ops;
2394 retval = tty_register_driver(normal);
2398 for (i = 0; i < drv->nr; i++)
2399 tty_port_destroy(&drv->state[i].port);
2400 put_tty_driver(normal);
2408 * uart_unregister_driver - remove a driver from the uart core layer
2409 * @drv: low level driver structure
2411 * Remove all references to a driver from the core driver. The low
2412 * level driver must have removed all its ports via the
2413 * uart_remove_one_port() if it registered them with uart_add_one_port().
2414 * (ie, drv->port == NULL)
2416 void uart_unregister_driver(struct uart_driver *drv)
2418 struct tty_driver *p = drv->tty_driver;
2421 tty_unregister_driver(p);
2423 for (i = 0; i < drv->nr; i++)
2424 tty_port_destroy(&drv->state[i].port);
2427 drv->tty_driver = NULL;
2430 struct tty_driver *uart_console_device(struct console *co, int *index)
2432 struct uart_driver *p = co->data;
2434 return p->tty_driver;
2437 static ssize_t uart_get_attr_uartclk(struct device *dev,
2438 struct device_attribute *attr, char *buf)
2440 struct serial_struct tmp;
2441 struct tty_port *port = dev_get_drvdata(dev);
2443 uart_get_info(port, &tmp);
2444 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2447 static ssize_t uart_get_attr_type(struct device *dev,
2448 struct device_attribute *attr, char *buf)
2450 struct serial_struct tmp;
2451 struct tty_port *port = dev_get_drvdata(dev);
2453 uart_get_info(port, &tmp);
2454 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2456 static ssize_t uart_get_attr_line(struct device *dev,
2457 struct device_attribute *attr, char *buf)
2459 struct serial_struct tmp;
2460 struct tty_port *port = dev_get_drvdata(dev);
2462 uart_get_info(port, &tmp);
2463 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2466 static ssize_t uart_get_attr_port(struct device *dev,
2467 struct device_attribute *attr, char *buf)
2469 struct serial_struct tmp;
2470 struct tty_port *port = dev_get_drvdata(dev);
2471 unsigned long ioaddr;
2473 uart_get_info(port, &tmp);
2475 if (HIGH_BITS_OFFSET)
2476 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2477 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2480 static ssize_t uart_get_attr_irq(struct device *dev,
2481 struct device_attribute *attr, char *buf)
2483 struct serial_struct tmp;
2484 struct tty_port *port = dev_get_drvdata(dev);
2486 uart_get_info(port, &tmp);
2487 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2490 static ssize_t uart_get_attr_flags(struct device *dev,
2491 struct device_attribute *attr, char *buf)
2493 struct serial_struct tmp;
2494 struct tty_port *port = dev_get_drvdata(dev);
2496 uart_get_info(port, &tmp);
2497 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2500 static ssize_t uart_get_attr_xmit_fifo_size(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.xmit_fifo_size);
2511 static ssize_t uart_get_attr_close_delay(struct device *dev,
2512 struct device_attribute *attr, char *buf)
2514 struct serial_struct tmp;
2515 struct tty_port *port = dev_get_drvdata(dev);
2517 uart_get_info(port, &tmp);
2518 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2522 static ssize_t uart_get_attr_closing_wait(struct device *dev,
2523 struct device_attribute *attr, char *buf)
2525 struct serial_struct tmp;
2526 struct tty_port *port = dev_get_drvdata(dev);
2528 uart_get_info(port, &tmp);
2529 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2532 static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2533 struct device_attribute *attr, char *buf)
2535 struct serial_struct tmp;
2536 struct tty_port *port = dev_get_drvdata(dev);
2538 uart_get_info(port, &tmp);
2539 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2542 static ssize_t uart_get_attr_io_type(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.io_type);
2552 static ssize_t uart_get_attr_iomem_base(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, "0x%lX\n", (unsigned long)tmp.iomem_base);
2562 static ssize_t uart_get_attr_iomem_reg_shift(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.iomem_reg_shift);
2572 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2573 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2574 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2575 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2576 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2577 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2578 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2579 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2580 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2581 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2582 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2583 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2584 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
2586 static struct attribute *tty_dev_attrs[] = {
2587 &dev_attr_type.attr,
2588 &dev_attr_line.attr,
2589 &dev_attr_port.attr,
2591 &dev_attr_flags.attr,
2592 &dev_attr_xmit_fifo_size.attr,
2593 &dev_attr_uartclk.attr,
2594 &dev_attr_close_delay.attr,
2595 &dev_attr_closing_wait.attr,
2596 &dev_attr_custom_divisor.attr,
2597 &dev_attr_io_type.attr,
2598 &dev_attr_iomem_base.attr,
2599 &dev_attr_iomem_reg_shift.attr,
2603 static const struct attribute_group tty_dev_attr_group = {
2604 .attrs = tty_dev_attrs,
2608 * uart_add_one_port - attach a driver-defined port structure
2609 * @drv: pointer to the uart low level driver structure for this port
2610 * @uport: uart port structure to use for this port.
2612 * This allows the driver to register its own uart_port structure
2613 * with the core driver. The main purpose is to allow the low
2614 * level uart drivers to expand uart_port, rather than having yet
2615 * more levels of structures.
2617 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2619 struct uart_state *state;
2620 struct tty_port *port;
2622 struct device *tty_dev;
2625 BUG_ON(in_interrupt());
2627 if (uport->line >= drv->nr)
2630 state = drv->state + uport->line;
2631 port = &state->port;
2633 mutex_lock(&port_mutex);
2634 mutex_lock(&port->mutex);
2635 if (state->uart_port) {
2640 /* Link the port to the driver state table and vice versa */
2641 state->uart_port = uport;
2642 uport->state = state;
2644 state->pm_state = UART_PM_STATE_UNDEFINED;
2645 uport->cons = drv->cons;
2648 * If this port is a console, then the spinlock is already
2651 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2652 spin_lock_init(&uport->lock);
2653 lockdep_set_class(&uport->lock, &port_lock_key);
2655 if (uport->cons && uport->dev)
2656 of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2658 uart_configure_port(drv, state, uport);
2661 if (uport->attr_group)
2664 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2666 if (!uport->tty_groups) {
2670 uport->tty_groups[0] = &tty_dev_attr_group;
2671 if (uport->attr_group)
2672 uport->tty_groups[1] = uport->attr_group;
2675 * Register the port whether it's detected or not. This allows
2676 * setserial to be used to alter this port's parameters.
2678 tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2679 uport->line, uport->dev, port, uport->tty_groups);
2680 if (likely(!IS_ERR(tty_dev))) {
2681 device_set_wakeup_capable(tty_dev, 1);
2683 dev_err(uport->dev, "Cannot register tty device on line %d\n",
2688 * Ensure UPF_DEAD is not set.
2690 uport->flags &= ~UPF_DEAD;
2693 mutex_unlock(&port->mutex);
2694 mutex_unlock(&port_mutex);
2700 * uart_remove_one_port - detach a driver defined port structure
2701 * @drv: pointer to the uart low level driver structure for this port
2702 * @uport: uart port structure for this port
2704 * This unhooks (and hangs up) the specified port structure from the
2705 * core driver. No further calls will be made to the low-level code
2708 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2710 struct uart_state *state = drv->state + uport->line;
2711 struct tty_port *port = &state->port;
2712 struct tty_struct *tty;
2715 BUG_ON(in_interrupt());
2717 if (state->uart_port != uport)
2718 dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2719 state->uart_port, uport);
2721 mutex_lock(&port_mutex);
2724 * Mark the port "dead" - this prevents any opens from
2725 * succeeding while we shut down the port.
2727 mutex_lock(&port->mutex);
2728 if (!state->uart_port) {
2729 mutex_unlock(&port->mutex);
2733 uport->flags |= UPF_DEAD;
2734 mutex_unlock(&port->mutex);
2737 * Remove the devices from the tty layer
2739 tty_unregister_device(drv->tty_driver, uport->line);
2741 tty = tty_port_tty_get(port);
2743 tty_vhangup(port->tty);
2748 * If the port is used as a console, unregister it
2750 if (uart_console(uport))
2751 unregister_console(uport->cons);
2754 * Free the port IO and memory resources, if any.
2756 if (uport->type != PORT_UNKNOWN)
2757 uport->ops->release_port(uport);
2758 kfree(uport->tty_groups);
2761 * Indicate that there isn't a port here anymore.
2763 uport->type = PORT_UNKNOWN;
2765 state->uart_port = NULL;
2767 mutex_unlock(&port_mutex);
2773 * Are the two ports equivalent?
2775 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2777 if (port1->iotype != port2->iotype)
2780 switch (port1->iotype) {
2782 return (port1->iobase == port2->iobase);
2784 return (port1->iobase == port2->iobase) &&
2785 (port1->hub6 == port2->hub6);
2790 return (port1->mapbase == port2->mapbase);
2794 EXPORT_SYMBOL(uart_match_port);
2797 * uart_handle_dcd_change - handle a change of carrier detect state
2798 * @uport: uart_port structure for the open port
2799 * @status: new carrier detect status, nonzero if active
2801 * Caller must hold uport->lock
2803 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2805 struct tty_port *port = &uport->state->port;
2806 struct tty_struct *tty = port->tty;
2807 struct tty_ldisc *ld;
2809 lockdep_assert_held_once(&uport->lock);
2812 ld = tty_ldisc_ref(tty);
2814 if (ld->ops->dcd_change)
2815 ld->ops->dcd_change(tty, status);
2816 tty_ldisc_deref(ld);
2820 uport->icount.dcd++;
2822 if (uart_dcd_enabled(uport)) {
2824 wake_up_interruptible(&port->open_wait);
2829 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2832 * uart_handle_cts_change - handle a change of clear-to-send state
2833 * @uport: uart_port structure for the open port
2834 * @status: new clear to send status, nonzero if active
2836 * Caller must hold uport->lock
2838 void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2840 lockdep_assert_held_once(&uport->lock);
2842 uport->icount.cts++;
2844 if (uart_cts_enabled(uport)) {
2845 if (uport->hw_stopped) {
2847 uport->hw_stopped = 0;
2848 uport->ops->start_tx(uport);
2849 uart_write_wakeup(uport);
2853 uport->hw_stopped = 1;
2854 uport->ops->stop_tx(uport);
2859 EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2862 * uart_insert_char - push a char to the uart layer
2864 * User is responsible to call tty_flip_buffer_push when they are done with
2867 * @port: corresponding port
2868 * @status: state of the serial port RX buffer (LSR for 8250)
2869 * @overrun: mask of overrun bits in @status
2870 * @ch: character to push
2871 * @flag: flag for the character (see TTY_NORMAL and friends)
2873 void uart_insert_char(struct uart_port *port, unsigned int status,
2874 unsigned int overrun, unsigned int ch, unsigned int flag)
2876 struct tty_port *tport = &port->state->port;
2878 if ((status & port->ignore_status_mask & ~overrun) == 0)
2879 if (tty_insert_flip_char(tport, ch, flag) == 0)
2880 ++port->icount.buf_overrun;
2883 * Overrun is special. Since it's reported immediately,
2884 * it doesn't affect the current character.
2886 if (status & ~port->ignore_status_mask & overrun)
2887 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2888 ++port->icount.buf_overrun;
2890 EXPORT_SYMBOL_GPL(uart_insert_char);
2892 EXPORT_SYMBOL(uart_write_wakeup);
2893 EXPORT_SYMBOL(uart_register_driver);
2894 EXPORT_SYMBOL(uart_unregister_driver);
2895 EXPORT_SYMBOL(uart_suspend_port);
2896 EXPORT_SYMBOL(uart_resume_port);
2897 EXPORT_SYMBOL(uart_add_one_port);
2898 EXPORT_SYMBOL(uart_remove_one_port);
2900 MODULE_DESCRIPTION("Serial driver core");
2901 MODULE_LICENSE("GPL");