xref: /openbmc/linux/sound/core/timer.c (revision ecba1060)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/delay.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/moduleparam.h>
28 #include <linux/string.h>
29 #include <sound/core.h>
30 #include <sound/timer.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 #include <sound/minors.h>
34 #include <sound/initval.h>
35 #include <linux/kmod.h>
36 
37 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
38 #define DEFAULT_TIMER_LIMIT 3
39 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
40 #define DEFAULT_TIMER_LIMIT 2
41 #else
42 #define DEFAULT_TIMER_LIMIT 1
43 #endif
44 
45 static int timer_limit = DEFAULT_TIMER_LIMIT;
46 static int timer_tstamp_monotonic = 1;
47 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
48 MODULE_DESCRIPTION("ALSA timer interface");
49 MODULE_LICENSE("GPL");
50 module_param(timer_limit, int, 0444);
51 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
52 module_param(timer_tstamp_monotonic, int, 0444);
53 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
54 
55 struct snd_timer_user {
56 	struct snd_timer_instance *timeri;
57 	int tread;		/* enhanced read with timestamps and events */
58 	unsigned long ticks;
59 	unsigned long overrun;
60 	int qhead;
61 	int qtail;
62 	int qused;
63 	int queue_size;
64 	struct snd_timer_read *queue;
65 	struct snd_timer_tread *tqueue;
66 	spinlock_t qlock;
67 	unsigned long last_resolution;
68 	unsigned int filter;
69 	struct timespec tstamp;		/* trigger tstamp */
70 	wait_queue_head_t qchange_sleep;
71 	struct fasync_struct *fasync;
72 	struct mutex tread_sem;
73 };
74 
75 /* list of timers */
76 static LIST_HEAD(snd_timer_list);
77 
78 /* list of slave instances */
79 static LIST_HEAD(snd_timer_slave_list);
80 
81 /* lock for slave active lists */
82 static DEFINE_SPINLOCK(slave_active_lock);
83 
84 static DEFINE_MUTEX(register_mutex);
85 
86 static int snd_timer_free(struct snd_timer *timer);
87 static int snd_timer_dev_free(struct snd_device *device);
88 static int snd_timer_dev_register(struct snd_device *device);
89 static int snd_timer_dev_disconnect(struct snd_device *device);
90 
91 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
92 
93 /*
94  * create a timer instance with the given owner string.
95  * when timer is not NULL, increments the module counter
96  */
97 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
98 							 struct snd_timer *timer)
99 {
100 	struct snd_timer_instance *timeri;
101 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
102 	if (timeri == NULL)
103 		return NULL;
104 	timeri->owner = kstrdup(owner, GFP_KERNEL);
105 	if (! timeri->owner) {
106 		kfree(timeri);
107 		return NULL;
108 	}
109 	INIT_LIST_HEAD(&timeri->open_list);
110 	INIT_LIST_HEAD(&timeri->active_list);
111 	INIT_LIST_HEAD(&timeri->ack_list);
112 	INIT_LIST_HEAD(&timeri->slave_list_head);
113 	INIT_LIST_HEAD(&timeri->slave_active_head);
114 
115 	timeri->timer = timer;
116 	if (timer && !try_module_get(timer->module)) {
117 		kfree(timeri->owner);
118 		kfree(timeri);
119 		return NULL;
120 	}
121 
122 	return timeri;
123 }
124 
125 /*
126  * find a timer instance from the given timer id
127  */
128 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
129 {
130 	struct snd_timer *timer = NULL;
131 
132 	list_for_each_entry(timer, &snd_timer_list, device_list) {
133 		if (timer->tmr_class != tid->dev_class)
134 			continue;
135 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
136 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
137 		    (timer->card == NULL ||
138 		     timer->card->number != tid->card))
139 			continue;
140 		if (timer->tmr_device != tid->device)
141 			continue;
142 		if (timer->tmr_subdevice != tid->subdevice)
143 			continue;
144 		return timer;
145 	}
146 	return NULL;
147 }
148 
149 #ifdef CONFIG_MODULES
150 
151 static void snd_timer_request(struct snd_timer_id *tid)
152 {
153 	switch (tid->dev_class) {
154 	case SNDRV_TIMER_CLASS_GLOBAL:
155 		if (tid->device < timer_limit)
156 			request_module("snd-timer-%i", tid->device);
157 		break;
158 	case SNDRV_TIMER_CLASS_CARD:
159 	case SNDRV_TIMER_CLASS_PCM:
160 		if (tid->card < snd_ecards_limit)
161 			request_module("snd-card-%i", tid->card);
162 		break;
163 	default:
164 		break;
165 	}
166 }
167 
168 #endif
169 
170 /*
171  * look for a master instance matching with the slave id of the given slave.
172  * when found, relink the open_link of the slave.
173  *
174  * call this with register_mutex down.
175  */
176 static void snd_timer_check_slave(struct snd_timer_instance *slave)
177 {
178 	struct snd_timer *timer;
179 	struct snd_timer_instance *master;
180 
181 	/* FIXME: it's really dumb to look up all entries.. */
182 	list_for_each_entry(timer, &snd_timer_list, device_list) {
183 		list_for_each_entry(master, &timer->open_list_head, open_list) {
184 			if (slave->slave_class == master->slave_class &&
185 			    slave->slave_id == master->slave_id) {
186 				list_del(&slave->open_list);
187 				list_add_tail(&slave->open_list,
188 					      &master->slave_list_head);
189 				spin_lock_irq(&slave_active_lock);
190 				slave->master = master;
191 				slave->timer = master->timer;
192 				spin_unlock_irq(&slave_active_lock);
193 				return;
194 			}
195 		}
196 	}
197 }
198 
199 /*
200  * look for slave instances matching with the slave id of the given master.
201  * when found, relink the open_link of slaves.
202  *
203  * call this with register_mutex down.
204  */
205 static void snd_timer_check_master(struct snd_timer_instance *master)
206 {
207 	struct snd_timer_instance *slave, *tmp;
208 
209 	/* check all pending slaves */
210 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
211 		if (slave->slave_class == master->slave_class &&
212 		    slave->slave_id == master->slave_id) {
213 			list_move_tail(&slave->open_list, &master->slave_list_head);
214 			spin_lock_irq(&slave_active_lock);
215 			slave->master = master;
216 			slave->timer = master->timer;
217 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
218 				list_add_tail(&slave->active_list,
219 					      &master->slave_active_head);
220 			spin_unlock_irq(&slave_active_lock);
221 		}
222 	}
223 }
224 
225 /*
226  * open a timer instance
227  * when opening a master, the slave id must be here given.
228  */
229 int snd_timer_open(struct snd_timer_instance **ti,
230 		   char *owner, struct snd_timer_id *tid,
231 		   unsigned int slave_id)
232 {
233 	struct snd_timer *timer;
234 	struct snd_timer_instance *timeri = NULL;
235 
236 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
237 		/* open a slave instance */
238 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
239 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
240 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
241 			return -EINVAL;
242 		}
243 		mutex_lock(&register_mutex);
244 		timeri = snd_timer_instance_new(owner, NULL);
245 		if (!timeri) {
246 			mutex_unlock(&register_mutex);
247 			return -ENOMEM;
248 		}
249 		timeri->slave_class = tid->dev_sclass;
250 		timeri->slave_id = tid->device;
251 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
252 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
253 		snd_timer_check_slave(timeri);
254 		mutex_unlock(&register_mutex);
255 		*ti = timeri;
256 		return 0;
257 	}
258 
259 	/* open a master instance */
260 	mutex_lock(&register_mutex);
261 	timer = snd_timer_find(tid);
262 #ifdef CONFIG_MODULES
263 	if (!timer) {
264 		mutex_unlock(&register_mutex);
265 		snd_timer_request(tid);
266 		mutex_lock(&register_mutex);
267 		timer = snd_timer_find(tid);
268 	}
269 #endif
270 	if (!timer) {
271 		mutex_unlock(&register_mutex);
272 		return -ENODEV;
273 	}
274 	if (!list_empty(&timer->open_list_head)) {
275 		timeri = list_entry(timer->open_list_head.next,
276 				    struct snd_timer_instance, open_list);
277 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
278 			mutex_unlock(&register_mutex);
279 			return -EBUSY;
280 		}
281 	}
282 	timeri = snd_timer_instance_new(owner, timer);
283 	if (!timeri) {
284 		mutex_unlock(&register_mutex);
285 		return -ENOMEM;
286 	}
287 	timeri->slave_class = tid->dev_sclass;
288 	timeri->slave_id = slave_id;
289 	if (list_empty(&timer->open_list_head) && timer->hw.open)
290 		timer->hw.open(timer);
291 	list_add_tail(&timeri->open_list, &timer->open_list_head);
292 	snd_timer_check_master(timeri);
293 	mutex_unlock(&register_mutex);
294 	*ti = timeri;
295 	return 0;
296 }
297 
298 static int _snd_timer_stop(struct snd_timer_instance *timeri,
299 			   int keep_flag, int event);
300 
301 /*
302  * close a timer instance
303  */
304 int snd_timer_close(struct snd_timer_instance *timeri)
305 {
306 	struct snd_timer *timer = NULL;
307 	struct snd_timer_instance *slave, *tmp;
308 
309 	if (snd_BUG_ON(!timeri))
310 		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 	if (timer_tstamp_monotonic)
386 		do_posix_clock_monotonic_gettime(&tstamp);
387 	else
388 		getnstimeofday(&tstamp);
389 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
390 		       event > SNDRV_TIMER_EVENT_PAUSE))
391 		return;
392 	if (event == SNDRV_TIMER_EVENT_START ||
393 	    event == SNDRV_TIMER_EVENT_CONTINUE)
394 		resolution = snd_timer_resolution(ti);
395 	if (ti->ccallback)
396 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
397 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
398 		return;
399 	timer = ti->timer;
400 	if (timer == NULL)
401 		return;
402 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
403 		return;
404 	spin_lock_irqsave(&timer->lock, flags);
405 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
406 		if (ts->ccallback)
407 			ts->ccallback(ti, event + 100, &tstamp, resolution);
408 	spin_unlock_irqrestore(&timer->lock, flags);
409 }
410 
411 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
412 			    unsigned long sticks)
413 {
414 	list_del(&timeri->active_list);
415 	list_add_tail(&timeri->active_list, &timer->active_list_head);
416 	if (timer->running) {
417 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
418 			goto __start_now;
419 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
420 		timeri->flags |= SNDRV_TIMER_IFLG_START;
421 		return 1;	/* delayed start */
422 	} else {
423 		timer->sticks = sticks;
424 		timer->hw.start(timer);
425 	      __start_now:
426 		timer->running++;
427 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
428 		return 0;
429 	}
430 }
431 
432 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
433 {
434 	unsigned long flags;
435 
436 	spin_lock_irqsave(&slave_active_lock, flags);
437 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
438 	if (timeri->master)
439 		list_add_tail(&timeri->active_list,
440 			      &timeri->master->slave_active_head);
441 	spin_unlock_irqrestore(&slave_active_lock, flags);
442 	return 1; /* delayed start */
443 }
444 
445 /*
446  *  start the timer instance
447  */
448 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
449 {
450 	struct snd_timer *timer;
451 	int result = -EINVAL;
452 	unsigned long flags;
453 
454 	if (timeri == NULL || ticks < 1)
455 		return -EINVAL;
456 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
457 		result = snd_timer_start_slave(timeri);
458 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
459 		return result;
460 	}
461 	timer = timeri->timer;
462 	if (timer == NULL)
463 		return -EINVAL;
464 	spin_lock_irqsave(&timer->lock, flags);
465 	timeri->ticks = timeri->cticks = ticks;
466 	timeri->pticks = 0;
467 	result = snd_timer_start1(timer, timeri, ticks);
468 	spin_unlock_irqrestore(&timer->lock, flags);
469 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
470 	return result;
471 }
472 
473 static int _snd_timer_stop(struct snd_timer_instance * timeri,
474 			   int keep_flag, int event)
475 {
476 	struct snd_timer *timer;
477 	unsigned long flags;
478 
479 	if (snd_BUG_ON(!timeri))
480 		return -ENXIO;
481 
482 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
483 		if (!keep_flag) {
484 			spin_lock_irqsave(&slave_active_lock, flags);
485 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
486 			spin_unlock_irqrestore(&slave_active_lock, flags);
487 		}
488 		goto __end;
489 	}
490 	timer = timeri->timer;
491 	if (!timer)
492 		return -EINVAL;
493 	spin_lock_irqsave(&timer->lock, flags);
494 	list_del_init(&timeri->ack_list);
495 	list_del_init(&timeri->active_list);
496 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
497 	    !(--timer->running)) {
498 		timer->hw.stop(timer);
499 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
500 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
501 			snd_timer_reschedule(timer, 0);
502 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
503 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
504 				timer->hw.start(timer);
505 			}
506 		}
507 	}
508 	if (!keep_flag)
509 		timeri->flags &=
510 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
511 	spin_unlock_irqrestore(&timer->lock, flags);
512       __end:
513 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
514 		snd_timer_notify1(timeri, event);
515 	return 0;
516 }
517 
518 /*
519  * stop the timer instance.
520  *
521  * do not call this from the timer callback!
522  */
523 int snd_timer_stop(struct snd_timer_instance *timeri)
524 {
525 	struct snd_timer *timer;
526 	unsigned long flags;
527 	int err;
528 
529 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
530 	if (err < 0)
531 		return err;
532 	timer = timeri->timer;
533 	spin_lock_irqsave(&timer->lock, flags);
534 	timeri->cticks = timeri->ticks;
535 	timeri->pticks = 0;
536 	spin_unlock_irqrestore(&timer->lock, flags);
537 	return 0;
538 }
539 
540 /*
541  * start again..  the tick is kept.
542  */
543 int snd_timer_continue(struct snd_timer_instance *timeri)
544 {
545 	struct snd_timer *timer;
546 	int result = -EINVAL;
547 	unsigned long flags;
548 
549 	if (timeri == NULL)
550 		return result;
551 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
552 		return snd_timer_start_slave(timeri);
553 	timer = timeri->timer;
554 	if (! timer)
555 		return -EINVAL;
556 	spin_lock_irqsave(&timer->lock, flags);
557 	if (!timeri->cticks)
558 		timeri->cticks = 1;
559 	timeri->pticks = 0;
560 	result = snd_timer_start1(timer, timeri, timer->sticks);
561 	spin_unlock_irqrestore(&timer->lock, flags);
562 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
563 	return result;
564 }
565 
566 /*
567  * pause.. remember the ticks left
568  */
569 int snd_timer_pause(struct snd_timer_instance * timeri)
570 {
571 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
572 }
573 
574 /*
575  * reschedule the timer
576  *
577  * start pending instances and check the scheduling ticks.
578  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
579  */
580 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
581 {
582 	struct snd_timer_instance *ti;
583 	unsigned long ticks = ~0UL;
584 
585 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
586 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
587 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
588 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
589 			timer->running++;
590 		}
591 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
592 			if (ticks > ti->cticks)
593 				ticks = ti->cticks;
594 		}
595 	}
596 	if (ticks == ~0UL) {
597 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
598 		return;
599 	}
600 	if (ticks > timer->hw.ticks)
601 		ticks = timer->hw.ticks;
602 	if (ticks_left != ticks)
603 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
604 	timer->sticks = ticks;
605 }
606 
607 /*
608  * timer tasklet
609  *
610  */
611 static void snd_timer_tasklet(unsigned long arg)
612 {
613 	struct snd_timer *timer = (struct snd_timer *) arg;
614 	struct snd_timer_instance *ti;
615 	struct list_head *p;
616 	unsigned long resolution, ticks;
617 	unsigned long flags;
618 
619 	spin_lock_irqsave(&timer->lock, flags);
620 	/* now process all callbacks */
621 	while (!list_empty(&timer->sack_list_head)) {
622 		p = timer->sack_list_head.next;		/* get first item */
623 		ti = list_entry(p, struct snd_timer_instance, ack_list);
624 
625 		/* remove from ack_list and make empty */
626 		list_del_init(p);
627 
628 		ticks = ti->pticks;
629 		ti->pticks = 0;
630 		resolution = ti->resolution;
631 
632 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
633 		spin_unlock(&timer->lock);
634 		if (ti->callback)
635 			ti->callback(ti, resolution, ticks);
636 		spin_lock(&timer->lock);
637 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
638 	}
639 	spin_unlock_irqrestore(&timer->lock, flags);
640 }
641 
642 /*
643  * timer interrupt
644  *
645  * ticks_left is usually equal to timer->sticks.
646  *
647  */
648 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
649 {
650 	struct snd_timer_instance *ti, *ts, *tmp;
651 	unsigned long resolution, ticks;
652 	struct list_head *p, *ack_list_head;
653 	unsigned long flags;
654 	int use_tasklet = 0;
655 
656 	if (timer == NULL)
657 		return;
658 
659 	spin_lock_irqsave(&timer->lock, flags);
660 
661 	/* remember the current resolution */
662 	if (timer->hw.c_resolution)
663 		resolution = timer->hw.c_resolution(timer);
664 	else
665 		resolution = timer->hw.resolution;
666 
667 	/* loop for all active instances
668 	 * Here we cannot use list_for_each_entry because the active_list of a
669 	 * processed instance is relinked to done_list_head before the callback
670 	 * is called.
671 	 */
672 	list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
673 				 active_list) {
674 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
675 			continue;
676 		ti->pticks += ticks_left;
677 		ti->resolution = resolution;
678 		if (ti->cticks < ticks_left)
679 			ti->cticks = 0;
680 		else
681 			ti->cticks -= ticks_left;
682 		if (ti->cticks) /* not expired */
683 			continue;
684 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
685 			ti->cticks = ti->ticks;
686 		} else {
687 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
688 			if (--timer->running)
689 				list_del(&ti->active_list);
690 		}
691 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
692 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
693 			ack_list_head = &timer->ack_list_head;
694 		else
695 			ack_list_head = &timer->sack_list_head;
696 		if (list_empty(&ti->ack_list))
697 			list_add_tail(&ti->ack_list, ack_list_head);
698 		list_for_each_entry(ts, &ti->slave_active_head, active_list) {
699 			ts->pticks = ti->pticks;
700 			ts->resolution = resolution;
701 			if (list_empty(&ts->ack_list))
702 				list_add_tail(&ts->ack_list, ack_list_head);
703 		}
704 	}
705 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
706 		snd_timer_reschedule(timer, timer->sticks);
707 	if (timer->running) {
708 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
709 			timer->hw.stop(timer);
710 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
711 		}
712 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
713 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
714 			/* restart timer */
715 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
716 			timer->hw.start(timer);
717 		}
718 	} else {
719 		timer->hw.stop(timer);
720 	}
721 
722 	/* now process all fast callbacks */
723 	while (!list_empty(&timer->ack_list_head)) {
724 		p = timer->ack_list_head.next;		/* get first item */
725 		ti = list_entry(p, struct snd_timer_instance, ack_list);
726 
727 		/* remove from ack_list and make empty */
728 		list_del_init(p);
729 
730 		ticks = ti->pticks;
731 		ti->pticks = 0;
732 
733 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
734 		spin_unlock(&timer->lock);
735 		if (ti->callback)
736 			ti->callback(ti, resolution, ticks);
737 		spin_lock(&timer->lock);
738 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
739 	}
740 
741 	/* do we have any slow callbacks? */
742 	use_tasklet = !list_empty(&timer->sack_list_head);
743 	spin_unlock_irqrestore(&timer->lock, flags);
744 
745 	if (use_tasklet)
746 		tasklet_schedule(&timer->task_queue);
747 }
748 
749 /*
750 
751  */
752 
753 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
754 		  struct snd_timer **rtimer)
755 {
756 	struct snd_timer *timer;
757 	int err;
758 	static struct snd_device_ops ops = {
759 		.dev_free = snd_timer_dev_free,
760 		.dev_register = snd_timer_dev_register,
761 		.dev_disconnect = snd_timer_dev_disconnect,
762 	};
763 
764 	if (snd_BUG_ON(!tid))
765 		return -EINVAL;
766 	if (rtimer)
767 		*rtimer = NULL;
768 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
769 	if (timer == NULL) {
770 		snd_printk(KERN_ERR "timer: cannot allocate\n");
771 		return -ENOMEM;
772 	}
773 	timer->tmr_class = tid->dev_class;
774 	timer->card = card;
775 	timer->tmr_device = tid->device;
776 	timer->tmr_subdevice = tid->subdevice;
777 	if (id)
778 		strlcpy(timer->id, id, sizeof(timer->id));
779 	INIT_LIST_HEAD(&timer->device_list);
780 	INIT_LIST_HEAD(&timer->open_list_head);
781 	INIT_LIST_HEAD(&timer->active_list_head);
782 	INIT_LIST_HEAD(&timer->ack_list_head);
783 	INIT_LIST_HEAD(&timer->sack_list_head);
784 	spin_lock_init(&timer->lock);
785 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
786 		     (unsigned long)timer);
787 	if (card != NULL) {
788 		timer->module = card->module;
789 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
790 		if (err < 0) {
791 			snd_timer_free(timer);
792 			return err;
793 		}
794 	}
795 	if (rtimer)
796 		*rtimer = timer;
797 	return 0;
798 }
799 
800 static int snd_timer_free(struct snd_timer *timer)
801 {
802 	if (!timer)
803 		return 0;
804 
805 	mutex_lock(&register_mutex);
806 	if (! list_empty(&timer->open_list_head)) {
807 		struct list_head *p, *n;
808 		struct snd_timer_instance *ti;
809 		snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
810 		list_for_each_safe(p, n, &timer->open_list_head) {
811 			list_del_init(p);
812 			ti = list_entry(p, struct snd_timer_instance, open_list);
813 			ti->timer = NULL;
814 		}
815 	}
816 	list_del(&timer->device_list);
817 	mutex_unlock(&register_mutex);
818 
819 	if (timer->private_free)
820 		timer->private_free(timer);
821 	kfree(timer);
822 	return 0;
823 }
824 
825 static int snd_timer_dev_free(struct snd_device *device)
826 {
827 	struct snd_timer *timer = device->device_data;
828 	return snd_timer_free(timer);
829 }
830 
831 static int snd_timer_dev_register(struct snd_device *dev)
832 {
833 	struct snd_timer *timer = dev->device_data;
834 	struct snd_timer *timer1;
835 
836 	if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
837 		return -ENXIO;
838 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
839 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
840 	    	return -EINVAL;
841 
842 	mutex_lock(&register_mutex);
843 	list_for_each_entry(timer1, &snd_timer_list, device_list) {
844 		if (timer1->tmr_class > timer->tmr_class)
845 			break;
846 		if (timer1->tmr_class < timer->tmr_class)
847 			continue;
848 		if (timer1->card && timer->card) {
849 			if (timer1->card->number > timer->card->number)
850 				break;
851 			if (timer1->card->number < timer->card->number)
852 				continue;
853 		}
854 		if (timer1->tmr_device > timer->tmr_device)
855 			break;
856 		if (timer1->tmr_device < timer->tmr_device)
857 			continue;
858 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
859 			break;
860 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
861 			continue;
862 		/* conflicts.. */
863 		mutex_unlock(&register_mutex);
864 		return -EBUSY;
865 	}
866 	list_add_tail(&timer->device_list, &timer1->device_list);
867 	mutex_unlock(&register_mutex);
868 	return 0;
869 }
870 
871 static int snd_timer_dev_disconnect(struct snd_device *device)
872 {
873 	struct snd_timer *timer = device->device_data;
874 	mutex_lock(&register_mutex);
875 	list_del_init(&timer->device_list);
876 	mutex_unlock(&register_mutex);
877 	return 0;
878 }
879 
880 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
881 {
882 	unsigned long flags;
883 	unsigned long resolution = 0;
884 	struct snd_timer_instance *ti, *ts;
885 
886 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
887 		return;
888 	if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
889 		       event > SNDRV_TIMER_EVENT_MRESUME))
890 		return;
891 	spin_lock_irqsave(&timer->lock, flags);
892 	if (event == SNDRV_TIMER_EVENT_MSTART ||
893 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
894 	    event == SNDRV_TIMER_EVENT_MRESUME) {
895 		if (timer->hw.c_resolution)
896 			resolution = timer->hw.c_resolution(timer);
897 		else
898 			resolution = timer->hw.resolution;
899 	}
900 	list_for_each_entry(ti, &timer->active_list_head, active_list) {
901 		if (ti->ccallback)
902 			ti->ccallback(ti, event, tstamp, resolution);
903 		list_for_each_entry(ts, &ti->slave_active_head, active_list)
904 			if (ts->ccallback)
905 				ts->ccallback(ts, event, tstamp, resolution);
906 	}
907 	spin_unlock_irqrestore(&timer->lock, flags);
908 }
909 
910 /*
911  * exported functions for global timers
912  */
913 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
914 {
915 	struct snd_timer_id tid;
916 
917 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
918 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
919 	tid.card = -1;
920 	tid.device = device;
921 	tid.subdevice = 0;
922 	return snd_timer_new(NULL, id, &tid, rtimer);
923 }
924 
925 int snd_timer_global_free(struct snd_timer *timer)
926 {
927 	return snd_timer_free(timer);
928 }
929 
930 int snd_timer_global_register(struct snd_timer *timer)
931 {
932 	struct snd_device dev;
933 
934 	memset(&dev, 0, sizeof(dev));
935 	dev.device_data = timer;
936 	return snd_timer_dev_register(&dev);
937 }
938 
939 /*
940  *  System timer
941  */
942 
943 struct snd_timer_system_private {
944 	struct timer_list tlist;
945 	unsigned long last_expires;
946 	unsigned long last_jiffies;
947 	unsigned long correction;
948 };
949 
950 static void snd_timer_s_function(unsigned long data)
951 {
952 	struct snd_timer *timer = (struct snd_timer *)data;
953 	struct snd_timer_system_private *priv = timer->private_data;
954 	unsigned long jiff = jiffies;
955 	if (time_after(jiff, priv->last_expires))
956 		priv->correction += (long)jiff - (long)priv->last_expires;
957 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
958 }
959 
960 static int snd_timer_s_start(struct snd_timer * timer)
961 {
962 	struct snd_timer_system_private *priv;
963 	unsigned long njiff;
964 
965 	priv = (struct snd_timer_system_private *) timer->private_data;
966 	njiff = (priv->last_jiffies = jiffies);
967 	if (priv->correction > timer->sticks - 1) {
968 		priv->correction -= timer->sticks - 1;
969 		njiff++;
970 	} else {
971 		njiff += timer->sticks - priv->correction;
972 		priv->correction = 0;
973 	}
974 	priv->last_expires = priv->tlist.expires = njiff;
975 	add_timer(&priv->tlist);
976 	return 0;
977 }
978 
979 static int snd_timer_s_stop(struct snd_timer * timer)
980 {
981 	struct snd_timer_system_private *priv;
982 	unsigned long jiff;
983 
984 	priv = (struct snd_timer_system_private *) timer->private_data;
985 	del_timer(&priv->tlist);
986 	jiff = jiffies;
987 	if (time_before(jiff, priv->last_expires))
988 		timer->sticks = priv->last_expires - jiff;
989 	else
990 		timer->sticks = 1;
991 	priv->correction = 0;
992 	return 0;
993 }
994 
995 static struct snd_timer_hardware snd_timer_system =
996 {
997 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
998 	.resolution =	1000000000L / HZ,
999 	.ticks =	10000000L,
1000 	.start =	snd_timer_s_start,
1001 	.stop =		snd_timer_s_stop
1002 };
1003 
1004 static void snd_timer_free_system(struct snd_timer *timer)
1005 {
1006 	kfree(timer->private_data);
1007 }
1008 
1009 static int snd_timer_register_system(void)
1010 {
1011 	struct snd_timer *timer;
1012 	struct snd_timer_system_private *priv;
1013 	int err;
1014 
1015 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1016 	if (err < 0)
1017 		return err;
1018 	strcpy(timer->name, "system timer");
1019 	timer->hw = snd_timer_system;
1020 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1021 	if (priv == NULL) {
1022 		snd_timer_free(timer);
1023 		return -ENOMEM;
1024 	}
1025 	init_timer(&priv->tlist);
1026 	priv->tlist.function = snd_timer_s_function;
1027 	priv->tlist.data = (unsigned long) timer;
1028 	timer->private_data = priv;
1029 	timer->private_free = snd_timer_free_system;
1030 	return snd_timer_global_register(timer);
1031 }
1032 
1033 #ifdef CONFIG_PROC_FS
1034 /*
1035  *  Info interface
1036  */
1037 
1038 static void snd_timer_proc_read(struct snd_info_entry *entry,
1039 				struct snd_info_buffer *buffer)
1040 {
1041 	struct snd_timer *timer;
1042 	struct snd_timer_instance *ti;
1043 
1044 	mutex_lock(&register_mutex);
1045 	list_for_each_entry(timer, &snd_timer_list, device_list) {
1046 		switch (timer->tmr_class) {
1047 		case SNDRV_TIMER_CLASS_GLOBAL:
1048 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1049 			break;
1050 		case SNDRV_TIMER_CLASS_CARD:
1051 			snd_iprintf(buffer, "C%i-%i: ",
1052 				    timer->card->number, timer->tmr_device);
1053 			break;
1054 		case SNDRV_TIMER_CLASS_PCM:
1055 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1056 				    timer->tmr_device, timer->tmr_subdevice);
1057 			break;
1058 		default:
1059 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1060 				    timer->card ? timer->card->number : -1,
1061 				    timer->tmr_device, timer->tmr_subdevice);
1062 		}
1063 		snd_iprintf(buffer, "%s :", timer->name);
1064 		if (timer->hw.resolution)
1065 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1066 				    timer->hw.resolution / 1000,
1067 				    timer->hw.resolution % 1000,
1068 				    timer->hw.ticks);
1069 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1070 			snd_iprintf(buffer, " SLAVE");
1071 		snd_iprintf(buffer, "\n");
1072 		list_for_each_entry(ti, &timer->open_list_head, open_list)
1073 			snd_iprintf(buffer, "  Client %s : %s\n",
1074 				    ti->owner ? ti->owner : "unknown",
1075 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1076 						 SNDRV_TIMER_IFLG_RUNNING)
1077 				    ? "running" : "stopped");
1078 	}
1079 	mutex_unlock(&register_mutex);
1080 }
1081 
1082 static struct snd_info_entry *snd_timer_proc_entry;
1083 
1084 static void __init snd_timer_proc_init(void)
1085 {
1086 	struct snd_info_entry *entry;
1087 
1088 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1089 	if (entry != NULL) {
1090 		entry->c.text.read = snd_timer_proc_read;
1091 		if (snd_info_register(entry) < 0) {
1092 			snd_info_free_entry(entry);
1093 			entry = NULL;
1094 		}
1095 	}
1096 	snd_timer_proc_entry = entry;
1097 }
1098 
1099 static void __exit snd_timer_proc_done(void)
1100 {
1101 	snd_info_free_entry(snd_timer_proc_entry);
1102 }
1103 #else /* !CONFIG_PROC_FS */
1104 #define snd_timer_proc_init()
1105 #define snd_timer_proc_done()
1106 #endif
1107 
1108 /*
1109  *  USER SPACE interface
1110  */
1111 
1112 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1113 				     unsigned long resolution,
1114 				     unsigned long ticks)
1115 {
1116 	struct snd_timer_user *tu = timeri->callback_data;
1117 	struct snd_timer_read *r;
1118 	int prev;
1119 
1120 	spin_lock(&tu->qlock);
1121 	if (tu->qused > 0) {
1122 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1123 		r = &tu->queue[prev];
1124 		if (r->resolution == resolution) {
1125 			r->ticks += ticks;
1126 			goto __wake;
1127 		}
1128 	}
1129 	if (tu->qused >= tu->queue_size) {
1130 		tu->overrun++;
1131 	} else {
1132 		r = &tu->queue[tu->qtail++];
1133 		tu->qtail %= tu->queue_size;
1134 		r->resolution = resolution;
1135 		r->ticks = ticks;
1136 		tu->qused++;
1137 	}
1138       __wake:
1139 	spin_unlock(&tu->qlock);
1140 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1141 	wake_up(&tu->qchange_sleep);
1142 }
1143 
1144 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1145 					    struct snd_timer_tread *tread)
1146 {
1147 	if (tu->qused >= tu->queue_size) {
1148 		tu->overrun++;
1149 	} else {
1150 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1151 		tu->qtail %= tu->queue_size;
1152 		tu->qused++;
1153 	}
1154 }
1155 
1156 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1157 				     int event,
1158 				     struct timespec *tstamp,
1159 				     unsigned long resolution)
1160 {
1161 	struct snd_timer_user *tu = timeri->callback_data;
1162 	struct snd_timer_tread r1;
1163 
1164 	if (event >= SNDRV_TIMER_EVENT_START &&
1165 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1166 		tu->tstamp = *tstamp;
1167 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1168 		return;
1169 	r1.event = event;
1170 	r1.tstamp = *tstamp;
1171 	r1.val = resolution;
1172 	spin_lock(&tu->qlock);
1173 	snd_timer_user_append_to_tqueue(tu, &r1);
1174 	spin_unlock(&tu->qlock);
1175 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1176 	wake_up(&tu->qchange_sleep);
1177 }
1178 
1179 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1180 				      unsigned long resolution,
1181 				      unsigned long ticks)
1182 {
1183 	struct snd_timer_user *tu = timeri->callback_data;
1184 	struct snd_timer_tread *r, r1;
1185 	struct timespec tstamp;
1186 	int prev, append = 0;
1187 
1188 	memset(&tstamp, 0, sizeof(tstamp));
1189 	spin_lock(&tu->qlock);
1190 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1191 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1192 		spin_unlock(&tu->qlock);
1193 		return;
1194 	}
1195 	if (tu->last_resolution != resolution || ticks > 0) {
1196 		if (timer_tstamp_monotonic)
1197 			do_posix_clock_monotonic_gettime(&tstamp);
1198 		else
1199 			getnstimeofday(&tstamp);
1200 	}
1201 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1202 	    tu->last_resolution != resolution) {
1203 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1204 		r1.tstamp = tstamp;
1205 		r1.val = resolution;
1206 		snd_timer_user_append_to_tqueue(tu, &r1);
1207 		tu->last_resolution = resolution;
1208 		append++;
1209 	}
1210 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1211 		goto __wake;
1212 	if (ticks == 0)
1213 		goto __wake;
1214 	if (tu->qused > 0) {
1215 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1216 		r = &tu->tqueue[prev];
1217 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1218 			r->tstamp = tstamp;
1219 			r->val += ticks;
1220 			append++;
1221 			goto __wake;
1222 		}
1223 	}
1224 	r1.event = SNDRV_TIMER_EVENT_TICK;
1225 	r1.tstamp = tstamp;
1226 	r1.val = ticks;
1227 	snd_timer_user_append_to_tqueue(tu, &r1);
1228 	append++;
1229       __wake:
1230 	spin_unlock(&tu->qlock);
1231 	if (append == 0)
1232 		return;
1233 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1234 	wake_up(&tu->qchange_sleep);
1235 }
1236 
1237 static int snd_timer_user_open(struct inode *inode, struct file *file)
1238 {
1239 	struct snd_timer_user *tu;
1240 
1241 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1242 	if (tu == NULL)
1243 		return -ENOMEM;
1244 	spin_lock_init(&tu->qlock);
1245 	init_waitqueue_head(&tu->qchange_sleep);
1246 	mutex_init(&tu->tread_sem);
1247 	tu->ticks = 1;
1248 	tu->queue_size = 128;
1249 	tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1250 			    GFP_KERNEL);
1251 	if (tu->queue == NULL) {
1252 		kfree(tu);
1253 		return -ENOMEM;
1254 	}
1255 	file->private_data = tu;
1256 	return 0;
1257 }
1258 
1259 static int snd_timer_user_release(struct inode *inode, struct file *file)
1260 {
1261 	struct snd_timer_user *tu;
1262 
1263 	if (file->private_data) {
1264 		tu = file->private_data;
1265 		file->private_data = NULL;
1266 		if (tu->timeri)
1267 			snd_timer_close(tu->timeri);
1268 		kfree(tu->queue);
1269 		kfree(tu->tqueue);
1270 		kfree(tu);
1271 	}
1272 	return 0;
1273 }
1274 
1275 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1276 {
1277 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1278 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1279 	id->card = -1;
1280 	id->device = -1;
1281 	id->subdevice = -1;
1282 }
1283 
1284 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1285 {
1286 	id->dev_class = timer->tmr_class;
1287 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1288 	id->card = timer->card ? timer->card->number : -1;
1289 	id->device = timer->tmr_device;
1290 	id->subdevice = timer->tmr_subdevice;
1291 }
1292 
1293 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1294 {
1295 	struct snd_timer_id id;
1296 	struct snd_timer *timer;
1297 	struct list_head *p;
1298 
1299 	if (copy_from_user(&id, _tid, sizeof(id)))
1300 		return -EFAULT;
1301 	mutex_lock(&register_mutex);
1302 	if (id.dev_class < 0) {		/* first item */
1303 		if (list_empty(&snd_timer_list))
1304 			snd_timer_user_zero_id(&id);
1305 		else {
1306 			timer = list_entry(snd_timer_list.next,
1307 					   struct snd_timer, device_list);
1308 			snd_timer_user_copy_id(&id, timer);
1309 		}
1310 	} else {
1311 		switch (id.dev_class) {
1312 		case SNDRV_TIMER_CLASS_GLOBAL:
1313 			id.device = id.device < 0 ? 0 : id.device + 1;
1314 			list_for_each(p, &snd_timer_list) {
1315 				timer = list_entry(p, struct snd_timer, device_list);
1316 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1317 					snd_timer_user_copy_id(&id, timer);
1318 					break;
1319 				}
1320 				if (timer->tmr_device >= id.device) {
1321 					snd_timer_user_copy_id(&id, timer);
1322 					break;
1323 				}
1324 			}
1325 			if (p == &snd_timer_list)
1326 				snd_timer_user_zero_id(&id);
1327 			break;
1328 		case SNDRV_TIMER_CLASS_CARD:
1329 		case SNDRV_TIMER_CLASS_PCM:
1330 			if (id.card < 0) {
1331 				id.card = 0;
1332 			} else {
1333 				if (id.card < 0) {
1334 					id.card = 0;
1335 				} else {
1336 					if (id.device < 0) {
1337 						id.device = 0;
1338 					} else {
1339 						if (id.subdevice < 0) {
1340 							id.subdevice = 0;
1341 						} else {
1342 							id.subdevice++;
1343 						}
1344 					}
1345 				}
1346 			}
1347 			list_for_each(p, &snd_timer_list) {
1348 				timer = list_entry(p, struct snd_timer, device_list);
1349 				if (timer->tmr_class > id.dev_class) {
1350 					snd_timer_user_copy_id(&id, timer);
1351 					break;
1352 				}
1353 				if (timer->tmr_class < id.dev_class)
1354 					continue;
1355 				if (timer->card->number > id.card) {
1356 					snd_timer_user_copy_id(&id, timer);
1357 					break;
1358 				}
1359 				if (timer->card->number < id.card)
1360 					continue;
1361 				if (timer->tmr_device > id.device) {
1362 					snd_timer_user_copy_id(&id, timer);
1363 					break;
1364 				}
1365 				if (timer->tmr_device < id.device)
1366 					continue;
1367 				if (timer->tmr_subdevice > id.subdevice) {
1368 					snd_timer_user_copy_id(&id, timer);
1369 					break;
1370 				}
1371 				if (timer->tmr_subdevice < id.subdevice)
1372 					continue;
1373 				snd_timer_user_copy_id(&id, timer);
1374 				break;
1375 			}
1376 			if (p == &snd_timer_list)
1377 				snd_timer_user_zero_id(&id);
1378 			break;
1379 		default:
1380 			snd_timer_user_zero_id(&id);
1381 		}
1382 	}
1383 	mutex_unlock(&register_mutex);
1384 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1385 		return -EFAULT;
1386 	return 0;
1387 }
1388 
1389 static int snd_timer_user_ginfo(struct file *file,
1390 				struct snd_timer_ginfo __user *_ginfo)
1391 {
1392 	struct snd_timer_ginfo *ginfo;
1393 	struct snd_timer_id tid;
1394 	struct snd_timer *t;
1395 	struct list_head *p;
1396 	int err = 0;
1397 
1398 	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1399 	if (IS_ERR(ginfo))
1400 		return PTR_ERR(ginfo);
1401 
1402 	tid = ginfo->tid;
1403 	memset(ginfo, 0, sizeof(*ginfo));
1404 	ginfo->tid = tid;
1405 	mutex_lock(&register_mutex);
1406 	t = snd_timer_find(&tid);
1407 	if (t != NULL) {
1408 		ginfo->card = t->card ? t->card->number : -1;
1409 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1410 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1411 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1412 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1413 		ginfo->resolution = t->hw.resolution;
1414 		if (t->hw.resolution_min > 0) {
1415 			ginfo->resolution_min = t->hw.resolution_min;
1416 			ginfo->resolution_max = t->hw.resolution_max;
1417 		}
1418 		list_for_each(p, &t->open_list_head) {
1419 			ginfo->clients++;
1420 		}
1421 	} else {
1422 		err = -ENODEV;
1423 	}
1424 	mutex_unlock(&register_mutex);
1425 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1426 		err = -EFAULT;
1427 	kfree(ginfo);
1428 	return err;
1429 }
1430 
1431 static int snd_timer_user_gparams(struct file *file,
1432 				  struct snd_timer_gparams __user *_gparams)
1433 {
1434 	struct snd_timer_gparams gparams;
1435 	struct snd_timer *t;
1436 	int err;
1437 
1438 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1439 		return -EFAULT;
1440 	mutex_lock(&register_mutex);
1441 	t = snd_timer_find(&gparams.tid);
1442 	if (!t) {
1443 		err = -ENODEV;
1444 		goto _error;
1445 	}
1446 	if (!list_empty(&t->open_list_head)) {
1447 		err = -EBUSY;
1448 		goto _error;
1449 	}
1450 	if (!t->hw.set_period) {
1451 		err = -ENOSYS;
1452 		goto _error;
1453 	}
1454 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1455 _error:
1456 	mutex_unlock(&register_mutex);
1457 	return err;
1458 }
1459 
1460 static int snd_timer_user_gstatus(struct file *file,
1461 				  struct snd_timer_gstatus __user *_gstatus)
1462 {
1463 	struct snd_timer_gstatus gstatus;
1464 	struct snd_timer_id tid;
1465 	struct snd_timer *t;
1466 	int err = 0;
1467 
1468 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1469 		return -EFAULT;
1470 	tid = gstatus.tid;
1471 	memset(&gstatus, 0, sizeof(gstatus));
1472 	gstatus.tid = tid;
1473 	mutex_lock(&register_mutex);
1474 	t = snd_timer_find(&tid);
1475 	if (t != NULL) {
1476 		if (t->hw.c_resolution)
1477 			gstatus.resolution = t->hw.c_resolution(t);
1478 		else
1479 			gstatus.resolution = t->hw.resolution;
1480 		if (t->hw.precise_resolution) {
1481 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1482 						 &gstatus.resolution_den);
1483 		} else {
1484 			gstatus.resolution_num = gstatus.resolution;
1485 			gstatus.resolution_den = 1000000000uL;
1486 		}
1487 	} else {
1488 		err = -ENODEV;
1489 	}
1490 	mutex_unlock(&register_mutex);
1491 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1492 		err = -EFAULT;
1493 	return err;
1494 }
1495 
1496 static int snd_timer_user_tselect(struct file *file,
1497 				  struct snd_timer_select __user *_tselect)
1498 {
1499 	struct snd_timer_user *tu;
1500 	struct snd_timer_select tselect;
1501 	char str[32];
1502 	int err = 0;
1503 
1504 	tu = file->private_data;
1505 	mutex_lock(&tu->tread_sem);
1506 	if (tu->timeri) {
1507 		snd_timer_close(tu->timeri);
1508 		tu->timeri = NULL;
1509 	}
1510 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1511 		err = -EFAULT;
1512 		goto __err;
1513 	}
1514 	sprintf(str, "application %i", current->pid);
1515 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1516 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1517 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1518 	if (err < 0)
1519 		goto __err;
1520 
1521 	kfree(tu->queue);
1522 	tu->queue = NULL;
1523 	kfree(tu->tqueue);
1524 	tu->tqueue = NULL;
1525 	if (tu->tread) {
1526 		tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1527 				     GFP_KERNEL);
1528 		if (tu->tqueue == NULL)
1529 			err = -ENOMEM;
1530 	} else {
1531 		tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1532 				    GFP_KERNEL);
1533 		if (tu->queue == NULL)
1534 			err = -ENOMEM;
1535 	}
1536 
1537       	if (err < 0) {
1538 		snd_timer_close(tu->timeri);
1539       		tu->timeri = NULL;
1540       	} else {
1541 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1542 		tu->timeri->callback = tu->tread
1543 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1544 		tu->timeri->ccallback = snd_timer_user_ccallback;
1545 		tu->timeri->callback_data = (void *)tu;
1546 	}
1547 
1548       __err:
1549       	mutex_unlock(&tu->tread_sem);
1550 	return err;
1551 }
1552 
1553 static int snd_timer_user_info(struct file *file,
1554 			       struct snd_timer_info __user *_info)
1555 {
1556 	struct snd_timer_user *tu;
1557 	struct snd_timer_info *info;
1558 	struct snd_timer *t;
1559 	int err = 0;
1560 
1561 	tu = file->private_data;
1562 	if (!tu->timeri)
1563 		return -EBADFD;
1564 	t = tu->timeri->timer;
1565 	if (!t)
1566 		return -EBADFD;
1567 
1568 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1569 	if (! info)
1570 		return -ENOMEM;
1571 	info->card = t->card ? t->card->number : -1;
1572 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1573 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1574 	strlcpy(info->id, t->id, sizeof(info->id));
1575 	strlcpy(info->name, t->name, sizeof(info->name));
1576 	info->resolution = t->hw.resolution;
1577 	if (copy_to_user(_info, info, sizeof(*_info)))
1578 		err = -EFAULT;
1579 	kfree(info);
1580 	return err;
1581 }
1582 
1583 static int snd_timer_user_params(struct file *file,
1584 				 struct snd_timer_params __user *_params)
1585 {
1586 	struct snd_timer_user *tu;
1587 	struct snd_timer_params params;
1588 	struct snd_timer *t;
1589 	struct snd_timer_read *tr;
1590 	struct snd_timer_tread *ttr;
1591 	int err;
1592 
1593 	tu = file->private_data;
1594 	if (!tu->timeri)
1595 		return -EBADFD;
1596 	t = tu->timeri->timer;
1597 	if (!t)
1598 		return -EBADFD;
1599 	if (copy_from_user(&params, _params, sizeof(params)))
1600 		return -EFAULT;
1601 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1602 		err = -EINVAL;
1603 		goto _end;
1604 	}
1605 	if (params.queue_size > 0 &&
1606 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1607 		err = -EINVAL;
1608 		goto _end;
1609 	}
1610 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1611 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1612 			      (1<<SNDRV_TIMER_EVENT_START)|
1613 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1614 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1615 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1616 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1617 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1618 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1619 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1620 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1621 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1622 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1623 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1624 		err = -EINVAL;
1625 		goto _end;
1626 	}
1627 	snd_timer_stop(tu->timeri);
1628 	spin_lock_irq(&t->lock);
1629 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1630 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1631 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1632 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1633 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1634 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1635 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1636 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1637 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1638 	spin_unlock_irq(&t->lock);
1639 	if (params.queue_size > 0 &&
1640 	    (unsigned int)tu->queue_size != params.queue_size) {
1641 		if (tu->tread) {
1642 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1643 				      GFP_KERNEL);
1644 			if (ttr) {
1645 				kfree(tu->tqueue);
1646 				tu->queue_size = params.queue_size;
1647 				tu->tqueue = ttr;
1648 			}
1649 		} else {
1650 			tr = kmalloc(params.queue_size * sizeof(*tr),
1651 				     GFP_KERNEL);
1652 			if (tr) {
1653 				kfree(tu->queue);
1654 				tu->queue_size = params.queue_size;
1655 				tu->queue = tr;
1656 			}
1657 		}
1658 	}
1659 	tu->qhead = tu->qtail = tu->qused = 0;
1660 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1661 		if (tu->tread) {
1662 			struct snd_timer_tread tread;
1663 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1664 			tread.tstamp.tv_sec = 0;
1665 			tread.tstamp.tv_nsec = 0;
1666 			tread.val = 0;
1667 			snd_timer_user_append_to_tqueue(tu, &tread);
1668 		} else {
1669 			struct snd_timer_read *r = &tu->queue[0];
1670 			r->resolution = 0;
1671 			r->ticks = 0;
1672 			tu->qused++;
1673 			tu->qtail++;
1674 		}
1675 	}
1676 	tu->filter = params.filter;
1677 	tu->ticks = params.ticks;
1678 	err = 0;
1679  _end:
1680 	if (copy_to_user(_params, &params, sizeof(params)))
1681 		return -EFAULT;
1682 	return err;
1683 }
1684 
1685 static int snd_timer_user_status(struct file *file,
1686 				 struct snd_timer_status __user *_status)
1687 {
1688 	struct snd_timer_user *tu;
1689 	struct snd_timer_status status;
1690 
1691 	tu = file->private_data;
1692 	if (!tu->timeri)
1693 		return -EBADFD;
1694 	memset(&status, 0, sizeof(status));
1695 	status.tstamp = tu->tstamp;
1696 	status.resolution = snd_timer_resolution(tu->timeri);
1697 	status.lost = tu->timeri->lost;
1698 	status.overrun = tu->overrun;
1699 	spin_lock_irq(&tu->qlock);
1700 	status.queue = tu->qused;
1701 	spin_unlock_irq(&tu->qlock);
1702 	if (copy_to_user(_status, &status, sizeof(status)))
1703 		return -EFAULT;
1704 	return 0;
1705 }
1706 
1707 static int snd_timer_user_start(struct file *file)
1708 {
1709 	int err;
1710 	struct snd_timer_user *tu;
1711 
1712 	tu = file->private_data;
1713 	if (!tu->timeri)
1714 		return -EBADFD;
1715 	snd_timer_stop(tu->timeri);
1716 	tu->timeri->lost = 0;
1717 	tu->last_resolution = 0;
1718 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1719 }
1720 
1721 static int snd_timer_user_stop(struct file *file)
1722 {
1723 	int err;
1724 	struct snd_timer_user *tu;
1725 
1726 	tu = file->private_data;
1727 	if (!tu->timeri)
1728 		return -EBADFD;
1729 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1730 }
1731 
1732 static int snd_timer_user_continue(struct file *file)
1733 {
1734 	int err;
1735 	struct snd_timer_user *tu;
1736 
1737 	tu = file->private_data;
1738 	if (!tu->timeri)
1739 		return -EBADFD;
1740 	tu->timeri->lost = 0;
1741 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1742 }
1743 
1744 static int snd_timer_user_pause(struct file *file)
1745 {
1746 	int err;
1747 	struct snd_timer_user *tu;
1748 
1749 	tu = file->private_data;
1750 	if (!tu->timeri)
1751 		return -EBADFD;
1752 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1753 }
1754 
1755 enum {
1756 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1757 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1758 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1759 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1760 };
1761 
1762 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1763 				 unsigned long arg)
1764 {
1765 	struct snd_timer_user *tu;
1766 	void __user *argp = (void __user *)arg;
1767 	int __user *p = argp;
1768 
1769 	tu = file->private_data;
1770 	switch (cmd) {
1771 	case SNDRV_TIMER_IOCTL_PVERSION:
1772 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1773 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1774 		return snd_timer_user_next_device(argp);
1775 	case SNDRV_TIMER_IOCTL_TREAD:
1776 	{
1777 		int xarg;
1778 
1779 		mutex_lock(&tu->tread_sem);
1780 		if (tu->timeri)	{	/* too late */
1781 			mutex_unlock(&tu->tread_sem);
1782 			return -EBUSY;
1783 		}
1784 		if (get_user(xarg, p)) {
1785 			mutex_unlock(&tu->tread_sem);
1786 			return -EFAULT;
1787 		}
1788 		tu->tread = xarg ? 1 : 0;
1789 		mutex_unlock(&tu->tread_sem);
1790 		return 0;
1791 	}
1792 	case SNDRV_TIMER_IOCTL_GINFO:
1793 		return snd_timer_user_ginfo(file, argp);
1794 	case SNDRV_TIMER_IOCTL_GPARAMS:
1795 		return snd_timer_user_gparams(file, argp);
1796 	case SNDRV_TIMER_IOCTL_GSTATUS:
1797 		return snd_timer_user_gstatus(file, argp);
1798 	case SNDRV_TIMER_IOCTL_SELECT:
1799 		return snd_timer_user_tselect(file, argp);
1800 	case SNDRV_TIMER_IOCTL_INFO:
1801 		return snd_timer_user_info(file, argp);
1802 	case SNDRV_TIMER_IOCTL_PARAMS:
1803 		return snd_timer_user_params(file, argp);
1804 	case SNDRV_TIMER_IOCTL_STATUS:
1805 		return snd_timer_user_status(file, argp);
1806 	case SNDRV_TIMER_IOCTL_START:
1807 	case SNDRV_TIMER_IOCTL_START_OLD:
1808 		return snd_timer_user_start(file);
1809 	case SNDRV_TIMER_IOCTL_STOP:
1810 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1811 		return snd_timer_user_stop(file);
1812 	case SNDRV_TIMER_IOCTL_CONTINUE:
1813 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1814 		return snd_timer_user_continue(file);
1815 	case SNDRV_TIMER_IOCTL_PAUSE:
1816 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1817 		return snd_timer_user_pause(file);
1818 	}
1819 	return -ENOTTY;
1820 }
1821 
1822 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1823 {
1824 	struct snd_timer_user *tu;
1825 
1826 	tu = file->private_data;
1827 	return fasync_helper(fd, file, on, &tu->fasync);
1828 }
1829 
1830 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1831 				   size_t count, loff_t *offset)
1832 {
1833 	struct snd_timer_user *tu;
1834 	long result = 0, unit;
1835 	int err = 0;
1836 
1837 	tu = file->private_data;
1838 	unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1839 	spin_lock_irq(&tu->qlock);
1840 	while ((long)count - result >= unit) {
1841 		while (!tu->qused) {
1842 			wait_queue_t wait;
1843 
1844 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1845 				err = -EAGAIN;
1846 				break;
1847 			}
1848 
1849 			set_current_state(TASK_INTERRUPTIBLE);
1850 			init_waitqueue_entry(&wait, current);
1851 			add_wait_queue(&tu->qchange_sleep, &wait);
1852 
1853 			spin_unlock_irq(&tu->qlock);
1854 			schedule();
1855 			spin_lock_irq(&tu->qlock);
1856 
1857 			remove_wait_queue(&tu->qchange_sleep, &wait);
1858 
1859 			if (signal_pending(current)) {
1860 				err = -ERESTARTSYS;
1861 				break;
1862 			}
1863 		}
1864 
1865 		spin_unlock_irq(&tu->qlock);
1866 		if (err < 0)
1867 			goto _error;
1868 
1869 		if (tu->tread) {
1870 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1871 					 sizeof(struct snd_timer_tread))) {
1872 				err = -EFAULT;
1873 				goto _error;
1874 			}
1875 		} else {
1876 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1877 					 sizeof(struct snd_timer_read))) {
1878 				err = -EFAULT;
1879 				goto _error;
1880 			}
1881 		}
1882 
1883 		tu->qhead %= tu->queue_size;
1884 
1885 		result += unit;
1886 		buffer += unit;
1887 
1888 		spin_lock_irq(&tu->qlock);
1889 		tu->qused--;
1890 	}
1891 	spin_unlock_irq(&tu->qlock);
1892  _error:
1893 	return result > 0 ? result : err;
1894 }
1895 
1896 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1897 {
1898         unsigned int mask;
1899         struct snd_timer_user *tu;
1900 
1901         tu = file->private_data;
1902 
1903         poll_wait(file, &tu->qchange_sleep, wait);
1904 
1905 	mask = 0;
1906 	if (tu->qused)
1907 		mask |= POLLIN | POLLRDNORM;
1908 
1909 	return mask;
1910 }
1911 
1912 #ifdef CONFIG_COMPAT
1913 #include "timer_compat.c"
1914 #else
1915 #define snd_timer_user_ioctl_compat	NULL
1916 #endif
1917 
1918 static const struct file_operations snd_timer_f_ops =
1919 {
1920 	.owner =	THIS_MODULE,
1921 	.read =		snd_timer_user_read,
1922 	.open =		snd_timer_user_open,
1923 	.release =	snd_timer_user_release,
1924 	.poll =		snd_timer_user_poll,
1925 	.unlocked_ioctl =	snd_timer_user_ioctl,
1926 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1927 	.fasync = 	snd_timer_user_fasync,
1928 };
1929 
1930 /*
1931  *  ENTRY functions
1932  */
1933 
1934 static int __init alsa_timer_init(void)
1935 {
1936 	int err;
1937 
1938 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1939 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1940 			      "system timer");
1941 #endif
1942 
1943 	if ((err = snd_timer_register_system()) < 0)
1944 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1945 			   err);
1946 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1947 				       &snd_timer_f_ops, NULL, "timer")) < 0)
1948 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1949 			   err);
1950 	snd_timer_proc_init();
1951 	return 0;
1952 }
1953 
1954 static void __exit alsa_timer_exit(void)
1955 {
1956 	struct list_head *p, *n;
1957 
1958 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1959 	/* unregister the system timer */
1960 	list_for_each_safe(p, n, &snd_timer_list) {
1961 		struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1962 		snd_timer_free(timer);
1963 	}
1964 	snd_timer_proc_done();
1965 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1966 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1967 #endif
1968 }
1969 
1970 module_init(alsa_timer_init)
1971 module_exit(alsa_timer_exit)
1972 
1973 EXPORT_SYMBOL(snd_timer_open);
1974 EXPORT_SYMBOL(snd_timer_close);
1975 EXPORT_SYMBOL(snd_timer_resolution);
1976 EXPORT_SYMBOL(snd_timer_start);
1977 EXPORT_SYMBOL(snd_timer_stop);
1978 EXPORT_SYMBOL(snd_timer_continue);
1979 EXPORT_SYMBOL(snd_timer_pause);
1980 EXPORT_SYMBOL(snd_timer_new);
1981 EXPORT_SYMBOL(snd_timer_notify);
1982 EXPORT_SYMBOL(snd_timer_global_new);
1983 EXPORT_SYMBOL(snd_timer_global_free);
1984 EXPORT_SYMBOL(snd_timer_global_register);
1985 EXPORT_SYMBOL(snd_timer_interrupt);
1986