xref: /linux/sound/core/timer.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/time.h>
28 #include <linux/mutex.h>
29 #include <linux/moduleparam.h>
30 #include <linux/string.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 #ifdef CONFIG_KERNELD
39 #include <linux/kerneld.h>
40 #endif
41 
42 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
43 #define DEFAULT_TIMER_LIMIT 3
44 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
45 #define DEFAULT_TIMER_LIMIT 2
46 #else
47 #define DEFAULT_TIMER_LIMIT 1
48 #endif
49 
50 static int timer_limit = DEFAULT_TIMER_LIMIT;
51 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
52 MODULE_DESCRIPTION("ALSA timer interface");
53 MODULE_LICENSE("GPL");
54 module_param(timer_limit, int, 0444);
55 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
56 
57 struct snd_timer_user {
58 	struct snd_timer_instance *timeri;
59 	int tread;		/* enhanced read with timestamps and events */
60 	unsigned long ticks;
61 	unsigned long overrun;
62 	int qhead;
63 	int qtail;
64 	int qused;
65 	int queue_size;
66 	struct snd_timer_read *queue;
67 	struct snd_timer_tread *tqueue;
68 	spinlock_t qlock;
69 	unsigned long last_resolution;
70 	unsigned int filter;
71 	struct timespec tstamp;		/* trigger tstamp */
72 	wait_queue_head_t qchange_sleep;
73 	struct fasync_struct *fasync;
74 	struct mutex tread_sem;
75 };
76 
77 /* list of timers */
78 static LIST_HEAD(snd_timer_list);
79 
80 /* list of slave instances */
81 static LIST_HEAD(snd_timer_slave_list);
82 
83 /* lock for slave active lists */
84 static DEFINE_SPINLOCK(slave_active_lock);
85 
86 static DEFINE_MUTEX(register_mutex);
87 
88 static int snd_timer_free(struct snd_timer *timer);
89 static int snd_timer_dev_free(struct snd_device *device);
90 static int snd_timer_dev_register(struct snd_device *device);
91 static int snd_timer_dev_unregister(struct snd_device *device);
92 
93 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
94 
95 /*
96  * create a timer instance with the given owner string.
97  * when timer is not NULL, increments the module counter
98  */
99 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
100 							 struct snd_timer *timer)
101 {
102 	struct snd_timer_instance *timeri;
103 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
104 	if (timeri == NULL)
105 		return NULL;
106 	timeri->owner = kstrdup(owner, GFP_KERNEL);
107 	if (! timeri->owner) {
108 		kfree(timeri);
109 		return NULL;
110 	}
111 	INIT_LIST_HEAD(&timeri->open_list);
112 	INIT_LIST_HEAD(&timeri->active_list);
113 	INIT_LIST_HEAD(&timeri->ack_list);
114 	INIT_LIST_HEAD(&timeri->slave_list_head);
115 	INIT_LIST_HEAD(&timeri->slave_active_head);
116 
117 	timeri->timer = timer;
118 	if (timer && !try_module_get(timer->module)) {
119 		kfree(timeri->owner);
120 		kfree(timeri);
121 		return NULL;
122 	}
123 
124 	return timeri;
125 }
126 
127 /*
128  * find a timer instance from the given timer id
129  */
130 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
131 {
132 	struct snd_timer *timer = NULL;
133 	struct list_head *p;
134 
135 	list_for_each(p, &snd_timer_list) {
136 		timer = list_entry(p, struct snd_timer, device_list);
137 
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_KMOD
155 
156 static void snd_timer_request(struct snd_timer_id *tid)
157 {
158 	if (! current->fs->root)
159 		return;
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 	struct list_head *p, *q;
188 
189 	/* FIXME: it's really dumb to look up all entries.. */
190 	list_for_each(p, &snd_timer_list) {
191 		timer = list_entry(p, struct snd_timer, device_list);
192 		list_for_each(q, &timer->open_list_head) {
193 			master = list_entry(q, struct snd_timer_instance, open_list);
194 			if (slave->slave_class == master->slave_class &&
195 			    slave->slave_id == master->slave_id) {
196 				list_del(&slave->open_list);
197 				list_add_tail(&slave->open_list,
198 					      &master->slave_list_head);
199 				spin_lock_irq(&slave_active_lock);
200 				slave->master = master;
201 				slave->timer = master->timer;
202 				spin_unlock_irq(&slave_active_lock);
203 				return;
204 			}
205 		}
206 	}
207 }
208 
209 /*
210  * look for slave instances matching with the slave id of the given master.
211  * when found, relink the open_link of slaves.
212  *
213  * call this with register_mutex down.
214  */
215 static void snd_timer_check_master(struct snd_timer_instance *master)
216 {
217 	struct snd_timer_instance *slave;
218 	struct list_head *p, *n;
219 
220 	/* check all pending slaves */
221 	list_for_each_safe(p, n, &snd_timer_slave_list) {
222 		slave = list_entry(p, struct snd_timer_instance, open_list);
223 		if (slave->slave_class == master->slave_class &&
224 		    slave->slave_id == master->slave_id) {
225 			list_del(p);
226 			list_add_tail(p, &master->slave_list_head);
227 			spin_lock_irq(&slave_active_lock);
228 			slave->master = master;
229 			slave->timer = master->timer;
230 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
231 				list_add_tail(&slave->active_list,
232 					      &master->slave_active_head);
233 			spin_unlock_irq(&slave_active_lock);
234 		}
235 	}
236 }
237 
238 /*
239  * open a timer instance
240  * when opening a master, the slave id must be here given.
241  */
242 int snd_timer_open(struct snd_timer_instance **ti,
243 		   char *owner, struct snd_timer_id *tid,
244 		   unsigned int slave_id)
245 {
246 	struct snd_timer *timer;
247 	struct snd_timer_instance *timeri = NULL;
248 
249 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
250 		/* open a slave instance */
251 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
252 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
253 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
254 			return -EINVAL;
255 		}
256 		mutex_lock(&register_mutex);
257 		timeri = snd_timer_instance_new(owner, NULL);
258 		if (!timeri) {
259 			mutex_unlock(&register_mutex);
260 			return -ENOMEM;
261 		}
262 		timeri->slave_class = tid->dev_sclass;
263 		timeri->slave_id = tid->device;
264 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
265 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
266 		snd_timer_check_slave(timeri);
267 		mutex_unlock(&register_mutex);
268 		*ti = timeri;
269 		return 0;
270 	}
271 
272 	/* open a master instance */
273 	mutex_lock(&register_mutex);
274 	timer = snd_timer_find(tid);
275 #ifdef CONFIG_KMOD
276 	if (timer == NULL) {
277 		mutex_unlock(&register_mutex);
278 		snd_timer_request(tid);
279 		mutex_lock(&register_mutex);
280 		timer = snd_timer_find(tid);
281 	}
282 #endif
283 	if (!timer) {
284 		mutex_unlock(&register_mutex);
285 		return -ENODEV;
286 	}
287 	if (!list_empty(&timer->open_list_head)) {
288 		timeri = list_entry(timer->open_list_head.next,
289 				    struct snd_timer_instance, open_list);
290 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
291 			mutex_unlock(&register_mutex);
292 			return -EBUSY;
293 		}
294 	}
295 	timeri = snd_timer_instance_new(owner, timer);
296 	if (!timeri) {
297 		mutex_unlock(&register_mutex);
298 		return -ENOMEM;
299 	}
300 	timeri->slave_class = tid->dev_sclass;
301 	timeri->slave_id = slave_id;
302 	if (list_empty(&timer->open_list_head) && timer->hw.open)
303 		timer->hw.open(timer);
304 	list_add_tail(&timeri->open_list, &timer->open_list_head);
305 	snd_timer_check_master(timeri);
306 	mutex_unlock(&register_mutex);
307 	*ti = timeri;
308 	return 0;
309 }
310 
311 static int _snd_timer_stop(struct snd_timer_instance *timeri,
312 			   int keep_flag, int event);
313 
314 /*
315  * close a timer instance
316  */
317 int snd_timer_close(struct snd_timer_instance *timeri)
318 {
319 	struct snd_timer *timer = NULL;
320 	struct list_head *p, *n;
321 	struct snd_timer_instance *slave;
322 
323 	snd_assert(timeri != NULL, return -ENXIO);
324 
325 	/* force to stop the timer */
326 	snd_timer_stop(timeri);
327 
328 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
329 		/* wait, until the active callback is finished */
330 		spin_lock_irq(&slave_active_lock);
331 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
332 			spin_unlock_irq(&slave_active_lock);
333 			udelay(10);
334 			spin_lock_irq(&slave_active_lock);
335 		}
336 		spin_unlock_irq(&slave_active_lock);
337 		mutex_lock(&register_mutex);
338 		list_del(&timeri->open_list);
339 		mutex_unlock(&register_mutex);
340 	} else {
341 		timer = timeri->timer;
342 		/* wait, until the active callback is finished */
343 		spin_lock_irq(&timer->lock);
344 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
345 			spin_unlock_irq(&timer->lock);
346 			udelay(10);
347 			spin_lock_irq(&timer->lock);
348 		}
349 		spin_unlock_irq(&timer->lock);
350 		mutex_lock(&register_mutex);
351 		list_del(&timeri->open_list);
352 		if (timer && list_empty(&timer->open_list_head) &&
353 		    timer->hw.close)
354 			timer->hw.close(timer);
355 		/* remove slave links */
356 		list_for_each_safe(p, n, &timeri->slave_list_head) {
357 			slave = list_entry(p, struct snd_timer_instance, open_list);
358 			spin_lock_irq(&slave_active_lock);
359 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
360 			list_del(p);
361 			list_add_tail(p, &snd_timer_slave_list);
362 			slave->master = NULL;
363 			slave->timer = NULL;
364 			spin_unlock_irq(&slave_active_lock);
365 		}
366 		mutex_unlock(&register_mutex);
367 	}
368 	if (timeri->private_free)
369 		timeri->private_free(timeri);
370 	kfree(timeri->owner);
371 	kfree(timeri);
372 	if (timer)
373 		module_put(timer->module);
374 	return 0;
375 }
376 
377 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
378 {
379 	struct snd_timer * timer;
380 
381 	if (timeri == NULL)
382 		return 0;
383 	if ((timer = timeri->timer) != NULL) {
384 		if (timer->hw.c_resolution)
385 			return timer->hw.c_resolution(timer);
386 		return timer->hw.resolution;
387 	}
388 	return 0;
389 }
390 
391 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
392 {
393 	struct snd_timer *timer;
394 	unsigned long flags;
395 	unsigned long resolution = 0;
396 	struct snd_timer_instance *ts;
397 	struct list_head *n;
398 	struct timespec tstamp;
399 
400 	getnstimeofday(&tstamp);
401 	snd_assert(event >= SNDRV_TIMER_EVENT_START &&
402 		   event <= SNDRV_TIMER_EVENT_PAUSE, return);
403 	if (event == SNDRV_TIMER_EVENT_START ||
404 	    event == SNDRV_TIMER_EVENT_CONTINUE)
405 		resolution = snd_timer_resolution(ti);
406 	if (ti->ccallback)
407 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
408 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
409 		return;
410 	timer = ti->timer;
411 	if (timer == NULL)
412 		return;
413 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
414 		return;
415 	spin_lock_irqsave(&timer->lock, flags);
416 	list_for_each(n, &ti->slave_active_head) {
417 		ts = list_entry(n, struct snd_timer_instance, active_list);
418 		if (ts->ccallback)
419 			ts->ccallback(ti, event + 100, &tstamp, resolution);
420 	}
421 	spin_unlock_irqrestore(&timer->lock, flags);
422 }
423 
424 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
425 			    unsigned long sticks)
426 {
427 	list_del(&timeri->active_list);
428 	list_add_tail(&timeri->active_list, &timer->active_list_head);
429 	if (timer->running) {
430 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
431 			goto __start_now;
432 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
433 		timeri->flags |= SNDRV_TIMER_IFLG_START;
434 		return 1;	/* delayed start */
435 	} else {
436 		timer->sticks = sticks;
437 		timer->hw.start(timer);
438 	      __start_now:
439 		timer->running++;
440 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
441 		return 0;
442 	}
443 }
444 
445 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
446 {
447 	unsigned long flags;
448 
449 	spin_lock_irqsave(&slave_active_lock, flags);
450 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
451 	if (timeri->master)
452 		list_add_tail(&timeri->active_list,
453 			      &timeri->master->slave_active_head);
454 	spin_unlock_irqrestore(&slave_active_lock, flags);
455 	return 1; /* delayed start */
456 }
457 
458 /*
459  *  start the timer instance
460  */
461 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
462 {
463 	struct snd_timer *timer;
464 	int result = -EINVAL;
465 	unsigned long flags;
466 
467 	if (timeri == NULL || ticks < 1)
468 		return -EINVAL;
469 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
470 		result = snd_timer_start_slave(timeri);
471 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
472 		return result;
473 	}
474 	timer = timeri->timer;
475 	if (timer == NULL)
476 		return -EINVAL;
477 	spin_lock_irqsave(&timer->lock, flags);
478 	timeri->ticks = timeri->cticks = ticks;
479 	timeri->pticks = 0;
480 	result = snd_timer_start1(timer, timeri, ticks);
481 	spin_unlock_irqrestore(&timer->lock, flags);
482 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
483 	return result;
484 }
485 
486 static int _snd_timer_stop(struct snd_timer_instance * timeri,
487 			   int keep_flag, int event)
488 {
489 	struct snd_timer *timer;
490 	unsigned long flags;
491 
492 	snd_assert(timeri != NULL, return -ENXIO);
493 
494 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
495 		if (!keep_flag) {
496 			spin_lock_irqsave(&slave_active_lock, flags);
497 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
498 			spin_unlock_irqrestore(&slave_active_lock, flags);
499 		}
500 		goto __end;
501 	}
502 	timer = timeri->timer;
503 	if (!timer)
504 		return -EINVAL;
505 	spin_lock_irqsave(&timer->lock, flags);
506 	list_del_init(&timeri->ack_list);
507 	list_del_init(&timeri->active_list);
508 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
509 	    !(--timer->running)) {
510 		timer->hw.stop(timer);
511 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
512 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
513 			snd_timer_reschedule(timer, 0);
514 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
515 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
516 				timer->hw.start(timer);
517 			}
518 		}
519 	}
520 	if (!keep_flag)
521 		timeri->flags &=
522 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
523 	spin_unlock_irqrestore(&timer->lock, flags);
524       __end:
525 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
526 		snd_timer_notify1(timeri, event);
527 	return 0;
528 }
529 
530 /*
531  * stop the timer instance.
532  *
533  * do not call this from the timer callback!
534  */
535 int snd_timer_stop(struct snd_timer_instance *timeri)
536 {
537 	struct snd_timer *timer;
538 	unsigned long flags;
539 	int err;
540 
541 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
542 	if (err < 0)
543 		return err;
544 	timer = timeri->timer;
545 	spin_lock_irqsave(&timer->lock, flags);
546 	timeri->cticks = timeri->ticks;
547 	timeri->pticks = 0;
548 	spin_unlock_irqrestore(&timer->lock, flags);
549 	return 0;
550 }
551 
552 /*
553  * start again..  the tick is kept.
554  */
555 int snd_timer_continue(struct snd_timer_instance *timeri)
556 {
557 	struct snd_timer *timer;
558 	int result = -EINVAL;
559 	unsigned long flags;
560 
561 	if (timeri == NULL)
562 		return result;
563 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
564 		return snd_timer_start_slave(timeri);
565 	timer = timeri->timer;
566 	if (! timer)
567 		return -EINVAL;
568 	spin_lock_irqsave(&timer->lock, flags);
569 	if (!timeri->cticks)
570 		timeri->cticks = 1;
571 	timeri->pticks = 0;
572 	result = snd_timer_start1(timer, timeri, timer->sticks);
573 	spin_unlock_irqrestore(&timer->lock, flags);
574 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
575 	return result;
576 }
577 
578 /*
579  * pause.. remember the ticks left
580  */
581 int snd_timer_pause(struct snd_timer_instance * timeri)
582 {
583 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
584 }
585 
586 /*
587  * reschedule the timer
588  *
589  * start pending instances and check the scheduling ticks.
590  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
591  */
592 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
593 {
594 	struct snd_timer_instance *ti;
595 	unsigned long ticks = ~0UL;
596 	struct list_head *p;
597 
598 	list_for_each(p, &timer->active_list_head) {
599 		ti = list_entry(p, struct snd_timer_instance, active_list);
600 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
601 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
602 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
603 			timer->running++;
604 		}
605 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
606 			if (ticks > ti->cticks)
607 				ticks = ti->cticks;
608 		}
609 	}
610 	if (ticks == ~0UL) {
611 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
612 		return;
613 	}
614 	if (ticks > timer->hw.ticks)
615 		ticks = timer->hw.ticks;
616 	if (ticks_left != ticks)
617 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
618 	timer->sticks = ticks;
619 }
620 
621 /*
622  * timer tasklet
623  *
624  */
625 static void snd_timer_tasklet(unsigned long arg)
626 {
627 	struct snd_timer *timer = (struct snd_timer *) arg;
628 	struct snd_timer_instance *ti;
629 	struct list_head *p;
630 	unsigned long resolution, ticks;
631 
632 	spin_lock(&timer->lock);
633 	/* now process all callbacks */
634 	while (!list_empty(&timer->sack_list_head)) {
635 		p = timer->sack_list_head.next;		/* get first item */
636 		ti = list_entry(p, struct snd_timer_instance, ack_list);
637 
638 		/* remove from ack_list and make empty */
639 		list_del_init(p);
640 
641 		ticks = ti->pticks;
642 		ti->pticks = 0;
643 		resolution = ti->resolution;
644 
645 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
646 		spin_unlock(&timer->lock);
647 		if (ti->callback)
648 			ti->callback(ti, resolution, ticks);
649 		spin_lock(&timer->lock);
650 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
651 	}
652 	spin_unlock(&timer->lock);
653 }
654 
655 /*
656  * timer interrupt
657  *
658  * ticks_left is usually equal to timer->sticks.
659  *
660  */
661 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
662 {
663 	struct snd_timer_instance *ti, *ts;
664 	unsigned long resolution, ticks;
665 	struct list_head *p, *q, *n, *ack_list_head;
666 	unsigned long flags;
667 	int use_tasklet = 0;
668 
669 	if (timer == NULL)
670 		return;
671 
672 	spin_lock_irqsave(&timer->lock, flags);
673 
674 	/* remember the current resolution */
675 	if (timer->hw.c_resolution)
676 		resolution = timer->hw.c_resolution(timer);
677 	else
678 		resolution = timer->hw.resolution;
679 
680 	/* loop for all active instances
681 	 * Here we cannot use list_for_each because the active_list of a
682 	 * processed instance is relinked to done_list_head before the callback
683 	 * is called.
684 	 */
685 	list_for_each_safe(p, n, &timer->active_list_head) {
686 		ti = list_entry(p, struct snd_timer_instance, active_list);
687 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
688 			continue;
689 		ti->pticks += ticks_left;
690 		ti->resolution = resolution;
691 		if (ti->cticks < ticks_left)
692 			ti->cticks = 0;
693 		else
694 			ti->cticks -= ticks_left;
695 		if (ti->cticks) /* not expired */
696 			continue;
697 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
698 			ti->cticks = ti->ticks;
699 		} else {
700 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
701 			if (--timer->running)
702 				list_del(p);
703 		}
704 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
705 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
706 			ack_list_head = &timer->ack_list_head;
707 		else
708 			ack_list_head = &timer->sack_list_head;
709 		if (list_empty(&ti->ack_list))
710 			list_add_tail(&ti->ack_list, ack_list_head);
711 		list_for_each(q, &ti->slave_active_head) {
712 			ts = list_entry(q, struct snd_timer_instance, active_list);
713 			ts->pticks = ti->pticks;
714 			ts->resolution = resolution;
715 			if (list_empty(&ts->ack_list))
716 				list_add_tail(&ts->ack_list, ack_list_head);
717 		}
718 	}
719 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
720 		snd_timer_reschedule(timer, ticks_left);
721 	if (timer->running) {
722 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
723 			timer->hw.stop(timer);
724 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
725 		}
726 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
727 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
728 			/* restart timer */
729 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
730 			timer->hw.start(timer);
731 		}
732 	} else {
733 		timer->hw.stop(timer);
734 	}
735 
736 	/* now process all fast callbacks */
737 	while (!list_empty(&timer->ack_list_head)) {
738 		p = timer->ack_list_head.next;		/* get first item */
739 		ti = list_entry(p, struct snd_timer_instance, ack_list);
740 
741 		/* remove from ack_list and make empty */
742 		list_del_init(p);
743 
744 		ticks = ti->pticks;
745 		ti->pticks = 0;
746 
747 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
748 		spin_unlock(&timer->lock);
749 		if (ti->callback)
750 			ti->callback(ti, resolution, ticks);
751 		spin_lock(&timer->lock);
752 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
753 	}
754 
755 	/* do we have any slow callbacks? */
756 	use_tasklet = !list_empty(&timer->sack_list_head);
757 	spin_unlock_irqrestore(&timer->lock, flags);
758 
759 	if (use_tasklet)
760 		tasklet_hi_schedule(&timer->task_queue);
761 }
762 
763 /*
764 
765  */
766 
767 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
768 		  struct snd_timer **rtimer)
769 {
770 	struct snd_timer *timer;
771 	int err;
772 	static struct snd_device_ops ops = {
773 		.dev_free = snd_timer_dev_free,
774 		.dev_register = snd_timer_dev_register,
775 		.dev_unregister = snd_timer_dev_unregister
776 	};
777 
778 	snd_assert(tid != NULL, return -EINVAL);
779 	snd_assert(rtimer != NULL, return -EINVAL);
780 	*rtimer = NULL;
781 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
782 	if (timer == NULL) {
783 		snd_printk(KERN_ERR "timer: cannot allocate\n");
784 		return -ENOMEM;
785 	}
786 	timer->tmr_class = tid->dev_class;
787 	timer->card = card;
788 	timer->tmr_device = tid->device;
789 	timer->tmr_subdevice = tid->subdevice;
790 	if (id)
791 		strlcpy(timer->id, id, sizeof(timer->id));
792 	INIT_LIST_HEAD(&timer->device_list);
793 	INIT_LIST_HEAD(&timer->open_list_head);
794 	INIT_LIST_HEAD(&timer->active_list_head);
795 	INIT_LIST_HEAD(&timer->ack_list_head);
796 	INIT_LIST_HEAD(&timer->sack_list_head);
797 	spin_lock_init(&timer->lock);
798 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
799 		     (unsigned long)timer);
800 	if (card != NULL) {
801 		timer->module = card->module;
802 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
803 		if (err < 0) {
804 			snd_timer_free(timer);
805 			return err;
806 		}
807 	}
808 	*rtimer = timer;
809 	return 0;
810 }
811 
812 static int snd_timer_free(struct snd_timer *timer)
813 {
814 	snd_assert(timer != NULL, return -ENXIO);
815 	if (timer->private_free)
816 		timer->private_free(timer);
817 	kfree(timer);
818 	return 0;
819 }
820 
821 static int snd_timer_dev_free(struct snd_device *device)
822 {
823 	struct snd_timer *timer = device->device_data;
824 	return snd_timer_free(timer);
825 }
826 
827 static int snd_timer_dev_register(struct snd_device *dev)
828 {
829 	struct snd_timer *timer = dev->device_data;
830 	struct snd_timer *timer1;
831 	struct list_head *p;
832 
833 	snd_assert(timer != NULL && timer->hw.start != NULL &&
834 		   timer->hw.stop != NULL, return -ENXIO);
835 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
836 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
837 	    	return -EINVAL;
838 
839 	mutex_lock(&register_mutex);
840 	list_for_each(p, &snd_timer_list) {
841 		timer1 = list_entry(p, struct snd_timer, device_list);
842 		if (timer1->tmr_class > timer->tmr_class)
843 			break;
844 		if (timer1->tmr_class < timer->tmr_class)
845 			continue;
846 		if (timer1->card && timer->card) {
847 			if (timer1->card->number > timer->card->number)
848 				break;
849 			if (timer1->card->number < timer->card->number)
850 				continue;
851 		}
852 		if (timer1->tmr_device > timer->tmr_device)
853 			break;
854 		if (timer1->tmr_device < timer->tmr_device)
855 			continue;
856 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
857 			break;
858 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
859 			continue;
860 		/* conflicts.. */
861 		mutex_unlock(&register_mutex);
862 		return -EBUSY;
863 	}
864 	list_add_tail(&timer->device_list, p);
865 	mutex_unlock(&register_mutex);
866 	return 0;
867 }
868 
869 static int snd_timer_unregister(struct snd_timer *timer)
870 {
871 	struct list_head *p, *n;
872 	struct snd_timer_instance *ti;
873 
874 	snd_assert(timer != NULL, return -ENXIO);
875 	mutex_lock(&register_mutex);
876 	if (! list_empty(&timer->open_list_head)) {
877 		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
878 		list_for_each_safe(p, n, &timer->open_list_head) {
879 			list_del_init(p);
880 			ti = list_entry(p, struct snd_timer_instance, open_list);
881 			ti->timer = NULL;
882 		}
883 	}
884 	list_del(&timer->device_list);
885 	mutex_unlock(&register_mutex);
886 	return snd_timer_free(timer);
887 }
888 
889 static int snd_timer_dev_unregister(struct snd_device *device)
890 {
891 	struct snd_timer *timer = device->device_data;
892 	return snd_timer_unregister(timer);
893 }
894 
895 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
896 {
897 	unsigned long flags;
898 	unsigned long resolution = 0;
899 	struct snd_timer_instance *ti, *ts;
900 	struct list_head *p, *n;
901 
902 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
903 		return;
904 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART &&
905 		   event <= SNDRV_TIMER_EVENT_MRESUME, return);
906 	spin_lock_irqsave(&timer->lock, flags);
907 	if (event == SNDRV_TIMER_EVENT_MSTART ||
908 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
909 	    event == SNDRV_TIMER_EVENT_MRESUME) {
910 		if (timer->hw.c_resolution)
911 			resolution = timer->hw.c_resolution(timer);
912 		else
913 			resolution = timer->hw.resolution;
914 	}
915 	list_for_each(p, &timer->active_list_head) {
916 		ti = list_entry(p, struct snd_timer_instance, active_list);
917 		if (ti->ccallback)
918 			ti->ccallback(ti, event, tstamp, resolution);
919 		list_for_each(n, &ti->slave_active_head) {
920 			ts = list_entry(n, struct snd_timer_instance, active_list);
921 			if (ts->ccallback)
922 				ts->ccallback(ts, event, tstamp, resolution);
923 		}
924 	}
925 	spin_unlock_irqrestore(&timer->lock, flags);
926 }
927 
928 /*
929  * exported functions for global timers
930  */
931 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
932 {
933 	struct snd_timer_id tid;
934 
935 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
936 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
937 	tid.card = -1;
938 	tid.device = device;
939 	tid.subdevice = 0;
940 	return snd_timer_new(NULL, id, &tid, rtimer);
941 }
942 
943 int snd_timer_global_free(struct snd_timer *timer)
944 {
945 	return snd_timer_free(timer);
946 }
947 
948 int snd_timer_global_register(struct snd_timer *timer)
949 {
950 	struct snd_device dev;
951 
952 	memset(&dev, 0, sizeof(dev));
953 	dev.device_data = timer;
954 	return snd_timer_dev_register(&dev);
955 }
956 
957 int snd_timer_global_unregister(struct snd_timer *timer)
958 {
959 	return snd_timer_unregister(timer);
960 }
961 
962 /*
963  *  System timer
964  */
965 
966 struct snd_timer_system_private {
967 	struct timer_list tlist;
968 	struct timer * timer;
969 	unsigned long last_expires;
970 	unsigned long last_jiffies;
971 	unsigned long correction;
972 };
973 
974 static void snd_timer_s_function(unsigned long data)
975 {
976 	struct snd_timer *timer = (struct snd_timer *)data;
977 	struct snd_timer_system_private *priv = timer->private_data;
978 	unsigned long jiff = jiffies;
979 	if (time_after(jiff, priv->last_expires))
980 		priv->correction = (long)jiff - (long)priv->last_expires;
981 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
982 }
983 
984 static int snd_timer_s_start(struct snd_timer * timer)
985 {
986 	struct snd_timer_system_private *priv;
987 	unsigned long njiff;
988 
989 	priv = (struct snd_timer_system_private *) timer->private_data;
990 	njiff = (priv->last_jiffies = jiffies);
991 	if (priv->correction > timer->sticks - 1) {
992 		priv->correction -= timer->sticks - 1;
993 		njiff++;
994 	} else {
995 		njiff += timer->sticks - priv->correction;
996 		priv->correction -= timer->sticks;
997 	}
998 	priv->last_expires = priv->tlist.expires = njiff;
999 	add_timer(&priv->tlist);
1000 	return 0;
1001 }
1002 
1003 static int snd_timer_s_stop(struct snd_timer * timer)
1004 {
1005 	struct snd_timer_system_private *priv;
1006 	unsigned long jiff;
1007 
1008 	priv = (struct snd_timer_system_private *) timer->private_data;
1009 	del_timer(&priv->tlist);
1010 	jiff = jiffies;
1011 	if (time_before(jiff, priv->last_expires))
1012 		timer->sticks = priv->last_expires - jiff;
1013 	else
1014 		timer->sticks = 1;
1015 	return 0;
1016 }
1017 
1018 static struct snd_timer_hardware snd_timer_system =
1019 {
1020 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1021 	.resolution =	1000000000L / HZ,
1022 	.ticks =	10000000L,
1023 	.start =	snd_timer_s_start,
1024 	.stop =		snd_timer_s_stop
1025 };
1026 
1027 static void snd_timer_free_system(struct snd_timer *timer)
1028 {
1029 	kfree(timer->private_data);
1030 }
1031 
1032 static int snd_timer_register_system(void)
1033 {
1034 	struct snd_timer *timer;
1035 	struct snd_timer_system_private *priv;
1036 	int err;
1037 
1038 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1039 	if (err < 0)
1040 		return err;
1041 	strcpy(timer->name, "system timer");
1042 	timer->hw = snd_timer_system;
1043 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1044 	if (priv == NULL) {
1045 		snd_timer_free(timer);
1046 		return -ENOMEM;
1047 	}
1048 	init_timer(&priv->tlist);
1049 	priv->tlist.function = snd_timer_s_function;
1050 	priv->tlist.data = (unsigned long) timer;
1051 	timer->private_data = priv;
1052 	timer->private_free = snd_timer_free_system;
1053 	return snd_timer_global_register(timer);
1054 }
1055 
1056 #ifdef CONFIG_PROC_FS
1057 /*
1058  *  Info interface
1059  */
1060 
1061 static void snd_timer_proc_read(struct snd_info_entry *entry,
1062 				struct snd_info_buffer *buffer)
1063 {
1064 	unsigned long flags;
1065 	struct snd_timer *timer;
1066 	struct snd_timer_instance *ti;
1067 	struct list_head *p, *q;
1068 
1069 	mutex_lock(&register_mutex);
1070 	list_for_each(p, &snd_timer_list) {
1071 		timer = list_entry(p, struct snd_timer, device_list);
1072 		switch (timer->tmr_class) {
1073 		case SNDRV_TIMER_CLASS_GLOBAL:
1074 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1075 			break;
1076 		case SNDRV_TIMER_CLASS_CARD:
1077 			snd_iprintf(buffer, "C%i-%i: ",
1078 				    timer->card->number, timer->tmr_device);
1079 			break;
1080 		case SNDRV_TIMER_CLASS_PCM:
1081 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1082 				    timer->tmr_device, timer->tmr_subdevice);
1083 			break;
1084 		default:
1085 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1086 				    timer->card ? timer->card->number : -1,
1087 				    timer->tmr_device, timer->tmr_subdevice);
1088 		}
1089 		snd_iprintf(buffer, "%s :", timer->name);
1090 		if (timer->hw.resolution)
1091 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1092 				    timer->hw.resolution / 1000,
1093 				    timer->hw.resolution % 1000,
1094 				    timer->hw.ticks);
1095 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1096 			snd_iprintf(buffer, " SLAVE");
1097 		snd_iprintf(buffer, "\n");
1098 		spin_lock_irqsave(&timer->lock, flags);
1099 		list_for_each(q, &timer->open_list_head) {
1100 			ti = list_entry(q, struct snd_timer_instance, open_list);
1101 			snd_iprintf(buffer, "  Client %s : %s\n",
1102 				    ti->owner ? ti->owner : "unknown",
1103 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1104 						 SNDRV_TIMER_IFLG_RUNNING)
1105 				    ? "running" : "stopped");
1106 		}
1107 		spin_unlock_irqrestore(&timer->lock, flags);
1108 	}
1109 	mutex_unlock(&register_mutex);
1110 }
1111 
1112 static struct snd_info_entry *snd_timer_proc_entry = NULL;
1113 
1114 static void __init snd_timer_proc_init(void)
1115 {
1116 	struct snd_info_entry *entry;
1117 
1118 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1119 	if (entry != NULL) {
1120 		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
1121 		entry->c.text.read = snd_timer_proc_read;
1122 		if (snd_info_register(entry) < 0) {
1123 			snd_info_free_entry(entry);
1124 			entry = NULL;
1125 		}
1126 	}
1127 	snd_timer_proc_entry = entry;
1128 }
1129 
1130 static void __exit snd_timer_proc_done(void)
1131 {
1132 	snd_info_unregister(snd_timer_proc_entry);
1133 }
1134 #else /* !CONFIG_PROC_FS */
1135 #define snd_timer_proc_init()
1136 #define snd_timer_proc_done()
1137 #endif
1138 
1139 /*
1140  *  USER SPACE interface
1141  */
1142 
1143 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1144 				     unsigned long resolution,
1145 				     unsigned long ticks)
1146 {
1147 	struct snd_timer_user *tu = timeri->callback_data;
1148 	struct snd_timer_read *r;
1149 	int prev;
1150 
1151 	spin_lock(&tu->qlock);
1152 	if (tu->qused > 0) {
1153 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1154 		r = &tu->queue[prev];
1155 		if (r->resolution == resolution) {
1156 			r->ticks += ticks;
1157 			goto __wake;
1158 		}
1159 	}
1160 	if (tu->qused >= tu->queue_size) {
1161 		tu->overrun++;
1162 	} else {
1163 		r = &tu->queue[tu->qtail++];
1164 		tu->qtail %= tu->queue_size;
1165 		r->resolution = resolution;
1166 		r->ticks = ticks;
1167 		tu->qused++;
1168 	}
1169       __wake:
1170 	spin_unlock(&tu->qlock);
1171 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1172 	wake_up(&tu->qchange_sleep);
1173 }
1174 
1175 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1176 					    struct snd_timer_tread *tread)
1177 {
1178 	if (tu->qused >= tu->queue_size) {
1179 		tu->overrun++;
1180 	} else {
1181 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1182 		tu->qtail %= tu->queue_size;
1183 		tu->qused++;
1184 	}
1185 }
1186 
1187 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1188 				     int event,
1189 				     struct timespec *tstamp,
1190 				     unsigned long resolution)
1191 {
1192 	struct snd_timer_user *tu = timeri->callback_data;
1193 	struct snd_timer_tread r1;
1194 
1195 	if (event >= SNDRV_TIMER_EVENT_START &&
1196 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1197 		tu->tstamp = *tstamp;
1198 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1199 		return;
1200 	r1.event = event;
1201 	r1.tstamp = *tstamp;
1202 	r1.val = resolution;
1203 	spin_lock(&tu->qlock);
1204 	snd_timer_user_append_to_tqueue(tu, &r1);
1205 	spin_unlock(&tu->qlock);
1206 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1207 	wake_up(&tu->qchange_sleep);
1208 }
1209 
1210 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1211 				      unsigned long resolution,
1212 				      unsigned long ticks)
1213 {
1214 	struct snd_timer_user *tu = timeri->callback_data;
1215 	struct snd_timer_tread *r, r1;
1216 	struct timespec tstamp;
1217 	int prev, append = 0;
1218 
1219 	memset(&tstamp, 0, sizeof(tstamp));
1220 	spin_lock(&tu->qlock);
1221 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1222 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1223 		spin_unlock(&tu->qlock);
1224 		return;
1225 	}
1226 	if (tu->last_resolution != resolution || ticks > 0)
1227 		getnstimeofday(&tstamp);
1228 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1229 	    tu->last_resolution != resolution) {
1230 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1231 		r1.tstamp = tstamp;
1232 		r1.val = resolution;
1233 		snd_timer_user_append_to_tqueue(tu, &r1);
1234 		tu->last_resolution = resolution;
1235 		append++;
1236 	}
1237 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1238 		goto __wake;
1239 	if (ticks == 0)
1240 		goto __wake;
1241 	if (tu->qused > 0) {
1242 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1243 		r = &tu->tqueue[prev];
1244 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1245 			r->tstamp = tstamp;
1246 			r->val += ticks;
1247 			append++;
1248 			goto __wake;
1249 		}
1250 	}
1251 	r1.event = SNDRV_TIMER_EVENT_TICK;
1252 	r1.tstamp = tstamp;
1253 	r1.val = ticks;
1254 	snd_timer_user_append_to_tqueue(tu, &r1);
1255 	append++;
1256       __wake:
1257 	spin_unlock(&tu->qlock);
1258 	if (append == 0)
1259 		return;
1260 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1261 	wake_up(&tu->qchange_sleep);
1262 }
1263 
1264 static int snd_timer_user_open(struct inode *inode, struct file *file)
1265 {
1266 	struct snd_timer_user *tu;
1267 
1268 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1269 	if (tu == NULL)
1270 		return -ENOMEM;
1271 	spin_lock_init(&tu->qlock);
1272 	init_waitqueue_head(&tu->qchange_sleep);
1273 	mutex_init(&tu->tread_sem);
1274 	tu->ticks = 1;
1275 	tu->queue_size = 128;
1276 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1277 			    GFP_KERNEL);
1278 	if (tu->queue == NULL) {
1279 		kfree(tu);
1280 		return -ENOMEM;
1281 	}
1282 	file->private_data = tu;
1283 	return 0;
1284 }
1285 
1286 static int snd_timer_user_release(struct inode *inode, struct file *file)
1287 {
1288 	struct snd_timer_user *tu;
1289 
1290 	if (file->private_data) {
1291 		tu = file->private_data;
1292 		file->private_data = NULL;
1293 		fasync_helper(-1, file, 0, &tu->fasync);
1294 		if (tu->timeri)
1295 			snd_timer_close(tu->timeri);
1296 		kfree(tu->queue);
1297 		kfree(tu->tqueue);
1298 		kfree(tu);
1299 	}
1300 	return 0;
1301 }
1302 
1303 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1304 {
1305 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1306 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1307 	id->card = -1;
1308 	id->device = -1;
1309 	id->subdevice = -1;
1310 }
1311 
1312 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1313 {
1314 	id->dev_class = timer->tmr_class;
1315 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1316 	id->card = timer->card ? timer->card->number : -1;
1317 	id->device = timer->tmr_device;
1318 	id->subdevice = timer->tmr_subdevice;
1319 }
1320 
1321 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1322 {
1323 	struct snd_timer_id id;
1324 	struct snd_timer *timer;
1325 	struct list_head *p;
1326 
1327 	if (copy_from_user(&id, _tid, sizeof(id)))
1328 		return -EFAULT;
1329 	mutex_lock(&register_mutex);
1330 	if (id.dev_class < 0) {		/* first item */
1331 		if (list_empty(&snd_timer_list))
1332 			snd_timer_user_zero_id(&id);
1333 		else {
1334 			timer = list_entry(snd_timer_list.next,
1335 					   struct snd_timer, device_list);
1336 			snd_timer_user_copy_id(&id, timer);
1337 		}
1338 	} else {
1339 		switch (id.dev_class) {
1340 		case SNDRV_TIMER_CLASS_GLOBAL:
1341 			id.device = id.device < 0 ? 0 : id.device + 1;
1342 			list_for_each(p, &snd_timer_list) {
1343 				timer = list_entry(p, struct snd_timer, device_list);
1344 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1345 					snd_timer_user_copy_id(&id, timer);
1346 					break;
1347 				}
1348 				if (timer->tmr_device >= id.device) {
1349 					snd_timer_user_copy_id(&id, timer);
1350 					break;
1351 				}
1352 			}
1353 			if (p == &snd_timer_list)
1354 				snd_timer_user_zero_id(&id);
1355 			break;
1356 		case SNDRV_TIMER_CLASS_CARD:
1357 		case SNDRV_TIMER_CLASS_PCM:
1358 			if (id.card < 0) {
1359 				id.card = 0;
1360 			} else {
1361 				if (id.card < 0) {
1362 					id.card = 0;
1363 				} else {
1364 					if (id.device < 0) {
1365 						id.device = 0;
1366 					} else {
1367 						if (id.subdevice < 0) {
1368 							id.subdevice = 0;
1369 						} else {
1370 							id.subdevice++;
1371 						}
1372 					}
1373 				}
1374 			}
1375 			list_for_each(p, &snd_timer_list) {
1376 				timer = list_entry(p, struct snd_timer, device_list);
1377 				if (timer->tmr_class > id.dev_class) {
1378 					snd_timer_user_copy_id(&id, timer);
1379 					break;
1380 				}
1381 				if (timer->tmr_class < id.dev_class)
1382 					continue;
1383 				if (timer->card->number > id.card) {
1384 					snd_timer_user_copy_id(&id, timer);
1385 					break;
1386 				}
1387 				if (timer->card->number < id.card)
1388 					continue;
1389 				if (timer->tmr_device > id.device) {
1390 					snd_timer_user_copy_id(&id, timer);
1391 					break;
1392 				}
1393 				if (timer->tmr_device < id.device)
1394 					continue;
1395 				if (timer->tmr_subdevice > id.subdevice) {
1396 					snd_timer_user_copy_id(&id, timer);
1397 					break;
1398 				}
1399 				if (timer->tmr_subdevice < id.subdevice)
1400 					continue;
1401 				snd_timer_user_copy_id(&id, timer);
1402 				break;
1403 			}
1404 			if (p == &snd_timer_list)
1405 				snd_timer_user_zero_id(&id);
1406 			break;
1407 		default:
1408 			snd_timer_user_zero_id(&id);
1409 		}
1410 	}
1411 	mutex_unlock(&register_mutex);
1412 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1413 		return -EFAULT;
1414 	return 0;
1415 }
1416 
1417 static int snd_timer_user_ginfo(struct file *file,
1418 				struct snd_timer_ginfo __user *_ginfo)
1419 {
1420 	struct snd_timer_ginfo *ginfo;
1421 	struct snd_timer_id tid;
1422 	struct snd_timer *t;
1423 	struct list_head *p;
1424 	int err = 0;
1425 
1426 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1427 	if (! ginfo)
1428 		return -ENOMEM;
1429 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1430 		kfree(ginfo);
1431 		return -EFAULT;
1432 	}
1433 	tid = ginfo->tid;
1434 	memset(ginfo, 0, sizeof(*ginfo));
1435 	ginfo->tid = tid;
1436 	mutex_lock(&register_mutex);
1437 	t = snd_timer_find(&tid);
1438 	if (t != NULL) {
1439 		ginfo->card = t->card ? t->card->number : -1;
1440 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1441 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1442 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1443 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1444 		ginfo->resolution = t->hw.resolution;
1445 		if (t->hw.resolution_min > 0) {
1446 			ginfo->resolution_min = t->hw.resolution_min;
1447 			ginfo->resolution_max = t->hw.resolution_max;
1448 		}
1449 		list_for_each(p, &t->open_list_head) {
1450 			ginfo->clients++;
1451 		}
1452 	} else {
1453 		err = -ENODEV;
1454 	}
1455 	mutex_unlock(&register_mutex);
1456 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1457 		err = -EFAULT;
1458 	kfree(ginfo);
1459 	return err;
1460 }
1461 
1462 static int snd_timer_user_gparams(struct file *file,
1463 				  struct snd_timer_gparams __user *_gparams)
1464 {
1465 	struct snd_timer_gparams gparams;
1466 	struct snd_timer *t;
1467 	int err;
1468 
1469 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1470 		return -EFAULT;
1471 	mutex_lock(&register_mutex);
1472 	t = snd_timer_find(&gparams.tid);
1473 	if (!t) {
1474 		err = -ENODEV;
1475 		goto _error;
1476 	}
1477 	if (!list_empty(&t->open_list_head)) {
1478 		err = -EBUSY;
1479 		goto _error;
1480 	}
1481 	if (!t->hw.set_period) {
1482 		err = -ENOSYS;
1483 		goto _error;
1484 	}
1485 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1486 _error:
1487 	mutex_unlock(&register_mutex);
1488 	return err;
1489 }
1490 
1491 static int snd_timer_user_gstatus(struct file *file,
1492 				  struct snd_timer_gstatus __user *_gstatus)
1493 {
1494 	struct snd_timer_gstatus gstatus;
1495 	struct snd_timer_id tid;
1496 	struct snd_timer *t;
1497 	int err = 0;
1498 
1499 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1500 		return -EFAULT;
1501 	tid = gstatus.tid;
1502 	memset(&gstatus, 0, sizeof(gstatus));
1503 	gstatus.tid = tid;
1504 	mutex_lock(&register_mutex);
1505 	t = snd_timer_find(&tid);
1506 	if (t != NULL) {
1507 		if (t->hw.c_resolution)
1508 			gstatus.resolution = t->hw.c_resolution(t);
1509 		else
1510 			gstatus.resolution = t->hw.resolution;
1511 		if (t->hw.precise_resolution) {
1512 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1513 						 &gstatus.resolution_den);
1514 		} else {
1515 			gstatus.resolution_num = gstatus.resolution;
1516 			gstatus.resolution_den = 1000000000uL;
1517 		}
1518 	} else {
1519 		err = -ENODEV;
1520 	}
1521 	mutex_unlock(&register_mutex);
1522 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1523 		err = -EFAULT;
1524 	return err;
1525 }
1526 
1527 static int snd_timer_user_tselect(struct file *file,
1528 				  struct snd_timer_select __user *_tselect)
1529 {
1530 	struct snd_timer_user *tu;
1531 	struct snd_timer_select tselect;
1532 	char str[32];
1533 	int err = 0;
1534 
1535 	tu = file->private_data;
1536 	mutex_lock(&tu->tread_sem);
1537 	if (tu->timeri) {
1538 		snd_timer_close(tu->timeri);
1539 		tu->timeri = NULL;
1540 	}
1541 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1542 		err = -EFAULT;
1543 		goto __err;
1544 	}
1545 	sprintf(str, "application %i", current->pid);
1546 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1547 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1548 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1549 	if (err < 0)
1550 		goto __err;
1551 
1552 	kfree(tu->queue);
1553 	tu->queue = NULL;
1554 	kfree(tu->tqueue);
1555 	tu->tqueue = NULL;
1556 	if (tu->tread) {
1557 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1558 				     GFP_KERNEL);
1559 		if (tu->tqueue == NULL)
1560 			err = -ENOMEM;
1561 	} else {
1562 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1563 				    GFP_KERNEL);
1564 		if (tu->queue == NULL)
1565 			err = -ENOMEM;
1566 	}
1567 
1568       	if (err < 0) {
1569 		snd_timer_close(tu->timeri);
1570       		tu->timeri = NULL;
1571       	} else {
1572 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1573 		tu->timeri->callback = tu->tread
1574 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1575 		tu->timeri->ccallback = snd_timer_user_ccallback;
1576 		tu->timeri->callback_data = (void *)tu;
1577 	}
1578 
1579       __err:
1580       	mutex_unlock(&tu->tread_sem);
1581 	return err;
1582 }
1583 
1584 static int snd_timer_user_info(struct file *file,
1585 			       struct snd_timer_info __user *_info)
1586 {
1587 	struct snd_timer_user *tu;
1588 	struct snd_timer_info *info;
1589 	struct snd_timer *t;
1590 	int err = 0;
1591 
1592 	tu = file->private_data;
1593 	snd_assert(tu->timeri != NULL, return -ENXIO);
1594 	t = tu->timeri->timer;
1595 	snd_assert(t != NULL, return -ENXIO);
1596 
1597 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1598 	if (! info)
1599 		return -ENOMEM;
1600 	info->card = t->card ? t->card->number : -1;
1601 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1602 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1603 	strlcpy(info->id, t->id, sizeof(info->id));
1604 	strlcpy(info->name, t->name, sizeof(info->name));
1605 	info->resolution = t->hw.resolution;
1606 	if (copy_to_user(_info, info, sizeof(*_info)))
1607 		err = -EFAULT;
1608 	kfree(info);
1609 	return err;
1610 }
1611 
1612 static int snd_timer_user_params(struct file *file,
1613 				 struct snd_timer_params __user *_params)
1614 {
1615 	struct snd_timer_user *tu;
1616 	struct snd_timer_params params;
1617 	struct snd_timer *t;
1618 	struct snd_timer_read *tr;
1619 	struct snd_timer_tread *ttr;
1620 	int err;
1621 
1622 	tu = file->private_data;
1623 	snd_assert(tu->timeri != NULL, return -ENXIO);
1624 	t = tu->timeri->timer;
1625 	snd_assert(t != NULL, return -ENXIO);
1626 	if (copy_from_user(&params, _params, sizeof(params)))
1627 		return -EFAULT;
1628 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1629 		err = -EINVAL;
1630 		goto _end;
1631 	}
1632 	if (params.queue_size > 0 &&
1633 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1634 		err = -EINVAL;
1635 		goto _end;
1636 	}
1637 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1638 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1639 			      (1<<SNDRV_TIMER_EVENT_START)|
1640 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1641 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1642 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1643 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1644 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1645 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1646 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1647 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1648 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1649 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1650 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1651 		err = -EINVAL;
1652 		goto _end;
1653 	}
1654 	snd_timer_stop(tu->timeri);
1655 	spin_lock_irq(&t->lock);
1656 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1657 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1658 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1659 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1660 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1661 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1662 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1663 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1664 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1665 	spin_unlock_irq(&t->lock);
1666 	if (params.queue_size > 0 &&
1667 	    (unsigned int)tu->queue_size != params.queue_size) {
1668 		if (tu->tread) {
1669 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1670 				      GFP_KERNEL);
1671 			if (ttr) {
1672 				kfree(tu->tqueue);
1673 				tu->queue_size = params.queue_size;
1674 				tu->tqueue = ttr;
1675 			}
1676 		} else {
1677 			tr = kmalloc(params.queue_size * sizeof(*tr),
1678 				     GFP_KERNEL);
1679 			if (tr) {
1680 				kfree(tu->queue);
1681 				tu->queue_size = params.queue_size;
1682 				tu->queue = tr;
1683 			}
1684 		}
1685 	}
1686 	tu->qhead = tu->qtail = tu->qused = 0;
1687 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1688 		if (tu->tread) {
1689 			struct snd_timer_tread tread;
1690 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1691 			tread.tstamp.tv_sec = 0;
1692 			tread.tstamp.tv_nsec = 0;
1693 			tread.val = 0;
1694 			snd_timer_user_append_to_tqueue(tu, &tread);
1695 		} else {
1696 			struct snd_timer_read *r = &tu->queue[0];
1697 			r->resolution = 0;
1698 			r->ticks = 0;
1699 			tu->qused++;
1700 			tu->qtail++;
1701 		}
1702 	}
1703 	tu->filter = params.filter;
1704 	tu->ticks = params.ticks;
1705 	err = 0;
1706  _end:
1707 	if (copy_to_user(_params, &params, sizeof(params)))
1708 		return -EFAULT;
1709 	return err;
1710 }
1711 
1712 static int snd_timer_user_status(struct file *file,
1713 				 struct snd_timer_status __user *_status)
1714 {
1715 	struct snd_timer_user *tu;
1716 	struct snd_timer_status status;
1717 
1718 	tu = file->private_data;
1719 	snd_assert(tu->timeri != NULL, return -ENXIO);
1720 	memset(&status, 0, sizeof(status));
1721 	status.tstamp = tu->tstamp;
1722 	status.resolution = snd_timer_resolution(tu->timeri);
1723 	status.lost = tu->timeri->lost;
1724 	status.overrun = tu->overrun;
1725 	spin_lock_irq(&tu->qlock);
1726 	status.queue = tu->qused;
1727 	spin_unlock_irq(&tu->qlock);
1728 	if (copy_to_user(_status, &status, sizeof(status)))
1729 		return -EFAULT;
1730 	return 0;
1731 }
1732 
1733 static int snd_timer_user_start(struct file *file)
1734 {
1735 	int err;
1736 	struct snd_timer_user *tu;
1737 
1738 	tu = file->private_data;
1739 	snd_assert(tu->timeri != NULL, return -ENXIO);
1740 	snd_timer_stop(tu->timeri);
1741 	tu->timeri->lost = 0;
1742 	tu->last_resolution = 0;
1743 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1744 }
1745 
1746 static int snd_timer_user_stop(struct file *file)
1747 {
1748 	int err;
1749 	struct snd_timer_user *tu;
1750 
1751 	tu = file->private_data;
1752 	snd_assert(tu->timeri != NULL, return -ENXIO);
1753 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1754 }
1755 
1756 static int snd_timer_user_continue(struct file *file)
1757 {
1758 	int err;
1759 	struct snd_timer_user *tu;
1760 
1761 	tu = file->private_data;
1762 	snd_assert(tu->timeri != NULL, return -ENXIO);
1763 	tu->timeri->lost = 0;
1764 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1765 }
1766 
1767 static int snd_timer_user_pause(struct file *file)
1768 {
1769 	int err;
1770 	struct snd_timer_user *tu;
1771 
1772 	tu = file->private_data;
1773 	snd_assert(tu->timeri != NULL, return -ENXIO);
1774 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1775 }
1776 
1777 enum {
1778 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1779 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1780 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1781 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1782 };
1783 
1784 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1785 				 unsigned long arg)
1786 {
1787 	struct snd_timer_user *tu;
1788 	void __user *argp = (void __user *)arg;
1789 	int __user *p = argp;
1790 
1791 	tu = file->private_data;
1792 	switch (cmd) {
1793 	case SNDRV_TIMER_IOCTL_PVERSION:
1794 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1795 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1796 		return snd_timer_user_next_device(argp);
1797 	case SNDRV_TIMER_IOCTL_TREAD:
1798 	{
1799 		int xarg;
1800 
1801 		mutex_lock(&tu->tread_sem);
1802 		if (tu->timeri)	{	/* too late */
1803 			mutex_unlock(&tu->tread_sem);
1804 			return -EBUSY;
1805 		}
1806 		if (get_user(xarg, p)) {
1807 			mutex_unlock(&tu->tread_sem);
1808 			return -EFAULT;
1809 		}
1810 		tu->tread = xarg ? 1 : 0;
1811 		mutex_unlock(&tu->tread_sem);
1812 		return 0;
1813 	}
1814 	case SNDRV_TIMER_IOCTL_GINFO:
1815 		return snd_timer_user_ginfo(file, argp);
1816 	case SNDRV_TIMER_IOCTL_GPARAMS:
1817 		return snd_timer_user_gparams(file, argp);
1818 	case SNDRV_TIMER_IOCTL_GSTATUS:
1819 		return snd_timer_user_gstatus(file, argp);
1820 	case SNDRV_TIMER_IOCTL_SELECT:
1821 		return snd_timer_user_tselect(file, argp);
1822 	case SNDRV_TIMER_IOCTL_INFO:
1823 		return snd_timer_user_info(file, argp);
1824 	case SNDRV_TIMER_IOCTL_PARAMS:
1825 		return snd_timer_user_params(file, argp);
1826 	case SNDRV_TIMER_IOCTL_STATUS:
1827 		return snd_timer_user_status(file, argp);
1828 	case SNDRV_TIMER_IOCTL_START:
1829 	case SNDRV_TIMER_IOCTL_START_OLD:
1830 		return snd_timer_user_start(file);
1831 	case SNDRV_TIMER_IOCTL_STOP:
1832 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1833 		return snd_timer_user_stop(file);
1834 	case SNDRV_TIMER_IOCTL_CONTINUE:
1835 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1836 		return snd_timer_user_continue(file);
1837 	case SNDRV_TIMER_IOCTL_PAUSE:
1838 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1839 		return snd_timer_user_pause(file);
1840 	}
1841 	return -ENOTTY;
1842 }
1843 
1844 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1845 {
1846 	struct snd_timer_user *tu;
1847 	int err;
1848 
1849 	tu = file->private_data;
1850 	err = fasync_helper(fd, file, on, &tu->fasync);
1851         if (err < 0)
1852 		return err;
1853 	return 0;
1854 }
1855 
1856 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1857 				   size_t count, loff_t *offset)
1858 {
1859 	struct snd_timer_user *tu;
1860 	long result = 0, unit;
1861 	int err = 0;
1862 
1863 	tu = file->private_data;
1864 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1865 	spin_lock_irq(&tu->qlock);
1866 	while ((long)count - result >= unit) {
1867 		while (!tu->qused) {
1868 			wait_queue_t wait;
1869 
1870 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1871 				err = -EAGAIN;
1872 				break;
1873 			}
1874 
1875 			set_current_state(TASK_INTERRUPTIBLE);
1876 			init_waitqueue_entry(&wait, current);
1877 			add_wait_queue(&tu->qchange_sleep, &wait);
1878 
1879 			spin_unlock_irq(&tu->qlock);
1880 			schedule();
1881 			spin_lock_irq(&tu->qlock);
1882 
1883 			remove_wait_queue(&tu->qchange_sleep, &wait);
1884 
1885 			if (signal_pending(current)) {
1886 				err = -ERESTARTSYS;
1887 				break;
1888 			}
1889 		}
1890 
1891 		spin_unlock_irq(&tu->qlock);
1892 		if (err < 0)
1893 			goto _error;
1894 
1895 		if (tu->tread) {
1896 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1897 					 sizeof(struct snd_timer_tread))) {
1898 				err = -EFAULT;
1899 				goto _error;
1900 			}
1901 		} else {
1902 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1903 					 sizeof(struct snd_timer_read))) {
1904 				err = -EFAULT;
1905 				goto _error;
1906 			}
1907 		}
1908 
1909 		tu->qhead %= tu->queue_size;
1910 
1911 		result += unit;
1912 		buffer += unit;
1913 
1914 		spin_lock_irq(&tu->qlock);
1915 		tu->qused--;
1916 	}
1917 	spin_unlock_irq(&tu->qlock);
1918  _error:
1919 	return result > 0 ? result : err;
1920 }
1921 
1922 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1923 {
1924         unsigned int mask;
1925         struct snd_timer_user *tu;
1926 
1927         tu = file->private_data;
1928 
1929         poll_wait(file, &tu->qchange_sleep, wait);
1930 
1931 	mask = 0;
1932 	if (tu->qused)
1933 		mask |= POLLIN | POLLRDNORM;
1934 
1935 	return mask;
1936 }
1937 
1938 #ifdef CONFIG_COMPAT
1939 #include "timer_compat.c"
1940 #else
1941 #define snd_timer_user_ioctl_compat	NULL
1942 #endif
1943 
1944 static struct file_operations snd_timer_f_ops =
1945 {
1946 	.owner =	THIS_MODULE,
1947 	.read =		snd_timer_user_read,
1948 	.open =		snd_timer_user_open,
1949 	.release =	snd_timer_user_release,
1950 	.poll =		snd_timer_user_poll,
1951 	.unlocked_ioctl =	snd_timer_user_ioctl,
1952 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1953 	.fasync = 	snd_timer_user_fasync,
1954 };
1955 
1956 /*
1957  *  ENTRY functions
1958  */
1959 
1960 static int __init alsa_timer_init(void)
1961 {
1962 	int err;
1963 
1964 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1965 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1966 			      "system timer");
1967 #endif
1968 
1969 	if ((err = snd_timer_register_system()) < 0)
1970 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1971 			   err);
1972 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1973 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1974 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1975 			   err);
1976 	snd_timer_proc_init();
1977 	return 0;
1978 }
1979 
1980 static void __exit alsa_timer_exit(void)
1981 {
1982 	struct list_head *p, *n;
1983 
1984 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1985 	/* unregister the system timer */
1986 	list_for_each_safe(p, n, &snd_timer_list) {
1987 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1988 		snd_timer_unregister(timer);
1989 	}
1990 	snd_timer_proc_done();
1991 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1992 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1993 #endif
1994 }
1995 
1996 module_init(alsa_timer_init)
1997 module_exit(alsa_timer_exit)
1998 
1999 EXPORT_SYMBOL(snd_timer_open);
2000 EXPORT_SYMBOL(snd_timer_close);
2001 EXPORT_SYMBOL(snd_timer_resolution);
2002 EXPORT_SYMBOL(snd_timer_start);
2003 EXPORT_SYMBOL(snd_timer_stop);
2004 EXPORT_SYMBOL(snd_timer_continue);
2005 EXPORT_SYMBOL(snd_timer_pause);
2006 EXPORT_SYMBOL(snd_timer_new);
2007 EXPORT_SYMBOL(snd_timer_notify);
2008 EXPORT_SYMBOL(snd_timer_global_new);
2009 EXPORT_SYMBOL(snd_timer_global_free);
2010 EXPORT_SYMBOL(snd_timer_global_register);
2011 EXPORT_SYMBOL(snd_timer_global_unregister);
2012 EXPORT_SYMBOL(snd_timer_interrupt);
2013