blob: f84982e508c7efc7e2eb6bcdca37f95ee22e8b67 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/drivers/char/core.c
3 *
4 * Driver core for serial ports
5 *
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * Copyright 1999 ARM Limited
9 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
10 *
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.
15 *
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.
20 *
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
24 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#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/serial_core.h>
31#include <linux/smp_lock.h>
32#include <linux/device.h>
33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
34#include <linux/delay.h>
Arjan van de Venf392ecf2006-01-12 18:44:32 +000035#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#include <asm/irq.h>
38#include <asm/uaccess.h>
39
40#undef DEBUG
41#ifdef DEBUG
42#define DPRINTK(x...) printk(x)
43#else
44#define DPRINTK(x...) do { } while (0)
45#endif
46
47/*
48 * This is used to lock changes in serial line configuration.
49 */
Arjan van de Venf392ecf2006-01-12 18:44:32 +000050static DEFINE_MUTEX(port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Ingo Molnar13e83592006-07-03 00:25:03 -070052/*
53 * lockdep: port->lock is initialized in two places, but we
54 * want only one lock-class:
55 */
56static struct lock_class_key port_lock_key;
57
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
59
60#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
61
62#ifdef CONFIG_SERIAL_CORE_CONSOLE
63#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
64#else
65#define uart_console(port) (0)
66#endif
67
Alan Cox606d0992006-12-08 02:38:45 -080068static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
70static void uart_change_pm(struct uart_state *state, int pm_state);
71
72/*
73 * This routine is used by the interrupt handler to schedule processing in
74 * the software interrupt portion of the driver.
75 */
76void uart_write_wakeup(struct uart_port *port)
77{
78 struct uart_info *info = port->info;
Pavel Machekd5f735e2006-03-07 21:55:20 -080079 /*
80 * This means you called this function _after_ the port was
81 * closed. No cookie for you.
82 */
83 BUG_ON(!info);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 tasklet_schedule(&info->tlet);
85}
86
87static void uart_stop(struct tty_struct *tty)
88{
89 struct uart_state *state = tty->driver_data;
90 struct uart_port *port = state->port;
91 unsigned long flags;
92
93 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +010094 port->ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 spin_unlock_irqrestore(&port->lock, flags);
96}
97
98static void __uart_start(struct tty_struct *tty)
99{
100 struct uart_state *state = tty->driver_data;
101 struct uart_port *port = state->port;
102
103 if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
104 !tty->stopped && !tty->hw_stopped)
Russell Kingb129a8c2005-08-31 10:12:14 +0100105 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
107
108static void uart_start(struct tty_struct *tty)
109{
110 struct uart_state *state = tty->driver_data;
111 struct uart_port *port = state->port;
112 unsigned long flags;
113
114 spin_lock_irqsave(&port->lock, flags);
115 __uart_start(tty);
116 spin_unlock_irqrestore(&port->lock, flags);
117}
118
119static void uart_tasklet_action(unsigned long data)
120{
121 struct uart_state *state = (struct uart_state *)data;
122 tty_wakeup(state->info->tty);
123}
124
125static inline void
126uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
127{
128 unsigned long flags;
129 unsigned int old;
130
131 spin_lock_irqsave(&port->lock, flags);
132 old = port->mctrl;
133 port->mctrl = (old & ~clear) | set;
134 if (old != port->mctrl)
135 port->ops->set_mctrl(port, port->mctrl);
136 spin_unlock_irqrestore(&port->lock, flags);
137}
138
139#define uart_set_mctrl(port,set) uart_update_mctrl(port,set,0)
140#define uart_clear_mctrl(port,clear) uart_update_mctrl(port,0,clear)
141
142/*
143 * Startup the port. This will be called once per open. All calls
144 * will be serialised by the per-port semaphore.
145 */
146static int uart_startup(struct uart_state *state, int init_hw)
147{
148 struct uart_info *info = state->info;
149 struct uart_port *port = state->port;
150 unsigned long page;
151 int retval = 0;
152
153 if (info->flags & UIF_INITIALIZED)
154 return 0;
155
156 /*
157 * Set the TTY IO error marker - we will only clear this
158 * once we have successfully opened the port. Also set
159 * up the tty->alt_speed kludge
160 */
Jayachandran Ca2436b22005-10-30 23:26:16 +0000161 set_bit(TTY_IO_ERROR, &info->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 if (port->type == PORT_UNKNOWN)
164 return 0;
165
166 /*
167 * Initialise and allocate the transmit and temporary
168 * buffer.
169 */
170 if (!info->xmit.buf) {
171 page = get_zeroed_page(GFP_KERNEL);
172 if (!page)
173 return -ENOMEM;
174
175 info->xmit.buf = (unsigned char *) page;
176 uart_circ_clear(&info->xmit);
177 }
178
179 retval = port->ops->startup(port);
180 if (retval == 0) {
181 if (init_hw) {
182 /*
183 * Initialise the hardware port settings.
184 */
185 uart_change_speed(state, NULL);
186
187 /*
188 * Setup the RTS and DTR signals once the
189 * port is open and ready to respond.
190 */
191 if (info->tty->termios->c_cflag & CBAUD)
192 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
193 }
194
Russell King0dd7a1a2005-06-29 18:40:53 +0100195 if (info->flags & UIF_CTS_FLOW) {
196 spin_lock_irq(&port->lock);
197 if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
198 info->tty->hw_stopped = 1;
199 spin_unlock_irq(&port->lock);
200 }
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 info->flags |= UIF_INITIALIZED;
203
204 clear_bit(TTY_IO_ERROR, &info->tty->flags);
205 }
206
207 if (retval && capable(CAP_SYS_ADMIN))
208 retval = 0;
209
210 return retval;
211}
212
213/*
214 * This routine will shutdown a serial port; interrupts are disabled, and
215 * DTR is dropped if the hangup on close termio flag is on. Calls to
216 * uart_shutdown are serialised by the per-port semaphore.
217 */
218static void uart_shutdown(struct uart_state *state)
219{
220 struct uart_info *info = state->info;
221 struct uart_port *port = state->port;
222
Russell Kingee31b332005-11-13 15:28:51 +0000223 /*
224 * Set the TTY IO error marker
225 */
226 if (info->tty)
227 set_bit(TTY_IO_ERROR, &info->tty->flags);
228
229 if (info->flags & UIF_INITIALIZED) {
230 info->flags &= ~UIF_INITIALIZED;
231
232 /*
233 * Turn off DTR and RTS early.
234 */
235 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
236 uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
237
238 /*
239 * clear delta_msr_wait queue to avoid mem leaks: we may free
240 * the irq here so the queue might never be woken up. Note
241 * that we won't end up waiting on delta_msr_wait again since
242 * any outstanding file descriptors should be pointing at
243 * hung_up_tty_fops now.
244 */
245 wake_up_interruptible(&info->delta_msr_wait);
246
247 /*
248 * Free the IRQ and disable the port.
249 */
250 port->ops->shutdown(port);
251
252 /*
253 * Ensure that the IRQ handler isn't running on another CPU.
254 */
255 synchronize_irq(port->irq);
256 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 /*
Russell Kingee31b332005-11-13 15:28:51 +0000259 * kill off our tasklet
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 */
Russell Kingee31b332005-11-13 15:28:51 +0000261 tasklet_kill(&info->tlet);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 /*
264 * Free the transmit buffer page.
265 */
266 if (info->xmit.buf) {
267 free_page((unsigned long)info->xmit.buf);
268 info->xmit.buf = NULL;
269 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270}
271
272/**
273 * uart_update_timeout - update per-port FIFO timeout.
274 * @port: uart_port structure describing the port
275 * @cflag: termios cflag value
276 * @baud: speed of the port
277 *
278 * Set the port FIFO timeout value. The @cflag value should
279 * reflect the actual hardware settings.
280 */
281void
282uart_update_timeout(struct uart_port *port, unsigned int cflag,
283 unsigned int baud)
284{
285 unsigned int bits;
286
287 /* byte size and parity */
288 switch (cflag & CSIZE) {
289 case CS5:
290 bits = 7;
291 break;
292 case CS6:
293 bits = 8;
294 break;
295 case CS7:
296 bits = 9;
297 break;
298 default:
299 bits = 10;
300 break; // CS8
301 }
302
303 if (cflag & CSTOPB)
304 bits++;
305 if (cflag & PARENB)
306 bits++;
307
308 /*
309 * The total number of bits to be transmitted in the fifo.
310 */
311 bits = bits * port->fifosize;
312
313 /*
314 * Figure the timeout to send the above number of bits.
315 * Add .02 seconds of slop
316 */
317 port->timeout = (HZ * bits) / baud + HZ/50;
318}
319
320EXPORT_SYMBOL(uart_update_timeout);
321
322/**
323 * uart_get_baud_rate - return baud rate for a particular port
324 * @port: uart_port structure describing the port in question.
325 * @termios: desired termios settings.
326 * @old: old termios (or NULL)
327 * @min: minimum acceptable baud rate
328 * @max: maximum acceptable baud rate
329 *
330 * Decode the termios structure into a numeric baud rate,
331 * taking account of the magic 38400 baud rate (with spd_*
332 * flags), and mapping the %B0 rate to 9600 baud.
333 *
334 * If the new baud rate is invalid, try the old termios setting.
335 * If it's still invalid, we try 9600 baud.
336 *
337 * Update the @termios structure to reflect the baud rate
338 * we're actually going to be using.
339 */
340unsigned int
Alan Cox606d0992006-12-08 02:38:45 -0800341uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
342 struct ktermios *old, unsigned int min, unsigned int max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343{
344 unsigned int try, baud, altbaud = 38400;
Russell King0077d452006-01-21 23:03:28 +0000345 upf_t flags = port->flags & UPF_SPD_MASK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
347 if (flags == UPF_SPD_HI)
348 altbaud = 57600;
349 if (flags == UPF_SPD_VHI)
350 altbaud = 115200;
351 if (flags == UPF_SPD_SHI)
352 altbaud = 230400;
353 if (flags == UPF_SPD_WARP)
354 altbaud = 460800;
355
356 for (try = 0; try < 2; try++) {
357 baud = tty_termios_baud_rate(termios);
358
359 /*
360 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
361 * Die! Die! Die!
362 */
363 if (baud == 38400)
364 baud = altbaud;
365
366 /*
367 * Special case: B0 rate.
368 */
369 if (baud == 0)
370 baud = 9600;
371
372 if (baud >= min && baud <= max)
373 return baud;
374
375 /*
376 * Oops, the quotient was zero. Try again with
377 * the old baud rate if possible.
378 */
379 termios->c_cflag &= ~CBAUD;
380 if (old) {
381 termios->c_cflag |= old->c_cflag & CBAUD;
382 old = NULL;
383 continue;
384 }
385
386 /*
387 * As a last resort, if the quotient is zero,
388 * default to 9600 bps
389 */
390 termios->c_cflag |= B9600;
391 }
392
393 return 0;
394}
395
396EXPORT_SYMBOL(uart_get_baud_rate);
397
398/**
399 * uart_get_divisor - return uart clock divisor
400 * @port: uart_port structure describing the port.
401 * @baud: desired baud rate
402 *
403 * Calculate the uart clock divisor for the port.
404 */
405unsigned int
406uart_get_divisor(struct uart_port *port, unsigned int baud)
407{
408 unsigned int quot;
409
410 /*
411 * Old custom speed handling.
412 */
413 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
414 quot = port->custom_divisor;
415 else
416 quot = (port->uartclk + (8 * baud)) / (16 * baud);
417
418 return quot;
419}
420
421EXPORT_SYMBOL(uart_get_divisor);
422
423static void
Alan Cox606d0992006-12-08 02:38:45 -0800424uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425{
426 struct tty_struct *tty = state->info->tty;
427 struct uart_port *port = state->port;
Alan Cox606d0992006-12-08 02:38:45 -0800428 struct ktermios *termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
430 /*
431 * If we have no tty, termios, or the port does not exist,
432 * then we can't set the parameters for this port.
433 */
434 if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
435 return;
436
437 termios = tty->termios;
438
439 /*
440 * Set flags based on termios cflag
441 */
442 if (termios->c_cflag & CRTSCTS)
443 state->info->flags |= UIF_CTS_FLOW;
444 else
445 state->info->flags &= ~UIF_CTS_FLOW;
446
447 if (termios->c_cflag & CLOCAL)
448 state->info->flags &= ~UIF_CHECK_CD;
449 else
450 state->info->flags |= UIF_CHECK_CD;
451
452 port->ops->set_termios(port, termios, old_termios);
453}
454
455static inline void
456__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
457{
458 unsigned long flags;
459
460 if (!circ->buf)
461 return;
462
463 spin_lock_irqsave(&port->lock, flags);
464 if (uart_circ_chars_free(circ) != 0) {
465 circ->buf[circ->head] = c;
466 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
467 }
468 spin_unlock_irqrestore(&port->lock, flags);
469}
470
471static void uart_put_char(struct tty_struct *tty, unsigned char ch)
472{
473 struct uart_state *state = tty->driver_data;
474
475 __uart_put_char(state->port, &state->info->xmit, ch);
476}
477
478static void uart_flush_chars(struct tty_struct *tty)
479{
480 uart_start(tty);
481}
482
483static int
Pavel Machekd5f735e2006-03-07 21:55:20 -0800484uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485{
486 struct uart_state *state = tty->driver_data;
Pavel Machekd5f735e2006-03-07 21:55:20 -0800487 struct uart_port *port;
488 struct circ_buf *circ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 unsigned long flags;
490 int c, ret = 0;
491
Pavel Machekd5f735e2006-03-07 21:55:20 -0800492 /*
493 * This means you called this function _after_ the port was
494 * closed. No cookie for you.
495 */
496 if (!state || !state->info) {
497 WARN_ON(1);
498 return -EL3HLT;
499 }
500
501 port = state->port;
502 circ = &state->info->xmit;
503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (!circ->buf)
505 return 0;
506
507 spin_lock_irqsave(&port->lock, flags);
508 while (1) {
509 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
510 if (count < c)
511 c = count;
512 if (c <= 0)
513 break;
514 memcpy(circ->buf + circ->head, buf, c);
515 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
516 buf += c;
517 count -= c;
518 ret += c;
519 }
520 spin_unlock_irqrestore(&port->lock, flags);
521
522 uart_start(tty);
523 return ret;
524}
525
526static int uart_write_room(struct tty_struct *tty)
527{
528 struct uart_state *state = tty->driver_data;
529
530 return uart_circ_chars_free(&state->info->xmit);
531}
532
533static int uart_chars_in_buffer(struct tty_struct *tty)
534{
535 struct uart_state *state = tty->driver_data;
536
537 return uart_circ_chars_pending(&state->info->xmit);
538}
539
540static void uart_flush_buffer(struct tty_struct *tty)
541{
542 struct uart_state *state = tty->driver_data;
543 struct uart_port *port = state->port;
544 unsigned long flags;
545
Pavel Machekd5f735e2006-03-07 21:55:20 -0800546 /*
547 * This means you called this function _after_ the port was
548 * closed. No cookie for you.
549 */
550 if (!state || !state->info) {
551 WARN_ON(1);
552 return;
553 }
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
556
557 spin_lock_irqsave(&port->lock, flags);
558 uart_circ_clear(&state->info->xmit);
559 spin_unlock_irqrestore(&port->lock, flags);
560 tty_wakeup(tty);
561}
562
563/*
564 * This function is used to send a high-priority XON/XOFF character to
565 * the device
566 */
567static void uart_send_xchar(struct tty_struct *tty, char ch)
568{
569 struct uart_state *state = tty->driver_data;
570 struct uart_port *port = state->port;
571 unsigned long flags;
572
573 if (port->ops->send_xchar)
574 port->ops->send_xchar(port, ch);
575 else {
576 port->x_char = ch;
577 if (ch) {
578 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +0100579 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 spin_unlock_irqrestore(&port->lock, flags);
581 }
582 }
583}
584
585static void uart_throttle(struct tty_struct *tty)
586{
587 struct uart_state *state = tty->driver_data;
588
589 if (I_IXOFF(tty))
590 uart_send_xchar(tty, STOP_CHAR(tty));
591
592 if (tty->termios->c_cflag & CRTSCTS)
593 uart_clear_mctrl(state->port, TIOCM_RTS);
594}
595
596static void uart_unthrottle(struct tty_struct *tty)
597{
598 struct uart_state *state = tty->driver_data;
599 struct uart_port *port = state->port;
600
601 if (I_IXOFF(tty)) {
602 if (port->x_char)
603 port->x_char = 0;
604 else
605 uart_send_xchar(tty, START_CHAR(tty));
606 }
607
608 if (tty->termios->c_cflag & CRTSCTS)
609 uart_set_mctrl(port, TIOCM_RTS);
610}
611
612static int uart_get_info(struct uart_state *state,
613 struct serial_struct __user *retinfo)
614{
615 struct uart_port *port = state->port;
616 struct serial_struct tmp;
617
618 memset(&tmp, 0, sizeof(tmp));
619 tmp.type = port->type;
620 tmp.line = port->line;
621 tmp.port = port->iobase;
622 if (HIGH_BITS_OFFSET)
623 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
624 tmp.irq = port->irq;
625 tmp.flags = port->flags;
626 tmp.xmit_fifo_size = port->fifosize;
627 tmp.baud_base = port->uartclk / 16;
628 tmp.close_delay = state->close_delay / 10;
629 tmp.closing_wait = state->closing_wait == USF_CLOSING_WAIT_NONE ?
630 ASYNC_CLOSING_WAIT_NONE :
631 state->closing_wait / 10;
632 tmp.custom_divisor = port->custom_divisor;
633 tmp.hub6 = port->hub6;
634 tmp.io_type = port->iotype;
635 tmp.iomem_reg_shift = port->regshift;
636 tmp.iomem_base = (void *)port->mapbase;
637
638 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
639 return -EFAULT;
640 return 0;
641}
642
643static int uart_set_info(struct uart_state *state,
644 struct serial_struct __user *newinfo)
645{
646 struct serial_struct new_serial;
647 struct uart_port *port = state->port;
648 unsigned long new_port;
Russell King0077d452006-01-21 23:03:28 +0000649 unsigned int change_irq, change_port, closing_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 unsigned int old_custom_divisor, close_delay;
Russell King0077d452006-01-21 23:03:28 +0000651 upf_t old_flags, new_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 int retval = 0;
653
654 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
655 return -EFAULT;
656
657 new_port = new_serial.port;
658 if (HIGH_BITS_OFFSET)
659 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
660
661 new_serial.irq = irq_canonicalize(new_serial.irq);
662 close_delay = new_serial.close_delay * 10;
663 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
664 USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
665
666 /*
667 * This semaphore protects state->count. It is also
668 * very useful to prevent opens. Also, take the
669 * port configuration semaphore to make sure that a
670 * module insertion/removal doesn't change anything
671 * under us.
672 */
Ingo Molnare2862f62006-01-13 21:37:07 +0000673 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
675 change_irq = new_serial.irq != port->irq;
676
677 /*
678 * Since changing the 'type' of the port changes its resource
679 * allocations, we should treat type changes the same as
680 * IO port changes.
681 */
682 change_port = new_port != port->iobase ||
683 (unsigned long)new_serial.iomem_base != port->mapbase ||
684 new_serial.hub6 != port->hub6 ||
685 new_serial.io_type != port->iotype ||
686 new_serial.iomem_reg_shift != port->regshift ||
687 new_serial.type != port->type;
688
689 old_flags = port->flags;
Russell King0077d452006-01-21 23:03:28 +0000690 new_flags = new_serial.flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 old_custom_divisor = port->custom_divisor;
692
693 if (!capable(CAP_SYS_ADMIN)) {
694 retval = -EPERM;
695 if (change_irq || change_port ||
696 (new_serial.baud_base != port->uartclk / 16) ||
697 (close_delay != state->close_delay) ||
698 (closing_wait != state->closing_wait) ||
Russell King947deee2006-07-02 20:45:51 +0100699 (new_serial.xmit_fifo_size &&
700 new_serial.xmit_fifo_size != port->fifosize) ||
Russell King0077d452006-01-21 23:03:28 +0000701 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 goto exit;
703 port->flags = ((port->flags & ~UPF_USR_MASK) |
Russell King0077d452006-01-21 23:03:28 +0000704 (new_flags & UPF_USR_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 port->custom_divisor = new_serial.custom_divisor;
706 goto check_and_exit;
707 }
708
709 /*
710 * Ask the low level driver to verify the settings.
711 */
712 if (port->ops->verify_port)
713 retval = port->ops->verify_port(port, &new_serial);
714
715 if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
716 (new_serial.baud_base < 9600))
717 retval = -EINVAL;
718
719 if (retval)
720 goto exit;
721
722 if (change_port || change_irq) {
723 retval = -EBUSY;
724
725 /*
726 * Make sure that we are the sole user of this port.
727 */
728 if (uart_users(state) > 1)
729 goto exit;
730
731 /*
732 * We need to shutdown the serial port at the old
733 * port/type/irq combination.
734 */
735 uart_shutdown(state);
736 }
737
738 if (change_port) {
739 unsigned long old_iobase, old_mapbase;
740 unsigned int old_type, old_iotype, old_hub6, old_shift;
741
742 old_iobase = port->iobase;
743 old_mapbase = port->mapbase;
744 old_type = port->type;
745 old_hub6 = port->hub6;
746 old_iotype = port->iotype;
747 old_shift = port->regshift;
748
749 /*
750 * Free and release old regions
751 */
752 if (old_type != PORT_UNKNOWN)
753 port->ops->release_port(port);
754
755 port->iobase = new_port;
756 port->type = new_serial.type;
757 port->hub6 = new_serial.hub6;
758 port->iotype = new_serial.io_type;
759 port->regshift = new_serial.iomem_reg_shift;
760 port->mapbase = (unsigned long)new_serial.iomem_base;
761
762 /*
763 * Claim and map the new regions
764 */
765 if (port->type != PORT_UNKNOWN) {
766 retval = port->ops->request_port(port);
767 } else {
768 /* Always success - Jean II */
769 retval = 0;
770 }
771
772 /*
773 * If we fail to request resources for the
774 * new port, try to restore the old settings.
775 */
776 if (retval && old_type != PORT_UNKNOWN) {
777 port->iobase = old_iobase;
778 port->type = old_type;
779 port->hub6 = old_hub6;
780 port->iotype = old_iotype;
781 port->regshift = old_shift;
782 port->mapbase = old_mapbase;
783 retval = port->ops->request_port(port);
784 /*
785 * If we failed to restore the old settings,
786 * we fail like this.
787 */
788 if (retval)
789 port->type = PORT_UNKNOWN;
790
791 /*
792 * We failed anyway.
793 */
794 retval = -EBUSY;
Ram Gupta80e3c2b2006-08-14 23:05:29 -0700795 goto exit; // Added to return the correct error -Ram Gupta
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
797 }
798
799 port->irq = new_serial.irq;
800 port->uartclk = new_serial.baud_base * 16;
801 port->flags = (port->flags & ~UPF_CHANGE_MASK) |
Russell King0077d452006-01-21 23:03:28 +0000802 (new_flags & UPF_CHANGE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 port->custom_divisor = new_serial.custom_divisor;
804 state->close_delay = close_delay;
805 state->closing_wait = closing_wait;
Russell King947deee2006-07-02 20:45:51 +0100806 if (new_serial.xmit_fifo_size)
807 port->fifosize = new_serial.xmit_fifo_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 if (state->info->tty)
809 state->info->tty->low_latency =
810 (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
811
812 check_and_exit:
813 retval = 0;
814 if (port->type == PORT_UNKNOWN)
815 goto exit;
816 if (state->info->flags & UIF_INITIALIZED) {
817 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
818 old_custom_divisor != port->custom_divisor) {
819 /*
820 * If they're setting up a custom divisor or speed,
821 * instead of clearing it, then bitch about it. No
822 * need to rate-limit; it's CAP_SYS_ADMIN only.
823 */
824 if (port->flags & UPF_SPD_MASK) {
825 char buf[64];
826 printk(KERN_NOTICE
827 "%s sets custom speed on %s. This "
828 "is deprecated.\n", current->comm,
829 tty_name(state->info->tty, buf));
830 }
831 uart_change_speed(state, NULL);
832 }
833 } else
834 retval = uart_startup(state, 1);
835 exit:
Ingo Molnare2862f62006-01-13 21:37:07 +0000836 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 return retval;
838}
839
840
841/*
842 * uart_get_lsr_info - get line status register info.
843 * Note: uart_ioctl protects us against hangups.
844 */
845static int uart_get_lsr_info(struct uart_state *state,
846 unsigned int __user *value)
847{
848 struct uart_port *port = state->port;
849 unsigned int result;
850
851 result = port->ops->tx_empty(port);
852
853 /*
854 * If we're about to load something into the transmit
855 * register, we'll pretend the transmitter isn't empty to
856 * avoid a race condition (depending on when the transmit
857 * interrupt happens).
858 */
859 if (port->x_char ||
860 ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
861 !state->info->tty->stopped && !state->info->tty->hw_stopped))
862 result &= ~TIOCSER_TEMT;
863
864 return put_user(result, value);
865}
866
867static int uart_tiocmget(struct tty_struct *tty, struct file *file)
868{
869 struct uart_state *state = tty->driver_data;
870 struct uart_port *port = state->port;
871 int result = -EIO;
872
Ingo Molnare2862f62006-01-13 21:37:07 +0000873 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 if ((!file || !tty_hung_up_p(file)) &&
875 !(tty->flags & (1 << TTY_IO_ERROR))) {
876 result = port->mctrl;
Russell Kingc5f46442005-06-29 09:42:38 +0100877
878 spin_lock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 result |= port->ops->get_mctrl(port);
Russell Kingc5f46442005-06-29 09:42:38 +0100880 spin_unlock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000882 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 return result;
885}
886
887static int
888uart_tiocmset(struct tty_struct *tty, struct file *file,
889 unsigned int set, unsigned int clear)
890{
891 struct uart_state *state = tty->driver_data;
892 struct uart_port *port = state->port;
893 int ret = -EIO;
894
Ingo Molnare2862f62006-01-13 21:37:07 +0000895 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 if ((!file || !tty_hung_up_p(file)) &&
897 !(tty->flags & (1 << TTY_IO_ERROR))) {
898 uart_update_mctrl(port, set, clear);
899 ret = 0;
900 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000901 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 return ret;
903}
904
905static void uart_break_ctl(struct tty_struct *tty, int break_state)
906{
907 struct uart_state *state = tty->driver_data;
908 struct uart_port *port = state->port;
909
910 BUG_ON(!kernel_locked());
911
Ingo Molnare2862f62006-01-13 21:37:07 +0000912 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913
914 if (port->type != PORT_UNKNOWN)
915 port->ops->break_ctl(port, break_state);
916
Ingo Molnare2862f62006-01-13 21:37:07 +0000917 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918}
919
920static int uart_do_autoconfig(struct uart_state *state)
921{
922 struct uart_port *port = state->port;
923 int flags, ret;
924
925 if (!capable(CAP_SYS_ADMIN))
926 return -EPERM;
927
928 /*
929 * Take the per-port semaphore. This prevents count from
930 * changing, and hence any extra opens of the port while
931 * we're auto-configuring.
932 */
Ingo Molnare2862f62006-01-13 21:37:07 +0000933 if (mutex_lock_interruptible(&state->mutex))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 return -ERESTARTSYS;
935
936 ret = -EBUSY;
937 if (uart_users(state) == 1) {
938 uart_shutdown(state);
939
940 /*
941 * If we already have a port type configured,
942 * we must release its resources.
943 */
944 if (port->type != PORT_UNKNOWN)
945 port->ops->release_port(port);
946
947 flags = UART_CONFIG_TYPE;
948 if (port->flags & UPF_AUTO_IRQ)
949 flags |= UART_CONFIG_IRQ;
950
951 /*
952 * This will claim the ports resources if
953 * a port is found.
954 */
955 port->ops->config_port(port, flags);
956
957 ret = uart_startup(state, 1);
958 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000959 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 return ret;
961}
962
963/*
964 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
965 * - mask passed in arg for lines of interest
966 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
967 * Caller should use TIOCGICOUNT to see which one it was
968 */
969static int
970uart_wait_modem_status(struct uart_state *state, unsigned long arg)
971{
972 struct uart_port *port = state->port;
973 DECLARE_WAITQUEUE(wait, current);
974 struct uart_icount cprev, cnow;
975 int ret;
976
977 /*
978 * note the counters on entry
979 */
980 spin_lock_irq(&port->lock);
981 memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
982
983 /*
984 * Force modem status interrupts on
985 */
986 port->ops->enable_ms(port);
987 spin_unlock_irq(&port->lock);
988
989 add_wait_queue(&state->info->delta_msr_wait, &wait);
990 for (;;) {
991 spin_lock_irq(&port->lock);
992 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
993 spin_unlock_irq(&port->lock);
994
995 set_current_state(TASK_INTERRUPTIBLE);
996
997 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
998 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
999 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
1000 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1001 ret = 0;
1002 break;
1003 }
1004
1005 schedule();
1006
1007 /* see if a signal did it */
1008 if (signal_pending(current)) {
1009 ret = -ERESTARTSYS;
1010 break;
1011 }
1012
1013 cprev = cnow;
1014 }
1015
1016 current->state = TASK_RUNNING;
1017 remove_wait_queue(&state->info->delta_msr_wait, &wait);
1018
1019 return ret;
1020}
1021
1022/*
1023 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1024 * Return: write counters to the user passed counter struct
1025 * NB: both 1->0 and 0->1 transitions are counted except for
1026 * RI where only 0->1 is counted.
1027 */
1028static int uart_get_count(struct uart_state *state,
1029 struct serial_icounter_struct __user *icnt)
1030{
1031 struct serial_icounter_struct icount;
1032 struct uart_icount cnow;
1033 struct uart_port *port = state->port;
1034
1035 spin_lock_irq(&port->lock);
1036 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1037 spin_unlock_irq(&port->lock);
1038
1039 icount.cts = cnow.cts;
1040 icount.dsr = cnow.dsr;
1041 icount.rng = cnow.rng;
1042 icount.dcd = cnow.dcd;
1043 icount.rx = cnow.rx;
1044 icount.tx = cnow.tx;
1045 icount.frame = cnow.frame;
1046 icount.overrun = cnow.overrun;
1047 icount.parity = cnow.parity;
1048 icount.brk = cnow.brk;
1049 icount.buf_overrun = cnow.buf_overrun;
1050
1051 return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1052}
1053
1054/*
1055 * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here.
1056 */
1057static int
1058uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1059 unsigned long arg)
1060{
1061 struct uart_state *state = tty->driver_data;
1062 void __user *uarg = (void __user *)arg;
1063 int ret = -ENOIOCTLCMD;
1064
1065 BUG_ON(!kernel_locked());
1066
1067 /*
1068 * These ioctls don't rely on the hardware to be present.
1069 */
1070 switch (cmd) {
1071 case TIOCGSERIAL:
1072 ret = uart_get_info(state, uarg);
1073 break;
1074
1075 case TIOCSSERIAL:
1076 ret = uart_set_info(state, uarg);
1077 break;
1078
1079 case TIOCSERCONFIG:
1080 ret = uart_do_autoconfig(state);
1081 break;
1082
1083 case TIOCSERGWILD: /* obsolete */
1084 case TIOCSERSWILD: /* obsolete */
1085 ret = 0;
1086 break;
1087 }
1088
1089 if (ret != -ENOIOCTLCMD)
1090 goto out;
1091
1092 if (tty->flags & (1 << TTY_IO_ERROR)) {
1093 ret = -EIO;
1094 goto out;
1095 }
1096
1097 /*
1098 * The following should only be used when hardware is present.
1099 */
1100 switch (cmd) {
1101 case TIOCMIWAIT:
1102 ret = uart_wait_modem_status(state, arg);
1103 break;
1104
1105 case TIOCGICOUNT:
1106 ret = uart_get_count(state, uarg);
1107 break;
1108 }
1109
1110 if (ret != -ENOIOCTLCMD)
1111 goto out;
1112
Ingo Molnare2862f62006-01-13 21:37:07 +00001113 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114
1115 if (tty_hung_up_p(filp)) {
1116 ret = -EIO;
1117 goto out_up;
1118 }
1119
1120 /*
1121 * All these rely on hardware being present and need to be
1122 * protected against the tty being hung up.
1123 */
1124 switch (cmd) {
1125 case TIOCSERGETLSR: /* Get line status register */
1126 ret = uart_get_lsr_info(state, uarg);
1127 break;
1128
1129 default: {
1130 struct uart_port *port = state->port;
1131 if (port->ops->ioctl)
1132 ret = port->ops->ioctl(port, cmd, arg);
1133 break;
1134 }
1135 }
1136 out_up:
Ingo Molnare2862f62006-01-13 21:37:07 +00001137 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 out:
1139 return ret;
1140}
1141
Alan Cox606d0992006-12-08 02:38:45 -08001142static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143{
1144 struct uart_state *state = tty->driver_data;
1145 unsigned long flags;
1146 unsigned int cflag = tty->termios->c_cflag;
1147
1148 BUG_ON(!kernel_locked());
1149
1150 /*
1151 * These are the bits that are used to setup various
1152 * flags in the low level driver.
1153 */
1154#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1155
1156 if ((cflag ^ old_termios->c_cflag) == 0 &&
1157 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1158 return;
1159
1160 uart_change_speed(state, old_termios);
1161
1162 /* Handle transition to B0 status */
1163 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1164 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1165
1166 /* Handle transition away from B0 status */
1167 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1168 unsigned int mask = TIOCM_DTR;
1169 if (!(cflag & CRTSCTS) ||
1170 !test_bit(TTY_THROTTLED, &tty->flags))
1171 mask |= TIOCM_RTS;
1172 uart_set_mctrl(state->port, mask);
1173 }
1174
1175 /* Handle turning off CRTSCTS */
1176 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1177 spin_lock_irqsave(&state->port->lock, flags);
1178 tty->hw_stopped = 0;
1179 __uart_start(tty);
1180 spin_unlock_irqrestore(&state->port->lock, flags);
1181 }
1182
Russell King0dd7a1a2005-06-29 18:40:53 +01001183 /* Handle turning on CRTSCTS */
1184 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1185 spin_lock_irqsave(&state->port->lock, flags);
1186 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1187 tty->hw_stopped = 1;
Russell Kingb129a8c2005-08-31 10:12:14 +01001188 state->port->ops->stop_tx(state->port);
Russell King0dd7a1a2005-06-29 18:40:53 +01001189 }
1190 spin_unlock_irqrestore(&state->port->lock, flags);
1191 }
1192
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193#if 0
1194 /*
1195 * No need to wake up processes in open wait, since they
1196 * sample the CLOCAL flag once, and don't recheck it.
1197 * XXX It's not clear whether the current behavior is correct
1198 * or not. Hence, this may change.....
1199 */
1200 if (!(old_termios->c_cflag & CLOCAL) &&
1201 (tty->termios->c_cflag & CLOCAL))
1202 wake_up_interruptible(&state->info->open_wait);
1203#endif
1204}
1205
1206/*
1207 * In 2.4.5, calls to this will be serialized via the BKL in
1208 * linux/drivers/char/tty_io.c:tty_release()
1209 * linux/drivers/char/tty_io.c:do_tty_handup()
1210 */
1211static void uart_close(struct tty_struct *tty, struct file *filp)
1212{
1213 struct uart_state *state = tty->driver_data;
1214 struct uart_port *port;
1215
1216 BUG_ON(!kernel_locked());
1217
1218 if (!state || !state->port)
1219 return;
1220
1221 port = state->port;
1222
1223 DPRINTK("uart_close(%d) called\n", port->line);
1224
Ingo Molnare2862f62006-01-13 21:37:07 +00001225 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226
1227 if (tty_hung_up_p(filp))
1228 goto done;
1229
1230 if ((tty->count == 1) && (state->count != 1)) {
1231 /*
1232 * Uh, oh. tty->count is 1, which means that the tty
1233 * structure will be freed. state->count should always
1234 * be one in these conditions. If it's greater than
1235 * one, we've got real problems, since it means the
1236 * serial port won't be shutdown.
1237 */
1238 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1239 "state->count is %d\n", state->count);
1240 state->count = 1;
1241 }
1242 if (--state->count < 0) {
1243 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1244 tty->name, state->count);
1245 state->count = 0;
1246 }
1247 if (state->count)
1248 goto done;
1249
1250 /*
1251 * Now we wait for the transmit buffer to clear; and we notify
1252 * the line discipline to only process XON/XOFF characters by
1253 * setting tty->closing.
1254 */
1255 tty->closing = 1;
1256
1257 if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1258 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1259
1260 /*
1261 * At this point, we stop accepting input. To do this, we
1262 * disable the receive line status interrupts.
1263 */
1264 if (state->info->flags & UIF_INITIALIZED) {
1265 unsigned long flags;
1266 spin_lock_irqsave(&port->lock, flags);
1267 port->ops->stop_rx(port);
1268 spin_unlock_irqrestore(&port->lock, flags);
1269 /*
1270 * Before we drop DTR, make sure the UART transmitter
1271 * has completely drained; this is especially
1272 * important if there is a transmit FIFO!
1273 */
1274 uart_wait_until_sent(tty, port->timeout);
1275 }
1276
1277 uart_shutdown(state);
1278 uart_flush_buffer(tty);
1279
1280 tty_ldisc_flush(tty);
1281
1282 tty->closing = 0;
1283 state->info->tty = NULL;
1284
1285 if (state->info->blocked_open) {
1286 if (state->close_delay)
1287 msleep_interruptible(state->close_delay);
1288 } else if (!uart_console(port)) {
1289 uart_change_pm(state, 3);
1290 }
1291
1292 /*
1293 * Wake up anyone trying to open this port.
1294 */
1295 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1296 wake_up_interruptible(&state->info->open_wait);
1297
1298 done:
Ingo Molnare2862f62006-01-13 21:37:07 +00001299 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300}
1301
1302static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1303{
1304 struct uart_state *state = tty->driver_data;
1305 struct uart_port *port = state->port;
1306 unsigned long char_time, expire;
1307
1308 BUG_ON(!kernel_locked());
1309
1310 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1311 return;
1312
1313 /*
1314 * Set the check interval to be 1/5 of the estimated time to
1315 * send a single character, and make it at least 1. The check
1316 * interval should also be less than the timeout.
1317 *
1318 * Note: we have to use pretty tight timings here to satisfy
1319 * the NIST-PCTS.
1320 */
1321 char_time = (port->timeout - HZ/50) / port->fifosize;
1322 char_time = char_time / 5;
1323 if (char_time == 0)
1324 char_time = 1;
1325 if (timeout && timeout < char_time)
1326 char_time = timeout;
1327
1328 /*
1329 * If the transmitter hasn't cleared in twice the approximate
1330 * amount of time to send the entire FIFO, it probably won't
1331 * ever clear. This assumes the UART isn't doing flow
1332 * control, which is currently the case. Hence, if it ever
1333 * takes longer than port->timeout, this is probably due to a
1334 * UART bug of some kind. So, we clamp the timeout parameter at
1335 * 2*port->timeout.
1336 */
1337 if (timeout == 0 || timeout > 2 * port->timeout)
1338 timeout = 2 * port->timeout;
1339
1340 expire = jiffies + timeout;
1341
1342 DPRINTK("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1343 port->line, jiffies, expire);
1344
1345 /*
1346 * Check whether the transmitter is empty every 'char_time'.
1347 * 'timeout' / 'expire' give us the maximum amount of time
1348 * we wait.
1349 */
1350 while (!port->ops->tx_empty(port)) {
1351 msleep_interruptible(jiffies_to_msecs(char_time));
1352 if (signal_pending(current))
1353 break;
1354 if (time_after(jiffies, expire))
1355 break;
1356 }
1357 set_current_state(TASK_RUNNING); /* might not be needed */
1358}
1359
1360/*
1361 * This is called with the BKL held in
1362 * linux/drivers/char/tty_io.c:do_tty_hangup()
1363 * We're called from the eventd thread, so we can sleep for
1364 * a _short_ time only.
1365 */
1366static void uart_hangup(struct tty_struct *tty)
1367{
1368 struct uart_state *state = tty->driver_data;
1369
1370 BUG_ON(!kernel_locked());
1371 DPRINTK("uart_hangup(%d)\n", state->port->line);
1372
Ingo Molnare2862f62006-01-13 21:37:07 +00001373 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1375 uart_flush_buffer(tty);
1376 uart_shutdown(state);
1377 state->count = 0;
1378 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1379 state->info->tty = NULL;
1380 wake_up_interruptible(&state->info->open_wait);
1381 wake_up_interruptible(&state->info->delta_msr_wait);
1382 }
Ingo Molnare2862f62006-01-13 21:37:07 +00001383 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384}
1385
1386/*
1387 * Copy across the serial console cflag setting into the termios settings
1388 * for the initial open of the port. This allows continuity between the
1389 * kernel settings, and the settings init adopts when it opens the port
1390 * for the first time.
1391 */
1392static void uart_update_termios(struct uart_state *state)
1393{
1394 struct tty_struct *tty = state->info->tty;
1395 struct uart_port *port = state->port;
1396
1397 if (uart_console(port) && port->cons->cflag) {
1398 tty->termios->c_cflag = port->cons->cflag;
1399 port->cons->cflag = 0;
1400 }
1401
1402 /*
1403 * If the device failed to grab its irq resources,
1404 * or some other error occurred, don't try to talk
1405 * to the port hardware.
1406 */
1407 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1408 /*
1409 * Make termios settings take effect.
1410 */
1411 uart_change_speed(state, NULL);
1412
1413 /*
1414 * And finally enable the RTS and DTR signals.
1415 */
1416 if (tty->termios->c_cflag & CBAUD)
1417 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1418 }
1419}
1420
1421/*
1422 * Block the open until the port is ready. We must be called with
1423 * the per-port semaphore held.
1424 */
1425static int
1426uart_block_til_ready(struct file *filp, struct uart_state *state)
1427{
1428 DECLARE_WAITQUEUE(wait, current);
1429 struct uart_info *info = state->info;
1430 struct uart_port *port = state->port;
Russell Kingc5f46442005-06-29 09:42:38 +01001431 unsigned int mctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432
1433 info->blocked_open++;
1434 state->count--;
1435
1436 add_wait_queue(&info->open_wait, &wait);
1437 while (1) {
1438 set_current_state(TASK_INTERRUPTIBLE);
1439
1440 /*
1441 * If we have been hung up, tell userspace/restart open.
1442 */
1443 if (tty_hung_up_p(filp) || info->tty == NULL)
1444 break;
1445
1446 /*
1447 * If the port has been closed, tell userspace/restart open.
1448 */
1449 if (!(info->flags & UIF_INITIALIZED))
1450 break;
1451
1452 /*
1453 * If non-blocking mode is set, or CLOCAL mode is set,
1454 * we don't want to wait for the modem status lines to
1455 * indicate that the port is ready.
1456 *
1457 * Also, if the port is not enabled/configured, we want
1458 * to allow the open to succeed here. Note that we will
1459 * have set TTY_IO_ERROR for a non-existant port.
1460 */
1461 if ((filp->f_flags & O_NONBLOCK) ||
1462 (info->tty->termios->c_cflag & CLOCAL) ||
1463 (info->tty->flags & (1 << TTY_IO_ERROR))) {
1464 break;
1465 }
1466
1467 /*
1468 * Set DTR to allow modem to know we're waiting. Do
1469 * not set RTS here - we want to make sure we catch
1470 * the data from the modem.
1471 */
1472 if (info->tty->termios->c_cflag & CBAUD)
1473 uart_set_mctrl(port, TIOCM_DTR);
1474
1475 /*
1476 * and wait for the carrier to indicate that the
1477 * modem is ready for us.
1478 */
Russell Kingc5f46442005-06-29 09:42:38 +01001479 spin_lock_irq(&port->lock);
Russell Kingf61051c2006-01-07 23:11:23 +00001480 port->ops->enable_ms(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001481 mctrl = port->ops->get_mctrl(port);
1482 spin_unlock_irq(&port->lock);
1483 if (mctrl & TIOCM_CAR)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 break;
1485
Ingo Molnare2862f62006-01-13 21:37:07 +00001486 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 schedule();
Ingo Molnare2862f62006-01-13 21:37:07 +00001488 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489
1490 if (signal_pending(current))
1491 break;
1492 }
1493 set_current_state(TASK_RUNNING);
1494 remove_wait_queue(&info->open_wait, &wait);
1495
1496 state->count++;
1497 info->blocked_open--;
1498
1499 if (signal_pending(current))
1500 return -ERESTARTSYS;
1501
1502 if (!info->tty || tty_hung_up_p(filp))
1503 return -EAGAIN;
1504
1505 return 0;
1506}
1507
1508static struct uart_state *uart_get(struct uart_driver *drv, int line)
1509{
1510 struct uart_state *state;
Russell King68ac64c2006-04-30 11:13:50 +01001511 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513 state = drv->state + line;
Ingo Molnare2862f62006-01-13 21:37:07 +00001514 if (mutex_lock_interruptible(&state->mutex)) {
Russell King68ac64c2006-04-30 11:13:50 +01001515 ret = -ERESTARTSYS;
1516 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001517 }
1518
1519 state->count++;
Russell King68ac64c2006-04-30 11:13:50 +01001520 if (!state->port || state->port->flags & UPF_DEAD) {
1521 ret = -ENXIO;
1522 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523 }
1524
1525 if (!state->info) {
1526 state->info = kmalloc(sizeof(struct uart_info), GFP_KERNEL);
1527 if (state->info) {
1528 memset(state->info, 0, sizeof(struct uart_info));
1529 init_waitqueue_head(&state->info->open_wait);
1530 init_waitqueue_head(&state->info->delta_msr_wait);
1531
1532 /*
1533 * Link the info into the other structures.
1534 */
1535 state->port->info = state->info;
1536
1537 tasklet_init(&state->info->tlet, uart_tasklet_action,
1538 (unsigned long)state);
1539 } else {
Russell King68ac64c2006-04-30 11:13:50 +01001540 ret = -ENOMEM;
1541 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 }
1543 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 return state;
Russell King68ac64c2006-04-30 11:13:50 +01001545
1546 err_unlock:
1547 state->count--;
1548 mutex_unlock(&state->mutex);
1549 err:
1550 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551}
1552
1553/*
1554 * In 2.4.5, calls to uart_open are serialised by the BKL in
1555 * linux/fs/devices.c:chrdev_open()
1556 * Note that if this fails, then uart_close() _will_ be called.
1557 *
1558 * In time, we want to scrap the "opening nonpresent ports"
1559 * behaviour and implement an alternative way for setserial
1560 * to set base addresses/ports/types. This will allow us to
1561 * get rid of a certain amount of extra tests.
1562 */
1563static int uart_open(struct tty_struct *tty, struct file *filp)
1564{
1565 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1566 struct uart_state *state;
1567 int retval, line = tty->index;
1568
1569 BUG_ON(!kernel_locked());
1570 DPRINTK("uart_open(%d) called\n", line);
1571
1572 /*
1573 * tty->driver->num won't change, so we won't fail here with
1574 * tty->driver_data set to something non-NULL (and therefore
1575 * we won't get caught by uart_close()).
1576 */
1577 retval = -ENODEV;
1578 if (line >= tty->driver->num)
1579 goto fail;
1580
1581 /*
1582 * We take the semaphore inside uart_get to guarantee that we won't
1583 * be re-entered while allocating the info structure, or while we
1584 * request any IRQs that the driver may need. This also has the nice
1585 * side-effect that it delays the action of uart_hangup, so we can
1586 * guarantee that info->tty will always contain something reasonable.
1587 */
1588 state = uart_get(drv, line);
1589 if (IS_ERR(state)) {
1590 retval = PTR_ERR(state);
1591 goto fail;
1592 }
1593
1594 /*
1595 * Once we set tty->driver_data here, we are guaranteed that
1596 * uart_close() will decrement the driver module use count.
1597 * Any failures from here onwards should not touch the count.
1598 */
1599 tty->driver_data = state;
1600 tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1601 tty->alt_speed = 0;
1602 state->info->tty = tty;
1603
1604 /*
1605 * If the port is in the middle of closing, bail out now.
1606 */
1607 if (tty_hung_up_p(filp)) {
1608 retval = -EAGAIN;
1609 state->count--;
Ingo Molnare2862f62006-01-13 21:37:07 +00001610 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 goto fail;
1612 }
1613
1614 /*
1615 * Make sure the device is in D0 state.
1616 */
1617 if (state->count == 1)
1618 uart_change_pm(state, 0);
1619
1620 /*
1621 * Start up the serial port.
1622 */
1623 retval = uart_startup(state, 0);
1624
1625 /*
1626 * If we succeeded, wait until the port is ready.
1627 */
1628 if (retval == 0)
1629 retval = uart_block_til_ready(filp, state);
Ingo Molnare2862f62006-01-13 21:37:07 +00001630 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631
1632 /*
1633 * If this is the first open to succeed, adjust things to suit.
1634 */
1635 if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1636 state->info->flags |= UIF_NORMAL_ACTIVE;
1637
1638 uart_update_termios(state);
1639 }
1640
1641 fail:
1642 return retval;
1643}
1644
1645static const char *uart_type(struct uart_port *port)
1646{
1647 const char *str = NULL;
1648
1649 if (port->ops->type)
1650 str = port->ops->type(port);
1651
1652 if (!str)
1653 str = "unknown";
1654
1655 return str;
1656}
1657
1658#ifdef CONFIG_PROC_FS
1659
1660static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1661{
1662 struct uart_state *state = drv->state + i;
1663 struct uart_port *port = state->port;
1664 char stat_buf[32];
1665 unsigned int status;
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001666 int mmio, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667
1668 if (!port)
1669 return 0;
1670
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001671 mmio = port->iotype >= UPIO_MEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672 ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1673 port->line, uart_type(port),
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001674 mmio ? "mmio:0x" : "port:",
1675 mmio ? port->mapbase : (unsigned long) port->iobase,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 port->irq);
1677
1678 if (port->type == PORT_UNKNOWN) {
1679 strcat(buf, "\n");
1680 return ret + 1;
1681 }
1682
1683 if(capable(CAP_SYS_ADMIN))
1684 {
Russell Kingc5f46442005-06-29 09:42:38 +01001685 spin_lock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 status = port->ops->get_mctrl(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001687 spin_unlock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001688
1689 ret += sprintf(buf + ret, " tx:%d rx:%d",
1690 port->icount.tx, port->icount.rx);
1691 if (port->icount.frame)
1692 ret += sprintf(buf + ret, " fe:%d",
1693 port->icount.frame);
1694 if (port->icount.parity)
1695 ret += sprintf(buf + ret, " pe:%d",
1696 port->icount.parity);
1697 if (port->icount.brk)
1698 ret += sprintf(buf + ret, " brk:%d",
1699 port->icount.brk);
1700 if (port->icount.overrun)
1701 ret += sprintf(buf + ret, " oe:%d",
1702 port->icount.overrun);
1703
1704#define INFOBIT(bit,str) \
1705 if (port->mctrl & (bit)) \
1706 strncat(stat_buf, (str), sizeof(stat_buf) - \
1707 strlen(stat_buf) - 2)
1708#define STATBIT(bit,str) \
1709 if (status & (bit)) \
1710 strncat(stat_buf, (str), sizeof(stat_buf) - \
1711 strlen(stat_buf) - 2)
1712
1713 stat_buf[0] = '\0';
1714 stat_buf[1] = '\0';
1715 INFOBIT(TIOCM_RTS, "|RTS");
1716 STATBIT(TIOCM_CTS, "|CTS");
1717 INFOBIT(TIOCM_DTR, "|DTR");
1718 STATBIT(TIOCM_DSR, "|DSR");
1719 STATBIT(TIOCM_CAR, "|CD");
1720 STATBIT(TIOCM_RNG, "|RI");
1721 if (stat_buf[0])
1722 stat_buf[0] = ' ';
1723 strcat(stat_buf, "\n");
1724
1725 ret += sprintf(buf + ret, stat_buf);
1726 } else {
1727 strcat(buf, "\n");
1728 ret++;
1729 }
1730#undef STATBIT
1731#undef INFOBIT
1732 return ret;
1733}
1734
1735static int uart_read_proc(char *page, char **start, off_t off,
1736 int count, int *eof, void *data)
1737{
1738 struct tty_driver *ttydrv = data;
1739 struct uart_driver *drv = ttydrv->driver_state;
1740 int i, len = 0, l;
1741 off_t begin = 0;
1742
1743 len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1744 "", "", "");
1745 for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1746 l = uart_line_info(page + len, drv, i);
1747 len += l;
1748 if (len + begin > off + count)
1749 goto done;
1750 if (len + begin < off) {
1751 begin += len;
1752 len = 0;
1753 }
1754 }
1755 *eof = 1;
1756 done:
1757 if (off >= len + begin)
1758 return 0;
1759 *start = page + (off - begin);
1760 return (count < begin + len - off) ? count : (begin + len - off);
1761}
1762#endif
1763
1764#ifdef CONFIG_SERIAL_CORE_CONSOLE
1765/*
Russell Kingd3587882006-03-20 20:00:09 +00001766 * uart_console_write - write a console message to a serial port
1767 * @port: the port to write the message
1768 * @s: array of characters
1769 * @count: number of characters in string to write
1770 * @write: function to write character to port
1771 */
1772void uart_console_write(struct uart_port *port, const char *s,
1773 unsigned int count,
1774 void (*putchar)(struct uart_port *, int))
1775{
1776 unsigned int i;
1777
1778 for (i = 0; i < count; i++, s++) {
1779 if (*s == '\n')
1780 putchar(port, '\r');
1781 putchar(port, *s);
1782 }
1783}
1784EXPORT_SYMBOL_GPL(uart_console_write);
1785
1786/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 * Check whether an invalid uart number has been specified, and
1788 * if so, search for the first available port that does have
1789 * console support.
1790 */
1791struct uart_port * __init
1792uart_get_console(struct uart_port *ports, int nr, struct console *co)
1793{
1794 int idx = co->index;
1795
1796 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1797 ports[idx].membase == NULL))
1798 for (idx = 0; idx < nr; idx++)
1799 if (ports[idx].iobase != 0 ||
1800 ports[idx].membase != NULL)
1801 break;
1802
1803 co->index = idx;
1804
1805 return ports + idx;
1806}
1807
1808/**
1809 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1810 * @options: pointer to option string
1811 * @baud: pointer to an 'int' variable for the baud rate.
1812 * @parity: pointer to an 'int' variable for the parity.
1813 * @bits: pointer to an 'int' variable for the number of data bits.
1814 * @flow: pointer to an 'int' variable for the flow control character.
1815 *
1816 * uart_parse_options decodes a string containing the serial console
1817 * options. The format of the string is <baud><parity><bits><flow>,
1818 * eg: 115200n8r
1819 */
1820void __init
1821uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1822{
1823 char *s = options;
1824
1825 *baud = simple_strtoul(s, NULL, 10);
1826 while (*s >= '0' && *s <= '9')
1827 s++;
1828 if (*s)
1829 *parity = *s++;
1830 if (*s)
1831 *bits = *s++ - '0';
1832 if (*s)
1833 *flow = *s;
1834}
1835
1836struct baud_rates {
1837 unsigned int rate;
1838 unsigned int cflag;
1839};
1840
Arjan van de Vencb3592b2005-11-28 21:04:11 +00001841static const struct baud_rates baud_rates[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 { 921600, B921600 },
1843 { 460800, B460800 },
1844 { 230400, B230400 },
1845 { 115200, B115200 },
1846 { 57600, B57600 },
1847 { 38400, B38400 },
1848 { 19200, B19200 },
1849 { 9600, B9600 },
1850 { 4800, B4800 },
1851 { 2400, B2400 },
1852 { 1200, B1200 },
1853 { 0, B38400 }
1854};
1855
1856/**
1857 * uart_set_options - setup the serial console parameters
1858 * @port: pointer to the serial ports uart_port structure
1859 * @co: console pointer
1860 * @baud: baud rate
1861 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1862 * @bits: number of data bits
1863 * @flow: flow control character - 'r' (rts)
1864 */
1865int __init
1866uart_set_options(struct uart_port *port, struct console *co,
1867 int baud, int parity, int bits, int flow)
1868{
Alan Cox606d0992006-12-08 02:38:45 -08001869 struct ktermios termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 int i;
1871
Russell King976ecd12005-07-03 21:05:45 +01001872 /*
1873 * Ensure that the serial console lock is initialised
1874 * early.
1875 */
1876 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07001877 lockdep_set_class(&port->lock, &port_lock_key);
Russell King976ecd12005-07-03 21:05:45 +01001878
Alan Cox606d0992006-12-08 02:38:45 -08001879 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880
1881 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1882
1883 /*
1884 * Construct a cflag setting.
1885 */
1886 for (i = 0; baud_rates[i].rate; i++)
1887 if (baud_rates[i].rate <= baud)
1888 break;
1889
1890 termios.c_cflag |= baud_rates[i].cflag;
1891
1892 if (bits == 7)
1893 termios.c_cflag |= CS7;
1894 else
1895 termios.c_cflag |= CS8;
1896
1897 switch (parity) {
1898 case 'o': case 'O':
1899 termios.c_cflag |= PARODD;
1900 /*fall through*/
1901 case 'e': case 'E':
1902 termios.c_cflag |= PARENB;
1903 break;
1904 }
1905
1906 if (flow == 'r')
1907 termios.c_cflag |= CRTSCTS;
1908
1909 port->ops->set_termios(port, &termios, NULL);
1910 co->cflag = termios.c_cflag;
1911
1912 return 0;
1913}
1914#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1915
1916static void uart_change_pm(struct uart_state *state, int pm_state)
1917{
1918 struct uart_port *port = state->port;
Andrew Victor1281e362006-05-16 11:28:49 +01001919
1920 if (state->pm_state != pm_state) {
1921 if (port->ops->pm)
1922 port->ops->pm(port, pm_state, state->pm_state);
1923 state->pm_state = pm_state;
1924 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925}
1926
1927int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1928{
1929 struct uart_state *state = drv->state + port->line;
1930
Ingo Molnare2862f62006-01-13 21:37:07 +00001931 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001933#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1934 if (uart_console(port)) {
1935 mutex_unlock(&state->mutex);
1936 return 0;
1937 }
1938#endif
1939
Linus Torvalds1da177e2005-04-16 15:20:36 -07001940 if (state->info && state->info->flags & UIF_INITIALIZED) {
Russell Kingba899db2006-01-21 22:45:50 +00001941 const struct uart_ops *ops = port->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942
Russell Kinga6b93a92006-10-01 17:17:40 +01001943 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1944 | UIF_SUSPENDED;
1945
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946 spin_lock_irq(&port->lock);
Russell Kingb129a8c2005-08-31 10:12:14 +01001947 ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001948 ops->set_mctrl(port, 0);
1949 ops->stop_rx(port);
1950 spin_unlock_irq(&port->lock);
1951
1952 /*
1953 * Wait for the transmitter to empty.
1954 */
1955 while (!ops->tx_empty(port)) {
1956 msleep(10);
1957 }
1958
1959 ops->shutdown(port);
1960 }
1961
1962 /*
1963 * Disable the console device before suspending.
1964 */
1965 if (uart_console(port))
1966 console_stop(port->cons);
1967
1968 uart_change_pm(state, 3);
1969
Ingo Molnare2862f62006-01-13 21:37:07 +00001970 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001971
1972 return 0;
1973}
1974
1975int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1976{
1977 struct uart_state *state = drv->state + port->line;
1978
Ingo Molnare2862f62006-01-13 21:37:07 +00001979 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001980
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001981#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1982 if (uart_console(port)) {
1983 mutex_unlock(&state->mutex);
1984 return 0;
1985 }
1986#endif
1987
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 uart_change_pm(state, 0);
1989
1990 /*
1991 * Re-enable the console device after suspending.
1992 */
1993 if (uart_console(port)) {
Alan Cox606d0992006-12-08 02:38:45 -08001994 struct ktermios termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995
1996 /*
1997 * First try to use the console cflag setting.
1998 */
Alan Cox606d0992006-12-08 02:38:45 -08001999 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002000 termios.c_cflag = port->cons->cflag;
2001
2002 /*
2003 * If that's unset, use the tty termios setting.
2004 */
2005 if (state->info && state->info->tty && termios.c_cflag == 0)
2006 termios = *state->info->tty->termios;
2007
2008 port->ops->set_termios(port, &termios, NULL);
2009 console_start(port->cons);
2010 }
2011
Russell Kinga6b93a92006-10-01 17:17:40 +01002012 if (state->info && state->info->flags & UIF_SUSPENDED) {
Russell Kingba899db2006-01-21 22:45:50 +00002013 const struct uart_ops *ops = port->ops;
Russell Kingee31b332005-11-13 15:28:51 +00002014 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015
2016 ops->set_mctrl(port, 0);
Russell Kingee31b332005-11-13 15:28:51 +00002017 ret = ops->startup(port);
2018 if (ret == 0) {
2019 uart_change_speed(state, NULL);
2020 spin_lock_irq(&port->lock);
2021 ops->set_mctrl(port, port->mctrl);
2022 ops->start_tx(port);
2023 spin_unlock_irq(&port->lock);
Russell Kinga6b93a92006-10-01 17:17:40 +01002024 state->info->flags |= UIF_INITIALIZED;
Russell Kingee31b332005-11-13 15:28:51 +00002025 } else {
2026 /*
2027 * Failed to resume - maybe hardware went away?
2028 * Clear the "initialized" flag so we won't try
2029 * to call the low level drivers shutdown method.
2030 */
Russell Kingee31b332005-11-13 15:28:51 +00002031 uart_shutdown(state);
2032 }
Russell Kinga6b93a92006-10-01 17:17:40 +01002033
2034 state->info->flags &= ~UIF_SUSPENDED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002035 }
2036
Ingo Molnare2862f62006-01-13 21:37:07 +00002037 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038
2039 return 0;
2040}
2041
2042static inline void
2043uart_report_port(struct uart_driver *drv, struct uart_port *port)
2044{
Russell King30b7a3b2005-09-03 15:30:21 +01002045 char address[64];
2046
Linus Torvalds1da177e2005-04-16 15:20:36 -07002047 switch (port->iotype) {
2048 case UPIO_PORT:
Russell King30b7a3b2005-09-03 15:30:21 +01002049 snprintf(address, sizeof(address),
2050 "I/O 0x%x", port->iobase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051 break;
2052 case UPIO_HUB6:
Russell King30b7a3b2005-09-03 15:30:21 +01002053 snprintf(address, sizeof(address),
2054 "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002055 break;
2056 case UPIO_MEM:
2057 case UPIO_MEM32:
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00002058 case UPIO_AU:
Zang Roy-r619113be91ec2006-06-30 02:29:58 -07002059 case UPIO_TSI:
Russell King30b7a3b2005-09-03 15:30:21 +01002060 snprintf(address, sizeof(address),
2061 "MMIO 0x%lx", port->mapbase);
2062 break;
2063 default:
2064 strlcpy(address, "*unknown*", sizeof(address));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065 break;
2066 }
Russell King30b7a3b2005-09-03 15:30:21 +01002067
Russell King0cf669d2005-10-31 11:42:22 +00002068 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2069 port->dev ? port->dev->bus_id : "",
2070 port->dev ? ": " : "",
Russell King30b7a3b2005-09-03 15:30:21 +01002071 drv->dev_name, port->line, address, port->irq, uart_type(port));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002072}
2073
2074static void
2075uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2076 struct uart_port *port)
2077{
2078 unsigned int flags;
2079
2080 /*
2081 * If there isn't a port here, don't do anything further.
2082 */
2083 if (!port->iobase && !port->mapbase && !port->membase)
2084 return;
2085
2086 /*
2087 * Now do the auto configuration stuff. Note that config_port
2088 * is expected to claim the resources and map the port for us.
2089 */
2090 flags = UART_CONFIG_TYPE;
2091 if (port->flags & UPF_AUTO_IRQ)
2092 flags |= UART_CONFIG_IRQ;
2093 if (port->flags & UPF_BOOT_AUTOCONF) {
2094 port->type = PORT_UNKNOWN;
2095 port->ops->config_port(port, flags);
2096 }
2097
2098 if (port->type != PORT_UNKNOWN) {
2099 unsigned long flags;
2100
2101 uart_report_port(drv, port);
2102
2103 /*
2104 * Ensure that the modem control lines are de-activated.
2105 * We probably don't need a spinlock around this, but
2106 */
2107 spin_lock_irqsave(&port->lock, flags);
2108 port->ops->set_mctrl(port, 0);
2109 spin_unlock_irqrestore(&port->lock, flags);
2110
2111 /*
2112 * Power down all ports by default, except the
2113 * console if we have one.
2114 */
2115 if (!uart_console(port))
2116 uart_change_pm(state, 3);
2117 }
2118}
2119
Jeff Dikeb68e31d2006-10-02 02:17:18 -07002120static const struct tty_operations uart_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002121 .open = uart_open,
2122 .close = uart_close,
2123 .write = uart_write,
2124 .put_char = uart_put_char,
2125 .flush_chars = uart_flush_chars,
2126 .write_room = uart_write_room,
2127 .chars_in_buffer= uart_chars_in_buffer,
2128 .flush_buffer = uart_flush_buffer,
2129 .ioctl = uart_ioctl,
2130 .throttle = uart_throttle,
2131 .unthrottle = uart_unthrottle,
2132 .send_xchar = uart_send_xchar,
2133 .set_termios = uart_set_termios,
2134 .stop = uart_stop,
2135 .start = uart_start,
2136 .hangup = uart_hangup,
2137 .break_ctl = uart_break_ctl,
2138 .wait_until_sent= uart_wait_until_sent,
2139#ifdef CONFIG_PROC_FS
2140 .read_proc = uart_read_proc,
2141#endif
2142 .tiocmget = uart_tiocmget,
2143 .tiocmset = uart_tiocmset,
2144};
2145
2146/**
2147 * uart_register_driver - register a driver with the uart core layer
2148 * @drv: low level driver structure
2149 *
2150 * Register a uart driver with the core driver. We in turn register
2151 * with the tty layer, and initialise the core driver per-port state.
2152 *
2153 * We have a proc file in /proc/tty/driver which is named after the
2154 * normal driver.
2155 *
2156 * drv->port should be NULL, and the per-port structures should be
2157 * registered using uart_add_one_port after this call has succeeded.
2158 */
2159int uart_register_driver(struct uart_driver *drv)
2160{
2161 struct tty_driver *normal = NULL;
2162 int i, retval;
2163
2164 BUG_ON(drv->state);
2165
2166 /*
2167 * Maybe we should be using a slab cache for this, especially if
2168 * we have a large number of ports to handle.
2169 */
2170 drv->state = kmalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2171 retval = -ENOMEM;
2172 if (!drv->state)
2173 goto out;
2174
2175 memset(drv->state, 0, sizeof(struct uart_state) * drv->nr);
2176
2177 normal = alloc_tty_driver(drv->nr);
2178 if (!normal)
2179 goto out;
2180
2181 drv->tty_driver = normal;
2182
2183 normal->owner = drv->owner;
2184 normal->driver_name = drv->driver_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185 normal->name = drv->dev_name;
2186 normal->major = drv->major;
2187 normal->minor_start = drv->minor;
2188 normal->type = TTY_DRIVER_TYPE_SERIAL;
2189 normal->subtype = SERIAL_TYPE_NORMAL;
2190 normal->init_termios = tty_std_termios;
2191 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
Alan Cox606d0992006-12-08 02:38:45 -08002192 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
Greg Kroah-Hartman331b8312005-06-20 21:15:16 -07002193 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002194 normal->driver_state = drv;
2195 tty_set_operations(normal, &uart_ops);
2196
2197 /*
2198 * Initialise the UART state(s).
2199 */
2200 for (i = 0; i < drv->nr; i++) {
2201 struct uart_state *state = drv->state + i;
2202
2203 state->close_delay = 500; /* .5 seconds */
2204 state->closing_wait = 30000; /* 30 seconds */
2205
Ingo Molnare2862f62006-01-13 21:37:07 +00002206 mutex_init(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002207 }
2208
2209 retval = tty_register_driver(normal);
2210 out:
2211 if (retval < 0) {
2212 put_tty_driver(normal);
2213 kfree(drv->state);
2214 }
2215 return retval;
2216}
2217
2218/**
2219 * uart_unregister_driver - remove a driver from the uart core layer
2220 * @drv: low level driver structure
2221 *
2222 * Remove all references to a driver from the core driver. The low
2223 * level driver must have removed all its ports via the
2224 * uart_remove_one_port() if it registered them with uart_add_one_port().
2225 * (ie, drv->port == NULL)
2226 */
2227void uart_unregister_driver(struct uart_driver *drv)
2228{
2229 struct tty_driver *p = drv->tty_driver;
2230 tty_unregister_driver(p);
2231 put_tty_driver(p);
2232 kfree(drv->state);
2233 drv->tty_driver = NULL;
2234}
2235
2236struct tty_driver *uart_console_device(struct console *co, int *index)
2237{
2238 struct uart_driver *p = co->data;
2239 *index = co->index;
2240 return p->tty_driver;
2241}
2242
2243/**
2244 * uart_add_one_port - attach a driver-defined port structure
2245 * @drv: pointer to the uart low level driver structure for this port
2246 * @port: uart port structure to use for this port.
2247 *
2248 * This allows the driver to register its own uart_port structure
2249 * with the core driver. The main purpose is to allow the low
2250 * level uart drivers to expand uart_port, rather than having yet
2251 * more levels of structures.
2252 */
2253int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2254{
2255 struct uart_state *state;
2256 int ret = 0;
2257
2258 BUG_ON(in_interrupt());
2259
2260 if (port->line >= drv->nr)
2261 return -EINVAL;
2262
2263 state = drv->state + port->line;
2264
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002265 mutex_lock(&port_mutex);
Russell King68ac64c2006-04-30 11:13:50 +01002266 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002267 if (state->port) {
2268 ret = -EINVAL;
2269 goto out;
2270 }
2271
2272 state->port = port;
2273
Linus Torvalds1da177e2005-04-16 15:20:36 -07002274 port->cons = drv->cons;
2275 port->info = state->info;
2276
Russell King976ecd12005-07-03 21:05:45 +01002277 /*
2278 * If this port is a console, then the spinlock is already
2279 * initialised.
2280 */
Ingo Molnar13e83592006-07-03 00:25:03 -07002281 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
Russell King976ecd12005-07-03 21:05:45 +01002282 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07002283 lockdep_set_class(&port->lock, &port_lock_key);
2284 }
Russell King976ecd12005-07-03 21:05:45 +01002285
Linus Torvalds1da177e2005-04-16 15:20:36 -07002286 uart_configure_port(drv, state, port);
2287
2288 /*
2289 * Register the port whether it's detected or not. This allows
2290 * setserial to be used to alter this ports parameters.
2291 */
2292 tty_register_device(drv->tty_driver, port->line, port->dev);
2293
2294 /*
2295 * If this driver supports console, and it hasn't been
2296 * successfully registered yet, try to re-register it.
2297 * It may be that the port was not available.
2298 */
2299 if (port->type != PORT_UNKNOWN &&
2300 port->cons && !(port->cons->flags & CON_ENABLED))
2301 register_console(port->cons);
2302
Russell King68ac64c2006-04-30 11:13:50 +01002303 /*
2304 * Ensure UPF_DEAD is not set.
2305 */
2306 port->flags &= ~UPF_DEAD;
2307
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308 out:
Russell King68ac64c2006-04-30 11:13:50 +01002309 mutex_unlock(&state->mutex);
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002310 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002311
2312 return ret;
2313}
2314
2315/**
2316 * uart_remove_one_port - detach a driver defined port structure
2317 * @drv: pointer to the uart low level driver structure for this port
2318 * @port: uart port structure for this port
2319 *
2320 * This unhooks (and hangs up) the specified port structure from the
2321 * core driver. No further calls will be made to the low-level code
2322 * for this port.
2323 */
2324int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2325{
2326 struct uart_state *state = drv->state + port->line;
Russell King68ac64c2006-04-30 11:13:50 +01002327 struct uart_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002328
2329 BUG_ON(in_interrupt());
2330
2331 if (state->port != port)
2332 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2333 state->port, port);
2334
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002335 mutex_lock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002336
2337 /*
Russell King68ac64c2006-04-30 11:13:50 +01002338 * Mark the port "dead" - this prevents any opens from
2339 * succeeding while we shut down the port.
2340 */
2341 mutex_lock(&state->mutex);
2342 port->flags |= UPF_DEAD;
2343 mutex_unlock(&state->mutex);
2344
2345 /*
Greg Kroah-Hartmanaa4148c2005-06-20 21:15:16 -07002346 * Remove the devices from the tty layer
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347 */
2348 tty_unregister_device(drv->tty_driver, port->line);
2349
Russell King68ac64c2006-04-30 11:13:50 +01002350 info = state->info;
2351 if (info && info->tty)
2352 tty_vhangup(info->tty);
2353
2354 /*
2355 * All users of this port should now be disconnected from
2356 * this driver, and the port shut down. We should be the
2357 * only thread fiddling with this port from now on.
2358 */
2359 state->info = NULL;
2360
2361 /*
2362 * Free the port IO and memory resources, if any.
2363 */
2364 if (port->type != PORT_UNKNOWN)
2365 port->ops->release_port(port);
2366
2367 /*
2368 * Indicate that there isn't a port here anymore.
2369 */
2370 port->type = PORT_UNKNOWN;
2371
2372 /*
2373 * Kill the tasklet, and free resources.
2374 */
2375 if (info) {
2376 tasklet_kill(&info->tlet);
2377 kfree(info);
2378 }
2379
Linus Torvalds1da177e2005-04-16 15:20:36 -07002380 state->port = NULL;
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002381 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382
2383 return 0;
2384}
2385
2386/*
2387 * Are the two ports equivalent?
2388 */
2389int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2390{
2391 if (port1->iotype != port2->iotype)
2392 return 0;
2393
2394 switch (port1->iotype) {
2395 case UPIO_PORT:
2396 return (port1->iobase == port2->iobase);
2397 case UPIO_HUB6:
2398 return (port1->iobase == port2->iobase) &&
2399 (port1->hub6 == port2->hub6);
2400 case UPIO_MEM:
Sergei Shtylyovd21b55d2006-08-28 19:49:03 +04002401 case UPIO_MEM32:
2402 case UPIO_AU:
2403 case UPIO_TSI:
Benjamin Herrenschmidt1624f002006-01-04 18:09:44 +00002404 return (port1->mapbase == port2->mapbase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002405 }
2406 return 0;
2407}
2408EXPORT_SYMBOL(uart_match_port);
2409
Linus Torvalds1da177e2005-04-16 15:20:36 -07002410EXPORT_SYMBOL(uart_write_wakeup);
2411EXPORT_SYMBOL(uart_register_driver);
2412EXPORT_SYMBOL(uart_unregister_driver);
2413EXPORT_SYMBOL(uart_suspend_port);
2414EXPORT_SYMBOL(uart_resume_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002415EXPORT_SYMBOL(uart_add_one_port);
2416EXPORT_SYMBOL(uart_remove_one_port);
2417
2418MODULE_DESCRIPTION("Serial driver core");
2419MODULE_LICENSE("GPL");