Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[zen-stable.git] / drivers / tty / serial / serial_core.c
blobdb7912cb7ae041a71a901437d3c835ee242530a9
1 /*
2 * Driver core for serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Copyright 1999 ARM Limited
7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/module.h>
24 #include <linux/tty.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/device.h>
31 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
32 #include <linux/serial_core.h>
33 #include <linux/delay.h>
34 #include <linux/mutex.h>
36 #include <asm/irq.h>
37 #include <asm/uaccess.h>
40 * This is used to lock changes in serial line configuration.
42 static DEFINE_MUTEX(port_mutex);
45 * lockdep: port->lock is initialized in two places, but we
46 * want only one lock-class:
48 static struct lock_class_key port_lock_key;
50 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52 #ifdef CONFIG_SERIAL_CORE_CONSOLE
53 #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
54 #else
55 #define uart_console(port) (0)
56 #endif
58 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
59 struct ktermios *old_termios);
60 static void __uart_wait_until_sent(struct uart_port *port, int timeout);
61 static void uart_change_pm(struct uart_state *state, int pm_state);
64 * This routine is used by the interrupt handler to schedule processing in
65 * the software interrupt portion of the driver.
67 void uart_write_wakeup(struct uart_port *port)
69 struct uart_state *state = port->state;
71 * This means you called this function _after_ the port was
72 * closed. No cookie for you.
74 BUG_ON(!state);
75 tasklet_schedule(&state->tlet);
78 static void uart_stop(struct tty_struct *tty)
80 struct uart_state *state = tty->driver_data;
81 struct uart_port *port = state->uart_port;
82 unsigned long flags;
84 spin_lock_irqsave(&port->lock, flags);
85 port->ops->stop_tx(port);
86 spin_unlock_irqrestore(&port->lock, flags);
89 static void __uart_start(struct tty_struct *tty)
91 struct uart_state *state = tty->driver_data;
92 struct uart_port *port = state->uart_port;
94 if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
95 !tty->stopped && !tty->hw_stopped)
96 port->ops->start_tx(port);
99 static void uart_start(struct tty_struct *tty)
101 struct uart_state *state = tty->driver_data;
102 struct uart_port *port = state->uart_port;
103 unsigned long flags;
105 spin_lock_irqsave(&port->lock, flags);
106 __uart_start(tty);
107 spin_unlock_irqrestore(&port->lock, flags);
110 static void uart_tasklet_action(unsigned long data)
112 struct uart_state *state = (struct uart_state *)data;
113 tty_wakeup(state->port.tty);
116 static inline void
117 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
119 unsigned long flags;
120 unsigned int old;
122 spin_lock_irqsave(&port->lock, flags);
123 old = port->mctrl;
124 port->mctrl = (old & ~clear) | set;
125 if (old != port->mctrl)
126 port->ops->set_mctrl(port, port->mctrl);
127 spin_unlock_irqrestore(&port->lock, flags);
130 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
131 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
134 * Startup the port. This will be called once per open. All calls
135 * will be serialised by the per-port mutex.
137 static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
139 struct uart_port *uport = state->uart_port;
140 struct tty_port *port = &state->port;
141 unsigned long page;
142 int retval = 0;
144 if (port->flags & ASYNC_INITIALIZED)
145 return 0;
148 * Set the TTY IO error marker - we will only clear this
149 * once we have successfully opened the port. Also set
150 * up the tty->alt_speed kludge
152 set_bit(TTY_IO_ERROR, &tty->flags);
154 if (uport->type == PORT_UNKNOWN)
155 return 0;
158 * Initialise and allocate the transmit and temporary
159 * buffer.
161 if (!state->xmit.buf) {
162 /* This is protected by the per port mutex */
163 page = get_zeroed_page(GFP_KERNEL);
164 if (!page)
165 return -ENOMEM;
167 state->xmit.buf = (unsigned char *) page;
168 uart_circ_clear(&state->xmit);
171 retval = uport->ops->startup(uport);
172 if (retval == 0) {
173 if (uart_console(uport) && uport->cons->cflag) {
174 tty->termios->c_cflag = uport->cons->cflag;
175 uport->cons->cflag = 0;
178 * Initialise the hardware port settings.
180 uart_change_speed(tty, state, NULL);
182 if (init_hw) {
184 * Setup the RTS and DTR signals once the
185 * port is open and ready to respond.
187 if (tty->termios->c_cflag & CBAUD)
188 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
191 if (port->flags & ASYNC_CTS_FLOW) {
192 spin_lock_irq(&uport->lock);
193 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
194 tty->hw_stopped = 1;
195 spin_unlock_irq(&uport->lock);
198 set_bit(ASYNCB_INITIALIZED, &port->flags);
200 clear_bit(TTY_IO_ERROR, &tty->flags);
203 if (retval && capable(CAP_SYS_ADMIN))
204 retval = 0;
206 return retval;
210 * This routine will shutdown a serial port; interrupts are disabled, and
211 * DTR is dropped if the hangup on close termio flag is on. Calls to
212 * uart_shutdown are serialised by the per-port semaphore.
214 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
216 struct uart_port *uport = state->uart_port;
217 struct tty_port *port = &state->port;
220 * Set the TTY IO error marker
222 if (tty)
223 set_bit(TTY_IO_ERROR, &tty->flags);
225 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
227 * Turn off DTR and RTS early.
229 if (!tty || (tty->termios->c_cflag & HUPCL))
230 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
233 * clear delta_msr_wait queue to avoid mem leaks: we may free
234 * the irq here so the queue might never be woken up. Note
235 * that we won't end up waiting on delta_msr_wait again since
236 * any outstanding file descriptors should be pointing at
237 * hung_up_tty_fops now.
239 wake_up_interruptible(&port->delta_msr_wait);
242 * Free the IRQ and disable the port.
244 uport->ops->shutdown(uport);
247 * Ensure that the IRQ handler isn't running on another CPU.
249 synchronize_irq(uport->irq);
253 * kill off our tasklet
255 tasklet_kill(&state->tlet);
258 * Free the transmit buffer page.
260 if (state->xmit.buf) {
261 free_page((unsigned long)state->xmit.buf);
262 state->xmit.buf = NULL;
267 * uart_update_timeout - update per-port FIFO timeout.
268 * @port: uart_port structure describing the port
269 * @cflag: termios cflag value
270 * @baud: speed of the port
272 * Set the port FIFO timeout value. The @cflag value should
273 * reflect the actual hardware settings.
275 void
276 uart_update_timeout(struct uart_port *port, unsigned int cflag,
277 unsigned int baud)
279 unsigned int bits;
281 /* byte size and parity */
282 switch (cflag & CSIZE) {
283 case CS5:
284 bits = 7;
285 break;
286 case CS6:
287 bits = 8;
288 break;
289 case CS7:
290 bits = 9;
291 break;
292 default:
293 bits = 10;
294 break; /* CS8 */
297 if (cflag & CSTOPB)
298 bits++;
299 if (cflag & PARENB)
300 bits++;
303 * The total number of bits to be transmitted in the fifo.
305 bits = bits * port->fifosize;
308 * Figure the timeout to send the above number of bits.
309 * Add .02 seconds of slop
311 port->timeout = (HZ * bits) / baud + HZ/50;
314 EXPORT_SYMBOL(uart_update_timeout);
317 * uart_get_baud_rate - return baud rate for a particular port
318 * @port: uart_port structure describing the port in question.
319 * @termios: desired termios settings.
320 * @old: old termios (or NULL)
321 * @min: minimum acceptable baud rate
322 * @max: maximum acceptable baud rate
324 * Decode the termios structure into a numeric baud rate,
325 * taking account of the magic 38400 baud rate (with spd_*
326 * flags), and mapping the %B0 rate to 9600 baud.
328 * If the new baud rate is invalid, try the old termios setting.
329 * If it's still invalid, we try 9600 baud.
331 * Update the @termios structure to reflect the baud rate
332 * we're actually going to be using. Don't do this for the case
333 * where B0 is requested ("hang up").
335 unsigned int
336 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
337 struct ktermios *old, unsigned int min, unsigned int max)
339 unsigned int try, baud, altbaud = 38400;
340 int hung_up = 0;
341 upf_t flags = port->flags & UPF_SPD_MASK;
343 if (flags == UPF_SPD_HI)
344 altbaud = 57600;
345 else if (flags == UPF_SPD_VHI)
346 altbaud = 115200;
347 else if (flags == UPF_SPD_SHI)
348 altbaud = 230400;
349 else if (flags == UPF_SPD_WARP)
350 altbaud = 460800;
352 for (try = 0; try < 2; try++) {
353 baud = tty_termios_baud_rate(termios);
356 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
357 * Die! Die! Die!
359 if (baud == 38400)
360 baud = altbaud;
363 * Special case: B0 rate.
365 if (baud == 0) {
366 hung_up = 1;
367 baud = 9600;
370 if (baud >= min && baud <= max)
371 return baud;
374 * Oops, the quotient was zero. Try again with
375 * the old baud rate if possible.
377 termios->c_cflag &= ~CBAUD;
378 if (old) {
379 baud = tty_termios_baud_rate(old);
380 if (!hung_up)
381 tty_termios_encode_baud_rate(termios,
382 baud, baud);
383 old = NULL;
384 continue;
388 * As a last resort, if the range cannot be met then clip to
389 * the nearest chip supported rate.
391 if (!hung_up) {
392 if (baud <= min)
393 tty_termios_encode_baud_rate(termios,
394 min + 1, min + 1);
395 else
396 tty_termios_encode_baud_rate(termios,
397 max - 1, max - 1);
400 /* Should never happen */
401 WARN_ON(1);
402 return 0;
405 EXPORT_SYMBOL(uart_get_baud_rate);
408 * uart_get_divisor - return uart clock divisor
409 * @port: uart_port structure describing the port.
410 * @baud: desired baud rate
412 * Calculate the uart clock divisor for the port.
414 unsigned int
415 uart_get_divisor(struct uart_port *port, unsigned int baud)
417 unsigned int quot;
420 * Old custom speed handling.
422 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
423 quot = port->custom_divisor;
424 else
425 quot = (port->uartclk + (8 * baud)) / (16 * baud);
427 return quot;
430 EXPORT_SYMBOL(uart_get_divisor);
432 /* FIXME: Consistent locking policy */
433 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
434 struct ktermios *old_termios)
436 struct tty_port *port = &state->port;
437 struct uart_port *uport = state->uart_port;
438 struct ktermios *termios;
441 * If we have no tty, termios, or the port does not exist,
442 * then we can't set the parameters for this port.
444 if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
445 return;
447 termios = tty->termios;
450 * Set flags based on termios cflag
452 if (termios->c_cflag & CRTSCTS)
453 set_bit(ASYNCB_CTS_FLOW, &port->flags);
454 else
455 clear_bit(ASYNCB_CTS_FLOW, &port->flags);
457 if (termios->c_cflag & CLOCAL)
458 clear_bit(ASYNCB_CHECK_CD, &port->flags);
459 else
460 set_bit(ASYNCB_CHECK_CD, &port->flags);
462 uport->ops->set_termios(uport, termios, old_termios);
465 static inline int __uart_put_char(struct uart_port *port,
466 struct circ_buf *circ, unsigned char c)
468 unsigned long flags;
469 int ret = 0;
471 if (!circ->buf)
472 return 0;
474 spin_lock_irqsave(&port->lock, flags);
475 if (uart_circ_chars_free(circ) != 0) {
476 circ->buf[circ->head] = c;
477 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
478 ret = 1;
480 spin_unlock_irqrestore(&port->lock, flags);
481 return ret;
484 static int uart_put_char(struct tty_struct *tty, unsigned char ch)
486 struct uart_state *state = tty->driver_data;
488 return __uart_put_char(state->uart_port, &state->xmit, ch);
491 static void uart_flush_chars(struct tty_struct *tty)
493 uart_start(tty);
496 static int uart_write(struct tty_struct *tty,
497 const unsigned char *buf, int count)
499 struct uart_state *state = tty->driver_data;
500 struct uart_port *port;
501 struct circ_buf *circ;
502 unsigned long flags;
503 int c, ret = 0;
506 * This means you called this function _after_ the port was
507 * closed. No cookie for you.
509 if (!state) {
510 WARN_ON(1);
511 return -EL3HLT;
514 port = state->uart_port;
515 circ = &state->xmit;
517 if (!circ->buf)
518 return 0;
520 spin_lock_irqsave(&port->lock, flags);
521 while (1) {
522 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
523 if (count < c)
524 c = count;
525 if (c <= 0)
526 break;
527 memcpy(circ->buf + circ->head, buf, c);
528 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
529 buf += c;
530 count -= c;
531 ret += c;
533 spin_unlock_irqrestore(&port->lock, flags);
535 uart_start(tty);
536 return ret;
539 static int uart_write_room(struct tty_struct *tty)
541 struct uart_state *state = tty->driver_data;
542 unsigned long flags;
543 int ret;
545 spin_lock_irqsave(&state->uart_port->lock, flags);
546 ret = uart_circ_chars_free(&state->xmit);
547 spin_unlock_irqrestore(&state->uart_port->lock, flags);
548 return ret;
551 static int uart_chars_in_buffer(struct tty_struct *tty)
553 struct uart_state *state = tty->driver_data;
554 unsigned long flags;
555 int ret;
557 spin_lock_irqsave(&state->uart_port->lock, flags);
558 ret = uart_circ_chars_pending(&state->xmit);
559 spin_unlock_irqrestore(&state->uart_port->lock, flags);
560 return ret;
563 static void uart_flush_buffer(struct tty_struct *tty)
565 struct uart_state *state = tty->driver_data;
566 struct uart_port *port;
567 unsigned long flags;
570 * This means you called this function _after_ the port was
571 * closed. No cookie for you.
573 if (!state) {
574 WARN_ON(1);
575 return;
578 port = state->uart_port;
579 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
581 spin_lock_irqsave(&port->lock, flags);
582 uart_circ_clear(&state->xmit);
583 if (port->ops->flush_buffer)
584 port->ops->flush_buffer(port);
585 spin_unlock_irqrestore(&port->lock, flags);
586 tty_wakeup(tty);
590 * This function is used to send a high-priority XON/XOFF character to
591 * the device
593 static void uart_send_xchar(struct tty_struct *tty, char ch)
595 struct uart_state *state = tty->driver_data;
596 struct uart_port *port = state->uart_port;
597 unsigned long flags;
599 if (port->ops->send_xchar)
600 port->ops->send_xchar(port, ch);
601 else {
602 port->x_char = ch;
603 if (ch) {
604 spin_lock_irqsave(&port->lock, flags);
605 port->ops->start_tx(port);
606 spin_unlock_irqrestore(&port->lock, flags);
611 static void uart_throttle(struct tty_struct *tty)
613 struct uart_state *state = tty->driver_data;
615 if (I_IXOFF(tty))
616 uart_send_xchar(tty, STOP_CHAR(tty));
618 if (tty->termios->c_cflag & CRTSCTS)
619 uart_clear_mctrl(state->uart_port, TIOCM_RTS);
622 static void uart_unthrottle(struct tty_struct *tty)
624 struct uart_state *state = tty->driver_data;
625 struct uart_port *port = state->uart_port;
627 if (I_IXOFF(tty)) {
628 if (port->x_char)
629 port->x_char = 0;
630 else
631 uart_send_xchar(tty, START_CHAR(tty));
634 if (tty->termios->c_cflag & CRTSCTS)
635 uart_set_mctrl(port, TIOCM_RTS);
638 static int uart_get_info(struct uart_state *state,
639 struct serial_struct __user *retinfo)
641 struct uart_port *uport = state->uart_port;
642 struct tty_port *port = &state->port;
643 struct serial_struct tmp;
645 memset(&tmp, 0, sizeof(tmp));
647 /* Ensure the state we copy is consistent and no hardware changes
648 occur as we go */
649 mutex_lock(&port->mutex);
651 tmp.type = uport->type;
652 tmp.line = uport->line;
653 tmp.port = uport->iobase;
654 if (HIGH_BITS_OFFSET)
655 tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
656 tmp.irq = uport->irq;
657 tmp.flags = uport->flags;
658 tmp.xmit_fifo_size = uport->fifosize;
659 tmp.baud_base = uport->uartclk / 16;
660 tmp.close_delay = port->close_delay / 10;
661 tmp.closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
662 ASYNC_CLOSING_WAIT_NONE :
663 port->closing_wait / 10;
664 tmp.custom_divisor = uport->custom_divisor;
665 tmp.hub6 = uport->hub6;
666 tmp.io_type = uport->iotype;
667 tmp.iomem_reg_shift = uport->regshift;
668 tmp.iomem_base = (void *)(unsigned long)uport->mapbase;
670 mutex_unlock(&port->mutex);
672 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
673 return -EFAULT;
674 return 0;
677 static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
678 struct serial_struct __user *newinfo)
680 struct serial_struct new_serial;
681 struct uart_port *uport = state->uart_port;
682 struct tty_port *port = &state->port;
683 unsigned long new_port;
684 unsigned int change_irq, change_port, closing_wait;
685 unsigned int old_custom_divisor, close_delay;
686 upf_t old_flags, new_flags;
687 int retval = 0;
689 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
690 return -EFAULT;
692 new_port = new_serial.port;
693 if (HIGH_BITS_OFFSET)
694 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
696 new_serial.irq = irq_canonicalize(new_serial.irq);
697 close_delay = new_serial.close_delay * 10;
698 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
699 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
702 * This semaphore protects port->count. It is also
703 * very useful to prevent opens. Also, take the
704 * port configuration semaphore to make sure that a
705 * module insertion/removal doesn't change anything
706 * under us.
708 mutex_lock(&port->mutex);
710 change_irq = !(uport->flags & UPF_FIXED_PORT)
711 && new_serial.irq != uport->irq;
714 * Since changing the 'type' of the port changes its resource
715 * allocations, we should treat type changes the same as
716 * IO port changes.
718 change_port = !(uport->flags & UPF_FIXED_PORT)
719 && (new_port != uport->iobase ||
720 (unsigned long)new_serial.iomem_base != uport->mapbase ||
721 new_serial.hub6 != uport->hub6 ||
722 new_serial.io_type != uport->iotype ||
723 new_serial.iomem_reg_shift != uport->regshift ||
724 new_serial.type != uport->type);
726 old_flags = uport->flags;
727 new_flags = new_serial.flags;
728 old_custom_divisor = uport->custom_divisor;
730 if (!capable(CAP_SYS_ADMIN)) {
731 retval = -EPERM;
732 if (change_irq || change_port ||
733 (new_serial.baud_base != uport->uartclk / 16) ||
734 (close_delay != port->close_delay) ||
735 (closing_wait != port->closing_wait) ||
736 (new_serial.xmit_fifo_size &&
737 new_serial.xmit_fifo_size != uport->fifosize) ||
738 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
739 goto exit;
740 uport->flags = ((uport->flags & ~UPF_USR_MASK) |
741 (new_flags & UPF_USR_MASK));
742 uport->custom_divisor = new_serial.custom_divisor;
743 goto check_and_exit;
747 * Ask the low level driver to verify the settings.
749 if (uport->ops->verify_port)
750 retval = uport->ops->verify_port(uport, &new_serial);
752 if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
753 (new_serial.baud_base < 9600))
754 retval = -EINVAL;
756 if (retval)
757 goto exit;
759 if (change_port || change_irq) {
760 retval = -EBUSY;
763 * Make sure that we are the sole user of this port.
765 if (tty_port_users(port) > 1)
766 goto exit;
769 * We need to shutdown the serial port at the old
770 * port/type/irq combination.
772 uart_shutdown(tty, state);
775 if (change_port) {
776 unsigned long old_iobase, old_mapbase;
777 unsigned int old_type, old_iotype, old_hub6, old_shift;
779 old_iobase = uport->iobase;
780 old_mapbase = uport->mapbase;
781 old_type = uport->type;
782 old_hub6 = uport->hub6;
783 old_iotype = uport->iotype;
784 old_shift = uport->regshift;
787 * Free and release old regions
789 if (old_type != PORT_UNKNOWN)
790 uport->ops->release_port(uport);
792 uport->iobase = new_port;
793 uport->type = new_serial.type;
794 uport->hub6 = new_serial.hub6;
795 uport->iotype = new_serial.io_type;
796 uport->regshift = new_serial.iomem_reg_shift;
797 uport->mapbase = (unsigned long)new_serial.iomem_base;
800 * Claim and map the new regions
802 if (uport->type != PORT_UNKNOWN) {
803 retval = uport->ops->request_port(uport);
804 } else {
805 /* Always success - Jean II */
806 retval = 0;
810 * If we fail to request resources for the
811 * new port, try to restore the old settings.
813 if (retval && old_type != PORT_UNKNOWN) {
814 uport->iobase = old_iobase;
815 uport->type = old_type;
816 uport->hub6 = old_hub6;
817 uport->iotype = old_iotype;
818 uport->regshift = old_shift;
819 uport->mapbase = old_mapbase;
820 retval = uport->ops->request_port(uport);
822 * If we failed to restore the old settings,
823 * we fail like this.
825 if (retval)
826 uport->type = PORT_UNKNOWN;
829 * We failed anyway.
831 retval = -EBUSY;
832 /* Added to return the correct error -Ram Gupta */
833 goto exit;
837 if (change_irq)
838 uport->irq = new_serial.irq;
839 if (!(uport->flags & UPF_FIXED_PORT))
840 uport->uartclk = new_serial.baud_base * 16;
841 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) |
842 (new_flags & UPF_CHANGE_MASK);
843 uport->custom_divisor = new_serial.custom_divisor;
844 port->close_delay = close_delay;
845 port->closing_wait = closing_wait;
846 if (new_serial.xmit_fifo_size)
847 uport->fifosize = new_serial.xmit_fifo_size;
848 if (port->tty)
849 port->tty->low_latency =
850 (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
852 check_and_exit:
853 retval = 0;
854 if (uport->type == PORT_UNKNOWN)
855 goto exit;
856 if (port->flags & ASYNC_INITIALIZED) {
857 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
858 old_custom_divisor != uport->custom_divisor) {
860 * If they're setting up a custom divisor or speed,
861 * instead of clearing it, then bitch about it. No
862 * need to rate-limit; it's CAP_SYS_ADMIN only.
864 if (uport->flags & UPF_SPD_MASK) {
865 char buf[64];
866 printk(KERN_NOTICE
867 "%s sets custom speed on %s. This "
868 "is deprecated.\n", current->comm,
869 tty_name(port->tty, buf));
871 uart_change_speed(tty, state, NULL);
873 } else
874 retval = uart_startup(tty, state, 1);
875 exit:
876 mutex_unlock(&port->mutex);
877 return retval;
881 * uart_get_lsr_info - get line status register info
882 * @tty: tty associated with the UART
883 * @state: UART being queried
884 * @value: returned modem value
886 * Note: uart_ioctl protects us against hangups.
888 static int uart_get_lsr_info(struct tty_struct *tty,
889 struct uart_state *state, unsigned int __user *value)
891 struct uart_port *uport = state->uart_port;
892 unsigned int result;
894 result = uport->ops->tx_empty(uport);
897 * If we're about to load something into the transmit
898 * register, we'll pretend the transmitter isn't empty to
899 * avoid a race condition (depending on when the transmit
900 * interrupt happens).
902 if (uport->x_char ||
903 ((uart_circ_chars_pending(&state->xmit) > 0) &&
904 !tty->stopped && !tty->hw_stopped))
905 result &= ~TIOCSER_TEMT;
907 return put_user(result, value);
910 static int uart_tiocmget(struct tty_struct *tty)
912 struct uart_state *state = tty->driver_data;
913 struct tty_port *port = &state->port;
914 struct uart_port *uport = state->uart_port;
915 int result = -EIO;
917 mutex_lock(&port->mutex);
918 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
919 result = uport->mctrl;
920 spin_lock_irq(&uport->lock);
921 result |= uport->ops->get_mctrl(uport);
922 spin_unlock_irq(&uport->lock);
924 mutex_unlock(&port->mutex);
926 return result;
929 static int
930 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
932 struct uart_state *state = tty->driver_data;
933 struct uart_port *uport = state->uart_port;
934 struct tty_port *port = &state->port;
935 int ret = -EIO;
937 mutex_lock(&port->mutex);
938 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
939 uart_update_mctrl(uport, set, clear);
940 ret = 0;
942 mutex_unlock(&port->mutex);
943 return ret;
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);
958 return 0;
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;
965 int flags, ret;
967 if (!capable(CAP_SYS_ADMIN))
968 return -EPERM;
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))
976 return -ERESTARTSYS;
978 ret = -EBUSY;
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
995 * a port is found.
997 uport->ops->config_port(uport, flags);
999 ret = uart_startup(tty, state, 1);
1001 mutex_unlock(&port->mutex);
1002 return ret;
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.
1014 static int
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;
1021 int ret;
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);
1036 for (;;) {
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))) {
1047 ret = 0;
1048 break;
1051 schedule();
1053 /* see if a signal did it */
1054 if (signal_pending(current)) {
1055 ret = -ERESTARTSYS;
1056 break;
1059 cprev = cnow;
1062 current->state = TASK_RUNNING;
1063 remove_wait_queue(&port->delta_msr_wait, &wait);
1065 return ret;
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;
1097 return 0;
1101 * Called via sys_ioctl. We can use spin_lock_irq() here.
1103 static int
1104 uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1105 unsigned long arg)
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.
1116 switch (cmd) {
1117 case TIOCGSERIAL:
1118 ret = uart_get_info(state, uarg);
1119 break;
1121 case TIOCSSERIAL:
1122 ret = uart_set_info(tty, state, uarg);
1123 break;
1125 case TIOCSERCONFIG:
1126 ret = uart_do_autoconfig(tty, state);
1127 break;
1129 case TIOCSERGWILD: /* obsolete */
1130 case TIOCSERSWILD: /* obsolete */
1131 ret = 0;
1132 break;
1135 if (ret != -ENOIOCTLCMD)
1136 goto out;
1138 if (tty->flags & (1 << TTY_IO_ERROR)) {
1139 ret = -EIO;
1140 goto out;
1144 * The following should only be used when hardware is present.
1146 switch (cmd) {
1147 case TIOCMIWAIT:
1148 ret = uart_wait_modem_status(state, arg);
1149 break;
1152 if (ret != -ENOIOCTLCMD)
1153 goto out;
1155 mutex_lock(&port->mutex);
1157 if (tty->flags & (1 << TTY_IO_ERROR)) {
1158 ret = -EIO;
1159 goto out_up;
1163 * All these rely on hardware being present and need to be
1164 * protected against the tty being hung up.
1166 switch (cmd) {
1167 case TIOCSERGETLSR: /* Get line status register */
1168 ret = uart_get_lsr_info(tty, state, uarg);
1169 break;
1171 default: {
1172 struct uart_port *uport = state->uart_port;
1173 if (uport->ops->ioctl)
1174 ret = uport->ops->ioctl(uport, cmd, arg);
1175 break;
1178 out_up:
1179 mutex_unlock(&port->mutex);
1180 out:
1181 return ret;
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) {
1212 return;
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))
1225 mask |= TIOCM_RTS;
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;
1233 __uart_start(tty);
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);
1248 * In 2.4.5, calls to this will be serialized via the BKL in
1249 * linux/drivers/char/tty_io.c:tty_release()
1250 * linux/drivers/char/tty_io.c:do_tty_handup()
1252 static void uart_close(struct tty_struct *tty, struct file *filp)
1254 struct uart_state *state = tty->driver_data;
1255 struct tty_port *port;
1256 struct uart_port *uport;
1257 unsigned long flags;
1259 BUG_ON(!tty_locked());
1261 if (!state)
1262 return;
1264 uport = state->uart_port;
1265 port = &state->port;
1267 pr_debug("uart_close(%d) called\n", uport->line);
1269 mutex_lock(&port->mutex);
1270 spin_lock_irqsave(&port->lock, flags);
1272 if (tty_hung_up_p(filp)) {
1273 spin_unlock_irqrestore(&port->lock, flags);
1274 goto done;
1277 if ((tty->count == 1) && (port->count != 1)) {
1279 * Uh, oh. tty->count is 1, which means that the tty
1280 * structure will be freed. port->count should always
1281 * be one in these conditions. If it's greater than
1282 * one, we've got real problems, since it means the
1283 * serial port won't be shutdown.
1285 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1286 "port->count is %d\n", port->count);
1287 port->count = 1;
1289 if (--port->count < 0) {
1290 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1291 tty->name, port->count);
1292 port->count = 0;
1294 if (port->count) {
1295 spin_unlock_irqrestore(&port->lock, flags);
1296 goto done;
1300 * Now we wait for the transmit buffer to clear; and we notify
1301 * the line discipline to only process XON/XOFF characters by
1302 * setting tty->closing.
1304 tty->closing = 1;
1305 spin_unlock_irqrestore(&port->lock, flags);
1307 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
1309 * hack: open-coded tty_wait_until_sent to avoid
1310 * recursive tty_lock
1312 long timeout = msecs_to_jiffies(port->closing_wait);
1313 if (wait_event_interruptible_timeout(tty->write_wait,
1314 !tty_chars_in_buffer(tty), timeout) >= 0)
1315 __uart_wait_until_sent(uport, timeout);
1319 * At this point, we stop accepting input. To do this, we
1320 * disable the receive line status interrupts.
1322 if (port->flags & ASYNC_INITIALIZED) {
1323 unsigned long flags;
1324 spin_lock_irqsave(&uport->lock, flags);
1325 uport->ops->stop_rx(uport);
1326 spin_unlock_irqrestore(&uport->lock, flags);
1328 * Before we drop DTR, make sure the UART transmitter
1329 * has completely drained; this is especially
1330 * important if there is a transmit FIFO!
1332 __uart_wait_until_sent(uport, uport->timeout);
1335 uart_shutdown(tty, state);
1336 uart_flush_buffer(tty);
1338 tty_ldisc_flush(tty);
1340 tty_port_tty_set(port, NULL);
1341 spin_lock_irqsave(&port->lock, flags);
1342 tty->closing = 0;
1344 if (port->blocked_open) {
1345 spin_unlock_irqrestore(&port->lock, flags);
1346 if (port->close_delay)
1347 msleep_interruptible(port->close_delay);
1348 spin_lock_irqsave(&port->lock, flags);
1349 } else if (!uart_console(uport)) {
1350 spin_unlock_irqrestore(&port->lock, flags);
1351 uart_change_pm(state, 3);
1352 spin_lock_irqsave(&port->lock, flags);
1356 * Wake up anyone trying to open this port.
1358 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1359 spin_unlock_irqrestore(&port->lock, flags);
1360 wake_up_interruptible(&port->open_wait);
1362 done:
1363 mutex_unlock(&port->mutex);
1366 static void __uart_wait_until_sent(struct uart_port *port, int timeout)
1368 unsigned long char_time, expire;
1370 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1371 return;
1374 * Set the check interval to be 1/5 of the estimated time to
1375 * send a single character, and make it at least 1. The check
1376 * interval should also be less than the timeout.
1378 * Note: we have to use pretty tight timings here to satisfy
1379 * the NIST-PCTS.
1381 char_time = (port->timeout - HZ/50) / port->fifosize;
1382 char_time = char_time / 5;
1383 if (char_time == 0)
1384 char_time = 1;
1385 if (timeout && timeout < char_time)
1386 char_time = timeout;
1389 * If the transmitter hasn't cleared in twice the approximate
1390 * amount of time to send the entire FIFO, it probably won't
1391 * ever clear. This assumes the UART isn't doing flow
1392 * control, which is currently the case. Hence, if it ever
1393 * takes longer than port->timeout, this is probably due to a
1394 * UART bug of some kind. So, we clamp the timeout parameter at
1395 * 2*port->timeout.
1397 if (timeout == 0 || timeout > 2 * port->timeout)
1398 timeout = 2 * port->timeout;
1400 expire = jiffies + timeout;
1402 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1403 port->line, jiffies, expire);
1406 * Check whether the transmitter is empty every 'char_time'.
1407 * 'timeout' / 'expire' give us the maximum amount of time
1408 * we wait.
1410 while (!port->ops->tx_empty(port)) {
1411 msleep_interruptible(jiffies_to_msecs(char_time));
1412 if (signal_pending(current))
1413 break;
1414 if (time_after(jiffies, expire))
1415 break;
1419 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1421 struct uart_state *state = tty->driver_data;
1422 struct uart_port *port = state->uart_port;
1424 tty_lock();
1425 __uart_wait_until_sent(port, timeout);
1426 tty_unlock();
1430 * This is called with the BKL held in
1431 * linux/drivers/char/tty_io.c:do_tty_hangup()
1432 * We're called from the eventd thread, so we can sleep for
1433 * a _short_ time only.
1435 static void uart_hangup(struct tty_struct *tty)
1437 struct uart_state *state = tty->driver_data;
1438 struct tty_port *port = &state->port;
1439 unsigned long flags;
1441 BUG_ON(!tty_locked());
1442 pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1444 mutex_lock(&port->mutex);
1445 if (port->flags & ASYNC_NORMAL_ACTIVE) {
1446 uart_flush_buffer(tty);
1447 uart_shutdown(tty, state);
1448 spin_lock_irqsave(&port->lock, flags);
1449 port->count = 0;
1450 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1451 spin_unlock_irqrestore(&port->lock, flags);
1452 tty_port_tty_set(port, NULL);
1453 wake_up_interruptible(&port->open_wait);
1454 wake_up_interruptible(&port->delta_msr_wait);
1456 mutex_unlock(&port->mutex);
1459 static int uart_carrier_raised(struct tty_port *port)
1461 struct uart_state *state = container_of(port, struct uart_state, port);
1462 struct uart_port *uport = state->uart_port;
1463 int mctrl;
1464 spin_lock_irq(&uport->lock);
1465 uport->ops->enable_ms(uport);
1466 mctrl = uport->ops->get_mctrl(uport);
1467 spin_unlock_irq(&uport->lock);
1468 if (mctrl & TIOCM_CAR)
1469 return 1;
1470 return 0;
1473 static void uart_dtr_rts(struct tty_port *port, int onoff)
1475 struct uart_state *state = container_of(port, struct uart_state, port);
1476 struct uart_port *uport = state->uart_port;
1478 if (onoff)
1479 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1480 else
1481 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1484 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1486 struct uart_state *state;
1487 struct tty_port *port;
1488 int ret = 0;
1490 state = drv->state + line;
1491 port = &state->port;
1492 if (mutex_lock_interruptible(&port->mutex)) {
1493 ret = -ERESTARTSYS;
1494 goto err;
1497 port->count++;
1498 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1499 ret = -ENXIO;
1500 goto err_unlock;
1502 return state;
1504 err_unlock:
1505 port->count--;
1506 mutex_unlock(&port->mutex);
1507 err:
1508 return ERR_PTR(ret);
1512 * calls to uart_open are serialised by the BKL in
1513 * fs/char_dev.c:chrdev_open()
1514 * Note that if this fails, then uart_close() _will_ be called.
1516 * In time, we want to scrap the "opening nonpresent ports"
1517 * behaviour and implement an alternative way for setserial
1518 * to set base addresses/ports/types. This will allow us to
1519 * get rid of a certain amount of extra tests.
1521 static int uart_open(struct tty_struct *tty, struct file *filp)
1523 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1524 struct uart_state *state;
1525 struct tty_port *port;
1526 int retval, line = tty->index;
1528 BUG_ON(!tty_locked());
1529 pr_debug("uart_open(%d) called\n", line);
1532 * We take the semaphore inside uart_get to guarantee that we won't
1533 * be re-entered while allocating the state structure, or while we
1534 * request any IRQs that the driver may need. This also has the nice
1535 * side-effect that it delays the action of uart_hangup, so we can
1536 * guarantee that state->port.tty will always contain something
1537 * reasonable.
1539 state = uart_get(drv, line);
1540 if (IS_ERR(state)) {
1541 retval = PTR_ERR(state);
1542 goto fail;
1544 port = &state->port;
1547 * Once we set tty->driver_data here, we are guaranteed that
1548 * uart_close() will decrement the driver module use count.
1549 * Any failures from here onwards should not touch the count.
1551 tty->driver_data = state;
1552 state->uart_port->state = state;
1553 tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1554 tty->alt_speed = 0;
1555 tty_port_tty_set(port, tty);
1558 * If the port is in the middle of closing, bail out now.
1560 if (tty_hung_up_p(filp)) {
1561 retval = -EAGAIN;
1562 port->count--;
1563 mutex_unlock(&port->mutex);
1564 goto fail;
1568 * Make sure the device is in D0 state.
1570 if (port->count == 1)
1571 uart_change_pm(state, 0);
1574 * Start up the serial port.
1576 retval = uart_startup(tty, state, 0);
1579 * If we succeeded, wait until the port is ready.
1581 mutex_unlock(&port->mutex);
1582 if (retval == 0)
1583 retval = tty_port_block_til_ready(port, tty, filp);
1585 fail:
1586 return retval;
1589 static const char *uart_type(struct uart_port *port)
1591 const char *str = NULL;
1593 if (port->ops->type)
1594 str = port->ops->type(port);
1596 if (!str)
1597 str = "unknown";
1599 return str;
1602 #ifdef CONFIG_PROC_FS
1604 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1606 struct uart_state *state = drv->state + i;
1607 struct tty_port *port = &state->port;
1608 int pm_state;
1609 struct uart_port *uport = state->uart_port;
1610 char stat_buf[32];
1611 unsigned int status;
1612 int mmio;
1614 if (!uport)
1615 return;
1617 mmio = uport->iotype >= UPIO_MEM;
1618 seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1619 uport->line, uart_type(uport),
1620 mmio ? "mmio:0x" : "port:",
1621 mmio ? (unsigned long long)uport->mapbase
1622 : (unsigned long long)uport->iobase,
1623 uport->irq);
1625 if (uport->type == PORT_UNKNOWN) {
1626 seq_putc(m, '\n');
1627 return;
1630 if (capable(CAP_SYS_ADMIN)) {
1631 mutex_lock(&port->mutex);
1632 pm_state = state->pm_state;
1633 if (pm_state)
1634 uart_change_pm(state, 0);
1635 spin_lock_irq(&uport->lock);
1636 status = uport->ops->get_mctrl(uport);
1637 spin_unlock_irq(&uport->lock);
1638 if (pm_state)
1639 uart_change_pm(state, pm_state);
1640 mutex_unlock(&port->mutex);
1642 seq_printf(m, " tx:%d rx:%d",
1643 uport->icount.tx, uport->icount.rx);
1644 if (uport->icount.frame)
1645 seq_printf(m, " fe:%d",
1646 uport->icount.frame);
1647 if (uport->icount.parity)
1648 seq_printf(m, " pe:%d",
1649 uport->icount.parity);
1650 if (uport->icount.brk)
1651 seq_printf(m, " brk:%d",
1652 uport->icount.brk);
1653 if (uport->icount.overrun)
1654 seq_printf(m, " oe:%d",
1655 uport->icount.overrun);
1657 #define INFOBIT(bit, str) \
1658 if (uport->mctrl & (bit)) \
1659 strncat(stat_buf, (str), sizeof(stat_buf) - \
1660 strlen(stat_buf) - 2)
1661 #define STATBIT(bit, str) \
1662 if (status & (bit)) \
1663 strncat(stat_buf, (str), sizeof(stat_buf) - \
1664 strlen(stat_buf) - 2)
1666 stat_buf[0] = '\0';
1667 stat_buf[1] = '\0';
1668 INFOBIT(TIOCM_RTS, "|RTS");
1669 STATBIT(TIOCM_CTS, "|CTS");
1670 INFOBIT(TIOCM_DTR, "|DTR");
1671 STATBIT(TIOCM_DSR, "|DSR");
1672 STATBIT(TIOCM_CAR, "|CD");
1673 STATBIT(TIOCM_RNG, "|RI");
1674 if (stat_buf[0])
1675 stat_buf[0] = ' ';
1677 seq_puts(m, stat_buf);
1679 seq_putc(m, '\n');
1680 #undef STATBIT
1681 #undef INFOBIT
1684 static int uart_proc_show(struct seq_file *m, void *v)
1686 struct tty_driver *ttydrv = m->private;
1687 struct uart_driver *drv = ttydrv->driver_state;
1688 int i;
1690 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1691 "", "", "");
1692 for (i = 0; i < drv->nr; i++)
1693 uart_line_info(m, drv, i);
1694 return 0;
1697 static int uart_proc_open(struct inode *inode, struct file *file)
1699 return single_open(file, uart_proc_show, PDE(inode)->data);
1702 static const struct file_operations uart_proc_fops = {
1703 .owner = THIS_MODULE,
1704 .open = uart_proc_open,
1705 .read = seq_read,
1706 .llseek = seq_lseek,
1707 .release = single_release,
1709 #endif
1711 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1713 * uart_console_write - write a console message to a serial port
1714 * @port: the port to write the message
1715 * @s: array of characters
1716 * @count: number of characters in string to write
1717 * @write: function to write character to port
1719 void uart_console_write(struct uart_port *port, const char *s,
1720 unsigned int count,
1721 void (*putchar)(struct uart_port *, int))
1723 unsigned int i;
1725 for (i = 0; i < count; i++, s++) {
1726 if (*s == '\n')
1727 putchar(port, '\r');
1728 putchar(port, *s);
1731 EXPORT_SYMBOL_GPL(uart_console_write);
1734 * Check whether an invalid uart number has been specified, and
1735 * if so, search for the first available port that does have
1736 * console support.
1738 struct uart_port * __init
1739 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1741 int idx = co->index;
1743 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1744 ports[idx].membase == NULL))
1745 for (idx = 0; idx < nr; idx++)
1746 if (ports[idx].iobase != 0 ||
1747 ports[idx].membase != NULL)
1748 break;
1750 co->index = idx;
1752 return ports + idx;
1756 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1757 * @options: pointer to option string
1758 * @baud: pointer to an 'int' variable for the baud rate.
1759 * @parity: pointer to an 'int' variable for the parity.
1760 * @bits: pointer to an 'int' variable for the number of data bits.
1761 * @flow: pointer to an 'int' variable for the flow control character.
1763 * uart_parse_options decodes a string containing the serial console
1764 * options. The format of the string is <baud><parity><bits><flow>,
1765 * eg: 115200n8r
1767 void
1768 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1770 char *s = options;
1772 *baud = simple_strtoul(s, NULL, 10);
1773 while (*s >= '0' && *s <= '9')
1774 s++;
1775 if (*s)
1776 *parity = *s++;
1777 if (*s)
1778 *bits = *s++ - '0';
1779 if (*s)
1780 *flow = *s;
1782 EXPORT_SYMBOL_GPL(uart_parse_options);
1784 struct baud_rates {
1785 unsigned int rate;
1786 unsigned int cflag;
1789 static const struct baud_rates baud_rates[] = {
1790 { 921600, B921600 },
1791 { 460800, B460800 },
1792 { 230400, B230400 },
1793 { 115200, B115200 },
1794 { 57600, B57600 },
1795 { 38400, B38400 },
1796 { 19200, B19200 },
1797 { 9600, B9600 },
1798 { 4800, B4800 },
1799 { 2400, B2400 },
1800 { 1200, B1200 },
1801 { 0, B38400 }
1805 * uart_set_options - setup the serial console parameters
1806 * @port: pointer to the serial ports uart_port structure
1807 * @co: console pointer
1808 * @baud: baud rate
1809 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1810 * @bits: number of data bits
1811 * @flow: flow control character - 'r' (rts)
1814 uart_set_options(struct uart_port *port, struct console *co,
1815 int baud, int parity, int bits, int flow)
1817 struct ktermios termios;
1818 static struct ktermios dummy;
1819 int i;
1822 * Ensure that the serial console lock is initialised
1823 * early.
1825 spin_lock_init(&port->lock);
1826 lockdep_set_class(&port->lock, &port_lock_key);
1828 memset(&termios, 0, sizeof(struct ktermios));
1830 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1833 * Construct a cflag setting.
1835 for (i = 0; baud_rates[i].rate; i++)
1836 if (baud_rates[i].rate <= baud)
1837 break;
1839 termios.c_cflag |= baud_rates[i].cflag;
1841 if (bits == 7)
1842 termios.c_cflag |= CS7;
1843 else
1844 termios.c_cflag |= CS8;
1846 switch (parity) {
1847 case 'o': case 'O':
1848 termios.c_cflag |= PARODD;
1849 /*fall through*/
1850 case 'e': case 'E':
1851 termios.c_cflag |= PARENB;
1852 break;
1855 if (flow == 'r')
1856 termios.c_cflag |= CRTSCTS;
1859 * some uarts on other side don't support no flow control.
1860 * So we set * DTR in host uart to make them happy
1862 port->mctrl |= TIOCM_DTR;
1864 port->ops->set_termios(port, &termios, &dummy);
1866 * Allow the setting of the UART parameters with a NULL console
1867 * too:
1869 if (co)
1870 co->cflag = termios.c_cflag;
1872 return 0;
1874 EXPORT_SYMBOL_GPL(uart_set_options);
1875 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1877 static void uart_change_pm(struct uart_state *state, int pm_state)
1879 struct uart_port *port = state->uart_port;
1881 if (state->pm_state != pm_state) {
1882 if (port->ops->pm)
1883 port->ops->pm(port, pm_state, state->pm_state);
1884 state->pm_state = pm_state;
1888 struct uart_match {
1889 struct uart_port *port;
1890 struct uart_driver *driver;
1893 static int serial_match_port(struct device *dev, void *data)
1895 struct uart_match *match = data;
1896 struct tty_driver *tty_drv = match->driver->tty_driver;
1897 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1898 match->port->line;
1900 return dev->devt == devt; /* Actually, only one tty per port */
1903 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1905 struct uart_state *state = drv->state + uport->line;
1906 struct tty_port *port = &state->port;
1907 struct device *tty_dev;
1908 struct uart_match match = {uport, drv};
1910 mutex_lock(&port->mutex);
1912 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1913 if (device_may_wakeup(tty_dev)) {
1914 if (!enable_irq_wake(uport->irq))
1915 uport->irq_wake = 1;
1916 put_device(tty_dev);
1917 mutex_unlock(&port->mutex);
1918 return 0;
1920 if (console_suspend_enabled || !uart_console(uport))
1921 uport->suspended = 1;
1923 if (port->flags & ASYNC_INITIALIZED) {
1924 const struct uart_ops *ops = uport->ops;
1925 int tries;
1927 if (console_suspend_enabled || !uart_console(uport)) {
1928 set_bit(ASYNCB_SUSPENDED, &port->flags);
1929 clear_bit(ASYNCB_INITIALIZED, &port->flags);
1931 spin_lock_irq(&uport->lock);
1932 ops->stop_tx(uport);
1933 ops->set_mctrl(uport, 0);
1934 ops->stop_rx(uport);
1935 spin_unlock_irq(&uport->lock);
1939 * Wait for the transmitter to empty.
1941 for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1942 msleep(10);
1943 if (!tries)
1944 printk(KERN_ERR "%s%s%s%d: Unable to drain "
1945 "transmitter\n",
1946 uport->dev ? dev_name(uport->dev) : "",
1947 uport->dev ? ": " : "",
1948 drv->dev_name,
1949 drv->tty_driver->name_base + uport->line);
1951 if (console_suspend_enabled || !uart_console(uport))
1952 ops->shutdown(uport);
1956 * Disable the console device before suspending.
1958 if (console_suspend_enabled && uart_console(uport))
1959 console_stop(uport->cons);
1961 if (console_suspend_enabled || !uart_console(uport))
1962 uart_change_pm(state, 3);
1964 mutex_unlock(&port->mutex);
1966 return 0;
1969 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1971 struct uart_state *state = drv->state + uport->line;
1972 struct tty_port *port = &state->port;
1973 struct device *tty_dev;
1974 struct uart_match match = {uport, drv};
1975 struct ktermios termios;
1977 mutex_lock(&port->mutex);
1979 tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1980 if (!uport->suspended && device_may_wakeup(tty_dev)) {
1981 if (uport->irq_wake) {
1982 disable_irq_wake(uport->irq);
1983 uport->irq_wake = 0;
1985 mutex_unlock(&port->mutex);
1986 return 0;
1988 uport->suspended = 0;
1991 * Re-enable the console device after suspending.
1993 if (uart_console(uport)) {
1995 * First try to use the console cflag setting.
1997 memset(&termios, 0, sizeof(struct ktermios));
1998 termios.c_cflag = uport->cons->cflag;
2001 * If that's unset, use the tty termios setting.
2003 if (port->tty && port->tty->termios && termios.c_cflag == 0)
2004 termios = *(port->tty->termios);
2006 uport->ops->set_termios(uport, &termios, NULL);
2007 if (console_suspend_enabled)
2008 console_start(uport->cons);
2011 if (port->flags & ASYNC_SUSPENDED) {
2012 const struct uart_ops *ops = uport->ops;
2013 int ret;
2015 uart_change_pm(state, 0);
2016 spin_lock_irq(&uport->lock);
2017 ops->set_mctrl(uport, 0);
2018 spin_unlock_irq(&uport->lock);
2019 if (console_suspend_enabled || !uart_console(uport)) {
2020 /* Protected by port mutex for now */
2021 struct tty_struct *tty = port->tty;
2022 ret = ops->startup(uport);
2023 if (ret == 0) {
2024 if (tty)
2025 uart_change_speed(tty, state, NULL);
2026 spin_lock_irq(&uport->lock);
2027 ops->set_mctrl(uport, uport->mctrl);
2028 ops->start_tx(uport);
2029 spin_unlock_irq(&uport->lock);
2030 set_bit(ASYNCB_INITIALIZED, &port->flags);
2031 } else {
2033 * Failed to resume - maybe hardware went away?
2034 * Clear the "initialized" flag so we won't try
2035 * to call the low level drivers shutdown method.
2037 uart_shutdown(tty, state);
2041 clear_bit(ASYNCB_SUSPENDED, &port->flags);
2044 mutex_unlock(&port->mutex);
2046 return 0;
2049 static inline void
2050 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2052 char address[64];
2054 switch (port->iotype) {
2055 case UPIO_PORT:
2056 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2057 break;
2058 case UPIO_HUB6:
2059 snprintf(address, sizeof(address),
2060 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2061 break;
2062 case UPIO_MEM:
2063 case UPIO_MEM32:
2064 case UPIO_AU:
2065 case UPIO_TSI:
2066 case UPIO_DWAPB:
2067 case UPIO_DWAPB32:
2068 snprintf(address, sizeof(address),
2069 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2070 break;
2071 default:
2072 strlcpy(address, "*unknown*", sizeof(address));
2073 break;
2076 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2077 port->dev ? dev_name(port->dev) : "",
2078 port->dev ? ": " : "",
2079 drv->dev_name,
2080 drv->tty_driver->name_base + port->line,
2081 address, port->irq, uart_type(port));
2084 static void
2085 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2086 struct uart_port *port)
2088 unsigned int flags;
2091 * If there isn't a port here, don't do anything further.
2093 if (!port->iobase && !port->mapbase && !port->membase)
2094 return;
2097 * Now do the auto configuration stuff. Note that config_port
2098 * is expected to claim the resources and map the port for us.
2100 flags = 0;
2101 if (port->flags & UPF_AUTO_IRQ)
2102 flags |= UART_CONFIG_IRQ;
2103 if (port->flags & UPF_BOOT_AUTOCONF) {
2104 if (!(port->flags & UPF_FIXED_TYPE)) {
2105 port->type = PORT_UNKNOWN;
2106 flags |= UART_CONFIG_TYPE;
2108 port->ops->config_port(port, flags);
2111 if (port->type != PORT_UNKNOWN) {
2112 unsigned long flags;
2114 uart_report_port(drv, port);
2116 /* Power up port for set_mctrl() */
2117 uart_change_pm(state, 0);
2120 * Ensure that the modem control lines are de-activated.
2121 * keep the DTR setting that is set in uart_set_options()
2122 * We probably don't need a spinlock around this, but
2124 spin_lock_irqsave(&port->lock, flags);
2125 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2126 spin_unlock_irqrestore(&port->lock, flags);
2129 * If this driver supports console, and it hasn't been
2130 * successfully registered yet, try to re-register it.
2131 * It may be that the port was not available.
2133 if (port->cons && !(port->cons->flags & CON_ENABLED))
2134 register_console(port->cons);
2137 * Power down all ports by default, except the
2138 * console if we have one.
2140 if (!uart_console(port))
2141 uart_change_pm(state, 3);
2145 #ifdef CONFIG_CONSOLE_POLL
2147 static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2149 struct uart_driver *drv = driver->driver_state;
2150 struct uart_state *state = drv->state + line;
2151 struct uart_port *port;
2152 int baud = 9600;
2153 int bits = 8;
2154 int parity = 'n';
2155 int flow = 'n';
2157 if (!state || !state->uart_port)
2158 return -1;
2160 port = state->uart_port;
2161 if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2162 return -1;
2164 if (options) {
2165 uart_parse_options(options, &baud, &parity, &bits, &flow);
2166 return uart_set_options(port, NULL, baud, parity, bits, flow);
2169 return 0;
2172 static int uart_poll_get_char(struct tty_driver *driver, int line)
2174 struct uart_driver *drv = driver->driver_state;
2175 struct uart_state *state = drv->state + line;
2176 struct uart_port *port;
2178 if (!state || !state->uart_port)
2179 return -1;
2181 port = state->uart_port;
2182 return port->ops->poll_get_char(port);
2185 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2187 struct uart_driver *drv = driver->driver_state;
2188 struct uart_state *state = drv->state + line;
2189 struct uart_port *port;
2191 if (!state || !state->uart_port)
2192 return;
2194 port = state->uart_port;
2195 port->ops->poll_put_char(port, ch);
2197 #endif
2199 static const struct tty_operations uart_ops = {
2200 .open = uart_open,
2201 .close = uart_close,
2202 .write = uart_write,
2203 .put_char = uart_put_char,
2204 .flush_chars = uart_flush_chars,
2205 .write_room = uart_write_room,
2206 .chars_in_buffer= uart_chars_in_buffer,
2207 .flush_buffer = uart_flush_buffer,
2208 .ioctl = uart_ioctl,
2209 .throttle = uart_throttle,
2210 .unthrottle = uart_unthrottle,
2211 .send_xchar = uart_send_xchar,
2212 .set_termios = uart_set_termios,
2213 .set_ldisc = uart_set_ldisc,
2214 .stop = uart_stop,
2215 .start = uart_start,
2216 .hangup = uart_hangup,
2217 .break_ctl = uart_break_ctl,
2218 .wait_until_sent= uart_wait_until_sent,
2219 #ifdef CONFIG_PROC_FS
2220 .proc_fops = &uart_proc_fops,
2221 #endif
2222 .tiocmget = uart_tiocmget,
2223 .tiocmset = uart_tiocmset,
2224 .get_icount = uart_get_icount,
2225 #ifdef CONFIG_CONSOLE_POLL
2226 .poll_init = uart_poll_init,
2227 .poll_get_char = uart_poll_get_char,
2228 .poll_put_char = uart_poll_put_char,
2229 #endif
2232 static const struct tty_port_operations uart_port_ops = {
2233 .carrier_raised = uart_carrier_raised,
2234 .dtr_rts = uart_dtr_rts,
2238 * uart_register_driver - register a driver with the uart core layer
2239 * @drv: low level driver structure
2241 * Register a uart driver with the core driver. We in turn register
2242 * with the tty layer, and initialise the core driver per-port state.
2244 * We have a proc file in /proc/tty/driver which is named after the
2245 * normal driver.
2247 * drv->port should be NULL, and the per-port structures should be
2248 * registered using uart_add_one_port after this call has succeeded.
2250 int uart_register_driver(struct uart_driver *drv)
2252 struct tty_driver *normal;
2253 int i, retval;
2255 BUG_ON(drv->state);
2258 * Maybe we should be using a slab cache for this, especially if
2259 * we have a large number of ports to handle.
2261 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2262 if (!drv->state)
2263 goto out;
2265 normal = alloc_tty_driver(drv->nr);
2266 if (!normal)
2267 goto out_kfree;
2269 drv->tty_driver = normal;
2271 normal->owner = drv->owner;
2272 normal->driver_name = drv->driver_name;
2273 normal->name = drv->dev_name;
2274 normal->major = drv->major;
2275 normal->minor_start = drv->minor;
2276 normal->type = TTY_DRIVER_TYPE_SERIAL;
2277 normal->subtype = SERIAL_TYPE_NORMAL;
2278 normal->init_termios = tty_std_termios;
2279 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2280 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2281 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2282 normal->driver_state = drv;
2283 tty_set_operations(normal, &uart_ops);
2286 * Initialise the UART state(s).
2288 for (i = 0; i < drv->nr; i++) {
2289 struct uart_state *state = drv->state + i;
2290 struct tty_port *port = &state->port;
2292 tty_port_init(port);
2293 port->ops = &uart_port_ops;
2294 port->close_delay = 500; /* .5 seconds */
2295 port->closing_wait = 30000; /* 30 seconds */
2296 tasklet_init(&state->tlet, uart_tasklet_action,
2297 (unsigned long)state);
2300 retval = tty_register_driver(normal);
2301 if (retval >= 0)
2302 return retval;
2304 put_tty_driver(normal);
2305 out_kfree:
2306 kfree(drv->state);
2307 out:
2308 return -ENOMEM;
2312 * uart_unregister_driver - remove a driver from the uart core layer
2313 * @drv: low level driver structure
2315 * Remove all references to a driver from the core driver. The low
2316 * level driver must have removed all its ports via the
2317 * uart_remove_one_port() if it registered them with uart_add_one_port().
2318 * (ie, drv->port == NULL)
2320 void uart_unregister_driver(struct uart_driver *drv)
2322 struct tty_driver *p = drv->tty_driver;
2323 tty_unregister_driver(p);
2324 put_tty_driver(p);
2325 kfree(drv->state);
2326 drv->tty_driver = NULL;
2329 struct tty_driver *uart_console_device(struct console *co, int *index)
2331 struct uart_driver *p = co->data;
2332 *index = co->index;
2333 return p->tty_driver;
2337 * uart_add_one_port - attach a driver-defined port structure
2338 * @drv: pointer to the uart low level driver structure for this port
2339 * @uport: uart port structure to use for this port.
2341 * This allows the driver to register its own uart_port structure
2342 * with the core driver. The main purpose is to allow the low
2343 * level uart drivers to expand uart_port, rather than having yet
2344 * more levels of structures.
2346 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2348 struct uart_state *state;
2349 struct tty_port *port;
2350 int ret = 0;
2351 struct device *tty_dev;
2353 BUG_ON(in_interrupt());
2355 if (uport->line >= drv->nr)
2356 return -EINVAL;
2358 state = drv->state + uport->line;
2359 port = &state->port;
2361 mutex_lock(&port_mutex);
2362 mutex_lock(&port->mutex);
2363 if (state->uart_port) {
2364 ret = -EINVAL;
2365 goto out;
2368 state->uart_port = uport;
2369 state->pm_state = -1;
2371 uport->cons = drv->cons;
2372 uport->state = state;
2375 * If this port is a console, then the spinlock is already
2376 * initialised.
2378 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2379 spin_lock_init(&uport->lock);
2380 lockdep_set_class(&uport->lock, &port_lock_key);
2383 uart_configure_port(drv, state, uport);
2386 * Register the port whether it's detected or not. This allows
2387 * setserial to be used to alter this ports parameters.
2389 tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2390 if (likely(!IS_ERR(tty_dev))) {
2391 device_init_wakeup(tty_dev, 1);
2392 device_set_wakeup_enable(tty_dev, 0);
2393 } else
2394 printk(KERN_ERR "Cannot register tty device on line %d\n",
2395 uport->line);
2398 * Ensure UPF_DEAD is not set.
2400 uport->flags &= ~UPF_DEAD;
2402 out:
2403 mutex_unlock(&port->mutex);
2404 mutex_unlock(&port_mutex);
2406 return ret;
2410 * uart_remove_one_port - detach a driver defined port structure
2411 * @drv: pointer to the uart low level driver structure for this port
2412 * @uport: uart port structure for this port
2414 * This unhooks (and hangs up) the specified port structure from the
2415 * core driver. No further calls will be made to the low-level code
2416 * for this port.
2418 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2420 struct uart_state *state = drv->state + uport->line;
2421 struct tty_port *port = &state->port;
2423 BUG_ON(in_interrupt());
2425 if (state->uart_port != uport)
2426 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2427 state->uart_port, uport);
2429 mutex_lock(&port_mutex);
2432 * Mark the port "dead" - this prevents any opens from
2433 * succeeding while we shut down the port.
2435 mutex_lock(&port->mutex);
2436 uport->flags |= UPF_DEAD;
2437 mutex_unlock(&port->mutex);
2440 * Remove the devices from the tty layer
2442 tty_unregister_device(drv->tty_driver, uport->line);
2444 if (port->tty)
2445 tty_vhangup(port->tty);
2448 * Free the port IO and memory resources, if any.
2450 if (uport->type != PORT_UNKNOWN)
2451 uport->ops->release_port(uport);
2454 * Indicate that there isn't a port here anymore.
2456 uport->type = PORT_UNKNOWN;
2459 * Kill the tasklet, and free resources.
2461 tasklet_kill(&state->tlet);
2463 state->uart_port = NULL;
2464 mutex_unlock(&port_mutex);
2466 return 0;
2470 * Are the two ports equivalent?
2472 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2474 if (port1->iotype != port2->iotype)
2475 return 0;
2477 switch (port1->iotype) {
2478 case UPIO_PORT:
2479 return (port1->iobase == port2->iobase);
2480 case UPIO_HUB6:
2481 return (port1->iobase == port2->iobase) &&
2482 (port1->hub6 == port2->hub6);
2483 case UPIO_MEM:
2484 case UPIO_MEM32:
2485 case UPIO_AU:
2486 case UPIO_TSI:
2487 case UPIO_DWAPB:
2488 case UPIO_DWAPB32:
2489 return (port1->mapbase == port2->mapbase);
2491 return 0;
2493 EXPORT_SYMBOL(uart_match_port);
2495 EXPORT_SYMBOL(uart_write_wakeup);
2496 EXPORT_SYMBOL(uart_register_driver);
2497 EXPORT_SYMBOL(uart_unregister_driver);
2498 EXPORT_SYMBOL(uart_suspend_port);
2499 EXPORT_SYMBOL(uart_resume_port);
2500 EXPORT_SYMBOL(uart_add_one_port);
2501 EXPORT_SYMBOL(uart_remove_one_port);
2503 MODULE_DESCRIPTION("Serial driver core");
2504 MODULE_LICENSE("GPL");