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 uart_port *port, 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 tasklet_schedule(&state->tlet);
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 (port->ops->wake_peer)
95 port->ops->wake_peer(port);
97 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
98 !tty->stopped && !tty->hw_stopped)
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);
113 static void uart_tasklet_action(unsigned long data)
115 struct uart_state *state = (struct uart_state *)data;
116 tty_wakeup(state->port.tty);
120 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
125 spin_lock_irqsave(&port->lock, flags);
127 port->mctrl = (old & ~clear) | set;
128 if (old != port->mctrl)
129 port->ops->set_mctrl(port, port->mctrl);
130 spin_unlock_irqrestore(&port->lock, flags);
133 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
134 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
137 * Startup the port. This will be called once per open. All calls
138 * will be serialised by the per-port mutex.
140 static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
142 struct uart_port *uport = state->uart_port;
143 struct tty_port *port = &state->port;
147 if (port->flags & ASYNC_INITIALIZED)
151 * Set the TTY IO error marker - we will only clear this
152 * once we have successfully opened the port. Also set
153 * up the tty->alt_speed kludge
155 set_bit(TTY_IO_ERROR, &tty->flags);
157 if (uport->type == PORT_UNKNOWN)
161 * Initialise and allocate the transmit and temporary
164 if (!state->xmit.buf) {
165 /* This is protected by the per port mutex */
166 page = get_zeroed_page(GFP_KERNEL);
170 state->xmit.buf = (unsigned char *) page;
171 uart_circ_clear(&state->xmit);
174 retval = uport->ops->startup(uport);
176 if (uart_console(uport) && uport->cons->cflag) {
177 tty->termios->c_cflag = uport->cons->cflag;
178 uport->cons->cflag = 0;
181 * Initialise the hardware port settings.
183 uart_change_speed(tty, state, NULL);
187 * Setup the RTS and DTR signals once the
188 * port is open and ready to respond.
190 if (tty->termios->c_cflag & CBAUD)
191 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
194 if (port->flags & ASYNC_CTS_FLOW) {
195 spin_lock_irq(&uport->lock);
196 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
198 spin_unlock_irq(&uport->lock);
201 set_bit(ASYNCB_INITIALIZED, &port->flags);
203 clear_bit(TTY_IO_ERROR, &tty->flags);
206 if (retval && capable(CAP_SYS_ADMIN))
213 * This routine will shutdown a serial port; interrupts are disabled, and
214 * DTR is dropped if the hangup on close termio flag is on. Calls to
215 * uart_shutdown are serialised by the per-port semaphore.
217 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
219 struct uart_port *uport = state->uart_port;
220 struct tty_port *port = &state->port;
223 * Set the TTY IO error marker
226 set_bit(TTY_IO_ERROR, &tty->flags);
228 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
230 * Turn off DTR and RTS early.
232 if (!tty || (tty->termios->c_cflag & HUPCL))
233 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
236 * clear delta_msr_wait queue to avoid mem leaks: we may free
237 * the irq here so the queue might never be woken up. Note
238 * that we won't end up waiting on delta_msr_wait again since
239 * any outstanding file descriptors should be pointing at
240 * hung_up_tty_fops now.
242 wake_up_interruptible(&port->delta_msr_wait);
245 * Free the IRQ and disable the port.
247 uport->ops->shutdown(uport);
250 * Ensure that the IRQ handler isn't running on another CPU.
252 synchronize_irq(uport->irq);
256 * kill off our tasklet
258 tasklet_kill(&state->tlet);
261 * Free the transmit buffer page.
263 if (state->xmit.buf) {
264 free_page((unsigned long)state->xmit.buf);
265 state->xmit.buf = NULL;
270 * uart_update_timeout - update per-port FIFO timeout.
271 * @port: uart_port structure describing the port
272 * @cflag: termios cflag value
273 * @baud: speed of the port
275 * Set the port FIFO timeout value. The @cflag value should
276 * reflect the actual hardware settings.
279 uart_update_timeout(struct uart_port *port, unsigned int cflag,
284 /* byte size and parity */
285 switch (cflag & CSIZE) {
306 * The total number of bits to be transmitted in the fifo.
308 bits = bits * port->fifosize;
311 * Figure the timeout to send the above number of bits.
312 * Add .02 seconds of slop
314 port->timeout = (HZ * bits) / baud + HZ/50;
317 EXPORT_SYMBOL(uart_update_timeout);
320 * uart_get_baud_rate - return baud rate for a particular port
321 * @port: uart_port structure describing the port in question.
322 * @termios: desired termios settings.
323 * @old: old termios (or NULL)
324 * @min: minimum acceptable baud rate
325 * @max: maximum acceptable baud rate
327 * Decode the termios structure into a numeric baud rate,
328 * taking account of the magic 38400 baud rate (with spd_*
329 * flags), and mapping the %B0 rate to 9600 baud.
331 * If the new baud rate is invalid, try the old termios setting.
332 * If it's still invalid, we try 9600 baud.
334 * Update the @termios structure to reflect the baud rate
335 * we're actually going to be using. Don't do this for the case
336 * where B0 is requested ("hang up").
339 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
340 struct ktermios *old, unsigned int min, unsigned int max)
342 unsigned int try, baud, altbaud = 38400;
344 upf_t flags = port->flags & UPF_SPD_MASK;
346 if (flags == UPF_SPD_HI)
348 else if (flags == UPF_SPD_VHI)
350 else if (flags == UPF_SPD_SHI)
352 else if (flags == UPF_SPD_WARP)
355 for (try = 0; try < 2; try++) {
356 baud = tty_termios_baud_rate(termios);
359 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
366 * Special case: B0 rate.
373 if (baud >= min && baud <= max)
377 * Oops, the quotient was zero. Try again with
378 * the old baud rate if possible.
380 termios->c_cflag &= ~CBAUD;
382 baud = tty_termios_baud_rate(old);
384 tty_termios_encode_baud_rate(termios,
391 * As a last resort, if the range cannot be met then clip to
392 * the nearest chip supported rate.
396 tty_termios_encode_baud_rate(termios,
399 tty_termios_encode_baud_rate(termios,
403 /* Should never happen */
408 EXPORT_SYMBOL(uart_get_baud_rate);
411 * uart_get_divisor - return uart clock divisor
412 * @port: uart_port structure describing the port.
413 * @baud: desired baud rate
415 * Calculate the uart clock divisor for the port.
418 uart_get_divisor(struct uart_port *port, unsigned int baud)
423 * Old custom speed handling.
425 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
426 quot = port->custom_divisor;
428 quot = (port->uartclk + (8 * baud)) / (16 * baud);
433 EXPORT_SYMBOL(uart_get_divisor);
435 /* FIXME: Consistent locking policy */
436 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
437 struct ktermios *old_termios)
439 struct tty_port *port = &state->port;
440 struct uart_port *uport = state->uart_port;
441 struct ktermios *termios;
444 * If we have no tty, termios, or the port does not exist,
445 * then we can't set the parameters for this port.
447 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
450 termios = tty->termios;
453 * Set flags based on termios cflag
455 if (termios->c_cflag & CRTSCTS)
456 set_bit(ASYNCB_CTS_FLOW, &port->flags);
458 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
460 if (termios->c_cflag & CLOCAL)
461 clear_bit(ASYNCB_CHECK_CD, &port->flags);
463 set_bit(ASYNCB_CHECK_CD, &port->flags);
465 uport->ops->set_termios(uport, termios, old_termios);
468 static inline int __uart_put_char(struct uart_port *port,
469 struct circ_buf *circ, unsigned char c)
477 spin_lock_irqsave(&port->lock, flags);
478 if (uart_circ_chars_free(circ) != 0) {
479 circ->buf[circ->head] = c;
480 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
483 spin_unlock_irqrestore(&port->lock, flags);
487 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
489 struct uart_state *state = tty->driver_data;
491 return __uart_put_char(state->uart_port, &state->xmit, ch);
494 static void uart_flush_chars(struct tty_struct *tty)
499 static int uart_write(struct tty_struct *tty,
500 const unsigned char *buf, int count)
502 struct uart_state *state = tty->driver_data;
503 struct uart_port *port;
504 struct circ_buf *circ;
509 * This means you called this function _after_ the port was
510 * closed. No cookie for you.
517 port = state->uart_port;
523 spin_lock_irqsave(&port->lock, flags);
525 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
530 memcpy(circ->buf + circ->head, buf, c);
531 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
536 spin_unlock_irqrestore(&port->lock, flags);
542 static int uart_write_room(struct tty_struct *tty)
544 struct uart_state *state = tty->driver_data;
548 spin_lock_irqsave(&state->uart_port->lock, flags);
549 ret = uart_circ_chars_free(&state->xmit);
550 spin_unlock_irqrestore(&state->uart_port->lock, flags);
554 static int uart_chars_in_buffer(struct tty_struct *tty)
556 struct uart_state *state = tty->driver_data;
560 spin_lock_irqsave(&state->uart_port->lock, flags);
561 ret = uart_circ_chars_pending(&state->xmit);
562 spin_unlock_irqrestore(&state->uart_port->lock, flags);
566 static void uart_flush_buffer(struct tty_struct *tty)
568 struct uart_state *state = tty->driver_data;
569 struct uart_port *port;
573 * This means you called this function _after_ the port was
574 * closed. No cookie for you.
581 port = state->uart_port;
582 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
584 spin_lock_irqsave(&port->lock, flags);
585 uart_circ_clear(&state->xmit);
586 if (port->ops->flush_buffer)
587 port->ops->flush_buffer(port);
588 spin_unlock_irqrestore(&port->lock, flags);
593 * This function is used to send a high-priority XON/XOFF character to
596 static void uart_send_xchar(struct tty_struct *tty, char ch)
598 struct uart_state *state = tty->driver_data;
599 struct uart_port *port = state->uart_port;
602 if (port->ops->send_xchar)
603 port->ops->send_xchar(port, ch);
607 spin_lock_irqsave(&port->lock, flags);
608 port->ops->start_tx(port);
609 spin_unlock_irqrestore(&port->lock, flags);
614 static void uart_throttle(struct tty_struct *tty)
616 struct uart_state *state = tty->driver_data;
619 uart_send_xchar(tty, STOP_CHAR(tty));
621 if (tty->termios->c_cflag & CRTSCTS)
622 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
625 static void uart_unthrottle(struct tty_struct *tty)
627 struct uart_state *state = tty->driver_data;
628 struct uart_port *port = state->uart_port;
634 uart_send_xchar(tty, START_CHAR(tty));
637 if (tty->termios->c_cflag & CRTSCTS)
638 uart_set_mctrl(port, TIOCM_RTS);
641 static int uart_get_info(struct uart_state *state,
642 struct serial_struct __user *retinfo)
644 struct uart_port *uport = state->uart_port;
645 struct tty_port *port = &state->port;
646 struct serial_struct tmp;
648 memset(&tmp, 0, sizeof(tmp));
650 /* Ensure the state we copy is consistent and no hardware changes
652 mutex_lock(&port->mutex);
654 tmp.type = uport->type;
655 tmp.line = uport->line;
656 tmp.port = uport->iobase;
657 if (HIGH_BITS_OFFSET)
658 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
659 tmp.irq = uport->irq;
660 tmp.flags = uport->flags;
661 tmp.xmit_fifo_size = uport->fifosize;
662 tmp.baud_base = uport->uartclk / 16;
663 tmp.close_delay = port->close_delay / 10;
664 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
665 ASYNC_CLOSING_WAIT_NONE :
666 port->closing_wait / 10;
667 tmp.custom_divisor = uport->custom_divisor;
668 tmp.hub6 = uport->hub6;
669 tmp.io_type = uport->iotype;
670 tmp.iomem_reg_shift = uport->regshift;
671 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
673 mutex_unlock(&port->mutex);
675 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
680 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
681 struct serial_struct __user *newinfo)
683 struct serial_struct new_serial;
684 struct uart_port *uport = state->uart_port;
685 struct tty_port *port = &state->port;
686 unsigned long new_port;
687 unsigned int change_irq, change_port, closing_wait;
688 unsigned int old_custom_divisor, close_delay;
689 upf_t old_flags, new_flags;
692 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
695 new_port = new_serial.port;
696 if (HIGH_BITS_OFFSET)
697 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
699 new_serial.irq = irq_canonicalize(new_serial.irq);
700 close_delay = new_serial.close_delay * 10;
701 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
702 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
705 * This semaphore protects port->count. It is also
706 * very useful to prevent opens. Also, take the
707 * port configuration semaphore to make sure that a
708 * module insertion/removal doesn't change anything
711 mutex_lock(&port->mutex);
713 change_irq = !(uport->flags & UPF_FIXED_PORT)
714 && new_serial.irq != uport->irq;
717 * Since changing the 'type' of the port changes its resource
718 * allocations, we should treat type changes the same as
721 change_port = !(uport->flags & UPF_FIXED_PORT)
722 && (new_port != uport->iobase ||
723 (unsigned long)new_serial.iomem_base != uport->mapbase ||
724 new_serial.hub6 != uport->hub6 ||
725 new_serial.io_type != uport->iotype ||
726 new_serial.iomem_reg_shift != uport->regshift ||
727 new_serial.type != uport->type);
729 old_flags = uport->flags;
730 new_flags = new_serial.flags;
731 old_custom_divisor = uport->custom_divisor;
733 if (!capable(CAP_SYS_ADMIN)) {
735 if (change_irq || change_port ||
736 (new_serial.baud_base != uport->uartclk / 16) ||
737 (close_delay != port->close_delay) ||
738 (closing_wait != port->closing_wait) ||
739 (new_serial.xmit_fifo_size &&
740 new_serial.xmit_fifo_size != uport->fifosize) ||
741 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
743 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
744 (new_flags & UPF_USR_MASK));
745 uport->custom_divisor = new_serial.custom_divisor;
750 * Ask the low level driver to verify the settings.
752 if (uport->ops->verify_port)
753 retval = uport->ops->verify_port(uport, &new_serial);
755 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
756 (new_serial.baud_base < 9600))
762 if (change_port || change_irq) {
766 * Make sure that we are the sole user of this port.
768 if (tty_port_users(port) > 1)
772 * We need to shutdown the serial port at the old
773 * port/type/irq combination.
775 uart_shutdown(tty, state);
779 unsigned long old_iobase, old_mapbase;
780 unsigned int old_type, old_iotype, old_hub6, old_shift;
782 old_iobase = uport->iobase;
783 old_mapbase = uport->mapbase;
784 old_type = uport->type;
785 old_hub6 = uport->hub6;
786 old_iotype = uport->iotype;
787 old_shift = uport->regshift;
790 * Free and release old regions
792 if (old_type != PORT_UNKNOWN)
793 uport->ops->release_port(uport);
795 uport->iobase = new_port;
796 uport->type = new_serial.type;
797 uport->hub6 = new_serial.hub6;
798 uport->iotype = new_serial.io_type;
799 uport->regshift = new_serial.iomem_reg_shift;
800 uport->mapbase = (unsigned long)new_serial.iomem_base;
803 * Claim and map the new regions
805 if (uport->type != PORT_UNKNOWN) {
806 retval = uport->ops->request_port(uport);
808 /* Always success - Jean II */
813 * If we fail to request resources for the
814 * new port, try to restore the old settings.
816 if (retval && old_type != PORT_UNKNOWN) {
817 uport->iobase = old_iobase;
818 uport->type = old_type;
819 uport->hub6 = old_hub6;
820 uport->iotype = old_iotype;
821 uport->regshift = old_shift;
822 uport->mapbase = old_mapbase;
823 retval = uport->ops->request_port(uport);
825 * If we failed to restore the old settings,
829 uport->type = PORT_UNKNOWN;
835 /* Added to return the correct error -Ram Gupta */
841 uport->irq = new_serial.irq;
842 if (!(uport->flags & UPF_FIXED_PORT))
843 uport->uartclk = new_serial.baud_base * 16;
844 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
845 (new_flags & UPF_CHANGE_MASK);
846 uport->custom_divisor = new_serial.custom_divisor;
847 port->close_delay = close_delay;
848 port->closing_wait = closing_wait;
849 if (new_serial.xmit_fifo_size)
850 uport->fifosize = new_serial.xmit_fifo_size;
852 port->tty->low_latency =
853 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
857 if (uport->type == PORT_UNKNOWN)
859 if (port->flags & ASYNC_INITIALIZED) {
860 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
861 old_custom_divisor != uport->custom_divisor) {
863 * If they're setting up a custom divisor or speed,
864 * instead of clearing it, then bitch about it. No
865 * need to rate-limit; it's CAP_SYS_ADMIN only.
867 if (uport->flags & UPF_SPD_MASK) {
870 "%s sets custom speed on %s. This "
871 "is deprecated.\n", current->comm,
872 tty_name(port->tty, buf));
874 uart_change_speed(tty, state, NULL);
877 retval = uart_startup(tty, state, 1);
879 mutex_unlock(&port->mutex);
884 * uart_get_lsr_info - get line status register info
885 * @tty: tty associated with the UART
886 * @state: UART being queried
887 * @value: returned modem value
889 * Note: uart_ioctl protects us against hangups.
891 static int uart_get_lsr_info(struct tty_struct *tty,
892 struct uart_state *state, unsigned int __user *value)
894 struct uart_port *uport = state->uart_port;
897 result = uport->ops->tx_empty(uport);
900 * If we're about to load something into the transmit
901 * register, we'll pretend the transmitter isn't empty to
902 * avoid a race condition (depending on when the transmit
903 * interrupt happens).
906 ((uart_circ_chars_pending(&state->xmit) > 0) &&
907 !tty->stopped && !tty->hw_stopped))
908 result &= ~TIOCSER_TEMT;
910 return put_user(result, value);
913 static int uart_tiocmget(struct tty_struct *tty)
915 struct uart_state *state = tty->driver_data;
916 struct tty_port *port = &state->port;
917 struct uart_port *uport = state->uart_port;
920 mutex_lock(&port->mutex);
921 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
922 result = uport->mctrl;
923 spin_lock_irq(&uport->lock);
924 result |= uport->ops->get_mctrl(uport);
925 spin_unlock_irq(&uport->lock);
927 mutex_unlock(&port->mutex);
933 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
935 struct uart_state *state = tty->driver_data;
936 struct uart_port *uport = state->uart_port;
937 struct tty_port *port = &state->port;
940 mutex_lock(&port->mutex);
941 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
942 uart_update_mctrl(uport, set, clear);
945 mutex_unlock(&port->mutex);
949 static int uart_break_ctl(struct tty_struct *tty, int break_state)
951 struct uart_state *state = tty->driver_data;
952 struct tty_port *port = &state->port;
953 struct uart_port *uport = state->uart_port;
955 mutex_lock(&port->mutex);
957 if (uport->type != PORT_UNKNOWN)
958 uport->ops->break_ctl(uport, break_state);
960 mutex_unlock(&port->mutex);
964 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
966 struct uart_port *uport = state->uart_port;
967 struct tty_port *port = &state->port;
970 if (!capable(CAP_SYS_ADMIN))
974 * Take the per-port semaphore. This prevents count from
975 * changing, and hence any extra opens of the port while
976 * we're auto-configuring.
978 if (mutex_lock_interruptible(&port->mutex))
982 if (tty_port_users(port) == 1) {
983 uart_shutdown(tty, state);
986 * If we already have a port type configured,
987 * we must release its resources.
989 if (uport->type != PORT_UNKNOWN)
990 uport->ops->release_port(uport);
992 flags = UART_CONFIG_TYPE;
993 if (uport->flags & UPF_AUTO_IRQ)
994 flags |= UART_CONFIG_IRQ;
997 * This will claim the ports resources if
1000 uport->ops->config_port(uport, flags);
1002 ret = uart_startup(tty, state, 1);
1004 mutex_unlock(&port->mutex);
1009 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1010 * - mask passed in arg for lines of interest
1011 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1012 * Caller should use TIOCGICOUNT to see which one it was
1014 * FIXME: This wants extracting into a common all driver implementation
1015 * of TIOCMWAIT using tty_port.
1018 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1020 struct uart_port *uport = state->uart_port;
1021 struct tty_port *port = &state->port;
1022 DECLARE_WAITQUEUE(wait, current);
1023 struct uart_icount cprev, cnow;
1027 * note the counters on entry
1029 spin_lock_irq(&uport->lock);
1030 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1033 * Force modem status interrupts on
1035 uport->ops->enable_ms(uport);
1036 spin_unlock_irq(&uport->lock);
1038 add_wait_queue(&port->delta_msr_wait, &wait);
1040 spin_lock_irq(&uport->lock);
1041 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1042 spin_unlock_irq(&uport->lock);
1044 set_current_state(TASK_INTERRUPTIBLE);
1046 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1047 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1048 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1049 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1056 /* see if a signal did it */
1057 if (signal_pending(current)) {
1065 current->state = TASK_RUNNING;
1066 remove_wait_queue(&port->delta_msr_wait, &wait);
1072 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1073 * Return: write counters to the user passed counter struct
1074 * NB: both 1->0 and 0->1 transitions are counted except for
1075 * RI where only 0->1 is counted.
1077 static int uart_get_icount(struct tty_struct *tty,
1078 struct serial_icounter_struct *icount)
1080 struct uart_state *state = tty->driver_data;
1081 struct uart_icount cnow;
1082 struct uart_port *uport = state->uart_port;
1084 spin_lock_irq(&uport->lock);
1085 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1086 spin_unlock_irq(&uport->lock);
1088 icount->cts = cnow.cts;
1089 icount->dsr = cnow.dsr;
1090 icount->rng = cnow.rng;
1091 icount->dcd = cnow.dcd;
1092 icount->rx = cnow.rx;
1093 icount->tx = cnow.tx;
1094 icount->frame = cnow.frame;
1095 icount->overrun = cnow.overrun;
1096 icount->parity = cnow.parity;
1097 icount->brk = cnow.brk;
1098 icount->buf_overrun = cnow.buf_overrun;
1104 * Called via sys_ioctl. We can use spin_lock_irq() here.
1107 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1110 struct uart_state *state = tty->driver_data;
1111 struct tty_port *port = &state->port;
1112 void __user *uarg = (void __user *)arg;
1113 int ret = -ENOIOCTLCMD;
1117 * These ioctls don't rely on the hardware to be present.
1121 ret = uart_get_info(state, uarg);
1125 ret = uart_set_info(tty, state, uarg);
1129 ret = uart_do_autoconfig(tty, state);
1132 case TIOCSERGWILD: /* obsolete */
1133 case TIOCSERSWILD: /* obsolete */
1138 if (ret != -ENOIOCTLCMD)
1141 if (tty->flags & (1 << TTY_IO_ERROR)) {
1147 * The following should only be used when hardware is present.
1151 ret = uart_wait_modem_status(state, arg);
1155 if (ret != -ENOIOCTLCMD)
1158 mutex_lock(&port->mutex);
1160 if (tty->flags & (1 << TTY_IO_ERROR)) {
1166 * All these rely on hardware being present and need to be
1167 * protected against the tty being hung up.
1170 case TIOCSERGETLSR: /* Get line status register */
1171 ret = uart_get_lsr_info(tty, state, uarg);
1175 struct uart_port *uport = state->uart_port;
1176 if (uport->ops->ioctl)
1177 ret = uport->ops->ioctl(uport, cmd, arg);
1182 mutex_unlock(&port->mutex);
1187 static void uart_set_ldisc(struct tty_struct *tty)
1189 struct uart_state *state = tty->driver_data;
1190 struct uart_port *uport = state->uart_port;
1192 if (uport->ops->set_ldisc)
1193 uport->ops->set_ldisc(uport, tty->termios->c_line);
1196 static void uart_set_termios(struct tty_struct *tty,
1197 struct ktermios *old_termios)
1199 struct uart_state *state = tty->driver_data;
1200 unsigned long flags;
1201 unsigned int cflag = tty->termios->c_cflag;
1205 * These are the bits that are used to setup various
1206 * flags in the low level driver. We can ignore the Bfoo
1207 * bits in c_cflag; c_[io]speed will always be set
1208 * appropriately by set_termios() in tty_ioctl.c
1210 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1211 if ((cflag ^ old_termios->c_cflag) == 0 &&
1212 tty->termios->c_ospeed == old_termios->c_ospeed &&
1213 tty->termios->c_ispeed == old_termios->c_ispeed &&
1214 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1218 uart_change_speed(tty, state, old_termios);
1220 /* Handle transition to B0 status */
1221 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1222 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1223 /* Handle transition away from B0 status */
1224 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1225 unsigned int mask = TIOCM_DTR;
1226 if (!(cflag & CRTSCTS) ||
1227 !test_bit(TTY_THROTTLED, &tty->flags))
1229 uart_set_mctrl(state->uart_port, mask);
1232 /* Handle turning off CRTSCTS */
1233 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1234 spin_lock_irqsave(&state->uart_port->lock, flags);
1235 tty->hw_stopped = 0;
1237 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1239 /* Handle turning on CRTSCTS */
1240 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1241 spin_lock_irqsave(&state->uart_port->lock, flags);
1242 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1243 tty->hw_stopped = 1;
1244 state->uart_port->ops->stop_tx(state->uart_port);
1246 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1251 * In 2.4.5, calls to this will be serialized via the BKL in
1252 * linux/drivers/char/tty_io.c:tty_release()
1253 * linux/drivers/char/tty_io.c:do_tty_handup()
1255 static void uart_close(struct tty_struct *tty, struct file *filp)
1257 struct uart_state *state = tty->driver_data;
1258 struct tty_port *port;
1259 struct uart_port *uport;
1260 unsigned long flags;
1262 BUG_ON(!tty_locked());
1267 uport = state->uart_port;
1268 port = &state->port;
1270 pr_debug("uart_close(%d) called\n", uport->line);
1272 mutex_lock(&port->mutex);
1273 spin_lock_irqsave(&port->lock, flags);
1275 if (tty_hung_up_p(filp)) {
1276 spin_unlock_irqrestore(&port->lock, flags);
1280 if ((tty->count == 1) && (port->count != 1)) {
1282 * Uh, oh. tty->count is 1, which means that the tty
1283 * structure will be freed. port->count should always
1284 * be one in these conditions. If it's greater than
1285 * one, we've got real problems, since it means the
1286 * serial port won't be shutdown.
1288 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1289 "port->count is %d\n", port->count);
1292 if (--port->count < 0) {
1293 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1294 tty->name, port->count);
1298 spin_unlock_irqrestore(&port->lock, flags);
1303 * Now we wait for the transmit buffer to clear; and we notify
1304 * the line discipline to only process XON/XOFF characters by
1305 * setting tty->closing.
1308 spin_unlock_irqrestore(&port->lock, flags);
1310 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
1312 * hack: open-coded tty_wait_until_sent to avoid
1313 * recursive tty_lock
1315 long timeout = msecs_to_jiffies(port->closing_wait);
1316 if (wait_event_interruptible_timeout(tty->write_wait,
1317 !tty_chars_in_buffer(tty), timeout) >= 0)
1318 __uart_wait_until_sent(uport, timeout);
1322 * At this point, we stop accepting input. To do this, we
1323 * disable the receive line status interrupts.
1325 if (port->flags & ASYNC_INITIALIZED) {
1326 unsigned long flags;
1327 spin_lock_irqsave(&uport->lock, flags);
1328 uport->ops->stop_rx(uport);
1329 spin_unlock_irqrestore(&uport->lock, flags);
1331 * Before we drop DTR, make sure the UART transmitter
1332 * has completely drained; this is especially
1333 * important if there is a transmit FIFO!
1335 __uart_wait_until_sent(uport, uport->timeout);
1338 uart_shutdown(tty, state);
1339 uart_flush_buffer(tty);
1341 tty_ldisc_flush(tty);
1343 tty_port_tty_set(port, NULL);
1344 spin_lock_irqsave(&port->lock, flags);
1347 if (port->blocked_open) {
1348 spin_unlock_irqrestore(&port->lock, flags);
1349 if (port->close_delay)
1350 msleep_interruptible(port->close_delay);
1351 spin_lock_irqsave(&port->lock, flags);
1352 } else if (!uart_console(uport)) {
1353 spin_unlock_irqrestore(&port->lock, flags);
1354 uart_change_pm(state, 3);
1355 spin_lock_irqsave(&port->lock, flags);
1359 * Wake up anyone trying to open this port.
1361 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1362 spin_unlock_irqrestore(&port->lock, flags);
1363 wake_up_interruptible(&port->open_wait);
1366 mutex_unlock(&port->mutex);
1369 static void __uart_wait_until_sent(struct uart_port *port, int timeout)
1371 unsigned long char_time, expire;
1373 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1377 * Set the check interval to be 1/5 of the estimated time to
1378 * send a single character, and make it at least 1. The check
1379 * interval should also be less than the timeout.
1381 * Note: we have to use pretty tight timings here to satisfy
1384 char_time = (port->timeout - HZ/50) / port->fifosize;
1385 char_time = char_time / 5;
1388 if (timeout && timeout < char_time)
1389 char_time = timeout;
1392 * If the transmitter hasn't cleared in twice the approximate
1393 * amount of time to send the entire FIFO, it probably won't
1394 * ever clear. This assumes the UART isn't doing flow
1395 * control, which is currently the case. Hence, if it ever
1396 * takes longer than port->timeout, this is probably due to a
1397 * UART bug of some kind. So, we clamp the timeout parameter at
1400 if (timeout == 0 || timeout > 2 * port->timeout)
1401 timeout = 2 * port->timeout;
1403 expire = jiffies + timeout;
1405 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1406 port->line, jiffies, expire);
1409 * Check whether the transmitter is empty every 'char_time'.
1410 * 'timeout' / 'expire' give us the maximum amount of time
1413 while (!port->ops->tx_empty(port)) {
1414 msleep_interruptible(jiffies_to_msecs(char_time));
1415 if (signal_pending(current))
1417 if (time_after(jiffies, expire))
1422 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1424 struct uart_state *state = tty->driver_data;
1425 struct uart_port *port = state->uart_port;
1428 __uart_wait_until_sent(port, timeout);
1433 * This is called with the BKL held in
1434 * linux/drivers/char/tty_io.c:do_tty_hangup()
1435 * We're called from the eventd thread, so we can sleep for
1436 * a _short_ time only.
1438 static void uart_hangup(struct tty_struct *tty)
1440 struct uart_state *state = tty->driver_data;
1441 struct tty_port *port = &state->port;
1442 unsigned long flags;
1444 BUG_ON(!tty_locked());
1445 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1447 mutex_lock(&port->mutex);
1448 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1449 uart_flush_buffer(tty);
1450 uart_shutdown(tty, state);
1451 spin_lock_irqsave(&port->lock, flags);
1453 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1454 spin_unlock_irqrestore(&port->lock, flags);
1455 tty_port_tty_set(port, NULL);
1456 wake_up_interruptible(&port->open_wait);
1457 wake_up_interruptible(&port->delta_msr_wait);
1459 mutex_unlock(&port->mutex);
1462 static int uart_carrier_raised(struct tty_port *port)
1464 struct uart_state *state = container_of(port, struct uart_state, port);
1465 struct uart_port *uport = state->uart_port;
1467 spin_lock_irq(&uport->lock);
1468 uport->ops->enable_ms(uport);
1469 mctrl = uport->ops->get_mctrl(uport);
1470 spin_unlock_irq(&uport->lock);
1471 if (mctrl & TIOCM_CAR)
1476 static void uart_dtr_rts(struct tty_port *port, int onoff)
1478 struct uart_state *state = container_of(port, struct uart_state, port);
1479 struct uart_port *uport = state->uart_port;
1482 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1484 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1487 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1489 struct uart_state *state;
1490 struct tty_port *port;
1493 state = drv->state + line;
1494 port = &state->port;
1495 if (mutex_lock_interruptible(&port->mutex)) {
1501 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1509 mutex_unlock(&port->mutex);
1511 return ERR_PTR(ret);
1515 * calls to uart_open are serialised by the BKL in
1516 * fs/char_dev.c:chrdev_open()
1517 * Note that if this fails, then uart_close() _will_ be called.
1519 * In time, we want to scrap the "opening nonpresent ports"
1520 * behaviour and implement an alternative way for setserial
1521 * to set base addresses/ports/types. This will allow us to
1522 * get rid of a certain amount of extra tests.
1524 static int uart_open(struct tty_struct *tty, struct file *filp)
1526 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1527 struct uart_state *state;
1528 struct tty_port *port;
1529 int retval, line = tty->index;
1531 BUG_ON(!tty_locked());
1532 pr_debug("uart_open(%d) called\n", line);
1535 * We take the semaphore inside uart_get to guarantee that we won't
1536 * be re-entered while allocating the state structure, or while we
1537 * request any IRQs that the driver may need. This also has the nice
1538 * side-effect that it delays the action of uart_hangup, so we can
1539 * guarantee that state->port.tty will always contain something
1542 state = uart_get(drv, line);
1543 if (IS_ERR(state)) {
1544 retval = PTR_ERR(state);
1547 port = &state->port;
1550 * Once we set tty->driver_data here, we are guaranteed that
1551 * uart_close() will decrement the driver module use count.
1552 * Any failures from here onwards should not touch the count.
1554 tty->driver_data = state;
1555 state->uart_port->state = state;
1556 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1558 tty_port_tty_set(port, tty);
1561 * If the port is in the middle of closing, bail out now.
1563 if (tty_hung_up_p(filp)) {
1566 mutex_unlock(&port->mutex);
1571 * Make sure the device is in D0 state.
1573 if (port->count == 1)
1574 uart_change_pm(state, 0);
1577 * Start up the serial port.
1579 retval = uart_startup(tty, state, 0);
1582 * If we succeeded, wait until the port is ready.
1584 mutex_unlock(&port->mutex);
1586 retval = tty_port_block_til_ready(port, tty, filp);
1592 static const char *uart_type(struct uart_port *port)
1594 const char *str = NULL;
1596 if (port->ops->type)
1597 str = port->ops->type(port);
1605 #ifdef CONFIG_PROC_FS
1607 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1609 struct uart_state *state = drv->state + i;
1610 struct tty_port *port = &state->port;
1612 struct uart_port *uport = state->uart_port;
1614 unsigned int status;
1620 mmio = uport->iotype >= UPIO_MEM;
1621 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1622 uport->line, uart_type(uport),
1623 mmio ? "mmio:0x" : "port:",
1624 mmio ? (unsigned long long)uport->mapbase
1625 : (unsigned long long)uport->iobase,
1628 if (uport->type == PORT_UNKNOWN) {
1633 if (capable(CAP_SYS_ADMIN)) {
1634 mutex_lock(&port->mutex);
1635 pm_state = state->pm_state;
1637 uart_change_pm(state, 0);
1638 spin_lock_irq(&uport->lock);
1639 status = uport->ops->get_mctrl(uport);
1640 spin_unlock_irq(&uport->lock);
1642 uart_change_pm(state, pm_state);
1643 mutex_unlock(&port->mutex);
1645 seq_printf(m, " tx:%d rx:%d",
1646 uport->icount.tx, uport->icount.rx);
1647 if (uport->icount.frame)
1648 seq_printf(m, " fe:%d",
1649 uport->icount.frame);
1650 if (uport->icount.parity)
1651 seq_printf(m, " pe:%d",
1652 uport->icount.parity);
1653 if (uport->icount.brk)
1654 seq_printf(m, " brk:%d",
1656 if (uport->icount.overrun)
1657 seq_printf(m, " oe:%d",
1658 uport->icount.overrun);
1660 #define INFOBIT(bit, str) \
1661 if (uport->mctrl & (bit)) \
1662 strncat(stat_buf, (str), sizeof(stat_buf) - \
1663 strlen(stat_buf) - 2)
1664 #define STATBIT(bit, str) \
1665 if (status & (bit)) \
1666 strncat(stat_buf, (str), sizeof(stat_buf) - \
1667 strlen(stat_buf) - 2)
1671 INFOBIT(TIOCM_RTS, "|RTS");
1672 STATBIT(TIOCM_CTS, "|CTS");
1673 INFOBIT(TIOCM_DTR, "|DTR");
1674 STATBIT(TIOCM_DSR, "|DSR");
1675 STATBIT(TIOCM_CAR, "|CD");
1676 STATBIT(TIOCM_RNG, "|RI");
1680 seq_puts(m, stat_buf);
1687 static int uart_proc_show(struct seq_file *m, void *v)
1689 struct tty_driver *ttydrv = m->private;
1690 struct uart_driver *drv = ttydrv->driver_state;
1693 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1695 for (i = 0; i < drv->nr; i++)
1696 uart_line_info(m, drv, i);
1700 static int uart_proc_open(struct inode *inode, struct file *file)
1702 return single_open(file, uart_proc_show, PDE(inode)->data);
1705 static const struct file_operations uart_proc_fops = {
1706 .owner = THIS_MODULE,
1707 .open = uart_proc_open,
1709 .llseek = seq_lseek,
1710 .release = single_release,
1714 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1716 * uart_console_write - write a console message to a serial port
1717 * @port: the port to write the message
1718 * @s: array of characters
1719 * @count: number of characters in string to write
1720 * @write: function to write character to port
1722 void uart_console_write(struct uart_port *port, const char *s,
1724 void (*putchar)(struct uart_port *, int))
1728 for (i = 0; i < count; i++, s++) {
1730 putchar(port, '\r');
1734 EXPORT_SYMBOL_GPL(uart_console_write);
1737 * Check whether an invalid uart number has been specified, and
1738 * if so, search for the first available port that does have
1741 struct uart_port * __init
1742 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1744 int idx = co->index;
1746 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1747 ports[idx].membase == NULL))
1748 for (idx = 0; idx < nr; idx++)
1749 if (ports[idx].iobase != 0 ||
1750 ports[idx].membase != NULL)
1759 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1760 * @options: pointer to option string
1761 * @baud: pointer to an 'int' variable for the baud rate.
1762 * @parity: pointer to an 'int' variable for the parity.
1763 * @bits: pointer to an 'int' variable for the number of data bits.
1764 * @flow: pointer to an 'int' variable for the flow control character.
1766 * uart_parse_options decodes a string containing the serial console
1767 * options. The format of the string is <baud><parity><bits><flow>,
1771 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1775 *baud = simple_strtoul(s, NULL, 10);
1776 while (*s >= '0' && *s <= '9')
1785 EXPORT_SYMBOL_GPL(uart_parse_options);
1792 static const struct baud_rates baud_rates[] = {
1793 { 921600, B921600 },
1794 { 460800, B460800 },
1795 { 230400, B230400 },
1796 { 115200, B115200 },
1808 * uart_set_options - setup the serial console parameters
1809 * @port: pointer to the serial ports uart_port structure
1810 * @co: console pointer
1812 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1813 * @bits: number of data bits
1814 * @flow: flow control character - 'r' (rts)
1817 uart_set_options(struct uart_port *port, struct console *co,
1818 int baud, int parity, int bits, int flow)
1820 struct ktermios termios;
1821 static struct ktermios dummy;
1825 * Ensure that the serial console lock is initialised
1828 spin_lock_init(&port->lock);
1829 lockdep_set_class(&port->lock, &port_lock_key);
1831 memset(&termios, 0, sizeof(struct ktermios));
1833 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1836 * Construct a cflag setting.
1838 for (i = 0; baud_rates[i].rate; i++)
1839 if (baud_rates[i].rate <= baud)
1842 termios.c_cflag |= baud_rates[i].cflag;
1845 termios.c_cflag |= CS7;
1847 termios.c_cflag |= CS8;
1851 termios.c_cflag |= PARODD;
1854 termios.c_cflag |= PARENB;
1859 termios.c_cflag |= CRTSCTS;
1862 * some uarts on other side don't support no flow control.
1863 * So we set * DTR in host uart to make them happy
1865 port->mctrl |= TIOCM_DTR;
1867 port->ops->set_termios(port, &termios, &dummy);
1869 * Allow the setting of the UART parameters with a NULL console
1873 co->cflag = termios.c_cflag;
1877 EXPORT_SYMBOL_GPL(uart_set_options);
1878 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1880 static void uart_change_pm(struct uart_state *state, int pm_state)
1882 struct uart_port *port = state->uart_port;
1884 if (state->pm_state != pm_state) {
1886 port->ops->pm(port, pm_state, state->pm_state);
1887 state->pm_state = pm_state;
1892 struct uart_port *port;
1893 struct uart_driver *driver;
1896 static int serial_match_port(struct device *dev, void *data)
1898 struct uart_match *match = data;
1899 struct tty_driver *tty_drv = match->driver->tty_driver;
1900 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1903 return dev->devt == devt; /* Actually, only one tty per port */
1906 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1908 struct uart_state *state = drv->state + uport->line;
1909 struct tty_port *port = &state->port;
1910 struct device *tty_dev;
1911 struct uart_match match = {uport, drv};
1913 mutex_lock(&port->mutex);
1915 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1916 if (device_may_wakeup(tty_dev)) {
1917 if (!enable_irq_wake(uport->irq))
1918 uport->irq_wake = 1;
1919 put_device(tty_dev);
1920 mutex_unlock(&port->mutex);
1923 if (console_suspend_enabled || !uart_console(uport))
1924 uport->suspended = 1;
1926 if (port->flags & ASYNC_INITIALIZED) {
1927 const struct uart_ops *ops = uport->ops;
1930 if (console_suspend_enabled || !uart_console(uport)) {
1931 set_bit(ASYNCB_SUSPENDED, &port->flags);
1932 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1934 spin_lock_irq(&uport->lock);
1935 ops->stop_tx(uport);
1936 ops->set_mctrl(uport, 0);
1937 ops->stop_rx(uport);
1938 spin_unlock_irq(&uport->lock);
1942 * Wait for the transmitter to empty.
1944 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1947 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1949 uport->dev ? dev_name(uport->dev) : "",
1950 uport->dev ? ": " : "",
1952 drv->tty_driver->name_base + uport->line);
1954 if (console_suspend_enabled || !uart_console(uport))
1955 ops->shutdown(uport);
1959 * Disable the console device before suspending.
1961 if (console_suspend_enabled && uart_console(uport))
1962 console_stop(uport->cons);
1964 if (console_suspend_enabled || !uart_console(uport))
1965 uart_change_pm(state, 3);
1967 mutex_unlock(&port->mutex);
1972 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1974 struct uart_state *state = drv->state + uport->line;
1975 struct tty_port *port = &state->port;
1976 struct device *tty_dev;
1977 struct uart_match match = {uport, drv};
1978 struct ktermios termios;
1980 mutex_lock(&port->mutex);
1982 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1983 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1984 if (uport->irq_wake) {
1985 disable_irq_wake(uport->irq);
1986 uport->irq_wake = 0;
1988 mutex_unlock(&port->mutex);
1991 uport->suspended = 0;
1994 * Re-enable the console device after suspending.
1996 if (uart_console(uport)) {
1998 * First try to use the console cflag setting.
2000 memset(&termios, 0, sizeof(struct ktermios));
2001 termios.c_cflag = uport->cons->cflag;
2004 * If that's unset, use the tty termios setting.
2006 if (port->tty && port->tty->termios && termios.c_cflag == 0)
2007 termios = *(port->tty->termios);
2009 if (console_suspend_enabled)
2010 uart_change_pm(state, 0);
2011 uport->ops->set_termios(uport, &termios, NULL);
2012 if (console_suspend_enabled)
2013 console_start(uport->cons);
2016 if (port->flags & ASYNC_SUSPENDED) {
2017 const struct uart_ops *ops = uport->ops;
2020 uart_change_pm(state, 0);
2021 spin_lock_irq(&uport->lock);
2022 ops->set_mctrl(uport, 0);
2023 spin_unlock_irq(&uport->lock);
2024 if (console_suspend_enabled || !uart_console(uport)) {
2025 /* Protected by port mutex for now */
2026 struct tty_struct *tty = port->tty;
2027 ret = ops->startup(uport);
2030 uart_change_speed(tty, state, NULL);
2031 spin_lock_irq(&uport->lock);
2032 ops->set_mctrl(uport, uport->mctrl);
2033 ops->start_tx(uport);
2034 spin_unlock_irq(&uport->lock);
2035 set_bit(ASYNCB_INITIALIZED, &port->flags);
2038 * Failed to resume - maybe hardware went away?
2039 * Clear the "initialized" flag so we won't try
2040 * to call the low level drivers shutdown method.
2042 uart_shutdown(tty, state);
2046 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2049 mutex_unlock(&port->mutex);
2055 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2059 switch (port->iotype) {
2061 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2064 snprintf(address, sizeof(address),
2065 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2073 snprintf(address, sizeof(address),
2074 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2077 strlcpy(address, "*unknown*", sizeof(address));
2081 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2082 port->dev ? dev_name(port->dev) : "",
2083 port->dev ? ": " : "",
2085 drv->tty_driver->name_base + port->line,
2086 address, port->irq, uart_type(port));
2090 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2091 struct uart_port *port)
2096 * If there isn't a port here, don't do anything further.
2098 if (!port->iobase && !port->mapbase && !port->membase)
2102 * Now do the auto configuration stuff. Note that config_port
2103 * is expected to claim the resources and map the port for us.
2106 if (port->flags & UPF_AUTO_IRQ)
2107 flags |= UART_CONFIG_IRQ;
2108 if (port->flags & UPF_BOOT_AUTOCONF) {
2109 if (!(port->flags & UPF_FIXED_TYPE)) {
2110 port->type = PORT_UNKNOWN;
2111 flags |= UART_CONFIG_TYPE;
2113 port->ops->config_port(port, flags);
2116 if (port->type != PORT_UNKNOWN) {
2117 unsigned long flags;
2119 uart_report_port(drv, port);
2121 /* Power up port for set_mctrl() */
2122 uart_change_pm(state, 0);
2125 * Ensure that the modem control lines are de-activated.
2126 * keep the DTR setting that is set in uart_set_options()
2127 * We probably don't need a spinlock around this, but
2129 spin_lock_irqsave(&port->lock, flags);
2130 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2131 spin_unlock_irqrestore(&port->lock, flags);
2134 * If this driver supports console, and it hasn't been
2135 * successfully registered yet, try to re-register it.
2136 * It may be that the port was not available.
2138 if (port->cons && !(port->cons->flags & CON_ENABLED))
2139 register_console(port->cons);
2142 * Power down all ports by default, except the
2143 * console if we have one.
2145 if (!uart_console(port))
2146 uart_change_pm(state, 3);
2150 #ifdef CONFIG_CONSOLE_POLL
2152 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2154 struct uart_driver *drv = driver->driver_state;
2155 struct uart_state *state = drv->state + line;
2156 struct uart_port *port;
2162 if (!state || !state->uart_port)
2165 port = state->uart_port;
2166 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2170 uart_parse_options(options, &baud, &parity, &bits, &flow);
2171 return uart_set_options(port, NULL, baud, parity, bits, flow);
2177 static int uart_poll_get_char(struct tty_driver *driver, int line)
2179 struct uart_driver *drv = driver->driver_state;
2180 struct uart_state *state = drv->state + line;
2181 struct uart_port *port;
2183 if (!state || !state->uart_port)
2186 port = state->uart_port;
2187 return port->ops->poll_get_char(port);
2190 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2192 struct uart_driver *drv = driver->driver_state;
2193 struct uart_state *state = drv->state + line;
2194 struct uart_port *port;
2196 if (!state || !state->uart_port)
2199 port = state->uart_port;
2200 port->ops->poll_put_char(port, ch);
2204 static const struct tty_operations uart_ops = {
2206 .close = uart_close,
2207 .write = uart_write,
2208 .put_char = uart_put_char,
2209 .flush_chars = uart_flush_chars,
2210 .write_room = uart_write_room,
2211 .chars_in_buffer= uart_chars_in_buffer,
2212 .flush_buffer = uart_flush_buffer,
2213 .ioctl = uart_ioctl,
2214 .throttle = uart_throttle,
2215 .unthrottle = uart_unthrottle,
2216 .send_xchar = uart_send_xchar,
2217 .set_termios = uart_set_termios,
2218 .set_ldisc = uart_set_ldisc,
2220 .start = uart_start,
2221 .hangup = uart_hangup,
2222 .break_ctl = uart_break_ctl,
2223 .wait_until_sent= uart_wait_until_sent,
2224 #ifdef CONFIG_PROC_FS
2225 .proc_fops = &uart_proc_fops,
2227 .tiocmget = uart_tiocmget,
2228 .tiocmset = uart_tiocmset,
2229 .get_icount = uart_get_icount,
2230 #ifdef CONFIG_CONSOLE_POLL
2231 .poll_init = uart_poll_init,
2232 .poll_get_char = uart_poll_get_char,
2233 .poll_put_char = uart_poll_put_char,
2237 static const struct tty_port_operations uart_port_ops = {
2238 .carrier_raised = uart_carrier_raised,
2239 .dtr_rts = uart_dtr_rts,
2243 * uart_register_driver - register a driver with the uart core layer
2244 * @drv: low level driver structure
2246 * Register a uart driver with the core driver. We in turn register
2247 * with the tty layer, and initialise the core driver per-port state.
2249 * We have a proc file in /proc/tty/driver which is named after the
2252 * drv->port should be NULL, and the per-port structures should be
2253 * registered using uart_add_one_port after this call has succeeded.
2255 int uart_register_driver(struct uart_driver *drv)
2257 struct tty_driver *normal;
2263 * Maybe we should be using a slab cache for this, especially if
2264 * we have a large number of ports to handle.
2266 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2270 normal = alloc_tty_driver(drv->nr);
2274 drv->tty_driver = normal;
2276 normal->owner = drv->owner;
2277 normal->driver_name = drv->driver_name;
2278 normal->name = drv->dev_name;
2279 normal->major = drv->major;
2280 normal->minor_start = drv->minor;
2281 normal->type = TTY_DRIVER_TYPE_SERIAL;
2282 normal->subtype = SERIAL_TYPE_NORMAL;
2283 normal->init_termios = tty_std_termios;
2284 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2285 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2286 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2287 normal->driver_state = drv;
2288 tty_set_operations(normal, &uart_ops);
2291 * Initialise the UART state(s).
2293 for (i = 0; i < drv->nr; i++) {
2294 struct uart_state *state = drv->state + i;
2295 struct tty_port *port = &state->port;
2297 tty_port_init(port);
2298 port->ops = &uart_port_ops;
2299 port->close_delay = 500; /* .5 seconds */
2300 port->closing_wait = 30000; /* 30 seconds */
2301 tasklet_init(&state->tlet, uart_tasklet_action,
2302 (unsigned long)state);
2305 retval = tty_register_driver(normal);
2309 put_tty_driver(normal);
2317 * uart_unregister_driver - remove a driver from the uart core layer
2318 * @drv: low level driver structure
2320 * Remove all references to a driver from the core driver. The low
2321 * level driver must have removed all its ports via the
2322 * uart_remove_one_port() if it registered them with uart_add_one_port().
2323 * (ie, drv->port == NULL)
2325 void uart_unregister_driver(struct uart_driver *drv)
2327 struct tty_driver *p = drv->tty_driver;
2328 tty_unregister_driver(p);
2332 drv->tty_driver = NULL;
2335 struct tty_driver *uart_console_device(struct console *co, int *index)
2337 struct uart_driver *p = co->data;
2339 return p->tty_driver;
2343 * uart_add_one_port - attach a driver-defined port structure
2344 * @drv: pointer to the uart low level driver structure for this port
2345 * @uport: uart port structure to use for this port.
2347 * This allows the driver to register its own uart_port structure
2348 * with the core driver. The main purpose is to allow the low
2349 * level uart drivers to expand uart_port, rather than having yet
2350 * more levels of structures.
2352 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2354 struct uart_state *state;
2355 struct tty_port *port;
2357 struct device *tty_dev;
2359 BUG_ON(in_interrupt());
2361 if (uport->line >= drv->nr)
2364 state = drv->state + uport->line;
2365 port = &state->port;
2367 mutex_lock(&port_mutex);
2368 mutex_lock(&port->mutex);
2369 if (state->uart_port) {
2374 state->uart_port = uport;
2375 state->pm_state = -1;
2377 uport->cons = drv->cons;
2378 uport->state = state;
2381 * If this port is a console, then the spinlock is already
2384 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2385 spin_lock_init(&uport->lock);
2386 lockdep_set_class(&uport->lock, &port_lock_key);
2389 uart_configure_port(drv, state, uport);
2392 * Register the port whether it's detected or not. This allows
2393 * setserial to be used to alter this ports parameters.
2395 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2396 if (likely(!IS_ERR(tty_dev))) {
2397 device_init_wakeup(tty_dev, 1);
2398 device_set_wakeup_enable(tty_dev, 0);
2400 printk(KERN_ERR "Cannot register tty device on line %d\n",
2404 * Ensure UPF_DEAD is not set.
2406 uport->flags &= ~UPF_DEAD;
2409 mutex_unlock(&port->mutex);
2410 mutex_unlock(&port_mutex);
2416 * uart_remove_one_port - detach a driver defined port structure
2417 * @drv: pointer to the uart low level driver structure for this port
2418 * @uport: uart port structure for this port
2420 * This unhooks (and hangs up) the specified port structure from the
2421 * core driver. No further calls will be made to the low-level code
2424 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2426 struct uart_state *state = drv->state + uport->line;
2427 struct tty_port *port = &state->port;
2429 BUG_ON(in_interrupt());
2431 if (state->uart_port != uport)
2432 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2433 state->uart_port, uport);
2435 mutex_lock(&port_mutex);
2438 * Mark the port "dead" - this prevents any opens from
2439 * succeeding while we shut down the port.
2441 mutex_lock(&port->mutex);
2442 uport->flags |= UPF_DEAD;
2443 mutex_unlock(&port->mutex);
2446 * Remove the devices from the tty layer
2448 tty_unregister_device(drv->tty_driver, uport->line);
2451 tty_vhangup(port->tty);
2454 * Free the port IO and memory resources, if any.
2456 if (uport->type != PORT_UNKNOWN)
2457 uport->ops->release_port(uport);
2460 * Indicate that there isn't a port here anymore.
2462 uport->type = PORT_UNKNOWN;
2465 * Kill the tasklet, and free resources.
2467 tasklet_kill(&state->tlet);
2469 state->uart_port = NULL;
2470 mutex_unlock(&port_mutex);
2476 * Are the two ports equivalent?
2478 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2480 if (port1->iotype != port2->iotype)
2483 switch (port1->iotype) {
2485 return (port1->iobase == port2->iobase);
2487 return (port1->iobase == port2->iobase) &&
2488 (port1->hub6 == port2->hub6);
2495 return (port1->mapbase == port2->mapbase);
2499 EXPORT_SYMBOL(uart_match_port);
2501 EXPORT_SYMBOL(uart_write_wakeup);
2502 EXPORT_SYMBOL(uart_register_driver);
2503 EXPORT_SYMBOL(uart_unregister_driver);
2504 EXPORT_SYMBOL(uart_suspend_port);
2505 EXPORT_SYMBOL(uart_resume_port);
2506 EXPORT_SYMBOL(uart_add_one_port);
2507 EXPORT_SYMBOL(uart_remove_one_port);
2509 MODULE_DESCRIPTION("Serial driver core");
2510 MODULE_LICENSE("GPL");