xref: /openbmc/linux/sound/core/timer.c (revision bc5aa3a0)
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 /* internal flags */
39 #define SNDRV_TIMER_IFLG_PAUSED		0x00010000
40 
41 #if IS_ENABLED(CONFIG_SND_HRTIMER)
42 #define DEFAULT_TIMER_LIMIT 4
43 #else
44 #define DEFAULT_TIMER_LIMIT 1
45 #endif
46 
47 static int timer_limit = DEFAULT_TIMER_LIMIT;
48 static int timer_tstamp_monotonic = 1;
49 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
50 MODULE_DESCRIPTION("ALSA timer interface");
51 MODULE_LICENSE("GPL");
52 module_param(timer_limit, int, 0444);
53 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
54 module_param(timer_tstamp_monotonic, int, 0444);
55 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
56 
57 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
58 MODULE_ALIAS("devname:snd/timer");
59 
60 struct snd_timer_user {
61 	struct snd_timer_instance *timeri;
62 	int tread;		/* enhanced read with timestamps and events */
63 	unsigned long ticks;
64 	unsigned long overrun;
65 	int qhead;
66 	int qtail;
67 	int qused;
68 	int queue_size;
69 	bool disconnected;
70 	struct snd_timer_read *queue;
71 	struct snd_timer_tread *tqueue;
72 	spinlock_t qlock;
73 	unsigned long last_resolution;
74 	unsigned int filter;
75 	struct timespec tstamp;		/* trigger tstamp */
76 	wait_queue_head_t qchange_sleep;
77 	struct fasync_struct *fasync;
78 	struct mutex ioctl_lock;
79 };
80 
81 /* list of timers */
82 static LIST_HEAD(snd_timer_list);
83 
84 /* list of slave instances */
85 static LIST_HEAD(snd_timer_slave_list);
86 
87 /* lock for slave active lists */
88 static DEFINE_SPINLOCK(slave_active_lock);
89 
90 static DEFINE_MUTEX(register_mutex);
91 
92 static int snd_timer_free(struct snd_timer *timer);
93 static int snd_timer_dev_free(struct snd_device *device);
94 static int snd_timer_dev_register(struct snd_device *device);
95 static int snd_timer_dev_disconnect(struct snd_device *device);
96 
97 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
98 
99 /*
100  * create a timer instance with the given owner string.
101  * when timer is not NULL, increments the module counter
102  */
103 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
104 							 struct snd_timer *timer)
105 {
106 	struct snd_timer_instance *timeri;
107 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
108 	if (timeri == NULL)
109 		return NULL;
110 	timeri->owner = kstrdup(owner, GFP_KERNEL);
111 	if (! timeri->owner) {
112 		kfree(timeri);
113 		return NULL;
114 	}
115 	INIT_LIST_HEAD(&timeri->open_list);
116 	INIT_LIST_HEAD(&timeri->active_list);
117 	INIT_LIST_HEAD(&timeri->ack_list);
118 	INIT_LIST_HEAD(&timeri->slave_list_head);
119 	INIT_LIST_HEAD(&timeri->slave_active_head);
120 
121 	timeri->timer = timer;
122 	if (timer && !try_module_get(timer->module)) {
123 		kfree(timeri->owner);
124 		kfree(timeri);
125 		return NULL;
126 	}
127 
128 	return timeri;
129 }
130 
131 /*
132  * find a timer instance from the given timer id
133  */
134 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
135 {
136 	struct snd_timer *timer = NULL;
137 
138 	list_for_each_entry(timer, &snd_timer_list, device_list) {
139 		if (timer->tmr_class != tid->dev_class)
140 			continue;
141 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
142 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
143 		    (timer->card == NULL ||
144 		     timer->card->number != tid->card))
145 			continue;
146 		if (timer->tmr_device != tid->device)
147 			continue;
148 		if (timer->tmr_subdevice != tid->subdevice)
149 			continue;
150 		return timer;
151 	}
152 	return NULL;
153 }
154 
155 #ifdef CONFIG_MODULES
156 
157 static void snd_timer_request(struct snd_timer_id *tid)
158 {
159 	switch (tid->dev_class) {
160 	case SNDRV_TIMER_CLASS_GLOBAL:
161 		if (tid->device < timer_limit)
162 			request_module("snd-timer-%i", tid->device);
163 		break;
164 	case SNDRV_TIMER_CLASS_CARD:
165 	case SNDRV_TIMER_CLASS_PCM:
166 		if (tid->card < snd_ecards_limit)
167 			request_module("snd-card-%i", tid->card);
168 		break;
169 	default:
170 		break;
171 	}
172 }
173 
174 #endif
175 
176 /*
177  * look for a master instance matching with the slave id of the given slave.
178  * when found, relink the open_link of the slave.
179  *
180  * call this with register_mutex down.
181  */
182 static void snd_timer_check_slave(struct snd_timer_instance *slave)
183 {
184 	struct snd_timer *timer;
185 	struct snd_timer_instance *master;
186 
187 	/* FIXME: it's really dumb to look up all entries.. */
188 	list_for_each_entry(timer, &snd_timer_list, device_list) {
189 		list_for_each_entry(master, &timer->open_list_head, open_list) {
190 			if (slave->slave_class == master->slave_class &&
191 			    slave->slave_id == master->slave_id) {
192 				list_move_tail(&slave->open_list,
193 					       &master->slave_list_head);
194 				spin_lock_irq(&slave_active_lock);
195 				slave->master = master;
196 				slave->timer = master->timer;
197 				spin_unlock_irq(&slave_active_lock);
198 				return;
199 			}
200 		}
201 	}
202 }
203 
204 /*
205  * look for slave instances matching with the slave id of the given master.
206  * when found, relink the open_link of slaves.
207  *
208  * call this with register_mutex down.
209  */
210 static void snd_timer_check_master(struct snd_timer_instance *master)
211 {
212 	struct snd_timer_instance *slave, *tmp;
213 
214 	/* check all pending slaves */
215 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
216 		if (slave->slave_class == master->slave_class &&
217 		    slave->slave_id == master->slave_id) {
218 			list_move_tail(&slave->open_list, &master->slave_list_head);
219 			spin_lock_irq(&slave_active_lock);
220 			spin_lock(&master->timer->lock);
221 			slave->master = master;
222 			slave->timer = master->timer;
223 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
224 				list_add_tail(&slave->active_list,
225 					      &master->slave_active_head);
226 			spin_unlock(&master->timer->lock);
227 			spin_unlock_irq(&slave_active_lock);
228 		}
229 	}
230 }
231 
232 /*
233  * open a timer instance
234  * when opening a master, the slave id must be here given.
235  */
236 int snd_timer_open(struct snd_timer_instance **ti,
237 		   char *owner, struct snd_timer_id *tid,
238 		   unsigned int slave_id)
239 {
240 	struct snd_timer *timer;
241 	struct snd_timer_instance *timeri = NULL;
242 
243 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
244 		/* open a slave instance */
245 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
246 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
247 			pr_debug("ALSA: timer: invalid slave class %i\n",
248 				 tid->dev_sclass);
249 			return -EINVAL;
250 		}
251 		mutex_lock(&register_mutex);
252 		timeri = snd_timer_instance_new(owner, NULL);
253 		if (!timeri) {
254 			mutex_unlock(&register_mutex);
255 			return -ENOMEM;
256 		}
257 		timeri->slave_class = tid->dev_sclass;
258 		timeri->slave_id = tid->device;
259 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
260 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
261 		snd_timer_check_slave(timeri);
262 		mutex_unlock(&register_mutex);
263 		*ti = timeri;
264 		return 0;
265 	}
266 
267 	/* open a master instance */
268 	mutex_lock(&register_mutex);
269 	timer = snd_timer_find(tid);
270 #ifdef CONFIG_MODULES
271 	if (!timer) {
272 		mutex_unlock(&register_mutex);
273 		snd_timer_request(tid);
274 		mutex_lock(&register_mutex);
275 		timer = snd_timer_find(tid);
276 	}
277 #endif
278 	if (!timer) {
279 		mutex_unlock(&register_mutex);
280 		return -ENODEV;
281 	}
282 	if (!list_empty(&timer->open_list_head)) {
283 		timeri = list_entry(timer->open_list_head.next,
284 				    struct snd_timer_instance, open_list);
285 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
286 			mutex_unlock(&register_mutex);
287 			return -EBUSY;
288 		}
289 	}
290 	timeri = snd_timer_instance_new(owner, timer);
291 	if (!timeri) {
292 		mutex_unlock(&register_mutex);
293 		return -ENOMEM;
294 	}
295 	/* take a card refcount for safe disconnection */
296 	if (timer->card)
297 		get_device(&timer->card->card_dev);
298 	timeri->slave_class = tid->dev_sclass;
299 	timeri->slave_id = slave_id;
300 
301 	if (list_empty(&timer->open_list_head) && timer->hw.open) {
302 		int err = timer->hw.open(timer);
303 		if (err) {
304 			kfree(timeri->owner);
305 			kfree(timeri);
306 
307 			if (timer->card)
308 				put_device(&timer->card->card_dev);
309 			module_put(timer->module);
310 			mutex_unlock(&register_mutex);
311 			return err;
312 		}
313 	}
314 
315 	list_add_tail(&timeri->open_list, &timer->open_list_head);
316 	snd_timer_check_master(timeri);
317 	mutex_unlock(&register_mutex);
318 	*ti = timeri;
319 	return 0;
320 }
321 
322 /*
323  * close a timer instance
324  */
325 int snd_timer_close(struct snd_timer_instance *timeri)
326 {
327 	struct snd_timer *timer = NULL;
328 	struct snd_timer_instance *slave, *tmp;
329 
330 	if (snd_BUG_ON(!timeri))
331 		return -ENXIO;
332 
333 	mutex_lock(&register_mutex);
334 	list_del(&timeri->open_list);
335 
336 	/* force to stop the timer */
337 	snd_timer_stop(timeri);
338 
339 	timer = timeri->timer;
340 	if (timer) {
341 		/* wait, until the active callback is finished */
342 		spin_lock_irq(&timer->lock);
343 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
344 			spin_unlock_irq(&timer->lock);
345 			udelay(10);
346 			spin_lock_irq(&timer->lock);
347 		}
348 		spin_unlock_irq(&timer->lock);
349 
350 		/* remove slave links */
351 		spin_lock_irq(&slave_active_lock);
352 		spin_lock(&timer->lock);
353 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
354 					 open_list) {
355 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
356 			slave->master = NULL;
357 			slave->timer = NULL;
358 			list_del_init(&slave->ack_list);
359 			list_del_init(&slave->active_list);
360 		}
361 		spin_unlock(&timer->lock);
362 		spin_unlock_irq(&slave_active_lock);
363 
364 		/* slave doesn't need to release timer resources below */
365 		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
366 			timer = NULL;
367 	}
368 
369 	if (timeri->private_free)
370 		timeri->private_free(timeri);
371 	kfree(timeri->owner);
372 	kfree(timeri);
373 
374 	if (timer) {
375 		if (list_empty(&timer->open_list_head) && timer->hw.close)
376 			timer->hw.close(timer);
377 		/* release a card refcount for safe disconnection */
378 		if (timer->card)
379 			put_device(&timer->card->card_dev);
380 		module_put(timer->module);
381 	}
382 
383 	mutex_unlock(&register_mutex);
384 	return 0;
385 }
386 
387 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
388 {
389 	struct snd_timer * timer;
390 
391 	if (timeri == NULL)
392 		return 0;
393 	if ((timer = timeri->timer) != NULL) {
394 		if (timer->hw.c_resolution)
395 			return timer->hw.c_resolution(timer);
396 		return timer->hw.resolution;
397 	}
398 	return 0;
399 }
400 
401 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
402 {
403 	struct snd_timer *timer;
404 	unsigned long resolution = 0;
405 	struct snd_timer_instance *ts;
406 	struct timespec tstamp;
407 
408 	if (timer_tstamp_monotonic)
409 		ktime_get_ts(&tstamp);
410 	else
411 		getnstimeofday(&tstamp);
412 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
413 		       event > SNDRV_TIMER_EVENT_PAUSE))
414 		return;
415 	if (event == SNDRV_TIMER_EVENT_START ||
416 	    event == SNDRV_TIMER_EVENT_CONTINUE)
417 		resolution = snd_timer_resolution(ti);
418 	if (ti->ccallback)
419 		ti->ccallback(ti, event, &tstamp, resolution);
420 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
421 		return;
422 	timer = ti->timer;
423 	if (timer == NULL)
424 		return;
425 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
426 		return;
427 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
428 		if (ts->ccallback)
429 			ts->ccallback(ts, event + 100, &tstamp, resolution);
430 }
431 
432 /* start/continue a master timer */
433 static int snd_timer_start1(struct snd_timer_instance *timeri,
434 			    bool start, unsigned long ticks)
435 {
436 	struct snd_timer *timer;
437 	int result;
438 	unsigned long flags;
439 
440 	timer = timeri->timer;
441 	if (!timer)
442 		return -EINVAL;
443 
444 	spin_lock_irqsave(&timer->lock, flags);
445 	if (timer->card && timer->card->shutdown) {
446 		result = -ENODEV;
447 		goto unlock;
448 	}
449 	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
450 			     SNDRV_TIMER_IFLG_START)) {
451 		result = -EBUSY;
452 		goto unlock;
453 	}
454 
455 	if (start)
456 		timeri->ticks = timeri->cticks = ticks;
457 	else if (!timeri->cticks)
458 		timeri->cticks = 1;
459 	timeri->pticks = 0;
460 
461 	list_move_tail(&timeri->active_list, &timer->active_list_head);
462 	if (timer->running) {
463 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
464 			goto __start_now;
465 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
466 		timeri->flags |= SNDRV_TIMER_IFLG_START;
467 		result = 1; /* delayed start */
468 	} else {
469 		if (start)
470 			timer->sticks = ticks;
471 		timer->hw.start(timer);
472 	      __start_now:
473 		timer->running++;
474 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
475 		result = 0;
476 	}
477 	snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
478 			  SNDRV_TIMER_EVENT_CONTINUE);
479  unlock:
480 	spin_unlock_irqrestore(&timer->lock, flags);
481 	return result;
482 }
483 
484 /* start/continue a slave timer */
485 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
486 				 bool start)
487 {
488 	unsigned long flags;
489 
490 	spin_lock_irqsave(&slave_active_lock, flags);
491 	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
492 		spin_unlock_irqrestore(&slave_active_lock, flags);
493 		return -EBUSY;
494 	}
495 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
496 	if (timeri->master && timeri->timer) {
497 		spin_lock(&timeri->timer->lock);
498 		list_add_tail(&timeri->active_list,
499 			      &timeri->master->slave_active_head);
500 		snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
501 				  SNDRV_TIMER_EVENT_CONTINUE);
502 		spin_unlock(&timeri->timer->lock);
503 	}
504 	spin_unlock_irqrestore(&slave_active_lock, flags);
505 	return 1; /* delayed start */
506 }
507 
508 /* stop/pause a master timer */
509 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
510 {
511 	struct snd_timer *timer;
512 	int result = 0;
513 	unsigned long flags;
514 
515 	timer = timeri->timer;
516 	if (!timer)
517 		return -EINVAL;
518 	spin_lock_irqsave(&timer->lock, flags);
519 	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
520 			       SNDRV_TIMER_IFLG_START))) {
521 		result = -EBUSY;
522 		goto unlock;
523 	}
524 	list_del_init(&timeri->ack_list);
525 	list_del_init(&timeri->active_list);
526 	if (timer->card && timer->card->shutdown)
527 		goto unlock;
528 	if (stop) {
529 		timeri->cticks = timeri->ticks;
530 		timeri->pticks = 0;
531 	}
532 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
533 	    !(--timer->running)) {
534 		timer->hw.stop(timer);
535 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
536 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
537 			snd_timer_reschedule(timer, 0);
538 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
539 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
540 				timer->hw.start(timer);
541 			}
542 		}
543 	}
544 	timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
545 	if (stop)
546 		timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
547 	else
548 		timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
549 	snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
550 			  SNDRV_TIMER_EVENT_CONTINUE);
551  unlock:
552 	spin_unlock_irqrestore(&timer->lock, flags);
553 	return result;
554 }
555 
556 /* stop/pause a slave timer */
557 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
558 {
559 	unsigned long flags;
560 
561 	spin_lock_irqsave(&slave_active_lock, flags);
562 	if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
563 		spin_unlock_irqrestore(&slave_active_lock, flags);
564 		return -EBUSY;
565 	}
566 	timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
567 	if (timeri->timer) {
568 		spin_lock(&timeri->timer->lock);
569 		list_del_init(&timeri->ack_list);
570 		list_del_init(&timeri->active_list);
571 		snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
572 				  SNDRV_TIMER_EVENT_CONTINUE);
573 		spin_unlock(&timeri->timer->lock);
574 	}
575 	spin_unlock_irqrestore(&slave_active_lock, flags);
576 	return 0;
577 }
578 
579 /*
580  *  start the timer instance
581  */
582 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
583 {
584 	if (timeri == NULL || ticks < 1)
585 		return -EINVAL;
586 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
587 		return snd_timer_start_slave(timeri, true);
588 	else
589 		return snd_timer_start1(timeri, true, ticks);
590 }
591 
592 /*
593  * stop the timer instance.
594  *
595  * do not call this from the timer callback!
596  */
597 int snd_timer_stop(struct snd_timer_instance *timeri)
598 {
599 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
600 		return snd_timer_stop_slave(timeri, true);
601 	else
602 		return snd_timer_stop1(timeri, true);
603 }
604 
605 /*
606  * start again..  the tick is kept.
607  */
608 int snd_timer_continue(struct snd_timer_instance *timeri)
609 {
610 	/* timer can continue only after pause */
611 	if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
612 		return -EINVAL;
613 
614 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
615 		return snd_timer_start_slave(timeri, false);
616 	else
617 		return snd_timer_start1(timeri, false, 0);
618 }
619 
620 /*
621  * pause.. remember the ticks left
622  */
623 int snd_timer_pause(struct snd_timer_instance * timeri)
624 {
625 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
626 		return snd_timer_stop_slave(timeri, false);
627 	else
628 		return snd_timer_stop1(timeri, false);
629 }
630 
631 /*
632  * reschedule the timer
633  *
634  * start pending instances and check the scheduling ticks.
635  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
636  */
637 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
638 {
639 	struct snd_timer_instance *ti;
640 	unsigned long ticks = ~0UL;
641 
642 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
643 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
644 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
645 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
646 			timer->running++;
647 		}
648 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
649 			if (ticks > ti->cticks)
650 				ticks = ti->cticks;
651 		}
652 	}
653 	if (ticks == ~0UL) {
654 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
655 		return;
656 	}
657 	if (ticks > timer->hw.ticks)
658 		ticks = timer->hw.ticks;
659 	if (ticks_left != ticks)
660 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
661 	timer->sticks = ticks;
662 }
663 
664 /*
665  * timer tasklet
666  *
667  */
668 static void snd_timer_tasklet(unsigned long arg)
669 {
670 	struct snd_timer *timer = (struct snd_timer *) arg;
671 	struct snd_timer_instance *ti;
672 	struct list_head *p;
673 	unsigned long resolution, ticks;
674 	unsigned long flags;
675 
676 	if (timer->card && timer->card->shutdown)
677 		return;
678 
679 	spin_lock_irqsave(&timer->lock, flags);
680 	/* now process all callbacks */
681 	while (!list_empty(&timer->sack_list_head)) {
682 		p = timer->sack_list_head.next;		/* get first item */
683 		ti = list_entry(p, struct snd_timer_instance, ack_list);
684 
685 		/* remove from ack_list and make empty */
686 		list_del_init(p);
687 
688 		ticks = ti->pticks;
689 		ti->pticks = 0;
690 		resolution = ti->resolution;
691 
692 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
693 		spin_unlock(&timer->lock);
694 		if (ti->callback)
695 			ti->callback(ti, resolution, ticks);
696 		spin_lock(&timer->lock);
697 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
698 	}
699 	spin_unlock_irqrestore(&timer->lock, flags);
700 }
701 
702 /*
703  * timer interrupt
704  *
705  * ticks_left is usually equal to timer->sticks.
706  *
707  */
708 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
709 {
710 	struct snd_timer_instance *ti, *ts, *tmp;
711 	unsigned long resolution, ticks;
712 	struct list_head *p, *ack_list_head;
713 	unsigned long flags;
714 	int use_tasklet = 0;
715 
716 	if (timer == NULL)
717 		return;
718 
719 	if (timer->card && timer->card->shutdown)
720 		return;
721 
722 	spin_lock_irqsave(&timer->lock, flags);
723 
724 	/* remember the current resolution */
725 	if (timer->hw.c_resolution)
726 		resolution = timer->hw.c_resolution(timer);
727 	else
728 		resolution = timer->hw.resolution;
729 
730 	/* loop for all active instances
731 	 * Here we cannot use list_for_each_entry because the active_list of a
732 	 * processed instance is relinked to done_list_head before the callback
733 	 * is called.
734 	 */
735 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
736 				 active_list) {
737 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
738 			continue;
739 		ti->pticks += ticks_left;
740 		ti->resolution = resolution;
741 		if (ti->cticks < ticks_left)
742 			ti->cticks = 0;
743 		else
744 			ti->cticks -= ticks_left;
745 		if (ti->cticks) /* not expired */
746 			continue;
747 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
748 			ti->cticks = ti->ticks;
749 		} else {
750 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
751 			--timer->running;
752 			list_del_init(&ti->active_list);
753 		}
754 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
755 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
756 			ack_list_head = &timer->ack_list_head;
757 		else
758 			ack_list_head = &timer->sack_list_head;
759 		if (list_empty(&ti->ack_list))
760 			list_add_tail(&ti->ack_list, ack_list_head);
761 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
762 			ts->pticks = ti->pticks;
763 			ts->resolution = resolution;
764 			if (list_empty(&ts->ack_list))
765 				list_add_tail(&ts->ack_list, ack_list_head);
766 		}
767 	}
768 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
769 		snd_timer_reschedule(timer, timer->sticks);
770 	if (timer->running) {
771 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
772 			timer->hw.stop(timer);
773 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
774 		}
775 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
776 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
777 			/* restart timer */
778 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
779 			timer->hw.start(timer);
780 		}
781 	} else {
782 		timer->hw.stop(timer);
783 	}
784 
785 	/* now process all fast callbacks */
786 	while (!list_empty(&timer->ack_list_head)) {
787 		p = timer->ack_list_head.next;		/* get first item */
788 		ti = list_entry(p, struct snd_timer_instance, ack_list);
789 
790 		/* remove from ack_list and make empty */
791 		list_del_init(p);
792 
793 		ticks = ti->pticks;
794 		ti->pticks = 0;
795 
796 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
797 		spin_unlock(&timer->lock);
798 		if (ti->callback)
799 			ti->callback(ti, resolution, ticks);
800 		spin_lock(&timer->lock);
801 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
802 	}
803 
804 	/* do we have any slow callbacks? */
805 	use_tasklet = !list_empty(&timer->sack_list_head);
806 	spin_unlock_irqrestore(&timer->lock, flags);
807 
808 	if (use_tasklet)
809 		tasklet_schedule(&timer->task_queue);
810 }
811 
812 /*
813 
814  */
815 
816 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
817 		  struct snd_timer **rtimer)
818 {
819 	struct snd_timer *timer;
820 	int err;
821 	static struct snd_device_ops ops = {
822 		.dev_free = snd_timer_dev_free,
823 		.dev_register = snd_timer_dev_register,
824 		.dev_disconnect = snd_timer_dev_disconnect,
825 	};
826 
827 	if (snd_BUG_ON(!tid))
828 		return -EINVAL;
829 	if (rtimer)
830 		*rtimer = NULL;
831 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
832 	if (!timer)
833 		return -ENOMEM;
834 	timer->tmr_class = tid->dev_class;
835 	timer->card = card;
836 	timer->tmr_device = tid->device;
837 	timer->tmr_subdevice = tid->subdevice;
838 	if (id)
839 		strlcpy(timer->id, id, sizeof(timer->id));
840 	timer->sticks = 1;
841 	INIT_LIST_HEAD(&timer->device_list);
842 	INIT_LIST_HEAD(&timer->open_list_head);
843 	INIT_LIST_HEAD(&timer->active_list_head);
844 	INIT_LIST_HEAD(&timer->ack_list_head);
845 	INIT_LIST_HEAD(&timer->sack_list_head);
846 	spin_lock_init(&timer->lock);
847 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
848 		     (unsigned long)timer);
849 	if (card != NULL) {
850 		timer->module = card->module;
851 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
852 		if (err < 0) {
853 			snd_timer_free(timer);
854 			return err;
855 		}
856 	}
857 	if (rtimer)
858 		*rtimer = timer;
859 	return 0;
860 }
861 
862 static int snd_timer_free(struct snd_timer *timer)
863 {
864 	if (!timer)
865 		return 0;
866 
867 	mutex_lock(&register_mutex);
868 	if (! list_empty(&timer->open_list_head)) {
869 		struct list_head *p, *n;
870 		struct snd_timer_instance *ti;
871 		pr_warn("ALSA: timer %p is busy?\n", timer);
872 		list_for_each_safe(p, n, &timer->open_list_head) {
873 			list_del_init(p);
874 			ti = list_entry(p, struct snd_timer_instance, open_list);
875 			ti->timer = NULL;
876 		}
877 	}
878 	list_del(&timer->device_list);
879 	mutex_unlock(&register_mutex);
880 
881 	if (timer->private_free)
882 		timer->private_free(timer);
883 	kfree(timer);
884 	return 0;
885 }
886 
887 static int snd_timer_dev_free(struct snd_device *device)
888 {
889 	struct snd_timer *timer = device->device_data;
890 	return snd_timer_free(timer);
891 }
892 
893 static int snd_timer_dev_register(struct snd_device *dev)
894 {
895 	struct snd_timer *timer = dev->device_data;
896 	struct snd_timer *timer1;
897 
898 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
899 		return -ENXIO;
900 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
901 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
902 	    	return -EINVAL;
903 
904 	mutex_lock(&register_mutex);
905 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
906 		if (timer1->tmr_class > timer->tmr_class)
907 			break;
908 		if (timer1->tmr_class < timer->tmr_class)
909 			continue;
910 		if (timer1->card && timer->card) {
911 			if (timer1->card->number > timer->card->number)
912 				break;
913 			if (timer1->card->number < timer->card->number)
914 				continue;
915 		}
916 		if (timer1->tmr_device > timer->tmr_device)
917 			break;
918 		if (timer1->tmr_device < timer->tmr_device)
919 			continue;
920 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
921 			break;
922 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
923 			continue;
924 		/* conflicts.. */
925 		mutex_unlock(&register_mutex);
926 		return -EBUSY;
927 	}
928 	list_add_tail(&timer->device_list, &timer1->device_list);
929 	mutex_unlock(&register_mutex);
930 	return 0;
931 }
932 
933 static int snd_timer_dev_disconnect(struct snd_device *device)
934 {
935 	struct snd_timer *timer = device->device_data;
936 	struct snd_timer_instance *ti;
937 
938 	mutex_lock(&register_mutex);
939 	list_del_init(&timer->device_list);
940 	/* wake up pending sleepers */
941 	list_for_each_entry(ti, &timer->open_list_head, open_list) {
942 		if (ti->disconnect)
943 			ti->disconnect(ti);
944 	}
945 	mutex_unlock(&register_mutex);
946 	return 0;
947 }
948 
949 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
950 {
951 	unsigned long flags;
952 	unsigned long resolution = 0;
953 	struct snd_timer_instance *ti, *ts;
954 
955 	if (timer->card && timer->card->shutdown)
956 		return;
957 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
958 		return;
959 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
960 		       event > SNDRV_TIMER_EVENT_MRESUME))
961 		return;
962 	spin_lock_irqsave(&timer->lock, flags);
963 	if (event == SNDRV_TIMER_EVENT_MSTART ||
964 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
965 	    event == SNDRV_TIMER_EVENT_MRESUME) {
966 		if (timer->hw.c_resolution)
967 			resolution = timer->hw.c_resolution(timer);
968 		else
969 			resolution = timer->hw.resolution;
970 	}
971 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
972 		if (ti->ccallback)
973 			ti->ccallback(ti, event, tstamp, resolution);
974 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
975 			if (ts->ccallback)
976 				ts->ccallback(ts, event, tstamp, resolution);
977 	}
978 	spin_unlock_irqrestore(&timer->lock, flags);
979 }
980 
981 /*
982  * exported functions for global timers
983  */
984 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
985 {
986 	struct snd_timer_id tid;
987 
988 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
989 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
990 	tid.card = -1;
991 	tid.device = device;
992 	tid.subdevice = 0;
993 	return snd_timer_new(NULL, id, &tid, rtimer);
994 }
995 
996 int snd_timer_global_free(struct snd_timer *timer)
997 {
998 	return snd_timer_free(timer);
999 }
1000 
1001 int snd_timer_global_register(struct snd_timer *timer)
1002 {
1003 	struct snd_device dev;
1004 
1005 	memset(&dev, 0, sizeof(dev));
1006 	dev.device_data = timer;
1007 	return snd_timer_dev_register(&dev);
1008 }
1009 
1010 /*
1011  *  System timer
1012  */
1013 
1014 struct snd_timer_system_private {
1015 	struct timer_list tlist;
1016 	unsigned long last_expires;
1017 	unsigned long last_jiffies;
1018 	unsigned long correction;
1019 };
1020 
1021 static void snd_timer_s_function(unsigned long data)
1022 {
1023 	struct snd_timer *timer = (struct snd_timer *)data;
1024 	struct snd_timer_system_private *priv = timer->private_data;
1025 	unsigned long jiff = jiffies;
1026 	if (time_after(jiff, priv->last_expires))
1027 		priv->correction += (long)jiff - (long)priv->last_expires;
1028 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1029 }
1030 
1031 static int snd_timer_s_start(struct snd_timer * timer)
1032 {
1033 	struct snd_timer_system_private *priv;
1034 	unsigned long njiff;
1035 
1036 	priv = (struct snd_timer_system_private *) timer->private_data;
1037 	njiff = (priv->last_jiffies = jiffies);
1038 	if (priv->correction > timer->sticks - 1) {
1039 		priv->correction -= timer->sticks - 1;
1040 		njiff++;
1041 	} else {
1042 		njiff += timer->sticks - priv->correction;
1043 		priv->correction = 0;
1044 	}
1045 	priv->last_expires = njiff;
1046 	mod_timer(&priv->tlist, njiff);
1047 	return 0;
1048 }
1049 
1050 static int snd_timer_s_stop(struct snd_timer * timer)
1051 {
1052 	struct snd_timer_system_private *priv;
1053 	unsigned long jiff;
1054 
1055 	priv = (struct snd_timer_system_private *) timer->private_data;
1056 	del_timer(&priv->tlist);
1057 	jiff = jiffies;
1058 	if (time_before(jiff, priv->last_expires))
1059 		timer->sticks = priv->last_expires - jiff;
1060 	else
1061 		timer->sticks = 1;
1062 	priv->correction = 0;
1063 	return 0;
1064 }
1065 
1066 static int snd_timer_s_close(struct snd_timer *timer)
1067 {
1068 	struct snd_timer_system_private *priv;
1069 
1070 	priv = (struct snd_timer_system_private *)timer->private_data;
1071 	del_timer_sync(&priv->tlist);
1072 	return 0;
1073 }
1074 
1075 static struct snd_timer_hardware snd_timer_system =
1076 {
1077 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1078 	.resolution =	1000000000L / HZ,
1079 	.ticks =	10000000L,
1080 	.close =	snd_timer_s_close,
1081 	.start =	snd_timer_s_start,
1082 	.stop =		snd_timer_s_stop
1083 };
1084 
1085 static void snd_timer_free_system(struct snd_timer *timer)
1086 {
1087 	kfree(timer->private_data);
1088 }
1089 
1090 static int snd_timer_register_system(void)
1091 {
1092 	struct snd_timer *timer;
1093 	struct snd_timer_system_private *priv;
1094 	int err;
1095 
1096 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1097 	if (err < 0)
1098 		return err;
1099 	strcpy(timer->name, "system timer");
1100 	timer->hw = snd_timer_system;
1101 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1102 	if (priv == NULL) {
1103 		snd_timer_free(timer);
1104 		return -ENOMEM;
1105 	}
1106 	setup_timer(&priv->tlist, snd_timer_s_function, (unsigned long) timer);
1107 	timer->private_data = priv;
1108 	timer->private_free = snd_timer_free_system;
1109 	return snd_timer_global_register(timer);
1110 }
1111 
1112 #ifdef CONFIG_SND_PROC_FS
1113 /*
1114  *  Info interface
1115  */
1116 
1117 static void snd_timer_proc_read(struct snd_info_entry *entry,
1118 				struct snd_info_buffer *buffer)
1119 {
1120 	struct snd_timer *timer;
1121 	struct snd_timer_instance *ti;
1122 
1123 	mutex_lock(&register_mutex);
1124 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1125 		if (timer->card && timer->card->shutdown)
1126 			continue;
1127 		switch (timer->tmr_class) {
1128 		case SNDRV_TIMER_CLASS_GLOBAL:
1129 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1130 			break;
1131 		case SNDRV_TIMER_CLASS_CARD:
1132 			snd_iprintf(buffer, "C%i-%i: ",
1133 				    timer->card->number, timer->tmr_device);
1134 			break;
1135 		case SNDRV_TIMER_CLASS_PCM:
1136 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1137 				    timer->tmr_device, timer->tmr_subdevice);
1138 			break;
1139 		default:
1140 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1141 				    timer->card ? timer->card->number : -1,
1142 				    timer->tmr_device, timer->tmr_subdevice);
1143 		}
1144 		snd_iprintf(buffer, "%s :", timer->name);
1145 		if (timer->hw.resolution)
1146 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1147 				    timer->hw.resolution / 1000,
1148 				    timer->hw.resolution % 1000,
1149 				    timer->hw.ticks);
1150 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1151 			snd_iprintf(buffer, " SLAVE");
1152 		snd_iprintf(buffer, "\n");
1153 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1154 			snd_iprintf(buffer, "  Client %s : %s\n",
1155 				    ti->owner ? ti->owner : "unknown",
1156 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1157 						 SNDRV_TIMER_IFLG_RUNNING)
1158 				    ? "running" : "stopped");
1159 	}
1160 	mutex_unlock(&register_mutex);
1161 }
1162 
1163 static struct snd_info_entry *snd_timer_proc_entry;
1164 
1165 static void __init snd_timer_proc_init(void)
1166 {
1167 	struct snd_info_entry *entry;
1168 
1169 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1170 	if (entry != NULL) {
1171 		entry->c.text.read = snd_timer_proc_read;
1172 		if (snd_info_register(entry) < 0) {
1173 			snd_info_free_entry(entry);
1174 			entry = NULL;
1175 		}
1176 	}
1177 	snd_timer_proc_entry = entry;
1178 }
1179 
1180 static void __exit snd_timer_proc_done(void)
1181 {
1182 	snd_info_free_entry(snd_timer_proc_entry);
1183 }
1184 #else /* !CONFIG_SND_PROC_FS */
1185 #define snd_timer_proc_init()
1186 #define snd_timer_proc_done()
1187 #endif
1188 
1189 /*
1190  *  USER SPACE interface
1191  */
1192 
1193 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1194 				     unsigned long resolution,
1195 				     unsigned long ticks)
1196 {
1197 	struct snd_timer_user *tu = timeri->callback_data;
1198 	struct snd_timer_read *r;
1199 	int prev;
1200 
1201 	spin_lock(&tu->qlock);
1202 	if (tu->qused > 0) {
1203 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1204 		r = &tu->queue[prev];
1205 		if (r->resolution == resolution) {
1206 			r->ticks += ticks;
1207 			goto __wake;
1208 		}
1209 	}
1210 	if (tu->qused >= tu->queue_size) {
1211 		tu->overrun++;
1212 	} else {
1213 		r = &tu->queue[tu->qtail++];
1214 		tu->qtail %= tu->queue_size;
1215 		r->resolution = resolution;
1216 		r->ticks = ticks;
1217 		tu->qused++;
1218 	}
1219       __wake:
1220 	spin_unlock(&tu->qlock);
1221 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1222 	wake_up(&tu->qchange_sleep);
1223 }
1224 
1225 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1226 					    struct snd_timer_tread *tread)
1227 {
1228 	if (tu->qused >= tu->queue_size) {
1229 		tu->overrun++;
1230 	} else {
1231 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1232 		tu->qtail %= tu->queue_size;
1233 		tu->qused++;
1234 	}
1235 }
1236 
1237 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1238 				     int event,
1239 				     struct timespec *tstamp,
1240 				     unsigned long resolution)
1241 {
1242 	struct snd_timer_user *tu = timeri->callback_data;
1243 	struct snd_timer_tread r1;
1244 	unsigned long flags;
1245 
1246 	if (event >= SNDRV_TIMER_EVENT_START &&
1247 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1248 		tu->tstamp = *tstamp;
1249 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1250 		return;
1251 	memset(&r1, 0, sizeof(r1));
1252 	r1.event = event;
1253 	r1.tstamp = *tstamp;
1254 	r1.val = resolution;
1255 	spin_lock_irqsave(&tu->qlock, flags);
1256 	snd_timer_user_append_to_tqueue(tu, &r1);
1257 	spin_unlock_irqrestore(&tu->qlock, flags);
1258 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1259 	wake_up(&tu->qchange_sleep);
1260 }
1261 
1262 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1263 {
1264 	struct snd_timer_user *tu = timeri->callback_data;
1265 
1266 	tu->disconnected = true;
1267 	wake_up(&tu->qchange_sleep);
1268 }
1269 
1270 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1271 				      unsigned long resolution,
1272 				      unsigned long ticks)
1273 {
1274 	struct snd_timer_user *tu = timeri->callback_data;
1275 	struct snd_timer_tread *r, r1;
1276 	struct timespec tstamp;
1277 	int prev, append = 0;
1278 
1279 	memset(&tstamp, 0, sizeof(tstamp));
1280 	spin_lock(&tu->qlock);
1281 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1282 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1283 		spin_unlock(&tu->qlock);
1284 		return;
1285 	}
1286 	if (tu->last_resolution != resolution || ticks > 0) {
1287 		if (timer_tstamp_monotonic)
1288 			ktime_get_ts(&tstamp);
1289 		else
1290 			getnstimeofday(&tstamp);
1291 	}
1292 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1293 	    tu->last_resolution != resolution) {
1294 		memset(&r1, 0, sizeof(r1));
1295 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1296 		r1.tstamp = tstamp;
1297 		r1.val = resolution;
1298 		snd_timer_user_append_to_tqueue(tu, &r1);
1299 		tu->last_resolution = resolution;
1300 		append++;
1301 	}
1302 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1303 		goto __wake;
1304 	if (ticks == 0)
1305 		goto __wake;
1306 	if (tu->qused > 0) {
1307 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1308 		r = &tu->tqueue[prev];
1309 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1310 			r->tstamp = tstamp;
1311 			r->val += ticks;
1312 			append++;
1313 			goto __wake;
1314 		}
1315 	}
1316 	r1.event = SNDRV_TIMER_EVENT_TICK;
1317 	r1.tstamp = tstamp;
1318 	r1.val = ticks;
1319 	snd_timer_user_append_to_tqueue(tu, &r1);
1320 	append++;
1321       __wake:
1322 	spin_unlock(&tu->qlock);
1323 	if (append == 0)
1324 		return;
1325 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1326 	wake_up(&tu->qchange_sleep);
1327 }
1328 
1329 static int snd_timer_user_open(struct inode *inode, struct file *file)
1330 {
1331 	struct snd_timer_user *tu;
1332 	int err;
1333 
1334 	err = nonseekable_open(inode, file);
1335 	if (err < 0)
1336 		return err;
1337 
1338 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1339 	if (tu == NULL)
1340 		return -ENOMEM;
1341 	spin_lock_init(&tu->qlock);
1342 	init_waitqueue_head(&tu->qchange_sleep);
1343 	mutex_init(&tu->ioctl_lock);
1344 	tu->ticks = 1;
1345 	tu->queue_size = 128;
1346 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1347 			    GFP_KERNEL);
1348 	if (tu->queue == NULL) {
1349 		kfree(tu);
1350 		return -ENOMEM;
1351 	}
1352 	file->private_data = tu;
1353 	return 0;
1354 }
1355 
1356 static int snd_timer_user_release(struct inode *inode, struct file *file)
1357 {
1358 	struct snd_timer_user *tu;
1359 
1360 	if (file->private_data) {
1361 		tu = file->private_data;
1362 		file->private_data = NULL;
1363 		mutex_lock(&tu->ioctl_lock);
1364 		if (tu->timeri)
1365 			snd_timer_close(tu->timeri);
1366 		mutex_unlock(&tu->ioctl_lock);
1367 		kfree(tu->queue);
1368 		kfree(tu->tqueue);
1369 		kfree(tu);
1370 	}
1371 	return 0;
1372 }
1373 
1374 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1375 {
1376 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1377 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1378 	id->card = -1;
1379 	id->device = -1;
1380 	id->subdevice = -1;
1381 }
1382 
1383 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1384 {
1385 	id->dev_class = timer->tmr_class;
1386 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1387 	id->card = timer->card ? timer->card->number : -1;
1388 	id->device = timer->tmr_device;
1389 	id->subdevice = timer->tmr_subdevice;
1390 }
1391 
1392 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1393 {
1394 	struct snd_timer_id id;
1395 	struct snd_timer *timer;
1396 	struct list_head *p;
1397 
1398 	if (copy_from_user(&id, _tid, sizeof(id)))
1399 		return -EFAULT;
1400 	mutex_lock(&register_mutex);
1401 	if (id.dev_class < 0) {		/* first item */
1402 		if (list_empty(&snd_timer_list))
1403 			snd_timer_user_zero_id(&id);
1404 		else {
1405 			timer = list_entry(snd_timer_list.next,
1406 					   struct snd_timer, device_list);
1407 			snd_timer_user_copy_id(&id, timer);
1408 		}
1409 	} else {
1410 		switch (id.dev_class) {
1411 		case SNDRV_TIMER_CLASS_GLOBAL:
1412 			id.device = id.device < 0 ? 0 : id.device + 1;
1413 			list_for_each(p, &snd_timer_list) {
1414 				timer = list_entry(p, struct snd_timer, device_list);
1415 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1416 					snd_timer_user_copy_id(&id, timer);
1417 					break;
1418 				}
1419 				if (timer->tmr_device >= id.device) {
1420 					snd_timer_user_copy_id(&id, timer);
1421 					break;
1422 				}
1423 			}
1424 			if (p == &snd_timer_list)
1425 				snd_timer_user_zero_id(&id);
1426 			break;
1427 		case SNDRV_TIMER_CLASS_CARD:
1428 		case SNDRV_TIMER_CLASS_PCM:
1429 			if (id.card < 0) {
1430 				id.card = 0;
1431 			} else {
1432 				if (id.card < 0) {
1433 					id.card = 0;
1434 				} else {
1435 					if (id.device < 0) {
1436 						id.device = 0;
1437 					} else {
1438 						if (id.subdevice < 0) {
1439 							id.subdevice = 0;
1440 						} else {
1441 							id.subdevice++;
1442 						}
1443 					}
1444 				}
1445 			}
1446 			list_for_each(p, &snd_timer_list) {
1447 				timer = list_entry(p, struct snd_timer, device_list);
1448 				if (timer->tmr_class > id.dev_class) {
1449 					snd_timer_user_copy_id(&id, timer);
1450 					break;
1451 				}
1452 				if (timer->tmr_class < id.dev_class)
1453 					continue;
1454 				if (timer->card->number > id.card) {
1455 					snd_timer_user_copy_id(&id, timer);
1456 					break;
1457 				}
1458 				if (timer->card->number < id.card)
1459 					continue;
1460 				if (timer->tmr_device > id.device) {
1461 					snd_timer_user_copy_id(&id, timer);
1462 					break;
1463 				}
1464 				if (timer->tmr_device < id.device)
1465 					continue;
1466 				if (timer->tmr_subdevice > id.subdevice) {
1467 					snd_timer_user_copy_id(&id, timer);
1468 					break;
1469 				}
1470 				if (timer->tmr_subdevice < id.subdevice)
1471 					continue;
1472 				snd_timer_user_copy_id(&id, timer);
1473 				break;
1474 			}
1475 			if (p == &snd_timer_list)
1476 				snd_timer_user_zero_id(&id);
1477 			break;
1478 		default:
1479 			snd_timer_user_zero_id(&id);
1480 		}
1481 	}
1482 	mutex_unlock(&register_mutex);
1483 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1484 		return -EFAULT;
1485 	return 0;
1486 }
1487 
1488 static int snd_timer_user_ginfo(struct file *file,
1489 				struct snd_timer_ginfo __user *_ginfo)
1490 {
1491 	struct snd_timer_ginfo *ginfo;
1492 	struct snd_timer_id tid;
1493 	struct snd_timer *t;
1494 	struct list_head *p;
1495 	int err = 0;
1496 
1497 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1498 	if (IS_ERR(ginfo))
1499 		return PTR_ERR(ginfo);
1500 
1501 	tid = ginfo->tid;
1502 	memset(ginfo, 0, sizeof(*ginfo));
1503 	ginfo->tid = tid;
1504 	mutex_lock(&register_mutex);
1505 	t = snd_timer_find(&tid);
1506 	if (t != NULL) {
1507 		ginfo->card = t->card ? t->card->number : -1;
1508 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1509 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1510 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1511 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1512 		ginfo->resolution = t->hw.resolution;
1513 		if (t->hw.resolution_min > 0) {
1514 			ginfo->resolution_min = t->hw.resolution_min;
1515 			ginfo->resolution_max = t->hw.resolution_max;
1516 		}
1517 		list_for_each(p, &t->open_list_head) {
1518 			ginfo->clients++;
1519 		}
1520 	} else {
1521 		err = -ENODEV;
1522 	}
1523 	mutex_unlock(&register_mutex);
1524 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1525 		err = -EFAULT;
1526 	kfree(ginfo);
1527 	return err;
1528 }
1529 
1530 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1531 {
1532 	struct snd_timer *t;
1533 	int err;
1534 
1535 	mutex_lock(&register_mutex);
1536 	t = snd_timer_find(&gparams->tid);
1537 	if (!t) {
1538 		err = -ENODEV;
1539 		goto _error;
1540 	}
1541 	if (!list_empty(&t->open_list_head)) {
1542 		err = -EBUSY;
1543 		goto _error;
1544 	}
1545 	if (!t->hw.set_period) {
1546 		err = -ENOSYS;
1547 		goto _error;
1548 	}
1549 	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1550 _error:
1551 	mutex_unlock(&register_mutex);
1552 	return err;
1553 }
1554 
1555 static int snd_timer_user_gparams(struct file *file,
1556 				  struct snd_timer_gparams __user *_gparams)
1557 {
1558 	struct snd_timer_gparams gparams;
1559 
1560 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1561 		return -EFAULT;
1562 	return timer_set_gparams(&gparams);
1563 }
1564 
1565 static int snd_timer_user_gstatus(struct file *file,
1566 				  struct snd_timer_gstatus __user *_gstatus)
1567 {
1568 	struct snd_timer_gstatus gstatus;
1569 	struct snd_timer_id tid;
1570 	struct snd_timer *t;
1571 	int err = 0;
1572 
1573 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1574 		return -EFAULT;
1575 	tid = gstatus.tid;
1576 	memset(&gstatus, 0, sizeof(gstatus));
1577 	gstatus.tid = tid;
1578 	mutex_lock(&register_mutex);
1579 	t = snd_timer_find(&tid);
1580 	if (t != NULL) {
1581 		if (t->hw.c_resolution)
1582 			gstatus.resolution = t->hw.c_resolution(t);
1583 		else
1584 			gstatus.resolution = t->hw.resolution;
1585 		if (t->hw.precise_resolution) {
1586 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1587 						 &gstatus.resolution_den);
1588 		} else {
1589 			gstatus.resolution_num = gstatus.resolution;
1590 			gstatus.resolution_den = 1000000000uL;
1591 		}
1592 	} else {
1593 		err = -ENODEV;
1594 	}
1595 	mutex_unlock(&register_mutex);
1596 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1597 		err = -EFAULT;
1598 	return err;
1599 }
1600 
1601 static int snd_timer_user_tselect(struct file *file,
1602 				  struct snd_timer_select __user *_tselect)
1603 {
1604 	struct snd_timer_user *tu;
1605 	struct snd_timer_select tselect;
1606 	char str[32];
1607 	int err = 0;
1608 
1609 	tu = file->private_data;
1610 	if (tu->timeri) {
1611 		snd_timer_close(tu->timeri);
1612 		tu->timeri = NULL;
1613 	}
1614 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1615 		err = -EFAULT;
1616 		goto __err;
1617 	}
1618 	sprintf(str, "application %i", current->pid);
1619 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1620 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1621 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1622 	if (err < 0)
1623 		goto __err;
1624 
1625 	kfree(tu->queue);
1626 	tu->queue = NULL;
1627 	kfree(tu->tqueue);
1628 	tu->tqueue = NULL;
1629 	if (tu->tread) {
1630 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1631 				     GFP_KERNEL);
1632 		if (tu->tqueue == NULL)
1633 			err = -ENOMEM;
1634 	} else {
1635 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1636 				    GFP_KERNEL);
1637 		if (tu->queue == NULL)
1638 			err = -ENOMEM;
1639 	}
1640 
1641       	if (err < 0) {
1642 		snd_timer_close(tu->timeri);
1643       		tu->timeri = NULL;
1644       	} else {
1645 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1646 		tu->timeri->callback = tu->tread
1647 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1648 		tu->timeri->ccallback = snd_timer_user_ccallback;
1649 		tu->timeri->callback_data = (void *)tu;
1650 		tu->timeri->disconnect = snd_timer_user_disconnect;
1651 	}
1652 
1653       __err:
1654 	return err;
1655 }
1656 
1657 static int snd_timer_user_info(struct file *file,
1658 			       struct snd_timer_info __user *_info)
1659 {
1660 	struct snd_timer_user *tu;
1661 	struct snd_timer_info *info;
1662 	struct snd_timer *t;
1663 	int err = 0;
1664 
1665 	tu = file->private_data;
1666 	if (!tu->timeri)
1667 		return -EBADFD;
1668 	t = tu->timeri->timer;
1669 	if (!t)
1670 		return -EBADFD;
1671 
1672 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1673 	if (! info)
1674 		return -ENOMEM;
1675 	info->card = t->card ? t->card->number : -1;
1676 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1677 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1678 	strlcpy(info->id, t->id, sizeof(info->id));
1679 	strlcpy(info->name, t->name, sizeof(info->name));
1680 	info->resolution = t->hw.resolution;
1681 	if (copy_to_user(_info, info, sizeof(*_info)))
1682 		err = -EFAULT;
1683 	kfree(info);
1684 	return err;
1685 }
1686 
1687 static int snd_timer_user_params(struct file *file,
1688 				 struct snd_timer_params __user *_params)
1689 {
1690 	struct snd_timer_user *tu;
1691 	struct snd_timer_params params;
1692 	struct snd_timer *t;
1693 	struct snd_timer_read *tr;
1694 	struct snd_timer_tread *ttr;
1695 	int err;
1696 
1697 	tu = file->private_data;
1698 	if (!tu->timeri)
1699 		return -EBADFD;
1700 	t = tu->timeri->timer;
1701 	if (!t)
1702 		return -EBADFD;
1703 	if (copy_from_user(&params, _params, sizeof(params)))
1704 		return -EFAULT;
1705 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1706 		err = -EINVAL;
1707 		goto _end;
1708 	}
1709 	if (params.queue_size > 0 &&
1710 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1711 		err = -EINVAL;
1712 		goto _end;
1713 	}
1714 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1715 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1716 			      (1<<SNDRV_TIMER_EVENT_START)|
1717 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1718 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1719 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1720 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1721 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1722 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1723 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1724 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1725 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1726 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1727 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1728 		err = -EINVAL;
1729 		goto _end;
1730 	}
1731 	snd_timer_stop(tu->timeri);
1732 	spin_lock_irq(&t->lock);
1733 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1734 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1735 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1736 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1737 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1738 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1739 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1740 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1741 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1742 	spin_unlock_irq(&t->lock);
1743 	if (params.queue_size > 0 &&
1744 	    (unsigned int)tu->queue_size != params.queue_size) {
1745 		if (tu->tread) {
1746 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1747 				      GFP_KERNEL);
1748 			if (ttr) {
1749 				kfree(tu->tqueue);
1750 				tu->queue_size = params.queue_size;
1751 				tu->tqueue = ttr;
1752 			}
1753 		} else {
1754 			tr = kmalloc(params.queue_size * sizeof(*tr),
1755 				     GFP_KERNEL);
1756 			if (tr) {
1757 				kfree(tu->queue);
1758 				tu->queue_size = params.queue_size;
1759 				tu->queue = tr;
1760 			}
1761 		}
1762 	}
1763 	tu->qhead = tu->qtail = tu->qused = 0;
1764 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1765 		if (tu->tread) {
1766 			struct snd_timer_tread tread;
1767 			memset(&tread, 0, sizeof(tread));
1768 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1769 			tread.tstamp.tv_sec = 0;
1770 			tread.tstamp.tv_nsec = 0;
1771 			tread.val = 0;
1772 			snd_timer_user_append_to_tqueue(tu, &tread);
1773 		} else {
1774 			struct snd_timer_read *r = &tu->queue[0];
1775 			r->resolution = 0;
1776 			r->ticks = 0;
1777 			tu->qused++;
1778 			tu->qtail++;
1779 		}
1780 	}
1781 	tu->filter = params.filter;
1782 	tu->ticks = params.ticks;
1783 	err = 0;
1784  _end:
1785 	if (copy_to_user(_params, &params, sizeof(params)))
1786 		return -EFAULT;
1787 	return err;
1788 }
1789 
1790 static int snd_timer_user_status(struct file *file,
1791 				 struct snd_timer_status __user *_status)
1792 {
1793 	struct snd_timer_user *tu;
1794 	struct snd_timer_status status;
1795 
1796 	tu = file->private_data;
1797 	if (!tu->timeri)
1798 		return -EBADFD;
1799 	memset(&status, 0, sizeof(status));
1800 	status.tstamp = tu->tstamp;
1801 	status.resolution = snd_timer_resolution(tu->timeri);
1802 	status.lost = tu->timeri->lost;
1803 	status.overrun = tu->overrun;
1804 	spin_lock_irq(&tu->qlock);
1805 	status.queue = tu->qused;
1806 	spin_unlock_irq(&tu->qlock);
1807 	if (copy_to_user(_status, &status, sizeof(status)))
1808 		return -EFAULT;
1809 	return 0;
1810 }
1811 
1812 static int snd_timer_user_start(struct file *file)
1813 {
1814 	int err;
1815 	struct snd_timer_user *tu;
1816 
1817 	tu = file->private_data;
1818 	if (!tu->timeri)
1819 		return -EBADFD;
1820 	snd_timer_stop(tu->timeri);
1821 	tu->timeri->lost = 0;
1822 	tu->last_resolution = 0;
1823 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1824 }
1825 
1826 static int snd_timer_user_stop(struct file *file)
1827 {
1828 	int err;
1829 	struct snd_timer_user *tu;
1830 
1831 	tu = file->private_data;
1832 	if (!tu->timeri)
1833 		return -EBADFD;
1834 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1835 }
1836 
1837 static int snd_timer_user_continue(struct file *file)
1838 {
1839 	int err;
1840 	struct snd_timer_user *tu;
1841 
1842 	tu = file->private_data;
1843 	if (!tu->timeri)
1844 		return -EBADFD;
1845 	/* start timer instead of continue if it's not used before */
1846 	if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1847 		return snd_timer_user_start(file);
1848 	tu->timeri->lost = 0;
1849 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1850 }
1851 
1852 static int snd_timer_user_pause(struct file *file)
1853 {
1854 	int err;
1855 	struct snd_timer_user *tu;
1856 
1857 	tu = file->private_data;
1858 	if (!tu->timeri)
1859 		return -EBADFD;
1860 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1861 }
1862 
1863 enum {
1864 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1865 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1866 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1867 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1868 };
1869 
1870 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1871 				 unsigned long arg)
1872 {
1873 	struct snd_timer_user *tu;
1874 	void __user *argp = (void __user *)arg;
1875 	int __user *p = argp;
1876 
1877 	tu = file->private_data;
1878 	switch (cmd) {
1879 	case SNDRV_TIMER_IOCTL_PVERSION:
1880 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1881 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1882 		return snd_timer_user_next_device(argp);
1883 	case SNDRV_TIMER_IOCTL_TREAD:
1884 	{
1885 		int xarg;
1886 
1887 		if (tu->timeri)	/* too late */
1888 			return -EBUSY;
1889 		if (get_user(xarg, p))
1890 			return -EFAULT;
1891 		tu->tread = xarg ? 1 : 0;
1892 		return 0;
1893 	}
1894 	case SNDRV_TIMER_IOCTL_GINFO:
1895 		return snd_timer_user_ginfo(file, argp);
1896 	case SNDRV_TIMER_IOCTL_GPARAMS:
1897 		return snd_timer_user_gparams(file, argp);
1898 	case SNDRV_TIMER_IOCTL_GSTATUS:
1899 		return snd_timer_user_gstatus(file, argp);
1900 	case SNDRV_TIMER_IOCTL_SELECT:
1901 		return snd_timer_user_tselect(file, argp);
1902 	case SNDRV_TIMER_IOCTL_INFO:
1903 		return snd_timer_user_info(file, argp);
1904 	case SNDRV_TIMER_IOCTL_PARAMS:
1905 		return snd_timer_user_params(file, argp);
1906 	case SNDRV_TIMER_IOCTL_STATUS:
1907 		return snd_timer_user_status(file, argp);
1908 	case SNDRV_TIMER_IOCTL_START:
1909 	case SNDRV_TIMER_IOCTL_START_OLD:
1910 		return snd_timer_user_start(file);
1911 	case SNDRV_TIMER_IOCTL_STOP:
1912 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1913 		return snd_timer_user_stop(file);
1914 	case SNDRV_TIMER_IOCTL_CONTINUE:
1915 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1916 		return snd_timer_user_continue(file);
1917 	case SNDRV_TIMER_IOCTL_PAUSE:
1918 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1919 		return snd_timer_user_pause(file);
1920 	}
1921 	return -ENOTTY;
1922 }
1923 
1924 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1925 				 unsigned long arg)
1926 {
1927 	struct snd_timer_user *tu = file->private_data;
1928 	long ret;
1929 
1930 	mutex_lock(&tu->ioctl_lock);
1931 	ret = __snd_timer_user_ioctl(file, cmd, arg);
1932 	mutex_unlock(&tu->ioctl_lock);
1933 	return ret;
1934 }
1935 
1936 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1937 {
1938 	struct snd_timer_user *tu;
1939 
1940 	tu = file->private_data;
1941 	return fasync_helper(fd, file, on, &tu->fasync);
1942 }
1943 
1944 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1945 				   size_t count, loff_t *offset)
1946 {
1947 	struct snd_timer_user *tu;
1948 	long result = 0, unit;
1949 	int qhead;
1950 	int err = 0;
1951 
1952 	tu = file->private_data;
1953 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1954 	spin_lock_irq(&tu->qlock);
1955 	while ((long)count - result >= unit) {
1956 		while (!tu->qused) {
1957 			wait_queue_t wait;
1958 
1959 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1960 				err = -EAGAIN;
1961 				goto _error;
1962 			}
1963 
1964 			set_current_state(TASK_INTERRUPTIBLE);
1965 			init_waitqueue_entry(&wait, current);
1966 			add_wait_queue(&tu->qchange_sleep, &wait);
1967 
1968 			spin_unlock_irq(&tu->qlock);
1969 			schedule();
1970 			spin_lock_irq(&tu->qlock);
1971 
1972 			remove_wait_queue(&tu->qchange_sleep, &wait);
1973 
1974 			if (tu->disconnected) {
1975 				err = -ENODEV;
1976 				goto _error;
1977 			}
1978 			if (signal_pending(current)) {
1979 				err = -ERESTARTSYS;
1980 				goto _error;
1981 			}
1982 		}
1983 
1984 		qhead = tu->qhead++;
1985 		tu->qhead %= tu->queue_size;
1986 		tu->qused--;
1987 		spin_unlock_irq(&tu->qlock);
1988 
1989 		mutex_lock(&tu->ioctl_lock);
1990 		if (tu->tread) {
1991 			if (copy_to_user(buffer, &tu->tqueue[qhead],
1992 					 sizeof(struct snd_timer_tread)))
1993 				err = -EFAULT;
1994 		} else {
1995 			if (copy_to_user(buffer, &tu->queue[qhead],
1996 					 sizeof(struct snd_timer_read)))
1997 				err = -EFAULT;
1998 		}
1999 		mutex_unlock(&tu->ioctl_lock);
2000 
2001 		spin_lock_irq(&tu->qlock);
2002 		if (err < 0)
2003 			goto _error;
2004 		result += unit;
2005 		buffer += unit;
2006 	}
2007  _error:
2008 	spin_unlock_irq(&tu->qlock);
2009 	return result > 0 ? result : err;
2010 }
2011 
2012 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
2013 {
2014         unsigned int mask;
2015         struct snd_timer_user *tu;
2016 
2017         tu = file->private_data;
2018 
2019         poll_wait(file, &tu->qchange_sleep, wait);
2020 
2021 	mask = 0;
2022 	if (tu->qused)
2023 		mask |= POLLIN | POLLRDNORM;
2024 	if (tu->disconnected)
2025 		mask |= POLLERR;
2026 
2027 	return mask;
2028 }
2029 
2030 #ifdef CONFIG_COMPAT
2031 #include "timer_compat.c"
2032 #else
2033 #define snd_timer_user_ioctl_compat	NULL
2034 #endif
2035 
2036 static const struct file_operations snd_timer_f_ops =
2037 {
2038 	.owner =	THIS_MODULE,
2039 	.read =		snd_timer_user_read,
2040 	.open =		snd_timer_user_open,
2041 	.release =	snd_timer_user_release,
2042 	.llseek =	no_llseek,
2043 	.poll =		snd_timer_user_poll,
2044 	.unlocked_ioctl =	snd_timer_user_ioctl,
2045 	.compat_ioctl =	snd_timer_user_ioctl_compat,
2046 	.fasync = 	snd_timer_user_fasync,
2047 };
2048 
2049 /* unregister the system timer */
2050 static void snd_timer_free_all(void)
2051 {
2052 	struct snd_timer *timer, *n;
2053 
2054 	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2055 		snd_timer_free(timer);
2056 }
2057 
2058 static struct device timer_dev;
2059 
2060 /*
2061  *  ENTRY functions
2062  */
2063 
2064 static int __init alsa_timer_init(void)
2065 {
2066 	int err;
2067 
2068 	snd_device_initialize(&timer_dev, NULL);
2069 	dev_set_name(&timer_dev, "timer");
2070 
2071 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2072 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2073 			      "system timer");
2074 #endif
2075 
2076 	err = snd_timer_register_system();
2077 	if (err < 0) {
2078 		pr_err("ALSA: unable to register system timer (%i)\n", err);
2079 		put_device(&timer_dev);
2080 		return err;
2081 	}
2082 
2083 	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2084 				  &snd_timer_f_ops, NULL, &timer_dev);
2085 	if (err < 0) {
2086 		pr_err("ALSA: unable to register timer device (%i)\n", err);
2087 		snd_timer_free_all();
2088 		put_device(&timer_dev);
2089 		return err;
2090 	}
2091 
2092 	snd_timer_proc_init();
2093 	return 0;
2094 }
2095 
2096 static void __exit alsa_timer_exit(void)
2097 {
2098 	snd_unregister_device(&timer_dev);
2099 	snd_timer_free_all();
2100 	put_device(&timer_dev);
2101 	snd_timer_proc_done();
2102 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2103 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2104 #endif
2105 }
2106 
2107 module_init(alsa_timer_init)
2108 module_exit(alsa_timer_exit)
2109 
2110 EXPORT_SYMBOL(snd_timer_open);
2111 EXPORT_SYMBOL(snd_timer_close);
2112 EXPORT_SYMBOL(snd_timer_resolution);
2113 EXPORT_SYMBOL(snd_timer_start);
2114 EXPORT_SYMBOL(snd_timer_stop);
2115 EXPORT_SYMBOL(snd_timer_continue);
2116 EXPORT_SYMBOL(snd_timer_pause);
2117 EXPORT_SYMBOL(snd_timer_new);
2118 EXPORT_SYMBOL(snd_timer_notify);
2119 EXPORT_SYMBOL(snd_timer_global_new);
2120 EXPORT_SYMBOL(snd_timer_global_free);
2121 EXPORT_SYMBOL(snd_timer_global_register);
2122 EXPORT_SYMBOL(snd_timer_interrupt);
2123