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/smp_lock.h>
33 #include <linux/device.h>
34 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
35 #include <linux/serial_core.h>
36 #include <linux/delay.h>
37 #include <linux/mutex.h>
40 #include <asm/uaccess.h>
43 * This is used to lock changes in serial line configuration.
45 static DEFINE_MUTEX(port_mutex);
48 * lockdep: port->lock is initialized in two places, but we
49 * want only one lock-class:
51 static struct lock_class_key port_lock_key;
53 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
55 #ifdef CONFIG_SERIAL_CORE_CONSOLE
56 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
58 #define uart_console(port) (0)
61 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
62 struct ktermios *old_termios);
63 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
64 static void uart_change_pm(struct uart_state *state, int pm_state);
67 * This routine is used by the interrupt handler to schedule processing in
68 * the software interrupt portion of the driver.
70 void uart_write_wakeup(struct uart_port *port)
72 struct uart_state *state = port->state;
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
78 tasklet_schedule(&state->tlet);
81 static void uart_stop(struct tty_struct *tty)
83 struct uart_state *state = tty->driver_data;
84 struct uart_port *port = state->uart_port;
87 spin_lock_irqsave(&port->lock, flags);
88 port->ops->stop_tx(port);
89 spin_unlock_irqrestore(&port->lock, flags);
92 static void __uart_start(struct tty_struct *tty)
94 struct uart_state *state = tty->driver_data;
95 struct uart_port *port = state->uart_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);
178 * Initialise the hardware port settings.
180 uart_change_speed(tty, state, NULL);
183 * Setup the RTS and DTR signals once the
184 * port is open and ready to respond.
186 if (tty->termios->c_cflag & CBAUD)
187 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
190 if (port->flags & ASYNC_CTS_FLOW) {
191 spin_lock_irq(&uport->lock);
192 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
194 spin_unlock_irq(&uport->lock);
197 set_bit(ASYNCB_INITIALIZED, &port->flags);
199 clear_bit(TTY_IO_ERROR, &tty->flags);
202 if (retval && capable(CAP_SYS_ADMIN))
209 * This routine will shutdown a serial port; interrupts are disabled, and
210 * DTR is dropped if the hangup on close termio flag is on. Calls to
211 * uart_shutdown are serialised by the per-port semaphore.
213 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
215 struct uart_port *uport = state->uart_port;
216 struct tty_port *port = &state->port;
219 * Set the TTY IO error marker
222 set_bit(TTY_IO_ERROR, &tty->flags);
224 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
226 * Turn off DTR and RTS early.
228 if (!tty || (tty->termios->c_cflag & HUPCL))
229 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
232 * clear delta_msr_wait queue to avoid mem leaks: we may free
233 * the irq here so the queue might never be woken up. Note
234 * that we won't end up waiting on delta_msr_wait again since
235 * any outstanding file descriptors should be pointing at
236 * hung_up_tty_fops now.
238 wake_up_interruptible(&port->delta_msr_wait);
241 * Free the IRQ and disable the port.
243 uport->ops->shutdown(uport);
246 * Ensure that the IRQ handler isn't running on another CPU.
248 synchronize_irq(uport->irq);
252 * kill off our tasklet
254 tasklet_kill(&state->tlet);
257 * Free the transmit buffer page.
259 if (state->xmit.buf) {
260 free_page((unsigned long)state->xmit.buf);
261 state->xmit.buf = NULL;
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
275 uart_update_timeout(struct uart_port *port, unsigned int cflag,
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
302 * The total number of bits to be transmitted in the fifo.
304 bits = bits * port->fifosize;
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
310 port->timeout = (HZ * bits) / baud + HZ/50;
313 EXPORT_SYMBOL(uart_update_timeout);
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using. Don't do this for the case
332 * where B0 is requested ("hang up").
335 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
338 unsigned int try, baud, altbaud = 38400;
340 upf_t flags = port->flags & UPF_SPD_MASK;
342 if (flags == UPF_SPD_HI)
344 else if (flags == UPF_SPD_VHI)
346 else if (flags == UPF_SPD_SHI)
348 else if (flags == UPF_SPD_WARP)
351 for (try = 0; try < 2; try++) {
352 baud = tty_termios_baud_rate(termios);
355 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
362 * Special case: B0 rate.
369 if (baud >= min && baud <= max)
373 * Oops, the quotient was zero. Try again with
374 * the old baud rate if possible.
376 termios->c_cflag &= ~CBAUD;
378 baud = tty_termios_baud_rate(old);
380 tty_termios_encode_baud_rate(termios,
387 * As a last resort, if the range cannot be met then clip to
388 * the nearest chip supported rate.
392 tty_termios_encode_baud_rate(termios,
395 tty_termios_encode_baud_rate(termios,
399 /* Should never happen */
404 EXPORT_SYMBOL(uart_get_baud_rate);
407 * uart_get_divisor - return uart clock divisor
408 * @port: uart_port structure describing the port.
409 * @baud: desired baud rate
411 * Calculate the uart clock divisor for the port.
414 uart_get_divisor(struct uart_port *port, unsigned int baud)
419 * Old custom speed handling.
421 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
422 quot = port->custom_divisor;
424 quot = (port->uartclk + (8 * baud)) / (16 * baud);
429 EXPORT_SYMBOL(uart_get_divisor);
431 /* FIXME: Consistent locking policy */
432 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
433 struct ktermios *old_termios)
435 struct tty_port *port = &state->port;
436 struct uart_port *uport = state->uart_port;
437 struct ktermios *termios;
440 * If we have no tty, termios, or the port does not exist,
441 * then we can't set the parameters for this port.
443 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
446 termios = tty->termios;
449 * Set flags based on termios cflag
451 if (termios->c_cflag & CRTSCTS)
452 set_bit(ASYNCB_CTS_FLOW, &port->flags);
454 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
456 if (termios->c_cflag & CLOCAL)
457 clear_bit(ASYNCB_CHECK_CD, &port->flags);
459 set_bit(ASYNCB_CHECK_CD, &port->flags);
461 uport->ops->set_termios(uport, termios, old_termios);
464 static inline int __uart_put_char(struct uart_port *port,
465 struct circ_buf *circ, unsigned char c)
473 spin_lock_irqsave(&port->lock, flags);
474 if (uart_circ_chars_free(circ) != 0) {
475 circ->buf[circ->head] = c;
476 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
479 spin_unlock_irqrestore(&port->lock, flags);
483 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
485 struct uart_state *state = tty->driver_data;
487 return __uart_put_char(state->uart_port, &state->xmit, ch);
490 static void uart_flush_chars(struct tty_struct *tty)
495 static int uart_write(struct tty_struct *tty,
496 const unsigned char *buf, int count)
498 struct uart_state *state = tty->driver_data;
499 struct uart_port *port;
500 struct circ_buf *circ;
505 * This means you called this function _after_ the port was
506 * closed. No cookie for you.
513 port = state->uart_port;
519 spin_lock_irqsave(&port->lock, flags);
521 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
526 memcpy(circ->buf + circ->head, buf, c);
527 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
532 spin_unlock_irqrestore(&port->lock, flags);
538 static int uart_write_room(struct tty_struct *tty)
540 struct uart_state *state = tty->driver_data;
544 spin_lock_irqsave(&state->uart_port->lock, flags);
545 ret = uart_circ_chars_free(&state->xmit);
546 spin_unlock_irqrestore(&state->uart_port->lock, flags);
550 static int uart_chars_in_buffer(struct tty_struct *tty)
552 struct uart_state *state = tty->driver_data;
556 spin_lock_irqsave(&state->uart_port->lock, flags);
557 ret = uart_circ_chars_pending(&state->xmit);
558 spin_unlock_irqrestore(&state->uart_port->lock, flags);
562 static void uart_flush_buffer(struct tty_struct *tty)
564 struct uart_state *state = tty->driver_data;
565 struct uart_port *port;
569 * This means you called this function _after_ the port was
570 * closed. No cookie for you.
577 port = state->uart_port;
578 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
580 spin_lock_irqsave(&port->lock, flags);
581 uart_circ_clear(&state->xmit);
582 if (port->ops->flush_buffer)
583 port->ops->flush_buffer(port);
584 spin_unlock_irqrestore(&port->lock, flags);
589 * This function is used to send a high-priority XON/XOFF character to
592 static void uart_send_xchar(struct tty_struct *tty, char ch)
594 struct uart_state *state = tty->driver_data;
595 struct uart_port *port = state->uart_port;
598 if (port->ops->send_xchar)
599 port->ops->send_xchar(port, ch);
603 spin_lock_irqsave(&port->lock, flags);
604 port->ops->start_tx(port);
605 spin_unlock_irqrestore(&port->lock, flags);
610 static void uart_throttle(struct tty_struct *tty)
612 struct uart_state *state = tty->driver_data;
615 uart_send_xchar(tty, STOP_CHAR(tty));
617 if (tty->termios->c_cflag & CRTSCTS)
618 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
621 static void uart_unthrottle(struct tty_struct *tty)
623 struct uart_state *state = tty->driver_data;
624 struct uart_port *port = state->uart_port;
630 uart_send_xchar(tty, START_CHAR(tty));
633 if (tty->termios->c_cflag & CRTSCTS)
634 uart_set_mctrl(port, TIOCM_RTS);
637 static int uart_get_info(struct uart_state *state,
638 struct serial_struct __user *retinfo)
640 struct uart_port *uport = state->uart_port;
641 struct tty_port *port = &state->port;
642 struct serial_struct tmp;
644 memset(&tmp, 0, sizeof(tmp));
646 /* Ensure the state we copy is consistent and no hardware changes
648 mutex_lock(&port->mutex);
650 tmp.type = uport->type;
651 tmp.line = uport->line;
652 tmp.port = uport->iobase;
653 if (HIGH_BITS_OFFSET)
654 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
655 tmp.irq = uport->irq;
656 tmp.flags = uport->flags;
657 tmp.xmit_fifo_size = uport->fifosize;
658 tmp.baud_base = uport->uartclk / 16;
659 tmp.close_delay = port->close_delay / 10;
660 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
661 ASYNC_CLOSING_WAIT_NONE :
662 port->closing_wait / 10;
663 tmp.custom_divisor = uport->custom_divisor;
664 tmp.hub6 = uport->hub6;
665 tmp.io_type = uport->iotype;
666 tmp.iomem_reg_shift = uport->regshift;
667 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
669 mutex_unlock(&port->mutex);
671 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
676 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
677 struct serial_struct __user *newinfo)
679 struct serial_struct new_serial;
680 struct uart_port *uport = state->uart_port;
681 struct tty_port *port = &state->port;
682 unsigned long new_port;
683 unsigned int change_irq, change_port, closing_wait;
684 unsigned int old_custom_divisor, close_delay;
685 upf_t old_flags, new_flags;
688 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
691 new_port = new_serial.port;
692 if (HIGH_BITS_OFFSET)
693 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
695 new_serial.irq = irq_canonicalize(new_serial.irq);
696 close_delay = new_serial.close_delay * 10;
697 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
698 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
701 * This semaphore protects port->count. It is also
702 * very useful to prevent opens. Also, take the
703 * port configuration semaphore to make sure that a
704 * module insertion/removal doesn't change anything
707 mutex_lock(&port->mutex);
709 change_irq = !(uport->flags & UPF_FIXED_PORT)
710 && new_serial.irq != uport->irq;
713 * Since changing the 'type' of the port changes its resource
714 * allocations, we should treat type changes the same as
717 change_port = !(uport->flags & UPF_FIXED_PORT)
718 && (new_port != uport->iobase ||
719 (unsigned long)new_serial.iomem_base != uport->mapbase ||
720 new_serial.hub6 != uport->hub6 ||
721 new_serial.io_type != uport->iotype ||
722 new_serial.iomem_reg_shift != uport->regshift ||
723 new_serial.type != uport->type);
725 old_flags = uport->flags;
726 new_flags = new_serial.flags;
727 old_custom_divisor = uport->custom_divisor;
729 if (!capable(CAP_SYS_ADMIN)) {
731 if (change_irq || change_port ||
732 (new_serial.baud_base != uport->uartclk / 16) ||
733 (close_delay != port->close_delay) ||
734 (closing_wait != port->closing_wait) ||
735 (new_serial.xmit_fifo_size &&
736 new_serial.xmit_fifo_size != uport->fifosize) ||
737 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
739 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
740 (new_flags & UPF_USR_MASK));
741 uport->custom_divisor = new_serial.custom_divisor;
746 * Ask the low level driver to verify the settings.
748 if (uport->ops->verify_port)
749 retval = uport->ops->verify_port(uport, &new_serial);
751 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
752 (new_serial.baud_base < 9600))
758 if (change_port || change_irq) {
762 * Make sure that we are the sole user of this port.
764 if (tty_port_users(port) > 1)
768 * We need to shutdown the serial port at the old
769 * port/type/irq combination.
771 uart_shutdown(tty, state);
775 unsigned long old_iobase, old_mapbase;
776 unsigned int old_type, old_iotype, old_hub6, old_shift;
778 old_iobase = uport->iobase;
779 old_mapbase = uport->mapbase;
780 old_type = uport->type;
781 old_hub6 = uport->hub6;
782 old_iotype = uport->iotype;
783 old_shift = uport->regshift;
786 * Free and release old regions
788 if (old_type != PORT_UNKNOWN)
789 uport->ops->release_port(uport);
791 uport->iobase = new_port;
792 uport->type = new_serial.type;
793 uport->hub6 = new_serial.hub6;
794 uport->iotype = new_serial.io_type;
795 uport->regshift = new_serial.iomem_reg_shift;
796 uport->mapbase = (unsigned long)new_serial.iomem_base;
799 * Claim and map the new regions
801 if (uport->type != PORT_UNKNOWN) {
802 retval = uport->ops->request_port(uport);
804 /* Always success - Jean II */
809 * If we fail to request resources for the
810 * new port, try to restore the old settings.
812 if (retval && old_type != PORT_UNKNOWN) {
813 uport->iobase = old_iobase;
814 uport->type = old_type;
815 uport->hub6 = old_hub6;
816 uport->iotype = old_iotype;
817 uport->regshift = old_shift;
818 uport->mapbase = old_mapbase;
819 retval = uport->ops->request_port(uport);
821 * If we failed to restore the old settings,
825 uport->type = PORT_UNKNOWN;
831 /* Added to return the correct error -Ram Gupta */
837 uport->irq = new_serial.irq;
838 if (!(uport->flags & UPF_FIXED_PORT))
839 uport->uartclk = new_serial.baud_base * 16;
840 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
841 (new_flags & UPF_CHANGE_MASK);
842 uport->custom_divisor = new_serial.custom_divisor;
843 port->close_delay = close_delay;
844 port->closing_wait = closing_wait;
845 if (new_serial.xmit_fifo_size)
846 uport->fifosize = new_serial.xmit_fifo_size;
848 port->tty->low_latency =
849 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
853 if (uport->type == PORT_UNKNOWN)
855 if (port->flags & ASYNC_INITIALIZED) {
856 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
857 old_custom_divisor != uport->custom_divisor) {
859 * If they're setting up a custom divisor or speed,
860 * instead of clearing it, then bitch about it. No
861 * need to rate-limit; it's CAP_SYS_ADMIN only.
863 if (uport->flags & UPF_SPD_MASK) {
866 "%s sets custom speed on %s. This "
867 "is deprecated.\n", current->comm,
868 tty_name(port->tty, buf));
870 uart_change_speed(tty, state, NULL);
873 retval = uart_startup(tty, state, 1);
875 mutex_unlock(&port->mutex);
880 * uart_get_lsr_info - get line status register info
881 * @tty: tty associated with the UART
882 * @state: UART being queried
883 * @value: returned modem value
885 * Note: uart_ioctl protects us against hangups.
887 static int uart_get_lsr_info(struct tty_struct *tty,
888 struct uart_state *state, unsigned int __user *value)
890 struct uart_port *uport = state->uart_port;
893 result = uport->ops->tx_empty(uport);
896 * If we're about to load something into the transmit
897 * register, we'll pretend the transmitter isn't empty to
898 * avoid a race condition (depending on when the transmit
899 * interrupt happens).
902 ((uart_circ_chars_pending(&state->xmit) > 0) &&
903 !tty->stopped && !tty->hw_stopped))
904 result &= ~TIOCSER_TEMT;
906 return put_user(result, value);
909 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
911 struct uart_state *state = tty->driver_data;
912 struct tty_port *port = &state->port;
913 struct uart_port *uport = state->uart_port;
916 mutex_lock(&port->mutex);
917 if ((!file || !tty_hung_up_p(file)) &&
918 !(tty->flags & (1 << TTY_IO_ERROR))) {
919 result = uport->mctrl;
921 spin_lock_irq(&uport->lock);
922 result |= uport->ops->get_mctrl(uport);
923 spin_unlock_irq(&uport->lock);
925 mutex_unlock(&port->mutex);
931 uart_tiocmset(struct tty_struct *tty, struct file *file,
932 unsigned int set, unsigned int clear)
934 struct uart_state *state = tty->driver_data;
935 struct uart_port *uport = state->uart_port;
936 struct tty_port *port = &state->port;
939 mutex_lock(&port->mutex);
940 if ((!file || !tty_hung_up_p(file)) &&
941 !(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_count(struct uart_state *state,
1078 struct serial_icounter_struct __user *icnt)
1080 struct serial_icounter_struct icount;
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;
1100 return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1104 * Called via sys_ioctl. We can use spin_lock_irq() here.
1107 uart_ioctl(struct tty_struct *tty, struct file *filp, 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 ret = uart_get_count(state, uarg);
1159 if (ret != -ENOIOCTLCMD)
1162 mutex_lock(&port->mutex);
1164 if (tty_hung_up_p(filp)) {
1170 * All these rely on hardware being present and need to be
1171 * protected against the tty being hung up.
1174 case TIOCSERGETLSR: /* Get line status register */
1175 ret = uart_get_lsr_info(tty, state, uarg);
1179 struct uart_port *uport = state->uart_port;
1180 if (uport->ops->ioctl)
1181 ret = uport->ops->ioctl(uport, cmd, arg);
1186 mutex_unlock(&port->mutex);
1191 static void uart_set_ldisc(struct tty_struct *tty)
1193 struct uart_state *state = tty->driver_data;
1194 struct uart_port *uport = state->uart_port;
1196 if (uport->ops->set_ldisc)
1197 uport->ops->set_ldisc(uport, tty->termios->c_line);
1200 static void uart_set_termios(struct tty_struct *tty,
1201 struct ktermios *old_termios)
1203 struct uart_state *state = tty->driver_data;
1204 unsigned long flags;
1205 unsigned int cflag = tty->termios->c_cflag;
1209 * These are the bits that are used to setup various
1210 * flags in the low level driver. We can ignore the Bfoo
1211 * bits in c_cflag; c_[io]speed will always be set
1212 * appropriately by set_termios() in tty_ioctl.c
1214 #define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1215 if ((cflag ^ old_termios->c_cflag) == 0 &&
1216 tty->termios->c_ospeed == old_termios->c_ospeed &&
1217 tty->termios->c_ispeed == old_termios->c_ispeed &&
1218 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1222 uart_change_speed(tty, state, old_termios);
1224 /* Handle transition to B0 status */
1225 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1226 uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1227 /* Handle transition away from B0 status */
1228 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1229 unsigned int mask = TIOCM_DTR;
1230 if (!(cflag & CRTSCTS) ||
1231 !test_bit(TTY_THROTTLED, &tty->flags))
1233 uart_set_mctrl(state->uart_port, mask);
1236 /* Handle turning off CRTSCTS */
1237 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1238 spin_lock_irqsave(&state->uart_port->lock, flags);
1239 tty->hw_stopped = 0;
1241 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1243 /* Handle turning on CRTSCTS */
1244 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1245 spin_lock_irqsave(&state->uart_port->lock, flags);
1246 if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1247 tty->hw_stopped = 1;
1248 state->uart_port->ops->stop_tx(state->uart_port);
1250 spin_unlock_irqrestore(&state->uart_port->lock, flags);
1254 * No need to wake up processes in open wait, since they
1255 * sample the CLOCAL flag once, and don't recheck it.
1256 * XXX It's not clear whether the current behavior is correct
1257 * or not. Hence, this may change.....
1259 if (!(old_termios->c_cflag & CLOCAL) &&
1260 (tty->termios->c_cflag & CLOCAL))
1261 wake_up_interruptible(&state->uart_port.open_wait);
1266 * In 2.4.5, calls to this will be serialized via the BKL in
1267 * linux/drivers/char/tty_io.c:tty_release()
1268 * linux/drivers/char/tty_io.c:do_tty_handup()
1270 static void uart_close(struct tty_struct *tty, struct file *filp)
1272 struct uart_state *state = tty->driver_data;
1273 struct tty_port *port;
1274 struct uart_port *uport;
1275 unsigned long flags;
1277 BUG_ON(!kernel_locked());
1282 uport = state->uart_port;
1283 port = &state->port;
1285 pr_debug("uart_close(%d) called\n", uport->line);
1287 mutex_lock(&port->mutex);
1288 spin_lock_irqsave(&port->lock, flags);
1290 if (tty_hung_up_p(filp)) {
1291 spin_unlock_irqrestore(&port->lock, flags);
1295 if ((tty->count == 1) && (port->count != 1)) {
1297 * Uh, oh. tty->count is 1, which means that the tty
1298 * structure will be freed. port->count should always
1299 * be one in these conditions. If it's greater than
1300 * one, we've got real problems, since it means the
1301 * serial port won't be shutdown.
1303 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1304 "port->count is %d\n", port->count);
1307 if (--port->count < 0) {
1308 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1309 tty->name, port->count);
1313 spin_unlock_irqrestore(&port->lock, flags);
1318 * Now we wait for the transmit buffer to clear; and we notify
1319 * the line discipline to only process XON/XOFF characters by
1320 * setting tty->closing.
1323 spin_unlock_irqrestore(&port->lock, flags);
1325 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1326 tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
1329 * At this point, we stop accepting input. To do this, we
1330 * disable the receive line status interrupts.
1332 if (port->flags & ASYNC_INITIALIZED) {
1333 unsigned long flags;
1334 spin_lock_irqsave(&uport->lock, flags);
1335 uport->ops->stop_rx(uport);
1336 spin_unlock_irqrestore(&uport->lock, flags);
1338 * Before we drop DTR, make sure the UART transmitter
1339 * has completely drained; this is especially
1340 * important if there is a transmit FIFO!
1342 uart_wait_until_sent(tty, uport->timeout);
1345 uart_shutdown(tty, state);
1346 uart_flush_buffer(tty);
1348 tty_ldisc_flush(tty);
1350 tty_port_tty_set(port, NULL);
1351 spin_lock_irqsave(&port->lock, flags);
1354 if (port->blocked_open) {
1355 spin_unlock_irqrestore(&port->lock, flags);
1356 if (port->close_delay)
1357 msleep_interruptible(port->close_delay);
1358 spin_lock_irqsave(&port->lock, flags);
1359 } else if (!uart_console(uport)) {
1360 spin_unlock_irqrestore(&port->lock, flags);
1361 uart_change_pm(state, 3);
1362 spin_lock_irqsave(&port->lock, flags);
1366 * Wake up anyone trying to open this port.
1368 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1369 spin_unlock_irqrestore(&port->lock, flags);
1370 wake_up_interruptible(&port->open_wait);
1373 mutex_unlock(&port->mutex);
1376 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1378 struct uart_state *state = tty->driver_data;
1379 struct uart_port *port = state->uart_port;
1380 unsigned long char_time, expire;
1382 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1388 * Set the check interval to be 1/5 of the estimated time to
1389 * send a single character, and make it at least 1. The check
1390 * interval should also be less than the timeout.
1392 * Note: we have to use pretty tight timings here to satisfy
1395 char_time = (port->timeout - HZ/50) / port->fifosize;
1396 char_time = char_time / 5;
1399 if (timeout && timeout < char_time)
1400 char_time = timeout;
1403 * If the transmitter hasn't cleared in twice the approximate
1404 * amount of time to send the entire FIFO, it probably won't
1405 * ever clear. This assumes the UART isn't doing flow
1406 * control, which is currently the case. Hence, if it ever
1407 * takes longer than port->timeout, this is probably due to a
1408 * UART bug of some kind. So, we clamp the timeout parameter at
1411 if (timeout == 0 || timeout > 2 * port->timeout)
1412 timeout = 2 * port->timeout;
1414 expire = jiffies + timeout;
1416 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1417 port->line, jiffies, expire);
1420 * Check whether the transmitter is empty every 'char_time'.
1421 * 'timeout' / 'expire' give us the maximum amount of time
1424 while (!port->ops->tx_empty(port)) {
1425 msleep_interruptible(jiffies_to_msecs(char_time));
1426 if (signal_pending(current))
1428 if (time_after(jiffies, expire))
1431 set_current_state(TASK_RUNNING); /* might not be needed */
1436 * This is called with the BKL held in
1437 * linux/drivers/char/tty_io.c:do_tty_hangup()
1438 * We're called from the eventd thread, so we can sleep for
1439 * a _short_ time only.
1441 static void uart_hangup(struct tty_struct *tty)
1443 struct uart_state *state = tty->driver_data;
1444 struct tty_port *port = &state->port;
1445 unsigned long flags;
1447 BUG_ON(!kernel_locked());
1448 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1450 mutex_lock(&port->mutex);
1451 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1452 uart_flush_buffer(tty);
1453 uart_shutdown(tty, state);
1454 spin_lock_irqsave(&port->lock, flags);
1456 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1457 spin_unlock_irqrestore(&port->lock, flags);
1458 tty_port_tty_set(port, NULL);
1459 wake_up_interruptible(&port->open_wait);
1460 wake_up_interruptible(&port->delta_msr_wait);
1462 mutex_unlock(&port->mutex);
1466 * uart_update_termios - update the terminal hw settings
1467 * @tty: tty associated with UART
1468 * @state: UART to update
1470 * Copy across the serial console cflag setting into the termios settings
1471 * for the initial open of the port. This allows continuity between the
1472 * kernel settings, and the settings init adopts when it opens the port
1473 * for the first time.
1475 static void uart_update_termios(struct tty_struct *tty,
1476 struct uart_state *state)
1478 struct uart_port *port = state->uart_port;
1480 if (uart_console(port) && port->cons->cflag) {
1481 tty->termios->c_cflag = port->cons->cflag;
1482 port->cons->cflag = 0;
1486 * If the device failed to grab its irq resources,
1487 * or some other error occurred, don't try to talk
1488 * to the port hardware.
1490 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1492 * Make termios settings take effect.
1494 uart_change_speed(tty, state, NULL);
1497 * And finally enable the RTS and DTR signals.
1499 if (tty->termios->c_cflag & CBAUD)
1500 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1504 static int uart_carrier_raised(struct tty_port *port)
1506 struct uart_state *state = container_of(port, struct uart_state, port);
1507 struct uart_port *uport = state->uart_port;
1509 spin_lock_irq(&uport->lock);
1510 uport->ops->enable_ms(uport);
1511 mctrl = uport->ops->get_mctrl(uport);
1512 spin_unlock_irq(&uport->lock);
1513 if (mctrl & TIOCM_CAR)
1518 static void uart_dtr_rts(struct tty_port *port, int onoff)
1520 struct uart_state *state = container_of(port, struct uart_state, port);
1521 struct uart_port *uport = state->uart_port;
1524 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1526 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1529 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1531 struct uart_state *state;
1532 struct tty_port *port;
1535 state = drv->state + line;
1536 port = &state->port;
1537 if (mutex_lock_interruptible(&port->mutex)) {
1543 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1551 mutex_unlock(&port->mutex);
1553 return ERR_PTR(ret);
1557 * calls to uart_open are serialised by the BKL in
1558 * fs/char_dev.c:chrdev_open()
1559 * Note that if this fails, then uart_close() _will_ be called.
1561 * In time, we want to scrap the "opening nonpresent ports"
1562 * behaviour and implement an alternative way for setserial
1563 * to set base addresses/ports/types. This will allow us to
1564 * get rid of a certain amount of extra tests.
1566 static int uart_open(struct tty_struct *tty, struct file *filp)
1568 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1569 struct uart_state *state;
1570 struct tty_port *port;
1571 int retval, line = tty->index;
1573 BUG_ON(!kernel_locked());
1574 pr_debug("uart_open(%d) called\n", line);
1577 * tty->driver->num won't change, so we won't fail here with
1578 * tty->driver_data set to something non-NULL (and therefore
1579 * we won't get caught by uart_close()).
1582 if (line >= tty->driver->num)
1586 * We take the semaphore inside uart_get to guarantee that we won't
1587 * be re-entered while allocating the state structure, or while we
1588 * request any IRQs that the driver may need. This also has the nice
1589 * side-effect that it delays the action of uart_hangup, so we can
1590 * guarantee that state->port.tty will always contain something
1593 state = uart_get(drv, line);
1594 if (IS_ERR(state)) {
1595 retval = PTR_ERR(state);
1598 port = &state->port;
1601 * Once we set tty->driver_data here, we are guaranteed that
1602 * uart_close() will decrement the driver module use count.
1603 * Any failures from here onwards should not touch the count.
1605 tty->driver_data = state;
1606 state->uart_port->state = state;
1607 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1609 tty_port_tty_set(port, tty);
1612 * If the port is in the middle of closing, bail out now.
1614 if (tty_hung_up_p(filp)) {
1617 mutex_unlock(&port->mutex);
1622 * Make sure the device is in D0 state.
1624 if (port->count == 1)
1625 uart_change_pm(state, 0);
1628 * Start up the serial port.
1630 retval = uart_startup(tty, state, 0);
1633 * If we succeeded, wait until the port is ready.
1635 mutex_unlock(&port->mutex);
1637 retval = tty_port_block_til_ready(port, tty, filp);
1640 * If this is the first open to succeed, adjust things to suit.
1642 if (retval == 0 && !(port->flags & ASYNC_NORMAL_ACTIVE)) {
1643 set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1645 uart_update_termios(tty, state);
1652 static const char *uart_type(struct uart_port *port)
1654 const char *str = NULL;
1656 if (port->ops->type)
1657 str = port->ops->type(port);
1665 #ifdef CONFIG_PROC_FS
1667 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1669 struct uart_state *state = drv->state + i;
1670 struct tty_port *port = &state->port;
1672 struct uart_port *uport = state->uart_port;
1674 unsigned int status;
1680 mmio = uport->iotype >= UPIO_MEM;
1681 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1682 uport->line, uart_type(uport),
1683 mmio ? "mmio:0x" : "port:",
1684 mmio ? (unsigned long long)uport->mapbase
1685 : (unsigned long long)uport->iobase,
1688 if (uport->type == PORT_UNKNOWN) {
1693 if (capable(CAP_SYS_ADMIN)) {
1694 mutex_lock(&port->mutex);
1695 pm_state = state->pm_state;
1697 uart_change_pm(state, 0);
1698 spin_lock_irq(&uport->lock);
1699 status = uport->ops->get_mctrl(uport);
1700 spin_unlock_irq(&uport->lock);
1702 uart_change_pm(state, pm_state);
1703 mutex_unlock(&port->mutex);
1705 seq_printf(m, " tx:%d rx:%d",
1706 uport->icount.tx, uport->icount.rx);
1707 if (uport->icount.frame)
1708 seq_printf(m, " fe:%d",
1709 uport->icount.frame);
1710 if (uport->icount.parity)
1711 seq_printf(m, " pe:%d",
1712 uport->icount.parity);
1713 if (uport->icount.brk)
1714 seq_printf(m, " brk:%d",
1716 if (uport->icount.overrun)
1717 seq_printf(m, " oe:%d",
1718 uport->icount.overrun);
1720 #define INFOBIT(bit, str) \
1721 if (uport->mctrl & (bit)) \
1722 strncat(stat_buf, (str), sizeof(stat_buf) - \
1723 strlen(stat_buf) - 2)
1724 #define STATBIT(bit, str) \
1725 if (status & (bit)) \
1726 strncat(stat_buf, (str), sizeof(stat_buf) - \
1727 strlen(stat_buf) - 2)
1731 INFOBIT(TIOCM_RTS, "|RTS");
1732 STATBIT(TIOCM_CTS, "|CTS");
1733 INFOBIT(TIOCM_DTR, "|DTR");
1734 STATBIT(TIOCM_DSR, "|DSR");
1735 STATBIT(TIOCM_CAR, "|CD");
1736 STATBIT(TIOCM_RNG, "|RI");
1740 seq_puts(m, stat_buf);
1747 static int uart_proc_show(struct seq_file *m, void *v)
1749 struct tty_driver *ttydrv = m->private;
1750 struct uart_driver *drv = ttydrv->driver_state;
1753 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1755 for (i = 0; i < drv->nr; i++)
1756 uart_line_info(m, drv, i);
1760 static int uart_proc_open(struct inode *inode, struct file *file)
1762 return single_open(file, uart_proc_show, PDE(inode)->data);
1765 static const struct file_operations uart_proc_fops = {
1766 .owner = THIS_MODULE,
1767 .open = uart_proc_open,
1769 .llseek = seq_lseek,
1770 .release = single_release,
1774 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1776 * uart_console_write - write a console message to a serial port
1777 * @port: the port to write the message
1778 * @s: array of characters
1779 * @count: number of characters in string to write
1780 * @write: function to write character to port
1782 void uart_console_write(struct uart_port *port, const char *s,
1784 void (*putchar)(struct uart_port *, int))
1788 for (i = 0; i < count; i++, s++) {
1790 putchar(port, '\r');
1794 EXPORT_SYMBOL_GPL(uart_console_write);
1797 * Check whether an invalid uart number has been specified, and
1798 * if so, search for the first available port that does have
1801 struct uart_port * __init
1802 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1804 int idx = co->index;
1806 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1807 ports[idx].membase == NULL))
1808 for (idx = 0; idx < nr; idx++)
1809 if (ports[idx].iobase != 0 ||
1810 ports[idx].membase != NULL)
1819 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1820 * @options: pointer to option string
1821 * @baud: pointer to an 'int' variable for the baud rate.
1822 * @parity: pointer to an 'int' variable for the parity.
1823 * @bits: pointer to an 'int' variable for the number of data bits.
1824 * @flow: pointer to an 'int' variable for the flow control character.
1826 * uart_parse_options decodes a string containing the serial console
1827 * options. The format of the string is <baud><parity><bits><flow>,
1831 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1835 *baud = simple_strtoul(s, NULL, 10);
1836 while (*s >= '0' && *s <= '9')
1845 EXPORT_SYMBOL_GPL(uart_parse_options);
1852 static const struct baud_rates baud_rates[] = {
1853 { 921600, B921600 },
1854 { 460800, B460800 },
1855 { 230400, B230400 },
1856 { 115200, B115200 },
1868 * uart_set_options - setup the serial console parameters
1869 * @port: pointer to the serial ports uart_port structure
1870 * @co: console pointer
1872 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1873 * @bits: number of data bits
1874 * @flow: flow control character - 'r' (rts)
1877 uart_set_options(struct uart_port *port, struct console *co,
1878 int baud, int parity, int bits, int flow)
1880 struct ktermios termios;
1881 static struct ktermios dummy;
1885 * Ensure that the serial console lock is initialised
1888 spin_lock_init(&port->lock);
1889 lockdep_set_class(&port->lock, &port_lock_key);
1891 memset(&termios, 0, sizeof(struct ktermios));
1893 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1896 * Construct a cflag setting.
1898 for (i = 0; baud_rates[i].rate; i++)
1899 if (baud_rates[i].rate <= baud)
1902 termios.c_cflag |= baud_rates[i].cflag;
1905 termios.c_cflag |= CS7;
1907 termios.c_cflag |= CS8;
1911 termios.c_cflag |= PARODD;
1914 termios.c_cflag |= PARENB;
1919 termios.c_cflag |= CRTSCTS;
1922 * some uarts on other side don't support no flow control.
1923 * So we set * DTR in host uart to make them happy
1925 port->mctrl |= TIOCM_DTR;
1927 port->ops->set_termios(port, &termios, &dummy);
1929 * Allow the setting of the UART parameters with a NULL console
1933 co->cflag = termios.c_cflag;
1937 EXPORT_SYMBOL_GPL(uart_set_options);
1938 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1940 static void uart_change_pm(struct uart_state *state, int pm_state)
1942 struct uart_port *port = state->uart_port;
1944 if (state->pm_state != pm_state) {
1946 port->ops->pm(port, pm_state, state->pm_state);
1947 state->pm_state = pm_state;
1952 struct uart_port *port;
1953 struct uart_driver *driver;
1956 static int serial_match_port(struct device *dev, void *data)
1958 struct uart_match *match = data;
1959 struct tty_driver *tty_drv = match->driver->tty_driver;
1960 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1963 return dev->devt == devt; /* Actually, only one tty per port */
1966 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1968 struct uart_state *state = drv->state + uport->line;
1969 struct tty_port *port = &state->port;
1970 struct device *tty_dev;
1971 struct uart_match match = {uport, drv};
1972 struct tty_struct *tty;
1974 mutex_lock(&port->mutex);
1976 /* Must be inside the mutex lock until we convert to tty_port */
1979 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1980 if (device_may_wakeup(tty_dev)) {
1981 enable_irq_wake(uport->irq);
1982 put_device(tty_dev);
1983 mutex_unlock(&port->mutex);
1986 if (console_suspend_enabled || !uart_console(uport))
1987 uport->suspended = 1;
1989 if (port->flags & ASYNC_INITIALIZED) {
1990 const struct uart_ops *ops = uport->ops;
1993 if (console_suspend_enabled || !uart_console(uport)) {
1994 set_bit(ASYNCB_SUSPENDED, &port->flags);
1995 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1997 spin_lock_irq(&uport->lock);
1998 ops->stop_tx(uport);
1999 ops->set_mctrl(uport, 0);
2000 ops->stop_rx(uport);
2001 spin_unlock_irq(&uport->lock);
2005 * Wait for the transmitter to empty.
2007 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2010 printk(KERN_ERR "%s%s%s%d: Unable to drain "
2012 uport->dev ? dev_name(uport->dev) : "",
2013 uport->dev ? ": " : "",
2015 drv->tty_driver->name_base + uport->line);
2017 if (console_suspend_enabled || !uart_console(uport))
2018 ops->shutdown(uport);
2022 * Disable the console device before suspending.
2024 if (console_suspend_enabled && uart_console(uport))
2025 console_stop(uport->cons);
2027 if (console_suspend_enabled || !uart_console(uport))
2028 uart_change_pm(state, 3);
2030 mutex_unlock(&port->mutex);
2035 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2037 struct uart_state *state = drv->state + uport->line;
2038 struct tty_port *port = &state->port;
2039 struct device *tty_dev;
2040 struct uart_match match = {uport, drv};
2041 struct ktermios termios;
2043 mutex_lock(&port->mutex);
2045 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2046 if (!uport->suspended && device_may_wakeup(tty_dev)) {
2047 disable_irq_wake(uport->irq);
2048 mutex_unlock(&port->mutex);
2051 uport->suspended = 0;
2054 * Re-enable the console device after suspending.
2056 if (uart_console(uport)) {
2057 uart_change_pm(state, 0);
2058 uport->ops->set_termios(uport, &termios, NULL);
2059 console_start(uport->cons);
2062 if (port->flags & ASYNC_SUSPENDED) {
2063 const struct uart_ops *ops = uport->ops;
2066 uart_change_pm(state, 0);
2067 spin_lock_irq(&uport->lock);
2068 ops->set_mctrl(uport, 0);
2069 spin_unlock_irq(&uport->lock);
2070 if (console_suspend_enabled || !uart_console(uport)) {
2071 /* Protected by port mutex for now */
2072 struct tty_struct *tty = port->tty;
2073 ret = ops->startup(uport);
2076 uart_change_speed(tty, state, NULL);
2077 spin_lock_irq(&uport->lock);
2078 ops->set_mctrl(uport, uport->mctrl);
2079 ops->start_tx(uport);
2080 spin_unlock_irq(&uport->lock);
2081 set_bit(ASYNCB_INITIALIZED, &port->flags);
2084 * Failed to resume - maybe hardware went away?
2085 * Clear the "initialized" flag so we won't try
2086 * to call the low level drivers shutdown method.
2088 uart_shutdown(tty, state);
2092 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2095 mutex_unlock(&port->mutex);
2101 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2105 switch (port->iotype) {
2107 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2110 snprintf(address, sizeof(address),
2111 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2118 snprintf(address, sizeof(address),
2119 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2122 strlcpy(address, "*unknown*", sizeof(address));
2126 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2127 port->dev ? dev_name(port->dev) : "",
2128 port->dev ? ": " : "",
2130 drv->tty_driver->name_base + port->line,
2131 address, port->irq, uart_type(port));
2135 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2136 struct uart_port *port)
2141 * If there isn't a port here, don't do anything further.
2143 if (!port->iobase && !port->mapbase && !port->membase)
2147 * Now do the auto configuration stuff. Note that config_port
2148 * is expected to claim the resources and map the port for us.
2151 if (port->flags & UPF_AUTO_IRQ)
2152 flags |= UART_CONFIG_IRQ;
2153 if (port->flags & UPF_BOOT_AUTOCONF) {
2154 if (!(port->flags & UPF_FIXED_TYPE)) {
2155 port->type = PORT_UNKNOWN;
2156 flags |= UART_CONFIG_TYPE;
2158 port->ops->config_port(port, flags);
2161 if (port->type != PORT_UNKNOWN) {
2162 unsigned long flags;
2164 uart_report_port(drv, port);
2166 /* Power up port for set_mctrl() */
2167 uart_change_pm(state, 0);
2170 * Ensure that the modem control lines are de-activated.
2171 * keep the DTR setting that is set in uart_set_options()
2172 * We probably don't need a spinlock around this, but
2174 spin_lock_irqsave(&port->lock, flags);
2175 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2176 spin_unlock_irqrestore(&port->lock, flags);
2179 * If this driver supports console, and it hasn't been
2180 * successfully registered yet, try to re-register it.
2181 * It may be that the port was not available.
2183 if (port->cons && !(port->cons->flags & CON_ENABLED))
2184 register_console(port->cons);
2187 * Power down all ports by default, except the
2188 * console if we have one.
2190 if (!uart_console(port))
2191 uart_change_pm(state, 3);
2195 #ifdef CONFIG_CONSOLE_POLL
2197 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2199 struct uart_driver *drv = driver->driver_state;
2200 struct uart_state *state = drv->state + line;
2201 struct uart_port *port;
2207 if (!state || !state->uart_port)
2210 port = state->uart_port;
2211 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2215 uart_parse_options(options, &baud, &parity, &bits, &flow);
2216 return uart_set_options(port, NULL, baud, parity, bits, flow);
2222 static int uart_poll_get_char(struct tty_driver *driver, int line)
2224 struct uart_driver *drv = driver->driver_state;
2225 struct uart_state *state = drv->state + line;
2226 struct uart_port *port;
2228 if (!state || !state->uart_port)
2231 port = state->uart_port;
2232 return port->ops->poll_get_char(port);
2235 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2237 struct uart_driver *drv = driver->driver_state;
2238 struct uart_state *state = drv->state + line;
2239 struct uart_port *port;
2241 if (!state || !state->uart_port)
2244 port = state->uart_port;
2245 port->ops->poll_put_char(port, ch);
2249 static const struct tty_operations uart_ops = {
2251 .close = uart_close,
2252 .write = uart_write,
2253 .put_char = uart_put_char,
2254 .flush_chars = uart_flush_chars,
2255 .write_room = uart_write_room,
2256 .chars_in_buffer= uart_chars_in_buffer,
2257 .flush_buffer = uart_flush_buffer,
2258 .ioctl = uart_ioctl,
2259 .throttle = uart_throttle,
2260 .unthrottle = uart_unthrottle,
2261 .send_xchar = uart_send_xchar,
2262 .set_termios = uart_set_termios,
2263 .set_ldisc = uart_set_ldisc,
2265 .start = uart_start,
2266 .hangup = uart_hangup,
2267 .break_ctl = uart_break_ctl,
2268 .wait_until_sent= uart_wait_until_sent,
2269 #ifdef CONFIG_PROC_FS
2270 .proc_fops = &uart_proc_fops,
2272 .tiocmget = uart_tiocmget,
2273 .tiocmset = uart_tiocmset,
2274 #ifdef CONFIG_CONSOLE_POLL
2275 .poll_init = uart_poll_init,
2276 .poll_get_char = uart_poll_get_char,
2277 .poll_put_char = uart_poll_put_char,
2281 static const struct tty_port_operations uart_port_ops = {
2282 .carrier_raised = uart_carrier_raised,
2283 .dtr_rts = uart_dtr_rts,
2287 * uart_register_driver - register a driver with the uart core layer
2288 * @drv: low level driver structure
2290 * Register a uart driver with the core driver. We in turn register
2291 * with the tty layer, and initialise the core driver per-port state.
2293 * We have a proc file in /proc/tty/driver which is named after the
2296 * drv->port should be NULL, and the per-port structures should be
2297 * registered using uart_add_one_port after this call has succeeded.
2299 int uart_register_driver(struct uart_driver *drv)
2301 struct tty_driver *normal;
2307 * Maybe we should be using a slab cache for this, especially if
2308 * we have a large number of ports to handle.
2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2314 normal = alloc_tty_driver(drv->nr);
2318 drv->tty_driver = normal;
2320 normal->owner = drv->owner;
2321 normal->driver_name = drv->driver_name;
2322 normal->name = drv->dev_name;
2323 normal->major = drv->major;
2324 normal->minor_start = drv->minor;
2325 normal->type = TTY_DRIVER_TYPE_SERIAL;
2326 normal->subtype = SERIAL_TYPE_NORMAL;
2327 normal->init_termios = tty_std_termios;
2328 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2329 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2330 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2331 normal->driver_state = drv;
2332 tty_set_operations(normal, &uart_ops);
2335 * Initialise the UART state(s).
2337 for (i = 0; i < drv->nr; i++) {
2338 struct uart_state *state = drv->state + i;
2339 struct tty_port *port = &state->port;
2341 tty_port_init(port);
2342 port->ops = &uart_port_ops;
2343 port->close_delay = 500; /* .5 seconds */
2344 port->closing_wait = 30000; /* 30 seconds */
2345 tasklet_init(&state->tlet, uart_tasklet_action,
2346 (unsigned long)state);
2349 retval = tty_register_driver(normal);
2353 put_tty_driver(normal);
2361 * uart_unregister_driver - remove a driver from the uart core layer
2362 * @drv: low level driver structure
2364 * Remove all references to a driver from the core driver. The low
2365 * level driver must have removed all its ports via the
2366 * uart_remove_one_port() if it registered them with uart_add_one_port().
2367 * (ie, drv->port == NULL)
2369 void uart_unregister_driver(struct uart_driver *drv)
2371 struct tty_driver *p = drv->tty_driver;
2372 tty_unregister_driver(p);
2375 drv->tty_driver = NULL;
2378 struct tty_driver *uart_console_device(struct console *co, int *index)
2380 struct uart_driver *p = co->data;
2382 return p->tty_driver;
2386 * uart_add_one_port - attach a driver-defined port structure
2387 * @drv: pointer to the uart low level driver structure for this port
2388 * @uport: uart port structure to use for this port.
2390 * This allows the driver to register its own uart_port structure
2391 * with the core driver. The main purpose is to allow the low
2392 * level uart drivers to expand uart_port, rather than having yet
2393 * more levels of structures.
2395 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2397 struct uart_state *state;
2398 struct tty_port *port;
2400 struct device *tty_dev;
2402 BUG_ON(in_interrupt());
2404 if (uport->line >= drv->nr)
2407 state = drv->state + uport->line;
2408 port = &state->port;
2410 mutex_lock(&port_mutex);
2411 mutex_lock(&port->mutex);
2412 if (state->uart_port) {
2417 state->uart_port = uport;
2418 state->pm_state = -1;
2420 uport->cons = drv->cons;
2421 uport->state = state;
2424 * If this port is a console, then the spinlock is already
2427 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2428 spin_lock_init(&uport->lock);
2429 lockdep_set_class(&uport->lock, &port_lock_key);
2432 uart_configure_port(drv, state, uport);
2435 * Register the port whether it's detected or not. This allows
2436 * setserial to be used to alter this ports parameters.
2438 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2439 if (likely(!IS_ERR(tty_dev))) {
2440 device_init_wakeup(tty_dev, 1);
2441 device_set_wakeup_enable(tty_dev, 0);
2443 printk(KERN_ERR "Cannot register tty device on line %d\n",
2447 * Ensure UPF_DEAD is not set.
2449 uport->flags &= ~UPF_DEAD;
2452 mutex_unlock(&port->mutex);
2453 mutex_unlock(&port_mutex);
2459 * uart_remove_one_port - detach a driver defined port structure
2460 * @drv: pointer to the uart low level driver structure for this port
2461 * @uport: uart port structure for this port
2463 * This unhooks (and hangs up) the specified port structure from the
2464 * core driver. No further calls will be made to the low-level code
2467 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2469 struct uart_state *state = drv->state + uport->line;
2470 struct tty_port *port = &state->port;
2472 BUG_ON(in_interrupt());
2474 if (state->uart_port != uport)
2475 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2476 state->uart_port, uport);
2478 mutex_lock(&port_mutex);
2481 * Mark the port "dead" - this prevents any opens from
2482 * succeeding while we shut down the port.
2484 mutex_lock(&port->mutex);
2485 uport->flags |= UPF_DEAD;
2486 mutex_unlock(&port->mutex);
2489 * Remove the devices from the tty layer
2491 tty_unregister_device(drv->tty_driver, uport->line);
2494 tty_vhangup(port->tty);
2497 * Free the port IO and memory resources, if any.
2499 if (uport->type != PORT_UNKNOWN)
2500 uport->ops->release_port(uport);
2503 * Indicate that there isn't a port here anymore.
2505 uport->type = PORT_UNKNOWN;
2508 * Kill the tasklet, and free resources.
2510 tasklet_kill(&state->tlet);
2512 state->uart_port = NULL;
2513 mutex_unlock(&port_mutex);
2519 * Are the two ports equivalent?
2521 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2523 if (port1->iotype != port2->iotype)
2526 switch (port1->iotype) {
2528 return (port1->iobase == port2->iobase);
2530 return (port1->iobase == port2->iobase) &&
2531 (port1->hub6 == port2->hub6);
2537 return (port1->mapbase == port2->mapbase);
2541 EXPORT_SYMBOL(uart_match_port);
2543 EXPORT_SYMBOL(uart_write_wakeup);
2544 EXPORT_SYMBOL(uart_register_driver);
2545 EXPORT_SYMBOL(uart_unregister_driver);
2546 EXPORT_SYMBOL(uart_suspend_port);
2547 EXPORT_SYMBOL(uart_resume_port);
2548 EXPORT_SYMBOL(uart_add_one_port);
2549 EXPORT_SYMBOL(uart_remove_one_port);
2551 MODULE_DESCRIPTION("Serial driver core");
2552 MODULE_LICENSE("GPL");