xref: /linux/sound/core/timer.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <sound/driver.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/time.h>
28 #include <linux/moduleparam.h>
29 #include <linux/string.h>
30 #include <sound/core.h>
31 #include <sound/timer.h>
32 #include <sound/control.h>
33 #include <sound/info.h>
34 #include <sound/minors.h>
35 #include <sound/initval.h>
36 #include <linux/kmod.h>
37 #ifdef CONFIG_KERNELD
38 #include <linux/kerneld.h>
39 #endif
40 
41 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
42 #define DEFAULT_TIMER_LIMIT 3
43 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
44 #define DEFAULT_TIMER_LIMIT 2
45 #else
46 #define DEFAULT_TIMER_LIMIT 1
47 #endif
48 
49 static int timer_limit = DEFAULT_TIMER_LIMIT;
50 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
51 MODULE_DESCRIPTION("ALSA timer interface");
52 MODULE_LICENSE("GPL");
53 module_param(timer_limit, int, 0444);
54 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
55 
56 typedef struct {
57 	snd_timer_instance_t *timeri;
58 	int tread;		/* enhanced read with timestamps and events */
59 	unsigned long ticks;
60 	unsigned long overrun;
61 	int qhead;
62 	int qtail;
63 	int qused;
64 	int queue_size;
65 	snd_timer_read_t *queue;
66 	snd_timer_tread_t *tqueue;
67 	spinlock_t qlock;
68 	unsigned long last_resolution;
69 	unsigned int filter;
70 	struct timespec tstamp;		/* trigger tstamp */
71 	wait_queue_head_t qchange_sleep;
72 	struct fasync_struct *fasync;
73 	struct semaphore tread_sem;
74 } snd_timer_user_t;
75 
76 /* list of timers */
77 static LIST_HEAD(snd_timer_list);
78 
79 /* list of slave instances */
80 static LIST_HEAD(snd_timer_slave_list);
81 
82 /* lock for slave active lists */
83 static DEFINE_SPINLOCK(slave_active_lock);
84 
85 static DECLARE_MUTEX(register_mutex);
86 
87 static int snd_timer_free(snd_timer_t *timer);
88 static int snd_timer_dev_free(snd_device_t *device);
89 static int snd_timer_dev_register(snd_device_t *device);
90 static int snd_timer_dev_unregister(snd_device_t *device);
91 
92 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left);
93 
94 /*
95  * create a timer instance with the given owner string.
96  * when timer is not NULL, increments the module counter
97  */
98 static snd_timer_instance_t *snd_timer_instance_new(char *owner,
99 						    snd_timer_t *timer)
100 {
101 	snd_timer_instance_t *timeri;
102 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
103 	if (timeri == NULL)
104 		return NULL;
105 	timeri->owner = kstrdup(owner, GFP_KERNEL);
106 	if (! timeri->owner) {
107 		kfree(timeri);
108 		return NULL;
109 	}
110 	INIT_LIST_HEAD(&timeri->open_list);
111 	INIT_LIST_HEAD(&timeri->active_list);
112 	INIT_LIST_HEAD(&timeri->ack_list);
113 	INIT_LIST_HEAD(&timeri->slave_list_head);
114 	INIT_LIST_HEAD(&timeri->slave_active_head);
115 
116 	timeri->timer = timer;
117 	if (timer && !try_module_get(timer->module)) {
118 		kfree(timeri->owner);
119 		kfree(timeri);
120 		return NULL;
121 	}
122 
123 	return timeri;
124 }
125 
126 /*
127  * find a timer instance from the given timer id
128  */
129 static snd_timer_t *snd_timer_find(snd_timer_id_t *tid)
130 {
131 	snd_timer_t *timer = NULL;
132 	struct list_head *p;
133 
134 	list_for_each(p, &snd_timer_list) {
135 		timer = list_entry(p, snd_timer_t, device_list);
136 
137 		if (timer->tmr_class != tid->dev_class)
138 			continue;
139 		if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
140 		     timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
141 		    (timer->card == NULL ||
142 		     timer->card->number != tid->card))
143 			continue;
144 		if (timer->tmr_device != tid->device)
145 			continue;
146 		if (timer->tmr_subdevice != tid->subdevice)
147 			continue;
148 		return timer;
149 	}
150 	return NULL;
151 }
152 
153 #ifdef CONFIG_KMOD
154 
155 static void snd_timer_request(snd_timer_id_t *tid)
156 {
157 	if (! current->fs->root)
158 		return;
159 	switch (tid->dev_class) {
160 	case SNDRV_TIMER_CLASS_GLOBAL:
161 		if (tid->device < timer_limit)
162 			request_module("snd-timer-%i", tid->device);
163 		break;
164 	case SNDRV_TIMER_CLASS_CARD:
165 	case SNDRV_TIMER_CLASS_PCM:
166 		if (tid->card < snd_ecards_limit)
167 			request_module("snd-card-%i", tid->card);
168 		break;
169 	default:
170 		break;
171 	}
172 }
173 
174 #endif
175 
176 /*
177  * look for a master instance matching with the slave id of the given slave.
178  * when found, relink the open_link of the slave.
179  *
180  * call this with register_mutex down.
181  */
182 static void snd_timer_check_slave(snd_timer_instance_t *slave)
183 {
184 	snd_timer_t *timer;
185 	snd_timer_instance_t *master;
186 	struct list_head *p, *q;
187 
188 	/* FIXME: it's really dumb to look up all entries.. */
189 	list_for_each(p, &snd_timer_list) {
190 		timer = list_entry(p, snd_timer_t, device_list);
191 		list_for_each(q, &timer->open_list_head) {
192 			master = list_entry(q, snd_timer_instance_t, open_list);
193 			if (slave->slave_class == master->slave_class &&
194 			    slave->slave_id == master->slave_id) {
195 				list_del(&slave->open_list);
196 				list_add_tail(&slave->open_list,
197 					      &master->slave_list_head);
198 				spin_lock_irq(&slave_active_lock);
199 				slave->master = master;
200 				slave->timer = master->timer;
201 				spin_unlock_irq(&slave_active_lock);
202 				return;
203 			}
204 		}
205 	}
206 }
207 
208 /*
209  * look for slave instances matching with the slave id of the given master.
210  * when found, relink the open_link of slaves.
211  *
212  * call this with register_mutex down.
213  */
214 static void snd_timer_check_master(snd_timer_instance_t *master)
215 {
216 	snd_timer_instance_t *slave;
217 	struct list_head *p, *n;
218 
219 	/* check all pending slaves */
220 	list_for_each_safe(p, n, &snd_timer_slave_list) {
221 		slave = list_entry(p, snd_timer_instance_t, open_list);
222 		if (slave->slave_class == master->slave_class &&
223 		    slave->slave_id == master->slave_id) {
224 			list_del(p);
225 			list_add_tail(p, &master->slave_list_head);
226 			spin_lock_irq(&slave_active_lock);
227 			slave->master = master;
228 			slave->timer = master->timer;
229 			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
230 				list_add_tail(&slave->active_list,
231 					      &master->slave_active_head);
232 			spin_unlock_irq(&slave_active_lock);
233 		}
234 	}
235 }
236 
237 /*
238  * open a timer instance
239  * when opening a master, the slave id must be here given.
240  */
241 int snd_timer_open(snd_timer_instance_t **ti,
242 		   char *owner, snd_timer_id_t *tid,
243 		   unsigned int slave_id)
244 {
245 	snd_timer_t *timer;
246 	snd_timer_instance_t *timeri = NULL;
247 
248 	if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
249 		/* open a slave instance */
250 		if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
251 		    tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
252 			snd_printd("invalid slave class %i\n", tid->dev_sclass);
253 			return -EINVAL;
254 		}
255 		down(&register_mutex);
256 		timeri = snd_timer_instance_new(owner, NULL);
257 		if (!timeri) {
258 			up(&register_mutex);
259 			return -ENOMEM;
260 		}
261 		timeri->slave_class = tid->dev_sclass;
262 		timeri->slave_id = tid->device;
263 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
264 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
265 		snd_timer_check_slave(timeri);
266 		up(&register_mutex);
267 		*ti = timeri;
268 		return 0;
269 	}
270 
271 	/* open a master instance */
272 	down(&register_mutex);
273 	timer = snd_timer_find(tid);
274 #ifdef CONFIG_KMOD
275 	if (timer == NULL) {
276 		up(&register_mutex);
277 		snd_timer_request(tid);
278 		down(&register_mutex);
279 		timer = snd_timer_find(tid);
280 	}
281 #endif
282 	if (!timer) {
283 		up(&register_mutex);
284 		return -ENODEV;
285 	}
286 	if (!list_empty(&timer->open_list_head)) {
287 		timeri = list_entry(timer->open_list_head.next,
288 				    snd_timer_instance_t, open_list);
289 		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
290 			up(&register_mutex);
291 			return -EBUSY;
292 		}
293 	}
294 	timeri = snd_timer_instance_new(owner, timer);
295 	if (!timeri) {
296 		up(&register_mutex);
297 		return -ENOMEM;
298 	}
299 	timeri->slave_class = tid->dev_sclass;
300 	timeri->slave_id = slave_id;
301 	if (list_empty(&timer->open_list_head) && timer->hw.open)
302 		timer->hw.open(timer);
303 	list_add_tail(&timeri->open_list, &timer->open_list_head);
304 	snd_timer_check_master(timeri);
305 	up(&register_mutex);
306 	*ti = timeri;
307 	return 0;
308 }
309 
310 static int _snd_timer_stop(snd_timer_instance_t * timeri,
311 			   int keep_flag, enum sndrv_timer_event event);
312 
313 /*
314  * close a timer instance
315  */
316 int snd_timer_close(snd_timer_instance_t * timeri)
317 {
318 	snd_timer_t *timer = NULL;
319 	struct list_head *p, *n;
320 	snd_timer_instance_t *slave;
321 
322 	snd_assert(timeri != NULL, return -ENXIO);
323 
324 	/* force to stop the timer */
325 	snd_timer_stop(timeri);
326 
327 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
328 		/* wait, until the active callback is finished */
329 		spin_lock_irq(&slave_active_lock);
330 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
331 			spin_unlock_irq(&slave_active_lock);
332 			udelay(10);
333 			spin_lock_irq(&slave_active_lock);
334 		}
335 		spin_unlock_irq(&slave_active_lock);
336 		down(&register_mutex);
337 		list_del(&timeri->open_list);
338 		up(&register_mutex);
339 	} else {
340 		timer = timeri->timer;
341 		/* wait, until the active callback is finished */
342 		spin_lock_irq(&timer->lock);
343 		while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
344 			spin_unlock_irq(&timer->lock);
345 			udelay(10);
346 			spin_lock_irq(&timer->lock);
347 		}
348 		spin_unlock_irq(&timer->lock);
349 		down(&register_mutex);
350 		list_del(&timeri->open_list);
351 		if (timer && list_empty(&timer->open_list_head) &&
352 		    timer->hw.close)
353 			timer->hw.close(timer);
354 		/* remove slave links */
355 		list_for_each_safe(p, n, &timeri->slave_list_head) {
356 			slave = list_entry(p, snd_timer_instance_t, open_list);
357 			spin_lock_irq(&slave_active_lock);
358 			_snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
359 			list_del(p);
360 			list_add_tail(p, &snd_timer_slave_list);
361 			slave->master = NULL;
362 			slave->timer = NULL;
363 			spin_unlock_irq(&slave_active_lock);
364 		}
365 		up(&register_mutex);
366 	}
367 	if (timeri->private_free)
368 		timeri->private_free(timeri);
369 	kfree(timeri->owner);
370 	kfree(timeri);
371 	if (timer)
372 		module_put(timer->module);
373 	return 0;
374 }
375 
376 unsigned long snd_timer_resolution(snd_timer_instance_t * timeri)
377 {
378 	snd_timer_t * timer;
379 
380 	if (timeri == NULL)
381 		return 0;
382 	if ((timer = timeri->timer) != NULL) {
383 		if (timer->hw.c_resolution)
384 			return timer->hw.c_resolution(timer);
385 		return timer->hw.resolution;
386 	}
387 	return 0;
388 }
389 
390 static void snd_timer_notify1(snd_timer_instance_t *ti,
391 			      enum sndrv_timer_event event)
392 {
393 	snd_timer_t *timer;
394 	unsigned long flags;
395 	unsigned long resolution = 0;
396 	snd_timer_instance_t *ts;
397 	struct list_head *n;
398 	struct timespec tstamp;
399 
400 	getnstimeofday(&tstamp);
401 	snd_assert(event >= SNDRV_TIMER_EVENT_START &&
402 		   event <= SNDRV_TIMER_EVENT_PAUSE, return);
403 	if (event == SNDRV_TIMER_EVENT_START ||
404 	    event == SNDRV_TIMER_EVENT_CONTINUE)
405 		resolution = snd_timer_resolution(ti);
406 	if (ti->ccallback)
407 		ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
408 	if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
409 		return;
410 	timer = ti->timer;
411 	if (timer == NULL)
412 		return;
413 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
414 		return;
415 	spin_lock_irqsave(&timer->lock, flags);
416 	list_for_each(n, &ti->slave_active_head) {
417 		ts = list_entry(n, snd_timer_instance_t, active_list);
418 		if (ts->ccallback)
419 			ts->ccallback(ti, event + 100, &tstamp, resolution);
420 	}
421 	spin_unlock_irqrestore(&timer->lock, flags);
422 }
423 
424 static int snd_timer_start1(snd_timer_t *timer, snd_timer_instance_t *timeri,
425 			    unsigned long sticks)
426 {
427 	list_del(&timeri->active_list);
428 	list_add_tail(&timeri->active_list, &timer->active_list_head);
429 	if (timer->running) {
430 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
431 			goto __start_now;
432 		timer->flags |= SNDRV_TIMER_FLG_RESCHED;
433 		timeri->flags |= SNDRV_TIMER_IFLG_START;
434 		return 1;	/* delayed start */
435 	} else {
436 		timer->sticks = sticks;
437 		timer->hw.start(timer);
438 	      __start_now:
439 		timer->running++;
440 		timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
441 		return 0;
442 	}
443 }
444 
445 static int snd_timer_start_slave(snd_timer_instance_t *timeri)
446 {
447 	unsigned long flags;
448 
449 	spin_lock_irqsave(&slave_active_lock, flags);
450 	timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
451 	if (timeri->master)
452 		list_add_tail(&timeri->active_list,
453 			      &timeri->master->slave_active_head);
454 	spin_unlock_irqrestore(&slave_active_lock, flags);
455 	return 1; /* delayed start */
456 }
457 
458 /*
459  *  start the timer instance
460  */
461 int snd_timer_start(snd_timer_instance_t * timeri, unsigned int ticks)
462 {
463 	snd_timer_t *timer;
464 	int result = -EINVAL;
465 	unsigned long flags;
466 
467 	if (timeri == NULL || ticks < 1)
468 		return -EINVAL;
469 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
470 		result = snd_timer_start_slave(timeri);
471 		snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
472 		return result;
473 	}
474 	timer = timeri->timer;
475 	if (timer == NULL)
476 		return -EINVAL;
477 	spin_lock_irqsave(&timer->lock, flags);
478 	timeri->ticks = timeri->cticks = ticks;
479 	timeri->pticks = 0;
480 	result = snd_timer_start1(timer, timeri, ticks);
481 	spin_unlock_irqrestore(&timer->lock, flags);
482 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
483 	return result;
484 }
485 
486 static int _snd_timer_stop(snd_timer_instance_t * timeri,
487 			   int keep_flag, enum sndrv_timer_event event)
488 {
489 	snd_timer_t *timer;
490 	unsigned long flags;
491 
492 	snd_assert(timeri != NULL, return -ENXIO);
493 
494 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
495 		if (!keep_flag) {
496 			spin_lock_irqsave(&slave_active_lock, flags);
497 			timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
498 			spin_unlock_irqrestore(&slave_active_lock, flags);
499 		}
500 		goto __end;
501 	}
502 	timer = timeri->timer;
503 	if (!timer)
504 		return -EINVAL;
505 	spin_lock_irqsave(&timer->lock, flags);
506 	list_del_init(&timeri->ack_list);
507 	list_del_init(&timeri->active_list);
508 	if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
509 	    !(--timer->running)) {
510 		timer->hw.stop(timer);
511 		if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
512 			timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
513 			snd_timer_reschedule(timer, 0);
514 			if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
515 				timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
516 				timer->hw.start(timer);
517 			}
518 		}
519 	}
520 	if (!keep_flag)
521 		timeri->flags &=
522 			~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
523 	spin_unlock_irqrestore(&timer->lock, flags);
524       __end:
525 	if (event != SNDRV_TIMER_EVENT_RESOLUTION)
526 		snd_timer_notify1(timeri, event);
527 	return 0;
528 }
529 
530 /*
531  * stop the timer instance.
532  *
533  * do not call this from the timer callback!
534  */
535 int snd_timer_stop(snd_timer_instance_t * timeri)
536 {
537 	snd_timer_t *timer;
538 	unsigned long flags;
539 	int err;
540 
541 	err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
542 	if (err < 0)
543 		return err;
544 	timer = timeri->timer;
545 	spin_lock_irqsave(&timer->lock, flags);
546 	timeri->cticks = timeri->ticks;
547 	timeri->pticks = 0;
548 	spin_unlock_irqrestore(&timer->lock, flags);
549 	return 0;
550 }
551 
552 /*
553  * start again..  the tick is kept.
554  */
555 int snd_timer_continue(snd_timer_instance_t * timeri)
556 {
557 	snd_timer_t *timer;
558 	int result = -EINVAL;
559 	unsigned long flags;
560 
561 	if (timeri == NULL)
562 		return result;
563 	if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
564 		return snd_timer_start_slave(timeri);
565 	timer = timeri->timer;
566 	if (! timer)
567 		return -EINVAL;
568 	spin_lock_irqsave(&timer->lock, flags);
569 	if (!timeri->cticks)
570 		timeri->cticks = 1;
571 	timeri->pticks = 0;
572 	result = snd_timer_start1(timer, timeri, timer->sticks);
573 	spin_unlock_irqrestore(&timer->lock, flags);
574 	snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
575 	return result;
576 }
577 
578 /*
579  * pause.. remember the ticks left
580  */
581 int snd_timer_pause(snd_timer_instance_t * timeri)
582 {
583 	return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
584 }
585 
586 /*
587  * reschedule the timer
588  *
589  * start pending instances and check the scheduling ticks.
590  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
591  */
592 static void snd_timer_reschedule(snd_timer_t * timer, unsigned long ticks_left)
593 {
594 	snd_timer_instance_t *ti;
595 	unsigned long ticks = ~0UL;
596 	struct list_head *p;
597 
598 	list_for_each(p, &timer->active_list_head) {
599 		ti = list_entry(p, snd_timer_instance_t, active_list);
600 		if (ti->flags & SNDRV_TIMER_IFLG_START) {
601 			ti->flags &= ~SNDRV_TIMER_IFLG_START;
602 			ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
603 			timer->running++;
604 		}
605 		if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
606 			if (ticks > ti->cticks)
607 				ticks = ti->cticks;
608 		}
609 	}
610 	if (ticks == ~0UL) {
611 		timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
612 		return;
613 	}
614 	if (ticks > timer->hw.ticks)
615 		ticks = timer->hw.ticks;
616 	if (ticks_left != ticks)
617 		timer->flags |= SNDRV_TIMER_FLG_CHANGE;
618 	timer->sticks = ticks;
619 }
620 
621 /*
622  * timer tasklet
623  *
624  */
625 static void snd_timer_tasklet(unsigned long arg)
626 {
627 	snd_timer_t *timer = (snd_timer_t *) arg;
628 	snd_timer_instance_t *ti;
629 	struct list_head *p;
630 	unsigned long resolution, ticks;
631 
632 	spin_lock(&timer->lock);
633 	/* now process all callbacks */
634 	while (!list_empty(&timer->sack_list_head)) {
635 		p = timer->sack_list_head.next;		/* get first item */
636 		ti = list_entry(p, snd_timer_instance_t, ack_list);
637 
638 		/* remove from ack_list and make empty */
639 		list_del_init(p);
640 
641 		ticks = ti->pticks;
642 		ti->pticks = 0;
643 		resolution = ti->resolution;
644 
645 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
646 		spin_unlock(&timer->lock);
647 		if (ti->callback)
648 			ti->callback(ti, resolution, ticks);
649 		spin_lock(&timer->lock);
650 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
651 	}
652 	spin_unlock(&timer->lock);
653 }
654 
655 /*
656  * timer interrupt
657  *
658  * ticks_left is usually equal to timer->sticks.
659  *
660  */
661 void snd_timer_interrupt(snd_timer_t * timer, unsigned long ticks_left)
662 {
663 	snd_timer_instance_t *ti, *ts;
664 	unsigned long resolution, ticks;
665 	struct list_head *p, *q, *n, *ack_list_head;
666 	int use_tasklet = 0;
667 
668 	if (timer == NULL)
669 		return;
670 
671 	spin_lock(&timer->lock);
672 
673 	/* remember the current resolution */
674 	if (timer->hw.c_resolution)
675 		resolution = timer->hw.c_resolution(timer);
676 	else
677 		resolution = timer->hw.resolution;
678 
679 	/* loop for all active instances
680 	 * Here we cannot use list_for_each because the active_list of a
681 	 * processed instance is relinked to done_list_head before the callback
682 	 * is called.
683 	 */
684 	list_for_each_safe(p, n, &timer->active_list_head) {
685 		ti = list_entry(p, snd_timer_instance_t, active_list);
686 		if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
687 			continue;
688 		ti->pticks += ticks_left;
689 		ti->resolution = resolution;
690 		if (ti->cticks < ticks_left)
691 			ti->cticks = 0;
692 		else
693 			ti->cticks -= ticks_left;
694 		if (ti->cticks) /* not expired */
695 			continue;
696 		if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
697 			ti->cticks = ti->ticks;
698 		} else {
699 			ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
700 			if (--timer->running)
701 				list_del(p);
702 		}
703 		if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
704 		    (ti->flags & SNDRV_TIMER_IFLG_FAST))
705 			ack_list_head = &timer->ack_list_head;
706 		else
707 			ack_list_head = &timer->sack_list_head;
708 		if (list_empty(&ti->ack_list))
709 			list_add_tail(&ti->ack_list, ack_list_head);
710 		list_for_each(q, &ti->slave_active_head) {
711 			ts = list_entry(q, snd_timer_instance_t, active_list);
712 			ts->pticks = ti->pticks;
713 			ts->resolution = resolution;
714 			if (list_empty(&ts->ack_list))
715 				list_add_tail(&ts->ack_list, ack_list_head);
716 		}
717 	}
718 	if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
719 		snd_timer_reschedule(timer, ticks_left);
720 	if (timer->running) {
721 		if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
722 			timer->hw.stop(timer);
723 			timer->flags |= SNDRV_TIMER_FLG_CHANGE;
724 		}
725 		if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
726 		    (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
727 			/* restart timer */
728 			timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
729 			timer->hw.start(timer);
730 		}
731 	} else {
732 		timer->hw.stop(timer);
733 	}
734 
735 	/* now process all fast callbacks */
736 	while (!list_empty(&timer->ack_list_head)) {
737 		p = timer->ack_list_head.next;		/* get first item */
738 		ti = list_entry(p, snd_timer_instance_t, ack_list);
739 
740 		/* remove from ack_list and make empty */
741 		list_del_init(p);
742 
743 		ticks = ti->pticks;
744 		ti->pticks = 0;
745 
746 		ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
747 		spin_unlock(&timer->lock);
748 		if (ti->callback)
749 			ti->callback(ti, resolution, ticks);
750 		spin_lock(&timer->lock);
751 		ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
752 	}
753 
754 	/* do we have any slow callbacks? */
755 	use_tasklet = !list_empty(&timer->sack_list_head);
756 	spin_unlock(&timer->lock);
757 
758 	if (use_tasklet)
759 		tasklet_hi_schedule(&timer->task_queue);
760 }
761 
762 /*
763 
764  */
765 
766 int snd_timer_new(snd_card_t *card, char *id, snd_timer_id_t *tid,
767 		  snd_timer_t **rtimer)
768 {
769 	snd_timer_t *timer;
770 	int err;
771 	static snd_device_ops_t ops = {
772 		.dev_free = snd_timer_dev_free,
773 		.dev_register = snd_timer_dev_register,
774 		.dev_unregister = snd_timer_dev_unregister
775 	};
776 
777 	snd_assert(tid != NULL, return -EINVAL);
778 	snd_assert(rtimer != NULL, return -EINVAL);
779 	*rtimer = NULL;
780 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
781 	if (timer == NULL)
782 		return -ENOMEM;
783 	timer->tmr_class = tid->dev_class;
784 	timer->card = card;
785 	timer->tmr_device = tid->device;
786 	timer->tmr_subdevice = tid->subdevice;
787 	if (id)
788 		strlcpy(timer->id, id, sizeof(timer->id));
789 	INIT_LIST_HEAD(&timer->device_list);
790 	INIT_LIST_HEAD(&timer->open_list_head);
791 	INIT_LIST_HEAD(&timer->active_list_head);
792 	INIT_LIST_HEAD(&timer->ack_list_head);
793 	INIT_LIST_HEAD(&timer->sack_list_head);
794 	spin_lock_init(&timer->lock);
795 	tasklet_init(&timer->task_queue, snd_timer_tasklet,
796 		     (unsigned long)timer);
797 	if (card != NULL) {
798 		timer->module = card->module;
799 		err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
800 		if (err < 0) {
801 			snd_timer_free(timer);
802 			return err;
803 		}
804 	}
805 	*rtimer = timer;
806 	return 0;
807 }
808 
809 static int snd_timer_free(snd_timer_t *timer)
810 {
811 	snd_assert(timer != NULL, return -ENXIO);
812 	if (timer->private_free)
813 		timer->private_free(timer);
814 	kfree(timer);
815 	return 0;
816 }
817 
818 static int snd_timer_dev_free(snd_device_t *device)
819 {
820 	snd_timer_t *timer = device->device_data;
821 	return snd_timer_free(timer);
822 }
823 
824 static int snd_timer_dev_register(snd_device_t *dev)
825 {
826 	snd_timer_t *timer = dev->device_data;
827 	snd_timer_t *timer1;
828 	struct list_head *p;
829 
830 	snd_assert(timer != NULL && timer->hw.start != NULL &&
831 		   timer->hw.stop != NULL, return -ENXIO);
832 	if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
833 	    !timer->hw.resolution && timer->hw.c_resolution == NULL)
834 	    	return -EINVAL;
835 
836 	down(&register_mutex);
837 	list_for_each(p, &snd_timer_list) {
838 		timer1 = list_entry(p, snd_timer_t, device_list);
839 		if (timer1->tmr_class > timer->tmr_class)
840 			break;
841 		if (timer1->tmr_class < timer->tmr_class)
842 			continue;
843 		if (timer1->card && timer->card) {
844 			if (timer1->card->number > timer->card->number)
845 				break;
846 			if (timer1->card->number < timer->card->number)
847 				continue;
848 		}
849 		if (timer1->tmr_device > timer->tmr_device)
850 			break;
851 		if (timer1->tmr_device < timer->tmr_device)
852 			continue;
853 		if (timer1->tmr_subdevice > timer->tmr_subdevice)
854 			break;
855 		if (timer1->tmr_subdevice < timer->tmr_subdevice)
856 			continue;
857 		/* conflicts.. */
858 		up(&register_mutex);
859 		return -EBUSY;
860 	}
861 	list_add_tail(&timer->device_list, p);
862 	up(&register_mutex);
863 	return 0;
864 }
865 
866 static int snd_timer_unregister(snd_timer_t *timer)
867 {
868 	struct list_head *p, *n;
869 	snd_timer_instance_t *ti;
870 
871 	snd_assert(timer != NULL, return -ENXIO);
872 	down(&register_mutex);
873 	if (! list_empty(&timer->open_list_head)) {
874 		snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
875 		list_for_each_safe(p, n, &timer->open_list_head) {
876 			list_del_init(p);
877 			ti = list_entry(p, snd_timer_instance_t, open_list);
878 			ti->timer = NULL;
879 		}
880 	}
881 	list_del(&timer->device_list);
882 	up(&register_mutex);
883 	return snd_timer_free(timer);
884 }
885 
886 static int snd_timer_dev_unregister(snd_device_t *device)
887 {
888 	snd_timer_t *timer = device->device_data;
889 	return snd_timer_unregister(timer);
890 }
891 
892 void snd_timer_notify(snd_timer_t *timer, enum sndrv_timer_event event,
893 		      struct timespec *tstamp)
894 {
895 	unsigned long flags;
896 	unsigned long resolution = 0;
897 	snd_timer_instance_t *ti, *ts;
898 	struct list_head *p, *n;
899 
900 	if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
901 		return;
902 	snd_assert(event >= SNDRV_TIMER_EVENT_MSTART &&
903 		   event <= SNDRV_TIMER_EVENT_MRESUME, return);
904 	spin_lock_irqsave(&timer->lock, flags);
905 	if (event == SNDRV_TIMER_EVENT_MSTART ||
906 	    event == SNDRV_TIMER_EVENT_MCONTINUE ||
907 	    event == SNDRV_TIMER_EVENT_MRESUME) {
908 		if (timer->hw.c_resolution)
909 			resolution = timer->hw.c_resolution(timer);
910 		else
911 			resolution = timer->hw.resolution;
912 	}
913 	list_for_each(p, &timer->active_list_head) {
914 		ti = list_entry(p, snd_timer_instance_t, active_list);
915 		if (ti->ccallback)
916 			ti->ccallback(ti, event, tstamp, resolution);
917 		list_for_each(n, &ti->slave_active_head) {
918 			ts = list_entry(n, snd_timer_instance_t, active_list);
919 			if (ts->ccallback)
920 				ts->ccallback(ts, event, tstamp, resolution);
921 		}
922 	}
923 	spin_unlock_irqrestore(&timer->lock, flags);
924 }
925 
926 /*
927  * exported functions for global timers
928  */
929 int snd_timer_global_new(char *id, int device, snd_timer_t **rtimer)
930 {
931 	snd_timer_id_t tid;
932 
933 	tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
934 	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
935 	tid.card = -1;
936 	tid.device = device;
937 	tid.subdevice = 0;
938 	return snd_timer_new(NULL, id, &tid, rtimer);
939 }
940 
941 int snd_timer_global_free(snd_timer_t *timer)
942 {
943 	return snd_timer_free(timer);
944 }
945 
946 int snd_timer_global_register(snd_timer_t *timer)
947 {
948 	snd_device_t dev;
949 
950 	memset(&dev, 0, sizeof(dev));
951 	dev.device_data = timer;
952 	return snd_timer_dev_register(&dev);
953 }
954 
955 int snd_timer_global_unregister(snd_timer_t *timer)
956 {
957 	return snd_timer_unregister(timer);
958 }
959 
960 /*
961  *  System timer
962  */
963 
964 struct snd_timer_system_private {
965 	struct timer_list tlist;
966 	struct timer * timer;
967 	unsigned long last_expires;
968 	unsigned long last_jiffies;
969 	unsigned long correction;
970 };
971 
972 static void snd_timer_s_function(unsigned long data)
973 {
974 	snd_timer_t *timer = (snd_timer_t *)data;
975 	struct snd_timer_system_private *priv = timer->private_data;
976 	unsigned long jiff = jiffies;
977 	if (time_after(jiff, priv->last_expires))
978 		priv->correction = (long)jiff - (long)priv->last_expires;
979 	snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
980 }
981 
982 static int snd_timer_s_start(snd_timer_t * timer)
983 {
984 	struct snd_timer_system_private *priv;
985 	unsigned long njiff;
986 
987 	priv = (struct snd_timer_system_private *) timer->private_data;
988 	njiff = (priv->last_jiffies = jiffies);
989 	if (priv->correction > timer->sticks - 1) {
990 		priv->correction -= timer->sticks - 1;
991 		njiff++;
992 	} else {
993 		njiff += timer->sticks - priv->correction;
994 		priv->correction -= timer->sticks;
995 	}
996 	priv->last_expires = priv->tlist.expires = njiff;
997 	add_timer(&priv->tlist);
998 	return 0;
999 }
1000 
1001 static int snd_timer_s_stop(snd_timer_t * timer)
1002 {
1003 	struct snd_timer_system_private *priv;
1004 	unsigned long jiff;
1005 
1006 	priv = (struct snd_timer_system_private *) timer->private_data;
1007 	del_timer(&priv->tlist);
1008 	jiff = jiffies;
1009 	if (time_before(jiff, priv->last_expires))
1010 		timer->sticks = priv->last_expires - jiff;
1011 	else
1012 		timer->sticks = 1;
1013 	return 0;
1014 }
1015 
1016 static struct _snd_timer_hardware snd_timer_system =
1017 {
1018 	.flags =	SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1019 	.resolution =	1000000000L / HZ,
1020 	.ticks =	10000000L,
1021 	.start =	snd_timer_s_start,
1022 	.stop =		snd_timer_s_stop
1023 };
1024 
1025 static void snd_timer_free_system(snd_timer_t *timer)
1026 {
1027 	kfree(timer->private_data);
1028 }
1029 
1030 static int snd_timer_register_system(void)
1031 {
1032 	snd_timer_t *timer;
1033 	struct snd_timer_system_private *priv;
1034 	int err;
1035 
1036 	err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1037 	if (err < 0)
1038 		return err;
1039 	strcpy(timer->name, "system timer");
1040 	timer->hw = snd_timer_system;
1041 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1042 	if (priv == NULL) {
1043 		snd_timer_free(timer);
1044 		return -ENOMEM;
1045 	}
1046 	init_timer(&priv->tlist);
1047 	priv->tlist.function = snd_timer_s_function;
1048 	priv->tlist.data = (unsigned long) timer;
1049 	timer->private_data = priv;
1050 	timer->private_free = snd_timer_free_system;
1051 	return snd_timer_global_register(timer);
1052 }
1053 
1054 /*
1055  *  Info interface
1056  */
1057 
1058 static void snd_timer_proc_read(snd_info_entry_t *entry,
1059 				snd_info_buffer_t * buffer)
1060 {
1061 	unsigned long flags;
1062 	snd_timer_t *timer;
1063 	snd_timer_instance_t *ti;
1064 	struct list_head *p, *q;
1065 
1066 	down(&register_mutex);
1067 	list_for_each(p, &snd_timer_list) {
1068 		timer = list_entry(p, snd_timer_t, device_list);
1069 		switch (timer->tmr_class) {
1070 		case SNDRV_TIMER_CLASS_GLOBAL:
1071 			snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1072 			break;
1073 		case SNDRV_TIMER_CLASS_CARD:
1074 			snd_iprintf(buffer, "C%i-%i: ",
1075 				    timer->card->number, timer->tmr_device);
1076 			break;
1077 		case SNDRV_TIMER_CLASS_PCM:
1078 			snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1079 				    timer->tmr_device, timer->tmr_subdevice);
1080 			break;
1081 		default:
1082 			snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1083 				    timer->card ? timer->card->number : -1,
1084 				    timer->tmr_device, timer->tmr_subdevice);
1085 		}
1086 		snd_iprintf(buffer, "%s :", timer->name);
1087 		if (timer->hw.resolution)
1088 			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1089 				    timer->hw.resolution / 1000,
1090 				    timer->hw.resolution % 1000,
1091 				    timer->hw.ticks);
1092 		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1093 			snd_iprintf(buffer, " SLAVE");
1094 		snd_iprintf(buffer, "\n");
1095 		spin_lock_irqsave(&timer->lock, flags);
1096 		list_for_each(q, &timer->open_list_head) {
1097 			ti = list_entry(q, snd_timer_instance_t, open_list);
1098 			snd_iprintf(buffer, "  Client %s : %s\n",
1099 				    ti->owner ? ti->owner : "unknown",
1100 				    ti->flags & (SNDRV_TIMER_IFLG_START |
1101 						 SNDRV_TIMER_IFLG_RUNNING)
1102 				    ? "running" : "stopped");
1103 		}
1104 		spin_unlock_irqrestore(&timer->lock, flags);
1105 	}
1106 	up(&register_mutex);
1107 }
1108 
1109 /*
1110  *  USER SPACE interface
1111  */
1112 
1113 static void snd_timer_user_interrupt(snd_timer_instance_t *timeri,
1114 				     unsigned long resolution,
1115 				     unsigned long ticks)
1116 {
1117 	snd_timer_user_t *tu = timeri->callback_data;
1118 	snd_timer_read_t *r;
1119 	int prev;
1120 
1121 	spin_lock(&tu->qlock);
1122 	if (tu->qused > 0) {
1123 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1124 		r = &tu->queue[prev];
1125 		if (r->resolution == resolution) {
1126 			r->ticks += ticks;
1127 			goto __wake;
1128 		}
1129 	}
1130 	if (tu->qused >= tu->queue_size) {
1131 		tu->overrun++;
1132 	} else {
1133 		r = &tu->queue[tu->qtail++];
1134 		tu->qtail %= tu->queue_size;
1135 		r->resolution = resolution;
1136 		r->ticks = ticks;
1137 		tu->qused++;
1138 	}
1139       __wake:
1140 	spin_unlock(&tu->qlock);
1141 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1142 	wake_up(&tu->qchange_sleep);
1143 }
1144 
1145 static void snd_timer_user_append_to_tqueue(snd_timer_user_t *tu,
1146 					    snd_timer_tread_t *tread)
1147 {
1148 	if (tu->qused >= tu->queue_size) {
1149 		tu->overrun++;
1150 	} else {
1151 		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1152 		tu->qtail %= tu->queue_size;
1153 		tu->qused++;
1154 	}
1155 }
1156 
1157 static void snd_timer_user_ccallback(snd_timer_instance_t *timeri,
1158 				     enum sndrv_timer_event event,
1159 				     struct timespec *tstamp,
1160 				     unsigned long resolution)
1161 {
1162 	snd_timer_user_t *tu = timeri->callback_data;
1163 	snd_timer_tread_t r1;
1164 
1165 	if (event >= SNDRV_TIMER_EVENT_START &&
1166 	    event <= SNDRV_TIMER_EVENT_PAUSE)
1167 		tu->tstamp = *tstamp;
1168 	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1169 		return;
1170 	r1.event = event;
1171 	r1.tstamp = *tstamp;
1172 	r1.val = resolution;
1173 	spin_lock(&tu->qlock);
1174 	snd_timer_user_append_to_tqueue(tu, &r1);
1175 	spin_unlock(&tu->qlock);
1176 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1177 	wake_up(&tu->qchange_sleep);
1178 }
1179 
1180 static void snd_timer_user_tinterrupt(snd_timer_instance_t *timeri,
1181 				      unsigned long resolution,
1182 				      unsigned long ticks)
1183 {
1184 	snd_timer_user_t *tu = timeri->callback_data;
1185 	snd_timer_tread_t *r, r1;
1186 	struct timespec tstamp;
1187 	int prev, append = 0;
1188 
1189 	memset(&tstamp, 0, sizeof(tstamp));
1190 	spin_lock(&tu->qlock);
1191 	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1192 			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1193 		spin_unlock(&tu->qlock);
1194 		return;
1195 	}
1196 	if (tu->last_resolution != resolution || ticks > 0)
1197 		getnstimeofday(&tstamp);
1198 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1199 	    tu->last_resolution != resolution) {
1200 		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1201 		r1.tstamp = tstamp;
1202 		r1.val = resolution;
1203 		snd_timer_user_append_to_tqueue(tu, &r1);
1204 		tu->last_resolution = resolution;
1205 		append++;
1206 	}
1207 	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1208 		goto __wake;
1209 	if (ticks == 0)
1210 		goto __wake;
1211 	if (tu->qused > 0) {
1212 		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1213 		r = &tu->tqueue[prev];
1214 		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1215 			r->tstamp = tstamp;
1216 			r->val += ticks;
1217 			append++;
1218 			goto __wake;
1219 		}
1220 	}
1221 	r1.event = SNDRV_TIMER_EVENT_TICK;
1222 	r1.tstamp = tstamp;
1223 	r1.val = ticks;
1224 	snd_timer_user_append_to_tqueue(tu, &r1);
1225 	append++;
1226       __wake:
1227 	spin_unlock(&tu->qlock);
1228 	if (append == 0)
1229 		return;
1230 	kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1231 	wake_up(&tu->qchange_sleep);
1232 }
1233 
1234 static int snd_timer_user_open(struct inode *inode, struct file *file)
1235 {
1236 	snd_timer_user_t *tu;
1237 
1238 	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1239 	if (tu == NULL)
1240 		return -ENOMEM;
1241 	spin_lock_init(&tu->qlock);
1242 	init_waitqueue_head(&tu->qchange_sleep);
1243 	init_MUTEX(&tu->tread_sem);
1244 	tu->ticks = 1;
1245 	tu->queue_size = 128;
1246 	tu->queue = kmalloc(tu->queue_size * sizeof(snd_timer_read_t),
1247 			    GFP_KERNEL);
1248 	if (tu->queue == NULL) {
1249 		kfree(tu);
1250 		return -ENOMEM;
1251 	}
1252 	file->private_data = tu;
1253 	return 0;
1254 }
1255 
1256 static int snd_timer_user_release(struct inode *inode, struct file *file)
1257 {
1258 	snd_timer_user_t *tu;
1259 
1260 	if (file->private_data) {
1261 		tu = file->private_data;
1262 		file->private_data = NULL;
1263 		fasync_helper(-1, file, 0, &tu->fasync);
1264 		if (tu->timeri)
1265 			snd_timer_close(tu->timeri);
1266 		kfree(tu->queue);
1267 		kfree(tu->tqueue);
1268 		kfree(tu);
1269 	}
1270 	return 0;
1271 }
1272 
1273 static void snd_timer_user_zero_id(snd_timer_id_t *id)
1274 {
1275 	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1276 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1277 	id->card = -1;
1278 	id->device = -1;
1279 	id->subdevice = -1;
1280 }
1281 
1282 static void snd_timer_user_copy_id(snd_timer_id_t *id, snd_timer_t *timer)
1283 {
1284 	id->dev_class = timer->tmr_class;
1285 	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1286 	id->card = timer->card ? timer->card->number : -1;
1287 	id->device = timer->tmr_device;
1288 	id->subdevice = timer->tmr_subdevice;
1289 }
1290 
1291 static int snd_timer_user_next_device(snd_timer_id_t __user *_tid)
1292 {
1293 	snd_timer_id_t id;
1294 	snd_timer_t *timer;
1295 	struct list_head *p;
1296 
1297 	if (copy_from_user(&id, _tid, sizeof(id)))
1298 		return -EFAULT;
1299 	down(&register_mutex);
1300 	if (id.dev_class < 0) {		/* first item */
1301 		if (list_empty(&snd_timer_list))
1302 			snd_timer_user_zero_id(&id);
1303 		else {
1304 			timer = list_entry(snd_timer_list.next,
1305 					   snd_timer_t, device_list);
1306 			snd_timer_user_copy_id(&id, timer);
1307 		}
1308 	} else {
1309 		switch (id.dev_class) {
1310 		case SNDRV_TIMER_CLASS_GLOBAL:
1311 			id.device = id.device < 0 ? 0 : id.device + 1;
1312 			list_for_each(p, &snd_timer_list) {
1313 				timer = list_entry(p, snd_timer_t, device_list);
1314 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1315 					snd_timer_user_copy_id(&id, timer);
1316 					break;
1317 				}
1318 				if (timer->tmr_device >= id.device) {
1319 					snd_timer_user_copy_id(&id, timer);
1320 					break;
1321 				}
1322 			}
1323 			if (p == &snd_timer_list)
1324 				snd_timer_user_zero_id(&id);
1325 			break;
1326 		case SNDRV_TIMER_CLASS_CARD:
1327 		case SNDRV_TIMER_CLASS_PCM:
1328 			if (id.card < 0) {
1329 				id.card = 0;
1330 			} else {
1331 				if (id.card < 0) {
1332 					id.card = 0;
1333 				} else {
1334 					if (id.device < 0) {
1335 						id.device = 0;
1336 					} else {
1337 						if (id.subdevice < 0) {
1338 							id.subdevice = 0;
1339 						} else {
1340 							id.subdevice++;
1341 						}
1342 					}
1343 				}
1344 			}
1345 			list_for_each(p, &snd_timer_list) {
1346 				timer = list_entry(p, snd_timer_t, device_list);
1347 				if (timer->tmr_class > id.dev_class) {
1348 					snd_timer_user_copy_id(&id, timer);
1349 					break;
1350 				}
1351 				if (timer->tmr_class < id.dev_class)
1352 					continue;
1353 				if (timer->card->number > id.card) {
1354 					snd_timer_user_copy_id(&id, timer);
1355 					break;
1356 				}
1357 				if (timer->card->number < id.card)
1358 					continue;
1359 				if (timer->tmr_device > id.device) {
1360 					snd_timer_user_copy_id(&id, timer);
1361 					break;
1362 				}
1363 				if (timer->tmr_device < id.device)
1364 					continue;
1365 				if (timer->tmr_subdevice > id.subdevice) {
1366 					snd_timer_user_copy_id(&id, timer);
1367 					break;
1368 				}
1369 				if (timer->tmr_subdevice < id.subdevice)
1370 					continue;
1371 				snd_timer_user_copy_id(&id, timer);
1372 				break;
1373 			}
1374 			if (p == &snd_timer_list)
1375 				snd_timer_user_zero_id(&id);
1376 			break;
1377 		default:
1378 			snd_timer_user_zero_id(&id);
1379 		}
1380 	}
1381 	up(&register_mutex);
1382 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1383 		return -EFAULT;
1384 	return 0;
1385 }
1386 
1387 static int snd_timer_user_ginfo(struct file *file,
1388 				snd_timer_ginfo_t __user *_ginfo)
1389 {
1390 	snd_timer_ginfo_t *ginfo;
1391 	snd_timer_id_t tid;
1392 	snd_timer_t *t;
1393 	struct list_head *p;
1394 	int err = 0;
1395 
1396 	ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1397 	if (! ginfo)
1398 		return -ENOMEM;
1399 	if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1400 		kfree(ginfo);
1401 		return -EFAULT;
1402 	}
1403 	tid = ginfo->tid;
1404 	memset(ginfo, 0, sizeof(*ginfo));
1405 	ginfo->tid = tid;
1406 	down(&register_mutex);
1407 	t = snd_timer_find(&tid);
1408 	if (t != NULL) {
1409 		ginfo->card = t->card ? t->card->number : -1;
1410 		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1411 			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1412 		strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1413 		strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1414 		ginfo->resolution = t->hw.resolution;
1415 		if (t->hw.resolution_min > 0) {
1416 			ginfo->resolution_min = t->hw.resolution_min;
1417 			ginfo->resolution_max = t->hw.resolution_max;
1418 		}
1419 		list_for_each(p, &t->open_list_head) {
1420 			ginfo->clients++;
1421 		}
1422 	} else {
1423 		err = -ENODEV;
1424 	}
1425 	up(&register_mutex);
1426 	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1427 		err = -EFAULT;
1428 	kfree(ginfo);
1429 	return err;
1430 }
1431 
1432 static int snd_timer_user_gparams(struct file *file,
1433 				  snd_timer_gparams_t __user *_gparams)
1434 {
1435 	snd_timer_gparams_t gparams;
1436 	snd_timer_t *t;
1437 	int err;
1438 
1439 	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1440 		return -EFAULT;
1441 	down(&register_mutex);
1442 	t = snd_timer_find(&gparams.tid);
1443 	if (!t) {
1444 		err = -ENODEV;
1445 		goto _error;
1446 	}
1447 	if (!list_empty(&t->open_list_head)) {
1448 		err = -EBUSY;
1449 		goto _error;
1450 	}
1451 	if (!t->hw.set_period) {
1452 		err = -ENOSYS;
1453 		goto _error;
1454 	}
1455 	err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1456 _error:
1457 	up(&register_mutex);
1458 	return err;
1459 }
1460 
1461 static int snd_timer_user_gstatus(struct file *file,
1462 				  snd_timer_gstatus_t __user *_gstatus)
1463 {
1464 	snd_timer_gstatus_t gstatus;
1465 	snd_timer_id_t tid;
1466 	snd_timer_t *t;
1467 	int err = 0;
1468 
1469 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1470 		return -EFAULT;
1471 	tid = gstatus.tid;
1472 	memset(&gstatus, 0, sizeof(gstatus));
1473 	gstatus.tid = tid;
1474 	down(&register_mutex);
1475 	t = snd_timer_find(&tid);
1476 	if (t != NULL) {
1477 		if (t->hw.c_resolution)
1478 			gstatus.resolution = t->hw.c_resolution(t);
1479 		else
1480 			gstatus.resolution = t->hw.resolution;
1481 		if (t->hw.precise_resolution) {
1482 			t->hw.precise_resolution(t, &gstatus.resolution_num,
1483 						 &gstatus.resolution_den);
1484 		} else {
1485 			gstatus.resolution_num = gstatus.resolution;
1486 			gstatus.resolution_den = 1000000000uL;
1487 		}
1488 	} else {
1489 		err = -ENODEV;
1490 	}
1491 	up(&register_mutex);
1492 	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1493 		err = -EFAULT;
1494 	return err;
1495 }
1496 
1497 static int snd_timer_user_tselect(struct file *file,
1498 				  snd_timer_select_t __user *_tselect)
1499 {
1500 	snd_timer_user_t *tu;
1501 	snd_timer_select_t tselect;
1502 	char str[32];
1503 	int err = 0;
1504 
1505 	tu = file->private_data;
1506 	down(&tu->tread_sem);
1507 	if (tu->timeri) {
1508 		snd_timer_close(tu->timeri);
1509 		tu->timeri = NULL;
1510 	}
1511 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1512 		err = -EFAULT;
1513 		goto __err;
1514 	}
1515 	sprintf(str, "application %i", current->pid);
1516 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1517 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1518 	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1519 	if (err < 0)
1520 		goto __err;
1521 
1522 	kfree(tu->queue);
1523 	tu->queue = NULL;
1524 	kfree(tu->tqueue);
1525 	tu->tqueue = NULL;
1526 	if (tu->tread) {
1527 		tu->tqueue = kmalloc(tu->queue_size * sizeof(snd_timer_tread_t),
1528 				     GFP_KERNEL);
1529 		if (tu->tqueue == NULL)
1530 			err = -ENOMEM;
1531 	} else {
1532 		tu->queue = kmalloc(tu->queue_size * sizeof(snd_timer_read_t),
1533 				    GFP_KERNEL);
1534 		if (tu->queue == NULL)
1535 			err = -ENOMEM;
1536 	}
1537 
1538       	if (err < 0) {
1539 		snd_timer_close(tu->timeri);
1540       		tu->timeri = NULL;
1541       	} else {
1542 		tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1543 		tu->timeri->callback = tu->tread
1544 			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1545 		tu->timeri->ccallback = snd_timer_user_ccallback;
1546 		tu->timeri->callback_data = (void *)tu;
1547 	}
1548 
1549       __err:
1550       	up(&tu->tread_sem);
1551 	return err;
1552 }
1553 
1554 static int snd_timer_user_info(struct file *file,
1555 			       snd_timer_info_t __user *_info)
1556 {
1557 	snd_timer_user_t *tu;
1558 	snd_timer_info_t *info;
1559 	snd_timer_t *t;
1560 	int err = 0;
1561 
1562 	tu = file->private_data;
1563 	snd_assert(tu->timeri != NULL, return -ENXIO);
1564 	t = tu->timeri->timer;
1565 	snd_assert(t != NULL, return -ENXIO);
1566 
1567 	info = kzalloc(sizeof(*info), GFP_KERNEL);
1568 	if (! info)
1569 		return -ENOMEM;
1570 	info->card = t->card ? t->card->number : -1;
1571 	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1572 		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1573 	strlcpy(info->id, t->id, sizeof(info->id));
1574 	strlcpy(info->name, t->name, sizeof(info->name));
1575 	info->resolution = t->hw.resolution;
1576 	if (copy_to_user(_info, info, sizeof(*_info)))
1577 		err = -EFAULT;
1578 	kfree(info);
1579 	return err;
1580 }
1581 
1582 static int snd_timer_user_params(struct file *file,
1583 				 snd_timer_params_t __user *_params)
1584 {
1585 	snd_timer_user_t *tu;
1586 	snd_timer_params_t params;
1587 	snd_timer_t *t;
1588 	snd_timer_read_t *tr;
1589 	snd_timer_tread_t *ttr;
1590 	int err;
1591 
1592 	tu = file->private_data;
1593 	snd_assert(tu->timeri != NULL, return -ENXIO);
1594 	t = tu->timeri->timer;
1595 	snd_assert(t != NULL, return -ENXIO);
1596 	if (copy_from_user(&params, _params, sizeof(params)))
1597 		return -EFAULT;
1598 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1599 		err = -EINVAL;
1600 		goto _end;
1601 	}
1602 	if (params.queue_size > 0 &&
1603 	    (params.queue_size < 32 || params.queue_size > 1024)) {
1604 		err = -EINVAL;
1605 		goto _end;
1606 	}
1607 	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1608 			      (1<<SNDRV_TIMER_EVENT_TICK)|
1609 			      (1<<SNDRV_TIMER_EVENT_START)|
1610 			      (1<<SNDRV_TIMER_EVENT_STOP)|
1611 			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1612 			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1613 			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1614 			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1615 			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1616 			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1617 			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1618 			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1619 			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1620 			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1621 		err = -EINVAL;
1622 		goto _end;
1623 	}
1624 	snd_timer_stop(tu->timeri);
1625 	spin_lock_irq(&t->lock);
1626 	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1627 			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1628 			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1629 	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1630 		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1631 	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1632 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1633 	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1634 		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1635 	spin_unlock_irq(&t->lock);
1636 	if (params.queue_size > 0 &&
1637 	    (unsigned int)tu->queue_size != params.queue_size) {
1638 		if (tu->tread) {
1639 			ttr = kmalloc(params.queue_size * sizeof(*ttr),
1640 				      GFP_KERNEL);
1641 			if (ttr) {
1642 				kfree(tu->tqueue);
1643 				tu->queue_size = params.queue_size;
1644 				tu->tqueue = ttr;
1645 			}
1646 		} else {
1647 			tr = kmalloc(params.queue_size * sizeof(*tr),
1648 				     GFP_KERNEL);
1649 			if (tr) {
1650 				kfree(tu->queue);
1651 				tu->queue_size = params.queue_size;
1652 				tu->queue = tr;
1653 			}
1654 		}
1655 	}
1656 	tu->qhead = tu->qtail = tu->qused = 0;
1657 	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1658 		if (tu->tread) {
1659 			snd_timer_tread_t tread;
1660 			tread.event = SNDRV_TIMER_EVENT_EARLY;
1661 			tread.tstamp.tv_sec = 0;
1662 			tread.tstamp.tv_nsec = 0;
1663 			tread.val = 0;
1664 			snd_timer_user_append_to_tqueue(tu, &tread);
1665 		} else {
1666 			snd_timer_read_t *r = &tu->queue[0];
1667 			r->resolution = 0;
1668 			r->ticks = 0;
1669 			tu->qused++;
1670 			tu->qtail++;
1671 		}
1672 	}
1673 	tu->filter = params.filter;
1674 	tu->ticks = params.ticks;
1675 	err = 0;
1676  _end:
1677 	if (copy_to_user(_params, &params, sizeof(params)))
1678 		return -EFAULT;
1679 	return err;
1680 }
1681 
1682 static int snd_timer_user_status(struct file *file,
1683 				 snd_timer_status_t __user *_status)
1684 {
1685 	snd_timer_user_t *tu;
1686 	snd_timer_status_t status;
1687 
1688 	tu = file->private_data;
1689 	snd_assert(tu->timeri != NULL, return -ENXIO);
1690 	memset(&status, 0, sizeof(status));
1691 	status.tstamp = tu->tstamp;
1692 	status.resolution = snd_timer_resolution(tu->timeri);
1693 	status.lost = tu->timeri->lost;
1694 	status.overrun = tu->overrun;
1695 	spin_lock_irq(&tu->qlock);
1696 	status.queue = tu->qused;
1697 	spin_unlock_irq(&tu->qlock);
1698 	if (copy_to_user(_status, &status, sizeof(status)))
1699 		return -EFAULT;
1700 	return 0;
1701 }
1702 
1703 static int snd_timer_user_start(struct file *file)
1704 {
1705 	int err;
1706 	snd_timer_user_t *tu;
1707 
1708 	tu = file->private_data;
1709 	snd_assert(tu->timeri != NULL, return -ENXIO);
1710 	snd_timer_stop(tu->timeri);
1711 	tu->timeri->lost = 0;
1712 	tu->last_resolution = 0;
1713 	return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1714 }
1715 
1716 static int snd_timer_user_stop(struct file *file)
1717 {
1718 	int err;
1719 	snd_timer_user_t *tu;
1720 
1721 	tu = file->private_data;
1722 	snd_assert(tu->timeri != NULL, return -ENXIO);
1723 	return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1724 }
1725 
1726 static int snd_timer_user_continue(struct file *file)
1727 {
1728 	int err;
1729 	snd_timer_user_t *tu;
1730 
1731 	tu = file->private_data;
1732 	snd_assert(tu->timeri != NULL, return -ENXIO);
1733 	tu->timeri->lost = 0;
1734 	return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1735 }
1736 
1737 static int snd_timer_user_pause(struct file *file)
1738 {
1739 	int err;
1740 	snd_timer_user_t *tu;
1741 
1742 	tu = file->private_data;
1743 	snd_assert(tu->timeri != NULL, return -ENXIO);
1744 	return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1745 }
1746 
1747 enum {
1748 	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1749 	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1750 	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1751 	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1752 };
1753 
1754 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1755 				 unsigned long arg)
1756 {
1757 	snd_timer_user_t *tu;
1758 	void __user *argp = (void __user *)arg;
1759 	int __user *p = argp;
1760 
1761 	tu = file->private_data;
1762 	switch (cmd) {
1763 	case SNDRV_TIMER_IOCTL_PVERSION:
1764 		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1765 	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1766 		return snd_timer_user_next_device(argp);
1767 	case SNDRV_TIMER_IOCTL_TREAD:
1768 	{
1769 		int xarg;
1770 
1771 		down(&tu->tread_sem);
1772 		if (tu->timeri)	{	/* too late */
1773 			up(&tu->tread_sem);
1774 			return -EBUSY;
1775 		}
1776 		if (get_user(xarg, p)) {
1777 			up(&tu->tread_sem);
1778 			return -EFAULT;
1779 		}
1780 		tu->tread = xarg ? 1 : 0;
1781 		up(&tu->tread_sem);
1782 		return 0;
1783 	}
1784 	case SNDRV_TIMER_IOCTL_GINFO:
1785 		return snd_timer_user_ginfo(file, argp);
1786 	case SNDRV_TIMER_IOCTL_GPARAMS:
1787 		return snd_timer_user_gparams(file, argp);
1788 	case SNDRV_TIMER_IOCTL_GSTATUS:
1789 		return snd_timer_user_gstatus(file, argp);
1790 	case SNDRV_TIMER_IOCTL_SELECT:
1791 		return snd_timer_user_tselect(file, argp);
1792 	case SNDRV_TIMER_IOCTL_INFO:
1793 		return snd_timer_user_info(file, argp);
1794 	case SNDRV_TIMER_IOCTL_PARAMS:
1795 		return snd_timer_user_params(file, argp);
1796 	case SNDRV_TIMER_IOCTL_STATUS:
1797 		return snd_timer_user_status(file, argp);
1798 	case SNDRV_TIMER_IOCTL_START:
1799 	case SNDRV_TIMER_IOCTL_START_OLD:
1800 		return snd_timer_user_start(file);
1801 	case SNDRV_TIMER_IOCTL_STOP:
1802 	case SNDRV_TIMER_IOCTL_STOP_OLD:
1803 		return snd_timer_user_stop(file);
1804 	case SNDRV_TIMER_IOCTL_CONTINUE:
1805 	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1806 		return snd_timer_user_continue(file);
1807 	case SNDRV_TIMER_IOCTL_PAUSE:
1808 	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1809 		return snd_timer_user_pause(file);
1810 	}
1811 	return -ENOTTY;
1812 }
1813 
1814 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1815 {
1816 	snd_timer_user_t *tu;
1817 	int err;
1818 
1819 	tu = file->private_data;
1820 	err = fasync_helper(fd, file, on, &tu->fasync);
1821         if (err < 0)
1822 		return err;
1823 	return 0;
1824 }
1825 
1826 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1827 				   size_t count, loff_t *offset)
1828 {
1829 	snd_timer_user_t *tu;
1830 	long result = 0, unit;
1831 	int err = 0;
1832 
1833 	tu = file->private_data;
1834 	unit = tu->tread ? sizeof(snd_timer_tread_t) : sizeof(snd_timer_read_t);
1835 	spin_lock_irq(&tu->qlock);
1836 	while ((long)count - result >= unit) {
1837 		while (!tu->qused) {
1838 			wait_queue_t wait;
1839 
1840 			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1841 				err = -EAGAIN;
1842 				break;
1843 			}
1844 
1845 			set_current_state(TASK_INTERRUPTIBLE);
1846 			init_waitqueue_entry(&wait, current);
1847 			add_wait_queue(&tu->qchange_sleep, &wait);
1848 
1849 			spin_unlock_irq(&tu->qlock);
1850 			schedule();
1851 			spin_lock_irq(&tu->qlock);
1852 
1853 			remove_wait_queue(&tu->qchange_sleep, &wait);
1854 
1855 			if (signal_pending(current)) {
1856 				err = -ERESTARTSYS;
1857 				break;
1858 			}
1859 		}
1860 
1861 		spin_unlock_irq(&tu->qlock);
1862 		if (err < 0)
1863 			goto _error;
1864 
1865 		if (tu->tread) {
1866 			if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1867 					 sizeof(snd_timer_tread_t))) {
1868 				err = -EFAULT;
1869 				goto _error;
1870 			}
1871 		} else {
1872 			if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1873 					 sizeof(snd_timer_read_t))) {
1874 				err = -EFAULT;
1875 				goto _error;
1876 			}
1877 		}
1878 
1879 		tu->qhead %= tu->queue_size;
1880 
1881 		result += unit;
1882 		buffer += unit;
1883 
1884 		spin_lock_irq(&tu->qlock);
1885 		tu->qused--;
1886 	}
1887 	spin_unlock_irq(&tu->qlock);
1888  _error:
1889 	return result > 0 ? result : err;
1890 }
1891 
1892 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1893 {
1894         unsigned int mask;
1895         snd_timer_user_t *tu;
1896 
1897         tu = file->private_data;
1898 
1899         poll_wait(file, &tu->qchange_sleep, wait);
1900 
1901 	mask = 0;
1902 	if (tu->qused)
1903 		mask |= POLLIN | POLLRDNORM;
1904 
1905 	return mask;
1906 }
1907 
1908 #ifdef CONFIG_COMPAT
1909 #include "timer_compat.c"
1910 #else
1911 #define snd_timer_user_ioctl_compat	NULL
1912 #endif
1913 
1914 static struct file_operations snd_timer_f_ops =
1915 {
1916 	.owner =	THIS_MODULE,
1917 	.read =		snd_timer_user_read,
1918 	.open =		snd_timer_user_open,
1919 	.release =	snd_timer_user_release,
1920 	.poll =		snd_timer_user_poll,
1921 	.unlocked_ioctl =	snd_timer_user_ioctl,
1922 	.compat_ioctl =	snd_timer_user_ioctl_compat,
1923 	.fasync = 	snd_timer_user_fasync,
1924 };
1925 
1926 static snd_minor_t snd_timer_reg =
1927 {
1928 	.comment =	"timer",
1929 	.f_ops =	&snd_timer_f_ops,
1930 };
1931 
1932 /*
1933  *  ENTRY functions
1934  */
1935 
1936 static snd_info_entry_t *snd_timer_proc_entry = NULL;
1937 
1938 static int __init alsa_timer_init(void)
1939 {
1940 	int err;
1941 	snd_info_entry_t *entry;
1942 
1943 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1944 	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1945 			      "system timer");
1946 #endif
1947 	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1948 	if (entry != NULL) {
1949 		entry->c.text.read_size = SNDRV_TIMER_DEVICES * 128;
1950 		entry->c.text.read = snd_timer_proc_read;
1951 		if (snd_info_register(entry) < 0) {
1952 			snd_info_free_entry(entry);
1953 			entry = NULL;
1954 		}
1955 	}
1956 	snd_timer_proc_entry = entry;
1957 	if ((err = snd_timer_register_system()) < 0)
1958 		snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1959 			   err);
1960 	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER,
1961 					NULL, 0, &snd_timer_reg, "timer"))<0)
1962 		snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1963 			   err);
1964 	return 0;
1965 }
1966 
1967 static void __exit alsa_timer_exit(void)
1968 {
1969 	struct list_head *p, *n;
1970 
1971 	snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1972 	/* unregister the system timer */
1973 	list_for_each_safe(p, n, &snd_timer_list) {
1974 		snd_timer_t *timer = list_entry(p, snd_timer_t, device_list);
1975 		snd_timer_unregister(timer);
1976 	}
1977 	if (snd_timer_proc_entry) {
1978 		snd_info_unregister(snd_timer_proc_entry);
1979 		snd_timer_proc_entry = NULL;
1980 	}
1981 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1982 	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1983 #endif
1984 }
1985 
1986 module_init(alsa_timer_init)
1987 module_exit(alsa_timer_exit)
1988 
1989 EXPORT_SYMBOL(snd_timer_open);
1990 EXPORT_SYMBOL(snd_timer_close);
1991 EXPORT_SYMBOL(snd_timer_resolution);
1992 EXPORT_SYMBOL(snd_timer_start);
1993 EXPORT_SYMBOL(snd_timer_stop);
1994 EXPORT_SYMBOL(snd_timer_continue);
1995 EXPORT_SYMBOL(snd_timer_pause);
1996 EXPORT_SYMBOL(snd_timer_new);
1997 EXPORT_SYMBOL(snd_timer_notify);
1998 EXPORT_SYMBOL(snd_timer_global_new);
1999 EXPORT_SYMBOL(snd_timer_global_free);
2000 EXPORT_SYMBOL(snd_timer_global_register);
2001 EXPORT_SYMBOL(snd_timer_global_unregister);
2002 EXPORT_SYMBOL(snd_timer_interrupt);
2003