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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070040/*
41 * This is used to lock changes in serial line configuration.
42 */
Arjan van de Venf392ecf2006-01-12 18:44:32 +000043static DEFINE_MUTEX(port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Ingo Molnar13e83592006-07-03 00:25:03 -070045/*
46 * lockdep: port->lock is initialized in two places, but we
47 * want only one lock-class:
48 */
49static struct lock_class_key port_lock_key;
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
52
53#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
54
55#ifdef CONFIG_SERIAL_CORE_CONSOLE
56#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
57#else
58#define uart_console(port) (0)
59#endif
60
Alan Coxa46c9992008-02-08 04:18:53 -080061static void uart_change_speed(struct uart_state *state,
62 struct ktermios *old_termios);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
64static void uart_change_pm(struct uart_state *state, int pm_state);
65
66/*
67 * This routine is used by the interrupt handler to schedule processing in
68 * the software interrupt portion of the driver.
69 */
70void uart_write_wakeup(struct uart_port *port)
71{
72 struct uart_info *info = port->info;
Pavel Machekd5f735e2006-03-07 21:55:20 -080073 /*
74 * This means you called this function _after_ the port was
75 * closed. No cookie for you.
76 */
77 BUG_ON(!info);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 tasklet_schedule(&info->tlet);
79}
80
81static void uart_stop(struct tty_struct *tty)
82{
83 struct uart_state *state = tty->driver_data;
84 struct uart_port *port = state->port;
85 unsigned long flags;
86
87 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +010088 port->ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 spin_unlock_irqrestore(&port->lock, flags);
90}
91
92static void __uart_start(struct tty_struct *tty)
93{
94 struct uart_state *state = tty->driver_data;
95 struct uart_port *port = state->port;
96
97 if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
98 !tty->stopped && !tty->hw_stopped)
Russell Kingb129a8c2005-08-31 10:12:14 +010099 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100}
101
102static void uart_start(struct tty_struct *tty)
103{
104 struct uart_state *state = tty->driver_data;
105 struct uart_port *port = state->port;
106 unsigned long flags;
107
108 spin_lock_irqsave(&port->lock, flags);
109 __uart_start(tty);
110 spin_unlock_irqrestore(&port->lock, flags);
111}
112
113static void uart_tasklet_action(unsigned long data)
114{
115 struct uart_state *state = (struct uart_state *)data;
116 tty_wakeup(state->info->tty);
117}
118
119static inline void
120uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
121{
122 unsigned long flags;
123 unsigned int old;
124
125 spin_lock_irqsave(&port->lock, flags);
126 old = port->mctrl;
127 port->mctrl = (old & ~clear) | set;
128 if (old != port->mctrl)
129 port->ops->set_mctrl(port, port->mctrl);
130 spin_unlock_irqrestore(&port->lock, flags);
131}
132
Alan Coxa46c9992008-02-08 04:18:53 -0800133#define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0)
134#define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
136/*
137 * Startup the port. This will be called once per open. All calls
138 * will be serialised by the per-port semaphore.
139 */
140static int uart_startup(struct uart_state *state, int init_hw)
141{
142 struct uart_info *info = state->info;
143 struct uart_port *port = state->port;
144 unsigned long page;
145 int retval = 0;
146
147 if (info->flags & UIF_INITIALIZED)
148 return 0;
149
150 /*
151 * Set the TTY IO error marker - we will only clear this
152 * once we have successfully opened the port. Also set
153 * up the tty->alt_speed kludge
154 */
Jayachandran Ca2436b22005-10-30 23:26:16 +0000155 set_bit(TTY_IO_ERROR, &info->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 if (port->type == PORT_UNKNOWN)
158 return 0;
159
160 /*
161 * Initialise and allocate the transmit and temporary
162 * buffer.
163 */
164 if (!info->xmit.buf) {
165 page = get_zeroed_page(GFP_KERNEL);
166 if (!page)
167 return -ENOMEM;
168
169 info->xmit.buf = (unsigned char *) page;
170 uart_circ_clear(&info->xmit);
171 }
172
173 retval = port->ops->startup(port);
174 if (retval == 0) {
175 if (init_hw) {
176 /*
177 * Initialise the hardware port settings.
178 */
179 uart_change_speed(state, NULL);
180
181 /*
182 * Setup the RTS and DTR signals once the
183 * port is open and ready to respond.
184 */
185 if (info->tty->termios->c_cflag & CBAUD)
186 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
187 }
188
Russell King0dd7a1a2005-06-29 18:40:53 +0100189 if (info->flags & UIF_CTS_FLOW) {
190 spin_lock_irq(&port->lock);
191 if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
192 info->tty->hw_stopped = 1;
193 spin_unlock_irq(&port->lock);
194 }
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 info->flags |= UIF_INITIALIZED;
197
198 clear_bit(TTY_IO_ERROR, &info->tty->flags);
199 }
200
201 if (retval && capable(CAP_SYS_ADMIN))
202 retval = 0;
203
204 return retval;
205}
206
207/*
208 * This routine will shutdown a serial port; interrupts are disabled, and
209 * DTR is dropped if the hangup on close termio flag is on. Calls to
210 * uart_shutdown are serialised by the per-port semaphore.
211 */
212static void uart_shutdown(struct uart_state *state)
213{
214 struct uart_info *info = state->info;
215 struct uart_port *port = state->port;
216
Russell Kingee31b332005-11-13 15:28:51 +0000217 /*
218 * Set the TTY IO error marker
219 */
220 if (info->tty)
221 set_bit(TTY_IO_ERROR, &info->tty->flags);
222
223 if (info->flags & UIF_INITIALIZED) {
224 info->flags &= ~UIF_INITIALIZED;
225
226 /*
227 * Turn off DTR and RTS early.
228 */
229 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
230 uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
231
232 /*
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.
238 */
239 wake_up_interruptible(&info->delta_msr_wait);
240
241 /*
242 * Free the IRQ and disable the port.
243 */
244 port->ops->shutdown(port);
245
246 /*
247 * Ensure that the IRQ handler isn't running on another CPU.
248 */
249 synchronize_irq(port->irq);
250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 /*
Russell Kingee31b332005-11-13 15:28:51 +0000253 * kill off our tasklet
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 */
Russell Kingee31b332005-11-13 15:28:51 +0000255 tasklet_kill(&info->tlet);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
257 /*
258 * Free the transmit buffer page.
259 */
260 if (info->xmit.buf) {
261 free_page((unsigned long)info->xmit.buf);
262 info->xmit.buf = NULL;
263 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264}
265
266/**
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
271 *
272 * Set the port FIFO timeout value. The @cflag value should
273 * reflect the actual hardware settings.
274 */
275void
276uart_update_timeout(struct uart_port *port, unsigned int cflag,
277 unsigned int baud)
278{
279 unsigned int bits;
280
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;
Alan Coxa46c9992008-02-08 04:18:53 -0800294 break; /* CS8 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 }
296
297 if (cflag & CSTOPB)
298 bits++;
299 if (cflag & PARENB)
300 bits++;
301
302 /*
303 * The total number of bits to be transmitted in the fifo.
304 */
305 bits = bits * port->fifosize;
306
307 /*
308 * Figure the timeout to send the above number of bits.
309 * Add .02 seconds of slop
310 */
311 port->timeout = (HZ * bits) / baud + HZ/50;
312}
313
314EXPORT_SYMBOL(uart_update_timeout);
315
316/**
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
323 *
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.
327 *
328 * If the new baud rate is invalid, try the old termios setting.
329 * If it's still invalid, we try 9600 baud.
330 *
331 * Update the @termios structure to reflect the baud rate
332 * we're actually going to be using.
333 */
334unsigned int
Alan Cox606d0992006-12-08 02:38:45 -0800335uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
336 struct ktermios *old, unsigned int min, unsigned int max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337{
338 unsigned int try, baud, altbaud = 38400;
Russell King0077d452006-01-21 23:03:28 +0000339 upf_t flags = port->flags & UPF_SPD_MASK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341 if (flags == UPF_SPD_HI)
342 altbaud = 57600;
343 if (flags == UPF_SPD_VHI)
344 altbaud = 115200;
345 if (flags == UPF_SPD_SHI)
346 altbaud = 230400;
347 if (flags == UPF_SPD_WARP)
348 altbaud = 460800;
349
350 for (try = 0; try < 2; try++) {
351 baud = tty_termios_baud_rate(termios);
352
353 /*
354 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
355 * Die! Die! Die!
356 */
357 if (baud == 38400)
358 baud = altbaud;
359
360 /*
361 * Special case: B0 rate.
362 */
363 if (baud == 0)
364 baud = 9600;
365
366 if (baud >= min && baud <= max)
367 return baud;
368
369 /*
370 * Oops, the quotient was zero. Try again with
371 * the old baud rate if possible.
372 */
373 termios->c_cflag &= ~CBAUD;
374 if (old) {
Alan Cox6d4d67b2008-02-04 22:27:53 -0800375 baud = tty_termios_baud_rate(old);
376 tty_termios_encode_baud_rate(termios, baud, baud);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 old = NULL;
378 continue;
379 }
380
381 /*
382 * As a last resort, if the quotient is zero,
383 * default to 9600 bps
384 */
Alan Cox6d4d67b2008-02-04 22:27:53 -0800385 tty_termios_encode_baud_rate(termios, 9600, 9600);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 }
387
388 return 0;
389}
390
391EXPORT_SYMBOL(uart_get_baud_rate);
392
393/**
394 * uart_get_divisor - return uart clock divisor
395 * @port: uart_port structure describing the port.
396 * @baud: desired baud rate
397 *
398 * Calculate the uart clock divisor for the port.
399 */
400unsigned int
401uart_get_divisor(struct uart_port *port, unsigned int baud)
402{
403 unsigned int quot;
404
405 /*
406 * Old custom speed handling.
407 */
408 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
409 quot = port->custom_divisor;
410 else
411 quot = (port->uartclk + (8 * baud)) / (16 * baud);
412
413 return quot;
414}
415
416EXPORT_SYMBOL(uart_get_divisor);
417
418static void
Alan Cox606d0992006-12-08 02:38:45 -0800419uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420{
421 struct tty_struct *tty = state->info->tty;
422 struct uart_port *port = state->port;
Alan Cox606d0992006-12-08 02:38:45 -0800423 struct ktermios *termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
425 /*
426 * If we have no tty, termios, or the port does not exist,
427 * then we can't set the parameters for this port.
428 */
429 if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
430 return;
431
432 termios = tty->termios;
433
434 /*
435 * Set flags based on termios cflag
436 */
437 if (termios->c_cflag & CRTSCTS)
438 state->info->flags |= UIF_CTS_FLOW;
439 else
440 state->info->flags &= ~UIF_CTS_FLOW;
441
442 if (termios->c_cflag & CLOCAL)
443 state->info->flags &= ~UIF_CHECK_CD;
444 else
445 state->info->flags |= UIF_CHECK_CD;
446
447 port->ops->set_termios(port, termios, old_termios);
448}
449
450static inline void
451__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
452{
453 unsigned long flags;
454
455 if (!circ->buf)
456 return;
457
458 spin_lock_irqsave(&port->lock, flags);
459 if (uart_circ_chars_free(circ) != 0) {
460 circ->buf[circ->head] = c;
461 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
462 }
463 spin_unlock_irqrestore(&port->lock, flags);
464}
465
466static void uart_put_char(struct tty_struct *tty, unsigned char ch)
467{
468 struct uart_state *state = tty->driver_data;
469
470 __uart_put_char(state->port, &state->info->xmit, ch);
471}
472
473static void uart_flush_chars(struct tty_struct *tty)
474{
475 uart_start(tty);
476}
477
478static int
Pavel Machekd5f735e2006-03-07 21:55:20 -0800479uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480{
481 struct uart_state *state = tty->driver_data;
Pavel Machekd5f735e2006-03-07 21:55:20 -0800482 struct uart_port *port;
483 struct circ_buf *circ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 unsigned long flags;
485 int c, ret = 0;
486
Pavel Machekd5f735e2006-03-07 21:55:20 -0800487 /*
488 * This means you called this function _after_ the port was
489 * closed. No cookie for you.
490 */
491 if (!state || !state->info) {
492 WARN_ON(1);
493 return -EL3HLT;
494 }
495
496 port = state->port;
497 circ = &state->info->xmit;
498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 if (!circ->buf)
500 return 0;
501
502 spin_lock_irqsave(&port->lock, flags);
503 while (1) {
504 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
505 if (count < c)
506 c = count;
507 if (c <= 0)
508 break;
509 memcpy(circ->buf + circ->head, buf, c);
510 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
511 buf += c;
512 count -= c;
513 ret += c;
514 }
515 spin_unlock_irqrestore(&port->lock, flags);
516
517 uart_start(tty);
518 return ret;
519}
520
521static int uart_write_room(struct tty_struct *tty)
522{
523 struct uart_state *state = tty->driver_data;
524
525 return uart_circ_chars_free(&state->info->xmit);
526}
527
528static int uart_chars_in_buffer(struct tty_struct *tty)
529{
530 struct uart_state *state = tty->driver_data;
531
532 return uart_circ_chars_pending(&state->info->xmit);
533}
534
535static void uart_flush_buffer(struct tty_struct *tty)
536{
537 struct uart_state *state = tty->driver_data;
538 struct uart_port *port = state->port;
539 unsigned long flags;
540
Pavel Machekd5f735e2006-03-07 21:55:20 -0800541 /*
542 * This means you called this function _after_ the port was
543 * closed. No cookie for you.
544 */
545 if (!state || !state->info) {
546 WARN_ON(1);
547 return;
548 }
549
Jiri Slabyeb3a1e12007-05-06 14:48:52 -0700550 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
552 spin_lock_irqsave(&port->lock, flags);
553 uart_circ_clear(&state->info->xmit);
554 spin_unlock_irqrestore(&port->lock, flags);
555 tty_wakeup(tty);
556}
557
558/*
559 * This function is used to send a high-priority XON/XOFF character to
560 * the device
561 */
562static void uart_send_xchar(struct tty_struct *tty, char ch)
563{
564 struct uart_state *state = tty->driver_data;
565 struct uart_port *port = state->port;
566 unsigned long flags;
567
568 if (port->ops->send_xchar)
569 port->ops->send_xchar(port, ch);
570 else {
571 port->x_char = ch;
572 if (ch) {
573 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +0100574 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 spin_unlock_irqrestore(&port->lock, flags);
576 }
577 }
578}
579
580static void uart_throttle(struct tty_struct *tty)
581{
582 struct uart_state *state = tty->driver_data;
583
584 if (I_IXOFF(tty))
585 uart_send_xchar(tty, STOP_CHAR(tty));
586
587 if (tty->termios->c_cflag & CRTSCTS)
588 uart_clear_mctrl(state->port, TIOCM_RTS);
589}
590
591static void uart_unthrottle(struct tty_struct *tty)
592{
593 struct uart_state *state = tty->driver_data;
594 struct uart_port *port = state->port;
595
596 if (I_IXOFF(tty)) {
597 if (port->x_char)
598 port->x_char = 0;
599 else
600 uart_send_xchar(tty, START_CHAR(tty));
601 }
602
603 if (tty->termios->c_cflag & CRTSCTS)
604 uart_set_mctrl(port, TIOCM_RTS);
605}
606
607static int uart_get_info(struct uart_state *state,
608 struct serial_struct __user *retinfo)
609{
610 struct uart_port *port = state->port;
611 struct serial_struct tmp;
612
613 memset(&tmp, 0, sizeof(tmp));
614 tmp.type = port->type;
615 tmp.line = port->line;
616 tmp.port = port->iobase;
617 if (HIGH_BITS_OFFSET)
618 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
619 tmp.irq = port->irq;
620 tmp.flags = port->flags;
621 tmp.xmit_fifo_size = port->fifosize;
622 tmp.baud_base = port->uartclk / 16;
623 tmp.close_delay = state->close_delay / 10;
624 tmp.closing_wait = state->closing_wait == USF_CLOSING_WAIT_NONE ?
625 ASYNC_CLOSING_WAIT_NONE :
Alan Coxa46c9992008-02-08 04:18:53 -0800626 state->closing_wait / 10;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 tmp.custom_divisor = port->custom_divisor;
628 tmp.hub6 = port->hub6;
629 tmp.io_type = port->iotype;
630 tmp.iomem_reg_shift = port->regshift;
Josh Boyer4f640ef2007-07-23 18:43:44 -0700631 tmp.iomem_base = (void *)(unsigned long)port->mapbase;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
634 return -EFAULT;
635 return 0;
636}
637
638static int uart_set_info(struct uart_state *state,
639 struct serial_struct __user *newinfo)
640{
641 struct serial_struct new_serial;
642 struct uart_port *port = state->port;
643 unsigned long new_port;
Russell King0077d452006-01-21 23:03:28 +0000644 unsigned int change_irq, change_port, closing_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 unsigned int old_custom_divisor, close_delay;
Russell King0077d452006-01-21 23:03:28 +0000646 upf_t old_flags, new_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 int retval = 0;
648
649 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
650 return -EFAULT;
651
652 new_port = new_serial.port;
653 if (HIGH_BITS_OFFSET)
654 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
655
656 new_serial.irq = irq_canonicalize(new_serial.irq);
657 close_delay = new_serial.close_delay * 10;
658 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
659 USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
660
661 /*
662 * This semaphore protects state->count. It is also
663 * very useful to prevent opens. Also, take the
664 * port configuration semaphore to make sure that a
665 * module insertion/removal doesn't change anything
666 * under us.
667 */
Ingo Molnare2862f62006-01-13 21:37:07 +0000668 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
David Gibsonabb4a232007-05-06 14:48:49 -0700670 change_irq = !(port->flags & UPF_FIXED_PORT)
671 && new_serial.irq != port->irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
673 /*
674 * Since changing the 'type' of the port changes its resource
675 * allocations, we should treat type changes the same as
676 * IO port changes.
677 */
David Gibsonabb4a232007-05-06 14:48:49 -0700678 change_port = !(port->flags & UPF_FIXED_PORT)
679 && (new_port != port->iobase ||
680 (unsigned long)new_serial.iomem_base != port->mapbase ||
681 new_serial.hub6 != port->hub6 ||
682 new_serial.io_type != port->iotype ||
683 new_serial.iomem_reg_shift != port->regshift ||
684 new_serial.type != port->type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
686 old_flags = port->flags;
Russell King0077d452006-01-21 23:03:28 +0000687 new_flags = new_serial.flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 old_custom_divisor = port->custom_divisor;
689
690 if (!capable(CAP_SYS_ADMIN)) {
691 retval = -EPERM;
692 if (change_irq || change_port ||
693 (new_serial.baud_base != port->uartclk / 16) ||
694 (close_delay != state->close_delay) ||
695 (closing_wait != state->closing_wait) ||
Russell King947deee2006-07-02 20:45:51 +0100696 (new_serial.xmit_fifo_size &&
697 new_serial.xmit_fifo_size != port->fifosize) ||
Russell King0077d452006-01-21 23:03:28 +0000698 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 goto exit;
700 port->flags = ((port->flags & ~UPF_USR_MASK) |
Russell King0077d452006-01-21 23:03:28 +0000701 (new_flags & UPF_USR_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 port->custom_divisor = new_serial.custom_divisor;
703 goto check_and_exit;
704 }
705
706 /*
707 * Ask the low level driver to verify the settings.
708 */
709 if (port->ops->verify_port)
710 retval = port->ops->verify_port(port, &new_serial);
711
712 if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
713 (new_serial.baud_base < 9600))
714 retval = -EINVAL;
715
716 if (retval)
717 goto exit;
718
719 if (change_port || change_irq) {
720 retval = -EBUSY;
721
722 /*
723 * Make sure that we are the sole user of this port.
724 */
725 if (uart_users(state) > 1)
726 goto exit;
727
728 /*
729 * We need to shutdown the serial port at the old
730 * port/type/irq combination.
731 */
732 uart_shutdown(state);
733 }
734
735 if (change_port) {
736 unsigned long old_iobase, old_mapbase;
737 unsigned int old_type, old_iotype, old_hub6, old_shift;
738
739 old_iobase = port->iobase;
740 old_mapbase = port->mapbase;
741 old_type = port->type;
742 old_hub6 = port->hub6;
743 old_iotype = port->iotype;
744 old_shift = port->regshift;
745
746 /*
747 * Free and release old regions
748 */
749 if (old_type != PORT_UNKNOWN)
750 port->ops->release_port(port);
751
752 port->iobase = new_port;
753 port->type = new_serial.type;
754 port->hub6 = new_serial.hub6;
755 port->iotype = new_serial.io_type;
756 port->regshift = new_serial.iomem_reg_shift;
757 port->mapbase = (unsigned long)new_serial.iomem_base;
758
759 /*
760 * Claim and map the new regions
761 */
762 if (port->type != PORT_UNKNOWN) {
763 retval = port->ops->request_port(port);
764 } else {
765 /* Always success - Jean II */
766 retval = 0;
767 }
768
769 /*
770 * If we fail to request resources for the
771 * new port, try to restore the old settings.
772 */
773 if (retval && old_type != PORT_UNKNOWN) {
774 port->iobase = old_iobase;
775 port->type = old_type;
776 port->hub6 = old_hub6;
777 port->iotype = old_iotype;
778 port->regshift = old_shift;
779 port->mapbase = old_mapbase;
780 retval = port->ops->request_port(port);
781 /*
782 * If we failed to restore the old settings,
783 * we fail like this.
784 */
785 if (retval)
786 port->type = PORT_UNKNOWN;
787
788 /*
789 * We failed anyway.
790 */
791 retval = -EBUSY;
Alan Coxa46c9992008-02-08 04:18:53 -0800792 /* Added to return the correct error -Ram Gupta */
793 goto exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 }
795 }
796
David Gibsonabb4a232007-05-06 14:48:49 -0700797 if (change_irq)
798 port->irq = new_serial.irq;
799 if (!(port->flags & UPF_FIXED_PORT))
800 port->uartclk = new_serial.baud_base * 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 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;
Alan Coxa46c9992008-02-08 04:18:53 -0800863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 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))) {
Alan Coxa46c9992008-02-08 04:18:53 -08001001 ret = 0;
1002 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 }
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 Coxa46c9992008-02-08 04:18:53 -08001142static void uart_set_termios(struct tty_struct *tty,
1143 struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144{
1145 struct uart_state *state = tty->driver_data;
1146 unsigned long flags;
1147 unsigned int cflag = tty->termios->c_cflag;
1148
1149 BUG_ON(!kernel_locked());
1150
1151 /*
1152 * These are the bits that are used to setup various
David Woodhouse20620d62007-08-22 14:01:11 -07001153 * flags in the low level driver. We can ignore the Bfoo
1154 * bits in c_cflag; c_[io]speed will always be set
1155 * appropriately by set_termios() in tty_ioctl.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 */
1157#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 if ((cflag ^ old_termios->c_cflag) == 0 &&
David Woodhouse20620d62007-08-22 14:01:11 -07001159 tty->termios->c_ospeed == old_termios->c_ospeed &&
1160 tty->termios->c_ispeed == old_termios->c_ispeed &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1162 return;
1163
1164 uart_change_speed(state, old_termios);
1165
1166 /* Handle transition to B0 status */
1167 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1168 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1169
1170 /* Handle transition away from B0 status */
1171 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1172 unsigned int mask = TIOCM_DTR;
1173 if (!(cflag & CRTSCTS) ||
1174 !test_bit(TTY_THROTTLED, &tty->flags))
1175 mask |= TIOCM_RTS;
1176 uart_set_mctrl(state->port, mask);
1177 }
1178
1179 /* Handle turning off CRTSCTS */
1180 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1181 spin_lock_irqsave(&state->port->lock, flags);
1182 tty->hw_stopped = 0;
1183 __uart_start(tty);
1184 spin_unlock_irqrestore(&state->port->lock, flags);
1185 }
1186
Russell King0dd7a1a2005-06-29 18:40:53 +01001187 /* Handle turning on CRTSCTS */
1188 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1189 spin_lock_irqsave(&state->port->lock, flags);
1190 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1191 tty->hw_stopped = 1;
Russell Kingb129a8c2005-08-31 10:12:14 +01001192 state->port->ops->stop_tx(state->port);
Russell King0dd7a1a2005-06-29 18:40:53 +01001193 }
1194 spin_unlock_irqrestore(&state->port->lock, flags);
1195 }
1196
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197#if 0
1198 /*
1199 * No need to wake up processes in open wait, since they
1200 * sample the CLOCAL flag once, and don't recheck it.
1201 * XXX It's not clear whether the current behavior is correct
1202 * or not. Hence, this may change.....
1203 */
1204 if (!(old_termios->c_cflag & CLOCAL) &&
1205 (tty->termios->c_cflag & CLOCAL))
1206 wake_up_interruptible(&state->info->open_wait);
1207#endif
1208}
1209
1210/*
1211 * In 2.4.5, calls to this will be serialized via the BKL in
1212 * linux/drivers/char/tty_io.c:tty_release()
1213 * linux/drivers/char/tty_io.c:do_tty_handup()
1214 */
1215static void uart_close(struct tty_struct *tty, struct file *filp)
1216{
1217 struct uart_state *state = tty->driver_data;
1218 struct uart_port *port;
Alan Coxa46c9992008-02-08 04:18:53 -08001219
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 BUG_ON(!kernel_locked());
1221
1222 if (!state || !state->port)
1223 return;
1224
1225 port = state->port;
1226
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001227 pr_debug("uart_close(%d) called\n", port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228
Ingo Molnare2862f62006-01-13 21:37:07 +00001229 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
1231 if (tty_hung_up_p(filp))
1232 goto done;
1233
1234 if ((tty->count == 1) && (state->count != 1)) {
1235 /*
1236 * Uh, oh. tty->count is 1, which means that the tty
1237 * structure will be freed. state->count should always
1238 * be one in these conditions. If it's greater than
1239 * one, we've got real problems, since it means the
1240 * serial port won't be shutdown.
1241 */
1242 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1243 "state->count is %d\n", state->count);
1244 state->count = 1;
1245 }
1246 if (--state->count < 0) {
1247 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1248 tty->name, state->count);
1249 state->count = 0;
1250 }
1251 if (state->count)
1252 goto done;
1253
1254 /*
1255 * Now we wait for the transmit buffer to clear; and we notify
1256 * the line discipline to only process XON/XOFF characters by
1257 * setting tty->closing.
1258 */
1259 tty->closing = 1;
1260
1261 if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1262 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1263
1264 /*
1265 * At this point, we stop accepting input. To do this, we
1266 * disable the receive line status interrupts.
1267 */
1268 if (state->info->flags & UIF_INITIALIZED) {
1269 unsigned long flags;
1270 spin_lock_irqsave(&port->lock, flags);
1271 port->ops->stop_rx(port);
1272 spin_unlock_irqrestore(&port->lock, flags);
1273 /*
1274 * Before we drop DTR, make sure the UART transmitter
1275 * has completely drained; this is especially
1276 * important if there is a transmit FIFO!
1277 */
1278 uart_wait_until_sent(tty, port->timeout);
1279 }
1280
1281 uart_shutdown(state);
1282 uart_flush_buffer(tty);
1283
Alan Coxa46c9992008-02-08 04:18:53 -08001284 tty_ldisc_flush(tty);
1285
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 tty->closing = 0;
1287 state->info->tty = NULL;
1288
1289 if (state->info->blocked_open) {
1290 if (state->close_delay)
1291 msleep_interruptible(state->close_delay);
1292 } else if (!uart_console(port)) {
1293 uart_change_pm(state, 3);
1294 }
1295
1296 /*
1297 * Wake up anyone trying to open this port.
1298 */
1299 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1300 wake_up_interruptible(&state->info->open_wait);
1301
1302 done:
Ingo Molnare2862f62006-01-13 21:37:07 +00001303 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304}
1305
1306static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1307{
1308 struct uart_state *state = tty->driver_data;
1309 struct uart_port *port = state->port;
1310 unsigned long char_time, expire;
1311
1312 BUG_ON(!kernel_locked());
1313
1314 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1315 return;
1316
1317 /*
1318 * Set the check interval to be 1/5 of the estimated time to
1319 * send a single character, and make it at least 1. The check
1320 * interval should also be less than the timeout.
1321 *
1322 * Note: we have to use pretty tight timings here to satisfy
1323 * the NIST-PCTS.
1324 */
1325 char_time = (port->timeout - HZ/50) / port->fifosize;
1326 char_time = char_time / 5;
1327 if (char_time == 0)
1328 char_time = 1;
1329 if (timeout && timeout < char_time)
1330 char_time = timeout;
1331
1332 /*
1333 * If the transmitter hasn't cleared in twice the approximate
1334 * amount of time to send the entire FIFO, it probably won't
1335 * ever clear. This assumes the UART isn't doing flow
1336 * control, which is currently the case. Hence, if it ever
1337 * takes longer than port->timeout, this is probably due to a
1338 * UART bug of some kind. So, we clamp the timeout parameter at
1339 * 2*port->timeout.
1340 */
1341 if (timeout == 0 || timeout > 2 * port->timeout)
1342 timeout = 2 * port->timeout;
1343
1344 expire = jiffies + timeout;
1345
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001346 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
Alan Coxa46c9992008-02-08 04:18:53 -08001347 port->line, jiffies, expire);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348
1349 /*
1350 * Check whether the transmitter is empty every 'char_time'.
1351 * 'timeout' / 'expire' give us the maximum amount of time
1352 * we wait.
1353 */
1354 while (!port->ops->tx_empty(port)) {
1355 msleep_interruptible(jiffies_to_msecs(char_time));
1356 if (signal_pending(current))
1357 break;
1358 if (time_after(jiffies, expire))
1359 break;
1360 }
1361 set_current_state(TASK_RUNNING); /* might not be needed */
1362}
1363
1364/*
1365 * This is called with the BKL held in
1366 * linux/drivers/char/tty_io.c:do_tty_hangup()
1367 * We're called from the eventd thread, so we can sleep for
1368 * a _short_ time only.
1369 */
1370static void uart_hangup(struct tty_struct *tty)
1371{
1372 struct uart_state *state = tty->driver_data;
1373
1374 BUG_ON(!kernel_locked());
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001375 pr_debug("uart_hangup(%d)\n", state->port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376
Ingo Molnare2862f62006-01-13 21:37:07 +00001377 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1379 uart_flush_buffer(tty);
1380 uart_shutdown(state);
1381 state->count = 0;
1382 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1383 state->info->tty = NULL;
1384 wake_up_interruptible(&state->info->open_wait);
1385 wake_up_interruptible(&state->info->delta_msr_wait);
1386 }
Ingo Molnare2862f62006-01-13 21:37:07 +00001387 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388}
1389
1390/*
1391 * Copy across the serial console cflag setting into the termios settings
1392 * for the initial open of the port. This allows continuity between the
1393 * kernel settings, and the settings init adopts when it opens the port
1394 * for the first time.
1395 */
1396static void uart_update_termios(struct uart_state *state)
1397{
1398 struct tty_struct *tty = state->info->tty;
1399 struct uart_port *port = state->port;
1400
1401 if (uart_console(port) && port->cons->cflag) {
1402 tty->termios->c_cflag = port->cons->cflag;
1403 port->cons->cflag = 0;
1404 }
1405
1406 /*
1407 * If the device failed to grab its irq resources,
1408 * or some other error occurred, don't try to talk
1409 * to the port hardware.
1410 */
1411 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1412 /*
1413 * Make termios settings take effect.
1414 */
1415 uart_change_speed(state, NULL);
1416
1417 /*
1418 * And finally enable the RTS and DTR signals.
1419 */
1420 if (tty->termios->c_cflag & CBAUD)
1421 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1422 }
1423}
1424
1425/*
1426 * Block the open until the port is ready. We must be called with
1427 * the per-port semaphore held.
1428 */
1429static int
1430uart_block_til_ready(struct file *filp, struct uart_state *state)
1431{
1432 DECLARE_WAITQUEUE(wait, current);
1433 struct uart_info *info = state->info;
1434 struct uart_port *port = state->port;
Russell Kingc5f46442005-06-29 09:42:38 +01001435 unsigned int mctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436
1437 info->blocked_open++;
1438 state->count--;
1439
1440 add_wait_queue(&info->open_wait, &wait);
1441 while (1) {
1442 set_current_state(TASK_INTERRUPTIBLE);
1443
1444 /*
1445 * If we have been hung up, tell userspace/restart open.
1446 */
1447 if (tty_hung_up_p(filp) || info->tty == NULL)
1448 break;
1449
1450 /*
1451 * If the port has been closed, tell userspace/restart open.
1452 */
1453 if (!(info->flags & UIF_INITIALIZED))
1454 break;
1455
1456 /*
1457 * If non-blocking mode is set, or CLOCAL mode is set,
1458 * we don't want to wait for the modem status lines to
1459 * indicate that the port is ready.
1460 *
1461 * Also, if the port is not enabled/configured, we want
1462 * to allow the open to succeed here. Note that we will
1463 * have set TTY_IO_ERROR for a non-existant port.
1464 */
1465 if ((filp->f_flags & O_NONBLOCK) ||
Alan Coxa46c9992008-02-08 04:18:53 -08001466 (info->tty->termios->c_cflag & CLOCAL) ||
1467 (info->tty->flags & (1 << TTY_IO_ERROR)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001469
1470 /*
1471 * Set DTR to allow modem to know we're waiting. Do
1472 * not set RTS here - we want to make sure we catch
1473 * the data from the modem.
1474 */
1475 if (info->tty->termios->c_cflag & CBAUD)
1476 uart_set_mctrl(port, TIOCM_DTR);
1477
1478 /*
1479 * and wait for the carrier to indicate that the
1480 * modem is ready for us.
1481 */
Russell Kingc5f46442005-06-29 09:42:38 +01001482 spin_lock_irq(&port->lock);
Russell Kingf61051c2006-01-07 23:11:23 +00001483 port->ops->enable_ms(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001484 mctrl = port->ops->get_mctrl(port);
1485 spin_unlock_irq(&port->lock);
1486 if (mctrl & TIOCM_CAR)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 break;
1488
Ingo Molnare2862f62006-01-13 21:37:07 +00001489 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 schedule();
Ingo Molnare2862f62006-01-13 21:37:07 +00001491 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492
1493 if (signal_pending(current))
1494 break;
1495 }
1496 set_current_state(TASK_RUNNING);
1497 remove_wait_queue(&info->open_wait, &wait);
1498
1499 state->count++;
1500 info->blocked_open--;
1501
1502 if (signal_pending(current))
1503 return -ERESTARTSYS;
1504
1505 if (!info->tty || tty_hung_up_p(filp))
1506 return -EAGAIN;
1507
1508 return 0;
1509}
1510
1511static struct uart_state *uart_get(struct uart_driver *drv, int line)
1512{
1513 struct uart_state *state;
Russell King68ac64c2006-04-30 11:13:50 +01001514 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 state = drv->state + line;
Ingo Molnare2862f62006-01-13 21:37:07 +00001517 if (mutex_lock_interruptible(&state->mutex)) {
Russell King68ac64c2006-04-30 11:13:50 +01001518 ret = -ERESTARTSYS;
1519 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 }
1521
1522 state->count++;
Russell King68ac64c2006-04-30 11:13:50 +01001523 if (!state->port || state->port->flags & UPF_DEAD) {
1524 ret = -ENXIO;
1525 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 }
1527
1528 if (!state->info) {
Burman Yan8f31bb32007-02-14 00:33:07 -08001529 state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 if (state->info) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531 init_waitqueue_head(&state->info->open_wait);
1532 init_waitqueue_head(&state->info->delta_msr_wait);
1533
1534 /*
1535 * Link the info into the other structures.
1536 */
1537 state->port->info = state->info;
1538
1539 tasklet_init(&state->info->tlet, uart_tasklet_action,
1540 (unsigned long)state);
1541 } else {
Russell King68ac64c2006-04-30 11:13:50 +01001542 ret = -ENOMEM;
1543 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 }
1545 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 return state;
Russell King68ac64c2006-04-30 11:13:50 +01001547
1548 err_unlock:
1549 state->count--;
1550 mutex_unlock(&state->mutex);
1551 err:
1552 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553}
1554
1555/*
Denis Cheng922f9cf2008-02-08 04:22:00 -08001556 * calls to uart_open are serialised by the BKL in
1557 * fs/char_dev.c:chrdev_open()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558 * Note that if this fails, then uart_close() _will_ be called.
1559 *
1560 * In time, we want to scrap the "opening nonpresent ports"
1561 * behaviour and implement an alternative way for setserial
1562 * to set base addresses/ports/types. This will allow us to
1563 * get rid of a certain amount of extra tests.
1564 */
1565static int uart_open(struct tty_struct *tty, struct file *filp)
1566{
1567 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1568 struct uart_state *state;
1569 int retval, line = tty->index;
1570
1571 BUG_ON(!kernel_locked());
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001572 pr_debug("uart_open(%d) called\n", line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573
1574 /*
1575 * tty->driver->num won't change, so we won't fail here with
1576 * tty->driver_data set to something non-NULL (and therefore
1577 * we won't get caught by uart_close()).
1578 */
1579 retval = -ENODEV;
1580 if (line >= tty->driver->num)
1581 goto fail;
1582
1583 /*
1584 * We take the semaphore inside uart_get to guarantee that we won't
1585 * be re-entered while allocating the info structure, or while we
1586 * request any IRQs that the driver may need. This also has the nice
1587 * side-effect that it delays the action of uart_hangup, so we can
1588 * guarantee that info->tty will always contain something reasonable.
1589 */
1590 state = uart_get(drv, line);
1591 if (IS_ERR(state)) {
1592 retval = PTR_ERR(state);
1593 goto fail;
1594 }
1595
1596 /*
1597 * Once we set tty->driver_data here, we are guaranteed that
1598 * uart_close() will decrement the driver module use count.
1599 * Any failures from here onwards should not touch the count.
1600 */
1601 tty->driver_data = state;
1602 tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1603 tty->alt_speed = 0;
1604 state->info->tty = tty;
1605
1606 /*
1607 * If the port is in the middle of closing, bail out now.
1608 */
1609 if (tty_hung_up_p(filp)) {
1610 retval = -EAGAIN;
1611 state->count--;
Ingo Molnare2862f62006-01-13 21:37:07 +00001612 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 goto fail;
1614 }
1615
1616 /*
1617 * Make sure the device is in D0 state.
1618 */
1619 if (state->count == 1)
1620 uart_change_pm(state, 0);
1621
1622 /*
1623 * Start up the serial port.
1624 */
1625 retval = uart_startup(state, 0);
1626
1627 /*
1628 * If we succeeded, wait until the port is ready.
1629 */
1630 if (retval == 0)
1631 retval = uart_block_til_ready(filp, state);
Ingo Molnare2862f62006-01-13 21:37:07 +00001632 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633
1634 /*
1635 * If this is the first open to succeed, adjust things to suit.
1636 */
1637 if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1638 state->info->flags |= UIF_NORMAL_ACTIVE;
1639
1640 uart_update_termios(state);
1641 }
1642
1643 fail:
1644 return retval;
1645}
1646
1647static const char *uart_type(struct uart_port *port)
1648{
1649 const char *str = NULL;
1650
1651 if (port->ops->type)
1652 str = port->ops->type(port);
1653
1654 if (!str)
1655 str = "unknown";
1656
1657 return str;
1658}
1659
1660#ifdef CONFIG_PROC_FS
1661
1662static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1663{
1664 struct uart_state *state = drv->state + i;
George G. Davis3689a0e2007-02-14 00:33:06 -08001665 int pm_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 struct uart_port *port = state->port;
1667 char stat_buf[32];
1668 unsigned int status;
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001669 int mmio, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670
1671 if (!port)
1672 return 0;
1673
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001674 mmio = port->iotype >= UPIO_MEM;
Josh Boyer4f640ef2007-07-23 18:43:44 -07001675 ret = sprintf(buf, "%d: uart:%s %s%08llX irq:%d",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 port->line, uart_type(port),
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001677 mmio ? "mmio:0x" : "port:",
Josh Boyer4f640ef2007-07-23 18:43:44 -07001678 mmio ? (unsigned long long)port->mapbase
Alan Coxa46c9992008-02-08 04:18:53 -08001679 : (unsigned long long) port->iobase,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 port->irq);
1681
1682 if (port->type == PORT_UNKNOWN) {
1683 strcat(buf, "\n");
1684 return ret + 1;
1685 }
1686
Alan Coxa46c9992008-02-08 04:18:53 -08001687 if (capable(CAP_SYS_ADMIN)) {
George G. Davis3689a0e2007-02-14 00:33:06 -08001688 mutex_lock(&state->mutex);
1689 pm_state = state->pm_state;
1690 if (pm_state)
1691 uart_change_pm(state, 0);
Russell Kingc5f46442005-06-29 09:42:38 +01001692 spin_lock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693 status = port->ops->get_mctrl(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001694 spin_unlock_irq(&port->lock);
George G. Davis3689a0e2007-02-14 00:33:06 -08001695 if (pm_state)
1696 uart_change_pm(state, pm_state);
1697 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698
1699 ret += sprintf(buf + ret, " tx:%d rx:%d",
1700 port->icount.tx, port->icount.rx);
1701 if (port->icount.frame)
1702 ret += sprintf(buf + ret, " fe:%d",
1703 port->icount.frame);
1704 if (port->icount.parity)
1705 ret += sprintf(buf + ret, " pe:%d",
1706 port->icount.parity);
1707 if (port->icount.brk)
1708 ret += sprintf(buf + ret, " brk:%d",
1709 port->icount.brk);
1710 if (port->icount.overrun)
1711 ret += sprintf(buf + ret, " oe:%d",
1712 port->icount.overrun);
Alan Coxa46c9992008-02-08 04:18:53 -08001713
1714#define INFOBIT(bit, str) \
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 if (port->mctrl & (bit)) \
1716 strncat(stat_buf, (str), sizeof(stat_buf) - \
1717 strlen(stat_buf) - 2)
Alan Coxa46c9992008-02-08 04:18:53 -08001718#define STATBIT(bit, str) \
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 if (status & (bit)) \
1720 strncat(stat_buf, (str), sizeof(stat_buf) - \
1721 strlen(stat_buf) - 2)
1722
1723 stat_buf[0] = '\0';
1724 stat_buf[1] = '\0';
1725 INFOBIT(TIOCM_RTS, "|RTS");
1726 STATBIT(TIOCM_CTS, "|CTS");
1727 INFOBIT(TIOCM_DTR, "|DTR");
1728 STATBIT(TIOCM_DSR, "|DSR");
1729 STATBIT(TIOCM_CAR, "|CD");
1730 STATBIT(TIOCM_RNG, "|RI");
1731 if (stat_buf[0])
1732 stat_buf[0] = ' ';
1733 strcat(stat_buf, "\n");
Alan Coxa46c9992008-02-08 04:18:53 -08001734
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 ret += sprintf(buf + ret, stat_buf);
1736 } else {
1737 strcat(buf, "\n");
1738 ret++;
1739 }
1740#undef STATBIT
1741#undef INFOBIT
1742 return ret;
1743}
1744
1745static int uart_read_proc(char *page, char **start, off_t off,
1746 int count, int *eof, void *data)
1747{
1748 struct tty_driver *ttydrv = data;
1749 struct uart_driver *drv = ttydrv->driver_state;
1750 int i, len = 0, l;
1751 off_t begin = 0;
1752
1753 len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1754 "", "", "");
1755 for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1756 l = uart_line_info(page + len, drv, i);
1757 len += l;
1758 if (len + begin > off + count)
1759 goto done;
1760 if (len + begin < off) {
1761 begin += len;
1762 len = 0;
1763 }
1764 }
1765 *eof = 1;
1766 done:
1767 if (off >= len + begin)
1768 return 0;
1769 *start = page + (off - begin);
1770 return (count < begin + len - off) ? count : (begin + len - off);
1771}
1772#endif
1773
1774#ifdef CONFIG_SERIAL_CORE_CONSOLE
1775/*
Russell Kingd3587882006-03-20 20:00:09 +00001776 * uart_console_write - write a console message to a serial port
1777 * @port: the port to write the message
1778 * @s: array of characters
1779 * @count: number of characters in string to write
1780 * @write: function to write character to port
1781 */
1782void uart_console_write(struct uart_port *port, const char *s,
1783 unsigned int count,
1784 void (*putchar)(struct uart_port *, int))
1785{
1786 unsigned int i;
1787
1788 for (i = 0; i < count; i++, s++) {
1789 if (*s == '\n')
1790 putchar(port, '\r');
1791 putchar(port, *s);
1792 }
1793}
1794EXPORT_SYMBOL_GPL(uart_console_write);
1795
1796/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797 * Check whether an invalid uart number has been specified, and
1798 * if so, search for the first available port that does have
1799 * console support.
1800 */
1801struct uart_port * __init
1802uart_get_console(struct uart_port *ports, int nr, struct console *co)
1803{
1804 int idx = co->index;
1805
1806 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1807 ports[idx].membase == NULL))
1808 for (idx = 0; idx < nr; idx++)
1809 if (ports[idx].iobase != 0 ||
1810 ports[idx].membase != NULL)
1811 break;
1812
1813 co->index = idx;
1814
1815 return ports + idx;
1816}
1817
1818/**
1819 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1820 * @options: pointer to option string
1821 * @baud: pointer to an 'int' variable for the baud rate.
1822 * @parity: pointer to an 'int' variable for the parity.
1823 * @bits: pointer to an 'int' variable for the number of data bits.
1824 * @flow: pointer to an 'int' variable for the flow control character.
1825 *
1826 * uart_parse_options decodes a string containing the serial console
1827 * options. The format of the string is <baud><parity><bits><flow>,
1828 * eg: 115200n8r
1829 */
1830void __init
1831uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1832{
1833 char *s = options;
1834
1835 *baud = simple_strtoul(s, NULL, 10);
1836 while (*s >= '0' && *s <= '9')
1837 s++;
1838 if (*s)
1839 *parity = *s++;
1840 if (*s)
1841 *bits = *s++ - '0';
1842 if (*s)
1843 *flow = *s;
1844}
1845
1846struct baud_rates {
1847 unsigned int rate;
1848 unsigned int cflag;
1849};
1850
Arjan van de Vencb3592b2005-11-28 21:04:11 +00001851static const struct baud_rates baud_rates[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852 { 921600, B921600 },
1853 { 460800, B460800 },
1854 { 230400, B230400 },
1855 { 115200, B115200 },
1856 { 57600, B57600 },
1857 { 38400, B38400 },
1858 { 19200, B19200 },
1859 { 9600, B9600 },
1860 { 4800, B4800 },
1861 { 2400, B2400 },
1862 { 1200, B1200 },
1863 { 0, B38400 }
1864};
1865
1866/**
1867 * uart_set_options - setup the serial console parameters
1868 * @port: pointer to the serial ports uart_port structure
1869 * @co: console pointer
1870 * @baud: baud rate
1871 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1872 * @bits: number of data bits
1873 * @flow: flow control character - 'r' (rts)
1874 */
1875int __init
1876uart_set_options(struct uart_port *port, struct console *co,
1877 int baud, int parity, int bits, int flow)
1878{
Alan Cox606d0992006-12-08 02:38:45 -08001879 struct ktermios termios;
Alan Cox149b36e2007-10-18 01:24:16 -07001880 static struct ktermios dummy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001881 int i;
1882
Russell King976ecd12005-07-03 21:05:45 +01001883 /*
1884 * Ensure that the serial console lock is initialised
1885 * early.
1886 */
1887 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07001888 lockdep_set_class(&port->lock, &port_lock_key);
Russell King976ecd12005-07-03 21:05:45 +01001889
Alan Cox606d0992006-12-08 02:38:45 -08001890 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001891
1892 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1893
1894 /*
1895 * Construct a cflag setting.
1896 */
1897 for (i = 0; baud_rates[i].rate; i++)
1898 if (baud_rates[i].rate <= baud)
1899 break;
1900
1901 termios.c_cflag |= baud_rates[i].cflag;
1902
1903 if (bits == 7)
1904 termios.c_cflag |= CS7;
1905 else
1906 termios.c_cflag |= CS8;
1907
1908 switch (parity) {
1909 case 'o': case 'O':
1910 termios.c_cflag |= PARODD;
1911 /*fall through*/
1912 case 'e': case 'E':
1913 termios.c_cflag |= PARENB;
1914 break;
1915 }
1916
1917 if (flow == 'r')
1918 termios.c_cflag |= CRTSCTS;
1919
Yinghai Lu79492682007-07-15 23:37:25 -07001920 /*
1921 * some uarts on other side don't support no flow control.
1922 * So we set * DTR in host uart to make them happy
1923 */
1924 port->mctrl |= TIOCM_DTR;
1925
Alan Cox149b36e2007-10-18 01:24:16 -07001926 port->ops->set_termios(port, &termios, &dummy);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001927 co->cflag = termios.c_cflag;
1928
1929 return 0;
1930}
1931#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1932
1933static void uart_change_pm(struct uart_state *state, int pm_state)
1934{
1935 struct uart_port *port = state->port;
Andrew Victor1281e362006-05-16 11:28:49 +01001936
1937 if (state->pm_state != pm_state) {
1938 if (port->ops->pm)
1939 port->ops->pm(port, pm_state, state->pm_state);
1940 state->pm_state = pm_state;
1941 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942}
1943
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07001944struct uart_match {
1945 struct uart_port *port;
1946 struct uart_driver *driver;
1947};
1948
1949static int serial_match_port(struct device *dev, void *data)
1950{
1951 struct uart_match *match = data;
1952 dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
1953
1954 return dev->devt == devt; /* Actually, only one tty per port */
1955}
1956
Linus Torvalds1da177e2005-04-16 15:20:36 -07001957int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1958{
1959 struct uart_state *state = drv->state + port->line;
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07001960 struct device *tty_dev;
1961 struct uart_match match = {port, drv};
Linus Torvalds1da177e2005-04-16 15:20:36 -07001962
Ingo Molnare2862f62006-01-13 21:37:07 +00001963 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964
Andres Salomon8f4ce8c2007-10-18 03:04:50 -07001965 if (!console_suspend_enabled && uart_console(port)) {
1966 /* we're going to avoid suspending serial console */
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001967 mutex_unlock(&state->mutex);
1968 return 0;
1969 }
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001970
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07001971 tty_dev = device_find_child(port->dev, &match, serial_match_port);
1972 if (device_may_wakeup(tty_dev)) {
1973 enable_irq_wake(port->irq);
1974 put_device(tty_dev);
1975 mutex_unlock(&state->mutex);
1976 return 0;
1977 }
1978 port->suspended = 1;
1979
Linus Torvalds1da177e2005-04-16 15:20:36 -07001980 if (state->info && state->info->flags & UIF_INITIALIZED) {
Russell Kingba899db2006-01-21 22:45:50 +00001981 const struct uart_ops *ops = port->ops;
Russell Kingc8c6bfa2008-02-04 22:27:52 -08001982 int tries;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001983
Russell Kinga6b93a92006-10-01 17:17:40 +01001984 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1985 | UIF_SUSPENDED;
1986
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 spin_lock_irq(&port->lock);
Russell Kingb129a8c2005-08-31 10:12:14 +01001988 ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989 ops->set_mctrl(port, 0);
1990 ops->stop_rx(port);
1991 spin_unlock_irq(&port->lock);
1992
1993 /*
1994 * Wait for the transmitter to empty.
1995 */
Alan Coxa46c9992008-02-08 04:18:53 -08001996 for (tries = 3; !ops->tx_empty(port) && tries; tries--)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001997 msleep(10);
Russell Kingc8c6bfa2008-02-04 22:27:52 -08001998 if (!tries)
Alan Coxa46c9992008-02-08 04:18:53 -08001999 printk(KERN_ERR "%s%s%s%d: Unable to drain "
2000 "transmitter\n",
Russell Kingc8c6bfa2008-02-04 22:27:52 -08002001 port->dev ? port->dev->bus_id : "",
2002 port->dev ? ": " : "",
2003 drv->dev_name, port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004
2005 ops->shutdown(port);
2006 }
2007
2008 /*
2009 * Disable the console device before suspending.
2010 */
2011 if (uart_console(port))
2012 console_stop(port->cons);
2013
2014 uart_change_pm(state, 3);
2015
Ingo Molnare2862f62006-01-13 21:37:07 +00002016 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002017
2018 return 0;
2019}
2020
2021int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
2022{
2023 struct uart_state *state = drv->state + port->line;
2024
Ingo Molnare2862f62006-01-13 21:37:07 +00002025 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026
Andres Salomon8f4ce8c2007-10-18 03:04:50 -07002027 if (!console_suspend_enabled && uart_console(port)) {
2028 /* no need to resume serial console, it wasn't suspended */
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07002029 mutex_unlock(&state->mutex);
2030 return 0;
2031 }
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07002032
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07002033 if (!port->suspended) {
2034 disable_irq_wake(port->irq);
2035 mutex_unlock(&state->mutex);
2036 return 0;
2037 }
2038 port->suspended = 0;
2039
Linus Torvalds1da177e2005-04-16 15:20:36 -07002040 /*
2041 * Re-enable the console device after suspending.
2042 */
2043 if (uart_console(port)) {
Alan Cox606d0992006-12-08 02:38:45 -08002044 struct ktermios termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045
2046 /*
2047 * First try to use the console cflag setting.
2048 */
Alan Cox606d0992006-12-08 02:38:45 -08002049 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 termios.c_cflag = port->cons->cflag;
2051
2052 /*
2053 * If that's unset, use the tty termios setting.
2054 */
2055 if (state->info && state->info->tty && termios.c_cflag == 0)
2056 termios = *state->info->tty->termios;
2057
Russell King9d778a62008-02-04 22:27:51 -08002058 uart_change_pm(state, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002059 port->ops->set_termios(port, &termios, NULL);
2060 console_start(port->cons);
2061 }
2062
Russell Kinga6b93a92006-10-01 17:17:40 +01002063 if (state->info && state->info->flags & UIF_SUSPENDED) {
Russell Kingba899db2006-01-21 22:45:50 +00002064 const struct uart_ops *ops = port->ops;
Russell Kingee31b332005-11-13 15:28:51 +00002065 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066
Russell King9d778a62008-02-04 22:27:51 -08002067 uart_change_pm(state, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068 ops->set_mctrl(port, 0);
Russell Kingee31b332005-11-13 15:28:51 +00002069 ret = ops->startup(port);
2070 if (ret == 0) {
2071 uart_change_speed(state, NULL);
2072 spin_lock_irq(&port->lock);
2073 ops->set_mctrl(port, port->mctrl);
2074 ops->start_tx(port);
2075 spin_unlock_irq(&port->lock);
Russell Kinga6b93a92006-10-01 17:17:40 +01002076 state->info->flags |= UIF_INITIALIZED;
Russell Kingee31b332005-11-13 15:28:51 +00002077 } else {
2078 /*
2079 * Failed to resume - maybe hardware went away?
2080 * Clear the "initialized" flag so we won't try
2081 * to call the low level drivers shutdown method.
2082 */
Russell Kingee31b332005-11-13 15:28:51 +00002083 uart_shutdown(state);
2084 }
Russell Kinga6b93a92006-10-01 17:17:40 +01002085
2086 state->info->flags &= ~UIF_SUSPENDED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002087 }
2088
Ingo Molnare2862f62006-01-13 21:37:07 +00002089 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002090
2091 return 0;
2092}
2093
2094static inline void
2095uart_report_port(struct uart_driver *drv, struct uart_port *port)
2096{
Russell King30b7a3b2005-09-03 15:30:21 +01002097 char address[64];
2098
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099 switch (port->iotype) {
2100 case UPIO_PORT:
Russell King30b7a3b2005-09-03 15:30:21 +01002101 snprintf(address, sizeof(address),
2102 "I/O 0x%x", port->iobase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002103 break;
2104 case UPIO_HUB6:
Russell King30b7a3b2005-09-03 15:30:21 +01002105 snprintf(address, sizeof(address),
2106 "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002107 break;
2108 case UPIO_MEM:
2109 case UPIO_MEM32:
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00002110 case UPIO_AU:
Zang Roy-r619113be91ec2006-06-30 02:29:58 -07002111 case UPIO_TSI:
Marc St-Jeanbeab6972007-05-06 14:48:45 -07002112 case UPIO_DWAPB:
Russell King30b7a3b2005-09-03 15:30:21 +01002113 snprintf(address, sizeof(address),
Josh Boyer4f640ef2007-07-23 18:43:44 -07002114 "MMIO 0x%llx", (unsigned long long)port->mapbase);
Russell King30b7a3b2005-09-03 15:30:21 +01002115 break;
2116 default:
2117 strlcpy(address, "*unknown*", sizeof(address));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002118 break;
2119 }
Russell King30b7a3b2005-09-03 15:30:21 +01002120
Russell King0cf669d2005-10-31 11:42:22 +00002121 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2122 port->dev ? port->dev->bus_id : "",
2123 port->dev ? ": " : "",
Russell King30b7a3b2005-09-03 15:30:21 +01002124 drv->dev_name, port->line, address, port->irq, uart_type(port));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002125}
2126
2127static void
2128uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2129 struct uart_port *port)
2130{
2131 unsigned int flags;
2132
2133 /*
2134 * If there isn't a port here, don't do anything further.
2135 */
2136 if (!port->iobase && !port->mapbase && !port->membase)
2137 return;
2138
2139 /*
2140 * Now do the auto configuration stuff. Note that config_port
2141 * is expected to claim the resources and map the port for us.
2142 */
2143 flags = UART_CONFIG_TYPE;
2144 if (port->flags & UPF_AUTO_IRQ)
2145 flags |= UART_CONFIG_IRQ;
2146 if (port->flags & UPF_BOOT_AUTOCONF) {
2147 port->type = PORT_UNKNOWN;
2148 port->ops->config_port(port, flags);
2149 }
2150
2151 if (port->type != PORT_UNKNOWN) {
2152 unsigned long flags;
2153
2154 uart_report_port(drv, port);
2155
George G. Davis3689a0e2007-02-14 00:33:06 -08002156 /* Power up port for set_mctrl() */
2157 uart_change_pm(state, 0);
2158
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159 /*
2160 * Ensure that the modem control lines are de-activated.
Yinghai Luc3e46422008-02-04 22:27:46 -08002161 * keep the DTR setting that is set in uart_set_options()
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 * We probably don't need a spinlock around this, but
2163 */
2164 spin_lock_irqsave(&port->lock, flags);
Yinghai Luc3e46422008-02-04 22:27:46 -08002165 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002166 spin_unlock_irqrestore(&port->lock, flags);
2167
2168 /*
Russell King97d97222007-09-01 21:25:09 +01002169 * If this driver supports console, and it hasn't been
2170 * successfully registered yet, try to re-register it.
2171 * It may be that the port was not available.
2172 */
2173 if (port->cons && !(port->cons->flags & CON_ENABLED))
2174 register_console(port->cons);
2175
2176 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002177 * Power down all ports by default, except the
2178 * console if we have one.
2179 */
2180 if (!uart_console(port))
2181 uart_change_pm(state, 3);
2182 }
2183}
2184
Jeff Dikeb68e31d2006-10-02 02:17:18 -07002185static const struct tty_operations uart_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186 .open = uart_open,
2187 .close = uart_close,
2188 .write = uart_write,
2189 .put_char = uart_put_char,
2190 .flush_chars = uart_flush_chars,
2191 .write_room = uart_write_room,
2192 .chars_in_buffer= uart_chars_in_buffer,
2193 .flush_buffer = uart_flush_buffer,
2194 .ioctl = uart_ioctl,
2195 .throttle = uart_throttle,
2196 .unthrottle = uart_unthrottle,
2197 .send_xchar = uart_send_xchar,
2198 .set_termios = uart_set_termios,
2199 .stop = uart_stop,
2200 .start = uart_start,
2201 .hangup = uart_hangup,
2202 .break_ctl = uart_break_ctl,
2203 .wait_until_sent= uart_wait_until_sent,
2204#ifdef CONFIG_PROC_FS
2205 .read_proc = uart_read_proc,
2206#endif
2207 .tiocmget = uart_tiocmget,
2208 .tiocmset = uart_tiocmset,
2209};
2210
2211/**
2212 * uart_register_driver - register a driver with the uart core layer
2213 * @drv: low level driver structure
2214 *
2215 * Register a uart driver with the core driver. We in turn register
2216 * with the tty layer, and initialise the core driver per-port state.
2217 *
2218 * We have a proc file in /proc/tty/driver which is named after the
2219 * normal driver.
2220 *
2221 * drv->port should be NULL, and the per-port structures should be
2222 * registered using uart_add_one_port after this call has succeeded.
2223 */
2224int uart_register_driver(struct uart_driver *drv)
2225{
2226 struct tty_driver *normal = NULL;
2227 int i, retval;
2228
2229 BUG_ON(drv->state);
2230
2231 /*
2232 * Maybe we should be using a slab cache for this, especially if
2233 * we have a large number of ports to handle.
2234 */
Burman Yan8f31bb32007-02-14 00:33:07 -08002235 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002236 retval = -ENOMEM;
2237 if (!drv->state)
2238 goto out;
2239
Linus Torvalds1da177e2005-04-16 15:20:36 -07002240 normal = alloc_tty_driver(drv->nr);
2241 if (!normal)
2242 goto out;
2243
2244 drv->tty_driver = normal;
2245
2246 normal->owner = drv->owner;
2247 normal->driver_name = drv->driver_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248 normal->name = drv->dev_name;
2249 normal->major = drv->major;
2250 normal->minor_start = drv->minor;
2251 normal->type = TTY_DRIVER_TYPE_SERIAL;
2252 normal->subtype = SERIAL_TYPE_NORMAL;
2253 normal->init_termios = tty_std_termios;
2254 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
Alan Cox606d0992006-12-08 02:38:45 -08002255 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
Greg Kroah-Hartman331b8312005-06-20 21:15:16 -07002256 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 normal->driver_state = drv;
2258 tty_set_operations(normal, &uart_ops);
2259
2260 /*
2261 * Initialise the UART state(s).
2262 */
2263 for (i = 0; i < drv->nr; i++) {
2264 struct uart_state *state = drv->state + i;
2265
2266 state->close_delay = 500; /* .5 seconds */
2267 state->closing_wait = 30000; /* 30 seconds */
2268
Ingo Molnare2862f62006-01-13 21:37:07 +00002269 mutex_init(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002270 }
2271
2272 retval = tty_register_driver(normal);
2273 out:
2274 if (retval < 0) {
2275 put_tty_driver(normal);
2276 kfree(drv->state);
2277 }
2278 return retval;
2279}
2280
2281/**
2282 * uart_unregister_driver - remove a driver from the uart core layer
2283 * @drv: low level driver structure
2284 *
2285 * Remove all references to a driver from the core driver. The low
2286 * level driver must have removed all its ports via the
2287 * uart_remove_one_port() if it registered them with uart_add_one_port().
2288 * (ie, drv->port == NULL)
2289 */
2290void uart_unregister_driver(struct uart_driver *drv)
2291{
2292 struct tty_driver *p = drv->tty_driver;
2293 tty_unregister_driver(p);
2294 put_tty_driver(p);
2295 kfree(drv->state);
2296 drv->tty_driver = NULL;
2297}
2298
2299struct tty_driver *uart_console_device(struct console *co, int *index)
2300{
2301 struct uart_driver *p = co->data;
2302 *index = co->index;
2303 return p->tty_driver;
2304}
2305
2306/**
2307 * uart_add_one_port - attach a driver-defined port structure
2308 * @drv: pointer to the uart low level driver structure for this port
2309 * @port: uart port structure to use for this port.
2310 *
2311 * This allows the driver to register its own uart_port structure
2312 * with the core driver. The main purpose is to allow the low
2313 * level uart drivers to expand uart_port, rather than having yet
2314 * more levels of structures.
2315 */
2316int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2317{
2318 struct uart_state *state;
2319 int ret = 0;
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07002320 struct device *tty_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002321
2322 BUG_ON(in_interrupt());
2323
2324 if (port->line >= drv->nr)
2325 return -EINVAL;
2326
2327 state = drv->state + port->line;
2328
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002329 mutex_lock(&port_mutex);
Russell King68ac64c2006-04-30 11:13:50 +01002330 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002331 if (state->port) {
2332 ret = -EINVAL;
2333 goto out;
2334 }
2335
2336 state->port = port;
Russell King97d97222007-09-01 21:25:09 +01002337 state->pm_state = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002338
Linus Torvalds1da177e2005-04-16 15:20:36 -07002339 port->cons = drv->cons;
2340 port->info = state->info;
2341
Russell King976ecd12005-07-03 21:05:45 +01002342 /*
2343 * If this port is a console, then the spinlock is already
2344 * initialised.
2345 */
Ingo Molnar13e83592006-07-03 00:25:03 -07002346 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
Russell King976ecd12005-07-03 21:05:45 +01002347 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07002348 lockdep_set_class(&port->lock, &port_lock_key);
2349 }
Russell King976ecd12005-07-03 21:05:45 +01002350
Linus Torvalds1da177e2005-04-16 15:20:36 -07002351 uart_configure_port(drv, state, port);
2352
2353 /*
2354 * Register the port whether it's detected or not. This allows
2355 * setserial to be used to alter this ports parameters.
2356 */
Guennadi Liakhovetskib3b708f2007-10-16 01:24:02 -07002357 tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
2358 if (likely(!IS_ERR(tty_dev))) {
2359 device_can_wakeup(tty_dev) = 1;
2360 device_set_wakeup_enable(tty_dev, 0);
2361 } else
2362 printk(KERN_ERR "Cannot register tty device on line %d\n",
2363 port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002364
2365 /*
Russell King68ac64c2006-04-30 11:13:50 +01002366 * Ensure UPF_DEAD is not set.
2367 */
2368 port->flags &= ~UPF_DEAD;
2369
Linus Torvalds1da177e2005-04-16 15:20:36 -07002370 out:
Russell King68ac64c2006-04-30 11:13:50 +01002371 mutex_unlock(&state->mutex);
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002372 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002373
2374 return ret;
2375}
2376
2377/**
2378 * uart_remove_one_port - detach a driver defined port structure
2379 * @drv: pointer to the uart low level driver structure for this port
2380 * @port: uart port structure for this port
2381 *
2382 * This unhooks (and hangs up) the specified port structure from the
2383 * core driver. No further calls will be made to the low-level code
2384 * for this port.
2385 */
2386int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2387{
2388 struct uart_state *state = drv->state + port->line;
Russell King68ac64c2006-04-30 11:13:50 +01002389 struct uart_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002390
2391 BUG_ON(in_interrupt());
2392
2393 if (state->port != port)
2394 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2395 state->port, port);
2396
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002397 mutex_lock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002398
2399 /*
Russell King68ac64c2006-04-30 11:13:50 +01002400 * Mark the port "dead" - this prevents any opens from
2401 * succeeding while we shut down the port.
2402 */
2403 mutex_lock(&state->mutex);
2404 port->flags |= UPF_DEAD;
2405 mutex_unlock(&state->mutex);
2406
2407 /*
Greg Kroah-Hartmanaa4148c2005-06-20 21:15:16 -07002408 * Remove the devices from the tty layer
Linus Torvalds1da177e2005-04-16 15:20:36 -07002409 */
2410 tty_unregister_device(drv->tty_driver, port->line);
2411
Russell King68ac64c2006-04-30 11:13:50 +01002412 info = state->info;
2413 if (info && info->tty)
2414 tty_vhangup(info->tty);
2415
2416 /*
2417 * All users of this port should now be disconnected from
2418 * this driver, and the port shut down. We should be the
2419 * only thread fiddling with this port from now on.
2420 */
2421 state->info = NULL;
2422
2423 /*
2424 * Free the port IO and memory resources, if any.
2425 */
2426 if (port->type != PORT_UNKNOWN)
2427 port->ops->release_port(port);
2428
2429 /*
2430 * Indicate that there isn't a port here anymore.
2431 */
2432 port->type = PORT_UNKNOWN;
2433
2434 /*
2435 * Kill the tasklet, and free resources.
2436 */
2437 if (info) {
2438 tasklet_kill(&info->tlet);
2439 kfree(info);
2440 }
2441
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442 state->port = NULL;
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002443 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002444
2445 return 0;
2446}
2447
2448/*
2449 * Are the two ports equivalent?
2450 */
2451int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2452{
2453 if (port1->iotype != port2->iotype)
2454 return 0;
2455
2456 switch (port1->iotype) {
2457 case UPIO_PORT:
2458 return (port1->iobase == port2->iobase);
2459 case UPIO_HUB6:
2460 return (port1->iobase == port2->iobase) &&
2461 (port1->hub6 == port2->hub6);
2462 case UPIO_MEM:
Sergei Shtylyovd21b55d2006-08-28 19:49:03 +04002463 case UPIO_MEM32:
2464 case UPIO_AU:
2465 case UPIO_TSI:
Marc St-Jeanbeab6972007-05-06 14:48:45 -07002466 case UPIO_DWAPB:
Benjamin Herrenschmidt1624f002006-01-04 18:09:44 +00002467 return (port1->mapbase == port2->mapbase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002468 }
2469 return 0;
2470}
2471EXPORT_SYMBOL(uart_match_port);
2472
Linus Torvalds1da177e2005-04-16 15:20:36 -07002473EXPORT_SYMBOL(uart_write_wakeup);
2474EXPORT_SYMBOL(uart_register_driver);
2475EXPORT_SYMBOL(uart_unregister_driver);
2476EXPORT_SYMBOL(uart_suspend_port);
2477EXPORT_SYMBOL(uart_resume_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002478EXPORT_SYMBOL(uart_add_one_port);
2479EXPORT_SYMBOL(uart_remove_one_port);
2480
2481MODULE_DESCRIPTION("Serial driver core");
2482MODULE_LICENSE("GPL");