xref: /openbmc/linux/sound/core/timer.c (revision 41e4b7dc)
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 EXPORT_SYMBOL(snd_timer_open);
323 
324 /*
325  * close a timer instance
326  */
327 int snd_timer_close(struct snd_timer_instance *timeri)
328 {
329 	struct snd_timer *timer = NULL;
330 	struct snd_timer_instance *slave, *tmp;
331 
332 	if (snd_BUG_ON(!timeri))
333 		return -ENXIO;
334 
335 	mutex_lock(&register_mutex);
336 	list_del(&timeri->open_list);
337 
338 	/* force to stop the timer */
339 	snd_timer_stop(timeri);
340 
341 	timer = timeri->timer;
342 	if (timer) {
343 		/* wait, until the active callback is finished */
344 		spin_lock_irq(&timer->lock);
345 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
346 			spin_unlock_irq(&timer->lock);
347 			udelay(10);
348 			spin_lock_irq(&timer->lock);
349 		}
350 		spin_unlock_irq(&timer->lock);
351 
352 		/* remove slave links */
353 		spin_lock_irq(&slave_active_lock);
354 		spin_lock(&timer->lock);
355 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
356 					 open_list) {
357 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
358 			slave->master = NULL;
359 			slave->timer = NULL;
360 			list_del_init(&slave->ack_list);
361 			list_del_init(&slave->active_list);
362 		}
363 		spin_unlock(&timer->lock);
364 		spin_unlock_irq(&slave_active_lock);
365 
366 		/* slave doesn't need to release timer resources below */
367 		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
368 			timer = NULL;
369 	}
370 
371 	if (timeri->private_free)
372 		timeri->private_free(timeri);
373 	kfree(timeri->owner);
374 	kfree(timeri);
375 
376 	if (timer) {
377 		if (list_empty(&timer->open_list_head) && timer->hw.close)
378 			timer->hw.close(timer);
379 		/* release a card refcount for safe disconnection */
380 		if (timer->card)
381 			put_device(&timer->card->card_dev);
382 		module_put(timer->module);
383 	}
384 
385 	mutex_unlock(&register_mutex);
386 	return 0;
387 }
388 EXPORT_SYMBOL(snd_timer_close);
389 
390 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
391 {
392 	struct snd_timer * timer;
393 
394 	if (timeri == NULL)
395 		return 0;
396 	timer = timeri->timer;
397 	if (timer) {
398 		if (timer->hw.c_resolution)
399 			return timer->hw.c_resolution(timer);
400 		return timer->hw.resolution;
401 	}
402 	return 0;
403 }
404 EXPORT_SYMBOL(snd_timer_resolution);
405 
406 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
407 {
408 	struct snd_timer *timer;
409 	unsigned long resolution = 0;
410 	struct snd_timer_instance *ts;
411 	struct timespec tstamp;
412 
413 	if (timer_tstamp_monotonic)
414 		ktime_get_ts(&tstamp);
415 	else
416 		getnstimeofday(&tstamp);
417 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
418 		       event > SNDRV_TIMER_EVENT_PAUSE))
419 		return;
420 	if (event == SNDRV_TIMER_EVENT_START ||
421 	    event == SNDRV_TIMER_EVENT_CONTINUE)
422 		resolution = snd_timer_resolution(ti);
423 	if (ti->ccallback)
424 		ti->ccallback(ti, event, &tstamp, resolution);
425 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
426 		return;
427 	timer = ti->timer;
428 	if (timer == NULL)
429 		return;
430 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
431 		return;
432 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
433 		if (ts->ccallback)
434 			ts->ccallback(ts, event + 100, &tstamp, resolution);
435 }
436 
437 /* start/continue a master timer */
438 static int snd_timer_start1(struct snd_timer_instance *timeri,
439 			    bool start, unsigned long ticks)
440 {
441 	struct snd_timer *timer;
442 	int result;
443 	unsigned long flags;
444 
445 	timer = timeri->timer;
446 	if (!timer)
447 		return -EINVAL;
448 
449 	spin_lock_irqsave(&timer->lock, flags);
450 	if (timer->card && timer->card->shutdown) {
451 		result = -ENODEV;
452 		goto unlock;
453 	}
454 	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
455 			     SNDRV_TIMER_IFLG_START)) {
456 		result = -EBUSY;
457 		goto unlock;
458 	}
459 
460 	if (start)
461 		timeri->ticks = timeri->cticks = ticks;
462 	else if (!timeri->cticks)
463 		timeri->cticks = 1;
464 	timeri->pticks = 0;
465 
466 	list_move_tail(&timeri->active_list, &timer->active_list_head);
467 	if (timer->running) {
468 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
469 			goto __start_now;
470 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
471 		timeri->flags |= SNDRV_TIMER_IFLG_START;
472 		result = 1; /* delayed start */
473 	} else {
474 		if (start)
475 			timer->sticks = ticks;
476 		timer->hw.start(timer);
477 	      __start_now:
478 		timer->running++;
479 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
480 		result = 0;
481 	}
482 	snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
483 			  SNDRV_TIMER_EVENT_CONTINUE);
484  unlock:
485 	spin_unlock_irqrestore(&timer->lock, flags);
486 	return result;
487 }
488 
489 /* start/continue a slave timer */
490 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
491 				 bool start)
492 {
493 	unsigned long flags;
494 
495 	spin_lock_irqsave(&slave_active_lock, flags);
496 	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
497 		spin_unlock_irqrestore(&slave_active_lock, flags);
498 		return -EBUSY;
499 	}
500 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
501 	if (timeri->master && timeri->timer) {
502 		spin_lock(&timeri->timer->lock);
503 		list_add_tail(&timeri->active_list,
504 			      &timeri->master->slave_active_head);
505 		snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
506 				  SNDRV_TIMER_EVENT_CONTINUE);
507 		spin_unlock(&timeri->timer->lock);
508 	}
509 	spin_unlock_irqrestore(&slave_active_lock, flags);
510 	return 1; /* delayed start */
511 }
512 
513 /* stop/pause a master timer */
514 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
515 {
516 	struct snd_timer *timer;
517 	int result = 0;
518 	unsigned long flags;
519 
520 	timer = timeri->timer;
521 	if (!timer)
522 		return -EINVAL;
523 	spin_lock_irqsave(&timer->lock, flags);
524 	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
525 			       SNDRV_TIMER_IFLG_START))) {
526 		result = -EBUSY;
527 		goto unlock;
528 	}
529 	list_del_init(&timeri->ack_list);
530 	list_del_init(&timeri->active_list);
531 	if (timer->card && timer->card->shutdown)
532 		goto unlock;
533 	if (stop) {
534 		timeri->cticks = timeri->ticks;
535 		timeri->pticks = 0;
536 	}
537 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
538 	    !(--timer->running)) {
539 		timer->hw.stop(timer);
540 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
541 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
542 			snd_timer_reschedule(timer, 0);
543 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
544 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
545 				timer->hw.start(timer);
546 			}
547 		}
548 	}
549 	timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
550 	if (stop)
551 		timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
552 	else
553 		timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
554 	snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
555 			  SNDRV_TIMER_EVENT_CONTINUE);
556  unlock:
557 	spin_unlock_irqrestore(&timer->lock, flags);
558 	return result;
559 }
560 
561 /* stop/pause a slave timer */
562 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
563 {
564 	unsigned long flags;
565 
566 	spin_lock_irqsave(&slave_active_lock, flags);
567 	if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
568 		spin_unlock_irqrestore(&slave_active_lock, flags);
569 		return -EBUSY;
570 	}
571 	timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
572 	if (timeri->timer) {
573 		spin_lock(&timeri->timer->lock);
574 		list_del_init(&timeri->ack_list);
575 		list_del_init(&timeri->active_list);
576 		snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
577 				  SNDRV_TIMER_EVENT_CONTINUE);
578 		spin_unlock(&timeri->timer->lock);
579 	}
580 	spin_unlock_irqrestore(&slave_active_lock, flags);
581 	return 0;
582 }
583 
584 /*
585  *  start the timer instance
586  */
587 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
588 {
589 	if (timeri == NULL || ticks < 1)
590 		return -EINVAL;
591 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
592 		return snd_timer_start_slave(timeri, true);
593 	else
594 		return snd_timer_start1(timeri, true, ticks);
595 }
596 EXPORT_SYMBOL(snd_timer_start);
597 
598 /*
599  * stop the timer instance.
600  *
601  * do not call this from the timer callback!
602  */
603 int snd_timer_stop(struct snd_timer_instance *timeri)
604 {
605 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
606 		return snd_timer_stop_slave(timeri, true);
607 	else
608 		return snd_timer_stop1(timeri, true);
609 }
610 EXPORT_SYMBOL(snd_timer_stop);
611 
612 /*
613  * start again..  the tick is kept.
614  */
615 int snd_timer_continue(struct snd_timer_instance *timeri)
616 {
617 	/* timer can continue only after pause */
618 	if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
619 		return -EINVAL;
620 
621 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
622 		return snd_timer_start_slave(timeri, false);
623 	else
624 		return snd_timer_start1(timeri, false, 0);
625 }
626 EXPORT_SYMBOL(snd_timer_continue);
627 
628 /*
629  * pause.. remember the ticks left
630  */
631 int snd_timer_pause(struct snd_timer_instance * timeri)
632 {
633 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
634 		return snd_timer_stop_slave(timeri, false);
635 	else
636 		return snd_timer_stop1(timeri, false);
637 }
638 EXPORT_SYMBOL(snd_timer_pause);
639 
640 /*
641  * reschedule the timer
642  *
643  * start pending instances and check the scheduling ticks.
644  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
645  */
646 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
647 {
648 	struct snd_timer_instance *ti;
649 	unsigned long ticks = ~0UL;
650 
651 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
652 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
653 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
654 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
655 			timer->running++;
656 		}
657 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
658 			if (ticks > ti->cticks)
659 				ticks = ti->cticks;
660 		}
661 	}
662 	if (ticks == ~0UL) {
663 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
664 		return;
665 	}
666 	if (ticks > timer->hw.ticks)
667 		ticks = timer->hw.ticks;
668 	if (ticks_left != ticks)
669 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
670 	timer->sticks = ticks;
671 }
672 
673 /*
674  * timer tasklet
675  *
676  */
677 static void snd_timer_tasklet(unsigned long arg)
678 {
679 	struct snd_timer *timer = (struct snd_timer *) arg;
680 	struct snd_timer_instance *ti;
681 	struct list_head *p;
682 	unsigned long resolution, ticks;
683 	unsigned long flags;
684 
685 	if (timer->card && timer->card->shutdown)
686 		return;
687 
688 	spin_lock_irqsave(&timer->lock, flags);
689 	/* now process all callbacks */
690 	while (!list_empty(&timer->sack_list_head)) {
691 		p = timer->sack_list_head.next;		/* get first item */
692 		ti = list_entry(p, struct snd_timer_instance, ack_list);
693 
694 		/* remove from ack_list and make empty */
695 		list_del_init(p);
696 
697 		ticks = ti->pticks;
698 		ti->pticks = 0;
699 		resolution = ti->resolution;
700 
701 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
702 		spin_unlock(&timer->lock);
703 		if (ti->callback)
704 			ti->callback(ti, resolution, ticks);
705 		spin_lock(&timer->lock);
706 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
707 	}
708 	spin_unlock_irqrestore(&timer->lock, flags);
709 }
710 
711 /*
712  * timer interrupt
713  *
714  * ticks_left is usually equal to timer->sticks.
715  *
716  */
717 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
718 {
719 	struct snd_timer_instance *ti, *ts, *tmp;
720 	unsigned long resolution, ticks;
721 	struct list_head *p, *ack_list_head;
722 	unsigned long flags;
723 	int use_tasklet = 0;
724 
725 	if (timer == NULL)
726 		return;
727 
728 	if (timer->card && timer->card->shutdown)
729 		return;
730 
731 	spin_lock_irqsave(&timer->lock, flags);
732 
733 	/* remember the current resolution */
734 	if (timer->hw.c_resolution)
735 		resolution = timer->hw.c_resolution(timer);
736 	else
737 		resolution = timer->hw.resolution;
738 
739 	/* loop for all active instances
740 	 * Here we cannot use list_for_each_entry because the active_list of a
741 	 * processed instance is relinked to done_list_head before the callback
742 	 * is called.
743 	 */
744 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
745 				 active_list) {
746 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
747 			continue;
748 		ti->pticks += ticks_left;
749 		ti->resolution = resolution;
750 		if (ti->cticks < ticks_left)
751 			ti->cticks = 0;
752 		else
753 			ti->cticks -= ticks_left;
754 		if (ti->cticks) /* not expired */
755 			continue;
756 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
757 			ti->cticks = ti->ticks;
758 		} else {
759 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
760 			--timer->running;
761 			list_del_init(&ti->active_list);
762 		}
763 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
764 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
765 			ack_list_head = &timer->ack_list_head;
766 		else
767 			ack_list_head = &timer->sack_list_head;
768 		if (list_empty(&ti->ack_list))
769 			list_add_tail(&ti->ack_list, ack_list_head);
770 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
771 			ts->pticks = ti->pticks;
772 			ts->resolution = resolution;
773 			if (list_empty(&ts->ack_list))
774 				list_add_tail(&ts->ack_list, ack_list_head);
775 		}
776 	}
777 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
778 		snd_timer_reschedule(timer, timer->sticks);
779 	if (timer->running) {
780 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
781 			timer->hw.stop(timer);
782 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
783 		}
784 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
785 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
786 			/* restart timer */
787 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
788 			timer->hw.start(timer);
789 		}
790 	} else {
791 		timer->hw.stop(timer);
792 	}
793 
794 	/* now process all fast callbacks */
795 	while (!list_empty(&timer->ack_list_head)) {
796 		p = timer->ack_list_head.next;		/* get first item */
797 		ti = list_entry(p, struct snd_timer_instance, ack_list);
798 
799 		/* remove from ack_list and make empty */
800 		list_del_init(p);
801 
802 		ticks = ti->pticks;
803 		ti->pticks = 0;
804 
805 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
806 		spin_unlock(&timer->lock);
807 		if (ti->callback)
808 			ti->callback(ti, resolution, ticks);
809 		spin_lock(&timer->lock);
810 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
811 	}
812 
813 	/* do we have any slow callbacks? */
814 	use_tasklet = !list_empty(&timer->sack_list_head);
815 	spin_unlock_irqrestore(&timer->lock, flags);
816 
817 	if (use_tasklet)
818 		tasklet_schedule(&timer->task_queue);
819 }
820 EXPORT_SYMBOL(snd_timer_interrupt);
821 
822 /*
823 
824  */
825 
826 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
827 		  struct snd_timer **rtimer)
828 {
829 	struct snd_timer *timer;
830 	int err;
831 	static struct snd_device_ops ops = {
832 		.dev_free = snd_timer_dev_free,
833 		.dev_register = snd_timer_dev_register,
834 		.dev_disconnect = snd_timer_dev_disconnect,
835 	};
836 
837 	if (snd_BUG_ON(!tid))
838 		return -EINVAL;
839 	if (rtimer)
840 		*rtimer = NULL;
841 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
842 	if (!timer)
843 		return -ENOMEM;
844 	timer->tmr_class = tid->dev_class;
845 	timer->card = card;
846 	timer->tmr_device = tid->device;
847 	timer->tmr_subdevice = tid->subdevice;
848 	if (id)
849 		strlcpy(timer->id, id, sizeof(timer->id));
850 	timer->sticks = 1;
851 	INIT_LIST_HEAD(&timer->device_list);
852 	INIT_LIST_HEAD(&timer->open_list_head);
853 	INIT_LIST_HEAD(&timer->active_list_head);
854 	INIT_LIST_HEAD(&timer->ack_list_head);
855 	INIT_LIST_HEAD(&timer->sack_list_head);
856 	spin_lock_init(&timer->lock);
857 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
858 		     (unsigned long)timer);
859 	if (card != NULL) {
860 		timer->module = card->module;
861 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
862 		if (err < 0) {
863 			snd_timer_free(timer);
864 			return err;
865 		}
866 	}
867 	if (rtimer)
868 		*rtimer = timer;
869 	return 0;
870 }
871 EXPORT_SYMBOL(snd_timer_new);
872 
873 static int snd_timer_free(struct snd_timer *timer)
874 {
875 	if (!timer)
876 		return 0;
877 
878 	mutex_lock(&register_mutex);
879 	if (! list_empty(&timer->open_list_head)) {
880 		struct list_head *p, *n;
881 		struct snd_timer_instance *ti;
882 		pr_warn("ALSA: timer %p is busy?\n", timer);
883 		list_for_each_safe(p, n, &timer->open_list_head) {
884 			list_del_init(p);
885 			ti = list_entry(p, struct snd_timer_instance, open_list);
886 			ti->timer = NULL;
887 		}
888 	}
889 	list_del(&timer->device_list);
890 	mutex_unlock(&register_mutex);
891 
892 	if (timer->private_free)
893 		timer->private_free(timer);
894 	kfree(timer);
895 	return 0;
896 }
897 
898 static int snd_timer_dev_free(struct snd_device *device)
899 {
900 	struct snd_timer *timer = device->device_data;
901 	return snd_timer_free(timer);
902 }
903 
904 static int snd_timer_dev_register(struct snd_device *dev)
905 {
906 	struct snd_timer *timer = dev->device_data;
907 	struct snd_timer *timer1;
908 
909 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
910 		return -ENXIO;
911 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
912 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
913 	    	return -EINVAL;
914 
915 	mutex_lock(&register_mutex);
916 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
917 		if (timer1->tmr_class > timer->tmr_class)
918 			break;
919 		if (timer1->tmr_class < timer->tmr_class)
920 			continue;
921 		if (timer1->card && timer->card) {
922 			if (timer1->card->number > timer->card->number)
923 				break;
924 			if (timer1->card->number < timer->card->number)
925 				continue;
926 		}
927 		if (timer1->tmr_device > timer->tmr_device)
928 			break;
929 		if (timer1->tmr_device < timer->tmr_device)
930 			continue;
931 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
932 			break;
933 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
934 			continue;
935 		/* conflicts.. */
936 		mutex_unlock(&register_mutex);
937 		return -EBUSY;
938 	}
939 	list_add_tail(&timer->device_list, &timer1->device_list);
940 	mutex_unlock(&register_mutex);
941 	return 0;
942 }
943 
944 static int snd_timer_dev_disconnect(struct snd_device *device)
945 {
946 	struct snd_timer *timer = device->device_data;
947 	struct snd_timer_instance *ti;
948 
949 	mutex_lock(&register_mutex);
950 	list_del_init(&timer->device_list);
951 	/* wake up pending sleepers */
952 	list_for_each_entry(ti, &timer->open_list_head, open_list) {
953 		if (ti->disconnect)
954 			ti->disconnect(ti);
955 	}
956 	mutex_unlock(&register_mutex);
957 	return 0;
958 }
959 
960 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
961 {
962 	unsigned long flags;
963 	unsigned long resolution = 0;
964 	struct snd_timer_instance *ti, *ts;
965 
966 	if (timer->card && timer->card->shutdown)
967 		return;
968 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
969 		return;
970 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
971 		       event > SNDRV_TIMER_EVENT_MRESUME))
972 		return;
973 	spin_lock_irqsave(&timer->lock, flags);
974 	if (event == SNDRV_TIMER_EVENT_MSTART ||
975 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
976 	    event == SNDRV_TIMER_EVENT_MRESUME) {
977 		if (timer->hw.c_resolution)
978 			resolution = timer->hw.c_resolution(timer);
979 		else
980 			resolution = timer->hw.resolution;
981 	}
982 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
983 		if (ti->ccallback)
984 			ti->ccallback(ti, event, tstamp, resolution);
985 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
986 			if (ts->ccallback)
987 				ts->ccallback(ts, event, tstamp, resolution);
988 	}
989 	spin_unlock_irqrestore(&timer->lock, flags);
990 }
991 EXPORT_SYMBOL(snd_timer_notify);
992 
993 /*
994  * exported functions for global timers
995  */
996 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
997 {
998 	struct snd_timer_id tid;
999 
1000 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1001 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1002 	tid.card = -1;
1003 	tid.device = device;
1004 	tid.subdevice = 0;
1005 	return snd_timer_new(NULL, id, &tid, rtimer);
1006 }
1007 EXPORT_SYMBOL(snd_timer_global_new);
1008 
1009 int snd_timer_global_free(struct snd_timer *timer)
1010 {
1011 	return snd_timer_free(timer);
1012 }
1013 EXPORT_SYMBOL(snd_timer_global_free);
1014 
1015 int snd_timer_global_register(struct snd_timer *timer)
1016 {
1017 	struct snd_device dev;
1018 
1019 	memset(&dev, 0, sizeof(dev));
1020 	dev.device_data = timer;
1021 	return snd_timer_dev_register(&dev);
1022 }
1023 EXPORT_SYMBOL(snd_timer_global_register);
1024 
1025 /*
1026  *  System timer
1027  */
1028 
1029 struct snd_timer_system_private {
1030 	struct timer_list tlist;
1031 	struct snd_timer *snd_timer;
1032 	unsigned long last_expires;
1033 	unsigned long last_jiffies;
1034 	unsigned long correction;
1035 };
1036 
1037 static void snd_timer_s_function(struct timer_list *t)
1038 {
1039 	struct snd_timer_system_private *priv = from_timer(priv, t,
1040 								tlist);
1041 	struct snd_timer *timer = priv->snd_timer;
1042 	unsigned long jiff = jiffies;
1043 	if (time_after(jiff, priv->last_expires))
1044 		priv->correction += (long)jiff - (long)priv->last_expires;
1045 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1046 }
1047 
1048 static int snd_timer_s_start(struct snd_timer * timer)
1049 {
1050 	struct snd_timer_system_private *priv;
1051 	unsigned long njiff;
1052 
1053 	priv = (struct snd_timer_system_private *) timer->private_data;
1054 	njiff = (priv->last_jiffies = jiffies);
1055 	if (priv->correction > timer->sticks - 1) {
1056 		priv->correction -= timer->sticks - 1;
1057 		njiff++;
1058 	} else {
1059 		njiff += timer->sticks - priv->correction;
1060 		priv->correction = 0;
1061 	}
1062 	priv->last_expires = njiff;
1063 	mod_timer(&priv->tlist, njiff);
1064 	return 0;
1065 }
1066 
1067 static int snd_timer_s_stop(struct snd_timer * timer)
1068 {
1069 	struct snd_timer_system_private *priv;
1070 	unsigned long jiff;
1071 
1072 	priv = (struct snd_timer_system_private *) timer->private_data;
1073 	del_timer(&priv->tlist);
1074 	jiff = jiffies;
1075 	if (time_before(jiff, priv->last_expires))
1076 		timer->sticks = priv->last_expires - jiff;
1077 	else
1078 		timer->sticks = 1;
1079 	priv->correction = 0;
1080 	return 0;
1081 }
1082 
1083 static int snd_timer_s_close(struct snd_timer *timer)
1084 {
1085 	struct snd_timer_system_private *priv;
1086 
1087 	priv = (struct snd_timer_system_private *)timer->private_data;
1088 	del_timer_sync(&priv->tlist);
1089 	return 0;
1090 }
1091 
1092 static struct snd_timer_hardware snd_timer_system =
1093 {
1094 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1095 	.resolution =	1000000000L / HZ,
1096 	.ticks =	10000000L,
1097 	.close =	snd_timer_s_close,
1098 	.start =	snd_timer_s_start,
1099 	.stop =		snd_timer_s_stop
1100 };
1101 
1102 static void snd_timer_free_system(struct snd_timer *timer)
1103 {
1104 	kfree(timer->private_data);
1105 }
1106 
1107 static int snd_timer_register_system(void)
1108 {
1109 	struct snd_timer *timer;
1110 	struct snd_timer_system_private *priv;
1111 	int err;
1112 
1113 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1114 	if (err < 0)
1115 		return err;
1116 	strcpy(timer->name, "system timer");
1117 	timer->hw = snd_timer_system;
1118 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1119 	if (priv == NULL) {
1120 		snd_timer_free(timer);
1121 		return -ENOMEM;
1122 	}
1123 	priv->snd_timer = timer;
1124 	timer_setup(&priv->tlist, snd_timer_s_function, 0);
1125 	timer->private_data = priv;
1126 	timer->private_free = snd_timer_free_system;
1127 	return snd_timer_global_register(timer);
1128 }
1129 
1130 #ifdef CONFIG_SND_PROC_FS
1131 /*
1132  *  Info interface
1133  */
1134 
1135 static void snd_timer_proc_read(struct snd_info_entry *entry,
1136 				struct snd_info_buffer *buffer)
1137 {
1138 	struct snd_timer *timer;
1139 	struct snd_timer_instance *ti;
1140 
1141 	mutex_lock(&register_mutex);
1142 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1143 		if (timer->card && timer->card->shutdown)
1144 			continue;
1145 		switch (timer->tmr_class) {
1146 		case SNDRV_TIMER_CLASS_GLOBAL:
1147 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1148 			break;
1149 		case SNDRV_TIMER_CLASS_CARD:
1150 			snd_iprintf(buffer, "C%i-%i: ",
1151 				    timer->card->number, timer->tmr_device);
1152 			break;
1153 		case SNDRV_TIMER_CLASS_PCM:
1154 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1155 				    timer->tmr_device, timer->tmr_subdevice);
1156 			break;
1157 		default:
1158 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1159 				    timer->card ? timer->card->number : -1,
1160 				    timer->tmr_device, timer->tmr_subdevice);
1161 		}
1162 		snd_iprintf(buffer, "%s :", timer->name);
1163 		if (timer->hw.resolution)
1164 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1165 				    timer->hw.resolution / 1000,
1166 				    timer->hw.resolution % 1000,
1167 				    timer->hw.ticks);
1168 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1169 			snd_iprintf(buffer, " SLAVE");
1170 		snd_iprintf(buffer, "\n");
1171 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1172 			snd_iprintf(buffer, "  Client %s : %s\n",
1173 				    ti->owner ? ti->owner : "unknown",
1174 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1175 						 SNDRV_TIMER_IFLG_RUNNING)
1176 				    ? "running" : "stopped");
1177 	}
1178 	mutex_unlock(&register_mutex);
1179 }
1180 
1181 static struct snd_info_entry *snd_timer_proc_entry;
1182 
1183 static void __init snd_timer_proc_init(void)
1184 {
1185 	struct snd_info_entry *entry;
1186 
1187 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1188 	if (entry != NULL) {
1189 		entry->c.text.read = snd_timer_proc_read;
1190 		if (snd_info_register(entry) < 0) {
1191 			snd_info_free_entry(entry);
1192 			entry = NULL;
1193 		}
1194 	}
1195 	snd_timer_proc_entry = entry;
1196 }
1197 
1198 static void __exit snd_timer_proc_done(void)
1199 {
1200 	snd_info_free_entry(snd_timer_proc_entry);
1201 }
1202 #else /* !CONFIG_SND_PROC_FS */
1203 #define snd_timer_proc_init()
1204 #define snd_timer_proc_done()
1205 #endif
1206 
1207 /*
1208  *  USER SPACE interface
1209  */
1210 
1211 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1212 				     unsigned long resolution,
1213 				     unsigned long ticks)
1214 {
1215 	struct snd_timer_user *tu = timeri->callback_data;
1216 	struct snd_timer_read *r;
1217 	int prev;
1218 
1219 	spin_lock(&tu->qlock);
1220 	if (tu->qused > 0) {
1221 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1222 		r = &tu->queue[prev];
1223 		if (r->resolution == resolution) {
1224 			r->ticks += ticks;
1225 			goto __wake;
1226 		}
1227 	}
1228 	if (tu->qused >= tu->queue_size) {
1229 		tu->overrun++;
1230 	} else {
1231 		r = &tu->queue[tu->qtail++];
1232 		tu->qtail %= tu->queue_size;
1233 		r->resolution = resolution;
1234 		r->ticks = ticks;
1235 		tu->qused++;
1236 	}
1237       __wake:
1238 	spin_unlock(&tu->qlock);
1239 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1240 	wake_up(&tu->qchange_sleep);
1241 }
1242 
1243 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1244 					    struct snd_timer_tread *tread)
1245 {
1246 	if (tu->qused >= tu->queue_size) {
1247 		tu->overrun++;
1248 	} else {
1249 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1250 		tu->qtail %= tu->queue_size;
1251 		tu->qused++;
1252 	}
1253 }
1254 
1255 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1256 				     int event,
1257 				     struct timespec *tstamp,
1258 				     unsigned long resolution)
1259 {
1260 	struct snd_timer_user *tu = timeri->callback_data;
1261 	struct snd_timer_tread r1;
1262 	unsigned long flags;
1263 
1264 	if (event >= SNDRV_TIMER_EVENT_START &&
1265 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1266 		tu->tstamp = *tstamp;
1267 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1268 		return;
1269 	memset(&r1, 0, sizeof(r1));
1270 	r1.event = event;
1271 	r1.tstamp = *tstamp;
1272 	r1.val = resolution;
1273 	spin_lock_irqsave(&tu->qlock, flags);
1274 	snd_timer_user_append_to_tqueue(tu, &r1);
1275 	spin_unlock_irqrestore(&tu->qlock, flags);
1276 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1277 	wake_up(&tu->qchange_sleep);
1278 }
1279 
1280 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1281 {
1282 	struct snd_timer_user *tu = timeri->callback_data;
1283 
1284 	tu->disconnected = true;
1285 	wake_up(&tu->qchange_sleep);
1286 }
1287 
1288 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1289 				      unsigned long resolution,
1290 				      unsigned long ticks)
1291 {
1292 	struct snd_timer_user *tu = timeri->callback_data;
1293 	struct snd_timer_tread *r, r1;
1294 	struct timespec tstamp;
1295 	int prev, append = 0;
1296 
1297 	memset(&r1, 0, sizeof(r1));
1298 	memset(&tstamp, 0, sizeof(tstamp));
1299 	spin_lock(&tu->qlock);
1300 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1301 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1302 		spin_unlock(&tu->qlock);
1303 		return;
1304 	}
1305 	if (tu->last_resolution != resolution || ticks > 0) {
1306 		if (timer_tstamp_monotonic)
1307 			ktime_get_ts(&tstamp);
1308 		else
1309 			getnstimeofday(&tstamp);
1310 	}
1311 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1312 	    tu->last_resolution != resolution) {
1313 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1314 		r1.tstamp = tstamp;
1315 		r1.val = resolution;
1316 		snd_timer_user_append_to_tqueue(tu, &r1);
1317 		tu->last_resolution = resolution;
1318 		append++;
1319 	}
1320 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1321 		goto __wake;
1322 	if (ticks == 0)
1323 		goto __wake;
1324 	if (tu->qused > 0) {
1325 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1326 		r = &tu->tqueue[prev];
1327 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1328 			r->tstamp = tstamp;
1329 			r->val += ticks;
1330 			append++;
1331 			goto __wake;
1332 		}
1333 	}
1334 	r1.event = SNDRV_TIMER_EVENT_TICK;
1335 	r1.tstamp = tstamp;
1336 	r1.val = ticks;
1337 	snd_timer_user_append_to_tqueue(tu, &r1);
1338 	append++;
1339       __wake:
1340 	spin_unlock(&tu->qlock);
1341 	if (append == 0)
1342 		return;
1343 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1344 	wake_up(&tu->qchange_sleep);
1345 }
1346 
1347 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1348 {
1349 	struct snd_timer_read *queue = NULL;
1350 	struct snd_timer_tread *tqueue = NULL;
1351 
1352 	if (tu->tread) {
1353 		tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1354 		if (!tqueue)
1355 			return -ENOMEM;
1356 	} else {
1357 		queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1358 		if (!queue)
1359 			return -ENOMEM;
1360 	}
1361 
1362 	spin_lock_irq(&tu->qlock);
1363 	kfree(tu->queue);
1364 	kfree(tu->tqueue);
1365 	tu->queue_size = size;
1366 	tu->queue = queue;
1367 	tu->tqueue = tqueue;
1368 	tu->qhead = tu->qtail = tu->qused = 0;
1369 	spin_unlock_irq(&tu->qlock);
1370 
1371 	return 0;
1372 }
1373 
1374 static int snd_timer_user_open(struct inode *inode, struct file *file)
1375 {
1376 	struct snd_timer_user *tu;
1377 	int err;
1378 
1379 	err = nonseekable_open(inode, file);
1380 	if (err < 0)
1381 		return err;
1382 
1383 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1384 	if (tu == NULL)
1385 		return -ENOMEM;
1386 	spin_lock_init(&tu->qlock);
1387 	init_waitqueue_head(&tu->qchange_sleep);
1388 	mutex_init(&tu->ioctl_lock);
1389 	tu->ticks = 1;
1390 	if (realloc_user_queue(tu, 128) < 0) {
1391 		kfree(tu);
1392 		return -ENOMEM;
1393 	}
1394 	file->private_data = tu;
1395 	return 0;
1396 }
1397 
1398 static int snd_timer_user_release(struct inode *inode, struct file *file)
1399 {
1400 	struct snd_timer_user *tu;
1401 
1402 	if (file->private_data) {
1403 		tu = file->private_data;
1404 		file->private_data = NULL;
1405 		mutex_lock(&tu->ioctl_lock);
1406 		if (tu->timeri)
1407 			snd_timer_close(tu->timeri);
1408 		mutex_unlock(&tu->ioctl_lock);
1409 		kfree(tu->queue);
1410 		kfree(tu->tqueue);
1411 		kfree(tu);
1412 	}
1413 	return 0;
1414 }
1415 
1416 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1417 {
1418 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1419 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1420 	id->card = -1;
1421 	id->device = -1;
1422 	id->subdevice = -1;
1423 }
1424 
1425 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1426 {
1427 	id->dev_class = timer->tmr_class;
1428 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1429 	id->card = timer->card ? timer->card->number : -1;
1430 	id->device = timer->tmr_device;
1431 	id->subdevice = timer->tmr_subdevice;
1432 }
1433 
1434 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1435 {
1436 	struct snd_timer_id id;
1437 	struct snd_timer *timer;
1438 	struct list_head *p;
1439 
1440 	if (copy_from_user(&id, _tid, sizeof(id)))
1441 		return -EFAULT;
1442 	mutex_lock(&register_mutex);
1443 	if (id.dev_class < 0) {		/* first item */
1444 		if (list_empty(&snd_timer_list))
1445 			snd_timer_user_zero_id(&id);
1446 		else {
1447 			timer = list_entry(snd_timer_list.next,
1448 					   struct snd_timer, device_list);
1449 			snd_timer_user_copy_id(&id, timer);
1450 		}
1451 	} else {
1452 		switch (id.dev_class) {
1453 		case SNDRV_TIMER_CLASS_GLOBAL:
1454 			id.device = id.device < 0 ? 0 : id.device + 1;
1455 			list_for_each(p, &snd_timer_list) {
1456 				timer = list_entry(p, struct snd_timer, device_list);
1457 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1458 					snd_timer_user_copy_id(&id, timer);
1459 					break;
1460 				}
1461 				if (timer->tmr_device >= id.device) {
1462 					snd_timer_user_copy_id(&id, timer);
1463 					break;
1464 				}
1465 			}
1466 			if (p == &snd_timer_list)
1467 				snd_timer_user_zero_id(&id);
1468 			break;
1469 		case SNDRV_TIMER_CLASS_CARD:
1470 		case SNDRV_TIMER_CLASS_PCM:
1471 			if (id.card < 0) {
1472 				id.card = 0;
1473 			} else {
1474 				if (id.device < 0) {
1475 					id.device = 0;
1476 				} else {
1477 					if (id.subdevice < 0)
1478 						id.subdevice = 0;
1479 					else
1480 						id.subdevice++;
1481 				}
1482 			}
1483 			list_for_each(p, &snd_timer_list) {
1484 				timer = list_entry(p, struct snd_timer, device_list);
1485 				if (timer->tmr_class > id.dev_class) {
1486 					snd_timer_user_copy_id(&id, timer);
1487 					break;
1488 				}
1489 				if (timer->tmr_class < id.dev_class)
1490 					continue;
1491 				if (timer->card->number > id.card) {
1492 					snd_timer_user_copy_id(&id, timer);
1493 					break;
1494 				}
1495 				if (timer->card->number < id.card)
1496 					continue;
1497 				if (timer->tmr_device > id.device) {
1498 					snd_timer_user_copy_id(&id, timer);
1499 					break;
1500 				}
1501 				if (timer->tmr_device < id.device)
1502 					continue;
1503 				if (timer->tmr_subdevice > id.subdevice) {
1504 					snd_timer_user_copy_id(&id, timer);
1505 					break;
1506 				}
1507 				if (timer->tmr_subdevice < id.subdevice)
1508 					continue;
1509 				snd_timer_user_copy_id(&id, timer);
1510 				break;
1511 			}
1512 			if (p == &snd_timer_list)
1513 				snd_timer_user_zero_id(&id);
1514 			break;
1515 		default:
1516 			snd_timer_user_zero_id(&id);
1517 		}
1518 	}
1519 	mutex_unlock(&register_mutex);
1520 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1521 		return -EFAULT;
1522 	return 0;
1523 }
1524 
1525 static int snd_timer_user_ginfo(struct file *file,
1526 				struct snd_timer_ginfo __user *_ginfo)
1527 {
1528 	struct snd_timer_ginfo *ginfo;
1529 	struct snd_timer_id tid;
1530 	struct snd_timer *t;
1531 	struct list_head *p;
1532 	int err = 0;
1533 
1534 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1535 	if (IS_ERR(ginfo))
1536 		return PTR_ERR(ginfo);
1537 
1538 	tid = ginfo->tid;
1539 	memset(ginfo, 0, sizeof(*ginfo));
1540 	ginfo->tid = tid;
1541 	mutex_lock(&register_mutex);
1542 	t = snd_timer_find(&tid);
1543 	if (t != NULL) {
1544 		ginfo->card = t->card ? t->card->number : -1;
1545 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1546 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1547 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1548 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1549 		ginfo->resolution = t->hw.resolution;
1550 		if (t->hw.resolution_min > 0) {
1551 			ginfo->resolution_min = t->hw.resolution_min;
1552 			ginfo->resolution_max = t->hw.resolution_max;
1553 		}
1554 		list_for_each(p, &t->open_list_head) {
1555 			ginfo->clients++;
1556 		}
1557 	} else {
1558 		err = -ENODEV;
1559 	}
1560 	mutex_unlock(&register_mutex);
1561 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1562 		err = -EFAULT;
1563 	kfree(ginfo);
1564 	return err;
1565 }
1566 
1567 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1568 {
1569 	struct snd_timer *t;
1570 	int err;
1571 
1572 	mutex_lock(&register_mutex);
1573 	t = snd_timer_find(&gparams->tid);
1574 	if (!t) {
1575 		err = -ENODEV;
1576 		goto _error;
1577 	}
1578 	if (!list_empty(&t->open_list_head)) {
1579 		err = -EBUSY;
1580 		goto _error;
1581 	}
1582 	if (!t->hw.set_period) {
1583 		err = -ENOSYS;
1584 		goto _error;
1585 	}
1586 	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1587 _error:
1588 	mutex_unlock(&register_mutex);
1589 	return err;
1590 }
1591 
1592 static int snd_timer_user_gparams(struct file *file,
1593 				  struct snd_timer_gparams __user *_gparams)
1594 {
1595 	struct snd_timer_gparams gparams;
1596 
1597 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1598 		return -EFAULT;
1599 	return timer_set_gparams(&gparams);
1600 }
1601 
1602 static int snd_timer_user_gstatus(struct file *file,
1603 				  struct snd_timer_gstatus __user *_gstatus)
1604 {
1605 	struct snd_timer_gstatus gstatus;
1606 	struct snd_timer_id tid;
1607 	struct snd_timer *t;
1608 	int err = 0;
1609 
1610 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1611 		return -EFAULT;
1612 	tid = gstatus.tid;
1613 	memset(&gstatus, 0, sizeof(gstatus));
1614 	gstatus.tid = tid;
1615 	mutex_lock(&register_mutex);
1616 	t = snd_timer_find(&tid);
1617 	if (t != NULL) {
1618 		if (t->hw.c_resolution)
1619 			gstatus.resolution = t->hw.c_resolution(t);
1620 		else
1621 			gstatus.resolution = t->hw.resolution;
1622 		if (t->hw.precise_resolution) {
1623 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1624 						 &gstatus.resolution_den);
1625 		} else {
1626 			gstatus.resolution_num = gstatus.resolution;
1627 			gstatus.resolution_den = 1000000000uL;
1628 		}
1629 	} else {
1630 		err = -ENODEV;
1631 	}
1632 	mutex_unlock(&register_mutex);
1633 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1634 		err = -EFAULT;
1635 	return err;
1636 }
1637 
1638 static int snd_timer_user_tselect(struct file *file,
1639 				  struct snd_timer_select __user *_tselect)
1640 {
1641 	struct snd_timer_user *tu;
1642 	struct snd_timer_select tselect;
1643 	char str[32];
1644 	int err = 0;
1645 
1646 	tu = file->private_data;
1647 	if (tu->timeri) {
1648 		snd_timer_close(tu->timeri);
1649 		tu->timeri = NULL;
1650 	}
1651 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1652 		err = -EFAULT;
1653 		goto __err;
1654 	}
1655 	sprintf(str, "application %i", current->pid);
1656 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1657 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1658 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1659 	if (err < 0)
1660 		goto __err;
1661 
1662 	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1663 	tu->timeri->callback = tu->tread
1664 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1665 	tu->timeri->ccallback = snd_timer_user_ccallback;
1666 	tu->timeri->callback_data = (void *)tu;
1667 	tu->timeri->disconnect = snd_timer_user_disconnect;
1668 
1669       __err:
1670 	return err;
1671 }
1672 
1673 static int snd_timer_user_info(struct file *file,
1674 			       struct snd_timer_info __user *_info)
1675 {
1676 	struct snd_timer_user *tu;
1677 	struct snd_timer_info *info;
1678 	struct snd_timer *t;
1679 	int err = 0;
1680 
1681 	tu = file->private_data;
1682 	if (!tu->timeri)
1683 		return -EBADFD;
1684 	t = tu->timeri->timer;
1685 	if (!t)
1686 		return -EBADFD;
1687 
1688 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1689 	if (! info)
1690 		return -ENOMEM;
1691 	info->card = t->card ? t->card->number : -1;
1692 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1693 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1694 	strlcpy(info->id, t->id, sizeof(info->id));
1695 	strlcpy(info->name, t->name, sizeof(info->name));
1696 	info->resolution = t->hw.resolution;
1697 	if (copy_to_user(_info, info, sizeof(*_info)))
1698 		err = -EFAULT;
1699 	kfree(info);
1700 	return err;
1701 }
1702 
1703 static int snd_timer_user_params(struct file *file,
1704 				 struct snd_timer_params __user *_params)
1705 {
1706 	struct snd_timer_user *tu;
1707 	struct snd_timer_params params;
1708 	struct snd_timer *t;
1709 	int err;
1710 
1711 	tu = file->private_data;
1712 	if (!tu->timeri)
1713 		return -EBADFD;
1714 	t = tu->timeri->timer;
1715 	if (!t)
1716 		return -EBADFD;
1717 	if (copy_from_user(&params, _params, sizeof(params)))
1718 		return -EFAULT;
1719 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1720 		u64 resolution;
1721 
1722 		if (params.ticks < 1) {
1723 			err = -EINVAL;
1724 			goto _end;
1725 		}
1726 
1727 		/* Don't allow resolution less than 1ms */
1728 		resolution = snd_timer_resolution(tu->timeri);
1729 		resolution *= params.ticks;
1730 		if (resolution < 1000000) {
1731 			err = -EINVAL;
1732 			goto _end;
1733 		}
1734 	}
1735 	if (params.queue_size > 0 &&
1736 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1737 		err = -EINVAL;
1738 		goto _end;
1739 	}
1740 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1741 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1742 			      (1<<SNDRV_TIMER_EVENT_START)|
1743 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1744 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1745 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1746 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1747 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1748 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1749 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1750 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1751 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1752 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1753 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1754 		err = -EINVAL;
1755 		goto _end;
1756 	}
1757 	snd_timer_stop(tu->timeri);
1758 	spin_lock_irq(&t->lock);
1759 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1760 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1761 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1762 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1763 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1764 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1765 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1766 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1767 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1768 	spin_unlock_irq(&t->lock);
1769 	if (params.queue_size > 0 &&
1770 	    (unsigned int)tu->queue_size != params.queue_size) {
1771 		err = realloc_user_queue(tu, params.queue_size);
1772 		if (err < 0)
1773 			goto _end;
1774 	}
1775 	spin_lock_irq(&tu->qlock);
1776 	tu->qhead = tu->qtail = tu->qused = 0;
1777 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1778 		if (tu->tread) {
1779 			struct snd_timer_tread tread;
1780 			memset(&tread, 0, sizeof(tread));
1781 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1782 			tread.tstamp.tv_sec = 0;
1783 			tread.tstamp.tv_nsec = 0;
1784 			tread.val = 0;
1785 			snd_timer_user_append_to_tqueue(tu, &tread);
1786 		} else {
1787 			struct snd_timer_read *r = &tu->queue[0];
1788 			r->resolution = 0;
1789 			r->ticks = 0;
1790 			tu->qused++;
1791 			tu->qtail++;
1792 		}
1793 	}
1794 	tu->filter = params.filter;
1795 	tu->ticks = params.ticks;
1796 	spin_unlock_irq(&tu->qlock);
1797 	err = 0;
1798  _end:
1799 	if (copy_to_user(_params, &params, sizeof(params)))
1800 		return -EFAULT;
1801 	return err;
1802 }
1803 
1804 static int snd_timer_user_status(struct file *file,
1805 				 struct snd_timer_status __user *_status)
1806 {
1807 	struct snd_timer_user *tu;
1808 	struct snd_timer_status status;
1809 
1810 	tu = file->private_data;
1811 	if (!tu->timeri)
1812 		return -EBADFD;
1813 	memset(&status, 0, sizeof(status));
1814 	status.tstamp = tu->tstamp;
1815 	status.resolution = snd_timer_resolution(tu->timeri);
1816 	status.lost = tu->timeri->lost;
1817 	status.overrun = tu->overrun;
1818 	spin_lock_irq(&tu->qlock);
1819 	status.queue = tu->qused;
1820 	spin_unlock_irq(&tu->qlock);
1821 	if (copy_to_user(_status, &status, sizeof(status)))
1822 		return -EFAULT;
1823 	return 0;
1824 }
1825 
1826 static int snd_timer_user_start(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 	snd_timer_stop(tu->timeri);
1835 	tu->timeri->lost = 0;
1836 	tu->last_resolution = 0;
1837 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1838 }
1839 
1840 static int snd_timer_user_stop(struct file *file)
1841 {
1842 	int err;
1843 	struct snd_timer_user *tu;
1844 
1845 	tu = file->private_data;
1846 	if (!tu->timeri)
1847 		return -EBADFD;
1848 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1849 }
1850 
1851 static int snd_timer_user_continue(struct file *file)
1852 {
1853 	int err;
1854 	struct snd_timer_user *tu;
1855 
1856 	tu = file->private_data;
1857 	if (!tu->timeri)
1858 		return -EBADFD;
1859 	/* start timer instead of continue if it's not used before */
1860 	if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1861 		return snd_timer_user_start(file);
1862 	tu->timeri->lost = 0;
1863 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1864 }
1865 
1866 static int snd_timer_user_pause(struct file *file)
1867 {
1868 	int err;
1869 	struct snd_timer_user *tu;
1870 
1871 	tu = file->private_data;
1872 	if (!tu->timeri)
1873 		return -EBADFD;
1874 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1875 }
1876 
1877 enum {
1878 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1879 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1880 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1881 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1882 };
1883 
1884 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1885 				 unsigned long arg)
1886 {
1887 	struct snd_timer_user *tu;
1888 	void __user *argp = (void __user *)arg;
1889 	int __user *p = argp;
1890 
1891 	tu = file->private_data;
1892 	switch (cmd) {
1893 	case SNDRV_TIMER_IOCTL_PVERSION:
1894 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1895 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1896 		return snd_timer_user_next_device(argp);
1897 	case SNDRV_TIMER_IOCTL_TREAD:
1898 	{
1899 		int xarg, old_tread;
1900 
1901 		if (tu->timeri)	/* too late */
1902 			return -EBUSY;
1903 		if (get_user(xarg, p))
1904 			return -EFAULT;
1905 		old_tread = tu->tread;
1906 		tu->tread = xarg ? 1 : 0;
1907 		if (tu->tread != old_tread &&
1908 		    realloc_user_queue(tu, tu->queue_size) < 0) {
1909 			tu->tread = old_tread;
1910 			return -ENOMEM;
1911 		}
1912 		return 0;
1913 	}
1914 	case SNDRV_TIMER_IOCTL_GINFO:
1915 		return snd_timer_user_ginfo(file, argp);
1916 	case SNDRV_TIMER_IOCTL_GPARAMS:
1917 		return snd_timer_user_gparams(file, argp);
1918 	case SNDRV_TIMER_IOCTL_GSTATUS:
1919 		return snd_timer_user_gstatus(file, argp);
1920 	case SNDRV_TIMER_IOCTL_SELECT:
1921 		return snd_timer_user_tselect(file, argp);
1922 	case SNDRV_TIMER_IOCTL_INFO:
1923 		return snd_timer_user_info(file, argp);
1924 	case SNDRV_TIMER_IOCTL_PARAMS:
1925 		return snd_timer_user_params(file, argp);
1926 	case SNDRV_TIMER_IOCTL_STATUS:
1927 		return snd_timer_user_status(file, argp);
1928 	case SNDRV_TIMER_IOCTL_START:
1929 	case SNDRV_TIMER_IOCTL_START_OLD:
1930 		return snd_timer_user_start(file);
1931 	case SNDRV_TIMER_IOCTL_STOP:
1932 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1933 		return snd_timer_user_stop(file);
1934 	case SNDRV_TIMER_IOCTL_CONTINUE:
1935 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1936 		return snd_timer_user_continue(file);
1937 	case SNDRV_TIMER_IOCTL_PAUSE:
1938 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1939 		return snd_timer_user_pause(file);
1940 	}
1941 	return -ENOTTY;
1942 }
1943 
1944 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1945 				 unsigned long arg)
1946 {
1947 	struct snd_timer_user *tu = file->private_data;
1948 	long ret;
1949 
1950 	mutex_lock(&tu->ioctl_lock);
1951 	ret = __snd_timer_user_ioctl(file, cmd, arg);
1952 	mutex_unlock(&tu->ioctl_lock);
1953 	return ret;
1954 }
1955 
1956 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1957 {
1958 	struct snd_timer_user *tu;
1959 
1960 	tu = file->private_data;
1961 	return fasync_helper(fd, file, on, &tu->fasync);
1962 }
1963 
1964 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1965 				   size_t count, loff_t *offset)
1966 {
1967 	struct snd_timer_user *tu;
1968 	long result = 0, unit;
1969 	int qhead;
1970 	int err = 0;
1971 
1972 	tu = file->private_data;
1973 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1974 	mutex_lock(&tu->ioctl_lock);
1975 	spin_lock_irq(&tu->qlock);
1976 	while ((long)count - result >= unit) {
1977 		while (!tu->qused) {
1978 			wait_queue_entry_t wait;
1979 
1980 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1981 				err = -EAGAIN;
1982 				goto _error;
1983 			}
1984 
1985 			set_current_state(TASK_INTERRUPTIBLE);
1986 			init_waitqueue_entry(&wait, current);
1987 			add_wait_queue(&tu->qchange_sleep, &wait);
1988 
1989 			spin_unlock_irq(&tu->qlock);
1990 			mutex_unlock(&tu->ioctl_lock);
1991 			schedule();
1992 			mutex_lock(&tu->ioctl_lock);
1993 			spin_lock_irq(&tu->qlock);
1994 
1995 			remove_wait_queue(&tu->qchange_sleep, &wait);
1996 
1997 			if (tu->disconnected) {
1998 				err = -ENODEV;
1999 				goto _error;
2000 			}
2001 			if (signal_pending(current)) {
2002 				err = -ERESTARTSYS;
2003 				goto _error;
2004 			}
2005 		}
2006 
2007 		qhead = tu->qhead++;
2008 		tu->qhead %= tu->queue_size;
2009 		tu->qused--;
2010 		spin_unlock_irq(&tu->qlock);
2011 
2012 		if (tu->tread) {
2013 			if (copy_to_user(buffer, &tu->tqueue[qhead],
2014 					 sizeof(struct snd_timer_tread)))
2015 				err = -EFAULT;
2016 		} else {
2017 			if (copy_to_user(buffer, &tu->queue[qhead],
2018 					 sizeof(struct snd_timer_read)))
2019 				err = -EFAULT;
2020 		}
2021 
2022 		spin_lock_irq(&tu->qlock);
2023 		if (err < 0)
2024 			goto _error;
2025 		result += unit;
2026 		buffer += unit;
2027 	}
2028  _error:
2029 	spin_unlock_irq(&tu->qlock);
2030 	mutex_unlock(&tu->ioctl_lock);
2031 	return result > 0 ? result : err;
2032 }
2033 
2034 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
2035 {
2036         unsigned int mask;
2037         struct snd_timer_user *tu;
2038 
2039         tu = file->private_data;
2040 
2041         poll_wait(file, &tu->qchange_sleep, wait);
2042 
2043 	mask = 0;
2044 	spin_lock_irq(&tu->qlock);
2045 	if (tu->qused)
2046 		mask |= POLLIN | POLLRDNORM;
2047 	if (tu->disconnected)
2048 		mask |= POLLERR;
2049 	spin_unlock_irq(&tu->qlock);
2050 
2051 	return mask;
2052 }
2053 
2054 #ifdef CONFIG_COMPAT
2055 #include "timer_compat.c"
2056 #else
2057 #define snd_timer_user_ioctl_compat	NULL
2058 #endif
2059 
2060 static const struct file_operations snd_timer_f_ops =
2061 {
2062 	.owner =	THIS_MODULE,
2063 	.read =		snd_timer_user_read,
2064 	.open =		snd_timer_user_open,
2065 	.release =	snd_timer_user_release,
2066 	.llseek =	no_llseek,
2067 	.poll =		snd_timer_user_poll,
2068 	.unlocked_ioctl =	snd_timer_user_ioctl,
2069 	.compat_ioctl =	snd_timer_user_ioctl_compat,
2070 	.fasync = 	snd_timer_user_fasync,
2071 };
2072 
2073 /* unregister the system timer */
2074 static void snd_timer_free_all(void)
2075 {
2076 	struct snd_timer *timer, *n;
2077 
2078 	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2079 		snd_timer_free(timer);
2080 }
2081 
2082 static struct device timer_dev;
2083 
2084 /*
2085  *  ENTRY functions
2086  */
2087 
2088 static int __init alsa_timer_init(void)
2089 {
2090 	int err;
2091 
2092 	snd_device_initialize(&timer_dev, NULL);
2093 	dev_set_name(&timer_dev, "timer");
2094 
2095 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2096 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2097 			      "system timer");
2098 #endif
2099 
2100 	err = snd_timer_register_system();
2101 	if (err < 0) {
2102 		pr_err("ALSA: unable to register system timer (%i)\n", err);
2103 		goto put_timer;
2104 	}
2105 
2106 	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2107 				  &snd_timer_f_ops, NULL, &timer_dev);
2108 	if (err < 0) {
2109 		pr_err("ALSA: unable to register timer device (%i)\n", err);
2110 		snd_timer_free_all();
2111 		goto put_timer;
2112 	}
2113 
2114 	snd_timer_proc_init();
2115 	return 0;
2116 
2117 put_timer:
2118 	put_device(&timer_dev);
2119 	return err;
2120 }
2121 
2122 static void __exit alsa_timer_exit(void)
2123 {
2124 	snd_unregister_device(&timer_dev);
2125 	snd_timer_free_all();
2126 	put_device(&timer_dev);
2127 	snd_timer_proc_done();
2128 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2129 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2130 #endif
2131 }
2132 
2133 module_init(alsa_timer_init)
2134 module_exit(alsa_timer_exit)
2135