xref: /linux/sound/core/timer.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/delay.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/moduleparam.h>
28 #include <linux/string.h>
29 #include <sound/core.h>
30 #include <sound/timer.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 #include <sound/minors.h>
34 #include <sound/initval.h>
35 #include <linux/kmod.h>
36 
37 #if defined(CONFIG_SND_HRTIMER) || defined(CONFIG_SND_HRTIMER_MODULE)
38 #define DEFAULT_TIMER_LIMIT 4
39 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
40 #define DEFAULT_TIMER_LIMIT 2
41 #else
42 #define DEFAULT_TIMER_LIMIT 1
43 #endif
44 
45 static int timer_limit = DEFAULT_TIMER_LIMIT;
46 static int timer_tstamp_monotonic = 1;
47 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
48 MODULE_DESCRIPTION("ALSA timer interface");
49 MODULE_LICENSE("GPL");
50 module_param(timer_limit, int, 0444);
51 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
52 module_param(timer_tstamp_monotonic, int, 0444);
53 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
54 
55 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
56 MODULE_ALIAS("devname:snd/timer");
57 
58 struct snd_timer_user {
59 	struct snd_timer_instance *timeri;
60 	int tread;		/* enhanced read with timestamps and events */
61 	unsigned long ticks;
62 	unsigned long overrun;
63 	int qhead;
64 	int qtail;
65 	int qused;
66 	int queue_size;
67 	struct snd_timer_read *queue;
68 	struct snd_timer_tread *tqueue;
69 	spinlock_t qlock;
70 	unsigned long last_resolution;
71 	unsigned int filter;
72 	struct timespec tstamp;		/* trigger tstamp */
73 	wait_queue_head_t qchange_sleep;
74 	struct fasync_struct *fasync;
75 	struct mutex tread_sem;
76 };
77 
78 /* list of timers */
79 static LIST_HEAD(snd_timer_list);
80 
81 /* list of slave instances */
82 static LIST_HEAD(snd_timer_slave_list);
83 
84 /* lock for slave active lists */
85 static DEFINE_SPINLOCK(slave_active_lock);
86 
87 static DEFINE_MUTEX(register_mutex);
88 
89 static int snd_timer_free(struct snd_timer *timer);
90 static int snd_timer_dev_free(struct snd_device *device);
91 static int snd_timer_dev_register(struct snd_device *device);
92 static int snd_timer_dev_disconnect(struct snd_device *device);
93 
94 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
95 
96 /*
97  * create a timer instance with the given owner string.
98  * when timer is not NULL, increments the module counter
99  */
100 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
101 							 struct snd_timer *timer)
102 {
103 	struct snd_timer_instance *timeri;
104 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
105 	if (timeri == NULL)
106 		return NULL;
107 	timeri->owner = kstrdup(owner, GFP_KERNEL);
108 	if (! timeri->owner) {
109 		kfree(timeri);
110 		return NULL;
111 	}
112 	INIT_LIST_HEAD(&timeri->open_list);
113 	INIT_LIST_HEAD(&timeri->active_list);
114 	INIT_LIST_HEAD(&timeri->ack_list);
115 	INIT_LIST_HEAD(&timeri->slave_list_head);
116 	INIT_LIST_HEAD(&timeri->slave_active_head);
117 
118 	timeri->timer = timer;
119 	if (timer && !try_module_get(timer->module)) {
120 		kfree(timeri->owner);
121 		kfree(timeri);
122 		return NULL;
123 	}
124 
125 	return timeri;
126 }
127 
128 /*
129  * find a timer instance from the given timer id
130  */
131 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
132 {
133 	struct snd_timer *timer = NULL;
134 
135 	list_for_each_entry(timer, &snd_timer_list, device_list) {
136 		if (timer->tmr_class != tid->dev_class)
137 			continue;
138 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
139 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
140 		    (timer->card == NULL ||
141 		     timer->card->number != tid->card))
142 			continue;
143 		if (timer->tmr_device != tid->device)
144 			continue;
145 		if (timer->tmr_subdevice != tid->subdevice)
146 			continue;
147 		return timer;
148 	}
149 	return NULL;
150 }
151 
152 #ifdef CONFIG_MODULES
153 
154 static void snd_timer_request(struct snd_timer_id *tid)
155 {
156 	switch (tid->dev_class) {
157 	case SNDRV_TIMER_CLASS_GLOBAL:
158 		if (tid->device < timer_limit)
159 			request_module("snd-timer-%i", tid->device);
160 		break;
161 	case SNDRV_TIMER_CLASS_CARD:
162 	case SNDRV_TIMER_CLASS_PCM:
163 		if (tid->card < snd_ecards_limit)
164 			request_module("snd-card-%i", tid->card);
165 		break;
166 	default:
167 		break;
168 	}
169 }
170 
171 #endif
172 
173 /*
174  * look for a master instance matching with the slave id of the given slave.
175  * when found, relink the open_link of the slave.
176  *
177  * call this with register_mutex down.
178  */
179 static void snd_timer_check_slave(struct snd_timer_instance *slave)
180 {
181 	struct snd_timer *timer;
182 	struct snd_timer_instance *master;
183 
184 	/* FIXME: it's really dumb to look up all entries.. */
185 	list_for_each_entry(timer, &snd_timer_list, device_list) {
186 		list_for_each_entry(master, &timer->open_list_head, open_list) {
187 			if (slave->slave_class == master->slave_class &&
188 			    slave->slave_id == master->slave_id) {
189 				list_move_tail(&slave->open_list,
190 					       &master->slave_list_head);
191 				spin_lock_irq(&slave_active_lock);
192 				slave->master = master;
193 				slave->timer = master->timer;
194 				spin_unlock_irq(&slave_active_lock);
195 				return;
196 			}
197 		}
198 	}
199 }
200 
201 /*
202  * look for slave instances matching with the slave id of the given master.
203  * when found, relink the open_link of slaves.
204  *
205  * call this with register_mutex down.
206  */
207 static void snd_timer_check_master(struct snd_timer_instance *master)
208 {
209 	struct snd_timer_instance *slave, *tmp;
210 
211 	/* check all pending slaves */
212 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
213 		if (slave->slave_class == master->slave_class &&
214 		    slave->slave_id == master->slave_id) {
215 			list_move_tail(&slave->open_list, &master->slave_list_head);
216 			spin_lock_irq(&slave_active_lock);
217 			slave->master = master;
218 			slave->timer = master->timer;
219 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
220 				list_add_tail(&slave->active_list,
221 					      &master->slave_active_head);
222 			spin_unlock_irq(&slave_active_lock);
223 		}
224 	}
225 }
226 
227 /*
228  * open a timer instance
229  * when opening a master, the slave id must be here given.
230  */
231 int snd_timer_open(struct snd_timer_instance **ti,
232 		   char *owner, struct snd_timer_id *tid,
233 		   unsigned int slave_id)
234 {
235 	struct snd_timer *timer;
236 	struct snd_timer_instance *timeri = NULL;
237 
238 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
239 		/* open a slave instance */
240 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
241 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
242 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
243 			return -EINVAL;
244 		}
245 		mutex_lock(&register_mutex);
246 		timeri = snd_timer_instance_new(owner, NULL);
247 		if (!timeri) {
248 			mutex_unlock(&register_mutex);
249 			return -ENOMEM;
250 		}
251 		timeri->slave_class = tid->dev_sclass;
252 		timeri->slave_id = tid->device;
253 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
254 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
255 		snd_timer_check_slave(timeri);
256 		mutex_unlock(&register_mutex);
257 		*ti = timeri;
258 		return 0;
259 	}
260 
261 	/* open a master instance */
262 	mutex_lock(&register_mutex);
263 	timer = snd_timer_find(tid);
264 #ifdef CONFIG_MODULES
265 	if (!timer) {
266 		mutex_unlock(&register_mutex);
267 		snd_timer_request(tid);
268 		mutex_lock(&register_mutex);
269 		timer = snd_timer_find(tid);
270 	}
271 #endif
272 	if (!timer) {
273 		mutex_unlock(&register_mutex);
274 		return -ENODEV;
275 	}
276 	if (!list_empty(&timer->open_list_head)) {
277 		timeri = list_entry(timer->open_list_head.next,
278 				    struct snd_timer_instance, open_list);
279 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
280 			mutex_unlock(&register_mutex);
281 			return -EBUSY;
282 		}
283 	}
284 	timeri = snd_timer_instance_new(owner, timer);
285 	if (!timeri) {
286 		mutex_unlock(&register_mutex);
287 		return -ENOMEM;
288 	}
289 	timeri->slave_class = tid->dev_sclass;
290 	timeri->slave_id = slave_id;
291 	if (list_empty(&timer->open_list_head) && timer->hw.open)
292 		timer->hw.open(timer);
293 	list_add_tail(&timeri->open_list, &timer->open_list_head);
294 	snd_timer_check_master(timeri);
295 	mutex_unlock(&register_mutex);
296 	*ti = timeri;
297 	return 0;
298 }
299 
300 static int _snd_timer_stop(struct snd_timer_instance *timeri,
301 			   int keep_flag, int event);
302 
303 /*
304  * close a timer instance
305  */
306 int snd_timer_close(struct snd_timer_instance *timeri)
307 {
308 	struct snd_timer *timer = NULL;
309 	struct snd_timer_instance *slave, *tmp;
310 
311 	if (snd_BUG_ON(!timeri))
312 		return -ENXIO;
313 
314 	/* force to stop the timer */
315 	snd_timer_stop(timeri);
316 
317 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
318 		/* wait, until the active callback is finished */
319 		spin_lock_irq(&slave_active_lock);
320 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
321 			spin_unlock_irq(&slave_active_lock);
322 			udelay(10);
323 			spin_lock_irq(&slave_active_lock);
324 		}
325 		spin_unlock_irq(&slave_active_lock);
326 		mutex_lock(&register_mutex);
327 		list_del(&timeri->open_list);
328 		mutex_unlock(&register_mutex);
329 	} else {
330 		timer = timeri->timer;
331 		if (snd_BUG_ON(!timer))
332 			goto out;
333 		/* wait, until the active callback is finished */
334 		spin_lock_irq(&timer->lock);
335 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
336 			spin_unlock_irq(&timer->lock);
337 			udelay(10);
338 			spin_lock_irq(&timer->lock);
339 		}
340 		spin_unlock_irq(&timer->lock);
341 		mutex_lock(&register_mutex);
342 		list_del(&timeri->open_list);
343 		if (timer && list_empty(&timer->open_list_head) &&
344 		    timer->hw.close)
345 			timer->hw.close(timer);
346 		/* remove slave links */
347 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
348 					 open_list) {
349 			spin_lock_irq(&slave_active_lock);
350 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
351 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
352 			slave->master = NULL;
353 			slave->timer = NULL;
354 			spin_unlock_irq(&slave_active_lock);
355 		}
356 		mutex_unlock(&register_mutex);
357 	}
358  out:
359 	if (timeri->private_free)
360 		timeri->private_free(timeri);
361 	kfree(timeri->owner);
362 	kfree(timeri);
363 	if (timer)
364 		module_put(timer->module);
365 	return 0;
366 }
367 
368 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
369 {
370 	struct snd_timer * timer;
371 
372 	if (timeri == NULL)
373 		return 0;
374 	if ((timer = timeri->timer) != NULL) {
375 		if (timer->hw.c_resolution)
376 			return timer->hw.c_resolution(timer);
377 		return timer->hw.resolution;
378 	}
379 	return 0;
380 }
381 
382 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
383 {
384 	struct snd_timer *timer;
385 	unsigned long flags;
386 	unsigned long resolution = 0;
387 	struct snd_timer_instance *ts;
388 	struct timespec tstamp;
389 
390 	if (timer_tstamp_monotonic)
391 		do_posix_clock_monotonic_gettime(&tstamp);
392 	else
393 		getnstimeofday(&tstamp);
394 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
395 		       event > SNDRV_TIMER_EVENT_PAUSE))
396 		return;
397 	if (event == SNDRV_TIMER_EVENT_START ||
398 	    event == SNDRV_TIMER_EVENT_CONTINUE)
399 		resolution = snd_timer_resolution(ti);
400 	if (ti->ccallback)
401 		ti->ccallback(ti, event, &tstamp, resolution);
402 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
403 		return;
404 	timer = ti->timer;
405 	if (timer == NULL)
406 		return;
407 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
408 		return;
409 	spin_lock_irqsave(&timer->lock, flags);
410 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
411 		if (ts->ccallback)
412 			ts->ccallback(ti, event + 100, &tstamp, resolution);
413 	spin_unlock_irqrestore(&timer->lock, flags);
414 }
415 
416 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
417 			    unsigned long sticks)
418 {
419 	list_move_tail(&timeri->active_list, &timer->active_list_head);
420 	if (timer->running) {
421 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
422 			goto __start_now;
423 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
424 		timeri->flags |= SNDRV_TIMER_IFLG_START;
425 		return 1;	/* delayed start */
426 	} else {
427 		timer->sticks = sticks;
428 		timer->hw.start(timer);
429 	      __start_now:
430 		timer->running++;
431 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
432 		return 0;
433 	}
434 }
435 
436 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
437 {
438 	unsigned long flags;
439 
440 	spin_lock_irqsave(&slave_active_lock, flags);
441 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
442 	if (timeri->master)
443 		list_add_tail(&timeri->active_list,
444 			      &timeri->master->slave_active_head);
445 	spin_unlock_irqrestore(&slave_active_lock, flags);
446 	return 1; /* delayed start */
447 }
448 
449 /*
450  *  start the timer instance
451  */
452 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
453 {
454 	struct snd_timer *timer;
455 	int result = -EINVAL;
456 	unsigned long flags;
457 
458 	if (timeri == NULL || ticks < 1)
459 		return -EINVAL;
460 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
461 		result = snd_timer_start_slave(timeri);
462 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
463 		return result;
464 	}
465 	timer = timeri->timer;
466 	if (timer == NULL)
467 		return -EINVAL;
468 	spin_lock_irqsave(&timer->lock, flags);
469 	timeri->ticks = timeri->cticks = ticks;
470 	timeri->pticks = 0;
471 	result = snd_timer_start1(timer, timeri, ticks);
472 	spin_unlock_irqrestore(&timer->lock, flags);
473 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
474 	return result;
475 }
476 
477 static int _snd_timer_stop(struct snd_timer_instance * timeri,
478 			   int keep_flag, int event)
479 {
480 	struct snd_timer *timer;
481 	unsigned long flags;
482 
483 	if (snd_BUG_ON(!timeri))
484 		return -ENXIO;
485 
486 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
487 		if (!keep_flag) {
488 			spin_lock_irqsave(&slave_active_lock, flags);
489 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
490 			spin_unlock_irqrestore(&slave_active_lock, flags);
491 		}
492 		goto __end;
493 	}
494 	timer = timeri->timer;
495 	if (!timer)
496 		return -EINVAL;
497 	spin_lock_irqsave(&timer->lock, flags);
498 	list_del_init(&timeri->ack_list);
499 	list_del_init(&timeri->active_list);
500 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
501 	    !(--timer->running)) {
502 		timer->hw.stop(timer);
503 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
504 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
505 			snd_timer_reschedule(timer, 0);
506 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
507 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
508 				timer->hw.start(timer);
509 			}
510 		}
511 	}
512 	if (!keep_flag)
513 		timeri->flags &=
514 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
515 	spin_unlock_irqrestore(&timer->lock, flags);
516       __end:
517 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
518 		snd_timer_notify1(timeri, event);
519 	return 0;
520 }
521 
522 /*
523  * stop the timer instance.
524  *
525  * do not call this from the timer callback!
526  */
527 int snd_timer_stop(struct snd_timer_instance *timeri)
528 {
529 	struct snd_timer *timer;
530 	unsigned long flags;
531 	int err;
532 
533 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
534 	if (err < 0)
535 		return err;
536 	timer = timeri->timer;
537 	if (!timer)
538 		return -EINVAL;
539 	spin_lock_irqsave(&timer->lock, flags);
540 	timeri->cticks = timeri->ticks;
541 	timeri->pticks = 0;
542 	spin_unlock_irqrestore(&timer->lock, flags);
543 	return 0;
544 }
545 
546 /*
547  * start again..  the tick is kept.
548  */
549 int snd_timer_continue(struct snd_timer_instance *timeri)
550 {
551 	struct snd_timer *timer;
552 	int result = -EINVAL;
553 	unsigned long flags;
554 
555 	if (timeri == NULL)
556 		return result;
557 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
558 		return snd_timer_start_slave(timeri);
559 	timer = timeri->timer;
560 	if (! timer)
561 		return -EINVAL;
562 	spin_lock_irqsave(&timer->lock, flags);
563 	if (!timeri->cticks)
564 		timeri->cticks = 1;
565 	timeri->pticks = 0;
566 	result = snd_timer_start1(timer, timeri, timer->sticks);
567 	spin_unlock_irqrestore(&timer->lock, flags);
568 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
569 	return result;
570 }
571 
572 /*
573  * pause.. remember the ticks left
574  */
575 int snd_timer_pause(struct snd_timer_instance * timeri)
576 {
577 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
578 }
579 
580 /*
581  * reschedule the timer
582  *
583  * start pending instances and check the scheduling ticks.
584  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
585  */
586 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
587 {
588 	struct snd_timer_instance *ti;
589 	unsigned long ticks = ~0UL;
590 
591 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
592 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
593 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
594 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
595 			timer->running++;
596 		}
597 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
598 			if (ticks > ti->cticks)
599 				ticks = ti->cticks;
600 		}
601 	}
602 	if (ticks == ~0UL) {
603 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
604 		return;
605 	}
606 	if (ticks > timer->hw.ticks)
607 		ticks = timer->hw.ticks;
608 	if (ticks_left != ticks)
609 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
610 	timer->sticks = ticks;
611 }
612 
613 /*
614  * timer tasklet
615  *
616  */
617 static void snd_timer_tasklet(unsigned long arg)
618 {
619 	struct snd_timer *timer = (struct snd_timer *) arg;
620 	struct snd_timer_instance *ti;
621 	struct list_head *p;
622 	unsigned long resolution, ticks;
623 	unsigned long flags;
624 
625 	spin_lock_irqsave(&timer->lock, flags);
626 	/* now process all callbacks */
627 	while (!list_empty(&timer->sack_list_head)) {
628 		p = timer->sack_list_head.next;		/* get first item */
629 		ti = list_entry(p, struct snd_timer_instance, ack_list);
630 
631 		/* remove from ack_list and make empty */
632 		list_del_init(p);
633 
634 		ticks = ti->pticks;
635 		ti->pticks = 0;
636 		resolution = ti->resolution;
637 
638 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
639 		spin_unlock(&timer->lock);
640 		if (ti->callback)
641 			ti->callback(ti, resolution, ticks);
642 		spin_lock(&timer->lock);
643 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
644 	}
645 	spin_unlock_irqrestore(&timer->lock, flags);
646 }
647 
648 /*
649  * timer interrupt
650  *
651  * ticks_left is usually equal to timer->sticks.
652  *
653  */
654 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
655 {
656 	struct snd_timer_instance *ti, *ts, *tmp;
657 	unsigned long resolution, ticks;
658 	struct list_head *p, *ack_list_head;
659 	unsigned long flags;
660 	int use_tasklet = 0;
661 
662 	if (timer == NULL)
663 		return;
664 
665 	spin_lock_irqsave(&timer->lock, flags);
666 
667 	/* remember the current resolution */
668 	if (timer->hw.c_resolution)
669 		resolution = timer->hw.c_resolution(timer);
670 	else
671 		resolution = timer->hw.resolution;
672 
673 	/* loop for all active instances
674 	 * Here we cannot use list_for_each_entry because the active_list of a
675 	 * processed instance is relinked to done_list_head before the callback
676 	 * is called.
677 	 */
678 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
679 				 active_list) {
680 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
681 			continue;
682 		ti->pticks += ticks_left;
683 		ti->resolution = resolution;
684 		if (ti->cticks < ticks_left)
685 			ti->cticks = 0;
686 		else
687 			ti->cticks -= ticks_left;
688 		if (ti->cticks) /* not expired */
689 			continue;
690 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
691 			ti->cticks = ti->ticks;
692 		} else {
693 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
694 			if (--timer->running)
695 				list_del(&ti->active_list);
696 		}
697 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
698 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
699 			ack_list_head = &timer->ack_list_head;
700 		else
701 			ack_list_head = &timer->sack_list_head;
702 		if (list_empty(&ti->ack_list))
703 			list_add_tail(&ti->ack_list, ack_list_head);
704 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
705 			ts->pticks = ti->pticks;
706 			ts->resolution = resolution;
707 			if (list_empty(&ts->ack_list))
708 				list_add_tail(&ts->ack_list, ack_list_head);
709 		}
710 	}
711 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
712 		snd_timer_reschedule(timer, timer->sticks);
713 	if (timer->running) {
714 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
715 			timer->hw.stop(timer);
716 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
717 		}
718 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
719 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
720 			/* restart timer */
721 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
722 			timer->hw.start(timer);
723 		}
724 	} else {
725 		timer->hw.stop(timer);
726 	}
727 
728 	/* now process all fast callbacks */
729 	while (!list_empty(&timer->ack_list_head)) {
730 		p = timer->ack_list_head.next;		/* get first item */
731 		ti = list_entry(p, struct snd_timer_instance, ack_list);
732 
733 		/* remove from ack_list and make empty */
734 		list_del_init(p);
735 
736 		ticks = ti->pticks;
737 		ti->pticks = 0;
738 
739 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
740 		spin_unlock(&timer->lock);
741 		if (ti->callback)
742 			ti->callback(ti, resolution, ticks);
743 		spin_lock(&timer->lock);
744 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
745 	}
746 
747 	/* do we have any slow callbacks? */
748 	use_tasklet = !list_empty(&timer->sack_list_head);
749 	spin_unlock_irqrestore(&timer->lock, flags);
750 
751 	if (use_tasklet)
752 		tasklet_schedule(&timer->task_queue);
753 }
754 
755 /*
756 
757  */
758 
759 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
760 		  struct snd_timer **rtimer)
761 {
762 	struct snd_timer *timer;
763 	int err;
764 	static struct snd_device_ops ops = {
765 		.dev_free = snd_timer_dev_free,
766 		.dev_register = snd_timer_dev_register,
767 		.dev_disconnect = snd_timer_dev_disconnect,
768 	};
769 
770 	if (snd_BUG_ON(!tid))
771 		return -EINVAL;
772 	if (rtimer)
773 		*rtimer = NULL;
774 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
775 	if (timer == NULL) {
776 		snd_printk(KERN_ERR "timer: cannot allocate\n");
777 		return -ENOMEM;
778 	}
779 	timer->tmr_class = tid->dev_class;
780 	timer->card = card;
781 	timer->tmr_device = tid->device;
782 	timer->tmr_subdevice = tid->subdevice;
783 	if (id)
784 		strlcpy(timer->id, id, sizeof(timer->id));
785 	INIT_LIST_HEAD(&timer->device_list);
786 	INIT_LIST_HEAD(&timer->open_list_head);
787 	INIT_LIST_HEAD(&timer->active_list_head);
788 	INIT_LIST_HEAD(&timer->ack_list_head);
789 	INIT_LIST_HEAD(&timer->sack_list_head);
790 	spin_lock_init(&timer->lock);
791 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
792 		     (unsigned long)timer);
793 	if (card != NULL) {
794 		timer->module = card->module;
795 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
796 		if (err < 0) {
797 			snd_timer_free(timer);
798 			return err;
799 		}
800 	}
801 	if (rtimer)
802 		*rtimer = timer;
803 	return 0;
804 }
805 
806 static int snd_timer_free(struct snd_timer *timer)
807 {
808 	if (!timer)
809 		return 0;
810 
811 	mutex_lock(&register_mutex);
812 	if (! list_empty(&timer->open_list_head)) {
813 		struct list_head *p, *n;
814 		struct snd_timer_instance *ti;
815 		snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
816 		list_for_each_safe(p, n, &timer->open_list_head) {
817 			list_del_init(p);
818 			ti = list_entry(p, struct snd_timer_instance, open_list);
819 			ti->timer = NULL;
820 		}
821 	}
822 	list_del(&timer->device_list);
823 	mutex_unlock(&register_mutex);
824 
825 	if (timer->private_free)
826 		timer->private_free(timer);
827 	kfree(timer);
828 	return 0;
829 }
830 
831 static int snd_timer_dev_free(struct snd_device *device)
832 {
833 	struct snd_timer *timer = device->device_data;
834 	return snd_timer_free(timer);
835 }
836 
837 static int snd_timer_dev_register(struct snd_device *dev)
838 {
839 	struct snd_timer *timer = dev->device_data;
840 	struct snd_timer *timer1;
841 
842 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
843 		return -ENXIO;
844 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
845 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
846 	    	return -EINVAL;
847 
848 	mutex_lock(&register_mutex);
849 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
850 		if (timer1->tmr_class > timer->tmr_class)
851 			break;
852 		if (timer1->tmr_class < timer->tmr_class)
853 			continue;
854 		if (timer1->card && timer->card) {
855 			if (timer1->card->number > timer->card->number)
856 				break;
857 			if (timer1->card->number < timer->card->number)
858 				continue;
859 		}
860 		if (timer1->tmr_device > timer->tmr_device)
861 			break;
862 		if (timer1->tmr_device < timer->tmr_device)
863 			continue;
864 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
865 			break;
866 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
867 			continue;
868 		/* conflicts.. */
869 		mutex_unlock(&register_mutex);
870 		return -EBUSY;
871 	}
872 	list_add_tail(&timer->device_list, &timer1->device_list);
873 	mutex_unlock(&register_mutex);
874 	return 0;
875 }
876 
877 static int snd_timer_dev_disconnect(struct snd_device *device)
878 {
879 	struct snd_timer *timer = device->device_data;
880 	mutex_lock(&register_mutex);
881 	list_del_init(&timer->device_list);
882 	mutex_unlock(&register_mutex);
883 	return 0;
884 }
885 
886 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
887 {
888 	unsigned long flags;
889 	unsigned long resolution = 0;
890 	struct snd_timer_instance *ti, *ts;
891 
892 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
893 		return;
894 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
895 		       event > SNDRV_TIMER_EVENT_MRESUME))
896 		return;
897 	spin_lock_irqsave(&timer->lock, flags);
898 	if (event == SNDRV_TIMER_EVENT_MSTART ||
899 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
900 	    event == SNDRV_TIMER_EVENT_MRESUME) {
901 		if (timer->hw.c_resolution)
902 			resolution = timer->hw.c_resolution(timer);
903 		else
904 			resolution = timer->hw.resolution;
905 	}
906 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
907 		if (ti->ccallback)
908 			ti->ccallback(ti, event, tstamp, resolution);
909 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
910 			if (ts->ccallback)
911 				ts->ccallback(ts, event, tstamp, resolution);
912 	}
913 	spin_unlock_irqrestore(&timer->lock, flags);
914 }
915 
916 /*
917  * exported functions for global timers
918  */
919 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
920 {
921 	struct snd_timer_id tid;
922 
923 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
924 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
925 	tid.card = -1;
926 	tid.device = device;
927 	tid.subdevice = 0;
928 	return snd_timer_new(NULL, id, &tid, rtimer);
929 }
930 
931 int snd_timer_global_free(struct snd_timer *timer)
932 {
933 	return snd_timer_free(timer);
934 }
935 
936 int snd_timer_global_register(struct snd_timer *timer)
937 {
938 	struct snd_device dev;
939 
940 	memset(&dev, 0, sizeof(dev));
941 	dev.device_data = timer;
942 	return snd_timer_dev_register(&dev);
943 }
944 
945 /*
946  *  System timer
947  */
948 
949 struct snd_timer_system_private {
950 	struct timer_list tlist;
951 	unsigned long last_expires;
952 	unsigned long last_jiffies;
953 	unsigned long correction;
954 };
955 
956 static void snd_timer_s_function(unsigned long data)
957 {
958 	struct snd_timer *timer = (struct snd_timer *)data;
959 	struct snd_timer_system_private *priv = timer->private_data;
960 	unsigned long jiff = jiffies;
961 	if (time_after(jiff, priv->last_expires))
962 		priv->correction += (long)jiff - (long)priv->last_expires;
963 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
964 }
965 
966 static int snd_timer_s_start(struct snd_timer * timer)
967 {
968 	struct snd_timer_system_private *priv;
969 	unsigned long njiff;
970 
971 	priv = (struct snd_timer_system_private *) timer->private_data;
972 	njiff = (priv->last_jiffies = jiffies);
973 	if (priv->correction > timer->sticks - 1) {
974 		priv->correction -= timer->sticks - 1;
975 		njiff++;
976 	} else {
977 		njiff += timer->sticks - priv->correction;
978 		priv->correction = 0;
979 	}
980 	priv->last_expires = priv->tlist.expires = njiff;
981 	add_timer(&priv->tlist);
982 	return 0;
983 }
984 
985 static int snd_timer_s_stop(struct snd_timer * timer)
986 {
987 	struct snd_timer_system_private *priv;
988 	unsigned long jiff;
989 
990 	priv = (struct snd_timer_system_private *) timer->private_data;
991 	del_timer(&priv->tlist);
992 	jiff = jiffies;
993 	if (time_before(jiff, priv->last_expires))
994 		timer->sticks = priv->last_expires - jiff;
995 	else
996 		timer->sticks = 1;
997 	priv->correction = 0;
998 	return 0;
999 }
1000 
1001 static struct snd_timer_hardware snd_timer_system =
1002 {
1003 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1004 	.resolution =	1000000000L / HZ,
1005 	.ticks =	10000000L,
1006 	.start =	snd_timer_s_start,
1007 	.stop =		snd_timer_s_stop
1008 };
1009 
1010 static void snd_timer_free_system(struct snd_timer *timer)
1011 {
1012 	kfree(timer->private_data);
1013 }
1014 
1015 static int snd_timer_register_system(void)
1016 {
1017 	struct snd_timer *timer;
1018 	struct snd_timer_system_private *priv;
1019 	int err;
1020 
1021 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1022 	if (err < 0)
1023 		return err;
1024 	strcpy(timer->name, "system timer");
1025 	timer->hw = snd_timer_system;
1026 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1027 	if (priv == NULL) {
1028 		snd_timer_free(timer);
1029 		return -ENOMEM;
1030 	}
1031 	init_timer(&priv->tlist);
1032 	priv->tlist.function = snd_timer_s_function;
1033 	priv->tlist.data = (unsigned long) timer;
1034 	timer->private_data = priv;
1035 	timer->private_free = snd_timer_free_system;
1036 	return snd_timer_global_register(timer);
1037 }
1038 
1039 #ifdef CONFIG_PROC_FS
1040 /*
1041  *  Info interface
1042  */
1043 
1044 static void snd_timer_proc_read(struct snd_info_entry *entry,
1045 				struct snd_info_buffer *buffer)
1046 {
1047 	struct snd_timer *timer;
1048 	struct snd_timer_instance *ti;
1049 
1050 	mutex_lock(&register_mutex);
1051 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1052 		switch (timer->tmr_class) {
1053 		case SNDRV_TIMER_CLASS_GLOBAL:
1054 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1055 			break;
1056 		case SNDRV_TIMER_CLASS_CARD:
1057 			snd_iprintf(buffer, "C%i-%i: ",
1058 				    timer->card->number, timer->tmr_device);
1059 			break;
1060 		case SNDRV_TIMER_CLASS_PCM:
1061 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1062 				    timer->tmr_device, timer->tmr_subdevice);
1063 			break;
1064 		default:
1065 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1066 				    timer->card ? timer->card->number : -1,
1067 				    timer->tmr_device, timer->tmr_subdevice);
1068 		}
1069 		snd_iprintf(buffer, "%s :", timer->name);
1070 		if (timer->hw.resolution)
1071 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1072 				    timer->hw.resolution / 1000,
1073 				    timer->hw.resolution % 1000,
1074 				    timer->hw.ticks);
1075 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1076 			snd_iprintf(buffer, " SLAVE");
1077 		snd_iprintf(buffer, "\n");
1078 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1079 			snd_iprintf(buffer, "  Client %s : %s\n",
1080 				    ti->owner ? ti->owner : "unknown",
1081 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1082 						 SNDRV_TIMER_IFLG_RUNNING)
1083 				    ? "running" : "stopped");
1084 	}
1085 	mutex_unlock(&register_mutex);
1086 }
1087 
1088 static struct snd_info_entry *snd_timer_proc_entry;
1089 
1090 static void __init snd_timer_proc_init(void)
1091 {
1092 	struct snd_info_entry *entry;
1093 
1094 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1095 	if (entry != NULL) {
1096 		entry->c.text.read = snd_timer_proc_read;
1097 		if (snd_info_register(entry) < 0) {
1098 			snd_info_free_entry(entry);
1099 			entry = NULL;
1100 		}
1101 	}
1102 	snd_timer_proc_entry = entry;
1103 }
1104 
1105 static void __exit snd_timer_proc_done(void)
1106 {
1107 	snd_info_free_entry(snd_timer_proc_entry);
1108 }
1109 #else /* !CONFIG_PROC_FS */
1110 #define snd_timer_proc_init()
1111 #define snd_timer_proc_done()
1112 #endif
1113 
1114 /*
1115  *  USER SPACE interface
1116  */
1117 
1118 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1119 				     unsigned long resolution,
1120 				     unsigned long ticks)
1121 {
1122 	struct snd_timer_user *tu = timeri->callback_data;
1123 	struct snd_timer_read *r;
1124 	int prev;
1125 
1126 	spin_lock(&tu->qlock);
1127 	if (tu->qused > 0) {
1128 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1129 		r = &tu->queue[prev];
1130 		if (r->resolution == resolution) {
1131 			r->ticks += ticks;
1132 			goto __wake;
1133 		}
1134 	}
1135 	if (tu->qused >= tu->queue_size) {
1136 		tu->overrun++;
1137 	} else {
1138 		r = &tu->queue[tu->qtail++];
1139 		tu->qtail %= tu->queue_size;
1140 		r->resolution = resolution;
1141 		r->ticks = ticks;
1142 		tu->qused++;
1143 	}
1144       __wake:
1145 	spin_unlock(&tu->qlock);
1146 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1147 	wake_up(&tu->qchange_sleep);
1148 }
1149 
1150 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1151 					    struct snd_timer_tread *tread)
1152 {
1153 	if (tu->qused >= tu->queue_size) {
1154 		tu->overrun++;
1155 	} else {
1156 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1157 		tu->qtail %= tu->queue_size;
1158 		tu->qused++;
1159 	}
1160 }
1161 
1162 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1163 				     int event,
1164 				     struct timespec *tstamp,
1165 				     unsigned long resolution)
1166 {
1167 	struct snd_timer_user *tu = timeri->callback_data;
1168 	struct snd_timer_tread r1;
1169 	unsigned long flags;
1170 
1171 	if (event >= SNDRV_TIMER_EVENT_START &&
1172 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1173 		tu->tstamp = *tstamp;
1174 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1175 		return;
1176 	r1.event = event;
1177 	r1.tstamp = *tstamp;
1178 	r1.val = resolution;
1179 	spin_lock_irqsave(&tu->qlock, flags);
1180 	snd_timer_user_append_to_tqueue(tu, &r1);
1181 	spin_unlock_irqrestore(&tu->qlock, flags);
1182 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1183 	wake_up(&tu->qchange_sleep);
1184 }
1185 
1186 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1187 				      unsigned long resolution,
1188 				      unsigned long ticks)
1189 {
1190 	struct snd_timer_user *tu = timeri->callback_data;
1191 	struct snd_timer_tread *r, r1;
1192 	struct timespec tstamp;
1193 	int prev, append = 0;
1194 
1195 	memset(&tstamp, 0, sizeof(tstamp));
1196 	spin_lock(&tu->qlock);
1197 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1198 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1199 		spin_unlock(&tu->qlock);
1200 		return;
1201 	}
1202 	if (tu->last_resolution != resolution || ticks > 0) {
1203 		if (timer_tstamp_monotonic)
1204 			do_posix_clock_monotonic_gettime(&tstamp);
1205 		else
1206 			getnstimeofday(&tstamp);
1207 	}
1208 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1209 	    tu->last_resolution != resolution) {
1210 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1211 		r1.tstamp = tstamp;
1212 		r1.val = resolution;
1213 		snd_timer_user_append_to_tqueue(tu, &r1);
1214 		tu->last_resolution = resolution;
1215 		append++;
1216 	}
1217 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1218 		goto __wake;
1219 	if (ticks == 0)
1220 		goto __wake;
1221 	if (tu->qused > 0) {
1222 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1223 		r = &tu->tqueue[prev];
1224 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1225 			r->tstamp = tstamp;
1226 			r->val += ticks;
1227 			append++;
1228 			goto __wake;
1229 		}
1230 	}
1231 	r1.event = SNDRV_TIMER_EVENT_TICK;
1232 	r1.tstamp = tstamp;
1233 	r1.val = ticks;
1234 	snd_timer_user_append_to_tqueue(tu, &r1);
1235 	append++;
1236       __wake:
1237 	spin_unlock(&tu->qlock);
1238 	if (append == 0)
1239 		return;
1240 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1241 	wake_up(&tu->qchange_sleep);
1242 }
1243 
1244 static int snd_timer_user_open(struct inode *inode, struct file *file)
1245 {
1246 	struct snd_timer_user *tu;
1247 	int err;
1248 
1249 	err = nonseekable_open(inode, file);
1250 	if (err < 0)
1251 		return err;
1252 
1253 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1254 	if (tu == NULL)
1255 		return -ENOMEM;
1256 	spin_lock_init(&tu->qlock);
1257 	init_waitqueue_head(&tu->qchange_sleep);
1258 	mutex_init(&tu->tread_sem);
1259 	tu->ticks = 1;
1260 	tu->queue_size = 128;
1261 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1262 			    GFP_KERNEL);
1263 	if (tu->queue == NULL) {
1264 		kfree(tu);
1265 		return -ENOMEM;
1266 	}
1267 	file->private_data = tu;
1268 	return 0;
1269 }
1270 
1271 static int snd_timer_user_release(struct inode *inode, struct file *file)
1272 {
1273 	struct snd_timer_user *tu;
1274 
1275 	if (file->private_data) {
1276 		tu = file->private_data;
1277 		file->private_data = NULL;
1278 		if (tu->timeri)
1279 			snd_timer_close(tu->timeri);
1280 		kfree(tu->queue);
1281 		kfree(tu->tqueue);
1282 		kfree(tu);
1283 	}
1284 	return 0;
1285 }
1286 
1287 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1288 {
1289 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1290 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1291 	id->card = -1;
1292 	id->device = -1;
1293 	id->subdevice = -1;
1294 }
1295 
1296 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1297 {
1298 	id->dev_class = timer->tmr_class;
1299 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1300 	id->card = timer->card ? timer->card->number : -1;
1301 	id->device = timer->tmr_device;
1302 	id->subdevice = timer->tmr_subdevice;
1303 }
1304 
1305 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1306 {
1307 	struct snd_timer_id id;
1308 	struct snd_timer *timer;
1309 	struct list_head *p;
1310 
1311 	if (copy_from_user(&id, _tid, sizeof(id)))
1312 		return -EFAULT;
1313 	mutex_lock(&register_mutex);
1314 	if (id.dev_class < 0) {		/* first item */
1315 		if (list_empty(&snd_timer_list))
1316 			snd_timer_user_zero_id(&id);
1317 		else {
1318 			timer = list_entry(snd_timer_list.next,
1319 					   struct snd_timer, device_list);
1320 			snd_timer_user_copy_id(&id, timer);
1321 		}
1322 	} else {
1323 		switch (id.dev_class) {
1324 		case SNDRV_TIMER_CLASS_GLOBAL:
1325 			id.device = id.device < 0 ? 0 : id.device + 1;
1326 			list_for_each(p, &snd_timer_list) {
1327 				timer = list_entry(p, struct snd_timer, device_list);
1328 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1329 					snd_timer_user_copy_id(&id, timer);
1330 					break;
1331 				}
1332 				if (timer->tmr_device >= id.device) {
1333 					snd_timer_user_copy_id(&id, timer);
1334 					break;
1335 				}
1336 			}
1337 			if (p == &snd_timer_list)
1338 				snd_timer_user_zero_id(&id);
1339 			break;
1340 		case SNDRV_TIMER_CLASS_CARD:
1341 		case SNDRV_TIMER_CLASS_PCM:
1342 			if (id.card < 0) {
1343 				id.card = 0;
1344 			} else {
1345 				if (id.card < 0) {
1346 					id.card = 0;
1347 				} else {
1348 					if (id.device < 0) {
1349 						id.device = 0;
1350 					} else {
1351 						if (id.subdevice < 0) {
1352 							id.subdevice = 0;
1353 						} else {
1354 							id.subdevice++;
1355 						}
1356 					}
1357 				}
1358 			}
1359 			list_for_each(p, &snd_timer_list) {
1360 				timer = list_entry(p, struct snd_timer, device_list);
1361 				if (timer->tmr_class > id.dev_class) {
1362 					snd_timer_user_copy_id(&id, timer);
1363 					break;
1364 				}
1365 				if (timer->tmr_class < id.dev_class)
1366 					continue;
1367 				if (timer->card->number > id.card) {
1368 					snd_timer_user_copy_id(&id, timer);
1369 					break;
1370 				}
1371 				if (timer->card->number < id.card)
1372 					continue;
1373 				if (timer->tmr_device > id.device) {
1374 					snd_timer_user_copy_id(&id, timer);
1375 					break;
1376 				}
1377 				if (timer->tmr_device < id.device)
1378 					continue;
1379 				if (timer->tmr_subdevice > id.subdevice) {
1380 					snd_timer_user_copy_id(&id, timer);
1381 					break;
1382 				}
1383 				if (timer->tmr_subdevice < id.subdevice)
1384 					continue;
1385 				snd_timer_user_copy_id(&id, timer);
1386 				break;
1387 			}
1388 			if (p == &snd_timer_list)
1389 				snd_timer_user_zero_id(&id);
1390 			break;
1391 		default:
1392 			snd_timer_user_zero_id(&id);
1393 		}
1394 	}
1395 	mutex_unlock(&register_mutex);
1396 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1397 		return -EFAULT;
1398 	return 0;
1399 }
1400 
1401 static int snd_timer_user_ginfo(struct file *file,
1402 				struct snd_timer_ginfo __user *_ginfo)
1403 {
1404 	struct snd_timer_ginfo *ginfo;
1405 	struct snd_timer_id tid;
1406 	struct snd_timer *t;
1407 	struct list_head *p;
1408 	int err = 0;
1409 
1410 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1411 	if (IS_ERR(ginfo))
1412 		return PTR_ERR(ginfo);
1413 
1414 	tid = ginfo->tid;
1415 	memset(ginfo, 0, sizeof(*ginfo));
1416 	ginfo->tid = tid;
1417 	mutex_lock(&register_mutex);
1418 	t = snd_timer_find(&tid);
1419 	if (t != NULL) {
1420 		ginfo->card = t->card ? t->card->number : -1;
1421 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1422 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1423 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1424 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1425 		ginfo->resolution = t->hw.resolution;
1426 		if (t->hw.resolution_min > 0) {
1427 			ginfo->resolution_min = t->hw.resolution_min;
1428 			ginfo->resolution_max = t->hw.resolution_max;
1429 		}
1430 		list_for_each(p, &t->open_list_head) {
1431 			ginfo->clients++;
1432 		}
1433 	} else {
1434 		err = -ENODEV;
1435 	}
1436 	mutex_unlock(&register_mutex);
1437 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1438 		err = -EFAULT;
1439 	kfree(ginfo);
1440 	return err;
1441 }
1442 
1443 static int snd_timer_user_gparams(struct file *file,
1444 				  struct snd_timer_gparams __user *_gparams)
1445 {
1446 	struct snd_timer_gparams gparams;
1447 	struct snd_timer *t;
1448 	int err;
1449 
1450 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1451 		return -EFAULT;
1452 	mutex_lock(&register_mutex);
1453 	t = snd_timer_find(&gparams.tid);
1454 	if (!t) {
1455 		err = -ENODEV;
1456 		goto _error;
1457 	}
1458 	if (!list_empty(&t->open_list_head)) {
1459 		err = -EBUSY;
1460 		goto _error;
1461 	}
1462 	if (!t->hw.set_period) {
1463 		err = -ENOSYS;
1464 		goto _error;
1465 	}
1466 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1467 _error:
1468 	mutex_unlock(&register_mutex);
1469 	return err;
1470 }
1471 
1472 static int snd_timer_user_gstatus(struct file *file,
1473 				  struct snd_timer_gstatus __user *_gstatus)
1474 {
1475 	struct snd_timer_gstatus gstatus;
1476 	struct snd_timer_id tid;
1477 	struct snd_timer *t;
1478 	int err = 0;
1479 
1480 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1481 		return -EFAULT;
1482 	tid = gstatus.tid;
1483 	memset(&gstatus, 0, sizeof(gstatus));
1484 	gstatus.tid = tid;
1485 	mutex_lock(&register_mutex);
1486 	t = snd_timer_find(&tid);
1487 	if (t != NULL) {
1488 		if (t->hw.c_resolution)
1489 			gstatus.resolution = t->hw.c_resolution(t);
1490 		else
1491 			gstatus.resolution = t->hw.resolution;
1492 		if (t->hw.precise_resolution) {
1493 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1494 						 &gstatus.resolution_den);
1495 		} else {
1496 			gstatus.resolution_num = gstatus.resolution;
1497 			gstatus.resolution_den = 1000000000uL;
1498 		}
1499 	} else {
1500 		err = -ENODEV;
1501 	}
1502 	mutex_unlock(&register_mutex);
1503 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1504 		err = -EFAULT;
1505 	return err;
1506 }
1507 
1508 static int snd_timer_user_tselect(struct file *file,
1509 				  struct snd_timer_select __user *_tselect)
1510 {
1511 	struct snd_timer_user *tu;
1512 	struct snd_timer_select tselect;
1513 	char str[32];
1514 	int err = 0;
1515 
1516 	tu = file->private_data;
1517 	mutex_lock(&tu->tread_sem);
1518 	if (tu->timeri) {
1519 		snd_timer_close(tu->timeri);
1520 		tu->timeri = NULL;
1521 	}
1522 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1523 		err = -EFAULT;
1524 		goto __err;
1525 	}
1526 	sprintf(str, "application %i", current->pid);
1527 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1528 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1529 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1530 	if (err < 0)
1531 		goto __err;
1532 
1533 	kfree(tu->queue);
1534 	tu->queue = NULL;
1535 	kfree(tu->tqueue);
1536 	tu->tqueue = NULL;
1537 	if (tu->tread) {
1538 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1539 				     GFP_KERNEL);
1540 		if (tu->tqueue == NULL)
1541 			err = -ENOMEM;
1542 	} else {
1543 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1544 				    GFP_KERNEL);
1545 		if (tu->queue == NULL)
1546 			err = -ENOMEM;
1547 	}
1548 
1549       	if (err < 0) {
1550 		snd_timer_close(tu->timeri);
1551       		tu->timeri = NULL;
1552       	} else {
1553 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1554 		tu->timeri->callback = tu->tread
1555 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1556 		tu->timeri->ccallback = snd_timer_user_ccallback;
1557 		tu->timeri->callback_data = (void *)tu;
1558 	}
1559 
1560       __err:
1561       	mutex_unlock(&tu->tread_sem);
1562 	return err;
1563 }
1564 
1565 static int snd_timer_user_info(struct file *file,
1566 			       struct snd_timer_info __user *_info)
1567 {
1568 	struct snd_timer_user *tu;
1569 	struct snd_timer_info *info;
1570 	struct snd_timer *t;
1571 	int err = 0;
1572 
1573 	tu = file->private_data;
1574 	if (!tu->timeri)
1575 		return -EBADFD;
1576 	t = tu->timeri->timer;
1577 	if (!t)
1578 		return -EBADFD;
1579 
1580 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1581 	if (! info)
1582 		return -ENOMEM;
1583 	info->card = t->card ? t->card->number : -1;
1584 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1585 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1586 	strlcpy(info->id, t->id, sizeof(info->id));
1587 	strlcpy(info->name, t->name, sizeof(info->name));
1588 	info->resolution = t->hw.resolution;
1589 	if (copy_to_user(_info, info, sizeof(*_info)))
1590 		err = -EFAULT;
1591 	kfree(info);
1592 	return err;
1593 }
1594 
1595 static int snd_timer_user_params(struct file *file,
1596 				 struct snd_timer_params __user *_params)
1597 {
1598 	struct snd_timer_user *tu;
1599 	struct snd_timer_params params;
1600 	struct snd_timer *t;
1601 	struct snd_timer_read *tr;
1602 	struct snd_timer_tread *ttr;
1603 	int err;
1604 
1605 	tu = file->private_data;
1606 	if (!tu->timeri)
1607 		return -EBADFD;
1608 	t = tu->timeri->timer;
1609 	if (!t)
1610 		return -EBADFD;
1611 	if (copy_from_user(&params, _params, sizeof(params)))
1612 		return -EFAULT;
1613 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1614 		err = -EINVAL;
1615 		goto _end;
1616 	}
1617 	if (params.queue_size > 0 &&
1618 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1619 		err = -EINVAL;
1620 		goto _end;
1621 	}
1622 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1623 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1624 			      (1<<SNDRV_TIMER_EVENT_START)|
1625 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1626 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1627 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1628 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1629 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1630 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1631 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1632 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1633 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1634 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1635 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1636 		err = -EINVAL;
1637 		goto _end;
1638 	}
1639 	snd_timer_stop(tu->timeri);
1640 	spin_lock_irq(&t->lock);
1641 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1642 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1643 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1644 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1645 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1646 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1647 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1648 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1649 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1650 	spin_unlock_irq(&t->lock);
1651 	if (params.queue_size > 0 &&
1652 	    (unsigned int)tu->queue_size != params.queue_size) {
1653 		if (tu->tread) {
1654 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1655 				      GFP_KERNEL);
1656 			if (ttr) {
1657 				kfree(tu->tqueue);
1658 				tu->queue_size = params.queue_size;
1659 				tu->tqueue = ttr;
1660 			}
1661 		} else {
1662 			tr = kmalloc(params.queue_size * sizeof(*tr),
1663 				     GFP_KERNEL);
1664 			if (tr) {
1665 				kfree(tu->queue);
1666 				tu->queue_size = params.queue_size;
1667 				tu->queue = tr;
1668 			}
1669 		}
1670 	}
1671 	tu->qhead = tu->qtail = tu->qused = 0;
1672 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1673 		if (tu->tread) {
1674 			struct snd_timer_tread tread;
1675 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1676 			tread.tstamp.tv_sec = 0;
1677 			tread.tstamp.tv_nsec = 0;
1678 			tread.val = 0;
1679 			snd_timer_user_append_to_tqueue(tu, &tread);
1680 		} else {
1681 			struct snd_timer_read *r = &tu->queue[0];
1682 			r->resolution = 0;
1683 			r->ticks = 0;
1684 			tu->qused++;
1685 			tu->qtail++;
1686 		}
1687 	}
1688 	tu->filter = params.filter;
1689 	tu->ticks = params.ticks;
1690 	err = 0;
1691  _end:
1692 	if (copy_to_user(_params, &params, sizeof(params)))
1693 		return -EFAULT;
1694 	return err;
1695 }
1696 
1697 static int snd_timer_user_status(struct file *file,
1698 				 struct snd_timer_status __user *_status)
1699 {
1700 	struct snd_timer_user *tu;
1701 	struct snd_timer_status status;
1702 
1703 	tu = file->private_data;
1704 	if (!tu->timeri)
1705 		return -EBADFD;
1706 	memset(&status, 0, sizeof(status));
1707 	status.tstamp = tu->tstamp;
1708 	status.resolution = snd_timer_resolution(tu->timeri);
1709 	status.lost = tu->timeri->lost;
1710 	status.overrun = tu->overrun;
1711 	spin_lock_irq(&tu->qlock);
1712 	status.queue = tu->qused;
1713 	spin_unlock_irq(&tu->qlock);
1714 	if (copy_to_user(_status, &status, sizeof(status)))
1715 		return -EFAULT;
1716 	return 0;
1717 }
1718 
1719 static int snd_timer_user_start(struct file *file)
1720 {
1721 	int err;
1722 	struct snd_timer_user *tu;
1723 
1724 	tu = file->private_data;
1725 	if (!tu->timeri)
1726 		return -EBADFD;
1727 	snd_timer_stop(tu->timeri);
1728 	tu->timeri->lost = 0;
1729 	tu->last_resolution = 0;
1730 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1731 }
1732 
1733 static int snd_timer_user_stop(struct file *file)
1734 {
1735 	int err;
1736 	struct snd_timer_user *tu;
1737 
1738 	tu = file->private_data;
1739 	if (!tu->timeri)
1740 		return -EBADFD;
1741 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1742 }
1743 
1744 static int snd_timer_user_continue(struct file *file)
1745 {
1746 	int err;
1747 	struct snd_timer_user *tu;
1748 
1749 	tu = file->private_data;
1750 	if (!tu->timeri)
1751 		return -EBADFD;
1752 	tu->timeri->lost = 0;
1753 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1754 }
1755 
1756 static int snd_timer_user_pause(struct file *file)
1757 {
1758 	int err;
1759 	struct snd_timer_user *tu;
1760 
1761 	tu = file->private_data;
1762 	if (!tu->timeri)
1763 		return -EBADFD;
1764 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1765 }
1766 
1767 enum {
1768 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1769 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1770 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1771 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1772 };
1773 
1774 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1775 				 unsigned long arg)
1776 {
1777 	struct snd_timer_user *tu;
1778 	void __user *argp = (void __user *)arg;
1779 	int __user *p = argp;
1780 
1781 	tu = file->private_data;
1782 	switch (cmd) {
1783 	case SNDRV_TIMER_IOCTL_PVERSION:
1784 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1785 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1786 		return snd_timer_user_next_device(argp);
1787 	case SNDRV_TIMER_IOCTL_TREAD:
1788 	{
1789 		int xarg;
1790 
1791 		mutex_lock(&tu->tread_sem);
1792 		if (tu->timeri)	{	/* too late */
1793 			mutex_unlock(&tu->tread_sem);
1794 			return -EBUSY;
1795 		}
1796 		if (get_user(xarg, p)) {
1797 			mutex_unlock(&tu->tread_sem);
1798 			return -EFAULT;
1799 		}
1800 		tu->tread = xarg ? 1 : 0;
1801 		mutex_unlock(&tu->tread_sem);
1802 		return 0;
1803 	}
1804 	case SNDRV_TIMER_IOCTL_GINFO:
1805 		return snd_timer_user_ginfo(file, argp);
1806 	case SNDRV_TIMER_IOCTL_GPARAMS:
1807 		return snd_timer_user_gparams(file, argp);
1808 	case SNDRV_TIMER_IOCTL_GSTATUS:
1809 		return snd_timer_user_gstatus(file, argp);
1810 	case SNDRV_TIMER_IOCTL_SELECT:
1811 		return snd_timer_user_tselect(file, argp);
1812 	case SNDRV_TIMER_IOCTL_INFO:
1813 		return snd_timer_user_info(file, argp);
1814 	case SNDRV_TIMER_IOCTL_PARAMS:
1815 		return snd_timer_user_params(file, argp);
1816 	case SNDRV_TIMER_IOCTL_STATUS:
1817 		return snd_timer_user_status(file, argp);
1818 	case SNDRV_TIMER_IOCTL_START:
1819 	case SNDRV_TIMER_IOCTL_START_OLD:
1820 		return snd_timer_user_start(file);
1821 	case SNDRV_TIMER_IOCTL_STOP:
1822 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1823 		return snd_timer_user_stop(file);
1824 	case SNDRV_TIMER_IOCTL_CONTINUE:
1825 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1826 		return snd_timer_user_continue(file);
1827 	case SNDRV_TIMER_IOCTL_PAUSE:
1828 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1829 		return snd_timer_user_pause(file);
1830 	}
1831 	return -ENOTTY;
1832 }
1833 
1834 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1835 {
1836 	struct snd_timer_user *tu;
1837 
1838 	tu = file->private_data;
1839 	return fasync_helper(fd, file, on, &tu->fasync);
1840 }
1841 
1842 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1843 				   size_t count, loff_t *offset)
1844 {
1845 	struct snd_timer_user *tu;
1846 	long result = 0, unit;
1847 	int err = 0;
1848 
1849 	tu = file->private_data;
1850 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1851 	spin_lock_irq(&tu->qlock);
1852 	while ((long)count - result >= unit) {
1853 		while (!tu->qused) {
1854 			wait_queue_t wait;
1855 
1856 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1857 				err = -EAGAIN;
1858 				break;
1859 			}
1860 
1861 			set_current_state(TASK_INTERRUPTIBLE);
1862 			init_waitqueue_entry(&wait, current);
1863 			add_wait_queue(&tu->qchange_sleep, &wait);
1864 
1865 			spin_unlock_irq(&tu->qlock);
1866 			schedule();
1867 			spin_lock_irq(&tu->qlock);
1868 
1869 			remove_wait_queue(&tu->qchange_sleep, &wait);
1870 
1871 			if (signal_pending(current)) {
1872 				err = -ERESTARTSYS;
1873 				break;
1874 			}
1875 		}
1876 
1877 		spin_unlock_irq(&tu->qlock);
1878 		if (err < 0)
1879 			goto _error;
1880 
1881 		if (tu->tread) {
1882 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1883 					 sizeof(struct snd_timer_tread))) {
1884 				err = -EFAULT;
1885 				goto _error;
1886 			}
1887 		} else {
1888 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1889 					 sizeof(struct snd_timer_read))) {
1890 				err = -EFAULT;
1891 				goto _error;
1892 			}
1893 		}
1894 
1895 		tu->qhead %= tu->queue_size;
1896 
1897 		result += unit;
1898 		buffer += unit;
1899 
1900 		spin_lock_irq(&tu->qlock);
1901 		tu->qused--;
1902 	}
1903 	spin_unlock_irq(&tu->qlock);
1904  _error:
1905 	return result > 0 ? result : err;
1906 }
1907 
1908 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1909 {
1910         unsigned int mask;
1911         struct snd_timer_user *tu;
1912 
1913         tu = file->private_data;
1914 
1915         poll_wait(file, &tu->qchange_sleep, wait);
1916 
1917 	mask = 0;
1918 	if (tu->qused)
1919 		mask |= POLLIN | POLLRDNORM;
1920 
1921 	return mask;
1922 }
1923 
1924 #ifdef CONFIG_COMPAT
1925 #include "timer_compat.c"
1926 #else
1927 #define snd_timer_user_ioctl_compat	NULL
1928 #endif
1929 
1930 static const struct file_operations snd_timer_f_ops =
1931 {
1932 	.owner =	THIS_MODULE,
1933 	.read =		snd_timer_user_read,
1934 	.open =		snd_timer_user_open,
1935 	.release =	snd_timer_user_release,
1936 	.llseek =	no_llseek,
1937 	.poll =		snd_timer_user_poll,
1938 	.unlocked_ioctl =	snd_timer_user_ioctl,
1939 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1940 	.fasync = 	snd_timer_user_fasync,
1941 };
1942 
1943 /*
1944  *  ENTRY functions
1945  */
1946 
1947 static int __init alsa_timer_init(void)
1948 {
1949 	int err;
1950 
1951 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1952 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1953 			      "system timer");
1954 #endif
1955 
1956 	if ((err = snd_timer_register_system()) < 0)
1957 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1958 			   err);
1959 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1960 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1961 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1962 			   err);
1963 	snd_timer_proc_init();
1964 	return 0;
1965 }
1966 
1967 static void __exit alsa_timer_exit(void)
1968 {
1969 	struct list_head *p, *n;
1970 
1971 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1972 	/* unregister the system timer */
1973 	list_for_each_safe(p, n, &snd_timer_list) {
1974 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1975 		snd_timer_free(timer);
1976 	}
1977 	snd_timer_proc_done();
1978 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1979 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1980 #endif
1981 }
1982 
1983 module_init(alsa_timer_init)
1984 module_exit(alsa_timer_exit)
1985 
1986 EXPORT_SYMBOL(snd_timer_open);
1987 EXPORT_SYMBOL(snd_timer_close);
1988 EXPORT_SYMBOL(snd_timer_resolution);
1989 EXPORT_SYMBOL(snd_timer_start);
1990 EXPORT_SYMBOL(snd_timer_stop);
1991 EXPORT_SYMBOL(snd_timer_continue);
1992 EXPORT_SYMBOL(snd_timer_pause);
1993 EXPORT_SYMBOL(snd_timer_new);
1994 EXPORT_SYMBOL(snd_timer_notify);
1995 EXPORT_SYMBOL(snd_timer_global_new);
1996 EXPORT_SYMBOL(snd_timer_global_free);
1997 EXPORT_SYMBOL(snd_timer_global_register);
1998 EXPORT_SYMBOL(snd_timer_interrupt);
1999