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/slab.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/device.h>
31 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
32 #include <linux/serial_core.h>
33 #include <linux/delay.h>
34 #include <linux/mutex.h>
37 #include <asm/uaccess.h>
40 * This is used to lock changes in serial line configuration.
42 static DEFINE_MUTEX(port_mutex);
45 * lockdep: port->lock is initialized in two places, but we
46 * want only one lock-class:
48 static struct lock_class_key port_lock_key;
50 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52 #ifdef CONFIG_SERIAL_CORE_CONSOLE
53 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
55 #define uart_console(port) (0)
58 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
59 struct ktermios *old_termios);
60 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
61 static void uart_change_pm(struct uart_state *state, int pm_state);
64 * This routine is used by the interrupt handler to schedule processing in
65 * the software interrupt portion of the driver.
67 void uart_write_wakeup(struct uart_port *port)
69 struct uart_state *state = port->state;
71 * This means you called this function _after_ the port was
72 * closed. No cookie for you.
75 tty_wakeup(state->port.tty);
78 static void uart_stop(struct tty_struct *tty)
80 struct uart_state *state = tty->driver_data;
81 struct uart_port *port = state->uart_port;
84 spin_lock_irqsave(&port->lock, flags);
85 port->ops->stop_tx(port);
86 spin_unlock_irqrestore(&port->lock, flags);
89 static void __uart_start(struct tty_struct *tty)
91 struct uart_state *state = tty->driver_data;
92 struct uart_port *port = state->uart_port;
94 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
95 !tty->stopped && !tty->hw_stopped)
96 port->ops->start_tx(port);
99 static void uart_start(struct tty_struct *tty)
101 struct uart_state *state = tty->driver_data;
102 struct uart_port *port = state->uart_port;
105 spin_lock_irqsave(&port->lock, flags);
107 spin_unlock_irqrestore(&port->lock, flags);
111 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
116 spin_lock_irqsave(&port->lock, flags);
118 port->mctrl = (old & ~clear) | set;
119 if (old != port->mctrl)
120 port->ops->set_mctrl(port, port->mctrl);
121 spin_unlock_irqrestore(&port->lock, flags);
124 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
125 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
128 * Startup the port. This will be called once per open. All calls
129 * will be serialised by the per-port mutex.
131 static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
133 struct uart_port *uport = state->uart_port;
134 struct tty_port *port = &state->port;
138 if (port->flags & ASYNC_INITIALIZED)
142 * Set the TTY IO error marker - we will only clear this
143 * once we have successfully opened the port. Also set
144 * up the tty->alt_speed kludge
146 set_bit(TTY_IO_ERROR, &tty->flags);
148 if (uport->type == PORT_UNKNOWN)
152 * Initialise and allocate the transmit and temporary
155 if (!state->xmit.buf) {
156 /* This is protected by the per port mutex */
157 page = get_zeroed_page(GFP_KERNEL);
161 state->xmit.buf = (unsigned char *) page;
162 uart_circ_clear(&state->xmit);
165 retval = uport->ops->startup(uport);
167 if (uart_console(uport) && uport->cons->cflag) {
168 tty->termios->c_cflag = uport->cons->cflag;
169 uport->cons->cflag = 0;
172 * Initialise the hardware port settings.
174 uart_change_speed(tty, state, NULL);
178 * Setup the RTS and DTR signals once the
179 * port is open and ready to respond.
181 if (tty->termios->c_cflag & CBAUD)
182 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
185 if (port->flags & ASYNC_CTS_FLOW) {
186 spin_lock_irq(&uport->lock);
187 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
189 spin_unlock_irq(&uport->lock);
192 set_bit(ASYNCB_INITIALIZED, &port->flags);
194 clear_bit(TTY_IO_ERROR, &tty->flags);
197 if (retval && capable(CAP_SYS_ADMIN))
204 * This routine will shutdown a serial port; interrupts are disabled, and
205 * DTR is dropped if the hangup on close termio flag is on. Calls to
206 * uart_shutdown are serialised by the per-port semaphore.
208 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
210 struct uart_port *uport = state->uart_port;
211 struct tty_port *port = &state->port;
214 * Set the TTY IO error marker
217 set_bit(TTY_IO_ERROR, &tty->flags);
219 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
221 * Turn off DTR and RTS early.
223 if (!tty || (tty->termios->c_cflag & HUPCL))
224 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
227 * clear delta_msr_wait queue to avoid mem leaks: we may free
228 * the irq here so the queue might never be woken up. Note
229 * that we won't end up waiting on delta_msr_wait again since
230 * any outstanding file descriptors should be pointing at
231 * hung_up_tty_fops now.
233 wake_up_interruptible(&port->delta_msr_wait);
236 * Free the IRQ and disable the port.
238 uport->ops->shutdown(uport);
241 * Ensure that the IRQ handler isn't running on another CPU.
243 synchronize_irq(uport->irq);
247 * It's possible for shutdown to be called after suspend if we get
248 * a DCD drop (hangup) at just the right time. Clear suspended bit so
249 * we don't try to resume a port that has been shutdown.
251 clear_bit(ASYNCB_SUSPENDED, &port->flags);
254 * Free the transmit buffer page.
256 if (state->xmit.buf) {
257 free_page((unsigned long)state->xmit.buf);
258 state->xmit.buf = NULL;
263 * uart_update_timeout - update per-port FIFO timeout.
264 * @port: uart_port structure describing the port
265 * @cflag: termios cflag value
266 * @baud: speed of the port
268 * Set the port FIFO timeout value. The @cflag value should
269 * reflect the actual hardware settings.
272 uart_update_timeout(struct uart_port *port, unsigned int cflag,
277 /* byte size and parity */
278 switch (cflag & CSIZE) {
299 * The total number of bits to be transmitted in the fifo.
301 bits = bits * port->fifosize;
304 * Figure the timeout to send the above number of bits.
305 * Add .02 seconds of slop
307 port->timeout = (HZ * bits) / baud + HZ/50;
310 EXPORT_SYMBOL(uart_update_timeout);
313 * uart_get_baud_rate - return baud rate for a particular port
314 * @port: uart_port structure describing the port in question.
315 * @termios: desired termios settings.
316 * @old: old termios (or NULL)
317 * @min: minimum acceptable baud rate
318 * @max: maximum acceptable baud rate
320 * Decode the termios structure into a numeric baud rate,
321 * taking account of the magic 38400 baud rate (with spd_*
322 * flags), and mapping the %B0 rate to 9600 baud.
324 * If the new baud rate is invalid, try the old termios setting.
325 * If it's still invalid, we try 9600 baud.
327 * Update the @termios structure to reflect the baud rate
328 * we're actually going to be using. Don't do this for the case
329 * where B0 is requested ("hang up").
332 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
333 struct ktermios *old, unsigned int min, unsigned int max)
335 unsigned int try, baud, altbaud = 38400;
337 upf_t flags = port->flags & UPF_SPD_MASK;
339 if (flags == UPF_SPD_HI)
341 else if (flags == UPF_SPD_VHI)
343 else if (flags == UPF_SPD_SHI)
345 else if (flags == UPF_SPD_WARP)
348 for (try = 0; try < 2; try++) {
349 baud = tty_termios_baud_rate(termios);
352 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
359 * Special case: B0 rate.
366 if (baud >= min && baud <= max)
370 * Oops, the quotient was zero. Try again with
371 * the old baud rate if possible.
373 termios->c_cflag &= ~CBAUD;
375 baud = tty_termios_baud_rate(old);
377 tty_termios_encode_baud_rate(termios,
384 * As a last resort, if the range cannot be met then clip to
385 * the nearest chip supported rate.
389 tty_termios_encode_baud_rate(termios,
392 tty_termios_encode_baud_rate(termios,
396 /* Should never happen */
401 EXPORT_SYMBOL(uart_get_baud_rate);
404 * uart_get_divisor - return uart clock divisor
405 * @port: uart_port structure describing the port.
406 * @baud: desired baud rate
408 * Calculate the uart clock divisor for the port.
411 uart_get_divisor(struct uart_port *port, unsigned int baud)
416 * Old custom speed handling.
418 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
419 quot = port->custom_divisor;
421 quot = (port->uartclk + (8 * baud)) / (16 * baud);
426 EXPORT_SYMBOL(uart_get_divisor);
428 /* FIXME: Consistent locking policy */
429 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
430 struct ktermios *old_termios)
432 struct tty_port *port = &state->port;
433 struct uart_port *uport = state->uart_port;
434 struct ktermios *termios;
437 * If we have no tty, termios, or the port does not exist,
438 * then we can't set the parameters for this port.
440 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
443 termios = tty->termios;
446 * Set flags based on termios cflag
448 if (termios->c_cflag & CRTSCTS)
449 set_bit(ASYNCB_CTS_FLOW, &port->flags);
451 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
453 if (termios->c_cflag & CLOCAL)
454 clear_bit(ASYNCB_CHECK_CD, &port->flags);
456 set_bit(ASYNCB_CHECK_CD, &port->flags);
458 uport->ops->set_termios(uport, termios, old_termios);
461 static inline int __uart_put_char(struct uart_port *port,
462 struct circ_buf *circ, unsigned char c)
470 spin_lock_irqsave(&port->lock, flags);
471 if (uart_circ_chars_free(circ) != 0) {
472 circ->buf[circ->head] = c;
473 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
476 spin_unlock_irqrestore(&port->lock, flags);
480 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
482 struct uart_state *state = tty->driver_data;
484 return __uart_put_char(state->uart_port, &state->xmit, ch);
487 static void uart_flush_chars(struct tty_struct *tty)
492 static int uart_write(struct tty_struct *tty,
493 const unsigned char *buf, int count)
495 struct uart_state *state = tty->driver_data;
496 struct uart_port *port;
497 struct circ_buf *circ;
502 * This means you called this function _after_ the port was
503 * closed. No cookie for you.
510 port = state->uart_port;
516 spin_lock_irqsave(&port->lock, flags);
518 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
523 memcpy(circ->buf + circ->head, buf, c);
524 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
529 spin_unlock_irqrestore(&port->lock, flags);
535 static int uart_write_room(struct tty_struct *tty)
537 struct uart_state *state = tty->driver_data;
541 spin_lock_irqsave(&state->uart_port->lock, flags);
542 ret = uart_circ_chars_free(&state->xmit);
543 spin_unlock_irqrestore(&state->uart_port->lock, flags);
547 static int uart_chars_in_buffer(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_pending(&state->xmit);
555 spin_unlock_irqrestore(&state->uart_port->lock, flags);
559 static void uart_flush_buffer(struct tty_struct *tty)
561 struct uart_state *state = tty->driver_data;
562 struct uart_port *port;
566 * This means you called this function _after_ the port was
567 * closed. No cookie for you.
574 port = state->uart_port;
575 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
577 spin_lock_irqsave(&port->lock, flags);
578 uart_circ_clear(&state->xmit);
579 if (port->ops->flush_buffer)
580 port->ops->flush_buffer(port);
581 spin_unlock_irqrestore(&port->lock, flags);
586 * This function is used to send a high-priority XON/XOFF character to
589 static void uart_send_xchar(struct tty_struct *tty, char ch)
591 struct uart_state *state = tty->driver_data;
592 struct uart_port *port = state->uart_port;
595 if (port->ops->send_xchar)
596 port->ops->send_xchar(port, ch);
600 spin_lock_irqsave(&port->lock, flags);
601 port->ops->start_tx(port);
602 spin_unlock_irqrestore(&port->lock, flags);
607 static void uart_throttle(struct tty_struct *tty)
609 struct uart_state *state = tty->driver_data;
612 uart_send_xchar(tty, STOP_CHAR(tty));
614 if (tty->termios->c_cflag & CRTSCTS)
615 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
618 static void uart_unthrottle(struct tty_struct *tty)
620 struct uart_state *state = tty->driver_data;
621 struct uart_port *port = state->uart_port;
627 uart_send_xchar(tty, START_CHAR(tty));
630 if (tty->termios->c_cflag & CRTSCTS)
631 uart_set_mctrl(port, TIOCM_RTS);
634 static int uart_get_info(struct uart_state *state,
635 struct serial_struct __user *retinfo)
637 struct uart_port *uport = state->uart_port;
638 struct tty_port *port = &state->port;
639 struct serial_struct tmp;
641 memset(&tmp, 0, sizeof(tmp));
643 /* Ensure the state we copy is consistent and no hardware changes
645 mutex_lock(&port->mutex);
647 tmp.type = uport->type;
648 tmp.line = uport->line;
649 tmp.port = uport->iobase;
650 if (HIGH_BITS_OFFSET)
651 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
652 tmp.irq = uport->irq;
653 tmp.flags = uport->flags;
654 tmp.xmit_fifo_size = uport->fifosize;
655 tmp.baud_base = uport->uartclk / 16;
656 tmp.close_delay = port->close_delay / 10;
657 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
658 ASYNC_CLOSING_WAIT_NONE :
659 port->closing_wait / 10;
660 tmp.custom_divisor = uport->custom_divisor;
661 tmp.hub6 = uport->hub6;
662 tmp.io_type = uport->iotype;
663 tmp.iomem_reg_shift = uport->regshift;
664 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
666 mutex_unlock(&port->mutex);
668 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
673 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
674 struct serial_struct __user *newinfo)
676 struct serial_struct new_serial;
677 struct uart_port *uport = state->uart_port;
678 struct tty_port *port = &state->port;
679 unsigned long new_port;
680 unsigned int change_irq, change_port, closing_wait;
681 unsigned int old_custom_divisor, close_delay;
682 upf_t old_flags, new_flags;
685 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
688 new_port = new_serial.port;
689 if (HIGH_BITS_OFFSET)
690 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
692 new_serial.irq = irq_canonicalize(new_serial.irq);
693 close_delay = new_serial.close_delay * 10;
694 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
695 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
698 * This semaphore protects port->count. It is also
699 * very useful to prevent opens. Also, take the
700 * port configuration semaphore to make sure that a
701 * module insertion/removal doesn't change anything
704 mutex_lock(&port->mutex);
706 change_irq = !(uport->flags & UPF_FIXED_PORT)
707 && new_serial.irq != uport->irq;
710 * Since changing the 'type' of the port changes its resource
711 * allocations, we should treat type changes the same as
714 change_port = !(uport->flags & UPF_FIXED_PORT)
715 && (new_port != uport->iobase ||
716 (unsigned long)new_serial.iomem_base != uport->mapbase ||
717 new_serial.hub6 != uport->hub6 ||
718 new_serial.io_type != uport->iotype ||
719 new_serial.iomem_reg_shift != uport->regshift ||
720 new_serial.type != uport->type);
722 old_flags = uport->flags;
723 new_flags = new_serial.flags;
724 old_custom_divisor = uport->custom_divisor;
726 if (!capable(CAP_SYS_ADMIN)) {
728 if (change_irq || change_port ||
729 (new_serial.baud_base != uport->uartclk / 16) ||
730 (close_delay != port->close_delay) ||
731 (closing_wait != port->closing_wait) ||
732 (new_serial.xmit_fifo_size &&
733 new_serial.xmit_fifo_size != uport->fifosize) ||
734 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
736 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
737 (new_flags & UPF_USR_MASK));
738 uport->custom_divisor = new_serial.custom_divisor;
743 * Ask the low level driver to verify the settings.
745 if (uport->ops->verify_port)
746 retval = uport->ops->verify_port(uport, &new_serial);
748 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
749 (new_serial.baud_base < 9600))
755 if (change_port || change_irq) {
759 * Make sure that we are the sole user of this port.
761 if (tty_port_users(port) > 1)
765 * We need to shutdown the serial port at the old
766 * port/type/irq combination.
768 uart_shutdown(tty, state);
772 unsigned long old_iobase, old_mapbase;
773 unsigned int old_type, old_iotype, old_hub6, old_shift;
775 old_iobase = uport->iobase;
776 old_mapbase = uport->mapbase;
777 old_type = uport->type;
778 old_hub6 = uport->hub6;
779 old_iotype = uport->iotype;
780 old_shift = uport->regshift;
783 * Free and release old regions
785 if (old_type != PORT_UNKNOWN)
786 uport->ops->release_port(uport);
788 uport->iobase = new_port;
789 uport->type = new_serial.type;
790 uport->hub6 = new_serial.hub6;
791 uport->iotype = new_serial.io_type;
792 uport->regshift = new_serial.iomem_reg_shift;
793 uport->mapbase = (unsigned long)new_serial.iomem_base;
796 * Claim and map the new regions
798 if (uport->type != PORT_UNKNOWN) {
799 retval = uport->ops->request_port(uport);
801 /* Always success - Jean II */
806 * If we fail to request resources for the
807 * new port, try to restore the old settings.
809 if (retval && old_type != PORT_UNKNOWN) {
810 uport->iobase = old_iobase;
811 uport->type = old_type;
812 uport->hub6 = old_hub6;
813 uport->iotype = old_iotype;
814 uport->regshift = old_shift;
815 uport->mapbase = old_mapbase;
816 retval = uport->ops->request_port(uport);
818 * If we failed to restore the old settings,
822 uport->type = PORT_UNKNOWN;
828 /* Added to return the correct error -Ram Gupta */
834 uport->irq = new_serial.irq;
835 if (!(uport->flags & UPF_FIXED_PORT))
836 uport->uartclk = new_serial.baud_base * 16;
837 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
838 (new_flags & UPF_CHANGE_MASK);
839 uport->custom_divisor = new_serial.custom_divisor;
840 port->close_delay = close_delay;
841 port->closing_wait = closing_wait;
842 if (new_serial.xmit_fifo_size)
843 uport->fifosize = new_serial.xmit_fifo_size;
845 port->tty->low_latency =
846 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
850 if (uport->type == PORT_UNKNOWN)
852 if (port->flags & ASYNC_INITIALIZED) {
853 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
854 old_custom_divisor != uport->custom_divisor) {
856 * If they're setting up a custom divisor or speed,
857 * instead of clearing it, then bitch about it. No
858 * need to rate-limit; it's CAP_SYS_ADMIN only.
860 if (uport->flags & UPF_SPD_MASK) {
863 "%s sets custom speed on %s. This "
864 "is deprecated.\n", current->comm,
865 tty_name(port->tty, buf));
867 uart_change_speed(tty, state, NULL);
870 retval = uart_startup(tty, state, 1);
872 mutex_unlock(&port->mutex);
877 * uart_get_lsr_info - get line status register info
878 * @tty: tty associated with the UART
879 * @state: UART being queried
880 * @value: returned modem value
882 * Note: uart_ioctl protects us against hangups.
884 static int uart_get_lsr_info(struct tty_struct *tty,
885 struct uart_state *state, unsigned int __user *value)
887 struct uart_port *uport = state->uart_port;
890 result = uport->ops->tx_empty(uport);
893 * If we're about to load something into the transmit
894 * register, we'll pretend the transmitter isn't empty to
895 * avoid a race condition (depending on when the transmit
896 * interrupt happens).
899 ((uart_circ_chars_pending(&state->xmit) > 0) &&
900 !tty->stopped && !tty->hw_stopped))
901 result &= ~TIOCSER_TEMT;
903 return put_user(result, value);
906 static int uart_tiocmget(struct tty_struct *tty)
908 struct uart_state *state = tty->driver_data;
909 struct tty_port *port = &state->port;
910 struct uart_port *uport = state->uart_port;
913 mutex_lock(&port->mutex);
914 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
915 result = uport->mctrl;
916 spin_lock_irq(&uport->lock);
917 result |= uport->ops->get_mctrl(uport);
918 spin_unlock_irq(&uport->lock);
920 mutex_unlock(&port->mutex);
926 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
928 struct uart_state *state = tty->driver_data;
929 struct uart_port *uport = state->uart_port;
930 struct tty_port *port = &state->port;
933 mutex_lock(&port->mutex);
934 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
935 uart_update_mctrl(uport, set, clear);
938 mutex_unlock(&port->mutex);
942 static int uart_break_ctl(struct tty_struct *tty, int break_state)
944 struct uart_state *state = tty->driver_data;
945 struct tty_port *port = &state->port;
946 struct uart_port *uport = state->uart_port;
948 mutex_lock(&port->mutex);
950 if (uport->type != PORT_UNKNOWN)
951 uport->ops->break_ctl(uport, break_state);
953 mutex_unlock(&port->mutex);
957 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
959 struct uart_port *uport = state->uart_port;
960 struct tty_port *port = &state->port;
963 if (!capable(CAP_SYS_ADMIN))
967 * Take the per-port semaphore. This prevents count from
968 * changing, and hence any extra opens of the port while
969 * we're auto-configuring.
971 if (mutex_lock_interruptible(&port->mutex))
975 if (tty_port_users(port) == 1) {
976 uart_shutdown(tty, state);
979 * If we already have a port type configured,
980 * we must release its resources.
982 if (uport->type != PORT_UNKNOWN)
983 uport->ops->release_port(uport);
985 flags = UART_CONFIG_TYPE;
986 if (uport->flags & UPF_AUTO_IRQ)
987 flags |= UART_CONFIG_IRQ;
990 * This will claim the ports resources if
993 uport->ops->config_port(uport, flags);
995 ret = uart_startup(tty, state, 1);
997 mutex_unlock(&port->mutex);
1002 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1003 * - mask passed in arg for lines of interest
1004 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1005 * Caller should use TIOCGICOUNT to see which one it was
1007 * FIXME: This wants extracting into a common all driver implementation
1008 * of TIOCMWAIT using tty_port.
1011 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1013 struct uart_port *uport = state->uart_port;
1014 struct tty_port *port = &state->port;
1015 DECLARE_WAITQUEUE(wait, current);
1016 struct uart_icount cprev, cnow;
1020 * note the counters on entry
1022 spin_lock_irq(&uport->lock);
1023 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1026 * Force modem status interrupts on
1028 uport->ops->enable_ms(uport);
1029 spin_unlock_irq(&uport->lock);
1031 add_wait_queue(&port->delta_msr_wait, &wait);
1033 spin_lock_irq(&uport->lock);
1034 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1035 spin_unlock_irq(&uport->lock);
1037 set_current_state(TASK_INTERRUPTIBLE);
1039 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1040 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1041 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1042 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1049 /* see if a signal did it */
1050 if (signal_pending(current)) {
1058 current->state = TASK_RUNNING;
1059 remove_wait_queue(&port->delta_msr_wait, &wait);
1065 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1066 * Return: write counters to the user passed counter struct
1067 * NB: both 1->0 and 0->1 transitions are counted except for
1068 * RI where only 0->1 is counted.
1070 static int uart_get_icount(struct tty_struct *tty,
1071 struct serial_icounter_struct *icount)
1073 struct uart_state *state = tty->driver_data;
1074 struct uart_icount cnow;
1075 struct uart_port *uport = state->uart_port;
1077 spin_lock_irq(&uport->lock);
1078 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1079 spin_unlock_irq(&uport->lock);
1081 icount->cts = cnow.cts;
1082 icount->dsr = cnow.dsr;
1083 icount->rng = cnow.rng;
1084 icount->dcd = cnow.dcd;
1085 icount->rx = cnow.rx;
1086 icount->tx = cnow.tx;
1087 icount->frame = cnow.frame;
1088 icount->overrun = cnow.overrun;
1089 icount->parity = cnow.parity;
1090 icount->brk = cnow.brk;
1091 icount->buf_overrun = cnow.buf_overrun;
1097 * Called via sys_ioctl. We can use spin_lock_irq() here.
1100 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1103 struct uart_state *state = tty->driver_data;
1104 struct tty_port *port = &state->port;
1105 void __user *uarg = (void __user *)arg;
1106 int ret = -ENOIOCTLCMD;
1110 * These ioctls don't rely on the hardware to be present.
1114 ret = uart_get_info(state, uarg);
1118 ret = uart_set_info(tty, state, uarg);
1122 ret = uart_do_autoconfig(tty, state);
1125 case TIOCSERGWILD: /* obsolete */
1126 case TIOCSERSWILD: /* obsolete */
1131 if (ret != -ENOIOCTLCMD)
1134 if (tty->flags & (1 << TTY_IO_ERROR)) {
1140 * The following should only be used when hardware is present.
1144 ret = uart_wait_modem_status(state, arg);
1148 if (ret != -ENOIOCTLCMD)
1151 mutex_lock(&port->mutex);
1153 if (tty->flags & (1 << TTY_IO_ERROR)) {
1159 * All these rely on hardware being present and need to be
1160 * protected against the tty being hung up.
1163 case TIOCSERGETLSR: /* Get line status register */
1164 ret = uart_get_lsr_info(tty, state, uarg);
1168 struct uart_port *uport = state->uart_port;
1169 if (uport->ops->ioctl)
1170 ret = uport->ops->ioctl(uport, cmd, arg);
1175 mutex_unlock(&port->mutex);
1180 static void uart_set_ldisc(struct tty_struct *tty)
1182 struct uart_state *state = tty->driver_data;
1183 struct uart_port *uport = state->uart_port;
1185 if (uport->ops->set_ldisc)
1186 uport->ops->set_ldisc(uport, tty->termios->c_line);
1189 static void uart_set_termios(struct tty_struct *tty,
1190 struct ktermios *old_termios)
1192 struct uart_state *state = tty->driver_data;
1193 unsigned long flags;
1194 unsigned int cflag = tty->termios->c_cflag;
1198 * These are the bits that are used to setup various
1199 * flags in the low level driver. We can ignore the Bfoo
1200 * bits in c_cflag; c_[io]speed will always be set
1201 * appropriately by set_termios() in tty_ioctl.c
1203 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1204 if ((cflag ^ old_termios->c_cflag) == 0 &&
1205 tty->termios->c_ospeed == old_termios->c_ospeed &&
1206 tty->termios->c_ispeed == old_termios->c_ispeed &&
1207 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1211 uart_change_speed(tty, state, old_termios);
1213 /* Handle transition to B0 status */
1214 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1215 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1216 /* Handle transition away from B0 status */
1217 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1218 unsigned int mask = TIOCM_DTR;
1219 if (!(cflag & CRTSCTS) ||
1220 !test_bit(TTY_THROTTLED, &tty->flags))
1222 uart_set_mctrl(state->uart_port, mask);
1225 /* Handle turning off CRTSCTS */
1226 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1227 spin_lock_irqsave(&state->uart_port->lock, flags);
1228 tty->hw_stopped = 0;
1230 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1232 /* Handle turning on CRTSCTS */
1233 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1234 spin_lock_irqsave(&state->uart_port->lock, flags);
1235 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1236 tty->hw_stopped = 1;
1237 state->uart_port->ops->stop_tx(state->uart_port);
1239 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1244 * In 2.4.5, calls to this will be serialized via the BKL in
1245 * linux/drivers/char/tty_io.c:tty_release()
1246 * linux/drivers/char/tty_io.c:do_tty_handup()
1248 static void uart_close(struct tty_struct *tty, struct file *filp)
1250 struct uart_state *state = tty->driver_data;
1251 struct tty_port *port;
1252 struct uart_port *uport;
1253 unsigned long flags;
1258 uport = state->uart_port;
1259 port = &state->port;
1261 pr_debug("uart_close(%d) called\n", uport->line);
1263 spin_lock_irqsave(&port->lock, flags);
1265 if (tty_hung_up_p(filp)) {
1266 spin_unlock_irqrestore(&port->lock, flags);
1270 if ((tty->count == 1) && (port->count != 1)) {
1272 * Uh, oh. tty->count is 1, which means that the tty
1273 * structure will be freed. port->count should always
1274 * be one in these conditions. If it's greater than
1275 * one, we've got real problems, since it means the
1276 * serial port won't be shutdown.
1278 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1279 "port->count is %d\n", port->count);
1282 if (--port->count < 0) {
1283 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1284 tty->name, port->count);
1288 spin_unlock_irqrestore(&port->lock, flags);
1293 * Now we wait for the transmit buffer to clear; and we notify
1294 * the line discipline to only process XON/XOFF characters by
1295 * setting tty->closing.
1297 set_bit(ASYNCB_CLOSING, &port->flags);
1299 spin_unlock_irqrestore(&port->lock, flags);
1301 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1302 tty_wait_until_sent_from_close(tty,
1303 msecs_to_jiffies(port->closing_wait));
1306 * At this point, we stop accepting input. To do this, we
1307 * disable the receive line status interrupts.
1309 if (port->flags & ASYNC_INITIALIZED) {
1310 unsigned long flags;
1311 spin_lock_irqsave(&uport->lock, flags);
1312 uport->ops->stop_rx(uport);
1313 spin_unlock_irqrestore(&uport->lock, flags);
1315 * Before we drop DTR, make sure the UART transmitter
1316 * has completely drained; this is especially
1317 * important if there is a transmit FIFO!
1319 uart_wait_until_sent(tty, uport->timeout);
1322 mutex_lock(&port->mutex);
1323 uart_shutdown(tty, state);
1324 uart_flush_buffer(tty);
1326 tty_ldisc_flush(tty);
1328 tty_port_tty_set(port, NULL);
1329 spin_lock_irqsave(&port->lock, flags);
1332 if (port->blocked_open) {
1333 spin_unlock_irqrestore(&port->lock, flags);
1334 if (port->close_delay)
1335 msleep_interruptible(port->close_delay);
1336 spin_lock_irqsave(&port->lock, flags);
1337 } else if (!uart_console(uport)) {
1338 spin_unlock_irqrestore(&port->lock, flags);
1339 uart_change_pm(state, 3);
1340 spin_lock_irqsave(&port->lock, flags);
1344 * Wake up anyone trying to open this port.
1346 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1347 clear_bit(ASYNCB_CLOSING, &port->flags);
1348 spin_unlock_irqrestore(&port->lock, flags);
1349 wake_up_interruptible(&port->open_wait);
1350 wake_up_interruptible(&port->close_wait);
1352 mutex_unlock(&port->mutex);
1355 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1357 struct uart_state *state = tty->driver_data;
1358 struct uart_port *port = state->uart_port;
1359 unsigned long char_time, expire;
1361 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1365 * Set the check interval to be 1/5 of the estimated time to
1366 * send a single character, and make it at least 1. The check
1367 * interval should also be less than the timeout.
1369 * Note: we have to use pretty tight timings here to satisfy
1372 char_time = (port->timeout - HZ/50) / port->fifosize;
1373 char_time = char_time / 5;
1376 if (timeout && timeout < char_time)
1377 char_time = timeout;
1380 * If the transmitter hasn't cleared in twice the approximate
1381 * amount of time to send the entire FIFO, it probably won't
1382 * ever clear. This assumes the UART isn't doing flow
1383 * control, which is currently the case. Hence, if it ever
1384 * takes longer than port->timeout, this is probably due to a
1385 * UART bug of some kind. So, we clamp the timeout parameter at
1388 if (timeout == 0 || timeout > 2 * port->timeout)
1389 timeout = 2 * port->timeout;
1391 expire = jiffies + timeout;
1393 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1394 port->line, jiffies, expire);
1397 * Check whether the transmitter is empty every 'char_time'.
1398 * 'timeout' / 'expire' give us the maximum amount of time
1401 while (!port->ops->tx_empty(port)) {
1402 msleep_interruptible(jiffies_to_msecs(char_time));
1403 if (signal_pending(current))
1405 if (time_after(jiffies, expire))
1411 * This is called with the BKL held in
1412 * linux/drivers/char/tty_io.c:do_tty_hangup()
1413 * We're called from the eventd thread, so we can sleep for
1414 * a _short_ time only.
1416 static void uart_hangup(struct tty_struct *tty)
1418 struct uart_state *state = tty->driver_data;
1419 struct tty_port *port = &state->port;
1420 unsigned long flags;
1422 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1424 mutex_lock(&port->mutex);
1425 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1426 uart_flush_buffer(tty);
1427 uart_shutdown(tty, state);
1428 spin_lock_irqsave(&port->lock, flags);
1430 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1431 spin_unlock_irqrestore(&port->lock, flags);
1432 tty_port_tty_set(port, NULL);
1433 wake_up_interruptible(&port->open_wait);
1434 wake_up_interruptible(&port->delta_msr_wait);
1436 mutex_unlock(&port->mutex);
1439 static int uart_carrier_raised(struct tty_port *port)
1441 struct uart_state *state = container_of(port, struct uart_state, port);
1442 struct uart_port *uport = state->uart_port;
1444 spin_lock_irq(&uport->lock);
1445 uport->ops->enable_ms(uport);
1446 mctrl = uport->ops->get_mctrl(uport);
1447 spin_unlock_irq(&uport->lock);
1448 if (mctrl & TIOCM_CAR)
1453 static void uart_dtr_rts(struct tty_port *port, int onoff)
1455 struct uart_state *state = container_of(port, struct uart_state, port);
1456 struct uart_port *uport = state->uart_port;
1459 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1461 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1464 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1466 struct uart_state *state;
1467 struct tty_port *port;
1470 state = drv->state + line;
1471 port = &state->port;
1472 if (mutex_lock_interruptible(&port->mutex)) {
1478 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1486 mutex_unlock(&port->mutex);
1488 return ERR_PTR(ret);
1492 * calls to uart_open are serialised by the BKL in
1493 * fs/char_dev.c:chrdev_open()
1494 * Note that if this fails, then uart_close() _will_ be called.
1496 * In time, we want to scrap the "opening nonpresent ports"
1497 * behaviour and implement an alternative way for setserial
1498 * to set base addresses/ports/types. This will allow us to
1499 * get rid of a certain amount of extra tests.
1501 static int uart_open(struct tty_struct *tty, struct file *filp)
1503 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1504 struct uart_state *state;
1505 struct tty_port *port;
1506 int retval, line = tty->index;
1508 pr_debug("uart_open(%d) called\n", line);
1511 * We take the semaphore inside uart_get to guarantee that we won't
1512 * be re-entered while allocating the state structure, or while we
1513 * request any IRQs that the driver may need. This also has the nice
1514 * side-effect that it delays the action of uart_hangup, so we can
1515 * guarantee that state->port.tty will always contain something
1518 state = uart_get(drv, line);
1519 if (IS_ERR(state)) {
1520 retval = PTR_ERR(state);
1523 port = &state->port;
1526 * Once we set tty->driver_data here, we are guaranteed that
1527 * uart_close() will decrement the driver module use count.
1528 * Any failures from here onwards should not touch the count.
1530 tty->driver_data = state;
1531 state->uart_port->state = state;
1532 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1534 tty_port_tty_set(port, tty);
1537 * If the port is in the middle of closing, bail out now.
1539 if (tty_hung_up_p(filp)) {
1542 mutex_unlock(&port->mutex);
1547 * Make sure the device is in D0 state.
1549 if (port->count == 1)
1550 uart_change_pm(state, 0);
1553 * Start up the serial port.
1555 retval = uart_startup(tty, state, 0);
1558 * If we succeeded, wait until the port is ready.
1560 mutex_unlock(&port->mutex);
1562 retval = tty_port_block_til_ready(port, tty, filp);
1568 static const char *uart_type(struct uart_port *port)
1570 const char *str = NULL;
1572 if (port->ops->type)
1573 str = port->ops->type(port);
1581 #ifdef CONFIG_PROC_FS
1583 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1585 struct uart_state *state = drv->state + i;
1586 struct tty_port *port = &state->port;
1588 struct uart_port *uport = state->uart_port;
1590 unsigned int status;
1596 mmio = uport->iotype >= UPIO_MEM;
1597 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1598 uport->line, uart_type(uport),
1599 mmio ? "mmio:0x" : "port:",
1600 mmio ? (unsigned long long)uport->mapbase
1601 : (unsigned long long)uport->iobase,
1604 if (uport->type == PORT_UNKNOWN) {
1609 if (capable(CAP_SYS_ADMIN)) {
1610 mutex_lock(&port->mutex);
1611 pm_state = state->pm_state;
1613 uart_change_pm(state, 0);
1614 spin_lock_irq(&uport->lock);
1615 status = uport->ops->get_mctrl(uport);
1616 spin_unlock_irq(&uport->lock);
1618 uart_change_pm(state, pm_state);
1619 mutex_unlock(&port->mutex);
1621 seq_printf(m, " tx:%d rx:%d",
1622 uport->icount.tx, uport->icount.rx);
1623 if (uport->icount.frame)
1624 seq_printf(m, " fe:%d",
1625 uport->icount.frame);
1626 if (uport->icount.parity)
1627 seq_printf(m, " pe:%d",
1628 uport->icount.parity);
1629 if (uport->icount.brk)
1630 seq_printf(m, " brk:%d",
1632 if (uport->icount.overrun)
1633 seq_printf(m, " oe:%d",
1634 uport->icount.overrun);
1636 #define INFOBIT(bit, str) \
1637 if (uport->mctrl & (bit)) \
1638 strncat(stat_buf, (str), sizeof(stat_buf) - \
1639 strlen(stat_buf) - 2)
1640 #define STATBIT(bit, str) \
1641 if (status & (bit)) \
1642 strncat(stat_buf, (str), sizeof(stat_buf) - \
1643 strlen(stat_buf) - 2)
1647 INFOBIT(TIOCM_RTS, "|RTS");
1648 STATBIT(TIOCM_CTS, "|CTS");
1649 INFOBIT(TIOCM_DTR, "|DTR");
1650 STATBIT(TIOCM_DSR, "|DSR");
1651 STATBIT(TIOCM_CAR, "|CD");
1652 STATBIT(TIOCM_RNG, "|RI");
1656 seq_puts(m, stat_buf);
1663 static int uart_proc_show(struct seq_file *m, void *v)
1665 struct tty_driver *ttydrv = m->private;
1666 struct uart_driver *drv = ttydrv->driver_state;
1669 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1671 for (i = 0; i < drv->nr; i++)
1672 uart_line_info(m, drv, i);
1676 static int uart_proc_open(struct inode *inode, struct file *file)
1678 return single_open(file, uart_proc_show, PDE(inode)->data);
1681 static const struct file_operations uart_proc_fops = {
1682 .owner = THIS_MODULE,
1683 .open = uart_proc_open,
1685 .llseek = seq_lseek,
1686 .release = single_release,
1690 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1692 * uart_console_write - write a console message to a serial port
1693 * @port: the port to write the message
1694 * @s: array of characters
1695 * @count: number of characters in string to write
1696 * @write: function to write character to port
1698 void uart_console_write(struct uart_port *port, const char *s,
1700 void (*putchar)(struct uart_port *, int))
1704 for (i = 0; i < count; i++, s++) {
1706 putchar(port, '\r');
1710 EXPORT_SYMBOL_GPL(uart_console_write);
1713 * Check whether an invalid uart number has been specified, and
1714 * if so, search for the first available port that does have
1717 struct uart_port * __init
1718 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1720 int idx = co->index;
1722 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1723 ports[idx].membase == NULL))
1724 for (idx = 0; idx < nr; idx++)
1725 if (ports[idx].iobase != 0 ||
1726 ports[idx].membase != NULL)
1735 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1736 * @options: pointer to option string
1737 * @baud: pointer to an 'int' variable for the baud rate.
1738 * @parity: pointer to an 'int' variable for the parity.
1739 * @bits: pointer to an 'int' variable for the number of data bits.
1740 * @flow: pointer to an 'int' variable for the flow control character.
1742 * uart_parse_options decodes a string containing the serial console
1743 * options. The format of the string is <baud><parity><bits><flow>,
1747 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1751 *baud = simple_strtoul(s, NULL, 10);
1752 while (*s >= '0' && *s <= '9')
1761 EXPORT_SYMBOL_GPL(uart_parse_options);
1768 static const struct baud_rates baud_rates[] = {
1769 { 921600, B921600 },
1770 { 460800, B460800 },
1771 { 230400, B230400 },
1772 { 115200, B115200 },
1784 * uart_set_options - setup the serial console parameters
1785 * @port: pointer to the serial ports uart_port structure
1786 * @co: console pointer
1788 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1789 * @bits: number of data bits
1790 * @flow: flow control character - 'r' (rts)
1793 uart_set_options(struct uart_port *port, struct console *co,
1794 int baud, int parity, int bits, int flow)
1796 struct ktermios termios;
1797 static struct ktermios dummy;
1801 * Ensure that the serial console lock is initialised
1804 spin_lock_init(&port->lock);
1805 lockdep_set_class(&port->lock, &port_lock_key);
1807 memset(&termios, 0, sizeof(struct ktermios));
1809 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1812 * Construct a cflag setting.
1814 for (i = 0; baud_rates[i].rate; i++)
1815 if (baud_rates[i].rate <= baud)
1818 termios.c_cflag |= baud_rates[i].cflag;
1821 termios.c_cflag |= CS7;
1823 termios.c_cflag |= CS8;
1827 termios.c_cflag |= PARODD;
1830 termios.c_cflag |= PARENB;
1835 termios.c_cflag |= CRTSCTS;
1838 * some uarts on other side don't support no flow control.
1839 * So we set * DTR in host uart to make them happy
1841 port->mctrl |= TIOCM_DTR;
1843 port->ops->set_termios(port, &termios, &dummy);
1845 * Allow the setting of the UART parameters with a NULL console
1849 co->cflag = termios.c_cflag;
1853 EXPORT_SYMBOL_GPL(uart_set_options);
1854 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1856 static void uart_change_pm(struct uart_state *state, int pm_state)
1858 struct uart_port *port = state->uart_port;
1860 if (state->pm_state != pm_state) {
1862 port->ops->pm(port, pm_state, state->pm_state);
1863 state->pm_state = pm_state;
1868 struct uart_port *port;
1869 struct uart_driver *driver;
1872 static int serial_match_port(struct device *dev, void *data)
1874 struct uart_match *match = data;
1875 struct tty_driver *tty_drv = match->driver->tty_driver;
1876 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1879 return dev->devt == devt; /* Actually, only one tty per port */
1882 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1884 struct uart_state *state = drv->state + uport->line;
1885 struct tty_port *port = &state->port;
1886 struct device *tty_dev;
1887 struct uart_match match = {uport, drv};
1889 mutex_lock(&port->mutex);
1891 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1892 if (device_may_wakeup(tty_dev)) {
1893 if (!enable_irq_wake(uport->irq))
1894 uport->irq_wake = 1;
1895 put_device(tty_dev);
1896 mutex_unlock(&port->mutex);
1899 if (console_suspend_enabled || !uart_console(uport))
1900 uport->suspended = 1;
1902 if (port->flags & ASYNC_INITIALIZED) {
1903 const struct uart_ops *ops = uport->ops;
1906 if (console_suspend_enabled || !uart_console(uport)) {
1907 set_bit(ASYNCB_SUSPENDED, &port->flags);
1908 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1910 spin_lock_irq(&uport->lock);
1911 ops->stop_tx(uport);
1912 ops->set_mctrl(uport, 0);
1913 ops->stop_rx(uport);
1914 spin_unlock_irq(&uport->lock);
1918 * Wait for the transmitter to empty.
1920 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1923 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1925 uport->dev ? dev_name(uport->dev) : "",
1926 uport->dev ? ": " : "",
1928 drv->tty_driver->name_base + uport->line);
1930 if (console_suspend_enabled || !uart_console(uport))
1931 ops->shutdown(uport);
1935 * Disable the console device before suspending.
1937 if (console_suspend_enabled && uart_console(uport))
1938 console_stop(uport->cons);
1940 if (console_suspend_enabled || !uart_console(uport))
1941 uart_change_pm(state, 3);
1943 mutex_unlock(&port->mutex);
1948 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1950 struct uart_state *state = drv->state + uport->line;
1951 struct tty_port *port = &state->port;
1952 struct device *tty_dev;
1953 struct uart_match match = {uport, drv};
1954 struct ktermios termios;
1956 mutex_lock(&port->mutex);
1958 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1959 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1960 if (uport->irq_wake) {
1961 disable_irq_wake(uport->irq);
1962 uport->irq_wake = 0;
1964 mutex_unlock(&port->mutex);
1967 uport->suspended = 0;
1970 * Re-enable the console device after suspending.
1972 if (uart_console(uport)) {
1974 * First try to use the console cflag setting.
1976 memset(&termios, 0, sizeof(struct ktermios));
1977 termios.c_cflag = uport->cons->cflag;
1980 * If that's unset, use the tty termios setting.
1982 if (port->tty && port->tty->termios && termios.c_cflag == 0)
1983 termios = *(port->tty->termios);
1985 if (console_suspend_enabled)
1986 uart_change_pm(state, 0);
1987 uport->ops->set_termios(uport, &termios, NULL);
1988 if (console_suspend_enabled)
1989 console_start(uport->cons);
1992 if (port->flags & ASYNC_SUSPENDED) {
1993 const struct uart_ops *ops = uport->ops;
1996 uart_change_pm(state, 0);
1997 spin_lock_irq(&uport->lock);
1998 ops->set_mctrl(uport, 0);
1999 spin_unlock_irq(&uport->lock);
2000 if (console_suspend_enabled || !uart_console(uport)) {
2001 /* Protected by port mutex for now */
2002 struct tty_struct *tty = port->tty;
2003 ret = ops->startup(uport);
2006 uart_change_speed(tty, state, NULL);
2007 spin_lock_irq(&uport->lock);
2008 ops->set_mctrl(uport, uport->mctrl);
2009 ops->start_tx(uport);
2010 spin_unlock_irq(&uport->lock);
2011 set_bit(ASYNCB_INITIALIZED, &port->flags);
2014 * Failed to resume - maybe hardware went away?
2015 * Clear the "initialized" flag so we won't try
2016 * to call the low level drivers shutdown method.
2018 uart_shutdown(tty, state);
2022 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2025 mutex_unlock(&port->mutex);
2031 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2035 switch (port->iotype) {
2037 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2040 snprintf(address, sizeof(address),
2041 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2047 snprintf(address, sizeof(address),
2048 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2051 strlcpy(address, "*unknown*", sizeof(address));
2055 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2056 port->dev ? dev_name(port->dev) : "",
2057 port->dev ? ": " : "",
2059 drv->tty_driver->name_base + port->line,
2060 address, port->irq, uart_type(port));
2064 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2065 struct uart_port *port)
2070 * If there isn't a port here, don't do anything further.
2072 if (!port->iobase && !port->mapbase && !port->membase)
2076 * Now do the auto configuration stuff. Note that config_port
2077 * is expected to claim the resources and map the port for us.
2080 if (port->flags & UPF_AUTO_IRQ)
2081 flags |= UART_CONFIG_IRQ;
2082 if (port->flags & UPF_BOOT_AUTOCONF) {
2083 if (!(port->flags & UPF_FIXED_TYPE)) {
2084 port->type = PORT_UNKNOWN;
2085 flags |= UART_CONFIG_TYPE;
2087 port->ops->config_port(port, flags);
2090 if (port->type != PORT_UNKNOWN) {
2091 unsigned long flags;
2093 uart_report_port(drv, port);
2095 /* Power up port for set_mctrl() */
2096 uart_change_pm(state, 0);
2099 * Ensure that the modem control lines are de-activated.
2100 * keep the DTR setting that is set in uart_set_options()
2101 * We probably don't need a spinlock around this, but
2103 spin_lock_irqsave(&port->lock, flags);
2104 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2105 spin_unlock_irqrestore(&port->lock, flags);
2108 * If this driver supports console, and it hasn't been
2109 * successfully registered yet, try to re-register it.
2110 * It may be that the port was not available.
2112 if (port->cons && !(port->cons->flags & CON_ENABLED))
2113 register_console(port->cons);
2116 * Power down all ports by default, except the
2117 * console if we have one.
2119 if (!uart_console(port))
2120 uart_change_pm(state, 3);
2124 #ifdef CONFIG_CONSOLE_POLL
2126 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2128 struct uart_driver *drv = driver->driver_state;
2129 struct uart_state *state = drv->state + line;
2130 struct uart_port *port;
2136 if (!state || !state->uart_port)
2139 port = state->uart_port;
2140 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2144 uart_parse_options(options, &baud, &parity, &bits, &flow);
2145 return uart_set_options(port, NULL, baud, parity, bits, flow);
2151 static int uart_poll_get_char(struct tty_driver *driver, int line)
2153 struct uart_driver *drv = driver->driver_state;
2154 struct uart_state *state = drv->state + line;
2155 struct uart_port *port;
2157 if (!state || !state->uart_port)
2160 port = state->uart_port;
2161 return port->ops->poll_get_char(port);
2164 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2166 struct uart_driver *drv = driver->driver_state;
2167 struct uart_state *state = drv->state + line;
2168 struct uart_port *port;
2170 if (!state || !state->uart_port)
2173 port = state->uart_port;
2174 port->ops->poll_put_char(port, ch);
2178 static const struct tty_operations uart_ops = {
2180 .close = uart_close,
2181 .write = uart_write,
2182 .put_char = uart_put_char,
2183 .flush_chars = uart_flush_chars,
2184 .write_room = uart_write_room,
2185 .chars_in_buffer= uart_chars_in_buffer,
2186 .flush_buffer = uart_flush_buffer,
2187 .ioctl = uart_ioctl,
2188 .throttle = uart_throttle,
2189 .unthrottle = uart_unthrottle,
2190 .send_xchar = uart_send_xchar,
2191 .set_termios = uart_set_termios,
2192 .set_ldisc = uart_set_ldisc,
2194 .start = uart_start,
2195 .hangup = uart_hangup,
2196 .break_ctl = uart_break_ctl,
2197 .wait_until_sent= uart_wait_until_sent,
2198 #ifdef CONFIG_PROC_FS
2199 .proc_fops = &uart_proc_fops,
2201 .tiocmget = uart_tiocmget,
2202 .tiocmset = uart_tiocmset,
2203 .get_icount = uart_get_icount,
2204 #ifdef CONFIG_CONSOLE_POLL
2205 .poll_init = uart_poll_init,
2206 .poll_get_char = uart_poll_get_char,
2207 .poll_put_char = uart_poll_put_char,
2211 static const struct tty_port_operations uart_port_ops = {
2212 .carrier_raised = uart_carrier_raised,
2213 .dtr_rts = uart_dtr_rts,
2217 * uart_register_driver - register a driver with the uart core layer
2218 * @drv: low level driver structure
2220 * Register a uart driver with the core driver. We in turn register
2221 * with the tty layer, and initialise the core driver per-port state.
2223 * We have a proc file in /proc/tty/driver which is named after the
2226 * drv->port should be NULL, and the per-port structures should be
2227 * registered using uart_add_one_port after this call has succeeded.
2229 int uart_register_driver(struct uart_driver *drv)
2231 struct tty_driver *normal;
2237 * Maybe we should be using a slab cache for this, especially if
2238 * we have a large number of ports to handle.
2240 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2244 normal = alloc_tty_driver(drv->nr);
2248 drv->tty_driver = normal;
2250 normal->owner = drv->owner;
2251 normal->driver_name = drv->driver_name;
2252 normal->name = drv->dev_name;
2253 normal->major = drv->major;
2254 normal->minor_start = drv->minor;
2255 normal->type = TTY_DRIVER_TYPE_SERIAL;
2256 normal->subtype = SERIAL_TYPE_NORMAL;
2257 normal->init_termios = tty_std_termios;
2258 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2259 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2260 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2261 normal->driver_state = drv;
2262 tty_set_operations(normal, &uart_ops);
2265 * Initialise the UART state(s).
2267 for (i = 0; i < drv->nr; i++) {
2268 struct uart_state *state = drv->state + i;
2269 struct tty_port *port = &state->port;
2271 tty_port_init(port);
2272 port->ops = &uart_port_ops;
2273 port->close_delay = 500; /* .5 seconds */
2274 port->closing_wait = 30000; /* 30 seconds */
2277 retval = tty_register_driver(normal);
2281 put_tty_driver(normal);
2289 * uart_unregister_driver - remove a driver from the uart core layer
2290 * @drv: low level driver structure
2292 * Remove all references to a driver from the core driver. The low
2293 * level driver must have removed all its ports via the
2294 * uart_remove_one_port() if it registered them with uart_add_one_port().
2295 * (ie, drv->port == NULL)
2297 void uart_unregister_driver(struct uart_driver *drv)
2299 struct tty_driver *p = drv->tty_driver;
2300 tty_unregister_driver(p);
2303 drv->tty_driver = NULL;
2306 struct tty_driver *uart_console_device(struct console *co, int *index)
2308 struct uart_driver *p = co->data;
2310 return p->tty_driver;
2314 * uart_add_one_port - attach a driver-defined port structure
2315 * @drv: pointer to the uart low level driver structure for this port
2316 * @uport: uart port structure to use for this port.
2318 * This allows the driver to register its own uart_port structure
2319 * with the core driver. The main purpose is to allow the low
2320 * level uart drivers to expand uart_port, rather than having yet
2321 * more levels of structures.
2323 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2325 struct uart_state *state;
2326 struct tty_port *port;
2328 struct device *tty_dev;
2330 BUG_ON(in_interrupt());
2332 if (uport->line >= drv->nr)
2335 state = drv->state + uport->line;
2336 port = &state->port;
2338 mutex_lock(&port_mutex);
2339 mutex_lock(&port->mutex);
2340 if (state->uart_port) {
2345 state->uart_port = uport;
2346 state->pm_state = -1;
2348 uport->cons = drv->cons;
2349 uport->state = state;
2352 * If this port is a console, then the spinlock is already
2355 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2356 spin_lock_init(&uport->lock);
2357 lockdep_set_class(&uport->lock, &port_lock_key);
2360 uart_configure_port(drv, state, uport);
2363 * Register the port whether it's detected or not. This allows
2364 * setserial to be used to alter this ports parameters.
2366 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2367 if (likely(!IS_ERR(tty_dev))) {
2368 device_init_wakeup(tty_dev, 1);
2369 device_set_wakeup_enable(tty_dev, 0);
2371 printk(KERN_ERR "Cannot register tty device on line %d\n",
2375 * Ensure UPF_DEAD is not set.
2377 uport->flags &= ~UPF_DEAD;
2380 mutex_unlock(&port->mutex);
2381 mutex_unlock(&port_mutex);
2387 * uart_remove_one_port - detach a driver defined port structure
2388 * @drv: pointer to the uart low level driver structure for this port
2389 * @uport: uart port structure for this port
2391 * This unhooks (and hangs up) the specified port structure from the
2392 * core driver. No further calls will be made to the low-level code
2395 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2397 struct uart_state *state = drv->state + uport->line;
2398 struct tty_port *port = &state->port;
2400 BUG_ON(in_interrupt());
2402 if (state->uart_port != uport)
2403 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2404 state->uart_port, uport);
2406 mutex_lock(&port_mutex);
2409 * Mark the port "dead" - this prevents any opens from
2410 * succeeding while we shut down the port.
2412 mutex_lock(&port->mutex);
2413 uport->flags |= UPF_DEAD;
2414 mutex_unlock(&port->mutex);
2417 * Remove the devices from the tty layer
2419 tty_unregister_device(drv->tty_driver, uport->line);
2422 tty_vhangup(port->tty);
2425 * Free the port IO and memory resources, if any.
2427 if (uport->type != PORT_UNKNOWN)
2428 uport->ops->release_port(uport);
2431 * Indicate that there isn't a port here anymore.
2433 uport->type = PORT_UNKNOWN;
2435 state->uart_port = NULL;
2436 mutex_unlock(&port_mutex);
2442 * Are the two ports equivalent?
2444 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2446 if (port1->iotype != port2->iotype)
2449 switch (port1->iotype) {
2451 return (port1->iobase == port2->iobase);
2453 return (port1->iobase == port2->iobase) &&
2454 (port1->hub6 == port2->hub6);
2459 return (port1->mapbase == port2->mapbase);
2463 EXPORT_SYMBOL(uart_match_port);
2465 EXPORT_SYMBOL(uart_write_wakeup);
2466 EXPORT_SYMBOL(uart_register_driver);
2467 EXPORT_SYMBOL(uart_unregister_driver);
2468 EXPORT_SYMBOL(uart_suspend_port);
2469 EXPORT_SYMBOL(uart_resume_port);
2470 EXPORT_SYMBOL(uart_add_one_port);
2471 EXPORT_SYMBOL(uart_remove_one_port);
2473 MODULE_DESCRIPTION("Serial driver core");
2474 MODULE_LICENSE("GPL");