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ALSA: snd-aloop - fix capture buffer silence
[deliverable/linux.git] / sound / drivers / aloop.c
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/initval.h>
43
44 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
45 MODULE_DESCRIPTION("A loopback soundcard");
46 MODULE_LICENSE("GPL");
47 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
48
49 #define MAX_PCM_SUBSTREAMS 8
50
51 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
52 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
53 static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
54 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
55 static int pcm_notify[SNDRV_CARDS];
56
57 module_param_array(index, int, NULL, 0444);
58 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
59 module_param_array(id, charp, NULL, 0444);
60 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
61 module_param_array(enable, bool, NULL, 0444);
62 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
63 module_param_array(pcm_substreams, int, NULL, 0444);
64 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
65 module_param_array(pcm_notify, int, NULL, 0444);
66 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
67
68 #define NO_PITCH 100000
69
70 struct loopback_pcm;
71
72 struct loopback_cable {
73 spinlock_t lock;
74 struct loopback_pcm *streams[2];
75 struct snd_pcm_hardware hw;
76 /* flags */
77 unsigned int valid;
78 unsigned int running;
79 };
80
81 struct loopback_setup {
82 unsigned int notify: 1;
83 unsigned int rate_shift;
84 unsigned int format;
85 unsigned int rate;
86 unsigned int channels;
87 struct snd_ctl_elem_id active_id;
88 struct snd_ctl_elem_id format_id;
89 struct snd_ctl_elem_id rate_id;
90 struct snd_ctl_elem_id channels_id;
91 };
92
93 struct loopback {
94 struct snd_card *card;
95 struct mutex cable_lock;
96 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
97 struct snd_pcm *pcm[2];
98 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
99 };
100
101 struct loopback_pcm {
102 struct loopback *loopback;
103 struct snd_pcm_substream *substream;
104 struct loopback_cable *cable;
105 unsigned int pcm_buffer_size;
106 unsigned int buf_pos; /* position in buffer */
107 unsigned int silent_size;
108 /* PCM parameters */
109 unsigned int pcm_period_size;
110 unsigned int pcm_bps; /* bytes per second */
111 unsigned int pcm_salign; /* bytes per sample * channels */
112 unsigned int pcm_rate_shift; /* rate shift value */
113 /* flags */
114 unsigned int period_update_pending :1;
115 /* timer stuff */
116 unsigned int irq_pos; /* fractional IRQ position */
117 unsigned int period_size_frac;
118 unsigned long last_jiffies;
119 struct timer_list timer;
120 };
121
122 static struct platform_device *devices[SNDRV_CARDS];
123
124 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
125 {
126 if (dpcm->pcm_rate_shift == NO_PITCH) {
127 x /= HZ;
128 } else {
129 x = div_u64(NO_PITCH * (unsigned long long)x,
130 HZ * (unsigned long long)dpcm->pcm_rate_shift);
131 }
132 return x - (x % dpcm->pcm_salign);
133 }
134
135 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
136 {
137 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
138 return x * HZ;
139 } else {
140 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
141 NO_PITCH);
142 }
143 return x;
144 }
145
146 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
147 {
148 int device = dpcm->substream->pstr->pcm->device;
149
150 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
151 device ^= 1;
152 return &dpcm->loopback->setup[dpcm->substream->number][device];
153 }
154
155 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
156 {
157 return get_setup(dpcm)->notify;
158 }
159
160 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
161 {
162 return get_setup(dpcm)->rate_shift;
163 }
164
165 static void loopback_timer_start(struct loopback_pcm *dpcm)
166 {
167 unsigned long tick;
168 unsigned int rate_shift = get_rate_shift(dpcm);
169
170 if (rate_shift != dpcm->pcm_rate_shift) {
171 dpcm->pcm_rate_shift = rate_shift;
172 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
173 }
174 tick = dpcm->period_size_frac - dpcm->irq_pos;
175 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
176 dpcm->timer.expires = jiffies + tick;
177 add_timer(&dpcm->timer);
178 }
179
180 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
181 {
182 del_timer(&dpcm->timer);
183 }
184
185 #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
186 #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
187 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
188
189 static int loopback_check_format(struct loopback_cable *cable, int stream)
190 {
191 struct snd_pcm_runtime *runtime;
192 struct loopback_setup *setup;
193 struct snd_card *card;
194 int check;
195
196 if (cable->valid != CABLE_VALID_BOTH) {
197 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
198 goto __notify;
199 return 0;
200 }
201 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
202 substream->runtime;
203 check = cable->hw.formats != (1ULL << runtime->format) ||
204 cable->hw.rate_min != runtime->rate ||
205 cable->hw.rate_max != runtime->rate ||
206 cable->hw.channels_min != runtime->channels ||
207 cable->hw.channels_max != runtime->channels;
208 if (!check)
209 return 0;
210 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
211 return -EIO;
212 } else {
213 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
214 substream, SNDRV_PCM_STATE_DRAINING);
215 __notify:
216 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
217 substream->runtime;
218 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
219 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
220 if (setup->format != runtime->format) {
221 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
222 &setup->format_id);
223 setup->format = runtime->format;
224 }
225 if (setup->rate != runtime->rate) {
226 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
227 &setup->rate_id);
228 setup->rate = runtime->rate;
229 }
230 if (setup->channels != runtime->channels) {
231 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
232 &setup->channels_id);
233 setup->channels = runtime->channels;
234 }
235 }
236 return 0;
237 }
238
239 static void loopback_active_notify(struct loopback_pcm *dpcm)
240 {
241 snd_ctl_notify(dpcm->loopback->card,
242 SNDRV_CTL_EVENT_MASK_VALUE,
243 &get_setup(dpcm)->active_id);
244 }
245
246 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
247 {
248 struct snd_pcm_runtime *runtime = substream->runtime;
249 struct loopback_pcm *dpcm = runtime->private_data;
250 struct loopback_cable *cable = dpcm->cable;
251 int err;
252
253 switch (cmd) {
254 case SNDRV_PCM_TRIGGER_START:
255 err = loopback_check_format(cable, substream->stream);
256 if (err < 0)
257 return err;
258 dpcm->last_jiffies = jiffies;
259 dpcm->pcm_rate_shift = 0;
260 loopback_timer_start(dpcm);
261 cable->running |= (1 << substream->stream);
262 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
263 loopback_active_notify(dpcm);
264 break;
265 case SNDRV_PCM_TRIGGER_STOP:
266 cable->running &= ~(1 << substream->stream);
267 loopback_timer_stop(dpcm);
268 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
269 loopback_active_notify(dpcm);
270 break;
271 default:
272 return -EINVAL;
273 }
274 return 0;
275 }
276
277 static int loopback_prepare(struct snd_pcm_substream *substream)
278 {
279 struct snd_pcm_runtime *runtime = substream->runtime;
280 struct loopback_pcm *dpcm = runtime->private_data;
281 struct loopback_cable *cable = dpcm->cable;
282 unsigned int bps, salign;
283
284 salign = (snd_pcm_format_width(runtime->format) *
285 runtime->channels) / 8;
286 bps = salign * runtime->rate;
287 if (bps <= 0 || salign <= 0)
288 return -EINVAL;
289
290 dpcm->buf_pos = 0;
291 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
292 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
293 /* clear capture buffer */
294 dpcm->silent_size = dpcm->pcm_buffer_size;
295 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
296 runtime->buffer_size * runtime->channels);
297 }
298
299 dpcm->irq_pos = 0;
300 dpcm->period_update_pending = 0;
301 dpcm->pcm_bps = bps;
302 dpcm->pcm_salign = salign;
303 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
304
305 mutex_lock(&dpcm->loopback->cable_lock);
306 if (!(cable->valid & ~(1 << substream->stream))) {
307 cable->hw.formats = (1ULL << runtime->format);
308 cable->hw.rate_min = runtime->rate;
309 cable->hw.rate_max = runtime->rate;
310 cable->hw.channels_min = runtime->channels;
311 cable->hw.channels_max = runtime->channels;
312 }
313 cable->valid |= 1 << substream->stream;
314 mutex_unlock(&dpcm->loopback->cable_lock);
315
316 return 0;
317 }
318
319 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
320 {
321 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
322 char *dst = runtime->dma_area;
323 unsigned int dst_off = dpcm->buf_pos;
324
325 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
326 return;
327 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
328 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
329
330 for (;;) {
331 unsigned int size = bytes;
332 if (dst_off + size > dpcm->pcm_buffer_size)
333 size = dpcm->pcm_buffer_size - dst_off;
334 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
335 bytes_to_frames(runtime, size) *
336 runtime->channels);
337 dpcm->silent_size += size;
338 bytes -= size;
339 if (!bytes)
340 break;
341 dst_off = 0;
342 }
343 }
344
345 static void copy_play_buf(struct loopback_pcm *play,
346 struct loopback_pcm *capt,
347 unsigned int bytes)
348 {
349 struct snd_pcm_runtime *runtime = play->substream->runtime;
350 char *src = runtime->dma_area;
351 char *dst = capt->substream->runtime->dma_area;
352 unsigned int src_off = play->buf_pos;
353 unsigned int dst_off = capt->buf_pos;
354 unsigned int clear_bytes = 0;
355
356 /* check if playback is draining, trim the capture copy size
357 * when our pointer is at the end of playback ring buffer */
358 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
359 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
360 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
361 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
362 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
363 appl_ptr1 += play->buf_pos / play->pcm_salign;
364 if (appl_ptr < appl_ptr1)
365 appl_ptr1 -= runtime->buffer_size;
366 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
367 if (diff < bytes) {
368 clear_bytes = bytes - diff;
369 bytes = diff;
370 }
371 }
372
373 for (;;) {
374 unsigned int size = bytes;
375 if (src_off + size > play->pcm_buffer_size)
376 size = play->pcm_buffer_size - src_off;
377 if (dst_off + size > capt->pcm_buffer_size)
378 size = capt->pcm_buffer_size - dst_off;
379 memcpy(dst + dst_off, src + src_off, size);
380 capt->silent_size = 0;
381 bytes -= size;
382 if (!bytes)
383 break;
384 src_off = (src_off + size) % play->pcm_buffer_size;
385 dst_off = (dst_off + size) % capt->pcm_buffer_size;
386 }
387
388 if (clear_bytes > 0) {
389 clear_capture_buf(capt, clear_bytes);
390 capt->silent_size = 0;
391 }
392 }
393
394 #define BYTEPOS_UPDATE_POSONLY 0
395 #define BYTEPOS_UPDATE_CLEAR 1
396 #define BYTEPOS_UPDATE_COPY 2
397
398 static void loopback_bytepos_update(struct loopback_pcm *dpcm,
399 unsigned int delta,
400 unsigned int cmd)
401 {
402 unsigned int count;
403 unsigned long last_pos;
404
405 last_pos = byte_pos(dpcm, dpcm->irq_pos);
406 dpcm->irq_pos += delta * dpcm->pcm_bps;
407 count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
408 if (!count)
409 return;
410 if (cmd == BYTEPOS_UPDATE_CLEAR)
411 clear_capture_buf(dpcm, count);
412 else if (cmd == BYTEPOS_UPDATE_COPY)
413 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
414 dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
415 count);
416 dpcm->buf_pos += count;
417 dpcm->buf_pos %= dpcm->pcm_buffer_size;
418 if (dpcm->irq_pos >= dpcm->period_size_frac) {
419 dpcm->irq_pos %= dpcm->period_size_frac;
420 dpcm->period_update_pending = 1;
421 }
422 }
423
424 static void loopback_pos_update(struct loopback_cable *cable)
425 {
426 struct loopback_pcm *dpcm_play =
427 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
428 struct loopback_pcm *dpcm_capt =
429 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
430 unsigned long delta_play = 0, delta_capt = 0;
431
432 spin_lock(&cable->lock);
433 if (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
434 delta_play = jiffies - dpcm_play->last_jiffies;
435 dpcm_play->last_jiffies += delta_play;
436 }
437
438 if (cable->running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
439 delta_capt = jiffies - dpcm_capt->last_jiffies;
440 dpcm_capt->last_jiffies += delta_capt;
441 }
442
443 if (delta_play == 0 && delta_capt == 0) {
444 spin_unlock(&cable->lock);
445 return;
446 }
447
448 if (delta_play > delta_capt) {
449 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
450 BYTEPOS_UPDATE_POSONLY);
451 delta_play = delta_capt;
452 } else if (delta_play < delta_capt) {
453 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
454 BYTEPOS_UPDATE_CLEAR);
455 delta_capt = delta_play;
456 }
457
458 if (delta_play == 0 && delta_capt == 0) {
459 spin_unlock(&cable->lock);
460 return;
461 }
462 /* note delta_capt == delta_play at this moment */
463 loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
464 loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
465 spin_unlock(&cable->lock);
466 }
467
468 static void loopback_timer_function(unsigned long data)
469 {
470 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
471 int stream;
472
473 loopback_pos_update(dpcm->cable);
474 stream = dpcm->substream->stream;
475 if (dpcm->cable->running & (1 << stream))
476 loopback_timer_start(dpcm);
477 if (dpcm->period_update_pending) {
478 dpcm->period_update_pending = 0;
479 if (dpcm->cable->running & (1 << stream))
480 snd_pcm_period_elapsed(dpcm->substream);
481 }
482 }
483
484 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
485 {
486 struct snd_pcm_runtime *runtime = substream->runtime;
487 struct loopback_pcm *dpcm = runtime->private_data;
488
489 loopback_pos_update(dpcm->cable);
490 return bytes_to_frames(runtime, dpcm->buf_pos);
491 }
492
493 static struct snd_pcm_hardware loopback_pcm_hardware =
494 {
495 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
496 SNDRV_PCM_INFO_MMAP_VALID),
497 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
498 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
499 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
500 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
501 .rate_min = 8000,
502 .rate_max = 192000,
503 .channels_min = 1,
504 .channels_max = 32,
505 .buffer_bytes_max = 2 * 1024 * 1024,
506 .period_bytes_min = 64,
507 .period_bytes_max = 2 * 1024 * 1024,
508 .periods_min = 1,
509 .periods_max = 1024,
510 .fifo_size = 0,
511 };
512
513 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
514 {
515 struct loopback_pcm *dpcm = runtime->private_data;
516 kfree(dpcm);
517 }
518
519 static int loopback_hw_params(struct snd_pcm_substream *substream,
520 struct snd_pcm_hw_params *params)
521 {
522 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
523 }
524
525 static int loopback_hw_free(struct snd_pcm_substream *substream)
526 {
527 struct snd_pcm_runtime *runtime = substream->runtime;
528 struct loopback_pcm *dpcm = runtime->private_data;
529 struct loopback_cable *cable = dpcm->cable;
530
531 mutex_lock(&dpcm->loopback->cable_lock);
532 cable->valid &= ~(1 << substream->stream);
533 mutex_unlock(&dpcm->loopback->cable_lock);
534 return snd_pcm_lib_free_pages(substream);
535 }
536
537 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
538 {
539 if (!substream->pcm->device)
540 return substream->stream;
541 else
542 return !substream->stream;
543 }
544
545 static int loopback_open(struct snd_pcm_substream *substream)
546 {
547 struct snd_pcm_runtime *runtime = substream->runtime;
548 struct loopback *loopback = substream->private_data;
549 struct loopback_pcm *dpcm;
550 struct loopback_cable *cable;
551 int err = 0;
552 int dev = get_cable_index(substream);
553
554 mutex_lock(&loopback->cable_lock);
555 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
556 if (!dpcm) {
557 err = -ENOMEM;
558 goto unlock;
559 }
560 dpcm->loopback = loopback;
561 dpcm->substream = substream;
562 setup_timer(&dpcm->timer, loopback_timer_function,
563 (unsigned long)dpcm);
564
565 cable = loopback->cables[substream->number][dev];
566 if (!cable) {
567 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
568 if (!cable) {
569 kfree(dpcm);
570 err = -ENOMEM;
571 goto unlock;
572 }
573 spin_lock_init(&cable->lock);
574 cable->hw = loopback_pcm_hardware;
575 loopback->cables[substream->number][dev] = cable;
576 }
577 dpcm->cable = cable;
578 cable->streams[substream->stream] = dpcm;
579
580 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
581
582 runtime->private_data = dpcm;
583 runtime->private_free = loopback_runtime_free;
584 if (get_notify(dpcm) &&
585 substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
586 runtime->hw = loopback_pcm_hardware;
587 } else {
588 runtime->hw = cable->hw;
589 }
590 unlock:
591 mutex_unlock(&loopback->cable_lock);
592 return err;
593 }
594
595 static int loopback_close(struct snd_pcm_substream *substream)
596 {
597 struct loopback *loopback = substream->private_data;
598 struct loopback_pcm *dpcm = substream->runtime->private_data;
599 struct loopback_cable *cable;
600 int dev = get_cable_index(substream);
601
602 loopback_timer_stop(dpcm);
603 mutex_lock(&loopback->cable_lock);
604 cable = loopback->cables[substream->number][dev];
605 if (cable->streams[!substream->stream]) {
606 /* other stream is still alive */
607 cable->streams[substream->stream] = NULL;
608 } else {
609 /* free the cable */
610 loopback->cables[substream->number][dev] = NULL;
611 kfree(cable);
612 }
613 mutex_unlock(&loopback->cable_lock);
614 return 0;
615 }
616
617 static struct snd_pcm_ops loopback_playback_ops = {
618 .open = loopback_open,
619 .close = loopback_close,
620 .ioctl = snd_pcm_lib_ioctl,
621 .hw_params = loopback_hw_params,
622 .hw_free = loopback_hw_free,
623 .prepare = loopback_prepare,
624 .trigger = loopback_trigger,
625 .pointer = loopback_pointer,
626 };
627
628 static struct snd_pcm_ops loopback_capture_ops = {
629 .open = loopback_open,
630 .close = loopback_close,
631 .ioctl = snd_pcm_lib_ioctl,
632 .hw_params = loopback_hw_params,
633 .hw_free = loopback_hw_free,
634 .prepare = loopback_prepare,
635 .trigger = loopback_trigger,
636 .pointer = loopback_pointer,
637 };
638
639 static int __devinit loopback_pcm_new(struct loopback *loopback,
640 int device, int substreams)
641 {
642 struct snd_pcm *pcm;
643 int err;
644
645 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
646 substreams, substreams, &pcm);
647 if (err < 0)
648 return err;
649 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
650 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
651
652 pcm->private_data = loopback;
653 pcm->info_flags = 0;
654 strcpy(pcm->name, "Loopback PCM");
655
656 loopback->pcm[device] = pcm;
657
658 snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
659 snd_dma_continuous_data(GFP_KERNEL),
660 0, 2 * 1024 * 1024);
661 return 0;
662 }
663
664 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
665 struct snd_ctl_elem_info *uinfo)
666 {
667 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
668 uinfo->count = 1;
669 uinfo->value.integer.min = 80000;
670 uinfo->value.integer.max = 120000;
671 uinfo->value.integer.step = 1;
672 return 0;
673 }
674
675 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
676 struct snd_ctl_elem_value *ucontrol)
677 {
678 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
679
680 ucontrol->value.integer.value[0] =
681 loopback->setup[kcontrol->id.subdevice]
682 [kcontrol->id.device].rate_shift;
683 return 0;
684 }
685
686 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
687 struct snd_ctl_elem_value *ucontrol)
688 {
689 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
690 unsigned int val;
691 int change = 0;
692
693 val = ucontrol->value.integer.value[0];
694 if (val < 80000)
695 val = 80000;
696 if (val > 120000)
697 val = 120000;
698 mutex_lock(&loopback->cable_lock);
699 if (val != loopback->setup[kcontrol->id.subdevice]
700 [kcontrol->id.device].rate_shift) {
701 loopback->setup[kcontrol->id.subdevice]
702 [kcontrol->id.device].rate_shift = val;
703 change = 1;
704 }
705 mutex_unlock(&loopback->cable_lock);
706 return change;
707 }
708
709 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
710 struct snd_ctl_elem_value *ucontrol)
711 {
712 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
713
714 ucontrol->value.integer.value[0] =
715 loopback->setup[kcontrol->id.subdevice]
716 [kcontrol->id.device].notify;
717 return 0;
718 }
719
720 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
721 struct snd_ctl_elem_value *ucontrol)
722 {
723 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
724 unsigned int val;
725 int change = 0;
726
727 val = ucontrol->value.integer.value[0] ? 1 : 0;
728 if (val != loopback->setup[kcontrol->id.subdevice]
729 [kcontrol->id.device].notify) {
730 loopback->setup[kcontrol->id.subdevice]
731 [kcontrol->id.device].notify = val;
732 change = 1;
733 }
734 return change;
735 }
736
737 static int loopback_active_get(struct snd_kcontrol *kcontrol,
738 struct snd_ctl_elem_value *ucontrol)
739 {
740 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
741 struct loopback_cable *cable = loopback->cables
742 [kcontrol->id.subdevice][kcontrol->id.device];
743 unsigned int val = 0;
744
745 if (cable != NULL)
746 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
747 1 : 0;
748 ucontrol->value.integer.value[0] = val;
749 return 0;
750 }
751
752 static int loopback_format_info(struct snd_kcontrol *kcontrol,
753 struct snd_ctl_elem_info *uinfo)
754 {
755 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
756 uinfo->count = 1;
757 uinfo->value.integer.min = 0;
758 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
759 uinfo->value.integer.step = 1;
760 return 0;
761 }
762
763 static int loopback_format_get(struct snd_kcontrol *kcontrol,
764 struct snd_ctl_elem_value *ucontrol)
765 {
766 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
767
768 ucontrol->value.integer.value[0] =
769 loopback->setup[kcontrol->id.subdevice]
770 [kcontrol->id.device].format;
771 return 0;
772 }
773
774 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
775 struct snd_ctl_elem_info *uinfo)
776 {
777 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
778 uinfo->count = 1;
779 uinfo->value.integer.min = 0;
780 uinfo->value.integer.max = 192000;
781 uinfo->value.integer.step = 1;
782 return 0;
783 }
784
785 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
786 struct snd_ctl_elem_value *ucontrol)
787 {
788 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
789
790 ucontrol->value.integer.value[0] =
791 loopback->setup[kcontrol->id.subdevice]
792 [kcontrol->id.device].rate;
793 return 0;
794 }
795
796 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
797 struct snd_ctl_elem_info *uinfo)
798 {
799 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
800 uinfo->count = 1;
801 uinfo->value.integer.min = 1;
802 uinfo->value.integer.max = 1024;
803 uinfo->value.integer.step = 1;
804 return 0;
805 }
806
807 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
808 struct snd_ctl_elem_value *ucontrol)
809 {
810 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
811
812 ucontrol->value.integer.value[0] =
813 loopback->setup[kcontrol->id.subdevice]
814 [kcontrol->id.device].channels;
815 return 0;
816 }
817
818 static struct snd_kcontrol_new loopback_controls[] __devinitdata = {
819 {
820 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
821 .name = "PCM Rate Shift 100000",
822 .info = loopback_rate_shift_info,
823 .get = loopback_rate_shift_get,
824 .put = loopback_rate_shift_put,
825 },
826 {
827 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
828 .name = "PCM Notify",
829 .info = snd_ctl_boolean_mono_info,
830 .get = loopback_notify_get,
831 .put = loopback_notify_put,
832 },
833 #define ACTIVE_IDX 2
834 {
835 .access = SNDRV_CTL_ELEM_ACCESS_READ,
836 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
837 .name = "PCM Slave Active",
838 .info = snd_ctl_boolean_mono_info,
839 .get = loopback_active_get,
840 },
841 #define FORMAT_IDX 3
842 {
843 .access = SNDRV_CTL_ELEM_ACCESS_READ,
844 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
845 .name = "PCM Slave Format",
846 .info = loopback_format_info,
847 .get = loopback_format_get
848 },
849 #define RATE_IDX 4
850 {
851 .access = SNDRV_CTL_ELEM_ACCESS_READ,
852 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
853 .name = "PCM Slave Rate",
854 .info = loopback_rate_info,
855 .get = loopback_rate_get
856 },
857 #define CHANNELS_IDX 5
858 {
859 .access = SNDRV_CTL_ELEM_ACCESS_READ,
860 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
861 .name = "PCM Slave Channels",
862 .info = loopback_channels_info,
863 .get = loopback_channels_get
864 }
865 };
866
867 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
868 {
869 struct snd_card *card = loopback->card;
870 struct snd_pcm *pcm;
871 struct snd_kcontrol *kctl;
872 struct loopback_setup *setup;
873 int err, dev, substr, substr_count, idx;
874
875 strcpy(card->mixername, "Loopback Mixer");
876 for (dev = 0; dev < 2; dev++) {
877 pcm = loopback->pcm[dev];
878 substr_count =
879 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
880 for (substr = 0; substr < substr_count; substr++) {
881 setup = &loopback->setup[substr][dev];
882 setup->notify = notify;
883 setup->rate_shift = NO_PITCH;
884 setup->format = SNDRV_PCM_FORMAT_S16_LE;
885 setup->rate = 48000;
886 setup->channels = 2;
887 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
888 idx++) {
889 kctl = snd_ctl_new1(&loopback_controls[idx],
890 loopback);
891 if (!kctl)
892 return -ENOMEM;
893 kctl->id.device = dev;
894 kctl->id.subdevice = substr;
895 switch (idx) {
896 case ACTIVE_IDX:
897 setup->active_id = kctl->id;
898 break;
899 case FORMAT_IDX:
900 setup->format_id = kctl->id;
901 break;
902 case RATE_IDX:
903 setup->rate_id = kctl->id;
904 break;
905 case CHANNELS_IDX:
906 setup->channels_id = kctl->id;
907 break;
908 default:
909 break;
910 }
911 err = snd_ctl_add(card, kctl);
912 if (err < 0)
913 return err;
914 }
915 }
916 }
917 return 0;
918 }
919
920 static int __devinit loopback_probe(struct platform_device *devptr)
921 {
922 struct snd_card *card;
923 struct loopback *loopback;
924 int dev = devptr->id;
925 int err;
926
927 err = snd_card_create(index[dev], id[dev], THIS_MODULE,
928 sizeof(struct loopback), &card);
929 if (err < 0)
930 return err;
931 loopback = card->private_data;
932
933 if (pcm_substreams[dev] < 1)
934 pcm_substreams[dev] = 1;
935 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
936 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
937
938 loopback->card = card;
939 mutex_init(&loopback->cable_lock);
940
941 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
942 if (err < 0)
943 goto __nodev;
944 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
945 if (err < 0)
946 goto __nodev;
947 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
948 if (err < 0)
949 goto __nodev;
950 strcpy(card->driver, "Loopback");
951 strcpy(card->shortname, "Loopback");
952 sprintf(card->longname, "Loopback %i", dev + 1);
953 err = snd_card_register(card);
954 if (!err) {
955 platform_set_drvdata(devptr, card);
956 return 0;
957 }
958 __nodev:
959 snd_card_free(card);
960 return err;
961 }
962
963 static int __devexit loopback_remove(struct platform_device *devptr)
964 {
965 snd_card_free(platform_get_drvdata(devptr));
966 platform_set_drvdata(devptr, NULL);
967 return 0;
968 }
969
970 #ifdef CONFIG_PM
971 static int loopback_suspend(struct platform_device *pdev,
972 pm_message_t state)
973 {
974 struct snd_card *card = platform_get_drvdata(pdev);
975 struct loopback *loopback = card->private_data;
976
977 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
978
979 snd_pcm_suspend_all(loopback->pcm[0]);
980 snd_pcm_suspend_all(loopback->pcm[1]);
981 return 0;
982 }
983
984 static int loopback_resume(struct platform_device *pdev)
985 {
986 struct snd_card *card = platform_get_drvdata(pdev);
987
988 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
989 return 0;
990 }
991 #endif
992
993 #define SND_LOOPBACK_DRIVER "snd_aloop"
994
995 static struct platform_driver loopback_driver = {
996 .probe = loopback_probe,
997 .remove = __devexit_p(loopback_remove),
998 #ifdef CONFIG_PM
999 .suspend = loopback_suspend,
1000 .resume = loopback_resume,
1001 #endif
1002 .driver = {
1003 .name = SND_LOOPBACK_DRIVER
1004 },
1005 };
1006
1007 static void loopback_unregister_all(void)
1008 {
1009 int i;
1010
1011 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1012 platform_device_unregister(devices[i]);
1013 platform_driver_unregister(&loopback_driver);
1014 }
1015
1016 static int __init alsa_card_loopback_init(void)
1017 {
1018 int i, err, cards;
1019
1020 err = platform_driver_register(&loopback_driver);
1021 if (err < 0)
1022 return err;
1023
1024
1025 cards = 0;
1026 for (i = 0; i < SNDRV_CARDS; i++) {
1027 struct platform_device *device;
1028 if (!enable[i])
1029 continue;
1030 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1031 i, NULL, 0);
1032 if (IS_ERR(device))
1033 continue;
1034 if (!platform_get_drvdata(device)) {
1035 platform_device_unregister(device);
1036 continue;
1037 }
1038 devices[i] = device;
1039 cards++;
1040 }
1041 if (!cards) {
1042 #ifdef MODULE
1043 printk(KERN_ERR "aloop: No loopback enabled\n");
1044 #endif
1045 loopback_unregister_all();
1046 return -ENODEV;
1047 }
1048 return 0;
1049 }
1050
1051 static void __exit alsa_card_loopback_exit(void)
1052 {
1053 loopback_unregister_all();
1054 }
1055
1056 module_init(alsa_card_loopback_init)
1057 module_exit(alsa_card_loopback_exit)
Linux kernel - Deliverables
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