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