source: GPL/trunk/alsa-kernel/drivers/aloop.c@ 684

Last change on this file since 684 was 679, checked in by David Azarewicz, 5 years ago

Merge changes from Paul's uniaud32next branch.
File size: 51.7 KB
Line 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Loopback soundcard
4 *
5 * Original code:
6 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
7 *
8 * More accurate positioning and full-duplex support:
9 * Copyright (c) Ahmet Ä°nan <ainan at mathematik.uni-freiburg.de>
10 *
11 * Major (almost complete) rewrite:
12 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
13 *
14 * A next major update in 2010 (separate timers for playback and capture):
15 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
16 */
17
18#include <linux/init.h>
19#include <linux/jiffies.h>
20#include <linux/slab.h>
21#include <linux/time.h>
22#include <linux/wait.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <sound/core.h>
26#include <sound/control.h>
27#include <sound/pcm.h>
28#include <sound/pcm_params.h>
29#include <sound/info.h>
30#include <sound/initval.h>
31#include <sound/timer.h>
32
33MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
34MODULE_DESCRIPTION("A loopback soundcard");
35MODULE_LICENSE("GPL");
36MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
37
38#define MAX_PCM_SUBSTREAMS 8
39
40static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
41static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
42static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
43static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
44static int pcm_notify[SNDRV_CARDS];
45static char *timer_source[SNDRV_CARDS];
46
47module_param_array(index, int, NULL, 0444);
48MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
49module_param_array(id, charp, NULL, 0444);
50MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
51module_param_array(enable, bool, NULL, 0444);
52MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
53module_param_array(pcm_substreams, int, NULL, 0444);
54MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
55module_param_array(pcm_notify, int, NULL, 0444);
56MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
57module_param_array(timer_source, charp, NULL, 0444);
58MODULE_PARM_DESC(timer_source, "Sound card name or number and device/subdevice number of timer to be used. Empty string for jiffies timer [default].");
59
60#define NO_PITCH 100000
61
62#define CABLE_VALID_PLAYBACK BIT(SNDRV_PCM_STREAM_PLAYBACK)
63#define CABLE_VALID_CAPTURE BIT(SNDRV_PCM_STREAM_CAPTURE)
64#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK | CABLE_VALID_CAPTURE)
65
66struct loopback_cable;
67struct loopback_pcm;
68
69struct loopback_ops {
70 /* optional
71 * call in loopback->cable_lock
72 */
73 int (*open)(struct loopback_pcm *dpcm);
74 /* required
75 * call in cable->lock
76 */
77 int (*start)(struct loopback_pcm *dpcm);
78 /* required
79 * call in cable->lock
80 */
81 int (*stop)(struct loopback_pcm *dpcm);
82 /* optional */
83 int (*stop_sync)(struct loopback_pcm *dpcm);
84 /* optional */
85 int (*close_substream)(struct loopback_pcm *dpcm);
86 /* optional
87 * call in loopback->cable_lock
88 */
89 int (*close_cable)(struct loopback_pcm *dpcm);
90 /* optional
91 * call in cable->lock
92 */
93 unsigned int (*pos_update)(struct loopback_cable *cable);
94 /* optional */
95 void (*dpcm_info)(struct loopback_pcm *dpcm,
96 struct snd_info_buffer *buffer);
97};
98
99struct loopback_cable {
100 spinlock_t lock;
101 struct loopback_pcm *streams[2];
102 struct snd_pcm_hardware hw;
103 /* flags */
104 unsigned int valid;
105 unsigned int running;
106 unsigned int pause;
107 /* timer specific */
108 struct loopback_ops *ops;
109 /* If sound timer is used */
110 struct {
111 int stream;
112 struct snd_timer_id id;
113 struct work_struct event_work;
114 struct snd_timer_instance *instance;
115 } snd_timer;
116};
117
118struct loopback_setup {
119 unsigned int notify: 1;
120 unsigned int rate_shift;
121 snd_pcm_format_t format;
122 unsigned int rate;
123 unsigned int channels;
124 struct snd_ctl_elem_id active_id;
125 struct snd_ctl_elem_id format_id;
126 struct snd_ctl_elem_id rate_id;
127 struct snd_ctl_elem_id channels_id;
128};
129
130struct loopback {
131 struct snd_card *card;
132 struct mutex cable_lock;
133 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
134 struct snd_pcm *pcm[2];
135 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
136 const char *timer_source;
137};
138
139struct loopback_pcm {
140 struct loopback *loopback;
141 struct snd_pcm_substream *substream;
142 struct loopback_cable *cable;
143 unsigned int pcm_buffer_size;
144 unsigned int buf_pos; /* position in buffer */
145 unsigned int silent_size;
146 /* PCM parameters */
147 unsigned int pcm_period_size;
148 unsigned int pcm_bps; /* bytes per second */
149 unsigned int pcm_salign; /* bytes per sample * channels */
150 unsigned int pcm_rate_shift; /* rate shift value */
151 /* flags */
152 unsigned int period_update_pending :1;
153 /* timer stuff */
154 unsigned int irq_pos; /* fractional IRQ position in jiffies
155 * ticks
156 */
157 unsigned int period_size_frac; /* period size in jiffies ticks */
158 unsigned int last_drift;
159 unsigned long last_jiffies;
160 /* If jiffies timer is used */
161 struct timer_list timer;
162};
163
164static struct platform_device *devices[SNDRV_CARDS];
165
166static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
167{
168 if (dpcm->pcm_rate_shift == NO_PITCH) {
169 x /= HZ;
170 } else {
171 x = div_u64(NO_PITCH * (unsigned long long)x,
172 HZ * (unsigned long long)dpcm->pcm_rate_shift);
173 }
174 return x - (x % dpcm->pcm_salign);
175}
176
177static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
178{
179 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
180 return x * HZ;
181 } else {
182 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
183 NO_PITCH);
184 }
185 return x;
186}
187
188static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
189{
190 int device = dpcm->substream->pstr->pcm->device;
191
192 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
193 device ^= 1;
194 return &dpcm->loopback->setup[dpcm->substream->number][device];
195}
196
197static inline unsigned int get_notify(struct loopback_pcm *dpcm)
198{
199 return get_setup(dpcm)->notify;
200}
201
202static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
203{
204 return get_setup(dpcm)->rate_shift;
205}
206
207/* call in cable->lock */
208static int loopback_jiffies_timer_start(struct loopback_pcm *dpcm)
209{
210 unsigned long tick;
211 unsigned int rate_shift = get_rate_shift(dpcm);
212
213 if (rate_shift != dpcm->pcm_rate_shift) {
214 dpcm->pcm_rate_shift = rate_shift;
215 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
216 }
217 if (dpcm->period_size_frac <= dpcm->irq_pos) {
218 dpcm->irq_pos %= dpcm->period_size_frac;
219 dpcm->period_update_pending = 1;
220 }
221 tick = dpcm->period_size_frac - dpcm->irq_pos;
222 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
223 mod_timer(&dpcm->timer, jiffies + tick);
224
225 return 0;
226}
227
228/* call in cable->lock */
229static int loopback_snd_timer_start(struct loopback_pcm *dpcm)
230{
231 struct loopback_cable *cable = dpcm->cable;
232 int err;
233
234 /* Loopback device has to use same period as timer card. Therefore
235 * wake up for each snd_pcm_period_elapsed() call of timer card.
236 */
237 err = snd_timer_start(cable->snd_timer.instance, 1);
238 if (err < 0) {
239 /* do not report error if trying to start but already
240 * running. For example called by opposite substream
241 * of the same cable
242 */
243 if (err == -EBUSY)
244 return 0;
245
246 pcm_err(dpcm->substream->pcm,
247 "snd_timer_start(%d,%d,%d) failed with %d",
248 cable->snd_timer.id.card,
249 cable->snd_timer.id.device,
250 cable->snd_timer.id.subdevice,
251 err);
252 }
253
254 return err;
255}
256
257/* call in cable->lock */
258static inline int loopback_jiffies_timer_stop(struct loopback_pcm *dpcm)
259{
260 del_timer(&dpcm->timer);
261 dpcm->timer.expires = 0;
262
263 return 0;
264}
265
266/* call in cable->lock */
267static int loopback_snd_timer_stop(struct loopback_pcm *dpcm)
268{
269 struct loopback_cable *cable = dpcm->cable;
270 int err;
271
272 /* only stop if both devices (playback and capture) are not running */
273 if (cable->running ^ cable->pause)
274 return 0;
275
276 err = snd_timer_stop(cable->snd_timer.instance);
277 if (err < 0) {
278 pcm_err(dpcm->substream->pcm,
279 "snd_timer_stop(%d,%d,%d) failed with %d",
280 cable->snd_timer.id.card,
281 cable->snd_timer.id.device,
282 cable->snd_timer.id.subdevice,
283 err);
284 }
285
286 return err;
287}
288
289static inline int loopback_jiffies_timer_stop_sync(struct loopback_pcm *dpcm)
290{
291 del_timer_sync(&dpcm->timer);
292
293 return 0;
294}
295
296/* call in loopback->cable_lock */
297static int loopback_snd_timer_close_cable(struct loopback_pcm *dpcm)
298{
299 struct loopback_cable *cable = dpcm->cable;
300
301 /* snd_timer was not opened */
302 if (!cable->snd_timer.instance)
303 return 0;
304
305 /* will only be called from free_cable() when other stream was
306 * already closed. Other stream cannot be reopened as long as
307 * loopback->cable_lock is locked. Therefore no need to lock
308 * cable->lock;
309 */
310 snd_timer_close(cable->snd_timer.instance);
311
312 /* wait till drain work has finished if requested */
313 cancel_work_sync(&cable->snd_timer.event_work);
314
315 snd_timer_instance_free(cable->snd_timer.instance);
316 memset(&cable->snd_timer, 0, sizeof(cable->snd_timer));
317
318 return 0;
319}
320
321static int loopback_check_format(struct loopback_cable *cable, int stream)
322{
323 struct snd_pcm_runtime *runtime, *cruntime;
324 struct loopback_setup *setup;
325 struct snd_card *card;
326 int check;
327
328 if (cable->valid != CABLE_VALID_BOTH) {
329 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
330 goto __notify;
331 return 0;
332 }
333 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
334 substream->runtime;
335 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
336 substream->runtime;
337 check = runtime->format != cruntime->format ||
338 runtime->rate != cruntime->rate ||
339 runtime->channels != cruntime->channels;
340 if (!check)
341 return 0;
342 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
343 return -EIO;
344 } else {
345 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
346 substream, SNDRV_PCM_STATE_DRAINING);
347 __notify:
348 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
349 substream->runtime;
350 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
351 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
352 if (setup->format != runtime->format) {
353 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
354 &setup->format_id);
355 setup->format = runtime->format;
356 }
357 if (setup->rate != runtime->rate) {
358 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
359 &setup->rate_id);
360 setup->rate = runtime->rate;
361 }
362 if (setup->channels != runtime->channels) {
363 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
364 &setup->channels_id);
365 setup->channels = runtime->channels;
366 }
367 }
368 return 0;
369}
370
371static void loopback_active_notify(struct loopback_pcm *dpcm)
372{
373 snd_ctl_notify(dpcm->loopback->card,
374 SNDRV_CTL_EVENT_MASK_VALUE,
375 &get_setup(dpcm)->active_id);
376}
377
378static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
379{
380 struct snd_pcm_runtime *runtime = substream->runtime;
381 struct loopback_pcm *dpcm = runtime->private_data;
382 struct loopback_cable *cable = dpcm->cable;
383 int err = 0, stream = 1 << substream->stream;
384
385 switch (cmd) {
386 case SNDRV_PCM_TRIGGER_START:
387 err = loopback_check_format(cable, substream->stream);
388 if (err < 0)
389 return err;
390 dpcm->last_jiffies = jiffies;
391 dpcm->pcm_rate_shift = 0;
392 dpcm->last_drift = 0;
393 spin_lock(&cable->lock);
394 cable->running |= stream;
395 cable->pause &= ~stream;
396 err = cable->ops->start(dpcm);
397 spin_unlock(&cable->lock);
398 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
399 loopback_active_notify(dpcm);
400 break;
401 case SNDRV_PCM_TRIGGER_STOP:
402 spin_lock(&cable->lock);
403 cable->running &= ~stream;
404 cable->pause &= ~stream;
405 err = cable->ops->stop(dpcm);
406 spin_unlock(&cable->lock);
407 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
408 loopback_active_notify(dpcm);
409 break;
410 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
411 case SNDRV_PCM_TRIGGER_SUSPEND:
412 spin_lock(&cable->lock);
413 cable->pause |= stream;
414 err = cable->ops->stop(dpcm);
415 spin_unlock(&cable->lock);
416 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
417 loopback_active_notify(dpcm);
418 break;
419 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
420 case SNDRV_PCM_TRIGGER_RESUME:
421 spin_lock(&cable->lock);
422 dpcm->last_jiffies = jiffies;
423 cable->pause &= ~stream;
424 err = cable->ops->start(dpcm);
425 spin_unlock(&cable->lock);
426 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
427 loopback_active_notify(dpcm);
428 break;
429 default:
430 return -EINVAL;
431 }
432 return err;
433}
434
435static void params_change(struct snd_pcm_substream *substream)
436{
437 struct snd_pcm_runtime *runtime = substream->runtime;
438 struct loopback_pcm *dpcm = runtime->private_data;
439 struct loopback_cable *cable = dpcm->cable;
440
441 cable->hw.formats = pcm_format_to_bits(runtime->format);
442 cable->hw.rate_min = runtime->rate;
443 cable->hw.rate_max = runtime->rate;
444 cable->hw.channels_min = runtime->channels;
445 cable->hw.channels_max = runtime->channels;
446
447 if (cable->snd_timer.instance) {
448 cable->hw.period_bytes_min =
449 frames_to_bytes(runtime, runtime->period_size);
450 cable->hw.period_bytes_max = cable->hw.period_bytes_min;
451 }
452
453}
454
455static int loopback_prepare(struct snd_pcm_substream *substream)
456{
457 struct snd_pcm_runtime *runtime = substream->runtime;
458 struct loopback_pcm *dpcm = runtime->private_data;
459 struct loopback_cable *cable = dpcm->cable;
460 int err, bps, salign;
461
462 if (cable->ops->stop_sync) {
463 err = cable->ops->stop_sync(dpcm);
464 if (err < 0)
465 return err;
466 }
467
468 salign = (snd_pcm_format_physical_width(runtime->format) *
469 runtime->channels) / 8;
470 bps = salign * runtime->rate;
471 if (bps <= 0 || salign <= 0)
472 return -EINVAL;
473
474 dpcm->buf_pos = 0;
475 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
476 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
477 /* clear capture buffer */
478 dpcm->silent_size = dpcm->pcm_buffer_size;
479 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
480 runtime->buffer_size * runtime->channels);
481 }
482
483 dpcm->irq_pos = 0;
484 dpcm->period_update_pending = 0;
485 dpcm->pcm_bps = bps;
486 dpcm->pcm_salign = salign;
487 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
488
489 mutex_lock(&dpcm->loopback->cable_lock);
490 if (!(cable->valid & ~(1 << substream->stream)) ||
491 (get_setup(dpcm)->notify &&
492 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
493 params_change(substream);
494 cable->valid |= 1 << substream->stream;
495 mutex_unlock(&dpcm->loopback->cable_lock);
496
497 return 0;
498}
499
500static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
501{
502 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
503 char *dst = runtime->dma_area;
504 unsigned int dst_off = dpcm->buf_pos;
505
506 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
507 return;
508 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
509 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
510
511 for (;;) {
512 unsigned int size = bytes;
513 if (dst_off + size > dpcm->pcm_buffer_size)
514 size = dpcm->pcm_buffer_size - dst_off;
515 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
516 bytes_to_frames(runtime, size) *
517 runtime->channels);
518 dpcm->silent_size += size;
519 bytes -= size;
520 if (!bytes)
521 break;
522 dst_off = 0;
523 }
524}
525
526static void copy_play_buf(struct loopback_pcm *play,
527 struct loopback_pcm *capt,
528 unsigned int bytes)
529{
530 struct snd_pcm_runtime *runtime = play->substream->runtime;
531 char *src = runtime->dma_area;
532 char *dst = capt->substream->runtime->dma_area;
533 unsigned int src_off = play->buf_pos;
534 unsigned int dst_off = capt->buf_pos;
535 unsigned int clear_bytes = 0;
536
537 /* check if playback is draining, trim the capture copy size
538 * when our pointer is at the end of playback ring buffer */
539 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
540 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
541 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
542 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
543 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
544 appl_ptr1 += play->buf_pos / play->pcm_salign;
545 if (appl_ptr < appl_ptr1)
546 appl_ptr1 -= runtime->buffer_size;
547 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
548 if (diff < bytes) {
549 clear_bytes = bytes - diff;
550 bytes = diff;
551 }
552 }
553
554 for (;;) {
555 unsigned int size = bytes;
556 if (src_off + size > play->pcm_buffer_size)
557 size = play->pcm_buffer_size - src_off;
558 if (dst_off + size > capt->pcm_buffer_size)
559 size = capt->pcm_buffer_size - dst_off;
560 memcpy(dst + dst_off, src + src_off, size);
561 capt->silent_size = 0;
562 bytes -= size;
563 if (!bytes)
564 break;
565 src_off = (src_off + size) % play->pcm_buffer_size;
566 dst_off = (dst_off + size) % capt->pcm_buffer_size;
567 }
568
569 if (clear_bytes > 0) {
570 clear_capture_buf(capt, clear_bytes);
571 capt->silent_size = 0;
572 }
573}
574
575static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
576 unsigned int jiffies_delta)
577{
578 unsigned long last_pos;
579 unsigned int delta;
580
581 last_pos = byte_pos(dpcm, dpcm->irq_pos);
582 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
583 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
584 if (delta >= dpcm->last_drift)
585 delta -= dpcm->last_drift;
586 dpcm->last_drift = 0;
587 if (dpcm->irq_pos >= dpcm->period_size_frac) {
588 dpcm->irq_pos %= dpcm->period_size_frac;
589 dpcm->period_update_pending = 1;
590 }
591 return delta;
592}
593
594static inline void bytepos_finish(struct loopback_pcm *dpcm,
595 unsigned int delta)
596{
597 dpcm->buf_pos += delta;
598 dpcm->buf_pos %= dpcm->pcm_buffer_size;
599}
600
601/* call in cable->lock */
602static unsigned int loopback_jiffies_timer_pos_update
603 (struct loopback_cable *cable)
604{
605 struct loopback_pcm *dpcm_play =
606 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
607 struct loopback_pcm *dpcm_capt =
608 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
609 unsigned long delta_play = 0, delta_capt = 0;
610 unsigned int running, count1, count2;
611
612 running = cable->running ^ cable->pause;
613 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
614 delta_play = jiffies - dpcm_play->last_jiffies;
615 dpcm_play->last_jiffies += delta_play;
616 }
617
618 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
619 delta_capt = jiffies - dpcm_capt->last_jiffies;
620 dpcm_capt->last_jiffies += delta_capt;
621 }
622
623 if (delta_play == 0 && delta_capt == 0)
624 goto unlock;
625
626 if (delta_play > delta_capt) {
627 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
628 bytepos_finish(dpcm_play, count1);
629 delta_play = delta_capt;
630 } else if (delta_play < delta_capt) {
631 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
632 clear_capture_buf(dpcm_capt, count1);
633 bytepos_finish(dpcm_capt, count1);
634 delta_capt = delta_play;
635 }
636
637 if (delta_play == 0 && delta_capt == 0)
638 goto unlock;
639
640 /* note delta_capt == delta_play at this moment */
641 count1 = bytepos_delta(dpcm_play, delta_play);
642 count2 = bytepos_delta(dpcm_capt, delta_capt);
643 if (count1 < count2) {
644 dpcm_capt->last_drift = count2 - count1;
645 count1 = count2;
646 } else if (count1 > count2) {
647 dpcm_play->last_drift = count1 - count2;
648 }
649 copy_play_buf(dpcm_play, dpcm_capt, count1);
650 bytepos_finish(dpcm_play, count1);
651 bytepos_finish(dpcm_capt, count1);
652 unlock:
653 return running;
654}
655
656static void loopback_jiffies_timer_function(struct timer_list *t)
657{
658 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
659 unsigned long flags;
660
661 spin_lock_irqsave(&dpcm->cable->lock, flags);
662 if (loopback_jiffies_timer_pos_update(dpcm->cable) &
663 (1 << dpcm->substream->stream)) {
664 loopback_jiffies_timer_start(dpcm);
665 if (dpcm->period_update_pending) {
666 dpcm->period_update_pending = 0;
667 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
668 /* need to unlock before calling below */
669 snd_pcm_period_elapsed(dpcm->substream);
670 return;
671 }
672 }
673 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
674}
675
676/* call in cable->lock */
677static int loopback_snd_timer_check_resolution(struct snd_pcm_runtime *runtime,
678 unsigned long resolution)
679{
680 if (resolution != runtime->timer_resolution) {
681 struct loopback_pcm *dpcm = runtime->private_data;
682 struct loopback_cable *cable = dpcm->cable;
683 /* Worst case estimation of possible values for resolution
684 * resolution <= (512 * 1024) frames / 8kHz in nsec
685 * resolution <= 65.536.000.000 nsec
686 *
687 * period_size <= 65.536.000.000 nsec / 1000nsec/usec * 192kHz +
688 * 500.000
689 * period_size <= 12.582.912.000.000 <64bit
690 * / 1.000.000 usec/sec
691 */
692 snd_pcm_uframes_t period_size_usec =
693 resolution / 1000 * runtime->rate;
694 /* round to nearest sample rate */
695 snd_pcm_uframes_t period_size =
696 (period_size_usec + 500 * 1000) / (1000 * 1000);
697
698 pcm_err(dpcm->substream->pcm,
699 "Period size (%lu frames) of loopback device is not corresponding to timer resolution (%lu nsec = %lu frames) of card timer %d,%d,%d. Use period size of %lu frames for loopback device.",
700 runtime->period_size, resolution, period_size,
701 cable->snd_timer.id.card,
702 cable->snd_timer.id.device,
703 cable->snd_timer.id.subdevice,
704 period_size);
705 return -EINVAL;
706 }
707 return 0;
708}
709
710static void loopback_snd_timer_period_elapsed(struct loopback_cable *cable,
711 int event,
712 unsigned long resolution)
713{
714 struct loopback_pcm *dpcm_play, *dpcm_capt;
715 struct snd_pcm_substream *substream_play, *substream_capt;
716 struct snd_pcm_runtime *valid_runtime;
717 unsigned int running, elapsed_bytes;
718 unsigned long flags;
719
720 spin_lock_irqsave(&cable->lock, flags);
721 running = cable->running ^ cable->pause;
722 /* no need to do anything if no stream is running */
723 if (!running) {
724 spin_unlock_irqrestore(&cable->lock, flags);
725 return;
726 }
727
728 dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
729 dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE];
730
731 if (event == SNDRV_TIMER_EVENT_MSTOP) {
732 if (!dpcm_play ||
733 dpcm_play->substream->runtime->status->state !=
734 SNDRV_PCM_STATE_DRAINING) {
735 spin_unlock_irqrestore(&cable->lock, flags);
736 return;
737 }
738 }
739
740 substream_play = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
741 dpcm_play->substream : NULL;
742 substream_capt = (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) ?
743 dpcm_capt->substream : NULL;
744 valid_runtime = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
745 dpcm_play->substream->runtime :
746 dpcm_capt->substream->runtime;
747
748 /* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */
749 if (event == SNDRV_TIMER_EVENT_TICK) {
750 /* The hardware rules guarantee that playback and capture period
751 * are the same. Therefore only one device has to be checked
752 * here.
753 */
754 if (loopback_snd_timer_check_resolution(valid_runtime,
755 resolution) < 0) {
756 spin_unlock_irqrestore(&cable->lock, flags);
757 if (substream_play)
758 snd_pcm_stop_xrun(substream_play);
759 if (substream_capt)
760 snd_pcm_stop_xrun(substream_capt);
761 return;
762 }
763 }
764
765 elapsed_bytes = frames_to_bytes(valid_runtime,
766 valid_runtime->period_size);
767 /* The same timer interrupt is used for playback and capture device */
768 if ((running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) &&
769 (running & (1 << SNDRV_PCM_STREAM_CAPTURE))) {
770 copy_play_buf(dpcm_play, dpcm_capt, elapsed_bytes);
771 bytepos_finish(dpcm_play, elapsed_bytes);
772 bytepos_finish(dpcm_capt, elapsed_bytes);
773 } else if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
774 bytepos_finish(dpcm_play, elapsed_bytes);
775 } else if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
776 clear_capture_buf(dpcm_capt, elapsed_bytes);
777 bytepos_finish(dpcm_capt, elapsed_bytes);
778 }
779 spin_unlock_irqrestore(&cable->lock, flags);
780
781 if (substream_play)
782 snd_pcm_period_elapsed(substream_play);
783 if (substream_capt)
784 snd_pcm_period_elapsed(substream_capt);
785}
786
787static void loopback_snd_timer_function(struct snd_timer_instance *timeri,
788 unsigned long resolution,
789 unsigned long ticks)
790{
791 struct loopback_cable *cable = timeri->callback_data;
792
793 loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_TICK,
794 resolution);
795}
796
797static void loopback_snd_timer_work(struct work_struct *work)
798{
799 struct loopback_cable *cable;
800
801 cable = container_of(work, struct loopback_cable, snd_timer.event_work);
802 loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_MSTOP, 0);
803}
804
805static void loopback_snd_timer_event(struct snd_timer_instance *timeri,
806 int event,
807 struct timespec64 *tstamp,
808 unsigned long resolution)
809{
810 /* Do not lock cable->lock here because timer->lock is already hold.
811 * There are other functions which first lock cable->lock and than
812 * timer->lock e.g.
813 * loopback_trigger()
814 * spin_lock(&cable->lock)
815 * loopback_snd_timer_start()
816 * snd_timer_start()
817 * spin_lock(&timer->lock)
818 * Therefore when using the oposit order of locks here it could result
819 * in a deadlock.
820 */
821
822 if (event == SNDRV_TIMER_EVENT_MSTOP) {
823 struct loopback_cable *cable = timeri->callback_data;
824
825 /* sound card of the timer was stopped. Therefore there will not
826 * be any further timer callbacks. Due to this forward audio
827 * data from here if in draining state. When still in running
828 * state the streaming will be aborted by the usual timeout. It
829 * should not be aborted here because may be the timer sound
830 * card does only a recovery and the timer is back soon.
831 * This work triggers loopback_snd_timer_work()
832 */
833 schedule_work(&cable->snd_timer.event_work);
834 }
835}
836
837static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm,
838 struct snd_info_buffer *buffer)
839{
840 snd_iprintf(buffer, " update_pending:\t%u\n",
841 dpcm->period_update_pending);
842 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
843 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
844 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
845 dpcm->last_jiffies, jiffies);
846 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
847}
848
849static void loopback_snd_timer_dpcm_info(struct loopback_pcm *dpcm,
850 struct snd_info_buffer *buffer)
851{
852 struct loopback_cable *cable = dpcm->cable;
853
854 snd_iprintf(buffer, " sound timer:\thw:%d,%d,%d\n",
855 cable->snd_timer.id.card,
856 cable->snd_timer.id.device,
857 cable->snd_timer.id.subdevice);
858 snd_iprintf(buffer, " timer open:\t\t%s\n",
859 (cable->snd_timer.stream == SNDRV_PCM_STREAM_CAPTURE) ?
860 "capture" : "playback");
861}
862
863static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
864{
865 struct snd_pcm_runtime *runtime = substream->runtime;
866 struct loopback_pcm *dpcm = runtime->private_data;
867 snd_pcm_uframes_t pos;
868
869 spin_lock(&dpcm->cable->lock);
870 if (dpcm->cable->ops->pos_update)
871 dpcm->cable->ops->pos_update(dpcm->cable);
872 pos = dpcm->buf_pos;
873 spin_unlock(&dpcm->cable->lock);
874 return bytes_to_frames(runtime, pos);
875}
876
877static const struct snd_pcm_hardware loopback_pcm_hardware =
878{
879 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
880 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
881 SNDRV_PCM_INFO_RESUME),
882 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
883 SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
884 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |
885 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
886 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
887 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
888 .rate_min = 8000,
889 .rate_max = 192000,
890 .channels_min = 1,
891 .channels_max = 32,
892 .buffer_bytes_max = 2 * 1024 * 1024,
893 .period_bytes_min = 64,
894 /* note check overflow in frac_pos() using pcm_rate_shift before
895 changing period_bytes_max value */
896 .period_bytes_max = 1024 * 1024,
897 .periods_min = 1,
898 .periods_max = 1024,
899 .fifo_size = 0,
900};
901
902static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
903{
904 struct loopback_pcm *dpcm = runtime->private_data;
905 kfree(dpcm);
906}
907
908static int loopback_hw_free(struct snd_pcm_substream *substream)
909{
910 struct snd_pcm_runtime *runtime = substream->runtime;
911 struct loopback_pcm *dpcm = runtime->private_data;
912 struct loopback_cable *cable = dpcm->cable;
913
914 mutex_lock(&dpcm->loopback->cable_lock);
915 cable->valid &= ~(1 << substream->stream);
916 mutex_unlock(&dpcm->loopback->cable_lock);
917 return 0;
918}
919
920static unsigned int get_cable_index(struct snd_pcm_substream *substream)
921{
922 if (!substream->pcm->device)
923 return substream->stream;
924 else
925 return !substream->stream;
926}
927
928static int rule_format(struct snd_pcm_hw_params *params,
929 struct snd_pcm_hw_rule *rule)
930{
931 struct loopback_pcm *dpcm = rule->private;
932 struct loopback_cable *cable = dpcm->cable;
933 struct snd_mask m;
934
935 snd_mask_none(&m);
936 mutex_lock(&dpcm->loopback->cable_lock);
937 m.bits[0] = (u_int32_t)cable->hw.formats;
938 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
939 mutex_unlock(&dpcm->loopback->cable_lock);
940 return snd_mask_refine(hw_param_mask(params, rule->var), &m);
941}
942
943static int rule_rate(struct snd_pcm_hw_params *params,
944 struct snd_pcm_hw_rule *rule)
945{
946 struct loopback_pcm *dpcm = rule->private;
947 struct loopback_cable *cable = dpcm->cable;
948 struct snd_interval t;
949
950 mutex_lock(&dpcm->loopback->cable_lock);
951 t.min = cable->hw.rate_min;
952 t.max = cable->hw.rate_max;
953 mutex_unlock(&dpcm->loopback->cable_lock);
954 t.openmin = t.openmax = 0;
955 t.integer = 0;
956 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
957}
958
959static int rule_channels(struct snd_pcm_hw_params *params,
960 struct snd_pcm_hw_rule *rule)
961{
962 struct loopback_pcm *dpcm = rule->private;
963 struct loopback_cable *cable = dpcm->cable;
964 struct snd_interval t;
965
966 mutex_lock(&dpcm->loopback->cable_lock);
967 t.min = cable->hw.channels_min;
968 t.max = cable->hw.channels_max;
969 mutex_unlock(&dpcm->loopback->cable_lock);
970 t.openmin = t.openmax = 0;
971 t.integer = 0;
972 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
973}
974
975static int rule_period_bytes(struct snd_pcm_hw_params *params,
976 struct snd_pcm_hw_rule *rule)
977{
978 struct loopback_pcm *dpcm = rule->private;
979 struct loopback_cable *cable = dpcm->cable;
980 struct snd_interval t;
981
982 mutex_lock(&dpcm->loopback->cable_lock);
983 t.min = cable->hw.period_bytes_min;
984 t.max = cable->hw.period_bytes_max;
985 mutex_unlock(&dpcm->loopback->cable_lock);
986 t.openmin = 0;
987 t.openmax = 0;
988 t.integer = 0;
989 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
990}
991
992static void free_cable(struct snd_pcm_substream *substream)
993{
994 struct loopback *loopback = substream->private_data;
995 int dev = get_cable_index(substream);
996 struct loopback_cable *cable;
997
998 cable = loopback->cables[substream->number][dev];
999 if (!cable)
1000 return;
1001 if (cable->streams[!substream->stream]) {
1002 /* other stream is still alive */
1003 spin_lock_irq(&cable->lock);
1004 cable->streams[substream->stream] = NULL;
1005 spin_unlock_irq(&cable->lock);
1006 } else {
1007 struct loopback_pcm *dpcm = substream->runtime->private_data;
1008
1009 if (cable->ops && cable->ops->close_cable && dpcm)
1010 cable->ops->close_cable(dpcm);
1011 /* free the cable */
1012 loopback->cables[substream->number][dev] = NULL;
1013 kfree(cable);
1014 }
1015}
1016
1017static int loopback_jiffies_timer_open(struct loopback_pcm *dpcm)
1018{
1019 timer_setup(&dpcm->timer, loopback_jiffies_timer_function, 0);
1020
1021 return 0;
1022}
1023
1024static struct loopback_ops loopback_jiffies_timer_ops = {
1025 .open = loopback_jiffies_timer_open,
1026 .start = loopback_jiffies_timer_start,
1027 .stop = loopback_jiffies_timer_stop,
1028 .stop_sync = loopback_jiffies_timer_stop_sync,
1029 .close_substream = loopback_jiffies_timer_stop_sync,
1030 .pos_update = loopback_jiffies_timer_pos_update,
1031 .dpcm_info = loopback_jiffies_timer_dpcm_info,
1032};
1033
1034static int loopback_parse_timer_id(const char *str,
1035 struct snd_timer_id *tid)
1036{
1037 /* [<pref>:](<card name>|<card idx>)[{.,}<dev idx>[{.,}<subdev idx>]] */
1038 const char * const sep_dev = ".,";
1039 const char * const sep_pref = ":";
1040 const char *name = str;
1041 char *sep, save = '\0';
1042 int card_idx = 0, dev = 0, subdev = 0;
1043 int err;
1044
1045 sep = strpbrk(str, sep_pref);
1046 if (sep)
1047 name = sep + 1;
1048 sep = strpbrk(name, sep_dev);
1049 if (sep) {
1050 save = *sep;
1051 *sep = '\0';
1052 }
1053 err = kstrtoint(name, 0, &card_idx);
1054 if (err == -EINVAL) {
1055 /* Must be the name, not number */
1056 for (card_idx = 0; card_idx < snd_ecards_limit; card_idx++) {
1057 struct snd_card *card = snd_card_ref(card_idx);
1058
1059 if (card) {
1060 if (!strcmp(card->id, name))
1061 err = 0;
1062 snd_card_unref(card);
1063 }
1064 if (!err)
1065 break;
1066 }
1067 }
1068 if (sep) {
1069 *sep = save;
1070 if (!err) {
1071 char *sep2, save2 = '\0';
1072
1073 sep2 = strpbrk(sep + 1, sep_dev);
1074 if (sep2) {
1075 save2 = *sep2;
1076 *sep2 = '\0';
1077 }
1078 err = kstrtoint(sep + 1, 0, &dev);
1079 if (sep2) {
1080 *sep2 = save2;
1081 if (!err)
1082 err = kstrtoint(sep2 + 1, 0, &subdev);
1083 }
1084 }
1085 }
1086 if (!err && tid) {
1087 tid->card = card_idx;
1088 tid->device = dev;
1089 tid->subdevice = subdev;
1090 }
1091 return err;
1092}
1093
1094/* call in loopback->cable_lock */
1095static int loopback_snd_timer_open(struct loopback_pcm *dpcm)
1096{
1097 int err = 0;
1098 struct snd_timer_id tid = {
1099 .dev_class = SNDRV_TIMER_CLASS_PCM,
1100 .dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION,
1101 };
1102 struct snd_timer_instance *timeri;
1103 struct loopback_cable *cable = dpcm->cable;
1104
1105 /* check if timer was already opened. It is only opened once
1106 * per playback and capture subdevice (aka cable).
1107 */
1108 if (cable->snd_timer.instance)
1109 goto exit;
1110
1111 err = loopback_parse_timer_id(dpcm->loopback->timer_source, &tid);
1112 if (err < 0) {
1113 pcm_err(dpcm->substream->pcm,
1114 "Parsing timer source \'%s\' failed with %d",
1115 dpcm->loopback->timer_source, err);
1116 goto exit;
1117 }
1118
1119 cable->snd_timer.stream = dpcm->substream->stream;
1120 cable->snd_timer.id = tid;
1121
1122 timeri = snd_timer_instance_new(dpcm->loopback->card->id);
1123 if (!timeri) {
1124 err = -ENOMEM;
1125 goto exit;
1126 }
1127 /* The callback has to be called from another work. If
1128 * SNDRV_TIMER_IFLG_FAST is specified it will be called from the
1129 * snd_pcm_period_elapsed() call of the selected sound card.
1130 * snd_pcm_period_elapsed() helds snd_pcm_stream_lock_irqsave().
1131 * Due to our callback loopback_snd_timer_function() also calls
1132 * snd_pcm_period_elapsed() which calls snd_pcm_stream_lock_irqsave().
1133 * This would end up in a dead lock.
1134 */
1135 timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1136 timeri->callback = loopback_snd_timer_function;
1137 timeri->callback_data = (void *)cable;
1138 timeri->ccallback = loopback_snd_timer_event;
1139
1140 /* initialise a work used for draining */
1141 INIT_WORK(&cable->snd_timer.event_work, loopback_snd_timer_work);
1142
1143 /* The mutex loopback->cable_lock is kept locked.
1144 * Therefore snd_timer_open() cannot be called a second time
1145 * by the other device of the same cable.
1146 * Therefore the following issue cannot happen:
1147 * [proc1] Call loopback_timer_open() ->
1148 * Unlock cable->lock for snd_timer_close/open() call
1149 * [proc2] Call loopback_timer_open() -> snd_timer_open(),
1150 * snd_timer_start()
1151 * [proc1] Call snd_timer_open() and overwrite running timer
1152 * instance
1153 */
1154 err = snd_timer_open(timeri, &cable->snd_timer.id, current->pid);
1155 if (err < 0) {
1156 pcm_err(dpcm->substream->pcm,
1157 "snd_timer_open (%d,%d,%d) failed with %d",
1158 cable->snd_timer.id.card,
1159 cable->snd_timer.id.device,
1160 cable->snd_timer.id.subdevice,
1161 err);
1162 snd_timer_instance_free(timeri);
1163 goto exit;
1164 }
1165
1166 cable->snd_timer.instance = timeri;
1167
1168exit:
1169 return err;
1170}
1171
1172/* stop_sync() is not required for sound timer because it does not need to be
1173 * restarted in loopback_prepare() on Xrun recovery
1174 */
1175static struct loopback_ops loopback_snd_timer_ops = {
1176 .open = loopback_snd_timer_open,
1177 .start = loopback_snd_timer_start,
1178 .stop = loopback_snd_timer_stop,
1179 .close_cable = loopback_snd_timer_close_cable,
1180 .dpcm_info = loopback_snd_timer_dpcm_info,
1181};
1182
1183static int loopback_open(struct snd_pcm_substream *substream)
1184{
1185 struct snd_pcm_runtime *runtime = substream->runtime;
1186 struct loopback *loopback = substream->private_data;
1187 struct loopback_pcm *dpcm;
1188 struct loopback_cable *cable = NULL;
1189 int err = 0;
1190 int dev = get_cable_index(substream);
1191
1192 mutex_lock(&loopback->cable_lock);
1193 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
1194 if (!dpcm) {
1195 err = -ENOMEM;
1196 goto unlock;
1197 }
1198 dpcm->loopback = loopback;
1199 dpcm->substream = substream;
1200
1201 cable = loopback->cables[substream->number][dev];
1202 if (!cable) {
1203 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
1204 if (!cable) {
1205 err = -ENOMEM;
1206 goto unlock;
1207 }
1208 spin_lock_init(&cable->lock);
1209 cable->hw = loopback_pcm_hardware;
1210 if (loopback->timer_source)
1211 cable->ops = &loopback_snd_timer_ops;
1212 else
1213 cable->ops = &loopback_jiffies_timer_ops;
1214 loopback->cables[substream->number][dev] = cable;
1215 }
1216 dpcm->cable = cable;
1217 runtime->private_data = dpcm;
1218
1219 if (cable->ops->open) {
1220 err = cable->ops->open(dpcm);
1221 if (err < 0)
1222 goto unlock;
1223 }
1224
1225 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
1226
1227 /* use dynamic rules based on actual runtime->hw values */
1228 /* note that the default rules created in the PCM midlevel code */
1229 /* are cached -> they do not reflect the actual state */
1230 err = snd_pcm_hw_rule_add(runtime, 0,
1231 SNDRV_PCM_HW_PARAM_FORMAT,
1232 rule_format, dpcm,
1233 SNDRV_PCM_HW_PARAM_FORMAT, -1);
1234 if (err < 0)
1235 goto unlock;
1236 err = snd_pcm_hw_rule_add(runtime, 0,
1237 SNDRV_PCM_HW_PARAM_RATE,
1238 rule_rate, dpcm,
1239 SNDRV_PCM_HW_PARAM_RATE, -1);
1240 if (err < 0)
1241 goto unlock;
1242 err = snd_pcm_hw_rule_add(runtime, 0,
1243 SNDRV_PCM_HW_PARAM_CHANNELS,
1244 rule_channels, dpcm,
1245 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
1246 if (err < 0)
1247 goto unlock;
1248
1249 /* In case of sound timer the period time of both devices of the same
1250 * loop has to be the same.
1251 * This rule only takes effect if a sound timer was chosen
1252 */
1253 if (cable->snd_timer.instance) {
1254 err = snd_pcm_hw_rule_add(runtime, 0,
1255 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
1256 rule_period_bytes, dpcm,
1257 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1);
1258 if (err < 0)
1259 goto unlock;
1260 }
1261
1262 /* loopback_runtime_free() has not to be called if kfree(dpcm) was
1263 * already called here. Otherwise it will end up with a double free.
1264 */
1265 runtime->private_free = loopback_runtime_free;
1266 if (get_notify(dpcm))
1267 runtime->hw = loopback_pcm_hardware;
1268 else
1269 runtime->hw = cable->hw;
1270
1271 spin_lock_irq(&cable->lock);
1272 cable->streams[substream->stream] = dpcm;
1273 spin_unlock_irq(&cable->lock);
1274
1275 unlock:
1276 if (err < 0) {
1277 free_cable(substream);
1278 kfree(dpcm);
1279 }
1280 mutex_unlock(&loopback->cable_lock);
1281 return err;
1282}
1283
1284static int loopback_close(struct snd_pcm_substream *substream)
1285{
1286 struct loopback *loopback = substream->private_data;
1287 struct loopback_pcm *dpcm = substream->runtime->private_data;
1288 int err = 0;
1289
1290 if (dpcm->cable->ops->close_substream)
1291 err = dpcm->cable->ops->close_substream(dpcm);
1292 mutex_lock(&loopback->cable_lock);
1293 free_cable(substream);
1294 mutex_unlock(&loopback->cable_lock);
1295 return err;
1296}
1297
1298static const struct snd_pcm_ops loopback_pcm_ops = {
1299 .open = loopback_open,
1300 .close = loopback_close,
1301 .hw_free = loopback_hw_free,
1302 .prepare = loopback_prepare,
1303 .trigger = loopback_trigger,
1304 .pointer = loopback_pointer,
1305};
1306
1307static int loopback_pcm_new(struct loopback *loopback,
1308 int device, int substreams)
1309{
1310 struct snd_pcm *pcm;
1311 int err;
1312
1313 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
1314 substreams, substreams, &pcm);
1315 if (err < 0)
1316 return err;
1317 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops);
1318 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops);
1319 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
1320
1321 pcm->private_data = loopback;
1322 pcm->info_flags = 0;
1323 strcpy(pcm->name, "Loopback PCM");
1324
1325 loopback->pcm[device] = pcm;
1326 return 0;
1327}
1328
1329static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
1330 struct snd_ctl_elem_info *uinfo)
1331{
1332 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1333 uinfo->count = 1;
1334 uinfo->value.integer.min = 80000;
1335 uinfo->value.integer.max = 120000;
1336 uinfo->value.integer.step = 1;
1337 return 0;
1338}
1339
1340static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
1341 struct snd_ctl_elem_value *ucontrol)
1342{
1343 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1344
1345 mutex_lock(&loopback->cable_lock);
1346 ucontrol->value.integer.value[0] =
1347 loopback->setup[kcontrol->id.subdevice]
1348 [kcontrol->id.device].rate_shift;
1349 mutex_unlock(&loopback->cable_lock);
1350 return 0;
1351}
1352
1353static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
1354 struct snd_ctl_elem_value *ucontrol)
1355{
1356 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1357 unsigned int val;
1358 int change = 0;
1359
1360 val = ucontrol->value.integer.value[0];
1361 if (val < 80000)
1362 val = 80000;
1363 if (val > 120000)
1364 val = 120000;
1365 mutex_lock(&loopback->cable_lock);
1366 if (val != loopback->setup[kcontrol->id.subdevice]
1367 [kcontrol->id.device].rate_shift) {
1368 loopback->setup[kcontrol->id.subdevice]
1369 [kcontrol->id.device].rate_shift = val;
1370 change = 1;
1371 }
1372 mutex_unlock(&loopback->cable_lock);
1373 return change;
1374}
1375
1376static int loopback_notify_get(struct snd_kcontrol *kcontrol,
1377 struct snd_ctl_elem_value *ucontrol)
1378{
1379 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1380
1381 mutex_lock(&loopback->cable_lock);
1382 ucontrol->value.integer.value[0] =
1383 loopback->setup[kcontrol->id.subdevice]
1384 [kcontrol->id.device].notify;
1385 mutex_unlock(&loopback->cable_lock);
1386 return 0;
1387}
1388
1389static int loopback_notify_put(struct snd_kcontrol *kcontrol,
1390 struct snd_ctl_elem_value *ucontrol)
1391{
1392 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1393 unsigned int val;
1394 int change = 0;
1395
1396 val = ucontrol->value.integer.value[0] ? 1 : 0;
1397 mutex_lock(&loopback->cable_lock);
1398 if (val != loopback->setup[kcontrol->id.subdevice]
1399 [kcontrol->id.device].notify) {
1400 loopback->setup[kcontrol->id.subdevice]
1401 [kcontrol->id.device].notify = val;
1402 change = 1;
1403 }
1404 mutex_unlock(&loopback->cable_lock);
1405 return change;
1406}
1407
1408static int loopback_active_get(struct snd_kcontrol *kcontrol,
1409 struct snd_ctl_elem_value *ucontrol)
1410{
1411 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1412 struct loopback_cable *cable;
1413
1414 unsigned int val = 0;
1415
1416 mutex_lock(&loopback->cable_lock);
1417 cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
1418 if (cable != NULL) {
1419 unsigned int running = cable->running ^ cable->pause;
1420
1421 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
1422 }
1423 mutex_unlock(&loopback->cable_lock);
1424 ucontrol->value.integer.value[0] = val;
1425 return 0;
1426}
1427
1428static int loopback_format_info(struct snd_kcontrol *kcontrol,
1429 struct snd_ctl_elem_info *uinfo)
1430{
1431 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1432 uinfo->count = 1;
1433 uinfo->value.integer.min = 0;
1434 uinfo->value.integer.max = (__force int)SNDRV_PCM_FORMAT_LAST;
1435 uinfo->value.integer.step = 1;
1436 return 0;
1437}
1438
1439static int loopback_format_get(struct snd_kcontrol *kcontrol,
1440 struct snd_ctl_elem_value *ucontrol)
1441{
1442 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1443
1444 ucontrol->value.integer.value[0] =
1445 (__force int)loopback->setup[kcontrol->id.subdevice]
1446 [kcontrol->id.device].format;
1447 return 0;
1448}
1449
1450static int loopback_rate_info(struct snd_kcontrol *kcontrol,
1451 struct snd_ctl_elem_info *uinfo)
1452{
1453 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1454 uinfo->count = 1;
1455 uinfo->value.integer.min = 0;
1456 uinfo->value.integer.max = 192000;
1457 uinfo->value.integer.step = 1;
1458 return 0;
1459}
1460
1461static int loopback_rate_get(struct snd_kcontrol *kcontrol,
1462 struct snd_ctl_elem_value *ucontrol)
1463{
1464 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1465
1466 mutex_lock(&loopback->cable_lock);
1467 ucontrol->value.integer.value[0] =
1468 loopback->setup[kcontrol->id.subdevice]
1469 [kcontrol->id.device].rate;
1470 mutex_unlock(&loopback->cable_lock);
1471 return 0;
1472}
1473
1474static int loopback_channels_info(struct snd_kcontrol *kcontrol,
1475 struct snd_ctl_elem_info *uinfo)
1476{
1477 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1478 uinfo->count = 1;
1479 uinfo->value.integer.min = 1;
1480 uinfo->value.integer.max = 1024;
1481 uinfo->value.integer.step = 1;
1482 return 0;
1483}
1484
1485static int loopback_channels_get(struct snd_kcontrol *kcontrol,
1486 struct snd_ctl_elem_value *ucontrol)
1487{
1488 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
1489
1490 mutex_lock(&loopback->cable_lock);
1491 ucontrol->value.integer.value[0] =
1492 loopback->setup[kcontrol->id.subdevice]
1493 [kcontrol->id.device].channels;
1494 mutex_unlock(&loopback->cable_lock);
1495 return 0;
1496}
1497
1498static const struct snd_kcontrol_new loopback_controls[] = {
1499{
1500 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1501 .name = "PCM Rate Shift 100000",
1502 .info = loopback_rate_shift_info,
1503 .get = loopback_rate_shift_get,
1504 .put = loopback_rate_shift_put,
1505},
1506{
1507 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1508 .name = "PCM Notify",
1509 .info = snd_ctl_boolean_mono_info,
1510 .get = loopback_notify_get,
1511 .put = loopback_notify_put,
1512},
1513#define ACTIVE_IDX 2
1514{
1515 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1516 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1517 .name = "PCM Slave Active",
1518 .info = snd_ctl_boolean_mono_info,
1519 .get = loopback_active_get,
1520},
1521#define FORMAT_IDX 3
1522{
1523 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1524 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1525 .name = "PCM Slave Format",
1526 .info = loopback_format_info,
1527 .get = loopback_format_get
1528},
1529#define RATE_IDX 4
1530{
1531 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1532 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1533 .name = "PCM Slave Rate",
1534 .info = loopback_rate_info,
1535 .get = loopback_rate_get
1536},
1537#define CHANNELS_IDX 5
1538{
1539 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1540 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1541 .name = "PCM Slave Channels",
1542 .info = loopback_channels_info,
1543 .get = loopback_channels_get
1544}
1545};
1546
1547static int loopback_mixer_new(struct loopback *loopback, int notify)
1548{
1549 struct snd_card *card = loopback->card;
1550 struct snd_pcm *pcm;
1551 struct snd_kcontrol *kctl;
1552 struct loopback_setup *setup;
1553 int err, dev, substr, substr_count, idx;
1554
1555 strcpy(card->mixername, "Loopback Mixer");
1556 for (dev = 0; dev < 2; dev++) {
1557 pcm = loopback->pcm[dev];
1558 substr_count =
1559 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1560 for (substr = 0; substr < substr_count; substr++) {
1561 setup = &loopback->setup[substr][dev];
1562 setup->notify = notify;
1563 setup->rate_shift = NO_PITCH;
1564 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1565 setup->rate = 48000;
1566 setup->channels = 2;
1567 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1568 idx++) {
1569 kctl = snd_ctl_new1(&loopback_controls[idx],
1570 loopback);
1571 if (!kctl)
1572 return -ENOMEM;
1573 kctl->id.device = dev;
1574 kctl->id.subdevice = substr;
1575 switch (idx) {
1576 case ACTIVE_IDX:
1577 setup->active_id = kctl->id;
1578 break;
1579 case FORMAT_IDX:
1580 setup->format_id = kctl->id;
1581 break;
1582 case RATE_IDX:
1583 setup->rate_id = kctl->id;
1584 break;
1585 case CHANNELS_IDX:
1586 setup->channels_id = kctl->id;
1587 break;
1588 default:
1589 break;
1590 }
1591 err = snd_ctl_add(card, kctl);
1592 if (err < 0)
1593 return err;
1594 }
1595 }
1596 }
1597 return 0;
1598}
1599
1600static void print_dpcm_info(struct snd_info_buffer *buffer,
1601 struct loopback_pcm *dpcm,
1602 const char *id)
1603{
1604 snd_iprintf(buffer, " %s\n", id);
1605 if (dpcm == NULL) {
1606 snd_iprintf(buffer, " inactive\n");
1607 return;
1608 }
1609 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1610 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1611 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1612 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1613 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1614 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1615 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1616 if (dpcm->cable->ops->dpcm_info)
1617 dpcm->cable->ops->dpcm_info(dpcm, buffer);
1618}
1619
1620static void print_substream_info(struct snd_info_buffer *buffer,
1621 struct loopback *loopback,
1622 int sub,
1623 int num)
1624{
1625 struct loopback_cable *cable = loopback->cables[sub][num];
1626
1627 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1628 if (cable == NULL) {
1629 snd_iprintf(buffer, " inactive\n");
1630 return;
1631 }
1632 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1633 snd_iprintf(buffer, " running: %u\n", cable->running);
1634 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1635 print_dpcm_info(buffer, cable->streams[0], "Playback");
1636 print_dpcm_info(buffer, cable->streams[1], "Capture");
1637}
1638
1639static void print_cable_info(struct snd_info_entry *entry,
1640 struct snd_info_buffer *buffer)
1641{
1642 struct loopback *loopback = entry->private_data;
1643 int sub, num;
1644
1645 mutex_lock(&loopback->cable_lock);
1646 num = entry->name[strlen(entry->name)-1];
1647 num = num == '0' ? 0 : 1;
1648 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1649 print_substream_info(buffer, loopback, sub, num);
1650 mutex_unlock(&loopback->cable_lock);
1651}
1652
1653static int loopback_cable_proc_new(struct loopback *loopback, int cidx)
1654{
1655 char name[32];
1656
1657 snprintf(name, sizeof(name), "cable#%d", cidx);
1658 return snd_card_ro_proc_new(loopback->card, name, loopback,
1659 print_cable_info);
1660}
1661
1662static void loopback_set_timer_source(struct loopback *loopback,
1663 const char *value)
1664{
1665 if (loopback->timer_source) {
1666 devm_kfree(loopback->card->dev, loopback->timer_source);
1667 loopback->timer_source = NULL;
1668 }
1669 if (value && *value)
1670 loopback->timer_source = devm_kstrdup(loopback->card->dev,
1671 value, GFP_KERNEL);
1672}
1673
1674static void print_timer_source_info(struct snd_info_entry *entry,
1675 struct snd_info_buffer *buffer)
1676{
1677 struct loopback *loopback = entry->private_data;
1678
1679 mutex_lock(&loopback->cable_lock);
1680 snd_iprintf(buffer, "%s\n",
1681 loopback->timer_source ? loopback->timer_source : "");
1682 mutex_unlock(&loopback->cable_lock);
1683}
1684
1685static void change_timer_source_info(struct snd_info_entry *entry,
1686 struct snd_info_buffer *buffer)
1687{
1688 struct loopback *loopback = entry->private_data;
1689 char line[64];
1690
1691 mutex_lock(&loopback->cable_lock);
1692 if (!snd_info_get_line(buffer, line, sizeof(line)))
1693 loopback_set_timer_source(loopback, strim(line));
1694 mutex_unlock(&loopback->cable_lock);
1695}
1696
1697static int loopback_timer_source_proc_new(struct loopback *loopback)
1698{
1699 return snd_card_rw_proc_new(loopback->card, "timer_source", loopback,
1700 print_timer_source_info,
1701 change_timer_source_info);
1702}
1703
1704static int loopback_probe(struct platform_device *devptr)
1705{
1706 struct snd_card *card;
1707 struct loopback *loopback;
1708 int dev = devptr->id;
1709 int err;
1710
1711 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1712 sizeof(struct loopback), &card);
1713 if (err < 0)
1714 return err;
1715 loopback = card->private_data;
1716
1717 if (pcm_substreams[dev] < 1)
1718 pcm_substreams[dev] = 1;
1719 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1720 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1721
1722 loopback->card = card;
1723 loopback_set_timer_source(loopback, timer_source[dev]);
1724
1725 mutex_init(&loopback->cable_lock);
1726
1727 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1728 if (err < 0)
1729 goto __nodev;
1730 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1731 if (err < 0)
1732 goto __nodev;
1733 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1734 if (err < 0)
1735 goto __nodev;
1736 loopback_cable_proc_new(loopback, 0);
1737 loopback_cable_proc_new(loopback, 1);
1738 loopback_timer_source_proc_new(loopback);
1739 strcpy(card->driver, "Loopback");
1740 strcpy(card->shortname, "Loopback");
1741 sprintf(card->longname, "Loopback %i", dev + 1);
1742 err = snd_card_register(card);
1743 if (!err) {
1744 platform_set_drvdata(devptr, card);
1745 return 0;
1746 }
1747 __nodev:
1748 snd_card_free(card);
1749 return err;
1750}
1751
1752static int loopback_remove(struct platform_device *devptr)
1753{
1754 snd_card_free(platform_get_drvdata(devptr));
1755 return 0;
1756}
1757
1758#ifdef CONFIG_PM_SLEEP
1759static int loopback_suspend(struct device *pdev)
1760{
1761 struct snd_card *card = dev_get_drvdata(pdev);
1762
1763 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1764 return 0;
1765}
1766
1767static int loopback_resume(struct device *pdev)
1768{
1769 struct snd_card *card = dev_get_drvdata(pdev);
1770
1771 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1772 return 0;
1773}
1774
1775static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1776#define LOOPBACK_PM_OPS &loopback_pm
1777#else
1778#define LOOPBACK_PM_OPS NULL
1779#endif
1780
1781#define SND_LOOPBACK_DRIVER "snd_aloop"
1782
1783static struct platform_driver loopback_driver = {
1784 .probe = loopback_probe,
1785 .remove = loopback_remove,
1786 .driver = {
1787 .name = SND_LOOPBACK_DRIVER,
1788 .pm = LOOPBACK_PM_OPS,
1789 },
1790};
1791
1792static void loopback_unregister_all(void)
1793{
1794 int i;
1795
1796 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1797 platform_device_unregister(devices[i]);
1798 platform_driver_unregister(&loopback_driver);
1799}
1800
1801static int __init alsa_card_loopback_init(void)
1802{
1803 int i, err, cards;
1804
1805 err = platform_driver_register(&loopback_driver);
1806 if (err < 0)
1807 return err;
1808
1809
1810 cards = 0;
1811 for (i = 0; i < SNDRV_CARDS; i++) {
1812 struct platform_device *device;
1813 if (!enable[i])
1814 continue;
1815 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1816 i, NULL, 0);
1817 if (IS_ERR(device))
1818 continue;
1819 if (!platform_get_drvdata(device)) {
1820 platform_device_unregister(device);
1821 continue;
1822 }
1823 devices[i] = device;
1824 cards++;
1825 }
1826 if (!cards) {
1827#ifdef MODULE
1828 printk(KERN_ERR "aloop: No loopback enabled\n");
1829#endif
1830 loopback_unregister_all();
1831 return -ENODEV;
1832 }
1833 return 0;
1834}
1835
1836static void __exit alsa_card_loopback_exit(void)
1837{
1838 loopback_unregister_all();
1839}
1840
1841module_init(alsa_card_loopback_init)
1842module_exit(alsa_card_loopback_exit)
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