xref: /linux/sound/core/timer.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 <linux/string.h>
30 #include <sound/core.h>
31 #include <sound/timer.h>
32 #include <sound/control.h>
33 #include <sound/info.h>
34 #include <sound/minors.h>
35 #include <sound/initval.h>
36 #include <linux/kmod.h>
37 #ifdef CONFIG_KERNELD
38 #include <linux/kerneld.h>
39 #endif
40 
41 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
42 #define DEFAULT_TIMER_LIMIT 3
43 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
44 #define DEFAULT_TIMER_LIMIT 2
45 #else
46 #define DEFAULT_TIMER_LIMIT 1
47 #endif
48 
49 static int timer_limit = DEFAULT_TIMER_LIMIT;
50 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
51 MODULE_DESCRIPTION("ALSA timer interface");
52 MODULE_LICENSE("GPL");
53 module_param(timer_limit, int, 0444);
54 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
55 
56 typedef struct {
57 	snd_timer_instance_t *timeri;
58 	int tread;			/* enhanced read with timestamps and events */
59 	unsigned long ticks;
60 	unsigned long overrun;
61 	int qhead;
62 	int qtail;
63 	int qused;
64 	int queue_size;
65 	snd_timer_read_t *queue;
66 	snd_timer_tread_t *tqueue;
67 	spinlock_t qlock;
68 	unsigned long last_resolution;
69 	unsigned int filter;
70 	struct timespec tstamp;		/* trigger tstamp */
71 	wait_queue_head_t qchange_sleep;
72 	struct fasync_struct *fasync;
73 	struct semaphore tread_sem;
74 } snd_timer_user_t;
75 
76 /* list of timers */
77 static LIST_HEAD(snd_timer_list);
78 
79 /* list of slave instances */
80 static LIST_HEAD(snd_timer_slave_list);
81 
82 /* lock for slave active lists */
83 static DEFINE_SPINLOCK(slave_active_lock);
84 
85 static DECLARE_MUTEX(register_mutex);
86 
87 static int snd_timer_free(snd_timer_t *timer);
88 static int snd_timer_dev_free(snd_device_t *device);
89 static int snd_timer_dev_register(snd_device_t *device);
90 static int snd_timer_dev_unregister(snd_device_t *device);
91 
92 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left);
93 
94 /*
95  * create a timer instance with the given owner string.
96  * when timer is not NULL, increments the module counter
97  */
98 static snd_timer_instance_t *snd_timer_instance_new(char *owner, snd_timer_t *timer)
99 {
100 	snd_timer_instance_t *timeri;
101 	timeri = kcalloc(1, sizeof(*timeri), GFP_KERNEL);
102 	if (timeri == NULL)
103 		return NULL;
104 	timeri->owner = kstrdup(owner, GFP_KERNEL);
105 	if (! timeri->owner) {
106 		kfree(timeri);
107 		return NULL;
108 	}
109 	INIT_LIST_HEAD(&timeri->open_list);
110 	INIT_LIST_HEAD(&timeri->active_list);
111 	INIT_LIST_HEAD(&timeri->ack_list);
112 	INIT_LIST_HEAD(&timeri->slave_list_head);
113 	INIT_LIST_HEAD(&timeri->slave_active_head);
114 
115 	timeri->timer = timer;
116 	if (timer && timer->card && !try_module_get(timer->card->module)) {
117 		kfree(timeri->owner);
118 		kfree(timeri);
119 		return NULL;
120 	}
121 
122 	return timeri;
123 }
124 
125 /*
126  * find a timer instance from the given timer id
127  */
128 static snd_timer_t *snd_timer_find(snd_timer_id_t *tid)
129 {
130 	snd_timer_t *timer = NULL;
131 	struct list_head *p;
132 
133 	list_for_each(p, &snd_timer_list) {
134 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
135 
136 		if (timer->tmr_class != tid->dev_class)
137 			continue;
138 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
139 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
140 		    (timer->card == NULL ||
141 		     timer->card->number != tid->card))
142 			continue;
143 		if (timer->tmr_device != tid->device)
144 			continue;
145 		if (timer->tmr_subdevice != tid->subdevice)
146 			continue;
147 		return timer;
148 	}
149 	return NULL;
150 }
151 
152 #ifdef CONFIG_KMOD
153 
154 static void snd_timer_request(snd_timer_id_t *tid)
155 {
156 	if (! current->fs->root)
157 		return;
158 	switch (tid->dev_class) {
159 	case SNDRV_TIMER_CLASS_GLOBAL:
160 		if (tid->device < timer_limit)
161 			request_module("snd-timer-%i", tid->device);
162 		break;
163 	case SNDRV_TIMER_CLASS_CARD:
164 	case SNDRV_TIMER_CLASS_PCM:
165 		if (tid->card < snd_ecards_limit)
166 			request_module("snd-card-%i", tid->card);
167 		break;
168 	default:
169 		break;
170 	}
171 }
172 
173 #endif
174 
175 /*
176  * look for a master instance matching with the slave id of the given slave.
177  * when found, relink the open_link of the slave.
178  *
179  * call this with register_mutex down.
180  */
181 static void snd_timer_check_slave(snd_timer_instance_t *slave)
182 {
183 	snd_timer_t *timer;
184 	snd_timer_instance_t *master;
185 	struct list_head *p, *q;
186 
187 	/* FIXME: it's really dumb to look up all entries.. */
188 	list_for_each(p, &snd_timer_list) {
189 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
190 		list_for_each(q, &timer->open_list_head) {
191 			master = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
192 			if (slave->slave_class == master->slave_class &&
193 			    slave->slave_id == master->slave_id) {
194 				list_del(&slave->open_list);
195 				list_add_tail(&slave->open_list, &master->slave_list_head);
196 				spin_lock_irq(&slave_active_lock);
197 				slave->master = master;
198 				slave->timer = master->timer;
199 				spin_unlock_irq(&slave_active_lock);
200 				return;
201 			}
202 		}
203 	}
204 }
205 
206 /*
207  * look for slave instances matching with the slave id of the given master.
208  * when found, relink the open_link of slaves.
209  *
210  * call this with register_mutex down.
211  */
212 static void snd_timer_check_master(snd_timer_instance_t *master)
213 {
214 	snd_timer_instance_t *slave;
215 	struct list_head *p, *n;
216 
217 	/* check all pending slaves */
218 	list_for_each_safe(p, n, &snd_timer_slave_list) {
219 		slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
220 		if (slave->slave_class == master->slave_class &&
221 		    slave->slave_id == master->slave_id) {
222 			list_del(p);
223 			list_add_tail(p, &master->slave_list_head);
224 			spin_lock_irq(&slave_active_lock);
225 			slave->master = master;
226 			slave->timer = master->timer;
227 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
228 				list_add_tail(&slave->active_list, &master->slave_active_head);
229 			spin_unlock_irq(&slave_active_lock);
230 		}
231 	}
232 }
233 
234 /*
235  * open a timer instance
236  * when opening a master, the slave id must be here given.
237  */
238 int snd_timer_open(snd_timer_instance_t **ti,
239 		   char *owner, snd_timer_id_t *tid,
240 		   unsigned int slave_id)
241 {
242 	snd_timer_t *timer;
243 	snd_timer_instance_t *timeri = NULL;
244 
245 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
246 		/* open a slave instance */
247 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
248 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
249 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
250 			return -EINVAL;
251 		}
252 		down(&register_mutex);
253 		timeri = snd_timer_instance_new(owner, NULL);
254 		timeri->slave_class = tid->dev_sclass;
255 		timeri->slave_id = tid->device;
256 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
257 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
258 		snd_timer_check_slave(timeri);
259 		up(&register_mutex);
260 		*ti = timeri;
261 		return 0;
262 	}
263 
264 	/* open a master instance */
265 	down(&register_mutex);
266 	timer = snd_timer_find(tid);
267 #ifdef CONFIG_KMOD
268 	if (timer == NULL) {
269 		up(&register_mutex);
270 		snd_timer_request(tid);
271 		down(&register_mutex);
272 		timer = snd_timer_find(tid);
273 	}
274 #endif
275 	if (timer) {
276 		if (!list_empty(&timer->open_list_head)) {
277 			timeri = (snd_timer_instance_t *)list_entry(timer->open_list_head.next, snd_timer_instance_t, open_list);
278 			if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
279 				up(&register_mutex);
280 				return -EBUSY;
281 			}
282 		}
283 		timeri = snd_timer_instance_new(owner, timer);
284 		if (timeri) {
285 			timeri->slave_class = tid->dev_sclass;
286 			timeri->slave_id = slave_id;
287 			if (list_empty(&timer->open_list_head) && timer->hw.open)
288 				timer->hw.open(timer);
289 			list_add_tail(&timeri->open_list, &timer->open_list_head);
290 			snd_timer_check_master(timeri);
291 		}
292 	} else {
293 		up(&register_mutex);
294 		return -ENODEV;
295 	}
296 	up(&register_mutex);
297 	*ti = timeri;
298 	return 0;
299 }
300 
301 static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event);
302 
303 /*
304  * close a timer instance
305  */
306 int snd_timer_close(snd_timer_instance_t * timeri)
307 {
308 	snd_timer_t *timer = NULL;
309 	struct list_head *p, *n;
310 	snd_timer_instance_t *slave;
311 
312 	snd_assert(timeri != NULL, return -ENXIO);
313 
314 	/* force to stop the timer */
315 	snd_timer_stop(timeri);
316 
317 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
318 		/* wait, until the active callback is finished */
319 		spin_lock_irq(&slave_active_lock);
320 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
321 			spin_unlock_irq(&slave_active_lock);
322 			udelay(10);
323 			spin_lock_irq(&slave_active_lock);
324 		}
325 		spin_unlock_irq(&slave_active_lock);
326 		down(&register_mutex);
327 		list_del(&timeri->open_list);
328 		up(&register_mutex);
329 	} else {
330 		timer = timeri->timer;
331 		/* wait, until the active callback is finished */
332 		spin_lock_irq(&timer->lock);
333 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
334 			spin_unlock_irq(&timer->lock);
335 			udelay(10);
336 			spin_lock_irq(&timer->lock);
337 		}
338 		spin_unlock_irq(&timer->lock);
339 		down(&register_mutex);
340 		list_del(&timeri->open_list);
341 		if (timer && list_empty(&timer->open_list_head) && timer->hw.close)
342 			timer->hw.close(timer);
343 		/* remove slave links */
344 		list_for_each_safe(p, n, &timeri->slave_list_head) {
345 			slave = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
346 			spin_lock_irq(&slave_active_lock);
347 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
348 			list_del(p);
349 			list_add_tail(p, &snd_timer_slave_list);
350 			slave->master = NULL;
351 			slave->timer = NULL;
352 			spin_unlock_irq(&slave_active_lock);
353 		}
354 		up(&register_mutex);
355 	}
356 	if (timeri->private_free)
357 		timeri->private_free(timeri);
358 	kfree(timeri->owner);
359 	kfree(timeri);
360 	if (timer && timer->card)
361 		module_put(timer->card->module);
362 	return 0;
363 }
364 
365 unsigned long snd_timer_resolution(snd_timer_instance_t * timeri)
366 {
367 	snd_timer_t * timer;
368 
369 	if (timeri == NULL)
370 		return 0;
371 	if ((timer = timeri->timer) != NULL) {
372 		if (timer->hw.c_resolution)
373 			return timer->hw.c_resolution(timer);
374 		return timer->hw.resolution;
375 	}
376 	return 0;
377 }
378 
379 static void snd_timer_notify1(snd_timer_instance_t *ti, enum sndrv_timer_event event)
380 {
381 	snd_timer_t *timer;
382 	unsigned long flags;
383 	unsigned long resolution = 0;
384 	snd_timer_instance_t *ts;
385 	struct list_head *n;
386 	struct timespec tstamp;
387 
388 	snd_timestamp_now(&tstamp, 1);
389 	snd_assert(event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE, return);
390 	if (event == SNDRV_TIMER_EVENT_START || event == SNDRV_TIMER_EVENT_CONTINUE)
391 		resolution = snd_timer_resolution(ti);
392 	if (ti->ccallback)
393 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
394 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
395 		return;
396 	timer = ti->timer;
397 	if (timer == NULL)
398 		return;
399 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
400 		return;
401 	spin_lock_irqsave(&timer->lock, flags);
402 	list_for_each(n, &ti->slave_active_head) {
403 		ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
404 		if (ts->ccallback)
405 			ts->ccallback(ti, event + 100, &tstamp, resolution);
406 	}
407 	spin_unlock_irqrestore(&timer->lock, flags);
408 }
409 
410 static int snd_timer_start1(snd_timer_t *timer, snd_timer_instance_t *timeri, unsigned long sticks)
411 {
412 	list_del(&timeri->active_list);
413 	list_add_tail(&timeri->active_list, &timer->active_list_head);
414 	if (timer->running) {
415 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
416 			goto __start_now;
417 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
418 		timeri->flags |= SNDRV_TIMER_IFLG_START;
419 		return 1;	/* delayed start */
420 	} else {
421 		timer->sticks = sticks;
422 		timer->hw.start(timer);
423 	      __start_now:
424 		timer->running++;
425 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
426 		return 0;
427 	}
428 }
429 
430 static int snd_timer_start_slave(snd_timer_instance_t *timeri)
431 {
432 	unsigned long flags;
433 
434 	spin_lock_irqsave(&slave_active_lock, flags);
435 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
436 	if (timeri->master)
437 		list_add_tail(&timeri->active_list, &timeri->master->slave_active_head);
438 	spin_unlock_irqrestore(&slave_active_lock, flags);
439 	return 1; /* delayed start */
440 }
441 
442 /*
443  *  start the timer instance
444  */
445 int snd_timer_start(snd_timer_instance_t * timeri, unsigned int ticks)
446 {
447 	snd_timer_t *timer;
448 	int result = -EINVAL;
449 	unsigned long flags;
450 
451 	if (timeri == NULL || ticks < 1)
452 		return -EINVAL;
453 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
454 		result = snd_timer_start_slave(timeri);
455 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
456 		return result;
457 	}
458 	timer = timeri->timer;
459 	if (timer == NULL)
460 		return -EINVAL;
461 	spin_lock_irqsave(&timer->lock, flags);
462 	timeri->ticks = timeri->cticks = ticks;
463 	timeri->pticks = 0;
464 	result = snd_timer_start1(timer, timeri, ticks);
465 	spin_unlock_irqrestore(&timer->lock, flags);
466 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
467 	return result;
468 }
469 
470 static int _snd_timer_stop(snd_timer_instance_t * timeri, int keep_flag, enum sndrv_timer_event event)
471 {
472 	snd_timer_t *timer;
473 	unsigned long flags;
474 
475 	snd_assert(timeri != NULL, return -ENXIO);
476 
477 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
478 		if (!keep_flag) {
479 			spin_lock_irqsave(&slave_active_lock, flags);
480 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
481 			spin_unlock_irqrestore(&slave_active_lock, flags);
482 		}
483 		goto __end;
484 	}
485 	timer = timeri->timer;
486 	if (!timer)
487 		return -EINVAL;
488 	spin_lock_irqsave(&timer->lock, flags);
489 	list_del_init(&timeri->ack_list);
490 	list_del_init(&timeri->active_list);
491 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
492 	    !(--timer->running)) {
493 		timer->hw.stop(timer);
494 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
495 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
496 			snd_timer_reschedule(timer, 0);
497 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
498 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
499 				timer->hw.start(timer);
500 			}
501 		}
502 	}
503 	if (!keep_flag)
504 		timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING|SNDRV_TIMER_IFLG_START);
505 	spin_unlock_irqrestore(&timer->lock, flags);
506       __end:
507 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
508 		snd_timer_notify1(timeri, event);
509 	return 0;
510 }
511 
512 /*
513  * stop the timer instance.
514  *
515  * do not call this from the timer callback!
516  */
517 int snd_timer_stop(snd_timer_instance_t * timeri)
518 {
519 	snd_timer_t *timer;
520 	unsigned long flags;
521 	int err;
522 
523 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
524 	if (err < 0)
525 		return err;
526 	timer = timeri->timer;
527 	spin_lock_irqsave(&timer->lock, flags);
528 	timeri->cticks = timeri->ticks;
529 	timeri->pticks = 0;
530 	spin_unlock_irqrestore(&timer->lock, flags);
531 	return 0;
532 }
533 
534 /*
535  * start again..  the tick is kept.
536  */
537 int snd_timer_continue(snd_timer_instance_t * timeri)
538 {
539 	snd_timer_t *timer;
540 	int result = -EINVAL;
541 	unsigned long flags;
542 
543 	if (timeri == NULL)
544 		return result;
545 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
546 		return snd_timer_start_slave(timeri);
547 	timer = timeri->timer;
548 	if (! timer)
549 		return -EINVAL;
550 	spin_lock_irqsave(&timer->lock, flags);
551 	if (!timeri->cticks)
552 		timeri->cticks = 1;
553 	timeri->pticks = 0;
554 	result = snd_timer_start1(timer, timeri, timer->sticks);
555 	spin_unlock_irqrestore(&timer->lock, flags);
556 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
557 	return result;
558 }
559 
560 /*
561  * pause.. remember the ticks left
562  */
563 int snd_timer_pause(snd_timer_instance_t * timeri)
564 {
565 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
566 }
567 
568 /*
569  * reschedule the timer
570  *
571  * start pending instances and check the scheduling ticks.
572  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
573  */
574 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left)
575 {
576 	snd_timer_instance_t *ti;
577 	unsigned long ticks = ~0UL;
578 	struct list_head *p;
579 
580 	list_for_each(p, &timer->active_list_head) {
581 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
582 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
583 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
584 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
585 			timer->running++;
586 		}
587 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
588 			if (ticks > ti->cticks)
589 				ticks = ti->cticks;
590 		}
591 	}
592 	if (ticks == ~0UL) {
593 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
594 		return;
595 	}
596 	if (ticks > timer->hw.ticks)
597 		ticks = timer->hw.ticks;
598 	if (ticks_left != ticks)
599 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
600 	timer->sticks = ticks;
601 }
602 
603 /*
604  * timer tasklet
605  *
606  */
607 static void snd_timer_tasklet(unsigned long arg)
608 {
609 	snd_timer_t *timer = (snd_timer_t *) arg;
610 	snd_timer_instance_t *ti;
611 	struct list_head *p;
612 	unsigned long resolution, ticks;
613 
614 	spin_lock(&timer->lock);
615 	/* now process all callbacks */
616 	while (!list_empty(&timer->sack_list_head)) {
617 		p = timer->sack_list_head.next;		/* get first item */
618 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
619 
620 		/* remove from ack_list and make empty */
621 		list_del_init(p);
622 
623 		ticks = ti->pticks;
624 		ti->pticks = 0;
625 		resolution = ti->resolution;
626 
627 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
628 		spin_unlock(&timer->lock);
629 		if (ti->callback)
630 			ti->callback(ti, resolution, ticks);
631 		spin_lock(&timer->lock);
632 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
633 	}
634 	spin_unlock(&timer->lock);
635 }
636 
637 /*
638  * timer interrupt
639  *
640  * ticks_left is usually equal to timer->sticks.
641  *
642  */
643 void snd_timer_interrupt(snd_timer_t * timer, unsigned long ticks_left)
644 {
645 	snd_timer_instance_t *ti, *ts;
646 	unsigned long resolution, ticks;
647 	struct list_head *p, *q, *n;
648 	int use_tasklet = 0;
649 
650 	if (timer == NULL)
651 		return;
652 
653 	spin_lock(&timer->lock);
654 
655 	/* remember the current resolution */
656 	if (timer->hw.c_resolution)
657 		resolution = timer->hw.c_resolution(timer);
658 	else
659 		resolution = timer->hw.resolution;
660 
661 	/* loop for all active instances
662 	 * here we cannot use list_for_each because the active_list of a processed
663 	 * instance is relinked to done_list_head before callback is called.
664 	 */
665 	list_for_each_safe(p, n, &timer->active_list_head) {
666 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
667 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
668 			continue;
669 		ti->pticks += ticks_left;
670 		ti->resolution = resolution;
671 		if (ti->cticks < ticks_left)
672 			ti->cticks = 0;
673 		else
674 			ti->cticks -= ticks_left;
675 		if (ti->cticks) /* not expired */
676 			continue;
677 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
678 			ti->cticks = ti->ticks;
679 		} else {
680 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
681 			if (--timer->running)
682 				list_del(p);
683 		}
684 		if (list_empty(&ti->ack_list)) {
685 			if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
686 			    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
687 				list_add_tail(&ti->ack_list, &timer->ack_list_head);
688 			} else {
689 				list_add_tail(&ti->ack_list, &timer->sack_list_head);
690 			}
691 		}
692 		list_for_each(q, &ti->slave_active_head) {
693 			ts = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, active_list);
694 			ts->pticks = ti->pticks;
695 			ts->resolution = resolution;
696 			if (list_empty(&ts->ack_list)) {
697 				if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
698 				    (ti->flags & SNDRV_TIMER_IFLG_FAST)) {
699 					list_add_tail(&ts->ack_list, &timer->ack_list_head);
700 				} else {
701 					list_add_tail(&ts->ack_list, &timer->sack_list_head);
702 				}
703 			}
704 		}
705 	}
706 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
707 		snd_timer_reschedule(timer, ticks_left);
708 	if (timer->running) {
709 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
710 			timer->hw.stop(timer);
711 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
712 		}
713 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
714 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
715 			/* restart timer */
716 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
717 			timer->hw.start(timer);
718 		}
719 	} else {
720 		timer->hw.stop(timer);
721 	}
722 
723 	/* now process all fast callbacks */
724 	while (!list_empty(&timer->ack_list_head)) {
725 		p = timer->ack_list_head.next;		/* get first item */
726 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, ack_list);
727 
728 		/* remove from ack_list and make empty */
729 		list_del_init(p);
730 
731 		ticks = ti->pticks;
732 		ti->pticks = 0;
733 
734 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
735 		spin_unlock(&timer->lock);
736 		if (ti->callback)
737 			ti->callback(ti, resolution, ticks);
738 		spin_lock(&timer->lock);
739 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
740 	}
741 
742 	/* do we have any slow callbacks? */
743 	use_tasklet = !list_empty(&timer->sack_list_head);
744 	spin_unlock(&timer->lock);
745 
746 	if (use_tasklet)
747 		tasklet_hi_schedule(&timer->task_queue);
748 }
749 
750 /*
751 
752  */
753 
754 int snd_timer_new(snd_card_t *card, char *id, snd_timer_id_t *tid, snd_timer_t ** rtimer)
755 {
756 	snd_timer_t *timer;
757 	int err;
758 	static snd_device_ops_t ops = {
759 		.dev_free = snd_timer_dev_free,
760 		.dev_register = snd_timer_dev_register,
761 		.dev_unregister = snd_timer_dev_unregister
762 	};
763 
764 	snd_assert(tid != NULL, return -EINVAL);
765 	snd_assert(rtimer != NULL, return -EINVAL);
766 	*rtimer = NULL;
767 	timer = kcalloc(1, sizeof(*timer), GFP_KERNEL);
768 	if (timer == NULL)
769 		return -ENOMEM;
770 	timer->tmr_class = tid->dev_class;
771 	timer->card = card;
772 	timer->tmr_device = tid->device;
773 	timer->tmr_subdevice = tid->subdevice;
774 	if (id)
775 		strlcpy(timer->id, id, sizeof(timer->id));
776 	INIT_LIST_HEAD(&timer->device_list);
777 	INIT_LIST_HEAD(&timer->open_list_head);
778 	INIT_LIST_HEAD(&timer->active_list_head);
779 	INIT_LIST_HEAD(&timer->ack_list_head);
780 	INIT_LIST_HEAD(&timer->sack_list_head);
781 	spin_lock_init(&timer->lock);
782 	tasklet_init(&timer->task_queue, snd_timer_tasklet, (unsigned long)timer);
783 	if (card != NULL) {
784 		if ((err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops)) < 0) {
785 			snd_timer_free(timer);
786 			return err;
787 		}
788 	}
789 	*rtimer = timer;
790 	return 0;
791 }
792 
793 static int snd_timer_free(snd_timer_t *timer)
794 {
795 	snd_assert(timer != NULL, return -ENXIO);
796 	if (timer->private_free)
797 		timer->private_free(timer);
798 	kfree(timer);
799 	return 0;
800 }
801 
802 int snd_timer_dev_free(snd_device_t *device)
803 {
804 	snd_timer_t *timer = device->device_data;
805 	return snd_timer_free(timer);
806 }
807 
808 int snd_timer_dev_register(snd_device_t *dev)
809 {
810 	snd_timer_t *timer = dev->device_data;
811 	snd_timer_t *timer1;
812 	struct list_head *p;
813 
814 	snd_assert(timer != NULL && timer->hw.start != NULL && timer->hw.stop != NULL, return -ENXIO);
815 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
816 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
817 	    	return -EINVAL;
818 
819 	down(&register_mutex);
820 	list_for_each(p, &snd_timer_list) {
821 		timer1 = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
822 		if (timer1->tmr_class > timer->tmr_class)
823 			break;
824 		if (timer1->tmr_class < timer->tmr_class)
825 			continue;
826 		if (timer1->card && timer->card) {
827 			if (timer1->card->number > timer->card->number)
828 				break;
829 			if (timer1->card->number < timer->card->number)
830 				continue;
831 		}
832 		if (timer1->tmr_device > timer->tmr_device)
833 			break;
834 		if (timer1->tmr_device < timer->tmr_device)
835 			continue;
836 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
837 			break;
838 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
839 			continue;
840 		/* conflicts.. */
841 		up(&register_mutex);
842 		return -EBUSY;
843 	}
844 	list_add_tail(&timer->device_list, p);
845 	up(&register_mutex);
846 	return 0;
847 }
848 
849 static int snd_timer_unregister(snd_timer_t *timer)
850 {
851 	struct list_head *p, *n;
852 	snd_timer_instance_t *ti;
853 
854 	snd_assert(timer != NULL, return -ENXIO);
855 	down(&register_mutex);
856 	if (! list_empty(&timer->open_list_head)) {
857 		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
858 		list_for_each_safe(p, n, &timer->open_list_head) {
859 			list_del_init(p);
860 			ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, open_list);
861 			ti->timer = NULL;
862 		}
863 	}
864 	list_del(&timer->device_list);
865 	up(&register_mutex);
866 	return snd_timer_free(timer);
867 }
868 
869 static int snd_timer_dev_unregister(snd_device_t *device)
870 {
871 	snd_timer_t *timer = device->device_data;
872 	return snd_timer_unregister(timer);
873 }
874 
875 void snd_timer_notify(snd_timer_t *timer, enum sndrv_timer_event event, struct timespec *tstamp)
876 {
877 	unsigned long flags;
878 	unsigned long resolution = 0;
879 	snd_timer_instance_t *ti, *ts;
880 	struct list_head *p, *n;
881 
882 	snd_runtime_check(timer->hw.flags & SNDRV_TIMER_HW_SLAVE, return);
883 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART && event <= SNDRV_TIMER_EVENT_MPAUSE, return);
884 	spin_lock_irqsave(&timer->lock, flags);
885 	if (event == SNDRV_TIMER_EVENT_MSTART || event == SNDRV_TIMER_EVENT_MCONTINUE) {
886 		if (timer->hw.c_resolution)
887 			resolution = timer->hw.c_resolution(timer);
888 		else
889 			resolution = timer->hw.resolution;
890 	}
891 	list_for_each(p, &timer->active_list_head) {
892 		ti = (snd_timer_instance_t *)list_entry(p, snd_timer_instance_t, active_list);
893 		if (ti->ccallback)
894 			ti->ccallback(ti, event, tstamp, resolution);
895 		list_for_each(n, &ti->slave_active_head) {
896 			ts = (snd_timer_instance_t *)list_entry(n, snd_timer_instance_t, active_list);
897 			if (ts->ccallback)
898 				ts->ccallback(ts, event, tstamp, resolution);
899 		}
900 	}
901 	spin_unlock_irqrestore(&timer->lock, flags);
902 }
903 
904 /*
905  * exported functions for global timers
906  */
907 int snd_timer_global_new(char *id, int device, snd_timer_t **rtimer)
908 {
909 	snd_timer_id_t tid;
910 
911 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
912 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
913 	tid.card = -1;
914 	tid.device = device;
915 	tid.subdevice = 0;
916 	return snd_timer_new(NULL, id, &tid, rtimer);
917 }
918 
919 int snd_timer_global_free(snd_timer_t *timer)
920 {
921 	return snd_timer_free(timer);
922 }
923 
924 int snd_timer_global_register(snd_timer_t *timer)
925 {
926 	snd_device_t dev;
927 
928 	memset(&dev, 0, sizeof(dev));
929 	dev.device_data = timer;
930 	return snd_timer_dev_register(&dev);
931 }
932 
933 int snd_timer_global_unregister(snd_timer_t *timer)
934 {
935 	return snd_timer_unregister(timer);
936 }
937 
938 /*
939  *  System timer
940  */
941 
942 struct snd_timer_system_private {
943 	struct timer_list tlist;
944 	struct timer * timer;
945 	unsigned long last_expires;
946 	unsigned long last_jiffies;
947 	unsigned long correction;
948 };
949 
950 static void snd_timer_s_function(unsigned long data)
951 {
952 	snd_timer_t *timer = (snd_timer_t *)data;
953 	struct snd_timer_system_private *priv = timer->private_data;
954 	unsigned long jiff = jiffies;
955 	if (time_after(jiff, priv->last_expires))
956 		priv->correction = (long)jiff - (long)priv->last_expires;
957 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
958 }
959 
960 static int snd_timer_s_start(snd_timer_t * timer)
961 {
962 	struct snd_timer_system_private *priv;
963 	unsigned long njiff;
964 
965 	priv = (struct snd_timer_system_private *) timer->private_data;
966 	njiff = (priv->last_jiffies = jiffies);
967 	if (priv->correction > timer->sticks - 1) {
968 		priv->correction -= timer->sticks - 1;
969 		njiff++;
970 	} else {
971 		njiff += timer->sticks - priv->correction;
972 		priv->correction -= timer->sticks;
973 	}
974 	priv->last_expires = priv->tlist.expires = njiff;
975 	add_timer(&priv->tlist);
976 	return 0;
977 }
978 
979 static int snd_timer_s_stop(snd_timer_t * timer)
980 {
981 	struct snd_timer_system_private *priv;
982 	unsigned long jiff;
983 
984 	priv = (struct snd_timer_system_private *) timer->private_data;
985 	del_timer(&priv->tlist);
986 	jiff = jiffies;
987 	if (time_before(jiff, priv->last_expires))
988 		timer->sticks = priv->last_expires - jiff;
989 	else
990 		timer->sticks = 1;
991 	return 0;
992 }
993 
994 static struct _snd_timer_hardware snd_timer_system =
995 {
996 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
997 	.resolution =	1000000000L / HZ,
998 	.ticks =	10000000L,
999 	.start =	snd_timer_s_start,
1000 	.stop =		snd_timer_s_stop
1001 };
1002 
1003 static void snd_timer_free_system(snd_timer_t *timer)
1004 {
1005 	kfree(timer->private_data);
1006 }
1007 
1008 static int snd_timer_register_system(void)
1009 {
1010 	snd_timer_t *timer;
1011 	struct snd_timer_system_private *priv;
1012 	int err;
1013 
1014 	if ((err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer)) < 0)
1015 		return err;
1016 	strcpy(timer->name, "system timer");
1017 	timer->hw = snd_timer_system;
1018 	priv = kcalloc(1, sizeof(*priv), GFP_KERNEL);
1019 	if (priv == NULL) {
1020 		snd_timer_free(timer);
1021 		return -ENOMEM;
1022 	}
1023 	init_timer(&priv->tlist);
1024 	priv->tlist.function = snd_timer_s_function;
1025 	priv->tlist.data = (unsigned long) timer;
1026 	timer->private_data = priv;
1027 	timer->private_free = snd_timer_free_system;
1028 	return snd_timer_global_register(timer);
1029 }
1030 
1031 /*
1032  *  Info interface
1033  */
1034 
1035 static void snd_timer_proc_read(snd_info_entry_t *entry,
1036 				snd_info_buffer_t * buffer)
1037 {
1038 	unsigned long flags;
1039 	snd_timer_t *timer;
1040 	snd_timer_instance_t *ti;
1041 	struct list_head *p, *q;
1042 
1043 	down(&register_mutex);
1044 	list_for_each(p, &snd_timer_list) {
1045 		timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1046 		switch (timer->tmr_class) {
1047 		case SNDRV_TIMER_CLASS_GLOBAL:
1048 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1049 			break;
1050 		case SNDRV_TIMER_CLASS_CARD:
1051 			snd_iprintf(buffer, "C%i-%i: ", timer->card->number, timer->tmr_device);
1052 			break;
1053 		case SNDRV_TIMER_CLASS_PCM:
1054 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number, timer->tmr_device, timer->tmr_subdevice);
1055 			break;
1056 		default:
1057 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class, timer->card ? timer->card->number : -1, timer->tmr_device, timer->tmr_subdevice);
1058 		}
1059 		snd_iprintf(buffer, "%s :", timer->name);
1060 		if (timer->hw.resolution)
1061 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)", timer->hw.resolution / 1000, timer->hw.resolution % 1000, timer->hw.ticks);
1062 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1063 			snd_iprintf(buffer, " SLAVE");
1064 		snd_iprintf(buffer, "\n");
1065 		spin_lock_irqsave(&timer->lock, flags);
1066 		list_for_each(q, &timer->open_list_head) {
1067 			ti = (snd_timer_instance_t *)list_entry(q, snd_timer_instance_t, open_list);
1068 			snd_iprintf(buffer, "  Client %s : %s : lost interrupts %li\n",
1069 					ti->owner ? ti->owner : "unknown",
1070 					ti->flags & (SNDRV_TIMER_IFLG_START|SNDRV_TIMER_IFLG_RUNNING) ? "running" : "stopped",
1071 					ti->lost);
1072 		}
1073 		spin_unlock_irqrestore(&timer->lock, flags);
1074 	}
1075 	up(&register_mutex);
1076 }
1077 
1078 /*
1079  *  USER SPACE interface
1080  */
1081 
1082 static void snd_timer_user_interrupt(snd_timer_instance_t *timeri,
1083 				     unsigned long resolution,
1084 				     unsigned long ticks)
1085 {
1086 	snd_timer_user_t *tu = timeri->callback_data;
1087 	snd_timer_read_t *r;
1088 	int prev;
1089 
1090 	spin_lock(&tu->qlock);
1091 	if (tu->qused > 0) {
1092 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1093 		r = &tu->queue[prev];
1094 		if (r->resolution == resolution) {
1095 			r->ticks += ticks;
1096 			goto __wake;
1097 		}
1098 	}
1099 	if (tu->qused >= tu->queue_size) {
1100 		tu->overrun++;
1101 	} else {
1102 		r = &tu->queue[tu->qtail++];
1103 		tu->qtail %= tu->queue_size;
1104 		r->resolution = resolution;
1105 		r->ticks = ticks;
1106 		tu->qused++;
1107 	}
1108       __wake:
1109 	spin_unlock(&tu->qlock);
1110 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1111 	wake_up(&tu->qchange_sleep);
1112 }
1113 
1114 static void snd_timer_user_append_to_tqueue(snd_timer_user_t *tu, snd_timer_tread_t *tread)
1115 {
1116 	if (tu->qused >= tu->queue_size) {
1117 		tu->overrun++;
1118 	} else {
1119 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1120 		tu->qtail %= tu->queue_size;
1121 		tu->qused++;
1122 	}
1123 }
1124 
1125 static void snd_timer_user_ccallback(snd_timer_instance_t *timeri,
1126 				     enum sndrv_timer_event event,
1127 				     struct timespec *tstamp,
1128 				     unsigned long resolution)
1129 {
1130 	snd_timer_user_t *tu = timeri->callback_data;
1131 	snd_timer_tread_t r1;
1132 
1133 	if (event >= SNDRV_TIMER_EVENT_START && event <= SNDRV_TIMER_EVENT_PAUSE)
1134 		tu->tstamp = *tstamp;
1135 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1136 		return;
1137 	r1.event = event;
1138 	r1.tstamp = *tstamp;
1139 	r1.val = resolution;
1140 	spin_lock(&tu->qlock);
1141 	snd_timer_user_append_to_tqueue(tu, &r1);
1142 	spin_unlock(&tu->qlock);
1143 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1144 	wake_up(&tu->qchange_sleep);
1145 }
1146 
1147 static void snd_timer_user_tinterrupt(snd_timer_instance_t *timeri,
1148 				      unsigned long resolution,
1149 				      unsigned long ticks)
1150 {
1151 	snd_timer_user_t *tu = timeri->callback_data;
1152 	snd_timer_tread_t *r, r1;
1153 	struct timespec tstamp;
1154 	int prev, append = 0;
1155 
1156 	snd_timestamp_zero(&tstamp);
1157 	spin_lock(&tu->qlock);
1158 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION)|(1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1159 		spin_unlock(&tu->qlock);
1160 		return;
1161 	}
1162 	if (tu->last_resolution != resolution || ticks > 0)
1163 		snd_timestamp_now(&tstamp, 1);
1164 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) && tu->last_resolution != resolution) {
1165 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1166 		r1.tstamp = tstamp;
1167 		r1.val = resolution;
1168 		snd_timer_user_append_to_tqueue(tu, &r1);
1169 		tu->last_resolution = resolution;
1170 		append++;
1171 	}
1172 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1173 		goto __wake;
1174 	if (ticks == 0)
1175 		goto __wake;
1176 	if (tu->qused > 0) {
1177 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1178 		r = &tu->tqueue[prev];
1179 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1180 			r->tstamp = tstamp;
1181 			r->val += ticks;
1182 			append++;
1183 			goto __wake;
1184 		}
1185 	}
1186 	r1.event = SNDRV_TIMER_EVENT_TICK;
1187 	r1.tstamp = tstamp;
1188 	r1.val = ticks;
1189 	snd_timer_user_append_to_tqueue(tu, &r1);
1190 	append++;
1191       __wake:
1192 	spin_unlock(&tu->qlock);
1193 	if (append == 0)
1194 		return;
1195 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1196 	wake_up(&tu->qchange_sleep);
1197 }
1198 
1199 static int snd_timer_user_open(struct inode *inode, struct file *file)
1200 {
1201 	snd_timer_user_t *tu;
1202 
1203 	tu = kcalloc(1, sizeof(*tu), GFP_KERNEL);
1204 	if (tu == NULL)
1205 		return -ENOMEM;
1206 	spin_lock_init(&tu->qlock);
1207 	init_waitqueue_head(&tu->qchange_sleep);
1208 	init_MUTEX(&tu->tread_sem);
1209 	tu->ticks = 1;
1210 	tu->queue_size = 128;
1211 	tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1212 	if (tu->queue == NULL) {
1213 		kfree(tu);
1214 		return -ENOMEM;
1215 	}
1216 	file->private_data = tu;
1217 	return 0;
1218 }
1219 
1220 static int snd_timer_user_release(struct inode *inode, struct file *file)
1221 {
1222 	snd_timer_user_t *tu;
1223 
1224 	if (file->private_data) {
1225 		tu = file->private_data;
1226 		file->private_data = NULL;
1227 		fasync_helper(-1, file, 0, &tu->fasync);
1228 		if (tu->timeri)
1229 			snd_timer_close(tu->timeri);
1230 		kfree(tu->queue);
1231 		kfree(tu->tqueue);
1232 		kfree(tu);
1233 	}
1234 	return 0;
1235 }
1236 
1237 static void snd_timer_user_zero_id(snd_timer_id_t *id)
1238 {
1239 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1240 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1241 	id->card = -1;
1242 	id->device = -1;
1243 	id->subdevice = -1;
1244 }
1245 
1246 static void snd_timer_user_copy_id(snd_timer_id_t *id, snd_timer_t *timer)
1247 {
1248 	id->dev_class = timer->tmr_class;
1249 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1250 	id->card = timer->card ? timer->card->number : -1;
1251 	id->device = timer->tmr_device;
1252 	id->subdevice = timer->tmr_subdevice;
1253 }
1254 
1255 static int snd_timer_user_next_device(snd_timer_id_t __user *_tid)
1256 {
1257 	snd_timer_id_t id;
1258 	snd_timer_t *timer;
1259 	struct list_head *p;
1260 
1261 	if (copy_from_user(&id, _tid, sizeof(id)))
1262 		return -EFAULT;
1263 	down(&register_mutex);
1264 	if (id.dev_class < 0) {		/* first item */
1265 		if (list_empty(&snd_timer_list))
1266 			snd_timer_user_zero_id(&id);
1267 		else {
1268 			timer = (snd_timer_t *)list_entry(snd_timer_list.next, snd_timer_t, device_list);
1269 			snd_timer_user_copy_id(&id, timer);
1270 		}
1271 	} else {
1272 		switch (id.dev_class) {
1273 		case SNDRV_TIMER_CLASS_GLOBAL:
1274 			id.device = id.device < 0 ? 0 : id.device + 1;
1275 			list_for_each(p, &snd_timer_list) {
1276 				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1277 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1278 					snd_timer_user_copy_id(&id, timer);
1279 					break;
1280 				}
1281 				if (timer->tmr_device >= id.device) {
1282 					snd_timer_user_copy_id(&id, timer);
1283 					break;
1284 				}
1285 			}
1286 			if (p == &snd_timer_list)
1287 				snd_timer_user_zero_id(&id);
1288 			break;
1289 		case SNDRV_TIMER_CLASS_CARD:
1290 		case SNDRV_TIMER_CLASS_PCM:
1291 			if (id.card < 0) {
1292 				id.card = 0;
1293 			} else {
1294 				if (id.card < 0) {
1295 					id.card = 0;
1296 				} else {
1297 					if (id.device < 0) {
1298 						id.device = 0;
1299 					} else {
1300 						id.subdevice = id.subdevice < 0 ? 0 : id.subdevice + 1;
1301 					}
1302 				}
1303 			}
1304 			list_for_each(p, &snd_timer_list) {
1305 				timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1306 				if (timer->tmr_class > id.dev_class) {
1307 					snd_timer_user_copy_id(&id, timer);
1308 					break;
1309 				}
1310 				if (timer->tmr_class < id.dev_class)
1311 					continue;
1312 				if (timer->card->number > id.card) {
1313 					snd_timer_user_copy_id(&id, timer);
1314 					break;
1315 				}
1316 				if (timer->card->number < id.card)
1317 					continue;
1318 				if (timer->tmr_device > id.device) {
1319 					snd_timer_user_copy_id(&id, timer);
1320 					break;
1321 				}
1322 				if (timer->tmr_device < id.device)
1323 					continue;
1324 				if (timer->tmr_subdevice > id.subdevice) {
1325 					snd_timer_user_copy_id(&id, timer);
1326 					break;
1327 				}
1328 				if (timer->tmr_subdevice < id.subdevice)
1329 					continue;
1330 				snd_timer_user_copy_id(&id, timer);
1331 				break;
1332 			}
1333 			if (p == &snd_timer_list)
1334 				snd_timer_user_zero_id(&id);
1335 			break;
1336 		default:
1337 			snd_timer_user_zero_id(&id);
1338 		}
1339 	}
1340 	up(&register_mutex);
1341 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1342 		return -EFAULT;
1343 	return 0;
1344 }
1345 
1346 static int snd_timer_user_ginfo(struct file *file, snd_timer_ginfo_t __user *_ginfo)
1347 {
1348 	snd_timer_ginfo_t *ginfo;
1349 	snd_timer_id_t tid;
1350 	snd_timer_t *t;
1351 	struct list_head *p;
1352 	int err = 0;
1353 
1354 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1355 	if (! ginfo)
1356 		return -ENOMEM;
1357 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1358 		kfree(ginfo);
1359 		return -EFAULT;
1360 	}
1361 	tid = ginfo->tid;
1362 	memset(ginfo, 0, sizeof(*ginfo));
1363 	ginfo->tid = tid;
1364 	down(&register_mutex);
1365 	t = snd_timer_find(&tid);
1366 	if (t != NULL) {
1367 		ginfo->card = t->card ? t->card->number : -1;
1368 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1369 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1370 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1371 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1372 		ginfo->resolution = t->hw.resolution;
1373 		if (t->hw.resolution_min > 0) {
1374 			ginfo->resolution_min = t->hw.resolution_min;
1375 			ginfo->resolution_max = t->hw.resolution_max;
1376 		}
1377 		list_for_each(p, &t->open_list_head) {
1378 			ginfo->clients++;
1379 		}
1380 	} else {
1381 		err = -ENODEV;
1382 	}
1383 	up(&register_mutex);
1384 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1385 		err = -EFAULT;
1386 	kfree(ginfo);
1387 	return err;
1388 }
1389 
1390 static int snd_timer_user_gparams(struct file *file, snd_timer_gparams_t __user *_gparams)
1391 {
1392 	snd_timer_gparams_t gparams;
1393 	snd_timer_t *t;
1394 	int err;
1395 
1396 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1397 		return -EFAULT;
1398 	down(&register_mutex);
1399 	t = snd_timer_find(&gparams.tid);
1400 	if (t != NULL) {
1401 		if (list_empty(&t->open_list_head)) {
1402 			if (t->hw.set_period)
1403 				err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1404 			else
1405 				err = -ENOSYS;
1406 		} else {
1407 			err = -EBUSY;
1408 		}
1409 	} else {
1410 		err = -ENODEV;
1411 	}
1412 	up(&register_mutex);
1413 	return err;
1414 }
1415 
1416 static int snd_timer_user_gstatus(struct file *file, snd_timer_gstatus_t __user *_gstatus)
1417 {
1418 	snd_timer_gstatus_t gstatus;
1419 	snd_timer_id_t tid;
1420 	snd_timer_t *t;
1421 	int err = 0;
1422 
1423 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1424 		return -EFAULT;
1425 	tid = gstatus.tid;
1426 	memset(&gstatus, 0, sizeof(gstatus));
1427 	gstatus.tid = tid;
1428 	down(&register_mutex);
1429 	t = snd_timer_find(&tid);
1430 	if (t != NULL) {
1431 		if (t->hw.c_resolution)
1432 			gstatus.resolution = t->hw.c_resolution(t);
1433 		else
1434 			gstatus.resolution = t->hw.resolution;
1435 		if (t->hw.precise_resolution) {
1436 			t->hw.precise_resolution(t, &gstatus.resolution_num, &gstatus.resolution_den);
1437 		} else {
1438 			gstatus.resolution_num = gstatus.resolution;
1439 			gstatus.resolution_den = 1000000000uL;
1440 		}
1441 	} else {
1442 		err = -ENODEV;
1443 	}
1444 	up(&register_mutex);
1445 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1446 		err = -EFAULT;
1447 	return err;
1448 }
1449 
1450 static int snd_timer_user_tselect(struct file *file, snd_timer_select_t __user *_tselect)
1451 {
1452 	snd_timer_user_t *tu;
1453 	snd_timer_select_t tselect;
1454 	char str[32];
1455 	int err = 0;
1456 
1457 	tu = file->private_data;
1458 	down(&tu->tread_sem);
1459 	if (tu->timeri) {
1460 		snd_timer_close(tu->timeri);
1461 		tu->timeri = NULL;
1462 	}
1463 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1464 		err = -EFAULT;
1465 		goto __err;
1466 	}
1467 	sprintf(str, "application %i", current->pid);
1468 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1469 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1470 	if ((err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid)) < 0)
1471 		goto __err;
1472 
1473 	kfree(tu->queue);
1474 	tu->queue = NULL;
1475 	kfree(tu->tqueue);
1476 	tu->tqueue = NULL;
1477 	if (tu->tread) {
1478 		tu->tqueue = (snd_timer_tread_t *)kmalloc(tu->queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
1479 		if (tu->tqueue == NULL)
1480 			err = -ENOMEM;
1481 	} else {
1482 		tu->queue = (snd_timer_read_t *)kmalloc(tu->queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1483 		if (tu->queue == NULL)
1484 			err = -ENOMEM;
1485 	}
1486 
1487       	if (err < 0) {
1488 		snd_timer_close(tu->timeri);
1489       		tu->timeri = NULL;
1490       	} else {
1491 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1492 		tu->timeri->callback = tu->tread ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1493 		tu->timeri->ccallback = snd_timer_user_ccallback;
1494 		tu->timeri->callback_data = (void *)tu;
1495 	}
1496 
1497       __err:
1498       	up(&tu->tread_sem);
1499 	return err;
1500 }
1501 
1502 static int snd_timer_user_info(struct file *file, snd_timer_info_t __user *_info)
1503 {
1504 	snd_timer_user_t *tu;
1505 	snd_timer_info_t *info;
1506 	snd_timer_t *t;
1507 	int err = 0;
1508 
1509 	tu = file->private_data;
1510 	snd_assert(tu->timeri != NULL, return -ENXIO);
1511 	t = tu->timeri->timer;
1512 	snd_assert(t != NULL, return -ENXIO);
1513 
1514 	info = kcalloc(1, sizeof(*info), GFP_KERNEL);
1515 	if (! info)
1516 		return -ENOMEM;
1517 	info->card = t->card ? t->card->number : -1;
1518 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1519 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1520 	strlcpy(info->id, t->id, sizeof(info->id));
1521 	strlcpy(info->name, t->name, sizeof(info->name));
1522 	info->resolution = t->hw.resolution;
1523 	if (copy_to_user(_info, info, sizeof(*_info)))
1524 		err = -EFAULT;
1525 	kfree(info);
1526 	return err;
1527 }
1528 
1529 static int snd_timer_user_params(struct file *file, snd_timer_params_t __user *_params)
1530 {
1531 	snd_timer_user_t *tu;
1532 	snd_timer_params_t params;
1533 	snd_timer_t *t;
1534 	snd_timer_read_t *tr;
1535 	snd_timer_tread_t *ttr;
1536 	int err;
1537 
1538 	tu = file->private_data;
1539 	snd_assert(tu->timeri != NULL, return -ENXIO);
1540 	t = tu->timeri->timer;
1541 	snd_assert(t != NULL, return -ENXIO);
1542 	if (copy_from_user(&params, _params, sizeof(params)))
1543 		return -EFAULT;
1544 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1545 		err = -EINVAL;
1546 		goto _end;
1547 	}
1548 	if (params.queue_size > 0 && (params.queue_size < 32 || params.queue_size > 1024)) {
1549 		err = -EINVAL;
1550 		goto _end;
1551 	}
1552 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1553 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1554 			      (1<<SNDRV_TIMER_EVENT_START)|
1555 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1556 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1557 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1558 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1559 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1560 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1561 			      (1<<SNDRV_TIMER_EVENT_MPAUSE))) {
1562 		err = -EINVAL;
1563 		goto _end;
1564 	}
1565 	snd_timer_stop(tu->timeri);
1566 	spin_lock_irq(&t->lock);
1567 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1568 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1569 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1570 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1571 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1572 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1573 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1574 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1575 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1576 	spin_unlock_irq(&t->lock);
1577 	if (params.queue_size > 0 && (unsigned int)tu->queue_size != params.queue_size) {
1578 		if (tu->tread) {
1579 			ttr = (snd_timer_tread_t *)kmalloc(params.queue_size * sizeof(snd_timer_tread_t), GFP_KERNEL);
1580 			if (ttr) {
1581 				kfree(tu->tqueue);
1582 				tu->queue_size = params.queue_size;
1583 				tu->tqueue = ttr;
1584 			}
1585 		} else {
1586 			tr = (snd_timer_read_t *)kmalloc(params.queue_size * sizeof(snd_timer_read_t), GFP_KERNEL);
1587 			if (tr) {
1588 				kfree(tu->queue);
1589 				tu->queue_size = params.queue_size;
1590 				tu->queue = tr;
1591 			}
1592 		}
1593 	}
1594 	tu->qhead = tu->qtail = tu->qused = 0;
1595 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1596 		if (tu->tread) {
1597 			snd_timer_tread_t tread;
1598 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1599 			tread.tstamp.tv_sec = 0;
1600 			tread.tstamp.tv_nsec = 0;
1601 			tread.val = 0;
1602 			snd_timer_user_append_to_tqueue(tu, &tread);
1603 		} else {
1604 			snd_timer_read_t *r = &tu->queue[0];
1605 			r->resolution = 0;
1606 			r->ticks = 0;
1607 			tu->qused++;
1608 			tu->qtail++;
1609 		}
1610 
1611 	}
1612 	tu->filter = params.filter;
1613 	tu->ticks = params.ticks;
1614 	err = 0;
1615  _end:
1616 	if (copy_to_user(_params, &params, sizeof(params)))
1617 		return -EFAULT;
1618 	return err;
1619 }
1620 
1621 static int snd_timer_user_status(struct file *file, snd_timer_status_t __user *_status)
1622 {
1623 	snd_timer_user_t *tu;
1624 	snd_timer_status_t status;
1625 
1626 	tu = file->private_data;
1627 	snd_assert(tu->timeri != NULL, return -ENXIO);
1628 	memset(&status, 0, sizeof(status));
1629 	status.tstamp = tu->tstamp;
1630 	status.resolution = snd_timer_resolution(tu->timeri);
1631 	status.lost = tu->timeri->lost;
1632 	status.overrun = tu->overrun;
1633 	spin_lock_irq(&tu->qlock);
1634 	status.queue = tu->qused;
1635 	spin_unlock_irq(&tu->qlock);
1636 	if (copy_to_user(_status, &status, sizeof(status)))
1637 		return -EFAULT;
1638 	return 0;
1639 }
1640 
1641 static int snd_timer_user_start(struct file *file)
1642 {
1643 	int err;
1644 	snd_timer_user_t *tu;
1645 
1646 	tu = file->private_data;
1647 	snd_assert(tu->timeri != NULL, return -ENXIO);
1648 	snd_timer_stop(tu->timeri);
1649 	tu->timeri->lost = 0;
1650 	tu->last_resolution = 0;
1651 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1652 }
1653 
1654 static int snd_timer_user_stop(struct file *file)
1655 {
1656 	int err;
1657 	snd_timer_user_t *tu;
1658 
1659 	tu = file->private_data;
1660 	snd_assert(tu->timeri != NULL, return -ENXIO);
1661 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1662 }
1663 
1664 static int snd_timer_user_continue(struct file *file)
1665 {
1666 	int err;
1667 	snd_timer_user_t *tu;
1668 
1669 	tu = file->private_data;
1670 	snd_assert(tu->timeri != NULL, return -ENXIO);
1671 	tu->timeri->lost = 0;
1672 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1673 }
1674 
1675 static int snd_timer_user_pause(struct file *file)
1676 {
1677 	int err;
1678 	snd_timer_user_t *tu;
1679 
1680 	tu = file->private_data;
1681 	snd_assert(tu->timeri != NULL, return -ENXIO);
1682 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1683 }
1684 
1685 enum {
1686 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1687 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1688 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1689 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1690 };
1691 
1692 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1693 {
1694 	snd_timer_user_t *tu;
1695 	void __user *argp = (void __user *)arg;
1696 	int __user *p = argp;
1697 
1698 	tu = file->private_data;
1699 	switch (cmd) {
1700 	case SNDRV_TIMER_IOCTL_PVERSION:
1701 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1702 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1703 		return snd_timer_user_next_device(argp);
1704 	case SNDRV_TIMER_IOCTL_TREAD:
1705 	{
1706 		int xarg;
1707 
1708 		down(&tu->tread_sem);
1709 		if (tu->timeri)	{	/* too late */
1710 			up(&tu->tread_sem);
1711 			return -EBUSY;
1712 		}
1713 		if (get_user(xarg, p)) {
1714 			up(&tu->tread_sem);
1715 			return -EFAULT;
1716 		}
1717 		tu->tread = xarg ? 1 : 0;
1718 		up(&tu->tread_sem);
1719 		return 0;
1720 	}
1721 	case SNDRV_TIMER_IOCTL_GINFO:
1722 		return snd_timer_user_ginfo(file, argp);
1723 	case SNDRV_TIMER_IOCTL_GPARAMS:
1724 		return snd_timer_user_gparams(file, argp);
1725 	case SNDRV_TIMER_IOCTL_GSTATUS:
1726 		return snd_timer_user_gstatus(file, argp);
1727 	case SNDRV_TIMER_IOCTL_SELECT:
1728 		return snd_timer_user_tselect(file, argp);
1729 	case SNDRV_TIMER_IOCTL_INFO:
1730 		return snd_timer_user_info(file, argp);
1731 	case SNDRV_TIMER_IOCTL_PARAMS:
1732 		return snd_timer_user_params(file, argp);
1733 	case SNDRV_TIMER_IOCTL_STATUS:
1734 		return snd_timer_user_status(file, argp);
1735 	case SNDRV_TIMER_IOCTL_START:
1736 	case SNDRV_TIMER_IOCTL_START_OLD:
1737 		return snd_timer_user_start(file);
1738 	case SNDRV_TIMER_IOCTL_STOP:
1739 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1740 		return snd_timer_user_stop(file);
1741 	case SNDRV_TIMER_IOCTL_CONTINUE:
1742 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1743 		return snd_timer_user_continue(file);
1744 	case SNDRV_TIMER_IOCTL_PAUSE:
1745 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1746 		return snd_timer_user_pause(file);
1747 	}
1748 	return -ENOTTY;
1749 }
1750 
1751 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1752 {
1753 	snd_timer_user_t *tu;
1754 	int err;
1755 
1756 	tu = file->private_data;
1757 	err = fasync_helper(fd, file, on, &tu->fasync);
1758         if (err < 0)
1759 		return err;
1760 	return 0;
1761 }
1762 
1763 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer, size_t count, loff_t *offset)
1764 {
1765 	snd_timer_user_t *tu;
1766 	long result = 0, unit;
1767 	int err = 0;
1768 
1769 	tu = file->private_data;
1770 	unit = tu->tread ? sizeof(snd_timer_tread_t) : sizeof(snd_timer_read_t);
1771 	spin_lock_irq(&tu->qlock);
1772 	while ((long)count - result >= unit) {
1773 		while (!tu->qused) {
1774 			wait_queue_t wait;
1775 
1776 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1777 				err = -EAGAIN;
1778 				break;
1779 			}
1780 
1781 			set_current_state(TASK_INTERRUPTIBLE);
1782 			init_waitqueue_entry(&wait, current);
1783 			add_wait_queue(&tu->qchange_sleep, &wait);
1784 
1785 			spin_unlock_irq(&tu->qlock);
1786 			schedule();
1787 			spin_lock_irq(&tu->qlock);
1788 
1789 			remove_wait_queue(&tu->qchange_sleep, &wait);
1790 
1791 			if (signal_pending(current)) {
1792 				err = -ERESTARTSYS;
1793 				break;
1794 			}
1795 		}
1796 
1797 		spin_unlock_irq(&tu->qlock);
1798 		if (err < 0)
1799 			goto _error;
1800 
1801 		if (tu->tread) {
1802 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++], sizeof(snd_timer_tread_t))) {
1803 				err = -EFAULT;
1804 				goto _error;
1805 			}
1806 		} else {
1807 			if (copy_to_user(buffer, &tu->queue[tu->qhead++], sizeof(snd_timer_read_t))) {
1808 				err = -EFAULT;
1809 				goto _error;
1810 			}
1811 		}
1812 
1813 		tu->qhead %= tu->queue_size;
1814 
1815 		result += unit;
1816 		buffer += unit;
1817 
1818 		spin_lock_irq(&tu->qlock);
1819 		tu->qused--;
1820 	}
1821 	spin_unlock_irq(&tu->qlock);
1822  _error:
1823 	return result > 0 ? result : err;
1824 }
1825 
1826 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1827 {
1828         unsigned int mask;
1829         snd_timer_user_t *tu;
1830 
1831         tu = file->private_data;
1832 
1833         poll_wait(file, &tu->qchange_sleep, wait);
1834 
1835 	mask = 0;
1836 	if (tu->qused)
1837 		mask |= POLLIN | POLLRDNORM;
1838 
1839 	return mask;
1840 }
1841 
1842 #ifdef CONFIG_COMPAT
1843 #include "timer_compat.c"
1844 #else
1845 #define snd_timer_user_ioctl_compat	NULL
1846 #endif
1847 
1848 static struct file_operations snd_timer_f_ops =
1849 {
1850 	.owner =	THIS_MODULE,
1851 	.read =		snd_timer_user_read,
1852 	.open =		snd_timer_user_open,
1853 	.release =	snd_timer_user_release,
1854 	.poll =		snd_timer_user_poll,
1855 	.unlocked_ioctl =	snd_timer_user_ioctl,
1856 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1857 	.fasync = 	snd_timer_user_fasync,
1858 };
1859 
1860 static snd_minor_t snd_timer_reg =
1861 {
1862 	.comment =	"timer",
1863 	.f_ops =	&snd_timer_f_ops,
1864 };
1865 
1866 /*
1867  *  ENTRY functions
1868  */
1869 
1870 static snd_info_entry_t *snd_timer_proc_entry = NULL;
1871 
1872 static int __init alsa_timer_init(void)
1873 {
1874 	int err;
1875 	snd_info_entry_t *entry;
1876 
1877 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1878 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1, "system timer");
1879 #endif
1880 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL)) != NULL) {
1881 		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
1882 		entry->c.text.read = snd_timer_proc_read;
1883 		if (snd_info_register(entry) < 0) {
1884 			snd_info_free_entry(entry);
1885 			entry = NULL;
1886 		}
1887 	}
1888 	snd_timer_proc_entry = entry;
1889 	if ((err = snd_timer_register_system()) < 0)
1890 		snd_printk(KERN_ERR "unable to register system timer (%i)\n", err);
1891 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER,
1892 					NULL, 0, &snd_timer_reg, "timer"))<0)
1893 		snd_printk(KERN_ERR "unable to register timer device (%i)\n", err);
1894 	return 0;
1895 }
1896 
1897 static void __exit alsa_timer_exit(void)
1898 {
1899 	struct list_head *p, *n;
1900 
1901 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1902 	/* unregister the system timer */
1903 	list_for_each_safe(p, n, &snd_timer_list) {
1904 		snd_timer_t *timer = (snd_timer_t *)list_entry(p, snd_timer_t, device_list);
1905 		snd_timer_unregister(timer);
1906 	}
1907 	if (snd_timer_proc_entry) {
1908 		snd_info_unregister(snd_timer_proc_entry);
1909 		snd_timer_proc_entry = NULL;
1910 	}
1911 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1912 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1913 #endif
1914 }
1915 
1916 module_init(alsa_timer_init)
1917 module_exit(alsa_timer_exit)
1918 
1919 EXPORT_SYMBOL(snd_timer_open);
1920 EXPORT_SYMBOL(snd_timer_close);
1921 EXPORT_SYMBOL(snd_timer_resolution);
1922 EXPORT_SYMBOL(snd_timer_start);
1923 EXPORT_SYMBOL(snd_timer_stop);
1924 EXPORT_SYMBOL(snd_timer_continue);
1925 EXPORT_SYMBOL(snd_timer_pause);
1926 EXPORT_SYMBOL(snd_timer_new);
1927 EXPORT_SYMBOL(snd_timer_notify);
1928 EXPORT_SYMBOL(snd_timer_global_new);
1929 EXPORT_SYMBOL(snd_timer_global_free);
1930 EXPORT_SYMBOL(snd_timer_global_register);
1931 EXPORT_SYMBOL(snd_timer_global_unregister);
1932 EXPORT_SYMBOL(snd_timer_interrupt);
1933