1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Timers abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7 #include <linux/delay.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/time.h>
11 #include <linux/mutex.h>
12 #include <linux/device.h>
13 #include <linux/module.h>
14 #include <linux/string.h>
15 #include <linux/sched/signal.h>
16 #include <sound/core.h>
17 #include <sound/timer.h>
18 #include <sound/control.h>
19 #include <sound/info.h>
20 #include <sound/minors.h>
21 #include <sound/initval.h>
22 #include <linux/kmod.h>
23
24 /* internal flags */
25 #define SNDRV_TIMER_IFLG_PAUSED 0x00010000
26 #define SNDRV_TIMER_IFLG_DEAD 0x00020000
27
28 #if IS_ENABLED(CONFIG_SND_HRTIMER)
29 #define DEFAULT_TIMER_LIMIT 4
30 #else
31 #define DEFAULT_TIMER_LIMIT 1
32 #endif
33
34 static int timer_limit = DEFAULT_TIMER_LIMIT;
35 static int timer_tstamp_monotonic = 1;
36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
37 MODULE_DESCRIPTION("ALSA timer interface");
38 MODULE_LICENSE("GPL");
39 module_param(timer_limit, int, 0444);
40 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
41 module_param(timer_tstamp_monotonic, int, 0444);
42 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
43
44 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
45 MODULE_ALIAS("devname:snd/timer");
46
47 struct snd_timer_user {
48 struct snd_timer_instance *timeri;
49 int tread; /* enhanced read with timestamps and events */
50 unsigned long ticks;
51 unsigned long overrun;
52 int qhead;
53 int qtail;
54 int qused;
55 int queue_size;
56 bool disconnected;
57 struct snd_timer_read *queue;
58 struct snd_timer_tread *tqueue;
59 spinlock_t qlock;
60 unsigned long last_resolution;
61 unsigned int filter;
62 struct timespec tstamp; /* trigger tstamp */
63 wait_queue_head_t qchange_sleep;
64 struct snd_fasync *fasync;
65 struct mutex ioctl_lock;
66 };
67
68 /* list of timers */
69 static LIST_HEAD(snd_timer_list);
70
71 /* list of slave instances */
72 static LIST_HEAD(snd_timer_slave_list);
73
74 /* lock for slave active lists */
75 static DEFINE_SPINLOCK(slave_active_lock);
76
77 #define MAX_SLAVE_INSTANCES 1000
78 static int num_slaves;
79
80 static DEFINE_MUTEX(register_mutex);
81
82 static int snd_timer_free(struct snd_timer *timer);
83 static int snd_timer_dev_free(struct snd_device *device);
84 static int snd_timer_dev_register(struct snd_device *device);
85 static int snd_timer_dev_disconnect(struct snd_device *device);
86
87 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
88
89 /*
90 * create a timer instance with the given owner string.
91 * when timer is not NULL, increments the module counter
92 */
snd_timer_instance_new(char * owner,struct snd_timer * timer)93 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
94 struct snd_timer *timer)
95 {
96 struct snd_timer_instance *timeri;
97 timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
98 if (timeri == NULL)
99 return NULL;
100 timeri->owner = kstrdup(owner, GFP_KERNEL);
101 if (! timeri->owner) {
102 kfree(timeri);
103 return NULL;
104 }
105 INIT_LIST_HEAD(&timeri->open_list);
106 INIT_LIST_HEAD(&timeri->active_list);
107 INIT_LIST_HEAD(&timeri->ack_list);
108 INIT_LIST_HEAD(&timeri->slave_list_head);
109 INIT_LIST_HEAD(&timeri->slave_active_head);
110
111 timeri->timer = timer;
112 if (timer && !try_module_get(timer->module)) {
113 kfree(timeri->owner);
114 kfree(timeri);
115 return NULL;
116 }
117
118 return timeri;
119 }
120
121 /*
122 * find a timer instance from the given timer id
123 */
snd_timer_find(struct snd_timer_id * tid)124 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
125 {
126 struct snd_timer *timer = NULL;
127
128 list_for_each_entry(timer, &snd_timer_list, device_list) {
129 if (timer->tmr_class != tid->dev_class)
130 continue;
131 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
132 timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
133 (timer->card == NULL ||
134 timer->card->number != tid->card))
135 continue;
136 if (timer->tmr_device != tid->device)
137 continue;
138 if (timer->tmr_subdevice != tid->subdevice)
139 continue;
140 return timer;
141 }
142 return NULL;
143 }
144
145 #ifdef CONFIG_MODULES
146
snd_timer_request(struct snd_timer_id * tid)147 static void snd_timer_request(struct snd_timer_id *tid)
148 {
149 switch (tid->dev_class) {
150 case SNDRV_TIMER_CLASS_GLOBAL:
151 if (tid->device < timer_limit)
152 request_module("snd-timer-%i", tid->device);
153 break;
154 case SNDRV_TIMER_CLASS_CARD:
155 case SNDRV_TIMER_CLASS_PCM:
156 if (tid->card < snd_ecards_limit)
157 request_module("snd-card-%i", tid->card);
158 break;
159 default:
160 break;
161 }
162 }
163
164 #endif
165
166 /*
167 * look for a master instance matching with the slave id of the given slave.
168 * when found, relink the open_link of the slave.
169 *
170 * call this with register_mutex down.
171 */
snd_timer_check_slave(struct snd_timer_instance * slave)172 static int snd_timer_check_slave(struct snd_timer_instance *slave)
173 {
174 struct snd_timer *timer;
175 struct snd_timer_instance *master;
176
177 /* FIXME: it's really dumb to look up all entries.. */
178 list_for_each_entry(timer, &snd_timer_list, device_list) {
179 list_for_each_entry(master, &timer->open_list_head, open_list) {
180 if (slave->slave_class == master->slave_class &&
181 slave->slave_id == master->slave_id) {
182 if (master->timer->num_instances >=
183 master->timer->max_instances)
184 return -EBUSY;
185 list_move_tail(&slave->open_list,
186 &master->slave_list_head);
187 master->timer->num_instances++;
188 spin_lock_irq(&slave_active_lock);
189 slave->master = master;
190 slave->timer = master->timer;
191 spin_unlock_irq(&slave_active_lock);
192 return 0;
193 }
194 }
195 }
196 return 0;
197 }
198
199 /*
200 * look for slave instances matching with the slave id of the given master.
201 * when found, relink the open_link of slaves.
202 *
203 * call this with register_mutex down.
204 */
snd_timer_check_master(struct snd_timer_instance * master)205 static int snd_timer_check_master(struct snd_timer_instance *master)
206 {
207 struct snd_timer_instance *slave, *tmp;
208
209 /* check all pending slaves */
210 list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
211 if (slave->slave_class == master->slave_class &&
212 slave->slave_id == master->slave_id) {
213 if (master->timer->num_instances >=
214 master->timer->max_instances)
215 return -EBUSY;
216 list_move_tail(&slave->open_list, &master->slave_list_head);
217 master->timer->num_instances++;
218 spin_lock_irq(&slave_active_lock);
219 spin_lock(&master->timer->lock);
220 slave->master = master;
221 slave->timer = master->timer;
222 if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
223 list_add_tail(&slave->active_list,
224 &master->slave_active_head);
225 spin_unlock(&master->timer->lock);
226 spin_unlock_irq(&slave_active_lock);
227 }
228 }
229 return 0;
230 }
231
232 static int snd_timer_close_locked(struct snd_timer_instance *timeri,
233 struct device **card_devp_to_put);
234
235 /*
236 * open a timer instance
237 * when opening a master, the slave id must be here given.
238 */
snd_timer_open(struct snd_timer_instance ** ti,char * owner,struct snd_timer_id * tid,unsigned int slave_id)239 int snd_timer_open(struct snd_timer_instance **ti,
240 char *owner, struct snd_timer_id *tid,
241 unsigned int slave_id)
242 {
243 struct snd_timer *timer;
244 struct snd_timer_instance *timeri = NULL;
245 struct device *card_dev_to_put = NULL;
246 int err;
247
248 mutex_lock(®ister_mutex);
249 if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
250 /* open a slave instance */
251 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
252 tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
253 pr_debug("ALSA: timer: invalid slave class %i\n",
254 tid->dev_sclass);
255 err = -EINVAL;
256 goto unlock;
257 }
258 if (num_slaves >= MAX_SLAVE_INSTANCES) {
259 err = -EBUSY;
260 goto unlock;
261 }
262 timeri = snd_timer_instance_new(owner, NULL);
263 if (!timeri) {
264 err = -ENOMEM;
265 goto unlock;
266 }
267 timeri->slave_class = tid->dev_sclass;
268 timeri->slave_id = tid->device;
269 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
270 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
271 num_slaves++;
272 err = snd_timer_check_slave(timeri);
273 if (err < 0) {
274 snd_timer_close_locked(timeri, &card_dev_to_put);
275 timeri = NULL;
276 }
277 goto unlock;
278 }
279
280 /* open a master instance */
281 timer = snd_timer_find(tid);
282 #ifdef CONFIG_MODULES
283 if (!timer) {
284 mutex_unlock(®ister_mutex);
285 snd_timer_request(tid);
286 mutex_lock(®ister_mutex);
287 timer = snd_timer_find(tid);
288 }
289 #endif
290 if (!timer) {
291 err = -ENODEV;
292 goto unlock;
293 }
294 if (!list_empty(&timer->open_list_head)) {
295 struct snd_timer_instance *t =
296 list_entry(timer->open_list_head.next,
297 struct snd_timer_instance, open_list);
298 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
299 err = -EBUSY;
300 goto unlock;
301 }
302 }
303 if (timer->num_instances >= timer->max_instances) {
304 err = -EBUSY;
305 goto unlock;
306 }
307 timeri = snd_timer_instance_new(owner, timer);
308 if (!timeri) {
309 err = -ENOMEM;
310 goto unlock;
311 }
312 /* take a card refcount for safe disconnection */
313 if (timer->card)
314 get_device(&timer->card->card_dev);
315 timeri->slave_class = tid->dev_sclass;
316 timeri->slave_id = slave_id;
317
318 if (list_empty(&timer->open_list_head) && timer->hw.open) {
319 err = timer->hw.open(timer);
320 if (err) {
321 kfree(timeri->owner);
322 kfree(timeri);
323 timeri = NULL;
324
325 if (timer->card)
326 card_dev_to_put = &timer->card->card_dev;
327 module_put(timer->module);
328 goto unlock;
329 }
330 }
331
332 list_add_tail(&timeri->open_list, &timer->open_list_head);
333 timer->num_instances++;
334 err = snd_timer_check_master(timeri);
335 if (err < 0) {
336 snd_timer_close_locked(timeri, &card_dev_to_put);
337 timeri = NULL;
338 }
339
340 unlock:
341 mutex_unlock(®ister_mutex);
342 /* put_device() is called after unlock for avoiding deadlock */
343 if (card_dev_to_put)
344 put_device(card_dev_to_put);
345 *ti = timeri;
346 return err;
347 }
348 EXPORT_SYMBOL(snd_timer_open);
349
350 /*
351 * close a timer instance
352 * call this with register_mutex down.
353 */
snd_timer_close_locked(struct snd_timer_instance * timeri,struct device ** card_devp_to_put)354 static int snd_timer_close_locked(struct snd_timer_instance *timeri,
355 struct device **card_devp_to_put)
356 {
357 struct snd_timer *timer = timeri->timer;
358 struct snd_timer_instance *slave, *tmp;
359
360 if (timer) {
361 spin_lock_irq(&timer->lock);
362 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
363 spin_unlock_irq(&timer->lock);
364 }
365
366 list_del(&timeri->open_list);
367 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
368 num_slaves--;
369
370 /* force to stop the timer */
371 snd_timer_stop(timeri);
372
373 if (timer) {
374 timer->num_instances--;
375 /* wait, until the active callback is finished */
376 spin_lock_irq(&timer->lock);
377 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
378 spin_unlock_irq(&timer->lock);
379 udelay(10);
380 spin_lock_irq(&timer->lock);
381 }
382 spin_unlock_irq(&timer->lock);
383
384 /* remove slave links */
385 spin_lock_irq(&slave_active_lock);
386 spin_lock(&timer->lock);
387 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
388 open_list) {
389 list_move_tail(&slave->open_list, &snd_timer_slave_list);
390 timer->num_instances--;
391 slave->master = NULL;
392 slave->timer = NULL;
393 list_del_init(&slave->ack_list);
394 list_del_init(&slave->active_list);
395 }
396 spin_unlock(&timer->lock);
397 spin_unlock_irq(&slave_active_lock);
398
399 /* slave doesn't need to release timer resources below */
400 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
401 timer = NULL;
402 }
403
404 if (timeri->private_free)
405 timeri->private_free(timeri);
406 kfree(timeri->owner);
407 kfree(timeri);
408
409 if (timer) {
410 if (list_empty(&timer->open_list_head) && timer->hw.close)
411 timer->hw.close(timer);
412 /* release a card refcount for safe disconnection */
413 if (timer->card)
414 *card_devp_to_put = &timer->card->card_dev;
415 module_put(timer->module);
416 }
417
418 return 0;
419 }
420
421 /*
422 * close a timer instance
423 */
snd_timer_close(struct snd_timer_instance * timeri)424 int snd_timer_close(struct snd_timer_instance *timeri)
425 {
426 struct device *card_dev_to_put = NULL;
427 int err;
428
429 if (snd_BUG_ON(!timeri))
430 return -ENXIO;
431
432 mutex_lock(®ister_mutex);
433 err = snd_timer_close_locked(timeri, &card_dev_to_put);
434 mutex_unlock(®ister_mutex);
435 /* put_device() is called after unlock for avoiding deadlock */
436 if (card_dev_to_put)
437 put_device(card_dev_to_put);
438 return err;
439 }
440 EXPORT_SYMBOL(snd_timer_close);
441
snd_timer_hw_resolution(struct snd_timer * timer)442 static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
443 {
444 if (timer->hw.c_resolution)
445 return timer->hw.c_resolution(timer);
446 else
447 return timer->hw.resolution;
448 }
449
snd_timer_resolution(struct snd_timer_instance * timeri)450 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
451 {
452 struct snd_timer * timer;
453 unsigned long ret = 0;
454 unsigned long flags;
455
456 if (timeri == NULL)
457 return 0;
458 timer = timeri->timer;
459 if (timer) {
460 spin_lock_irqsave(&timer->lock, flags);
461 ret = snd_timer_hw_resolution(timer);
462 spin_unlock_irqrestore(&timer->lock, flags);
463 }
464 return ret;
465 }
466 EXPORT_SYMBOL(snd_timer_resolution);
467
snd_timer_notify1(struct snd_timer_instance * ti,int event)468 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
469 {
470 struct snd_timer *timer = ti->timer;
471 unsigned long resolution = 0;
472 struct snd_timer_instance *ts;
473 struct timespec tstamp;
474
475 if (timer_tstamp_monotonic)
476 ktime_get_ts(&tstamp);
477 else
478 getnstimeofday(&tstamp);
479 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
480 event > SNDRV_TIMER_EVENT_PAUSE))
481 return;
482 if (timer &&
483 (event == SNDRV_TIMER_EVENT_START ||
484 event == SNDRV_TIMER_EVENT_CONTINUE))
485 resolution = snd_timer_hw_resolution(timer);
486 if (ti->ccallback)
487 ti->ccallback(ti, event, &tstamp, resolution);
488 if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
489 return;
490 if (timer == NULL)
491 return;
492 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
493 return;
494 event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
495 list_for_each_entry(ts, &ti->slave_active_head, active_list)
496 if (ts->ccallback)
497 ts->ccallback(ts, event, &tstamp, resolution);
498 }
499
500 /* start/continue a master timer */
snd_timer_start1(struct snd_timer_instance * timeri,bool start,unsigned long ticks)501 static int snd_timer_start1(struct snd_timer_instance *timeri,
502 bool start, unsigned long ticks)
503 {
504 struct snd_timer *timer;
505 int result;
506 unsigned long flags;
507
508 timer = timeri->timer;
509 if (!timer)
510 return -EINVAL;
511
512 spin_lock_irqsave(&timer->lock, flags);
513 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
514 result = -EINVAL;
515 goto unlock;
516 }
517 if (timer->card && timer->card->shutdown) {
518 result = -ENODEV;
519 goto unlock;
520 }
521 if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
522 SNDRV_TIMER_IFLG_START)) {
523 result = -EBUSY;
524 goto unlock;
525 }
526
527 if (start)
528 timeri->ticks = timeri->cticks = ticks;
529 else if (!timeri->cticks)
530 timeri->cticks = 1;
531 timeri->pticks = 0;
532
533 list_move_tail(&timeri->active_list, &timer->active_list_head);
534 if (timer->running) {
535 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
536 goto __start_now;
537 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
538 timeri->flags |= SNDRV_TIMER_IFLG_START;
539 result = 1; /* delayed start */
540 } else {
541 if (start)
542 timer->sticks = ticks;
543 timer->hw.start(timer);
544 __start_now:
545 timer->running++;
546 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
547 result = 0;
548 }
549 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
550 SNDRV_TIMER_EVENT_CONTINUE);
551 unlock:
552 spin_unlock_irqrestore(&timer->lock, flags);
553 return result;
554 }
555
556 /* start/continue a slave timer */
snd_timer_start_slave(struct snd_timer_instance * timeri,bool start)557 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
558 bool start)
559 {
560 unsigned long flags;
561 int err;
562
563 spin_lock_irqsave(&slave_active_lock, flags);
564 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
565 err = -EINVAL;
566 goto unlock;
567 }
568 if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
569 err = -EBUSY;
570 goto unlock;
571 }
572 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
573 if (timeri->master && timeri->timer) {
574 spin_lock(&timeri->timer->lock);
575 list_add_tail(&timeri->active_list,
576 &timeri->master->slave_active_head);
577 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
578 SNDRV_TIMER_EVENT_CONTINUE);
579 spin_unlock(&timeri->timer->lock);
580 }
581 err = 1; /* delayed start */
582 unlock:
583 spin_unlock_irqrestore(&slave_active_lock, flags);
584 return err;
585 }
586
587 /* stop/pause a master timer */
snd_timer_stop1(struct snd_timer_instance * timeri,bool stop)588 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
589 {
590 struct snd_timer *timer;
591 int result = 0;
592 unsigned long flags;
593
594 timer = timeri->timer;
595 if (!timer)
596 return -EINVAL;
597 spin_lock_irqsave(&timer->lock, flags);
598 list_del_init(&timeri->ack_list);
599 list_del_init(&timeri->active_list);
600 if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
601 SNDRV_TIMER_IFLG_START))) {
602 result = -EBUSY;
603 goto unlock;
604 }
605 if (timer->card && timer->card->shutdown)
606 goto unlock;
607 if (stop) {
608 timeri->cticks = timeri->ticks;
609 timeri->pticks = 0;
610 }
611 if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
612 !(--timer->running)) {
613 timer->hw.stop(timer);
614 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
615 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
616 snd_timer_reschedule(timer, 0);
617 if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
618 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
619 timer->hw.start(timer);
620 }
621 }
622 }
623 timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
624 if (stop)
625 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
626 else
627 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
628 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
629 SNDRV_TIMER_EVENT_PAUSE);
630 unlock:
631 spin_unlock_irqrestore(&timer->lock, flags);
632 return result;
633 }
634
635 /* stop/pause a slave timer */
snd_timer_stop_slave(struct snd_timer_instance * timeri,bool stop)636 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
637 {
638 unsigned long flags;
639 bool running;
640
641 spin_lock_irqsave(&slave_active_lock, flags);
642 running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
643 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
644 if (timeri->timer) {
645 spin_lock(&timeri->timer->lock);
646 list_del_init(&timeri->ack_list);
647 list_del_init(&timeri->active_list);
648 if (running)
649 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
650 SNDRV_TIMER_EVENT_PAUSE);
651 spin_unlock(&timeri->timer->lock);
652 }
653 spin_unlock_irqrestore(&slave_active_lock, flags);
654 return running ? 0 : -EBUSY;
655 }
656
657 /*
658 * start the timer instance
659 */
snd_timer_start(struct snd_timer_instance * timeri,unsigned int ticks)660 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
661 {
662 if (timeri == NULL || ticks < 1)
663 return -EINVAL;
664 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
665 return snd_timer_start_slave(timeri, true);
666 else
667 return snd_timer_start1(timeri, true, ticks);
668 }
669 EXPORT_SYMBOL(snd_timer_start);
670
671 /*
672 * stop the timer instance.
673 *
674 * do not call this from the timer callback!
675 */
snd_timer_stop(struct snd_timer_instance * timeri)676 int snd_timer_stop(struct snd_timer_instance *timeri)
677 {
678 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
679 return snd_timer_stop_slave(timeri, true);
680 else
681 return snd_timer_stop1(timeri, true);
682 }
683 EXPORT_SYMBOL(snd_timer_stop);
684
685 /*
686 * start again.. the tick is kept.
687 */
snd_timer_continue(struct snd_timer_instance * timeri)688 int snd_timer_continue(struct snd_timer_instance *timeri)
689 {
690 /* timer can continue only after pause */
691 if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
692 return -EINVAL;
693
694 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
695 return snd_timer_start_slave(timeri, false);
696 else
697 return snd_timer_start1(timeri, false, 0);
698 }
699 EXPORT_SYMBOL(snd_timer_continue);
700
701 /*
702 * pause.. remember the ticks left
703 */
snd_timer_pause(struct snd_timer_instance * timeri)704 int snd_timer_pause(struct snd_timer_instance * timeri)
705 {
706 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
707 return snd_timer_stop_slave(timeri, false);
708 else
709 return snd_timer_stop1(timeri, false);
710 }
711 EXPORT_SYMBOL(snd_timer_pause);
712
713 /*
714 * reschedule the timer
715 *
716 * start pending instances and check the scheduling ticks.
717 * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
718 */
snd_timer_reschedule(struct snd_timer * timer,unsigned long ticks_left)719 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
720 {
721 struct snd_timer_instance *ti;
722 unsigned long ticks = ~0UL;
723
724 list_for_each_entry(ti, &timer->active_list_head, active_list) {
725 if (ti->flags & SNDRV_TIMER_IFLG_START) {
726 ti->flags &= ~SNDRV_TIMER_IFLG_START;
727 ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
728 timer->running++;
729 }
730 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
731 if (ticks > ti->cticks)
732 ticks = ti->cticks;
733 }
734 }
735 if (ticks == ~0UL) {
736 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
737 return;
738 }
739 if (ticks > timer->hw.ticks)
740 ticks = timer->hw.ticks;
741 if (ticks_left != ticks)
742 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
743 timer->sticks = ticks;
744 }
745
746 /* call callbacks in timer ack list */
snd_timer_process_callbacks(struct snd_timer * timer,struct list_head * head)747 static void snd_timer_process_callbacks(struct snd_timer *timer,
748 struct list_head *head)
749 {
750 struct snd_timer_instance *ti;
751 unsigned long resolution, ticks;
752
753 while (!list_empty(head)) {
754 ti = list_first_entry(head, struct snd_timer_instance,
755 ack_list);
756
757 /* remove from ack_list and make empty */
758 list_del_init(&ti->ack_list);
759
760 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
761 ticks = ti->pticks;
762 ti->pticks = 0;
763 resolution = ti->resolution;
764 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
765 spin_unlock(&timer->lock);
766 if (ti->callback)
767 ti->callback(ti, resolution, ticks);
768 spin_lock(&timer->lock);
769 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
770 }
771 }
772 }
773
774 /* clear pending instances from ack list */
snd_timer_clear_callbacks(struct snd_timer * timer,struct list_head * head)775 static void snd_timer_clear_callbacks(struct snd_timer *timer,
776 struct list_head *head)
777 {
778 unsigned long flags;
779
780 spin_lock_irqsave(&timer->lock, flags);
781 while (!list_empty(head))
782 list_del_init(head->next);
783 spin_unlock_irqrestore(&timer->lock, flags);
784 }
785
786 /*
787 * timer tasklet
788 *
789 */
snd_timer_tasklet(unsigned long arg)790 static void snd_timer_tasklet(unsigned long arg)
791 {
792 struct snd_timer *timer = (struct snd_timer *) arg;
793 unsigned long flags;
794
795 if (timer->card && timer->card->shutdown) {
796 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
797 return;
798 }
799
800 spin_lock_irqsave(&timer->lock, flags);
801 snd_timer_process_callbacks(timer, &timer->sack_list_head);
802 spin_unlock_irqrestore(&timer->lock, flags);
803 }
804
805 /*
806 * timer interrupt
807 *
808 * ticks_left is usually equal to timer->sticks.
809 *
810 */
snd_timer_interrupt(struct snd_timer * timer,unsigned long ticks_left)811 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
812 {
813 struct snd_timer_instance *ti, *ts, *tmp;
814 unsigned long resolution;
815 struct list_head *ack_list_head;
816 unsigned long flags;
817 int use_tasklet = 0;
818
819 if (timer == NULL)
820 return;
821
822 if (timer->card && timer->card->shutdown) {
823 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
824 return;
825 }
826
827 spin_lock_irqsave(&timer->lock, flags);
828
829 /* remember the current resolution */
830 resolution = snd_timer_hw_resolution(timer);
831
832 /* loop for all active instances
833 * Here we cannot use list_for_each_entry because the active_list of a
834 * processed instance is relinked to done_list_head before the callback
835 * is called.
836 */
837 list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
838 active_list) {
839 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
840 continue;
841 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
842 continue;
843 ti->pticks += ticks_left;
844 ti->resolution = resolution;
845 if (ti->cticks < ticks_left)
846 ti->cticks = 0;
847 else
848 ti->cticks -= ticks_left;
849 if (ti->cticks) /* not expired */
850 continue;
851 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
852 ti->cticks = ti->ticks;
853 } else {
854 ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
855 --timer->running;
856 list_del_init(&ti->active_list);
857 }
858 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
859 (ti->flags & SNDRV_TIMER_IFLG_FAST))
860 ack_list_head = &timer->ack_list_head;
861 else
862 ack_list_head = &timer->sack_list_head;
863 if (list_empty(&ti->ack_list))
864 list_add_tail(&ti->ack_list, ack_list_head);
865 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
866 ts->pticks = ti->pticks;
867 ts->resolution = resolution;
868 if (list_empty(&ts->ack_list))
869 list_add_tail(&ts->ack_list, ack_list_head);
870 }
871 }
872 if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
873 snd_timer_reschedule(timer, timer->sticks);
874 if (timer->running) {
875 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
876 timer->hw.stop(timer);
877 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
878 }
879 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
880 (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
881 /* restart timer */
882 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
883 timer->hw.start(timer);
884 }
885 } else {
886 timer->hw.stop(timer);
887 }
888
889 /* now process all fast callbacks */
890 snd_timer_process_callbacks(timer, &timer->ack_list_head);
891
892 /* do we have any slow callbacks? */
893 use_tasklet = !list_empty(&timer->sack_list_head);
894 spin_unlock_irqrestore(&timer->lock, flags);
895
896 if (use_tasklet)
897 tasklet_schedule(&timer->task_queue);
898 }
899 EXPORT_SYMBOL(snd_timer_interrupt);
900
901 /*
902
903 */
904
snd_timer_new(struct snd_card * card,char * id,struct snd_timer_id * tid,struct snd_timer ** rtimer)905 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
906 struct snd_timer **rtimer)
907 {
908 struct snd_timer *timer;
909 int err;
910 static struct snd_device_ops ops = {
911 .dev_free = snd_timer_dev_free,
912 .dev_register = snd_timer_dev_register,
913 .dev_disconnect = snd_timer_dev_disconnect,
914 };
915
916 if (snd_BUG_ON(!tid))
917 return -EINVAL;
918 if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
919 tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
920 if (WARN_ON(!card))
921 return -EINVAL;
922 }
923 if (rtimer)
924 *rtimer = NULL;
925 timer = kzalloc(sizeof(*timer), GFP_KERNEL);
926 if (!timer)
927 return -ENOMEM;
928 timer->tmr_class = tid->dev_class;
929 timer->card = card;
930 timer->tmr_device = tid->device;
931 timer->tmr_subdevice = tid->subdevice;
932 if (id)
933 strlcpy(timer->id, id, sizeof(timer->id));
934 timer->sticks = 1;
935 INIT_LIST_HEAD(&timer->device_list);
936 INIT_LIST_HEAD(&timer->open_list_head);
937 INIT_LIST_HEAD(&timer->active_list_head);
938 INIT_LIST_HEAD(&timer->ack_list_head);
939 INIT_LIST_HEAD(&timer->sack_list_head);
940 spin_lock_init(&timer->lock);
941 tasklet_init(&timer->task_queue, snd_timer_tasklet,
942 (unsigned long)timer);
943 timer->max_instances = 1000; /* default limit per timer */
944 if (card != NULL) {
945 timer->module = card->module;
946 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
947 if (err < 0) {
948 snd_timer_free(timer);
949 return err;
950 }
951 }
952 if (rtimer)
953 *rtimer = timer;
954 return 0;
955 }
956 EXPORT_SYMBOL(snd_timer_new);
957
snd_timer_free(struct snd_timer * timer)958 static int snd_timer_free(struct snd_timer *timer)
959 {
960 if (!timer)
961 return 0;
962
963 mutex_lock(®ister_mutex);
964 if (! list_empty(&timer->open_list_head)) {
965 struct list_head *p, *n;
966 struct snd_timer_instance *ti;
967 pr_warn("ALSA: timer %p is busy?\n", timer);
968 list_for_each_safe(p, n, &timer->open_list_head) {
969 list_del_init(p);
970 ti = list_entry(p, struct snd_timer_instance, open_list);
971 ti->timer = NULL;
972 }
973 }
974 list_del(&timer->device_list);
975 mutex_unlock(®ister_mutex);
976
977 if (timer->private_free)
978 timer->private_free(timer);
979 kfree(timer);
980 return 0;
981 }
982
snd_timer_dev_free(struct snd_device * device)983 static int snd_timer_dev_free(struct snd_device *device)
984 {
985 struct snd_timer *timer = device->device_data;
986 return snd_timer_free(timer);
987 }
988
snd_timer_dev_register(struct snd_device * dev)989 static int snd_timer_dev_register(struct snd_device *dev)
990 {
991 struct snd_timer *timer = dev->device_data;
992 struct snd_timer *timer1;
993
994 if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
995 return -ENXIO;
996 if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
997 !timer->hw.resolution && timer->hw.c_resolution == NULL)
998 return -EINVAL;
999
1000 mutex_lock(®ister_mutex);
1001 list_for_each_entry(timer1, &snd_timer_list, device_list) {
1002 if (timer1->tmr_class > timer->tmr_class)
1003 break;
1004 if (timer1->tmr_class < timer->tmr_class)
1005 continue;
1006 if (timer1->card && timer->card) {
1007 if (timer1->card->number > timer->card->number)
1008 break;
1009 if (timer1->card->number < timer->card->number)
1010 continue;
1011 }
1012 if (timer1->tmr_device > timer->tmr_device)
1013 break;
1014 if (timer1->tmr_device < timer->tmr_device)
1015 continue;
1016 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1017 break;
1018 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1019 continue;
1020 /* conflicts.. */
1021 mutex_unlock(®ister_mutex);
1022 return -EBUSY;
1023 }
1024 list_add_tail(&timer->device_list, &timer1->device_list);
1025 mutex_unlock(®ister_mutex);
1026 return 0;
1027 }
1028
snd_timer_dev_disconnect(struct snd_device * device)1029 static int snd_timer_dev_disconnect(struct snd_device *device)
1030 {
1031 struct snd_timer *timer = device->device_data;
1032 struct snd_timer_instance *ti;
1033
1034 mutex_lock(®ister_mutex);
1035 list_del_init(&timer->device_list);
1036 /* wake up pending sleepers */
1037 list_for_each_entry(ti, &timer->open_list_head, open_list) {
1038 if (ti->disconnect)
1039 ti->disconnect(ti);
1040 }
1041 mutex_unlock(®ister_mutex);
1042 return 0;
1043 }
1044
snd_timer_notify(struct snd_timer * timer,int event,struct timespec * tstamp)1045 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
1046 {
1047 unsigned long flags;
1048 unsigned long resolution = 0;
1049 struct snd_timer_instance *ti, *ts;
1050
1051 if (timer->card && timer->card->shutdown)
1052 return;
1053 if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1054 return;
1055 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1056 event > SNDRV_TIMER_EVENT_MRESUME))
1057 return;
1058 spin_lock_irqsave(&timer->lock, flags);
1059 if (event == SNDRV_TIMER_EVENT_MSTART ||
1060 event == SNDRV_TIMER_EVENT_MCONTINUE ||
1061 event == SNDRV_TIMER_EVENT_MRESUME)
1062 resolution = snd_timer_hw_resolution(timer);
1063 list_for_each_entry(ti, &timer->active_list_head, active_list) {
1064 if (ti->ccallback)
1065 ti->ccallback(ti, event, tstamp, resolution);
1066 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1067 if (ts->ccallback)
1068 ts->ccallback(ts, event, tstamp, resolution);
1069 }
1070 spin_unlock_irqrestore(&timer->lock, flags);
1071 }
1072 EXPORT_SYMBOL(snd_timer_notify);
1073
1074 /*
1075 * exported functions for global timers
1076 */
snd_timer_global_new(char * id,int device,struct snd_timer ** rtimer)1077 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1078 {
1079 struct snd_timer_id tid;
1080
1081 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1082 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1083 tid.card = -1;
1084 tid.device = device;
1085 tid.subdevice = 0;
1086 return snd_timer_new(NULL, id, &tid, rtimer);
1087 }
1088 EXPORT_SYMBOL(snd_timer_global_new);
1089
snd_timer_global_free(struct snd_timer * timer)1090 int snd_timer_global_free(struct snd_timer *timer)
1091 {
1092 return snd_timer_free(timer);
1093 }
1094 EXPORT_SYMBOL(snd_timer_global_free);
1095
snd_timer_global_register(struct snd_timer * timer)1096 int snd_timer_global_register(struct snd_timer *timer)
1097 {
1098 struct snd_device dev;
1099
1100 memset(&dev, 0, sizeof(dev));
1101 dev.device_data = timer;
1102 return snd_timer_dev_register(&dev);
1103 }
1104 EXPORT_SYMBOL(snd_timer_global_register);
1105
1106 /*
1107 * System timer
1108 */
1109
1110 struct snd_timer_system_private {
1111 struct timer_list tlist;
1112 struct snd_timer *snd_timer;
1113 unsigned long last_expires;
1114 unsigned long last_jiffies;
1115 unsigned long correction;
1116 };
1117
snd_timer_s_function(struct timer_list * t)1118 static void snd_timer_s_function(struct timer_list *t)
1119 {
1120 struct snd_timer_system_private *priv = from_timer(priv, t,
1121 tlist);
1122 struct snd_timer *timer = priv->snd_timer;
1123 unsigned long jiff = jiffies;
1124 if (time_after(jiff, priv->last_expires))
1125 priv->correction += (long)jiff - (long)priv->last_expires;
1126 snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1127 }
1128
snd_timer_s_start(struct snd_timer * timer)1129 static int snd_timer_s_start(struct snd_timer * timer)
1130 {
1131 struct snd_timer_system_private *priv;
1132 unsigned long njiff;
1133
1134 priv = (struct snd_timer_system_private *) timer->private_data;
1135 njiff = (priv->last_jiffies = jiffies);
1136 if (priv->correction > timer->sticks - 1) {
1137 priv->correction -= timer->sticks - 1;
1138 njiff++;
1139 } else {
1140 njiff += timer->sticks - priv->correction;
1141 priv->correction = 0;
1142 }
1143 priv->last_expires = njiff;
1144 mod_timer(&priv->tlist, njiff);
1145 return 0;
1146 }
1147
snd_timer_s_stop(struct snd_timer * timer)1148 static int snd_timer_s_stop(struct snd_timer * timer)
1149 {
1150 struct snd_timer_system_private *priv;
1151 unsigned long jiff;
1152
1153 priv = (struct snd_timer_system_private *) timer->private_data;
1154 del_timer(&priv->tlist);
1155 jiff = jiffies;
1156 if (time_before(jiff, priv->last_expires))
1157 timer->sticks = priv->last_expires - jiff;
1158 else
1159 timer->sticks = 1;
1160 priv->correction = 0;
1161 return 0;
1162 }
1163
snd_timer_s_close(struct snd_timer * timer)1164 static int snd_timer_s_close(struct snd_timer *timer)
1165 {
1166 struct snd_timer_system_private *priv;
1167
1168 priv = (struct snd_timer_system_private *)timer->private_data;
1169 del_timer_sync(&priv->tlist);
1170 return 0;
1171 }
1172
1173 static struct snd_timer_hardware snd_timer_system =
1174 {
1175 .flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1176 .resolution = 1000000000L / HZ,
1177 .ticks = 10000000L,
1178 .close = snd_timer_s_close,
1179 .start = snd_timer_s_start,
1180 .stop = snd_timer_s_stop
1181 };
1182
snd_timer_free_system(struct snd_timer * timer)1183 static void snd_timer_free_system(struct snd_timer *timer)
1184 {
1185 kfree(timer->private_data);
1186 }
1187
snd_timer_register_system(void)1188 static int snd_timer_register_system(void)
1189 {
1190 struct snd_timer *timer;
1191 struct snd_timer_system_private *priv;
1192 int err;
1193
1194 err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1195 if (err < 0)
1196 return err;
1197 strcpy(timer->name, "system timer");
1198 timer->hw = snd_timer_system;
1199 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1200 if (priv == NULL) {
1201 snd_timer_free(timer);
1202 return -ENOMEM;
1203 }
1204 priv->snd_timer = timer;
1205 timer_setup(&priv->tlist, snd_timer_s_function, 0);
1206 timer->private_data = priv;
1207 timer->private_free = snd_timer_free_system;
1208 return snd_timer_global_register(timer);
1209 }
1210
1211 #ifdef CONFIG_SND_PROC_FS
1212 /*
1213 * Info interface
1214 */
1215
snd_timer_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)1216 static void snd_timer_proc_read(struct snd_info_entry *entry,
1217 struct snd_info_buffer *buffer)
1218 {
1219 struct snd_timer *timer;
1220 struct snd_timer_instance *ti;
1221
1222 mutex_lock(®ister_mutex);
1223 list_for_each_entry(timer, &snd_timer_list, device_list) {
1224 if (timer->card && timer->card->shutdown)
1225 continue;
1226 switch (timer->tmr_class) {
1227 case SNDRV_TIMER_CLASS_GLOBAL:
1228 snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1229 break;
1230 case SNDRV_TIMER_CLASS_CARD:
1231 snd_iprintf(buffer, "C%i-%i: ",
1232 timer->card->number, timer->tmr_device);
1233 break;
1234 case SNDRV_TIMER_CLASS_PCM:
1235 snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1236 timer->tmr_device, timer->tmr_subdevice);
1237 break;
1238 default:
1239 snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1240 timer->card ? timer->card->number : -1,
1241 timer->tmr_device, timer->tmr_subdevice);
1242 }
1243 snd_iprintf(buffer, "%s :", timer->name);
1244 if (timer->hw.resolution)
1245 snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1246 timer->hw.resolution / 1000,
1247 timer->hw.resolution % 1000,
1248 timer->hw.ticks);
1249 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1250 snd_iprintf(buffer, " SLAVE");
1251 snd_iprintf(buffer, "\n");
1252 list_for_each_entry(ti, &timer->open_list_head, open_list)
1253 snd_iprintf(buffer, " Client %s : %s\n",
1254 ti->owner ? ti->owner : "unknown",
1255 ti->flags & (SNDRV_TIMER_IFLG_START |
1256 SNDRV_TIMER_IFLG_RUNNING)
1257 ? "running" : "stopped");
1258 }
1259 mutex_unlock(®ister_mutex);
1260 }
1261
1262 static struct snd_info_entry *snd_timer_proc_entry;
1263
snd_timer_proc_init(void)1264 static void __init snd_timer_proc_init(void)
1265 {
1266 struct snd_info_entry *entry;
1267
1268 entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1269 if (entry != NULL) {
1270 entry->c.text.read = snd_timer_proc_read;
1271 if (snd_info_register(entry) < 0) {
1272 snd_info_free_entry(entry);
1273 entry = NULL;
1274 }
1275 }
1276 snd_timer_proc_entry = entry;
1277 }
1278
snd_timer_proc_done(void)1279 static void __exit snd_timer_proc_done(void)
1280 {
1281 snd_info_free_entry(snd_timer_proc_entry);
1282 }
1283 #else /* !CONFIG_SND_PROC_FS */
1284 #define snd_timer_proc_init()
1285 #define snd_timer_proc_done()
1286 #endif
1287
1288 /*
1289 * USER SPACE interface
1290 */
1291
snd_timer_user_interrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1292 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1293 unsigned long resolution,
1294 unsigned long ticks)
1295 {
1296 struct snd_timer_user *tu = timeri->callback_data;
1297 struct snd_timer_read *r;
1298 int prev;
1299
1300 spin_lock(&tu->qlock);
1301 if (tu->qused > 0) {
1302 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1303 r = &tu->queue[prev];
1304 if (r->resolution == resolution) {
1305 r->ticks += ticks;
1306 goto __wake;
1307 }
1308 }
1309 if (tu->qused >= tu->queue_size) {
1310 tu->overrun++;
1311 } else {
1312 r = &tu->queue[tu->qtail++];
1313 tu->qtail %= tu->queue_size;
1314 r->resolution = resolution;
1315 r->ticks = ticks;
1316 tu->qused++;
1317 }
1318 __wake:
1319 spin_unlock(&tu->qlock);
1320 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1321 wake_up(&tu->qchange_sleep);
1322 }
1323
snd_timer_user_append_to_tqueue(struct snd_timer_user * tu,struct snd_timer_tread * tread)1324 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1325 struct snd_timer_tread *tread)
1326 {
1327 if (tu->qused >= tu->queue_size) {
1328 tu->overrun++;
1329 } else {
1330 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1331 tu->qtail %= tu->queue_size;
1332 tu->qused++;
1333 }
1334 }
1335
snd_timer_user_ccallback(struct snd_timer_instance * timeri,int event,struct timespec * tstamp,unsigned long resolution)1336 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1337 int event,
1338 struct timespec *tstamp,
1339 unsigned long resolution)
1340 {
1341 struct snd_timer_user *tu = timeri->callback_data;
1342 struct snd_timer_tread r1;
1343 unsigned long flags;
1344
1345 if (event >= SNDRV_TIMER_EVENT_START &&
1346 event <= SNDRV_TIMER_EVENT_PAUSE)
1347 tu->tstamp = *tstamp;
1348 if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1349 return;
1350 memset(&r1, 0, sizeof(r1));
1351 r1.event = event;
1352 r1.tstamp = *tstamp;
1353 r1.val = resolution;
1354 spin_lock_irqsave(&tu->qlock, flags);
1355 snd_timer_user_append_to_tqueue(tu, &r1);
1356 spin_unlock_irqrestore(&tu->qlock, flags);
1357 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1358 wake_up(&tu->qchange_sleep);
1359 }
1360
snd_timer_user_disconnect(struct snd_timer_instance * timeri)1361 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1362 {
1363 struct snd_timer_user *tu = timeri->callback_data;
1364
1365 tu->disconnected = true;
1366 wake_up(&tu->qchange_sleep);
1367 }
1368
snd_timer_user_tinterrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)1369 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1370 unsigned long resolution,
1371 unsigned long ticks)
1372 {
1373 struct snd_timer_user *tu = timeri->callback_data;
1374 struct snd_timer_tread *r, r1;
1375 struct timespec tstamp;
1376 int prev, append = 0;
1377
1378 memset(&r1, 0, sizeof(r1));
1379 memset(&tstamp, 0, sizeof(tstamp));
1380 spin_lock(&tu->qlock);
1381 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1382 (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1383 spin_unlock(&tu->qlock);
1384 return;
1385 }
1386 if (tu->last_resolution != resolution || ticks > 0) {
1387 if (timer_tstamp_monotonic)
1388 ktime_get_ts(&tstamp);
1389 else
1390 getnstimeofday(&tstamp);
1391 }
1392 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1393 tu->last_resolution != resolution) {
1394 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1395 r1.tstamp = tstamp;
1396 r1.val = resolution;
1397 snd_timer_user_append_to_tqueue(tu, &r1);
1398 tu->last_resolution = resolution;
1399 append++;
1400 }
1401 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1402 goto __wake;
1403 if (ticks == 0)
1404 goto __wake;
1405 if (tu->qused > 0) {
1406 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1407 r = &tu->tqueue[prev];
1408 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1409 r->tstamp = tstamp;
1410 r->val += ticks;
1411 append++;
1412 goto __wake;
1413 }
1414 }
1415 r1.event = SNDRV_TIMER_EVENT_TICK;
1416 r1.tstamp = tstamp;
1417 r1.val = ticks;
1418 snd_timer_user_append_to_tqueue(tu, &r1);
1419 append++;
1420 __wake:
1421 spin_unlock(&tu->qlock);
1422 if (append == 0)
1423 return;
1424 snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1425 wake_up(&tu->qchange_sleep);
1426 }
1427
realloc_user_queue(struct snd_timer_user * tu,int size)1428 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1429 {
1430 struct snd_timer_read *queue = NULL;
1431 struct snd_timer_tread *tqueue = NULL;
1432
1433 if (tu->tread) {
1434 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1435 if (!tqueue)
1436 return -ENOMEM;
1437 } else {
1438 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1439 if (!queue)
1440 return -ENOMEM;
1441 }
1442
1443 spin_lock_irq(&tu->qlock);
1444 kfree(tu->queue);
1445 kfree(tu->tqueue);
1446 tu->queue_size = size;
1447 tu->queue = queue;
1448 tu->tqueue = tqueue;
1449 tu->qhead = tu->qtail = tu->qused = 0;
1450 spin_unlock_irq(&tu->qlock);
1451
1452 return 0;
1453 }
1454
snd_timer_user_open(struct inode * inode,struct file * file)1455 static int snd_timer_user_open(struct inode *inode, struct file *file)
1456 {
1457 struct snd_timer_user *tu;
1458 int err;
1459
1460 err = stream_open(inode, file);
1461 if (err < 0)
1462 return err;
1463
1464 tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1465 if (tu == NULL)
1466 return -ENOMEM;
1467 spin_lock_init(&tu->qlock);
1468 init_waitqueue_head(&tu->qchange_sleep);
1469 mutex_init(&tu->ioctl_lock);
1470 tu->ticks = 1;
1471 if (realloc_user_queue(tu, 128) < 0) {
1472 kfree(tu);
1473 return -ENOMEM;
1474 }
1475 file->private_data = tu;
1476 return 0;
1477 }
1478
snd_timer_user_release(struct inode * inode,struct file * file)1479 static int snd_timer_user_release(struct inode *inode, struct file *file)
1480 {
1481 struct snd_timer_user *tu;
1482
1483 if (file->private_data) {
1484 tu = file->private_data;
1485 file->private_data = NULL;
1486 mutex_lock(&tu->ioctl_lock);
1487 if (tu->timeri)
1488 snd_timer_close(tu->timeri);
1489 mutex_unlock(&tu->ioctl_lock);
1490 snd_fasync_free(tu->fasync);
1491 kfree(tu->queue);
1492 kfree(tu->tqueue);
1493 kfree(tu);
1494 }
1495 return 0;
1496 }
1497
snd_timer_user_zero_id(struct snd_timer_id * id)1498 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1499 {
1500 id->dev_class = SNDRV_TIMER_CLASS_NONE;
1501 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1502 id->card = -1;
1503 id->device = -1;
1504 id->subdevice = -1;
1505 }
1506
snd_timer_user_copy_id(struct snd_timer_id * id,struct snd_timer * timer)1507 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1508 {
1509 id->dev_class = timer->tmr_class;
1510 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1511 id->card = timer->card ? timer->card->number : -1;
1512 id->device = timer->tmr_device;
1513 id->subdevice = timer->tmr_subdevice;
1514 }
1515
snd_timer_user_next_device(struct snd_timer_id __user * _tid)1516 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1517 {
1518 struct snd_timer_id id;
1519 struct snd_timer *timer;
1520 struct list_head *p;
1521
1522 if (copy_from_user(&id, _tid, sizeof(id)))
1523 return -EFAULT;
1524 mutex_lock(®ister_mutex);
1525 if (id.dev_class < 0) { /* first item */
1526 if (list_empty(&snd_timer_list))
1527 snd_timer_user_zero_id(&id);
1528 else {
1529 timer = list_entry(snd_timer_list.next,
1530 struct snd_timer, device_list);
1531 snd_timer_user_copy_id(&id, timer);
1532 }
1533 } else {
1534 switch (id.dev_class) {
1535 case SNDRV_TIMER_CLASS_GLOBAL:
1536 id.device = id.device < 0 ? 0 : id.device + 1;
1537 list_for_each(p, &snd_timer_list) {
1538 timer = list_entry(p, struct snd_timer, device_list);
1539 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1540 snd_timer_user_copy_id(&id, timer);
1541 break;
1542 }
1543 if (timer->tmr_device >= id.device) {
1544 snd_timer_user_copy_id(&id, timer);
1545 break;
1546 }
1547 }
1548 if (p == &snd_timer_list)
1549 snd_timer_user_zero_id(&id);
1550 break;
1551 case SNDRV_TIMER_CLASS_CARD:
1552 case SNDRV_TIMER_CLASS_PCM:
1553 if (id.card < 0) {
1554 id.card = 0;
1555 } else {
1556 if (id.device < 0) {
1557 id.device = 0;
1558 } else {
1559 if (id.subdevice < 0)
1560 id.subdevice = 0;
1561 else if (id.subdevice < INT_MAX)
1562 id.subdevice++;
1563 }
1564 }
1565 list_for_each(p, &snd_timer_list) {
1566 timer = list_entry(p, struct snd_timer, device_list);
1567 if (timer->tmr_class > id.dev_class) {
1568 snd_timer_user_copy_id(&id, timer);
1569 break;
1570 }
1571 if (timer->tmr_class < id.dev_class)
1572 continue;
1573 if (timer->card->number > id.card) {
1574 snd_timer_user_copy_id(&id, timer);
1575 break;
1576 }
1577 if (timer->card->number < id.card)
1578 continue;
1579 if (timer->tmr_device > id.device) {
1580 snd_timer_user_copy_id(&id, timer);
1581 break;
1582 }
1583 if (timer->tmr_device < id.device)
1584 continue;
1585 if (timer->tmr_subdevice > id.subdevice) {
1586 snd_timer_user_copy_id(&id, timer);
1587 break;
1588 }
1589 if (timer->tmr_subdevice < id.subdevice)
1590 continue;
1591 snd_timer_user_copy_id(&id, timer);
1592 break;
1593 }
1594 if (p == &snd_timer_list)
1595 snd_timer_user_zero_id(&id);
1596 break;
1597 default:
1598 snd_timer_user_zero_id(&id);
1599 }
1600 }
1601 mutex_unlock(®ister_mutex);
1602 if (copy_to_user(_tid, &id, sizeof(*_tid)))
1603 return -EFAULT;
1604 return 0;
1605 }
1606
snd_timer_user_ginfo(struct file * file,struct snd_timer_ginfo __user * _ginfo)1607 static int snd_timer_user_ginfo(struct file *file,
1608 struct snd_timer_ginfo __user *_ginfo)
1609 {
1610 struct snd_timer_ginfo *ginfo;
1611 struct snd_timer_id tid;
1612 struct snd_timer *t;
1613 struct list_head *p;
1614 int err = 0;
1615
1616 ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1617 if (IS_ERR(ginfo))
1618 return PTR_ERR(ginfo);
1619
1620 tid = ginfo->tid;
1621 memset(ginfo, 0, sizeof(*ginfo));
1622 ginfo->tid = tid;
1623 mutex_lock(®ister_mutex);
1624 t = snd_timer_find(&tid);
1625 if (t != NULL) {
1626 ginfo->card = t->card ? t->card->number : -1;
1627 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1628 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1629 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1630 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1631 ginfo->resolution = t->hw.resolution;
1632 if (t->hw.resolution_min > 0) {
1633 ginfo->resolution_min = t->hw.resolution_min;
1634 ginfo->resolution_max = t->hw.resolution_max;
1635 }
1636 list_for_each(p, &t->open_list_head) {
1637 ginfo->clients++;
1638 }
1639 } else {
1640 err = -ENODEV;
1641 }
1642 mutex_unlock(®ister_mutex);
1643 if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1644 err = -EFAULT;
1645 kfree(ginfo);
1646 return err;
1647 }
1648
timer_set_gparams(struct snd_timer_gparams * gparams)1649 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1650 {
1651 struct snd_timer *t;
1652 int err;
1653
1654 mutex_lock(®ister_mutex);
1655 t = snd_timer_find(&gparams->tid);
1656 if (!t) {
1657 err = -ENODEV;
1658 goto _error;
1659 }
1660 if (!list_empty(&t->open_list_head)) {
1661 err = -EBUSY;
1662 goto _error;
1663 }
1664 if (!t->hw.set_period) {
1665 err = -ENOSYS;
1666 goto _error;
1667 }
1668 err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1669 _error:
1670 mutex_unlock(®ister_mutex);
1671 return err;
1672 }
1673
snd_timer_user_gparams(struct file * file,struct snd_timer_gparams __user * _gparams)1674 static int snd_timer_user_gparams(struct file *file,
1675 struct snd_timer_gparams __user *_gparams)
1676 {
1677 struct snd_timer_gparams gparams;
1678
1679 if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1680 return -EFAULT;
1681 return timer_set_gparams(&gparams);
1682 }
1683
snd_timer_user_gstatus(struct file * file,struct snd_timer_gstatus __user * _gstatus)1684 static int snd_timer_user_gstatus(struct file *file,
1685 struct snd_timer_gstatus __user *_gstatus)
1686 {
1687 struct snd_timer_gstatus gstatus;
1688 struct snd_timer_id tid;
1689 struct snd_timer *t;
1690 int err = 0;
1691
1692 if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1693 return -EFAULT;
1694 tid = gstatus.tid;
1695 memset(&gstatus, 0, sizeof(gstatus));
1696 gstatus.tid = tid;
1697 mutex_lock(®ister_mutex);
1698 t = snd_timer_find(&tid);
1699 if (t != NULL) {
1700 spin_lock_irq(&t->lock);
1701 gstatus.resolution = snd_timer_hw_resolution(t);
1702 if (t->hw.precise_resolution) {
1703 t->hw.precise_resolution(t, &gstatus.resolution_num,
1704 &gstatus.resolution_den);
1705 } else {
1706 gstatus.resolution_num = gstatus.resolution;
1707 gstatus.resolution_den = 1000000000uL;
1708 }
1709 spin_unlock_irq(&t->lock);
1710 } else {
1711 err = -ENODEV;
1712 }
1713 mutex_unlock(®ister_mutex);
1714 if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1715 err = -EFAULT;
1716 return err;
1717 }
1718
snd_timer_user_tselect(struct file * file,struct snd_timer_select __user * _tselect)1719 static int snd_timer_user_tselect(struct file *file,
1720 struct snd_timer_select __user *_tselect)
1721 {
1722 struct snd_timer_user *tu;
1723 struct snd_timer_select tselect;
1724 char str[32];
1725 int err = 0;
1726
1727 tu = file->private_data;
1728 if (tu->timeri) {
1729 snd_timer_close(tu->timeri);
1730 tu->timeri = NULL;
1731 }
1732 if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1733 err = -EFAULT;
1734 goto __err;
1735 }
1736 sprintf(str, "application %i", current->pid);
1737 if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1738 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1739 err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1740 if (err < 0)
1741 goto __err;
1742
1743 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1744 tu->timeri->callback = tu->tread
1745 ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1746 tu->timeri->ccallback = snd_timer_user_ccallback;
1747 tu->timeri->callback_data = (void *)tu;
1748 tu->timeri->disconnect = snd_timer_user_disconnect;
1749
1750 __err:
1751 return err;
1752 }
1753
snd_timer_user_info(struct file * file,struct snd_timer_info __user * _info)1754 static int snd_timer_user_info(struct file *file,
1755 struct snd_timer_info __user *_info)
1756 {
1757 struct snd_timer_user *tu;
1758 struct snd_timer_info *info;
1759 struct snd_timer *t;
1760 int err = 0;
1761
1762 tu = file->private_data;
1763 if (!tu->timeri)
1764 return -EBADFD;
1765 t = tu->timeri->timer;
1766 if (!t)
1767 return -EBADFD;
1768
1769 info = kzalloc(sizeof(*info), GFP_KERNEL);
1770 if (! info)
1771 return -ENOMEM;
1772 info->card = t->card ? t->card->number : -1;
1773 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1774 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1775 strlcpy(info->id, t->id, sizeof(info->id));
1776 strlcpy(info->name, t->name, sizeof(info->name));
1777 info->resolution = t->hw.resolution;
1778 if (copy_to_user(_info, info, sizeof(*_info)))
1779 err = -EFAULT;
1780 kfree(info);
1781 return err;
1782 }
1783
snd_timer_user_params(struct file * file,struct snd_timer_params __user * _params)1784 static int snd_timer_user_params(struct file *file,
1785 struct snd_timer_params __user *_params)
1786 {
1787 struct snd_timer_user *tu;
1788 struct snd_timer_params params;
1789 struct snd_timer *t;
1790 int err;
1791
1792 tu = file->private_data;
1793 if (!tu->timeri)
1794 return -EBADFD;
1795 t = tu->timeri->timer;
1796 if (!t)
1797 return -EBADFD;
1798 if (copy_from_user(¶ms, _params, sizeof(params)))
1799 return -EFAULT;
1800 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1801 u64 resolution;
1802
1803 if (params.ticks < 1) {
1804 err = -EINVAL;
1805 goto _end;
1806 }
1807
1808 /* Don't allow resolution less than 1ms */
1809 resolution = snd_timer_resolution(tu->timeri);
1810 resolution *= params.ticks;
1811 if (resolution < 1000000) {
1812 err = -EINVAL;
1813 goto _end;
1814 }
1815 }
1816 if (params.queue_size > 0 &&
1817 (params.queue_size < 32 || params.queue_size > 1024)) {
1818 err = -EINVAL;
1819 goto _end;
1820 }
1821 if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1822 (1<<SNDRV_TIMER_EVENT_TICK)|
1823 (1<<SNDRV_TIMER_EVENT_START)|
1824 (1<<SNDRV_TIMER_EVENT_STOP)|
1825 (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1826 (1<<SNDRV_TIMER_EVENT_PAUSE)|
1827 (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1828 (1<<SNDRV_TIMER_EVENT_RESUME)|
1829 (1<<SNDRV_TIMER_EVENT_MSTART)|
1830 (1<<SNDRV_TIMER_EVENT_MSTOP)|
1831 (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1832 (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1833 (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1834 (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1835 err = -EINVAL;
1836 goto _end;
1837 }
1838 snd_timer_stop(tu->timeri);
1839 spin_lock_irq(&t->lock);
1840 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1841 SNDRV_TIMER_IFLG_EXCLUSIVE|
1842 SNDRV_TIMER_IFLG_EARLY_EVENT);
1843 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1844 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1845 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1846 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1847 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1848 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1849 spin_unlock_irq(&t->lock);
1850 if (params.queue_size > 0 &&
1851 (unsigned int)tu->queue_size != params.queue_size) {
1852 err = realloc_user_queue(tu, params.queue_size);
1853 if (err < 0)
1854 goto _end;
1855 }
1856 spin_lock_irq(&tu->qlock);
1857 tu->qhead = tu->qtail = tu->qused = 0;
1858 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1859 if (tu->tread) {
1860 struct snd_timer_tread tread;
1861 memset(&tread, 0, sizeof(tread));
1862 tread.event = SNDRV_TIMER_EVENT_EARLY;
1863 tread.tstamp.tv_sec = 0;
1864 tread.tstamp.tv_nsec = 0;
1865 tread.val = 0;
1866 snd_timer_user_append_to_tqueue(tu, &tread);
1867 } else {
1868 struct snd_timer_read *r = &tu->queue[0];
1869 r->resolution = 0;
1870 r->ticks = 0;
1871 tu->qused++;
1872 tu->qtail++;
1873 }
1874 }
1875 tu->filter = params.filter;
1876 tu->ticks = params.ticks;
1877 spin_unlock_irq(&tu->qlock);
1878 err = 0;
1879 _end:
1880 if (copy_to_user(_params, ¶ms, sizeof(params)))
1881 return -EFAULT;
1882 return err;
1883 }
1884
snd_timer_user_status(struct file * file,struct snd_timer_status __user * _status)1885 static int snd_timer_user_status(struct file *file,
1886 struct snd_timer_status __user *_status)
1887 {
1888 struct snd_timer_user *tu;
1889 struct snd_timer_status status;
1890
1891 tu = file->private_data;
1892 if (!tu->timeri)
1893 return -EBADFD;
1894 memset(&status, 0, sizeof(status));
1895 status.tstamp = tu->tstamp;
1896 status.resolution = snd_timer_resolution(tu->timeri);
1897 status.lost = tu->timeri->lost;
1898 status.overrun = tu->overrun;
1899 spin_lock_irq(&tu->qlock);
1900 status.queue = tu->qused;
1901 spin_unlock_irq(&tu->qlock);
1902 if (copy_to_user(_status, &status, sizeof(status)))
1903 return -EFAULT;
1904 return 0;
1905 }
1906
snd_timer_user_start(struct file * file)1907 static int snd_timer_user_start(struct file *file)
1908 {
1909 int err;
1910 struct snd_timer_user *tu;
1911
1912 tu = file->private_data;
1913 if (!tu->timeri)
1914 return -EBADFD;
1915 snd_timer_stop(tu->timeri);
1916 tu->timeri->lost = 0;
1917 tu->last_resolution = 0;
1918 err = snd_timer_start(tu->timeri, tu->ticks);
1919 if (err < 0)
1920 return err;
1921 return 0;
1922 }
1923
snd_timer_user_stop(struct file * file)1924 static int snd_timer_user_stop(struct file *file)
1925 {
1926 int err;
1927 struct snd_timer_user *tu;
1928
1929 tu = file->private_data;
1930 if (!tu->timeri)
1931 return -EBADFD;
1932 err = snd_timer_stop(tu->timeri);
1933 if (err < 0)
1934 return err;
1935 return 0;
1936 }
1937
snd_timer_user_continue(struct file * file)1938 static int snd_timer_user_continue(struct file *file)
1939 {
1940 int err;
1941 struct snd_timer_user *tu;
1942
1943 tu = file->private_data;
1944 if (!tu->timeri)
1945 return -EBADFD;
1946 /* start timer instead of continue if it's not used before */
1947 if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1948 return snd_timer_user_start(file);
1949 tu->timeri->lost = 0;
1950 err = snd_timer_continue(tu->timeri);
1951 if (err < 0)
1952 return err;
1953 return 0;
1954 }
1955
snd_timer_user_pause(struct file * file)1956 static int snd_timer_user_pause(struct file *file)
1957 {
1958 int err;
1959 struct snd_timer_user *tu;
1960
1961 tu = file->private_data;
1962 if (!tu->timeri)
1963 return -EBADFD;
1964 err = snd_timer_pause(tu->timeri);
1965 if (err < 0)
1966 return err;
1967 return 0;
1968 }
1969
1970 enum {
1971 SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1972 SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1973 SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1974 SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1975 };
1976
__snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1977 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1978 unsigned long arg)
1979 {
1980 struct snd_timer_user *tu;
1981 void __user *argp = (void __user *)arg;
1982 int __user *p = argp;
1983
1984 tu = file->private_data;
1985 switch (cmd) {
1986 case SNDRV_TIMER_IOCTL_PVERSION:
1987 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1988 case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1989 return snd_timer_user_next_device(argp);
1990 case SNDRV_TIMER_IOCTL_TREAD:
1991 {
1992 int xarg, old_tread;
1993
1994 if (tu->timeri) /* too late */
1995 return -EBUSY;
1996 if (get_user(xarg, p))
1997 return -EFAULT;
1998 old_tread = tu->tread;
1999 tu->tread = xarg ? 1 : 0;
2000 if (tu->tread != old_tread &&
2001 realloc_user_queue(tu, tu->queue_size) < 0) {
2002 tu->tread = old_tread;
2003 return -ENOMEM;
2004 }
2005 return 0;
2006 }
2007 case SNDRV_TIMER_IOCTL_GINFO:
2008 return snd_timer_user_ginfo(file, argp);
2009 case SNDRV_TIMER_IOCTL_GPARAMS:
2010 return snd_timer_user_gparams(file, argp);
2011 case SNDRV_TIMER_IOCTL_GSTATUS:
2012 return snd_timer_user_gstatus(file, argp);
2013 case SNDRV_TIMER_IOCTL_SELECT:
2014 return snd_timer_user_tselect(file, argp);
2015 case SNDRV_TIMER_IOCTL_INFO:
2016 return snd_timer_user_info(file, argp);
2017 case SNDRV_TIMER_IOCTL_PARAMS:
2018 return snd_timer_user_params(file, argp);
2019 case SNDRV_TIMER_IOCTL_STATUS:
2020 return snd_timer_user_status(file, argp);
2021 case SNDRV_TIMER_IOCTL_START:
2022 case SNDRV_TIMER_IOCTL_START_OLD:
2023 return snd_timer_user_start(file);
2024 case SNDRV_TIMER_IOCTL_STOP:
2025 case SNDRV_TIMER_IOCTL_STOP_OLD:
2026 return snd_timer_user_stop(file);
2027 case SNDRV_TIMER_IOCTL_CONTINUE:
2028 case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2029 return snd_timer_user_continue(file);
2030 case SNDRV_TIMER_IOCTL_PAUSE:
2031 case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2032 return snd_timer_user_pause(file);
2033 }
2034 return -ENOTTY;
2035 }
2036
snd_timer_user_ioctl(struct file * file,unsigned int cmd,unsigned long arg)2037 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2038 unsigned long arg)
2039 {
2040 struct snd_timer_user *tu = file->private_data;
2041 long ret;
2042
2043 mutex_lock(&tu->ioctl_lock);
2044 ret = __snd_timer_user_ioctl(file, cmd, arg);
2045 mutex_unlock(&tu->ioctl_lock);
2046 return ret;
2047 }
2048
snd_timer_user_fasync(int fd,struct file * file,int on)2049 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2050 {
2051 struct snd_timer_user *tu;
2052
2053 tu = file->private_data;
2054 return snd_fasync_helper(fd, file, on, &tu->fasync);
2055 }
2056
snd_timer_user_read(struct file * file,char __user * buffer,size_t count,loff_t * offset)2057 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2058 size_t count, loff_t *offset)
2059 {
2060 struct snd_timer_user *tu;
2061 long result = 0, unit;
2062 int qhead;
2063 int err = 0;
2064
2065 tu = file->private_data;
2066 unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
2067 mutex_lock(&tu->ioctl_lock);
2068 spin_lock_irq(&tu->qlock);
2069 while ((long)count - result >= unit) {
2070 while (!tu->qused) {
2071 wait_queue_entry_t wait;
2072
2073 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2074 err = -EAGAIN;
2075 goto _error;
2076 }
2077
2078 set_current_state(TASK_INTERRUPTIBLE);
2079 init_waitqueue_entry(&wait, current);
2080 add_wait_queue(&tu->qchange_sleep, &wait);
2081
2082 spin_unlock_irq(&tu->qlock);
2083 mutex_unlock(&tu->ioctl_lock);
2084 schedule();
2085 mutex_lock(&tu->ioctl_lock);
2086 spin_lock_irq(&tu->qlock);
2087
2088 remove_wait_queue(&tu->qchange_sleep, &wait);
2089
2090 if (tu->disconnected) {
2091 err = -ENODEV;
2092 goto _error;
2093 }
2094 if (signal_pending(current)) {
2095 err = -ERESTARTSYS;
2096 goto _error;
2097 }
2098 }
2099
2100 qhead = tu->qhead++;
2101 tu->qhead %= tu->queue_size;
2102 tu->qused--;
2103 spin_unlock_irq(&tu->qlock);
2104
2105 if (tu->tread) {
2106 if (copy_to_user(buffer, &tu->tqueue[qhead],
2107 sizeof(struct snd_timer_tread)))
2108 err = -EFAULT;
2109 } else {
2110 if (copy_to_user(buffer, &tu->queue[qhead],
2111 sizeof(struct snd_timer_read)))
2112 err = -EFAULT;
2113 }
2114
2115 spin_lock_irq(&tu->qlock);
2116 if (err < 0)
2117 goto _error;
2118 result += unit;
2119 buffer += unit;
2120 }
2121 _error:
2122 spin_unlock_irq(&tu->qlock);
2123 mutex_unlock(&tu->ioctl_lock);
2124 return result > 0 ? result : err;
2125 }
2126
snd_timer_user_poll(struct file * file,poll_table * wait)2127 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2128 {
2129 __poll_t mask;
2130 struct snd_timer_user *tu;
2131
2132 tu = file->private_data;
2133
2134 poll_wait(file, &tu->qchange_sleep, wait);
2135
2136 mask = 0;
2137 spin_lock_irq(&tu->qlock);
2138 if (tu->qused)
2139 mask |= EPOLLIN | EPOLLRDNORM;
2140 if (tu->disconnected)
2141 mask |= EPOLLERR;
2142 spin_unlock_irq(&tu->qlock);
2143
2144 return mask;
2145 }
2146
2147 #ifdef CONFIG_COMPAT
2148 #include "timer_compat.c"
2149 #else
2150 #define snd_timer_user_ioctl_compat NULL
2151 #endif
2152
2153 static const struct file_operations snd_timer_f_ops =
2154 {
2155 .owner = THIS_MODULE,
2156 .read = snd_timer_user_read,
2157 .open = snd_timer_user_open,
2158 .release = snd_timer_user_release,
2159 .llseek = no_llseek,
2160 .poll = snd_timer_user_poll,
2161 .unlocked_ioctl = snd_timer_user_ioctl,
2162 .compat_ioctl = snd_timer_user_ioctl_compat,
2163 .fasync = snd_timer_user_fasync,
2164 };
2165
2166 /* unregister the system timer */
snd_timer_free_all(void)2167 static void snd_timer_free_all(void)
2168 {
2169 struct snd_timer *timer, *n;
2170
2171 list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2172 snd_timer_free(timer);
2173 }
2174
2175 static struct device timer_dev;
2176
2177 /*
2178 * ENTRY functions
2179 */
2180
alsa_timer_init(void)2181 static int __init alsa_timer_init(void)
2182 {
2183 int err;
2184
2185 snd_device_initialize(&timer_dev, NULL);
2186 dev_set_name(&timer_dev, "timer");
2187
2188 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2189 snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2190 "system timer");
2191 #endif
2192
2193 err = snd_timer_register_system();
2194 if (err < 0) {
2195 pr_err("ALSA: unable to register system timer (%i)\n", err);
2196 goto put_timer;
2197 }
2198
2199 err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2200 &snd_timer_f_ops, NULL, &timer_dev);
2201 if (err < 0) {
2202 pr_err("ALSA: unable to register timer device (%i)\n", err);
2203 snd_timer_free_all();
2204 goto put_timer;
2205 }
2206
2207 snd_timer_proc_init();
2208 return 0;
2209
2210 put_timer:
2211 put_device(&timer_dev);
2212 return err;
2213 }
2214
alsa_timer_exit(void)2215 static void __exit alsa_timer_exit(void)
2216 {
2217 snd_unregister_device(&timer_dev);
2218 snd_timer_free_all();
2219 put_device(&timer_dev);
2220 snd_timer_proc_done();
2221 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2222 snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2223 #endif
2224 }
2225
2226 module_init(alsa_timer_init)
2227 module_exit(alsa_timer_exit)
2228