xref: /openbmc/linux/sound/core/timer.c (revision 87c2ce3b)
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 struct snd_timer_user {
57 	struct snd_timer_instance *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 	struct snd_timer_read *queue;
66 	struct snd_timer_tread *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 };
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(struct snd_timer *timer);
88 static int snd_timer_dev_free(struct snd_device *device);
89 static int snd_timer_dev_register(struct snd_device *device);
90 static int snd_timer_dev_unregister(struct snd_device *device);
91 
92 static void snd_timer_reschedule(struct snd_timer * 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 struct snd_timer_instance *snd_timer_instance_new(char *owner,
99 							 struct snd_timer *timer)
100 {
101 	struct snd_timer_instance *timeri;
102 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
103 	if (timeri == NULL)
104 		return NULL;
105 	timeri->owner = kstrdup(owner, GFP_KERNEL);
106 	if (! timeri->owner) {
107 		kfree(timeri);
108 		return NULL;
109 	}
110 	INIT_LIST_HEAD(&timeri->open_list);
111 	INIT_LIST_HEAD(&timeri->active_list);
112 	INIT_LIST_HEAD(&timeri->ack_list);
113 	INIT_LIST_HEAD(&timeri->slave_list_head);
114 	INIT_LIST_HEAD(&timeri->slave_active_head);
115 
116 	timeri->timer = timer;
117 	if (timer && !try_module_get(timer->module)) {
118 		kfree(timeri->owner);
119 		kfree(timeri);
120 		return NULL;
121 	}
122 
123 	return timeri;
124 }
125 
126 /*
127  * find a timer instance from the given timer id
128  */
129 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
130 {
131 	struct snd_timer *timer = NULL;
132 	struct list_head *p;
133 
134 	list_for_each(p, &snd_timer_list) {
135 		timer = list_entry(p, struct snd_timer, device_list);
136 
137 		if (timer->tmr_class != tid->dev_class)
138 			continue;
139 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
140 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
141 		    (timer->card == NULL ||
142 		     timer->card->number != tid->card))
143 			continue;
144 		if (timer->tmr_device != tid->device)
145 			continue;
146 		if (timer->tmr_subdevice != tid->subdevice)
147 			continue;
148 		return timer;
149 	}
150 	return NULL;
151 }
152 
153 #ifdef CONFIG_KMOD
154 
155 static void snd_timer_request(struct snd_timer_id *tid)
156 {
157 	if (! current->fs->root)
158 		return;
159 	switch (tid->dev_class) {
160 	case SNDRV_TIMER_CLASS_GLOBAL:
161 		if (tid->device < timer_limit)
162 			request_module("snd-timer-%i", tid->device);
163 		break;
164 	case SNDRV_TIMER_CLASS_CARD:
165 	case SNDRV_TIMER_CLASS_PCM:
166 		if (tid->card < snd_ecards_limit)
167 			request_module("snd-card-%i", tid->card);
168 		break;
169 	default:
170 		break;
171 	}
172 }
173 
174 #endif
175 
176 /*
177  * look for a master instance matching with the slave id of the given slave.
178  * when found, relink the open_link of the slave.
179  *
180  * call this with register_mutex down.
181  */
182 static void snd_timer_check_slave(struct snd_timer_instance *slave)
183 {
184 	struct snd_timer *timer;
185 	struct snd_timer_instance *master;
186 	struct list_head *p, *q;
187 
188 	/* FIXME: it's really dumb to look up all entries.. */
189 	list_for_each(p, &snd_timer_list) {
190 		timer = list_entry(p, struct snd_timer, device_list);
191 		list_for_each(q, &timer->open_list_head) {
192 			master = list_entry(q, struct snd_timer_instance, open_list);
193 			if (slave->slave_class == master->slave_class &&
194 			    slave->slave_id == master->slave_id) {
195 				list_del(&slave->open_list);
196 				list_add_tail(&slave->open_list,
197 					      &master->slave_list_head);
198 				spin_lock_irq(&slave_active_lock);
199 				slave->master = master;
200 				slave->timer = master->timer;
201 				spin_unlock_irq(&slave_active_lock);
202 				return;
203 			}
204 		}
205 	}
206 }
207 
208 /*
209  * look for slave instances matching with the slave id of the given master.
210  * when found, relink the open_link of slaves.
211  *
212  * call this with register_mutex down.
213  */
214 static void snd_timer_check_master(struct snd_timer_instance *master)
215 {
216 	struct snd_timer_instance *slave;
217 	struct list_head *p, *n;
218 
219 	/* check all pending slaves */
220 	list_for_each_safe(p, n, &snd_timer_slave_list) {
221 		slave = list_entry(p, struct snd_timer_instance, open_list);
222 		if (slave->slave_class == master->slave_class &&
223 		    slave->slave_id == master->slave_id) {
224 			list_del(p);
225 			list_add_tail(p, &master->slave_list_head);
226 			spin_lock_irq(&slave_active_lock);
227 			slave->master = master;
228 			slave->timer = master->timer;
229 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
230 				list_add_tail(&slave->active_list,
231 					      &master->slave_active_head);
232 			spin_unlock_irq(&slave_active_lock);
233 		}
234 	}
235 }
236 
237 /*
238  * open a timer instance
239  * when opening a master, the slave id must be here given.
240  */
241 int snd_timer_open(struct snd_timer_instance **ti,
242 		   char *owner, struct snd_timer_id *tid,
243 		   unsigned int slave_id)
244 {
245 	struct snd_timer *timer;
246 	struct snd_timer_instance *timeri = NULL;
247 
248 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
249 		/* open a slave instance */
250 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
251 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
252 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
253 			return -EINVAL;
254 		}
255 		down(&register_mutex);
256 		timeri = snd_timer_instance_new(owner, NULL);
257 		if (!timeri) {
258 			up(&register_mutex);
259 			return -ENOMEM;
260 		}
261 		timeri->slave_class = tid->dev_sclass;
262 		timeri->slave_id = tid->device;
263 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
264 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
265 		snd_timer_check_slave(timeri);
266 		up(&register_mutex);
267 		*ti = timeri;
268 		return 0;
269 	}
270 
271 	/* open a master instance */
272 	down(&register_mutex);
273 	timer = snd_timer_find(tid);
274 #ifdef CONFIG_KMOD
275 	if (timer == NULL) {
276 		up(&register_mutex);
277 		snd_timer_request(tid);
278 		down(&register_mutex);
279 		timer = snd_timer_find(tid);
280 	}
281 #endif
282 	if (!timer) {
283 		up(&register_mutex);
284 		return -ENODEV;
285 	}
286 	if (!list_empty(&timer->open_list_head)) {
287 		timeri = list_entry(timer->open_list_head.next,
288 				    struct snd_timer_instance, open_list);
289 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
290 			up(&register_mutex);
291 			return -EBUSY;
292 		}
293 	}
294 	timeri = snd_timer_instance_new(owner, timer);
295 	if (!timeri) {
296 		up(&register_mutex);
297 		return -ENOMEM;
298 	}
299 	timeri->slave_class = tid->dev_sclass;
300 	timeri->slave_id = slave_id;
301 	if (list_empty(&timer->open_list_head) && timer->hw.open)
302 		timer->hw.open(timer);
303 	list_add_tail(&timeri->open_list, &timer->open_list_head);
304 	snd_timer_check_master(timeri);
305 	up(&register_mutex);
306 	*ti = timeri;
307 	return 0;
308 }
309 
310 static int _snd_timer_stop(struct snd_timer_instance *timeri,
311 			   int keep_flag, int event);
312 
313 /*
314  * close a timer instance
315  */
316 int snd_timer_close(struct snd_timer_instance *timeri)
317 {
318 	struct snd_timer *timer = NULL;
319 	struct list_head *p, *n;
320 	struct snd_timer_instance *slave;
321 
322 	snd_assert(timeri != NULL, return -ENXIO);
323 
324 	/* force to stop the timer */
325 	snd_timer_stop(timeri);
326 
327 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
328 		/* wait, until the active callback is finished */
329 		spin_lock_irq(&slave_active_lock);
330 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
331 			spin_unlock_irq(&slave_active_lock);
332 			udelay(10);
333 			spin_lock_irq(&slave_active_lock);
334 		}
335 		spin_unlock_irq(&slave_active_lock);
336 		down(&register_mutex);
337 		list_del(&timeri->open_list);
338 		up(&register_mutex);
339 	} else {
340 		timer = timeri->timer;
341 		/* wait, until the active callback is finished */
342 		spin_lock_irq(&timer->lock);
343 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
344 			spin_unlock_irq(&timer->lock);
345 			udelay(10);
346 			spin_lock_irq(&timer->lock);
347 		}
348 		spin_unlock_irq(&timer->lock);
349 		down(&register_mutex);
350 		list_del(&timeri->open_list);
351 		if (timer && list_empty(&timer->open_list_head) &&
352 		    timer->hw.close)
353 			timer->hw.close(timer);
354 		/* remove slave links */
355 		list_for_each_safe(p, n, &timeri->slave_list_head) {
356 			slave = list_entry(p, struct snd_timer_instance, open_list);
357 			spin_lock_irq(&slave_active_lock);
358 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
359 			list_del(p);
360 			list_add_tail(p, &snd_timer_slave_list);
361 			slave->master = NULL;
362 			slave->timer = NULL;
363 			spin_unlock_irq(&slave_active_lock);
364 		}
365 		up(&register_mutex);
366 	}
367 	if (timeri->private_free)
368 		timeri->private_free(timeri);
369 	kfree(timeri->owner);
370 	kfree(timeri);
371 	if (timer)
372 		module_put(timer->module);
373 	return 0;
374 }
375 
376 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
377 {
378 	struct snd_timer * timer;
379 
380 	if (timeri == NULL)
381 		return 0;
382 	if ((timer = timeri->timer) != NULL) {
383 		if (timer->hw.c_resolution)
384 			return timer->hw.c_resolution(timer);
385 		return timer->hw.resolution;
386 	}
387 	return 0;
388 }
389 
390 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
391 {
392 	struct snd_timer *timer;
393 	unsigned long flags;
394 	unsigned long resolution = 0;
395 	struct snd_timer_instance *ts;
396 	struct list_head *n;
397 	struct timespec tstamp;
398 
399 	getnstimeofday(&tstamp);
400 	snd_assert(event >= SNDRV_TIMER_EVENT_START &&
401 		   event <= SNDRV_TIMER_EVENT_PAUSE, return);
402 	if (event == SNDRV_TIMER_EVENT_START ||
403 	    event == SNDRV_TIMER_EVENT_CONTINUE)
404 		resolution = snd_timer_resolution(ti);
405 	if (ti->ccallback)
406 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
407 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
408 		return;
409 	timer = ti->timer;
410 	if (timer == NULL)
411 		return;
412 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
413 		return;
414 	spin_lock_irqsave(&timer->lock, flags);
415 	list_for_each(n, &ti->slave_active_head) {
416 		ts = list_entry(n, struct snd_timer_instance, active_list);
417 		if (ts->ccallback)
418 			ts->ccallback(ti, event + 100, &tstamp, resolution);
419 	}
420 	spin_unlock_irqrestore(&timer->lock, flags);
421 }
422 
423 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
424 			    unsigned long sticks)
425 {
426 	list_del(&timeri->active_list);
427 	list_add_tail(&timeri->active_list, &timer->active_list_head);
428 	if (timer->running) {
429 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
430 			goto __start_now;
431 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
432 		timeri->flags |= SNDRV_TIMER_IFLG_START;
433 		return 1;	/* delayed start */
434 	} else {
435 		timer->sticks = sticks;
436 		timer->hw.start(timer);
437 	      __start_now:
438 		timer->running++;
439 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
440 		return 0;
441 	}
442 }
443 
444 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
445 {
446 	unsigned long flags;
447 
448 	spin_lock_irqsave(&slave_active_lock, flags);
449 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
450 	if (timeri->master)
451 		list_add_tail(&timeri->active_list,
452 			      &timeri->master->slave_active_head);
453 	spin_unlock_irqrestore(&slave_active_lock, flags);
454 	return 1; /* delayed start */
455 }
456 
457 /*
458  *  start the timer instance
459  */
460 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
461 {
462 	struct snd_timer *timer;
463 	int result = -EINVAL;
464 	unsigned long flags;
465 
466 	if (timeri == NULL || ticks < 1)
467 		return -EINVAL;
468 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
469 		result = snd_timer_start_slave(timeri);
470 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
471 		return result;
472 	}
473 	timer = timeri->timer;
474 	if (timer == NULL)
475 		return -EINVAL;
476 	spin_lock_irqsave(&timer->lock, flags);
477 	timeri->ticks = timeri->cticks = ticks;
478 	timeri->pticks = 0;
479 	result = snd_timer_start1(timer, timeri, ticks);
480 	spin_unlock_irqrestore(&timer->lock, flags);
481 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
482 	return result;
483 }
484 
485 static int _snd_timer_stop(struct snd_timer_instance * timeri,
486 			   int keep_flag, int event)
487 {
488 	struct snd_timer *timer;
489 	unsigned long flags;
490 
491 	snd_assert(timeri != NULL, return -ENXIO);
492 
493 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
494 		if (!keep_flag) {
495 			spin_lock_irqsave(&slave_active_lock, flags);
496 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
497 			spin_unlock_irqrestore(&slave_active_lock, flags);
498 		}
499 		goto __end;
500 	}
501 	timer = timeri->timer;
502 	if (!timer)
503 		return -EINVAL;
504 	spin_lock_irqsave(&timer->lock, flags);
505 	list_del_init(&timeri->ack_list);
506 	list_del_init(&timeri->active_list);
507 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
508 	    !(--timer->running)) {
509 		timer->hw.stop(timer);
510 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
511 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
512 			snd_timer_reschedule(timer, 0);
513 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
514 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
515 				timer->hw.start(timer);
516 			}
517 		}
518 	}
519 	if (!keep_flag)
520 		timeri->flags &=
521 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
522 	spin_unlock_irqrestore(&timer->lock, flags);
523       __end:
524 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
525 		snd_timer_notify1(timeri, event);
526 	return 0;
527 }
528 
529 /*
530  * stop the timer instance.
531  *
532  * do not call this from the timer callback!
533  */
534 int snd_timer_stop(struct snd_timer_instance *timeri)
535 {
536 	struct snd_timer *timer;
537 	unsigned long flags;
538 	int err;
539 
540 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
541 	if (err < 0)
542 		return err;
543 	timer = timeri->timer;
544 	spin_lock_irqsave(&timer->lock, flags);
545 	timeri->cticks = timeri->ticks;
546 	timeri->pticks = 0;
547 	spin_unlock_irqrestore(&timer->lock, flags);
548 	return 0;
549 }
550 
551 /*
552  * start again..  the tick is kept.
553  */
554 int snd_timer_continue(struct snd_timer_instance *timeri)
555 {
556 	struct snd_timer *timer;
557 	int result = -EINVAL;
558 	unsigned long flags;
559 
560 	if (timeri == NULL)
561 		return result;
562 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
563 		return snd_timer_start_slave(timeri);
564 	timer = timeri->timer;
565 	if (! timer)
566 		return -EINVAL;
567 	spin_lock_irqsave(&timer->lock, flags);
568 	if (!timeri->cticks)
569 		timeri->cticks = 1;
570 	timeri->pticks = 0;
571 	result = snd_timer_start1(timer, timeri, timer->sticks);
572 	spin_unlock_irqrestore(&timer->lock, flags);
573 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
574 	return result;
575 }
576 
577 /*
578  * pause.. remember the ticks left
579  */
580 int snd_timer_pause(struct snd_timer_instance * timeri)
581 {
582 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
583 }
584 
585 /*
586  * reschedule the timer
587  *
588  * start pending instances and check the scheduling ticks.
589  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
590  */
591 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
592 {
593 	struct snd_timer_instance *ti;
594 	unsigned long ticks = ~0UL;
595 	struct list_head *p;
596 
597 	list_for_each(p, &timer->active_list_head) {
598 		ti = list_entry(p, struct snd_timer_instance, active_list);
599 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
600 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
601 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
602 			timer->running++;
603 		}
604 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
605 			if (ticks > ti->cticks)
606 				ticks = ti->cticks;
607 		}
608 	}
609 	if (ticks == ~0UL) {
610 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
611 		return;
612 	}
613 	if (ticks > timer->hw.ticks)
614 		ticks = timer->hw.ticks;
615 	if (ticks_left != ticks)
616 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
617 	timer->sticks = ticks;
618 }
619 
620 /*
621  * timer tasklet
622  *
623  */
624 static void snd_timer_tasklet(unsigned long arg)
625 {
626 	struct snd_timer *timer = (struct snd_timer *) arg;
627 	struct snd_timer_instance *ti;
628 	struct list_head *p;
629 	unsigned long resolution, ticks;
630 
631 	spin_lock(&timer->lock);
632 	/* now process all callbacks */
633 	while (!list_empty(&timer->sack_list_head)) {
634 		p = timer->sack_list_head.next;		/* get first item */
635 		ti = list_entry(p, struct snd_timer_instance, ack_list);
636 
637 		/* remove from ack_list and make empty */
638 		list_del_init(p);
639 
640 		ticks = ti->pticks;
641 		ti->pticks = 0;
642 		resolution = ti->resolution;
643 
644 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
645 		spin_unlock(&timer->lock);
646 		if (ti->callback)
647 			ti->callback(ti, resolution, ticks);
648 		spin_lock(&timer->lock);
649 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
650 	}
651 	spin_unlock(&timer->lock);
652 }
653 
654 /*
655  * timer interrupt
656  *
657  * ticks_left is usually equal to timer->sticks.
658  *
659  */
660 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
661 {
662 	struct snd_timer_instance *ti, *ts;
663 	unsigned long resolution, ticks;
664 	struct list_head *p, *q, *n, *ack_list_head;
665 	unsigned long flags;
666 	int use_tasklet = 0;
667 
668 	if (timer == NULL)
669 		return;
670 
671 	spin_lock_irqsave(&timer->lock, flags);
672 
673 	/* remember the current resolution */
674 	if (timer->hw.c_resolution)
675 		resolution = timer->hw.c_resolution(timer);
676 	else
677 		resolution = timer->hw.resolution;
678 
679 	/* loop for all active instances
680 	 * Here we cannot use list_for_each because the active_list of a
681 	 * processed instance is relinked to done_list_head before the callback
682 	 * is called.
683 	 */
684 	list_for_each_safe(p, n, &timer->active_list_head) {
685 		ti = list_entry(p, struct snd_timer_instance, active_list);
686 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
687 			continue;
688 		ti->pticks += ticks_left;
689 		ti->resolution = resolution;
690 		if (ti->cticks < ticks_left)
691 			ti->cticks = 0;
692 		else
693 			ti->cticks -= ticks_left;
694 		if (ti->cticks) /* not expired */
695 			continue;
696 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
697 			ti->cticks = ti->ticks;
698 		} else {
699 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
700 			if (--timer->running)
701 				list_del(p);
702 		}
703 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
704 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
705 			ack_list_head = &timer->ack_list_head;
706 		else
707 			ack_list_head = &timer->sack_list_head;
708 		if (list_empty(&ti->ack_list))
709 			list_add_tail(&ti->ack_list, ack_list_head);
710 		list_for_each(q, &ti->slave_active_head) {
711 			ts = list_entry(q, struct snd_timer_instance, active_list);
712 			ts->pticks = ti->pticks;
713 			ts->resolution = resolution;
714 			if (list_empty(&ts->ack_list))
715 				list_add_tail(&ts->ack_list, ack_list_head);
716 		}
717 	}
718 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
719 		snd_timer_reschedule(timer, ticks_left);
720 	if (timer->running) {
721 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
722 			timer->hw.stop(timer);
723 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
724 		}
725 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
726 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
727 			/* restart timer */
728 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
729 			timer->hw.start(timer);
730 		}
731 	} else {
732 		timer->hw.stop(timer);
733 	}
734 
735 	/* now process all fast callbacks */
736 	while (!list_empty(&timer->ack_list_head)) {
737 		p = timer->ack_list_head.next;		/* get first item */
738 		ti = list_entry(p, struct snd_timer_instance, ack_list);
739 
740 		/* remove from ack_list and make empty */
741 		list_del_init(p);
742 
743 		ticks = ti->pticks;
744 		ti->pticks = 0;
745 
746 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
747 		spin_unlock(&timer->lock);
748 		if (ti->callback)
749 			ti->callback(ti, resolution, ticks);
750 		spin_lock(&timer->lock);
751 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
752 	}
753 
754 	/* do we have any slow callbacks? */
755 	use_tasklet = !list_empty(&timer->sack_list_head);
756 	spin_unlock_irqrestore(&timer->lock, flags);
757 
758 	if (use_tasklet)
759 		tasklet_hi_schedule(&timer->task_queue);
760 }
761 
762 /*
763 
764  */
765 
766 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
767 		  struct snd_timer **rtimer)
768 {
769 	struct snd_timer *timer;
770 	int err;
771 	static struct snd_device_ops ops = {
772 		.dev_free = snd_timer_dev_free,
773 		.dev_register = snd_timer_dev_register,
774 		.dev_unregister = snd_timer_dev_unregister
775 	};
776 
777 	snd_assert(tid != NULL, return -EINVAL);
778 	snd_assert(rtimer != NULL, return -EINVAL);
779 	*rtimer = NULL;
780 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
781 	if (timer == NULL) {
782 		snd_printk(KERN_ERR "timer: cannot allocate\n");
783 		return -ENOMEM;
784 	}
785 	timer->tmr_class = tid->dev_class;
786 	timer->card = card;
787 	timer->tmr_device = tid->device;
788 	timer->tmr_subdevice = tid->subdevice;
789 	if (id)
790 		strlcpy(timer->id, id, sizeof(timer->id));
791 	INIT_LIST_HEAD(&timer->device_list);
792 	INIT_LIST_HEAD(&timer->open_list_head);
793 	INIT_LIST_HEAD(&timer->active_list_head);
794 	INIT_LIST_HEAD(&timer->ack_list_head);
795 	INIT_LIST_HEAD(&timer->sack_list_head);
796 	spin_lock_init(&timer->lock);
797 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
798 		     (unsigned long)timer);
799 	if (card != NULL) {
800 		timer->module = card->module;
801 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
802 		if (err < 0) {
803 			snd_timer_free(timer);
804 			return err;
805 		}
806 	}
807 	*rtimer = timer;
808 	return 0;
809 }
810 
811 static int snd_timer_free(struct snd_timer *timer)
812 {
813 	snd_assert(timer != NULL, return -ENXIO);
814 	if (timer->private_free)
815 		timer->private_free(timer);
816 	kfree(timer);
817 	return 0;
818 }
819 
820 static int snd_timer_dev_free(struct snd_device *device)
821 {
822 	struct snd_timer *timer = device->device_data;
823 	return snd_timer_free(timer);
824 }
825 
826 static int snd_timer_dev_register(struct snd_device *dev)
827 {
828 	struct snd_timer *timer = dev->device_data;
829 	struct snd_timer *timer1;
830 	struct list_head *p;
831 
832 	snd_assert(timer != NULL && timer->hw.start != NULL &&
833 		   timer->hw.stop != NULL, return -ENXIO);
834 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
835 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
836 	    	return -EINVAL;
837 
838 	down(&register_mutex);
839 	list_for_each(p, &snd_timer_list) {
840 		timer1 = list_entry(p, struct snd_timer, device_list);
841 		if (timer1->tmr_class > timer->tmr_class)
842 			break;
843 		if (timer1->tmr_class < timer->tmr_class)
844 			continue;
845 		if (timer1->card && timer->card) {
846 			if (timer1->card->number > timer->card->number)
847 				break;
848 			if (timer1->card->number < timer->card->number)
849 				continue;
850 		}
851 		if (timer1->tmr_device > timer->tmr_device)
852 			break;
853 		if (timer1->tmr_device < timer->tmr_device)
854 			continue;
855 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
856 			break;
857 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
858 			continue;
859 		/* conflicts.. */
860 		up(&register_mutex);
861 		return -EBUSY;
862 	}
863 	list_add_tail(&timer->device_list, p);
864 	up(&register_mutex);
865 	return 0;
866 }
867 
868 static int snd_timer_unregister(struct snd_timer *timer)
869 {
870 	struct list_head *p, *n;
871 	struct snd_timer_instance *ti;
872 
873 	snd_assert(timer != NULL, return -ENXIO);
874 	down(&register_mutex);
875 	if (! list_empty(&timer->open_list_head)) {
876 		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
877 		list_for_each_safe(p, n, &timer->open_list_head) {
878 			list_del_init(p);
879 			ti = list_entry(p, struct snd_timer_instance, open_list);
880 			ti->timer = NULL;
881 		}
882 	}
883 	list_del(&timer->device_list);
884 	up(&register_mutex);
885 	return snd_timer_free(timer);
886 }
887 
888 static int snd_timer_dev_unregister(struct snd_device *device)
889 {
890 	struct snd_timer *timer = device->device_data;
891 	return snd_timer_unregister(timer);
892 }
893 
894 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
895 {
896 	unsigned long flags;
897 	unsigned long resolution = 0;
898 	struct snd_timer_instance *ti, *ts;
899 	struct list_head *p, *n;
900 
901 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
902 		return;
903 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART &&
904 		   event <= SNDRV_TIMER_EVENT_MRESUME, return);
905 	spin_lock_irqsave(&timer->lock, flags);
906 	if (event == SNDRV_TIMER_EVENT_MSTART ||
907 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
908 	    event == SNDRV_TIMER_EVENT_MRESUME) {
909 		if (timer->hw.c_resolution)
910 			resolution = timer->hw.c_resolution(timer);
911 		else
912 			resolution = timer->hw.resolution;
913 	}
914 	list_for_each(p, &timer->active_list_head) {
915 		ti = list_entry(p, struct snd_timer_instance, active_list);
916 		if (ti->ccallback)
917 			ti->ccallback(ti, event, tstamp, resolution);
918 		list_for_each(n, &ti->slave_active_head) {
919 			ts = list_entry(n, struct snd_timer_instance, active_list);
920 			if (ts->ccallback)
921 				ts->ccallback(ts, event, tstamp, resolution);
922 		}
923 	}
924 	spin_unlock_irqrestore(&timer->lock, flags);
925 }
926 
927 /*
928  * exported functions for global timers
929  */
930 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
931 {
932 	struct snd_timer_id tid;
933 
934 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
935 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
936 	tid.card = -1;
937 	tid.device = device;
938 	tid.subdevice = 0;
939 	return snd_timer_new(NULL, id, &tid, rtimer);
940 }
941 
942 int snd_timer_global_free(struct snd_timer *timer)
943 {
944 	return snd_timer_free(timer);
945 }
946 
947 int snd_timer_global_register(struct snd_timer *timer)
948 {
949 	struct snd_device dev;
950 
951 	memset(&dev, 0, sizeof(dev));
952 	dev.device_data = timer;
953 	return snd_timer_dev_register(&dev);
954 }
955 
956 int snd_timer_global_unregister(struct snd_timer *timer)
957 {
958 	return snd_timer_unregister(timer);
959 }
960 
961 /*
962  *  System timer
963  */
964 
965 struct snd_timer_system_private {
966 	struct timer_list tlist;
967 	struct timer * timer;
968 	unsigned long last_expires;
969 	unsigned long last_jiffies;
970 	unsigned long correction;
971 };
972 
973 static void snd_timer_s_function(unsigned long data)
974 {
975 	struct snd_timer *timer = (struct snd_timer *)data;
976 	struct snd_timer_system_private *priv = timer->private_data;
977 	unsigned long jiff = jiffies;
978 	if (time_after(jiff, priv->last_expires))
979 		priv->correction = (long)jiff - (long)priv->last_expires;
980 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
981 }
982 
983 static int snd_timer_s_start(struct snd_timer * timer)
984 {
985 	struct snd_timer_system_private *priv;
986 	unsigned long njiff;
987 
988 	priv = (struct snd_timer_system_private *) timer->private_data;
989 	njiff = (priv->last_jiffies = jiffies);
990 	if (priv->correction > timer->sticks - 1) {
991 		priv->correction -= timer->sticks - 1;
992 		njiff++;
993 	} else {
994 		njiff += timer->sticks - priv->correction;
995 		priv->correction -= timer->sticks;
996 	}
997 	priv->last_expires = priv->tlist.expires = njiff;
998 	add_timer(&priv->tlist);
999 	return 0;
1000 }
1001 
1002 static int snd_timer_s_stop(struct snd_timer * timer)
1003 {
1004 	struct snd_timer_system_private *priv;
1005 	unsigned long jiff;
1006 
1007 	priv = (struct snd_timer_system_private *) timer->private_data;
1008 	del_timer(&priv->tlist);
1009 	jiff = jiffies;
1010 	if (time_before(jiff, priv->last_expires))
1011 		timer->sticks = priv->last_expires - jiff;
1012 	else
1013 		timer->sticks = 1;
1014 	return 0;
1015 }
1016 
1017 static struct snd_timer_hardware snd_timer_system =
1018 {
1019 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1020 	.resolution =	1000000000L / HZ,
1021 	.ticks =	10000000L,
1022 	.start =	snd_timer_s_start,
1023 	.stop =		snd_timer_s_stop
1024 };
1025 
1026 static void snd_timer_free_system(struct snd_timer *timer)
1027 {
1028 	kfree(timer->private_data);
1029 }
1030 
1031 static int snd_timer_register_system(void)
1032 {
1033 	struct snd_timer *timer;
1034 	struct snd_timer_system_private *priv;
1035 	int err;
1036 
1037 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1038 	if (err < 0)
1039 		return err;
1040 	strcpy(timer->name, "system timer");
1041 	timer->hw = snd_timer_system;
1042 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1043 	if (priv == NULL) {
1044 		snd_timer_free(timer);
1045 		return -ENOMEM;
1046 	}
1047 	init_timer(&priv->tlist);
1048 	priv->tlist.function = snd_timer_s_function;
1049 	priv->tlist.data = (unsigned long) timer;
1050 	timer->private_data = priv;
1051 	timer->private_free = snd_timer_free_system;
1052 	return snd_timer_global_register(timer);
1053 }
1054 
1055 #ifdef CONFIG_PROC_FS
1056 /*
1057  *  Info interface
1058  */
1059 
1060 static void snd_timer_proc_read(struct snd_info_entry *entry,
1061 				struct snd_info_buffer *buffer)
1062 {
1063 	unsigned long flags;
1064 	struct snd_timer *timer;
1065 	struct snd_timer_instance *ti;
1066 	struct list_head *p, *q;
1067 
1068 	down(&register_mutex);
1069 	list_for_each(p, &snd_timer_list) {
1070 		timer = list_entry(p, struct snd_timer, device_list);
1071 		switch (timer->tmr_class) {
1072 		case SNDRV_TIMER_CLASS_GLOBAL:
1073 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1074 			break;
1075 		case SNDRV_TIMER_CLASS_CARD:
1076 			snd_iprintf(buffer, "C%i-%i: ",
1077 				    timer->card->number, timer->tmr_device);
1078 			break;
1079 		case SNDRV_TIMER_CLASS_PCM:
1080 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1081 				    timer->tmr_device, timer->tmr_subdevice);
1082 			break;
1083 		default:
1084 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1085 				    timer->card ? timer->card->number : -1,
1086 				    timer->tmr_device, timer->tmr_subdevice);
1087 		}
1088 		snd_iprintf(buffer, "%s :", timer->name);
1089 		if (timer->hw.resolution)
1090 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1091 				    timer->hw.resolution / 1000,
1092 				    timer->hw.resolution % 1000,
1093 				    timer->hw.ticks);
1094 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1095 			snd_iprintf(buffer, " SLAVE");
1096 		snd_iprintf(buffer, "\n");
1097 		spin_lock_irqsave(&timer->lock, flags);
1098 		list_for_each(q, &timer->open_list_head) {
1099 			ti = list_entry(q, struct snd_timer_instance, open_list);
1100 			snd_iprintf(buffer, "  Client %s : %s\n",
1101 				    ti->owner ? ti->owner : "unknown",
1102 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1103 						 SNDRV_TIMER_IFLG_RUNNING)
1104 				    ? "running" : "stopped");
1105 		}
1106 		spin_unlock_irqrestore(&timer->lock, flags);
1107 	}
1108 	up(&register_mutex);
1109 }
1110 
1111 static struct snd_info_entry *snd_timer_proc_entry = NULL;
1112 
1113 static void __init snd_timer_proc_init(void)
1114 {
1115 	struct snd_info_entry *entry;
1116 
1117 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1118 	if (entry != NULL) {
1119 		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
1120 		entry->c.text.read = snd_timer_proc_read;
1121 		if (snd_info_register(entry) < 0) {
1122 			snd_info_free_entry(entry);
1123 			entry = NULL;
1124 		}
1125 	}
1126 	snd_timer_proc_entry = entry;
1127 }
1128 
1129 static void __exit snd_timer_proc_done(void)
1130 {
1131 	snd_info_unregister(snd_timer_proc_entry);
1132 }
1133 #else /* !CONFIG_PROC_FS */
1134 #define snd_timer_proc_init()
1135 #define snd_timer_proc_done()
1136 #endif
1137 
1138 /*
1139  *  USER SPACE interface
1140  */
1141 
1142 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1143 				     unsigned long resolution,
1144 				     unsigned long ticks)
1145 {
1146 	struct snd_timer_user *tu = timeri->callback_data;
1147 	struct snd_timer_read *r;
1148 	int prev;
1149 
1150 	spin_lock(&tu->qlock);
1151 	if (tu->qused > 0) {
1152 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1153 		r = &tu->queue[prev];
1154 		if (r->resolution == resolution) {
1155 			r->ticks += ticks;
1156 			goto __wake;
1157 		}
1158 	}
1159 	if (tu->qused >= tu->queue_size) {
1160 		tu->overrun++;
1161 	} else {
1162 		r = &tu->queue[tu->qtail++];
1163 		tu->qtail %= tu->queue_size;
1164 		r->resolution = resolution;
1165 		r->ticks = ticks;
1166 		tu->qused++;
1167 	}
1168       __wake:
1169 	spin_unlock(&tu->qlock);
1170 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1171 	wake_up(&tu->qchange_sleep);
1172 }
1173 
1174 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1175 					    struct snd_timer_tread *tread)
1176 {
1177 	if (tu->qused >= tu->queue_size) {
1178 		tu->overrun++;
1179 	} else {
1180 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1181 		tu->qtail %= tu->queue_size;
1182 		tu->qused++;
1183 	}
1184 }
1185 
1186 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1187 				     int event,
1188 				     struct timespec *tstamp,
1189 				     unsigned long resolution)
1190 {
1191 	struct snd_timer_user *tu = timeri->callback_data;
1192 	struct snd_timer_tread r1;
1193 
1194 	if (event >= SNDRV_TIMER_EVENT_START &&
1195 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1196 		tu->tstamp = *tstamp;
1197 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1198 		return;
1199 	r1.event = event;
1200 	r1.tstamp = *tstamp;
1201 	r1.val = resolution;
1202 	spin_lock(&tu->qlock);
1203 	snd_timer_user_append_to_tqueue(tu, &r1);
1204 	spin_unlock(&tu->qlock);
1205 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1206 	wake_up(&tu->qchange_sleep);
1207 }
1208 
1209 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1210 				      unsigned long resolution,
1211 				      unsigned long ticks)
1212 {
1213 	struct snd_timer_user *tu = timeri->callback_data;
1214 	struct snd_timer_tread *r, r1;
1215 	struct timespec tstamp;
1216 	int prev, append = 0;
1217 
1218 	memset(&tstamp, 0, sizeof(tstamp));
1219 	spin_lock(&tu->qlock);
1220 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1221 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1222 		spin_unlock(&tu->qlock);
1223 		return;
1224 	}
1225 	if (tu->last_resolution != resolution || ticks > 0)
1226 		getnstimeofday(&tstamp);
1227 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1228 	    tu->last_resolution != resolution) {
1229 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1230 		r1.tstamp = tstamp;
1231 		r1.val = resolution;
1232 		snd_timer_user_append_to_tqueue(tu, &r1);
1233 		tu->last_resolution = resolution;
1234 		append++;
1235 	}
1236 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1237 		goto __wake;
1238 	if (ticks == 0)
1239 		goto __wake;
1240 	if (tu->qused > 0) {
1241 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1242 		r = &tu->tqueue[prev];
1243 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1244 			r->tstamp = tstamp;
1245 			r->val += ticks;
1246 			append++;
1247 			goto __wake;
1248 		}
1249 	}
1250 	r1.event = SNDRV_TIMER_EVENT_TICK;
1251 	r1.tstamp = tstamp;
1252 	r1.val = ticks;
1253 	snd_timer_user_append_to_tqueue(tu, &r1);
1254 	append++;
1255       __wake:
1256 	spin_unlock(&tu->qlock);
1257 	if (append == 0)
1258 		return;
1259 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1260 	wake_up(&tu->qchange_sleep);
1261 }
1262 
1263 static int snd_timer_user_open(struct inode *inode, struct file *file)
1264 {
1265 	struct snd_timer_user *tu;
1266 
1267 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1268 	if (tu == NULL)
1269 		return -ENOMEM;
1270 	spin_lock_init(&tu->qlock);
1271 	init_waitqueue_head(&tu->qchange_sleep);
1272 	init_MUTEX(&tu->tread_sem);
1273 	tu->ticks = 1;
1274 	tu->queue_size = 128;
1275 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1276 			    GFP_KERNEL);
1277 	if (tu->queue == NULL) {
1278 		kfree(tu);
1279 		return -ENOMEM;
1280 	}
1281 	file->private_data = tu;
1282 	return 0;
1283 }
1284 
1285 static int snd_timer_user_release(struct inode *inode, struct file *file)
1286 {
1287 	struct snd_timer_user *tu;
1288 
1289 	if (file->private_data) {
1290 		tu = file->private_data;
1291 		file->private_data = NULL;
1292 		fasync_helper(-1, file, 0, &tu->fasync);
1293 		if (tu->timeri)
1294 			snd_timer_close(tu->timeri);
1295 		kfree(tu->queue);
1296 		kfree(tu->tqueue);
1297 		kfree(tu);
1298 	}
1299 	return 0;
1300 }
1301 
1302 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1303 {
1304 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1305 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1306 	id->card = -1;
1307 	id->device = -1;
1308 	id->subdevice = -1;
1309 }
1310 
1311 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1312 {
1313 	id->dev_class = timer->tmr_class;
1314 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1315 	id->card = timer->card ? timer->card->number : -1;
1316 	id->device = timer->tmr_device;
1317 	id->subdevice = timer->tmr_subdevice;
1318 }
1319 
1320 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1321 {
1322 	struct snd_timer_id id;
1323 	struct snd_timer *timer;
1324 	struct list_head *p;
1325 
1326 	if (copy_from_user(&id, _tid, sizeof(id)))
1327 		return -EFAULT;
1328 	down(&register_mutex);
1329 	if (id.dev_class < 0) {		/* first item */
1330 		if (list_empty(&snd_timer_list))
1331 			snd_timer_user_zero_id(&id);
1332 		else {
1333 			timer = list_entry(snd_timer_list.next,
1334 					   struct snd_timer, device_list);
1335 			snd_timer_user_copy_id(&id, timer);
1336 		}
1337 	} else {
1338 		switch (id.dev_class) {
1339 		case SNDRV_TIMER_CLASS_GLOBAL:
1340 			id.device = id.device < 0 ? 0 : id.device + 1;
1341 			list_for_each(p, &snd_timer_list) {
1342 				timer = list_entry(p, struct snd_timer, device_list);
1343 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1344 					snd_timer_user_copy_id(&id, timer);
1345 					break;
1346 				}
1347 				if (timer->tmr_device >= id.device) {
1348 					snd_timer_user_copy_id(&id, timer);
1349 					break;
1350 				}
1351 			}
1352 			if (p == &snd_timer_list)
1353 				snd_timer_user_zero_id(&id);
1354 			break;
1355 		case SNDRV_TIMER_CLASS_CARD:
1356 		case SNDRV_TIMER_CLASS_PCM:
1357 			if (id.card < 0) {
1358 				id.card = 0;
1359 			} else {
1360 				if (id.card < 0) {
1361 					id.card = 0;
1362 				} else {
1363 					if (id.device < 0) {
1364 						id.device = 0;
1365 					} else {
1366 						if (id.subdevice < 0) {
1367 							id.subdevice = 0;
1368 						} else {
1369 							id.subdevice++;
1370 						}
1371 					}
1372 				}
1373 			}
1374 			list_for_each(p, &snd_timer_list) {
1375 				timer = list_entry(p, struct snd_timer, device_list);
1376 				if (timer->tmr_class > id.dev_class) {
1377 					snd_timer_user_copy_id(&id, timer);
1378 					break;
1379 				}
1380 				if (timer->tmr_class < id.dev_class)
1381 					continue;
1382 				if (timer->card->number > id.card) {
1383 					snd_timer_user_copy_id(&id, timer);
1384 					break;
1385 				}
1386 				if (timer->card->number < id.card)
1387 					continue;
1388 				if (timer->tmr_device > id.device) {
1389 					snd_timer_user_copy_id(&id, timer);
1390 					break;
1391 				}
1392 				if (timer->tmr_device < id.device)
1393 					continue;
1394 				if (timer->tmr_subdevice > id.subdevice) {
1395 					snd_timer_user_copy_id(&id, timer);
1396 					break;
1397 				}
1398 				if (timer->tmr_subdevice < id.subdevice)
1399 					continue;
1400 				snd_timer_user_copy_id(&id, timer);
1401 				break;
1402 			}
1403 			if (p == &snd_timer_list)
1404 				snd_timer_user_zero_id(&id);
1405 			break;
1406 		default:
1407 			snd_timer_user_zero_id(&id);
1408 		}
1409 	}
1410 	up(&register_mutex);
1411 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1412 		return -EFAULT;
1413 	return 0;
1414 }
1415 
1416 static int snd_timer_user_ginfo(struct file *file,
1417 				struct snd_timer_ginfo __user *_ginfo)
1418 {
1419 	struct snd_timer_ginfo *ginfo;
1420 	struct snd_timer_id tid;
1421 	struct snd_timer *t;
1422 	struct list_head *p;
1423 	int err = 0;
1424 
1425 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1426 	if (! ginfo)
1427 		return -ENOMEM;
1428 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1429 		kfree(ginfo);
1430 		return -EFAULT;
1431 	}
1432 	tid = ginfo->tid;
1433 	memset(ginfo, 0, sizeof(*ginfo));
1434 	ginfo->tid = tid;
1435 	down(&register_mutex);
1436 	t = snd_timer_find(&tid);
1437 	if (t != NULL) {
1438 		ginfo->card = t->card ? t->card->number : -1;
1439 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1440 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1441 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1442 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1443 		ginfo->resolution = t->hw.resolution;
1444 		if (t->hw.resolution_min > 0) {
1445 			ginfo->resolution_min = t->hw.resolution_min;
1446 			ginfo->resolution_max = t->hw.resolution_max;
1447 		}
1448 		list_for_each(p, &t->open_list_head) {
1449 			ginfo->clients++;
1450 		}
1451 	} else {
1452 		err = -ENODEV;
1453 	}
1454 	up(&register_mutex);
1455 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1456 		err = -EFAULT;
1457 	kfree(ginfo);
1458 	return err;
1459 }
1460 
1461 static int snd_timer_user_gparams(struct file *file,
1462 				  struct snd_timer_gparams __user *_gparams)
1463 {
1464 	struct snd_timer_gparams gparams;
1465 	struct snd_timer *t;
1466 	int err;
1467 
1468 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1469 		return -EFAULT;
1470 	down(&register_mutex);
1471 	t = snd_timer_find(&gparams.tid);
1472 	if (!t) {
1473 		err = -ENODEV;
1474 		goto _error;
1475 	}
1476 	if (!list_empty(&t->open_list_head)) {
1477 		err = -EBUSY;
1478 		goto _error;
1479 	}
1480 	if (!t->hw.set_period) {
1481 		err = -ENOSYS;
1482 		goto _error;
1483 	}
1484 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1485 _error:
1486 	up(&register_mutex);
1487 	return err;
1488 }
1489 
1490 static int snd_timer_user_gstatus(struct file *file,
1491 				  struct snd_timer_gstatus __user *_gstatus)
1492 {
1493 	struct snd_timer_gstatus gstatus;
1494 	struct snd_timer_id tid;
1495 	struct snd_timer *t;
1496 	int err = 0;
1497 
1498 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1499 		return -EFAULT;
1500 	tid = gstatus.tid;
1501 	memset(&gstatus, 0, sizeof(gstatus));
1502 	gstatus.tid = tid;
1503 	down(&register_mutex);
1504 	t = snd_timer_find(&tid);
1505 	if (t != NULL) {
1506 		if (t->hw.c_resolution)
1507 			gstatus.resolution = t->hw.c_resolution(t);
1508 		else
1509 			gstatus.resolution = t->hw.resolution;
1510 		if (t->hw.precise_resolution) {
1511 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1512 						 &gstatus.resolution_den);
1513 		} else {
1514 			gstatus.resolution_num = gstatus.resolution;
1515 			gstatus.resolution_den = 1000000000uL;
1516 		}
1517 	} else {
1518 		err = -ENODEV;
1519 	}
1520 	up(&register_mutex);
1521 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1522 		err = -EFAULT;
1523 	return err;
1524 }
1525 
1526 static int snd_timer_user_tselect(struct file *file,
1527 				  struct snd_timer_select __user *_tselect)
1528 {
1529 	struct snd_timer_user *tu;
1530 	struct snd_timer_select tselect;
1531 	char str[32];
1532 	int err = 0;
1533 
1534 	tu = file->private_data;
1535 	down(&tu->tread_sem);
1536 	if (tu->timeri) {
1537 		snd_timer_close(tu->timeri);
1538 		tu->timeri = NULL;
1539 	}
1540 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1541 		err = -EFAULT;
1542 		goto __err;
1543 	}
1544 	sprintf(str, "application %i", current->pid);
1545 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1546 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1547 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1548 	if (err < 0)
1549 		goto __err;
1550 
1551 	kfree(tu->queue);
1552 	tu->queue = NULL;
1553 	kfree(tu->tqueue);
1554 	tu->tqueue = NULL;
1555 	if (tu->tread) {
1556 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1557 				     GFP_KERNEL);
1558 		if (tu->tqueue == NULL)
1559 			err = -ENOMEM;
1560 	} else {
1561 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1562 				    GFP_KERNEL);
1563 		if (tu->queue == NULL)
1564 			err = -ENOMEM;
1565 	}
1566 
1567       	if (err < 0) {
1568 		snd_timer_close(tu->timeri);
1569       		tu->timeri = NULL;
1570       	} else {
1571 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1572 		tu->timeri->callback = tu->tread
1573 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1574 		tu->timeri->ccallback = snd_timer_user_ccallback;
1575 		tu->timeri->callback_data = (void *)tu;
1576 	}
1577 
1578       __err:
1579       	up(&tu->tread_sem);
1580 	return err;
1581 }
1582 
1583 static int snd_timer_user_info(struct file *file,
1584 			       struct snd_timer_info __user *_info)
1585 {
1586 	struct snd_timer_user *tu;
1587 	struct snd_timer_info *info;
1588 	struct snd_timer *t;
1589 	int err = 0;
1590 
1591 	tu = file->private_data;
1592 	snd_assert(tu->timeri != NULL, return -ENXIO);
1593 	t = tu->timeri->timer;
1594 	snd_assert(t != NULL, return -ENXIO);
1595 
1596 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1597 	if (! info)
1598 		return -ENOMEM;
1599 	info->card = t->card ? t->card->number : -1;
1600 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1601 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1602 	strlcpy(info->id, t->id, sizeof(info->id));
1603 	strlcpy(info->name, t->name, sizeof(info->name));
1604 	info->resolution = t->hw.resolution;
1605 	if (copy_to_user(_info, info, sizeof(*_info)))
1606 		err = -EFAULT;
1607 	kfree(info);
1608 	return err;
1609 }
1610 
1611 static int snd_timer_user_params(struct file *file,
1612 				 struct snd_timer_params __user *_params)
1613 {
1614 	struct snd_timer_user *tu;
1615 	struct snd_timer_params params;
1616 	struct snd_timer *t;
1617 	struct snd_timer_read *tr;
1618 	struct snd_timer_tread *ttr;
1619 	int err;
1620 
1621 	tu = file->private_data;
1622 	snd_assert(tu->timeri != NULL, return -ENXIO);
1623 	t = tu->timeri->timer;
1624 	snd_assert(t != NULL, return -ENXIO);
1625 	if (copy_from_user(&params, _params, sizeof(params)))
1626 		return -EFAULT;
1627 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1628 		err = -EINVAL;
1629 		goto _end;
1630 	}
1631 	if (params.queue_size > 0 &&
1632 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1633 		err = -EINVAL;
1634 		goto _end;
1635 	}
1636 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1637 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1638 			      (1<<SNDRV_TIMER_EVENT_START)|
1639 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1640 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1641 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1642 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1643 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1644 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1645 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1646 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1647 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1648 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1649 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1650 		err = -EINVAL;
1651 		goto _end;
1652 	}
1653 	snd_timer_stop(tu->timeri);
1654 	spin_lock_irq(&t->lock);
1655 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1656 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1657 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1658 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1659 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1660 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1661 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1662 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1663 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1664 	spin_unlock_irq(&t->lock);
1665 	if (params.queue_size > 0 &&
1666 	    (unsigned int)tu->queue_size != params.queue_size) {
1667 		if (tu->tread) {
1668 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1669 				      GFP_KERNEL);
1670 			if (ttr) {
1671 				kfree(tu->tqueue);
1672 				tu->queue_size = params.queue_size;
1673 				tu->tqueue = ttr;
1674 			}
1675 		} else {
1676 			tr = kmalloc(params.queue_size * sizeof(*tr),
1677 				     GFP_KERNEL);
1678 			if (tr) {
1679 				kfree(tu->queue);
1680 				tu->queue_size = params.queue_size;
1681 				tu->queue = tr;
1682 			}
1683 		}
1684 	}
1685 	tu->qhead = tu->qtail = tu->qused = 0;
1686 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1687 		if (tu->tread) {
1688 			struct snd_timer_tread tread;
1689 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1690 			tread.tstamp.tv_sec = 0;
1691 			tread.tstamp.tv_nsec = 0;
1692 			tread.val = 0;
1693 			snd_timer_user_append_to_tqueue(tu, &tread);
1694 		} else {
1695 			struct snd_timer_read *r = &tu->queue[0];
1696 			r->resolution = 0;
1697 			r->ticks = 0;
1698 			tu->qused++;
1699 			tu->qtail++;
1700 		}
1701 	}
1702 	tu->filter = params.filter;
1703 	tu->ticks = params.ticks;
1704 	err = 0;
1705  _end:
1706 	if (copy_to_user(_params, &params, sizeof(params)))
1707 		return -EFAULT;
1708 	return err;
1709 }
1710 
1711 static int snd_timer_user_status(struct file *file,
1712 				 struct snd_timer_status __user *_status)
1713 {
1714 	struct snd_timer_user *tu;
1715 	struct snd_timer_status status;
1716 
1717 	tu = file->private_data;
1718 	snd_assert(tu->timeri != NULL, return -ENXIO);
1719 	memset(&status, 0, sizeof(status));
1720 	status.tstamp = tu->tstamp;
1721 	status.resolution = snd_timer_resolution(tu->timeri);
1722 	status.lost = tu->timeri->lost;
1723 	status.overrun = tu->overrun;
1724 	spin_lock_irq(&tu->qlock);
1725 	status.queue = tu->qused;
1726 	spin_unlock_irq(&tu->qlock);
1727 	if (copy_to_user(_status, &status, sizeof(status)))
1728 		return -EFAULT;
1729 	return 0;
1730 }
1731 
1732 static int snd_timer_user_start(struct file *file)
1733 {
1734 	int err;
1735 	struct snd_timer_user *tu;
1736 
1737 	tu = file->private_data;
1738 	snd_assert(tu->timeri != NULL, return -ENXIO);
1739 	snd_timer_stop(tu->timeri);
1740 	tu->timeri->lost = 0;
1741 	tu->last_resolution = 0;
1742 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1743 }
1744 
1745 static int snd_timer_user_stop(struct file *file)
1746 {
1747 	int err;
1748 	struct snd_timer_user *tu;
1749 
1750 	tu = file->private_data;
1751 	snd_assert(tu->timeri != NULL, return -ENXIO);
1752 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1753 }
1754 
1755 static int snd_timer_user_continue(struct file *file)
1756 {
1757 	int err;
1758 	struct snd_timer_user *tu;
1759 
1760 	tu = file->private_data;
1761 	snd_assert(tu->timeri != NULL, return -ENXIO);
1762 	tu->timeri->lost = 0;
1763 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1764 }
1765 
1766 static int snd_timer_user_pause(struct file *file)
1767 {
1768 	int err;
1769 	struct snd_timer_user *tu;
1770 
1771 	tu = file->private_data;
1772 	snd_assert(tu->timeri != NULL, return -ENXIO);
1773 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1774 }
1775 
1776 enum {
1777 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1778 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1779 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1780 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1781 };
1782 
1783 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1784 				 unsigned long arg)
1785 {
1786 	struct snd_timer_user *tu;
1787 	void __user *argp = (void __user *)arg;
1788 	int __user *p = argp;
1789 
1790 	tu = file->private_data;
1791 	switch (cmd) {
1792 	case SNDRV_TIMER_IOCTL_PVERSION:
1793 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1794 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1795 		return snd_timer_user_next_device(argp);
1796 	case SNDRV_TIMER_IOCTL_TREAD:
1797 	{
1798 		int xarg;
1799 
1800 		down(&tu->tread_sem);
1801 		if (tu->timeri)	{	/* too late */
1802 			up(&tu->tread_sem);
1803 			return -EBUSY;
1804 		}
1805 		if (get_user(xarg, p)) {
1806 			up(&tu->tread_sem);
1807 			return -EFAULT;
1808 		}
1809 		tu->tread = xarg ? 1 : 0;
1810 		up(&tu->tread_sem);
1811 		return 0;
1812 	}
1813 	case SNDRV_TIMER_IOCTL_GINFO:
1814 		return snd_timer_user_ginfo(file, argp);
1815 	case SNDRV_TIMER_IOCTL_GPARAMS:
1816 		return snd_timer_user_gparams(file, argp);
1817 	case SNDRV_TIMER_IOCTL_GSTATUS:
1818 		return snd_timer_user_gstatus(file, argp);
1819 	case SNDRV_TIMER_IOCTL_SELECT:
1820 		return snd_timer_user_tselect(file, argp);
1821 	case SNDRV_TIMER_IOCTL_INFO:
1822 		return snd_timer_user_info(file, argp);
1823 	case SNDRV_TIMER_IOCTL_PARAMS:
1824 		return snd_timer_user_params(file, argp);
1825 	case SNDRV_TIMER_IOCTL_STATUS:
1826 		return snd_timer_user_status(file, argp);
1827 	case SNDRV_TIMER_IOCTL_START:
1828 	case SNDRV_TIMER_IOCTL_START_OLD:
1829 		return snd_timer_user_start(file);
1830 	case SNDRV_TIMER_IOCTL_STOP:
1831 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1832 		return snd_timer_user_stop(file);
1833 	case SNDRV_TIMER_IOCTL_CONTINUE:
1834 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1835 		return snd_timer_user_continue(file);
1836 	case SNDRV_TIMER_IOCTL_PAUSE:
1837 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1838 		return snd_timer_user_pause(file);
1839 	}
1840 	return -ENOTTY;
1841 }
1842 
1843 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1844 {
1845 	struct snd_timer_user *tu;
1846 	int err;
1847 
1848 	tu = file->private_data;
1849 	err = fasync_helper(fd, file, on, &tu->fasync);
1850         if (err < 0)
1851 		return err;
1852 	return 0;
1853 }
1854 
1855 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1856 				   size_t count, loff_t *offset)
1857 {
1858 	struct snd_timer_user *tu;
1859 	long result = 0, unit;
1860 	int err = 0;
1861 
1862 	tu = file->private_data;
1863 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1864 	spin_lock_irq(&tu->qlock);
1865 	while ((long)count - result >= unit) {
1866 		while (!tu->qused) {
1867 			wait_queue_t wait;
1868 
1869 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1870 				err = -EAGAIN;
1871 				break;
1872 			}
1873 
1874 			set_current_state(TASK_INTERRUPTIBLE);
1875 			init_waitqueue_entry(&wait, current);
1876 			add_wait_queue(&tu->qchange_sleep, &wait);
1877 
1878 			spin_unlock_irq(&tu->qlock);
1879 			schedule();
1880 			spin_lock_irq(&tu->qlock);
1881 
1882 			remove_wait_queue(&tu->qchange_sleep, &wait);
1883 
1884 			if (signal_pending(current)) {
1885 				err = -ERESTARTSYS;
1886 				break;
1887 			}
1888 		}
1889 
1890 		spin_unlock_irq(&tu->qlock);
1891 		if (err < 0)
1892 			goto _error;
1893 
1894 		if (tu->tread) {
1895 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1896 					 sizeof(struct snd_timer_tread))) {
1897 				err = -EFAULT;
1898 				goto _error;
1899 			}
1900 		} else {
1901 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1902 					 sizeof(struct snd_timer_read))) {
1903 				err = -EFAULT;
1904 				goto _error;
1905 			}
1906 		}
1907 
1908 		tu->qhead %= tu->queue_size;
1909 
1910 		result += unit;
1911 		buffer += unit;
1912 
1913 		spin_lock_irq(&tu->qlock);
1914 		tu->qused--;
1915 	}
1916 	spin_unlock_irq(&tu->qlock);
1917  _error:
1918 	return result > 0 ? result : err;
1919 }
1920 
1921 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1922 {
1923         unsigned int mask;
1924         struct snd_timer_user *tu;
1925 
1926         tu = file->private_data;
1927 
1928         poll_wait(file, &tu->qchange_sleep, wait);
1929 
1930 	mask = 0;
1931 	if (tu->qused)
1932 		mask |= POLLIN | POLLRDNORM;
1933 
1934 	return mask;
1935 }
1936 
1937 #ifdef CONFIG_COMPAT
1938 #include "timer_compat.c"
1939 #else
1940 #define snd_timer_user_ioctl_compat	NULL
1941 #endif
1942 
1943 static struct file_operations snd_timer_f_ops =
1944 {
1945 	.owner =	THIS_MODULE,
1946 	.read =		snd_timer_user_read,
1947 	.open =		snd_timer_user_open,
1948 	.release =	snd_timer_user_release,
1949 	.poll =		snd_timer_user_poll,
1950 	.unlocked_ioctl =	snd_timer_user_ioctl,
1951 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1952 	.fasync = 	snd_timer_user_fasync,
1953 };
1954 
1955 /*
1956  *  ENTRY functions
1957  */
1958 
1959 static int __init alsa_timer_init(void)
1960 {
1961 	int err;
1962 
1963 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1964 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1965 			      "system timer");
1966 #endif
1967 
1968 	if ((err = snd_timer_register_system()) < 0)
1969 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1970 			   err);
1971 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1972 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1973 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1974 			   err);
1975 	snd_timer_proc_init();
1976 	return 0;
1977 }
1978 
1979 static void __exit alsa_timer_exit(void)
1980 {
1981 	struct list_head *p, *n;
1982 
1983 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1984 	/* unregister the system timer */
1985 	list_for_each_safe(p, n, &snd_timer_list) {
1986 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1987 		snd_timer_unregister(timer);
1988 	}
1989 	snd_timer_proc_done();
1990 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1991 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1992 #endif
1993 }
1994 
1995 module_init(alsa_timer_init)
1996 module_exit(alsa_timer_exit)
1997 
1998 EXPORT_SYMBOL(snd_timer_open);
1999 EXPORT_SYMBOL(snd_timer_close);
2000 EXPORT_SYMBOL(snd_timer_resolution);
2001 EXPORT_SYMBOL(snd_timer_start);
2002 EXPORT_SYMBOL(snd_timer_stop);
2003 EXPORT_SYMBOL(snd_timer_continue);
2004 EXPORT_SYMBOL(snd_timer_pause);
2005 EXPORT_SYMBOL(snd_timer_new);
2006 EXPORT_SYMBOL(snd_timer_notify);
2007 EXPORT_SYMBOL(snd_timer_global_new);
2008 EXPORT_SYMBOL(snd_timer_global_free);
2009 EXPORT_SYMBOL(snd_timer_global_register);
2010 EXPORT_SYMBOL(snd_timer_global_unregister);
2011 EXPORT_SYMBOL(snd_timer_interrupt);
2012