1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Timers abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/delay.h>
8#include <linux/init.h>
9#include <linux/slab.h>
10#include <linux/time.h>
11#include <linux/mutex.h>
12#include <linux/device.h>
13#include <linux/module.h>
14#include <linux/string.h>
15#include <linux/sched/signal.h>
16#include <sound/core.h>
17#include <sound/timer.h>
18#include <sound/control.h>
19#include <sound/info.h>
20#include <sound/minors.h>
21#include <sound/initval.h>
22#include <linux/kmod.h>
23
24/* internal flags */
25#define SNDRV_TIMER_IFLG_PAUSED 0x00010000
26#define SNDRV_TIMER_IFLG_DEAD 0x00020000
27
28#if IS_ENABLED(CONFIG_SND_HRTIMER)
29#define DEFAULT_TIMER_LIMIT 4
30#else
31#define DEFAULT_TIMER_LIMIT 1
32#endif
33
34static int timer_limit = DEFAULT_TIMER_LIMIT;
35static int timer_tstamp_monotonic = 1;
36MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
37MODULE_DESCRIPTION("ALSA timer interface");
38MODULE_LICENSE("GPL");
39module_param(timer_limit, int, 0444);
40MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
41module_param(timer_tstamp_monotonic, int, 0444);
42MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
43
44MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
45MODULE_ALIAS("devname:snd/timer");
46
47enum timer_tread_format {
48 TREAD_FORMAT_NONE = 0,
49 TREAD_FORMAT_TIME64,
50 TREAD_FORMAT_TIME32,
51};
52
53struct snd_timer_tread32 {
54 int event;
55 s32 tstamp_sec;
56 s32 tstamp_nsec;
57 unsigned int val;
58};
59
60struct snd_timer_tread64 {
61 int event;
62 u8 pad1[4];
63 s64 tstamp_sec;
64 s64 tstamp_nsec;
65 unsigned int val;
66 u8 pad2[4];
67};
68
69struct snd_timer_user {
70 struct snd_timer_instance *timeri;
71 int tread; /* enhanced read with timestamps and events */
72 unsigned long ticks;
73 unsigned long overrun;
74 int qhead;
75 int qtail;
76 int qused;
77 int queue_size;
78 bool disconnected;
79 struct snd_timer_read *queue;
80 struct snd_timer_tread64 *tqueue;
81 spinlock_t qlock;
82 unsigned long last_resolution;
83 unsigned int filter;
84 struct timespec64 tstamp; /* trigger tstamp */
85 wait_queue_head_t qchange_sleep;
86 struct snd_fasync *fasync;
87 struct mutex ioctl_lock;
88};
89
90struct snd_timer_status32 {
91 s32 tstamp_sec; /* Timestamp - last update */
92 s32 tstamp_nsec;
93 unsigned int resolution; /* current period resolution in ns */
94 unsigned int lost; /* counter of master tick lost */
95 unsigned int overrun; /* count of read queue overruns */
96 unsigned int queue; /* used queue size */
97 unsigned char reserved[64]; /* reserved */
98};
99
100#define SNDRV_TIMER_IOCTL_STATUS32 _IOR('T', 0x14, struct snd_timer_status32)
101
102struct snd_timer_status64 {
103 s64 tstamp_sec; /* Timestamp - last update */
104 s64 tstamp_nsec;
105 unsigned int resolution; /* current period resolution in ns */
106 unsigned int lost; /* counter of master tick lost */
107 unsigned int overrun; /* count of read queue overruns */
108 unsigned int queue; /* used queue size */
109 unsigned char reserved[64]; /* reserved */
110};
111
112#define SNDRV_TIMER_IOCTL_STATUS64 _IOR('T', 0x14, struct snd_timer_status64)
113
114/* list of timers */
115static LIST_HEAD(snd_timer_list);
116
117/* list of slave instances */
118static LIST_HEAD(snd_timer_slave_list);
119
120/* lock for slave active lists */
121static DEFINE_SPINLOCK(slave_active_lock);
122
123#define MAX_SLAVE_INSTANCES 1000
124static int num_slaves;
125
126static DEFINE_MUTEX(register_mutex);
127
128static int snd_timer_free(struct snd_timer *timer);
129static int snd_timer_dev_free(struct snd_device *device);
130static int snd_timer_dev_register(struct snd_device *device);
131static int snd_timer_dev_disconnect(struct snd_device *device);
132
133static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
134
135/*
136 * create a timer instance with the given owner string.
137 */
138struct snd_timer_instance *snd_timer_instance_new(const char *owner)
139{
140 struct snd_timer_instance *timeri;
141
142 timeri = kzalloc(size: sizeof(*timeri), GFP_KERNEL);
143 if (timeri == NULL)
144 return NULL;
145 timeri->owner = kstrdup(s: owner, GFP_KERNEL);
146 if (! timeri->owner) {
147 kfree(objp: timeri);
148 return NULL;
149 }
150 INIT_LIST_HEAD(list: &timeri->open_list);
151 INIT_LIST_HEAD(list: &timeri->active_list);
152 INIT_LIST_HEAD(list: &timeri->ack_list);
153 INIT_LIST_HEAD(list: &timeri->slave_list_head);
154 INIT_LIST_HEAD(list: &timeri->slave_active_head);
155
156 return timeri;
157}
158EXPORT_SYMBOL(snd_timer_instance_new);
159
160void snd_timer_instance_free(struct snd_timer_instance *timeri)
161{
162 if (timeri) {
163 if (timeri->private_free)
164 timeri->private_free(timeri);
165 kfree(objp: timeri->owner);
166 kfree(objp: timeri);
167 }
168}
169EXPORT_SYMBOL(snd_timer_instance_free);
170
171/*
172 * find a timer instance from the given timer id
173 */
174static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
175{
176 struct snd_timer *timer;
177
178 list_for_each_entry(timer, &snd_timer_list, device_list) {
179 if (timer->tmr_class != tid->dev_class)
180 continue;
181 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
182 timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
183 (timer->card == NULL ||
184 timer->card->number != tid->card))
185 continue;
186 if (timer->tmr_device != tid->device)
187 continue;
188 if (timer->tmr_subdevice != tid->subdevice)
189 continue;
190 return timer;
191 }
192 return NULL;
193}
194
195#ifdef CONFIG_MODULES
196
197static void snd_timer_request(struct snd_timer_id *tid)
198{
199 switch (tid->dev_class) {
200 case SNDRV_TIMER_CLASS_GLOBAL:
201 if (tid->device < timer_limit)
202 request_module("snd-timer-%i", tid->device);
203 break;
204 case SNDRV_TIMER_CLASS_CARD:
205 case SNDRV_TIMER_CLASS_PCM:
206 if (tid->card < snd_ecards_limit)
207 request_module("snd-card-%i", tid->card);
208 break;
209 default:
210 break;
211 }
212}
213
214#endif
215
216/* move the slave if it belongs to the master; return 1 if match */
217static int check_matching_master_slave(struct snd_timer_instance *master,
218 struct snd_timer_instance *slave)
219{
220 if (slave->slave_class != master->slave_class ||
221 slave->slave_id != master->slave_id)
222 return 0;
223 if (master->timer->num_instances >= master->timer->max_instances)
224 return -EBUSY;
225 list_move_tail(list: &slave->open_list, head: &master->slave_list_head);
226 master->timer->num_instances++;
227 spin_lock_irq(lock: &slave_active_lock);
228 spin_lock(lock: &master->timer->lock);
229 slave->master = master;
230 slave->timer = master->timer;
231 if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
232 list_add_tail(new: &slave->active_list, head: &master->slave_active_head);
233 spin_unlock(lock: &master->timer->lock);
234 spin_unlock_irq(lock: &slave_active_lock);
235 return 1;
236}
237
238/*
239 * look for a master instance matching with the slave id of the given slave.
240 * when found, relink the open_link of the slave.
241 *
242 * call this with register_mutex down.
243 */
244static int snd_timer_check_slave(struct snd_timer_instance *slave)
245{
246 struct snd_timer *timer;
247 struct snd_timer_instance *master;
248 int err = 0;
249
250 /* FIXME: it's really dumb to look up all entries.. */
251 list_for_each_entry(timer, &snd_timer_list, device_list) {
252 list_for_each_entry(master, &timer->open_list_head, open_list) {
253 err = check_matching_master_slave(master, slave);
254 if (err != 0) /* match found or error */
255 goto out;
256 }
257 }
258 out:
259 return err < 0 ? err : 0;
260}
261
262/*
263 * look for slave instances matching with the slave id of the given master.
264 * when found, relink the open_link of slaves.
265 *
266 * call this with register_mutex down.
267 */
268static int snd_timer_check_master(struct snd_timer_instance *master)
269{
270 struct snd_timer_instance *slave, *tmp;
271 int err = 0;
272
273 /* check all pending slaves */
274 list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
275 err = check_matching_master_slave(master, slave);
276 if (err < 0)
277 break;
278 }
279 return err < 0 ? err : 0;
280}
281
282static void snd_timer_close_locked(struct snd_timer_instance *timeri,
283 struct device **card_devp_to_put);
284
285/*
286 * open a timer instance
287 * when opening a master, the slave id must be here given.
288 */
289int snd_timer_open(struct snd_timer_instance *timeri,
290 struct snd_timer_id *tid,
291 unsigned int slave_id)
292{
293 struct snd_timer *timer;
294 struct device *card_dev_to_put = NULL;
295 int err;
296
297 mutex_lock(&register_mutex);
298 if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
299 /* open a slave instance */
300 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
301 tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
302 pr_debug("ALSA: timer: invalid slave class %i\n",
303 tid->dev_sclass);
304 err = -EINVAL;
305 goto unlock;
306 }
307 if (num_slaves >= MAX_SLAVE_INSTANCES) {
308 err = -EBUSY;
309 goto unlock;
310 }
311 timeri->slave_class = tid->dev_sclass;
312 timeri->slave_id = tid->device;
313 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
314 list_add_tail(new: &timeri->open_list, head: &snd_timer_slave_list);
315 num_slaves++;
316 err = snd_timer_check_slave(slave: timeri);
317 goto list_added;
318 }
319
320 /* open a master instance */
321 timer = snd_timer_find(tid);
322#ifdef CONFIG_MODULES
323 if (!timer) {
324 mutex_unlock(lock: &register_mutex);
325 snd_timer_request(tid);
326 mutex_lock(&register_mutex);
327 timer = snd_timer_find(tid);
328 }
329#endif
330 if (!timer) {
331 err = -ENODEV;
332 goto unlock;
333 }
334 if (!list_empty(head: &timer->open_list_head)) {
335 struct snd_timer_instance *t =
336 list_entry(timer->open_list_head.next,
337 struct snd_timer_instance, open_list);
338 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
339 err = -EBUSY;
340 goto unlock;
341 }
342 }
343 if (timer->num_instances >= timer->max_instances) {
344 err = -EBUSY;
345 goto unlock;
346 }
347 if (!try_module_get(module: timer->module)) {
348 err = -EBUSY;
349 goto unlock;
350 }
351 /* take a card refcount for safe disconnection */
352 if (timer->card) {
353 get_device(dev: &timer->card->card_dev);
354 card_dev_to_put = &timer->card->card_dev;
355 }
356
357 if (list_empty(head: &timer->open_list_head) && timer->hw.open) {
358 err = timer->hw.open(timer);
359 if (err) {
360 module_put(module: timer->module);
361 goto unlock;
362 }
363 }
364
365 timeri->timer = timer;
366 timeri->slave_class = tid->dev_sclass;
367 timeri->slave_id = slave_id;
368
369 list_add_tail(new: &timeri->open_list, head: &timer->open_list_head);
370 timer->num_instances++;
371 err = snd_timer_check_master(master: timeri);
372list_added:
373 if (err < 0)
374 snd_timer_close_locked(timeri, card_devp_to_put: &card_dev_to_put);
375
376 unlock:
377 mutex_unlock(lock: &register_mutex);
378 /* put_device() is called after unlock for avoiding deadlock */
379 if (err < 0 && card_dev_to_put)
380 put_device(dev: card_dev_to_put);
381 return err;
382}
383EXPORT_SYMBOL(snd_timer_open);
384
385/*
386 * close a timer instance
387 * call this with register_mutex down.
388 */
389static void snd_timer_close_locked(struct snd_timer_instance *timeri,
390 struct device **card_devp_to_put)
391{
392 struct snd_timer *timer = timeri->timer;
393 struct snd_timer_instance *slave, *tmp;
394
395 if (timer) {
396 spin_lock_irq(lock: &timer->lock);
397 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
398 spin_unlock_irq(lock: &timer->lock);
399 }
400
401 if (!list_empty(head: &timeri->open_list)) {
402 list_del_init(entry: &timeri->open_list);
403 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
404 num_slaves--;
405 }
406
407 /* force to stop the timer */
408 snd_timer_stop(timeri);
409
410 if (timer) {
411 timer->num_instances--;
412 /* wait, until the active callback is finished */
413 spin_lock_irq(lock: &timer->lock);
414 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
415 spin_unlock_irq(lock: &timer->lock);
416 udelay(10);
417 spin_lock_irq(lock: &timer->lock);
418 }
419 spin_unlock_irq(lock: &timer->lock);
420
421 /* remove slave links */
422 spin_lock_irq(lock: &slave_active_lock);
423 spin_lock(lock: &timer->lock);
424 timeri->timer = NULL;
425 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
426 open_list) {
427 list_move_tail(list: &slave->open_list, head: &snd_timer_slave_list);
428 timer->num_instances--;
429 slave->master = NULL;
430 slave->timer = NULL;
431 list_del_init(entry: &slave->ack_list);
432 list_del_init(entry: &slave->active_list);
433 }
434 spin_unlock(lock: &timer->lock);
435 spin_unlock_irq(lock: &slave_active_lock);
436
437 /* slave doesn't need to release timer resources below */
438 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
439 timer = NULL;
440 }
441
442 if (timer) {
443 if (list_empty(head: &timer->open_list_head) && timer->hw.close)
444 timer->hw.close(timer);
445 /* release a card refcount for safe disconnection */
446 if (timer->card)
447 *card_devp_to_put = &timer->card->card_dev;
448 module_put(module: timer->module);
449 }
450}
451
452/*
453 * close a timer instance
454 */
455void snd_timer_close(struct snd_timer_instance *timeri)
456{
457 struct device *card_dev_to_put = NULL;
458
459 if (snd_BUG_ON(!timeri))
460 return;
461
462 mutex_lock(&register_mutex);
463 snd_timer_close_locked(timeri, card_devp_to_put: &card_dev_to_put);
464 mutex_unlock(lock: &register_mutex);
465 /* put_device() is called after unlock for avoiding deadlock */
466 if (card_dev_to_put)
467 put_device(dev: card_dev_to_put);
468}
469EXPORT_SYMBOL(snd_timer_close);
470
471static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
472{
473 if (timer->hw.c_resolution)
474 return timer->hw.c_resolution(timer);
475 else
476 return timer->hw.resolution;
477}
478
479unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
480{
481 struct snd_timer * timer;
482 unsigned long ret = 0;
483 unsigned long flags;
484
485 if (timeri == NULL)
486 return 0;
487 timer = timeri->timer;
488 if (timer) {
489 spin_lock_irqsave(&timer->lock, flags);
490 ret = snd_timer_hw_resolution(timer);
491 spin_unlock_irqrestore(lock: &timer->lock, flags);
492 }
493 return ret;
494}
495EXPORT_SYMBOL(snd_timer_resolution);
496
497static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
498{
499 struct snd_timer *timer = ti->timer;
500 unsigned long resolution = 0;
501 struct snd_timer_instance *ts;
502 struct timespec64 tstamp;
503
504 if (timer_tstamp_monotonic)
505 ktime_get_ts64(ts: &tstamp);
506 else
507 ktime_get_real_ts64(tv: &tstamp);
508 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
509 event > SNDRV_TIMER_EVENT_PAUSE))
510 return;
511 if (timer &&
512 (event == SNDRV_TIMER_EVENT_START ||
513 event == SNDRV_TIMER_EVENT_CONTINUE))
514 resolution = snd_timer_hw_resolution(timer);
515 if (ti->ccallback)
516 ti->ccallback(ti, event, &tstamp, resolution);
517 if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
518 return;
519 if (timer == NULL)
520 return;
521 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
522 return;
523 event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
524 list_for_each_entry(ts, &ti->slave_active_head, active_list)
525 if (ts->ccallback)
526 ts->ccallback(ts, event, &tstamp, resolution);
527}
528
529/* start/continue a master timer */
530static int snd_timer_start1(struct snd_timer_instance *timeri,
531 bool start, unsigned long ticks)
532{
533 struct snd_timer *timer;
534 int result;
535 unsigned long flags;
536
537 timer = timeri->timer;
538 if (!timer)
539 return -EINVAL;
540
541 spin_lock_irqsave(&timer->lock, flags);
542 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
543 result = -EINVAL;
544 goto unlock;
545 }
546 if (timer->card && timer->card->shutdown) {
547 result = -ENODEV;
548 goto unlock;
549 }
550 if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
551 SNDRV_TIMER_IFLG_START)) {
552 result = -EBUSY;
553 goto unlock;
554 }
555
556 if (start)
557 timeri->ticks = timeri->cticks = ticks;
558 else if (!timeri->cticks)
559 timeri->cticks = 1;
560 timeri->pticks = 0;
561
562 list_move_tail(list: &timeri->active_list, head: &timer->active_list_head);
563 if (timer->running) {
564 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
565 goto __start_now;
566 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
567 timeri->flags |= SNDRV_TIMER_IFLG_START;
568 result = 1; /* delayed start */
569 } else {
570 if (start)
571 timer->sticks = ticks;
572 timer->hw.start(timer);
573 __start_now:
574 timer->running++;
575 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
576 result = 0;
577 }
578 snd_timer_notify1(ti: timeri, event: start ? SNDRV_TIMER_EVENT_START :
579 SNDRV_TIMER_EVENT_CONTINUE);
580 unlock:
581 spin_unlock_irqrestore(lock: &timer->lock, flags);
582 return result;
583}
584
585/* start/continue a slave timer */
586static int snd_timer_start_slave(struct snd_timer_instance *timeri,
587 bool start)
588{
589 unsigned long flags;
590 int err;
591
592 spin_lock_irqsave(&slave_active_lock, flags);
593 if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
594 err = -EINVAL;
595 goto unlock;
596 }
597 if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
598 err = -EBUSY;
599 goto unlock;
600 }
601 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
602 if (timeri->master && timeri->timer) {
603 spin_lock(lock: &timeri->timer->lock);
604 list_add_tail(new: &timeri->active_list,
605 head: &timeri->master->slave_active_head);
606 snd_timer_notify1(ti: timeri, event: start ? SNDRV_TIMER_EVENT_START :
607 SNDRV_TIMER_EVENT_CONTINUE);
608 spin_unlock(lock: &timeri->timer->lock);
609 }
610 err = 1; /* delayed start */
611 unlock:
612 spin_unlock_irqrestore(lock: &slave_active_lock, flags);
613 return err;
614}
615
616/* stop/pause a master timer */
617static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
618{
619 struct snd_timer *timer;
620 int result = 0;
621 unsigned long flags;
622
623 timer = timeri->timer;
624 if (!timer)
625 return -EINVAL;
626 spin_lock_irqsave(&timer->lock, flags);
627 list_del_init(entry: &timeri->ack_list);
628 list_del_init(entry: &timeri->active_list);
629 if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
630 SNDRV_TIMER_IFLG_START))) {
631 result = -EBUSY;
632 goto unlock;
633 }
634 if (timer->card && timer->card->shutdown)
635 goto unlock;
636 if (stop) {
637 timeri->cticks = timeri->ticks;
638 timeri->pticks = 0;
639 }
640 if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
641 !(--timer->running)) {
642 timer->hw.stop(timer);
643 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
644 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
645 snd_timer_reschedule(timer, ticks_left: 0);
646 if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
647 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
648 timer->hw.start(timer);
649 }
650 }
651 }
652 timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
653 if (stop)
654 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
655 else
656 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
657 snd_timer_notify1(ti: timeri, event: stop ? SNDRV_TIMER_EVENT_STOP :
658 SNDRV_TIMER_EVENT_PAUSE);
659 unlock:
660 spin_unlock_irqrestore(lock: &timer->lock, flags);
661 return result;
662}
663
664/* stop/pause a slave timer */
665static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
666{
667 unsigned long flags;
668 bool running;
669
670 spin_lock_irqsave(&slave_active_lock, flags);
671 running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
672 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
673 if (timeri->timer) {
674 spin_lock(lock: &timeri->timer->lock);
675 list_del_init(entry: &timeri->ack_list);
676 list_del_init(entry: &timeri->active_list);
677 if (running)
678 snd_timer_notify1(ti: timeri, event: stop ? SNDRV_TIMER_EVENT_STOP :
679 SNDRV_TIMER_EVENT_PAUSE);
680 spin_unlock(lock: &timeri->timer->lock);
681 }
682 spin_unlock_irqrestore(lock: &slave_active_lock, flags);
683 return running ? 0 : -EBUSY;
684}
685
686/*
687 * start the timer instance
688 */
689int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
690{
691 if (timeri == NULL || ticks < 1)
692 return -EINVAL;
693 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
694 return snd_timer_start_slave(timeri, start: true);
695 else
696 return snd_timer_start1(timeri, start: true, ticks);
697}
698EXPORT_SYMBOL(snd_timer_start);
699
700/*
701 * stop the timer instance.
702 *
703 * do not call this from the timer callback!
704 */
705int snd_timer_stop(struct snd_timer_instance *timeri)
706{
707 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
708 return snd_timer_stop_slave(timeri, stop: true);
709 else
710 return snd_timer_stop1(timeri, stop: true);
711}
712EXPORT_SYMBOL(snd_timer_stop);
713
714/*
715 * start again.. the tick is kept.
716 */
717int snd_timer_continue(struct snd_timer_instance *timeri)
718{
719 /* timer can continue only after pause */
720 if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
721 return -EINVAL;
722
723 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
724 return snd_timer_start_slave(timeri, start: false);
725 else
726 return snd_timer_start1(timeri, start: false, ticks: 0);
727}
728EXPORT_SYMBOL(snd_timer_continue);
729
730/*
731 * pause.. remember the ticks left
732 */
733int snd_timer_pause(struct snd_timer_instance * timeri)
734{
735 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
736 return snd_timer_stop_slave(timeri, stop: false);
737 else
738 return snd_timer_stop1(timeri, stop: false);
739}
740EXPORT_SYMBOL(snd_timer_pause);
741
742/*
743 * reschedule the timer
744 *
745 * start pending instances and check the scheduling ticks.
746 * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
747 */
748static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
749{
750 struct snd_timer_instance *ti;
751 unsigned long ticks = ~0UL;
752
753 list_for_each_entry(ti, &timer->active_list_head, active_list) {
754 if (ti->flags & SNDRV_TIMER_IFLG_START) {
755 ti->flags &= ~SNDRV_TIMER_IFLG_START;
756 ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
757 timer->running++;
758 }
759 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
760 if (ticks > ti->cticks)
761 ticks = ti->cticks;
762 }
763 }
764 if (ticks == ~0UL) {
765 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
766 return;
767 }
768 if (ticks > timer->hw.ticks)
769 ticks = timer->hw.ticks;
770 if (ticks_left != ticks)
771 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
772 timer->sticks = ticks;
773}
774
775/* call callbacks in timer ack list */
776static void snd_timer_process_callbacks(struct snd_timer *timer,
777 struct list_head *head)
778{
779 struct snd_timer_instance *ti;
780 unsigned long resolution, ticks;
781
782 while (!list_empty(head)) {
783 ti = list_first_entry(head, struct snd_timer_instance,
784 ack_list);
785
786 /* remove from ack_list and make empty */
787 list_del_init(entry: &ti->ack_list);
788
789 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
790 ticks = ti->pticks;
791 ti->pticks = 0;
792 resolution = ti->resolution;
793 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
794 spin_unlock(lock: &timer->lock);
795 if (ti->callback)
796 ti->callback(ti, resolution, ticks);
797 spin_lock(lock: &timer->lock);
798 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
799 }
800 }
801}
802
803/* clear pending instances from ack list */
804static void snd_timer_clear_callbacks(struct snd_timer *timer,
805 struct list_head *head)
806{
807 unsigned long flags;
808
809 spin_lock_irqsave(&timer->lock, flags);
810 while (!list_empty(head))
811 list_del_init(entry: head->next);
812 spin_unlock_irqrestore(lock: &timer->lock, flags);
813}
814
815/*
816 * timer work
817 *
818 */
819static void snd_timer_work(struct work_struct *work)
820{
821 struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
822 unsigned long flags;
823
824 if (timer->card && timer->card->shutdown) {
825 snd_timer_clear_callbacks(timer, head: &timer->sack_list_head);
826 return;
827 }
828
829 spin_lock_irqsave(&timer->lock, flags);
830 snd_timer_process_callbacks(timer, head: &timer->sack_list_head);
831 spin_unlock_irqrestore(lock: &timer->lock, flags);
832}
833
834/*
835 * timer interrupt
836 *
837 * ticks_left is usually equal to timer->sticks.
838 *
839 */
840void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
841{
842 struct snd_timer_instance *ti, *ts, *tmp;
843 unsigned long resolution;
844 struct list_head *ack_list_head;
845 unsigned long flags;
846 bool use_work = false;
847
848 if (timer == NULL)
849 return;
850
851 if (timer->card && timer->card->shutdown) {
852 snd_timer_clear_callbacks(timer, head: &timer->ack_list_head);
853 return;
854 }
855
856 spin_lock_irqsave(&timer->lock, flags);
857
858 /* remember the current resolution */
859 resolution = snd_timer_hw_resolution(timer);
860
861 /* loop for all active instances
862 * Here we cannot use list_for_each_entry because the active_list of a
863 * processed instance is relinked to done_list_head before the callback
864 * is called.
865 */
866 list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
867 active_list) {
868 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
869 continue;
870 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
871 continue;
872 ti->pticks += ticks_left;
873 ti->resolution = resolution;
874 if (ti->cticks < ticks_left)
875 ti->cticks = 0;
876 else
877 ti->cticks -= ticks_left;
878 if (ti->cticks) /* not expired */
879 continue;
880 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
881 ti->cticks = ti->ticks;
882 } else {
883 ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
884 --timer->running;
885 list_del_init(entry: &ti->active_list);
886 }
887 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
888 (ti->flags & SNDRV_TIMER_IFLG_FAST))
889 ack_list_head = &timer->ack_list_head;
890 else
891 ack_list_head = &timer->sack_list_head;
892 if (list_empty(head: &ti->ack_list))
893 list_add_tail(new: &ti->ack_list, head: ack_list_head);
894 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
895 ts->pticks = ti->pticks;
896 ts->resolution = resolution;
897 if (list_empty(head: &ts->ack_list))
898 list_add_tail(new: &ts->ack_list, head: ack_list_head);
899 }
900 }
901 if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
902 snd_timer_reschedule(timer, ticks_left: timer->sticks);
903 if (timer->running) {
904 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
905 timer->hw.stop(timer);
906 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
907 }
908 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
909 (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
910 /* restart timer */
911 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
912 timer->hw.start(timer);
913 }
914 } else {
915 timer->hw.stop(timer);
916 }
917
918 /* now process all fast callbacks */
919 snd_timer_process_callbacks(timer, head: &timer->ack_list_head);
920
921 /* do we have any slow callbacks? */
922 use_work = !list_empty(head: &timer->sack_list_head);
923 spin_unlock_irqrestore(lock: &timer->lock, flags);
924
925 if (use_work)
926 queue_work(wq: system_highpri_wq, work: &timer->task_work);
927}
928EXPORT_SYMBOL(snd_timer_interrupt);
929
930/*
931
932 */
933
934int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
935 struct snd_timer **rtimer)
936{
937 struct snd_timer *timer;
938 int err;
939 static const struct snd_device_ops ops = {
940 .dev_free = snd_timer_dev_free,
941 .dev_register = snd_timer_dev_register,
942 .dev_disconnect = snd_timer_dev_disconnect,
943 };
944
945 if (snd_BUG_ON(!tid))
946 return -EINVAL;
947 if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
948 tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
949 if (WARN_ON(!card))
950 return -EINVAL;
951 }
952 if (rtimer)
953 *rtimer = NULL;
954 timer = kzalloc(size: sizeof(*timer), GFP_KERNEL);
955 if (!timer)
956 return -ENOMEM;
957 timer->tmr_class = tid->dev_class;
958 timer->card = card;
959 timer->tmr_device = tid->device;
960 timer->tmr_subdevice = tid->subdevice;
961 if (id)
962 strscpy(p: timer->id, q: id, size: sizeof(timer->id));
963 timer->sticks = 1;
964 INIT_LIST_HEAD(list: &timer->device_list);
965 INIT_LIST_HEAD(list: &timer->open_list_head);
966 INIT_LIST_HEAD(list: &timer->active_list_head);
967 INIT_LIST_HEAD(list: &timer->ack_list_head);
968 INIT_LIST_HEAD(list: &timer->sack_list_head);
969 spin_lock_init(&timer->lock);
970 INIT_WORK(&timer->task_work, snd_timer_work);
971 timer->max_instances = 1000; /* default limit per timer */
972 if (card != NULL) {
973 timer->module = card->module;
974 err = snd_device_new(card, type: SNDRV_DEV_TIMER, device_data: timer, ops: &ops);
975 if (err < 0) {
976 snd_timer_free(timer);
977 return err;
978 }
979 }
980 if (rtimer)
981 *rtimer = timer;
982 return 0;
983}
984EXPORT_SYMBOL(snd_timer_new);
985
986static int snd_timer_free(struct snd_timer *timer)
987{
988 if (!timer)
989 return 0;
990
991 mutex_lock(&register_mutex);
992 if (! list_empty(head: &timer->open_list_head)) {
993 struct list_head *p, *n;
994 struct snd_timer_instance *ti;
995 pr_warn("ALSA: timer %p is busy?\n", timer);
996 list_for_each_safe(p, n, &timer->open_list_head) {
997 list_del_init(entry: p);
998 ti = list_entry(p, struct snd_timer_instance, open_list);
999 ti->timer = NULL;
1000 }
1001 }
1002 list_del(entry: &timer->device_list);
1003 mutex_unlock(lock: &register_mutex);
1004
1005 if (timer->private_free)
1006 timer->private_free(timer);
1007 kfree(objp: timer);
1008 return 0;
1009}
1010
1011static int snd_timer_dev_free(struct snd_device *device)
1012{
1013 struct snd_timer *timer = device->device_data;
1014 return snd_timer_free(timer);
1015}
1016
1017static int snd_timer_dev_register(struct snd_device *dev)
1018{
1019 struct snd_timer *timer = dev->device_data;
1020 struct snd_timer *timer1;
1021
1022 if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1023 return -ENXIO;
1024 if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1025 !timer->hw.resolution && timer->hw.c_resolution == NULL)
1026 return -EINVAL;
1027
1028 mutex_lock(&register_mutex);
1029 list_for_each_entry(timer1, &snd_timer_list, device_list) {
1030 if (timer1->tmr_class > timer->tmr_class)
1031 break;
1032 if (timer1->tmr_class < timer->tmr_class)
1033 continue;
1034 if (timer1->card && timer->card) {
1035 if (timer1->card->number > timer->card->number)
1036 break;
1037 if (timer1->card->number < timer->card->number)
1038 continue;
1039 }
1040 if (timer1->tmr_device > timer->tmr_device)
1041 break;
1042 if (timer1->tmr_device < timer->tmr_device)
1043 continue;
1044 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1045 break;
1046 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1047 continue;
1048 /* conflicts.. */
1049 mutex_unlock(lock: &register_mutex);
1050 return -EBUSY;
1051 }
1052 list_add_tail(new: &timer->device_list, head: &timer1->device_list);
1053 mutex_unlock(lock: &register_mutex);
1054 return 0;
1055}
1056
1057static int snd_timer_dev_disconnect(struct snd_device *device)
1058{
1059 struct snd_timer *timer = device->device_data;
1060 struct snd_timer_instance *ti;
1061
1062 mutex_lock(&register_mutex);
1063 list_del_init(entry: &timer->device_list);
1064 /* wake up pending sleepers */
1065 list_for_each_entry(ti, &timer->open_list_head, open_list) {
1066 if (ti->disconnect)
1067 ti->disconnect(ti);
1068 }
1069 mutex_unlock(lock: &register_mutex);
1070 return 0;
1071}
1072
1073void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1074{
1075 unsigned long flags;
1076 unsigned long resolution = 0;
1077 struct snd_timer_instance *ti, *ts;
1078
1079 if (timer->card && timer->card->shutdown)
1080 return;
1081 if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1082 return;
1083 if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1084 event > SNDRV_TIMER_EVENT_MRESUME))
1085 return;
1086 spin_lock_irqsave(&timer->lock, flags);
1087 if (event == SNDRV_TIMER_EVENT_MSTART ||
1088 event == SNDRV_TIMER_EVENT_MCONTINUE ||
1089 event == SNDRV_TIMER_EVENT_MRESUME)
1090 resolution = snd_timer_hw_resolution(timer);
1091 list_for_each_entry(ti, &timer->active_list_head, active_list) {
1092 if (ti->ccallback)
1093 ti->ccallback(ti, event, tstamp, resolution);
1094 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1095 if (ts->ccallback)
1096 ts->ccallback(ts, event, tstamp, resolution);
1097 }
1098 spin_unlock_irqrestore(lock: &timer->lock, flags);
1099}
1100EXPORT_SYMBOL(snd_timer_notify);
1101
1102/*
1103 * exported functions for global timers
1104 */
1105int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1106{
1107 struct snd_timer_id tid;
1108
1109 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1110 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1111 tid.card = -1;
1112 tid.device = device;
1113 tid.subdevice = 0;
1114 return snd_timer_new(NULL, id, &tid, rtimer);
1115}
1116EXPORT_SYMBOL(snd_timer_global_new);
1117
1118int snd_timer_global_free(struct snd_timer *timer)
1119{
1120 return snd_timer_free(timer);
1121}
1122EXPORT_SYMBOL(snd_timer_global_free);
1123
1124int snd_timer_global_register(struct snd_timer *timer)
1125{
1126 struct snd_device dev;
1127
1128 memset(&dev, 0, sizeof(dev));
1129 dev.device_data = timer;
1130 return snd_timer_dev_register(dev: &dev);
1131}
1132EXPORT_SYMBOL(snd_timer_global_register);
1133
1134/*
1135 * System timer
1136 */
1137
1138struct snd_timer_system_private {
1139 struct timer_list tlist;
1140 struct snd_timer *snd_timer;
1141 unsigned long last_expires;
1142 unsigned long last_jiffies;
1143 unsigned long correction;
1144};
1145
1146static void snd_timer_s_function(struct timer_list *t)
1147{
1148 struct snd_timer_system_private *priv = from_timer(priv, t,
1149 tlist);
1150 struct snd_timer *timer = priv->snd_timer;
1151 unsigned long jiff = jiffies;
1152 if (time_after(jiff, priv->last_expires))
1153 priv->correction += (long)jiff - (long)priv->last_expires;
1154 snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1155}
1156
1157static int snd_timer_s_start(struct snd_timer * timer)
1158{
1159 struct snd_timer_system_private *priv;
1160 unsigned long njiff;
1161
1162 priv = (struct snd_timer_system_private *) timer->private_data;
1163 njiff = (priv->last_jiffies = jiffies);
1164 if (priv->correction > timer->sticks - 1) {
1165 priv->correction -= timer->sticks - 1;
1166 njiff++;
1167 } else {
1168 njiff += timer->sticks - priv->correction;
1169 priv->correction = 0;
1170 }
1171 priv->last_expires = njiff;
1172 mod_timer(timer: &priv->tlist, expires: njiff);
1173 return 0;
1174}
1175
1176static int snd_timer_s_stop(struct snd_timer * timer)
1177{
1178 struct snd_timer_system_private *priv;
1179 unsigned long jiff;
1180
1181 priv = (struct snd_timer_system_private *) timer->private_data;
1182 del_timer(timer: &priv->tlist);
1183 jiff = jiffies;
1184 if (time_before(jiff, priv->last_expires))
1185 timer->sticks = priv->last_expires - jiff;
1186 else
1187 timer->sticks = 1;
1188 priv->correction = 0;
1189 return 0;
1190}
1191
1192static int snd_timer_s_close(struct snd_timer *timer)
1193{
1194 struct snd_timer_system_private *priv;
1195
1196 priv = (struct snd_timer_system_private *)timer->private_data;
1197 del_timer_sync(timer: &priv->tlist);
1198 return 0;
1199}
1200
1201static const struct snd_timer_hardware snd_timer_system =
1202{
1203 .flags = SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1204 .resolution = 1000000000L / HZ,
1205 .ticks = 10000000L,
1206 .close = snd_timer_s_close,
1207 .start = snd_timer_s_start,
1208 .stop = snd_timer_s_stop
1209};
1210
1211static void snd_timer_free_system(struct snd_timer *timer)
1212{
1213 kfree(objp: timer->private_data);
1214}
1215
1216static int snd_timer_register_system(void)
1217{
1218 struct snd_timer *timer;
1219 struct snd_timer_system_private *priv;
1220 int err;
1221
1222 err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1223 if (err < 0)
1224 return err;
1225 strcpy(p: timer->name, q: "system timer");
1226 timer->hw = snd_timer_system;
1227 priv = kzalloc(size: sizeof(*priv), GFP_KERNEL);
1228 if (priv == NULL) {
1229 snd_timer_free(timer);
1230 return -ENOMEM;
1231 }
1232 priv->snd_timer = timer;
1233 timer_setup(&priv->tlist, snd_timer_s_function, 0);
1234 timer->private_data = priv;
1235 timer->private_free = snd_timer_free_system;
1236 return snd_timer_global_register(timer);
1237}
1238
1239#ifdef CONFIG_SND_PROC_FS
1240/*
1241 * Info interface
1242 */
1243
1244static void snd_timer_proc_read(struct snd_info_entry *entry,
1245 struct snd_info_buffer *buffer)
1246{
1247 struct snd_timer *timer;
1248 struct snd_timer_instance *ti;
1249 unsigned long resolution;
1250
1251 mutex_lock(&register_mutex);
1252 list_for_each_entry(timer, &snd_timer_list, device_list) {
1253 if (timer->card && timer->card->shutdown)
1254 continue;
1255 switch (timer->tmr_class) {
1256 case SNDRV_TIMER_CLASS_GLOBAL:
1257 snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1258 break;
1259 case SNDRV_TIMER_CLASS_CARD:
1260 snd_iprintf(buffer, "C%i-%i: ",
1261 timer->card->number, timer->tmr_device);
1262 break;
1263 case SNDRV_TIMER_CLASS_PCM:
1264 snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1265 timer->tmr_device, timer->tmr_subdevice);
1266 break;
1267 default:
1268 snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1269 timer->card ? timer->card->number : -1,
1270 timer->tmr_device, timer->tmr_subdevice);
1271 }
1272 snd_iprintf(buffer, "%s :", timer->name);
1273 spin_lock_irq(lock: &timer->lock);
1274 resolution = snd_timer_hw_resolution(timer);
1275 spin_unlock_irq(lock: &timer->lock);
1276 if (resolution)
1277 snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1278 resolution / 1000,
1279 resolution % 1000,
1280 timer->hw.ticks);
1281 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1282 snd_iprintf(buffer, " SLAVE");
1283 snd_iprintf(buffer, "\n");
1284 list_for_each_entry(ti, &timer->open_list_head, open_list)
1285 snd_iprintf(buffer, " Client %s : %s\n",
1286 ti->owner ? ti->owner : "unknown",
1287 (ti->flags & (SNDRV_TIMER_IFLG_START |
1288 SNDRV_TIMER_IFLG_RUNNING))
1289 ? "running" : "stopped");
1290 }
1291 mutex_unlock(lock: &register_mutex);
1292}
1293
1294static struct snd_info_entry *snd_timer_proc_entry;
1295
1296static void __init snd_timer_proc_init(void)
1297{
1298 struct snd_info_entry *entry;
1299
1300 entry = snd_info_create_module_entry(THIS_MODULE, name: "timers", NULL);
1301 if (entry != NULL) {
1302 entry->c.text.read = snd_timer_proc_read;
1303 if (snd_info_register(entry) < 0) {
1304 snd_info_free_entry(entry);
1305 entry = NULL;
1306 }
1307 }
1308 snd_timer_proc_entry = entry;
1309}
1310
1311static void __exit snd_timer_proc_done(void)
1312{
1313 snd_info_free_entry(entry: snd_timer_proc_entry);
1314}
1315#else /* !CONFIG_SND_PROC_FS */
1316#define snd_timer_proc_init()
1317#define snd_timer_proc_done()
1318#endif
1319
1320/*
1321 * USER SPACE interface
1322 */
1323
1324static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1325 unsigned long resolution,
1326 unsigned long ticks)
1327{
1328 struct snd_timer_user *tu = timeri->callback_data;
1329 struct snd_timer_read *r;
1330 int prev;
1331
1332 spin_lock(lock: &tu->qlock);
1333 if (tu->qused > 0) {
1334 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1335 r = &tu->queue[prev];
1336 if (r->resolution == resolution) {
1337 r->ticks += ticks;
1338 goto __wake;
1339 }
1340 }
1341 if (tu->qused >= tu->queue_size) {
1342 tu->overrun++;
1343 } else {
1344 r = &tu->queue[tu->qtail++];
1345 tu->qtail %= tu->queue_size;
1346 r->resolution = resolution;
1347 r->ticks = ticks;
1348 tu->qused++;
1349 }
1350 __wake:
1351 spin_unlock(lock: &tu->qlock);
1352 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1353 wake_up(&tu->qchange_sleep);
1354}
1355
1356static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1357 struct snd_timer_tread64 *tread)
1358{
1359 if (tu->qused >= tu->queue_size) {
1360 tu->overrun++;
1361 } else {
1362 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1363 tu->qtail %= tu->queue_size;
1364 tu->qused++;
1365 }
1366}
1367
1368static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1369 int event,
1370 struct timespec64 *tstamp,
1371 unsigned long resolution)
1372{
1373 struct snd_timer_user *tu = timeri->callback_data;
1374 struct snd_timer_tread64 r1;
1375 unsigned long flags;
1376
1377 if (event >= SNDRV_TIMER_EVENT_START &&
1378 event <= SNDRV_TIMER_EVENT_PAUSE)
1379 tu->tstamp = *tstamp;
1380 if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1381 return;
1382 memset(&r1, 0, sizeof(r1));
1383 r1.event = event;
1384 r1.tstamp_sec = tstamp->tv_sec;
1385 r1.tstamp_nsec = tstamp->tv_nsec;
1386 r1.val = resolution;
1387 spin_lock_irqsave(&tu->qlock, flags);
1388 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1389 spin_unlock_irqrestore(lock: &tu->qlock, flags);
1390 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1391 wake_up(&tu->qchange_sleep);
1392}
1393
1394static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1395{
1396 struct snd_timer_user *tu = timeri->callback_data;
1397
1398 tu->disconnected = true;
1399 wake_up(&tu->qchange_sleep);
1400}
1401
1402static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1403 unsigned long resolution,
1404 unsigned long ticks)
1405{
1406 struct snd_timer_user *tu = timeri->callback_data;
1407 struct snd_timer_tread64 *r, r1;
1408 struct timespec64 tstamp;
1409 int prev, append = 0;
1410
1411 memset(&r1, 0, sizeof(r1));
1412 memset(&tstamp, 0, sizeof(tstamp));
1413 spin_lock(lock: &tu->qlock);
1414 if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1415 (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1416 spin_unlock(lock: &tu->qlock);
1417 return;
1418 }
1419 if (tu->last_resolution != resolution || ticks > 0) {
1420 if (timer_tstamp_monotonic)
1421 ktime_get_ts64(ts: &tstamp);
1422 else
1423 ktime_get_real_ts64(tv: &tstamp);
1424 }
1425 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1426 tu->last_resolution != resolution) {
1427 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1428 r1.tstamp_sec = tstamp.tv_sec;
1429 r1.tstamp_nsec = tstamp.tv_nsec;
1430 r1.val = resolution;
1431 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1432 tu->last_resolution = resolution;
1433 append++;
1434 }
1435 if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1436 goto __wake;
1437 if (ticks == 0)
1438 goto __wake;
1439 if (tu->qused > 0) {
1440 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1441 r = &tu->tqueue[prev];
1442 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1443 r->tstamp_sec = tstamp.tv_sec;
1444 r->tstamp_nsec = tstamp.tv_nsec;
1445 r->val += ticks;
1446 append++;
1447 goto __wake;
1448 }
1449 }
1450 r1.event = SNDRV_TIMER_EVENT_TICK;
1451 r1.tstamp_sec = tstamp.tv_sec;
1452 r1.tstamp_nsec = tstamp.tv_nsec;
1453 r1.val = ticks;
1454 snd_timer_user_append_to_tqueue(tu, tread: &r1);
1455 append++;
1456 __wake:
1457 spin_unlock(lock: &tu->qlock);
1458 if (append == 0)
1459 return;
1460 snd_kill_fasync(fasync: tu->fasync, SIGIO, POLL_IN);
1461 wake_up(&tu->qchange_sleep);
1462}
1463
1464static int realloc_user_queue(struct snd_timer_user *tu, int size)
1465{
1466 struct snd_timer_read *queue = NULL;
1467 struct snd_timer_tread64 *tqueue = NULL;
1468
1469 if (tu->tread) {
1470 tqueue = kcalloc(n: size, size: sizeof(*tqueue), GFP_KERNEL);
1471 if (!tqueue)
1472 return -ENOMEM;
1473 } else {
1474 queue = kcalloc(n: size, size: sizeof(*queue), GFP_KERNEL);
1475 if (!queue)
1476 return -ENOMEM;
1477 }
1478
1479 spin_lock_irq(lock: &tu->qlock);
1480 kfree(objp: tu->queue);
1481 kfree(objp: tu->tqueue);
1482 tu->queue_size = size;
1483 tu->queue = queue;
1484 tu->tqueue = tqueue;
1485 tu->qhead = tu->qtail = tu->qused = 0;
1486 spin_unlock_irq(lock: &tu->qlock);
1487
1488 return 0;
1489}
1490
1491static int snd_timer_user_open(struct inode *inode, struct file *file)
1492{
1493 struct snd_timer_user *tu;
1494 int err;
1495
1496 err = stream_open(inode, filp: file);
1497 if (err < 0)
1498 return err;
1499
1500 tu = kzalloc(size: sizeof(*tu), GFP_KERNEL);
1501 if (tu == NULL)
1502 return -ENOMEM;
1503 spin_lock_init(&tu->qlock);
1504 init_waitqueue_head(&tu->qchange_sleep);
1505 mutex_init(&tu->ioctl_lock);
1506 tu->ticks = 1;
1507 if (realloc_user_queue(tu, size: 128) < 0) {
1508 kfree(objp: tu);
1509 return -ENOMEM;
1510 }
1511 file->private_data = tu;
1512 return 0;
1513}
1514
1515static int snd_timer_user_release(struct inode *inode, struct file *file)
1516{
1517 struct snd_timer_user *tu;
1518
1519 if (file->private_data) {
1520 tu = file->private_data;
1521 file->private_data = NULL;
1522 mutex_lock(&tu->ioctl_lock);
1523 if (tu->timeri) {
1524 snd_timer_close(tu->timeri);
1525 snd_timer_instance_free(tu->timeri);
1526 }
1527 mutex_unlock(lock: &tu->ioctl_lock);
1528 snd_fasync_free(fasync: tu->fasync);
1529 kfree(objp: tu->queue);
1530 kfree(objp: tu->tqueue);
1531 kfree(objp: tu);
1532 }
1533 return 0;
1534}
1535
1536static void snd_timer_user_zero_id(struct snd_timer_id *id)
1537{
1538 id->dev_class = SNDRV_TIMER_CLASS_NONE;
1539 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1540 id->card = -1;
1541 id->device = -1;
1542 id->subdevice = -1;
1543}
1544
1545static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1546{
1547 id->dev_class = timer->tmr_class;
1548 id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1549 id->card = timer->card ? timer->card->number : -1;
1550 id->device = timer->tmr_device;
1551 id->subdevice = timer->tmr_subdevice;
1552}
1553
1554static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1555{
1556 struct snd_timer_id id;
1557 struct snd_timer *timer;
1558 struct list_head *p;
1559
1560 if (copy_from_user(to: &id, from: _tid, n: sizeof(id)))
1561 return -EFAULT;
1562 mutex_lock(&register_mutex);
1563 if (id.dev_class < 0) { /* first item */
1564 if (list_empty(head: &snd_timer_list))
1565 snd_timer_user_zero_id(id: &id);
1566 else {
1567 timer = list_entry(snd_timer_list.next,
1568 struct snd_timer, device_list);
1569 snd_timer_user_copy_id(id: &id, timer);
1570 }
1571 } else {
1572 switch (id.dev_class) {
1573 case SNDRV_TIMER_CLASS_GLOBAL:
1574 id.device = id.device < 0 ? 0 : id.device + 1;
1575 list_for_each(p, &snd_timer_list) {
1576 timer = list_entry(p, struct snd_timer, device_list);
1577 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1578 snd_timer_user_copy_id(id: &id, timer);
1579 break;
1580 }
1581 if (timer->tmr_device >= id.device) {
1582 snd_timer_user_copy_id(id: &id, timer);
1583 break;
1584 }
1585 }
1586 if (p == &snd_timer_list)
1587 snd_timer_user_zero_id(id: &id);
1588 break;
1589 case SNDRV_TIMER_CLASS_CARD:
1590 case SNDRV_TIMER_CLASS_PCM:
1591 if (id.card < 0) {
1592 id.card = 0;
1593 } else {
1594 if (id.device < 0) {
1595 id.device = 0;
1596 } else {
1597 if (id.subdevice < 0)
1598 id.subdevice = 0;
1599 else if (id.subdevice < INT_MAX)
1600 id.subdevice++;
1601 }
1602 }
1603 list_for_each(p, &snd_timer_list) {
1604 timer = list_entry(p, struct snd_timer, device_list);
1605 if (timer->tmr_class > id.dev_class) {
1606 snd_timer_user_copy_id(id: &id, timer);
1607 break;
1608 }
1609 if (timer->tmr_class < id.dev_class)
1610 continue;
1611 if (timer->card->number > id.card) {
1612 snd_timer_user_copy_id(id: &id, timer);
1613 break;
1614 }
1615 if (timer->card->number < id.card)
1616 continue;
1617 if (timer->tmr_device > id.device) {
1618 snd_timer_user_copy_id(id: &id, timer);
1619 break;
1620 }
1621 if (timer->tmr_device < id.device)
1622 continue;
1623 if (timer->tmr_subdevice > id.subdevice) {
1624 snd_timer_user_copy_id(id: &id, timer);
1625 break;
1626 }
1627 if (timer->tmr_subdevice < id.subdevice)
1628 continue;
1629 snd_timer_user_copy_id(id: &id, timer);
1630 break;
1631 }
1632 if (p == &snd_timer_list)
1633 snd_timer_user_zero_id(id: &id);
1634 break;
1635 default:
1636 snd_timer_user_zero_id(id: &id);
1637 }
1638 }
1639 mutex_unlock(lock: &register_mutex);
1640 if (copy_to_user(to: _tid, from: &id, n: sizeof(*_tid)))
1641 return -EFAULT;
1642 return 0;
1643}
1644
1645static int snd_timer_user_ginfo(struct file *file,
1646 struct snd_timer_ginfo __user *_ginfo)
1647{
1648 struct snd_timer_ginfo *ginfo;
1649 struct snd_timer_id tid;
1650 struct snd_timer *t;
1651 struct list_head *p;
1652 int err = 0;
1653
1654 ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1655 if (IS_ERR(ptr: ginfo))
1656 return PTR_ERR(ptr: ginfo);
1657
1658 tid = ginfo->tid;
1659 memset(ginfo, 0, sizeof(*ginfo));
1660 ginfo->tid = tid;
1661 mutex_lock(&register_mutex);
1662 t = snd_timer_find(tid: &tid);
1663 if (t != NULL) {
1664 ginfo->card = t->card ? t->card->number : -1;
1665 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1666 ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1667 strscpy(p: ginfo->id, q: t->id, size: sizeof(ginfo->id));
1668 strscpy(p: ginfo->name, q: t->name, size: sizeof(ginfo->name));
1669 spin_lock_irq(lock: &t->lock);
1670 ginfo->resolution = snd_timer_hw_resolution(timer: t);
1671 spin_unlock_irq(lock: &t->lock);
1672 if (t->hw.resolution_min > 0) {
1673 ginfo->resolution_min = t->hw.resolution_min;
1674 ginfo->resolution_max = t->hw.resolution_max;
1675 }
1676 list_for_each(p, &t->open_list_head) {
1677 ginfo->clients++;
1678 }
1679 } else {
1680 err = -ENODEV;
1681 }
1682 mutex_unlock(lock: &register_mutex);
1683 if (err >= 0 && copy_to_user(to: _ginfo, from: ginfo, n: sizeof(*ginfo)))
1684 err = -EFAULT;
1685 kfree(objp: ginfo);
1686 return err;
1687}
1688
1689static int timer_set_gparams(struct snd_timer_gparams *gparams)
1690{
1691 struct snd_timer *t;
1692 int err;
1693
1694 mutex_lock(&register_mutex);
1695 t = snd_timer_find(tid: &gparams->tid);
1696 if (!t) {
1697 err = -ENODEV;
1698 goto _error;
1699 }
1700 if (!list_empty(head: &t->open_list_head)) {
1701 err = -EBUSY;
1702 goto _error;
1703 }
1704 if (!t->hw.set_period) {
1705 err = -ENOSYS;
1706 goto _error;
1707 }
1708 err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1709_error:
1710 mutex_unlock(lock: &register_mutex);
1711 return err;
1712}
1713
1714static int snd_timer_user_gparams(struct file *file,
1715 struct snd_timer_gparams __user *_gparams)
1716{
1717 struct snd_timer_gparams gparams;
1718
1719 if (copy_from_user(to: &gparams, from: _gparams, n: sizeof(gparams)))
1720 return -EFAULT;
1721 return timer_set_gparams(gparams: &gparams);
1722}
1723
1724static int snd_timer_user_gstatus(struct file *file,
1725 struct snd_timer_gstatus __user *_gstatus)
1726{
1727 struct snd_timer_gstatus gstatus;
1728 struct snd_timer_id tid;
1729 struct snd_timer *t;
1730 int err = 0;
1731
1732 if (copy_from_user(to: &gstatus, from: _gstatus, n: sizeof(gstatus)))
1733 return -EFAULT;
1734 tid = gstatus.tid;
1735 memset(&gstatus, 0, sizeof(gstatus));
1736 gstatus.tid = tid;
1737 mutex_lock(&register_mutex);
1738 t = snd_timer_find(tid: &tid);
1739 if (t != NULL) {
1740 spin_lock_irq(lock: &t->lock);
1741 gstatus.resolution = snd_timer_hw_resolution(timer: t);
1742 if (t->hw.precise_resolution) {
1743 t->hw.precise_resolution(t, &gstatus.resolution_num,
1744 &gstatus.resolution_den);
1745 } else {
1746 gstatus.resolution_num = gstatus.resolution;
1747 gstatus.resolution_den = 1000000000uL;
1748 }
1749 spin_unlock_irq(lock: &t->lock);
1750 } else {
1751 err = -ENODEV;
1752 }
1753 mutex_unlock(lock: &register_mutex);
1754 if (err >= 0 && copy_to_user(to: _gstatus, from: &gstatus, n: sizeof(gstatus)))
1755 err = -EFAULT;
1756 return err;
1757}
1758
1759static int snd_timer_user_tselect(struct file *file,
1760 struct snd_timer_select __user *_tselect)
1761{
1762 struct snd_timer_user *tu;
1763 struct snd_timer_select tselect;
1764 char str[32];
1765 int err = 0;
1766
1767 tu = file->private_data;
1768 if (tu->timeri) {
1769 snd_timer_close(tu->timeri);
1770 snd_timer_instance_free(tu->timeri);
1771 tu->timeri = NULL;
1772 }
1773 if (copy_from_user(to: &tselect, from: _tselect, n: sizeof(tselect))) {
1774 err = -EFAULT;
1775 goto __err;
1776 }
1777 sprintf(buf: str, fmt: "application %i", current->pid);
1778 if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1779 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1780 tu->timeri = snd_timer_instance_new(str);
1781 if (!tu->timeri) {
1782 err = -ENOMEM;
1783 goto __err;
1784 }
1785
1786 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1787 tu->timeri->callback = tu->tread
1788 ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1789 tu->timeri->ccallback = snd_timer_user_ccallback;
1790 tu->timeri->callback_data = (void *)tu;
1791 tu->timeri->disconnect = snd_timer_user_disconnect;
1792
1793 err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1794 if (err < 0) {
1795 snd_timer_instance_free(tu->timeri);
1796 tu->timeri = NULL;
1797 }
1798
1799 __err:
1800 return err;
1801}
1802
1803static int snd_timer_user_info(struct file *file,
1804 struct snd_timer_info __user *_info)
1805{
1806 struct snd_timer_user *tu;
1807 struct snd_timer_info *info;
1808 struct snd_timer *t;
1809 int err = 0;
1810
1811 tu = file->private_data;
1812 if (!tu->timeri)
1813 return -EBADFD;
1814 t = tu->timeri->timer;
1815 if (!t)
1816 return -EBADFD;
1817
1818 info = kzalloc(size: sizeof(*info), GFP_KERNEL);
1819 if (! info)
1820 return -ENOMEM;
1821 info->card = t->card ? t->card->number : -1;
1822 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1823 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1824 strscpy(p: info->id, q: t->id, size: sizeof(info->id));
1825 strscpy(p: info->name, q: t->name, size: sizeof(info->name));
1826 spin_lock_irq(lock: &t->lock);
1827 info->resolution = snd_timer_hw_resolution(timer: t);
1828 spin_unlock_irq(lock: &t->lock);
1829 if (copy_to_user(to: _info, from: info, n: sizeof(*_info)))
1830 err = -EFAULT;
1831 kfree(objp: info);
1832 return err;
1833}
1834
1835static int snd_timer_user_params(struct file *file,
1836 struct snd_timer_params __user *_params)
1837{
1838 struct snd_timer_user *tu;
1839 struct snd_timer_params params;
1840 struct snd_timer *t;
1841 int err;
1842
1843 tu = file->private_data;
1844 if (!tu->timeri)
1845 return -EBADFD;
1846 t = tu->timeri->timer;
1847 if (!t)
1848 return -EBADFD;
1849 if (copy_from_user(to: &params, from: _params, n: sizeof(params)))
1850 return -EFAULT;
1851 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1852 u64 resolution;
1853
1854 if (params.ticks < 1) {
1855 err = -EINVAL;
1856 goto _end;
1857 }
1858
1859 /* Don't allow resolution less than 1ms */
1860 resolution = snd_timer_resolution(tu->timeri);
1861 resolution *= params.ticks;
1862 if (resolution < 1000000) {
1863 err = -EINVAL;
1864 goto _end;
1865 }
1866 }
1867 if (params.queue_size > 0 &&
1868 (params.queue_size < 32 || params.queue_size > 1024)) {
1869 err = -EINVAL;
1870 goto _end;
1871 }
1872 if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1873 (1<<SNDRV_TIMER_EVENT_TICK)|
1874 (1<<SNDRV_TIMER_EVENT_START)|
1875 (1<<SNDRV_TIMER_EVENT_STOP)|
1876 (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1877 (1<<SNDRV_TIMER_EVENT_PAUSE)|
1878 (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1879 (1<<SNDRV_TIMER_EVENT_RESUME)|
1880 (1<<SNDRV_TIMER_EVENT_MSTART)|
1881 (1<<SNDRV_TIMER_EVENT_MSTOP)|
1882 (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1883 (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1884 (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1885 (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1886 err = -EINVAL;
1887 goto _end;
1888 }
1889 snd_timer_stop(tu->timeri);
1890 spin_lock_irq(lock: &t->lock);
1891 tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1892 SNDRV_TIMER_IFLG_EXCLUSIVE|
1893 SNDRV_TIMER_IFLG_EARLY_EVENT);
1894 if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1895 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1896 if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1897 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1898 if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1899 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1900 spin_unlock_irq(lock: &t->lock);
1901 if (params.queue_size > 0 &&
1902 (unsigned int)tu->queue_size != params.queue_size) {
1903 err = realloc_user_queue(tu, size: params.queue_size);
1904 if (err < 0)
1905 goto _end;
1906 }
1907 spin_lock_irq(lock: &tu->qlock);
1908 tu->qhead = tu->qtail = tu->qused = 0;
1909 if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1910 if (tu->tread) {
1911 struct snd_timer_tread64 tread;
1912 memset(&tread, 0, sizeof(tread));
1913 tread.event = SNDRV_TIMER_EVENT_EARLY;
1914 tread.tstamp_sec = 0;
1915 tread.tstamp_nsec = 0;
1916 tread.val = 0;
1917 snd_timer_user_append_to_tqueue(tu, tread: &tread);
1918 } else {
1919 struct snd_timer_read *r = &tu->queue[0];
1920 r->resolution = 0;
1921 r->ticks = 0;
1922 tu->qused++;
1923 tu->qtail++;
1924 }
1925 }
1926 tu->filter = params.filter;
1927 tu->ticks = params.ticks;
1928 spin_unlock_irq(lock: &tu->qlock);
1929 err = 0;
1930 _end:
1931 if (copy_to_user(to: _params, from: &params, n: sizeof(params)))
1932 return -EFAULT;
1933 return err;
1934}
1935
1936static int snd_timer_user_status32(struct file *file,
1937 struct snd_timer_status32 __user *_status)
1938 {
1939 struct snd_timer_user *tu;
1940 struct snd_timer_status32 status;
1941
1942 tu = file->private_data;
1943 if (!tu->timeri)
1944 return -EBADFD;
1945 memset(&status, 0, sizeof(status));
1946 status.tstamp_sec = tu->tstamp.tv_sec;
1947 status.tstamp_nsec = tu->tstamp.tv_nsec;
1948 status.resolution = snd_timer_resolution(tu->timeri);
1949 status.lost = tu->timeri->lost;
1950 status.overrun = tu->overrun;
1951 spin_lock_irq(lock: &tu->qlock);
1952 status.queue = tu->qused;
1953 spin_unlock_irq(lock: &tu->qlock);
1954 if (copy_to_user(to: _status, from: &status, n: sizeof(status)))
1955 return -EFAULT;
1956 return 0;
1957}
1958
1959static int snd_timer_user_status64(struct file *file,
1960 struct snd_timer_status64 __user *_status)
1961{
1962 struct snd_timer_user *tu;
1963 struct snd_timer_status64 status;
1964
1965 tu = file->private_data;
1966 if (!tu->timeri)
1967 return -EBADFD;
1968 memset(&status, 0, sizeof(status));
1969 status.tstamp_sec = tu->tstamp.tv_sec;
1970 status.tstamp_nsec = tu->tstamp.tv_nsec;
1971 status.resolution = snd_timer_resolution(tu->timeri);
1972 status.lost = tu->timeri->lost;
1973 status.overrun = tu->overrun;
1974 spin_lock_irq(lock: &tu->qlock);
1975 status.queue = tu->qused;
1976 spin_unlock_irq(lock: &tu->qlock);
1977 if (copy_to_user(to: _status, from: &status, n: sizeof(status)))
1978 return -EFAULT;
1979 return 0;
1980}
1981
1982static int snd_timer_user_start(struct file *file)
1983{
1984 int err;
1985 struct snd_timer_user *tu;
1986
1987 tu = file->private_data;
1988 if (!tu->timeri)
1989 return -EBADFD;
1990 snd_timer_stop(tu->timeri);
1991 tu->timeri->lost = 0;
1992 tu->last_resolution = 0;
1993 err = snd_timer_start(tu->timeri, tu->ticks);
1994 if (err < 0)
1995 return err;
1996 return 0;
1997}
1998
1999static int snd_timer_user_stop(struct file *file)
2000{
2001 int err;
2002 struct snd_timer_user *tu;
2003
2004 tu = file->private_data;
2005 if (!tu->timeri)
2006 return -EBADFD;
2007 err = snd_timer_stop(tu->timeri);
2008 if (err < 0)
2009 return err;
2010 return 0;
2011}
2012
2013static int snd_timer_user_continue(struct file *file)
2014{
2015 int err;
2016 struct snd_timer_user *tu;
2017
2018 tu = file->private_data;
2019 if (!tu->timeri)
2020 return -EBADFD;
2021 /* start timer instead of continue if it's not used before */
2022 if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2023 return snd_timer_user_start(file);
2024 tu->timeri->lost = 0;
2025 err = snd_timer_continue(tu->timeri);
2026 if (err < 0)
2027 return err;
2028 return 0;
2029}
2030
2031static int snd_timer_user_pause(struct file *file)
2032{
2033 int err;
2034 struct snd_timer_user *tu;
2035
2036 tu = file->private_data;
2037 if (!tu->timeri)
2038 return -EBADFD;
2039 err = snd_timer_pause(tu->timeri);
2040 if (err < 0)
2041 return err;
2042 return 0;
2043}
2044
2045static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2046 unsigned int cmd, bool compat)
2047{
2048 int __user *p = argp;
2049 int xarg, old_tread;
2050
2051 if (tu->timeri) /* too late */
2052 return -EBUSY;
2053 if (get_user(xarg, p))
2054 return -EFAULT;
2055
2056 old_tread = tu->tread;
2057
2058 if (!xarg)
2059 tu->tread = TREAD_FORMAT_NONE;
2060 else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2061 (IS_ENABLED(CONFIG_64BIT) && !compat))
2062 tu->tread = TREAD_FORMAT_TIME64;
2063 else
2064 tu->tread = TREAD_FORMAT_TIME32;
2065
2066 if (tu->tread != old_tread &&
2067 realloc_user_queue(tu, size: tu->queue_size) < 0) {
2068 tu->tread = old_tread;
2069 return -ENOMEM;
2070 }
2071
2072 return 0;
2073}
2074
2075enum {
2076 SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2077 SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2078 SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2079 SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2080};
2081
2082static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2083 unsigned long arg, bool compat)
2084{
2085 struct snd_timer_user *tu;
2086 void __user *argp = (void __user *)arg;
2087 int __user *p = argp;
2088
2089 tu = file->private_data;
2090 switch (cmd) {
2091 case SNDRV_TIMER_IOCTL_PVERSION:
2092 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2093 case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2094 return snd_timer_user_next_device(tid: argp);
2095 case SNDRV_TIMER_IOCTL_TREAD_OLD:
2096 case SNDRV_TIMER_IOCTL_TREAD64:
2097 return snd_timer_user_tread(argp, tu, cmd, compat);
2098 case SNDRV_TIMER_IOCTL_GINFO:
2099 return snd_timer_user_ginfo(file, ginfo: argp);
2100 case SNDRV_TIMER_IOCTL_GPARAMS:
2101 return snd_timer_user_gparams(file, gparams: argp);
2102 case SNDRV_TIMER_IOCTL_GSTATUS:
2103 return snd_timer_user_gstatus(file, gstatus: argp);
2104 case SNDRV_TIMER_IOCTL_SELECT:
2105 return snd_timer_user_tselect(file, tselect: argp);
2106 case SNDRV_TIMER_IOCTL_INFO:
2107 return snd_timer_user_info(file, info: argp);
2108 case SNDRV_TIMER_IOCTL_PARAMS:
2109 return snd_timer_user_params(file, params: argp);
2110 case SNDRV_TIMER_IOCTL_STATUS32:
2111 return snd_timer_user_status32(file, status: argp);
2112 case SNDRV_TIMER_IOCTL_STATUS64:
2113 return snd_timer_user_status64(file, status: argp);
2114 case SNDRV_TIMER_IOCTL_START:
2115 case SNDRV_TIMER_IOCTL_START_OLD:
2116 return snd_timer_user_start(file);
2117 case SNDRV_TIMER_IOCTL_STOP:
2118 case SNDRV_TIMER_IOCTL_STOP_OLD:
2119 return snd_timer_user_stop(file);
2120 case SNDRV_TIMER_IOCTL_CONTINUE:
2121 case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2122 return snd_timer_user_continue(file);
2123 case SNDRV_TIMER_IOCTL_PAUSE:
2124 case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2125 return snd_timer_user_pause(file);
2126 }
2127 return -ENOTTY;
2128}
2129
2130static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2131 unsigned long arg)
2132{
2133 struct snd_timer_user *tu = file->private_data;
2134 long ret;
2135
2136 mutex_lock(&tu->ioctl_lock);
2137 ret = __snd_timer_user_ioctl(file, cmd, arg, compat: false);
2138 mutex_unlock(lock: &tu->ioctl_lock);
2139 return ret;
2140}
2141
2142static int snd_timer_user_fasync(int fd, struct file * file, int on)
2143{
2144 struct snd_timer_user *tu;
2145
2146 tu = file->private_data;
2147 return snd_fasync_helper(fd, file, on, fasyncp: &tu->fasync);
2148}
2149
2150static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2151 size_t count, loff_t *offset)
2152{
2153 struct snd_timer_tread64 *tread;
2154 struct snd_timer_tread32 tread32;
2155 struct snd_timer_user *tu;
2156 long result = 0, unit;
2157 int qhead;
2158 int err = 0;
2159
2160 tu = file->private_data;
2161 switch (tu->tread) {
2162 case TREAD_FORMAT_TIME64:
2163 unit = sizeof(struct snd_timer_tread64);
2164 break;
2165 case TREAD_FORMAT_TIME32:
2166 unit = sizeof(struct snd_timer_tread32);
2167 break;
2168 case TREAD_FORMAT_NONE:
2169 unit = sizeof(struct snd_timer_read);
2170 break;
2171 default:
2172 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2173 return -ENOTSUPP;
2174 }
2175
2176 mutex_lock(&tu->ioctl_lock);
2177 spin_lock_irq(lock: &tu->qlock);
2178 while ((long)count - result >= unit) {
2179 while (!tu->qused) {
2180 wait_queue_entry_t wait;
2181
2182 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2183 err = -EAGAIN;
2184 goto _error;
2185 }
2186
2187 set_current_state(TASK_INTERRUPTIBLE);
2188 init_waitqueue_entry(wq_entry: &wait, current);
2189 add_wait_queue(wq_head: &tu->qchange_sleep, wq_entry: &wait);
2190
2191 spin_unlock_irq(lock: &tu->qlock);
2192 mutex_unlock(lock: &tu->ioctl_lock);
2193 schedule();
2194 mutex_lock(&tu->ioctl_lock);
2195 spin_lock_irq(lock: &tu->qlock);
2196
2197 remove_wait_queue(wq_head: &tu->qchange_sleep, wq_entry: &wait);
2198
2199 if (tu->disconnected) {
2200 err = -ENODEV;
2201 goto _error;
2202 }
2203 if (signal_pending(current)) {
2204 err = -ERESTARTSYS;
2205 goto _error;
2206 }
2207 }
2208
2209 qhead = tu->qhead++;
2210 tu->qhead %= tu->queue_size;
2211 tu->qused--;
2212 spin_unlock_irq(lock: &tu->qlock);
2213
2214 tread = &tu->tqueue[qhead];
2215
2216 switch (tu->tread) {
2217 case TREAD_FORMAT_TIME64:
2218 if (copy_to_user(to: buffer, from: tread,
2219 n: sizeof(struct snd_timer_tread64)))
2220 err = -EFAULT;
2221 break;
2222 case TREAD_FORMAT_TIME32:
2223 memset(&tread32, 0, sizeof(tread32));
2224 tread32 = (struct snd_timer_tread32) {
2225 .event = tread->event,
2226 .tstamp_sec = tread->tstamp_sec,
2227 .tstamp_nsec = tread->tstamp_nsec,
2228 .val = tread->val,
2229 };
2230
2231 if (copy_to_user(to: buffer, from: &tread32, n: sizeof(tread32)))
2232 err = -EFAULT;
2233 break;
2234 case TREAD_FORMAT_NONE:
2235 if (copy_to_user(to: buffer, from: &tu->queue[qhead],
2236 n: sizeof(struct snd_timer_read)))
2237 err = -EFAULT;
2238 break;
2239 default:
2240 err = -ENOTSUPP;
2241 break;
2242 }
2243
2244 spin_lock_irq(lock: &tu->qlock);
2245 if (err < 0)
2246 goto _error;
2247 result += unit;
2248 buffer += unit;
2249 }
2250 _error:
2251 spin_unlock_irq(lock: &tu->qlock);
2252 mutex_unlock(lock: &tu->ioctl_lock);
2253 return result > 0 ? result : err;
2254}
2255
2256static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2257{
2258 __poll_t mask;
2259 struct snd_timer_user *tu;
2260
2261 tu = file->private_data;
2262
2263 poll_wait(filp: file, wait_address: &tu->qchange_sleep, p: wait);
2264
2265 mask = 0;
2266 spin_lock_irq(lock: &tu->qlock);
2267 if (tu->qused)
2268 mask |= EPOLLIN | EPOLLRDNORM;
2269 if (tu->disconnected)
2270 mask |= EPOLLERR;
2271 spin_unlock_irq(lock: &tu->qlock);
2272
2273 return mask;
2274}
2275
2276#ifdef CONFIG_COMPAT
2277#include "timer_compat.c"
2278#else
2279#define snd_timer_user_ioctl_compat NULL
2280#endif
2281
2282static const struct file_operations snd_timer_f_ops =
2283{
2284 .owner = THIS_MODULE,
2285 .read = snd_timer_user_read,
2286 .open = snd_timer_user_open,
2287 .release = snd_timer_user_release,
2288 .llseek = no_llseek,
2289 .poll = snd_timer_user_poll,
2290 .unlocked_ioctl = snd_timer_user_ioctl,
2291 .compat_ioctl = snd_timer_user_ioctl_compat,
2292 .fasync = snd_timer_user_fasync,
2293};
2294
2295/* unregister the system timer */
2296static void snd_timer_free_all(void)
2297{
2298 struct snd_timer *timer, *n;
2299
2300 list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2301 snd_timer_free(timer);
2302}
2303
2304static struct device *timer_dev;
2305
2306/*
2307 * ENTRY functions
2308 */
2309
2310static int __init alsa_timer_init(void)
2311{
2312 int err;
2313
2314 err = snd_device_alloc(dev_p: &timer_dev, NULL);
2315 if (err < 0)
2316 return err;
2317 dev_set_name(dev: timer_dev, name: "timer");
2318
2319#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2320 snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2321 string: "system timer");
2322#endif
2323
2324 err = snd_timer_register_system();
2325 if (err < 0) {
2326 pr_err("ALSA: unable to register system timer (%i)\n", err);
2327 goto put_timer;
2328 }
2329
2330 err = snd_register_device(type: SNDRV_DEVICE_TYPE_TIMER, NULL, dev: 0,
2331 f_ops: &snd_timer_f_ops, NULL, device: timer_dev);
2332 if (err < 0) {
2333 pr_err("ALSA: unable to register timer device (%i)\n", err);
2334 snd_timer_free_all();
2335 goto put_timer;
2336 }
2337
2338 snd_timer_proc_init();
2339 return 0;
2340
2341put_timer:
2342 put_device(dev: timer_dev);
2343 return err;
2344}
2345
2346static void __exit alsa_timer_exit(void)
2347{
2348 snd_unregister_device(dev: timer_dev);
2349 snd_timer_free_all();
2350 put_device(dev: timer_dev);
2351 snd_timer_proc_done();
2352#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2353 snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2354#endif
2355}
2356
2357module_init(alsa_timer_init)
2358module_exit(alsa_timer_exit)
2359

source code of linux/sound/core/timer.c