xref: /linux/sound/core/timer.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <sound/driver.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/time.h>
28 #include <linux/mutex.h>
29 #include <linux/moduleparam.h>
30 #include <linux/string.h>
31 #include <sound/core.h>
32 #include <sound/timer.h>
33 #include <sound/control.h>
34 #include <sound/info.h>
35 #include <sound/minors.h>
36 #include <sound/initval.h>
37 #include <linux/kmod.h>
38 
39 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
40 #define DEFAULT_TIMER_LIMIT 3
41 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
42 #define DEFAULT_TIMER_LIMIT 2
43 #else
44 #define DEFAULT_TIMER_LIMIT 1
45 #endif
46 
47 static int timer_limit = DEFAULT_TIMER_LIMIT;
48 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
49 MODULE_DESCRIPTION("ALSA timer interface");
50 MODULE_LICENSE("GPL");
51 module_param(timer_limit, int, 0444);
52 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
53 
54 struct snd_timer_user {
55 	struct snd_timer_instance *timeri;
56 	int tread;		/* enhanced read with timestamps and events */
57 	unsigned long ticks;
58 	unsigned long overrun;
59 	int qhead;
60 	int qtail;
61 	int qused;
62 	int queue_size;
63 	struct snd_timer_read *queue;
64 	struct snd_timer_tread *tqueue;
65 	spinlock_t qlock;
66 	unsigned long last_resolution;
67 	unsigned int filter;
68 	struct timespec tstamp;		/* trigger tstamp */
69 	wait_queue_head_t qchange_sleep;
70 	struct fasync_struct *fasync;
71 	struct mutex tread_sem;
72 };
73 
74 /* list of timers */
75 static LIST_HEAD(snd_timer_list);
76 
77 /* list of slave instances */
78 static LIST_HEAD(snd_timer_slave_list);
79 
80 /* lock for slave active lists */
81 static DEFINE_SPINLOCK(slave_active_lock);
82 
83 static DEFINE_MUTEX(register_mutex);
84 
85 static int snd_timer_free(struct snd_timer *timer);
86 static int snd_timer_dev_free(struct snd_device *device);
87 static int snd_timer_dev_register(struct snd_device *device);
88 static int snd_timer_dev_disconnect(struct snd_device *device);
89 
90 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
91 
92 /*
93  * create a timer instance with the given owner string.
94  * when timer is not NULL, increments the module counter
95  */
96 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
97 							 struct snd_timer *timer)
98 {
99 	struct snd_timer_instance *timeri;
100 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
101 	if (timeri == NULL)
102 		return NULL;
103 	timeri->owner = kstrdup(owner, GFP_KERNEL);
104 	if (! timeri->owner) {
105 		kfree(timeri);
106 		return NULL;
107 	}
108 	INIT_LIST_HEAD(&timeri->open_list);
109 	INIT_LIST_HEAD(&timeri->active_list);
110 	INIT_LIST_HEAD(&timeri->ack_list);
111 	INIT_LIST_HEAD(&timeri->slave_list_head);
112 	INIT_LIST_HEAD(&timeri->slave_active_head);
113 
114 	timeri->timer = timer;
115 	if (timer && !try_module_get(timer->module)) {
116 		kfree(timeri->owner);
117 		kfree(timeri);
118 		return NULL;
119 	}
120 
121 	return timeri;
122 }
123 
124 /*
125  * find a timer instance from the given timer id
126  */
127 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
128 {
129 	struct snd_timer *timer = NULL;
130 
131 	list_for_each_entry(timer, &snd_timer_list, device_list) {
132 		if (timer->tmr_class != tid->dev_class)
133 			continue;
134 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
135 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
136 		    (timer->card == NULL ||
137 		     timer->card->number != tid->card))
138 			continue;
139 		if (timer->tmr_device != tid->device)
140 			continue;
141 		if (timer->tmr_subdevice != tid->subdevice)
142 			continue;
143 		return timer;
144 	}
145 	return NULL;
146 }
147 
148 #ifdef CONFIG_KMOD
149 
150 static void snd_timer_request(struct snd_timer_id *tid)
151 {
152 	if (! current->fs->root)
153 		return;
154 	switch (tid->dev_class) {
155 	case SNDRV_TIMER_CLASS_GLOBAL:
156 		if (tid->device < timer_limit)
157 			request_module("snd-timer-%i", tid->device);
158 		break;
159 	case SNDRV_TIMER_CLASS_CARD:
160 	case SNDRV_TIMER_CLASS_PCM:
161 		if (tid->card < snd_ecards_limit)
162 			request_module("snd-card-%i", tid->card);
163 		break;
164 	default:
165 		break;
166 	}
167 }
168 
169 #endif
170 
171 /*
172  * look for a master instance matching with the slave id of the given slave.
173  * when found, relink the open_link of the slave.
174  *
175  * call this with register_mutex down.
176  */
177 static void snd_timer_check_slave(struct snd_timer_instance *slave)
178 {
179 	struct snd_timer *timer;
180 	struct snd_timer_instance *master;
181 
182 	/* FIXME: it's really dumb to look up all entries.. */
183 	list_for_each_entry(timer, &snd_timer_list, device_list) {
184 		list_for_each_entry(master, &timer->open_list_head, open_list) {
185 			if (slave->slave_class == master->slave_class &&
186 			    slave->slave_id == master->slave_id) {
187 				list_del(&slave->open_list);
188 				list_add_tail(&slave->open_list,
189 					      &master->slave_list_head);
190 				spin_lock_irq(&slave_active_lock);
191 				slave->master = master;
192 				slave->timer = master->timer;
193 				spin_unlock_irq(&slave_active_lock);
194 				return;
195 			}
196 		}
197 	}
198 }
199 
200 /*
201  * look for slave instances matching with the slave id of the given master.
202  * when found, relink the open_link of slaves.
203  *
204  * call this with register_mutex down.
205  */
206 static void snd_timer_check_master(struct snd_timer_instance *master)
207 {
208 	struct snd_timer_instance *slave, *tmp;
209 
210 	/* check all pending slaves */
211 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
212 		if (slave->slave_class == master->slave_class &&
213 		    slave->slave_id == master->slave_id) {
214 			list_move_tail(&slave->open_list, &master->slave_list_head);
215 			spin_lock_irq(&slave_active_lock);
216 			slave->master = master;
217 			slave->timer = master->timer;
218 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
219 				list_add_tail(&slave->active_list,
220 					      &master->slave_active_head);
221 			spin_unlock_irq(&slave_active_lock);
222 		}
223 	}
224 }
225 
226 /*
227  * open a timer instance
228  * when opening a master, the slave id must be here given.
229  */
230 int snd_timer_open(struct snd_timer_instance **ti,
231 		   char *owner, struct snd_timer_id *tid,
232 		   unsigned int slave_id)
233 {
234 	struct snd_timer *timer;
235 	struct snd_timer_instance *timeri = NULL;
236 
237 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
238 		/* open a slave instance */
239 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
240 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
241 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
242 			return -EINVAL;
243 		}
244 		mutex_lock(&register_mutex);
245 		timeri = snd_timer_instance_new(owner, NULL);
246 		if (!timeri) {
247 			mutex_unlock(&register_mutex);
248 			return -ENOMEM;
249 		}
250 		timeri->slave_class = tid->dev_sclass;
251 		timeri->slave_id = tid->device;
252 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
253 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
254 		snd_timer_check_slave(timeri);
255 		mutex_unlock(&register_mutex);
256 		*ti = timeri;
257 		return 0;
258 	}
259 
260 	/* open a master instance */
261 	mutex_lock(&register_mutex);
262 	timer = snd_timer_find(tid);
263 #ifdef CONFIG_KMOD
264 	if (timer == NULL) {
265 		mutex_unlock(&register_mutex);
266 		snd_timer_request(tid);
267 		mutex_lock(&register_mutex);
268 		timer = snd_timer_find(tid);
269 	}
270 #endif
271 	if (!timer) {
272 		mutex_unlock(&register_mutex);
273 		return -ENODEV;
274 	}
275 	if (!list_empty(&timer->open_list_head)) {
276 		timeri = list_entry(timer->open_list_head.next,
277 				    struct snd_timer_instance, open_list);
278 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
279 			mutex_unlock(&register_mutex);
280 			return -EBUSY;
281 		}
282 	}
283 	timeri = snd_timer_instance_new(owner, timer);
284 	if (!timeri) {
285 		mutex_unlock(&register_mutex);
286 		return -ENOMEM;
287 	}
288 	timeri->slave_class = tid->dev_sclass;
289 	timeri->slave_id = slave_id;
290 	if (list_empty(&timer->open_list_head) && timer->hw.open)
291 		timer->hw.open(timer);
292 	list_add_tail(&timeri->open_list, &timer->open_list_head);
293 	snd_timer_check_master(timeri);
294 	mutex_unlock(&register_mutex);
295 	*ti = timeri;
296 	return 0;
297 }
298 
299 static int _snd_timer_stop(struct snd_timer_instance *timeri,
300 			   int keep_flag, int event);
301 
302 /*
303  * close a timer instance
304  */
305 int snd_timer_close(struct snd_timer_instance *timeri)
306 {
307 	struct snd_timer *timer = NULL;
308 	struct snd_timer_instance *slave, *tmp;
309 
310 	snd_assert(timeri != NULL, return -ENXIO);
311 
312 	/* force to stop the timer */
313 	snd_timer_stop(timeri);
314 
315 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
316 		/* wait, until the active callback is finished */
317 		spin_lock_irq(&slave_active_lock);
318 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
319 			spin_unlock_irq(&slave_active_lock);
320 			udelay(10);
321 			spin_lock_irq(&slave_active_lock);
322 		}
323 		spin_unlock_irq(&slave_active_lock);
324 		mutex_lock(&register_mutex);
325 		list_del(&timeri->open_list);
326 		mutex_unlock(&register_mutex);
327 	} else {
328 		timer = timeri->timer;
329 		/* wait, until the active callback is finished */
330 		spin_lock_irq(&timer->lock);
331 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
332 			spin_unlock_irq(&timer->lock);
333 			udelay(10);
334 			spin_lock_irq(&timer->lock);
335 		}
336 		spin_unlock_irq(&timer->lock);
337 		mutex_lock(&register_mutex);
338 		list_del(&timeri->open_list);
339 		if (timer && list_empty(&timer->open_list_head) &&
340 		    timer->hw.close)
341 			timer->hw.close(timer);
342 		/* remove slave links */
343 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
344 					 open_list) {
345 			spin_lock_irq(&slave_active_lock);
346 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
347 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
348 			slave->master = NULL;
349 			slave->timer = NULL;
350 			spin_unlock_irq(&slave_active_lock);
351 		}
352 		mutex_unlock(&register_mutex);
353 	}
354 	if (timeri->private_free)
355 		timeri->private_free(timeri);
356 	kfree(timeri->owner);
357 	kfree(timeri);
358 	if (timer)
359 		module_put(timer->module);
360 	return 0;
361 }
362 
363 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
364 {
365 	struct snd_timer * timer;
366 
367 	if (timeri == NULL)
368 		return 0;
369 	if ((timer = timeri->timer) != NULL) {
370 		if (timer->hw.c_resolution)
371 			return timer->hw.c_resolution(timer);
372 		return timer->hw.resolution;
373 	}
374 	return 0;
375 }
376 
377 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
378 {
379 	struct snd_timer *timer;
380 	unsigned long flags;
381 	unsigned long resolution = 0;
382 	struct snd_timer_instance *ts;
383 	struct timespec tstamp;
384 
385 	getnstimeofday(&tstamp);
386 	snd_assert(event >= SNDRV_TIMER_EVENT_START &&
387 		   event <= SNDRV_TIMER_EVENT_PAUSE, return);
388 	if (event == SNDRV_TIMER_EVENT_START ||
389 	    event == SNDRV_TIMER_EVENT_CONTINUE)
390 		resolution = snd_timer_resolution(ti);
391 	if (ti->ccallback)
392 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
393 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
394 		return;
395 	timer = ti->timer;
396 	if (timer == NULL)
397 		return;
398 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
399 		return;
400 	spin_lock_irqsave(&timer->lock, flags);
401 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
402 		if (ts->ccallback)
403 			ts->ccallback(ti, event + 100, &tstamp, resolution);
404 	spin_unlock_irqrestore(&timer->lock, flags);
405 }
406 
407 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
408 			    unsigned long sticks)
409 {
410 	list_del(&timeri->active_list);
411 	list_add_tail(&timeri->active_list, &timer->active_list_head);
412 	if (timer->running) {
413 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
414 			goto __start_now;
415 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
416 		timeri->flags |= SNDRV_TIMER_IFLG_START;
417 		return 1;	/* delayed start */
418 	} else {
419 		timer->sticks = sticks;
420 		timer->hw.start(timer);
421 	      __start_now:
422 		timer->running++;
423 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
424 		return 0;
425 	}
426 }
427 
428 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
429 {
430 	unsigned long flags;
431 
432 	spin_lock_irqsave(&slave_active_lock, flags);
433 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
434 	if (timeri->master)
435 		list_add_tail(&timeri->active_list,
436 			      &timeri->master->slave_active_head);
437 	spin_unlock_irqrestore(&slave_active_lock, flags);
438 	return 1; /* delayed start */
439 }
440 
441 /*
442  *  start the timer instance
443  */
444 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
445 {
446 	struct snd_timer *timer;
447 	int result = -EINVAL;
448 	unsigned long flags;
449 
450 	if (timeri == NULL || ticks < 1)
451 		return -EINVAL;
452 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
453 		result = snd_timer_start_slave(timeri);
454 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
455 		return result;
456 	}
457 	timer = timeri->timer;
458 	if (timer == NULL)
459 		return -EINVAL;
460 	spin_lock_irqsave(&timer->lock, flags);
461 	timeri->ticks = timeri->cticks = ticks;
462 	timeri->pticks = 0;
463 	result = snd_timer_start1(timer, timeri, ticks);
464 	spin_unlock_irqrestore(&timer->lock, flags);
465 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
466 	return result;
467 }
468 
469 static int _snd_timer_stop(struct snd_timer_instance * timeri,
470 			   int keep_flag, int event)
471 {
472 	struct snd_timer *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 &=
505 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
506 	spin_unlock_irqrestore(&timer->lock, flags);
507       __end:
508 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
509 		snd_timer_notify1(timeri, event);
510 	return 0;
511 }
512 
513 /*
514  * stop the timer instance.
515  *
516  * do not call this from the timer callback!
517  */
518 int snd_timer_stop(struct snd_timer_instance *timeri)
519 {
520 	struct snd_timer *timer;
521 	unsigned long flags;
522 	int err;
523 
524 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
525 	if (err < 0)
526 		return err;
527 	timer = timeri->timer;
528 	spin_lock_irqsave(&timer->lock, flags);
529 	timeri->cticks = timeri->ticks;
530 	timeri->pticks = 0;
531 	spin_unlock_irqrestore(&timer->lock, flags);
532 	return 0;
533 }
534 
535 /*
536  * start again..  the tick is kept.
537  */
538 int snd_timer_continue(struct snd_timer_instance *timeri)
539 {
540 	struct snd_timer *timer;
541 	int result = -EINVAL;
542 	unsigned long flags;
543 
544 	if (timeri == NULL)
545 		return result;
546 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
547 		return snd_timer_start_slave(timeri);
548 	timer = timeri->timer;
549 	if (! timer)
550 		return -EINVAL;
551 	spin_lock_irqsave(&timer->lock, flags);
552 	if (!timeri->cticks)
553 		timeri->cticks = 1;
554 	timeri->pticks = 0;
555 	result = snd_timer_start1(timer, timeri, timer->sticks);
556 	spin_unlock_irqrestore(&timer->lock, flags);
557 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
558 	return result;
559 }
560 
561 /*
562  * pause.. remember the ticks left
563  */
564 int snd_timer_pause(struct snd_timer_instance * timeri)
565 {
566 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
567 }
568 
569 /*
570  * reschedule the timer
571  *
572  * start pending instances and check the scheduling ticks.
573  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
574  */
575 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
576 {
577 	struct snd_timer_instance *ti;
578 	unsigned long ticks = ~0UL;
579 
580 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
581 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
582 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
583 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
584 			timer->running++;
585 		}
586 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
587 			if (ticks > ti->cticks)
588 				ticks = ti->cticks;
589 		}
590 	}
591 	if (ticks == ~0UL) {
592 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
593 		return;
594 	}
595 	if (ticks > timer->hw.ticks)
596 		ticks = timer->hw.ticks;
597 	if (ticks_left != ticks)
598 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
599 	timer->sticks = ticks;
600 }
601 
602 /*
603  * timer tasklet
604  *
605  */
606 static void snd_timer_tasklet(unsigned long arg)
607 {
608 	struct snd_timer *timer = (struct snd_timer *) arg;
609 	struct snd_timer_instance *ti;
610 	struct list_head *p;
611 	unsigned long resolution, ticks;
612 	unsigned long flags;
613 
614 	spin_lock_irqsave(&timer->lock, flags);
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 = list_entry(p, struct snd_timer_instance, 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_irqrestore(&timer->lock, flags);
635 }
636 
637 /*
638  * timer interrupt
639  *
640  * ticks_left is usually equal to timer->sticks.
641  *
642  */
643 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
644 {
645 	struct snd_timer_instance *ti, *ts, *tmp;
646 	unsigned long resolution, ticks;
647 	struct list_head *p, *ack_list_head;
648 	unsigned long flags;
649 	int use_tasklet = 0;
650 
651 	if (timer == NULL)
652 		return;
653 
654 	spin_lock_irqsave(&timer->lock, flags);
655 
656 	/* remember the current resolution */
657 	if (timer->hw.c_resolution)
658 		resolution = timer->hw.c_resolution(timer);
659 	else
660 		resolution = timer->hw.resolution;
661 
662 	/* loop for all active instances
663 	 * Here we cannot use list_for_each_entry because the active_list of a
664 	 * processed instance is relinked to done_list_head before the callback
665 	 * is called.
666 	 */
667 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
668 				 active_list) {
669 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
670 			continue;
671 		ti->pticks += ticks_left;
672 		ti->resolution = resolution;
673 		if (ti->cticks < ticks_left)
674 			ti->cticks = 0;
675 		else
676 			ti->cticks -= ticks_left;
677 		if (ti->cticks) /* not expired */
678 			continue;
679 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
680 			ti->cticks = ti->ticks;
681 		} else {
682 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
683 			if (--timer->running)
684 				list_del(&ti->active_list);
685 		}
686 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
687 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
688 			ack_list_head = &timer->ack_list_head;
689 		else
690 			ack_list_head = &timer->sack_list_head;
691 		if (list_empty(&ti->ack_list))
692 			list_add_tail(&ti->ack_list, ack_list_head);
693 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
694 			ts->pticks = ti->pticks;
695 			ts->resolution = resolution;
696 			if (list_empty(&ts->ack_list))
697 				list_add_tail(&ts->ack_list, ack_list_head);
698 		}
699 	}
700 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
701 		snd_timer_reschedule(timer, timer->sticks);
702 	if (timer->running) {
703 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
704 			timer->hw.stop(timer);
705 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
706 		}
707 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
708 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
709 			/* restart timer */
710 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
711 			timer->hw.start(timer);
712 		}
713 	} else {
714 		timer->hw.stop(timer);
715 	}
716 
717 	/* now process all fast callbacks */
718 	while (!list_empty(&timer->ack_list_head)) {
719 		p = timer->ack_list_head.next;		/* get first item */
720 		ti = list_entry(p, struct snd_timer_instance, ack_list);
721 
722 		/* remove from ack_list and make empty */
723 		list_del_init(p);
724 
725 		ticks = ti->pticks;
726 		ti->pticks = 0;
727 
728 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
729 		spin_unlock(&timer->lock);
730 		if (ti->callback)
731 			ti->callback(ti, resolution, ticks);
732 		spin_lock(&timer->lock);
733 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
734 	}
735 
736 	/* do we have any slow callbacks? */
737 	use_tasklet = !list_empty(&timer->sack_list_head);
738 	spin_unlock_irqrestore(&timer->lock, flags);
739 
740 	if (use_tasklet)
741 		tasklet_hi_schedule(&timer->task_queue);
742 }
743 
744 /*
745 
746  */
747 
748 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
749 		  struct snd_timer **rtimer)
750 {
751 	struct snd_timer *timer;
752 	int err;
753 	static struct snd_device_ops ops = {
754 		.dev_free = snd_timer_dev_free,
755 		.dev_register = snd_timer_dev_register,
756 		.dev_disconnect = snd_timer_dev_disconnect,
757 	};
758 
759 	snd_assert(tid != NULL, return -EINVAL);
760 	snd_assert(rtimer != NULL, return -EINVAL);
761 	*rtimer = NULL;
762 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
763 	if (timer == NULL) {
764 		snd_printk(KERN_ERR "timer: cannot allocate\n");
765 		return -ENOMEM;
766 	}
767 	timer->tmr_class = tid->dev_class;
768 	timer->card = card;
769 	timer->tmr_device = tid->device;
770 	timer->tmr_subdevice = tid->subdevice;
771 	if (id)
772 		strlcpy(timer->id, id, sizeof(timer->id));
773 	INIT_LIST_HEAD(&timer->device_list);
774 	INIT_LIST_HEAD(&timer->open_list_head);
775 	INIT_LIST_HEAD(&timer->active_list_head);
776 	INIT_LIST_HEAD(&timer->ack_list_head);
777 	INIT_LIST_HEAD(&timer->sack_list_head);
778 	spin_lock_init(&timer->lock);
779 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
780 		     (unsigned long)timer);
781 	if (card != NULL) {
782 		timer->module = card->module;
783 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
784 		if (err < 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(struct snd_timer *timer)
794 {
795 	snd_assert(timer != NULL, return -ENXIO);
796 
797 	mutex_lock(&register_mutex);
798 	if (! list_empty(&timer->open_list_head)) {
799 		struct list_head *p, *n;
800 		struct snd_timer_instance *ti;
801 		snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
802 		list_for_each_safe(p, n, &timer->open_list_head) {
803 			list_del_init(p);
804 			ti = list_entry(p, struct snd_timer_instance, open_list);
805 			ti->timer = NULL;
806 		}
807 	}
808 	list_del(&timer->device_list);
809 	mutex_unlock(&register_mutex);
810 
811 	if (timer->private_free)
812 		timer->private_free(timer);
813 	kfree(timer);
814 	return 0;
815 }
816 
817 static int snd_timer_dev_free(struct snd_device *device)
818 {
819 	struct snd_timer *timer = device->device_data;
820 	return snd_timer_free(timer);
821 }
822 
823 static int snd_timer_dev_register(struct snd_device *dev)
824 {
825 	struct snd_timer *timer = dev->device_data;
826 	struct snd_timer *timer1;
827 
828 	snd_assert(timer != NULL && timer->hw.start != NULL &&
829 		   timer->hw.stop != NULL, return -ENXIO);
830 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
831 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
832 	    	return -EINVAL;
833 
834 	mutex_lock(&register_mutex);
835 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
836 		if (timer1->tmr_class > timer->tmr_class)
837 			break;
838 		if (timer1->tmr_class < timer->tmr_class)
839 			continue;
840 		if (timer1->card && timer->card) {
841 			if (timer1->card->number > timer->card->number)
842 				break;
843 			if (timer1->card->number < timer->card->number)
844 				continue;
845 		}
846 		if (timer1->tmr_device > timer->tmr_device)
847 			break;
848 		if (timer1->tmr_device < timer->tmr_device)
849 			continue;
850 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
851 			break;
852 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
853 			continue;
854 		/* conflicts.. */
855 		mutex_unlock(&register_mutex);
856 		return -EBUSY;
857 	}
858 	list_add_tail(&timer->device_list, &timer1->device_list);
859 	mutex_unlock(&register_mutex);
860 	return 0;
861 }
862 
863 static int snd_timer_dev_disconnect(struct snd_device *device)
864 {
865 	struct snd_timer *timer = device->device_data;
866 	mutex_lock(&register_mutex);
867 	list_del_init(&timer->device_list);
868 	mutex_unlock(&register_mutex);
869 	return 0;
870 }
871 
872 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
873 {
874 	unsigned long flags;
875 	unsigned long resolution = 0;
876 	struct snd_timer_instance *ti, *ts;
877 
878 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
879 		return;
880 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART &&
881 		   event <= SNDRV_TIMER_EVENT_MRESUME, return);
882 	spin_lock_irqsave(&timer->lock, flags);
883 	if (event == SNDRV_TIMER_EVENT_MSTART ||
884 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
885 	    event == SNDRV_TIMER_EVENT_MRESUME) {
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_entry(ti, &timer->active_list_head, active_list) {
892 		if (ti->ccallback)
893 			ti->ccallback(ti, event, tstamp, resolution);
894 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
895 			if (ts->ccallback)
896 				ts->ccallback(ts, event, tstamp, resolution);
897 	}
898 	spin_unlock_irqrestore(&timer->lock, flags);
899 }
900 
901 /*
902  * exported functions for global timers
903  */
904 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
905 {
906 	struct snd_timer_id tid;
907 
908 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
909 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
910 	tid.card = -1;
911 	tid.device = device;
912 	tid.subdevice = 0;
913 	return snd_timer_new(NULL, id, &tid, rtimer);
914 }
915 
916 int snd_timer_global_free(struct snd_timer *timer)
917 {
918 	return snd_timer_free(timer);
919 }
920 
921 int snd_timer_global_register(struct snd_timer *timer)
922 {
923 	struct snd_device dev;
924 
925 	memset(&dev, 0, sizeof(dev));
926 	dev.device_data = timer;
927 	return snd_timer_dev_register(&dev);
928 }
929 
930 /*
931  *  System timer
932  */
933 
934 struct snd_timer_system_private {
935 	struct timer_list tlist;
936 	unsigned long last_expires;
937 	unsigned long last_jiffies;
938 	unsigned long correction;
939 };
940 
941 static void snd_timer_s_function(unsigned long data)
942 {
943 	struct snd_timer *timer = (struct snd_timer *)data;
944 	struct snd_timer_system_private *priv = timer->private_data;
945 	unsigned long jiff = jiffies;
946 	if (time_after(jiff, priv->last_expires))
947 		priv->correction += (long)jiff - (long)priv->last_expires;
948 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
949 }
950 
951 static int snd_timer_s_start(struct snd_timer * timer)
952 {
953 	struct snd_timer_system_private *priv;
954 	unsigned long njiff;
955 
956 	priv = (struct snd_timer_system_private *) timer->private_data;
957 	njiff = (priv->last_jiffies = jiffies);
958 	if (priv->correction > timer->sticks - 1) {
959 		priv->correction -= timer->sticks - 1;
960 		njiff++;
961 	} else {
962 		njiff += timer->sticks - priv->correction;
963 		priv->correction = 0;
964 	}
965 	priv->last_expires = priv->tlist.expires = njiff;
966 	add_timer(&priv->tlist);
967 	return 0;
968 }
969 
970 static int snd_timer_s_stop(struct snd_timer * timer)
971 {
972 	struct snd_timer_system_private *priv;
973 	unsigned long jiff;
974 
975 	priv = (struct snd_timer_system_private *) timer->private_data;
976 	del_timer(&priv->tlist);
977 	jiff = jiffies;
978 	if (time_before(jiff, priv->last_expires))
979 		timer->sticks = priv->last_expires - jiff;
980 	else
981 		timer->sticks = 1;
982 	priv->correction = 0;
983 	return 0;
984 }
985 
986 static struct snd_timer_hardware snd_timer_system =
987 {
988 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
989 	.resolution =	1000000000L / HZ,
990 	.ticks =	10000000L,
991 	.start =	snd_timer_s_start,
992 	.stop =		snd_timer_s_stop
993 };
994 
995 static void snd_timer_free_system(struct snd_timer *timer)
996 {
997 	kfree(timer->private_data);
998 }
999 
1000 static int snd_timer_register_system(void)
1001 {
1002 	struct snd_timer *timer;
1003 	struct snd_timer_system_private *priv;
1004 	int err;
1005 
1006 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1007 	if (err < 0)
1008 		return err;
1009 	strcpy(timer->name, "system timer");
1010 	timer->hw = snd_timer_system;
1011 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1012 	if (priv == NULL) {
1013 		snd_timer_free(timer);
1014 		return -ENOMEM;
1015 	}
1016 	init_timer(&priv->tlist);
1017 	priv->tlist.function = snd_timer_s_function;
1018 	priv->tlist.data = (unsigned long) timer;
1019 	timer->private_data = priv;
1020 	timer->private_free = snd_timer_free_system;
1021 	return snd_timer_global_register(timer);
1022 }
1023 
1024 #ifdef CONFIG_PROC_FS
1025 /*
1026  *  Info interface
1027  */
1028 
1029 static void snd_timer_proc_read(struct snd_info_entry *entry,
1030 				struct snd_info_buffer *buffer)
1031 {
1032 	struct snd_timer *timer;
1033 	struct snd_timer_instance *ti;
1034 
1035 	mutex_lock(&register_mutex);
1036 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1037 		switch (timer->tmr_class) {
1038 		case SNDRV_TIMER_CLASS_GLOBAL:
1039 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1040 			break;
1041 		case SNDRV_TIMER_CLASS_CARD:
1042 			snd_iprintf(buffer, "C%i-%i: ",
1043 				    timer->card->number, timer->tmr_device);
1044 			break;
1045 		case SNDRV_TIMER_CLASS_PCM:
1046 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1047 				    timer->tmr_device, timer->tmr_subdevice);
1048 			break;
1049 		default:
1050 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1051 				    timer->card ? timer->card->number : -1,
1052 				    timer->tmr_device, timer->tmr_subdevice);
1053 		}
1054 		snd_iprintf(buffer, "%s :", timer->name);
1055 		if (timer->hw.resolution)
1056 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1057 				    timer->hw.resolution / 1000,
1058 				    timer->hw.resolution % 1000,
1059 				    timer->hw.ticks);
1060 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1061 			snd_iprintf(buffer, " SLAVE");
1062 		snd_iprintf(buffer, "\n");
1063 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1064 			snd_iprintf(buffer, "  Client %s : %s\n",
1065 				    ti->owner ? ti->owner : "unknown",
1066 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1067 						 SNDRV_TIMER_IFLG_RUNNING)
1068 				    ? "running" : "stopped");
1069 	}
1070 	mutex_unlock(&register_mutex);
1071 }
1072 
1073 static struct snd_info_entry *snd_timer_proc_entry;
1074 
1075 static void __init snd_timer_proc_init(void)
1076 {
1077 	struct snd_info_entry *entry;
1078 
1079 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1080 	if (entry != NULL) {
1081 		entry->c.text.read = snd_timer_proc_read;
1082 		if (snd_info_register(entry) < 0) {
1083 			snd_info_free_entry(entry);
1084 			entry = NULL;
1085 		}
1086 	}
1087 	snd_timer_proc_entry = entry;
1088 }
1089 
1090 static void __exit snd_timer_proc_done(void)
1091 {
1092 	snd_info_free_entry(snd_timer_proc_entry);
1093 }
1094 #else /* !CONFIG_PROC_FS */
1095 #define snd_timer_proc_init()
1096 #define snd_timer_proc_done()
1097 #endif
1098 
1099 /*
1100  *  USER SPACE interface
1101  */
1102 
1103 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1104 				     unsigned long resolution,
1105 				     unsigned long ticks)
1106 {
1107 	struct snd_timer_user *tu = timeri->callback_data;
1108 	struct snd_timer_read *r;
1109 	int prev;
1110 
1111 	spin_lock(&tu->qlock);
1112 	if (tu->qused > 0) {
1113 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1114 		r = &tu->queue[prev];
1115 		if (r->resolution == resolution) {
1116 			r->ticks += ticks;
1117 			goto __wake;
1118 		}
1119 	}
1120 	if (tu->qused >= tu->queue_size) {
1121 		tu->overrun++;
1122 	} else {
1123 		r = &tu->queue[tu->qtail++];
1124 		tu->qtail %= tu->queue_size;
1125 		r->resolution = resolution;
1126 		r->ticks = ticks;
1127 		tu->qused++;
1128 	}
1129       __wake:
1130 	spin_unlock(&tu->qlock);
1131 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1132 	wake_up(&tu->qchange_sleep);
1133 }
1134 
1135 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1136 					    struct snd_timer_tread *tread)
1137 {
1138 	if (tu->qused >= tu->queue_size) {
1139 		tu->overrun++;
1140 	} else {
1141 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1142 		tu->qtail %= tu->queue_size;
1143 		tu->qused++;
1144 	}
1145 }
1146 
1147 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1148 				     int event,
1149 				     struct timespec *tstamp,
1150 				     unsigned long resolution)
1151 {
1152 	struct snd_timer_user *tu = timeri->callback_data;
1153 	struct snd_timer_tread r1;
1154 
1155 	if (event >= SNDRV_TIMER_EVENT_START &&
1156 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1157 		tu->tstamp = *tstamp;
1158 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1159 		return;
1160 	r1.event = event;
1161 	r1.tstamp = *tstamp;
1162 	r1.val = resolution;
1163 	spin_lock(&tu->qlock);
1164 	snd_timer_user_append_to_tqueue(tu, &r1);
1165 	spin_unlock(&tu->qlock);
1166 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1167 	wake_up(&tu->qchange_sleep);
1168 }
1169 
1170 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1171 				      unsigned long resolution,
1172 				      unsigned long ticks)
1173 {
1174 	struct snd_timer_user *tu = timeri->callback_data;
1175 	struct snd_timer_tread *r, r1;
1176 	struct timespec tstamp;
1177 	int prev, append = 0;
1178 
1179 	memset(&tstamp, 0, sizeof(tstamp));
1180 	spin_lock(&tu->qlock);
1181 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1182 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1183 		spin_unlock(&tu->qlock);
1184 		return;
1185 	}
1186 	if (tu->last_resolution != resolution || ticks > 0)
1187 		getnstimeofday(&tstamp);
1188 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1189 	    tu->last_resolution != resolution) {
1190 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1191 		r1.tstamp = tstamp;
1192 		r1.val = resolution;
1193 		snd_timer_user_append_to_tqueue(tu, &r1);
1194 		tu->last_resolution = resolution;
1195 		append++;
1196 	}
1197 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1198 		goto __wake;
1199 	if (ticks == 0)
1200 		goto __wake;
1201 	if (tu->qused > 0) {
1202 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1203 		r = &tu->tqueue[prev];
1204 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1205 			r->tstamp = tstamp;
1206 			r->val += ticks;
1207 			append++;
1208 			goto __wake;
1209 		}
1210 	}
1211 	r1.event = SNDRV_TIMER_EVENT_TICK;
1212 	r1.tstamp = tstamp;
1213 	r1.val = ticks;
1214 	snd_timer_user_append_to_tqueue(tu, &r1);
1215 	append++;
1216       __wake:
1217 	spin_unlock(&tu->qlock);
1218 	if (append == 0)
1219 		return;
1220 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1221 	wake_up(&tu->qchange_sleep);
1222 }
1223 
1224 static int snd_timer_user_open(struct inode *inode, struct file *file)
1225 {
1226 	struct snd_timer_user *tu;
1227 
1228 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1229 	if (tu == NULL)
1230 		return -ENOMEM;
1231 	spin_lock_init(&tu->qlock);
1232 	init_waitqueue_head(&tu->qchange_sleep);
1233 	mutex_init(&tu->tread_sem);
1234 	tu->ticks = 1;
1235 	tu->queue_size = 128;
1236 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1237 			    GFP_KERNEL);
1238 	if (tu->queue == NULL) {
1239 		kfree(tu);
1240 		return -ENOMEM;
1241 	}
1242 	file->private_data = tu;
1243 	return 0;
1244 }
1245 
1246 static int snd_timer_user_release(struct inode *inode, struct file *file)
1247 {
1248 	struct snd_timer_user *tu;
1249 
1250 	if (file->private_data) {
1251 		tu = file->private_data;
1252 		file->private_data = NULL;
1253 		fasync_helper(-1, file, 0, &tu->fasync);
1254 		if (tu->timeri)
1255 			snd_timer_close(tu->timeri);
1256 		kfree(tu->queue);
1257 		kfree(tu->tqueue);
1258 		kfree(tu);
1259 	}
1260 	return 0;
1261 }
1262 
1263 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1264 {
1265 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1266 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1267 	id->card = -1;
1268 	id->device = -1;
1269 	id->subdevice = -1;
1270 }
1271 
1272 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1273 {
1274 	id->dev_class = timer->tmr_class;
1275 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1276 	id->card = timer->card ? timer->card->number : -1;
1277 	id->device = timer->tmr_device;
1278 	id->subdevice = timer->tmr_subdevice;
1279 }
1280 
1281 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1282 {
1283 	struct snd_timer_id id;
1284 	struct snd_timer *timer;
1285 	struct list_head *p;
1286 
1287 	if (copy_from_user(&id, _tid, sizeof(id)))
1288 		return -EFAULT;
1289 	mutex_lock(&register_mutex);
1290 	if (id.dev_class < 0) {		/* first item */
1291 		if (list_empty(&snd_timer_list))
1292 			snd_timer_user_zero_id(&id);
1293 		else {
1294 			timer = list_entry(snd_timer_list.next,
1295 					   struct snd_timer, device_list);
1296 			snd_timer_user_copy_id(&id, timer);
1297 		}
1298 	} else {
1299 		switch (id.dev_class) {
1300 		case SNDRV_TIMER_CLASS_GLOBAL:
1301 			id.device = id.device < 0 ? 0 : id.device + 1;
1302 			list_for_each(p, &snd_timer_list) {
1303 				timer = list_entry(p, struct snd_timer, device_list);
1304 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1305 					snd_timer_user_copy_id(&id, timer);
1306 					break;
1307 				}
1308 				if (timer->tmr_device >= id.device) {
1309 					snd_timer_user_copy_id(&id, timer);
1310 					break;
1311 				}
1312 			}
1313 			if (p == &snd_timer_list)
1314 				snd_timer_user_zero_id(&id);
1315 			break;
1316 		case SNDRV_TIMER_CLASS_CARD:
1317 		case SNDRV_TIMER_CLASS_PCM:
1318 			if (id.card < 0) {
1319 				id.card = 0;
1320 			} else {
1321 				if (id.card < 0) {
1322 					id.card = 0;
1323 				} else {
1324 					if (id.device < 0) {
1325 						id.device = 0;
1326 					} else {
1327 						if (id.subdevice < 0) {
1328 							id.subdevice = 0;
1329 						} else {
1330 							id.subdevice++;
1331 						}
1332 					}
1333 				}
1334 			}
1335 			list_for_each(p, &snd_timer_list) {
1336 				timer = list_entry(p, struct snd_timer, device_list);
1337 				if (timer->tmr_class > id.dev_class) {
1338 					snd_timer_user_copy_id(&id, timer);
1339 					break;
1340 				}
1341 				if (timer->tmr_class < id.dev_class)
1342 					continue;
1343 				if (timer->card->number > id.card) {
1344 					snd_timer_user_copy_id(&id, timer);
1345 					break;
1346 				}
1347 				if (timer->card->number < id.card)
1348 					continue;
1349 				if (timer->tmr_device > id.device) {
1350 					snd_timer_user_copy_id(&id, timer);
1351 					break;
1352 				}
1353 				if (timer->tmr_device < id.device)
1354 					continue;
1355 				if (timer->tmr_subdevice > id.subdevice) {
1356 					snd_timer_user_copy_id(&id, timer);
1357 					break;
1358 				}
1359 				if (timer->tmr_subdevice < id.subdevice)
1360 					continue;
1361 				snd_timer_user_copy_id(&id, timer);
1362 				break;
1363 			}
1364 			if (p == &snd_timer_list)
1365 				snd_timer_user_zero_id(&id);
1366 			break;
1367 		default:
1368 			snd_timer_user_zero_id(&id);
1369 		}
1370 	}
1371 	mutex_unlock(&register_mutex);
1372 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1373 		return -EFAULT;
1374 	return 0;
1375 }
1376 
1377 static int snd_timer_user_ginfo(struct file *file,
1378 				struct snd_timer_ginfo __user *_ginfo)
1379 {
1380 	struct snd_timer_ginfo *ginfo;
1381 	struct snd_timer_id tid;
1382 	struct snd_timer *t;
1383 	struct list_head *p;
1384 	int err = 0;
1385 
1386 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1387 	if (! ginfo)
1388 		return -ENOMEM;
1389 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1390 		kfree(ginfo);
1391 		return -EFAULT;
1392 	}
1393 	tid = ginfo->tid;
1394 	memset(ginfo, 0, sizeof(*ginfo));
1395 	ginfo->tid = tid;
1396 	mutex_lock(&register_mutex);
1397 	t = snd_timer_find(&tid);
1398 	if (t != NULL) {
1399 		ginfo->card = t->card ? t->card->number : -1;
1400 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1401 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1402 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1403 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1404 		ginfo->resolution = t->hw.resolution;
1405 		if (t->hw.resolution_min > 0) {
1406 			ginfo->resolution_min = t->hw.resolution_min;
1407 			ginfo->resolution_max = t->hw.resolution_max;
1408 		}
1409 		list_for_each(p, &t->open_list_head) {
1410 			ginfo->clients++;
1411 		}
1412 	} else {
1413 		err = -ENODEV;
1414 	}
1415 	mutex_unlock(&register_mutex);
1416 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1417 		err = -EFAULT;
1418 	kfree(ginfo);
1419 	return err;
1420 }
1421 
1422 static int snd_timer_user_gparams(struct file *file,
1423 				  struct snd_timer_gparams __user *_gparams)
1424 {
1425 	struct snd_timer_gparams gparams;
1426 	struct snd_timer *t;
1427 	int err;
1428 
1429 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1430 		return -EFAULT;
1431 	mutex_lock(&register_mutex);
1432 	t = snd_timer_find(&gparams.tid);
1433 	if (!t) {
1434 		err = -ENODEV;
1435 		goto _error;
1436 	}
1437 	if (!list_empty(&t->open_list_head)) {
1438 		err = -EBUSY;
1439 		goto _error;
1440 	}
1441 	if (!t->hw.set_period) {
1442 		err = -ENOSYS;
1443 		goto _error;
1444 	}
1445 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1446 _error:
1447 	mutex_unlock(&register_mutex);
1448 	return err;
1449 }
1450 
1451 static int snd_timer_user_gstatus(struct file *file,
1452 				  struct snd_timer_gstatus __user *_gstatus)
1453 {
1454 	struct snd_timer_gstatus gstatus;
1455 	struct snd_timer_id tid;
1456 	struct snd_timer *t;
1457 	int err = 0;
1458 
1459 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1460 		return -EFAULT;
1461 	tid = gstatus.tid;
1462 	memset(&gstatus, 0, sizeof(gstatus));
1463 	gstatus.tid = tid;
1464 	mutex_lock(&register_mutex);
1465 	t = snd_timer_find(&tid);
1466 	if (t != NULL) {
1467 		if (t->hw.c_resolution)
1468 			gstatus.resolution = t->hw.c_resolution(t);
1469 		else
1470 			gstatus.resolution = t->hw.resolution;
1471 		if (t->hw.precise_resolution) {
1472 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1473 						 &gstatus.resolution_den);
1474 		} else {
1475 			gstatus.resolution_num = gstatus.resolution;
1476 			gstatus.resolution_den = 1000000000uL;
1477 		}
1478 	} else {
1479 		err = -ENODEV;
1480 	}
1481 	mutex_unlock(&register_mutex);
1482 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1483 		err = -EFAULT;
1484 	return err;
1485 }
1486 
1487 static int snd_timer_user_tselect(struct file *file,
1488 				  struct snd_timer_select __user *_tselect)
1489 {
1490 	struct snd_timer_user *tu;
1491 	struct snd_timer_select tselect;
1492 	char str[32];
1493 	int err = 0;
1494 
1495 	tu = file->private_data;
1496 	mutex_lock(&tu->tread_sem);
1497 	if (tu->timeri) {
1498 		snd_timer_close(tu->timeri);
1499 		tu->timeri = NULL;
1500 	}
1501 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1502 		err = -EFAULT;
1503 		goto __err;
1504 	}
1505 	sprintf(str, "application %i", current->pid);
1506 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1507 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1508 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1509 	if (err < 0)
1510 		goto __err;
1511 
1512 	kfree(tu->queue);
1513 	tu->queue = NULL;
1514 	kfree(tu->tqueue);
1515 	tu->tqueue = NULL;
1516 	if (tu->tread) {
1517 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1518 				     GFP_KERNEL);
1519 		if (tu->tqueue == NULL)
1520 			err = -ENOMEM;
1521 	} else {
1522 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1523 				    GFP_KERNEL);
1524 		if (tu->queue == NULL)
1525 			err = -ENOMEM;
1526 	}
1527 
1528       	if (err < 0) {
1529 		snd_timer_close(tu->timeri);
1530       		tu->timeri = NULL;
1531       	} else {
1532 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1533 		tu->timeri->callback = tu->tread
1534 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1535 		tu->timeri->ccallback = snd_timer_user_ccallback;
1536 		tu->timeri->callback_data = (void *)tu;
1537 	}
1538 
1539       __err:
1540       	mutex_unlock(&tu->tread_sem);
1541 	return err;
1542 }
1543 
1544 static int snd_timer_user_info(struct file *file,
1545 			       struct snd_timer_info __user *_info)
1546 {
1547 	struct snd_timer_user *tu;
1548 	struct snd_timer_info *info;
1549 	struct snd_timer *t;
1550 	int err = 0;
1551 
1552 	tu = file->private_data;
1553 	snd_assert(tu->timeri != NULL, return -ENXIO);
1554 	t = tu->timeri->timer;
1555 	snd_assert(t != NULL, return -ENXIO);
1556 
1557 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1558 	if (! info)
1559 		return -ENOMEM;
1560 	info->card = t->card ? t->card->number : -1;
1561 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1562 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1563 	strlcpy(info->id, t->id, sizeof(info->id));
1564 	strlcpy(info->name, t->name, sizeof(info->name));
1565 	info->resolution = t->hw.resolution;
1566 	if (copy_to_user(_info, info, sizeof(*_info)))
1567 		err = -EFAULT;
1568 	kfree(info);
1569 	return err;
1570 }
1571 
1572 static int snd_timer_user_params(struct file *file,
1573 				 struct snd_timer_params __user *_params)
1574 {
1575 	struct snd_timer_user *tu;
1576 	struct snd_timer_params params;
1577 	struct snd_timer *t;
1578 	struct snd_timer_read *tr;
1579 	struct snd_timer_tread *ttr;
1580 	int err;
1581 
1582 	tu = file->private_data;
1583 	snd_assert(tu->timeri != NULL, return -ENXIO);
1584 	t = tu->timeri->timer;
1585 	snd_assert(t != NULL, return -ENXIO);
1586 	if (copy_from_user(&params, _params, sizeof(params)))
1587 		return -EFAULT;
1588 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1589 		err = -EINVAL;
1590 		goto _end;
1591 	}
1592 	if (params.queue_size > 0 &&
1593 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1594 		err = -EINVAL;
1595 		goto _end;
1596 	}
1597 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1598 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1599 			      (1<<SNDRV_TIMER_EVENT_START)|
1600 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1601 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1602 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1603 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1604 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1605 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1606 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1607 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1608 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1609 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1610 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1611 		err = -EINVAL;
1612 		goto _end;
1613 	}
1614 	snd_timer_stop(tu->timeri);
1615 	spin_lock_irq(&t->lock);
1616 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1617 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1618 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1619 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1620 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1621 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1622 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1623 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1624 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1625 	spin_unlock_irq(&t->lock);
1626 	if (params.queue_size > 0 &&
1627 	    (unsigned int)tu->queue_size != params.queue_size) {
1628 		if (tu->tread) {
1629 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1630 				      GFP_KERNEL);
1631 			if (ttr) {
1632 				kfree(tu->tqueue);
1633 				tu->queue_size = params.queue_size;
1634 				tu->tqueue = ttr;
1635 			}
1636 		} else {
1637 			tr = kmalloc(params.queue_size * sizeof(*tr),
1638 				     GFP_KERNEL);
1639 			if (tr) {
1640 				kfree(tu->queue);
1641 				tu->queue_size = params.queue_size;
1642 				tu->queue = tr;
1643 			}
1644 		}
1645 	}
1646 	tu->qhead = tu->qtail = tu->qused = 0;
1647 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1648 		if (tu->tread) {
1649 			struct snd_timer_tread tread;
1650 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1651 			tread.tstamp.tv_sec = 0;
1652 			tread.tstamp.tv_nsec = 0;
1653 			tread.val = 0;
1654 			snd_timer_user_append_to_tqueue(tu, &tread);
1655 		} else {
1656 			struct snd_timer_read *r = &tu->queue[0];
1657 			r->resolution = 0;
1658 			r->ticks = 0;
1659 			tu->qused++;
1660 			tu->qtail++;
1661 		}
1662 	}
1663 	tu->filter = params.filter;
1664 	tu->ticks = params.ticks;
1665 	err = 0;
1666  _end:
1667 	if (copy_to_user(_params, &params, sizeof(params)))
1668 		return -EFAULT;
1669 	return err;
1670 }
1671 
1672 static int snd_timer_user_status(struct file *file,
1673 				 struct snd_timer_status __user *_status)
1674 {
1675 	struct snd_timer_user *tu;
1676 	struct snd_timer_status status;
1677 
1678 	tu = file->private_data;
1679 	snd_assert(tu->timeri != NULL, return -ENXIO);
1680 	memset(&status, 0, sizeof(status));
1681 	status.tstamp = tu->tstamp;
1682 	status.resolution = snd_timer_resolution(tu->timeri);
1683 	status.lost = tu->timeri->lost;
1684 	status.overrun = tu->overrun;
1685 	spin_lock_irq(&tu->qlock);
1686 	status.queue = tu->qused;
1687 	spin_unlock_irq(&tu->qlock);
1688 	if (copy_to_user(_status, &status, sizeof(status)))
1689 		return -EFAULT;
1690 	return 0;
1691 }
1692 
1693 static int snd_timer_user_start(struct file *file)
1694 {
1695 	int err;
1696 	struct snd_timer_user *tu;
1697 
1698 	tu = file->private_data;
1699 	snd_assert(tu->timeri != NULL, return -ENXIO);
1700 	snd_timer_stop(tu->timeri);
1701 	tu->timeri->lost = 0;
1702 	tu->last_resolution = 0;
1703 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1704 }
1705 
1706 static int snd_timer_user_stop(struct file *file)
1707 {
1708 	int err;
1709 	struct snd_timer_user *tu;
1710 
1711 	tu = file->private_data;
1712 	snd_assert(tu->timeri != NULL, return -ENXIO);
1713 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1714 }
1715 
1716 static int snd_timer_user_continue(struct file *file)
1717 {
1718 	int err;
1719 	struct snd_timer_user *tu;
1720 
1721 	tu = file->private_data;
1722 	snd_assert(tu->timeri != NULL, return -ENXIO);
1723 	tu->timeri->lost = 0;
1724 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1725 }
1726 
1727 static int snd_timer_user_pause(struct file *file)
1728 {
1729 	int err;
1730 	struct snd_timer_user *tu;
1731 
1732 	tu = file->private_data;
1733 	snd_assert(tu->timeri != NULL, return -ENXIO);
1734 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1735 }
1736 
1737 enum {
1738 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1739 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1740 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1741 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1742 };
1743 
1744 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1745 				 unsigned long arg)
1746 {
1747 	struct snd_timer_user *tu;
1748 	void __user *argp = (void __user *)arg;
1749 	int __user *p = argp;
1750 
1751 	tu = file->private_data;
1752 	switch (cmd) {
1753 	case SNDRV_TIMER_IOCTL_PVERSION:
1754 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1755 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1756 		return snd_timer_user_next_device(argp);
1757 	case SNDRV_TIMER_IOCTL_TREAD:
1758 	{
1759 		int xarg;
1760 
1761 		mutex_lock(&tu->tread_sem);
1762 		if (tu->timeri)	{	/* too late */
1763 			mutex_unlock(&tu->tread_sem);
1764 			return -EBUSY;
1765 		}
1766 		if (get_user(xarg, p)) {
1767 			mutex_unlock(&tu->tread_sem);
1768 			return -EFAULT;
1769 		}
1770 		tu->tread = xarg ? 1 : 0;
1771 		mutex_unlock(&tu->tread_sem);
1772 		return 0;
1773 	}
1774 	case SNDRV_TIMER_IOCTL_GINFO:
1775 		return snd_timer_user_ginfo(file, argp);
1776 	case SNDRV_TIMER_IOCTL_GPARAMS:
1777 		return snd_timer_user_gparams(file, argp);
1778 	case SNDRV_TIMER_IOCTL_GSTATUS:
1779 		return snd_timer_user_gstatus(file, argp);
1780 	case SNDRV_TIMER_IOCTL_SELECT:
1781 		return snd_timer_user_tselect(file, argp);
1782 	case SNDRV_TIMER_IOCTL_INFO:
1783 		return snd_timer_user_info(file, argp);
1784 	case SNDRV_TIMER_IOCTL_PARAMS:
1785 		return snd_timer_user_params(file, argp);
1786 	case SNDRV_TIMER_IOCTL_STATUS:
1787 		return snd_timer_user_status(file, argp);
1788 	case SNDRV_TIMER_IOCTL_START:
1789 	case SNDRV_TIMER_IOCTL_START_OLD:
1790 		return snd_timer_user_start(file);
1791 	case SNDRV_TIMER_IOCTL_STOP:
1792 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1793 		return snd_timer_user_stop(file);
1794 	case SNDRV_TIMER_IOCTL_CONTINUE:
1795 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1796 		return snd_timer_user_continue(file);
1797 	case SNDRV_TIMER_IOCTL_PAUSE:
1798 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1799 		return snd_timer_user_pause(file);
1800 	}
1801 	return -ENOTTY;
1802 }
1803 
1804 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1805 {
1806 	struct snd_timer_user *tu;
1807 	int err;
1808 
1809 	tu = file->private_data;
1810 	err = fasync_helper(fd, file, on, &tu->fasync);
1811         if (err < 0)
1812 		return err;
1813 	return 0;
1814 }
1815 
1816 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1817 				   size_t count, loff_t *offset)
1818 {
1819 	struct snd_timer_user *tu;
1820 	long result = 0, unit;
1821 	int err = 0;
1822 
1823 	tu = file->private_data;
1824 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1825 	spin_lock_irq(&tu->qlock);
1826 	while ((long)count - result >= unit) {
1827 		while (!tu->qused) {
1828 			wait_queue_t wait;
1829 
1830 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1831 				err = -EAGAIN;
1832 				break;
1833 			}
1834 
1835 			set_current_state(TASK_INTERRUPTIBLE);
1836 			init_waitqueue_entry(&wait, current);
1837 			add_wait_queue(&tu->qchange_sleep, &wait);
1838 
1839 			spin_unlock_irq(&tu->qlock);
1840 			schedule();
1841 			spin_lock_irq(&tu->qlock);
1842 
1843 			remove_wait_queue(&tu->qchange_sleep, &wait);
1844 
1845 			if (signal_pending(current)) {
1846 				err = -ERESTARTSYS;
1847 				break;
1848 			}
1849 		}
1850 
1851 		spin_unlock_irq(&tu->qlock);
1852 		if (err < 0)
1853 			goto _error;
1854 
1855 		if (tu->tread) {
1856 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1857 					 sizeof(struct snd_timer_tread))) {
1858 				err = -EFAULT;
1859 				goto _error;
1860 			}
1861 		} else {
1862 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1863 					 sizeof(struct snd_timer_read))) {
1864 				err = -EFAULT;
1865 				goto _error;
1866 			}
1867 		}
1868 
1869 		tu->qhead %= tu->queue_size;
1870 
1871 		result += unit;
1872 		buffer += unit;
1873 
1874 		spin_lock_irq(&tu->qlock);
1875 		tu->qused--;
1876 	}
1877 	spin_unlock_irq(&tu->qlock);
1878  _error:
1879 	return result > 0 ? result : err;
1880 }
1881 
1882 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1883 {
1884         unsigned int mask;
1885         struct snd_timer_user *tu;
1886 
1887         tu = file->private_data;
1888 
1889         poll_wait(file, &tu->qchange_sleep, wait);
1890 
1891 	mask = 0;
1892 	if (tu->qused)
1893 		mask |= POLLIN | POLLRDNORM;
1894 
1895 	return mask;
1896 }
1897 
1898 #ifdef CONFIG_COMPAT
1899 #include "timer_compat.c"
1900 #else
1901 #define snd_timer_user_ioctl_compat	NULL
1902 #endif
1903 
1904 static const struct file_operations snd_timer_f_ops =
1905 {
1906 	.owner =	THIS_MODULE,
1907 	.read =		snd_timer_user_read,
1908 	.open =		snd_timer_user_open,
1909 	.release =	snd_timer_user_release,
1910 	.poll =		snd_timer_user_poll,
1911 	.unlocked_ioctl =	snd_timer_user_ioctl,
1912 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1913 	.fasync = 	snd_timer_user_fasync,
1914 };
1915 
1916 /*
1917  *  ENTRY functions
1918  */
1919 
1920 static int __init alsa_timer_init(void)
1921 {
1922 	int err;
1923 
1924 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1925 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1926 			      "system timer");
1927 #endif
1928 
1929 	if ((err = snd_timer_register_system()) < 0)
1930 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1931 			   err);
1932 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1933 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1934 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1935 			   err);
1936 	snd_timer_proc_init();
1937 	return 0;
1938 }
1939 
1940 static void __exit alsa_timer_exit(void)
1941 {
1942 	struct list_head *p, *n;
1943 
1944 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1945 	/* unregister the system timer */
1946 	list_for_each_safe(p, n, &snd_timer_list) {
1947 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1948 		snd_timer_free(timer);
1949 	}
1950 	snd_timer_proc_done();
1951 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1952 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1953 #endif
1954 }
1955 
1956 module_init(alsa_timer_init)
1957 module_exit(alsa_timer_exit)
1958 
1959 EXPORT_SYMBOL(snd_timer_open);
1960 EXPORT_SYMBOL(snd_timer_close);
1961 EXPORT_SYMBOL(snd_timer_resolution);
1962 EXPORT_SYMBOL(snd_timer_start);
1963 EXPORT_SYMBOL(snd_timer_stop);
1964 EXPORT_SYMBOL(snd_timer_continue);
1965 EXPORT_SYMBOL(snd_timer_pause);
1966 EXPORT_SYMBOL(snd_timer_new);
1967 EXPORT_SYMBOL(snd_timer_notify);
1968 EXPORT_SYMBOL(snd_timer_global_new);
1969 EXPORT_SYMBOL(snd_timer_global_free);
1970 EXPORT_SYMBOL(snd_timer_global_register);
1971 EXPORT_SYMBOL(snd_timer_interrupt);
1972