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1/*
2 * Loopback soundcard
3 *
4 * Original code:
5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
6 *
7 * More accurate positioning and full-duplex support:
8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
9 *
10 * Major (almost complete) rewrite:
11 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
12 *
13 * A next major update in 2010 (separate timers for playback and capture):
14 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 *
30 */
31
32#include <linux/init.h>
33#include <linux/jiffies.h>
34#include <linux/slab.h>
35#include <linux/time.h>
36#include <linux/wait.h>
37#include <linux/module.h>
38#include <linux/platform_device.h>
39#include <sound/core.h>
40#include <sound/control.h>
41#include <sound/pcm.h>
42#include <sound/info.h>
43#include <sound/initval.h>
44
45MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
46MODULE_DESCRIPTION("A loopback soundcard");
47MODULE_LICENSE("GPL");
48MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
49
50#define MAX_PCM_SUBSTREAMS 8
51
52static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
53static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
54static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
55static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
56static int pcm_notify[SNDRV_CARDS];
57
58module_param_array(index, int, NULL, 0444);
59MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
60module_param_array(id, charp, NULL, 0444);
61MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
62module_param_array(enable, bool, NULL, 0444);
63MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
64module_param_array(pcm_substreams, int, NULL, 0444);
65MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
66module_param_array(pcm_notify, int, NULL, 0444);
67MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
68
69#define NO_PITCH 100000
70
71struct loopback_pcm;
72
73struct loopback_cable {
74 spinlock_t lock;
75 struct loopback_pcm *streams[2];
76 struct snd_pcm_hardware hw;
77 /* flags */
78 unsigned int valid;
79 unsigned int running;
80 unsigned int pause;
81};
82
83struct loopback_setup {
84 unsigned int notify: 1;
85 unsigned int rate_shift;
86 unsigned int format;
87 unsigned int rate;
88 unsigned int channels;
89 struct snd_ctl_elem_id active_id;
90 struct snd_ctl_elem_id format_id;
91 struct snd_ctl_elem_id rate_id;
92 struct snd_ctl_elem_id channels_id;
93};
94
95struct loopback {
96 struct snd_card *card;
97 struct mutex cable_lock;
98 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
99 struct snd_pcm *pcm[2];
100 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
101};
102
103struct loopback_pcm {
104 struct loopback *loopback;
105 struct snd_pcm_substream *substream;
106 struct loopback_cable *cable;
107 unsigned int pcm_buffer_size;
108 unsigned int buf_pos; /* position in buffer */
109 unsigned int silent_size;
110 /* PCM parameters */
111 unsigned int pcm_period_size;
112 unsigned int pcm_bps; /* bytes per second */
113 unsigned int pcm_salign; /* bytes per sample * channels */
114 unsigned int pcm_rate_shift; /* rate shift value */
115 /* flags */
116 unsigned int period_update_pending :1;
117 /* timer stuff */
118 unsigned int irq_pos; /* fractional IRQ position */
119 unsigned int period_size_frac;
120 unsigned int last_drift;
121 unsigned long last_jiffies;
122 struct timer_list timer;
123};
124
125static struct platform_device *devices[SNDRV_CARDS];
126
127static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
128{
129 if (dpcm->pcm_rate_shift == NO_PITCH) {
130 x /= HZ;
131 } else {
132 x = div_u64(NO_PITCH * (unsigned long long)x,
133 HZ * (unsigned long long)dpcm->pcm_rate_shift);
134 }
135 return x - (x % dpcm->pcm_salign);
136}
137
138static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
139{
140 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
141 return x * HZ;
142 } else {
143 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
144 NO_PITCH);
145 }
146 return x;
147}
148
149static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
150{
151 int device = dpcm->substream->pstr->pcm->device;
152
153 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
154 device ^= 1;
155 return &dpcm->loopback->setup[dpcm->substream->number][device];
156}
157
158static inline unsigned int get_notify(struct loopback_pcm *dpcm)
159{
160 return get_setup(dpcm)->notify;
161}
162
163static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
164{
165 return get_setup(dpcm)->rate_shift;
166}
167
168/* call in cable->lock */
169static void loopback_timer_start(struct loopback_pcm *dpcm)
170{
171 unsigned long tick;
172 unsigned int rate_shift = get_rate_shift(dpcm);
173
174 if (rate_shift != dpcm->pcm_rate_shift) {
175 dpcm->pcm_rate_shift = rate_shift;
176 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
177 }
178 if (dpcm->period_size_frac <= dpcm->irq_pos) {
179 dpcm->irq_pos %= dpcm->period_size_frac;
180 dpcm->period_update_pending = 1;
181 }
182 tick = dpcm->period_size_frac - dpcm->irq_pos;
183 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
184 dpcm->timer.expires = jiffies + tick;
185 add_timer(&dpcm->timer);
186}
187
188/* call in cable->lock */
189static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
190{
191 del_timer(&dpcm->timer);
192 dpcm->timer.expires = 0;
193}
194
195#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
196#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
197#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
198
199static int loopback_check_format(struct loopback_cable *cable, int stream)
200{
201 struct snd_pcm_runtime *runtime, *cruntime;
202 struct loopback_setup *setup;
203 struct snd_card *card;
204 int check;
205
206 if (cable->valid != CABLE_VALID_BOTH) {
207 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
208 goto __notify;
209 return 0;
210 }
211 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
212 substream->runtime;
213 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
214 substream->runtime;
215 check = runtime->format != cruntime->format ||
216 runtime->rate != cruntime->rate ||
217 runtime->channels != cruntime->channels;
218 if (!check)
219 return 0;
220 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
221 return -EIO;
222 } else {
223 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
224 substream, SNDRV_PCM_STATE_DRAINING);
225 __notify:
226 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
227 substream->runtime;
228 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
229 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
230 if (setup->format != runtime->format) {
231 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
232 &setup->format_id);
233 setup->format = runtime->format;
234 }
235 if (setup->rate != runtime->rate) {
236 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
237 &setup->rate_id);
238 setup->rate = runtime->rate;
239 }
240 if (setup->channels != runtime->channels) {
241 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
242 &setup->channels_id);
243 setup->channels = runtime->channels;
244 }
245 }
246 return 0;
247}
248
249static void loopback_active_notify(struct loopback_pcm *dpcm)
250{
251 snd_ctl_notify(dpcm->loopback->card,
252 SNDRV_CTL_EVENT_MASK_VALUE,
253 &get_setup(dpcm)->active_id);
254}
255
256static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
257{
258 struct snd_pcm_runtime *runtime = substream->runtime;
259 struct loopback_pcm *dpcm = runtime->private_data;
260 struct loopback_cable *cable = dpcm->cable;
261 int err, stream = 1 << substream->stream;
262
263 switch (cmd) {
264 case SNDRV_PCM_TRIGGER_START:
265 err = loopback_check_format(cable, substream->stream);
266 if (err < 0)
267 return err;
268 dpcm->last_jiffies = jiffies;
269 dpcm->pcm_rate_shift = 0;
270 dpcm->last_drift = 0;
271 spin_lock(&cable->lock);
272 cable->running |= stream;
273 cable->pause &= ~stream;
274 loopback_timer_start(dpcm);
275 spin_unlock(&cable->lock);
276 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
277 loopback_active_notify(dpcm);
278 break;
279 case SNDRV_PCM_TRIGGER_STOP:
280 spin_lock(&cable->lock);
281 cable->running &= ~stream;
282 cable->pause &= ~stream;
283 loopback_timer_stop(dpcm);
284 spin_unlock(&cable->lock);
285 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
286 loopback_active_notify(dpcm);
287 break;
288 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
289 case SNDRV_PCM_TRIGGER_SUSPEND:
290 spin_lock(&cable->lock);
291 cable->pause |= stream;
292 loopback_timer_stop(dpcm);
293 spin_unlock(&cable->lock);
294 break;
295 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
296 case SNDRV_PCM_TRIGGER_RESUME:
297 spin_lock(&cable->lock);
298 dpcm->last_jiffies = jiffies;
299 cable->pause &= ~stream;
300 loopback_timer_start(dpcm);
301 spin_unlock(&cable->lock);
302 break;
303 default:
304 return -EINVAL;
305 }
306 return 0;
307}
308
309static void params_change_substream(struct loopback_pcm *dpcm,
310 struct snd_pcm_runtime *runtime)
311{
312 struct snd_pcm_runtime *dst_runtime;
313
314 if (dpcm == NULL || dpcm->substream == NULL)
315 return;
316 dst_runtime = dpcm->substream->runtime;
317 if (dst_runtime == NULL)
318 return;
319 dst_runtime->hw = dpcm->cable->hw;
320}
321
322static void params_change(struct snd_pcm_substream *substream)
323{
324 struct snd_pcm_runtime *runtime = substream->runtime;
325 struct loopback_pcm *dpcm = runtime->private_data;
326 struct loopback_cable *cable = dpcm->cable;
327
328 cable->hw.formats = pcm_format_to_bits(runtime->format);
329 cable->hw.rate_min = runtime->rate;
330 cable->hw.rate_max = runtime->rate;
331 cable->hw.channels_min = runtime->channels;
332 cable->hw.channels_max = runtime->channels;
333 params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
334 runtime);
335 params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
336 runtime);
337}
338
339static int loopback_prepare(struct snd_pcm_substream *substream)
340{
341 struct snd_pcm_runtime *runtime = substream->runtime;
342 struct loopback_pcm *dpcm = runtime->private_data;
343 struct loopback_cable *cable = dpcm->cable;
344 int bps, salign;
345
346 salign = (snd_pcm_format_width(runtime->format) *
347 runtime->channels) / 8;
348 bps = salign * runtime->rate;
349 if (bps <= 0 || salign <= 0)
350 return -EINVAL;
351
352 dpcm->buf_pos = 0;
353 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
354 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
355 /* clear capture buffer */
356 dpcm->silent_size = dpcm->pcm_buffer_size;
357 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
358 runtime->buffer_size * runtime->channels);
359 }
360
361 dpcm->irq_pos = 0;
362 dpcm->period_update_pending = 0;
363 dpcm->pcm_bps = bps;
364 dpcm->pcm_salign = salign;
365 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
366
367 mutex_lock(&dpcm->loopback->cable_lock);
368 if (!(cable->valid & ~(1 << substream->stream)) ||
369 (get_setup(dpcm)->notify &&
370 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
371 params_change(substream);
372 cable->valid |= 1 << substream->stream;
373 mutex_unlock(&dpcm->loopback->cable_lock);
374
375 return 0;
376}
377
378static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
379{
380 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
381 char *dst = runtime->dma_area;
382 unsigned int dst_off = dpcm->buf_pos;
383
384 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
385 return;
386 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
387 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
388
389 for (;;) {
390 unsigned int size = bytes;
391 if (dst_off + size > dpcm->pcm_buffer_size)
392 size = dpcm->pcm_buffer_size - dst_off;
393 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
394 bytes_to_frames(runtime, size) *
395 runtime->channels);
396 dpcm->silent_size += size;
397 bytes -= size;
398 if (!bytes)
399 break;
400 dst_off = 0;
401 }
402}
403
404static void copy_play_buf(struct loopback_pcm *play,
405 struct loopback_pcm *capt,
406 unsigned int bytes)
407{
408 struct snd_pcm_runtime *runtime = play->substream->runtime;
409 char *src = runtime->dma_area;
410 char *dst = capt->substream->runtime->dma_area;
411 unsigned int src_off = play->buf_pos;
412 unsigned int dst_off = capt->buf_pos;
413 unsigned int clear_bytes = 0;
414
415 /* check if playback is draining, trim the capture copy size
416 * when our pointer is at the end of playback ring buffer */
417 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
418 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
419 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
420 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
421 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
422 appl_ptr1 += play->buf_pos / play->pcm_salign;
423 if (appl_ptr < appl_ptr1)
424 appl_ptr1 -= runtime->buffer_size;
425 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
426 if (diff < bytes) {
427 clear_bytes = bytes - diff;
428 bytes = diff;
429 }
430 }
431
432 for (;;) {
433 unsigned int size = bytes;
434 if (src_off + size > play->pcm_buffer_size)
435 size = play->pcm_buffer_size - src_off;
436 if (dst_off + size > capt->pcm_buffer_size)
437 size = capt->pcm_buffer_size - dst_off;
438 memcpy(dst + dst_off, src + src_off, size);
439 capt->silent_size = 0;
440 bytes -= size;
441 if (!bytes)
442 break;
443 src_off = (src_off + size) % play->pcm_buffer_size;
444 dst_off = (dst_off + size) % capt->pcm_buffer_size;
445 }
446
447 if (clear_bytes > 0) {
448 clear_capture_buf(capt, clear_bytes);
449 capt->silent_size = 0;
450 }
451}
452
453static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
454 unsigned int jiffies_delta)
455{
456 unsigned long last_pos;
457 unsigned int delta;
458
459 last_pos = byte_pos(dpcm, dpcm->irq_pos);
460 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
461 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
462 if (delta >= dpcm->last_drift)
463 delta -= dpcm->last_drift;
464 dpcm->last_drift = 0;
465 if (dpcm->irq_pos >= dpcm->period_size_frac) {
466 dpcm->irq_pos %= dpcm->period_size_frac;
467 dpcm->period_update_pending = 1;
468 }
469 return delta;
470}
471
472static inline void bytepos_finish(struct loopback_pcm *dpcm,
473 unsigned int delta)
474{
475 dpcm->buf_pos += delta;
476 dpcm->buf_pos %= dpcm->pcm_buffer_size;
477}
478
479/* call in cable->lock */
480static unsigned int loopback_pos_update(struct loopback_cable *cable)
481{
482 struct loopback_pcm *dpcm_play =
483 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
484 struct loopback_pcm *dpcm_capt =
485 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
486 unsigned long delta_play = 0, delta_capt = 0;
487 unsigned int running, count1, count2;
488
489 running = cable->running ^ cable->pause;
490 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
491 delta_play = jiffies - dpcm_play->last_jiffies;
492 dpcm_play->last_jiffies += delta_play;
493 }
494
495 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
496 delta_capt = jiffies - dpcm_capt->last_jiffies;
497 dpcm_capt->last_jiffies += delta_capt;
498 }
499
500 if (delta_play == 0 && delta_capt == 0)
501 goto unlock;
502
503 if (delta_play > delta_capt) {
504 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
505 bytepos_finish(dpcm_play, count1);
506 delta_play = delta_capt;
507 } else if (delta_play < delta_capt) {
508 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
509 clear_capture_buf(dpcm_capt, count1);
510 bytepos_finish(dpcm_capt, count1);
511 delta_capt = delta_play;
512 }
513
514 if (delta_play == 0 && delta_capt == 0)
515 goto unlock;
516
517 /* note delta_capt == delta_play at this moment */
518 count1 = bytepos_delta(dpcm_play, delta_play);
519 count2 = bytepos_delta(dpcm_capt, delta_capt);
520 if (count1 < count2) {
521 dpcm_capt->last_drift = count2 - count1;
522 count1 = count2;
523 } else if (count1 > count2) {
524 dpcm_play->last_drift = count1 - count2;
525 }
526 copy_play_buf(dpcm_play, dpcm_capt, count1);
527 bytepos_finish(dpcm_play, count1);
528 bytepos_finish(dpcm_capt, count1);
529 unlock:
530 return running;
531}
532
533static void loopback_timer_function(unsigned long data)
534{
535 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
536 unsigned long flags;
537
538 spin_lock_irqsave(&dpcm->cable->lock, flags);
539 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
540 loopback_timer_start(dpcm);
541 if (dpcm->period_update_pending) {
542 dpcm->period_update_pending = 0;
543 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
544 /* need to unlock before calling below */
545 snd_pcm_period_elapsed(dpcm->substream);
546 return;
547 }
548 }
549 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
550}
551
552static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
553{
554 struct snd_pcm_runtime *runtime = substream->runtime;
555 struct loopback_pcm *dpcm = runtime->private_data;
556 snd_pcm_uframes_t pos;
557
558 spin_lock(&dpcm->cable->lock);
559 loopback_pos_update(dpcm->cable);
560 pos = dpcm->buf_pos;
561 spin_unlock(&dpcm->cable->lock);
562 return bytes_to_frames(runtime, pos);
563}
564
565static struct snd_pcm_hardware loopback_pcm_hardware =
566{
567 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
568 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
569 SNDRV_PCM_INFO_RESUME),
570 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
571 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
572 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
573 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
574 .rate_min = 8000,
575 .rate_max = 192000,
576 .channels_min = 1,
577 .channels_max = 32,
578 .buffer_bytes_max = 2 * 1024 * 1024,
579 .period_bytes_min = 64,
580 /* note check overflow in frac_pos() using pcm_rate_shift before
581 changing period_bytes_max value */
582 .period_bytes_max = 1024 * 1024,
583 .periods_min = 1,
584 .periods_max = 1024,
585 .fifo_size = 0,
586};
587
588static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
589{
590 struct loopback_pcm *dpcm = runtime->private_data;
591 kfree(dpcm);
592}
593
594static int loopback_hw_params(struct snd_pcm_substream *substream,
595 struct snd_pcm_hw_params *params)
596{
597 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
598 params_buffer_bytes(params));
599}
600
601static int loopback_hw_free(struct snd_pcm_substream *substream)
602{
603 struct snd_pcm_runtime *runtime = substream->runtime;
604 struct loopback_pcm *dpcm = runtime->private_data;
605 struct loopback_cable *cable = dpcm->cable;
606
607 mutex_lock(&dpcm->loopback->cable_lock);
608 cable->valid &= ~(1 << substream->stream);
609 mutex_unlock(&dpcm->loopback->cable_lock);
610 return snd_pcm_lib_free_vmalloc_buffer(substream);
611}
612
613static unsigned int get_cable_index(struct snd_pcm_substream *substream)
614{
615 if (!substream->pcm->device)
616 return substream->stream;
617 else
618 return !substream->stream;
619}
620
621static int rule_format(struct snd_pcm_hw_params *params,
622 struct snd_pcm_hw_rule *rule)
623{
624
625 struct snd_pcm_hardware *hw = rule->private;
626 struct snd_mask *maskp = hw_param_mask(params, rule->var);
627
628 maskp->bits[0] &= (u_int32_t)hw->formats;
629 maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
630 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
631 if (! maskp->bits[0] && ! maskp->bits[1])
632 return -EINVAL;
633 return 0;
634}
635
636static int rule_rate(struct snd_pcm_hw_params *params,
637 struct snd_pcm_hw_rule *rule)
638{
639 struct snd_pcm_hardware *hw = rule->private;
640 struct snd_interval t;
641
642 t.min = hw->rate_min;
643 t.max = hw->rate_max;
644 t.openmin = t.openmax = 0;
645 t.integer = 0;
646 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
647}
648
649static int rule_channels(struct snd_pcm_hw_params *params,
650 struct snd_pcm_hw_rule *rule)
651{
652 struct snd_pcm_hardware *hw = rule->private;
653 struct snd_interval t;
654
655 t.min = hw->channels_min;
656 t.max = hw->channels_max;
657 t.openmin = t.openmax = 0;
658 t.integer = 0;
659 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
660}
661
662static int loopback_open(struct snd_pcm_substream *substream)
663{
664 struct snd_pcm_runtime *runtime = substream->runtime;
665 struct loopback *loopback = substream->private_data;
666 struct loopback_pcm *dpcm;
667 struct loopback_cable *cable;
668 int err = 0;
669 int dev = get_cable_index(substream);
670
671 mutex_lock(&loopback->cable_lock);
672 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
673 if (!dpcm) {
674 err = -ENOMEM;
675 goto unlock;
676 }
677 dpcm->loopback = loopback;
678 dpcm->substream = substream;
679 setup_timer(&dpcm->timer, loopback_timer_function,
680 (unsigned long)dpcm);
681
682 cable = loopback->cables[substream->number][dev];
683 if (!cable) {
684 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
685 if (!cable) {
686 kfree(dpcm);
687 err = -ENOMEM;
688 goto unlock;
689 }
690 spin_lock_init(&cable->lock);
691 cable->hw = loopback_pcm_hardware;
692 loopback->cables[substream->number][dev] = cable;
693 }
694 dpcm->cable = cable;
695 cable->streams[substream->stream] = dpcm;
696
697 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
698
699 /* use dynamic rules based on actual runtime->hw values */
700 /* note that the default rules created in the PCM midlevel code */
701 /* are cached -> they do not reflect the actual state */
702 err = snd_pcm_hw_rule_add(runtime, 0,
703 SNDRV_PCM_HW_PARAM_FORMAT,
704 rule_format, &runtime->hw,
705 SNDRV_PCM_HW_PARAM_FORMAT, -1);
706 if (err < 0)
707 goto unlock;
708 err = snd_pcm_hw_rule_add(runtime, 0,
709 SNDRV_PCM_HW_PARAM_RATE,
710 rule_rate, &runtime->hw,
711 SNDRV_PCM_HW_PARAM_RATE, -1);
712 if (err < 0)
713 goto unlock;
714 err = snd_pcm_hw_rule_add(runtime, 0,
715 SNDRV_PCM_HW_PARAM_CHANNELS,
716 rule_channels, &runtime->hw,
717 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
718 if (err < 0)
719 goto unlock;
720
721 runtime->private_data = dpcm;
722 runtime->private_free = loopback_runtime_free;
723 if (get_notify(dpcm))
724 runtime->hw = loopback_pcm_hardware;
725 else
726 runtime->hw = cable->hw;
727 unlock:
728 mutex_unlock(&loopback->cable_lock);
729 return err;
730}
731
732static int loopback_close(struct snd_pcm_substream *substream)
733{
734 struct loopback *loopback = substream->private_data;
735 struct loopback_pcm *dpcm = substream->runtime->private_data;
736 struct loopback_cable *cable;
737 int dev = get_cable_index(substream);
738
739 loopback_timer_stop(dpcm);
740 mutex_lock(&loopback->cable_lock);
741 cable = loopback->cables[substream->number][dev];
742 if (cable->streams[!substream->stream]) {
743 /* other stream is still alive */
744 cable->streams[substream->stream] = NULL;
745 } else {
746 /* free the cable */
747 loopback->cables[substream->number][dev] = NULL;
748 kfree(cable);
749 }
750 mutex_unlock(&loopback->cable_lock);
751 return 0;
752}
753
754static struct snd_pcm_ops loopback_playback_ops = {
755 .open = loopback_open,
756 .close = loopback_close,
757 .ioctl = snd_pcm_lib_ioctl,
758 .hw_params = loopback_hw_params,
759 .hw_free = loopback_hw_free,
760 .prepare = loopback_prepare,
761 .trigger = loopback_trigger,
762 .pointer = loopback_pointer,
763 .page = snd_pcm_lib_get_vmalloc_page,
764 .mmap = snd_pcm_lib_mmap_vmalloc,
765};
766
767static struct snd_pcm_ops loopback_capture_ops = {
768 .open = loopback_open,
769 .close = loopback_close,
770 .ioctl = snd_pcm_lib_ioctl,
771 .hw_params = loopback_hw_params,
772 .hw_free = loopback_hw_free,
773 .prepare = loopback_prepare,
774 .trigger = loopback_trigger,
775 .pointer = loopback_pointer,
776 .page = snd_pcm_lib_get_vmalloc_page,
777 .mmap = snd_pcm_lib_mmap_vmalloc,
778};
779
780static int loopback_pcm_new(struct loopback *loopback,
781 int device, int substreams)
782{
783 struct snd_pcm *pcm;
784 int err;
785
786 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
787 substreams, substreams, &pcm);
788 if (err < 0)
789 return err;
790 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
791 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
792
793 pcm->private_data = loopback;
794 pcm->info_flags = 0;
795 strcpy(pcm->name, "Loopback PCM");
796
797 loopback->pcm[device] = pcm;
798 return 0;
799}
800
801static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
802 struct snd_ctl_elem_info *uinfo)
803{
804 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
805 uinfo->count = 1;
806 uinfo->value.integer.min = 80000;
807 uinfo->value.integer.max = 120000;
808 uinfo->value.integer.step = 1;
809 return 0;
810}
811
812static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
813 struct snd_ctl_elem_value *ucontrol)
814{
815 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
816
817 ucontrol->value.integer.value[0] =
818 loopback->setup[kcontrol->id.subdevice]
819 [kcontrol->id.device].rate_shift;
820 return 0;
821}
822
823static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
824 struct snd_ctl_elem_value *ucontrol)
825{
826 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
827 unsigned int val;
828 int change = 0;
829
830 val = ucontrol->value.integer.value[0];
831 if (val < 80000)
832 val = 80000;
833 if (val > 120000)
834 val = 120000;
835 mutex_lock(&loopback->cable_lock);
836 if (val != loopback->setup[kcontrol->id.subdevice]
837 [kcontrol->id.device].rate_shift) {
838 loopback->setup[kcontrol->id.subdevice]
839 [kcontrol->id.device].rate_shift = val;
840 change = 1;
841 }
842 mutex_unlock(&loopback->cable_lock);
843 return change;
844}
845
846static int loopback_notify_get(struct snd_kcontrol *kcontrol,
847 struct snd_ctl_elem_value *ucontrol)
848{
849 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
850
851 ucontrol->value.integer.value[0] =
852 loopback->setup[kcontrol->id.subdevice]
853 [kcontrol->id.device].notify;
854 return 0;
855}
856
857static int loopback_notify_put(struct snd_kcontrol *kcontrol,
858 struct snd_ctl_elem_value *ucontrol)
859{
860 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
861 unsigned int val;
862 int change = 0;
863
864 val = ucontrol->value.integer.value[0] ? 1 : 0;
865 if (val != loopback->setup[kcontrol->id.subdevice]
866 [kcontrol->id.device].notify) {
867 loopback->setup[kcontrol->id.subdevice]
868 [kcontrol->id.device].notify = val;
869 change = 1;
870 }
871 return change;
872}
873
874static int loopback_active_get(struct snd_kcontrol *kcontrol,
875 struct snd_ctl_elem_value *ucontrol)
876{
877 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
878 struct loopback_cable *cable = loopback->cables
879 [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
880 unsigned int val = 0;
881
882 if (cable != NULL)
883 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
884 1 : 0;
885 ucontrol->value.integer.value[0] = val;
886 return 0;
887}
888
889static int loopback_format_info(struct snd_kcontrol *kcontrol,
890 struct snd_ctl_elem_info *uinfo)
891{
892 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
893 uinfo->count = 1;
894 uinfo->value.integer.min = 0;
895 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
896 uinfo->value.integer.step = 1;
897 return 0;
898}
899
900static int loopback_format_get(struct snd_kcontrol *kcontrol,
901 struct snd_ctl_elem_value *ucontrol)
902{
903 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
904
905 ucontrol->value.integer.value[0] =
906 loopback->setup[kcontrol->id.subdevice]
907 [kcontrol->id.device].format;
908 return 0;
909}
910
911static int loopback_rate_info(struct snd_kcontrol *kcontrol,
912 struct snd_ctl_elem_info *uinfo)
913{
914 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
915 uinfo->count = 1;
916 uinfo->value.integer.min = 0;
917 uinfo->value.integer.max = 192000;
918 uinfo->value.integer.step = 1;
919 return 0;
920}
921
922static int loopback_rate_get(struct snd_kcontrol *kcontrol,
923 struct snd_ctl_elem_value *ucontrol)
924{
925 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
926
927 ucontrol->value.integer.value[0] =
928 loopback->setup[kcontrol->id.subdevice]
929 [kcontrol->id.device].rate;
930 return 0;
931}
932
933static int loopback_channels_info(struct snd_kcontrol *kcontrol,
934 struct snd_ctl_elem_info *uinfo)
935{
936 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
937 uinfo->count = 1;
938 uinfo->value.integer.min = 1;
939 uinfo->value.integer.max = 1024;
940 uinfo->value.integer.step = 1;
941 return 0;
942}
943
944static int loopback_channels_get(struct snd_kcontrol *kcontrol,
945 struct snd_ctl_elem_value *ucontrol)
946{
947 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
948
949 ucontrol->value.integer.value[0] =
950 loopback->setup[kcontrol->id.subdevice]
951 [kcontrol->id.device].channels;
952 return 0;
953}
954
955static struct snd_kcontrol_new loopback_controls[] = {
956{
957 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
958 .name = "PCM Rate Shift 100000",
959 .info = loopback_rate_shift_info,
960 .get = loopback_rate_shift_get,
961 .put = loopback_rate_shift_put,
962},
963{
964 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
965 .name = "PCM Notify",
966 .info = snd_ctl_boolean_mono_info,
967 .get = loopback_notify_get,
968 .put = loopback_notify_put,
969},
970#define ACTIVE_IDX 2
971{
972 .access = SNDRV_CTL_ELEM_ACCESS_READ,
973 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
974 .name = "PCM Slave Active",
975 .info = snd_ctl_boolean_mono_info,
976 .get = loopback_active_get,
977},
978#define FORMAT_IDX 3
979{
980 .access = SNDRV_CTL_ELEM_ACCESS_READ,
981 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
982 .name = "PCM Slave Format",
983 .info = loopback_format_info,
984 .get = loopback_format_get
985},
986#define RATE_IDX 4
987{
988 .access = SNDRV_CTL_ELEM_ACCESS_READ,
989 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
990 .name = "PCM Slave Rate",
991 .info = loopback_rate_info,
992 .get = loopback_rate_get
993},
994#define CHANNELS_IDX 5
995{
996 .access = SNDRV_CTL_ELEM_ACCESS_READ,
997 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
998 .name = "PCM Slave Channels",
999 .info = loopback_channels_info,
1000 .get = loopback_channels_get
1001}
1002};
1003
1004static int loopback_mixer_new(struct loopback *loopback, int notify)
1005{
1006 struct snd_card *card = loopback->card;
1007 struct snd_pcm *pcm;
1008 struct snd_kcontrol *kctl;
1009 struct loopback_setup *setup;
1010 int err, dev, substr, substr_count, idx;
1011
1012 strcpy(card->mixername, "Loopback Mixer");
1013 for (dev = 0; dev < 2; dev++) {
1014 pcm = loopback->pcm[dev];
1015 substr_count =
1016 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1017 for (substr = 0; substr < substr_count; substr++) {
1018 setup = &loopback->setup[substr][dev];
1019 setup->notify = notify;
1020 setup->rate_shift = NO_PITCH;
1021 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1022 setup->rate = 48000;
1023 setup->channels = 2;
1024 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1025 idx++) {
1026 kctl = snd_ctl_new1(&loopback_controls[idx],
1027 loopback);
1028 if (!kctl)
1029 return -ENOMEM;
1030 kctl->id.device = dev;
1031 kctl->id.subdevice = substr;
1032 switch (idx) {
1033 case ACTIVE_IDX:
1034 setup->active_id = kctl->id;
1035 break;
1036 case FORMAT_IDX:
1037 setup->format_id = kctl->id;
1038 break;
1039 case RATE_IDX:
1040 setup->rate_id = kctl->id;
1041 break;
1042 case CHANNELS_IDX:
1043 setup->channels_id = kctl->id;
1044 break;
1045 default:
1046 break;
1047 }
1048 err = snd_ctl_add(card, kctl);
1049 if (err < 0)
1050 return err;
1051 }
1052 }
1053 }
1054 return 0;
1055}
1056
1057#ifdef CONFIG_PROC_FS
1058
1059static void print_dpcm_info(struct snd_info_buffer *buffer,
1060 struct loopback_pcm *dpcm,
1061 const char *id)
1062{
1063 snd_iprintf(buffer, " %s\n", id);
1064 if (dpcm == NULL) {
1065 snd_iprintf(buffer, " inactive\n");
1066 return;
1067 }
1068 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1069 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1070 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1071 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1072 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1073 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1074 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1075 snd_iprintf(buffer, " update_pending:\t%u\n",
1076 dpcm->period_update_pending);
1077 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1078 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1079 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1080 dpcm->last_jiffies, jiffies);
1081 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1082}
1083
1084static void print_substream_info(struct snd_info_buffer *buffer,
1085 struct loopback *loopback,
1086 int sub,
1087 int num)
1088{
1089 struct loopback_cable *cable = loopback->cables[sub][num];
1090
1091 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1092 if (cable == NULL) {
1093 snd_iprintf(buffer, " inactive\n");
1094 return;
1095 }
1096 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1097 snd_iprintf(buffer, " running: %u\n", cable->running);
1098 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1099 print_dpcm_info(buffer, cable->streams[0], "Playback");
1100 print_dpcm_info(buffer, cable->streams[1], "Capture");
1101}
1102
1103static void print_cable_info(struct snd_info_entry *entry,
1104 struct snd_info_buffer *buffer)
1105{
1106 struct loopback *loopback = entry->private_data;
1107 int sub, num;
1108
1109 mutex_lock(&loopback->cable_lock);
1110 num = entry->name[strlen(entry->name)-1];
1111 num = num == '0' ? 0 : 1;
1112 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1113 print_substream_info(buffer, loopback, sub, num);
1114 mutex_unlock(&loopback->cable_lock);
1115}
1116
1117static int loopback_proc_new(struct loopback *loopback, int cidx)
1118{
1119 char name[32];
1120 struct snd_info_entry *entry;
1121 int err;
1122
1123 snprintf(name, sizeof(name), "cable#%d", cidx);
1124 err = snd_card_proc_new(loopback->card, name, &entry);
1125 if (err < 0)
1126 return err;
1127
1128 snd_info_set_text_ops(entry, loopback, print_cable_info);
1129 return 0;
1130}
1131
1132#else /* !CONFIG_PROC_FS */
1133
1134#define loopback_proc_new(loopback, cidx) do { } while (0)
1135
1136#endif
1137
1138static int loopback_probe(struct platform_device *devptr)
1139{
1140 struct snd_card *card;
1141 struct loopback *loopback;
1142 int dev = devptr->id;
1143 int err;
1144
1145 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1146 sizeof(struct loopback), &card);
1147 if (err < 0)
1148 return err;
1149 loopback = card->private_data;
1150
1151 if (pcm_substreams[dev] < 1)
1152 pcm_substreams[dev] = 1;
1153 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1154 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1155
1156 loopback->card = card;
1157 mutex_init(&loopback->cable_lock);
1158
1159 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1160 if (err < 0)
1161 goto __nodev;
1162 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1163 if (err < 0)
1164 goto __nodev;
1165 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1166 if (err < 0)
1167 goto __nodev;
1168 loopback_proc_new(loopback, 0);
1169 loopback_proc_new(loopback, 1);
1170 strcpy(card->driver, "Loopback");
1171 strcpy(card->shortname, "Loopback");
1172 sprintf(card->longname, "Loopback %i", dev + 1);
1173 err = snd_card_register(card);
1174 if (!err) {
1175 platform_set_drvdata(devptr, card);
1176 return 0;
1177 }
1178 __nodev:
1179 snd_card_free(card);
1180 return err;
1181}
1182
1183static int loopback_remove(struct platform_device *devptr)
1184{
1185 snd_card_free(platform_get_drvdata(devptr));
1186 return 0;
1187}
1188
1189#ifdef CONFIG_PM_SLEEP
1190static int loopback_suspend(struct device *pdev)
1191{
1192 struct snd_card *card = dev_get_drvdata(pdev);
1193 struct loopback *loopback = card->private_data;
1194
1195 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1196
1197 snd_pcm_suspend_all(loopback->pcm[0]);
1198 snd_pcm_suspend_all(loopback->pcm[1]);
1199 return 0;
1200}
1201
1202static int loopback_resume(struct device *pdev)
1203{
1204 struct snd_card *card = dev_get_drvdata(pdev);
1205
1206 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1207 return 0;
1208}
1209
1210static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1211#define LOOPBACK_PM_OPS &loopback_pm
1212#else
1213#define LOOPBACK_PM_OPS NULL
1214#endif
1215
1216#define SND_LOOPBACK_DRIVER "snd_aloop"
1217
1218static struct platform_driver loopback_driver = {
1219 .probe = loopback_probe,
1220 .remove = loopback_remove,
1221 .driver = {
1222 .name = SND_LOOPBACK_DRIVER,
1223 .owner = THIS_MODULE,
1224 .pm = LOOPBACK_PM_OPS,
1225 },
1226};
1227
1228static void loopback_unregister_all(void)
1229{
1230 int i;
1231
1232 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1233 platform_device_unregister(devices[i]);
1234 platform_driver_unregister(&loopback_driver);
1235}
1236
1237static int __init alsa_card_loopback_init(void)
1238{
1239 int i, err, cards;
1240
1241 err = platform_driver_register(&loopback_driver);
1242 if (err < 0)
1243 return err;
1244
1245
1246 cards = 0;
1247 for (i = 0; i < SNDRV_CARDS; i++) {
1248 struct platform_device *device;
1249 if (!enable[i])
1250 continue;
1251 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1252 i, NULL, 0);
1253 if (IS_ERR(device))
1254 continue;
1255 if (!platform_get_drvdata(device)) {
1256 platform_device_unregister(device);
1257 continue;
1258 }
1259 devices[i] = device;
1260 cards++;
1261 }
1262 if (!cards) {
1263#ifdef MODULE
1264 printk(KERN_ERR "aloop: No loopback enabled\n");
1265#endif
1266 loopback_unregister_all();
1267 return -ENODEV;
1268 }
1269 return 0;
1270}
1271
1272static void __exit alsa_card_loopback_exit(void)
1273{
1274 loopback_unregister_all();
1275}
1276
1277module_init(alsa_card_loopback_init)
1278module_exit(alsa_card_loopback_exit)
1/*
2 * Loopback soundcard
3 *
4 * Original code:
5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
6 *
7 * More accurate positioning and full-duplex support:
8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
9 *
10 * Major (almost complete) rewrite:
11 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
12 *
13 * A next major update in 2010 (separate timers for playback and capture):
14 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 *
30 */
31
32#include <linux/init.h>
33#include <linux/jiffies.h>
34#include <linux/slab.h>
35#include <linux/time.h>
36#include <linux/wait.h>
37#include <linux/moduleparam.h>
38#include <linux/platform_device.h>
39#include <sound/core.h>
40#include <sound/control.h>
41#include <sound/pcm.h>
42#include <sound/info.h>
43#include <sound/initval.h>
44
45MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
46MODULE_DESCRIPTION("A loopback soundcard");
47MODULE_LICENSE("GPL");
48MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
49
50#define MAX_PCM_SUBSTREAMS 8
51
52static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
53static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
54static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
55static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
56static int pcm_notify[SNDRV_CARDS];
57
58module_param_array(index, int, NULL, 0444);
59MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
60module_param_array(id, charp, NULL, 0444);
61MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
62module_param_array(enable, bool, NULL, 0444);
63MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
64module_param_array(pcm_substreams, int, NULL, 0444);
65MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
66module_param_array(pcm_notify, int, NULL, 0444);
67MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
68
69#define NO_PITCH 100000
70
71struct loopback_pcm;
72
73struct loopback_cable {
74 spinlock_t lock;
75 struct loopback_pcm *streams[2];
76 struct snd_pcm_hardware hw;
77 /* flags */
78 unsigned int valid;
79 unsigned int running;
80 unsigned int pause;
81};
82
83struct loopback_setup {
84 unsigned int notify: 1;
85 unsigned int rate_shift;
86 unsigned int format;
87 unsigned int rate;
88 unsigned int channels;
89 struct snd_ctl_elem_id active_id;
90 struct snd_ctl_elem_id format_id;
91 struct snd_ctl_elem_id rate_id;
92 struct snd_ctl_elem_id channels_id;
93};
94
95struct loopback {
96 struct snd_card *card;
97 struct mutex cable_lock;
98 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
99 struct snd_pcm *pcm[2];
100 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
101};
102
103struct loopback_pcm {
104 struct loopback *loopback;
105 struct snd_pcm_substream *substream;
106 struct loopback_cable *cable;
107 unsigned int pcm_buffer_size;
108 unsigned int buf_pos; /* position in buffer */
109 unsigned int silent_size;
110 /* PCM parameters */
111 unsigned int pcm_period_size;
112 unsigned int pcm_bps; /* bytes per second */
113 unsigned int pcm_salign; /* bytes per sample * channels */
114 unsigned int pcm_rate_shift; /* rate shift value */
115 /* flags */
116 unsigned int period_update_pending :1;
117 /* timer stuff */
118 unsigned int irq_pos; /* fractional IRQ position */
119 unsigned int period_size_frac;
120 unsigned long last_jiffies;
121 struct timer_list timer;
122};
123
124static struct platform_device *devices[SNDRV_CARDS];
125
126static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
127{
128 if (dpcm->pcm_rate_shift == NO_PITCH) {
129 x /= HZ;
130 } else {
131 x = div_u64(NO_PITCH * (unsigned long long)x,
132 HZ * (unsigned long long)dpcm->pcm_rate_shift);
133 }
134 return x - (x % dpcm->pcm_salign);
135}
136
137static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
138{
139 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
140 return x * HZ;
141 } else {
142 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
143 NO_PITCH);
144 }
145 return x;
146}
147
148static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
149{
150 int device = dpcm->substream->pstr->pcm->device;
151
152 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
153 device ^= 1;
154 return &dpcm->loopback->setup[dpcm->substream->number][device];
155}
156
157static inline unsigned int get_notify(struct loopback_pcm *dpcm)
158{
159 return get_setup(dpcm)->notify;
160}
161
162static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
163{
164 return get_setup(dpcm)->rate_shift;
165}
166
167static void loopback_timer_start(struct loopback_pcm *dpcm)
168{
169 unsigned long tick;
170 unsigned int rate_shift = get_rate_shift(dpcm);
171
172 if (rate_shift != dpcm->pcm_rate_shift) {
173 dpcm->pcm_rate_shift = rate_shift;
174 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
175 }
176 if (dpcm->period_size_frac <= dpcm->irq_pos) {
177 dpcm->irq_pos %= dpcm->period_size_frac;
178 dpcm->period_update_pending = 1;
179 }
180 tick = dpcm->period_size_frac - dpcm->irq_pos;
181 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
182 dpcm->timer.expires = jiffies + tick;
183 add_timer(&dpcm->timer);
184}
185
186static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
187{
188 del_timer(&dpcm->timer);
189 dpcm->timer.expires = 0;
190}
191
192#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
193#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
194#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
195
196static int loopback_check_format(struct loopback_cable *cable, int stream)
197{
198 struct snd_pcm_runtime *runtime, *cruntime;
199 struct loopback_setup *setup;
200 struct snd_card *card;
201 int check;
202
203 if (cable->valid != CABLE_VALID_BOTH) {
204 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
205 goto __notify;
206 return 0;
207 }
208 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
209 substream->runtime;
210 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
211 substream->runtime;
212 check = runtime->format != cruntime->format ||
213 runtime->rate != cruntime->rate ||
214 runtime->channels != cruntime->channels;
215 if (!check)
216 return 0;
217 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
218 return -EIO;
219 } else {
220 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
221 substream, SNDRV_PCM_STATE_DRAINING);
222 __notify:
223 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
224 substream->runtime;
225 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
226 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
227 if (setup->format != runtime->format) {
228 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
229 &setup->format_id);
230 setup->format = runtime->format;
231 }
232 if (setup->rate != runtime->rate) {
233 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
234 &setup->rate_id);
235 setup->rate = runtime->rate;
236 }
237 if (setup->channels != runtime->channels) {
238 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
239 &setup->channels_id);
240 setup->channels = runtime->channels;
241 }
242 }
243 return 0;
244}
245
246static void loopback_active_notify(struct loopback_pcm *dpcm)
247{
248 snd_ctl_notify(dpcm->loopback->card,
249 SNDRV_CTL_EVENT_MASK_VALUE,
250 &get_setup(dpcm)->active_id);
251}
252
253static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
254{
255 struct snd_pcm_runtime *runtime = substream->runtime;
256 struct loopback_pcm *dpcm = runtime->private_data;
257 struct loopback_cable *cable = dpcm->cable;
258 int err, stream = 1 << substream->stream;
259
260 switch (cmd) {
261 case SNDRV_PCM_TRIGGER_START:
262 err = loopback_check_format(cable, substream->stream);
263 if (err < 0)
264 return err;
265 dpcm->last_jiffies = jiffies;
266 dpcm->pcm_rate_shift = 0;
267 spin_lock(&cable->lock);
268 cable->running |= stream;
269 cable->pause &= ~stream;
270 spin_unlock(&cable->lock);
271 loopback_timer_start(dpcm);
272 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
273 loopback_active_notify(dpcm);
274 break;
275 case SNDRV_PCM_TRIGGER_STOP:
276 spin_lock(&cable->lock);
277 cable->running &= ~stream;
278 cable->pause &= ~stream;
279 spin_unlock(&cable->lock);
280 loopback_timer_stop(dpcm);
281 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
282 loopback_active_notify(dpcm);
283 break;
284 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
285 spin_lock(&cable->lock);
286 cable->pause |= stream;
287 spin_unlock(&cable->lock);
288 loopback_timer_stop(dpcm);
289 break;
290 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
291 spin_lock(&cable->lock);
292 dpcm->last_jiffies = jiffies;
293 cable->pause &= ~stream;
294 spin_unlock(&cable->lock);
295 loopback_timer_start(dpcm);
296 break;
297 default:
298 return -EINVAL;
299 }
300 return 0;
301}
302
303static void params_change_substream(struct loopback_pcm *dpcm,
304 struct snd_pcm_runtime *runtime)
305{
306 struct snd_pcm_runtime *dst_runtime;
307
308 if (dpcm == NULL || dpcm->substream == NULL)
309 return;
310 dst_runtime = dpcm->substream->runtime;
311 if (dst_runtime == NULL)
312 return;
313 dst_runtime->hw = dpcm->cable->hw;
314}
315
316static void params_change(struct snd_pcm_substream *substream)
317{
318 struct snd_pcm_runtime *runtime = substream->runtime;
319 struct loopback_pcm *dpcm = runtime->private_data;
320 struct loopback_cable *cable = dpcm->cable;
321
322 cable->hw.formats = (1ULL << runtime->format);
323 cable->hw.rate_min = runtime->rate;
324 cable->hw.rate_max = runtime->rate;
325 cable->hw.channels_min = runtime->channels;
326 cable->hw.channels_max = runtime->channels;
327 params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
328 runtime);
329 params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
330 runtime);
331}
332
333static int loopback_prepare(struct snd_pcm_substream *substream)
334{
335 struct snd_pcm_runtime *runtime = substream->runtime;
336 struct loopback_pcm *dpcm = runtime->private_data;
337 struct loopback_cable *cable = dpcm->cable;
338 int bps, salign;
339
340 salign = (snd_pcm_format_width(runtime->format) *
341 runtime->channels) / 8;
342 bps = salign * runtime->rate;
343 if (bps <= 0 || salign <= 0)
344 return -EINVAL;
345
346 dpcm->buf_pos = 0;
347 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
348 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
349 /* clear capture buffer */
350 dpcm->silent_size = dpcm->pcm_buffer_size;
351 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
352 runtime->buffer_size * runtime->channels);
353 }
354
355 dpcm->irq_pos = 0;
356 dpcm->period_update_pending = 0;
357 dpcm->pcm_bps = bps;
358 dpcm->pcm_salign = salign;
359 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
360
361 mutex_lock(&dpcm->loopback->cable_lock);
362 if (!(cable->valid & ~(1 << substream->stream)) ||
363 (get_setup(dpcm)->notify &&
364 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
365 params_change(substream);
366 cable->valid |= 1 << substream->stream;
367 mutex_unlock(&dpcm->loopback->cable_lock);
368
369 return 0;
370}
371
372static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
373{
374 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
375 char *dst = runtime->dma_area;
376 unsigned int dst_off = dpcm->buf_pos;
377
378 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
379 return;
380 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
381 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
382
383 for (;;) {
384 unsigned int size = bytes;
385 if (dst_off + size > dpcm->pcm_buffer_size)
386 size = dpcm->pcm_buffer_size - dst_off;
387 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
388 bytes_to_frames(runtime, size) *
389 runtime->channels);
390 dpcm->silent_size += size;
391 bytes -= size;
392 if (!bytes)
393 break;
394 dst_off = 0;
395 }
396}
397
398static void copy_play_buf(struct loopback_pcm *play,
399 struct loopback_pcm *capt,
400 unsigned int bytes)
401{
402 struct snd_pcm_runtime *runtime = play->substream->runtime;
403 char *src = runtime->dma_area;
404 char *dst = capt->substream->runtime->dma_area;
405 unsigned int src_off = play->buf_pos;
406 unsigned int dst_off = capt->buf_pos;
407 unsigned int clear_bytes = 0;
408
409 /* check if playback is draining, trim the capture copy size
410 * when our pointer is at the end of playback ring buffer */
411 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
412 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
413 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
414 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
415 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
416 appl_ptr1 += play->buf_pos / play->pcm_salign;
417 if (appl_ptr < appl_ptr1)
418 appl_ptr1 -= runtime->buffer_size;
419 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
420 if (diff < bytes) {
421 clear_bytes = bytes - diff;
422 bytes = diff;
423 }
424 }
425
426 for (;;) {
427 unsigned int size = bytes;
428 if (src_off + size > play->pcm_buffer_size)
429 size = play->pcm_buffer_size - src_off;
430 if (dst_off + size > capt->pcm_buffer_size)
431 size = capt->pcm_buffer_size - dst_off;
432 memcpy(dst + dst_off, src + src_off, size);
433 capt->silent_size = 0;
434 bytes -= size;
435 if (!bytes)
436 break;
437 src_off = (src_off + size) % play->pcm_buffer_size;
438 dst_off = (dst_off + size) % capt->pcm_buffer_size;
439 }
440
441 if (clear_bytes > 0) {
442 clear_capture_buf(capt, clear_bytes);
443 capt->silent_size = 0;
444 }
445}
446
447#define BYTEPOS_UPDATE_POSONLY 0
448#define BYTEPOS_UPDATE_CLEAR 1
449#define BYTEPOS_UPDATE_COPY 2
450
451static void loopback_bytepos_update(struct loopback_pcm *dpcm,
452 unsigned int delta,
453 unsigned int cmd)
454{
455 unsigned int count;
456 unsigned long last_pos;
457
458 last_pos = byte_pos(dpcm, dpcm->irq_pos);
459 dpcm->irq_pos += delta * dpcm->pcm_bps;
460 count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
461 if (!count)
462 return;
463 if (cmd == BYTEPOS_UPDATE_CLEAR)
464 clear_capture_buf(dpcm, count);
465 else if (cmd == BYTEPOS_UPDATE_COPY)
466 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
467 dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
468 count);
469 dpcm->buf_pos += count;
470 dpcm->buf_pos %= dpcm->pcm_buffer_size;
471 if (dpcm->irq_pos >= dpcm->period_size_frac) {
472 dpcm->irq_pos %= dpcm->period_size_frac;
473 dpcm->period_update_pending = 1;
474 }
475}
476
477static unsigned int loopback_pos_update(struct loopback_cable *cable)
478{
479 struct loopback_pcm *dpcm_play =
480 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
481 struct loopback_pcm *dpcm_capt =
482 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
483 unsigned long delta_play = 0, delta_capt = 0;
484 unsigned int running;
485 unsigned long flags;
486
487 spin_lock_irqsave(&cable->lock, flags);
488 running = cable->running ^ cable->pause;
489 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
490 delta_play = jiffies - dpcm_play->last_jiffies;
491 dpcm_play->last_jiffies += delta_play;
492 }
493
494 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
495 delta_capt = jiffies - dpcm_capt->last_jiffies;
496 dpcm_capt->last_jiffies += delta_capt;
497 }
498
499 if (delta_play == 0 && delta_capt == 0)
500 goto unlock;
501
502 if (delta_play > delta_capt) {
503 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
504 BYTEPOS_UPDATE_POSONLY);
505 delta_play = delta_capt;
506 } else if (delta_play < delta_capt) {
507 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
508 BYTEPOS_UPDATE_CLEAR);
509 delta_capt = delta_play;
510 }
511
512 if (delta_play == 0 && delta_capt == 0)
513 goto unlock;
514
515 /* note delta_capt == delta_play at this moment */
516 loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
517 loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
518 unlock:
519 spin_unlock_irqrestore(&cable->lock, flags);
520 return running;
521}
522
523static void loopback_timer_function(unsigned long data)
524{
525 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
526 unsigned int running;
527
528 running = loopback_pos_update(dpcm->cable);
529 if (running & (1 << dpcm->substream->stream)) {
530 loopback_timer_start(dpcm);
531 if (dpcm->period_update_pending) {
532 dpcm->period_update_pending = 0;
533 snd_pcm_period_elapsed(dpcm->substream);
534 }
535 }
536}
537
538static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
539{
540 struct snd_pcm_runtime *runtime = substream->runtime;
541 struct loopback_pcm *dpcm = runtime->private_data;
542
543 loopback_pos_update(dpcm->cable);
544 return bytes_to_frames(runtime, dpcm->buf_pos);
545}
546
547static struct snd_pcm_hardware loopback_pcm_hardware =
548{
549 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
550 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE),
551 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
552 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
553 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
554 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
555 .rate_min = 8000,
556 .rate_max = 192000,
557 .channels_min = 1,
558 .channels_max = 32,
559 .buffer_bytes_max = 2 * 1024 * 1024,
560 .period_bytes_min = 64,
561 /* note check overflow in frac_pos() using pcm_rate_shift before
562 changing period_bytes_max value */
563 .period_bytes_max = 1024 * 1024,
564 .periods_min = 1,
565 .periods_max = 1024,
566 .fifo_size = 0,
567};
568
569static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
570{
571 struct loopback_pcm *dpcm = runtime->private_data;
572 kfree(dpcm);
573}
574
575static int loopback_hw_params(struct snd_pcm_substream *substream,
576 struct snd_pcm_hw_params *params)
577{
578 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
579}
580
581static int loopback_hw_free(struct snd_pcm_substream *substream)
582{
583 struct snd_pcm_runtime *runtime = substream->runtime;
584 struct loopback_pcm *dpcm = runtime->private_data;
585 struct loopback_cable *cable = dpcm->cable;
586
587 mutex_lock(&dpcm->loopback->cable_lock);
588 cable->valid &= ~(1 << substream->stream);
589 mutex_unlock(&dpcm->loopback->cable_lock);
590 return snd_pcm_lib_free_pages(substream);
591}
592
593static unsigned int get_cable_index(struct snd_pcm_substream *substream)
594{
595 if (!substream->pcm->device)
596 return substream->stream;
597 else
598 return !substream->stream;
599}
600
601static int rule_format(struct snd_pcm_hw_params *params,
602 struct snd_pcm_hw_rule *rule)
603{
604
605 struct snd_pcm_hardware *hw = rule->private;
606 struct snd_mask *maskp = hw_param_mask(params, rule->var);
607
608 maskp->bits[0] &= (u_int32_t)hw->formats;
609 maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
610 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
611 if (! maskp->bits[0] && ! maskp->bits[1])
612 return -EINVAL;
613 return 0;
614}
615
616static int rule_rate(struct snd_pcm_hw_params *params,
617 struct snd_pcm_hw_rule *rule)
618{
619 struct snd_pcm_hardware *hw = rule->private;
620 struct snd_interval t;
621
622 t.min = hw->rate_min;
623 t.max = hw->rate_max;
624 t.openmin = t.openmax = 0;
625 t.integer = 0;
626 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
627}
628
629static int rule_channels(struct snd_pcm_hw_params *params,
630 struct snd_pcm_hw_rule *rule)
631{
632 struct snd_pcm_hardware *hw = rule->private;
633 struct snd_interval t;
634
635 t.min = hw->channels_min;
636 t.max = hw->channels_max;
637 t.openmin = t.openmax = 0;
638 t.integer = 0;
639 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
640}
641
642static int loopback_open(struct snd_pcm_substream *substream)
643{
644 struct snd_pcm_runtime *runtime = substream->runtime;
645 struct loopback *loopback = substream->private_data;
646 struct loopback_pcm *dpcm;
647 struct loopback_cable *cable;
648 int err = 0;
649 int dev = get_cable_index(substream);
650
651 mutex_lock(&loopback->cable_lock);
652 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
653 if (!dpcm) {
654 err = -ENOMEM;
655 goto unlock;
656 }
657 dpcm->loopback = loopback;
658 dpcm->substream = substream;
659 setup_timer(&dpcm->timer, loopback_timer_function,
660 (unsigned long)dpcm);
661
662 cable = loopback->cables[substream->number][dev];
663 if (!cable) {
664 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
665 if (!cable) {
666 kfree(dpcm);
667 err = -ENOMEM;
668 goto unlock;
669 }
670 spin_lock_init(&cable->lock);
671 cable->hw = loopback_pcm_hardware;
672 loopback->cables[substream->number][dev] = cable;
673 }
674 dpcm->cable = cable;
675 cable->streams[substream->stream] = dpcm;
676
677 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
678
679 /* use dynamic rules based on actual runtime->hw values */
680 /* note that the default rules created in the PCM midlevel code */
681 /* are cached -> they do not reflect the actual state */
682 err = snd_pcm_hw_rule_add(runtime, 0,
683 SNDRV_PCM_HW_PARAM_FORMAT,
684 rule_format, &runtime->hw,
685 SNDRV_PCM_HW_PARAM_FORMAT, -1);
686 if (err < 0)
687 goto unlock;
688 err = snd_pcm_hw_rule_add(runtime, 0,
689 SNDRV_PCM_HW_PARAM_RATE,
690 rule_rate, &runtime->hw,
691 SNDRV_PCM_HW_PARAM_RATE, -1);
692 if (err < 0)
693 goto unlock;
694 err = snd_pcm_hw_rule_add(runtime, 0,
695 SNDRV_PCM_HW_PARAM_CHANNELS,
696 rule_channels, &runtime->hw,
697 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
698 if (err < 0)
699 goto unlock;
700
701 runtime->private_data = dpcm;
702 runtime->private_free = loopback_runtime_free;
703 if (get_notify(dpcm))
704 runtime->hw = loopback_pcm_hardware;
705 else
706 runtime->hw = cable->hw;
707 unlock:
708 mutex_unlock(&loopback->cable_lock);
709 return err;
710}
711
712static int loopback_close(struct snd_pcm_substream *substream)
713{
714 struct loopback *loopback = substream->private_data;
715 struct loopback_pcm *dpcm = substream->runtime->private_data;
716 struct loopback_cable *cable;
717 int dev = get_cable_index(substream);
718
719 loopback_timer_stop(dpcm);
720 mutex_lock(&loopback->cable_lock);
721 cable = loopback->cables[substream->number][dev];
722 if (cable->streams[!substream->stream]) {
723 /* other stream is still alive */
724 cable->streams[substream->stream] = NULL;
725 } else {
726 /* free the cable */
727 loopback->cables[substream->number][dev] = NULL;
728 kfree(cable);
729 }
730 mutex_unlock(&loopback->cable_lock);
731 return 0;
732}
733
734static struct snd_pcm_ops loopback_playback_ops = {
735 .open = loopback_open,
736 .close = loopback_close,
737 .ioctl = snd_pcm_lib_ioctl,
738 .hw_params = loopback_hw_params,
739 .hw_free = loopback_hw_free,
740 .prepare = loopback_prepare,
741 .trigger = loopback_trigger,
742 .pointer = loopback_pointer,
743};
744
745static struct snd_pcm_ops loopback_capture_ops = {
746 .open = loopback_open,
747 .close = loopback_close,
748 .ioctl = snd_pcm_lib_ioctl,
749 .hw_params = loopback_hw_params,
750 .hw_free = loopback_hw_free,
751 .prepare = loopback_prepare,
752 .trigger = loopback_trigger,
753 .pointer = loopback_pointer,
754};
755
756static int __devinit loopback_pcm_new(struct loopback *loopback,
757 int device, int substreams)
758{
759 struct snd_pcm *pcm;
760 int err;
761
762 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
763 substreams, substreams, &pcm);
764 if (err < 0)
765 return err;
766 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
767 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
768
769 pcm->private_data = loopback;
770 pcm->info_flags = 0;
771 strcpy(pcm->name, "Loopback PCM");
772
773 loopback->pcm[device] = pcm;
774
775 snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
776 snd_dma_continuous_data(GFP_KERNEL),
777 0, 2 * 1024 * 1024);
778 return 0;
779}
780
781static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
782 struct snd_ctl_elem_info *uinfo)
783{
784 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
785 uinfo->count = 1;
786 uinfo->value.integer.min = 80000;
787 uinfo->value.integer.max = 120000;
788 uinfo->value.integer.step = 1;
789 return 0;
790}
791
792static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
793 struct snd_ctl_elem_value *ucontrol)
794{
795 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
796
797 ucontrol->value.integer.value[0] =
798 loopback->setup[kcontrol->id.subdevice]
799 [kcontrol->id.device].rate_shift;
800 return 0;
801}
802
803static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
804 struct snd_ctl_elem_value *ucontrol)
805{
806 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
807 unsigned int val;
808 int change = 0;
809
810 val = ucontrol->value.integer.value[0];
811 if (val < 80000)
812 val = 80000;
813 if (val > 120000)
814 val = 120000;
815 mutex_lock(&loopback->cable_lock);
816 if (val != loopback->setup[kcontrol->id.subdevice]
817 [kcontrol->id.device].rate_shift) {
818 loopback->setup[kcontrol->id.subdevice]
819 [kcontrol->id.device].rate_shift = val;
820 change = 1;
821 }
822 mutex_unlock(&loopback->cable_lock);
823 return change;
824}
825
826static int loopback_notify_get(struct snd_kcontrol *kcontrol,
827 struct snd_ctl_elem_value *ucontrol)
828{
829 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
830
831 ucontrol->value.integer.value[0] =
832 loopback->setup[kcontrol->id.subdevice]
833 [kcontrol->id.device].notify;
834 return 0;
835}
836
837static int loopback_notify_put(struct snd_kcontrol *kcontrol,
838 struct snd_ctl_elem_value *ucontrol)
839{
840 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
841 unsigned int val;
842 int change = 0;
843
844 val = ucontrol->value.integer.value[0] ? 1 : 0;
845 if (val != loopback->setup[kcontrol->id.subdevice]
846 [kcontrol->id.device].notify) {
847 loopback->setup[kcontrol->id.subdevice]
848 [kcontrol->id.device].notify = val;
849 change = 1;
850 }
851 return change;
852}
853
854static int loopback_active_get(struct snd_kcontrol *kcontrol,
855 struct snd_ctl_elem_value *ucontrol)
856{
857 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
858 struct loopback_cable *cable = loopback->cables
859 [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
860 unsigned int val = 0;
861
862 if (cable != NULL)
863 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
864 1 : 0;
865 ucontrol->value.integer.value[0] = val;
866 return 0;
867}
868
869static int loopback_format_info(struct snd_kcontrol *kcontrol,
870 struct snd_ctl_elem_info *uinfo)
871{
872 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
873 uinfo->count = 1;
874 uinfo->value.integer.min = 0;
875 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
876 uinfo->value.integer.step = 1;
877 return 0;
878}
879
880static int loopback_format_get(struct snd_kcontrol *kcontrol,
881 struct snd_ctl_elem_value *ucontrol)
882{
883 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
884
885 ucontrol->value.integer.value[0] =
886 loopback->setup[kcontrol->id.subdevice]
887 [kcontrol->id.device].format;
888 return 0;
889}
890
891static int loopback_rate_info(struct snd_kcontrol *kcontrol,
892 struct snd_ctl_elem_info *uinfo)
893{
894 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
895 uinfo->count = 1;
896 uinfo->value.integer.min = 0;
897 uinfo->value.integer.max = 192000;
898 uinfo->value.integer.step = 1;
899 return 0;
900}
901
902static int loopback_rate_get(struct snd_kcontrol *kcontrol,
903 struct snd_ctl_elem_value *ucontrol)
904{
905 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
906
907 ucontrol->value.integer.value[0] =
908 loopback->setup[kcontrol->id.subdevice]
909 [kcontrol->id.device].rate;
910 return 0;
911}
912
913static int loopback_channels_info(struct snd_kcontrol *kcontrol,
914 struct snd_ctl_elem_info *uinfo)
915{
916 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
917 uinfo->count = 1;
918 uinfo->value.integer.min = 1;
919 uinfo->value.integer.max = 1024;
920 uinfo->value.integer.step = 1;
921 return 0;
922}
923
924static int loopback_channels_get(struct snd_kcontrol *kcontrol,
925 struct snd_ctl_elem_value *ucontrol)
926{
927 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
928
929 ucontrol->value.integer.value[0] =
930 loopback->setup[kcontrol->id.subdevice]
931 [kcontrol->id.device].channels;
932 return 0;
933}
934
935static struct snd_kcontrol_new loopback_controls[] __devinitdata = {
936{
937 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
938 .name = "PCM Rate Shift 100000",
939 .info = loopback_rate_shift_info,
940 .get = loopback_rate_shift_get,
941 .put = loopback_rate_shift_put,
942},
943{
944 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
945 .name = "PCM Notify",
946 .info = snd_ctl_boolean_mono_info,
947 .get = loopback_notify_get,
948 .put = loopback_notify_put,
949},
950#define ACTIVE_IDX 2
951{
952 .access = SNDRV_CTL_ELEM_ACCESS_READ,
953 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
954 .name = "PCM Slave Active",
955 .info = snd_ctl_boolean_mono_info,
956 .get = loopback_active_get,
957},
958#define FORMAT_IDX 3
959{
960 .access = SNDRV_CTL_ELEM_ACCESS_READ,
961 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
962 .name = "PCM Slave Format",
963 .info = loopback_format_info,
964 .get = loopback_format_get
965},
966#define RATE_IDX 4
967{
968 .access = SNDRV_CTL_ELEM_ACCESS_READ,
969 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
970 .name = "PCM Slave Rate",
971 .info = loopback_rate_info,
972 .get = loopback_rate_get
973},
974#define CHANNELS_IDX 5
975{
976 .access = SNDRV_CTL_ELEM_ACCESS_READ,
977 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
978 .name = "PCM Slave Channels",
979 .info = loopback_channels_info,
980 .get = loopback_channels_get
981}
982};
983
984static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
985{
986 struct snd_card *card = loopback->card;
987 struct snd_pcm *pcm;
988 struct snd_kcontrol *kctl;
989 struct loopback_setup *setup;
990 int err, dev, substr, substr_count, idx;
991
992 strcpy(card->mixername, "Loopback Mixer");
993 for (dev = 0; dev < 2; dev++) {
994 pcm = loopback->pcm[dev];
995 substr_count =
996 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
997 for (substr = 0; substr < substr_count; substr++) {
998 setup = &loopback->setup[substr][dev];
999 setup->notify = notify;
1000 setup->rate_shift = NO_PITCH;
1001 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1002 setup->rate = 48000;
1003 setup->channels = 2;
1004 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1005 idx++) {
1006 kctl = snd_ctl_new1(&loopback_controls[idx],
1007 loopback);
1008 if (!kctl)
1009 return -ENOMEM;
1010 kctl->id.device = dev;
1011 kctl->id.subdevice = substr;
1012 switch (idx) {
1013 case ACTIVE_IDX:
1014 setup->active_id = kctl->id;
1015 break;
1016 case FORMAT_IDX:
1017 setup->format_id = kctl->id;
1018 break;
1019 case RATE_IDX:
1020 setup->rate_id = kctl->id;
1021 break;
1022 case CHANNELS_IDX:
1023 setup->channels_id = kctl->id;
1024 break;
1025 default:
1026 break;
1027 }
1028 err = snd_ctl_add(card, kctl);
1029 if (err < 0)
1030 return err;
1031 }
1032 }
1033 }
1034 return 0;
1035}
1036
1037#ifdef CONFIG_PROC_FS
1038
1039static void print_dpcm_info(struct snd_info_buffer *buffer,
1040 struct loopback_pcm *dpcm,
1041 const char *id)
1042{
1043 snd_iprintf(buffer, " %s\n", id);
1044 if (dpcm == NULL) {
1045 snd_iprintf(buffer, " inactive\n");
1046 return;
1047 }
1048 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1049 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1050 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1051 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1052 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1053 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1054 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1055 snd_iprintf(buffer, " update_pending:\t%u\n",
1056 dpcm->period_update_pending);
1057 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1058 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1059 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1060 dpcm->last_jiffies, jiffies);
1061 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1062}
1063
1064static void print_substream_info(struct snd_info_buffer *buffer,
1065 struct loopback *loopback,
1066 int sub,
1067 int num)
1068{
1069 struct loopback_cable *cable = loopback->cables[sub][num];
1070
1071 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1072 if (cable == NULL) {
1073 snd_iprintf(buffer, " inactive\n");
1074 return;
1075 }
1076 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1077 snd_iprintf(buffer, " running: %u\n", cable->running);
1078 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1079 print_dpcm_info(buffer, cable->streams[0], "Playback");
1080 print_dpcm_info(buffer, cable->streams[1], "Capture");
1081}
1082
1083static void print_cable_info(struct snd_info_entry *entry,
1084 struct snd_info_buffer *buffer)
1085{
1086 struct loopback *loopback = entry->private_data;
1087 int sub, num;
1088
1089 mutex_lock(&loopback->cable_lock);
1090 num = entry->name[strlen(entry->name)-1];
1091 num = num == '0' ? 0 : 1;
1092 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1093 print_substream_info(buffer, loopback, sub, num);
1094 mutex_unlock(&loopback->cable_lock);
1095}
1096
1097static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1098{
1099 char name[32];
1100 struct snd_info_entry *entry;
1101 int err;
1102
1103 snprintf(name, sizeof(name), "cable#%d", cidx);
1104 err = snd_card_proc_new(loopback->card, name, &entry);
1105 if (err < 0)
1106 return err;
1107
1108 snd_info_set_text_ops(entry, loopback, print_cable_info);
1109 return 0;
1110}
1111
1112#else /* !CONFIG_PROC_FS */
1113
1114#define loopback_proc_new(loopback, cidx) do { } while (0)
1115
1116#endif
1117
1118static int __devinit loopback_probe(struct platform_device *devptr)
1119{
1120 struct snd_card *card;
1121 struct loopback *loopback;
1122 int dev = devptr->id;
1123 int err;
1124
1125 err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1126 sizeof(struct loopback), &card);
1127 if (err < 0)
1128 return err;
1129 loopback = card->private_data;
1130
1131 if (pcm_substreams[dev] < 1)
1132 pcm_substreams[dev] = 1;
1133 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1134 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1135
1136 loopback->card = card;
1137 mutex_init(&loopback->cable_lock);
1138
1139 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1140 if (err < 0)
1141 goto __nodev;
1142 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1143 if (err < 0)
1144 goto __nodev;
1145 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1146 if (err < 0)
1147 goto __nodev;
1148 loopback_proc_new(loopback, 0);
1149 loopback_proc_new(loopback, 1);
1150 strcpy(card->driver, "Loopback");
1151 strcpy(card->shortname, "Loopback");
1152 sprintf(card->longname, "Loopback %i", dev + 1);
1153 err = snd_card_register(card);
1154 if (!err) {
1155 platform_set_drvdata(devptr, card);
1156 return 0;
1157 }
1158 __nodev:
1159 snd_card_free(card);
1160 return err;
1161}
1162
1163static int __devexit loopback_remove(struct platform_device *devptr)
1164{
1165 snd_card_free(platform_get_drvdata(devptr));
1166 platform_set_drvdata(devptr, NULL);
1167 return 0;
1168}
1169
1170#ifdef CONFIG_PM
1171static int loopback_suspend(struct platform_device *pdev,
1172 pm_message_t state)
1173{
1174 struct snd_card *card = platform_get_drvdata(pdev);
1175 struct loopback *loopback = card->private_data;
1176
1177 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1178
1179 snd_pcm_suspend_all(loopback->pcm[0]);
1180 snd_pcm_suspend_all(loopback->pcm[1]);
1181 return 0;
1182}
1183
1184static int loopback_resume(struct platform_device *pdev)
1185{
1186 struct snd_card *card = platform_get_drvdata(pdev);
1187
1188 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1189 return 0;
1190}
1191#endif
1192
1193#define SND_LOOPBACK_DRIVER "snd_aloop"
1194
1195static struct platform_driver loopback_driver = {
1196 .probe = loopback_probe,
1197 .remove = __devexit_p(loopback_remove),
1198#ifdef CONFIG_PM
1199 .suspend = loopback_suspend,
1200 .resume = loopback_resume,
1201#endif
1202 .driver = {
1203 .name = SND_LOOPBACK_DRIVER
1204 },
1205};
1206
1207static void loopback_unregister_all(void)
1208{
1209 int i;
1210
1211 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1212 platform_device_unregister(devices[i]);
1213 platform_driver_unregister(&loopback_driver);
1214}
1215
1216static int __init alsa_card_loopback_init(void)
1217{
1218 int i, err, cards;
1219
1220 err = platform_driver_register(&loopback_driver);
1221 if (err < 0)
1222 return err;
1223
1224
1225 cards = 0;
1226 for (i = 0; i < SNDRV_CARDS; i++) {
1227 struct platform_device *device;
1228 if (!enable[i])
1229 continue;
1230 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1231 i, NULL, 0);
1232 if (IS_ERR(device))
1233 continue;
1234 if (!platform_get_drvdata(device)) {
1235 platform_device_unregister(device);
1236 continue;
1237 }
1238 devices[i] = device;
1239 cards++;
1240 }
1241 if (!cards) {
1242#ifdef MODULE
1243 printk(KERN_ERR "aloop: No loopback enabled\n");
1244#endif
1245 loopback_unregister_all();
1246 return -ENODEV;
1247 }
1248 return 0;
1249}
1250
1251static void __exit alsa_card_loopback_exit(void)
1252{
1253 loopback_unregister_all();
1254}
1255
1256module_init(alsa_card_loopback_init)
1257module_exit(alsa_card_loopback_exit)