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TOMOYO Linux Cross Reference
Linux/sound/core/timer.c

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

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