[ALSA] Fix a deadlock in snd-rtctimer
[safe/jmp/linux-2.6] / sound / core / timer.c
1 /*
2  *  Timers abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21
22 #include <sound/driver.h>
23 #include <linux/delay.h>
24 #include <linux/init.h>
25 #include <linux/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/time.h>
28 #include <linux/mutex.h>
29 #include <linux/moduleparam.h>
30 #include <linux/string.h>
31 #include <sound/core.h>
32 #include <sound/timer.h>
33 #include <sound/control.h>
34 #include <sound/info.h>
35 #include <sound/minors.h>
36 #include <sound/initval.h>
37 #include <linux/kmod.h>
38 #ifdef CONFIG_KERNELD
39 #include <linux/kerneld.h>
40 #endif
41
42 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
43 #define DEFAULT_TIMER_LIMIT 3
44 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
45 #define DEFAULT_TIMER_LIMIT 2
46 #else
47 #define DEFAULT_TIMER_LIMIT 1
48 #endif
49
50 static int timer_limit = DEFAULT_TIMER_LIMIT;
51 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Takashi Iwai <tiwai@suse.de>");
52 MODULE_DESCRIPTION("ALSA timer interface");
53 MODULE_LICENSE("GPL");
54 module_param(timer_limit, int, 0444);
55 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
56
57 struct snd_timer_user {
58         struct snd_timer_instance *timeri;
59         int tread;              /* enhanced read with timestamps and events */
60         unsigned long ticks;
61         unsigned long overrun;
62         int qhead;
63         int qtail;
64         int qused;
65         int queue_size;
66         struct snd_timer_read *queue;
67         struct snd_timer_tread *tqueue;
68         spinlock_t qlock;
69         unsigned long last_resolution;
70         unsigned int filter;
71         struct timespec tstamp;         /* trigger tstamp */
72         wait_queue_head_t qchange_sleep;
73         struct fasync_struct *fasync;
74         struct mutex tread_sem;
75 };
76
77 /* list of timers */
78 static LIST_HEAD(snd_timer_list);
79
80 /* list of slave instances */
81 static LIST_HEAD(snd_timer_slave_list);
82
83 /* lock for slave active lists */
84 static DEFINE_SPINLOCK(slave_active_lock);
85
86 static DEFINE_MUTEX(register_mutex);
87
88 static int snd_timer_free(struct snd_timer *timer);
89 static int snd_timer_dev_free(struct snd_device *device);
90 static int snd_timer_dev_register(struct snd_device *device);
91 static int snd_timer_dev_unregister(struct snd_device *device);
92
93 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
94
95 /*
96  * create a timer instance with the given owner string.
97  * when timer is not NULL, increments the module counter
98  */
99 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
100                                                          struct snd_timer *timer)
101 {
102         struct snd_timer_instance *timeri;
103         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
104         if (timeri == NULL)
105                 return NULL;
106         timeri->owner = kstrdup(owner, GFP_KERNEL);
107         if (! timeri->owner) {
108                 kfree(timeri);
109                 return NULL;
110         }
111         INIT_LIST_HEAD(&timeri->open_list);
112         INIT_LIST_HEAD(&timeri->active_list);
113         INIT_LIST_HEAD(&timeri->ack_list);
114         INIT_LIST_HEAD(&timeri->slave_list_head);
115         INIT_LIST_HEAD(&timeri->slave_active_head);
116
117         timeri->timer = timer;
118         if (timer && !try_module_get(timer->module)) {
119                 kfree(timeri->owner);
120                 kfree(timeri);
121                 return NULL;
122         }
123
124         return timeri;
125 }
126
127 /*
128  * find a timer instance from the given timer id
129  */
130 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
131 {
132         struct snd_timer *timer = NULL;
133         struct list_head *p;
134
135         list_for_each(p, &snd_timer_list) {
136                 timer = list_entry(p, struct snd_timer, device_list);
137
138                 if (timer->tmr_class != tid->dev_class)
139                         continue;
140                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
141                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
142                     (timer->card == NULL ||
143                      timer->card->number != tid->card))
144                         continue;
145                 if (timer->tmr_device != tid->device)
146                         continue;
147                 if (timer->tmr_subdevice != tid->subdevice)
148                         continue;
149                 return timer;
150         }
151         return NULL;
152 }
153
154 #ifdef CONFIG_KMOD
155
156 static void snd_timer_request(struct snd_timer_id *tid)
157 {
158         if (! current->fs->root)
159                 return;
160         switch (tid->dev_class) {
161         case SNDRV_TIMER_CLASS_GLOBAL:
162                 if (tid->device < timer_limit)
163                         request_module("snd-timer-%i", tid->device);
164                 break;
165         case SNDRV_TIMER_CLASS_CARD:
166         case SNDRV_TIMER_CLASS_PCM:
167                 if (tid->card < snd_ecards_limit)
168                         request_module("snd-card-%i", tid->card);
169                 break;
170         default:
171                 break;
172         }
173 }
174
175 #endif
176
177 /*
178  * look for a master instance matching with the slave id of the given slave.
179  * when found, relink the open_link of the slave.
180  *
181  * call this with register_mutex down.
182  */
183 static void snd_timer_check_slave(struct snd_timer_instance *slave)
184 {
185         struct snd_timer *timer;
186         struct snd_timer_instance *master;
187         struct list_head *p, *q;
188
189         /* FIXME: it's really dumb to look up all entries.. */
190         list_for_each(p, &snd_timer_list) {
191                 timer = list_entry(p, struct snd_timer, device_list);
192                 list_for_each(q, &timer->open_list_head) {
193                         master = list_entry(q, struct snd_timer_instance, open_list);
194                         if (slave->slave_class == master->slave_class &&
195                             slave->slave_id == master->slave_id) {
196                                 list_del(&slave->open_list);
197                                 list_add_tail(&slave->open_list,
198                                               &master->slave_list_head);
199                                 spin_lock_irq(&slave_active_lock);
200                                 slave->master = master;
201                                 slave->timer = master->timer;
202                                 spin_unlock_irq(&slave_active_lock);
203                                 return;
204                         }
205                 }
206         }
207 }
208
209 /*
210  * look for slave instances matching with the slave id of the given master.
211  * when found, relink the open_link of slaves.
212  *
213  * call this with register_mutex down.
214  */
215 static void snd_timer_check_master(struct snd_timer_instance *master)
216 {
217         struct snd_timer_instance *slave;
218         struct list_head *p, *n;
219
220         /* check all pending slaves */
221         list_for_each_safe(p, n, &snd_timer_slave_list) {
222                 slave = list_entry(p, struct snd_timer_instance, open_list);
223                 if (slave->slave_class == master->slave_class &&
224                     slave->slave_id == master->slave_id) {
225                         list_del(p);
226                         list_add_tail(p, &master->slave_list_head);
227                         spin_lock_irq(&slave_active_lock);
228                         slave->master = master;
229                         slave->timer = master->timer;
230                         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
231                                 list_add_tail(&slave->active_list,
232                                               &master->slave_active_head);
233                         spin_unlock_irq(&slave_active_lock);
234                 }
235         }
236 }
237
238 /*
239  * open a timer instance
240  * when opening a master, the slave id must be here given.
241  */
242 int snd_timer_open(struct snd_timer_instance **ti,
243                    char *owner, struct snd_timer_id *tid,
244                    unsigned int slave_id)
245 {
246         struct snd_timer *timer;
247         struct snd_timer_instance *timeri = NULL;
248
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                         snd_printd("invalid slave class %i\n", tid->dev_sclass);
254                         return -EINVAL;
255                 }
256                 mutex_lock(&register_mutex);
257                 timeri = snd_timer_instance_new(owner, NULL);
258                 if (!timeri) {
259                         mutex_unlock(&register_mutex);
260                         return -ENOMEM;
261                 }
262                 timeri->slave_class = tid->dev_sclass;
263                 timeri->slave_id = tid->device;
264                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
265                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
266                 snd_timer_check_slave(timeri);
267                 mutex_unlock(&register_mutex);
268                 *ti = timeri;
269                 return 0;
270         }
271
272         /* open a master instance */
273         mutex_lock(&register_mutex);
274         timer = snd_timer_find(tid);
275 #ifdef CONFIG_KMOD
276         if (timer == NULL) {
277                 mutex_unlock(&register_mutex);
278                 snd_timer_request(tid);
279                 mutex_lock(&register_mutex);
280                 timer = snd_timer_find(tid);
281         }
282 #endif
283         if (!timer) {
284                 mutex_unlock(&register_mutex);
285                 return -ENODEV;
286         }
287         if (!list_empty(&timer->open_list_head)) {
288                 timeri = list_entry(timer->open_list_head.next,
289                                     struct snd_timer_instance, open_list);
290                 if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
291                         mutex_unlock(&register_mutex);
292                         return -EBUSY;
293                 }
294         }
295         timeri = snd_timer_instance_new(owner, timer);
296         if (!timeri) {
297                 mutex_unlock(&register_mutex);
298                 return -ENOMEM;
299         }
300         timeri->slave_class = tid->dev_sclass;
301         timeri->slave_id = slave_id;
302         if (list_empty(&timer->open_list_head) && timer->hw.open)
303                 timer->hw.open(timer);
304         list_add_tail(&timeri->open_list, &timer->open_list_head);
305         snd_timer_check_master(timeri);
306         mutex_unlock(&register_mutex);
307         *ti = timeri;
308         return 0;
309 }
310
311 static int _snd_timer_stop(struct snd_timer_instance *timeri,
312                            int keep_flag, int event);
313
314 /*
315  * close a timer instance
316  */
317 int snd_timer_close(struct snd_timer_instance *timeri)
318 {
319         struct snd_timer *timer = NULL;
320         struct list_head *p, *n;
321         struct snd_timer_instance *slave;
322
323         snd_assert(timeri != NULL, return -ENXIO);
324
325         /* force to stop the timer */
326         snd_timer_stop(timeri);
327
328         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
329                 /* wait, until the active callback is finished */
330                 spin_lock_irq(&slave_active_lock);
331                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
332                         spin_unlock_irq(&slave_active_lock);
333                         udelay(10);
334                         spin_lock_irq(&slave_active_lock);
335                 }
336                 spin_unlock_irq(&slave_active_lock);
337                 mutex_lock(&register_mutex);
338                 list_del(&timeri->open_list);
339                 mutex_unlock(&register_mutex);
340         } else {
341                 timer = timeri->timer;
342                 /* wait, until the active callback is finished */
343                 spin_lock_irq(&timer->lock);
344                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
345                         spin_unlock_irq(&timer->lock);
346                         udelay(10);
347                         spin_lock_irq(&timer->lock);
348                 }
349                 spin_unlock_irq(&timer->lock);
350                 mutex_lock(&register_mutex);
351                 list_del(&timeri->open_list);
352                 if (timer && list_empty(&timer->open_list_head) &&
353                     timer->hw.close)
354                         timer->hw.close(timer);
355                 /* remove slave links */
356                 list_for_each_safe(p, n, &timeri->slave_list_head) {
357                         slave = list_entry(p, struct snd_timer_instance, open_list);
358                         spin_lock_irq(&slave_active_lock);
359                         _snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
360                         list_del(p);
361                         list_add_tail(p, &snd_timer_slave_list);
362                         slave->master = NULL;
363                         slave->timer = NULL;
364                         spin_unlock_irq(&slave_active_lock);
365                 }
366                 mutex_unlock(&register_mutex);
367         }
368         if (timeri->private_free)
369                 timeri->private_free(timeri);
370         kfree(timeri->owner);
371         kfree(timeri);
372         if (timer)
373                 module_put(timer->module);
374         return 0;
375 }
376
377 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
378 {
379         struct snd_timer * timer;
380
381         if (timeri == NULL)
382                 return 0;
383         if ((timer = timeri->timer) != NULL) {
384                 if (timer->hw.c_resolution)
385                         return timer->hw.c_resolution(timer);
386                 return timer->hw.resolution;
387         }
388         return 0;
389 }
390
391 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
392 {
393         struct snd_timer *timer;
394         unsigned long flags;
395         unsigned long resolution = 0;
396         struct snd_timer_instance *ts;
397         struct list_head *n;
398         struct timespec tstamp;
399
400         getnstimeofday(&tstamp);
401         snd_assert(event >= SNDRV_TIMER_EVENT_START &&
402                    event <= SNDRV_TIMER_EVENT_PAUSE, return);
403         if (event == SNDRV_TIMER_EVENT_START ||
404             event == SNDRV_TIMER_EVENT_CONTINUE)
405                 resolution = snd_timer_resolution(ti);
406         if (ti->ccallback)
407                 ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
408         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
409                 return;
410         timer = ti->timer;
411         if (timer == NULL)
412                 return;
413         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
414                 return;
415         spin_lock_irqsave(&timer->lock, flags);
416         list_for_each(n, &ti->slave_active_head) {
417                 ts = list_entry(n, struct snd_timer_instance, active_list);
418                 if (ts->ccallback)
419                         ts->ccallback(ti, event + 100, &tstamp, resolution);
420         }
421         spin_unlock_irqrestore(&timer->lock, flags);
422 }
423
424 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
425                             unsigned long sticks)
426 {
427         list_del(&timeri->active_list);
428         list_add_tail(&timeri->active_list, &timer->active_list_head);
429         if (timer->running) {
430                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
431                         goto __start_now;
432                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
433                 timeri->flags |= SNDRV_TIMER_IFLG_START;
434                 return 1;       /* delayed start */
435         } else {
436                 timer->sticks = sticks;
437                 timer->hw.start(timer);
438               __start_now:
439                 timer->running++;
440                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
441                 return 0;
442         }
443 }
444
445 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
446 {
447         unsigned long flags;
448
449         spin_lock_irqsave(&slave_active_lock, flags);
450         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
451         if (timeri->master)
452                 list_add_tail(&timeri->active_list,
453                               &timeri->master->slave_active_head);
454         spin_unlock_irqrestore(&slave_active_lock, flags);
455         return 1; /* delayed start */
456 }
457
458 /*
459  *  start the timer instance
460  */
461 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
462 {
463         struct snd_timer *timer;
464         int result = -EINVAL;
465         unsigned long flags;
466
467         if (timeri == NULL || ticks < 1)
468                 return -EINVAL;
469         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
470                 result = snd_timer_start_slave(timeri);
471                 snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
472                 return result;
473         }
474         timer = timeri->timer;
475         if (timer == NULL)
476                 return -EINVAL;
477         spin_lock_irqsave(&timer->lock, flags);
478         timeri->ticks = timeri->cticks = ticks;
479         timeri->pticks = 0;
480         result = snd_timer_start1(timer, timeri, ticks);
481         spin_unlock_irqrestore(&timer->lock, flags);
482         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
483         return result;
484 }
485
486 static int _snd_timer_stop(struct snd_timer_instance * timeri,
487                            int keep_flag, int event)
488 {
489         struct snd_timer *timer;
490         unsigned long flags;
491
492         snd_assert(timeri != NULL, return -ENXIO);
493
494         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
495                 if (!keep_flag) {
496                         spin_lock_irqsave(&slave_active_lock, flags);
497                         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
498                         spin_unlock_irqrestore(&slave_active_lock, flags);
499                 }
500                 goto __end;
501         }
502         timer = timeri->timer;
503         if (!timer)
504                 return -EINVAL;
505         spin_lock_irqsave(&timer->lock, flags);
506         list_del_init(&timeri->ack_list);
507         list_del_init(&timeri->active_list);
508         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
509             !(--timer->running)) {
510                 timer->hw.stop(timer);
511                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
512                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
513                         snd_timer_reschedule(timer, 0);
514                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
515                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
516                                 timer->hw.start(timer);
517                         }
518                 }
519         }
520         if (!keep_flag)
521                 timeri->flags &=
522                         ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
523         spin_unlock_irqrestore(&timer->lock, flags);
524       __end:
525         if (event != SNDRV_TIMER_EVENT_RESOLUTION)
526                 snd_timer_notify1(timeri, event);
527         return 0;
528 }
529
530 /*
531  * stop the timer instance.
532  *
533  * do not call this from the timer callback!
534  */
535 int snd_timer_stop(struct snd_timer_instance *timeri)
536 {
537         struct snd_timer *timer;
538         unsigned long flags;
539         int err;
540
541         err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
542         if (err < 0)
543                 return err;
544         timer = timeri->timer;
545         spin_lock_irqsave(&timer->lock, flags);
546         timeri->cticks = timeri->ticks;
547         timeri->pticks = 0;
548         spin_unlock_irqrestore(&timer->lock, flags);
549         return 0;
550 }
551
552 /*
553  * start again..  the tick is kept.
554  */
555 int snd_timer_continue(struct snd_timer_instance *timeri)
556 {
557         struct snd_timer *timer;
558         int result = -EINVAL;
559         unsigned long flags;
560
561         if (timeri == NULL)
562                 return result;
563         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
564                 return snd_timer_start_slave(timeri);
565         timer = timeri->timer;
566         if (! timer)
567                 return -EINVAL;
568         spin_lock_irqsave(&timer->lock, flags);
569         if (!timeri->cticks)
570                 timeri->cticks = 1;
571         timeri->pticks = 0;
572         result = snd_timer_start1(timer, timeri, timer->sticks);
573         spin_unlock_irqrestore(&timer->lock, flags);
574         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
575         return result;
576 }
577
578 /*
579  * pause.. remember the ticks left
580  */
581 int snd_timer_pause(struct snd_timer_instance * timeri)
582 {
583         return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
584 }
585
586 /*
587  * reschedule the timer
588  *
589  * start pending instances and check the scheduling ticks.
590  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
591  */
592 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
593 {
594         struct snd_timer_instance *ti;
595         unsigned long ticks = ~0UL;
596         struct list_head *p;
597
598         list_for_each(p, &timer->active_list_head) {
599                 ti = list_entry(p, struct snd_timer_instance, active_list);
600                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
601                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
602                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
603                         timer->running++;
604                 }
605                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
606                         if (ticks > ti->cticks)
607                                 ticks = ti->cticks;
608                 }
609         }
610         if (ticks == ~0UL) {
611                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
612                 return;
613         }
614         if (ticks > timer->hw.ticks)
615                 ticks = timer->hw.ticks;
616         if (ticks_left != ticks)
617                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
618         timer->sticks = ticks;
619 }
620
621 /*
622  * timer tasklet
623  *
624  */
625 static void snd_timer_tasklet(unsigned long arg)
626 {
627         struct snd_timer *timer = (struct snd_timer *) arg;
628         struct snd_timer_instance *ti;
629         struct list_head *p;
630         unsigned long resolution, ticks;
631         unsigned long flags;
632
633         spin_lock_irqsave(&timer->lock, flags);
634         /* now process all callbacks */
635         while (!list_empty(&timer->sack_list_head)) {
636                 p = timer->sack_list_head.next;         /* get first item */
637                 ti = list_entry(p, struct snd_timer_instance, ack_list);
638
639                 /* remove from ack_list and make empty */
640                 list_del_init(p);
641
642                 ticks = ti->pticks;
643                 ti->pticks = 0;
644                 resolution = ti->resolution;
645
646                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
647                 spin_unlock(&timer->lock);
648                 if (ti->callback)
649                         ti->callback(ti, resolution, ticks);
650                 spin_lock(&timer->lock);
651                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
652         }
653         spin_unlock_irqrestore(&timer->lock, flags);
654 }
655
656 /*
657  * timer interrupt
658  *
659  * ticks_left is usually equal to timer->sticks.
660  *
661  */
662 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
663 {
664         struct snd_timer_instance *ti, *ts;
665         unsigned long resolution, ticks;
666         struct list_head *p, *q, *n, *ack_list_head;
667         unsigned long flags;
668         int use_tasklet = 0;
669
670         if (timer == NULL)
671                 return;
672
673         spin_lock_irqsave(&timer->lock, flags);
674
675         /* remember the current resolution */
676         if (timer->hw.c_resolution)
677                 resolution = timer->hw.c_resolution(timer);
678         else
679                 resolution = timer->hw.resolution;
680
681         /* loop for all active instances
682          * Here we cannot use list_for_each because the active_list of a
683          * processed instance is relinked to done_list_head before the callback
684          * is called.
685          */
686         list_for_each_safe(p, n, &timer->active_list_head) {
687                 ti = list_entry(p, struct snd_timer_instance, active_list);
688                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
689                         continue;
690                 ti->pticks += ticks_left;
691                 ti->resolution = resolution;
692                 if (ti->cticks < ticks_left)
693                         ti->cticks = 0;
694                 else
695                         ti->cticks -= ticks_left;
696                 if (ti->cticks) /* not expired */
697                         continue;
698                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
699                         ti->cticks = ti->ticks;
700                 } else {
701                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
702                         if (--timer->running)
703                                 list_del(p);
704                 }
705                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
706                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
707                         ack_list_head = &timer->ack_list_head;
708                 else
709                         ack_list_head = &timer->sack_list_head;
710                 if (list_empty(&ti->ack_list))
711                         list_add_tail(&ti->ack_list, ack_list_head);
712                 list_for_each(q, &ti->slave_active_head) {
713                         ts = list_entry(q, struct snd_timer_instance, active_list);
714                         ts->pticks = ti->pticks;
715                         ts->resolution = resolution;
716                         if (list_empty(&ts->ack_list))
717                                 list_add_tail(&ts->ack_list, ack_list_head);
718                 }
719         }
720         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
721                 snd_timer_reschedule(timer, ticks_left);
722         if (timer->running) {
723                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
724                         timer->hw.stop(timer);
725                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
726                 }
727                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
728                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
729                         /* restart timer */
730                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
731                         timer->hw.start(timer);
732                 }
733         } else {
734                 timer->hw.stop(timer);
735         }
736
737         /* now process all fast callbacks */
738         while (!list_empty(&timer->ack_list_head)) {
739                 p = timer->ack_list_head.next;          /* get first item */
740                 ti = list_entry(p, struct snd_timer_instance, ack_list);
741
742                 /* remove from ack_list and make empty */
743                 list_del_init(p);
744
745                 ticks = ti->pticks;
746                 ti->pticks = 0;
747
748                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
749                 spin_unlock(&timer->lock);
750                 if (ti->callback)
751                         ti->callback(ti, resolution, ticks);
752                 spin_lock(&timer->lock);
753                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
754         }
755
756         /* do we have any slow callbacks? */
757         use_tasklet = !list_empty(&timer->sack_list_head);
758         spin_unlock_irqrestore(&timer->lock, flags);
759
760         if (use_tasklet)
761                 tasklet_hi_schedule(&timer->task_queue);
762 }
763
764 /*
765
766  */
767
768 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
769                   struct snd_timer **rtimer)
770 {
771         struct snd_timer *timer;
772         int err;
773         static struct snd_device_ops ops = {
774                 .dev_free = snd_timer_dev_free,
775                 .dev_register = snd_timer_dev_register,
776                 .dev_unregister = snd_timer_dev_unregister
777         };
778
779         snd_assert(tid != NULL, return -EINVAL);
780         snd_assert(rtimer != NULL, return -EINVAL);
781         *rtimer = NULL;
782         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
783         if (timer == NULL) {
784                 snd_printk(KERN_ERR "timer: cannot allocate\n");
785                 return -ENOMEM;
786         }
787         timer->tmr_class = tid->dev_class;
788         timer->card = card;
789         timer->tmr_device = tid->device;
790         timer->tmr_subdevice = tid->subdevice;
791         if (id)
792                 strlcpy(timer->id, id, sizeof(timer->id));
793         INIT_LIST_HEAD(&timer->device_list);
794         INIT_LIST_HEAD(&timer->open_list_head);
795         INIT_LIST_HEAD(&timer->active_list_head);
796         INIT_LIST_HEAD(&timer->ack_list_head);
797         INIT_LIST_HEAD(&timer->sack_list_head);
798         spin_lock_init(&timer->lock);
799         tasklet_init(&timer->task_queue, snd_timer_tasklet,
800                      (unsigned long)timer);
801         if (card != NULL) {
802                 timer->module = card->module;
803                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
804                 if (err < 0) {
805                         snd_timer_free(timer);
806                         return err;
807                 }
808         }
809         *rtimer = timer;
810         return 0;
811 }
812
813 static int snd_timer_free(struct snd_timer *timer)
814 {
815         snd_assert(timer != NULL, return -ENXIO);
816         if (timer->private_free)
817                 timer->private_free(timer);
818         kfree(timer);
819         return 0;
820 }
821
822 static int snd_timer_dev_free(struct snd_device *device)
823 {
824         struct snd_timer *timer = device->device_data;
825         return snd_timer_free(timer);
826 }
827
828 static int snd_timer_dev_register(struct snd_device *dev)
829 {
830         struct snd_timer *timer = dev->device_data;
831         struct snd_timer *timer1;
832         struct list_head *p;
833
834         snd_assert(timer != NULL && timer->hw.start != NULL &&
835                    timer->hw.stop != NULL, return -ENXIO);
836         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
837             !timer->hw.resolution && timer->hw.c_resolution == NULL)
838                 return -EINVAL;
839
840         mutex_lock(&register_mutex);
841         list_for_each(p, &snd_timer_list) {
842                 timer1 = list_entry(p, struct snd_timer, device_list);
843                 if (timer1->tmr_class > timer->tmr_class)
844                         break;
845                 if (timer1->tmr_class < timer->tmr_class)
846                         continue;
847                 if (timer1->card && timer->card) {
848                         if (timer1->card->number > timer->card->number)
849                                 break;
850                         if (timer1->card->number < timer->card->number)
851                                 continue;
852                 }
853                 if (timer1->tmr_device > timer->tmr_device)
854                         break;
855                 if (timer1->tmr_device < timer->tmr_device)
856                         continue;
857                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
858                         break;
859                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
860                         continue;
861                 /* conflicts.. */
862                 mutex_unlock(&register_mutex);
863                 return -EBUSY;
864         }
865         list_add_tail(&timer->device_list, p);
866         mutex_unlock(&register_mutex);
867         return 0;
868 }
869
870 static int snd_timer_unregister(struct snd_timer *timer)
871 {
872         struct list_head *p, *n;
873         struct snd_timer_instance *ti;
874
875         snd_assert(timer != NULL, return -ENXIO);
876         mutex_lock(&register_mutex);
877         if (! list_empty(&timer->open_list_head)) {
878                 snd_printk(KERN_WARNING "timer 0x%lx is busy?\n", (long)timer);
879                 list_for_each_safe(p, n, &timer->open_list_head) {
880                         list_del_init(p);
881                         ti = list_entry(p, struct snd_timer_instance, open_list);
882                         ti->timer = NULL;
883                 }
884         }
885         list_del(&timer->device_list);
886         mutex_unlock(&register_mutex);
887         return snd_timer_free(timer);
888 }
889
890 static int snd_timer_dev_unregister(struct snd_device *device)
891 {
892         struct snd_timer *timer = device->device_data;
893         return snd_timer_unregister(timer);
894 }
895
896 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
897 {
898         unsigned long flags;
899         unsigned long resolution = 0;
900         struct snd_timer_instance *ti, *ts;
901         struct list_head *p, *n;
902
903         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
904                 return;
905         snd_assert(event >= SNDRV_TIMER_EVENT_MSTART &&
906                    event <= SNDRV_TIMER_EVENT_MRESUME, return);
907         spin_lock_irqsave(&timer->lock, flags);
908         if (event == SNDRV_TIMER_EVENT_MSTART ||
909             event == SNDRV_TIMER_EVENT_MCONTINUE ||
910             event == SNDRV_TIMER_EVENT_MRESUME) {
911                 if (timer->hw.c_resolution)
912                         resolution = timer->hw.c_resolution(timer);
913                 else
914                         resolution = timer->hw.resolution;
915         }
916         list_for_each(p, &timer->active_list_head) {
917                 ti = list_entry(p, struct snd_timer_instance, active_list);
918                 if (ti->ccallback)
919                         ti->ccallback(ti, event, tstamp, resolution);
920                 list_for_each(n, &ti->slave_active_head) {
921                         ts = list_entry(n, struct snd_timer_instance, active_list);
922                         if (ts->ccallback)
923                                 ts->ccallback(ts, event, tstamp, resolution);
924                 }
925         }
926         spin_unlock_irqrestore(&timer->lock, flags);
927 }
928
929 /*
930  * exported functions for global timers
931  */
932 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
933 {
934         struct snd_timer_id tid;
935
936         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
937         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
938         tid.card = -1;
939         tid.device = device;
940         tid.subdevice = 0;
941         return snd_timer_new(NULL, id, &tid, rtimer);
942 }
943
944 int snd_timer_global_free(struct snd_timer *timer)
945 {
946         return snd_timer_free(timer);
947 }
948
949 int snd_timer_global_register(struct snd_timer *timer)
950 {
951         struct snd_device dev;
952
953         memset(&dev, 0, sizeof(dev));
954         dev.device_data = timer;
955         return snd_timer_dev_register(&dev);
956 }
957
958 int snd_timer_global_unregister(struct snd_timer *timer)
959 {
960         return snd_timer_unregister(timer);
961 }
962
963 /*
964  *  System timer
965  */
966
967 struct snd_timer_system_private {
968         struct timer_list tlist;
969         struct timer * timer;
970         unsigned long last_expires;
971         unsigned long last_jiffies;
972         unsigned long correction;
973 };
974
975 static void snd_timer_s_function(unsigned long data)
976 {
977         struct snd_timer *timer = (struct snd_timer *)data;
978         struct snd_timer_system_private *priv = timer->private_data;
979         unsigned long jiff = jiffies;
980         if (time_after(jiff, priv->last_expires))
981                 priv->correction = (long)jiff - (long)priv->last_expires;
982         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
983 }
984
985 static int snd_timer_s_start(struct snd_timer * timer)
986 {
987         struct snd_timer_system_private *priv;
988         unsigned long njiff;
989
990         priv = (struct snd_timer_system_private *) timer->private_data;
991         njiff = (priv->last_jiffies = jiffies);
992         if (priv->correction > timer->sticks - 1) {
993                 priv->correction -= timer->sticks - 1;
994                 njiff++;
995         } else {
996                 njiff += timer->sticks - priv->correction;
997                 priv->correction -= timer->sticks;
998         }
999         priv->last_expires = priv->tlist.expires = njiff;
1000         add_timer(&priv->tlist);
1001         return 0;
1002 }
1003
1004 static int snd_timer_s_stop(struct snd_timer * timer)
1005 {
1006         struct snd_timer_system_private *priv;
1007         unsigned long jiff;
1008
1009         priv = (struct snd_timer_system_private *) timer->private_data;
1010         del_timer(&priv->tlist);
1011         jiff = jiffies;
1012         if (time_before(jiff, priv->last_expires))
1013                 timer->sticks = priv->last_expires - jiff;
1014         else
1015                 timer->sticks = 1;
1016         return 0;
1017 }
1018
1019 static struct snd_timer_hardware snd_timer_system =
1020 {
1021         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1022         .resolution =   1000000000L / HZ,
1023         .ticks =        10000000L,
1024         .start =        snd_timer_s_start,
1025         .stop =         snd_timer_s_stop
1026 };
1027
1028 static void snd_timer_free_system(struct snd_timer *timer)
1029 {
1030         kfree(timer->private_data);
1031 }
1032
1033 static int snd_timer_register_system(void)
1034 {
1035         struct snd_timer *timer;
1036         struct snd_timer_system_private *priv;
1037         int err;
1038
1039         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1040         if (err < 0)
1041                 return err;
1042         strcpy(timer->name, "system timer");
1043         timer->hw = snd_timer_system;
1044         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1045         if (priv == NULL) {
1046                 snd_timer_free(timer);
1047                 return -ENOMEM;
1048         }
1049         init_timer(&priv->tlist);
1050         priv->tlist.function = snd_timer_s_function;
1051         priv->tlist.data = (unsigned long) timer;
1052         timer->private_data = priv;
1053         timer->private_free = snd_timer_free_system;
1054         return snd_timer_global_register(timer);
1055 }
1056
1057 #ifdef CONFIG_PROC_FS
1058 /*
1059  *  Info interface
1060  */
1061
1062 static void snd_timer_proc_read(struct snd_info_entry *entry,
1063                                 struct snd_info_buffer *buffer)
1064 {
1065         struct snd_timer *timer;
1066         struct snd_timer_instance *ti;
1067         struct list_head *p, *q;
1068
1069         mutex_lock(&register_mutex);
1070         list_for_each(p, &snd_timer_list) {
1071                 timer = list_entry(p, struct snd_timer, device_list);
1072                 switch (timer->tmr_class) {
1073                 case SNDRV_TIMER_CLASS_GLOBAL:
1074                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1075                         break;
1076                 case SNDRV_TIMER_CLASS_CARD:
1077                         snd_iprintf(buffer, "C%i-%i: ",
1078                                     timer->card->number, timer->tmr_device);
1079                         break;
1080                 case SNDRV_TIMER_CLASS_PCM:
1081                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1082                                     timer->tmr_device, timer->tmr_subdevice);
1083                         break;
1084                 default:
1085                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1086                                     timer->card ? timer->card->number : -1,
1087                                     timer->tmr_device, timer->tmr_subdevice);
1088                 }
1089                 snd_iprintf(buffer, "%s :", timer->name);
1090                 if (timer->hw.resolution)
1091                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1092                                     timer->hw.resolution / 1000,
1093                                     timer->hw.resolution % 1000,
1094                                     timer->hw.ticks);
1095                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1096                         snd_iprintf(buffer, " SLAVE");
1097                 snd_iprintf(buffer, "\n");
1098                 list_for_each(q, &timer->open_list_head) {
1099                         ti = list_entry(q, struct snd_timer_instance, open_list);
1100                         snd_iprintf(buffer, "  Client %s : %s\n",
1101                                     ti->owner ? ti->owner : "unknown",
1102                                     ti->flags & (SNDRV_TIMER_IFLG_START |
1103                                                  SNDRV_TIMER_IFLG_RUNNING)
1104                                     ? "running" : "stopped");
1105                 }
1106         }
1107         mutex_unlock(&register_mutex);
1108 }
1109
1110 static struct snd_info_entry *snd_timer_proc_entry;
1111
1112 static void __init snd_timer_proc_init(void)
1113 {
1114         struct snd_info_entry *entry;
1115
1116         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1117         if (entry != NULL) {
1118                 entry->c.text.read = snd_timer_proc_read;
1119                 if (snd_info_register(entry) < 0) {
1120                         snd_info_free_entry(entry);
1121                         entry = NULL;
1122                 }
1123         }
1124         snd_timer_proc_entry = entry;
1125 }
1126
1127 static void __exit snd_timer_proc_done(void)
1128 {
1129         snd_info_unregister(snd_timer_proc_entry);
1130 }
1131 #else /* !CONFIG_PROC_FS */
1132 #define snd_timer_proc_init()
1133 #define snd_timer_proc_done()
1134 #endif
1135
1136 /*
1137  *  USER SPACE interface
1138  */
1139
1140 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1141                                      unsigned long resolution,
1142                                      unsigned long ticks)
1143 {
1144         struct snd_timer_user *tu = timeri->callback_data;
1145         struct snd_timer_read *r;
1146         int prev;
1147
1148         spin_lock(&tu->qlock);
1149         if (tu->qused > 0) {
1150                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1151                 r = &tu->queue[prev];
1152                 if (r->resolution == resolution) {
1153                         r->ticks += ticks;
1154                         goto __wake;
1155                 }
1156         }
1157         if (tu->qused >= tu->queue_size) {
1158                 tu->overrun++;
1159         } else {
1160                 r = &tu->queue[tu->qtail++];
1161                 tu->qtail %= tu->queue_size;
1162                 r->resolution = resolution;
1163                 r->ticks = ticks;
1164                 tu->qused++;
1165         }
1166       __wake:
1167         spin_unlock(&tu->qlock);
1168         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1169         wake_up(&tu->qchange_sleep);
1170 }
1171
1172 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1173                                             struct snd_timer_tread *tread)
1174 {
1175         if (tu->qused >= tu->queue_size) {
1176                 tu->overrun++;
1177         } else {
1178                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1179                 tu->qtail %= tu->queue_size;
1180                 tu->qused++;
1181         }
1182 }
1183
1184 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1185                                      int event,
1186                                      struct timespec *tstamp,
1187                                      unsigned long resolution)
1188 {
1189         struct snd_timer_user *tu = timeri->callback_data;
1190         struct snd_timer_tread r1;
1191
1192         if (event >= SNDRV_TIMER_EVENT_START &&
1193             event <= SNDRV_TIMER_EVENT_PAUSE)
1194                 tu->tstamp = *tstamp;
1195         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1196                 return;
1197         r1.event = event;
1198         r1.tstamp = *tstamp;
1199         r1.val = resolution;
1200         spin_lock(&tu->qlock);
1201         snd_timer_user_append_to_tqueue(tu, &r1);
1202         spin_unlock(&tu->qlock);
1203         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1204         wake_up(&tu->qchange_sleep);
1205 }
1206
1207 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1208                                       unsigned long resolution,
1209                                       unsigned long ticks)
1210 {
1211         struct snd_timer_user *tu = timeri->callback_data;
1212         struct snd_timer_tread *r, r1;
1213         struct timespec tstamp;
1214         int prev, append = 0;
1215
1216         memset(&tstamp, 0, sizeof(tstamp));
1217         spin_lock(&tu->qlock);
1218         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1219                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1220                 spin_unlock(&tu->qlock);
1221                 return;
1222         }
1223         if (tu->last_resolution != resolution || ticks > 0)
1224                 getnstimeofday(&tstamp);
1225         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1226             tu->last_resolution != resolution) {
1227                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1228                 r1.tstamp = tstamp;
1229                 r1.val = resolution;
1230                 snd_timer_user_append_to_tqueue(tu, &r1);
1231                 tu->last_resolution = resolution;
1232                 append++;
1233         }
1234         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1235                 goto __wake;
1236         if (ticks == 0)
1237                 goto __wake;
1238         if (tu->qused > 0) {
1239                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1240                 r = &tu->tqueue[prev];
1241                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1242                         r->tstamp = tstamp;
1243                         r->val += ticks;
1244                         append++;
1245                         goto __wake;
1246                 }
1247         }
1248         r1.event = SNDRV_TIMER_EVENT_TICK;
1249         r1.tstamp = tstamp;
1250         r1.val = ticks;
1251         snd_timer_user_append_to_tqueue(tu, &r1);
1252         append++;
1253       __wake:
1254         spin_unlock(&tu->qlock);
1255         if (append == 0)
1256                 return;
1257         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1258         wake_up(&tu->qchange_sleep);
1259 }
1260
1261 static int snd_timer_user_open(struct inode *inode, struct file *file)
1262 {
1263         struct snd_timer_user *tu;
1264
1265         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1266         if (tu == NULL)
1267                 return -ENOMEM;
1268         spin_lock_init(&tu->qlock);
1269         init_waitqueue_head(&tu->qchange_sleep);
1270         mutex_init(&tu->tread_sem);
1271         tu->ticks = 1;
1272         tu->queue_size = 128;
1273         tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1274                             GFP_KERNEL);
1275         if (tu->queue == NULL) {
1276                 kfree(tu);
1277                 return -ENOMEM;
1278         }
1279         file->private_data = tu;
1280         return 0;
1281 }
1282
1283 static int snd_timer_user_release(struct inode *inode, struct file *file)
1284 {
1285         struct snd_timer_user *tu;
1286
1287         if (file->private_data) {
1288                 tu = file->private_data;
1289                 file->private_data = NULL;
1290                 fasync_helper(-1, file, 0, &tu->fasync);
1291                 if (tu->timeri)
1292                         snd_timer_close(tu->timeri);
1293                 kfree(tu->queue);
1294                 kfree(tu->tqueue);
1295                 kfree(tu);
1296         }
1297         return 0;
1298 }
1299
1300 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1301 {
1302         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1303         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1304         id->card = -1;
1305         id->device = -1;
1306         id->subdevice = -1;
1307 }
1308
1309 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1310 {
1311         id->dev_class = timer->tmr_class;
1312         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1313         id->card = timer->card ? timer->card->number : -1;
1314         id->device = timer->tmr_device;
1315         id->subdevice = timer->tmr_subdevice;
1316 }
1317
1318 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1319 {
1320         struct snd_timer_id id;
1321         struct snd_timer *timer;
1322         struct list_head *p;
1323
1324         if (copy_from_user(&id, _tid, sizeof(id)))
1325                 return -EFAULT;
1326         mutex_lock(&register_mutex);
1327         if (id.dev_class < 0) {         /* first item */
1328                 if (list_empty(&snd_timer_list))
1329                         snd_timer_user_zero_id(&id);
1330                 else {
1331                         timer = list_entry(snd_timer_list.next,
1332                                            struct snd_timer, device_list);
1333                         snd_timer_user_copy_id(&id, timer);
1334                 }
1335         } else {
1336                 switch (id.dev_class) {
1337                 case SNDRV_TIMER_CLASS_GLOBAL:
1338                         id.device = id.device < 0 ? 0 : id.device + 1;
1339                         list_for_each(p, &snd_timer_list) {
1340                                 timer = list_entry(p, struct snd_timer, device_list);
1341                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1342                                         snd_timer_user_copy_id(&id, timer);
1343                                         break;
1344                                 }
1345                                 if (timer->tmr_device >= id.device) {
1346                                         snd_timer_user_copy_id(&id, timer);
1347                                         break;
1348                                 }
1349                         }
1350                         if (p == &snd_timer_list)
1351                                 snd_timer_user_zero_id(&id);
1352                         break;
1353                 case SNDRV_TIMER_CLASS_CARD:
1354                 case SNDRV_TIMER_CLASS_PCM:
1355                         if (id.card < 0) {
1356                                 id.card = 0;
1357                         } else {
1358                                 if (id.card < 0) {
1359                                         id.card = 0;
1360                                 } else {
1361                                         if (id.device < 0) {
1362                                                 id.device = 0;
1363                                         } else {
1364                                                 if (id.subdevice < 0) {
1365                                                         id.subdevice = 0;
1366                                                 } else {
1367                                                         id.subdevice++;
1368                                                 }
1369                                         }
1370                                 }
1371                         }
1372                         list_for_each(p, &snd_timer_list) {
1373                                 timer = list_entry(p, struct snd_timer, device_list);
1374                                 if (timer->tmr_class > id.dev_class) {
1375                                         snd_timer_user_copy_id(&id, timer);
1376                                         break;
1377                                 }
1378                                 if (timer->tmr_class < id.dev_class)
1379                                         continue;
1380                                 if (timer->card->number > id.card) {
1381                                         snd_timer_user_copy_id(&id, timer);
1382                                         break;
1383                                 }
1384                                 if (timer->card->number < id.card)
1385                                         continue;
1386                                 if (timer->tmr_device > id.device) {
1387                                         snd_timer_user_copy_id(&id, timer);
1388                                         break;
1389                                 }
1390                                 if (timer->tmr_device < id.device)
1391                                         continue;
1392                                 if (timer->tmr_subdevice > id.subdevice) {
1393                                         snd_timer_user_copy_id(&id, timer);
1394                                         break;
1395                                 }
1396                                 if (timer->tmr_subdevice < id.subdevice)
1397                                         continue;
1398                                 snd_timer_user_copy_id(&id, timer);
1399                                 break;
1400                         }
1401                         if (p == &snd_timer_list)
1402                                 snd_timer_user_zero_id(&id);
1403                         break;
1404                 default:
1405                         snd_timer_user_zero_id(&id);
1406                 }
1407         }
1408         mutex_unlock(&register_mutex);
1409         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1410                 return -EFAULT;
1411         return 0;
1412 }
1413
1414 static int snd_timer_user_ginfo(struct file *file,
1415                                 struct snd_timer_ginfo __user *_ginfo)
1416 {
1417         struct snd_timer_ginfo *ginfo;
1418         struct snd_timer_id tid;
1419         struct snd_timer *t;
1420         struct list_head *p;
1421         int err = 0;
1422
1423         ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1424         if (! ginfo)
1425                 return -ENOMEM;
1426         if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1427                 kfree(ginfo);
1428                 return -EFAULT;
1429         }
1430         tid = ginfo->tid;
1431         memset(ginfo, 0, sizeof(*ginfo));
1432         ginfo->tid = tid;
1433         mutex_lock(&register_mutex);
1434         t = snd_timer_find(&tid);
1435         if (t != NULL) {
1436                 ginfo->card = t->card ? t->card->number : -1;
1437                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1438                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1439                 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1440                 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1441                 ginfo->resolution = t->hw.resolution;
1442                 if (t->hw.resolution_min > 0) {
1443                         ginfo->resolution_min = t->hw.resolution_min;
1444                         ginfo->resolution_max = t->hw.resolution_max;
1445                 }
1446                 list_for_each(p, &t->open_list_head) {
1447                         ginfo->clients++;
1448                 }
1449         } else {
1450                 err = -ENODEV;
1451         }
1452         mutex_unlock(&register_mutex);
1453         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1454                 err = -EFAULT;
1455         kfree(ginfo);
1456         return err;
1457 }
1458
1459 static int snd_timer_user_gparams(struct file *file,
1460                                   struct snd_timer_gparams __user *_gparams)
1461 {
1462         struct snd_timer_gparams gparams;
1463         struct snd_timer *t;
1464         int err;
1465
1466         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1467                 return -EFAULT;
1468         mutex_lock(&register_mutex);
1469         t = snd_timer_find(&gparams.tid);
1470         if (!t) {
1471                 err = -ENODEV;
1472                 goto _error;
1473         }
1474         if (!list_empty(&t->open_list_head)) {
1475                 err = -EBUSY;
1476                 goto _error;
1477         }
1478         if (!t->hw.set_period) {
1479                 err = -ENOSYS;
1480                 goto _error;
1481         }
1482         err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1483 _error:
1484         mutex_unlock(&register_mutex);
1485         return err;
1486 }
1487
1488 static int snd_timer_user_gstatus(struct file *file,
1489                                   struct snd_timer_gstatus __user *_gstatus)
1490 {
1491         struct snd_timer_gstatus gstatus;
1492         struct snd_timer_id tid;
1493         struct snd_timer *t;
1494         int err = 0;
1495
1496         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1497                 return -EFAULT;
1498         tid = gstatus.tid;
1499         memset(&gstatus, 0, sizeof(gstatus));
1500         gstatus.tid = tid;
1501         mutex_lock(&register_mutex);
1502         t = snd_timer_find(&tid);
1503         if (t != NULL) {
1504                 if (t->hw.c_resolution)
1505                         gstatus.resolution = t->hw.c_resolution(t);
1506                 else
1507                         gstatus.resolution = t->hw.resolution;
1508                 if (t->hw.precise_resolution) {
1509                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1510                                                  &gstatus.resolution_den);
1511                 } else {
1512                         gstatus.resolution_num = gstatus.resolution;
1513                         gstatus.resolution_den = 1000000000uL;
1514                 }
1515         } else {
1516                 err = -ENODEV;
1517         }
1518         mutex_unlock(&register_mutex);
1519         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1520                 err = -EFAULT;
1521         return err;
1522 }
1523
1524 static int snd_timer_user_tselect(struct file *file,
1525                                   struct snd_timer_select __user *_tselect)
1526 {
1527         struct snd_timer_user *tu;
1528         struct snd_timer_select tselect;
1529         char str[32];
1530         int err = 0;
1531
1532         tu = file->private_data;
1533         mutex_lock(&tu->tread_sem);
1534         if (tu->timeri) {
1535                 snd_timer_close(tu->timeri);
1536                 tu->timeri = NULL;
1537         }
1538         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1539                 err = -EFAULT;
1540                 goto __err;
1541         }
1542         sprintf(str, "application %i", current->pid);
1543         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1544                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1545         err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1546         if (err < 0)
1547                 goto __err;
1548
1549         kfree(tu->queue);
1550         tu->queue = NULL;
1551         kfree(tu->tqueue);
1552         tu->tqueue = NULL;
1553         if (tu->tread) {
1554                 tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1555                                      GFP_KERNEL);
1556                 if (tu->tqueue == NULL)
1557                         err = -ENOMEM;
1558         } else {
1559                 tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1560                                     GFP_KERNEL);
1561                 if (tu->queue == NULL)
1562                         err = -ENOMEM;
1563         }
1564
1565         if (err < 0) {
1566                 snd_timer_close(tu->timeri);
1567                 tu->timeri = NULL;
1568         } else {
1569                 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1570                 tu->timeri->callback = tu->tread
1571                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1572                 tu->timeri->ccallback = snd_timer_user_ccallback;
1573                 tu->timeri->callback_data = (void *)tu;
1574         }
1575
1576       __err:
1577         mutex_unlock(&tu->tread_sem);
1578         return err;
1579 }
1580
1581 static int snd_timer_user_info(struct file *file,
1582                                struct snd_timer_info __user *_info)
1583 {
1584         struct snd_timer_user *tu;
1585         struct snd_timer_info *info;
1586         struct snd_timer *t;
1587         int err = 0;
1588
1589         tu = file->private_data;
1590         snd_assert(tu->timeri != NULL, return -ENXIO);
1591         t = tu->timeri->timer;
1592         snd_assert(t != NULL, return -ENXIO);
1593
1594         info = kzalloc(sizeof(*info), GFP_KERNEL);
1595         if (! info)
1596                 return -ENOMEM;
1597         info->card = t->card ? t->card->number : -1;
1598         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1599                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1600         strlcpy(info->id, t->id, sizeof(info->id));
1601         strlcpy(info->name, t->name, sizeof(info->name));
1602         info->resolution = t->hw.resolution;
1603         if (copy_to_user(_info, info, sizeof(*_info)))
1604                 err = -EFAULT;
1605         kfree(info);
1606         return err;
1607 }
1608
1609 static int snd_timer_user_params(struct file *file,
1610                                  struct snd_timer_params __user *_params)
1611 {
1612         struct snd_timer_user *tu;
1613         struct snd_timer_params params;
1614         struct snd_timer *t;
1615         struct snd_timer_read *tr;
1616         struct snd_timer_tread *ttr;
1617         int err;
1618
1619         tu = file->private_data;
1620         snd_assert(tu->timeri != NULL, return -ENXIO);
1621         t = tu->timeri->timer;
1622         snd_assert(t != NULL, return -ENXIO);
1623         if (copy_from_user(&params, _params, sizeof(params)))
1624                 return -EFAULT;
1625         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1626                 err = -EINVAL;
1627                 goto _end;
1628         }
1629         if (params.queue_size > 0 &&
1630             (params.queue_size < 32 || params.queue_size > 1024)) {
1631                 err = -EINVAL;
1632                 goto _end;
1633         }
1634         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1635                               (1<<SNDRV_TIMER_EVENT_TICK)|
1636                               (1<<SNDRV_TIMER_EVENT_START)|
1637                               (1<<SNDRV_TIMER_EVENT_STOP)|
1638                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1639                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1640                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1641                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1642                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1643                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1644                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1645                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1646                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1647                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1648                 err = -EINVAL;
1649                 goto _end;
1650         }
1651         snd_timer_stop(tu->timeri);
1652         spin_lock_irq(&t->lock);
1653         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1654                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1655                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1656         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1657                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1658         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1659                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1660         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1661                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1662         spin_unlock_irq(&t->lock);
1663         if (params.queue_size > 0 &&
1664             (unsigned int)tu->queue_size != params.queue_size) {
1665                 if (tu->tread) {
1666                         ttr = kmalloc(params.queue_size * sizeof(*ttr),
1667                                       GFP_KERNEL);
1668                         if (ttr) {
1669                                 kfree(tu->tqueue);
1670                                 tu->queue_size = params.queue_size;
1671                                 tu->tqueue = ttr;
1672                         }
1673                 } else {
1674                         tr = kmalloc(params.queue_size * sizeof(*tr),
1675                                      GFP_KERNEL);
1676                         if (tr) {
1677                                 kfree(tu->queue);
1678                                 tu->queue_size = params.queue_size;
1679                                 tu->queue = tr;
1680                         }
1681                 }
1682         }
1683         tu->qhead = tu->qtail = tu->qused = 0;
1684         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1685                 if (tu->tread) {
1686                         struct snd_timer_tread tread;
1687                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1688                         tread.tstamp.tv_sec = 0;
1689                         tread.tstamp.tv_nsec = 0;
1690                         tread.val = 0;
1691                         snd_timer_user_append_to_tqueue(tu, &tread);
1692                 } else {
1693                         struct snd_timer_read *r = &tu->queue[0];
1694                         r->resolution = 0;
1695                         r->ticks = 0;
1696                         tu->qused++;
1697                         tu->qtail++;
1698                 }
1699         }
1700         tu->filter = params.filter;
1701         tu->ticks = params.ticks;
1702         err = 0;
1703  _end:
1704         if (copy_to_user(_params, &params, sizeof(params)))
1705                 return -EFAULT;
1706         return err;
1707 }
1708
1709 static int snd_timer_user_status(struct file *file,
1710                                  struct snd_timer_status __user *_status)
1711 {
1712         struct snd_timer_user *tu;
1713         struct snd_timer_status status;
1714
1715         tu = file->private_data;
1716         snd_assert(tu->timeri != NULL, return -ENXIO);
1717         memset(&status, 0, sizeof(status));
1718         status.tstamp = tu->tstamp;
1719         status.resolution = snd_timer_resolution(tu->timeri);
1720         status.lost = tu->timeri->lost;
1721         status.overrun = tu->overrun;
1722         spin_lock_irq(&tu->qlock);
1723         status.queue = tu->qused;
1724         spin_unlock_irq(&tu->qlock);
1725         if (copy_to_user(_status, &status, sizeof(status)))
1726                 return -EFAULT;
1727         return 0;
1728 }
1729
1730 static int snd_timer_user_start(struct file *file)
1731 {
1732         int err;
1733         struct snd_timer_user *tu;
1734
1735         tu = file->private_data;
1736         snd_assert(tu->timeri != NULL, return -ENXIO);
1737         snd_timer_stop(tu->timeri);
1738         tu->timeri->lost = 0;
1739         tu->last_resolution = 0;
1740         return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1741 }
1742
1743 static int snd_timer_user_stop(struct file *file)
1744 {
1745         int err;
1746         struct snd_timer_user *tu;
1747
1748         tu = file->private_data;
1749         snd_assert(tu->timeri != NULL, return -ENXIO);
1750         return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1751 }
1752
1753 static int snd_timer_user_continue(struct file *file)
1754 {
1755         int err;
1756         struct snd_timer_user *tu;
1757
1758         tu = file->private_data;
1759         snd_assert(tu->timeri != NULL, return -ENXIO);
1760         tu->timeri->lost = 0;
1761         return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1762 }
1763
1764 static int snd_timer_user_pause(struct file *file)
1765 {
1766         int err;
1767         struct snd_timer_user *tu;
1768
1769         tu = file->private_data;
1770         snd_assert(tu->timeri != NULL, return -ENXIO);
1771         return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1772 }
1773
1774 enum {
1775         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1776         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1777         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1778         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1779 };
1780
1781 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1782                                  unsigned long arg)
1783 {
1784         struct snd_timer_user *tu;
1785         void __user *argp = (void __user *)arg;
1786         int __user *p = argp;
1787
1788         tu = file->private_data;
1789         switch (cmd) {
1790         case SNDRV_TIMER_IOCTL_PVERSION:
1791                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1792         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1793                 return snd_timer_user_next_device(argp);
1794         case SNDRV_TIMER_IOCTL_TREAD:
1795         {
1796                 int xarg;
1797
1798                 mutex_lock(&tu->tread_sem);
1799                 if (tu->timeri) {       /* too late */
1800                         mutex_unlock(&tu->tread_sem);
1801                         return -EBUSY;
1802                 }
1803                 if (get_user(xarg, p)) {
1804                         mutex_unlock(&tu->tread_sem);
1805                         return -EFAULT;
1806                 }
1807                 tu->tread = xarg ? 1 : 0;
1808                 mutex_unlock(&tu->tread_sem);
1809                 return 0;
1810         }
1811         case SNDRV_TIMER_IOCTL_GINFO:
1812                 return snd_timer_user_ginfo(file, argp);
1813         case SNDRV_TIMER_IOCTL_GPARAMS:
1814                 return snd_timer_user_gparams(file, argp);
1815         case SNDRV_TIMER_IOCTL_GSTATUS:
1816                 return snd_timer_user_gstatus(file, argp);
1817         case SNDRV_TIMER_IOCTL_SELECT:
1818                 return snd_timer_user_tselect(file, argp);
1819         case SNDRV_TIMER_IOCTL_INFO:
1820                 return snd_timer_user_info(file, argp);
1821         case SNDRV_TIMER_IOCTL_PARAMS:
1822                 return snd_timer_user_params(file, argp);
1823         case SNDRV_TIMER_IOCTL_STATUS:
1824                 return snd_timer_user_status(file, argp);
1825         case SNDRV_TIMER_IOCTL_START:
1826         case SNDRV_TIMER_IOCTL_START_OLD:
1827                 return snd_timer_user_start(file);
1828         case SNDRV_TIMER_IOCTL_STOP:
1829         case SNDRV_TIMER_IOCTL_STOP_OLD:
1830                 return snd_timer_user_stop(file);
1831         case SNDRV_TIMER_IOCTL_CONTINUE:
1832         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1833                 return snd_timer_user_continue(file);
1834         case SNDRV_TIMER_IOCTL_PAUSE:
1835         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1836                 return snd_timer_user_pause(file);
1837         }
1838         return -ENOTTY;
1839 }
1840
1841 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1842 {
1843         struct snd_timer_user *tu;
1844         int err;
1845
1846         tu = file->private_data;
1847         err = fasync_helper(fd, file, on, &tu->fasync);
1848         if (err < 0)
1849                 return err;
1850         return 0;
1851 }
1852
1853 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1854                                    size_t count, loff_t *offset)
1855 {
1856         struct snd_timer_user *tu;
1857         long result = 0, unit;
1858         int err = 0;
1859
1860         tu = file->private_data;
1861         unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1862         spin_lock_irq(&tu->qlock);
1863         while ((long)count - result >= unit) {
1864                 while (!tu->qused) {
1865                         wait_queue_t wait;
1866
1867                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1868                                 err = -EAGAIN;
1869                                 break;
1870                         }
1871
1872                         set_current_state(TASK_INTERRUPTIBLE);
1873                         init_waitqueue_entry(&wait, current);
1874                         add_wait_queue(&tu->qchange_sleep, &wait);
1875
1876                         spin_unlock_irq(&tu->qlock);
1877                         schedule();
1878                         spin_lock_irq(&tu->qlock);
1879
1880                         remove_wait_queue(&tu->qchange_sleep, &wait);
1881
1882                         if (signal_pending(current)) {
1883                                 err = -ERESTARTSYS;
1884                                 break;
1885                         }
1886                 }
1887
1888                 spin_unlock_irq(&tu->qlock);
1889                 if (err < 0)
1890                         goto _error;
1891
1892                 if (tu->tread) {
1893                         if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1894                                          sizeof(struct snd_timer_tread))) {
1895                                 err = -EFAULT;
1896                                 goto _error;
1897                         }
1898                 } else {
1899                         if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1900                                          sizeof(struct snd_timer_read))) {
1901                                 err = -EFAULT;
1902                                 goto _error;
1903                         }
1904                 }
1905
1906                 tu->qhead %= tu->queue_size;
1907
1908                 result += unit;
1909                 buffer += unit;
1910
1911                 spin_lock_irq(&tu->qlock);
1912                 tu->qused--;
1913         }
1914         spin_unlock_irq(&tu->qlock);
1915  _error:
1916         return result > 0 ? result : err;
1917 }
1918
1919 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1920 {
1921         unsigned int mask;
1922         struct snd_timer_user *tu;
1923
1924         tu = file->private_data;
1925
1926         poll_wait(file, &tu->qchange_sleep, wait);
1927
1928         mask = 0;
1929         if (tu->qused)
1930                 mask |= POLLIN | POLLRDNORM;
1931
1932         return mask;
1933 }
1934
1935 #ifdef CONFIG_COMPAT
1936 #include "timer_compat.c"
1937 #else
1938 #define snd_timer_user_ioctl_compat     NULL
1939 #endif
1940
1941 static struct file_operations snd_timer_f_ops =
1942 {
1943         .owner =        THIS_MODULE,
1944         .read =         snd_timer_user_read,
1945         .open =         snd_timer_user_open,
1946         .release =      snd_timer_user_release,
1947         .poll =         snd_timer_user_poll,
1948         .unlocked_ioctl =       snd_timer_user_ioctl,
1949         .compat_ioctl = snd_timer_user_ioctl_compat,
1950         .fasync =       snd_timer_user_fasync,
1951 };
1952
1953 /*
1954  *  ENTRY functions
1955  */
1956
1957 static int __init alsa_timer_init(void)
1958 {
1959         int err;
1960
1961 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1962         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1963                               "system timer");
1964 #endif
1965
1966         if ((err = snd_timer_register_system()) < 0)
1967                 snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1968                            err);
1969         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1970                                        &snd_timer_f_ops, NULL, "timer")) < 0)
1971                 snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1972                            err);
1973         snd_timer_proc_init();
1974         return 0;
1975 }
1976
1977 static void __exit alsa_timer_exit(void)
1978 {
1979         struct list_head *p, *n;
1980
1981         snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1982         /* unregister the system timer */
1983         list_for_each_safe(p, n, &snd_timer_list) {
1984                 struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1985                 snd_timer_unregister(timer);
1986         }
1987         snd_timer_proc_done();
1988 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1989         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1990 #endif
1991 }
1992
1993 module_init(alsa_timer_init)
1994 module_exit(alsa_timer_exit)
1995
1996 EXPORT_SYMBOL(snd_timer_open);
1997 EXPORT_SYMBOL(snd_timer_close);
1998 EXPORT_SYMBOL(snd_timer_resolution);
1999 EXPORT_SYMBOL(snd_timer_start);
2000 EXPORT_SYMBOL(snd_timer_stop);
2001 EXPORT_SYMBOL(snd_timer_continue);
2002 EXPORT_SYMBOL(snd_timer_pause);
2003 EXPORT_SYMBOL(snd_timer_new);
2004 EXPORT_SYMBOL(snd_timer_notify);
2005 EXPORT_SYMBOL(snd_timer_global_new);
2006 EXPORT_SYMBOL(snd_timer_global_free);
2007 EXPORT_SYMBOL(snd_timer_global_register);
2008 EXPORT_SYMBOL(snd_timer_global_unregister);
2009 EXPORT_SYMBOL(snd_timer_interrupt);