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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;
53static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
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
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;
109 unsigned int silent_size;
110
111 unsigned int pcm_period_size;
112 unsigned int pcm_bps;
113 unsigned int pcm_salign;
114 unsigned int pcm_rate_shift;
115
116 unsigned int period_update_pending :1;
117
118 unsigned int irq_pos;
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) {
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
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 mod_timer(&dpcm->timer, jiffies + tick);
185}
186
187
188static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
189{
190 del_timer(&dpcm->timer);
191 dpcm->timer.expires = 0;
192}
193
194#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
195#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
196#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
197
198static int loopback_check_format(struct loopback_cable *cable, int stream)
199{
200 struct snd_pcm_runtime *runtime, *cruntime;
201 struct loopback_setup *setup;
202 struct snd_card *card;
203 int check;
204
205 if (cable->valid != CABLE_VALID_BOTH) {
206 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
207 goto __notify;
208 return 0;
209 }
210 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
211 substream->runtime;
212 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
213 substream->runtime;
214 check = runtime->format != cruntime->format ||
215 runtime->rate != cruntime->rate ||
216 runtime->channels != cruntime->channels;
217 if (!check)
218 return 0;
219 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
220 return -EIO;
221 } else {
222 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
223 substream, SNDRV_PCM_STATE_DRAINING);
224 __notify:
225 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
226 substream->runtime;
227 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
228 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
229 if (setup->format != runtime->format) {
230 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
231 &setup->format_id);
232 setup->format = runtime->format;
233 }
234 if (setup->rate != runtime->rate) {
235 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
236 &setup->rate_id);
237 setup->rate = runtime->rate;
238 }
239 if (setup->channels != runtime->channels) {
240 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
241 &setup->channels_id);
242 setup->channels = runtime->channels;
243 }
244 }
245 return 0;
246}
247
248static void loopback_active_notify(struct loopback_pcm *dpcm)
249{
250 snd_ctl_notify(dpcm->loopback->card,
251 SNDRV_CTL_EVENT_MASK_VALUE,
252 &get_setup(dpcm)->active_id);
253}
254
255static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
256{
257 struct snd_pcm_runtime *runtime = substream->runtime;
258 struct loopback_pcm *dpcm = runtime->private_data;
259 struct loopback_cable *cable = dpcm->cable;
260 int err, stream = 1 << substream->stream;
261
262 switch (cmd) {
263 case SNDRV_PCM_TRIGGER_START:
264 err = loopback_check_format(cable, substream->stream);
265 if (err < 0)
266 return err;
267 dpcm->last_jiffies = jiffies;
268 dpcm->pcm_rate_shift = 0;
269 dpcm->last_drift = 0;
270 spin_lock(&cable->lock);
271 cable->running |= stream;
272 cable->pause &= ~stream;
273 loopback_timer_start(dpcm);
274 spin_unlock(&cable->lock);
275 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
276 loopback_active_notify(dpcm);
277 break;
278 case SNDRV_PCM_TRIGGER_STOP:
279 spin_lock(&cable->lock);
280 cable->running &= ~stream;
281 cable->pause &= ~stream;
282 loopback_timer_stop(dpcm);
283 spin_unlock(&cable->lock);
284 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
285 loopback_active_notify(dpcm);
286 break;
287 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
288 case SNDRV_PCM_TRIGGER_SUSPEND:
289 spin_lock(&cable->lock);
290 cable->pause |= stream;
291 loopback_timer_stop(dpcm);
292 spin_unlock(&cable->lock);
293 break;
294 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
295 case SNDRV_PCM_TRIGGER_RESUME:
296 spin_lock(&cable->lock);
297 dpcm->last_jiffies = jiffies;
298 cable->pause &= ~stream;
299 loopback_timer_start(dpcm);
300 spin_unlock(&cable->lock);
301 break;
302 default:
303 return -EINVAL;
304 }
305 return 0;
306}
307
308static void params_change_substream(struct loopback_pcm *dpcm,
309 struct snd_pcm_runtime *runtime)
310{
311 struct snd_pcm_runtime *dst_runtime;
312
313 if (dpcm == NULL || dpcm->substream == NULL)
314 return;
315 dst_runtime = dpcm->substream->runtime;
316 if (dst_runtime == NULL)
317 return;
318 dst_runtime->hw = dpcm->cable->hw;
319}
320
321static void params_change(struct snd_pcm_substream *substream)
322{
323 struct snd_pcm_runtime *runtime = substream->runtime;
324 struct loopback_pcm *dpcm = runtime->private_data;
325 struct loopback_cable *cable = dpcm->cable;
326
327 cable->hw.formats = pcm_format_to_bits(runtime->format);
328 cable->hw.rate_min = runtime->rate;
329 cable->hw.rate_max = runtime->rate;
330 cable->hw.channels_min = runtime->channels;
331 cable->hw.channels_max = runtime->channels;
332 params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
333 runtime);
334 params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
335 runtime);
336}
337
338static int loopback_prepare(struct snd_pcm_substream *substream)
339{
340 struct snd_pcm_runtime *runtime = substream->runtime;
341 struct loopback_pcm *dpcm = runtime->private_data;
342 struct loopback_cable *cable = dpcm->cable;
343 int bps, salign;
344
345 salign = (snd_pcm_format_width(runtime->format) *
346 runtime->channels) / 8;
347 bps = salign * runtime->rate;
348 if (bps <= 0 || salign <= 0)
349 return -EINVAL;
350
351 dpcm->buf_pos = 0;
352 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
353 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
354
355 dpcm->silent_size = dpcm->pcm_buffer_size;
356 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
357 runtime->buffer_size * runtime->channels);
358 }
359
360 dpcm->irq_pos = 0;
361 dpcm->period_update_pending = 0;
362 dpcm->pcm_bps = bps;
363 dpcm->pcm_salign = salign;
364 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
365
366 mutex_lock(&dpcm->loopback->cable_lock);
367 if (!(cable->valid & ~(1 << substream->stream)) ||
368 (get_setup(dpcm)->notify &&
369 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
370 params_change(substream);
371 cable->valid |= 1 << substream->stream;
372 mutex_unlock(&dpcm->loopback->cable_lock);
373
374 return 0;
375}
376
377static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
378{
379 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
380 char *dst = runtime->dma_area;
381 unsigned int dst_off = dpcm->buf_pos;
382
383 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
384 return;
385 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
386 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
387
388 for (;;) {
389 unsigned int size = bytes;
390 if (dst_off + size > dpcm->pcm_buffer_size)
391 size = dpcm->pcm_buffer_size - dst_off;
392 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
393 bytes_to_frames(runtime, size) *
394 runtime->channels);
395 dpcm->silent_size += size;
396 bytes -= size;
397 if (!bytes)
398 break;
399 dst_off = 0;
400 }
401}
402
403static void copy_play_buf(struct loopback_pcm *play,
404 struct loopback_pcm *capt,
405 unsigned int bytes)
406{
407 struct snd_pcm_runtime *runtime = play->substream->runtime;
408 char *src = runtime->dma_area;
409 char *dst = capt->substream->runtime->dma_area;
410 unsigned int src_off = play->buf_pos;
411 unsigned int dst_off = capt->buf_pos;
412 unsigned int clear_bytes = 0;
413
414
415
416 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
417 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
418 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
419 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
420 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
421 appl_ptr1 += play->buf_pos / play->pcm_salign;
422 if (appl_ptr < appl_ptr1)
423 appl_ptr1 -= runtime->buffer_size;
424 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
425 if (diff < bytes) {
426 clear_bytes = bytes - diff;
427 bytes = diff;
428 }
429 }
430
431 for (;;) {
432 unsigned int size = bytes;
433 if (src_off + size > play->pcm_buffer_size)
434 size = play->pcm_buffer_size - src_off;
435 if (dst_off + size > capt->pcm_buffer_size)
436 size = capt->pcm_buffer_size - dst_off;
437 memcpy(dst + dst_off, src + src_off, size);
438 capt->silent_size = 0;
439 bytes -= size;
440 if (!bytes)
441 break;
442 src_off = (src_off + size) % play->pcm_buffer_size;
443 dst_off = (dst_off + size) % capt->pcm_buffer_size;
444 }
445
446 if (clear_bytes > 0) {
447 clear_capture_buf(capt, clear_bytes);
448 capt->silent_size = 0;
449 }
450}
451
452static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
453 unsigned int jiffies_delta)
454{
455 unsigned long last_pos;
456 unsigned int delta;
457
458 last_pos = byte_pos(dpcm, dpcm->irq_pos);
459 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
460 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
461 if (delta >= dpcm->last_drift)
462 delta -= dpcm->last_drift;
463 dpcm->last_drift = 0;
464 if (dpcm->irq_pos >= dpcm->period_size_frac) {
465 dpcm->irq_pos %= dpcm->period_size_frac;
466 dpcm->period_update_pending = 1;
467 }
468 return delta;
469}
470
471static inline void bytepos_finish(struct loopback_pcm *dpcm,
472 unsigned int delta)
473{
474 dpcm->buf_pos += delta;
475 dpcm->buf_pos %= dpcm->pcm_buffer_size;
476}
477
478
479static unsigned int loopback_pos_update(struct loopback_cable *cable)
480{
481 struct loopback_pcm *dpcm_play =
482 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
483 struct loopback_pcm *dpcm_capt =
484 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
485 unsigned long delta_play = 0, delta_capt = 0;
486 unsigned int running, count1, count2;
487
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 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
504 bytepos_finish(dpcm_play, count1);
505 delta_play = delta_capt;
506 } else if (delta_play < delta_capt) {
507 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
508 clear_capture_buf(dpcm_capt, count1);
509 bytepos_finish(dpcm_capt, count1);
510 delta_capt = delta_play;
511 }
512
513 if (delta_play == 0 && delta_capt == 0)
514 goto unlock;
515
516
517 count1 = bytepos_delta(dpcm_play, delta_play);
518 count2 = bytepos_delta(dpcm_capt, delta_capt);
519 if (count1 < count2) {
520 dpcm_capt->last_drift = count2 - count1;
521 count1 = count2;
522 } else if (count1 > count2) {
523 dpcm_play->last_drift = count1 - count2;
524 }
525 copy_play_buf(dpcm_play, dpcm_capt, count1);
526 bytepos_finish(dpcm_play, count1);
527 bytepos_finish(dpcm_capt, count1);
528 unlock:
529 return running;
530}
531
532static void loopback_timer_function(unsigned long data)
533{
534 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
535 unsigned long flags;
536
537 spin_lock_irqsave(&dpcm->cable->lock, flags);
538 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
539 loopback_timer_start(dpcm);
540 if (dpcm->period_update_pending) {
541 dpcm->period_update_pending = 0;
542 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
543
544 snd_pcm_period_elapsed(dpcm->substream);
545 return;
546 }
547 }
548 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
549}
550
551static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
552{
553 struct snd_pcm_runtime *runtime = substream->runtime;
554 struct loopback_pcm *dpcm = runtime->private_data;
555 snd_pcm_uframes_t pos;
556
557 spin_lock(&dpcm->cable->lock);
558 loopback_pos_update(dpcm->cable);
559 pos = dpcm->buf_pos;
560 spin_unlock(&dpcm->cable->lock);
561 return bytes_to_frames(runtime, pos);
562}
563
564static const struct snd_pcm_hardware loopback_pcm_hardware =
565{
566 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
567 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
568 SNDRV_PCM_INFO_RESUME),
569 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
570 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
571 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
572 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
573 .rate_min = 8000,
574 .rate_max = 192000,
575 .channels_min = 1,
576 .channels_max = 32,
577 .buffer_bytes_max = 2 * 1024 * 1024,
578 .period_bytes_min = 64,
579
580
581 .period_bytes_max = 1024 * 1024,
582 .periods_min = 1,
583 .periods_max = 1024,
584 .fifo_size = 0,
585};
586
587static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
588{
589 struct loopback_pcm *dpcm = runtime->private_data;
590 kfree(dpcm);
591}
592
593static int loopback_hw_params(struct snd_pcm_substream *substream,
594 struct snd_pcm_hw_params *params)
595{
596 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
597 params_buffer_bytes(params));
598}
599
600static int loopback_hw_free(struct snd_pcm_substream *substream)
601{
602 struct snd_pcm_runtime *runtime = substream->runtime;
603 struct loopback_pcm *dpcm = runtime->private_data;
604 struct loopback_cable *cable = dpcm->cable;
605
606 mutex_lock(&dpcm->loopback->cable_lock);
607 cable->valid &= ~(1 << substream->stream);
608 mutex_unlock(&dpcm->loopback->cable_lock);
609 return snd_pcm_lib_free_vmalloc_buffer(substream);
610}
611
612static unsigned int get_cable_index(struct snd_pcm_substream *substream)
613{
614 if (!substream->pcm->device)
615 return substream->stream;
616 else
617 return !substream->stream;
618}
619
620static int rule_format(struct snd_pcm_hw_params *params,
621 struct snd_pcm_hw_rule *rule)
622{
623
624 struct snd_pcm_hardware *hw = rule->private;
625 struct snd_mask *maskp = hw_param_mask(params, rule->var);
626
627 maskp->bits[0] &= (u_int32_t)hw->formats;
628 maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
629 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8);
630 if (! maskp->bits[0] && ! maskp->bits[1])
631 return -EINVAL;
632 return 0;
633}
634
635static int rule_rate(struct snd_pcm_hw_params *params,
636 struct snd_pcm_hw_rule *rule)
637{
638 struct snd_pcm_hardware *hw = rule->private;
639 struct snd_interval t;
640
641 t.min = hw->rate_min;
642 t.max = hw->rate_max;
643 t.openmin = t.openmax = 0;
644 t.integer = 0;
645 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
646}
647
648static int rule_channels(struct snd_pcm_hw_params *params,
649 struct snd_pcm_hw_rule *rule)
650{
651 struct snd_pcm_hardware *hw = rule->private;
652 struct snd_interval t;
653
654 t.min = hw->channels_min;
655 t.max = hw->channels_max;
656 t.openmin = t.openmax = 0;
657 t.integer = 0;
658 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
659}
660
661static int loopback_open(struct snd_pcm_substream *substream)
662{
663 struct snd_pcm_runtime *runtime = substream->runtime;
664 struct loopback *loopback = substream->private_data;
665 struct loopback_pcm *dpcm;
666 struct loopback_cable *cable;
667 int err = 0;
668 int dev = get_cable_index(substream);
669
670 mutex_lock(&loopback->cable_lock);
671 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
672 if (!dpcm) {
673 err = -ENOMEM;
674 goto unlock;
675 }
676 dpcm->loopback = loopback;
677 dpcm->substream = substream;
678 setup_timer(&dpcm->timer, loopback_timer_function,
679 (unsigned long)dpcm);
680
681 cable = loopback->cables[substream->number][dev];
682 if (!cable) {
683 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
684 if (!cable) {
685 kfree(dpcm);
686 err = -ENOMEM;
687 goto unlock;
688 }
689 spin_lock_init(&cable->lock);
690 cable->hw = loopback_pcm_hardware;
691 loopback->cables[substream->number][dev] = cable;
692 }
693 dpcm->cable = cable;
694 cable->streams[substream->stream] = dpcm;
695
696 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
697
698
699
700
701 err = snd_pcm_hw_rule_add(runtime, 0,
702 SNDRV_PCM_HW_PARAM_FORMAT,
703 rule_format, &runtime->hw,
704 SNDRV_PCM_HW_PARAM_FORMAT, -1);
705 if (err < 0)
706 goto unlock;
707 err = snd_pcm_hw_rule_add(runtime, 0,
708 SNDRV_PCM_HW_PARAM_RATE,
709 rule_rate, &runtime->hw,
710 SNDRV_PCM_HW_PARAM_RATE, -1);
711 if (err < 0)
712 goto unlock;
713 err = snd_pcm_hw_rule_add(runtime, 0,
714 SNDRV_PCM_HW_PARAM_CHANNELS,
715 rule_channels, &runtime->hw,
716 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
717 if (err < 0)
718 goto unlock;
719
720 runtime->private_data = dpcm;
721 runtime->private_free = loopback_runtime_free;
722 if (get_notify(dpcm))
723 runtime->hw = loopback_pcm_hardware;
724 else
725 runtime->hw = cable->hw;
726 unlock:
727 mutex_unlock(&loopback->cable_lock);
728 return err;
729}
730
731static int loopback_close(struct snd_pcm_substream *substream)
732{
733 struct loopback *loopback = substream->private_data;
734 struct loopback_pcm *dpcm = substream->runtime->private_data;
735 struct loopback_cable *cable;
736 int dev = get_cable_index(substream);
737
738 loopback_timer_stop(dpcm);
739 mutex_lock(&loopback->cable_lock);
740 cable = loopback->cables[substream->number][dev];
741 if (cable->streams[!substream->stream]) {
742
743 cable->streams[substream->stream] = NULL;
744 } else {
745
746 loopback->cables[substream->number][dev] = NULL;
747 kfree(cable);
748 }
749 mutex_unlock(&loopback->cable_lock);
750 return 0;
751}
752
753static const struct snd_pcm_ops loopback_playback_ops = {
754 .open = loopback_open,
755 .close = loopback_close,
756 .ioctl = snd_pcm_lib_ioctl,
757 .hw_params = loopback_hw_params,
758 .hw_free = loopback_hw_free,
759 .prepare = loopback_prepare,
760 .trigger = loopback_trigger,
761 .pointer = loopback_pointer,
762 .page = snd_pcm_lib_get_vmalloc_page,
763 .mmap = snd_pcm_lib_mmap_vmalloc,
764};
765
766static const struct snd_pcm_ops loopback_capture_ops = {
767 .open = loopback_open,
768 .close = loopback_close,
769 .ioctl = snd_pcm_lib_ioctl,
770 .hw_params = loopback_hw_params,
771 .hw_free = loopback_hw_free,
772 .prepare = loopback_prepare,
773 .trigger = loopback_trigger,
774 .pointer = loopback_pointer,
775 .page = snd_pcm_lib_get_vmalloc_page,
776 .mmap = snd_pcm_lib_mmap_vmalloc,
777};
778
779static int loopback_pcm_new(struct loopback *loopback,
780 int device, int substreams)
781{
782 struct snd_pcm *pcm;
783 int err;
784
785 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
786 substreams, substreams, &pcm);
787 if (err < 0)
788 return err;
789 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
790 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
791
792 pcm->private_data = loopback;
793 pcm->info_flags = 0;
794 strcpy(pcm->name, "Loopback PCM");
795
796 loopback->pcm[device] = pcm;
797 return 0;
798}
799
800static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
801 struct snd_ctl_elem_info *uinfo)
802{
803 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
804 uinfo->count = 1;
805 uinfo->value.integer.min = 80000;
806 uinfo->value.integer.max = 120000;
807 uinfo->value.integer.step = 1;
808 return 0;
809}
810
811static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
812 struct snd_ctl_elem_value *ucontrol)
813{
814 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
815
816 ucontrol->value.integer.value[0] =
817 loopback->setup[kcontrol->id.subdevice]
818 [kcontrol->id.device].rate_shift;
819 return 0;
820}
821
822static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
823 struct snd_ctl_elem_value *ucontrol)
824{
825 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
826 unsigned int val;
827 int change = 0;
828
829 val = ucontrol->value.integer.value[0];
830 if (val < 80000)
831 val = 80000;
832 if (val > 120000)
833 val = 120000;
834 mutex_lock(&loopback->cable_lock);
835 if (val != loopback->setup[kcontrol->id.subdevice]
836 [kcontrol->id.device].rate_shift) {
837 loopback->setup[kcontrol->id.subdevice]
838 [kcontrol->id.device].rate_shift = val;
839 change = 1;
840 }
841 mutex_unlock(&loopback->cable_lock);
842 return change;
843}
844
845static int loopback_notify_get(struct snd_kcontrol *kcontrol,
846 struct snd_ctl_elem_value *ucontrol)
847{
848 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
849
850 ucontrol->value.integer.value[0] =
851 loopback->setup[kcontrol->id.subdevice]
852 [kcontrol->id.device].notify;
853 return 0;
854}
855
856static int loopback_notify_put(struct snd_kcontrol *kcontrol,
857 struct snd_ctl_elem_value *ucontrol)
858{
859 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
860 unsigned int val;
861 int change = 0;
862
863 val = ucontrol->value.integer.value[0] ? 1 : 0;
864 if (val != loopback->setup[kcontrol->id.subdevice]
865 [kcontrol->id.device].notify) {
866 loopback->setup[kcontrol->id.subdevice]
867 [kcontrol->id.device].notify = val;
868 change = 1;
869 }
870 return change;
871}
872
873static int loopback_active_get(struct snd_kcontrol *kcontrol,
874 struct snd_ctl_elem_value *ucontrol)
875{
876 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
877 struct loopback_cable *cable = loopback->cables
878 [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
879 unsigned int val = 0;
880
881 if (cable != NULL)
882 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
883 1 : 0;
884 ucontrol->value.integer.value[0] = val;
885 return 0;
886}
887
888static int loopback_format_info(struct snd_kcontrol *kcontrol,
889 struct snd_ctl_elem_info *uinfo)
890{
891 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
892 uinfo->count = 1;
893 uinfo->value.integer.min = 0;
894 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
895 uinfo->value.integer.step = 1;
896 return 0;
897}
898
899static int loopback_format_get(struct snd_kcontrol *kcontrol,
900 struct snd_ctl_elem_value *ucontrol)
901{
902 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
903
904 ucontrol->value.integer.value[0] =
905 loopback->setup[kcontrol->id.subdevice]
906 [kcontrol->id.device].format;
907 return 0;
908}
909
910static int loopback_rate_info(struct snd_kcontrol *kcontrol,
911 struct snd_ctl_elem_info *uinfo)
912{
913 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
914 uinfo->count = 1;
915 uinfo->value.integer.min = 0;
916 uinfo->value.integer.max = 192000;
917 uinfo->value.integer.step = 1;
918 return 0;
919}
920
921static int loopback_rate_get(struct snd_kcontrol *kcontrol,
922 struct snd_ctl_elem_value *ucontrol)
923{
924 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
925
926 ucontrol->value.integer.value[0] =
927 loopback->setup[kcontrol->id.subdevice]
928 [kcontrol->id.device].rate;
929 return 0;
930}
931
932static int loopback_channels_info(struct snd_kcontrol *kcontrol,
933 struct snd_ctl_elem_info *uinfo)
934{
935 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
936 uinfo->count = 1;
937 uinfo->value.integer.min = 1;
938 uinfo->value.integer.max = 1024;
939 uinfo->value.integer.step = 1;
940 return 0;
941}
942
943static int loopback_channels_get(struct snd_kcontrol *kcontrol,
944 struct snd_ctl_elem_value *ucontrol)
945{
946 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
947
948 ucontrol->value.integer.value[0] =
949 loopback->setup[kcontrol->id.subdevice]
950 [kcontrol->id.device].channels;
951 return 0;
952}
953
954static struct snd_kcontrol_new loopback_controls[] = {
955{
956 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
957 .name = "PCM Rate Shift 100000",
958 .info = loopback_rate_shift_info,
959 .get = loopback_rate_shift_get,
960 .put = loopback_rate_shift_put,
961},
962{
963 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
964 .name = "PCM Notify",
965 .info = snd_ctl_boolean_mono_info,
966 .get = loopback_notify_get,
967 .put = loopback_notify_put,
968},
969#define ACTIVE_IDX 2
970{
971 .access = SNDRV_CTL_ELEM_ACCESS_READ,
972 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
973 .name = "PCM Slave Active",
974 .info = snd_ctl_boolean_mono_info,
975 .get = loopback_active_get,
976},
977#define FORMAT_IDX 3
978{
979 .access = SNDRV_CTL_ELEM_ACCESS_READ,
980 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
981 .name = "PCM Slave Format",
982 .info = loopback_format_info,
983 .get = loopback_format_get
984},
985#define RATE_IDX 4
986{
987 .access = SNDRV_CTL_ELEM_ACCESS_READ,
988 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
989 .name = "PCM Slave Rate",
990 .info = loopback_rate_info,
991 .get = loopback_rate_get
992},
993#define CHANNELS_IDX 5
994{
995 .access = SNDRV_CTL_ELEM_ACCESS_READ,
996 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
997 .name = "PCM Slave Channels",
998 .info = loopback_channels_info,
999 .get = loopback_channels_get
1000}
1001};
1002
1003static int loopback_mixer_new(struct loopback *loopback, int notify)
1004{
1005 struct snd_card *card = loopback->card;
1006 struct snd_pcm *pcm;
1007 struct snd_kcontrol *kctl;
1008 struct loopback_setup *setup;
1009 int err, dev, substr, substr_count, idx;
1010
1011 strcpy(card->mixername, "Loopback Mixer");
1012 for (dev = 0; dev < 2; dev++) {
1013 pcm = loopback->pcm[dev];
1014 substr_count =
1015 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1016 for (substr = 0; substr < substr_count; substr++) {
1017 setup = &loopback->setup[substr][dev];
1018 setup->notify = notify;
1019 setup->rate_shift = NO_PITCH;
1020 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1021 setup->rate = 48000;
1022 setup->channels = 2;
1023 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1024 idx++) {
1025 kctl = snd_ctl_new1(&loopback_controls[idx],
1026 loopback);
1027 if (!kctl)
1028 return -ENOMEM;
1029 kctl->id.device = dev;
1030 kctl->id.subdevice = substr;
1031 switch (idx) {
1032 case ACTIVE_IDX:
1033 setup->active_id = kctl->id;
1034 break;
1035 case FORMAT_IDX:
1036 setup->format_id = kctl->id;
1037 break;
1038 case RATE_IDX:
1039 setup->rate_id = kctl->id;
1040 break;
1041 case CHANNELS_IDX:
1042 setup->channels_id = kctl->id;
1043 break;
1044 default:
1045 break;
1046 }
1047 err = snd_ctl_add(card, kctl);
1048 if (err < 0)
1049 return err;
1050 }
1051 }
1052 }
1053 return 0;
1054}
1055
1056static void print_dpcm_info(struct snd_info_buffer *buffer,
1057 struct loopback_pcm *dpcm,
1058 const char *id)
1059{
1060 snd_iprintf(buffer, " %s\n", id);
1061 if (dpcm == NULL) {
1062 snd_iprintf(buffer, " inactive\n");
1063 return;
1064 }
1065 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1066 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1067 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1068 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1069 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1070 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1071 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1072 snd_iprintf(buffer, " update_pending:\t%u\n",
1073 dpcm->period_update_pending);
1074 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1075 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1076 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1077 dpcm->last_jiffies, jiffies);
1078 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1079}
1080
1081static void print_substream_info(struct snd_info_buffer *buffer,
1082 struct loopback *loopback,
1083 int sub,
1084 int num)
1085{
1086 struct loopback_cable *cable = loopback->cables[sub][num];
1087
1088 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1089 if (cable == NULL) {
1090 snd_iprintf(buffer, " inactive\n");
1091 return;
1092 }
1093 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1094 snd_iprintf(buffer, " running: %u\n", cable->running);
1095 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1096 print_dpcm_info(buffer, cable->streams[0], "Playback");
1097 print_dpcm_info(buffer, cable->streams[1], "Capture");
1098}
1099
1100static void print_cable_info(struct snd_info_entry *entry,
1101 struct snd_info_buffer *buffer)
1102{
1103 struct loopback *loopback = entry->private_data;
1104 int sub, num;
1105
1106 mutex_lock(&loopback->cable_lock);
1107 num = entry->name[strlen(entry->name)-1];
1108 num = num == '0' ? 0 : 1;
1109 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1110 print_substream_info(buffer, loopback, sub, num);
1111 mutex_unlock(&loopback->cable_lock);
1112}
1113
1114static int loopback_proc_new(struct loopback *loopback, int cidx)
1115{
1116 char name[32];
1117 struct snd_info_entry *entry;
1118 int err;
1119
1120 snprintf(name, sizeof(name), "cable#%d", cidx);
1121 err = snd_card_proc_new(loopback->card, name, &entry);
1122 if (err < 0)
1123 return err;
1124
1125 snd_info_set_text_ops(entry, loopback, print_cable_info);
1126 return 0;
1127}
1128
1129static int loopback_probe(struct platform_device *devptr)
1130{
1131 struct snd_card *card;
1132 struct loopback *loopback;
1133 int dev = devptr->id;
1134 int err;
1135
1136 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1137 sizeof(struct loopback), &card);
1138 if (err < 0)
1139 return err;
1140 loopback = card->private_data;
1141
1142 if (pcm_substreams[dev] < 1)
1143 pcm_substreams[dev] = 1;
1144 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1145 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1146
1147 loopback->card = card;
1148 mutex_init(&loopback->cable_lock);
1149
1150 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1151 if (err < 0)
1152 goto __nodev;
1153 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1154 if (err < 0)
1155 goto __nodev;
1156 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1157 if (err < 0)
1158 goto __nodev;
1159 loopback_proc_new(loopback, 0);
1160 loopback_proc_new(loopback, 1);
1161 strcpy(card->driver, "Loopback");
1162 strcpy(card->shortname, "Loopback");
1163 sprintf(card->longname, "Loopback %i", dev + 1);
1164 err = snd_card_register(card);
1165 if (!err) {
1166 platform_set_drvdata(devptr, card);
1167 return 0;
1168 }
1169 __nodev:
1170 snd_card_free(card);
1171 return err;
1172}
1173
1174static int loopback_remove(struct platform_device *devptr)
1175{
1176 snd_card_free(platform_get_drvdata(devptr));
1177 return 0;
1178}
1179
1180#ifdef CONFIG_PM_SLEEP
1181static int loopback_suspend(struct device *pdev)
1182{
1183 struct snd_card *card = dev_get_drvdata(pdev);
1184 struct loopback *loopback = card->private_data;
1185
1186 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1187
1188 snd_pcm_suspend_all(loopback->pcm[0]);
1189 snd_pcm_suspend_all(loopback->pcm[1]);
1190 return 0;
1191}
1192
1193static int loopback_resume(struct device *pdev)
1194{
1195 struct snd_card *card = dev_get_drvdata(pdev);
1196
1197 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1198 return 0;
1199}
1200
1201static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1202#define LOOPBACK_PM_OPS &loopback_pm
1203#else
1204#define LOOPBACK_PM_OPS NULL
1205#endif
1206
1207#define SND_LOOPBACK_DRIVER "snd_aloop"
1208
1209static struct platform_driver loopback_driver = {
1210 .probe = loopback_probe,
1211 .remove = loopback_remove,
1212 .driver = {
1213 .name = SND_LOOPBACK_DRIVER,
1214 .pm = LOOPBACK_PM_OPS,
1215 },
1216};
1217
1218static void loopback_unregister_all(void)
1219{
1220 int i;
1221
1222 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1223 platform_device_unregister(devices[i]);
1224 platform_driver_unregister(&loopback_driver);
1225}
1226
1227static int __init alsa_card_loopback_init(void)
1228{
1229 int i, err, cards;
1230
1231 err = platform_driver_register(&loopback_driver);
1232 if (err < 0)
1233 return err;
1234
1235
1236 cards = 0;
1237 for (i = 0; i < SNDRV_CARDS; i++) {
1238 struct platform_device *device;
1239 if (!enable[i])
1240 continue;
1241 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1242 i, NULL, 0);
1243 if (IS_ERR(device))
1244 continue;
1245 if (!platform_get_drvdata(device)) {
1246 platform_device_unregister(device);
1247 continue;
1248 }
1249 devices[i] = device;
1250 cards++;
1251 }
1252 if (!cards) {
1253#ifdef MODULE
1254 printk(KERN_ERR "aloop: No loopback enabled\n");
1255#endif
1256 loopback_unregister_all();
1257 return -ENODEV;
1258 }
1259 return 0;
1260}
1261
1262static void __exit alsa_card_loopback_exit(void)
1263{
1264 loopback_unregister_all();
1265}
1266
1267module_init(alsa_card_loopback_init)
1268module_exit(alsa_card_loopback_exit)
1269
