xref: /openbmc/linux/sound/core/timer.c (revision 8e9356c6)
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/device.h>
28 #include <linux/module.h>
29 #include <linux/string.h>
30 #include <sound/core.h>
31 #include <sound/timer.h>
32 #include <sound/control.h>
33 #include <sound/info.h>
34 #include <sound/minors.h>
35 #include <sound/initval.h>
36 #include <linux/kmod.h>
37 
38 #if defined(CONFIG_SND_HRTIMER) || defined(CONFIG_SND_HRTIMER_MODULE)
39 #define DEFAULT_TIMER_LIMIT 4
40 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
41 #define DEFAULT_TIMER_LIMIT 2
42 #else
43 #define DEFAULT_TIMER_LIMIT 1
44 #endif
45 
46 static int timer_limit = DEFAULT_TIMER_LIMIT;
47 static int timer_tstamp_monotonic = 1;
48 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
49 MODULE_DESCRIPTION("ALSA timer interface");
50 MODULE_LICENSE("GPL");
51 module_param(timer_limit, int, 0444);
52 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
53 module_param(timer_tstamp_monotonic, int, 0444);
54 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
55 
56 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
57 MODULE_ALIAS("devname:snd/timer");
58 
59 struct snd_timer_user {
60 	struct snd_timer_instance *timeri;
61 	int tread;		/* enhanced read with timestamps and events */
62 	unsigned long ticks;
63 	unsigned long overrun;
64 	int qhead;
65 	int qtail;
66 	int qused;
67 	int queue_size;
68 	struct snd_timer_read *queue;
69 	struct snd_timer_tread *tqueue;
70 	spinlock_t qlock;
71 	unsigned long last_resolution;
72 	unsigned int filter;
73 	struct timespec tstamp;		/* trigger tstamp */
74 	wait_queue_head_t qchange_sleep;
75 	struct fasync_struct *fasync;
76 	struct mutex tread_sem;
77 };
78 
79 /* list of timers */
80 static LIST_HEAD(snd_timer_list);
81 
82 /* list of slave instances */
83 static LIST_HEAD(snd_timer_slave_list);
84 
85 /* lock for slave active lists */
86 static DEFINE_SPINLOCK(slave_active_lock);
87 
88 static DEFINE_MUTEX(register_mutex);
89 
90 static int snd_timer_free(struct snd_timer *timer);
91 static int snd_timer_dev_free(struct snd_device *device);
92 static int snd_timer_dev_register(struct snd_device *device);
93 static int snd_timer_dev_disconnect(struct snd_device *device);
94 
95 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
96 
97 /*
98  * create a timer instance with the given owner string.
99  * when timer is not NULL, increments the module counter
100  */
101 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
102 							 struct snd_timer *timer)
103 {
104 	struct snd_timer_instance *timeri;
105 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
106 	if (timeri == NULL)
107 		return NULL;
108 	timeri->owner = kstrdup(owner, GFP_KERNEL);
109 	if (! timeri->owner) {
110 		kfree(timeri);
111 		return NULL;
112 	}
113 	INIT_LIST_HEAD(&timeri->open_list);
114 	INIT_LIST_HEAD(&timeri->active_list);
115 	INIT_LIST_HEAD(&timeri->ack_list);
116 	INIT_LIST_HEAD(&timeri->slave_list_head);
117 	INIT_LIST_HEAD(&timeri->slave_active_head);
118 
119 	timeri->timer = timer;
120 	if (timer && !try_module_get(timer->module)) {
121 		kfree(timeri->owner);
122 		kfree(timeri);
123 		return NULL;
124 	}
125 
126 	return timeri;
127 }
128 
129 /*
130  * find a timer instance from the given timer id
131  */
132 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
133 {
134 	struct snd_timer *timer = NULL;
135 
136 	list_for_each_entry(timer, &snd_timer_list, device_list) {
137 		if (timer->tmr_class != tid->dev_class)
138 			continue;
139 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
140 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
141 		    (timer->card == NULL ||
142 		     timer->card->number != tid->card))
143 			continue;
144 		if (timer->tmr_device != tid->device)
145 			continue;
146 		if (timer->tmr_subdevice != tid->subdevice)
147 			continue;
148 		return timer;
149 	}
150 	return NULL;
151 }
152 
153 #ifdef CONFIG_MODULES
154 
155 static void snd_timer_request(struct snd_timer_id *tid)
156 {
157 	switch (tid->dev_class) {
158 	case SNDRV_TIMER_CLASS_GLOBAL:
159 		if (tid->device < timer_limit)
160 			request_module("snd-timer-%i", tid->device);
161 		break;
162 	case SNDRV_TIMER_CLASS_CARD:
163 	case SNDRV_TIMER_CLASS_PCM:
164 		if (tid->card < snd_ecards_limit)
165 			request_module("snd-card-%i", tid->card);
166 		break;
167 	default:
168 		break;
169 	}
170 }
171 
172 #endif
173 
174 /*
175  * look for a master instance matching with the slave id of the given slave.
176  * when found, relink the open_link of the slave.
177  *
178  * call this with register_mutex down.
179  */
180 static void snd_timer_check_slave(struct snd_timer_instance *slave)
181 {
182 	struct snd_timer *timer;
183 	struct snd_timer_instance *master;
184 
185 	/* FIXME: it's really dumb to look up all entries.. */
186 	list_for_each_entry(timer, &snd_timer_list, device_list) {
187 		list_for_each_entry(master, &timer->open_list_head, open_list) {
188 			if (slave->slave_class == master->slave_class &&
189 			    slave->slave_id == master->slave_id) {
190 				list_move_tail(&slave->open_list,
191 					       &master->slave_list_head);
192 				spin_lock_irq(&slave_active_lock);
193 				slave->master = master;
194 				slave->timer = master->timer;
195 				spin_unlock_irq(&slave_active_lock);
196 				return;
197 			}
198 		}
199 	}
200 }
201 
202 /*
203  * look for slave instances matching with the slave id of the given master.
204  * when found, relink the open_link of slaves.
205  *
206  * call this with register_mutex down.
207  */
208 static void snd_timer_check_master(struct snd_timer_instance *master)
209 {
210 	struct snd_timer_instance *slave, *tmp;
211 
212 	/* check all pending slaves */
213 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
214 		if (slave->slave_class == master->slave_class &&
215 		    slave->slave_id == master->slave_id) {
216 			list_move_tail(&slave->open_list, &master->slave_list_head);
217 			spin_lock_irq(&slave_active_lock);
218 			slave->master = master;
219 			slave->timer = master->timer;
220 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
221 				list_add_tail(&slave->active_list,
222 					      &master->slave_active_head);
223 			spin_unlock_irq(&slave_active_lock);
224 		}
225 	}
226 }
227 
228 /*
229  * open a timer instance
230  * when opening a master, the slave id must be here given.
231  */
232 int snd_timer_open(struct snd_timer_instance **ti,
233 		   char *owner, struct snd_timer_id *tid,
234 		   unsigned int slave_id)
235 {
236 	struct snd_timer *timer;
237 	struct snd_timer_instance *timeri = NULL;
238 
239 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
240 		/* open a slave instance */
241 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
242 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
243 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
244 			return -EINVAL;
245 		}
246 		mutex_lock(&register_mutex);
247 		timeri = snd_timer_instance_new(owner, NULL);
248 		if (!timeri) {
249 			mutex_unlock(&register_mutex);
250 			return -ENOMEM;
251 		}
252 		timeri->slave_class = tid->dev_sclass;
253 		timeri->slave_id = tid->device;
254 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
255 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
256 		snd_timer_check_slave(timeri);
257 		mutex_unlock(&register_mutex);
258 		*ti = timeri;
259 		return 0;
260 	}
261 
262 	/* open a master instance */
263 	mutex_lock(&register_mutex);
264 	timer = snd_timer_find(tid);
265 #ifdef CONFIG_MODULES
266 	if (!timer) {
267 		mutex_unlock(&register_mutex);
268 		snd_timer_request(tid);
269 		mutex_lock(&register_mutex);
270 		timer = snd_timer_find(tid);
271 	}
272 #endif
273 	if (!timer) {
274 		mutex_unlock(&register_mutex);
275 		return -ENODEV;
276 	}
277 	if (!list_empty(&timer->open_list_head)) {
278 		timeri = list_entry(timer->open_list_head.next,
279 				    struct snd_timer_instance, open_list);
280 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
281 			mutex_unlock(&register_mutex);
282 			return -EBUSY;
283 		}
284 	}
285 	timeri = snd_timer_instance_new(owner, timer);
286 	if (!timeri) {
287 		mutex_unlock(&register_mutex);
288 		return -ENOMEM;
289 	}
290 	timeri->slave_class = tid->dev_sclass;
291 	timeri->slave_id = slave_id;
292 	if (list_empty(&timer->open_list_head) && timer->hw.open)
293 		timer->hw.open(timer);
294 	list_add_tail(&timeri->open_list, &timer->open_list_head);
295 	snd_timer_check_master(timeri);
296 	mutex_unlock(&register_mutex);
297 	*ti = timeri;
298 	return 0;
299 }
300 
301 static int _snd_timer_stop(struct snd_timer_instance *timeri,
302 			   int keep_flag, int event);
303 
304 /*
305  * close a timer instance
306  */
307 int snd_timer_close(struct snd_timer_instance *timeri)
308 {
309 	struct snd_timer *timer = NULL;
310 	struct snd_timer_instance *slave, *tmp;
311 
312 	if (snd_BUG_ON(!timeri))
313 		return -ENXIO;
314 
315 	/* force to stop the timer */
316 	snd_timer_stop(timeri);
317 
318 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
319 		/* wait, until the active callback is finished */
320 		spin_lock_irq(&slave_active_lock);
321 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
322 			spin_unlock_irq(&slave_active_lock);
323 			udelay(10);
324 			spin_lock_irq(&slave_active_lock);
325 		}
326 		spin_unlock_irq(&slave_active_lock);
327 		mutex_lock(&register_mutex);
328 		list_del(&timeri->open_list);
329 		mutex_unlock(&register_mutex);
330 	} else {
331 		timer = timeri->timer;
332 		if (snd_BUG_ON(!timer))
333 			goto out;
334 		/* wait, until the active callback is finished */
335 		spin_lock_irq(&timer->lock);
336 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
337 			spin_unlock_irq(&timer->lock);
338 			udelay(10);
339 			spin_lock_irq(&timer->lock);
340 		}
341 		spin_unlock_irq(&timer->lock);
342 		mutex_lock(&register_mutex);
343 		list_del(&timeri->open_list);
344 		if (timer && list_empty(&timer->open_list_head) &&
345 		    timer->hw.close)
346 			timer->hw.close(timer);
347 		/* remove slave links */
348 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
349 					 open_list) {
350 			spin_lock_irq(&slave_active_lock);
351 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
352 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
353 			slave->master = NULL;
354 			slave->timer = NULL;
355 			spin_unlock_irq(&slave_active_lock);
356 		}
357 		mutex_unlock(&register_mutex);
358 	}
359  out:
360 	if (timeri->private_free)
361 		timeri->private_free(timeri);
362 	kfree(timeri->owner);
363 	kfree(timeri);
364 	if (timer)
365 		module_put(timer->module);
366 	return 0;
367 }
368 
369 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
370 {
371 	struct snd_timer * timer;
372 
373 	if (timeri == NULL)
374 		return 0;
375 	if ((timer = timeri->timer) != NULL) {
376 		if (timer->hw.c_resolution)
377 			return timer->hw.c_resolution(timer);
378 		return timer->hw.resolution;
379 	}
380 	return 0;
381 }
382 
383 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
384 {
385 	struct snd_timer *timer;
386 	unsigned long flags;
387 	unsigned long resolution = 0;
388 	struct snd_timer_instance *ts;
389 	struct timespec tstamp;
390 
391 	if (timer_tstamp_monotonic)
392 		do_posix_clock_monotonic_gettime(&tstamp);
393 	else
394 		getnstimeofday(&tstamp);
395 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
396 		       event > SNDRV_TIMER_EVENT_PAUSE))
397 		return;
398 	if (event == SNDRV_TIMER_EVENT_START ||
399 	    event == SNDRV_TIMER_EVENT_CONTINUE)
400 		resolution = snd_timer_resolution(ti);
401 	if (ti->ccallback)
402 		ti->ccallback(ti, event, &tstamp, resolution);
403 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
404 		return;
405 	timer = ti->timer;
406 	if (timer == NULL)
407 		return;
408 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
409 		return;
410 	spin_lock_irqsave(&timer->lock, flags);
411 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
412 		if (ts->ccallback)
413 			ts->ccallback(ti, event + 100, &tstamp, resolution);
414 	spin_unlock_irqrestore(&timer->lock, flags);
415 }
416 
417 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
418 			    unsigned long sticks)
419 {
420 	list_move_tail(&timeri->active_list, &timer->active_list_head);
421 	if (timer->running) {
422 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
423 			goto __start_now;
424 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
425 		timeri->flags |= SNDRV_TIMER_IFLG_START;
426 		return 1;	/* delayed start */
427 	} else {
428 		timer->sticks = sticks;
429 		timer->hw.start(timer);
430 	      __start_now:
431 		timer->running++;
432 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
433 		return 0;
434 	}
435 }
436 
437 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
438 {
439 	unsigned long flags;
440 
441 	spin_lock_irqsave(&slave_active_lock, flags);
442 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
443 	if (timeri->master)
444 		list_add_tail(&timeri->active_list,
445 			      &timeri->master->slave_active_head);
446 	spin_unlock_irqrestore(&slave_active_lock, flags);
447 	return 1; /* delayed start */
448 }
449 
450 /*
451  *  start the timer instance
452  */
453 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
454 {
455 	struct snd_timer *timer;
456 	int result = -EINVAL;
457 	unsigned long flags;
458 
459 	if (timeri == NULL || ticks < 1)
460 		return -EINVAL;
461 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
462 		result = snd_timer_start_slave(timeri);
463 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
464 		return result;
465 	}
466 	timer = timeri->timer;
467 	if (timer == NULL)
468 		return -EINVAL;
469 	spin_lock_irqsave(&timer->lock, flags);
470 	timeri->ticks = timeri->cticks = ticks;
471 	timeri->pticks = 0;
472 	result = snd_timer_start1(timer, timeri, ticks);
473 	spin_unlock_irqrestore(&timer->lock, flags);
474 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
475 	return result;
476 }
477 
478 static int _snd_timer_stop(struct snd_timer_instance * timeri,
479 			   int keep_flag, int event)
480 {
481 	struct snd_timer *timer;
482 	unsigned long flags;
483 
484 	if (snd_BUG_ON(!timeri))
485 		return -ENXIO;
486 
487 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
488 		if (!keep_flag) {
489 			spin_lock_irqsave(&slave_active_lock, flags);
490 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
491 			spin_unlock_irqrestore(&slave_active_lock, flags);
492 		}
493 		goto __end;
494 	}
495 	timer = timeri->timer;
496 	if (!timer)
497 		return -EINVAL;
498 	spin_lock_irqsave(&timer->lock, flags);
499 	list_del_init(&timeri->ack_list);
500 	list_del_init(&timeri->active_list);
501 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
502 	    !(--timer->running)) {
503 		timer->hw.stop(timer);
504 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
505 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
506 			snd_timer_reschedule(timer, 0);
507 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
508 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
509 				timer->hw.start(timer);
510 			}
511 		}
512 	}
513 	if (!keep_flag)
514 		timeri->flags &=
515 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
516 	spin_unlock_irqrestore(&timer->lock, flags);
517       __end:
518 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
519 		snd_timer_notify1(timeri, event);
520 	return 0;
521 }
522 
523 /*
524  * stop the timer instance.
525  *
526  * do not call this from the timer callback!
527  */
528 int snd_timer_stop(struct snd_timer_instance *timeri)
529 {
530 	struct snd_timer *timer;
531 	unsigned long flags;
532 	int err;
533 
534 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
535 	if (err < 0)
536 		return err;
537 	timer = timeri->timer;
538 	if (!timer)
539 		return -EINVAL;
540 	spin_lock_irqsave(&timer->lock, flags);
541 	timeri->cticks = timeri->ticks;
542 	timeri->pticks = 0;
543 	spin_unlock_irqrestore(&timer->lock, flags);
544 	return 0;
545 }
546 
547 /*
548  * start again..  the tick is kept.
549  */
550 int snd_timer_continue(struct snd_timer_instance *timeri)
551 {
552 	struct snd_timer *timer;
553 	int result = -EINVAL;
554 	unsigned long flags;
555 
556 	if (timeri == NULL)
557 		return result;
558 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
559 		return snd_timer_start_slave(timeri);
560 	timer = timeri->timer;
561 	if (! timer)
562 		return -EINVAL;
563 	spin_lock_irqsave(&timer->lock, flags);
564 	if (!timeri->cticks)
565 		timeri->cticks = 1;
566 	timeri->pticks = 0;
567 	result = snd_timer_start1(timer, timeri, timer->sticks);
568 	spin_unlock_irqrestore(&timer->lock, flags);
569 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
570 	return result;
571 }
572 
573 /*
574  * pause.. remember the ticks left
575  */
576 int snd_timer_pause(struct snd_timer_instance * timeri)
577 {
578 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
579 }
580 
581 /*
582  * reschedule the timer
583  *
584  * start pending instances and check the scheduling ticks.
585  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
586  */
587 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
588 {
589 	struct snd_timer_instance *ti;
590 	unsigned long ticks = ~0UL;
591 
592 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
593 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
594 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
595 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
596 			timer->running++;
597 		}
598 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
599 			if (ticks > ti->cticks)
600 				ticks = ti->cticks;
601 		}
602 	}
603 	if (ticks == ~0UL) {
604 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
605 		return;
606 	}
607 	if (ticks > timer->hw.ticks)
608 		ticks = timer->hw.ticks;
609 	if (ticks_left != ticks)
610 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
611 	timer->sticks = ticks;
612 }
613 
614 /*
615  * timer tasklet
616  *
617  */
618 static void snd_timer_tasklet(unsigned long arg)
619 {
620 	struct snd_timer *timer = (struct snd_timer *) arg;
621 	struct snd_timer_instance *ti;
622 	struct list_head *p;
623 	unsigned long resolution, ticks;
624 	unsigned long flags;
625 
626 	spin_lock_irqsave(&timer->lock, flags);
627 	/* now process all callbacks */
628 	while (!list_empty(&timer->sack_list_head)) {
629 		p = timer->sack_list_head.next;		/* get first item */
630 		ti = list_entry(p, struct snd_timer_instance, ack_list);
631 
632 		/* remove from ack_list and make empty */
633 		list_del_init(p);
634 
635 		ticks = ti->pticks;
636 		ti->pticks = 0;
637 		resolution = ti->resolution;
638 
639 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
640 		spin_unlock(&timer->lock);
641 		if (ti->callback)
642 			ti->callback(ti, resolution, ticks);
643 		spin_lock(&timer->lock);
644 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
645 	}
646 	spin_unlock_irqrestore(&timer->lock, flags);
647 }
648 
649 /*
650  * timer interrupt
651  *
652  * ticks_left is usually equal to timer->sticks.
653  *
654  */
655 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
656 {
657 	struct snd_timer_instance *ti, *ts, *tmp;
658 	unsigned long resolution, ticks;
659 	struct list_head *p, *ack_list_head;
660 	unsigned long flags;
661 	int use_tasklet = 0;
662 
663 	if (timer == NULL)
664 		return;
665 
666 	spin_lock_irqsave(&timer->lock, flags);
667 
668 	/* remember the current resolution */
669 	if (timer->hw.c_resolution)
670 		resolution = timer->hw.c_resolution(timer);
671 	else
672 		resolution = timer->hw.resolution;
673 
674 	/* loop for all active instances
675 	 * Here we cannot use list_for_each_entry because the active_list of a
676 	 * processed instance is relinked to done_list_head before the callback
677 	 * is called.
678 	 */
679 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
680 				 active_list) {
681 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
682 			continue;
683 		ti->pticks += ticks_left;
684 		ti->resolution = resolution;
685 		if (ti->cticks < ticks_left)
686 			ti->cticks = 0;
687 		else
688 			ti->cticks -= ticks_left;
689 		if (ti->cticks) /* not expired */
690 			continue;
691 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
692 			ti->cticks = ti->ticks;
693 		} else {
694 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
695 			if (--timer->running)
696 				list_del(&ti->active_list);
697 		}
698 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
699 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
700 			ack_list_head = &timer->ack_list_head;
701 		else
702 			ack_list_head = &timer->sack_list_head;
703 		if (list_empty(&ti->ack_list))
704 			list_add_tail(&ti->ack_list, ack_list_head);
705 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
706 			ts->pticks = ti->pticks;
707 			ts->resolution = resolution;
708 			if (list_empty(&ts->ack_list))
709 				list_add_tail(&ts->ack_list, ack_list_head);
710 		}
711 	}
712 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
713 		snd_timer_reschedule(timer, timer->sticks);
714 	if (timer->running) {
715 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
716 			timer->hw.stop(timer);
717 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
718 		}
719 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
720 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
721 			/* restart timer */
722 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
723 			timer->hw.start(timer);
724 		}
725 	} else {
726 		timer->hw.stop(timer);
727 	}
728 
729 	/* now process all fast callbacks */
730 	while (!list_empty(&timer->ack_list_head)) {
731 		p = timer->ack_list_head.next;		/* get first item */
732 		ti = list_entry(p, struct snd_timer_instance, ack_list);
733 
734 		/* remove from ack_list and make empty */
735 		list_del_init(p);
736 
737 		ticks = ti->pticks;
738 		ti->pticks = 0;
739 
740 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
741 		spin_unlock(&timer->lock);
742 		if (ti->callback)
743 			ti->callback(ti, resolution, ticks);
744 		spin_lock(&timer->lock);
745 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
746 	}
747 
748 	/* do we have any slow callbacks? */
749 	use_tasklet = !list_empty(&timer->sack_list_head);
750 	spin_unlock_irqrestore(&timer->lock, flags);
751 
752 	if (use_tasklet)
753 		tasklet_schedule(&timer->task_queue);
754 }
755 
756 /*
757 
758  */
759 
760 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
761 		  struct snd_timer **rtimer)
762 {
763 	struct snd_timer *timer;
764 	int err;
765 	static struct snd_device_ops ops = {
766 		.dev_free = snd_timer_dev_free,
767 		.dev_register = snd_timer_dev_register,
768 		.dev_disconnect = snd_timer_dev_disconnect,
769 	};
770 
771 	if (snd_BUG_ON(!tid))
772 		return -EINVAL;
773 	if (rtimer)
774 		*rtimer = NULL;
775 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
776 	if (timer == NULL) {
777 		snd_printk(KERN_ERR "timer: cannot allocate\n");
778 		return -ENOMEM;
779 	}
780 	timer->tmr_class = tid->dev_class;
781 	timer->card = card;
782 	timer->tmr_device = tid->device;
783 	timer->tmr_subdevice = tid->subdevice;
784 	if (id)
785 		strlcpy(timer->id, id, sizeof(timer->id));
786 	INIT_LIST_HEAD(&timer->device_list);
787 	INIT_LIST_HEAD(&timer->open_list_head);
788 	INIT_LIST_HEAD(&timer->active_list_head);
789 	INIT_LIST_HEAD(&timer->ack_list_head);
790 	INIT_LIST_HEAD(&timer->sack_list_head);
791 	spin_lock_init(&timer->lock);
792 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
793 		     (unsigned long)timer);
794 	if (card != NULL) {
795 		timer->module = card->module;
796 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
797 		if (err < 0) {
798 			snd_timer_free(timer);
799 			return err;
800 		}
801 	}
802 	if (rtimer)
803 		*rtimer = timer;
804 	return 0;
805 }
806 
807 static int snd_timer_free(struct snd_timer *timer)
808 {
809 	if (!timer)
810 		return 0;
811 
812 	mutex_lock(&register_mutex);
813 	if (! list_empty(&timer->open_list_head)) {
814 		struct list_head *p, *n;
815 		struct snd_timer_instance *ti;
816 		snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
817 		list_for_each_safe(p, n, &timer->open_list_head) {
818 			list_del_init(p);
819 			ti = list_entry(p, struct snd_timer_instance, open_list);
820 			ti->timer = NULL;
821 		}
822 	}
823 	list_del(&timer->device_list);
824 	mutex_unlock(&register_mutex);
825 
826 	if (timer->private_free)
827 		timer->private_free(timer);
828 	kfree(timer);
829 	return 0;
830 }
831 
832 static int snd_timer_dev_free(struct snd_device *device)
833 {
834 	struct snd_timer *timer = device->device_data;
835 	return snd_timer_free(timer);
836 }
837 
838 static int snd_timer_dev_register(struct snd_device *dev)
839 {
840 	struct snd_timer *timer = dev->device_data;
841 	struct snd_timer *timer1;
842 
843 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
844 		return -ENXIO;
845 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
846 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
847 	    	return -EINVAL;
848 
849 	mutex_lock(&register_mutex);
850 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
851 		if (timer1->tmr_class > timer->tmr_class)
852 			break;
853 		if (timer1->tmr_class < timer->tmr_class)
854 			continue;
855 		if (timer1->card && timer->card) {
856 			if (timer1->card->number > timer->card->number)
857 				break;
858 			if (timer1->card->number < timer->card->number)
859 				continue;
860 		}
861 		if (timer1->tmr_device > timer->tmr_device)
862 			break;
863 		if (timer1->tmr_device < timer->tmr_device)
864 			continue;
865 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
866 			break;
867 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
868 			continue;
869 		/* conflicts.. */
870 		mutex_unlock(&register_mutex);
871 		return -EBUSY;
872 	}
873 	list_add_tail(&timer->device_list, &timer1->device_list);
874 	mutex_unlock(&register_mutex);
875 	return 0;
876 }
877 
878 static int snd_timer_dev_disconnect(struct snd_device *device)
879 {
880 	struct snd_timer *timer = device->device_data;
881 	mutex_lock(&register_mutex);
882 	list_del_init(&timer->device_list);
883 	mutex_unlock(&register_mutex);
884 	return 0;
885 }
886 
887 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
888 {
889 	unsigned long flags;
890 	unsigned long resolution = 0;
891 	struct snd_timer_instance *ti, *ts;
892 
893 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
894 		return;
895 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
896 		       event > SNDRV_TIMER_EVENT_MRESUME))
897 		return;
898 	spin_lock_irqsave(&timer->lock, flags);
899 	if (event == SNDRV_TIMER_EVENT_MSTART ||
900 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
901 	    event == SNDRV_TIMER_EVENT_MRESUME) {
902 		if (timer->hw.c_resolution)
903 			resolution = timer->hw.c_resolution(timer);
904 		else
905 			resolution = timer->hw.resolution;
906 	}
907 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
908 		if (ti->ccallback)
909 			ti->ccallback(ti, event, tstamp, resolution);
910 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
911 			if (ts->ccallback)
912 				ts->ccallback(ts, event, tstamp, resolution);
913 	}
914 	spin_unlock_irqrestore(&timer->lock, flags);
915 }
916 
917 /*
918  * exported functions for global timers
919  */
920 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
921 {
922 	struct snd_timer_id tid;
923 
924 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
925 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
926 	tid.card = -1;
927 	tid.device = device;
928 	tid.subdevice = 0;
929 	return snd_timer_new(NULL, id, &tid, rtimer);
930 }
931 
932 int snd_timer_global_free(struct snd_timer *timer)
933 {
934 	return snd_timer_free(timer);
935 }
936 
937 int snd_timer_global_register(struct snd_timer *timer)
938 {
939 	struct snd_device dev;
940 
941 	memset(&dev, 0, sizeof(dev));
942 	dev.device_data = timer;
943 	return snd_timer_dev_register(&dev);
944 }
945 
946 /*
947  *  System timer
948  */
949 
950 struct snd_timer_system_private {
951 	struct timer_list tlist;
952 	unsigned long last_expires;
953 	unsigned long last_jiffies;
954 	unsigned long correction;
955 };
956 
957 static void snd_timer_s_function(unsigned long data)
958 {
959 	struct snd_timer *timer = (struct snd_timer *)data;
960 	struct snd_timer_system_private *priv = timer->private_data;
961 	unsigned long jiff = jiffies;
962 	if (time_after(jiff, priv->last_expires))
963 		priv->correction += (long)jiff - (long)priv->last_expires;
964 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
965 }
966 
967 static int snd_timer_s_start(struct snd_timer * timer)
968 {
969 	struct snd_timer_system_private *priv;
970 	unsigned long njiff;
971 
972 	priv = (struct snd_timer_system_private *) timer->private_data;
973 	njiff = (priv->last_jiffies = jiffies);
974 	if (priv->correction > timer->sticks - 1) {
975 		priv->correction -= timer->sticks - 1;
976 		njiff++;
977 	} else {
978 		njiff += timer->sticks - priv->correction;
979 		priv->correction = 0;
980 	}
981 	priv->last_expires = priv->tlist.expires = njiff;
982 	add_timer(&priv->tlist);
983 	return 0;
984 }
985 
986 static int snd_timer_s_stop(struct snd_timer * timer)
987 {
988 	struct snd_timer_system_private *priv;
989 	unsigned long jiff;
990 
991 	priv = (struct snd_timer_system_private *) timer->private_data;
992 	del_timer(&priv->tlist);
993 	jiff = jiffies;
994 	if (time_before(jiff, priv->last_expires))
995 		timer->sticks = priv->last_expires - jiff;
996 	else
997 		timer->sticks = 1;
998 	priv->correction = 0;
999 	return 0;
1000 }
1001 
1002 static struct snd_timer_hardware snd_timer_system =
1003 {
1004 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1005 	.resolution =	1000000000L / HZ,
1006 	.ticks =	10000000L,
1007 	.start =	snd_timer_s_start,
1008 	.stop =		snd_timer_s_stop
1009 };
1010 
1011 static void snd_timer_free_system(struct snd_timer *timer)
1012 {
1013 	kfree(timer->private_data);
1014 }
1015 
1016 static int snd_timer_register_system(void)
1017 {
1018 	struct snd_timer *timer;
1019 	struct snd_timer_system_private *priv;
1020 	int err;
1021 
1022 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1023 	if (err < 0)
1024 		return err;
1025 	strcpy(timer->name, "system timer");
1026 	timer->hw = snd_timer_system;
1027 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1028 	if (priv == NULL) {
1029 		snd_timer_free(timer);
1030 		return -ENOMEM;
1031 	}
1032 	init_timer(&priv->tlist);
1033 	priv->tlist.function = snd_timer_s_function;
1034 	priv->tlist.data = (unsigned long) timer;
1035 	timer->private_data = priv;
1036 	timer->private_free = snd_timer_free_system;
1037 	return snd_timer_global_register(timer);
1038 }
1039 
1040 #ifdef CONFIG_PROC_FS
1041 /*
1042  *  Info interface
1043  */
1044 
1045 static void snd_timer_proc_read(struct snd_info_entry *entry,
1046 				struct snd_info_buffer *buffer)
1047 {
1048 	struct snd_timer *timer;
1049 	struct snd_timer_instance *ti;
1050 
1051 	mutex_lock(&register_mutex);
1052 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1053 		switch (timer->tmr_class) {
1054 		case SNDRV_TIMER_CLASS_GLOBAL:
1055 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1056 			break;
1057 		case SNDRV_TIMER_CLASS_CARD:
1058 			snd_iprintf(buffer, "C%i-%i: ",
1059 				    timer->card->number, timer->tmr_device);
1060 			break;
1061 		case SNDRV_TIMER_CLASS_PCM:
1062 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1063 				    timer->tmr_device, timer->tmr_subdevice);
1064 			break;
1065 		default:
1066 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1067 				    timer->card ? timer->card->number : -1,
1068 				    timer->tmr_device, timer->tmr_subdevice);
1069 		}
1070 		snd_iprintf(buffer, "%s :", timer->name);
1071 		if (timer->hw.resolution)
1072 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1073 				    timer->hw.resolution / 1000,
1074 				    timer->hw.resolution % 1000,
1075 				    timer->hw.ticks);
1076 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1077 			snd_iprintf(buffer, " SLAVE");
1078 		snd_iprintf(buffer, "\n");
1079 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1080 			snd_iprintf(buffer, "  Client %s : %s\n",
1081 				    ti->owner ? ti->owner : "unknown",
1082 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1083 						 SNDRV_TIMER_IFLG_RUNNING)
1084 				    ? "running" : "stopped");
1085 	}
1086 	mutex_unlock(&register_mutex);
1087 }
1088 
1089 static struct snd_info_entry *snd_timer_proc_entry;
1090 
1091 static void __init snd_timer_proc_init(void)
1092 {
1093 	struct snd_info_entry *entry;
1094 
1095 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1096 	if (entry != NULL) {
1097 		entry->c.text.read = snd_timer_proc_read;
1098 		if (snd_info_register(entry) < 0) {
1099 			snd_info_free_entry(entry);
1100 			entry = NULL;
1101 		}
1102 	}
1103 	snd_timer_proc_entry = entry;
1104 }
1105 
1106 static void __exit snd_timer_proc_done(void)
1107 {
1108 	snd_info_free_entry(snd_timer_proc_entry);
1109 }
1110 #else /* !CONFIG_PROC_FS */
1111 #define snd_timer_proc_init()
1112 #define snd_timer_proc_done()
1113 #endif
1114 
1115 /*
1116  *  USER SPACE interface
1117  */
1118 
1119 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1120 				     unsigned long resolution,
1121 				     unsigned long ticks)
1122 {
1123 	struct snd_timer_user *tu = timeri->callback_data;
1124 	struct snd_timer_read *r;
1125 	int prev;
1126 
1127 	spin_lock(&tu->qlock);
1128 	if (tu->qused > 0) {
1129 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1130 		r = &tu->queue[prev];
1131 		if (r->resolution == resolution) {
1132 			r->ticks += ticks;
1133 			goto __wake;
1134 		}
1135 	}
1136 	if (tu->qused >= tu->queue_size) {
1137 		tu->overrun++;
1138 	} else {
1139 		r = &tu->queue[tu->qtail++];
1140 		tu->qtail %= tu->queue_size;
1141 		r->resolution = resolution;
1142 		r->ticks = ticks;
1143 		tu->qused++;
1144 	}
1145       __wake:
1146 	spin_unlock(&tu->qlock);
1147 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1148 	wake_up(&tu->qchange_sleep);
1149 }
1150 
1151 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1152 					    struct snd_timer_tread *tread)
1153 {
1154 	if (tu->qused >= tu->queue_size) {
1155 		tu->overrun++;
1156 	} else {
1157 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1158 		tu->qtail %= tu->queue_size;
1159 		tu->qused++;
1160 	}
1161 }
1162 
1163 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1164 				     int event,
1165 				     struct timespec *tstamp,
1166 				     unsigned long resolution)
1167 {
1168 	struct snd_timer_user *tu = timeri->callback_data;
1169 	struct snd_timer_tread r1;
1170 	unsigned long flags;
1171 
1172 	if (event >= SNDRV_TIMER_EVENT_START &&
1173 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1174 		tu->tstamp = *tstamp;
1175 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1176 		return;
1177 	r1.event = event;
1178 	r1.tstamp = *tstamp;
1179 	r1.val = resolution;
1180 	spin_lock_irqsave(&tu->qlock, flags);
1181 	snd_timer_user_append_to_tqueue(tu, &r1);
1182 	spin_unlock_irqrestore(&tu->qlock, flags);
1183 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1184 	wake_up(&tu->qchange_sleep);
1185 }
1186 
1187 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1188 				      unsigned long resolution,
1189 				      unsigned long ticks)
1190 {
1191 	struct snd_timer_user *tu = timeri->callback_data;
1192 	struct snd_timer_tread *r, r1;
1193 	struct timespec tstamp;
1194 	int prev, append = 0;
1195 
1196 	memset(&tstamp, 0, sizeof(tstamp));
1197 	spin_lock(&tu->qlock);
1198 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1199 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1200 		spin_unlock(&tu->qlock);
1201 		return;
1202 	}
1203 	if (tu->last_resolution != resolution || ticks > 0) {
1204 		if (timer_tstamp_monotonic)
1205 			do_posix_clock_monotonic_gettime(&tstamp);
1206 		else
1207 			getnstimeofday(&tstamp);
1208 	}
1209 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1210 	    tu->last_resolution != resolution) {
1211 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1212 		r1.tstamp = tstamp;
1213 		r1.val = resolution;
1214 		snd_timer_user_append_to_tqueue(tu, &r1);
1215 		tu->last_resolution = resolution;
1216 		append++;
1217 	}
1218 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1219 		goto __wake;
1220 	if (ticks == 0)
1221 		goto __wake;
1222 	if (tu->qused > 0) {
1223 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1224 		r = &tu->tqueue[prev];
1225 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1226 			r->tstamp = tstamp;
1227 			r->val += ticks;
1228 			append++;
1229 			goto __wake;
1230 		}
1231 	}
1232 	r1.event = SNDRV_TIMER_EVENT_TICK;
1233 	r1.tstamp = tstamp;
1234 	r1.val = ticks;
1235 	snd_timer_user_append_to_tqueue(tu, &r1);
1236 	append++;
1237       __wake:
1238 	spin_unlock(&tu->qlock);
1239 	if (append == 0)
1240 		return;
1241 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1242 	wake_up(&tu->qchange_sleep);
1243 }
1244 
1245 static int snd_timer_user_open(struct inode *inode, struct file *file)
1246 {
1247 	struct snd_timer_user *tu;
1248 	int err;
1249 
1250 	err = nonseekable_open(inode, file);
1251 	if (err < 0)
1252 		return err;
1253 
1254 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1255 	if (tu == NULL)
1256 		return -ENOMEM;
1257 	spin_lock_init(&tu->qlock);
1258 	init_waitqueue_head(&tu->qchange_sleep);
1259 	mutex_init(&tu->tread_sem);
1260 	tu->ticks = 1;
1261 	tu->queue_size = 128;
1262 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1263 			    GFP_KERNEL);
1264 	if (tu->queue == NULL) {
1265 		kfree(tu);
1266 		return -ENOMEM;
1267 	}
1268 	file->private_data = tu;
1269 	return 0;
1270 }
1271 
1272 static int snd_timer_user_release(struct inode *inode, struct file *file)
1273 {
1274 	struct snd_timer_user *tu;
1275 
1276 	if (file->private_data) {
1277 		tu = file->private_data;
1278 		file->private_data = NULL;
1279 		if (tu->timeri)
1280 			snd_timer_close(tu->timeri);
1281 		kfree(tu->queue);
1282 		kfree(tu->tqueue);
1283 		kfree(tu);
1284 	}
1285 	return 0;
1286 }
1287 
1288 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1289 {
1290 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1291 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1292 	id->card = -1;
1293 	id->device = -1;
1294 	id->subdevice = -1;
1295 }
1296 
1297 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1298 {
1299 	id->dev_class = timer->tmr_class;
1300 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1301 	id->card = timer->card ? timer->card->number : -1;
1302 	id->device = timer->tmr_device;
1303 	id->subdevice = timer->tmr_subdevice;
1304 }
1305 
1306 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1307 {
1308 	struct snd_timer_id id;
1309 	struct snd_timer *timer;
1310 	struct list_head *p;
1311 
1312 	if (copy_from_user(&id, _tid, sizeof(id)))
1313 		return -EFAULT;
1314 	mutex_lock(&register_mutex);
1315 	if (id.dev_class < 0) {		/* first item */
1316 		if (list_empty(&snd_timer_list))
1317 			snd_timer_user_zero_id(&id);
1318 		else {
1319 			timer = list_entry(snd_timer_list.next,
1320 					   struct snd_timer, device_list);
1321 			snd_timer_user_copy_id(&id, timer);
1322 		}
1323 	} else {
1324 		switch (id.dev_class) {
1325 		case SNDRV_TIMER_CLASS_GLOBAL:
1326 			id.device = id.device < 0 ? 0 : id.device + 1;
1327 			list_for_each(p, &snd_timer_list) {
1328 				timer = list_entry(p, struct snd_timer, device_list);
1329 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1330 					snd_timer_user_copy_id(&id, timer);
1331 					break;
1332 				}
1333 				if (timer->tmr_device >= id.device) {
1334 					snd_timer_user_copy_id(&id, timer);
1335 					break;
1336 				}
1337 			}
1338 			if (p == &snd_timer_list)
1339 				snd_timer_user_zero_id(&id);
1340 			break;
1341 		case SNDRV_TIMER_CLASS_CARD:
1342 		case SNDRV_TIMER_CLASS_PCM:
1343 			if (id.card < 0) {
1344 				id.card = 0;
1345 			} else {
1346 				if (id.card < 0) {
1347 					id.card = 0;
1348 				} else {
1349 					if (id.device < 0) {
1350 						id.device = 0;
1351 					} else {
1352 						if (id.subdevice < 0) {
1353 							id.subdevice = 0;
1354 						} else {
1355 							id.subdevice++;
1356 						}
1357 					}
1358 				}
1359 			}
1360 			list_for_each(p, &snd_timer_list) {
1361 				timer = list_entry(p, struct snd_timer, device_list);
1362 				if (timer->tmr_class > id.dev_class) {
1363 					snd_timer_user_copy_id(&id, timer);
1364 					break;
1365 				}
1366 				if (timer->tmr_class < id.dev_class)
1367 					continue;
1368 				if (timer->card->number > id.card) {
1369 					snd_timer_user_copy_id(&id, timer);
1370 					break;
1371 				}
1372 				if (timer->card->number < id.card)
1373 					continue;
1374 				if (timer->tmr_device > id.device) {
1375 					snd_timer_user_copy_id(&id, timer);
1376 					break;
1377 				}
1378 				if (timer->tmr_device < id.device)
1379 					continue;
1380 				if (timer->tmr_subdevice > id.subdevice) {
1381 					snd_timer_user_copy_id(&id, timer);
1382 					break;
1383 				}
1384 				if (timer->tmr_subdevice < id.subdevice)
1385 					continue;
1386 				snd_timer_user_copy_id(&id, timer);
1387 				break;
1388 			}
1389 			if (p == &snd_timer_list)
1390 				snd_timer_user_zero_id(&id);
1391 			break;
1392 		default:
1393 			snd_timer_user_zero_id(&id);
1394 		}
1395 	}
1396 	mutex_unlock(&register_mutex);
1397 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1398 		return -EFAULT;
1399 	return 0;
1400 }
1401 
1402 static int snd_timer_user_ginfo(struct file *file,
1403 				struct snd_timer_ginfo __user *_ginfo)
1404 {
1405 	struct snd_timer_ginfo *ginfo;
1406 	struct snd_timer_id tid;
1407 	struct snd_timer *t;
1408 	struct list_head *p;
1409 	int err = 0;
1410 
1411 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1412 	if (IS_ERR(ginfo))
1413 		return PTR_ERR(ginfo);
1414 
1415 	tid = ginfo->tid;
1416 	memset(ginfo, 0, sizeof(*ginfo));
1417 	ginfo->tid = tid;
1418 	mutex_lock(&register_mutex);
1419 	t = snd_timer_find(&tid);
1420 	if (t != NULL) {
1421 		ginfo->card = t->card ? t->card->number : -1;
1422 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1423 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1424 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1425 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1426 		ginfo->resolution = t->hw.resolution;
1427 		if (t->hw.resolution_min > 0) {
1428 			ginfo->resolution_min = t->hw.resolution_min;
1429 			ginfo->resolution_max = t->hw.resolution_max;
1430 		}
1431 		list_for_each(p, &t->open_list_head) {
1432 			ginfo->clients++;
1433 		}
1434 	} else {
1435 		err = -ENODEV;
1436 	}
1437 	mutex_unlock(&register_mutex);
1438 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1439 		err = -EFAULT;
1440 	kfree(ginfo);
1441 	return err;
1442 }
1443 
1444 static int snd_timer_user_gparams(struct file *file,
1445 				  struct snd_timer_gparams __user *_gparams)
1446 {
1447 	struct snd_timer_gparams gparams;
1448 	struct snd_timer *t;
1449 	int err;
1450 
1451 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1452 		return -EFAULT;
1453 	mutex_lock(&register_mutex);
1454 	t = snd_timer_find(&gparams.tid);
1455 	if (!t) {
1456 		err = -ENODEV;
1457 		goto _error;
1458 	}
1459 	if (!list_empty(&t->open_list_head)) {
1460 		err = -EBUSY;
1461 		goto _error;
1462 	}
1463 	if (!t->hw.set_period) {
1464 		err = -ENOSYS;
1465 		goto _error;
1466 	}
1467 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1468 _error:
1469 	mutex_unlock(&register_mutex);
1470 	return err;
1471 }
1472 
1473 static int snd_timer_user_gstatus(struct file *file,
1474 				  struct snd_timer_gstatus __user *_gstatus)
1475 {
1476 	struct snd_timer_gstatus gstatus;
1477 	struct snd_timer_id tid;
1478 	struct snd_timer *t;
1479 	int err = 0;
1480 
1481 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1482 		return -EFAULT;
1483 	tid = gstatus.tid;
1484 	memset(&gstatus, 0, sizeof(gstatus));
1485 	gstatus.tid = tid;
1486 	mutex_lock(&register_mutex);
1487 	t = snd_timer_find(&tid);
1488 	if (t != NULL) {
1489 		if (t->hw.c_resolution)
1490 			gstatus.resolution = t->hw.c_resolution(t);
1491 		else
1492 			gstatus.resolution = t->hw.resolution;
1493 		if (t->hw.precise_resolution) {
1494 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1495 						 &gstatus.resolution_den);
1496 		} else {
1497 			gstatus.resolution_num = gstatus.resolution;
1498 			gstatus.resolution_den = 1000000000uL;
1499 		}
1500 	} else {
1501 		err = -ENODEV;
1502 	}
1503 	mutex_unlock(&register_mutex);
1504 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1505 		err = -EFAULT;
1506 	return err;
1507 }
1508 
1509 static int snd_timer_user_tselect(struct file *file,
1510 				  struct snd_timer_select __user *_tselect)
1511 {
1512 	struct snd_timer_user *tu;
1513 	struct snd_timer_select tselect;
1514 	char str[32];
1515 	int err = 0;
1516 
1517 	tu = file->private_data;
1518 	mutex_lock(&tu->tread_sem);
1519 	if (tu->timeri) {
1520 		snd_timer_close(tu->timeri);
1521 		tu->timeri = NULL;
1522 	}
1523 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1524 		err = -EFAULT;
1525 		goto __err;
1526 	}
1527 	sprintf(str, "application %i", current->pid);
1528 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1529 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1530 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1531 	if (err < 0)
1532 		goto __err;
1533 
1534 	kfree(tu->queue);
1535 	tu->queue = NULL;
1536 	kfree(tu->tqueue);
1537 	tu->tqueue = NULL;
1538 	if (tu->tread) {
1539 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1540 				     GFP_KERNEL);
1541 		if (tu->tqueue == NULL)
1542 			err = -ENOMEM;
1543 	} else {
1544 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1545 				    GFP_KERNEL);
1546 		if (tu->queue == NULL)
1547 			err = -ENOMEM;
1548 	}
1549 
1550       	if (err < 0) {
1551 		snd_timer_close(tu->timeri);
1552       		tu->timeri = NULL;
1553       	} else {
1554 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1555 		tu->timeri->callback = tu->tread
1556 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1557 		tu->timeri->ccallback = snd_timer_user_ccallback;
1558 		tu->timeri->callback_data = (void *)tu;
1559 	}
1560 
1561       __err:
1562       	mutex_unlock(&tu->tread_sem);
1563 	return err;
1564 }
1565 
1566 static int snd_timer_user_info(struct file *file,
1567 			       struct snd_timer_info __user *_info)
1568 {
1569 	struct snd_timer_user *tu;
1570 	struct snd_timer_info *info;
1571 	struct snd_timer *t;
1572 	int err = 0;
1573 
1574 	tu = file->private_data;
1575 	if (!tu->timeri)
1576 		return -EBADFD;
1577 	t = tu->timeri->timer;
1578 	if (!t)
1579 		return -EBADFD;
1580 
1581 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1582 	if (! info)
1583 		return -ENOMEM;
1584 	info->card = t->card ? t->card->number : -1;
1585 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1586 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1587 	strlcpy(info->id, t->id, sizeof(info->id));
1588 	strlcpy(info->name, t->name, sizeof(info->name));
1589 	info->resolution = t->hw.resolution;
1590 	if (copy_to_user(_info, info, sizeof(*_info)))
1591 		err = -EFAULT;
1592 	kfree(info);
1593 	return err;
1594 }
1595 
1596 static int snd_timer_user_params(struct file *file,
1597 				 struct snd_timer_params __user *_params)
1598 {
1599 	struct snd_timer_user *tu;
1600 	struct snd_timer_params params;
1601 	struct snd_timer *t;
1602 	struct snd_timer_read *tr;
1603 	struct snd_timer_tread *ttr;
1604 	int err;
1605 
1606 	tu = file->private_data;
1607 	if (!tu->timeri)
1608 		return -EBADFD;
1609 	t = tu->timeri->timer;
1610 	if (!t)
1611 		return -EBADFD;
1612 	if (copy_from_user(&params, _params, sizeof(params)))
1613 		return -EFAULT;
1614 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1615 		err = -EINVAL;
1616 		goto _end;
1617 	}
1618 	if (params.queue_size > 0 &&
1619 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1620 		err = -EINVAL;
1621 		goto _end;
1622 	}
1623 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1624 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1625 			      (1<<SNDRV_TIMER_EVENT_START)|
1626 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1627 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1628 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1629 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1630 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1631 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1632 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1633 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1634 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1635 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1636 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1637 		err = -EINVAL;
1638 		goto _end;
1639 	}
1640 	snd_timer_stop(tu->timeri);
1641 	spin_lock_irq(&t->lock);
1642 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1643 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1644 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1645 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1646 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1647 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1648 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1649 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1650 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1651 	spin_unlock_irq(&t->lock);
1652 	if (params.queue_size > 0 &&
1653 	    (unsigned int)tu->queue_size != params.queue_size) {
1654 		if (tu->tread) {
1655 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1656 				      GFP_KERNEL);
1657 			if (ttr) {
1658 				kfree(tu->tqueue);
1659 				tu->queue_size = params.queue_size;
1660 				tu->tqueue = ttr;
1661 			}
1662 		} else {
1663 			tr = kmalloc(params.queue_size * sizeof(*tr),
1664 				     GFP_KERNEL);
1665 			if (tr) {
1666 				kfree(tu->queue);
1667 				tu->queue_size = params.queue_size;
1668 				tu->queue = tr;
1669 			}
1670 		}
1671 	}
1672 	tu->qhead = tu->qtail = tu->qused = 0;
1673 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1674 		if (tu->tread) {
1675 			struct snd_timer_tread tread;
1676 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1677 			tread.tstamp.tv_sec = 0;
1678 			tread.tstamp.tv_nsec = 0;
1679 			tread.val = 0;
1680 			snd_timer_user_append_to_tqueue(tu, &tread);
1681 		} else {
1682 			struct snd_timer_read *r = &tu->queue[0];
1683 			r->resolution = 0;
1684 			r->ticks = 0;
1685 			tu->qused++;
1686 			tu->qtail++;
1687 		}
1688 	}
1689 	tu->filter = params.filter;
1690 	tu->ticks = params.ticks;
1691 	err = 0;
1692  _end:
1693 	if (copy_to_user(_params, &params, sizeof(params)))
1694 		return -EFAULT;
1695 	return err;
1696 }
1697 
1698 static int snd_timer_user_status(struct file *file,
1699 				 struct snd_timer_status __user *_status)
1700 {
1701 	struct snd_timer_user *tu;
1702 	struct snd_timer_status status;
1703 
1704 	tu = file->private_data;
1705 	if (!tu->timeri)
1706 		return -EBADFD;
1707 	memset(&status, 0, sizeof(status));
1708 	status.tstamp = tu->tstamp;
1709 	status.resolution = snd_timer_resolution(tu->timeri);
1710 	status.lost = tu->timeri->lost;
1711 	status.overrun = tu->overrun;
1712 	spin_lock_irq(&tu->qlock);
1713 	status.queue = tu->qused;
1714 	spin_unlock_irq(&tu->qlock);
1715 	if (copy_to_user(_status, &status, sizeof(status)))
1716 		return -EFAULT;
1717 	return 0;
1718 }
1719 
1720 static int snd_timer_user_start(struct file *file)
1721 {
1722 	int err;
1723 	struct snd_timer_user *tu;
1724 
1725 	tu = file->private_data;
1726 	if (!tu->timeri)
1727 		return -EBADFD;
1728 	snd_timer_stop(tu->timeri);
1729 	tu->timeri->lost = 0;
1730 	tu->last_resolution = 0;
1731 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1732 }
1733 
1734 static int snd_timer_user_stop(struct file *file)
1735 {
1736 	int err;
1737 	struct snd_timer_user *tu;
1738 
1739 	tu = file->private_data;
1740 	if (!tu->timeri)
1741 		return -EBADFD;
1742 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1743 }
1744 
1745 static int snd_timer_user_continue(struct file *file)
1746 {
1747 	int err;
1748 	struct snd_timer_user *tu;
1749 
1750 	tu = file->private_data;
1751 	if (!tu->timeri)
1752 		return -EBADFD;
1753 	tu->timeri->lost = 0;
1754 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1755 }
1756 
1757 static int snd_timer_user_pause(struct file *file)
1758 {
1759 	int err;
1760 	struct snd_timer_user *tu;
1761 
1762 	tu = file->private_data;
1763 	if (!tu->timeri)
1764 		return -EBADFD;
1765 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1766 }
1767 
1768 enum {
1769 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1770 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1771 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1772 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1773 };
1774 
1775 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1776 				 unsigned long arg)
1777 {
1778 	struct snd_timer_user *tu;
1779 	void __user *argp = (void __user *)arg;
1780 	int __user *p = argp;
1781 
1782 	tu = file->private_data;
1783 	switch (cmd) {
1784 	case SNDRV_TIMER_IOCTL_PVERSION:
1785 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1786 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1787 		return snd_timer_user_next_device(argp);
1788 	case SNDRV_TIMER_IOCTL_TREAD:
1789 	{
1790 		int xarg;
1791 
1792 		mutex_lock(&tu->tread_sem);
1793 		if (tu->timeri)	{	/* too late */
1794 			mutex_unlock(&tu->tread_sem);
1795 			return -EBUSY;
1796 		}
1797 		if (get_user(xarg, p)) {
1798 			mutex_unlock(&tu->tread_sem);
1799 			return -EFAULT;
1800 		}
1801 		tu->tread = xarg ? 1 : 0;
1802 		mutex_unlock(&tu->tread_sem);
1803 		return 0;
1804 	}
1805 	case SNDRV_TIMER_IOCTL_GINFO:
1806 		return snd_timer_user_ginfo(file, argp);
1807 	case SNDRV_TIMER_IOCTL_GPARAMS:
1808 		return snd_timer_user_gparams(file, argp);
1809 	case SNDRV_TIMER_IOCTL_GSTATUS:
1810 		return snd_timer_user_gstatus(file, argp);
1811 	case SNDRV_TIMER_IOCTL_SELECT:
1812 		return snd_timer_user_tselect(file, argp);
1813 	case SNDRV_TIMER_IOCTL_INFO:
1814 		return snd_timer_user_info(file, argp);
1815 	case SNDRV_TIMER_IOCTL_PARAMS:
1816 		return snd_timer_user_params(file, argp);
1817 	case SNDRV_TIMER_IOCTL_STATUS:
1818 		return snd_timer_user_status(file, argp);
1819 	case SNDRV_TIMER_IOCTL_START:
1820 	case SNDRV_TIMER_IOCTL_START_OLD:
1821 		return snd_timer_user_start(file);
1822 	case SNDRV_TIMER_IOCTL_STOP:
1823 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1824 		return snd_timer_user_stop(file);
1825 	case SNDRV_TIMER_IOCTL_CONTINUE:
1826 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1827 		return snd_timer_user_continue(file);
1828 	case SNDRV_TIMER_IOCTL_PAUSE:
1829 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1830 		return snd_timer_user_pause(file);
1831 	}
1832 	return -ENOTTY;
1833 }
1834 
1835 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1836 {
1837 	struct snd_timer_user *tu;
1838 
1839 	tu = file->private_data;
1840 	return fasync_helper(fd, file, on, &tu->fasync);
1841 }
1842 
1843 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1844 				   size_t count, loff_t *offset)
1845 {
1846 	struct snd_timer_user *tu;
1847 	long result = 0, unit;
1848 	int err = 0;
1849 
1850 	tu = file->private_data;
1851 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1852 	spin_lock_irq(&tu->qlock);
1853 	while ((long)count - result >= unit) {
1854 		while (!tu->qused) {
1855 			wait_queue_t wait;
1856 
1857 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1858 				err = -EAGAIN;
1859 				break;
1860 			}
1861 
1862 			set_current_state(TASK_INTERRUPTIBLE);
1863 			init_waitqueue_entry(&wait, current);
1864 			add_wait_queue(&tu->qchange_sleep, &wait);
1865 
1866 			spin_unlock_irq(&tu->qlock);
1867 			schedule();
1868 			spin_lock_irq(&tu->qlock);
1869 
1870 			remove_wait_queue(&tu->qchange_sleep, &wait);
1871 
1872 			if (signal_pending(current)) {
1873 				err = -ERESTARTSYS;
1874 				break;
1875 			}
1876 		}
1877 
1878 		spin_unlock_irq(&tu->qlock);
1879 		if (err < 0)
1880 			goto _error;
1881 
1882 		if (tu->tread) {
1883 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1884 					 sizeof(struct snd_timer_tread))) {
1885 				err = -EFAULT;
1886 				goto _error;
1887 			}
1888 		} else {
1889 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1890 					 sizeof(struct snd_timer_read))) {
1891 				err = -EFAULT;
1892 				goto _error;
1893 			}
1894 		}
1895 
1896 		tu->qhead %= tu->queue_size;
1897 
1898 		result += unit;
1899 		buffer += unit;
1900 
1901 		spin_lock_irq(&tu->qlock);
1902 		tu->qused--;
1903 	}
1904 	spin_unlock_irq(&tu->qlock);
1905  _error:
1906 	return result > 0 ? result : err;
1907 }
1908 
1909 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1910 {
1911         unsigned int mask;
1912         struct snd_timer_user *tu;
1913 
1914         tu = file->private_data;
1915 
1916         poll_wait(file, &tu->qchange_sleep, wait);
1917 
1918 	mask = 0;
1919 	if (tu->qused)
1920 		mask |= POLLIN | POLLRDNORM;
1921 
1922 	return mask;
1923 }
1924 
1925 #ifdef CONFIG_COMPAT
1926 #include "timer_compat.c"
1927 #else
1928 #define snd_timer_user_ioctl_compat	NULL
1929 #endif
1930 
1931 static const struct file_operations snd_timer_f_ops =
1932 {
1933 	.owner =	THIS_MODULE,
1934 	.read =		snd_timer_user_read,
1935 	.open =		snd_timer_user_open,
1936 	.release =	snd_timer_user_release,
1937 	.llseek =	no_llseek,
1938 	.poll =		snd_timer_user_poll,
1939 	.unlocked_ioctl =	snd_timer_user_ioctl,
1940 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1941 	.fasync = 	snd_timer_user_fasync,
1942 };
1943 
1944 /*
1945  *  ENTRY functions
1946  */
1947 
1948 static int __init alsa_timer_init(void)
1949 {
1950 	int err;
1951 
1952 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1953 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1954 			      "system timer");
1955 #endif
1956 
1957 	if ((err = snd_timer_register_system()) < 0)
1958 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1959 			   err);
1960 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1961 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1962 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1963 			   err);
1964 	snd_timer_proc_init();
1965 	return 0;
1966 }
1967 
1968 static void __exit alsa_timer_exit(void)
1969 {
1970 	struct list_head *p, *n;
1971 
1972 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1973 	/* unregister the system timer */
1974 	list_for_each_safe(p, n, &snd_timer_list) {
1975 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1976 		snd_timer_free(timer);
1977 	}
1978 	snd_timer_proc_done();
1979 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1980 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1981 #endif
1982 }
1983 
1984 module_init(alsa_timer_init)
1985 module_exit(alsa_timer_exit)
1986 
1987 EXPORT_SYMBOL(snd_timer_open);
1988 EXPORT_SYMBOL(snd_timer_close);
1989 EXPORT_SYMBOL(snd_timer_resolution);
1990 EXPORT_SYMBOL(snd_timer_start);
1991 EXPORT_SYMBOL(snd_timer_stop);
1992 EXPORT_SYMBOL(snd_timer_continue);
1993 EXPORT_SYMBOL(snd_timer_pause);
1994 EXPORT_SYMBOL(snd_timer_new);
1995 EXPORT_SYMBOL(snd_timer_notify);
1996 EXPORT_SYMBOL(snd_timer_global_new);
1997 EXPORT_SYMBOL(snd_timer_global_free);
1998 EXPORT_SYMBOL(snd_timer_global_register);
1999 EXPORT_SYMBOL(snd_timer_interrupt);
2000