xref: /openbmc/linux/sound/core/timer.c (revision 2596e07a)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/delay.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/device.h>
28 #include <linux/module.h>
29 #include <linux/string.h>
30 #include <sound/core.h>
31 #include <sound/timer.h>
32 #include <sound/control.h>
33 #include <sound/info.h>
34 #include <sound/minors.h>
35 #include <sound/initval.h>
36 #include <linux/kmod.h>
37 
38 #if IS_ENABLED(CONFIG_SND_HRTIMER)
39 #define DEFAULT_TIMER_LIMIT 4
40 #elif IS_ENABLED(CONFIG_SND_RTCTIMER)
41 #define DEFAULT_TIMER_LIMIT 2
42 #else
43 #define DEFAULT_TIMER_LIMIT 1
44 #endif
45 
46 static int timer_limit = DEFAULT_TIMER_LIMIT;
47 static int timer_tstamp_monotonic = 1;
48 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
49 MODULE_DESCRIPTION("ALSA timer interface");
50 MODULE_LICENSE("GPL");
51 module_param(timer_limit, int, 0444);
52 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
53 module_param(timer_tstamp_monotonic, int, 0444);
54 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
55 
56 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
57 MODULE_ALIAS("devname:snd/timer");
58 
59 struct snd_timer_user {
60 	struct snd_timer_instance *timeri;
61 	int tread;		/* enhanced read with timestamps and events */
62 	unsigned long ticks;
63 	unsigned long overrun;
64 	int qhead;
65 	int qtail;
66 	int qused;
67 	int queue_size;
68 	bool disconnected;
69 	struct snd_timer_read *queue;
70 	struct snd_timer_tread *tqueue;
71 	spinlock_t qlock;
72 	unsigned long last_resolution;
73 	unsigned int filter;
74 	struct timespec tstamp;		/* trigger tstamp */
75 	wait_queue_head_t qchange_sleep;
76 	struct fasync_struct *fasync;
77 	struct mutex ioctl_lock;
78 };
79 
80 /* list of timers */
81 static LIST_HEAD(snd_timer_list);
82 
83 /* list of slave instances */
84 static LIST_HEAD(snd_timer_slave_list);
85 
86 /* lock for slave active lists */
87 static DEFINE_SPINLOCK(slave_active_lock);
88 
89 static DEFINE_MUTEX(register_mutex);
90 
91 static int snd_timer_free(struct snd_timer *timer);
92 static int snd_timer_dev_free(struct snd_device *device);
93 static int snd_timer_dev_register(struct snd_device *device);
94 static int snd_timer_dev_disconnect(struct snd_device *device);
95 
96 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
97 
98 /*
99  * create a timer instance with the given owner string.
100  * when timer is not NULL, increments the module counter
101  */
102 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
103 							 struct snd_timer *timer)
104 {
105 	struct snd_timer_instance *timeri;
106 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
107 	if (timeri == NULL)
108 		return NULL;
109 	timeri->owner = kstrdup(owner, GFP_KERNEL);
110 	if (! timeri->owner) {
111 		kfree(timeri);
112 		return NULL;
113 	}
114 	INIT_LIST_HEAD(&timeri->open_list);
115 	INIT_LIST_HEAD(&timeri->active_list);
116 	INIT_LIST_HEAD(&timeri->ack_list);
117 	INIT_LIST_HEAD(&timeri->slave_list_head);
118 	INIT_LIST_HEAD(&timeri->slave_active_head);
119 
120 	timeri->timer = timer;
121 	if (timer && !try_module_get(timer->module)) {
122 		kfree(timeri->owner);
123 		kfree(timeri);
124 		return NULL;
125 	}
126 
127 	return timeri;
128 }
129 
130 /*
131  * find a timer instance from the given timer id
132  */
133 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
134 {
135 	struct snd_timer *timer = NULL;
136 
137 	list_for_each_entry(timer, &snd_timer_list, device_list) {
138 		if (timer->tmr_class != tid->dev_class)
139 			continue;
140 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
141 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
142 		    (timer->card == NULL ||
143 		     timer->card->number != tid->card))
144 			continue;
145 		if (timer->tmr_device != tid->device)
146 			continue;
147 		if (timer->tmr_subdevice != tid->subdevice)
148 			continue;
149 		return timer;
150 	}
151 	return NULL;
152 }
153 
154 #ifdef CONFIG_MODULES
155 
156 static void snd_timer_request(struct snd_timer_id *tid)
157 {
158 	switch (tid->dev_class) {
159 	case SNDRV_TIMER_CLASS_GLOBAL:
160 		if (tid->device < timer_limit)
161 			request_module("snd-timer-%i", tid->device);
162 		break;
163 	case SNDRV_TIMER_CLASS_CARD:
164 	case SNDRV_TIMER_CLASS_PCM:
165 		if (tid->card < snd_ecards_limit)
166 			request_module("snd-card-%i", tid->card);
167 		break;
168 	default:
169 		break;
170 	}
171 }
172 
173 #endif
174 
175 /*
176  * look for a master instance matching with the slave id of the given slave.
177  * when found, relink the open_link of the slave.
178  *
179  * call this with register_mutex down.
180  */
181 static void snd_timer_check_slave(struct snd_timer_instance *slave)
182 {
183 	struct snd_timer *timer;
184 	struct snd_timer_instance *master;
185 
186 	/* FIXME: it's really dumb to look up all entries.. */
187 	list_for_each_entry(timer, &snd_timer_list, device_list) {
188 		list_for_each_entry(master, &timer->open_list_head, open_list) {
189 			if (slave->slave_class == master->slave_class &&
190 			    slave->slave_id == master->slave_id) {
191 				list_move_tail(&slave->open_list,
192 					       &master->slave_list_head);
193 				spin_lock_irq(&slave_active_lock);
194 				slave->master = master;
195 				slave->timer = master->timer;
196 				spin_unlock_irq(&slave_active_lock);
197 				return;
198 			}
199 		}
200 	}
201 }
202 
203 /*
204  * look for slave instances matching with the slave id of the given master.
205  * when found, relink the open_link of slaves.
206  *
207  * call this with register_mutex down.
208  */
209 static void snd_timer_check_master(struct snd_timer_instance *master)
210 {
211 	struct snd_timer_instance *slave, *tmp;
212 
213 	/* check all pending slaves */
214 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
215 		if (slave->slave_class == master->slave_class &&
216 		    slave->slave_id == master->slave_id) {
217 			list_move_tail(&slave->open_list, &master->slave_list_head);
218 			spin_lock_irq(&slave_active_lock);
219 			spin_lock(&master->timer->lock);
220 			slave->master = master;
221 			slave->timer = master->timer;
222 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
223 				list_add_tail(&slave->active_list,
224 					      &master->slave_active_head);
225 			spin_unlock(&master->timer->lock);
226 			spin_unlock_irq(&slave_active_lock);
227 		}
228 	}
229 }
230 
231 /*
232  * open a timer instance
233  * when opening a master, the slave id must be here given.
234  */
235 int snd_timer_open(struct snd_timer_instance **ti,
236 		   char *owner, struct snd_timer_id *tid,
237 		   unsigned int slave_id)
238 {
239 	struct snd_timer *timer;
240 	struct snd_timer_instance *timeri = NULL;
241 
242 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
243 		/* open a slave instance */
244 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
245 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
246 			pr_debug("ALSA: timer: invalid slave class %i\n",
247 				 tid->dev_sclass);
248 			return -EINVAL;
249 		}
250 		mutex_lock(&register_mutex);
251 		timeri = snd_timer_instance_new(owner, NULL);
252 		if (!timeri) {
253 			mutex_unlock(&register_mutex);
254 			return -ENOMEM;
255 		}
256 		timeri->slave_class = tid->dev_sclass;
257 		timeri->slave_id = tid->device;
258 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
259 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
260 		snd_timer_check_slave(timeri);
261 		mutex_unlock(&register_mutex);
262 		*ti = timeri;
263 		return 0;
264 	}
265 
266 	/* open a master instance */
267 	mutex_lock(&register_mutex);
268 	timer = snd_timer_find(tid);
269 #ifdef CONFIG_MODULES
270 	if (!timer) {
271 		mutex_unlock(&register_mutex);
272 		snd_timer_request(tid);
273 		mutex_lock(&register_mutex);
274 		timer = snd_timer_find(tid);
275 	}
276 #endif
277 	if (!timer) {
278 		mutex_unlock(&register_mutex);
279 		return -ENODEV;
280 	}
281 	if (!list_empty(&timer->open_list_head)) {
282 		timeri = list_entry(timer->open_list_head.next,
283 				    struct snd_timer_instance, open_list);
284 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
285 			mutex_unlock(&register_mutex);
286 			return -EBUSY;
287 		}
288 	}
289 	timeri = snd_timer_instance_new(owner, timer);
290 	if (!timeri) {
291 		mutex_unlock(&register_mutex);
292 		return -ENOMEM;
293 	}
294 	/* take a card refcount for safe disconnection */
295 	if (timer->card)
296 		get_device(&timer->card->card_dev);
297 	timeri->slave_class = tid->dev_sclass;
298 	timeri->slave_id = slave_id;
299 	if (list_empty(&timer->open_list_head) && timer->hw.open)
300 		timer->hw.open(timer);
301 	list_add_tail(&timeri->open_list, &timer->open_list_head);
302 	snd_timer_check_master(timeri);
303 	mutex_unlock(&register_mutex);
304 	*ti = timeri;
305 	return 0;
306 }
307 
308 static int _snd_timer_stop(struct snd_timer_instance *timeri, int event);
309 
310 /*
311  * close a timer instance
312  */
313 int snd_timer_close(struct snd_timer_instance *timeri)
314 {
315 	struct snd_timer *timer = NULL;
316 	struct snd_timer_instance *slave, *tmp;
317 
318 	if (snd_BUG_ON(!timeri))
319 		return -ENXIO;
320 
321 	/* force to stop the timer */
322 	snd_timer_stop(timeri);
323 
324 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
325 		/* wait, until the active callback is finished */
326 		spin_lock_irq(&slave_active_lock);
327 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
328 			spin_unlock_irq(&slave_active_lock);
329 			udelay(10);
330 			spin_lock_irq(&slave_active_lock);
331 		}
332 		spin_unlock_irq(&slave_active_lock);
333 		mutex_lock(&register_mutex);
334 		list_del(&timeri->open_list);
335 		mutex_unlock(&register_mutex);
336 	} else {
337 		timer = timeri->timer;
338 		if (snd_BUG_ON(!timer))
339 			goto out;
340 		/* wait, until the active callback is finished */
341 		spin_lock_irq(&timer->lock);
342 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
343 			spin_unlock_irq(&timer->lock);
344 			udelay(10);
345 			spin_lock_irq(&timer->lock);
346 		}
347 		spin_unlock_irq(&timer->lock);
348 		mutex_lock(&register_mutex);
349 		list_del(&timeri->open_list);
350 		if (list_empty(&timer->open_list_head) &&
351 		    timer->hw.close)
352 			timer->hw.close(timer);
353 		/* remove slave links */
354 		spin_lock_irq(&slave_active_lock);
355 		spin_lock(&timer->lock);
356 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
357 					 open_list) {
358 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
359 			slave->master = NULL;
360 			slave->timer = NULL;
361 			list_del_init(&slave->ack_list);
362 			list_del_init(&slave->active_list);
363 		}
364 		spin_unlock(&timer->lock);
365 		spin_unlock_irq(&slave_active_lock);
366 		/* release a card refcount for safe disconnection */
367 		if (timer->card)
368 			put_device(&timer->card->card_dev);
369 		mutex_unlock(&register_mutex);
370 	}
371  out:
372 	if (timeri->private_free)
373 		timeri->private_free(timeri);
374 	kfree(timeri->owner);
375 	kfree(timeri);
376 	if (timer)
377 		module_put(timer->module);
378 	return 0;
379 }
380 
381 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
382 {
383 	struct snd_timer * timer;
384 
385 	if (timeri == NULL)
386 		return 0;
387 	if ((timer = timeri->timer) != NULL) {
388 		if (timer->hw.c_resolution)
389 			return timer->hw.c_resolution(timer);
390 		return timer->hw.resolution;
391 	}
392 	return 0;
393 }
394 
395 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
396 {
397 	struct snd_timer *timer;
398 	unsigned long flags;
399 	unsigned long resolution = 0;
400 	struct snd_timer_instance *ts;
401 	struct timespec tstamp;
402 
403 	if (timer_tstamp_monotonic)
404 		ktime_get_ts(&tstamp);
405 	else
406 		getnstimeofday(&tstamp);
407 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
408 		       event > SNDRV_TIMER_EVENT_PAUSE))
409 		return;
410 	if (event == SNDRV_TIMER_EVENT_START ||
411 	    event == SNDRV_TIMER_EVENT_CONTINUE)
412 		resolution = snd_timer_resolution(ti);
413 	if (ti->ccallback)
414 		ti->ccallback(ti, event, &tstamp, resolution);
415 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
416 		return;
417 	timer = ti->timer;
418 	if (timer == NULL)
419 		return;
420 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
421 		return;
422 	spin_lock_irqsave(&timer->lock, flags);
423 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
424 		if (ts->ccallback)
425 			ts->ccallback(ts, event + 100, &tstamp, resolution);
426 	spin_unlock_irqrestore(&timer->lock, flags);
427 }
428 
429 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
430 			    unsigned long sticks)
431 {
432 	list_move_tail(&timeri->active_list, &timer->active_list_head);
433 	if (timer->running) {
434 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
435 			goto __start_now;
436 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
437 		timeri->flags |= SNDRV_TIMER_IFLG_START;
438 		return 1;	/* delayed start */
439 	} else {
440 		timer->sticks = sticks;
441 		timer->hw.start(timer);
442 	      __start_now:
443 		timer->running++;
444 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
445 		return 0;
446 	}
447 }
448 
449 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
450 {
451 	unsigned long flags;
452 
453 	spin_lock_irqsave(&slave_active_lock, flags);
454 	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
455 		spin_unlock_irqrestore(&slave_active_lock, flags);
456 		return -EBUSY;
457 	}
458 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
459 	if (timeri->master && timeri->timer) {
460 		spin_lock(&timeri->timer->lock);
461 		list_add_tail(&timeri->active_list,
462 			      &timeri->master->slave_active_head);
463 		spin_unlock(&timeri->timer->lock);
464 	}
465 	spin_unlock_irqrestore(&slave_active_lock, flags);
466 	return 1; /* delayed start */
467 }
468 
469 /*
470  *  start the timer instance
471  */
472 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
473 {
474 	struct snd_timer *timer;
475 	int result = -EINVAL;
476 	unsigned long flags;
477 
478 	if (timeri == NULL || ticks < 1)
479 		return -EINVAL;
480 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
481 		result = snd_timer_start_slave(timeri);
482 		if (result >= 0)
483 			snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
484 		return result;
485 	}
486 	timer = timeri->timer;
487 	if (timer == NULL)
488 		return -EINVAL;
489 	if (timer->card && timer->card->shutdown)
490 		return -ENODEV;
491 	spin_lock_irqsave(&timer->lock, flags);
492 	if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
493 			     SNDRV_TIMER_IFLG_START)) {
494 		result = -EBUSY;
495 		goto unlock;
496 	}
497 	timeri->ticks = timeri->cticks = ticks;
498 	timeri->pticks = 0;
499 	result = snd_timer_start1(timer, timeri, ticks);
500  unlock:
501 	spin_unlock_irqrestore(&timer->lock, flags);
502 	if (result >= 0)
503 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
504 	return result;
505 }
506 
507 static int _snd_timer_stop(struct snd_timer_instance *timeri, int event)
508 {
509 	struct snd_timer *timer;
510 	unsigned long flags;
511 
512 	if (snd_BUG_ON(!timeri))
513 		return -ENXIO;
514 
515 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
516 		spin_lock_irqsave(&slave_active_lock, flags);
517 		if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
518 			spin_unlock_irqrestore(&slave_active_lock, flags);
519 			return -EBUSY;
520 		}
521 		if (timeri->timer)
522 			spin_lock(&timeri->timer->lock);
523 		timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
524 		list_del_init(&timeri->ack_list);
525 		list_del_init(&timeri->active_list);
526 		if (timeri->timer)
527 			spin_unlock(&timeri->timer->lock);
528 		spin_unlock_irqrestore(&slave_active_lock, flags);
529 		goto __end;
530 	}
531 	timer = timeri->timer;
532 	if (!timer)
533 		return -EINVAL;
534 	spin_lock_irqsave(&timer->lock, flags);
535 	if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
536 			       SNDRV_TIMER_IFLG_START))) {
537 		spin_unlock_irqrestore(&timer->lock, flags);
538 		return -EBUSY;
539 	}
540 	list_del_init(&timeri->ack_list);
541 	list_del_init(&timeri->active_list);
542 	if (timer->card && timer->card->shutdown) {
543 		spin_unlock_irqrestore(&timer->lock, flags);
544 		return 0;
545 	}
546 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
547 	    !(--timer->running)) {
548 		timer->hw.stop(timer);
549 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
550 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
551 			snd_timer_reschedule(timer, 0);
552 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
553 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
554 				timer->hw.start(timer);
555 			}
556 		}
557 	}
558 	timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
559 	spin_unlock_irqrestore(&timer->lock, flags);
560       __end:
561 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
562 		snd_timer_notify1(timeri, event);
563 	return 0;
564 }
565 
566 /*
567  * stop the timer instance.
568  *
569  * do not call this from the timer callback!
570  */
571 int snd_timer_stop(struct snd_timer_instance *timeri)
572 {
573 	struct snd_timer *timer;
574 	unsigned long flags;
575 	int err;
576 
577 	err = _snd_timer_stop(timeri, SNDRV_TIMER_EVENT_STOP);
578 	if (err < 0)
579 		return err;
580 	timer = timeri->timer;
581 	if (!timer)
582 		return -EINVAL;
583 	spin_lock_irqsave(&timer->lock, flags);
584 	timeri->cticks = timeri->ticks;
585 	timeri->pticks = 0;
586 	spin_unlock_irqrestore(&timer->lock, flags);
587 	return 0;
588 }
589 
590 /*
591  * start again..  the tick is kept.
592  */
593 int snd_timer_continue(struct snd_timer_instance *timeri)
594 {
595 	struct snd_timer *timer;
596 	int result = -EINVAL;
597 	unsigned long flags;
598 
599 	if (timeri == NULL)
600 		return result;
601 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
602 		return snd_timer_start_slave(timeri);
603 	timer = timeri->timer;
604 	if (! timer)
605 		return -EINVAL;
606 	if (timer->card && timer->card->shutdown)
607 		return -ENODEV;
608 	spin_lock_irqsave(&timer->lock, flags);
609 	if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
610 		result = -EBUSY;
611 		goto unlock;
612 	}
613 	if (!timeri->cticks)
614 		timeri->cticks = 1;
615 	timeri->pticks = 0;
616 	result = snd_timer_start1(timer, timeri, timer->sticks);
617  unlock:
618 	spin_unlock_irqrestore(&timer->lock, flags);
619 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
620 	return result;
621 }
622 
623 /*
624  * pause.. remember the ticks left
625  */
626 int snd_timer_pause(struct snd_timer_instance * timeri)
627 {
628 	return _snd_timer_stop(timeri, SNDRV_TIMER_EVENT_PAUSE);
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 	INIT_LIST_HEAD(&timer->device_list);
841 	INIT_LIST_HEAD(&timer->open_list_head);
842 	INIT_LIST_HEAD(&timer->active_list_head);
843 	INIT_LIST_HEAD(&timer->ack_list_head);
844 	INIT_LIST_HEAD(&timer->sack_list_head);
845 	spin_lock_init(&timer->lock);
846 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
847 		     (unsigned long)timer);
848 	if (card != NULL) {
849 		timer->module = card->module;
850 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
851 		if (err < 0) {
852 			snd_timer_free(timer);
853 			return err;
854 		}
855 	}
856 	if (rtimer)
857 		*rtimer = timer;
858 	return 0;
859 }
860 
861 static int snd_timer_free(struct snd_timer *timer)
862 {
863 	if (!timer)
864 		return 0;
865 
866 	mutex_lock(&register_mutex);
867 	if (! list_empty(&timer->open_list_head)) {
868 		struct list_head *p, *n;
869 		struct snd_timer_instance *ti;
870 		pr_warn("ALSA: timer %p is busy?\n", timer);
871 		list_for_each_safe(p, n, &timer->open_list_head) {
872 			list_del_init(p);
873 			ti = list_entry(p, struct snd_timer_instance, open_list);
874 			ti->timer = NULL;
875 		}
876 	}
877 	list_del(&timer->device_list);
878 	mutex_unlock(&register_mutex);
879 
880 	if (timer->private_free)
881 		timer->private_free(timer);
882 	kfree(timer);
883 	return 0;
884 }
885 
886 static int snd_timer_dev_free(struct snd_device *device)
887 {
888 	struct snd_timer *timer = device->device_data;
889 	return snd_timer_free(timer);
890 }
891 
892 static int snd_timer_dev_register(struct snd_device *dev)
893 {
894 	struct snd_timer *timer = dev->device_data;
895 	struct snd_timer *timer1;
896 
897 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
898 		return -ENXIO;
899 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
900 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
901 	    	return -EINVAL;
902 
903 	mutex_lock(&register_mutex);
904 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
905 		if (timer1->tmr_class > timer->tmr_class)
906 			break;
907 		if (timer1->tmr_class < timer->tmr_class)
908 			continue;
909 		if (timer1->card && timer->card) {
910 			if (timer1->card->number > timer->card->number)
911 				break;
912 			if (timer1->card->number < timer->card->number)
913 				continue;
914 		}
915 		if (timer1->tmr_device > timer->tmr_device)
916 			break;
917 		if (timer1->tmr_device < timer->tmr_device)
918 			continue;
919 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
920 			break;
921 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
922 			continue;
923 		/* conflicts.. */
924 		mutex_unlock(&register_mutex);
925 		return -EBUSY;
926 	}
927 	list_add_tail(&timer->device_list, &timer1->device_list);
928 	mutex_unlock(&register_mutex);
929 	return 0;
930 }
931 
932 static int snd_timer_dev_disconnect(struct snd_device *device)
933 {
934 	struct snd_timer *timer = device->device_data;
935 	struct snd_timer_instance *ti;
936 
937 	mutex_lock(&register_mutex);
938 	list_del_init(&timer->device_list);
939 	/* wake up pending sleepers */
940 	list_for_each_entry(ti, &timer->open_list_head, open_list) {
941 		if (ti->disconnect)
942 			ti->disconnect(ti);
943 	}
944 	mutex_unlock(&register_mutex);
945 	return 0;
946 }
947 
948 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
949 {
950 	unsigned long flags;
951 	unsigned long resolution = 0;
952 	struct snd_timer_instance *ti, *ts;
953 
954 	if (timer->card && timer->card->shutdown)
955 		return;
956 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
957 		return;
958 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
959 		       event > SNDRV_TIMER_EVENT_MRESUME))
960 		return;
961 	spin_lock_irqsave(&timer->lock, flags);
962 	if (event == SNDRV_TIMER_EVENT_MSTART ||
963 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
964 	    event == SNDRV_TIMER_EVENT_MRESUME) {
965 		if (timer->hw.c_resolution)
966 			resolution = timer->hw.c_resolution(timer);
967 		else
968 			resolution = timer->hw.resolution;
969 	}
970 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
971 		if (ti->ccallback)
972 			ti->ccallback(ti, event, tstamp, resolution);
973 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
974 			if (ts->ccallback)
975 				ts->ccallback(ts, event, tstamp, resolution);
976 	}
977 	spin_unlock_irqrestore(&timer->lock, flags);
978 }
979 
980 /*
981  * exported functions for global timers
982  */
983 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
984 {
985 	struct snd_timer_id tid;
986 
987 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
988 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
989 	tid.card = -1;
990 	tid.device = device;
991 	tid.subdevice = 0;
992 	return snd_timer_new(NULL, id, &tid, rtimer);
993 }
994 
995 int snd_timer_global_free(struct snd_timer *timer)
996 {
997 	return snd_timer_free(timer);
998 }
999 
1000 int snd_timer_global_register(struct snd_timer *timer)
1001 {
1002 	struct snd_device dev;
1003 
1004 	memset(&dev, 0, sizeof(dev));
1005 	dev.device_data = timer;
1006 	return snd_timer_dev_register(&dev);
1007 }
1008 
1009 /*
1010  *  System timer
1011  */
1012 
1013 struct snd_timer_system_private {
1014 	struct timer_list tlist;
1015 	unsigned long last_expires;
1016 	unsigned long last_jiffies;
1017 	unsigned long correction;
1018 };
1019 
1020 static void snd_timer_s_function(unsigned long data)
1021 {
1022 	struct snd_timer *timer = (struct snd_timer *)data;
1023 	struct snd_timer_system_private *priv = timer->private_data;
1024 	unsigned long jiff = jiffies;
1025 	if (time_after(jiff, priv->last_expires))
1026 		priv->correction += (long)jiff - (long)priv->last_expires;
1027 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1028 }
1029 
1030 static int snd_timer_s_start(struct snd_timer * timer)
1031 {
1032 	struct snd_timer_system_private *priv;
1033 	unsigned long njiff;
1034 
1035 	priv = (struct snd_timer_system_private *) timer->private_data;
1036 	njiff = (priv->last_jiffies = jiffies);
1037 	if (priv->correction > timer->sticks - 1) {
1038 		priv->correction -= timer->sticks - 1;
1039 		njiff++;
1040 	} else {
1041 		njiff += timer->sticks - priv->correction;
1042 		priv->correction = 0;
1043 	}
1044 	priv->last_expires = priv->tlist.expires = njiff;
1045 	add_timer(&priv->tlist);
1046 	return 0;
1047 }
1048 
1049 static int snd_timer_s_stop(struct snd_timer * timer)
1050 {
1051 	struct snd_timer_system_private *priv;
1052 	unsigned long jiff;
1053 
1054 	priv = (struct snd_timer_system_private *) timer->private_data;
1055 	del_timer(&priv->tlist);
1056 	jiff = jiffies;
1057 	if (time_before(jiff, priv->last_expires))
1058 		timer->sticks = priv->last_expires - jiff;
1059 	else
1060 		timer->sticks = 1;
1061 	priv->correction = 0;
1062 	return 0;
1063 }
1064 
1065 static int snd_timer_s_close(struct snd_timer *timer)
1066 {
1067 	struct snd_timer_system_private *priv;
1068 
1069 	priv = (struct snd_timer_system_private *)timer->private_data;
1070 	del_timer_sync(&priv->tlist);
1071 	return 0;
1072 }
1073 
1074 static struct snd_timer_hardware snd_timer_system =
1075 {
1076 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1077 	.resolution =	1000000000L / HZ,
1078 	.ticks =	10000000L,
1079 	.close =	snd_timer_s_close,
1080 	.start =	snd_timer_s_start,
1081 	.stop =		snd_timer_s_stop
1082 };
1083 
1084 static void snd_timer_free_system(struct snd_timer *timer)
1085 {
1086 	kfree(timer->private_data);
1087 }
1088 
1089 static int snd_timer_register_system(void)
1090 {
1091 	struct snd_timer *timer;
1092 	struct snd_timer_system_private *priv;
1093 	int err;
1094 
1095 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1096 	if (err < 0)
1097 		return err;
1098 	strcpy(timer->name, "system timer");
1099 	timer->hw = snd_timer_system;
1100 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1101 	if (priv == NULL) {
1102 		snd_timer_free(timer);
1103 		return -ENOMEM;
1104 	}
1105 	setup_timer(&priv->tlist, snd_timer_s_function, (unsigned long) timer);
1106 	timer->private_data = priv;
1107 	timer->private_free = snd_timer_free_system;
1108 	return snd_timer_global_register(timer);
1109 }
1110 
1111 #ifdef CONFIG_SND_PROC_FS
1112 /*
1113  *  Info interface
1114  */
1115 
1116 static void snd_timer_proc_read(struct snd_info_entry *entry,
1117 				struct snd_info_buffer *buffer)
1118 {
1119 	struct snd_timer *timer;
1120 	struct snd_timer_instance *ti;
1121 
1122 	mutex_lock(&register_mutex);
1123 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1124 		if (timer->card && timer->card->shutdown)
1125 			continue;
1126 		switch (timer->tmr_class) {
1127 		case SNDRV_TIMER_CLASS_GLOBAL:
1128 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1129 			break;
1130 		case SNDRV_TIMER_CLASS_CARD:
1131 			snd_iprintf(buffer, "C%i-%i: ",
1132 				    timer->card->number, timer->tmr_device);
1133 			break;
1134 		case SNDRV_TIMER_CLASS_PCM:
1135 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1136 				    timer->tmr_device, timer->tmr_subdevice);
1137 			break;
1138 		default:
1139 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1140 				    timer->card ? timer->card->number : -1,
1141 				    timer->tmr_device, timer->tmr_subdevice);
1142 		}
1143 		snd_iprintf(buffer, "%s :", timer->name);
1144 		if (timer->hw.resolution)
1145 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1146 				    timer->hw.resolution / 1000,
1147 				    timer->hw.resolution % 1000,
1148 				    timer->hw.ticks);
1149 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1150 			snd_iprintf(buffer, " SLAVE");
1151 		snd_iprintf(buffer, "\n");
1152 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1153 			snd_iprintf(buffer, "  Client %s : %s\n",
1154 				    ti->owner ? ti->owner : "unknown",
1155 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1156 						 SNDRV_TIMER_IFLG_RUNNING)
1157 				    ? "running" : "stopped");
1158 	}
1159 	mutex_unlock(&register_mutex);
1160 }
1161 
1162 static struct snd_info_entry *snd_timer_proc_entry;
1163 
1164 static void __init snd_timer_proc_init(void)
1165 {
1166 	struct snd_info_entry *entry;
1167 
1168 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1169 	if (entry != NULL) {
1170 		entry->c.text.read = snd_timer_proc_read;
1171 		if (snd_info_register(entry) < 0) {
1172 			snd_info_free_entry(entry);
1173 			entry = NULL;
1174 		}
1175 	}
1176 	snd_timer_proc_entry = entry;
1177 }
1178 
1179 static void __exit snd_timer_proc_done(void)
1180 {
1181 	snd_info_free_entry(snd_timer_proc_entry);
1182 }
1183 #else /* !CONFIG_SND_PROC_FS */
1184 #define snd_timer_proc_init()
1185 #define snd_timer_proc_done()
1186 #endif
1187 
1188 /*
1189  *  USER SPACE interface
1190  */
1191 
1192 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1193 				     unsigned long resolution,
1194 				     unsigned long ticks)
1195 {
1196 	struct snd_timer_user *tu = timeri->callback_data;
1197 	struct snd_timer_read *r;
1198 	int prev;
1199 
1200 	spin_lock(&tu->qlock);
1201 	if (tu->qused > 0) {
1202 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1203 		r = &tu->queue[prev];
1204 		if (r->resolution == resolution) {
1205 			r->ticks += ticks;
1206 			goto __wake;
1207 		}
1208 	}
1209 	if (tu->qused >= tu->queue_size) {
1210 		tu->overrun++;
1211 	} else {
1212 		r = &tu->queue[tu->qtail++];
1213 		tu->qtail %= tu->queue_size;
1214 		r->resolution = resolution;
1215 		r->ticks = ticks;
1216 		tu->qused++;
1217 	}
1218       __wake:
1219 	spin_unlock(&tu->qlock);
1220 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1221 	wake_up(&tu->qchange_sleep);
1222 }
1223 
1224 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1225 					    struct snd_timer_tread *tread)
1226 {
1227 	if (tu->qused >= tu->queue_size) {
1228 		tu->overrun++;
1229 	} else {
1230 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1231 		tu->qtail %= tu->queue_size;
1232 		tu->qused++;
1233 	}
1234 }
1235 
1236 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1237 				     int event,
1238 				     struct timespec *tstamp,
1239 				     unsigned long resolution)
1240 {
1241 	struct snd_timer_user *tu = timeri->callback_data;
1242 	struct snd_timer_tread r1;
1243 	unsigned long flags;
1244 
1245 	if (event >= SNDRV_TIMER_EVENT_START &&
1246 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1247 		tu->tstamp = *tstamp;
1248 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1249 		return;
1250 	r1.event = event;
1251 	r1.tstamp = *tstamp;
1252 	r1.val = resolution;
1253 	spin_lock_irqsave(&tu->qlock, flags);
1254 	snd_timer_user_append_to_tqueue(tu, &r1);
1255 	spin_unlock_irqrestore(&tu->qlock, flags);
1256 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1257 	wake_up(&tu->qchange_sleep);
1258 }
1259 
1260 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1261 {
1262 	struct snd_timer_user *tu = timeri->callback_data;
1263 
1264 	tu->disconnected = true;
1265 	wake_up(&tu->qchange_sleep);
1266 }
1267 
1268 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1269 				      unsigned long resolution,
1270 				      unsigned long ticks)
1271 {
1272 	struct snd_timer_user *tu = timeri->callback_data;
1273 	struct snd_timer_tread *r, r1;
1274 	struct timespec tstamp;
1275 	int prev, append = 0;
1276 
1277 	memset(&tstamp, 0, sizeof(tstamp));
1278 	spin_lock(&tu->qlock);
1279 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1280 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1281 		spin_unlock(&tu->qlock);
1282 		return;
1283 	}
1284 	if (tu->last_resolution != resolution || ticks > 0) {
1285 		if (timer_tstamp_monotonic)
1286 			ktime_get_ts(&tstamp);
1287 		else
1288 			getnstimeofday(&tstamp);
1289 	}
1290 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1291 	    tu->last_resolution != resolution) {
1292 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1293 		r1.tstamp = tstamp;
1294 		r1.val = resolution;
1295 		snd_timer_user_append_to_tqueue(tu, &r1);
1296 		tu->last_resolution = resolution;
1297 		append++;
1298 	}
1299 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1300 		goto __wake;
1301 	if (ticks == 0)
1302 		goto __wake;
1303 	if (tu->qused > 0) {
1304 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1305 		r = &tu->tqueue[prev];
1306 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1307 			r->tstamp = tstamp;
1308 			r->val += ticks;
1309 			append++;
1310 			goto __wake;
1311 		}
1312 	}
1313 	r1.event = SNDRV_TIMER_EVENT_TICK;
1314 	r1.tstamp = tstamp;
1315 	r1.val = ticks;
1316 	snd_timer_user_append_to_tqueue(tu, &r1);
1317 	append++;
1318       __wake:
1319 	spin_unlock(&tu->qlock);
1320 	if (append == 0)
1321 		return;
1322 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1323 	wake_up(&tu->qchange_sleep);
1324 }
1325 
1326 static int snd_timer_user_open(struct inode *inode, struct file *file)
1327 {
1328 	struct snd_timer_user *tu;
1329 	int err;
1330 
1331 	err = nonseekable_open(inode, file);
1332 	if (err < 0)
1333 		return err;
1334 
1335 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1336 	if (tu == NULL)
1337 		return -ENOMEM;
1338 	spin_lock_init(&tu->qlock);
1339 	init_waitqueue_head(&tu->qchange_sleep);
1340 	mutex_init(&tu->ioctl_lock);
1341 	tu->ticks = 1;
1342 	tu->queue_size = 128;
1343 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1344 			    GFP_KERNEL);
1345 	if (tu->queue == NULL) {
1346 		kfree(tu);
1347 		return -ENOMEM;
1348 	}
1349 	file->private_data = tu;
1350 	return 0;
1351 }
1352 
1353 static int snd_timer_user_release(struct inode *inode, struct file *file)
1354 {
1355 	struct snd_timer_user *tu;
1356 
1357 	if (file->private_data) {
1358 		tu = file->private_data;
1359 		file->private_data = NULL;
1360 		mutex_lock(&tu->ioctl_lock);
1361 		if (tu->timeri)
1362 			snd_timer_close(tu->timeri);
1363 		mutex_unlock(&tu->ioctl_lock);
1364 		kfree(tu->queue);
1365 		kfree(tu->tqueue);
1366 		kfree(tu);
1367 	}
1368 	return 0;
1369 }
1370 
1371 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1372 {
1373 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1374 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1375 	id->card = -1;
1376 	id->device = -1;
1377 	id->subdevice = -1;
1378 }
1379 
1380 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1381 {
1382 	id->dev_class = timer->tmr_class;
1383 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1384 	id->card = timer->card ? timer->card->number : -1;
1385 	id->device = timer->tmr_device;
1386 	id->subdevice = timer->tmr_subdevice;
1387 }
1388 
1389 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1390 {
1391 	struct snd_timer_id id;
1392 	struct snd_timer *timer;
1393 	struct list_head *p;
1394 
1395 	if (copy_from_user(&id, _tid, sizeof(id)))
1396 		return -EFAULT;
1397 	mutex_lock(&register_mutex);
1398 	if (id.dev_class < 0) {		/* first item */
1399 		if (list_empty(&snd_timer_list))
1400 			snd_timer_user_zero_id(&id);
1401 		else {
1402 			timer = list_entry(snd_timer_list.next,
1403 					   struct snd_timer, device_list);
1404 			snd_timer_user_copy_id(&id, timer);
1405 		}
1406 	} else {
1407 		switch (id.dev_class) {
1408 		case SNDRV_TIMER_CLASS_GLOBAL:
1409 			id.device = id.device < 0 ? 0 : id.device + 1;
1410 			list_for_each(p, &snd_timer_list) {
1411 				timer = list_entry(p, struct snd_timer, device_list);
1412 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1413 					snd_timer_user_copy_id(&id, timer);
1414 					break;
1415 				}
1416 				if (timer->tmr_device >= id.device) {
1417 					snd_timer_user_copy_id(&id, timer);
1418 					break;
1419 				}
1420 			}
1421 			if (p == &snd_timer_list)
1422 				snd_timer_user_zero_id(&id);
1423 			break;
1424 		case SNDRV_TIMER_CLASS_CARD:
1425 		case SNDRV_TIMER_CLASS_PCM:
1426 			if (id.card < 0) {
1427 				id.card = 0;
1428 			} else {
1429 				if (id.card < 0) {
1430 					id.card = 0;
1431 				} else {
1432 					if (id.device < 0) {
1433 						id.device = 0;
1434 					} else {
1435 						if (id.subdevice < 0) {
1436 							id.subdevice = 0;
1437 						} else {
1438 							id.subdevice++;
1439 						}
1440 					}
1441 				}
1442 			}
1443 			list_for_each(p, &snd_timer_list) {
1444 				timer = list_entry(p, struct snd_timer, device_list);
1445 				if (timer->tmr_class > id.dev_class) {
1446 					snd_timer_user_copy_id(&id, timer);
1447 					break;
1448 				}
1449 				if (timer->tmr_class < id.dev_class)
1450 					continue;
1451 				if (timer->card->number > id.card) {
1452 					snd_timer_user_copy_id(&id, timer);
1453 					break;
1454 				}
1455 				if (timer->card->number < id.card)
1456 					continue;
1457 				if (timer->tmr_device > id.device) {
1458 					snd_timer_user_copy_id(&id, timer);
1459 					break;
1460 				}
1461 				if (timer->tmr_device < id.device)
1462 					continue;
1463 				if (timer->tmr_subdevice > id.subdevice) {
1464 					snd_timer_user_copy_id(&id, timer);
1465 					break;
1466 				}
1467 				if (timer->tmr_subdevice < id.subdevice)
1468 					continue;
1469 				snd_timer_user_copy_id(&id, timer);
1470 				break;
1471 			}
1472 			if (p == &snd_timer_list)
1473 				snd_timer_user_zero_id(&id);
1474 			break;
1475 		default:
1476 			snd_timer_user_zero_id(&id);
1477 		}
1478 	}
1479 	mutex_unlock(&register_mutex);
1480 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1481 		return -EFAULT;
1482 	return 0;
1483 }
1484 
1485 static int snd_timer_user_ginfo(struct file *file,
1486 				struct snd_timer_ginfo __user *_ginfo)
1487 {
1488 	struct snd_timer_ginfo *ginfo;
1489 	struct snd_timer_id tid;
1490 	struct snd_timer *t;
1491 	struct list_head *p;
1492 	int err = 0;
1493 
1494 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1495 	if (IS_ERR(ginfo))
1496 		return PTR_ERR(ginfo);
1497 
1498 	tid = ginfo->tid;
1499 	memset(ginfo, 0, sizeof(*ginfo));
1500 	ginfo->tid = tid;
1501 	mutex_lock(&register_mutex);
1502 	t = snd_timer_find(&tid);
1503 	if (t != NULL) {
1504 		ginfo->card = t->card ? t->card->number : -1;
1505 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1506 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1507 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1508 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1509 		ginfo->resolution = t->hw.resolution;
1510 		if (t->hw.resolution_min > 0) {
1511 			ginfo->resolution_min = t->hw.resolution_min;
1512 			ginfo->resolution_max = t->hw.resolution_max;
1513 		}
1514 		list_for_each(p, &t->open_list_head) {
1515 			ginfo->clients++;
1516 		}
1517 	} else {
1518 		err = -ENODEV;
1519 	}
1520 	mutex_unlock(&register_mutex);
1521 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1522 		err = -EFAULT;
1523 	kfree(ginfo);
1524 	return err;
1525 }
1526 
1527 static int snd_timer_user_gparams(struct file *file,
1528 				  struct snd_timer_gparams __user *_gparams)
1529 {
1530 	struct snd_timer_gparams gparams;
1531 	struct snd_timer *t;
1532 	int err;
1533 
1534 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1535 		return -EFAULT;
1536 	mutex_lock(&register_mutex);
1537 	t = snd_timer_find(&gparams.tid);
1538 	if (!t) {
1539 		err = -ENODEV;
1540 		goto _error;
1541 	}
1542 	if (!list_empty(&t->open_list_head)) {
1543 		err = -EBUSY;
1544 		goto _error;
1545 	}
1546 	if (!t->hw.set_period) {
1547 		err = -ENOSYS;
1548 		goto _error;
1549 	}
1550 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1551 _error:
1552 	mutex_unlock(&register_mutex);
1553 	return err;
1554 }
1555 
1556 static int snd_timer_user_gstatus(struct file *file,
1557 				  struct snd_timer_gstatus __user *_gstatus)
1558 {
1559 	struct snd_timer_gstatus gstatus;
1560 	struct snd_timer_id tid;
1561 	struct snd_timer *t;
1562 	int err = 0;
1563 
1564 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1565 		return -EFAULT;
1566 	tid = gstatus.tid;
1567 	memset(&gstatus, 0, sizeof(gstatus));
1568 	gstatus.tid = tid;
1569 	mutex_lock(&register_mutex);
1570 	t = snd_timer_find(&tid);
1571 	if (t != NULL) {
1572 		if (t->hw.c_resolution)
1573 			gstatus.resolution = t->hw.c_resolution(t);
1574 		else
1575 			gstatus.resolution = t->hw.resolution;
1576 		if (t->hw.precise_resolution) {
1577 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1578 						 &gstatus.resolution_den);
1579 		} else {
1580 			gstatus.resolution_num = gstatus.resolution;
1581 			gstatus.resolution_den = 1000000000uL;
1582 		}
1583 	} else {
1584 		err = -ENODEV;
1585 	}
1586 	mutex_unlock(&register_mutex);
1587 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1588 		err = -EFAULT;
1589 	return err;
1590 }
1591 
1592 static int snd_timer_user_tselect(struct file *file,
1593 				  struct snd_timer_select __user *_tselect)
1594 {
1595 	struct snd_timer_user *tu;
1596 	struct snd_timer_select tselect;
1597 	char str[32];
1598 	int err = 0;
1599 
1600 	tu = file->private_data;
1601 	if (tu->timeri) {
1602 		snd_timer_close(tu->timeri);
1603 		tu->timeri = NULL;
1604 	}
1605 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1606 		err = -EFAULT;
1607 		goto __err;
1608 	}
1609 	sprintf(str, "application %i", current->pid);
1610 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1611 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1612 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1613 	if (err < 0)
1614 		goto __err;
1615 
1616 	kfree(tu->queue);
1617 	tu->queue = NULL;
1618 	kfree(tu->tqueue);
1619 	tu->tqueue = NULL;
1620 	if (tu->tread) {
1621 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1622 				     GFP_KERNEL);
1623 		if (tu->tqueue == NULL)
1624 			err = -ENOMEM;
1625 	} else {
1626 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1627 				    GFP_KERNEL);
1628 		if (tu->queue == NULL)
1629 			err = -ENOMEM;
1630 	}
1631 
1632       	if (err < 0) {
1633 		snd_timer_close(tu->timeri);
1634       		tu->timeri = NULL;
1635       	} else {
1636 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1637 		tu->timeri->callback = tu->tread
1638 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1639 		tu->timeri->ccallback = snd_timer_user_ccallback;
1640 		tu->timeri->callback_data = (void *)tu;
1641 		tu->timeri->disconnect = snd_timer_user_disconnect;
1642 	}
1643 
1644       __err:
1645 	return err;
1646 }
1647 
1648 static int snd_timer_user_info(struct file *file,
1649 			       struct snd_timer_info __user *_info)
1650 {
1651 	struct snd_timer_user *tu;
1652 	struct snd_timer_info *info;
1653 	struct snd_timer *t;
1654 	int err = 0;
1655 
1656 	tu = file->private_data;
1657 	if (!tu->timeri)
1658 		return -EBADFD;
1659 	t = tu->timeri->timer;
1660 	if (!t)
1661 		return -EBADFD;
1662 
1663 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1664 	if (! info)
1665 		return -ENOMEM;
1666 	info->card = t->card ? t->card->number : -1;
1667 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1668 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1669 	strlcpy(info->id, t->id, sizeof(info->id));
1670 	strlcpy(info->name, t->name, sizeof(info->name));
1671 	info->resolution = t->hw.resolution;
1672 	if (copy_to_user(_info, info, sizeof(*_info)))
1673 		err = -EFAULT;
1674 	kfree(info);
1675 	return err;
1676 }
1677 
1678 static int snd_timer_user_params(struct file *file,
1679 				 struct snd_timer_params __user *_params)
1680 {
1681 	struct snd_timer_user *tu;
1682 	struct snd_timer_params params;
1683 	struct snd_timer *t;
1684 	struct snd_timer_read *tr;
1685 	struct snd_timer_tread *ttr;
1686 	int err;
1687 
1688 	tu = file->private_data;
1689 	if (!tu->timeri)
1690 		return -EBADFD;
1691 	t = tu->timeri->timer;
1692 	if (!t)
1693 		return -EBADFD;
1694 	if (copy_from_user(&params, _params, sizeof(params)))
1695 		return -EFAULT;
1696 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1697 		err = -EINVAL;
1698 		goto _end;
1699 	}
1700 	if (params.queue_size > 0 &&
1701 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1702 		err = -EINVAL;
1703 		goto _end;
1704 	}
1705 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1706 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1707 			      (1<<SNDRV_TIMER_EVENT_START)|
1708 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1709 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1710 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1711 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1712 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1713 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1714 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1715 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1716 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1717 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1718 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1719 		err = -EINVAL;
1720 		goto _end;
1721 	}
1722 	snd_timer_stop(tu->timeri);
1723 	spin_lock_irq(&t->lock);
1724 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1725 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1726 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1727 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1728 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1729 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1730 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1731 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1732 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1733 	spin_unlock_irq(&t->lock);
1734 	if (params.queue_size > 0 &&
1735 	    (unsigned int)tu->queue_size != params.queue_size) {
1736 		if (tu->tread) {
1737 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1738 				      GFP_KERNEL);
1739 			if (ttr) {
1740 				kfree(tu->tqueue);
1741 				tu->queue_size = params.queue_size;
1742 				tu->tqueue = ttr;
1743 			}
1744 		} else {
1745 			tr = kmalloc(params.queue_size * sizeof(*tr),
1746 				     GFP_KERNEL);
1747 			if (tr) {
1748 				kfree(tu->queue);
1749 				tu->queue_size = params.queue_size;
1750 				tu->queue = tr;
1751 			}
1752 		}
1753 	}
1754 	tu->qhead = tu->qtail = tu->qused = 0;
1755 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1756 		if (tu->tread) {
1757 			struct snd_timer_tread tread;
1758 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1759 			tread.tstamp.tv_sec = 0;
1760 			tread.tstamp.tv_nsec = 0;
1761 			tread.val = 0;
1762 			snd_timer_user_append_to_tqueue(tu, &tread);
1763 		} else {
1764 			struct snd_timer_read *r = &tu->queue[0];
1765 			r->resolution = 0;
1766 			r->ticks = 0;
1767 			tu->qused++;
1768 			tu->qtail++;
1769 		}
1770 	}
1771 	tu->filter = params.filter;
1772 	tu->ticks = params.ticks;
1773 	err = 0;
1774  _end:
1775 	if (copy_to_user(_params, &params, sizeof(params)))
1776 		return -EFAULT;
1777 	return err;
1778 }
1779 
1780 static int snd_timer_user_status(struct file *file,
1781 				 struct snd_timer_status __user *_status)
1782 {
1783 	struct snd_timer_user *tu;
1784 	struct snd_timer_status status;
1785 
1786 	tu = file->private_data;
1787 	if (!tu->timeri)
1788 		return -EBADFD;
1789 	memset(&status, 0, sizeof(status));
1790 	status.tstamp = tu->tstamp;
1791 	status.resolution = snd_timer_resolution(tu->timeri);
1792 	status.lost = tu->timeri->lost;
1793 	status.overrun = tu->overrun;
1794 	spin_lock_irq(&tu->qlock);
1795 	status.queue = tu->qused;
1796 	spin_unlock_irq(&tu->qlock);
1797 	if (copy_to_user(_status, &status, sizeof(status)))
1798 		return -EFAULT;
1799 	return 0;
1800 }
1801 
1802 static int snd_timer_user_start(struct file *file)
1803 {
1804 	int err;
1805 	struct snd_timer_user *tu;
1806 
1807 	tu = file->private_data;
1808 	if (!tu->timeri)
1809 		return -EBADFD;
1810 	snd_timer_stop(tu->timeri);
1811 	tu->timeri->lost = 0;
1812 	tu->last_resolution = 0;
1813 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1814 }
1815 
1816 static int snd_timer_user_stop(struct file *file)
1817 {
1818 	int err;
1819 	struct snd_timer_user *tu;
1820 
1821 	tu = file->private_data;
1822 	if (!tu->timeri)
1823 		return -EBADFD;
1824 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1825 }
1826 
1827 static int snd_timer_user_continue(struct file *file)
1828 {
1829 	int err;
1830 	struct snd_timer_user *tu;
1831 
1832 	tu = file->private_data;
1833 	if (!tu->timeri)
1834 		return -EBADFD;
1835 	tu->timeri->lost = 0;
1836 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1837 }
1838 
1839 static int snd_timer_user_pause(struct file *file)
1840 {
1841 	int err;
1842 	struct snd_timer_user *tu;
1843 
1844 	tu = file->private_data;
1845 	if (!tu->timeri)
1846 		return -EBADFD;
1847 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1848 }
1849 
1850 enum {
1851 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1852 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1853 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1854 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1855 };
1856 
1857 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1858 				 unsigned long arg)
1859 {
1860 	struct snd_timer_user *tu;
1861 	void __user *argp = (void __user *)arg;
1862 	int __user *p = argp;
1863 
1864 	tu = file->private_data;
1865 	switch (cmd) {
1866 	case SNDRV_TIMER_IOCTL_PVERSION:
1867 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1868 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1869 		return snd_timer_user_next_device(argp);
1870 	case SNDRV_TIMER_IOCTL_TREAD:
1871 	{
1872 		int xarg;
1873 
1874 		if (tu->timeri)	/* too late */
1875 			return -EBUSY;
1876 		if (get_user(xarg, p))
1877 			return -EFAULT;
1878 		tu->tread = xarg ? 1 : 0;
1879 		return 0;
1880 	}
1881 	case SNDRV_TIMER_IOCTL_GINFO:
1882 		return snd_timer_user_ginfo(file, argp);
1883 	case SNDRV_TIMER_IOCTL_GPARAMS:
1884 		return snd_timer_user_gparams(file, argp);
1885 	case SNDRV_TIMER_IOCTL_GSTATUS:
1886 		return snd_timer_user_gstatus(file, argp);
1887 	case SNDRV_TIMER_IOCTL_SELECT:
1888 		return snd_timer_user_tselect(file, argp);
1889 	case SNDRV_TIMER_IOCTL_INFO:
1890 		return snd_timer_user_info(file, argp);
1891 	case SNDRV_TIMER_IOCTL_PARAMS:
1892 		return snd_timer_user_params(file, argp);
1893 	case SNDRV_TIMER_IOCTL_STATUS:
1894 		return snd_timer_user_status(file, argp);
1895 	case SNDRV_TIMER_IOCTL_START:
1896 	case SNDRV_TIMER_IOCTL_START_OLD:
1897 		return snd_timer_user_start(file);
1898 	case SNDRV_TIMER_IOCTL_STOP:
1899 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1900 		return snd_timer_user_stop(file);
1901 	case SNDRV_TIMER_IOCTL_CONTINUE:
1902 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1903 		return snd_timer_user_continue(file);
1904 	case SNDRV_TIMER_IOCTL_PAUSE:
1905 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1906 		return snd_timer_user_pause(file);
1907 	}
1908 	return -ENOTTY;
1909 }
1910 
1911 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1912 				 unsigned long arg)
1913 {
1914 	struct snd_timer_user *tu = file->private_data;
1915 	long ret;
1916 
1917 	mutex_lock(&tu->ioctl_lock);
1918 	ret = __snd_timer_user_ioctl(file, cmd, arg);
1919 	mutex_unlock(&tu->ioctl_lock);
1920 	return ret;
1921 }
1922 
1923 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1924 {
1925 	struct snd_timer_user *tu;
1926 
1927 	tu = file->private_data;
1928 	return fasync_helper(fd, file, on, &tu->fasync);
1929 }
1930 
1931 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1932 				   size_t count, loff_t *offset)
1933 {
1934 	struct snd_timer_user *tu;
1935 	long result = 0, unit;
1936 	int qhead;
1937 	int err = 0;
1938 
1939 	tu = file->private_data;
1940 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1941 	spin_lock_irq(&tu->qlock);
1942 	while ((long)count - result >= unit) {
1943 		while (!tu->qused) {
1944 			wait_queue_t wait;
1945 
1946 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1947 				err = -EAGAIN;
1948 				goto _error;
1949 			}
1950 
1951 			set_current_state(TASK_INTERRUPTIBLE);
1952 			init_waitqueue_entry(&wait, current);
1953 			add_wait_queue(&tu->qchange_sleep, &wait);
1954 
1955 			spin_unlock_irq(&tu->qlock);
1956 			schedule();
1957 			spin_lock_irq(&tu->qlock);
1958 
1959 			remove_wait_queue(&tu->qchange_sleep, &wait);
1960 
1961 			if (tu->disconnected) {
1962 				err = -ENODEV;
1963 				goto _error;
1964 			}
1965 			if (signal_pending(current)) {
1966 				err = -ERESTARTSYS;
1967 				goto _error;
1968 			}
1969 		}
1970 
1971 		qhead = tu->qhead++;
1972 		tu->qhead %= tu->queue_size;
1973 		spin_unlock_irq(&tu->qlock);
1974 
1975 		if (tu->tread) {
1976 			if (copy_to_user(buffer, &tu->tqueue[qhead],
1977 					 sizeof(struct snd_timer_tread)))
1978 				err = -EFAULT;
1979 		} else {
1980 			if (copy_to_user(buffer, &tu->queue[qhead],
1981 					 sizeof(struct snd_timer_read)))
1982 				err = -EFAULT;
1983 		}
1984 
1985 		spin_lock_irq(&tu->qlock);
1986 		tu->qused--;
1987 		if (err < 0)
1988 			goto _error;
1989 		result += unit;
1990 		buffer += unit;
1991 	}
1992  _error:
1993 	spin_unlock_irq(&tu->qlock);
1994 	return result > 0 ? result : err;
1995 }
1996 
1997 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1998 {
1999         unsigned int mask;
2000         struct snd_timer_user *tu;
2001 
2002         tu = file->private_data;
2003 
2004         poll_wait(file, &tu->qchange_sleep, wait);
2005 
2006 	mask = 0;
2007 	if (tu->qused)
2008 		mask |= POLLIN | POLLRDNORM;
2009 	if (tu->disconnected)
2010 		mask |= POLLERR;
2011 
2012 	return mask;
2013 }
2014 
2015 #ifdef CONFIG_COMPAT
2016 #include "timer_compat.c"
2017 #else
2018 #define snd_timer_user_ioctl_compat	NULL
2019 #endif
2020 
2021 static const struct file_operations snd_timer_f_ops =
2022 {
2023 	.owner =	THIS_MODULE,
2024 	.read =		snd_timer_user_read,
2025 	.open =		snd_timer_user_open,
2026 	.release =	snd_timer_user_release,
2027 	.llseek =	no_llseek,
2028 	.poll =		snd_timer_user_poll,
2029 	.unlocked_ioctl =	snd_timer_user_ioctl,
2030 	.compat_ioctl =	snd_timer_user_ioctl_compat,
2031 	.fasync = 	snd_timer_user_fasync,
2032 };
2033 
2034 /* unregister the system timer */
2035 static void snd_timer_free_all(void)
2036 {
2037 	struct snd_timer *timer, *n;
2038 
2039 	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2040 		snd_timer_free(timer);
2041 }
2042 
2043 static struct device timer_dev;
2044 
2045 /*
2046  *  ENTRY functions
2047  */
2048 
2049 static int __init alsa_timer_init(void)
2050 {
2051 	int err;
2052 
2053 	snd_device_initialize(&timer_dev, NULL);
2054 	dev_set_name(&timer_dev, "timer");
2055 
2056 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2057 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2058 			      "system timer");
2059 #endif
2060 
2061 	err = snd_timer_register_system();
2062 	if (err < 0) {
2063 		pr_err("ALSA: unable to register system timer (%i)\n", err);
2064 		put_device(&timer_dev);
2065 		return err;
2066 	}
2067 
2068 	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2069 				  &snd_timer_f_ops, NULL, &timer_dev);
2070 	if (err < 0) {
2071 		pr_err("ALSA: unable to register timer device (%i)\n", err);
2072 		snd_timer_free_all();
2073 		put_device(&timer_dev);
2074 		return err;
2075 	}
2076 
2077 	snd_timer_proc_init();
2078 	return 0;
2079 }
2080 
2081 static void __exit alsa_timer_exit(void)
2082 {
2083 	snd_unregister_device(&timer_dev);
2084 	snd_timer_free_all();
2085 	put_device(&timer_dev);
2086 	snd_timer_proc_done();
2087 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2088 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2089 #endif
2090 }
2091 
2092 module_init(alsa_timer_init)
2093 module_exit(alsa_timer_exit)
2094 
2095 EXPORT_SYMBOL(snd_timer_open);
2096 EXPORT_SYMBOL(snd_timer_close);
2097 EXPORT_SYMBOL(snd_timer_resolution);
2098 EXPORT_SYMBOL(snd_timer_start);
2099 EXPORT_SYMBOL(snd_timer_stop);
2100 EXPORT_SYMBOL(snd_timer_continue);
2101 EXPORT_SYMBOL(snd_timer_pause);
2102 EXPORT_SYMBOL(snd_timer_new);
2103 EXPORT_SYMBOL(snd_timer_notify);
2104 EXPORT_SYMBOL(snd_timer_global_new);
2105 EXPORT_SYMBOL(snd_timer_global_free);
2106 EXPORT_SYMBOL(snd_timer_global_register);
2107 EXPORT_SYMBOL(snd_timer_interrupt);
2108