xref: /openbmc/linux/sound/core/timer.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/moduleparam.h>
29 #include <sound/core.h>
30 #include <sound/timer.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 #include <sound/minors.h>
34 #include <sound/initval.h>
35 #include <linux/kmod.h>
36 #ifdef CONFIG_KERNELD
37 #include <linux/kerneld.h>
38 #endif
39 
40 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
41 #define DEFAULT_TIMER_LIMIT 3
42 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
43 #define DEFAULT_TIMER_LIMIT 2
44 #else
45 #define DEFAULT_TIMER_LIMIT 1
46 #endif
47 
48 static int timer_limit = DEFAULT_TIMER_LIMIT;
49 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
50 MODULE_DESCRIPTION("ALSA timer interface");
51 MODULE_LICENSE("GPL");
52 module_param(timer_limit, int, 0444);
53 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
54 
55 typedef struct {
56 	snd_timer_instance_t *timeri;
57 	int tread;			/* enhanced read with timestamps and events */
58 	unsigned long ticks;
59 	unsigned long overrun;
60 	int qhead;
61 	int qtail;
62 	int qused;
63 	int queue_size;
64 	snd_timer_read_t *queue;
65 	snd_timer_tread_t *tqueue;
66 	spinlock_t qlock;
67 	unsigned long last_resolution;
68 	unsigned int filter;
69 	struct timespec tstamp;		/* trigger tstamp */
70 	wait_queue_head_t qchange_sleep;
71 	struct fasync_struct *fasync;
72 } snd_timer_user_t;
73 
74 /* list of timers */
75 static LIST_HEAD(snd_timer_list);
76 
77 /* list of slave instances */
78 static LIST_HEAD(snd_timer_slave_list);
79 
80 /* lock for slave active lists */
81 static DEFINE_SPINLOCK(slave_active_lock);
82 
83 static DECLARE_MUTEX(register_mutex);
84 
85 static int snd_timer_free(snd_timer_t *timer);
86 static int snd_timer_dev_free(snd_device_t *device);
87 static int snd_timer_dev_register(snd_device_t *device);
88 static int snd_timer_dev_unregister(snd_device_t *device);
89 
90 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left);
91 
92 /*
93  * create a timer instance with the given owner string.
94  * when timer is not NULL, increments the module counter
95  */
96 static snd_timer_instance_t *snd_timer_instance_new(char *owner, snd_timer_t *timer)
97 {
98 	snd_timer_instance_t *timeri;
99 	timeri = kcalloc(1, sizeof(*timeri), GFP_KERNEL);
100 	if (timeri == NULL)
101 		return NULL;
102 	timeri->owner = snd_kmalloc_strdup(owner, GFP_KERNEL);
103 	if (! timeri->owner) {
104 		kfree(timeri);
105 		return NULL;
106 	}
107 	INIT_LIST_HEAD(&timeri->open_list);
108 	INIT_LIST_HEAD(&timeri->active_list);
109 	INIT_LIST_HEAD(&timeri->ack_list);
110 	INIT_LIST_HEAD(&timeri->slave_list_head);
111 	INIT_LIST_HEAD(&timeri->slave_active_head);
112 
113 	timeri->timer = timer;
114 	if (timer && timer->card && !try_module_get(timer->card->module)) {
115 		kfree(timeri->owner);
116 		kfree(timeri);
117 		return NULL;
118 	}
119 
120 	return timeri;
121 }
122 
123 /*
124  * find a timer instance from the given timer id
125  */
126 static snd_timer_t *snd_timer_find(snd_timer_id_t *tid)
127 {
128 	snd_timer_t *timer = NULL;
129 	struct list_head *p;
130 
131 	list_for_each(p, &snd_timer_list) {
132 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
133 
134 		if (timer->tmr_class != tid->dev_class)
135 			continue;
136 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
137 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
138 		    (timer->card == NULL ||
139 		     timer->card->number != tid->card))
140 			continue;
141 		if (timer->tmr_device != tid->device)
142 			continue;
143 		if (timer->tmr_subdevice != tid->subdevice)
144 			continue;
145 		return timer;
146 	}
147 	return NULL;
148 }
149 
150 #ifdef CONFIG_KMOD
151 
152 static void snd_timer_request(snd_timer_id_t *tid)
153 {
154 	if (! current->fs->root)
155 		return;
156 	switch (tid->dev_class) {
157 	case SNDRV_TIMER_CLASS_GLOBAL:
158 		if (tid->device < timer_limit)
159 			request_module("snd-timer-%i", tid->device);
160 		break;
161 	case SNDRV_TIMER_CLASS_CARD:
162 	case SNDRV_TIMER_CLASS_PCM:
163 		if (tid->card < snd_ecards_limit)
164 			request_module("snd-card-%i", tid->card);
165 		break;
166 	default:
167 		break;
168 	}
169 }
170 
171 #endif
172 
173 /*
174  * look for a master instance matching with the slave id of the given slave.
175  * when found, relink the open_link of the slave.
176  *
177  * call this with register_mutex down.
178  */
179 static void snd_timer_check_slave(snd_timer_instance_t *slave)
180 {
181 	snd_timer_t *timer;
182 	snd_timer_instance_t *master;
183 	struct list_head *p, *q;
184 
185 	/* FIXME: it's really dumb to look up all entries.. */
186 	list_for_each(p, &snd_timer_list) {
187 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
188 		list_for_each(q, &timer->open_list_head) {
189 			master = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
190 			if (slave->slave_class == master->slave_class &&
191 			    slave->slave_id == master->slave_id) {
192 				list_del(&slave->open_list);
193 				list_add_tail(&slave->open_list, &master->slave_list_head);
194 				spin_lock_irq(&slave_active_lock);
195 				slave->master = master;
196 				slave->timer = master->timer;
197 				spin_unlock_irq(&slave_active_lock);
198 				return;
199 			}
200 		}
201 	}
202 }
203 
204 /*
205  * look for slave instances matching with the slave id of the given master.
206  * when found, relink the open_link of slaves.
207  *
208  * call this with register_mutex down.
209  */
210 static void snd_timer_check_master(snd_timer_instance_t *master)
211 {
212 	snd_timer_instance_t *slave;
213 	struct list_head *p, *n;
214 
215 	/* check all pending slaves */
216 	list_for_each_safe(p, n, &snd_timer_slave_list) {
217 		slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
218 		if (slave->slave_class == master->slave_class &&
219 		    slave->slave_id == master->slave_id) {
220 			list_del(p);
221 			list_add_tail(p, &master->slave_list_head);
222 			spin_lock_irq(&slave_active_lock);
223 			slave->master = master;
224 			slave->timer = master->timer;
225 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
226 				list_add_tail(&slave->active_list, &master->slave_active_head);
227 			spin_unlock_irq(&slave_active_lock);
228 		}
229 	}
230 }
231 
232 /*
233  * open a timer instance
234  * when opening a master, the slave id must be here given.
235  */
236 int snd_timer_open(snd_timer_instance_t **ti,
237 		   char *owner, snd_timer_id_t *tid,
238 		   unsigned int slave_id)
239 {
240 	snd_timer_t *timer;
241 	snd_timer_instance_t *timeri = NULL;
242 
243 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
244 		/* open a slave instance */
245 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
246 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
247 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
248 			return -EINVAL;
249 		}
250 		down(&register_mutex);
251 		timeri = snd_timer_instance_new(owner, NULL);
252 		timeri->slave_class = tid->dev_sclass;
253 		timeri->slave_id = tid->device;
254 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
255 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
256 		snd_timer_check_slave(timeri);
257 		up(&register_mutex);
258 		*ti = timeri;
259 		return 0;
260 	}
261 
262 	/* open a master instance */
263 	down(&register_mutex);
264 	timer = snd_timer_find(tid);
265 #ifdef CONFIG_KMOD
266 	if (timer == NULL) {
267 		up(&register_mutex);
268 		snd_timer_request(tid);
269 		down(&register_mutex);
270 		timer = snd_timer_find(tid);
271 	}
272 #endif
273 	if (timer) {
274 		if (!list_empty(&timer->open_list_head)) {
275 			timeri = (snd_timer_instance_t *)list_entry(timer->open_list_head.next, snd_timer_instance_t, open_list);
276 			if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
277 				up(&register_mutex);
278 				return -EBUSY;
279 			}
280 		}
281 		timeri = snd_timer_instance_new(owner, timer);
282 		if (timeri) {
283 			timeri->slave_class = tid->dev_sclass;
284 			timeri->slave_id = slave_id;
285 			if (list_empty(&timer->open_list_head) && timer->hw.open)
286 				timer->hw.open(timer);
287 			list_add_tail(&timeri->open_list, &timer->open_list_head);
288 			snd_timer_check_master(timeri);
289 		}
290 	} else {
291 		up(&register_mutex);
292 		return -ENODEV;
293 	}
294 	up(&register_mutex);
295 	*ti = timeri;
296 	return 0;
297 }
298 
299 static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event);
300 
301 /*
302  * close a timer instance
303  */
304 int snd_timer_close(snd_timer_instance_t * timeri)
305 {
306 	snd_timer_t *timer = NULL;
307 	struct list_head *p, *n;
308 	snd_timer_instance_t *slave;
309 
310 	snd_assert(timeri != NULL, return -ENXIO);
311 
312 	/* force to stop the timer */
313 	snd_timer_stop(timeri);
314 
315 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
316 		/* wait, until the active callback is finished */
317 		spin_lock_irq(&slave_active_lock);
318 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
319 			spin_unlock_irq(&slave_active_lock);
320 			udelay(10);
321 			spin_lock_irq(&slave_active_lock);
322 		}
323 		spin_unlock_irq(&slave_active_lock);
324 		down(&register_mutex);
325 		list_del(&timeri->open_list);
326 		up(&register_mutex);
327 	} else {
328 		timer = timeri->timer;
329 		/* wait, until the active callback is finished */
330 		spin_lock_irq(&timer->lock);
331 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
332 			spin_unlock_irq(&timer->lock);
333 			udelay(10);
334 			spin_lock_irq(&timer->lock);
335 		}
336 		spin_unlock_irq(&timer->lock);
337 		down(&register_mutex);
338 		list_del(&timeri->open_list);
339 		if (timer && list_empty(&timer->open_list_head) && timer->hw.close)
340 			timer->hw.close(timer);
341 		/* remove slave links */
342 		list_for_each_safe(p, n, &timeri->slave_list_head) {
343 			slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
344 			spin_lock_irq(&slave_active_lock);
345 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
346 			list_del(p);
347 			list_add_tail(p, &snd_timer_slave_list);
348 			slave->master = NULL;
349 			slave->timer = NULL;
350 			spin_unlock_irq(&slave_active_lock);
351 		}
352 		up(&register_mutex);
353 	}
354 	if (timeri->private_free)
355 		timeri->private_free(timeri);
356 	kfree(timeri->owner);
357 	kfree(timeri);
358 	if (timer && timer->card)
359 		module_put(timer->card->module);
360 	return 0;
361 }
362 
363 unsigned long snd_timer_resolution(snd_timer_instance_t * timeri)
364 {
365 	snd_timer_t * timer;
366 
367 	if (timeri == NULL)
368 		return 0;
369 	if ((timer = timeri->timer) != NULL) {
370 		if (timer->hw.c_resolution)
371 			return timer->hw.c_resolution(timer);
372 		return timer->hw.resolution;
373 	}
374 	return 0;
375 }
376 
377 static void snd_timer_notify1(snd_timer_instance_t *ti, enum sndrv_timer_event event)
378 {
379 	snd_timer_t *timer;
380 	unsigned long flags;
381 	unsigned long resolution = 0;
382 	snd_timer_instance_t *ts;
383 	struct list_head *n;
384 	struct timespec tstamp;
385 
386 	snd_timestamp_now(&tstamp, 1);
387 	snd_assert(event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE, return);
388 	if (event == SNDRV_TIMER_EVENT_START || event == SNDRV_TIMER_EVENT_CONTINUE)
389 		resolution = snd_timer_resolution(ti);
390 	if (ti->ccallback)
391 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
392 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
393 		return;
394 	timer = ti->timer;
395 	if (timer == NULL)
396 		return;
397 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
398 		return;
399 	spin_lock_irqsave(&timer->lock, flags);
400 	list_for_each(n, &ti->slave_active_head) {
401 		ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
402 		if (ts->ccallback)
403 			ts->ccallback(ti, event + 100, &tstamp, resolution);
404 	}
405 	spin_unlock_irqrestore(&timer->lock, flags);
406 }
407 
408 static int snd_timer_start1(snd_timer_t *timer, snd_timer_instance_t *timeri, unsigned long sticks)
409 {
410 	list_del(&timeri->active_list);
411 	list_add_tail(&timeri->active_list, &timer->active_list_head);
412 	if (timer->running) {
413 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
414 			goto __start_now;
415 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
416 		timeri->flags |= SNDRV_TIMER_IFLG_START;
417 		return 1;	/* delayed start */
418 	} else {
419 		timer->sticks = sticks;
420 		timer->hw.start(timer);
421 	      __start_now:
422 		timer->running++;
423 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
424 		return 0;
425 	}
426 }
427 
428 static int snd_timer_start_slave(snd_timer_instance_t *timeri)
429 {
430 	unsigned long flags;
431 
432 	spin_lock_irqsave(&slave_active_lock, flags);
433 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
434 	if (timeri->master)
435 		list_add_tail(&timeri->active_list, &timeri->master->slave_active_head);
436 	spin_unlock_irqrestore(&slave_active_lock, flags);
437 	return 1; /* delayed start */
438 }
439 
440 /*
441  *  start the timer instance
442  */
443 int snd_timer_start(snd_timer_instance_t * timeri, unsigned int ticks)
444 {
445 	snd_timer_t *timer;
446 	int result = -EINVAL;
447 	unsigned long flags;
448 
449 	if (timeri == NULL || ticks < 1)
450 		return -EINVAL;
451 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
452 		result = snd_timer_start_slave(timeri);
453 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
454 		return result;
455 	}
456 	timer = timeri->timer;
457 	if (timer == NULL)
458 		return -EINVAL;
459 	spin_lock_irqsave(&timer->lock, flags);
460 	timeri->ticks = timeri->cticks = ticks;
461 	timeri->pticks = 0;
462 	result = snd_timer_start1(timer, timeri, ticks);
463 	spin_unlock_irqrestore(&timer->lock, flags);
464 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
465 	return result;
466 }
467 
468 static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event)
469 {
470 	snd_timer_t *timer;
471 	unsigned long flags;
472 
473 	snd_assert(timeri != NULL, return -ENXIO);
474 
475 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
476 		if (!keep_flag) {
477 			spin_lock_irqsave(&slave_active_lock, flags);
478 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
479 			spin_unlock_irqrestore(&slave_active_lock, flags);
480 		}
481 		goto __end;
482 	}
483 	timer = timeri->timer;
484 	if (!timer)
485 		return -EINVAL;
486 	spin_lock_irqsave(&timer->lock, flags);
487 	list_del_init(&timeri->ack_list);
488 	list_del_init(&timeri->active_list);
489 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
490 	    !(--timer->running)) {
491 		timer->hw.stop(timer);
492 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
493 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
494 			snd_timer_reschedule(timer, 0);
495 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
496 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
497 				timer->hw.start(timer);
498 			}
499 		}
500 	}
501 	if (!keep_flag)
502 		timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING|SNDRV_TIMER_IFLG_START);
503 	spin_unlock_irqrestore(&timer->lock, flags);
504       __end:
505 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
506 		snd_timer_notify1(timeri, event);
507 	return 0;
508 }
509 
510 /*
511  * stop the timer instance.
512  *
513  * do not call this from the timer callback!
514  */
515 int snd_timer_stop(snd_timer_instance_t * timeri)
516 {
517 	snd_timer_t *timer;
518 	unsigned long flags;
519 	int err;
520 
521 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
522 	if (err < 0)
523 		return err;
524 	timer = timeri->timer;
525 	spin_lock_irqsave(&timer->lock, flags);
526 	timeri->cticks = timeri->ticks;
527 	timeri->pticks = 0;
528 	spin_unlock_irqrestore(&timer->lock, flags);
529 	return 0;
530 }
531 
532 /*
533  * start again..  the tick is kept.
534  */
535 int snd_timer_continue(snd_timer_instance_t * timeri)
536 {
537 	snd_timer_t *timer;
538 	int result = -EINVAL;
539 	unsigned long flags;
540 
541 	if (timeri == NULL)
542 		return result;
543 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
544 		return snd_timer_start_slave(timeri);
545 	timer = timeri->timer;
546 	if (! timer)
547 		return -EINVAL;
548 	spin_lock_irqsave(&timer->lock, flags);
549 	if (!timeri->cticks)
550 		timeri->cticks = 1;
551 	timeri->pticks = 0;
552 	result = snd_timer_start1(timer, timeri, timer->sticks);
553 	spin_unlock_irqrestore(&timer->lock, flags);
554 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
555 	return result;
556 }
557 
558 /*
559  * pause.. remember the ticks left
560  */
561 int snd_timer_pause(snd_timer_instance_t * timeri)
562 {
563 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
564 }
565 
566 /*
567  * reschedule the timer
568  *
569  * start pending instances and check the scheduling ticks.
570  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
571  */
572 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left)
573 {
574 	snd_timer_instance_t *ti;
575 	unsigned long ticks = ~0UL;
576 	struct list_head *p;
577 
578 	list_for_each(p, &timer->active_list_head) {
579 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
580 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
581 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
582 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
583 			timer->running++;
584 		}
585 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
586 			if (ticks > ti->cticks)
587 				ticks = ti->cticks;
588 		}
589 	}
590 	if (ticks == ~0UL) {
591 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
592 		return;
593 	}
594 	if (ticks > timer->hw.ticks)
595 		ticks = timer->hw.ticks;
596 	if (ticks_left != ticks)
597 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
598 	timer->sticks = ticks;
599 }
600 
601 /*
602  * timer tasklet
603  *
604  */
605 static void snd_timer_tasklet(unsigned long arg)
606 {
607 	snd_timer_t *timer = (snd_timer_t *) arg;
608 	snd_timer_instance_t *ti;
609 	struct list_head *p;
610 	unsigned long resolution, ticks;
611 
612 	spin_lock(&timer->lock);
613 	/* now process all callbacks */
614 	while (!list_empty(&timer->sack_list_head)) {
615 		p = timer->sack_list_head.next;		/* get first item */
616 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
617 
618 		/* remove from ack_list and make empty */
619 		list_del_init(p);
620 
621 		ticks = ti->pticks;
622 		ti->pticks = 0;
623 		resolution = ti->resolution;
624 
625 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
626 		spin_unlock(&timer->lock);
627 		if (ti->callback)
628 			ti->callback(ti, resolution, ticks);
629 		spin_lock(&timer->lock);
630 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
631 	}
632 	spin_unlock(&timer->lock);
633 }
634 
635 /*
636  * timer interrupt
637  *
638  * ticks_left is usually equal to timer->sticks.
639  *
640  */
641 void snd_timer_interrupt(snd_timer_t * timer, unsigned long ticks_left)
642 {
643 	snd_timer_instance_t *ti, *ts;
644 	unsigned long resolution, ticks;
645 	struct list_head *p, *q, *n;
646 	int use_tasklet = 0;
647 
648 	if (timer == NULL)
649 		return;
650 
651 	spin_lock(&timer->lock);
652 
653 	/* remember the current resolution */
654 	if (timer->hw.c_resolution)
655 		resolution = timer->hw.c_resolution(timer);
656 	else
657 		resolution = timer->hw.resolution;
658 
659 	/* loop for all active instances
660 	 * here we cannot use list_for_each because the active_list of a processed
661 	 * instance is relinked to done_list_head before callback is called.
662 	 */
663 	list_for_each_safe(p, n, &timer->active_list_head) {
664 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
665 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
666 			continue;
667 		ti->pticks += ticks_left;
668 		ti->resolution = resolution;
669 		if (ti->cticks < ticks_left)
670 			ti->cticks = 0;
671 		else
672 			ti->cticks -= ticks_left;
673 		if (ti->cticks) /* not expired */
674 			continue;
675 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
676 			ti->cticks = ti->ticks;
677 		} else {
678 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
679 			if (--timer->running)
680 				list_del(p);
681 		}
682 		if (list_empty(&ti->ack_list)) {
683 			if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
684 			    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
685 				list_add_tail(&ti->ack_list, &timer->ack_list_head);
686 			} else {
687 				list_add_tail(&ti->ack_list, &timer->sack_list_head);
688 			}
689 		}
690 		list_for_each(q, &ti->slave_active_head) {
691 			ts = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, active_list);
692 			ts->pticks = ti->pticks;
693 			ts->resolution = resolution;
694 			if (list_empty(&ts->ack_list)) {
695 				if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
696 				    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
697 					list_add_tail(&ts->ack_list, &timer->ack_list_head);
698 				} else {
699 					list_add_tail(&ts->ack_list, &timer->sack_list_head);
700 				}
701 			}
702 		}
703 	}
704 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
705 		snd_timer_reschedule(timer, ticks_left);
706 	if (timer->running) {
707 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
708 			timer->hw.stop(timer);
709 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
710 		}
711 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
712 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
713 			/* restart timer */
714 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
715 			timer->hw.start(timer);
716 		}
717 	} else {
718 		timer->hw.stop(timer);
719 	}
720 
721 	/* now process all fast callbacks */
722 	while (!list_empty(&timer->ack_list_head)) {
723 		p = timer->ack_list_head.next;		/* get first item */
724 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
725 
726 		/* remove from ack_list and make empty */
727 		list_del_init(p);
728 
729 		ticks = ti->pticks;
730 		ti->pticks = 0;
731 
732 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
733 		spin_unlock(&timer->lock);
734 		if (ti->callback)
735 			ti->callback(ti, resolution, ticks);
736 		spin_lock(&timer->lock);
737 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
738 	}
739 
740 	/* do we have any slow callbacks? */
741 	use_tasklet = !list_empty(&timer->sack_list_head);
742 	spin_unlock(&timer->lock);
743 
744 	if (use_tasklet)
745 		tasklet_hi_schedule(&timer->task_queue);
746 }
747 
748 /*
749 
750  */
751 
752 int snd_timer_new(snd_card_t *card, char *id, snd_timer_id_t *tid, snd_timer_t ** rtimer)
753 {
754 	snd_timer_t *timer;
755 	int err;
756 	static snd_device_ops_t ops = {
757 		.dev_free = snd_timer_dev_free,
758 		.dev_register = snd_timer_dev_register,
759 		.dev_unregister = snd_timer_dev_unregister
760 	};
761 
762 	snd_assert(tid != NULL, return -EINVAL);
763 	snd_assert(rtimer != NULL, return -EINVAL);
764 	*rtimer = NULL;
765 	timer = kcalloc(1, sizeof(*timer), GFP_KERNEL);
766 	if (timer == NULL)
767 		return -ENOMEM;
768 	timer->tmr_class = tid->dev_class;
769 	timer->card = card;
770 	timer->tmr_device = tid->device;
771 	timer->tmr_subdevice = tid->subdevice;
772 	if (id)
773 		strlcpy(timer->id, id, sizeof(timer->id));
774 	INIT_LIST_HEAD(&timer->device_list);
775 	INIT_LIST_HEAD(&timer->open_list_head);
776 	INIT_LIST_HEAD(&timer->active_list_head);
777 	INIT_LIST_HEAD(&timer->ack_list_head);
778 	INIT_LIST_HEAD(&timer->sack_list_head);
779 	spin_lock_init(&timer->lock);
780 	tasklet_init(&timer->task_queue, snd_timer_tasklet, (unsigned long)timer);
781 	if (card != NULL) {
782 		if ((err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops)) < 0) {
783 			snd_timer_free(timer);
784 			return err;
785 		}
786 	}
787 	*rtimer = timer;
788 	return 0;
789 }
790 
791 static int snd_timer_free(snd_timer_t *timer)
792 {
793 	snd_assert(timer != NULL, return -ENXIO);
794 	if (timer->private_free)
795 		timer->private_free(timer);
796 	kfree(timer);
797 	return 0;
798 }
799 
800 int snd_timer_dev_free(snd_device_t *device)
801 {
802 	snd_timer_t *timer = device->device_data;
803 	return snd_timer_free(timer);
804 }
805 
806 int snd_timer_dev_register(snd_device_t *dev)
807 {
808 	snd_timer_t *timer = dev->device_data;
809 	snd_timer_t *timer1;
810 	struct list_head *p;
811 
812 	snd_assert(timer != NULL && timer->hw.start != NULL && timer->hw.stop != NULL, return -ENXIO);
813 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
814 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
815 	    	return -EINVAL;
816 
817 	down(&register_mutex);
818 	list_for_each(p, &snd_timer_list) {
819 		timer1 = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
820 		if (timer1->tmr_class > timer->tmr_class)
821 			break;
822 		if (timer1->tmr_class < timer->tmr_class)
823 			continue;
824 		if (timer1->card && timer->card) {
825 			if (timer1->card->number > timer->card->number)
826 				break;
827 			if (timer1->card->number < timer->card->number)
828 				continue;
829 		}
830 		if (timer1->tmr_device > timer->tmr_device)
831 			break;
832 		if (timer1->tmr_device < timer->tmr_device)
833 			continue;
834 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
835 			break;
836 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
837 			continue;
838 		/* conflicts.. */
839 		up(&register_mutex);
840 		return -EBUSY;
841 	}
842 	list_add_tail(&timer->device_list, p);
843 	up(&register_mutex);
844 	return 0;
845 }
846 
847 int snd_timer_unregister(snd_timer_t *timer)
848 {
849 	struct list_head *p, *n;
850 	snd_timer_instance_t *ti;
851 
852 	snd_assert(timer != NULL, return -ENXIO);
853 	down(&register_mutex);
854 	if (! list_empty(&timer->open_list_head)) {
855 		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
856 		list_for_each_safe(p, n, &timer->open_list_head) {
857 			list_del_init(p);
858 			ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
859 			ti->timer = NULL;
860 		}
861 	}
862 	list_del(&timer->device_list);
863 	up(&register_mutex);
864 	return snd_timer_free(timer);
865 }
866 
867 static int snd_timer_dev_unregister(snd_device_t *device)
868 {
869 	snd_timer_t *timer = device->device_data;
870 	return snd_timer_unregister(timer);
871 }
872 
873 void snd_timer_notify(snd_timer_t *timer, enum sndrv_timer_event event, struct timespec *tstamp)
874 {
875 	unsigned long flags;
876 	unsigned long resolution = 0;
877 	snd_timer_instance_t *ti, *ts;
878 	struct list_head *p, *n;
879 
880 	snd_runtime_check(timer->hw.flags & SNDRV_TIMER_HW_SLAVE, return);
881 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART && event <= SNDRV_TIMER_EVENT_MPAUSE, return);
882 	spin_lock_irqsave(&timer->lock, flags);
883 	if (event == SNDRV_TIMER_EVENT_MSTART || event == SNDRV_TIMER_EVENT_MCONTINUE) {
884 		if (timer->hw.c_resolution)
885 			resolution = timer->hw.c_resolution(timer);
886 		else
887 			resolution = timer->hw.resolution;
888 	}
889 	list_for_each(p, &timer->active_list_head) {
890 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
891 		if (ti->ccallback)
892 			ti->ccallback(ti, event, tstamp, resolution);
893 		list_for_each(n, &ti->slave_active_head) {
894 			ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
895 			if (ts->ccallback)
896 				ts->ccallback(ts, event, tstamp, resolution);
897 		}
898 	}
899 	spin_unlock_irqrestore(&timer->lock, flags);
900 }
901 
902 /*
903  * exported functions for global timers
904  */
905 int snd_timer_global_new(char *id, int device, snd_timer_t **rtimer)
906 {
907 	snd_timer_id_t tid;
908 
909 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
910 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
911 	tid.card = -1;
912 	tid.device = device;
913 	tid.subdevice = 0;
914 	return snd_timer_new(NULL, id, &tid, rtimer);
915 }
916 
917 int snd_timer_global_free(snd_timer_t *timer)
918 {
919 	return snd_timer_free(timer);
920 }
921 
922 int snd_timer_global_register(snd_timer_t *timer)
923 {
924 	snd_device_t dev;
925 
926 	memset(&dev, 0, sizeof(dev));
927 	dev.device_data = timer;
928 	return snd_timer_dev_register(&dev);
929 }
930 
931 int snd_timer_global_unregister(snd_timer_t *timer)
932 {
933 	return snd_timer_unregister(timer);
934 }
935 
936 /*
937  *  System timer
938  */
939 
940 struct snd_timer_system_private {
941 	struct timer_list tlist;
942 	struct timer * timer;
943 	unsigned long last_expires;
944 	unsigned long last_jiffies;
945 	unsigned long correction;
946 };
947 
948 unsigned int snd_timer_system_resolution(void)
949 {
950 	return 1000000000L / HZ;
951 }
952 
953 static void snd_timer_s_function(unsigned long data)
954 {
955 	snd_timer_t *timer = (snd_timer_t *)data;
956 	struct snd_timer_system_private *priv = timer->private_data;
957 	unsigned long jiff = jiffies;
958 	if (time_after(jiff, priv->last_expires))
959 		priv->correction = (long)jiff - (long)priv->last_expires;
960 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
961 }
962 
963 static int snd_timer_s_start(snd_timer_t * timer)
964 {
965 	struct snd_timer_system_private *priv;
966 	unsigned long njiff;
967 
968 	priv = (struct snd_timer_system_private *) timer->private_data;
969 	njiff = (priv->last_jiffies = jiffies);
970 	if (priv->correction > timer->sticks - 1) {
971 		priv->correction -= timer->sticks - 1;
972 		njiff++;
973 	} else {
974 		njiff += timer->sticks - priv->correction;
975 		priv->correction -= timer->sticks;
976 	}
977 	priv->last_expires = priv->tlist.expires = njiff;
978 	add_timer(&priv->tlist);
979 	return 0;
980 }
981 
982 static int snd_timer_s_stop(snd_timer_t * timer)
983 {
984 	struct snd_timer_system_private *priv;
985 	unsigned long jiff;
986 
987 	priv = (struct snd_timer_system_private *) timer->private_data;
988 	del_timer(&priv->tlist);
989 	jiff = jiffies;
990 	if (time_before(jiff, priv->last_expires))
991 		timer->sticks = priv->last_expires - jiff;
992 	else
993 		timer->sticks = 1;
994 	return 0;
995 }
996 
997 static struct _snd_timer_hardware snd_timer_system =
998 {
999 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1000 	.resolution =	1000000000L / HZ,
1001 	.ticks =	10000000L,
1002 	.start =	snd_timer_s_start,
1003 	.stop =		snd_timer_s_stop
1004 };
1005 
1006 static void snd_timer_free_system(snd_timer_t *timer)
1007 {
1008 	kfree(timer->private_data);
1009 }
1010 
1011 static int snd_timer_register_system(void)
1012 {
1013 	snd_timer_t *timer;
1014 	struct snd_timer_system_private *priv;
1015 	int err;
1016 
1017 	if ((err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer)) < 0)
1018 		return err;
1019 	strcpy(timer->name, "system timer");
1020 	timer->hw = snd_timer_system;
1021 	priv = kcalloc(1, sizeof(*priv), GFP_KERNEL);
1022 	if (priv == NULL) {
1023 		snd_timer_free(timer);
1024 		return -ENOMEM;
1025 	}
1026 	init_timer(&priv->tlist);
1027 	priv->tlist.function = snd_timer_s_function;
1028 	priv->tlist.data = (unsigned long) timer;
1029 	timer->private_data = priv;
1030 	timer->private_free = snd_timer_free_system;
1031 	return snd_timer_global_register(timer);
1032 }
1033 
1034 /*
1035  *  Info interface
1036  */
1037 
1038 static void snd_timer_proc_read(snd_info_entry_t *entry,
1039 				snd_info_buffer_t * buffer)
1040 {
1041 	unsigned long flags;
1042 	snd_timer_t *timer;
1043 	snd_timer_instance_t *ti;
1044 	struct list_head *p, *q;
1045 
1046 	down(&register_mutex);
1047 	list_for_each(p, &snd_timer_list) {
1048 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1049 		switch (timer->tmr_class) {
1050 		case SNDRV_TIMER_CLASS_GLOBAL:
1051 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1052 			break;
1053 		case SNDRV_TIMER_CLASS_CARD:
1054 			snd_iprintf(buffer, "C%i-%i: ", timer->card->number, timer->tmr_device);
1055 			break;
1056 		case SNDRV_TIMER_CLASS_PCM:
1057 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number, timer->tmr_device, timer->tmr_subdevice);
1058 			break;
1059 		default:
1060 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class, timer->card ? timer->card->number : -1, timer->tmr_device, timer->tmr_subdevice);
1061 		}
1062 		snd_iprintf(buffer, "%s :", timer->name);
1063 		if (timer->hw.resolution)
1064 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)", timer->hw.resolution / 1000, timer->hw.resolution % 1000, timer->hw.ticks);
1065 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1066 			snd_iprintf(buffer, " SLAVE");
1067 		snd_iprintf(buffer, "\n");
1068 		spin_lock_irqsave(&timer->lock, flags);
1069 		list_for_each(q, &timer->open_list_head) {
1070 			ti = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
1071 			snd_iprintf(buffer, "  Client %s : %s : lost interrupts %li\n",
1072 					ti->owner ? ti->owner : "unknown",
1073 					ti->flags & (SNDRV_TIMER_IFLG_START|SNDRV_TIMER_IFLG_RUNNING) ? "running" : "stopped",
1074 					ti->lost);
1075 		}
1076 		spin_unlock_irqrestore(&timer->lock, flags);
1077 	}
1078 	up(&register_mutex);
1079 }
1080 
1081 /*
1082  *  USER SPACE interface
1083  */
1084 
1085 static void snd_timer_user_interrupt(snd_timer_instance_t *timeri,
1086 				     unsigned long resolution,
1087 				     unsigned long ticks)
1088 {
1089 	snd_timer_user_t *tu = timeri->callback_data;
1090 	snd_timer_read_t *r;
1091 	int prev;
1092 
1093 	spin_lock(&tu->qlock);
1094 	if (tu->qused > 0) {
1095 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1096 		r = &tu->queue[prev];
1097 		if (r->resolution == resolution) {
1098 			r->ticks += ticks;
1099 			goto __wake;
1100 		}
1101 	}
1102 	if (tu->qused >= tu->queue_size) {
1103 		tu->overrun++;
1104 	} else {
1105 		r = &tu->queue[tu->qtail++];
1106 		tu->qtail %= tu->queue_size;
1107 		r->resolution = resolution;
1108 		r->ticks = ticks;
1109 		tu->qused++;
1110 	}
1111       __wake:
1112 	spin_unlock(&tu->qlock);
1113 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1114 	wake_up(&tu->qchange_sleep);
1115 }
1116 
1117 static void snd_timer_user_append_to_tqueue(snd_timer_user_t *tu, snd_timer_tread_t *tread)
1118 {
1119 	if (tu->qused >= tu->queue_size) {
1120 		tu->overrun++;
1121 	} else {
1122 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1123 		tu->qtail %= tu->queue_size;
1124 		tu->qused++;
1125 	}
1126 }
1127 
1128 static void snd_timer_user_ccallback(snd_timer_instance_t *timeri,
1129 				     enum sndrv_timer_event event,
1130 				     struct timespec *tstamp,
1131 				     unsigned long resolution)
1132 {
1133 	snd_timer_user_t *tu = timeri->callback_data;
1134 	snd_timer_tread_t r1;
1135 
1136 	if (event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE)
1137 		tu->tstamp = *tstamp;
1138 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1139 		return;
1140 	r1.event = event;
1141 	r1.tstamp = *tstamp;
1142 	r1.val = resolution;
1143 	spin_lock(&tu->qlock);
1144 	snd_timer_user_append_to_tqueue(tu, &r1);
1145 	spin_unlock(&tu->qlock);
1146 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1147 	wake_up(&tu->qchange_sleep);
1148 }
1149 
1150 static void snd_timer_user_tinterrupt(snd_timer_instance_t *timeri,
1151 				      unsigned long resolution,
1152 				      unsigned long ticks)
1153 {
1154 	snd_timer_user_t *tu = timeri->callback_data;
1155 	snd_timer_tread_t *r, r1;
1156 	struct timespec tstamp;
1157 	int prev, append = 0;
1158 
1159 	snd_timestamp_zero(&tstamp);
1160 	spin_lock(&tu->qlock);
1161 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION)|(1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1162 		spin_unlock(&tu->qlock);
1163 		return;
1164 	}
1165 	if (tu->last_resolution != resolution || ticks > 0)
1166 		snd_timestamp_now(&tstamp, 1);
1167 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) && tu->last_resolution != resolution) {
1168 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1169 		r1.tstamp = tstamp;
1170 		r1.val = resolution;
1171 		snd_timer_user_append_to_tqueue(tu, &r1);
1172 		tu->last_resolution = resolution;
1173 		append++;
1174 	}
1175 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1176 		goto __wake;
1177 	if (ticks == 0)
1178 		goto __wake;
1179 	if (tu->qused > 0) {
1180 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1181 		r = &tu->tqueue[prev];
1182 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1183 			r->tstamp = tstamp;
1184 			r->val += ticks;
1185 			append++;
1186 			goto __wake;
1187 		}
1188 	}
1189 	r1.event = SNDRV_TIMER_EVENT_TICK;
1190 	r1.tstamp = tstamp;
1191 	r1.val = ticks;
1192 	snd_timer_user_append_to_tqueue(tu, &r1);
1193 	append++;
1194       __wake:
1195 	spin_unlock(&tu->qlock);
1196 	if (append == 0)
1197 		return;
1198 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1199 	wake_up(&tu->qchange_sleep);
1200 }
1201 
1202 static int snd_timer_user_open(struct inode *inode, struct file *file)
1203 {
1204 	snd_timer_user_t *tu;
1205 
1206 	tu = kcalloc(1, sizeof(*tu), GFP_KERNEL);
1207 	if (tu == NULL)
1208 		return -ENOMEM;
1209 	spin_lock_init(&tu->qlock);
1210 	init_waitqueue_head(&tu->qchange_sleep);
1211 	tu->ticks = 1;
1212 	tu->queue_size = 128;
1213 	tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1214 	if (tu->queue == NULL) {
1215 		kfree(tu);
1216 		return -ENOMEM;
1217 	}
1218 	file->private_data = tu;
1219 	return 0;
1220 }
1221 
1222 static int snd_timer_user_release(struct inode *inode, struct file *file)
1223 {
1224 	snd_timer_user_t *tu;
1225 
1226 	if (file->private_data) {
1227 		tu = file->private_data;
1228 		file->private_data = NULL;
1229 		fasync_helper(-1, file, 0, &tu->fasync);
1230 		if (tu->timeri)
1231 			snd_timer_close(tu->timeri);
1232 		kfree(tu->queue);
1233 		kfree(tu->tqueue);
1234 		kfree(tu);
1235 	}
1236 	return 0;
1237 }
1238 
1239 static void snd_timer_user_zero_id(snd_timer_id_t *id)
1240 {
1241 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1242 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1243 	id->card = -1;
1244 	id->device = -1;
1245 	id->subdevice = -1;
1246 }
1247 
1248 static void snd_timer_user_copy_id(snd_timer_id_t *id, snd_timer_t *timer)
1249 {
1250 	id->dev_class = timer->tmr_class;
1251 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1252 	id->card = timer->card ? timer->card->number : -1;
1253 	id->device = timer->tmr_device;
1254 	id->subdevice = timer->tmr_subdevice;
1255 }
1256 
1257 static int snd_timer_user_next_device(snd_timer_id_t __user *_tid)
1258 {
1259 	snd_timer_id_t id;
1260 	snd_timer_t *timer;
1261 	struct list_head *p;
1262 
1263 	if (copy_from_user(&id, _tid, sizeof(id)))
1264 		return -EFAULT;
1265 	down(&register_mutex);
1266 	if (id.dev_class < 0) {		/* first item */
1267 		if (list_empty(&snd_timer_list))
1268 			snd_timer_user_zero_id(&id);
1269 		else {
1270 			timer = (snd_timer_t *)list_entry(snd_timer_list.next, snd_timer_t, device_list);
1271 			snd_timer_user_copy_id(&id, timer);
1272 		}
1273 	} else {
1274 		switch (id.dev_class) {
1275 		case SNDRV_TIMER_CLASS_GLOBAL:
1276 			id.device = id.device < 0 ? 0 : id.device + 1;
1277 			list_for_each(p, &snd_timer_list) {
1278 				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1279 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1280 					snd_timer_user_copy_id(&id, timer);
1281 					break;
1282 				}
1283 				if (timer->tmr_device >= id.device) {
1284 					snd_timer_user_copy_id(&id, timer);
1285 					break;
1286 				}
1287 			}
1288 			if (p == &snd_timer_list)
1289 				snd_timer_user_zero_id(&id);
1290 			break;
1291 		case SNDRV_TIMER_CLASS_CARD:
1292 		case SNDRV_TIMER_CLASS_PCM:
1293 			if (id.card < 0) {
1294 				id.card = 0;
1295 			} else {
1296 				if (id.card < 0) {
1297 					id.card = 0;
1298 				} else {
1299 					if (id.device < 0) {
1300 						id.device = 0;
1301 					} else {
1302 						id.subdevice = id.subdevice < 0 ? 0 : id.subdevice + 1;
1303 					}
1304 				}
1305 			}
1306 			list_for_each(p, &snd_timer_list) {
1307 				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1308 				if (timer->tmr_class > id.dev_class) {
1309 					snd_timer_user_copy_id(&id, timer);
1310 					break;
1311 				}
1312 				if (timer->tmr_class < id.dev_class)
1313 					continue;
1314 				if (timer->card->number > id.card) {
1315 					snd_timer_user_copy_id(&id, timer);
1316 					break;
1317 				}
1318 				if (timer->card->number < id.card)
1319 					continue;
1320 				if (timer->tmr_device > id.device) {
1321 					snd_timer_user_copy_id(&id, timer);
1322 					break;
1323 				}
1324 				if (timer->tmr_device < id.device)
1325 					continue;
1326 				if (timer->tmr_subdevice > id.subdevice) {
1327 					snd_timer_user_copy_id(&id, timer);
1328 					break;
1329 				}
1330 				if (timer->tmr_subdevice < id.subdevice)
1331 					continue;
1332 				snd_timer_user_copy_id(&id, timer);
1333 				break;
1334 			}
1335 			if (p == &snd_timer_list)
1336 				snd_timer_user_zero_id(&id);
1337 			break;
1338 		default:
1339 			snd_timer_user_zero_id(&id);
1340 		}
1341 	}
1342 	up(&register_mutex);
1343 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1344 		return -EFAULT;
1345 	return 0;
1346 }
1347 
1348 static int snd_timer_user_ginfo(struct file *file, snd_timer_ginfo_t __user *_ginfo)
1349 {
1350 	snd_timer_ginfo_t *ginfo;
1351 	snd_timer_id_t tid;
1352 	snd_timer_t *t;
1353 	struct list_head *p;
1354 	int err = 0;
1355 
1356 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1357 	if (! ginfo)
1358 		return -ENOMEM;
1359 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1360 		kfree(ginfo);
1361 		return -EFAULT;
1362 	}
1363 	tid = ginfo->tid;
1364 	memset(ginfo, 0, sizeof(*ginfo));
1365 	ginfo->tid = tid;
1366 	down(&register_mutex);
1367 	t = snd_timer_find(&tid);
1368 	if (t != NULL) {
1369 		ginfo->card = t->card ? t->card->number : -1;
1370 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1371 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1372 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1373 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1374 		ginfo->resolution = t->hw.resolution;
1375 		if (t->hw.resolution_min > 0) {
1376 			ginfo->resolution_min = t->hw.resolution_min;
1377 			ginfo->resolution_max = t->hw.resolution_max;
1378 		}
1379 		list_for_each(p, &t->open_list_head) {
1380 			ginfo->clients++;
1381 		}
1382 	} else {
1383 		err = -ENODEV;
1384 	}
1385 	up(&register_mutex);
1386 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1387 		err = -EFAULT;
1388 	kfree(ginfo);
1389 	return err;
1390 }
1391 
1392 static int snd_timer_user_gparams(struct file *file, snd_timer_gparams_t __user *_gparams)
1393 {
1394 	snd_timer_gparams_t gparams;
1395 	snd_timer_t *t;
1396 	int err;
1397 
1398 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1399 		return -EFAULT;
1400 	down(&register_mutex);
1401 	t = snd_timer_find(&gparams.tid);
1402 	if (t != NULL) {
1403 		if (list_empty(&t->open_list_head)) {
1404 			if (t->hw.set_period)
1405 				err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1406 			else
1407 				err = -ENOSYS;
1408 		} else {
1409 			err = -EBUSY;
1410 		}
1411 	} else {
1412 		err = -ENODEV;
1413 	}
1414 	up(&register_mutex);
1415 	return err;
1416 }
1417 
1418 static int snd_timer_user_gstatus(struct file *file, snd_timer_gstatus_t __user *_gstatus)
1419 {
1420 	snd_timer_gstatus_t gstatus;
1421 	snd_timer_id_t tid;
1422 	snd_timer_t *t;
1423 	int err = 0;
1424 
1425 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1426 		return -EFAULT;
1427 	tid = gstatus.tid;
1428 	memset(&gstatus, 0, sizeof(gstatus));
1429 	gstatus.tid = tid;
1430 	down(&register_mutex);
1431 	t = snd_timer_find(&tid);
1432 	if (t != NULL) {
1433 		if (t->hw.c_resolution)
1434 			gstatus.resolution = t->hw.c_resolution(t);
1435 		else
1436 			gstatus.resolution = t->hw.resolution;
1437 		if (t->hw.precise_resolution) {
1438 			t->hw.precise_resolution(t, &gstatus.resolution_num, &gstatus.resolution_den);
1439 		} else {
1440 			gstatus.resolution_num = gstatus.resolution;
1441 			gstatus.resolution_den = 1000000000uL;
1442 		}
1443 	} else {
1444 		err = -ENODEV;
1445 	}
1446 	up(&register_mutex);
1447 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1448 		err = -EFAULT;
1449 	return err;
1450 }
1451 
1452 static int snd_timer_user_tselect(struct file *file, snd_timer_select_t __user *_tselect)
1453 {
1454 	snd_timer_user_t *tu;
1455 	snd_timer_select_t tselect;
1456 	char str[32];
1457 	int err;
1458 
1459 	tu = file->private_data;
1460 	if (tu->timeri)
1461 		snd_timer_close(tu->timeri);
1462 	if (copy_from_user(&tselect, _tselect, sizeof(tselect)))
1463 		return -EFAULT;
1464 	sprintf(str, "application %i", current->pid);
1465 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1466 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1467 	if ((err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid)) < 0)
1468 		return err;
1469 
1470 	if (tu->queue) {
1471 		kfree(tu->queue);
1472 		tu->queue = NULL;
1473 	}
1474 	if (tu->tqueue) {
1475 		kfree(tu->tqueue);
1476 		tu->tqueue = NULL;
1477 	}
1478 	if (tu->tread) {
1479 		tu->tqueue = (snd_timer_tread_t *)kmalloc(tu->queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
1480 		if (tu->tqueue == NULL) {
1481 			snd_timer_close(tu->timeri);
1482 			return -ENOMEM;
1483 		}
1484 	} else {
1485 		tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1486 		if (tu->queue == NULL) {
1487 			snd_timer_close(tu->timeri);
1488 			return -ENOMEM;
1489 		}
1490 	}
1491 
1492 	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1493 	tu->timeri->callback = tu->tread ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1494 	tu->timeri->ccallback = snd_timer_user_ccallback;
1495 	tu->timeri->callback_data = (void *)tu;
1496 	return 0;
1497 }
1498 
1499 static int snd_timer_user_info(struct file *file, snd_timer_info_t __user *_info)
1500 {
1501 	snd_timer_user_t *tu;
1502 	snd_timer_info_t *info;
1503 	snd_timer_t *t;
1504 	int err = 0;
1505 
1506 	tu = file->private_data;
1507 	snd_assert(tu->timeri != NULL, return -ENXIO);
1508 	t = tu->timeri->timer;
1509 	snd_assert(t != NULL, return -ENXIO);
1510 
1511 	info = kcalloc(1, sizeof(*info), GFP_KERNEL);
1512 	if (! info)
1513 		return -ENOMEM;
1514 	info->card = t->card ? t->card->number : -1;
1515 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1516 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1517 	strlcpy(info->id, t->id, sizeof(info->id));
1518 	strlcpy(info->name, t->name, sizeof(info->name));
1519 	info->resolution = t->hw.resolution;
1520 	if (copy_to_user(_info, info, sizeof(*_info)))
1521 		err = -EFAULT;
1522 	kfree(info);
1523 	return err;
1524 }
1525 
1526 static int snd_timer_user_params(struct file *file, snd_timer_params_t __user *_params)
1527 {
1528 	snd_timer_user_t *tu;
1529 	snd_timer_params_t params;
1530 	snd_timer_t *t;
1531 	snd_timer_read_t *tr;
1532 	snd_timer_tread_t *ttr;
1533 	int err;
1534 
1535 	tu = file->private_data;
1536 	snd_assert(tu->timeri != NULL, return -ENXIO);
1537 	t = tu->timeri->timer;
1538 	snd_assert(t != NULL, return -ENXIO);
1539 	if (copy_from_user(&params, _params, sizeof(params)))
1540 		return -EFAULT;
1541 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1542 		err = -EINVAL;
1543 		goto _end;
1544 	}
1545 	if (params.queue_size > 0 && (params.queue_size < 32 || params.queue_size > 1024)) {
1546 		err = -EINVAL;
1547 		goto _end;
1548 	}
1549 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1550 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1551 			      (1<<SNDRV_TIMER_EVENT_START)|
1552 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1553 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1554 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1555 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1556 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1557 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1558 			      (1<<SNDRV_TIMER_EVENT_MPAUSE))) {
1559 		err = -EINVAL;
1560 		goto _end;
1561 	}
1562 	snd_timer_stop(tu->timeri);
1563 	spin_lock_irq(&t->lock);
1564 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1565 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1566 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1567 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1568 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1569 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1570 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1571 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1572 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1573 	spin_unlock_irq(&t->lock);
1574 	if (params.queue_size > 0 && (unsigned int)tu->queue_size != params.queue_size) {
1575 		if (tu->tread) {
1576 			ttr = (snd_timer_tread_t *)kmalloc(params.queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
1577 			if (ttr) {
1578 				kfree(tu->tqueue);
1579 				tu->queue_size = params.queue_size;
1580 				tu->tqueue = ttr;
1581 			}
1582 		} else {
1583 			tr = (snd_timer_read_t *)kmalloc(params.queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1584 			if (tr) {
1585 				kfree(tu->queue);
1586 				tu->queue_size = params.queue_size;
1587 				tu->queue = tr;
1588 			}
1589 		}
1590 	}
1591 	tu->qhead = tu->qtail = tu->qused = 0;
1592 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1593 		if (tu->tread) {
1594 			snd_timer_tread_t tread;
1595 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1596 			tread.tstamp.tv_sec = 0;
1597 			tread.tstamp.tv_nsec = 0;
1598 			tread.val = 0;
1599 			snd_timer_user_append_to_tqueue(tu, &tread);
1600 		} else {
1601 			snd_timer_read_t *r = &tu->queue[0];
1602 			r->resolution = 0;
1603 			r->ticks = 0;
1604 			tu->qused++;
1605 			tu->qtail++;
1606 		}
1607 
1608 	}
1609 	tu->filter = params.filter;
1610 	tu->ticks = params.ticks;
1611 	err = 0;
1612  _end:
1613 	if (copy_to_user(_params, &params, sizeof(params)))
1614 		return -EFAULT;
1615 	return err;
1616 }
1617 
1618 static int snd_timer_user_status(struct file *file, snd_timer_status_t __user *_status)
1619 {
1620 	snd_timer_user_t *tu;
1621 	snd_timer_status_t status;
1622 
1623 	tu = file->private_data;
1624 	snd_assert(tu->timeri != NULL, return -ENXIO);
1625 	memset(&status, 0, sizeof(status));
1626 	status.tstamp = tu->tstamp;
1627 	status.resolution = snd_timer_resolution(tu->timeri);
1628 	status.lost = tu->timeri->lost;
1629 	status.overrun = tu->overrun;
1630 	spin_lock_irq(&tu->qlock);
1631 	status.queue = tu->qused;
1632 	spin_unlock_irq(&tu->qlock);
1633 	if (copy_to_user(_status, &status, sizeof(status)))
1634 		return -EFAULT;
1635 	return 0;
1636 }
1637 
1638 static int snd_timer_user_start(struct file *file)
1639 {
1640 	int err;
1641 	snd_timer_user_t *tu;
1642 
1643 	tu = file->private_data;
1644 	snd_assert(tu->timeri != NULL, return -ENXIO);
1645 	snd_timer_stop(tu->timeri);
1646 	tu->timeri->lost = 0;
1647 	tu->last_resolution = 0;
1648 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1649 }
1650 
1651 static int snd_timer_user_stop(struct file *file)
1652 {
1653 	int err;
1654 	snd_timer_user_t *tu;
1655 
1656 	tu = file->private_data;
1657 	snd_assert(tu->timeri != NULL, return -ENXIO);
1658 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1659 }
1660 
1661 static int snd_timer_user_continue(struct file *file)
1662 {
1663 	int err;
1664 	snd_timer_user_t *tu;
1665 
1666 	tu = file->private_data;
1667 	snd_assert(tu->timeri != NULL, return -ENXIO);
1668 	tu->timeri->lost = 0;
1669 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1670 }
1671 
1672 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1673 {
1674 	snd_timer_user_t *tu;
1675 	void __user *argp = (void __user *)arg;
1676 	int __user *p = argp;
1677 
1678 	tu = file->private_data;
1679 	switch (cmd) {
1680 	case SNDRV_TIMER_IOCTL_PVERSION:
1681 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1682 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1683 		return snd_timer_user_next_device(argp);
1684 	case SNDRV_TIMER_IOCTL_TREAD:
1685 	{
1686 		int xarg;
1687 
1688 		if (tu->timeri)		/* too late */
1689 			return -EBUSY;
1690 		if (get_user(xarg, p))
1691 			return -EFAULT;
1692 		tu->tread = xarg ? 1 : 0;
1693 		return 0;
1694 	}
1695 	case SNDRV_TIMER_IOCTL_GINFO:
1696 		return snd_timer_user_ginfo(file, argp);
1697 	case SNDRV_TIMER_IOCTL_GPARAMS:
1698 		return snd_timer_user_gparams(file, argp);
1699 	case SNDRV_TIMER_IOCTL_GSTATUS:
1700 		return snd_timer_user_gstatus(file, argp);
1701 	case SNDRV_TIMER_IOCTL_SELECT:
1702 		return snd_timer_user_tselect(file, argp);
1703 	case SNDRV_TIMER_IOCTL_INFO:
1704 		return snd_timer_user_info(file, argp);
1705 	case SNDRV_TIMER_IOCTL_PARAMS:
1706 		return snd_timer_user_params(file, argp);
1707 	case SNDRV_TIMER_IOCTL_STATUS:
1708 		return snd_timer_user_status(file, argp);
1709 	case SNDRV_TIMER_IOCTL_START:
1710 		return snd_timer_user_start(file);
1711 	case SNDRV_TIMER_IOCTL_STOP:
1712 		return snd_timer_user_stop(file);
1713 	case SNDRV_TIMER_IOCTL_CONTINUE:
1714 		return snd_timer_user_continue(file);
1715 	}
1716 	return -ENOTTY;
1717 }
1718 
1719 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1720 {
1721 	snd_timer_user_t *tu;
1722 	int err;
1723 
1724 	tu = file->private_data;
1725 	err = fasync_helper(fd, file, on, &tu->fasync);
1726         if (err < 0)
1727 		return err;
1728 	return 0;
1729 }
1730 
1731 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer, size_t count, loff_t *offset)
1732 {
1733 	snd_timer_user_t *tu;
1734 	long result = 0, unit;
1735 	int err = 0;
1736 
1737 	tu = file->private_data;
1738 	unit = tu->tread ? sizeof(snd_timer_tread_t) : sizeof(snd_timer_read_t);
1739 	spin_lock_irq(&tu->qlock);
1740 	while ((long)count - result >= unit) {
1741 		while (!tu->qused) {
1742 			wait_queue_t wait;
1743 
1744 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1745 				err = -EAGAIN;
1746 				break;
1747 			}
1748 
1749 			set_current_state(TASK_INTERRUPTIBLE);
1750 			init_waitqueue_entry(&wait, current);
1751 			add_wait_queue(&tu->qchange_sleep, &wait);
1752 
1753 			spin_unlock_irq(&tu->qlock);
1754 			schedule();
1755 			spin_lock_irq(&tu->qlock);
1756 
1757 			remove_wait_queue(&tu->qchange_sleep, &wait);
1758 
1759 			if (signal_pending(current)) {
1760 				err = -ERESTARTSYS;
1761 				break;
1762 			}
1763 		}
1764 
1765 		spin_unlock_irq(&tu->qlock);
1766 		if (err < 0)
1767 			goto _error;
1768 
1769 		if (tu->tread) {
1770 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++], sizeof(snd_timer_tread_t))) {
1771 				err = -EFAULT;
1772 				goto _error;
1773 			}
1774 		} else {
1775 			if (copy_to_user(buffer, &tu->queue[tu->qhead++], sizeof(snd_timer_read_t))) {
1776 				err = -EFAULT;
1777 				goto _error;
1778 			}
1779 		}
1780 
1781 		tu->qhead %= tu->queue_size;
1782 
1783 		result += unit;
1784 		buffer += unit;
1785 
1786 		spin_lock_irq(&tu->qlock);
1787 		tu->qused--;
1788 	}
1789 	spin_unlock_irq(&tu->qlock);
1790  _error:
1791 	return result > 0 ? result : err;
1792 }
1793 
1794 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1795 {
1796         unsigned int mask;
1797         snd_timer_user_t *tu;
1798 
1799         tu = file->private_data;
1800 
1801         poll_wait(file, &tu->qchange_sleep, wait);
1802 
1803 	mask = 0;
1804 	if (tu->qused)
1805 		mask |= POLLIN | POLLRDNORM;
1806 
1807 	return mask;
1808 }
1809 
1810 #ifdef CONFIG_COMPAT
1811 #include "timer_compat.c"
1812 #else
1813 #define snd_timer_user_ioctl_compat	NULL
1814 #endif
1815 
1816 static struct file_operations snd_timer_f_ops =
1817 {
1818 	.owner =	THIS_MODULE,
1819 	.read =		snd_timer_user_read,
1820 	.open =		snd_timer_user_open,
1821 	.release =	snd_timer_user_release,
1822 	.poll =		snd_timer_user_poll,
1823 	.unlocked_ioctl =	snd_timer_user_ioctl,
1824 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1825 	.fasync = 	snd_timer_user_fasync,
1826 };
1827 
1828 static snd_minor_t snd_timer_reg =
1829 {
1830 	.comment =	"timer",
1831 	.f_ops =	&snd_timer_f_ops,
1832 };
1833 
1834 /*
1835  *  ENTRY functions
1836  */
1837 
1838 static snd_info_entry_t *snd_timer_proc_entry = NULL;
1839 
1840 static int __init alsa_timer_init(void)
1841 {
1842 	int err;
1843 	snd_info_entry_t *entry;
1844 
1845 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1846 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1, "system timer");
1847 #endif
1848 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL)) != NULL) {
1849 		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
1850 		entry->c.text.read = snd_timer_proc_read;
1851 		if (snd_info_register(entry) < 0) {
1852 			snd_info_free_entry(entry);
1853 			entry = NULL;
1854 		}
1855 	}
1856 	snd_timer_proc_entry = entry;
1857 	if ((err = snd_timer_register_system()) < 0)
1858 		snd_printk(KERN_ERR "unable to register system timer (%i)\n", err);
1859 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER,
1860 					NULL, 0, &snd_timer_reg, "timer"))<0)
1861 		snd_printk(KERN_ERR "unable to register timer device (%i)\n", err);
1862 	return 0;
1863 }
1864 
1865 static void __exit alsa_timer_exit(void)
1866 {
1867 	struct list_head *p, *n;
1868 
1869 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1870 	/* unregister the system timer */
1871 	list_for_each_safe(p, n, &snd_timer_list) {
1872 		snd_timer_t *timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1873 		snd_timer_unregister(timer);
1874 	}
1875 	if (snd_timer_proc_entry) {
1876 		snd_info_unregister(snd_timer_proc_entry);
1877 		snd_timer_proc_entry = NULL;
1878 	}
1879 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1880 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1881 #endif
1882 }
1883 
1884 module_init(alsa_timer_init)
1885 module_exit(alsa_timer_exit)
1886 
1887 EXPORT_SYMBOL(snd_timer_open);
1888 EXPORT_SYMBOL(snd_timer_close);
1889 EXPORT_SYMBOL(snd_timer_resolution);
1890 EXPORT_SYMBOL(snd_timer_start);
1891 EXPORT_SYMBOL(snd_timer_stop);
1892 EXPORT_SYMBOL(snd_timer_continue);
1893 EXPORT_SYMBOL(snd_timer_pause);
1894 EXPORT_SYMBOL(snd_timer_new);
1895 EXPORT_SYMBOL(snd_timer_notify);
1896 EXPORT_SYMBOL(snd_timer_global_new);
1897 EXPORT_SYMBOL(snd_timer_global_free);
1898 EXPORT_SYMBOL(snd_timer_global_register);
1899 EXPORT_SYMBOL(snd_timer_global_unregister);
1900 EXPORT_SYMBOL(snd_timer_interrupt);
1901 EXPORT_SYMBOL(snd_timer_system_resolution);
1902