2 * linux/drivers/char/core.c
4 * Driver core for serial ports
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 * Copyright 1999 ARM Limited
9 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/module.h>
26 #include <linux/tty.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/device.h>
33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34 #include <linux/serial_core.h>
35 #include <linux/delay.h>
36 #include <linux/mutex.h>
39 #include <asm/uaccess.h>
42 * This is used to lock changes in serial line configuration.
44 static DEFINE_MUTEX(port_mutex);
47 * lockdep: port->lock is initialized in two places, but we
48 * want only one lock-class:
50 static struct lock_class_key port_lock_key;
52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
54 #ifdef CONFIG_SERIAL_CORE_CONSOLE
55 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
57 #define uart_console(port) (0)
60 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
61 struct ktermios *old_termios);
62 static void __uart_wait_until_sent(struct uart_port *port, int timeout);
63 static void uart_change_pm(struct uart_state *state, int pm_state);
66 * This routine is used by the interrupt handler to schedule processing in
67 * the software interrupt portion of the driver.
69 void uart_write_wakeup(struct uart_port *port)
71 struct uart_state *state = port->state;
73 * This means you called this function _after_ the port was
74 * closed. No cookie for you.
77 tasklet_schedule(&state->tlet);
80 static void uart_stop(struct tty_struct *tty)
82 struct uart_state *state = tty->driver_data;
83 struct uart_port *port = state->uart_port;
86 spin_lock_irqsave(&port->lock, flags);
87 port->ops->stop_tx(port);
88 spin_unlock_irqrestore(&port->lock, flags);
91 static void __uart_start(struct tty_struct *tty)
93 struct uart_state *state = tty->driver_data;
94 struct uart_port *port = state->uart_port;
96 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
97 !tty->stopped && !tty->hw_stopped)
98 port->ops->start_tx(port);
101 static void uart_start(struct tty_struct *tty)
103 struct uart_state *state = tty->driver_data;
104 struct uart_port *port = state->uart_port;
107 spin_lock_irqsave(&port->lock, flags);
109 spin_unlock_irqrestore(&port->lock, flags);
112 static void uart_tasklet_action(unsigned long data)
114 struct uart_state *state = (struct uart_state *)data;
115 tty_wakeup(state->port.tty);
119 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
124 spin_lock_irqsave(&port->lock, flags);
126 port->mctrl = (old & ~clear) | set;
127 if (old != port->mctrl)
128 port->ops->set_mctrl(port, port->mctrl);
129 spin_unlock_irqrestore(&port->lock, flags);
132 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
133 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
136 * Startup the port. This will be called once per open. All calls
137 * will be serialised by the per-port mutex.
139 static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
141 struct uart_port *uport = state->uart_port;
142 struct tty_port *port = &state->port;
146 if (port->flags & ASYNC_INITIALIZED)
150 * Set the TTY IO error marker - we will only clear this
151 * once we have successfully opened the port. Also set
152 * up the tty->alt_speed kludge
154 set_bit(TTY_IO_ERROR, &tty->flags);
156 if (uport->type == PORT_UNKNOWN)
160 * Initialise and allocate the transmit and temporary
163 if (!state->xmit.buf) {
164 /* This is protected by the per port mutex */
165 page = get_zeroed_page(GFP_KERNEL);
169 state->xmit.buf = (unsigned char *) page;
170 uart_circ_clear(&state->xmit);
173 retval = uport->ops->startup(uport);
177 * Initialise the hardware port settings.
179 uart_change_speed(tty, state, NULL);
182 * Setup the RTS and DTR signals once the
183 * port is open and ready to respond.
185 if (tty->termios->c_cflag & CBAUD)
186 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
189 if (port->flags & ASYNC_CTS_FLOW) {
190 spin_lock_irq(&uport->lock);
191 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
193 spin_unlock_irq(&uport->lock);
196 set_bit(ASYNCB_INITIALIZED, &port->flags);
198 clear_bit(TTY_IO_ERROR, &tty->flags);
201 if (retval && capable(CAP_SYS_ADMIN))
208 * This routine will shutdown a serial port; interrupts are disabled, and
209 * DTR is dropped if the hangup on close termio flag is on. Calls to
210 * uart_shutdown are serialised by the per-port semaphore.
212 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
214 struct uart_port *uport = state->uart_port;
215 struct tty_port *port = &state->port;
218 * Set the TTY IO error marker
221 set_bit(TTY_IO_ERROR, &tty->flags);
223 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
225 * Turn off DTR and RTS early.
227 if (!tty || (tty->termios->c_cflag & HUPCL))
228 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
231 * clear delta_msr_wait queue to avoid mem leaks: we may free
232 * the irq here so the queue might never be woken up. Note
233 * that we won't end up waiting on delta_msr_wait again since
234 * any outstanding file descriptors should be pointing at
235 * hung_up_tty_fops now.
237 wake_up_interruptible(&port->delta_msr_wait);
240 * Free the IRQ and disable the port.
242 uport->ops->shutdown(uport);
245 * Ensure that the IRQ handler isn't running on another CPU.
247 synchronize_irq(uport->irq);
251 * kill off our tasklet
253 tasklet_kill(&state->tlet);
256 * Free the transmit buffer page.
258 if (state->xmit.buf) {
259 free_page((unsigned long)state->xmit.buf);
260 state->xmit.buf = NULL;
265 * uart_update_timeout - update per-port FIFO timeout.
266 * @port: uart_port structure describing the port
267 * @cflag: termios cflag value
268 * @baud: speed of the port
270 * Set the port FIFO timeout value. The @cflag value should
271 * reflect the actual hardware settings.
274 uart_update_timeout(struct uart_port *port, unsigned int cflag,
279 /* byte size and parity */
280 switch (cflag & CSIZE) {
301 * The total number of bits to be transmitted in the fifo.
303 bits = bits * port->fifosize;
306 * Figure the timeout to send the above number of bits.
307 * Add .02 seconds of slop
309 port->timeout = (HZ * bits) / baud + HZ/50;
312 EXPORT_SYMBOL(uart_update_timeout);
315 * uart_get_baud_rate - return baud rate for a particular port
316 * @port: uart_port structure describing the port in question.
317 * @termios: desired termios settings.
318 * @old: old termios (or NULL)
319 * @min: minimum acceptable baud rate
320 * @max: maximum acceptable baud rate
322 * Decode the termios structure into a numeric baud rate,
323 * taking account of the magic 38400 baud rate (with spd_*
324 * flags), and mapping the %B0 rate to 9600 baud.
326 * If the new baud rate is invalid, try the old termios setting.
327 * If it's still invalid, we try 9600 baud.
329 * Update the @termios structure to reflect the baud rate
330 * we're actually going to be using. Don't do this for the case
331 * where B0 is requested ("hang up").
334 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
335 struct ktermios *old, unsigned int min, unsigned int max)
337 unsigned int try, baud, altbaud = 38400;
339 upf_t flags = port->flags & UPF_SPD_MASK;
341 if (flags == UPF_SPD_HI)
343 else if (flags == UPF_SPD_VHI)
345 else if (flags == UPF_SPD_SHI)
347 else if (flags == UPF_SPD_WARP)
350 for (try = 0; try < 2; try++) {
351 baud = tty_termios_baud_rate(termios);
354 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
361 * Special case: B0 rate.
368 if (baud >= min && baud <= max)
372 * Oops, the quotient was zero. Try again with
373 * the old baud rate if possible.
375 termios->c_cflag &= ~CBAUD;
377 baud = tty_termios_baud_rate(old);
379 tty_termios_encode_baud_rate(termios,
386 * As a last resort, if the range cannot be met then clip to
387 * the nearest chip supported rate.
391 tty_termios_encode_baud_rate(termios,
394 tty_termios_encode_baud_rate(termios,
398 /* Should never happen */
403 EXPORT_SYMBOL(uart_get_baud_rate);
406 * uart_get_divisor - return uart clock divisor
407 * @port: uart_port structure describing the port.
408 * @baud: desired baud rate
410 * Calculate the uart clock divisor for the port.
413 uart_get_divisor(struct uart_port *port, unsigned int baud)
418 * Old custom speed handling.
420 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
421 quot = port->custom_divisor;
423 quot = (port->uartclk + (8 * baud)) / (16 * baud);
428 EXPORT_SYMBOL(uart_get_divisor);
430 /* FIXME: Consistent locking policy */
431 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
432 struct ktermios *old_termios)
434 struct tty_port *port = &state->port;
435 struct uart_port *uport = state->uart_port;
436 struct ktermios *termios;
439 * If we have no tty, termios, or the port does not exist,
440 * then we can't set the parameters for this port.
442 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
445 termios = tty->termios;
448 * Set flags based on termios cflag
450 if (termios->c_cflag & CRTSCTS)
451 set_bit(ASYNCB_CTS_FLOW, &port->flags);
453 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
455 if (termios->c_cflag & CLOCAL)
456 clear_bit(ASYNCB_CHECK_CD, &port->flags);
458 set_bit(ASYNCB_CHECK_CD, &port->flags);
460 uport->ops->set_termios(uport, termios, old_termios);
463 static inline int __uart_put_char(struct uart_port *port,
464 struct circ_buf *circ, unsigned char c)
472 spin_lock_irqsave(&port->lock, flags);
473 if (uart_circ_chars_free(circ) != 0) {
474 circ->buf[circ->head] = c;
475 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
478 spin_unlock_irqrestore(&port->lock, flags);
482 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
484 struct uart_state *state = tty->driver_data;
486 return __uart_put_char(state->uart_port, &state->xmit, ch);
489 static void uart_flush_chars(struct tty_struct *tty)
494 static int uart_write(struct tty_struct *tty,
495 const unsigned char *buf, int count)
497 struct uart_state *state = tty->driver_data;
498 struct uart_port *port;
499 struct circ_buf *circ;
504 * This means you called this function _after_ the port was
505 * closed. No cookie for you.
512 port = state->uart_port;
518 spin_lock_irqsave(&port->lock, flags);
520 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
525 memcpy(circ->buf + circ->head, buf, c);
526 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
531 spin_unlock_irqrestore(&port->lock, flags);
537 static int uart_write_room(struct tty_struct *tty)
539 struct uart_state *state = tty->driver_data;
543 spin_lock_irqsave(&state->uart_port->lock, flags);
544 ret = uart_circ_chars_free(&state->xmit);
545 spin_unlock_irqrestore(&state->uart_port->lock, flags);
549 static int uart_chars_in_buffer(struct tty_struct *tty)
551 struct uart_state *state = tty->driver_data;
555 spin_lock_irqsave(&state->uart_port->lock, flags);
556 ret = uart_circ_chars_pending(&state->xmit);
557 spin_unlock_irqrestore(&state->uart_port->lock, flags);
561 static void uart_flush_buffer(struct tty_struct *tty)
563 struct uart_state *state = tty->driver_data;
564 struct uart_port *port;
568 * This means you called this function _after_ the port was
569 * closed. No cookie for you.
576 port = state->uart_port;
577 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
579 spin_lock_irqsave(&port->lock, flags);
580 uart_circ_clear(&state->xmit);
581 if (port->ops->flush_buffer)
582 port->ops->flush_buffer(port);
583 spin_unlock_irqrestore(&port->lock, flags);
588 * This function is used to send a high-priority XON/XOFF character to
591 static void uart_send_xchar(struct tty_struct *tty, char ch)
593 struct uart_state *state = tty->driver_data;
594 struct uart_port *port = state->uart_port;
597 if (port->ops->send_xchar)
598 port->ops->send_xchar(port, ch);
602 spin_lock_irqsave(&port->lock, flags);
603 port->ops->start_tx(port);
604 spin_unlock_irqrestore(&port->lock, flags);
609 static void uart_throttle(struct tty_struct *tty)
611 struct uart_state *state = tty->driver_data;
614 uart_send_xchar(tty, STOP_CHAR(tty));
616 if (tty->termios->c_cflag & CRTSCTS)
617 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
620 static void uart_unthrottle(struct tty_struct *tty)
622 struct uart_state *state = tty->driver_data;
623 struct uart_port *port = state->uart_port;
629 uart_send_xchar(tty, START_CHAR(tty));
632 if (tty->termios->c_cflag & CRTSCTS)
633 uart_set_mctrl(port, TIOCM_RTS);
636 static int uart_get_info(struct uart_state *state,
637 struct serial_struct __user *retinfo)
639 struct uart_port *uport = state->uart_port;
640 struct tty_port *port = &state->port;
641 struct serial_struct tmp;
643 memset(&tmp, 0, sizeof(tmp));
645 /* Ensure the state we copy is consistent and no hardware changes
647 mutex_lock(&port->mutex);
649 tmp.type = uport->type;
650 tmp.line = uport->line;
651 tmp.port = uport->iobase;
652 if (HIGH_BITS_OFFSET)
653 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
654 tmp.irq = uport->irq;
655 tmp.flags = uport->flags;
656 tmp.xmit_fifo_size = uport->fifosize;
657 tmp.baud_base = uport->uartclk / 16;
658 tmp.close_delay = port->close_delay / 10;
659 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
660 ASYNC_CLOSING_WAIT_NONE :
661 port->closing_wait / 10;
662 tmp.custom_divisor = uport->custom_divisor;
663 tmp.hub6 = uport->hub6;
664 tmp.io_type = uport->iotype;
665 tmp.iomem_reg_shift = uport->regshift;
666 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
668 mutex_unlock(&port->mutex);
670 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
675 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
676 struct serial_struct __user *newinfo)
678 struct serial_struct new_serial;
679 struct uart_port *uport = state->uart_port;
680 struct tty_port *port = &state->port;
681 unsigned long new_port;
682 unsigned int change_irq, change_port, closing_wait;
683 unsigned int old_custom_divisor, close_delay;
684 upf_t old_flags, new_flags;
687 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
690 new_port = new_serial.port;
691 if (HIGH_BITS_OFFSET)
692 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
694 new_serial.irq = irq_canonicalize(new_serial.irq);
695 close_delay = new_serial.close_delay * 10;
696 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
697 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
700 * This semaphore protects port->count. It is also
701 * very useful to prevent opens. Also, take the
702 * port configuration semaphore to make sure that a
703 * module insertion/removal doesn't change anything
706 mutex_lock(&port->mutex);
708 change_irq = !(uport->flags & UPF_FIXED_PORT)
709 && new_serial.irq != uport->irq;
712 * Since changing the 'type' of the port changes its resource
713 * allocations, we should treat type changes the same as
716 change_port = !(uport->flags & UPF_FIXED_PORT)
717 && (new_port != uport->iobase ||
718 (unsigned long)new_serial.iomem_base != uport->mapbase ||
719 new_serial.hub6 != uport->hub6 ||
720 new_serial.io_type != uport->iotype ||
721 new_serial.iomem_reg_shift != uport->regshift ||
722 new_serial.type != uport->type);
724 old_flags = uport->flags;
725 new_flags = new_serial.flags;
726 old_custom_divisor = uport->custom_divisor;
728 if (!capable(CAP_SYS_ADMIN)) {
730 if (change_irq || change_port ||
731 (new_serial.baud_base != uport->uartclk / 16) ||
732 (close_delay != port->close_delay) ||
733 (closing_wait != port->closing_wait) ||
734 (new_serial.xmit_fifo_size &&
735 new_serial.xmit_fifo_size != uport->fifosize) ||
736 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
738 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
739 (new_flags & UPF_USR_MASK));
740 uport->custom_divisor = new_serial.custom_divisor;
745 * Ask the low level driver to verify the settings.
747 if (uport->ops->verify_port)
748 retval = uport->ops->verify_port(uport, &new_serial);
750 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
751 (new_serial.baud_base < 9600))
757 if (change_port || change_irq) {
761 * Make sure that we are the sole user of this port.
763 if (tty_port_users(port) > 1)
767 * We need to shutdown the serial port at the old
768 * port/type/irq combination.
770 uart_shutdown(tty, state);
774 unsigned long old_iobase, old_mapbase;
775 unsigned int old_type, old_iotype, old_hub6, old_shift;
777 old_iobase = uport->iobase;
778 old_mapbase = uport->mapbase;
779 old_type = uport->type;
780 old_hub6 = uport->hub6;
781 old_iotype = uport->iotype;
782 old_shift = uport->regshift;
785 * Free and release old regions
787 if (old_type != PORT_UNKNOWN)
788 uport->ops->release_port(uport);
790 uport->iobase = new_port;
791 uport->type = new_serial.type;
792 uport->hub6 = new_serial.hub6;
793 uport->iotype = new_serial.io_type;
794 uport->regshift = new_serial.iomem_reg_shift;
795 uport->mapbase = (unsigned long)new_serial.iomem_base;
798 * Claim and map the new regions
800 if (uport->type != PORT_UNKNOWN) {
801 retval = uport->ops->request_port(uport);
803 /* Always success - Jean II */
808 * If we fail to request resources for the
809 * new port, try to restore the old settings.
811 if (retval && old_type != PORT_UNKNOWN) {
812 uport->iobase = old_iobase;
813 uport->type = old_type;
814 uport->hub6 = old_hub6;
815 uport->iotype = old_iotype;
816 uport->regshift = old_shift;
817 uport->mapbase = old_mapbase;
818 retval = uport->ops->request_port(uport);
820 * If we failed to restore the old settings,
824 uport->type = PORT_UNKNOWN;
830 /* Added to return the correct error -Ram Gupta */
836 uport->irq = new_serial.irq;
837 if (!(uport->flags & UPF_FIXED_PORT))
838 uport->uartclk = new_serial.baud_base * 16;
839 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
840 (new_flags & UPF_CHANGE_MASK);
841 uport->custom_divisor = new_serial.custom_divisor;
842 port->close_delay = close_delay;
843 port->closing_wait = closing_wait;
844 if (new_serial.xmit_fifo_size)
845 uport->fifosize = new_serial.xmit_fifo_size;
847 port->tty->low_latency =
848 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
852 if (uport->type == PORT_UNKNOWN)
854 if (port->flags & ASYNC_INITIALIZED) {
855 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
856 old_custom_divisor != uport->custom_divisor) {
858 * If they're setting up a custom divisor or speed,
859 * instead of clearing it, then bitch about it. No
860 * need to rate-limit; it's CAP_SYS_ADMIN only.
862 if (uport->flags & UPF_SPD_MASK) {
865 "%s sets custom speed on %s. This "
866 "is deprecated.\n", current->comm,
867 tty_name(port->tty, buf));
869 uart_change_speed(tty, state, NULL);
872 retval = uart_startup(tty, state, 1);
874 mutex_unlock(&port->mutex);
879 * uart_get_lsr_info - get line status register info
880 * @tty: tty associated with the UART
881 * @state: UART being queried
882 * @value: returned modem value
884 * Note: uart_ioctl protects us against hangups.
886 static int uart_get_lsr_info(struct tty_struct *tty,
887 struct uart_state *state, unsigned int __user *value)
889 struct uart_port *uport = state->uart_port;
892 result = uport->ops->tx_empty(uport);
895 * If we're about to load something into the transmit
896 * register, we'll pretend the transmitter isn't empty to
897 * avoid a race condition (depending on when the transmit
898 * interrupt happens).
901 ((uart_circ_chars_pending(&state->xmit) > 0) &&
902 !tty->stopped && !tty->hw_stopped))
903 result &= ~TIOCSER_TEMT;
905 return put_user(result, value);
908 static int uart_tiocmget(struct tty_struct *tty)
910 struct uart_state *state = tty->driver_data;
911 struct tty_port *port = &state->port;
912 struct uart_port *uport = state->uart_port;
915 mutex_lock(&port->mutex);
916 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
917 result = uport->mctrl;
918 spin_lock_irq(&uport->lock);
919 result |= uport->ops->get_mctrl(uport);
920 spin_unlock_irq(&uport->lock);
922 mutex_unlock(&port->mutex);
928 uart_tiocmset(struct tty_struct *tty, struct file *file,
929 unsigned int set, unsigned int clear)
931 struct uart_state *state = tty->driver_data;
932 struct uart_port *uport = state->uart_port;
933 struct tty_port *port = &state->port;
936 mutex_lock(&port->mutex);
937 if ((!file || !tty_hung_up_p(file)) &&
938 !(tty->flags & (1 << TTY_IO_ERROR))) {
939 uart_update_mctrl(uport, set, clear);
942 mutex_unlock(&port->mutex);
946 static int uart_break_ctl(struct tty_struct *tty, int break_state)
948 struct uart_state *state = tty->driver_data;
949 struct tty_port *port = &state->port;
950 struct uart_port *uport = state->uart_port;
952 mutex_lock(&port->mutex);
954 if (uport->type != PORT_UNKNOWN)
955 uport->ops->break_ctl(uport, break_state);
957 mutex_unlock(&port->mutex);
961 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
963 struct uart_port *uport = state->uart_port;
964 struct tty_port *port = &state->port;
967 if (!capable(CAP_SYS_ADMIN))
971 * Take the per-port semaphore. This prevents count from
972 * changing, and hence any extra opens of the port while
973 * we're auto-configuring.
975 if (mutex_lock_interruptible(&port->mutex))
979 if (tty_port_users(port) == 1) {
980 uart_shutdown(tty, state);
983 * If we already have a port type configured,
984 * we must release its resources.
986 if (uport->type != PORT_UNKNOWN)
987 uport->ops->release_port(uport);
989 flags = UART_CONFIG_TYPE;
990 if (uport->flags & UPF_AUTO_IRQ)
991 flags |= UART_CONFIG_IRQ;
994 * This will claim the ports resources if
997 uport->ops->config_port(uport, flags);
999 ret = uart_startup(tty, state, 1);
1001 mutex_unlock(&port->mutex);
1006 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1007 * - mask passed in arg for lines of interest
1008 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1009 * Caller should use TIOCGICOUNT to see which one it was
1011 * FIXME: This wants extracting into a common all driver implementation
1012 * of TIOCMWAIT using tty_port.
1015 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1017 struct uart_port *uport = state->uart_port;
1018 struct tty_port *port = &state->port;
1019 DECLARE_WAITQUEUE(wait, current);
1020 struct uart_icount cprev, cnow;
1024 * note the counters on entry
1026 spin_lock_irq(&uport->lock);
1027 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1030 * Force modem status interrupts on
1032 uport->ops->enable_ms(uport);
1033 spin_unlock_irq(&uport->lock);
1035 add_wait_queue(&port->delta_msr_wait, &wait);
1037 spin_lock_irq(&uport->lock);
1038 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1039 spin_unlock_irq(&uport->lock);
1041 set_current_state(TASK_INTERRUPTIBLE);
1043 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1044 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1045 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1046 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1053 /* see if a signal did it */
1054 if (signal_pending(current)) {
1062 current->state = TASK_RUNNING;
1063 remove_wait_queue(&port->delta_msr_wait, &wait);
1069 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1070 * Return: write counters to the user passed counter struct
1071 * NB: both 1->0 and 0->1 transitions are counted except for
1072 * RI where only 0->1 is counted.
1074 static int uart_get_icount(struct tty_struct *tty,
1075 struct serial_icounter_struct *icount)
1077 struct uart_state *state = tty->driver_data;
1078 struct uart_icount cnow;
1079 struct uart_port *uport = state->uart_port;
1081 spin_lock_irq(&uport->lock);
1082 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1083 spin_unlock_irq(&uport->lock);
1085 icount->cts = cnow.cts;
1086 icount->dsr = cnow.dsr;
1087 icount->rng = cnow.rng;
1088 icount->dcd = cnow.dcd;
1089 icount->rx = cnow.rx;
1090 icount->tx = cnow.tx;
1091 icount->frame = cnow.frame;
1092 icount->overrun = cnow.overrun;
1093 icount->parity = cnow.parity;
1094 icount->brk = cnow.brk;
1095 icount->buf_overrun = cnow.buf_overrun;
1101 * Called via sys_ioctl. We can use spin_lock_irq() here.
1104 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1107 struct uart_state *state = tty->driver_data;
1108 struct tty_port *port = &state->port;
1109 void __user *uarg = (void __user *)arg;
1110 int ret = -ENOIOCTLCMD;
1114 * These ioctls don't rely on the hardware to be present.
1118 ret = uart_get_info(state, uarg);
1122 ret = uart_set_info(tty, state, uarg);
1126 ret = uart_do_autoconfig(tty, state);
1129 case TIOCSERGWILD: /* obsolete */
1130 case TIOCSERSWILD: /* obsolete */
1135 if (ret != -ENOIOCTLCMD)
1138 if (tty->flags & (1 << TTY_IO_ERROR)) {
1144 * The following should only be used when hardware is present.
1148 ret = uart_wait_modem_status(state, arg);
1152 if (ret != -ENOIOCTLCMD)
1155 mutex_lock(&port->mutex);
1157 if (tty_hung_up_p(filp)) {
1163 * All these rely on hardware being present and need to be
1164 * protected against the tty being hung up.
1167 case TIOCSERGETLSR: /* Get line status register */
1168 ret = uart_get_lsr_info(tty, state, uarg);
1172 struct uart_port *uport = state->uart_port;
1173 if (uport->ops->ioctl)
1174 ret = uport->ops->ioctl(uport, cmd, arg);
1179 mutex_unlock(&port->mutex);
1184 static void uart_set_ldisc(struct tty_struct *tty)
1186 struct uart_state *state = tty->driver_data;
1187 struct uart_port *uport = state->uart_port;
1189 if (uport->ops->set_ldisc)
1190 uport->ops->set_ldisc(uport, tty->termios->c_line);
1193 static void uart_set_termios(struct tty_struct *tty,
1194 struct ktermios *old_termios)
1196 struct uart_state *state = tty->driver_data;
1197 unsigned long flags;
1198 unsigned int cflag = tty->termios->c_cflag;
1202 * These are the bits that are used to setup various
1203 * flags in the low level driver. We can ignore the Bfoo
1204 * bits in c_cflag; c_[io]speed will always be set
1205 * appropriately by set_termios() in tty_ioctl.c
1207 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1208 if ((cflag ^ old_termios->c_cflag) == 0 &&
1209 tty->termios->c_ospeed == old_termios->c_ospeed &&
1210 tty->termios->c_ispeed == old_termios->c_ispeed &&
1211 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1215 uart_change_speed(tty, state, old_termios);
1217 /* Handle transition to B0 status */
1218 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1219 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1220 /* Handle transition away from B0 status */
1221 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1222 unsigned int mask = TIOCM_DTR;
1223 if (!(cflag & CRTSCTS) ||
1224 !test_bit(TTY_THROTTLED, &tty->flags))
1226 uart_set_mctrl(state->uart_port, mask);
1229 /* Handle turning off CRTSCTS */
1230 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1231 spin_lock_irqsave(&state->uart_port->lock, flags);
1232 tty->hw_stopped = 0;
1234 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1236 /* Handle turning on CRTSCTS */
1237 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1238 spin_lock_irqsave(&state->uart_port->lock, flags);
1239 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1240 tty->hw_stopped = 1;
1241 state->uart_port->ops->stop_tx(state->uart_port);
1243 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1247 * No need to wake up processes in open wait, since they
1248 * sample the CLOCAL flag once, and don't recheck it.
1249 * XXX It's not clear whether the current behavior is correct
1250 * or not. Hence, this may change.....
1252 if (!(old_termios->c_cflag & CLOCAL) &&
1253 (tty->termios->c_cflag & CLOCAL))
1254 wake_up_interruptible(&state->uart_port.open_wait);
1259 * In 2.4.5, calls to this will be serialized via the BKL in
1260 * linux/drivers/char/tty_io.c:tty_release()
1261 * linux/drivers/char/tty_io.c:do_tty_handup()
1263 static void uart_close(struct tty_struct *tty, struct file *filp)
1265 struct uart_state *state = tty->driver_data;
1266 struct tty_port *port;
1267 struct uart_port *uport;
1268 unsigned long flags;
1270 BUG_ON(!tty_locked());
1275 uport = state->uart_port;
1276 port = &state->port;
1278 pr_debug("uart_close(%d) called\n", uport->line);
1280 mutex_lock(&port->mutex);
1281 spin_lock_irqsave(&port->lock, flags);
1283 if (tty_hung_up_p(filp)) {
1284 spin_unlock_irqrestore(&port->lock, flags);
1288 if ((tty->count == 1) && (port->count != 1)) {
1290 * Uh, oh. tty->count is 1, which means that the tty
1291 * structure will be freed. port->count should always
1292 * be one in these conditions. If it's greater than
1293 * one, we've got real problems, since it means the
1294 * serial port won't be shutdown.
1296 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1297 "port->count is %d\n", port->count);
1300 if (--port->count < 0) {
1301 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1302 tty->name, port->count);
1306 spin_unlock_irqrestore(&port->lock, flags);
1311 * Now we wait for the transmit buffer to clear; and we notify
1312 * the line discipline to only process XON/XOFF characters by
1313 * setting tty->closing.
1316 spin_unlock_irqrestore(&port->lock, flags);
1318 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
1320 * hack: open-coded tty_wait_until_sent to avoid
1321 * recursive tty_lock
1323 long timeout = msecs_to_jiffies(port->closing_wait);
1324 if (wait_event_interruptible_timeout(tty->write_wait,
1325 !tty_chars_in_buffer(tty), timeout) >= 0)
1326 __uart_wait_until_sent(uport, timeout);
1330 * At this point, we stop accepting input. To do this, we
1331 * disable the receive line status interrupts.
1333 if (port->flags & ASYNC_INITIALIZED) {
1334 unsigned long flags;
1335 spin_lock_irqsave(&uport->lock, flags);
1336 uport->ops->stop_rx(uport);
1337 spin_unlock_irqrestore(&uport->lock, flags);
1339 * Before we drop DTR, make sure the UART transmitter
1340 * has completely drained; this is especially
1341 * important if there is a transmit FIFO!
1343 __uart_wait_until_sent(uport, uport->timeout);
1346 uart_shutdown(tty, state);
1347 uart_flush_buffer(tty);
1349 tty_ldisc_flush(tty);
1351 tty_port_tty_set(port, NULL);
1352 spin_lock_irqsave(&port->lock, flags);
1355 if (port->blocked_open) {
1356 spin_unlock_irqrestore(&port->lock, flags);
1357 if (port->close_delay)
1358 msleep_interruptible(port->close_delay);
1359 spin_lock_irqsave(&port->lock, flags);
1360 } else if (!uart_console(uport)) {
1361 spin_unlock_irqrestore(&port->lock, flags);
1362 uart_change_pm(state, 3);
1363 spin_lock_irqsave(&port->lock, flags);
1367 * Wake up anyone trying to open this port.
1369 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1370 spin_unlock_irqrestore(&port->lock, flags);
1371 wake_up_interruptible(&port->open_wait);
1374 mutex_unlock(&port->mutex);
1377 static void __uart_wait_until_sent(struct uart_port *port, int timeout)
1379 unsigned long char_time, expire;
1381 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1385 * Set the check interval to be 1/5 of the estimated time to
1386 * send a single character, and make it at least 1. The check
1387 * interval should also be less than the timeout.
1389 * Note: we have to use pretty tight timings here to satisfy
1392 char_time = (port->timeout - HZ/50) / port->fifosize;
1393 char_time = char_time / 5;
1396 if (timeout && timeout < char_time)
1397 char_time = timeout;
1400 * If the transmitter hasn't cleared in twice the approximate
1401 * amount of time to send the entire FIFO, it probably won't
1402 * ever clear. This assumes the UART isn't doing flow
1403 * control, which is currently the case. Hence, if it ever
1404 * takes longer than port->timeout, this is probably due to a
1405 * UART bug of some kind. So, we clamp the timeout parameter at
1408 if (timeout == 0 || timeout > 2 * port->timeout)
1409 timeout = 2 * port->timeout;
1411 expire = jiffies + timeout;
1413 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1414 port->line, jiffies, expire);
1417 * Check whether the transmitter is empty every 'char_time'.
1418 * 'timeout' / 'expire' give us the maximum amount of time
1421 while (!port->ops->tx_empty(port)) {
1422 msleep_interruptible(jiffies_to_msecs(char_time));
1423 if (signal_pending(current))
1425 if (time_after(jiffies, expire))
1428 set_current_state(TASK_RUNNING); /* might not be needed */
1431 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1433 struct uart_state *state = tty->driver_data;
1434 struct uart_port *port = state->uart_port;
1437 __uart_wait_until_sent(port, timeout);
1442 * This is called with the BKL held in
1443 * linux/drivers/char/tty_io.c:do_tty_hangup()
1444 * We're called from the eventd thread, so we can sleep for
1445 * a _short_ time only.
1447 static void uart_hangup(struct tty_struct *tty)
1449 struct uart_state *state = tty->driver_data;
1450 struct tty_port *port = &state->port;
1451 unsigned long flags;
1453 BUG_ON(!tty_locked());
1454 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1456 mutex_lock(&port->mutex);
1457 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1458 uart_flush_buffer(tty);
1459 uart_shutdown(tty, state);
1460 spin_lock_irqsave(&port->lock, flags);
1462 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1463 spin_unlock_irqrestore(&port->lock, flags);
1464 tty_port_tty_set(port, NULL);
1465 wake_up_interruptible(&port->open_wait);
1466 wake_up_interruptible(&port->delta_msr_wait);
1468 mutex_unlock(&port->mutex);
1472 * uart_update_termios - update the terminal hw settings
1473 * @tty: tty associated with UART
1474 * @state: UART to update
1476 * Copy across the serial console cflag setting into the termios settings
1477 * for the initial open of the port. This allows continuity between the
1478 * kernel settings, and the settings init adopts when it opens the port
1479 * for the first time.
1481 static void uart_update_termios(struct tty_struct *tty,
1482 struct uart_state *state)
1484 struct uart_port *port = state->uart_port;
1486 if (uart_console(port) && port->cons->cflag) {
1487 tty->termios->c_cflag = port->cons->cflag;
1488 port->cons->cflag = 0;
1492 * If the device failed to grab its irq resources,
1493 * or some other error occurred, don't try to talk
1494 * to the port hardware.
1496 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1498 * Make termios settings take effect.
1500 uart_change_speed(tty, state, NULL);
1503 * And finally enable the RTS and DTR signals.
1505 if (tty->termios->c_cflag & CBAUD)
1506 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1510 static int uart_carrier_raised(struct tty_port *port)
1512 struct uart_state *state = container_of(port, struct uart_state, port);
1513 struct uart_port *uport = state->uart_port;
1515 spin_lock_irq(&uport->lock);
1516 uport->ops->enable_ms(uport);
1517 mctrl = uport->ops->get_mctrl(uport);
1518 spin_unlock_irq(&uport->lock);
1519 if (mctrl & TIOCM_CAR)
1524 static void uart_dtr_rts(struct tty_port *port, int onoff)
1526 struct uart_state *state = container_of(port, struct uart_state, port);
1527 struct uart_port *uport = state->uart_port;
1530 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1533 * If this is the first open to succeed,
1534 * adjust things to suit.
1536 if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags))
1537 uart_update_termios(port->tty, state);
1540 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1543 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1545 struct uart_state *state;
1546 struct tty_port *port;
1549 state = drv->state + line;
1550 port = &state->port;
1551 if (mutex_lock_interruptible(&port->mutex)) {
1557 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1565 mutex_unlock(&port->mutex);
1567 return ERR_PTR(ret);
1571 * calls to uart_open are serialised by the BKL in
1572 * fs/char_dev.c:chrdev_open()
1573 * Note that if this fails, then uart_close() _will_ be called.
1575 * In time, we want to scrap the "opening nonpresent ports"
1576 * behaviour and implement an alternative way for setserial
1577 * to set base addresses/ports/types. This will allow us to
1578 * get rid of a certain amount of extra tests.
1580 static int uart_open(struct tty_struct *tty, struct file *filp)
1582 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1583 struct uart_state *state;
1584 struct tty_port *port;
1585 int retval, line = tty->index;
1587 BUG_ON(!tty_locked());
1588 pr_debug("uart_open(%d) called\n", line);
1591 * tty->driver->num won't change, so we won't fail here with
1592 * tty->driver_data set to something non-NULL (and therefore
1593 * we won't get caught by uart_close()).
1596 if (line >= tty->driver->num)
1600 * We take the semaphore inside uart_get to guarantee that we won't
1601 * be re-entered while allocating the state structure, or while we
1602 * request any IRQs that the driver may need. This also has the nice
1603 * side-effect that it delays the action of uart_hangup, so we can
1604 * guarantee that state->port.tty will always contain something
1607 state = uart_get(drv, line);
1608 if (IS_ERR(state)) {
1609 retval = PTR_ERR(state);
1612 port = &state->port;
1615 * Once we set tty->driver_data here, we are guaranteed that
1616 * uart_close() will decrement the driver module use count.
1617 * Any failures from here onwards should not touch the count.
1619 tty->driver_data = state;
1620 state->uart_port->state = state;
1621 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1623 tty_port_tty_set(port, tty);
1626 * If the port is in the middle of closing, bail out now.
1628 if (tty_hung_up_p(filp)) {
1631 mutex_unlock(&port->mutex);
1636 * Make sure the device is in D0 state.
1638 if (port->count == 1)
1639 uart_change_pm(state, 0);
1642 * Start up the serial port.
1644 retval = uart_startup(tty, state, 0);
1647 * If we succeeded, wait until the port is ready.
1649 mutex_unlock(&port->mutex);
1651 retval = tty_port_block_til_ready(port, tty, filp);
1657 static const char *uart_type(struct uart_port *port)
1659 const char *str = NULL;
1661 if (port->ops->type)
1662 str = port->ops->type(port);
1670 #ifdef CONFIG_PROC_FS
1672 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1674 struct uart_state *state = drv->state + i;
1675 struct tty_port *port = &state->port;
1677 struct uart_port *uport = state->uart_port;
1679 unsigned int status;
1685 mmio = uport->iotype >= UPIO_MEM;
1686 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1687 uport->line, uart_type(uport),
1688 mmio ? "mmio:0x" : "port:",
1689 mmio ? (unsigned long long)uport->mapbase
1690 : (unsigned long long)uport->iobase,
1693 if (uport->type == PORT_UNKNOWN) {
1698 if (capable(CAP_SYS_ADMIN)) {
1699 mutex_lock(&port->mutex);
1700 pm_state = state->pm_state;
1702 uart_change_pm(state, 0);
1703 spin_lock_irq(&uport->lock);
1704 status = uport->ops->get_mctrl(uport);
1705 spin_unlock_irq(&uport->lock);
1707 uart_change_pm(state, pm_state);
1708 mutex_unlock(&port->mutex);
1710 seq_printf(m, " tx:%d rx:%d",
1711 uport->icount.tx, uport->icount.rx);
1712 if (uport->icount.frame)
1713 seq_printf(m, " fe:%d",
1714 uport->icount.frame);
1715 if (uport->icount.parity)
1716 seq_printf(m, " pe:%d",
1717 uport->icount.parity);
1718 if (uport->icount.brk)
1719 seq_printf(m, " brk:%d",
1721 if (uport->icount.overrun)
1722 seq_printf(m, " oe:%d",
1723 uport->icount.overrun);
1725 #define INFOBIT(bit, str) \
1726 if (uport->mctrl & (bit)) \
1727 strncat(stat_buf, (str), sizeof(stat_buf) - \
1728 strlen(stat_buf) - 2)
1729 #define STATBIT(bit, str) \
1730 if (status & (bit)) \
1731 strncat(stat_buf, (str), sizeof(stat_buf) - \
1732 strlen(stat_buf) - 2)
1736 INFOBIT(TIOCM_RTS, "|RTS");
1737 STATBIT(TIOCM_CTS, "|CTS");
1738 INFOBIT(TIOCM_DTR, "|DTR");
1739 STATBIT(TIOCM_DSR, "|DSR");
1740 STATBIT(TIOCM_CAR, "|CD");
1741 STATBIT(TIOCM_RNG, "|RI");
1745 seq_puts(m, stat_buf);
1752 static int uart_proc_show(struct seq_file *m, void *v)
1754 struct tty_driver *ttydrv = m->private;
1755 struct uart_driver *drv = ttydrv->driver_state;
1758 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1760 for (i = 0; i < drv->nr; i++)
1761 uart_line_info(m, drv, i);
1765 static int uart_proc_open(struct inode *inode, struct file *file)
1767 return single_open(file, uart_proc_show, PDE(inode)->data);
1770 static const struct file_operations uart_proc_fops = {
1771 .owner = THIS_MODULE,
1772 .open = uart_proc_open,
1774 .llseek = seq_lseek,
1775 .release = single_release,
1779 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1781 * uart_console_write - write a console message to a serial port
1782 * @port: the port to write the message
1783 * @s: array of characters
1784 * @count: number of characters in string to write
1785 * @write: function to write character to port
1787 void uart_console_write(struct uart_port *port, const char *s,
1789 void (*putchar)(struct uart_port *, int))
1793 for (i = 0; i < count; i++, s++) {
1795 putchar(port, '\r');
1799 EXPORT_SYMBOL_GPL(uart_console_write);
1802 * Check whether an invalid uart number has been specified, and
1803 * if so, search for the first available port that does have
1806 struct uart_port * __init
1807 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1809 int idx = co->index;
1811 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1812 ports[idx].membase == NULL))
1813 for (idx = 0; idx < nr; idx++)
1814 if (ports[idx].iobase != 0 ||
1815 ports[idx].membase != NULL)
1824 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1825 * @options: pointer to option string
1826 * @baud: pointer to an 'int' variable for the baud rate.
1827 * @parity: pointer to an 'int' variable for the parity.
1828 * @bits: pointer to an 'int' variable for the number of data bits.
1829 * @flow: pointer to an 'int' variable for the flow control character.
1831 * uart_parse_options decodes a string containing the serial console
1832 * options. The format of the string is <baud><parity><bits><flow>,
1836 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1840 *baud = simple_strtoul(s, NULL, 10);
1841 while (*s >= '0' && *s <= '9')
1850 EXPORT_SYMBOL_GPL(uart_parse_options);
1857 static const struct baud_rates baud_rates[] = {
1858 { 921600, B921600 },
1859 { 460800, B460800 },
1860 { 230400, B230400 },
1861 { 115200, B115200 },
1873 * uart_set_options - setup the serial console parameters
1874 * @port: pointer to the serial ports uart_port structure
1875 * @co: console pointer
1877 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1878 * @bits: number of data bits
1879 * @flow: flow control character - 'r' (rts)
1882 uart_set_options(struct uart_port *port, struct console *co,
1883 int baud, int parity, int bits, int flow)
1885 struct ktermios termios;
1886 static struct ktermios dummy;
1890 * Ensure that the serial console lock is initialised
1893 spin_lock_init(&port->lock);
1894 lockdep_set_class(&port->lock, &port_lock_key);
1896 memset(&termios, 0, sizeof(struct ktermios));
1898 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1901 * Construct a cflag setting.
1903 for (i = 0; baud_rates[i].rate; i++)
1904 if (baud_rates[i].rate <= baud)
1907 termios.c_cflag |= baud_rates[i].cflag;
1910 termios.c_cflag |= CS7;
1912 termios.c_cflag |= CS8;
1916 termios.c_cflag |= PARODD;
1919 termios.c_cflag |= PARENB;
1924 termios.c_cflag |= CRTSCTS;
1927 * some uarts on other side don't support no flow control.
1928 * So we set * DTR in host uart to make them happy
1930 port->mctrl |= TIOCM_DTR;
1932 port->ops->set_termios(port, &termios, &dummy);
1934 * Allow the setting of the UART parameters with a NULL console
1938 co->cflag = termios.c_cflag;
1942 EXPORT_SYMBOL_GPL(uart_set_options);
1943 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1945 static void uart_change_pm(struct uart_state *state, int pm_state)
1947 struct uart_port *port = state->uart_port;
1949 if (state->pm_state != pm_state) {
1951 port->ops->pm(port, pm_state, state->pm_state);
1952 state->pm_state = pm_state;
1957 struct uart_port *port;
1958 struct uart_driver *driver;
1961 static int serial_match_port(struct device *dev, void *data)
1963 struct uart_match *match = data;
1964 struct tty_driver *tty_drv = match->driver->tty_driver;
1965 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1968 return dev->devt == devt; /* Actually, only one tty per port */
1971 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1973 struct uart_state *state = drv->state + uport->line;
1974 struct tty_port *port = &state->port;
1975 struct device *tty_dev;
1976 struct uart_match match = {uport, drv};
1977 struct tty_struct *tty;
1979 mutex_lock(&port->mutex);
1981 /* Must be inside the mutex lock until we convert to tty_port */
1984 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1985 if (device_may_wakeup(tty_dev)) {
1986 if (!enable_irq_wake(uport->irq))
1987 uport->irq_wake = 1;
1988 put_device(tty_dev);
1989 mutex_unlock(&port->mutex);
1992 if (console_suspend_enabled || !uart_console(uport))
1993 uport->suspended = 1;
1995 if (port->flags & ASYNC_INITIALIZED) {
1996 const struct uart_ops *ops = uport->ops;
1999 if (console_suspend_enabled || !uart_console(uport)) {
2000 set_bit(ASYNCB_SUSPENDED, &port->flags);
2001 clear_bit(ASYNCB_INITIALIZED, &port->flags);
2003 spin_lock_irq(&uport->lock);
2004 ops->stop_tx(uport);
2005 ops->set_mctrl(uport, 0);
2006 ops->stop_rx(uport);
2007 spin_unlock_irq(&uport->lock);
2011 * Wait for the transmitter to empty.
2013 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2016 printk(KERN_ERR "%s%s%s%d: Unable to drain "
2018 uport->dev ? dev_name(uport->dev) : "",
2019 uport->dev ? ": " : "",
2021 drv->tty_driver->name_base + uport->line);
2023 if (console_suspend_enabled || !uart_console(uport))
2024 ops->shutdown(uport);
2028 * Disable the console device before suspending.
2030 if (console_suspend_enabled && uart_console(uport))
2031 console_stop(uport->cons);
2033 if (console_suspend_enabled || !uart_console(uport))
2034 uart_change_pm(state, 3);
2036 mutex_unlock(&port->mutex);
2041 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2043 struct uart_state *state = drv->state + uport->line;
2044 struct tty_port *port = &state->port;
2045 struct device *tty_dev;
2046 struct uart_match match = {uport, drv};
2047 struct ktermios termios;
2049 mutex_lock(&port->mutex);
2051 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2052 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2053 if (uport->irq_wake) {
2054 disable_irq_wake(uport->irq);
2055 uport->irq_wake = 0;
2057 mutex_unlock(&port->mutex);
2060 uport->suspended = 0;
2063 * Re-enable the console device after suspending.
2065 if (uart_console(uport)) {
2067 * First try to use the console cflag setting.
2069 memset(&termios, 0, sizeof(struct ktermios));
2070 termios.c_cflag = uport->cons->cflag;
2073 * If that's unset, use the tty termios setting.
2075 if (port->tty && port->tty->termios && termios.c_cflag == 0)
2076 termios = *(port->tty->termios);
2078 uport->ops->set_termios(uport, &termios, NULL);
2079 if (console_suspend_enabled)
2080 console_start(uport->cons);
2083 if (port->flags & ASYNC_SUSPENDED) {
2084 const struct uart_ops *ops = uport->ops;
2087 uart_change_pm(state, 0);
2088 spin_lock_irq(&uport->lock);
2089 ops->set_mctrl(uport, 0);
2090 spin_unlock_irq(&uport->lock);
2091 if (console_suspend_enabled || !uart_console(uport)) {
2092 /* Protected by port mutex for now */
2093 struct tty_struct *tty = port->tty;
2094 ret = ops->startup(uport);
2097 uart_change_speed(tty, state, NULL);
2098 spin_lock_irq(&uport->lock);
2099 ops->set_mctrl(uport, uport->mctrl);
2100 ops->start_tx(uport);
2101 spin_unlock_irq(&uport->lock);
2102 set_bit(ASYNCB_INITIALIZED, &port->flags);
2105 * Failed to resume - maybe hardware went away?
2106 * Clear the "initialized" flag so we won't try
2107 * to call the low level drivers shutdown method.
2109 uart_shutdown(tty, state);
2113 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2116 mutex_unlock(&port->mutex);
2122 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2126 switch (port->iotype) {
2128 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2131 snprintf(address, sizeof(address),
2132 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2140 snprintf(address, sizeof(address),
2141 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2144 strlcpy(address, "*unknown*", sizeof(address));
2148 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2149 port->dev ? dev_name(port->dev) : "",
2150 port->dev ? ": " : "",
2152 drv->tty_driver->name_base + port->line,
2153 address, port->irq, uart_type(port));
2157 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2158 struct uart_port *port)
2163 * If there isn't a port here, don't do anything further.
2165 if (!port->iobase && !port->mapbase && !port->membase)
2169 * Now do the auto configuration stuff. Note that config_port
2170 * is expected to claim the resources and map the port for us.
2173 if (port->flags & UPF_AUTO_IRQ)
2174 flags |= UART_CONFIG_IRQ;
2175 if (port->flags & UPF_BOOT_AUTOCONF) {
2176 if (!(port->flags & UPF_FIXED_TYPE)) {
2177 port->type = PORT_UNKNOWN;
2178 flags |= UART_CONFIG_TYPE;
2180 port->ops->config_port(port, flags);
2183 if (port->type != PORT_UNKNOWN) {
2184 unsigned long flags;
2186 uart_report_port(drv, port);
2188 /* Power up port for set_mctrl() */
2189 uart_change_pm(state, 0);
2192 * Ensure that the modem control lines are de-activated.
2193 * keep the DTR setting that is set in uart_set_options()
2194 * We probably don't need a spinlock around this, but
2196 spin_lock_irqsave(&port->lock, flags);
2197 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2198 spin_unlock_irqrestore(&port->lock, flags);
2201 * If this driver supports console, and it hasn't been
2202 * successfully registered yet, try to re-register it.
2203 * It may be that the port was not available.
2205 if (port->cons && !(port->cons->flags & CON_ENABLED))
2206 register_console(port->cons);
2209 * Power down all ports by default, except the
2210 * console if we have one.
2212 if (!uart_console(port))
2213 uart_change_pm(state, 3);
2217 #ifdef CONFIG_CONSOLE_POLL
2219 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2221 struct uart_driver *drv = driver->driver_state;
2222 struct uart_state *state = drv->state + line;
2223 struct uart_port *port;
2229 if (!state || !state->uart_port)
2232 port = state->uart_port;
2233 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2237 uart_parse_options(options, &baud, &parity, &bits, &flow);
2238 return uart_set_options(port, NULL, baud, parity, bits, flow);
2244 static int uart_poll_get_char(struct tty_driver *driver, int line)
2246 struct uart_driver *drv = driver->driver_state;
2247 struct uart_state *state = drv->state + line;
2248 struct uart_port *port;
2250 if (!state || !state->uart_port)
2253 port = state->uart_port;
2254 return port->ops->poll_get_char(port);
2257 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2259 struct uart_driver *drv = driver->driver_state;
2260 struct uart_state *state = drv->state + line;
2261 struct uart_port *port;
2263 if (!state || !state->uart_port)
2266 port = state->uart_port;
2267 port->ops->poll_put_char(port, ch);
2271 static const struct tty_operations uart_ops = {
2273 .close = uart_close,
2274 .write = uart_write,
2275 .put_char = uart_put_char,
2276 .flush_chars = uart_flush_chars,
2277 .write_room = uart_write_room,
2278 .chars_in_buffer= uart_chars_in_buffer,
2279 .flush_buffer = uart_flush_buffer,
2280 .ioctl = uart_ioctl,
2281 .throttle = uart_throttle,
2282 .unthrottle = uart_unthrottle,
2283 .send_xchar = uart_send_xchar,
2284 .set_termios = uart_set_termios,
2285 .set_ldisc = uart_set_ldisc,
2287 .start = uart_start,
2288 .hangup = uart_hangup,
2289 .break_ctl = uart_break_ctl,
2290 .wait_until_sent= uart_wait_until_sent,
2291 #ifdef CONFIG_PROC_FS
2292 .proc_fops = &uart_proc_fops,
2294 .tiocmget = uart_tiocmget,
2295 .tiocmset = uart_tiocmset,
2296 .get_icount = uart_get_icount,
2297 #ifdef CONFIG_CONSOLE_POLL
2298 .poll_init = uart_poll_init,
2299 .poll_get_char = uart_poll_get_char,
2300 .poll_put_char = uart_poll_put_char,
2304 static const struct tty_port_operations uart_port_ops = {
2305 .carrier_raised = uart_carrier_raised,
2306 .dtr_rts = uart_dtr_rts,
2310 * uart_register_driver - register a driver with the uart core layer
2311 * @drv: low level driver structure
2313 * Register a uart driver with the core driver. We in turn register
2314 * with the tty layer, and initialise the core driver per-port state.
2316 * We have a proc file in /proc/tty/driver which is named after the
2319 * drv->port should be NULL, and the per-port structures should be
2320 * registered using uart_add_one_port after this call has succeeded.
2322 int uart_register_driver(struct uart_driver *drv)
2324 struct tty_driver *normal;
2330 * Maybe we should be using a slab cache for this, especially if
2331 * we have a large number of ports to handle.
2333 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2337 normal = alloc_tty_driver(drv->nr);
2341 drv->tty_driver = normal;
2343 normal->owner = drv->owner;
2344 normal->driver_name = drv->driver_name;
2345 normal->name = drv->dev_name;
2346 normal->major = drv->major;
2347 normal->minor_start = drv->minor;
2348 normal->type = TTY_DRIVER_TYPE_SERIAL;
2349 normal->subtype = SERIAL_TYPE_NORMAL;
2350 normal->init_termios = tty_std_termios;
2351 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2352 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2353 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2354 normal->driver_state = drv;
2355 tty_set_operations(normal, &uart_ops);
2358 * Initialise the UART state(s).
2360 for (i = 0; i < drv->nr; i++) {
2361 struct uart_state *state = drv->state + i;
2362 struct tty_port *port = &state->port;
2364 tty_port_init(port);
2365 port->ops = &uart_port_ops;
2366 port->close_delay = 500; /* .5 seconds */
2367 port->closing_wait = 30000; /* 30 seconds */
2368 tasklet_init(&state->tlet, uart_tasklet_action,
2369 (unsigned long)state);
2372 retval = tty_register_driver(normal);
2376 put_tty_driver(normal);
2384 * uart_unregister_driver - remove a driver from the uart core layer
2385 * @drv: low level driver structure
2387 * Remove all references to a driver from the core driver. The low
2388 * level driver must have removed all its ports via the
2389 * uart_remove_one_port() if it registered them with uart_add_one_port().
2390 * (ie, drv->port == NULL)
2392 void uart_unregister_driver(struct uart_driver *drv)
2394 struct tty_driver *p = drv->tty_driver;
2395 tty_unregister_driver(p);
2398 drv->tty_driver = NULL;
2401 struct tty_driver *uart_console_device(struct console *co, int *index)
2403 struct uart_driver *p = co->data;
2405 return p->tty_driver;
2409 * uart_add_one_port - attach a driver-defined port structure
2410 * @drv: pointer to the uart low level driver structure for this port
2411 * @uport: uart port structure to use for this port.
2413 * This allows the driver to register its own uart_port structure
2414 * with the core driver. The main purpose is to allow the low
2415 * level uart drivers to expand uart_port, rather than having yet
2416 * more levels of structures.
2418 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2420 struct uart_state *state;
2421 struct tty_port *port;
2423 struct device *tty_dev;
2425 BUG_ON(in_interrupt());
2427 if (uport->line >= drv->nr)
2430 state = drv->state + uport->line;
2431 port = &state->port;
2433 mutex_lock(&port_mutex);
2434 mutex_lock(&port->mutex);
2435 if (state->uart_port) {
2440 state->uart_port = uport;
2441 state->pm_state = -1;
2443 uport->cons = drv->cons;
2444 uport->state = state;
2447 * If this port is a console, then the spinlock is already
2450 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2451 spin_lock_init(&uport->lock);
2452 lockdep_set_class(&uport->lock, &port_lock_key);
2455 uart_configure_port(drv, state, uport);
2458 * Register the port whether it's detected or not. This allows
2459 * setserial to be used to alter this ports parameters.
2461 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2462 if (likely(!IS_ERR(tty_dev))) {
2463 device_init_wakeup(tty_dev, 1);
2464 device_set_wakeup_enable(tty_dev, 0);
2466 printk(KERN_ERR "Cannot register tty device on line %d\n",
2470 * Ensure UPF_DEAD is not set.
2472 uport->flags &= ~UPF_DEAD;
2475 mutex_unlock(&port->mutex);
2476 mutex_unlock(&port_mutex);
2482 * uart_remove_one_port - detach a driver defined port structure
2483 * @drv: pointer to the uart low level driver structure for this port
2484 * @uport: uart port structure for this port
2486 * This unhooks (and hangs up) the specified port structure from the
2487 * core driver. No further calls will be made to the low-level code
2490 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2492 struct uart_state *state = drv->state + uport->line;
2493 struct tty_port *port = &state->port;
2495 BUG_ON(in_interrupt());
2497 if (state->uart_port != uport)
2498 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2499 state->uart_port, uport);
2501 mutex_lock(&port_mutex);
2504 * Mark the port "dead" - this prevents any opens from
2505 * succeeding while we shut down the port.
2507 mutex_lock(&port->mutex);
2508 uport->flags |= UPF_DEAD;
2509 mutex_unlock(&port->mutex);
2512 * Remove the devices from the tty layer
2514 tty_unregister_device(drv->tty_driver, uport->line);
2517 tty_vhangup(port->tty);
2520 * Free the port IO and memory resources, if any.
2522 if (uport->type != PORT_UNKNOWN)
2523 uport->ops->release_port(uport);
2526 * Indicate that there isn't a port here anymore.
2528 uport->type = PORT_UNKNOWN;
2531 * Kill the tasklet, and free resources.
2533 tasklet_kill(&state->tlet);
2535 state->uart_port = NULL;
2536 mutex_unlock(&port_mutex);
2542 * Are the two ports equivalent?
2544 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2546 if (port1->iotype != port2->iotype)
2549 switch (port1->iotype) {
2551 return (port1->iobase == port2->iobase);
2553 return (port1->iobase == port2->iobase) &&
2554 (port1->hub6 == port2->hub6);
2561 return (port1->mapbase == port2->mapbase);
2565 EXPORT_SYMBOL(uart_match_port);
2567 EXPORT_SYMBOL(uart_write_wakeup);
2568 EXPORT_SYMBOL(uart_register_driver);
2569 EXPORT_SYMBOL(uart_unregister_driver);
2570 EXPORT_SYMBOL(uart_suspend_port);
2571 EXPORT_SYMBOL(uart_resume_port);
2572 EXPORT_SYMBOL(uart_add_one_port);
2573 EXPORT_SYMBOL(uart_remove_one_port);
2575 MODULE_DESCRIPTION("Serial driver core");
2576 MODULE_LICENSE("GPL");