blob: 326020f86f757e98ef6f148754cdb1e355ee75b3 [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
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 Cox606d0992006-12-08 02:38:45 -080061static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
63static void uart_change_pm(struct uart_state *state, int pm_state);
64
65/*
66 * This routine is used by the interrupt handler to schedule processing in
67 * the software interrupt portion of the driver.
68 */
69void uart_write_wakeup(struct uart_port *port)
70{
71 struct uart_info *info = port->info;
Pavel Machekd5f735e2006-03-07 21:55:20 -080072 /*
73 * This means you called this function _after_ the port was
74 * closed. No cookie for you.
75 */
76 BUG_ON(!info);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 tasklet_schedule(&info->tlet);
78}
79
80static void uart_stop(struct tty_struct *tty)
81{
82 struct uart_state *state = tty->driver_data;
83 struct uart_port *port = state->port;
84 unsigned long flags;
85
86 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +010087 port->ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 spin_unlock_irqrestore(&port->lock, flags);
89}
90
91static void __uart_start(struct tty_struct *tty)
92{
93 struct uart_state *state = tty->driver_data;
94 struct uart_port *port = state->port;
95
96 if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
97 !tty->stopped && !tty->hw_stopped)
Russell Kingb129a8c2005-08-31 10:12:14 +010098 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
101static void uart_start(struct tty_struct *tty)
102{
103 struct uart_state *state = tty->driver_data;
104 struct uart_port *port = state->port;
105 unsigned long flags;
106
107 spin_lock_irqsave(&port->lock, flags);
108 __uart_start(tty);
109 spin_unlock_irqrestore(&port->lock, flags);
110}
111
112static void uart_tasklet_action(unsigned long data)
113{
114 struct uart_state *state = (struct uart_state *)data;
115 tty_wakeup(state->info->tty);
116}
117
118static inline void
119uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
120{
121 unsigned long flags;
122 unsigned int old;
123
124 spin_lock_irqsave(&port->lock, flags);
125 old = port->mctrl;
126 port->mctrl = (old & ~clear) | set;
127 if (old != port->mctrl)
128 port->ops->set_mctrl(port, port->mctrl);
129 spin_unlock_irqrestore(&port->lock, flags);
130}
131
132#define uart_set_mctrl(port,set) uart_update_mctrl(port,set,0)
133#define uart_clear_mctrl(port,clear) uart_update_mctrl(port,0,clear)
134
135/*
136 * Startup the port. This will be called once per open. All calls
137 * will be serialised by the per-port semaphore.
138 */
139static int uart_startup(struct uart_state *state, int init_hw)
140{
141 struct uart_info *info = state->info;
142 struct uart_port *port = state->port;
143 unsigned long page;
144 int retval = 0;
145
146 if (info->flags & UIF_INITIALIZED)
147 return 0;
148
149 /*
150 * Set the TTY IO error marker - we will only clear this
151 * once we have successfully opened the port. Also set
152 * up the tty->alt_speed kludge
153 */
Jayachandran Ca2436b22005-10-30 23:26:16 +0000154 set_bit(TTY_IO_ERROR, &info->tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 if (port->type == PORT_UNKNOWN)
157 return 0;
158
159 /*
160 * Initialise and allocate the transmit and temporary
161 * buffer.
162 */
163 if (!info->xmit.buf) {
164 page = get_zeroed_page(GFP_KERNEL);
165 if (!page)
166 return -ENOMEM;
167
168 info->xmit.buf = (unsigned char *) page;
169 uart_circ_clear(&info->xmit);
170 }
171
172 retval = port->ops->startup(port);
173 if (retval == 0) {
174 if (init_hw) {
175 /*
176 * Initialise the hardware port settings.
177 */
178 uart_change_speed(state, NULL);
179
180 /*
181 * Setup the RTS and DTR signals once the
182 * port is open and ready to respond.
183 */
184 if (info->tty->termios->c_cflag & CBAUD)
185 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
186 }
187
Russell King0dd7a1a2005-06-29 18:40:53 +0100188 if (info->flags & UIF_CTS_FLOW) {
189 spin_lock_irq(&port->lock);
190 if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
191 info->tty->hw_stopped = 1;
192 spin_unlock_irq(&port->lock);
193 }
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 info->flags |= UIF_INITIALIZED;
196
197 clear_bit(TTY_IO_ERROR, &info->tty->flags);
198 }
199
200 if (retval && capable(CAP_SYS_ADMIN))
201 retval = 0;
202
203 return retval;
204}
205
206/*
207 * This routine will shutdown a serial port; interrupts are disabled, and
208 * DTR is dropped if the hangup on close termio flag is on. Calls to
209 * uart_shutdown are serialised by the per-port semaphore.
210 */
211static void uart_shutdown(struct uart_state *state)
212{
213 struct uart_info *info = state->info;
214 struct uart_port *port = state->port;
215
Russell Kingee31b332005-11-13 15:28:51 +0000216 /*
217 * Set the TTY IO error marker
218 */
219 if (info->tty)
220 set_bit(TTY_IO_ERROR, &info->tty->flags);
221
222 if (info->flags & UIF_INITIALIZED) {
223 info->flags &= ~UIF_INITIALIZED;
224
225 /*
226 * Turn off DTR and RTS early.
227 */
228 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
229 uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
230
231 /*
232 * clear delta_msr_wait queue to avoid mem leaks: we may free
233 * the irq here so the queue might never be woken up. Note
234 * that we won't end up waiting on delta_msr_wait again since
235 * any outstanding file descriptors should be pointing at
236 * hung_up_tty_fops now.
237 */
238 wake_up_interruptible(&info->delta_msr_wait);
239
240 /*
241 * Free the IRQ and disable the port.
242 */
243 port->ops->shutdown(port);
244
245 /*
246 * Ensure that the IRQ handler isn't running on another CPU.
247 */
248 synchronize_irq(port->irq);
249 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251 /*
Russell Kingee31b332005-11-13 15:28:51 +0000252 * kill off our tasklet
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 */
Russell Kingee31b332005-11-13 15:28:51 +0000254 tasklet_kill(&info->tlet);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 /*
257 * Free the transmit buffer page.
258 */
259 if (info->xmit.buf) {
260 free_page((unsigned long)info->xmit.buf);
261 info->xmit.buf = NULL;
262 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263}
264
265/**
266 * uart_update_timeout - update per-port FIFO timeout.
267 * @port: uart_port structure describing the port
268 * @cflag: termios cflag value
269 * @baud: speed of the port
270 *
271 * Set the port FIFO timeout value. The @cflag value should
272 * reflect the actual hardware settings.
273 */
274void
275uart_update_timeout(struct uart_port *port, unsigned int cflag,
276 unsigned int baud)
277{
278 unsigned int bits;
279
280 /* byte size and parity */
281 switch (cflag & CSIZE) {
282 case CS5:
283 bits = 7;
284 break;
285 case CS6:
286 bits = 8;
287 break;
288 case CS7:
289 bits = 9;
290 break;
291 default:
292 bits = 10;
293 break; // CS8
294 }
295
296 if (cflag & CSTOPB)
297 bits++;
298 if (cflag & PARENB)
299 bits++;
300
301 /*
302 * The total number of bits to be transmitted in the fifo.
303 */
304 bits = bits * port->fifosize;
305
306 /*
307 * Figure the timeout to send the above number of bits.
308 * Add .02 seconds of slop
309 */
310 port->timeout = (HZ * bits) / baud + HZ/50;
311}
312
313EXPORT_SYMBOL(uart_update_timeout);
314
315/**
316 * uart_get_baud_rate - return baud rate for a particular port
317 * @port: uart_port structure describing the port in question.
318 * @termios: desired termios settings.
319 * @old: old termios (or NULL)
320 * @min: minimum acceptable baud rate
321 * @max: maximum acceptable baud rate
322 *
323 * Decode the termios structure into a numeric baud rate,
324 * taking account of the magic 38400 baud rate (with spd_*
325 * flags), and mapping the %B0 rate to 9600 baud.
326 *
327 * If the new baud rate is invalid, try the old termios setting.
328 * If it's still invalid, we try 9600 baud.
329 *
330 * Update the @termios structure to reflect the baud rate
331 * we're actually going to be using.
332 */
333unsigned int
Alan Cox606d0992006-12-08 02:38:45 -0800334uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
335 struct ktermios *old, unsigned int min, unsigned int max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
337 unsigned int try, baud, altbaud = 38400;
Russell King0077d452006-01-21 23:03:28 +0000338 upf_t flags = port->flags & UPF_SPD_MASK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
340 if (flags == UPF_SPD_HI)
341 altbaud = 57600;
342 if (flags == UPF_SPD_VHI)
343 altbaud = 115200;
344 if (flags == UPF_SPD_SHI)
345 altbaud = 230400;
346 if (flags == UPF_SPD_WARP)
347 altbaud = 460800;
348
349 for (try = 0; try < 2; try++) {
350 baud = tty_termios_baud_rate(termios);
351
352 /*
353 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
354 * Die! Die! Die!
355 */
356 if (baud == 38400)
357 baud = altbaud;
358
359 /*
360 * Special case: B0 rate.
361 */
362 if (baud == 0)
363 baud = 9600;
364
365 if (baud >= min && baud <= max)
366 return baud;
367
368 /*
369 * Oops, the quotient was zero. Try again with
370 * the old baud rate if possible.
371 */
372 termios->c_cflag &= ~CBAUD;
373 if (old) {
374 termios->c_cflag |= old->c_cflag & CBAUD;
375 old = NULL;
376 continue;
377 }
378
379 /*
380 * As a last resort, if the quotient is zero,
381 * default to 9600 bps
382 */
383 termios->c_cflag |= B9600;
384 }
385
386 return 0;
387}
388
389EXPORT_SYMBOL(uart_get_baud_rate);
390
391/**
392 * uart_get_divisor - return uart clock divisor
393 * @port: uart_port structure describing the port.
394 * @baud: desired baud rate
395 *
396 * Calculate the uart clock divisor for the port.
397 */
398unsigned int
399uart_get_divisor(struct uart_port *port, unsigned int baud)
400{
401 unsigned int quot;
402
403 /*
404 * Old custom speed handling.
405 */
406 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
407 quot = port->custom_divisor;
408 else
409 quot = (port->uartclk + (8 * baud)) / (16 * baud);
410
411 return quot;
412}
413
414EXPORT_SYMBOL(uart_get_divisor);
415
416static void
Alan Cox606d0992006-12-08 02:38:45 -0800417uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418{
419 struct tty_struct *tty = state->info->tty;
420 struct uart_port *port = state->port;
Alan Cox606d0992006-12-08 02:38:45 -0800421 struct ktermios *termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
423 /*
424 * If we have no tty, termios, or the port does not exist,
425 * then we can't set the parameters for this port.
426 */
427 if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
428 return;
429
430 termios = tty->termios;
431
432 /*
433 * Set flags based on termios cflag
434 */
435 if (termios->c_cflag & CRTSCTS)
436 state->info->flags |= UIF_CTS_FLOW;
437 else
438 state->info->flags &= ~UIF_CTS_FLOW;
439
440 if (termios->c_cflag & CLOCAL)
441 state->info->flags &= ~UIF_CHECK_CD;
442 else
443 state->info->flags |= UIF_CHECK_CD;
444
445 port->ops->set_termios(port, termios, old_termios);
446}
447
448static inline void
449__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
450{
451 unsigned long flags;
452
453 if (!circ->buf)
454 return;
455
456 spin_lock_irqsave(&port->lock, flags);
457 if (uart_circ_chars_free(circ) != 0) {
458 circ->buf[circ->head] = c;
459 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
460 }
461 spin_unlock_irqrestore(&port->lock, flags);
462}
463
464static void uart_put_char(struct tty_struct *tty, unsigned char ch)
465{
466 struct uart_state *state = tty->driver_data;
467
468 __uart_put_char(state->port, &state->info->xmit, ch);
469}
470
471static void uart_flush_chars(struct tty_struct *tty)
472{
473 uart_start(tty);
474}
475
476static int
Pavel Machekd5f735e2006-03-07 21:55:20 -0800477uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
479 struct uart_state *state = tty->driver_data;
Pavel Machekd5f735e2006-03-07 21:55:20 -0800480 struct uart_port *port;
481 struct circ_buf *circ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 unsigned long flags;
483 int c, ret = 0;
484
Pavel Machekd5f735e2006-03-07 21:55:20 -0800485 /*
486 * This means you called this function _after_ the port was
487 * closed. No cookie for you.
488 */
489 if (!state || !state->info) {
490 WARN_ON(1);
491 return -EL3HLT;
492 }
493
494 port = state->port;
495 circ = &state->info->xmit;
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 if (!circ->buf)
498 return 0;
499
500 spin_lock_irqsave(&port->lock, flags);
501 while (1) {
502 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
503 if (count < c)
504 c = count;
505 if (c <= 0)
506 break;
507 memcpy(circ->buf + circ->head, buf, c);
508 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
509 buf += c;
510 count -= c;
511 ret += c;
512 }
513 spin_unlock_irqrestore(&port->lock, flags);
514
515 uart_start(tty);
516 return ret;
517}
518
519static int uart_write_room(struct tty_struct *tty)
520{
521 struct uart_state *state = tty->driver_data;
522
523 return uart_circ_chars_free(&state->info->xmit);
524}
525
526static int uart_chars_in_buffer(struct tty_struct *tty)
527{
528 struct uart_state *state = tty->driver_data;
529
530 return uart_circ_chars_pending(&state->info->xmit);
531}
532
533static void uart_flush_buffer(struct tty_struct *tty)
534{
535 struct uart_state *state = tty->driver_data;
536 struct uart_port *port = state->port;
537 unsigned long flags;
538
Pavel Machekd5f735e2006-03-07 21:55:20 -0800539 /*
540 * This means you called this function _after_ the port was
541 * closed. No cookie for you.
542 */
543 if (!state || !state->info) {
544 WARN_ON(1);
545 return;
546 }
547
Jiri Slabyeb3a1e12007-05-06 14:48:52 -0700548 pr_debug("uart_flush_buffer(%d) called\n", tty->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 spin_lock_irqsave(&port->lock, flags);
551 uart_circ_clear(&state->info->xmit);
552 spin_unlock_irqrestore(&port->lock, flags);
553 tty_wakeup(tty);
554}
555
556/*
557 * This function is used to send a high-priority XON/XOFF character to
558 * the device
559 */
560static void uart_send_xchar(struct tty_struct *tty, char ch)
561{
562 struct uart_state *state = tty->driver_data;
563 struct uart_port *port = state->port;
564 unsigned long flags;
565
566 if (port->ops->send_xchar)
567 port->ops->send_xchar(port, ch);
568 else {
569 port->x_char = ch;
570 if (ch) {
571 spin_lock_irqsave(&port->lock, flags);
Russell Kingb129a8c2005-08-31 10:12:14 +0100572 port->ops->start_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 spin_unlock_irqrestore(&port->lock, flags);
574 }
575 }
576}
577
578static void uart_throttle(struct tty_struct *tty)
579{
580 struct uart_state *state = tty->driver_data;
581
582 if (I_IXOFF(tty))
583 uart_send_xchar(tty, STOP_CHAR(tty));
584
585 if (tty->termios->c_cflag & CRTSCTS)
586 uart_clear_mctrl(state->port, TIOCM_RTS);
587}
588
589static void uart_unthrottle(struct tty_struct *tty)
590{
591 struct uart_state *state = tty->driver_data;
592 struct uart_port *port = state->port;
593
594 if (I_IXOFF(tty)) {
595 if (port->x_char)
596 port->x_char = 0;
597 else
598 uart_send_xchar(tty, START_CHAR(tty));
599 }
600
601 if (tty->termios->c_cflag & CRTSCTS)
602 uart_set_mctrl(port, TIOCM_RTS);
603}
604
605static int uart_get_info(struct uart_state *state,
606 struct serial_struct __user *retinfo)
607{
608 struct uart_port *port = state->port;
609 struct serial_struct tmp;
610
611 memset(&tmp, 0, sizeof(tmp));
612 tmp.type = port->type;
613 tmp.line = port->line;
614 tmp.port = port->iobase;
615 if (HIGH_BITS_OFFSET)
616 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
617 tmp.irq = port->irq;
618 tmp.flags = port->flags;
619 tmp.xmit_fifo_size = port->fifosize;
620 tmp.baud_base = port->uartclk / 16;
621 tmp.close_delay = state->close_delay / 10;
622 tmp.closing_wait = state->closing_wait == USF_CLOSING_WAIT_NONE ?
623 ASYNC_CLOSING_WAIT_NONE :
624 state->closing_wait / 10;
625 tmp.custom_divisor = port->custom_divisor;
626 tmp.hub6 = port->hub6;
627 tmp.io_type = port->iotype;
628 tmp.iomem_reg_shift = port->regshift;
629 tmp.iomem_base = (void *)port->mapbase;
630
631 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
632 return -EFAULT;
633 return 0;
634}
635
636static int uart_set_info(struct uart_state *state,
637 struct serial_struct __user *newinfo)
638{
639 struct serial_struct new_serial;
640 struct uart_port *port = state->port;
641 unsigned long new_port;
Russell King0077d452006-01-21 23:03:28 +0000642 unsigned int change_irq, change_port, closing_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 unsigned int old_custom_divisor, close_delay;
Russell King0077d452006-01-21 23:03:28 +0000644 upf_t old_flags, new_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 int retval = 0;
646
647 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
648 return -EFAULT;
649
650 new_port = new_serial.port;
651 if (HIGH_BITS_OFFSET)
652 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
653
654 new_serial.irq = irq_canonicalize(new_serial.irq);
655 close_delay = new_serial.close_delay * 10;
656 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
657 USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
658
659 /*
660 * This semaphore protects state->count. It is also
661 * very useful to prevent opens. Also, take the
662 * port configuration semaphore to make sure that a
663 * module insertion/removal doesn't change anything
664 * under us.
665 */
Ingo Molnare2862f62006-01-13 21:37:07 +0000666 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
David Gibsonabb4a232007-05-06 14:48:49 -0700668 change_irq = !(port->flags & UPF_FIXED_PORT)
669 && new_serial.irq != port->irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
671 /*
672 * Since changing the 'type' of the port changes its resource
673 * allocations, we should treat type changes the same as
674 * IO port changes.
675 */
David Gibsonabb4a232007-05-06 14:48:49 -0700676 change_port = !(port->flags & UPF_FIXED_PORT)
677 && (new_port != port->iobase ||
678 (unsigned long)new_serial.iomem_base != port->mapbase ||
679 new_serial.hub6 != port->hub6 ||
680 new_serial.io_type != port->iotype ||
681 new_serial.iomem_reg_shift != port->regshift ||
682 new_serial.type != port->type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684 old_flags = port->flags;
Russell King0077d452006-01-21 23:03:28 +0000685 new_flags = new_serial.flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 old_custom_divisor = port->custom_divisor;
687
688 if (!capable(CAP_SYS_ADMIN)) {
689 retval = -EPERM;
690 if (change_irq || change_port ||
691 (new_serial.baud_base != port->uartclk / 16) ||
692 (close_delay != state->close_delay) ||
693 (closing_wait != state->closing_wait) ||
Russell King947deee2006-07-02 20:45:51 +0100694 (new_serial.xmit_fifo_size &&
695 new_serial.xmit_fifo_size != port->fifosize) ||
Russell King0077d452006-01-21 23:03:28 +0000696 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 goto exit;
698 port->flags = ((port->flags & ~UPF_USR_MASK) |
Russell King0077d452006-01-21 23:03:28 +0000699 (new_flags & UPF_USR_MASK));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 port->custom_divisor = new_serial.custom_divisor;
701 goto check_and_exit;
702 }
703
704 /*
705 * Ask the low level driver to verify the settings.
706 */
707 if (port->ops->verify_port)
708 retval = port->ops->verify_port(port, &new_serial);
709
710 if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
711 (new_serial.baud_base < 9600))
712 retval = -EINVAL;
713
714 if (retval)
715 goto exit;
716
717 if (change_port || change_irq) {
718 retval = -EBUSY;
719
720 /*
721 * Make sure that we are the sole user of this port.
722 */
723 if (uart_users(state) > 1)
724 goto exit;
725
726 /*
727 * We need to shutdown the serial port at the old
728 * port/type/irq combination.
729 */
730 uart_shutdown(state);
731 }
732
733 if (change_port) {
734 unsigned long old_iobase, old_mapbase;
735 unsigned int old_type, old_iotype, old_hub6, old_shift;
736
737 old_iobase = port->iobase;
738 old_mapbase = port->mapbase;
739 old_type = port->type;
740 old_hub6 = port->hub6;
741 old_iotype = port->iotype;
742 old_shift = port->regshift;
743
744 /*
745 * Free and release old regions
746 */
747 if (old_type != PORT_UNKNOWN)
748 port->ops->release_port(port);
749
750 port->iobase = new_port;
751 port->type = new_serial.type;
752 port->hub6 = new_serial.hub6;
753 port->iotype = new_serial.io_type;
754 port->regshift = new_serial.iomem_reg_shift;
755 port->mapbase = (unsigned long)new_serial.iomem_base;
756
757 /*
758 * Claim and map the new regions
759 */
760 if (port->type != PORT_UNKNOWN) {
761 retval = port->ops->request_port(port);
762 } else {
763 /* Always success - Jean II */
764 retval = 0;
765 }
766
767 /*
768 * If we fail to request resources for the
769 * new port, try to restore the old settings.
770 */
771 if (retval && old_type != PORT_UNKNOWN) {
772 port->iobase = old_iobase;
773 port->type = old_type;
774 port->hub6 = old_hub6;
775 port->iotype = old_iotype;
776 port->regshift = old_shift;
777 port->mapbase = old_mapbase;
778 retval = port->ops->request_port(port);
779 /*
780 * If we failed to restore the old settings,
781 * we fail like this.
782 */
783 if (retval)
784 port->type = PORT_UNKNOWN;
785
786 /*
787 * We failed anyway.
788 */
789 retval = -EBUSY;
Ram Gupta80e3c2b2006-08-14 23:05:29 -0700790 goto exit; // Added to return the correct error -Ram Gupta
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 }
792 }
793
David Gibsonabb4a232007-05-06 14:48:49 -0700794 if (change_irq)
795 port->irq = new_serial.irq;
796 if (!(port->flags & UPF_FIXED_PORT))
797 port->uartclk = new_serial.baud_base * 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 port->flags = (port->flags & ~UPF_CHANGE_MASK) |
Russell King0077d452006-01-21 23:03:28 +0000799 (new_flags & UPF_CHANGE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 port->custom_divisor = new_serial.custom_divisor;
801 state->close_delay = close_delay;
802 state->closing_wait = closing_wait;
Russell King947deee2006-07-02 20:45:51 +0100803 if (new_serial.xmit_fifo_size)
804 port->fifosize = new_serial.xmit_fifo_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 if (state->info->tty)
806 state->info->tty->low_latency =
807 (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
808
809 check_and_exit:
810 retval = 0;
811 if (port->type == PORT_UNKNOWN)
812 goto exit;
813 if (state->info->flags & UIF_INITIALIZED) {
814 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
815 old_custom_divisor != port->custom_divisor) {
816 /*
817 * If they're setting up a custom divisor or speed,
818 * instead of clearing it, then bitch about it. No
819 * need to rate-limit; it's CAP_SYS_ADMIN only.
820 */
821 if (port->flags & UPF_SPD_MASK) {
822 char buf[64];
823 printk(KERN_NOTICE
824 "%s sets custom speed on %s. This "
825 "is deprecated.\n", current->comm,
826 tty_name(state->info->tty, buf));
827 }
828 uart_change_speed(state, NULL);
829 }
830 } else
831 retval = uart_startup(state, 1);
832 exit:
Ingo Molnare2862f62006-01-13 21:37:07 +0000833 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 return retval;
835}
836
837
838/*
839 * uart_get_lsr_info - get line status register info.
840 * Note: uart_ioctl protects us against hangups.
841 */
842static int uart_get_lsr_info(struct uart_state *state,
843 unsigned int __user *value)
844{
845 struct uart_port *port = state->port;
846 unsigned int result;
847
848 result = port->ops->tx_empty(port);
849
850 /*
851 * If we're about to load something into the transmit
852 * register, we'll pretend the transmitter isn't empty to
853 * avoid a race condition (depending on when the transmit
854 * interrupt happens).
855 */
856 if (port->x_char ||
857 ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
858 !state->info->tty->stopped && !state->info->tty->hw_stopped))
859 result &= ~TIOCSER_TEMT;
860
861 return put_user(result, value);
862}
863
864static int uart_tiocmget(struct tty_struct *tty, struct file *file)
865{
866 struct uart_state *state = tty->driver_data;
867 struct uart_port *port = state->port;
868 int result = -EIO;
869
Ingo Molnare2862f62006-01-13 21:37:07 +0000870 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 if ((!file || !tty_hung_up_p(file)) &&
872 !(tty->flags & (1 << TTY_IO_ERROR))) {
873 result = port->mctrl;
Russell Kingc5f46442005-06-29 09:42:38 +0100874
875 spin_lock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 result |= port->ops->get_mctrl(port);
Russell Kingc5f46442005-06-29 09:42:38 +0100877 spin_unlock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000879 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
881 return result;
882}
883
884static int
885uart_tiocmset(struct tty_struct *tty, struct file *file,
886 unsigned int set, unsigned int clear)
887{
888 struct uart_state *state = tty->driver_data;
889 struct uart_port *port = state->port;
890 int ret = -EIO;
891
Ingo Molnare2862f62006-01-13 21:37:07 +0000892 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 if ((!file || !tty_hung_up_p(file)) &&
894 !(tty->flags & (1 << TTY_IO_ERROR))) {
895 uart_update_mctrl(port, set, clear);
896 ret = 0;
897 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000898 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 return ret;
900}
901
902static void uart_break_ctl(struct tty_struct *tty, int break_state)
903{
904 struct uart_state *state = tty->driver_data;
905 struct uart_port *port = state->port;
906
907 BUG_ON(!kernel_locked());
908
Ingo Molnare2862f62006-01-13 21:37:07 +0000909 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 if (port->type != PORT_UNKNOWN)
912 port->ops->break_ctl(port, break_state);
913
Ingo Molnare2862f62006-01-13 21:37:07 +0000914 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915}
916
917static int uart_do_autoconfig(struct uart_state *state)
918{
919 struct uart_port *port = state->port;
920 int flags, ret;
921
922 if (!capable(CAP_SYS_ADMIN))
923 return -EPERM;
924
925 /*
926 * Take the per-port semaphore. This prevents count from
927 * changing, and hence any extra opens of the port while
928 * we're auto-configuring.
929 */
Ingo Molnare2862f62006-01-13 21:37:07 +0000930 if (mutex_lock_interruptible(&state->mutex))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 return -ERESTARTSYS;
932
933 ret = -EBUSY;
934 if (uart_users(state) == 1) {
935 uart_shutdown(state);
936
937 /*
938 * If we already have a port type configured,
939 * we must release its resources.
940 */
941 if (port->type != PORT_UNKNOWN)
942 port->ops->release_port(port);
943
944 flags = UART_CONFIG_TYPE;
945 if (port->flags & UPF_AUTO_IRQ)
946 flags |= UART_CONFIG_IRQ;
947
948 /*
949 * This will claim the ports resources if
950 * a port is found.
951 */
952 port->ops->config_port(port, flags);
953
954 ret = uart_startup(state, 1);
955 }
Ingo Molnare2862f62006-01-13 21:37:07 +0000956 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 return ret;
958}
959
960/*
961 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
962 * - mask passed in arg for lines of interest
963 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
964 * Caller should use TIOCGICOUNT to see which one it was
965 */
966static int
967uart_wait_modem_status(struct uart_state *state, unsigned long arg)
968{
969 struct uart_port *port = state->port;
970 DECLARE_WAITQUEUE(wait, current);
971 struct uart_icount cprev, cnow;
972 int ret;
973
974 /*
975 * note the counters on entry
976 */
977 spin_lock_irq(&port->lock);
978 memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
979
980 /*
981 * Force modem status interrupts on
982 */
983 port->ops->enable_ms(port);
984 spin_unlock_irq(&port->lock);
985
986 add_wait_queue(&state->info->delta_msr_wait, &wait);
987 for (;;) {
988 spin_lock_irq(&port->lock);
989 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
990 spin_unlock_irq(&port->lock);
991
992 set_current_state(TASK_INTERRUPTIBLE);
993
994 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
995 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
996 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
997 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
998 ret = 0;
999 break;
1000 }
1001
1002 schedule();
1003
1004 /* see if a signal did it */
1005 if (signal_pending(current)) {
1006 ret = -ERESTARTSYS;
1007 break;
1008 }
1009
1010 cprev = cnow;
1011 }
1012
1013 current->state = TASK_RUNNING;
1014 remove_wait_queue(&state->info->delta_msr_wait, &wait);
1015
1016 return ret;
1017}
1018
1019/*
1020 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1021 * Return: write counters to the user passed counter struct
1022 * NB: both 1->0 and 0->1 transitions are counted except for
1023 * RI where only 0->1 is counted.
1024 */
1025static int uart_get_count(struct uart_state *state,
1026 struct serial_icounter_struct __user *icnt)
1027{
1028 struct serial_icounter_struct icount;
1029 struct uart_icount cnow;
1030 struct uart_port *port = state->port;
1031
1032 spin_lock_irq(&port->lock);
1033 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1034 spin_unlock_irq(&port->lock);
1035
1036 icount.cts = cnow.cts;
1037 icount.dsr = cnow.dsr;
1038 icount.rng = cnow.rng;
1039 icount.dcd = cnow.dcd;
1040 icount.rx = cnow.rx;
1041 icount.tx = cnow.tx;
1042 icount.frame = cnow.frame;
1043 icount.overrun = cnow.overrun;
1044 icount.parity = cnow.parity;
1045 icount.brk = cnow.brk;
1046 icount.buf_overrun = cnow.buf_overrun;
1047
1048 return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1049}
1050
1051/*
1052 * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here.
1053 */
1054static int
1055uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1056 unsigned long arg)
1057{
1058 struct uart_state *state = tty->driver_data;
1059 void __user *uarg = (void __user *)arg;
1060 int ret = -ENOIOCTLCMD;
1061
1062 BUG_ON(!kernel_locked());
1063
1064 /*
1065 * These ioctls don't rely on the hardware to be present.
1066 */
1067 switch (cmd) {
1068 case TIOCGSERIAL:
1069 ret = uart_get_info(state, uarg);
1070 break;
1071
1072 case TIOCSSERIAL:
1073 ret = uart_set_info(state, uarg);
1074 break;
1075
1076 case TIOCSERCONFIG:
1077 ret = uart_do_autoconfig(state);
1078 break;
1079
1080 case TIOCSERGWILD: /* obsolete */
1081 case TIOCSERSWILD: /* obsolete */
1082 ret = 0;
1083 break;
1084 }
1085
1086 if (ret != -ENOIOCTLCMD)
1087 goto out;
1088
1089 if (tty->flags & (1 << TTY_IO_ERROR)) {
1090 ret = -EIO;
1091 goto out;
1092 }
1093
1094 /*
1095 * The following should only be used when hardware is present.
1096 */
1097 switch (cmd) {
1098 case TIOCMIWAIT:
1099 ret = uart_wait_modem_status(state, arg);
1100 break;
1101
1102 case TIOCGICOUNT:
1103 ret = uart_get_count(state, uarg);
1104 break;
1105 }
1106
1107 if (ret != -ENOIOCTLCMD)
1108 goto out;
1109
Ingo Molnare2862f62006-01-13 21:37:07 +00001110 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
1112 if (tty_hung_up_p(filp)) {
1113 ret = -EIO;
1114 goto out_up;
1115 }
1116
1117 /*
1118 * All these rely on hardware being present and need to be
1119 * protected against the tty being hung up.
1120 */
1121 switch (cmd) {
1122 case TIOCSERGETLSR: /* Get line status register */
1123 ret = uart_get_lsr_info(state, uarg);
1124 break;
1125
1126 default: {
1127 struct uart_port *port = state->port;
1128 if (port->ops->ioctl)
1129 ret = port->ops->ioctl(port, cmd, arg);
1130 break;
1131 }
1132 }
1133 out_up:
Ingo Molnare2862f62006-01-13 21:37:07 +00001134 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 out:
1136 return ret;
1137}
1138
Alan Cox606d0992006-12-08 02:38:45 -08001139static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140{
1141 struct uart_state *state = tty->driver_data;
1142 unsigned long flags;
1143 unsigned int cflag = tty->termios->c_cflag;
1144
1145 BUG_ON(!kernel_locked());
1146
1147 /*
1148 * These are the bits that are used to setup various
1149 * flags in the low level driver.
1150 */
1151#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1152
1153 if ((cflag ^ old_termios->c_cflag) == 0 &&
1154 RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1155 return;
1156
1157 uart_change_speed(state, old_termios);
1158
1159 /* Handle transition to B0 status */
1160 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1161 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1162
1163 /* Handle transition away from B0 status */
1164 if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1165 unsigned int mask = TIOCM_DTR;
1166 if (!(cflag & CRTSCTS) ||
1167 !test_bit(TTY_THROTTLED, &tty->flags))
1168 mask |= TIOCM_RTS;
1169 uart_set_mctrl(state->port, mask);
1170 }
1171
1172 /* Handle turning off CRTSCTS */
1173 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1174 spin_lock_irqsave(&state->port->lock, flags);
1175 tty->hw_stopped = 0;
1176 __uart_start(tty);
1177 spin_unlock_irqrestore(&state->port->lock, flags);
1178 }
1179
Russell King0dd7a1a2005-06-29 18:40:53 +01001180 /* Handle turning on CRTSCTS */
1181 if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1182 spin_lock_irqsave(&state->port->lock, flags);
1183 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1184 tty->hw_stopped = 1;
Russell Kingb129a8c2005-08-31 10:12:14 +01001185 state->port->ops->stop_tx(state->port);
Russell King0dd7a1a2005-06-29 18:40:53 +01001186 }
1187 spin_unlock_irqrestore(&state->port->lock, flags);
1188 }
1189
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190#if 0
1191 /*
1192 * No need to wake up processes in open wait, since they
1193 * sample the CLOCAL flag once, and don't recheck it.
1194 * XXX It's not clear whether the current behavior is correct
1195 * or not. Hence, this may change.....
1196 */
1197 if (!(old_termios->c_cflag & CLOCAL) &&
1198 (tty->termios->c_cflag & CLOCAL))
1199 wake_up_interruptible(&state->info->open_wait);
1200#endif
1201}
1202
1203/*
1204 * In 2.4.5, calls to this will be serialized via the BKL in
1205 * linux/drivers/char/tty_io.c:tty_release()
1206 * linux/drivers/char/tty_io.c:do_tty_handup()
1207 */
1208static void uart_close(struct tty_struct *tty, struct file *filp)
1209{
1210 struct uart_state *state = tty->driver_data;
1211 struct uart_port *port;
1212
1213 BUG_ON(!kernel_locked());
1214
1215 if (!state || !state->port)
1216 return;
1217
1218 port = state->port;
1219
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001220 pr_debug("uart_close(%d) called\n", port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221
Ingo Molnare2862f62006-01-13 21:37:07 +00001222 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223
1224 if (tty_hung_up_p(filp))
1225 goto done;
1226
1227 if ((tty->count == 1) && (state->count != 1)) {
1228 /*
1229 * Uh, oh. tty->count is 1, which means that the tty
1230 * structure will be freed. state->count should always
1231 * be one in these conditions. If it's greater than
1232 * one, we've got real problems, since it means the
1233 * serial port won't be shutdown.
1234 */
1235 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1236 "state->count is %d\n", state->count);
1237 state->count = 1;
1238 }
1239 if (--state->count < 0) {
1240 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1241 tty->name, state->count);
1242 state->count = 0;
1243 }
1244 if (state->count)
1245 goto done;
1246
1247 /*
1248 * Now we wait for the transmit buffer to clear; and we notify
1249 * the line discipline to only process XON/XOFF characters by
1250 * setting tty->closing.
1251 */
1252 tty->closing = 1;
1253
1254 if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1255 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1256
1257 /*
1258 * At this point, we stop accepting input. To do this, we
1259 * disable the receive line status interrupts.
1260 */
1261 if (state->info->flags & UIF_INITIALIZED) {
1262 unsigned long flags;
1263 spin_lock_irqsave(&port->lock, flags);
1264 port->ops->stop_rx(port);
1265 spin_unlock_irqrestore(&port->lock, flags);
1266 /*
1267 * Before we drop DTR, make sure the UART transmitter
1268 * has completely drained; this is especially
1269 * important if there is a transmit FIFO!
1270 */
1271 uart_wait_until_sent(tty, port->timeout);
1272 }
1273
1274 uart_shutdown(state);
1275 uart_flush_buffer(tty);
1276
1277 tty_ldisc_flush(tty);
1278
1279 tty->closing = 0;
1280 state->info->tty = NULL;
1281
1282 if (state->info->blocked_open) {
1283 if (state->close_delay)
1284 msleep_interruptible(state->close_delay);
1285 } else if (!uart_console(port)) {
1286 uart_change_pm(state, 3);
1287 }
1288
1289 /*
1290 * Wake up anyone trying to open this port.
1291 */
1292 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1293 wake_up_interruptible(&state->info->open_wait);
1294
1295 done:
Ingo Molnare2862f62006-01-13 21:37:07 +00001296 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297}
1298
1299static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1300{
1301 struct uart_state *state = tty->driver_data;
1302 struct uart_port *port = state->port;
1303 unsigned long char_time, expire;
1304
1305 BUG_ON(!kernel_locked());
1306
1307 if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1308 return;
1309
1310 /*
1311 * Set the check interval to be 1/5 of the estimated time to
1312 * send a single character, and make it at least 1. The check
1313 * interval should also be less than the timeout.
1314 *
1315 * Note: we have to use pretty tight timings here to satisfy
1316 * the NIST-PCTS.
1317 */
1318 char_time = (port->timeout - HZ/50) / port->fifosize;
1319 char_time = char_time / 5;
1320 if (char_time == 0)
1321 char_time = 1;
1322 if (timeout && timeout < char_time)
1323 char_time = timeout;
1324
1325 /*
1326 * If the transmitter hasn't cleared in twice the approximate
1327 * amount of time to send the entire FIFO, it probably won't
1328 * ever clear. This assumes the UART isn't doing flow
1329 * control, which is currently the case. Hence, if it ever
1330 * takes longer than port->timeout, this is probably due to a
1331 * UART bug of some kind. So, we clamp the timeout parameter at
1332 * 2*port->timeout.
1333 */
1334 if (timeout == 0 || timeout > 2 * port->timeout)
1335 timeout = 2 * port->timeout;
1336
1337 expire = jiffies + timeout;
1338
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001339 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 port->line, jiffies, expire);
1341
1342 /*
1343 * Check whether the transmitter is empty every 'char_time'.
1344 * 'timeout' / 'expire' give us the maximum amount of time
1345 * we wait.
1346 */
1347 while (!port->ops->tx_empty(port)) {
1348 msleep_interruptible(jiffies_to_msecs(char_time));
1349 if (signal_pending(current))
1350 break;
1351 if (time_after(jiffies, expire))
1352 break;
1353 }
1354 set_current_state(TASK_RUNNING); /* might not be needed */
1355}
1356
1357/*
1358 * This is called with the BKL held in
1359 * linux/drivers/char/tty_io.c:do_tty_hangup()
1360 * We're called from the eventd thread, so we can sleep for
1361 * a _short_ time only.
1362 */
1363static void uart_hangup(struct tty_struct *tty)
1364{
1365 struct uart_state *state = tty->driver_data;
1366
1367 BUG_ON(!kernel_locked());
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001368 pr_debug("uart_hangup(%d)\n", state->port->line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369
Ingo Molnare2862f62006-01-13 21:37:07 +00001370 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1372 uart_flush_buffer(tty);
1373 uart_shutdown(state);
1374 state->count = 0;
1375 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1376 state->info->tty = NULL;
1377 wake_up_interruptible(&state->info->open_wait);
1378 wake_up_interruptible(&state->info->delta_msr_wait);
1379 }
Ingo Molnare2862f62006-01-13 21:37:07 +00001380 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381}
1382
1383/*
1384 * Copy across the serial console cflag setting into the termios settings
1385 * for the initial open of the port. This allows continuity between the
1386 * kernel settings, and the settings init adopts when it opens the port
1387 * for the first time.
1388 */
1389static void uart_update_termios(struct uart_state *state)
1390{
1391 struct tty_struct *tty = state->info->tty;
1392 struct uart_port *port = state->port;
1393
1394 if (uart_console(port) && port->cons->cflag) {
1395 tty->termios->c_cflag = port->cons->cflag;
1396 port->cons->cflag = 0;
1397 }
1398
1399 /*
1400 * If the device failed to grab its irq resources,
1401 * or some other error occurred, don't try to talk
1402 * to the port hardware.
1403 */
1404 if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1405 /*
1406 * Make termios settings take effect.
1407 */
1408 uart_change_speed(state, NULL);
1409
1410 /*
1411 * And finally enable the RTS and DTR signals.
1412 */
1413 if (tty->termios->c_cflag & CBAUD)
1414 uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1415 }
1416}
1417
1418/*
1419 * Block the open until the port is ready. We must be called with
1420 * the per-port semaphore held.
1421 */
1422static int
1423uart_block_til_ready(struct file *filp, struct uart_state *state)
1424{
1425 DECLARE_WAITQUEUE(wait, current);
1426 struct uart_info *info = state->info;
1427 struct uart_port *port = state->port;
Russell Kingc5f46442005-06-29 09:42:38 +01001428 unsigned int mctrl;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429
1430 info->blocked_open++;
1431 state->count--;
1432
1433 add_wait_queue(&info->open_wait, &wait);
1434 while (1) {
1435 set_current_state(TASK_INTERRUPTIBLE);
1436
1437 /*
1438 * If we have been hung up, tell userspace/restart open.
1439 */
1440 if (tty_hung_up_p(filp) || info->tty == NULL)
1441 break;
1442
1443 /*
1444 * If the port has been closed, tell userspace/restart open.
1445 */
1446 if (!(info->flags & UIF_INITIALIZED))
1447 break;
1448
1449 /*
1450 * If non-blocking mode is set, or CLOCAL mode is set,
1451 * we don't want to wait for the modem status lines to
1452 * indicate that the port is ready.
1453 *
1454 * Also, if the port is not enabled/configured, we want
1455 * to allow the open to succeed here. Note that we will
1456 * have set TTY_IO_ERROR for a non-existant port.
1457 */
1458 if ((filp->f_flags & O_NONBLOCK) ||
1459 (info->tty->termios->c_cflag & CLOCAL) ||
1460 (info->tty->flags & (1 << TTY_IO_ERROR))) {
1461 break;
1462 }
1463
1464 /*
1465 * Set DTR to allow modem to know we're waiting. Do
1466 * not set RTS here - we want to make sure we catch
1467 * the data from the modem.
1468 */
1469 if (info->tty->termios->c_cflag & CBAUD)
1470 uart_set_mctrl(port, TIOCM_DTR);
1471
1472 /*
1473 * and wait for the carrier to indicate that the
1474 * modem is ready for us.
1475 */
Russell Kingc5f46442005-06-29 09:42:38 +01001476 spin_lock_irq(&port->lock);
Russell Kingf61051c2006-01-07 23:11:23 +00001477 port->ops->enable_ms(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001478 mctrl = port->ops->get_mctrl(port);
1479 spin_unlock_irq(&port->lock);
1480 if (mctrl & TIOCM_CAR)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481 break;
1482
Ingo Molnare2862f62006-01-13 21:37:07 +00001483 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 schedule();
Ingo Molnare2862f62006-01-13 21:37:07 +00001485 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486
1487 if (signal_pending(current))
1488 break;
1489 }
1490 set_current_state(TASK_RUNNING);
1491 remove_wait_queue(&info->open_wait, &wait);
1492
1493 state->count++;
1494 info->blocked_open--;
1495
1496 if (signal_pending(current))
1497 return -ERESTARTSYS;
1498
1499 if (!info->tty || tty_hung_up_p(filp))
1500 return -EAGAIN;
1501
1502 return 0;
1503}
1504
1505static struct uart_state *uart_get(struct uart_driver *drv, int line)
1506{
1507 struct uart_state *state;
Russell King68ac64c2006-04-30 11:13:50 +01001508 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001509
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 state = drv->state + line;
Ingo Molnare2862f62006-01-13 21:37:07 +00001511 if (mutex_lock_interruptible(&state->mutex)) {
Russell King68ac64c2006-04-30 11:13:50 +01001512 ret = -ERESTARTSYS;
1513 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514 }
1515
1516 state->count++;
Russell King68ac64c2006-04-30 11:13:50 +01001517 if (!state->port || state->port->flags & UPF_DEAD) {
1518 ret = -ENXIO;
1519 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 }
1521
1522 if (!state->info) {
Burman Yan8f31bb32007-02-14 00:33:07 -08001523 state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 if (state->info) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525 init_waitqueue_head(&state->info->open_wait);
1526 init_waitqueue_head(&state->info->delta_msr_wait);
1527
1528 /*
1529 * Link the info into the other structures.
1530 */
1531 state->port->info = state->info;
1532
1533 tasklet_init(&state->info->tlet, uart_tasklet_action,
1534 (unsigned long)state);
1535 } else {
Russell King68ac64c2006-04-30 11:13:50 +01001536 ret = -ENOMEM;
1537 goto err_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538 }
1539 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 return state;
Russell King68ac64c2006-04-30 11:13:50 +01001541
1542 err_unlock:
1543 state->count--;
1544 mutex_unlock(&state->mutex);
1545 err:
1546 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001547}
1548
1549/*
1550 * In 2.4.5, calls to uart_open are serialised by the BKL in
1551 * linux/fs/devices.c:chrdev_open()
1552 * Note that if this fails, then uart_close() _will_ be called.
1553 *
1554 * In time, we want to scrap the "opening nonpresent ports"
1555 * behaviour and implement an alternative way for setserial
1556 * to set base addresses/ports/types. This will allow us to
1557 * get rid of a certain amount of extra tests.
1558 */
1559static int uart_open(struct tty_struct *tty, struct file *filp)
1560{
1561 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1562 struct uart_state *state;
1563 int retval, line = tty->index;
1564
1565 BUG_ON(!kernel_locked());
Jiri Slabyeb3a1e12007-05-06 14:48:52 -07001566 pr_debug("uart_open(%d) called\n", line);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567
1568 /*
1569 * tty->driver->num won't change, so we won't fail here with
1570 * tty->driver_data set to something non-NULL (and therefore
1571 * we won't get caught by uart_close()).
1572 */
1573 retval = -ENODEV;
1574 if (line >= tty->driver->num)
1575 goto fail;
1576
1577 /*
1578 * We take the semaphore inside uart_get to guarantee that we won't
1579 * be re-entered while allocating the info structure, or while we
1580 * request any IRQs that the driver may need. This also has the nice
1581 * side-effect that it delays the action of uart_hangup, so we can
1582 * guarantee that info->tty will always contain something reasonable.
1583 */
1584 state = uart_get(drv, line);
1585 if (IS_ERR(state)) {
1586 retval = PTR_ERR(state);
1587 goto fail;
1588 }
1589
1590 /*
1591 * Once we set tty->driver_data here, we are guaranteed that
1592 * uart_close() will decrement the driver module use count.
1593 * Any failures from here onwards should not touch the count.
1594 */
1595 tty->driver_data = state;
1596 tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1597 tty->alt_speed = 0;
1598 state->info->tty = tty;
1599
1600 /*
1601 * If the port is in the middle of closing, bail out now.
1602 */
1603 if (tty_hung_up_p(filp)) {
1604 retval = -EAGAIN;
1605 state->count--;
Ingo Molnare2862f62006-01-13 21:37:07 +00001606 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 goto fail;
1608 }
1609
1610 /*
1611 * Make sure the device is in D0 state.
1612 */
1613 if (state->count == 1)
1614 uart_change_pm(state, 0);
1615
1616 /*
1617 * Start up the serial port.
1618 */
1619 retval = uart_startup(state, 0);
1620
1621 /*
1622 * If we succeeded, wait until the port is ready.
1623 */
1624 if (retval == 0)
1625 retval = uart_block_til_ready(filp, state);
Ingo Molnare2862f62006-01-13 21:37:07 +00001626 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001627
1628 /*
1629 * If this is the first open to succeed, adjust things to suit.
1630 */
1631 if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1632 state->info->flags |= UIF_NORMAL_ACTIVE;
1633
1634 uart_update_termios(state);
1635 }
1636
1637 fail:
1638 return retval;
1639}
1640
1641static const char *uart_type(struct uart_port *port)
1642{
1643 const char *str = NULL;
1644
1645 if (port->ops->type)
1646 str = port->ops->type(port);
1647
1648 if (!str)
1649 str = "unknown";
1650
1651 return str;
1652}
1653
1654#ifdef CONFIG_PROC_FS
1655
1656static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1657{
1658 struct uart_state *state = drv->state + i;
George G. Davis3689a0e2007-02-14 00:33:06 -08001659 int pm_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660 struct uart_port *port = state->port;
1661 char stat_buf[32];
1662 unsigned int status;
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001663 int mmio, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664
1665 if (!port)
1666 return 0;
1667
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001668 mmio = port->iotype >= UPIO_MEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669 ret = sprintf(buf, "%d: uart:%s %s%08lX irq:%d",
1670 port->line, uart_type(port),
Sergei Shtylyov6c6a2332006-09-04 00:04:20 +04001671 mmio ? "mmio:0x" : "port:",
1672 mmio ? port->mapbase : (unsigned long) port->iobase,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 port->irq);
1674
1675 if (port->type == PORT_UNKNOWN) {
1676 strcat(buf, "\n");
1677 return ret + 1;
1678 }
1679
1680 if(capable(CAP_SYS_ADMIN))
1681 {
George G. Davis3689a0e2007-02-14 00:33:06 -08001682 mutex_lock(&state->mutex);
1683 pm_state = state->pm_state;
1684 if (pm_state)
1685 uart_change_pm(state, 0);
Russell Kingc5f46442005-06-29 09:42:38 +01001686 spin_lock_irq(&port->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687 status = port->ops->get_mctrl(port);
Russell Kingc5f46442005-06-29 09:42:38 +01001688 spin_unlock_irq(&port->lock);
George G. Davis3689a0e2007-02-14 00:33:06 -08001689 if (pm_state)
1690 uart_change_pm(state, pm_state);
1691 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692
1693 ret += sprintf(buf + ret, " tx:%d rx:%d",
1694 port->icount.tx, port->icount.rx);
1695 if (port->icount.frame)
1696 ret += sprintf(buf + ret, " fe:%d",
1697 port->icount.frame);
1698 if (port->icount.parity)
1699 ret += sprintf(buf + ret, " pe:%d",
1700 port->icount.parity);
1701 if (port->icount.brk)
1702 ret += sprintf(buf + ret, " brk:%d",
1703 port->icount.brk);
1704 if (port->icount.overrun)
1705 ret += sprintf(buf + ret, " oe:%d",
1706 port->icount.overrun);
1707
1708#define INFOBIT(bit,str) \
1709 if (port->mctrl & (bit)) \
1710 strncat(stat_buf, (str), sizeof(stat_buf) - \
1711 strlen(stat_buf) - 2)
1712#define STATBIT(bit,str) \
1713 if (status & (bit)) \
1714 strncat(stat_buf, (str), sizeof(stat_buf) - \
1715 strlen(stat_buf) - 2)
1716
1717 stat_buf[0] = '\0';
1718 stat_buf[1] = '\0';
1719 INFOBIT(TIOCM_RTS, "|RTS");
1720 STATBIT(TIOCM_CTS, "|CTS");
1721 INFOBIT(TIOCM_DTR, "|DTR");
1722 STATBIT(TIOCM_DSR, "|DSR");
1723 STATBIT(TIOCM_CAR, "|CD");
1724 STATBIT(TIOCM_RNG, "|RI");
1725 if (stat_buf[0])
1726 stat_buf[0] = ' ';
1727 strcat(stat_buf, "\n");
1728
1729 ret += sprintf(buf + ret, stat_buf);
1730 } else {
1731 strcat(buf, "\n");
1732 ret++;
1733 }
1734#undef STATBIT
1735#undef INFOBIT
1736 return ret;
1737}
1738
1739static int uart_read_proc(char *page, char **start, off_t off,
1740 int count, int *eof, void *data)
1741{
1742 struct tty_driver *ttydrv = data;
1743 struct uart_driver *drv = ttydrv->driver_state;
1744 int i, len = 0, l;
1745 off_t begin = 0;
1746
1747 len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1748 "", "", "");
1749 for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1750 l = uart_line_info(page + len, drv, i);
1751 len += l;
1752 if (len + begin > off + count)
1753 goto done;
1754 if (len + begin < off) {
1755 begin += len;
1756 len = 0;
1757 }
1758 }
1759 *eof = 1;
1760 done:
1761 if (off >= len + begin)
1762 return 0;
1763 *start = page + (off - begin);
1764 return (count < begin + len - off) ? count : (begin + len - off);
1765}
1766#endif
1767
1768#ifdef CONFIG_SERIAL_CORE_CONSOLE
1769/*
Russell Kingd3587882006-03-20 20:00:09 +00001770 * uart_console_write - write a console message to a serial port
1771 * @port: the port to write the message
1772 * @s: array of characters
1773 * @count: number of characters in string to write
1774 * @write: function to write character to port
1775 */
1776void uart_console_write(struct uart_port *port, const char *s,
1777 unsigned int count,
1778 void (*putchar)(struct uart_port *, int))
1779{
1780 unsigned int i;
1781
1782 for (i = 0; i < count; i++, s++) {
1783 if (*s == '\n')
1784 putchar(port, '\r');
1785 putchar(port, *s);
1786 }
1787}
1788EXPORT_SYMBOL_GPL(uart_console_write);
1789
1790/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001791 * Check whether an invalid uart number has been specified, and
1792 * if so, search for the first available port that does have
1793 * console support.
1794 */
1795struct uart_port * __init
1796uart_get_console(struct uart_port *ports, int nr, struct console *co)
1797{
1798 int idx = co->index;
1799
1800 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1801 ports[idx].membase == NULL))
1802 for (idx = 0; idx < nr; idx++)
1803 if (ports[idx].iobase != 0 ||
1804 ports[idx].membase != NULL)
1805 break;
1806
1807 co->index = idx;
1808
1809 return ports + idx;
1810}
1811
1812/**
1813 * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1814 * @options: pointer to option string
1815 * @baud: pointer to an 'int' variable for the baud rate.
1816 * @parity: pointer to an 'int' variable for the parity.
1817 * @bits: pointer to an 'int' variable for the number of data bits.
1818 * @flow: pointer to an 'int' variable for the flow control character.
1819 *
1820 * uart_parse_options decodes a string containing the serial console
1821 * options. The format of the string is <baud><parity><bits><flow>,
1822 * eg: 115200n8r
1823 */
1824void __init
1825uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1826{
1827 char *s = options;
1828
1829 *baud = simple_strtoul(s, NULL, 10);
1830 while (*s >= '0' && *s <= '9')
1831 s++;
1832 if (*s)
1833 *parity = *s++;
1834 if (*s)
1835 *bits = *s++ - '0';
1836 if (*s)
1837 *flow = *s;
1838}
1839
1840struct baud_rates {
1841 unsigned int rate;
1842 unsigned int cflag;
1843};
1844
Arjan van de Vencb3592b2005-11-28 21:04:11 +00001845static const struct baud_rates baud_rates[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846 { 921600, B921600 },
1847 { 460800, B460800 },
1848 { 230400, B230400 },
1849 { 115200, B115200 },
1850 { 57600, B57600 },
1851 { 38400, B38400 },
1852 { 19200, B19200 },
1853 { 9600, B9600 },
1854 { 4800, B4800 },
1855 { 2400, B2400 },
1856 { 1200, B1200 },
1857 { 0, B38400 }
1858};
1859
1860/**
1861 * uart_set_options - setup the serial console parameters
1862 * @port: pointer to the serial ports uart_port structure
1863 * @co: console pointer
1864 * @baud: baud rate
1865 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1866 * @bits: number of data bits
1867 * @flow: flow control character - 'r' (rts)
1868 */
1869int __init
1870uart_set_options(struct uart_port *port, struct console *co,
1871 int baud, int parity, int bits, int flow)
1872{
Alan Cox606d0992006-12-08 02:38:45 -08001873 struct ktermios termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874 int i;
1875
Russell King976ecd12005-07-03 21:05:45 +01001876 /*
1877 * Ensure that the serial console lock is initialised
1878 * early.
1879 */
1880 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07001881 lockdep_set_class(&port->lock, &port_lock_key);
Russell King976ecd12005-07-03 21:05:45 +01001882
Alan Cox606d0992006-12-08 02:38:45 -08001883 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884
1885 termios.c_cflag = CREAD | HUPCL | CLOCAL;
1886
1887 /*
1888 * Construct a cflag setting.
1889 */
1890 for (i = 0; baud_rates[i].rate; i++)
1891 if (baud_rates[i].rate <= baud)
1892 break;
1893
1894 termios.c_cflag |= baud_rates[i].cflag;
1895
1896 if (bits == 7)
1897 termios.c_cflag |= CS7;
1898 else
1899 termios.c_cflag |= CS8;
1900
1901 switch (parity) {
1902 case 'o': case 'O':
1903 termios.c_cflag |= PARODD;
1904 /*fall through*/
1905 case 'e': case 'E':
1906 termios.c_cflag |= PARENB;
1907 break;
1908 }
1909
1910 if (flow == 'r')
1911 termios.c_cflag |= CRTSCTS;
1912
1913 port->ops->set_termios(port, &termios, NULL);
1914 co->cflag = termios.c_cflag;
1915
1916 return 0;
1917}
1918#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1919
1920static void uart_change_pm(struct uart_state *state, int pm_state)
1921{
1922 struct uart_port *port = state->port;
Andrew Victor1281e362006-05-16 11:28:49 +01001923
1924 if (state->pm_state != pm_state) {
1925 if (port->ops->pm)
1926 port->ops->pm(port, pm_state, state->pm_state);
1927 state->pm_state = pm_state;
1928 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001929}
1930
1931int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1932{
1933 struct uart_state *state = drv->state + port->line;
1934
Ingo Molnare2862f62006-01-13 21:37:07 +00001935 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001937#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1938 if (uart_console(port)) {
1939 mutex_unlock(&state->mutex);
1940 return 0;
1941 }
1942#endif
1943
Linus Torvalds1da177e2005-04-16 15:20:36 -07001944 if (state->info && state->info->flags & UIF_INITIALIZED) {
Russell Kingba899db2006-01-21 22:45:50 +00001945 const struct uart_ops *ops = port->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946
Russell Kinga6b93a92006-10-01 17:17:40 +01001947 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1948 | UIF_SUSPENDED;
1949
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950 spin_lock_irq(&port->lock);
Russell Kingb129a8c2005-08-31 10:12:14 +01001951 ops->stop_tx(port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001952 ops->set_mctrl(port, 0);
1953 ops->stop_rx(port);
1954 spin_unlock_irq(&port->lock);
1955
1956 /*
1957 * Wait for the transmitter to empty.
1958 */
1959 while (!ops->tx_empty(port)) {
1960 msleep(10);
1961 }
1962
1963 ops->shutdown(port);
1964 }
1965
1966 /*
1967 * Disable the console device before suspending.
1968 */
1969 if (uart_console(port))
1970 console_stop(port->cons);
1971
1972 uart_change_pm(state, 3);
1973
Ingo Molnare2862f62006-01-13 21:37:07 +00001974 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001975
1976 return 0;
1977}
1978
1979int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
1980{
1981 struct uart_state *state = drv->state + port->line;
1982
Ingo Molnare2862f62006-01-13 21:37:07 +00001983 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984
Rafael J. Wysockie1da95a2006-09-25 23:32:57 -07001985#ifdef CONFIG_DISABLE_CONSOLE_SUSPEND
1986 if (uart_console(port)) {
1987 mutex_unlock(&state->mutex);
1988 return 0;
1989 }
1990#endif
1991
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 uart_change_pm(state, 0);
1993
1994 /*
1995 * Re-enable the console device after suspending.
1996 */
1997 if (uart_console(port)) {
Alan Cox606d0992006-12-08 02:38:45 -08001998 struct ktermios termios;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999
2000 /*
2001 * First try to use the console cflag setting.
2002 */
Alan Cox606d0992006-12-08 02:38:45 -08002003 memset(&termios, 0, sizeof(struct ktermios));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004 termios.c_cflag = port->cons->cflag;
2005
2006 /*
2007 * If that's unset, use the tty termios setting.
2008 */
2009 if (state->info && state->info->tty && termios.c_cflag == 0)
2010 termios = *state->info->tty->termios;
2011
2012 port->ops->set_termios(port, &termios, NULL);
2013 console_start(port->cons);
2014 }
2015
Russell Kinga6b93a92006-10-01 17:17:40 +01002016 if (state->info && state->info->flags & UIF_SUSPENDED) {
Russell Kingba899db2006-01-21 22:45:50 +00002017 const struct uart_ops *ops = port->ops;
Russell Kingee31b332005-11-13 15:28:51 +00002018 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019
2020 ops->set_mctrl(port, 0);
Russell Kingee31b332005-11-13 15:28:51 +00002021 ret = ops->startup(port);
2022 if (ret == 0) {
2023 uart_change_speed(state, NULL);
2024 spin_lock_irq(&port->lock);
2025 ops->set_mctrl(port, port->mctrl);
2026 ops->start_tx(port);
2027 spin_unlock_irq(&port->lock);
Russell Kinga6b93a92006-10-01 17:17:40 +01002028 state->info->flags |= UIF_INITIALIZED;
Russell Kingee31b332005-11-13 15:28:51 +00002029 } else {
2030 /*
2031 * Failed to resume - maybe hardware went away?
2032 * Clear the "initialized" flag so we won't try
2033 * to call the low level drivers shutdown method.
2034 */
Russell Kingee31b332005-11-13 15:28:51 +00002035 uart_shutdown(state);
2036 }
Russell Kinga6b93a92006-10-01 17:17:40 +01002037
2038 state->info->flags &= ~UIF_SUSPENDED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002039 }
2040
Ingo Molnare2862f62006-01-13 21:37:07 +00002041 mutex_unlock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042
2043 return 0;
2044}
2045
2046static inline void
2047uart_report_port(struct uart_driver *drv, struct uart_port *port)
2048{
Russell King30b7a3b2005-09-03 15:30:21 +01002049 char address[64];
2050
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051 switch (port->iotype) {
2052 case UPIO_PORT:
Russell King30b7a3b2005-09-03 15:30:21 +01002053 snprintf(address, sizeof(address),
2054 "I/O 0x%x", port->iobase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002055 break;
2056 case UPIO_HUB6:
Russell King30b7a3b2005-09-03 15:30:21 +01002057 snprintf(address, sizeof(address),
2058 "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002059 break;
2060 case UPIO_MEM:
2061 case UPIO_MEM32:
Pantelis Antoniou21c614a2005-11-06 09:07:03 +00002062 case UPIO_AU:
Zang Roy-r619113be91ec2006-06-30 02:29:58 -07002063 case UPIO_TSI:
Marc St-Jeanbeab6972007-05-06 14:48:45 -07002064 case UPIO_DWAPB:
Russell King30b7a3b2005-09-03 15:30:21 +01002065 snprintf(address, sizeof(address),
2066 "MMIO 0x%lx", port->mapbase);
2067 break;
2068 default:
2069 strlcpy(address, "*unknown*", sizeof(address));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 break;
2071 }
Russell King30b7a3b2005-09-03 15:30:21 +01002072
Russell King0cf669d2005-10-31 11:42:22 +00002073 printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2074 port->dev ? port->dev->bus_id : "",
2075 port->dev ? ": " : "",
Russell King30b7a3b2005-09-03 15:30:21 +01002076 drv->dev_name, port->line, address, port->irq, uart_type(port));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077}
2078
2079static void
2080uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2081 struct uart_port *port)
2082{
2083 unsigned int flags;
2084
2085 /*
2086 * If there isn't a port here, don't do anything further.
2087 */
2088 if (!port->iobase && !port->mapbase && !port->membase)
2089 return;
2090
2091 /*
2092 * Now do the auto configuration stuff. Note that config_port
2093 * is expected to claim the resources and map the port for us.
2094 */
2095 flags = UART_CONFIG_TYPE;
2096 if (port->flags & UPF_AUTO_IRQ)
2097 flags |= UART_CONFIG_IRQ;
2098 if (port->flags & UPF_BOOT_AUTOCONF) {
2099 port->type = PORT_UNKNOWN;
2100 port->ops->config_port(port, flags);
2101 }
2102
2103 if (port->type != PORT_UNKNOWN) {
2104 unsigned long flags;
2105
2106 uart_report_port(drv, port);
2107
George G. Davis3689a0e2007-02-14 00:33:06 -08002108 /* Power up port for set_mctrl() */
2109 uart_change_pm(state, 0);
2110
Linus Torvalds1da177e2005-04-16 15:20:36 -07002111 /*
2112 * Ensure that the modem control lines are de-activated.
2113 * We probably don't need a spinlock around this, but
2114 */
2115 spin_lock_irqsave(&port->lock, flags);
2116 port->ops->set_mctrl(port, 0);
2117 spin_unlock_irqrestore(&port->lock, flags);
2118
2119 /*
2120 * Power down all ports by default, except the
2121 * console if we have one.
2122 */
2123 if (!uart_console(port))
2124 uart_change_pm(state, 3);
2125 }
2126}
2127
Jeff Dikeb68e31d2006-10-02 02:17:18 -07002128static const struct tty_operations uart_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002129 .open = uart_open,
2130 .close = uart_close,
2131 .write = uart_write,
2132 .put_char = uart_put_char,
2133 .flush_chars = uart_flush_chars,
2134 .write_room = uart_write_room,
2135 .chars_in_buffer= uart_chars_in_buffer,
2136 .flush_buffer = uart_flush_buffer,
2137 .ioctl = uart_ioctl,
2138 .throttle = uart_throttle,
2139 .unthrottle = uart_unthrottle,
2140 .send_xchar = uart_send_xchar,
2141 .set_termios = uart_set_termios,
2142 .stop = uart_stop,
2143 .start = uart_start,
2144 .hangup = uart_hangup,
2145 .break_ctl = uart_break_ctl,
2146 .wait_until_sent= uart_wait_until_sent,
2147#ifdef CONFIG_PROC_FS
2148 .read_proc = uart_read_proc,
2149#endif
2150 .tiocmget = uart_tiocmget,
2151 .tiocmset = uart_tiocmset,
2152};
2153
2154/**
2155 * uart_register_driver - register a driver with the uart core layer
2156 * @drv: low level driver structure
2157 *
2158 * Register a uart driver with the core driver. We in turn register
2159 * with the tty layer, and initialise the core driver per-port state.
2160 *
2161 * We have a proc file in /proc/tty/driver which is named after the
2162 * normal driver.
2163 *
2164 * drv->port should be NULL, and the per-port structures should be
2165 * registered using uart_add_one_port after this call has succeeded.
2166 */
2167int uart_register_driver(struct uart_driver *drv)
2168{
2169 struct tty_driver *normal = NULL;
2170 int i, retval;
2171
2172 BUG_ON(drv->state);
2173
2174 /*
2175 * Maybe we should be using a slab cache for this, especially if
2176 * we have a large number of ports to handle.
2177 */
Burman Yan8f31bb32007-02-14 00:33:07 -08002178 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179 retval = -ENOMEM;
2180 if (!drv->state)
2181 goto out;
2182
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183 normal = alloc_tty_driver(drv->nr);
2184 if (!normal)
2185 goto out;
2186
2187 drv->tty_driver = normal;
2188
2189 normal->owner = drv->owner;
2190 normal->driver_name = drv->driver_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191 normal->name = drv->dev_name;
2192 normal->major = drv->major;
2193 normal->minor_start = drv->minor;
2194 normal->type = TTY_DRIVER_TYPE_SERIAL;
2195 normal->subtype = SERIAL_TYPE_NORMAL;
2196 normal->init_termios = tty_std_termios;
2197 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
Alan Cox606d0992006-12-08 02:38:45 -08002198 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
Greg Kroah-Hartman331b8312005-06-20 21:15:16 -07002199 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 normal->driver_state = drv;
2201 tty_set_operations(normal, &uart_ops);
2202
2203 /*
2204 * Initialise the UART state(s).
2205 */
2206 for (i = 0; i < drv->nr; i++) {
2207 struct uart_state *state = drv->state + i;
2208
2209 state->close_delay = 500; /* .5 seconds */
2210 state->closing_wait = 30000; /* 30 seconds */
2211
Ingo Molnare2862f62006-01-13 21:37:07 +00002212 mutex_init(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002213 }
2214
2215 retval = tty_register_driver(normal);
2216 out:
2217 if (retval < 0) {
2218 put_tty_driver(normal);
2219 kfree(drv->state);
2220 }
2221 return retval;
2222}
2223
2224/**
2225 * uart_unregister_driver - remove a driver from the uart core layer
2226 * @drv: low level driver structure
2227 *
2228 * Remove all references to a driver from the core driver. The low
2229 * level driver must have removed all its ports via the
2230 * uart_remove_one_port() if it registered them with uart_add_one_port().
2231 * (ie, drv->port == NULL)
2232 */
2233void uart_unregister_driver(struct uart_driver *drv)
2234{
2235 struct tty_driver *p = drv->tty_driver;
2236 tty_unregister_driver(p);
2237 put_tty_driver(p);
2238 kfree(drv->state);
2239 drv->tty_driver = NULL;
2240}
2241
2242struct tty_driver *uart_console_device(struct console *co, int *index)
2243{
2244 struct uart_driver *p = co->data;
2245 *index = co->index;
2246 return p->tty_driver;
2247}
2248
2249/**
2250 * uart_add_one_port - attach a driver-defined port structure
2251 * @drv: pointer to the uart low level driver structure for this port
2252 * @port: uart port structure to use for this port.
2253 *
2254 * This allows the driver to register its own uart_port structure
2255 * with the core driver. The main purpose is to allow the low
2256 * level uart drivers to expand uart_port, rather than having yet
2257 * more levels of structures.
2258 */
2259int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2260{
2261 struct uart_state *state;
2262 int ret = 0;
2263
2264 BUG_ON(in_interrupt());
2265
2266 if (port->line >= drv->nr)
2267 return -EINVAL;
2268
2269 state = drv->state + port->line;
2270
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002271 mutex_lock(&port_mutex);
Russell King68ac64c2006-04-30 11:13:50 +01002272 mutex_lock(&state->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273 if (state->port) {
2274 ret = -EINVAL;
2275 goto out;
2276 }
2277
2278 state->port = port;
2279
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280 port->cons = drv->cons;
2281 port->info = state->info;
2282
Russell King976ecd12005-07-03 21:05:45 +01002283 /*
2284 * If this port is a console, then the spinlock is already
2285 * initialised.
2286 */
Ingo Molnar13e83592006-07-03 00:25:03 -07002287 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
Russell King976ecd12005-07-03 21:05:45 +01002288 spin_lock_init(&port->lock);
Ingo Molnar13e83592006-07-03 00:25:03 -07002289 lockdep_set_class(&port->lock, &port_lock_key);
2290 }
Russell King976ecd12005-07-03 21:05:45 +01002291
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292 uart_configure_port(drv, state, port);
2293
2294 /*
2295 * Register the port whether it's detected or not. This allows
2296 * setserial to be used to alter this ports parameters.
2297 */
2298 tty_register_device(drv->tty_driver, port->line, port->dev);
2299
2300 /*
2301 * If this driver supports console, and it hasn't been
2302 * successfully registered yet, try to re-register it.
2303 * It may be that the port was not available.
2304 */
2305 if (port->type != PORT_UNKNOWN &&
2306 port->cons && !(port->cons->flags & CON_ENABLED))
2307 register_console(port->cons);
2308
Russell King68ac64c2006-04-30 11:13:50 +01002309 /*
2310 * Ensure UPF_DEAD is not set.
2311 */
2312 port->flags &= ~UPF_DEAD;
2313
Linus Torvalds1da177e2005-04-16 15:20:36 -07002314 out:
Russell King68ac64c2006-04-30 11:13:50 +01002315 mutex_unlock(&state->mutex);
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002316 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002317
2318 return ret;
2319}
2320
2321/**
2322 * uart_remove_one_port - detach a driver defined port structure
2323 * @drv: pointer to the uart low level driver structure for this port
2324 * @port: uart port structure for this port
2325 *
2326 * This unhooks (and hangs up) the specified port structure from the
2327 * core driver. No further calls will be made to the low-level code
2328 * for this port.
2329 */
2330int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2331{
2332 struct uart_state *state = drv->state + port->line;
Russell King68ac64c2006-04-30 11:13:50 +01002333 struct uart_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002334
2335 BUG_ON(in_interrupt());
2336
2337 if (state->port != port)
2338 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2339 state->port, port);
2340
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002341 mutex_lock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002342
2343 /*
Russell King68ac64c2006-04-30 11:13:50 +01002344 * Mark the port "dead" - this prevents any opens from
2345 * succeeding while we shut down the port.
2346 */
2347 mutex_lock(&state->mutex);
2348 port->flags |= UPF_DEAD;
2349 mutex_unlock(&state->mutex);
2350
2351 /*
Greg Kroah-Hartmanaa4148c2005-06-20 21:15:16 -07002352 * Remove the devices from the tty layer
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353 */
2354 tty_unregister_device(drv->tty_driver, port->line);
2355
Russell King68ac64c2006-04-30 11:13:50 +01002356 info = state->info;
2357 if (info && info->tty)
2358 tty_vhangup(info->tty);
2359
2360 /*
2361 * All users of this port should now be disconnected from
2362 * this driver, and the port shut down. We should be the
2363 * only thread fiddling with this port from now on.
2364 */
2365 state->info = NULL;
2366
2367 /*
2368 * Free the port IO and memory resources, if any.
2369 */
2370 if (port->type != PORT_UNKNOWN)
2371 port->ops->release_port(port);
2372
2373 /*
2374 * Indicate that there isn't a port here anymore.
2375 */
2376 port->type = PORT_UNKNOWN;
2377
2378 /*
2379 * Kill the tasklet, and free resources.
2380 */
2381 if (info) {
2382 tasklet_kill(&info->tlet);
2383 kfree(info);
2384 }
2385
Linus Torvalds1da177e2005-04-16 15:20:36 -07002386 state->port = NULL;
Arjan van de Venf392ecf2006-01-12 18:44:32 +00002387 mutex_unlock(&port_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002388
2389 return 0;
2390}
2391
2392/*
2393 * Are the two ports equivalent?
2394 */
2395int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2396{
2397 if (port1->iotype != port2->iotype)
2398 return 0;
2399
2400 switch (port1->iotype) {
2401 case UPIO_PORT:
2402 return (port1->iobase == port2->iobase);
2403 case UPIO_HUB6:
2404 return (port1->iobase == port2->iobase) &&
2405 (port1->hub6 == port2->hub6);
2406 case UPIO_MEM:
Sergei Shtylyovd21b55d2006-08-28 19:49:03 +04002407 case UPIO_MEM32:
2408 case UPIO_AU:
2409 case UPIO_TSI:
Marc St-Jeanbeab6972007-05-06 14:48:45 -07002410 case UPIO_DWAPB:
Benjamin Herrenschmidt1624f002006-01-04 18:09:44 +00002411 return (port1->mapbase == port2->mapbase);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002412 }
2413 return 0;
2414}
2415EXPORT_SYMBOL(uart_match_port);
2416
Linus Torvalds1da177e2005-04-16 15:20:36 -07002417EXPORT_SYMBOL(uart_write_wakeup);
2418EXPORT_SYMBOL(uart_register_driver);
2419EXPORT_SYMBOL(uart_unregister_driver);
2420EXPORT_SYMBOL(uart_suspend_port);
2421EXPORT_SYMBOL(uart_resume_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002422EXPORT_SYMBOL(uart_add_one_port);
2423EXPORT_SYMBOL(uart_remove_one_port);
2424
2425MODULE_DESCRIPTION("Serial driver core");
2426MODULE_LICENSE("GPL");