xref: /openbmc/linux/sound/core/timer.c (revision f7d84fa7)
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 <linux/sched/signal.h>
31 #include <sound/core.h>
32 #include <sound/timer.h>
33 #include <sound/control.h>
34 #include <sound/info.h>
35 #include <sound/minors.h>
36 #include <sound/initval.h>
37 #include <linux/kmod.h>
38 
39 /* internal flags */
40 #define SNDRV_TIMER_IFLG_PAUSED		0x00010000
41 
42 #if IS_ENABLED(CONFIG_SND_HRTIMER)
43 #define DEFAULT_TIMER_LIMIT 4
44 #else
45 #define DEFAULT_TIMER_LIMIT 1
46 #endif
47 
48 static int timer_limit = DEFAULT_TIMER_LIMIT;
49 static int timer_tstamp_monotonic = 1;
50 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
51 MODULE_DESCRIPTION("ALSA timer interface");
52 MODULE_LICENSE("GPL");
53 module_param(timer_limit, int, 0444);
54 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
55 module_param(timer_tstamp_monotonic, int, 0444);
56 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
57 
58 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
59 MODULE_ALIAS("devname:snd/timer");
60 
61 struct snd_timer_user {
62 	struct snd_timer_instance *timeri;
63 	int tread;		/* enhanced read with timestamps and events */
64 	unsigned long ticks;
65 	unsigned long overrun;
66 	int qhead;
67 	int qtail;
68 	int qused;
69 	int queue_size;
70 	bool disconnected;
71 	struct snd_timer_read *queue;
72 	struct snd_timer_tread *tqueue;
73 	spinlock_t qlock;
74 	unsigned long last_resolution;
75 	unsigned int filter;
76 	struct timespec tstamp;		/* trigger tstamp */
77 	wait_queue_head_t qchange_sleep;
78 	struct fasync_struct *fasync;
79 	struct mutex ioctl_lock;
80 };
81 
82 /* list of timers */
83 static LIST_HEAD(snd_timer_list);
84 
85 /* list of slave instances */
86 static LIST_HEAD(snd_timer_slave_list);
87 
88 /* lock for slave active lists */
89 static DEFINE_SPINLOCK(slave_active_lock);
90 
91 static DEFINE_MUTEX(register_mutex);
92 
93 static int snd_timer_free(struct snd_timer *timer);
94 static int snd_timer_dev_free(struct snd_device *device);
95 static int snd_timer_dev_register(struct snd_device *device);
96 static int snd_timer_dev_disconnect(struct snd_device *device);
97 
98 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
99 
100 /*
101  * create a timer instance with the given owner string.
102  * when timer is not NULL, increments the module counter
103  */
104 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
105 							 struct snd_timer *timer)
106 {
107 	struct snd_timer_instance *timeri;
108 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
109 	if (timeri == NULL)
110 		return NULL;
111 	timeri->owner = kstrdup(owner, GFP_KERNEL);
112 	if (! timeri->owner) {
113 		kfree(timeri);
114 		return NULL;
115 	}
116 	INIT_LIST_HEAD(&timeri->open_list);
117 	INIT_LIST_HEAD(&timeri->active_list);
118 	INIT_LIST_HEAD(&timeri->ack_list);
119 	INIT_LIST_HEAD(&timeri->slave_list_head);
120 	INIT_LIST_HEAD(&timeri->slave_active_head);
121 
122 	timeri->timer = timer;
123 	if (timer && !try_module_get(timer->module)) {
124 		kfree(timeri->owner);
125 		kfree(timeri);
126 		return NULL;
127 	}
128 
129 	return timeri;
130 }
131 
132 /*
133  * find a timer instance from the given timer id
134  */
135 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
136 {
137 	struct snd_timer *timer = NULL;
138 
139 	list_for_each_entry(timer, &snd_timer_list, device_list) {
140 		if (timer->tmr_class != tid->dev_class)
141 			continue;
142 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
143 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
144 		    (timer->card == NULL ||
145 		     timer->card->number != tid->card))
146 			continue;
147 		if (timer->tmr_device != tid->device)
148 			continue;
149 		if (timer->tmr_subdevice != tid->subdevice)
150 			continue;
151 		return timer;
152 	}
153 	return NULL;
154 }
155 
156 #ifdef CONFIG_MODULES
157 
158 static void snd_timer_request(struct snd_timer_id *tid)
159 {
160 	switch (tid->dev_class) {
161 	case SNDRV_TIMER_CLASS_GLOBAL:
162 		if (tid->device < timer_limit)
163 			request_module("snd-timer-%i", tid->device);
164 		break;
165 	case SNDRV_TIMER_CLASS_CARD:
166 	case SNDRV_TIMER_CLASS_PCM:
167 		if (tid->card < snd_ecards_limit)
168 			request_module("snd-card-%i", tid->card);
169 		break;
170 	default:
171 		break;
172 	}
173 }
174 
175 #endif
176 
177 /*
178  * look for a master instance matching with the slave id of the given slave.
179  * when found, relink the open_link of the slave.
180  *
181  * call this with register_mutex down.
182  */
183 static void snd_timer_check_slave(struct snd_timer_instance *slave)
184 {
185 	struct snd_timer *timer;
186 	struct snd_timer_instance *master;
187 
188 	/* FIXME: it's really dumb to look up all entries.. */
189 	list_for_each_entry(timer, &snd_timer_list, device_list) {
190 		list_for_each_entry(master, &timer->open_list_head, open_list) {
191 			if (slave->slave_class == master->slave_class &&
192 			    slave->slave_id == master->slave_id) {
193 				list_move_tail(&slave->open_list,
194 					       &master->slave_list_head);
195 				spin_lock_irq(&slave_active_lock);
196 				slave->master = master;
197 				slave->timer = master->timer;
198 				spin_unlock_irq(&slave_active_lock);
199 				return;
200 			}
201 		}
202 	}
203 }
204 
205 /*
206  * look for slave instances matching with the slave id of the given master.
207  * when found, relink the open_link of slaves.
208  *
209  * call this with register_mutex down.
210  */
211 static void snd_timer_check_master(struct snd_timer_instance *master)
212 {
213 	struct snd_timer_instance *slave, *tmp;
214 
215 	/* check all pending slaves */
216 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
217 		if (slave->slave_class == master->slave_class &&
218 		    slave->slave_id == master->slave_id) {
219 			list_move_tail(&slave->open_list, &master->slave_list_head);
220 			spin_lock_irq(&slave_active_lock);
221 			spin_lock(&master->timer->lock);
222 			slave->master = master;
223 			slave->timer = master->timer;
224 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
225 				list_add_tail(&slave->active_list,
226 					      &master->slave_active_head);
227 			spin_unlock(&master->timer->lock);
228 			spin_unlock_irq(&slave_active_lock);
229 		}
230 	}
231 }
232 
233 /*
234  * open a timer instance
235  * when opening a master, the slave id must be here given.
236  */
237 int snd_timer_open(struct snd_timer_instance **ti,
238 		   char *owner, struct snd_timer_id *tid,
239 		   unsigned int slave_id)
240 {
241 	struct snd_timer *timer;
242 	struct snd_timer_instance *timeri = NULL;
243 
244 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
245 		/* open a slave instance */
246 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
247 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
248 			pr_debug("ALSA: timer: invalid slave class %i\n",
249 				 tid->dev_sclass);
250 			return -EINVAL;
251 		}
252 		mutex_lock(&register_mutex);
253 		timeri = snd_timer_instance_new(owner, NULL);
254 		if (!timeri) {
255 			mutex_unlock(&register_mutex);
256 			return -ENOMEM;
257 		}
258 		timeri->slave_class = tid->dev_sclass;
259 		timeri->slave_id = tid->device;
260 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
261 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
262 		snd_timer_check_slave(timeri);
263 		mutex_unlock(&register_mutex);
264 		*ti = timeri;
265 		return 0;
266 	}
267 
268 	/* open a master instance */
269 	mutex_lock(&register_mutex);
270 	timer = snd_timer_find(tid);
271 #ifdef CONFIG_MODULES
272 	if (!timer) {
273 		mutex_unlock(&register_mutex);
274 		snd_timer_request(tid);
275 		mutex_lock(&register_mutex);
276 		timer = snd_timer_find(tid);
277 	}
278 #endif
279 	if (!timer) {
280 		mutex_unlock(&register_mutex);
281 		return -ENODEV;
282 	}
283 	if (!list_empty(&timer->open_list_head)) {
284 		timeri = list_entry(timer->open_list_head.next,
285 				    struct snd_timer_instance, open_list);
286 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
287 			mutex_unlock(&register_mutex);
288 			return -EBUSY;
289 		}
290 	}
291 	timeri = snd_timer_instance_new(owner, timer);
292 	if (!timeri) {
293 		mutex_unlock(&register_mutex);
294 		return -ENOMEM;
295 	}
296 	/* take a card refcount for safe disconnection */
297 	if (timer->card)
298 		get_device(&timer->card->card_dev);
299 	timeri->slave_class = tid->dev_sclass;
300 	timeri->slave_id = slave_id;
301 
302 	if (list_empty(&timer->open_list_head) && timer->hw.open) {
303 		int err = timer->hw.open(timer);
304 		if (err) {
305 			kfree(timeri->owner);
306 			kfree(timeri);
307 
308 			if (timer->card)
309 				put_device(&timer->card->card_dev);
310 			module_put(timer->module);
311 			mutex_unlock(&register_mutex);
312 			return err;
313 		}
314 	}
315 
316 	list_add_tail(&timeri->open_list, &timer->open_list_head);
317 	snd_timer_check_master(timeri);
318 	mutex_unlock(&register_mutex);
319 	*ti = timeri;
320 	return 0;
321 }
322 
323 /*
324  * close a timer instance
325  */
326 int snd_timer_close(struct snd_timer_instance *timeri)
327 {
328 	struct snd_timer *timer = NULL;
329 	struct snd_timer_instance *slave, *tmp;
330 
331 	if (snd_BUG_ON(!timeri))
332 		return -ENXIO;
333 
334 	mutex_lock(&register_mutex);
335 	list_del(&timeri->open_list);
336 
337 	/* force to stop the timer */
338 	snd_timer_stop(timeri);
339 
340 	timer = timeri->timer;
341 	if (timer) {
342 		/* wait, until the active callback is finished */
343 		spin_lock_irq(&timer->lock);
344 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
345 			spin_unlock_irq(&timer->lock);
346 			udelay(10);
347 			spin_lock_irq(&timer->lock);
348 		}
349 		spin_unlock_irq(&timer->lock);
350 
351 		/* remove slave links */
352 		spin_lock_irq(&slave_active_lock);
353 		spin_lock(&timer->lock);
354 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
355 					 open_list) {
356 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
357 			slave->master = NULL;
358 			slave->timer = NULL;
359 			list_del_init(&slave->ack_list);
360 			list_del_init(&slave->active_list);
361 		}
362 		spin_unlock(&timer->lock);
363 		spin_unlock_irq(&slave_active_lock);
364 
365 		/* slave doesn't need to release timer resources below */
366 		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
367 			timer = NULL;
368 	}
369 
370 	if (timeri->private_free)
371 		timeri->private_free(timeri);
372 	kfree(timeri->owner);
373 	kfree(timeri);
374 
375 	if (timer) {
376 		if (list_empty(&timer->open_list_head) && timer->hw.close)
377 			timer->hw.close(timer);
378 		/* release a card refcount for safe disconnection */
379 		if (timer->card)
380 			put_device(&timer->card->card_dev);
381 		module_put(timer->module);
382 	}
383 
384 	mutex_unlock(&register_mutex);
385 	return 0;
386 }
387 
388 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
389 {
390 	struct snd_timer * timer;
391 
392 	if (timeri == NULL)
393 		return 0;
394 	if ((timer = timeri->timer) != NULL) {
395 		if (timer->hw.c_resolution)
396 			return timer->hw.c_resolution(timer);
397 		return timer->hw.resolution;
398 	}
399 	return 0;
400 }
401 
402 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
403 {
404 	struct snd_timer *timer;
405 	unsigned long resolution = 0;
406 	struct snd_timer_instance *ts;
407 	struct timespec tstamp;
408 
409 	if (timer_tstamp_monotonic)
410 		ktime_get_ts(&tstamp);
411 	else
412 		getnstimeofday(&tstamp);
413 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
414 		       event > SNDRV_TIMER_EVENT_PAUSE))
415 		return;
416 	if (event == SNDRV_TIMER_EVENT_START ||
417 	    event == SNDRV_TIMER_EVENT_CONTINUE)
418 		resolution = snd_timer_resolution(ti);
419 	if (ti->ccallback)
420 		ti->ccallback(ti, event, &tstamp, resolution);
421 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
422 		return;
423 	timer = ti->timer;
424 	if (timer == NULL)
425 		return;
426 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
427 		return;
428 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
429 		if (ts->ccallback)
430 			ts->ccallback(ts, event + 100, &tstamp, resolution);
431 }
432 
433 /* start/continue a master timer */
434 static int snd_timer_start1(struct snd_timer_instance *timeri,
435 			    bool start, unsigned long ticks)
436 {
437 	struct snd_timer *timer;
438 	int result;
439 	unsigned long flags;
440 
441 	timer = timeri->timer;
442 	if (!timer)
443 		return -EINVAL;
444 
445 	spin_lock_irqsave(&timer->lock, flags);
446 	if (timer->card && timer->card->shutdown) {
447 		result = -ENODEV;
448 		goto unlock;
449 	}
450 	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
451 			     SNDRV_TIMER_IFLG_START)) {
452 		result = -EBUSY;
453 		goto unlock;
454 	}
455 
456 	if (start)
457 		timeri->ticks = timeri->cticks = ticks;
458 	else if (!timeri->cticks)
459 		timeri->cticks = 1;
460 	timeri->pticks = 0;
461 
462 	list_move_tail(&timeri->active_list, &timer->active_list_head);
463 	if (timer->running) {
464 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
465 			goto __start_now;
466 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
467 		timeri->flags |= SNDRV_TIMER_IFLG_START;
468 		result = 1; /* delayed start */
469 	} else {
470 		if (start)
471 			timer->sticks = ticks;
472 		timer->hw.start(timer);
473 	      __start_now:
474 		timer->running++;
475 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
476 		result = 0;
477 	}
478 	snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
479 			  SNDRV_TIMER_EVENT_CONTINUE);
480  unlock:
481 	spin_unlock_irqrestore(&timer->lock, flags);
482 	return result;
483 }
484 
485 /* start/continue a slave timer */
486 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
487 				 bool start)
488 {
489 	unsigned long flags;
490 
491 	spin_lock_irqsave(&slave_active_lock, flags);
492 	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
493 		spin_unlock_irqrestore(&slave_active_lock, flags);
494 		return -EBUSY;
495 	}
496 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
497 	if (timeri->master && timeri->timer) {
498 		spin_lock(&timeri->timer->lock);
499 		list_add_tail(&timeri->active_list,
500 			      &timeri->master->slave_active_head);
501 		snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
502 				  SNDRV_TIMER_EVENT_CONTINUE);
503 		spin_unlock(&timeri->timer->lock);
504 	}
505 	spin_unlock_irqrestore(&slave_active_lock, flags);
506 	return 1; /* delayed start */
507 }
508 
509 /* stop/pause a master timer */
510 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
511 {
512 	struct snd_timer *timer;
513 	int result = 0;
514 	unsigned long flags;
515 
516 	timer = timeri->timer;
517 	if (!timer)
518 		return -EINVAL;
519 	spin_lock_irqsave(&timer->lock, flags);
520 	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
521 			       SNDRV_TIMER_IFLG_START))) {
522 		result = -EBUSY;
523 		goto unlock;
524 	}
525 	list_del_init(&timeri->ack_list);
526 	list_del_init(&timeri->active_list);
527 	if (timer->card && timer->card->shutdown)
528 		goto unlock;
529 	if (stop) {
530 		timeri->cticks = timeri->ticks;
531 		timeri->pticks = 0;
532 	}
533 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
534 	    !(--timer->running)) {
535 		timer->hw.stop(timer);
536 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
537 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
538 			snd_timer_reschedule(timer, 0);
539 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
540 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
541 				timer->hw.start(timer);
542 			}
543 		}
544 	}
545 	timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
546 	if (stop)
547 		timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
548 	else
549 		timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
550 	snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
551 			  SNDRV_TIMER_EVENT_CONTINUE);
552  unlock:
553 	spin_unlock_irqrestore(&timer->lock, flags);
554 	return result;
555 }
556 
557 /* stop/pause a slave timer */
558 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
559 {
560 	unsigned long flags;
561 
562 	spin_lock_irqsave(&slave_active_lock, flags);
563 	if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
564 		spin_unlock_irqrestore(&slave_active_lock, flags);
565 		return -EBUSY;
566 	}
567 	timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
568 	if (timeri->timer) {
569 		spin_lock(&timeri->timer->lock);
570 		list_del_init(&timeri->ack_list);
571 		list_del_init(&timeri->active_list);
572 		snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
573 				  SNDRV_TIMER_EVENT_CONTINUE);
574 		spin_unlock(&timeri->timer->lock);
575 	}
576 	spin_unlock_irqrestore(&slave_active_lock, flags);
577 	return 0;
578 }
579 
580 /*
581  *  start the timer instance
582  */
583 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
584 {
585 	if (timeri == NULL || ticks < 1)
586 		return -EINVAL;
587 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
588 		return snd_timer_start_slave(timeri, true);
589 	else
590 		return snd_timer_start1(timeri, true, ticks);
591 }
592 
593 /*
594  * stop the timer instance.
595  *
596  * do not call this from the timer callback!
597  */
598 int snd_timer_stop(struct snd_timer_instance *timeri)
599 {
600 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
601 		return snd_timer_stop_slave(timeri, true);
602 	else
603 		return snd_timer_stop1(timeri, true);
604 }
605 
606 /*
607  * start again..  the tick is kept.
608  */
609 int snd_timer_continue(struct snd_timer_instance *timeri)
610 {
611 	/* timer can continue only after pause */
612 	if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
613 		return -EINVAL;
614 
615 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
616 		return snd_timer_start_slave(timeri, false);
617 	else
618 		return snd_timer_start1(timeri, false, 0);
619 }
620 
621 /*
622  * pause.. remember the ticks left
623  */
624 int snd_timer_pause(struct snd_timer_instance * timeri)
625 {
626 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
627 		return snd_timer_stop_slave(timeri, false);
628 	else
629 		return snd_timer_stop1(timeri, false);
630 }
631 
632 /*
633  * reschedule the timer
634  *
635  * start pending instances and check the scheduling ticks.
636  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
637  */
638 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
639 {
640 	struct snd_timer_instance *ti;
641 	unsigned long ticks = ~0UL;
642 
643 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
644 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
645 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
646 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
647 			timer->running++;
648 		}
649 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
650 			if (ticks > ti->cticks)
651 				ticks = ti->cticks;
652 		}
653 	}
654 	if (ticks == ~0UL) {
655 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
656 		return;
657 	}
658 	if (ticks > timer->hw.ticks)
659 		ticks = timer->hw.ticks;
660 	if (ticks_left != ticks)
661 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
662 	timer->sticks = ticks;
663 }
664 
665 /*
666  * timer tasklet
667  *
668  */
669 static void snd_timer_tasklet(unsigned long arg)
670 {
671 	struct snd_timer *timer = (struct snd_timer *) arg;
672 	struct snd_timer_instance *ti;
673 	struct list_head *p;
674 	unsigned long resolution, ticks;
675 	unsigned long flags;
676 
677 	if (timer->card && timer->card->shutdown)
678 		return;
679 
680 	spin_lock_irqsave(&timer->lock, flags);
681 	/* now process all callbacks */
682 	while (!list_empty(&timer->sack_list_head)) {
683 		p = timer->sack_list_head.next;		/* get first item */
684 		ti = list_entry(p, struct snd_timer_instance, ack_list);
685 
686 		/* remove from ack_list and make empty */
687 		list_del_init(p);
688 
689 		ticks = ti->pticks;
690 		ti->pticks = 0;
691 		resolution = ti->resolution;
692 
693 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
694 		spin_unlock(&timer->lock);
695 		if (ti->callback)
696 			ti->callback(ti, resolution, ticks);
697 		spin_lock(&timer->lock);
698 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
699 	}
700 	spin_unlock_irqrestore(&timer->lock, flags);
701 }
702 
703 /*
704  * timer interrupt
705  *
706  * ticks_left is usually equal to timer->sticks.
707  *
708  */
709 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
710 {
711 	struct snd_timer_instance *ti, *ts, *tmp;
712 	unsigned long resolution, ticks;
713 	struct list_head *p, *ack_list_head;
714 	unsigned long flags;
715 	int use_tasklet = 0;
716 
717 	if (timer == NULL)
718 		return;
719 
720 	if (timer->card && timer->card->shutdown)
721 		return;
722 
723 	spin_lock_irqsave(&timer->lock, flags);
724 
725 	/* remember the current resolution */
726 	if (timer->hw.c_resolution)
727 		resolution = timer->hw.c_resolution(timer);
728 	else
729 		resolution = timer->hw.resolution;
730 
731 	/* loop for all active instances
732 	 * Here we cannot use list_for_each_entry because the active_list of a
733 	 * processed instance is relinked to done_list_head before the callback
734 	 * is called.
735 	 */
736 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
737 				 active_list) {
738 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
739 			continue;
740 		ti->pticks += ticks_left;
741 		ti->resolution = resolution;
742 		if (ti->cticks < ticks_left)
743 			ti->cticks = 0;
744 		else
745 			ti->cticks -= ticks_left;
746 		if (ti->cticks) /* not expired */
747 			continue;
748 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
749 			ti->cticks = ti->ticks;
750 		} else {
751 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
752 			--timer->running;
753 			list_del_init(&ti->active_list);
754 		}
755 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
756 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
757 			ack_list_head = &timer->ack_list_head;
758 		else
759 			ack_list_head = &timer->sack_list_head;
760 		if (list_empty(&ti->ack_list))
761 			list_add_tail(&ti->ack_list, ack_list_head);
762 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
763 			ts->pticks = ti->pticks;
764 			ts->resolution = resolution;
765 			if (list_empty(&ts->ack_list))
766 				list_add_tail(&ts->ack_list, ack_list_head);
767 		}
768 	}
769 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
770 		snd_timer_reschedule(timer, timer->sticks);
771 	if (timer->running) {
772 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
773 			timer->hw.stop(timer);
774 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
775 		}
776 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
777 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
778 			/* restart timer */
779 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
780 			timer->hw.start(timer);
781 		}
782 	} else {
783 		timer->hw.stop(timer);
784 	}
785 
786 	/* now process all fast callbacks */
787 	while (!list_empty(&timer->ack_list_head)) {
788 		p = timer->ack_list_head.next;		/* get first item */
789 		ti = list_entry(p, struct snd_timer_instance, ack_list);
790 
791 		/* remove from ack_list and make empty */
792 		list_del_init(p);
793 
794 		ticks = ti->pticks;
795 		ti->pticks = 0;
796 
797 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
798 		spin_unlock(&timer->lock);
799 		if (ti->callback)
800 			ti->callback(ti, resolution, ticks);
801 		spin_lock(&timer->lock);
802 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
803 	}
804 
805 	/* do we have any slow callbacks? */
806 	use_tasklet = !list_empty(&timer->sack_list_head);
807 	spin_unlock_irqrestore(&timer->lock, flags);
808 
809 	if (use_tasklet)
810 		tasklet_schedule(&timer->task_queue);
811 }
812 
813 /*
814 
815  */
816 
817 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
818 		  struct snd_timer **rtimer)
819 {
820 	struct snd_timer *timer;
821 	int err;
822 	static struct snd_device_ops ops = {
823 		.dev_free = snd_timer_dev_free,
824 		.dev_register = snd_timer_dev_register,
825 		.dev_disconnect = snd_timer_dev_disconnect,
826 	};
827 
828 	if (snd_BUG_ON(!tid))
829 		return -EINVAL;
830 	if (rtimer)
831 		*rtimer = NULL;
832 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
833 	if (!timer)
834 		return -ENOMEM;
835 	timer->tmr_class = tid->dev_class;
836 	timer->card = card;
837 	timer->tmr_device = tid->device;
838 	timer->tmr_subdevice = tid->subdevice;
839 	if (id)
840 		strlcpy(timer->id, id, sizeof(timer->id));
841 	timer->sticks = 1;
842 	INIT_LIST_HEAD(&timer->device_list);
843 	INIT_LIST_HEAD(&timer->open_list_head);
844 	INIT_LIST_HEAD(&timer->active_list_head);
845 	INIT_LIST_HEAD(&timer->ack_list_head);
846 	INIT_LIST_HEAD(&timer->sack_list_head);
847 	spin_lock_init(&timer->lock);
848 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
849 		     (unsigned long)timer);
850 	if (card != NULL) {
851 		timer->module = card->module;
852 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
853 		if (err < 0) {
854 			snd_timer_free(timer);
855 			return err;
856 		}
857 	}
858 	if (rtimer)
859 		*rtimer = timer;
860 	return 0;
861 }
862 
863 static int snd_timer_free(struct snd_timer *timer)
864 {
865 	if (!timer)
866 		return 0;
867 
868 	mutex_lock(&register_mutex);
869 	if (! list_empty(&timer->open_list_head)) {
870 		struct list_head *p, *n;
871 		struct snd_timer_instance *ti;
872 		pr_warn("ALSA: timer %p is busy?\n", timer);
873 		list_for_each_safe(p, n, &timer->open_list_head) {
874 			list_del_init(p);
875 			ti = list_entry(p, struct snd_timer_instance, open_list);
876 			ti->timer = NULL;
877 		}
878 	}
879 	list_del(&timer->device_list);
880 	mutex_unlock(&register_mutex);
881 
882 	if (timer->private_free)
883 		timer->private_free(timer);
884 	kfree(timer);
885 	return 0;
886 }
887 
888 static int snd_timer_dev_free(struct snd_device *device)
889 {
890 	struct snd_timer *timer = device->device_data;
891 	return snd_timer_free(timer);
892 }
893 
894 static int snd_timer_dev_register(struct snd_device *dev)
895 {
896 	struct snd_timer *timer = dev->device_data;
897 	struct snd_timer *timer1;
898 
899 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
900 		return -ENXIO;
901 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
902 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
903 	    	return -EINVAL;
904 
905 	mutex_lock(&register_mutex);
906 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
907 		if (timer1->tmr_class > timer->tmr_class)
908 			break;
909 		if (timer1->tmr_class < timer->tmr_class)
910 			continue;
911 		if (timer1->card && timer->card) {
912 			if (timer1->card->number > timer->card->number)
913 				break;
914 			if (timer1->card->number < timer->card->number)
915 				continue;
916 		}
917 		if (timer1->tmr_device > timer->tmr_device)
918 			break;
919 		if (timer1->tmr_device < timer->tmr_device)
920 			continue;
921 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
922 			break;
923 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
924 			continue;
925 		/* conflicts.. */
926 		mutex_unlock(&register_mutex);
927 		return -EBUSY;
928 	}
929 	list_add_tail(&timer->device_list, &timer1->device_list);
930 	mutex_unlock(&register_mutex);
931 	return 0;
932 }
933 
934 static int snd_timer_dev_disconnect(struct snd_device *device)
935 {
936 	struct snd_timer *timer = device->device_data;
937 	struct snd_timer_instance *ti;
938 
939 	mutex_lock(&register_mutex);
940 	list_del_init(&timer->device_list);
941 	/* wake up pending sleepers */
942 	list_for_each_entry(ti, &timer->open_list_head, open_list) {
943 		if (ti->disconnect)
944 			ti->disconnect(ti);
945 	}
946 	mutex_unlock(&register_mutex);
947 	return 0;
948 }
949 
950 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
951 {
952 	unsigned long flags;
953 	unsigned long resolution = 0;
954 	struct snd_timer_instance *ti, *ts;
955 
956 	if (timer->card && timer->card->shutdown)
957 		return;
958 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
959 		return;
960 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
961 		       event > SNDRV_TIMER_EVENT_MRESUME))
962 		return;
963 	spin_lock_irqsave(&timer->lock, flags);
964 	if (event == SNDRV_TIMER_EVENT_MSTART ||
965 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
966 	    event == SNDRV_TIMER_EVENT_MRESUME) {
967 		if (timer->hw.c_resolution)
968 			resolution = timer->hw.c_resolution(timer);
969 		else
970 			resolution = timer->hw.resolution;
971 	}
972 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
973 		if (ti->ccallback)
974 			ti->ccallback(ti, event, tstamp, resolution);
975 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
976 			if (ts->ccallback)
977 				ts->ccallback(ts, event, tstamp, resolution);
978 	}
979 	spin_unlock_irqrestore(&timer->lock, flags);
980 }
981 
982 /*
983  * exported functions for global timers
984  */
985 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
986 {
987 	struct snd_timer_id tid;
988 
989 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
990 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
991 	tid.card = -1;
992 	tid.device = device;
993 	tid.subdevice = 0;
994 	return snd_timer_new(NULL, id, &tid, rtimer);
995 }
996 
997 int snd_timer_global_free(struct snd_timer *timer)
998 {
999 	return snd_timer_free(timer);
1000 }
1001 
1002 int snd_timer_global_register(struct snd_timer *timer)
1003 {
1004 	struct snd_device dev;
1005 
1006 	memset(&dev, 0, sizeof(dev));
1007 	dev.device_data = timer;
1008 	return snd_timer_dev_register(&dev);
1009 }
1010 
1011 /*
1012  *  System timer
1013  */
1014 
1015 struct snd_timer_system_private {
1016 	struct timer_list tlist;
1017 	unsigned long last_expires;
1018 	unsigned long last_jiffies;
1019 	unsigned long correction;
1020 };
1021 
1022 static void snd_timer_s_function(unsigned long data)
1023 {
1024 	struct snd_timer *timer = (struct snd_timer *)data;
1025 	struct snd_timer_system_private *priv = timer->private_data;
1026 	unsigned long jiff = jiffies;
1027 	if (time_after(jiff, priv->last_expires))
1028 		priv->correction += (long)jiff - (long)priv->last_expires;
1029 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1030 }
1031 
1032 static int snd_timer_s_start(struct snd_timer * timer)
1033 {
1034 	struct snd_timer_system_private *priv;
1035 	unsigned long njiff;
1036 
1037 	priv = (struct snd_timer_system_private *) timer->private_data;
1038 	njiff = (priv->last_jiffies = jiffies);
1039 	if (priv->correction > timer->sticks - 1) {
1040 		priv->correction -= timer->sticks - 1;
1041 		njiff++;
1042 	} else {
1043 		njiff += timer->sticks - priv->correction;
1044 		priv->correction = 0;
1045 	}
1046 	priv->last_expires = njiff;
1047 	mod_timer(&priv->tlist, njiff);
1048 	return 0;
1049 }
1050 
1051 static int snd_timer_s_stop(struct snd_timer * timer)
1052 {
1053 	struct snd_timer_system_private *priv;
1054 	unsigned long jiff;
1055 
1056 	priv = (struct snd_timer_system_private *) timer->private_data;
1057 	del_timer(&priv->tlist);
1058 	jiff = jiffies;
1059 	if (time_before(jiff, priv->last_expires))
1060 		timer->sticks = priv->last_expires - jiff;
1061 	else
1062 		timer->sticks = 1;
1063 	priv->correction = 0;
1064 	return 0;
1065 }
1066 
1067 static int snd_timer_s_close(struct snd_timer *timer)
1068 {
1069 	struct snd_timer_system_private *priv;
1070 
1071 	priv = (struct snd_timer_system_private *)timer->private_data;
1072 	del_timer_sync(&priv->tlist);
1073 	return 0;
1074 }
1075 
1076 static struct snd_timer_hardware snd_timer_system =
1077 {
1078 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1079 	.resolution =	1000000000L / HZ,
1080 	.ticks =	10000000L,
1081 	.close =	snd_timer_s_close,
1082 	.start =	snd_timer_s_start,
1083 	.stop =		snd_timer_s_stop
1084 };
1085 
1086 static void snd_timer_free_system(struct snd_timer *timer)
1087 {
1088 	kfree(timer->private_data);
1089 }
1090 
1091 static int snd_timer_register_system(void)
1092 {
1093 	struct snd_timer *timer;
1094 	struct snd_timer_system_private *priv;
1095 	int err;
1096 
1097 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1098 	if (err < 0)
1099 		return err;
1100 	strcpy(timer->name, "system timer");
1101 	timer->hw = snd_timer_system;
1102 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1103 	if (priv == NULL) {
1104 		snd_timer_free(timer);
1105 		return -ENOMEM;
1106 	}
1107 	setup_timer(&priv->tlist, snd_timer_s_function, (unsigned long) timer);
1108 	timer->private_data = priv;
1109 	timer->private_free = snd_timer_free_system;
1110 	return snd_timer_global_register(timer);
1111 }
1112 
1113 #ifdef CONFIG_SND_PROC_FS
1114 /*
1115  *  Info interface
1116  */
1117 
1118 static void snd_timer_proc_read(struct snd_info_entry *entry,
1119 				struct snd_info_buffer *buffer)
1120 {
1121 	struct snd_timer *timer;
1122 	struct snd_timer_instance *ti;
1123 
1124 	mutex_lock(&register_mutex);
1125 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1126 		if (timer->card && timer->card->shutdown)
1127 			continue;
1128 		switch (timer->tmr_class) {
1129 		case SNDRV_TIMER_CLASS_GLOBAL:
1130 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1131 			break;
1132 		case SNDRV_TIMER_CLASS_CARD:
1133 			snd_iprintf(buffer, "C%i-%i: ",
1134 				    timer->card->number, timer->tmr_device);
1135 			break;
1136 		case SNDRV_TIMER_CLASS_PCM:
1137 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1138 				    timer->tmr_device, timer->tmr_subdevice);
1139 			break;
1140 		default:
1141 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1142 				    timer->card ? timer->card->number : -1,
1143 				    timer->tmr_device, timer->tmr_subdevice);
1144 		}
1145 		snd_iprintf(buffer, "%s :", timer->name);
1146 		if (timer->hw.resolution)
1147 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1148 				    timer->hw.resolution / 1000,
1149 				    timer->hw.resolution % 1000,
1150 				    timer->hw.ticks);
1151 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1152 			snd_iprintf(buffer, " SLAVE");
1153 		snd_iprintf(buffer, "\n");
1154 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1155 			snd_iprintf(buffer, "  Client %s : %s\n",
1156 				    ti->owner ? ti->owner : "unknown",
1157 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1158 						 SNDRV_TIMER_IFLG_RUNNING)
1159 				    ? "running" : "stopped");
1160 	}
1161 	mutex_unlock(&register_mutex);
1162 }
1163 
1164 static struct snd_info_entry *snd_timer_proc_entry;
1165 
1166 static void __init snd_timer_proc_init(void)
1167 {
1168 	struct snd_info_entry *entry;
1169 
1170 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1171 	if (entry != NULL) {
1172 		entry->c.text.read = snd_timer_proc_read;
1173 		if (snd_info_register(entry) < 0) {
1174 			snd_info_free_entry(entry);
1175 			entry = NULL;
1176 		}
1177 	}
1178 	snd_timer_proc_entry = entry;
1179 }
1180 
1181 static void __exit snd_timer_proc_done(void)
1182 {
1183 	snd_info_free_entry(snd_timer_proc_entry);
1184 }
1185 #else /* !CONFIG_SND_PROC_FS */
1186 #define snd_timer_proc_init()
1187 #define snd_timer_proc_done()
1188 #endif
1189 
1190 /*
1191  *  USER SPACE interface
1192  */
1193 
1194 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1195 				     unsigned long resolution,
1196 				     unsigned long ticks)
1197 {
1198 	struct snd_timer_user *tu = timeri->callback_data;
1199 	struct snd_timer_read *r;
1200 	int prev;
1201 
1202 	spin_lock(&tu->qlock);
1203 	if (tu->qused > 0) {
1204 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1205 		r = &tu->queue[prev];
1206 		if (r->resolution == resolution) {
1207 			r->ticks += ticks;
1208 			goto __wake;
1209 		}
1210 	}
1211 	if (tu->qused >= tu->queue_size) {
1212 		tu->overrun++;
1213 	} else {
1214 		r = &tu->queue[tu->qtail++];
1215 		tu->qtail %= tu->queue_size;
1216 		r->resolution = resolution;
1217 		r->ticks = ticks;
1218 		tu->qused++;
1219 	}
1220       __wake:
1221 	spin_unlock(&tu->qlock);
1222 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1223 	wake_up(&tu->qchange_sleep);
1224 }
1225 
1226 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1227 					    struct snd_timer_tread *tread)
1228 {
1229 	if (tu->qused >= tu->queue_size) {
1230 		tu->overrun++;
1231 	} else {
1232 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1233 		tu->qtail %= tu->queue_size;
1234 		tu->qused++;
1235 	}
1236 }
1237 
1238 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1239 				     int event,
1240 				     struct timespec *tstamp,
1241 				     unsigned long resolution)
1242 {
1243 	struct snd_timer_user *tu = timeri->callback_data;
1244 	struct snd_timer_tread r1;
1245 	unsigned long flags;
1246 
1247 	if (event >= SNDRV_TIMER_EVENT_START &&
1248 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1249 		tu->tstamp = *tstamp;
1250 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1251 		return;
1252 	memset(&r1, 0, sizeof(r1));
1253 	r1.event = event;
1254 	r1.tstamp = *tstamp;
1255 	r1.val = resolution;
1256 	spin_lock_irqsave(&tu->qlock, flags);
1257 	snd_timer_user_append_to_tqueue(tu, &r1);
1258 	spin_unlock_irqrestore(&tu->qlock, flags);
1259 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1260 	wake_up(&tu->qchange_sleep);
1261 }
1262 
1263 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1264 {
1265 	struct snd_timer_user *tu = timeri->callback_data;
1266 
1267 	tu->disconnected = true;
1268 	wake_up(&tu->qchange_sleep);
1269 }
1270 
1271 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1272 				      unsigned long resolution,
1273 				      unsigned long ticks)
1274 {
1275 	struct snd_timer_user *tu = timeri->callback_data;
1276 	struct snd_timer_tread *r, r1;
1277 	struct timespec tstamp;
1278 	int prev, append = 0;
1279 
1280 	memset(&r1, 0, sizeof(r1));
1281 	memset(&tstamp, 0, sizeof(tstamp));
1282 	spin_lock(&tu->qlock);
1283 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1284 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1285 		spin_unlock(&tu->qlock);
1286 		return;
1287 	}
1288 	if (tu->last_resolution != resolution || ticks > 0) {
1289 		if (timer_tstamp_monotonic)
1290 			ktime_get_ts(&tstamp);
1291 		else
1292 			getnstimeofday(&tstamp);
1293 	}
1294 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1295 	    tu->last_resolution != resolution) {
1296 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1297 		r1.tstamp = tstamp;
1298 		r1.val = resolution;
1299 		snd_timer_user_append_to_tqueue(tu, &r1);
1300 		tu->last_resolution = resolution;
1301 		append++;
1302 	}
1303 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1304 		goto __wake;
1305 	if (ticks == 0)
1306 		goto __wake;
1307 	if (tu->qused > 0) {
1308 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1309 		r = &tu->tqueue[prev];
1310 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1311 			r->tstamp = tstamp;
1312 			r->val += ticks;
1313 			append++;
1314 			goto __wake;
1315 		}
1316 	}
1317 	r1.event = SNDRV_TIMER_EVENT_TICK;
1318 	r1.tstamp = tstamp;
1319 	r1.val = ticks;
1320 	snd_timer_user_append_to_tqueue(tu, &r1);
1321 	append++;
1322       __wake:
1323 	spin_unlock(&tu->qlock);
1324 	if (append == 0)
1325 		return;
1326 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1327 	wake_up(&tu->qchange_sleep);
1328 }
1329 
1330 static int snd_timer_user_open(struct inode *inode, struct file *file)
1331 {
1332 	struct snd_timer_user *tu;
1333 	int err;
1334 
1335 	err = nonseekable_open(inode, file);
1336 	if (err < 0)
1337 		return err;
1338 
1339 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1340 	if (tu == NULL)
1341 		return -ENOMEM;
1342 	spin_lock_init(&tu->qlock);
1343 	init_waitqueue_head(&tu->qchange_sleep);
1344 	mutex_init(&tu->ioctl_lock);
1345 	tu->ticks = 1;
1346 	tu->queue_size = 128;
1347 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1348 			    GFP_KERNEL);
1349 	if (tu->queue == NULL) {
1350 		kfree(tu);
1351 		return -ENOMEM;
1352 	}
1353 	file->private_data = tu;
1354 	return 0;
1355 }
1356 
1357 static int snd_timer_user_release(struct inode *inode, struct file *file)
1358 {
1359 	struct snd_timer_user *tu;
1360 
1361 	if (file->private_data) {
1362 		tu = file->private_data;
1363 		file->private_data = NULL;
1364 		mutex_lock(&tu->ioctl_lock);
1365 		if (tu->timeri)
1366 			snd_timer_close(tu->timeri);
1367 		mutex_unlock(&tu->ioctl_lock);
1368 		kfree(tu->queue);
1369 		kfree(tu->tqueue);
1370 		kfree(tu);
1371 	}
1372 	return 0;
1373 }
1374 
1375 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1376 {
1377 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1378 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1379 	id->card = -1;
1380 	id->device = -1;
1381 	id->subdevice = -1;
1382 }
1383 
1384 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1385 {
1386 	id->dev_class = timer->tmr_class;
1387 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1388 	id->card = timer->card ? timer->card->number : -1;
1389 	id->device = timer->tmr_device;
1390 	id->subdevice = timer->tmr_subdevice;
1391 }
1392 
1393 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1394 {
1395 	struct snd_timer_id id;
1396 	struct snd_timer *timer;
1397 	struct list_head *p;
1398 
1399 	if (copy_from_user(&id, _tid, sizeof(id)))
1400 		return -EFAULT;
1401 	mutex_lock(&register_mutex);
1402 	if (id.dev_class < 0) {		/* first item */
1403 		if (list_empty(&snd_timer_list))
1404 			snd_timer_user_zero_id(&id);
1405 		else {
1406 			timer = list_entry(snd_timer_list.next,
1407 					   struct snd_timer, device_list);
1408 			snd_timer_user_copy_id(&id, timer);
1409 		}
1410 	} else {
1411 		switch (id.dev_class) {
1412 		case SNDRV_TIMER_CLASS_GLOBAL:
1413 			id.device = id.device < 0 ? 0 : id.device + 1;
1414 			list_for_each(p, &snd_timer_list) {
1415 				timer = list_entry(p, struct snd_timer, device_list);
1416 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1417 					snd_timer_user_copy_id(&id, timer);
1418 					break;
1419 				}
1420 				if (timer->tmr_device >= id.device) {
1421 					snd_timer_user_copy_id(&id, timer);
1422 					break;
1423 				}
1424 			}
1425 			if (p == &snd_timer_list)
1426 				snd_timer_user_zero_id(&id);
1427 			break;
1428 		case SNDRV_TIMER_CLASS_CARD:
1429 		case SNDRV_TIMER_CLASS_PCM:
1430 			if (id.card < 0) {
1431 				id.card = 0;
1432 			} else {
1433 				if (id.device < 0) {
1434 					id.device = 0;
1435 				} else {
1436 					if (id.subdevice < 0)
1437 						id.subdevice = 0;
1438 					else
1439 						id.subdevice++;
1440 				}
1441 			}
1442 			list_for_each(p, &snd_timer_list) {
1443 				timer = list_entry(p, struct snd_timer, device_list);
1444 				if (timer->tmr_class > id.dev_class) {
1445 					snd_timer_user_copy_id(&id, timer);
1446 					break;
1447 				}
1448 				if (timer->tmr_class < id.dev_class)
1449 					continue;
1450 				if (timer->card->number > id.card) {
1451 					snd_timer_user_copy_id(&id, timer);
1452 					break;
1453 				}
1454 				if (timer->card->number < id.card)
1455 					continue;
1456 				if (timer->tmr_device > id.device) {
1457 					snd_timer_user_copy_id(&id, timer);
1458 					break;
1459 				}
1460 				if (timer->tmr_device < id.device)
1461 					continue;
1462 				if (timer->tmr_subdevice > id.subdevice) {
1463 					snd_timer_user_copy_id(&id, timer);
1464 					break;
1465 				}
1466 				if (timer->tmr_subdevice < id.subdevice)
1467 					continue;
1468 				snd_timer_user_copy_id(&id, timer);
1469 				break;
1470 			}
1471 			if (p == &snd_timer_list)
1472 				snd_timer_user_zero_id(&id);
1473 			break;
1474 		default:
1475 			snd_timer_user_zero_id(&id);
1476 		}
1477 	}
1478 	mutex_unlock(&register_mutex);
1479 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1480 		return -EFAULT;
1481 	return 0;
1482 }
1483 
1484 static int snd_timer_user_ginfo(struct file *file,
1485 				struct snd_timer_ginfo __user *_ginfo)
1486 {
1487 	struct snd_timer_ginfo *ginfo;
1488 	struct snd_timer_id tid;
1489 	struct snd_timer *t;
1490 	struct list_head *p;
1491 	int err = 0;
1492 
1493 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1494 	if (IS_ERR(ginfo))
1495 		return PTR_ERR(ginfo);
1496 
1497 	tid = ginfo->tid;
1498 	memset(ginfo, 0, sizeof(*ginfo));
1499 	ginfo->tid = tid;
1500 	mutex_lock(&register_mutex);
1501 	t = snd_timer_find(&tid);
1502 	if (t != NULL) {
1503 		ginfo->card = t->card ? t->card->number : -1;
1504 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1505 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1506 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1507 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1508 		ginfo->resolution = t->hw.resolution;
1509 		if (t->hw.resolution_min > 0) {
1510 			ginfo->resolution_min = t->hw.resolution_min;
1511 			ginfo->resolution_max = t->hw.resolution_max;
1512 		}
1513 		list_for_each(p, &t->open_list_head) {
1514 			ginfo->clients++;
1515 		}
1516 	} else {
1517 		err = -ENODEV;
1518 	}
1519 	mutex_unlock(&register_mutex);
1520 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1521 		err = -EFAULT;
1522 	kfree(ginfo);
1523 	return err;
1524 }
1525 
1526 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1527 {
1528 	struct snd_timer *t;
1529 	int err;
1530 
1531 	mutex_lock(&register_mutex);
1532 	t = snd_timer_find(&gparams->tid);
1533 	if (!t) {
1534 		err = -ENODEV;
1535 		goto _error;
1536 	}
1537 	if (!list_empty(&t->open_list_head)) {
1538 		err = -EBUSY;
1539 		goto _error;
1540 	}
1541 	if (!t->hw.set_period) {
1542 		err = -ENOSYS;
1543 		goto _error;
1544 	}
1545 	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1546 _error:
1547 	mutex_unlock(&register_mutex);
1548 	return err;
1549 }
1550 
1551 static int snd_timer_user_gparams(struct file *file,
1552 				  struct snd_timer_gparams __user *_gparams)
1553 {
1554 	struct snd_timer_gparams gparams;
1555 
1556 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1557 		return -EFAULT;
1558 	return timer_set_gparams(&gparams);
1559 }
1560 
1561 static int snd_timer_user_gstatus(struct file *file,
1562 				  struct snd_timer_gstatus __user *_gstatus)
1563 {
1564 	struct snd_timer_gstatus gstatus;
1565 	struct snd_timer_id tid;
1566 	struct snd_timer *t;
1567 	int err = 0;
1568 
1569 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1570 		return -EFAULT;
1571 	tid = gstatus.tid;
1572 	memset(&gstatus, 0, sizeof(gstatus));
1573 	gstatus.tid = tid;
1574 	mutex_lock(&register_mutex);
1575 	t = snd_timer_find(&tid);
1576 	if (t != NULL) {
1577 		if (t->hw.c_resolution)
1578 			gstatus.resolution = t->hw.c_resolution(t);
1579 		else
1580 			gstatus.resolution = t->hw.resolution;
1581 		if (t->hw.precise_resolution) {
1582 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1583 						 &gstatus.resolution_den);
1584 		} else {
1585 			gstatus.resolution_num = gstatus.resolution;
1586 			gstatus.resolution_den = 1000000000uL;
1587 		}
1588 	} else {
1589 		err = -ENODEV;
1590 	}
1591 	mutex_unlock(&register_mutex);
1592 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1593 		err = -EFAULT;
1594 	return err;
1595 }
1596 
1597 static int snd_timer_user_tselect(struct file *file,
1598 				  struct snd_timer_select __user *_tselect)
1599 {
1600 	struct snd_timer_user *tu;
1601 	struct snd_timer_select tselect;
1602 	char str[32];
1603 	int err = 0;
1604 
1605 	tu = file->private_data;
1606 	if (tu->timeri) {
1607 		snd_timer_close(tu->timeri);
1608 		tu->timeri = NULL;
1609 	}
1610 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1611 		err = -EFAULT;
1612 		goto __err;
1613 	}
1614 	sprintf(str, "application %i", current->pid);
1615 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1616 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1617 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1618 	if (err < 0)
1619 		goto __err;
1620 
1621 	tu->qhead = tu->qtail = tu->qused = 0;
1622 	kfree(tu->queue);
1623 	tu->queue = NULL;
1624 	kfree(tu->tqueue);
1625 	tu->tqueue = NULL;
1626 	if (tu->tread) {
1627 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1628 				     GFP_KERNEL);
1629 		if (tu->tqueue == NULL)
1630 			err = -ENOMEM;
1631 	} else {
1632 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1633 				    GFP_KERNEL);
1634 		if (tu->queue == NULL)
1635 			err = -ENOMEM;
1636 	}
1637 
1638       	if (err < 0) {
1639 		snd_timer_close(tu->timeri);
1640       		tu->timeri = NULL;
1641       	} else {
1642 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1643 		tu->timeri->callback = tu->tread
1644 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1645 		tu->timeri->ccallback = snd_timer_user_ccallback;
1646 		tu->timeri->callback_data = (void *)tu;
1647 		tu->timeri->disconnect = snd_timer_user_disconnect;
1648 	}
1649 
1650       __err:
1651 	return err;
1652 }
1653 
1654 static int snd_timer_user_info(struct file *file,
1655 			       struct snd_timer_info __user *_info)
1656 {
1657 	struct snd_timer_user *tu;
1658 	struct snd_timer_info *info;
1659 	struct snd_timer *t;
1660 	int err = 0;
1661 
1662 	tu = file->private_data;
1663 	if (!tu->timeri)
1664 		return -EBADFD;
1665 	t = tu->timeri->timer;
1666 	if (!t)
1667 		return -EBADFD;
1668 
1669 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1670 	if (! info)
1671 		return -ENOMEM;
1672 	info->card = t->card ? t->card->number : -1;
1673 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1674 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1675 	strlcpy(info->id, t->id, sizeof(info->id));
1676 	strlcpy(info->name, t->name, sizeof(info->name));
1677 	info->resolution = t->hw.resolution;
1678 	if (copy_to_user(_info, info, sizeof(*_info)))
1679 		err = -EFAULT;
1680 	kfree(info);
1681 	return err;
1682 }
1683 
1684 static int snd_timer_user_params(struct file *file,
1685 				 struct snd_timer_params __user *_params)
1686 {
1687 	struct snd_timer_user *tu;
1688 	struct snd_timer_params params;
1689 	struct snd_timer *t;
1690 	struct snd_timer_read *tr;
1691 	struct snd_timer_tread *ttr;
1692 	int err;
1693 
1694 	tu = file->private_data;
1695 	if (!tu->timeri)
1696 		return -EBADFD;
1697 	t = tu->timeri->timer;
1698 	if (!t)
1699 		return -EBADFD;
1700 	if (copy_from_user(&params, _params, sizeof(params)))
1701 		return -EFAULT;
1702 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1703 		u64 resolution;
1704 
1705 		if (params.ticks < 1) {
1706 			err = -EINVAL;
1707 			goto _end;
1708 		}
1709 
1710 		/* Don't allow resolution less than 1ms */
1711 		resolution = snd_timer_resolution(tu->timeri);
1712 		resolution *= params.ticks;
1713 		if (resolution < 1000000) {
1714 			err = -EINVAL;
1715 			goto _end;
1716 		}
1717 	}
1718 	if (params.queue_size > 0 &&
1719 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1720 		err = -EINVAL;
1721 		goto _end;
1722 	}
1723 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1724 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1725 			      (1<<SNDRV_TIMER_EVENT_START)|
1726 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1727 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1728 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1729 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1730 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1731 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1732 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1733 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1734 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1735 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1736 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1737 		err = -EINVAL;
1738 		goto _end;
1739 	}
1740 	snd_timer_stop(tu->timeri);
1741 	spin_lock_irq(&t->lock);
1742 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1743 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1744 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1745 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1746 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1747 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1748 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1749 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1750 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1751 	spin_unlock_irq(&t->lock);
1752 	if (params.queue_size > 0 &&
1753 	    (unsigned int)tu->queue_size != params.queue_size) {
1754 		if (tu->tread) {
1755 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1756 				      GFP_KERNEL);
1757 			if (ttr) {
1758 				kfree(tu->tqueue);
1759 				tu->queue_size = params.queue_size;
1760 				tu->tqueue = ttr;
1761 			}
1762 		} else {
1763 			tr = kmalloc(params.queue_size * sizeof(*tr),
1764 				     GFP_KERNEL);
1765 			if (tr) {
1766 				kfree(tu->queue);
1767 				tu->queue_size = params.queue_size;
1768 				tu->queue = tr;
1769 			}
1770 		}
1771 	}
1772 	tu->qhead = tu->qtail = tu->qused = 0;
1773 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1774 		if (tu->tread) {
1775 			struct snd_timer_tread tread;
1776 			memset(&tread, 0, sizeof(tread));
1777 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1778 			tread.tstamp.tv_sec = 0;
1779 			tread.tstamp.tv_nsec = 0;
1780 			tread.val = 0;
1781 			snd_timer_user_append_to_tqueue(tu, &tread);
1782 		} else {
1783 			struct snd_timer_read *r = &tu->queue[0];
1784 			r->resolution = 0;
1785 			r->ticks = 0;
1786 			tu->qused++;
1787 			tu->qtail++;
1788 		}
1789 	}
1790 	tu->filter = params.filter;
1791 	tu->ticks = params.ticks;
1792 	err = 0;
1793  _end:
1794 	if (copy_to_user(_params, &params, sizeof(params)))
1795 		return -EFAULT;
1796 	return err;
1797 }
1798 
1799 static int snd_timer_user_status(struct file *file,
1800 				 struct snd_timer_status __user *_status)
1801 {
1802 	struct snd_timer_user *tu;
1803 	struct snd_timer_status status;
1804 
1805 	tu = file->private_data;
1806 	if (!tu->timeri)
1807 		return -EBADFD;
1808 	memset(&status, 0, sizeof(status));
1809 	status.tstamp = tu->tstamp;
1810 	status.resolution = snd_timer_resolution(tu->timeri);
1811 	status.lost = tu->timeri->lost;
1812 	status.overrun = tu->overrun;
1813 	spin_lock_irq(&tu->qlock);
1814 	status.queue = tu->qused;
1815 	spin_unlock_irq(&tu->qlock);
1816 	if (copy_to_user(_status, &status, sizeof(status)))
1817 		return -EFAULT;
1818 	return 0;
1819 }
1820 
1821 static int snd_timer_user_start(struct file *file)
1822 {
1823 	int err;
1824 	struct snd_timer_user *tu;
1825 
1826 	tu = file->private_data;
1827 	if (!tu->timeri)
1828 		return -EBADFD;
1829 	snd_timer_stop(tu->timeri);
1830 	tu->timeri->lost = 0;
1831 	tu->last_resolution = 0;
1832 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1833 }
1834 
1835 static int snd_timer_user_stop(struct file *file)
1836 {
1837 	int err;
1838 	struct snd_timer_user *tu;
1839 
1840 	tu = file->private_data;
1841 	if (!tu->timeri)
1842 		return -EBADFD;
1843 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1844 }
1845 
1846 static int snd_timer_user_continue(struct file *file)
1847 {
1848 	int err;
1849 	struct snd_timer_user *tu;
1850 
1851 	tu = file->private_data;
1852 	if (!tu->timeri)
1853 		return -EBADFD;
1854 	/* start timer instead of continue if it's not used before */
1855 	if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1856 		return snd_timer_user_start(file);
1857 	tu->timeri->lost = 0;
1858 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1859 }
1860 
1861 static int snd_timer_user_pause(struct file *file)
1862 {
1863 	int err;
1864 	struct snd_timer_user *tu;
1865 
1866 	tu = file->private_data;
1867 	if (!tu->timeri)
1868 		return -EBADFD;
1869 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1870 }
1871 
1872 enum {
1873 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1874 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1875 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1876 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1877 };
1878 
1879 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1880 				 unsigned long arg)
1881 {
1882 	struct snd_timer_user *tu;
1883 	void __user *argp = (void __user *)arg;
1884 	int __user *p = argp;
1885 
1886 	tu = file->private_data;
1887 	switch (cmd) {
1888 	case SNDRV_TIMER_IOCTL_PVERSION:
1889 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1890 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1891 		return snd_timer_user_next_device(argp);
1892 	case SNDRV_TIMER_IOCTL_TREAD:
1893 	{
1894 		int xarg;
1895 
1896 		if (tu->timeri)	/* too late */
1897 			return -EBUSY;
1898 		if (get_user(xarg, p))
1899 			return -EFAULT;
1900 		tu->tread = xarg ? 1 : 0;
1901 		return 0;
1902 	}
1903 	case SNDRV_TIMER_IOCTL_GINFO:
1904 		return snd_timer_user_ginfo(file, argp);
1905 	case SNDRV_TIMER_IOCTL_GPARAMS:
1906 		return snd_timer_user_gparams(file, argp);
1907 	case SNDRV_TIMER_IOCTL_GSTATUS:
1908 		return snd_timer_user_gstatus(file, argp);
1909 	case SNDRV_TIMER_IOCTL_SELECT:
1910 		return snd_timer_user_tselect(file, argp);
1911 	case SNDRV_TIMER_IOCTL_INFO:
1912 		return snd_timer_user_info(file, argp);
1913 	case SNDRV_TIMER_IOCTL_PARAMS:
1914 		return snd_timer_user_params(file, argp);
1915 	case SNDRV_TIMER_IOCTL_STATUS:
1916 		return snd_timer_user_status(file, argp);
1917 	case SNDRV_TIMER_IOCTL_START:
1918 	case SNDRV_TIMER_IOCTL_START_OLD:
1919 		return snd_timer_user_start(file);
1920 	case SNDRV_TIMER_IOCTL_STOP:
1921 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1922 		return snd_timer_user_stop(file);
1923 	case SNDRV_TIMER_IOCTL_CONTINUE:
1924 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1925 		return snd_timer_user_continue(file);
1926 	case SNDRV_TIMER_IOCTL_PAUSE:
1927 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1928 		return snd_timer_user_pause(file);
1929 	}
1930 	return -ENOTTY;
1931 }
1932 
1933 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1934 				 unsigned long arg)
1935 {
1936 	struct snd_timer_user *tu = file->private_data;
1937 	long ret;
1938 
1939 	mutex_lock(&tu->ioctl_lock);
1940 	ret = __snd_timer_user_ioctl(file, cmd, arg);
1941 	mutex_unlock(&tu->ioctl_lock);
1942 	return ret;
1943 }
1944 
1945 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1946 {
1947 	struct snd_timer_user *tu;
1948 
1949 	tu = file->private_data;
1950 	return fasync_helper(fd, file, on, &tu->fasync);
1951 }
1952 
1953 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1954 				   size_t count, loff_t *offset)
1955 {
1956 	struct snd_timer_user *tu;
1957 	long result = 0, unit;
1958 	int qhead;
1959 	int err = 0;
1960 
1961 	tu = file->private_data;
1962 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1963 	mutex_lock(&tu->ioctl_lock);
1964 	spin_lock_irq(&tu->qlock);
1965 	while ((long)count - result >= unit) {
1966 		while (!tu->qused) {
1967 			wait_queue_t wait;
1968 
1969 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1970 				err = -EAGAIN;
1971 				goto _error;
1972 			}
1973 
1974 			set_current_state(TASK_INTERRUPTIBLE);
1975 			init_waitqueue_entry(&wait, current);
1976 			add_wait_queue(&tu->qchange_sleep, &wait);
1977 
1978 			spin_unlock_irq(&tu->qlock);
1979 			mutex_unlock(&tu->ioctl_lock);
1980 			schedule();
1981 			mutex_lock(&tu->ioctl_lock);
1982 			spin_lock_irq(&tu->qlock);
1983 
1984 			remove_wait_queue(&tu->qchange_sleep, &wait);
1985 
1986 			if (tu->disconnected) {
1987 				err = -ENODEV;
1988 				goto _error;
1989 			}
1990 			if (signal_pending(current)) {
1991 				err = -ERESTARTSYS;
1992 				goto _error;
1993 			}
1994 		}
1995 
1996 		qhead = tu->qhead++;
1997 		tu->qhead %= tu->queue_size;
1998 		tu->qused--;
1999 		spin_unlock_irq(&tu->qlock);
2000 
2001 		if (tu->tread) {
2002 			if (copy_to_user(buffer, &tu->tqueue[qhead],
2003 					 sizeof(struct snd_timer_tread)))
2004 				err = -EFAULT;
2005 		} else {
2006 			if (copy_to_user(buffer, &tu->queue[qhead],
2007 					 sizeof(struct snd_timer_read)))
2008 				err = -EFAULT;
2009 		}
2010 
2011 		spin_lock_irq(&tu->qlock);
2012 		if (err < 0)
2013 			goto _error;
2014 		result += unit;
2015 		buffer += unit;
2016 	}
2017  _error:
2018 	spin_unlock_irq(&tu->qlock);
2019 	mutex_unlock(&tu->ioctl_lock);
2020 	return result > 0 ? result : err;
2021 }
2022 
2023 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
2024 {
2025         unsigned int mask;
2026         struct snd_timer_user *tu;
2027 
2028         tu = file->private_data;
2029 
2030         poll_wait(file, &tu->qchange_sleep, wait);
2031 
2032 	mask = 0;
2033 	if (tu->qused)
2034 		mask |= POLLIN | POLLRDNORM;
2035 	if (tu->disconnected)
2036 		mask |= POLLERR;
2037 
2038 	return mask;
2039 }
2040 
2041 #ifdef CONFIG_COMPAT
2042 #include "timer_compat.c"
2043 #else
2044 #define snd_timer_user_ioctl_compat	NULL
2045 #endif
2046 
2047 static const struct file_operations snd_timer_f_ops =
2048 {
2049 	.owner =	THIS_MODULE,
2050 	.read =		snd_timer_user_read,
2051 	.open =		snd_timer_user_open,
2052 	.release =	snd_timer_user_release,
2053 	.llseek =	no_llseek,
2054 	.poll =		snd_timer_user_poll,
2055 	.unlocked_ioctl =	snd_timer_user_ioctl,
2056 	.compat_ioctl =	snd_timer_user_ioctl_compat,
2057 	.fasync = 	snd_timer_user_fasync,
2058 };
2059 
2060 /* unregister the system timer */
2061 static void snd_timer_free_all(void)
2062 {
2063 	struct snd_timer *timer, *n;
2064 
2065 	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2066 		snd_timer_free(timer);
2067 }
2068 
2069 static struct device timer_dev;
2070 
2071 /*
2072  *  ENTRY functions
2073  */
2074 
2075 static int __init alsa_timer_init(void)
2076 {
2077 	int err;
2078 
2079 	snd_device_initialize(&timer_dev, NULL);
2080 	dev_set_name(&timer_dev, "timer");
2081 
2082 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2083 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2084 			      "system timer");
2085 #endif
2086 
2087 	err = snd_timer_register_system();
2088 	if (err < 0) {
2089 		pr_err("ALSA: unable to register system timer (%i)\n", err);
2090 		put_device(&timer_dev);
2091 		return err;
2092 	}
2093 
2094 	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2095 				  &snd_timer_f_ops, NULL, &timer_dev);
2096 	if (err < 0) {
2097 		pr_err("ALSA: unable to register timer device (%i)\n", err);
2098 		snd_timer_free_all();
2099 		put_device(&timer_dev);
2100 		return err;
2101 	}
2102 
2103 	snd_timer_proc_init();
2104 	return 0;
2105 }
2106 
2107 static void __exit alsa_timer_exit(void)
2108 {
2109 	snd_unregister_device(&timer_dev);
2110 	snd_timer_free_all();
2111 	put_device(&timer_dev);
2112 	snd_timer_proc_done();
2113 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2114 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2115 #endif
2116 }
2117 
2118 module_init(alsa_timer_init)
2119 module_exit(alsa_timer_exit)
2120 
2121 EXPORT_SYMBOL(snd_timer_open);
2122 EXPORT_SYMBOL(snd_timer_close);
2123 EXPORT_SYMBOL(snd_timer_resolution);
2124 EXPORT_SYMBOL(snd_timer_start);
2125 EXPORT_SYMBOL(snd_timer_stop);
2126 EXPORT_SYMBOL(snd_timer_continue);
2127 EXPORT_SYMBOL(snd_timer_pause);
2128 EXPORT_SYMBOL(snd_timer_new);
2129 EXPORT_SYMBOL(snd_timer_notify);
2130 EXPORT_SYMBOL(snd_timer_global_new);
2131 EXPORT_SYMBOL(snd_timer_global_free);
2132 EXPORT_SYMBOL(snd_timer_global_register);
2133 EXPORT_SYMBOL(snd_timer_interrupt);
2134