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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/pcm_params.h>
43#include <sound/info.h>
44#include <sound/initval.h>
45
46MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
47MODULE_DESCRIPTION("A loopback soundcard");
48MODULE_LICENSE("GPL");
49MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
50
51#define MAX_PCM_SUBSTREAMS 8
52
53static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
54static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
55static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
56static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
57static int pcm_notify[SNDRV_CARDS];
58
59module_param_array(index, int, NULL, 0444);
60MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
61module_param_array(id, charp, NULL, 0444);
62MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
63module_param_array(enable, bool, NULL, 0444);
64MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
65module_param_array(pcm_substreams, int, NULL, 0444);
66MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
67module_param_array(pcm_notify, int, NULL, 0444);
68MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
69
70#define NO_PITCH 100000
71
72struct loopback_pcm;
73
74struct loopback_cable {
75 spinlock_t lock;
76 struct loopback_pcm *streams[2];
77 struct snd_pcm_hardware hw;
78
79 unsigned int valid;
80 unsigned int running;
81 unsigned int pause;
82};
83
84struct loopback_setup {
85 unsigned int notify: 1;
86 unsigned int rate_shift;
87 unsigned int format;
88 unsigned int rate;
89 unsigned int channels;
90 struct snd_ctl_elem_id active_id;
91 struct snd_ctl_elem_id format_id;
92 struct snd_ctl_elem_id rate_id;
93 struct snd_ctl_elem_id channels_id;
94};
95
96struct loopback {
97 struct snd_card *card;
98 struct mutex cable_lock;
99 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
100 struct snd_pcm *pcm[2];
101 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
102};
103
104struct loopback_pcm {
105 struct loopback *loopback;
106 struct snd_pcm_substream *substream;
107 struct loopback_cable *cable;
108 unsigned int pcm_buffer_size;
109 unsigned int buf_pos;
110 unsigned int silent_size;
111
112 unsigned int pcm_period_size;
113 unsigned int pcm_bps;
114 unsigned int pcm_salign;
115 unsigned int pcm_rate_shift;
116
117 unsigned int period_update_pending :1;
118
119 unsigned int irq_pos;
120 unsigned int period_size_frac;
121 unsigned int last_drift;
122 unsigned long last_jiffies;
123 struct timer_list timer;
124};
125
126static struct platform_device *devices[SNDRV_CARDS];
127
128static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
129{
130 if (dpcm->pcm_rate_shift == NO_PITCH) {
131 x /= HZ;
132 } else {
133 x = div_u64(NO_PITCH * (unsigned long long)x,
134 HZ * (unsigned long long)dpcm->pcm_rate_shift);
135 }
136 return x - (x % dpcm->pcm_salign);
137}
138
139static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
140{
141 if (dpcm->pcm_rate_shift == NO_PITCH) {
142 return x * HZ;
143 } else {
144 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
145 NO_PITCH);
146 }
147 return x;
148}
149
150static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
151{
152 int device = dpcm->substream->pstr->pcm->device;
153
154 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
155 device ^= 1;
156 return &dpcm->loopback->setup[dpcm->substream->number][device];
157}
158
159static inline unsigned int get_notify(struct loopback_pcm *dpcm)
160{
161 return get_setup(dpcm)->notify;
162}
163
164static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
165{
166 return get_setup(dpcm)->rate_shift;
167}
168
169
170static void loopback_timer_start(struct loopback_pcm *dpcm)
171{
172 unsigned long tick;
173 unsigned int rate_shift = get_rate_shift(dpcm);
174
175 if (rate_shift != dpcm->pcm_rate_shift) {
176 dpcm->pcm_rate_shift = rate_shift;
177 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
178 }
179 if (dpcm->period_size_frac <= dpcm->irq_pos) {
180 dpcm->irq_pos %= dpcm->period_size_frac;
181 dpcm->period_update_pending = 1;
182 }
183 tick = dpcm->period_size_frac - dpcm->irq_pos;
184 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
185 mod_timer(&dpcm->timer, jiffies + tick);
186}
187
188
189static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
190{
191 del_timer(&dpcm->timer);
192 dpcm->timer.expires = 0;
193}
194
195static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm)
196{
197 del_timer_sync(&dpcm->timer);
198}
199
200#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
201#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
202#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
203
204static int loopback_check_format(struct loopback_cable *cable, int stream)
205{
206 struct snd_pcm_runtime *runtime, *cruntime;
207 struct loopback_setup *setup;
208 struct snd_card *card;
209 int check;
210
211 if (cable->valid != CABLE_VALID_BOTH) {
212 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
213 goto __notify;
214 return 0;
215 }
216 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
217 substream->runtime;
218 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
219 substream->runtime;
220 check = runtime->format != cruntime->format ||
221 runtime->rate != cruntime->rate ||
222 runtime->channels != cruntime->channels;
223 if (!check)
224 return 0;
225 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
226 return -EIO;
227 } else {
228 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
229 substream, SNDRV_PCM_STATE_DRAINING);
230 __notify:
231 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
232 substream->runtime;
233 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
234 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
235 if (setup->format != runtime->format) {
236 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
237 &setup->format_id);
238 setup->format = runtime->format;
239 }
240 if (setup->rate != runtime->rate) {
241 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
242 &setup->rate_id);
243 setup->rate = runtime->rate;
244 }
245 if (setup->channels != runtime->channels) {
246 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
247 &setup->channels_id);
248 setup->channels = runtime->channels;
249 }
250 }
251 return 0;
252}
253
254static void loopback_active_notify(struct loopback_pcm *dpcm)
255{
256 snd_ctl_notify(dpcm->loopback->card,
257 SNDRV_CTL_EVENT_MASK_VALUE,
258 &get_setup(dpcm)->active_id);
259}
260
261static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
262{
263 struct snd_pcm_runtime *runtime = substream->runtime;
264 struct loopback_pcm *dpcm = runtime->private_data;
265 struct loopback_cable *cable = dpcm->cable;
266 int err, stream = 1 << substream->stream;
267
268 switch (cmd) {
269 case SNDRV_PCM_TRIGGER_START:
270 err = loopback_check_format(cable, substream->stream);
271 if (err < 0)
272 return err;
273 dpcm->last_jiffies = jiffies;
274 dpcm->pcm_rate_shift = 0;
275 dpcm->last_drift = 0;
276 spin_lock(&cable->lock);
277 cable->running |= stream;
278 cable->pause &= ~stream;
279 loopback_timer_start(dpcm);
280 spin_unlock(&cable->lock);
281 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
282 loopback_active_notify(dpcm);
283 break;
284 case SNDRV_PCM_TRIGGER_STOP:
285 spin_lock(&cable->lock);
286 cable->running &= ~stream;
287 cable->pause &= ~stream;
288 loopback_timer_stop(dpcm);
289 spin_unlock(&cable->lock);
290 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
291 loopback_active_notify(dpcm);
292 break;
293 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
294 case SNDRV_PCM_TRIGGER_SUSPEND:
295 spin_lock(&cable->lock);
296 cable->pause |= stream;
297 loopback_timer_stop(dpcm);
298 spin_unlock(&cable->lock);
299 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
300 loopback_active_notify(dpcm);
301 break;
302 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
303 case SNDRV_PCM_TRIGGER_RESUME:
304 spin_lock(&cable->lock);
305 dpcm->last_jiffies = jiffies;
306 cable->pause &= ~stream;
307 loopback_timer_start(dpcm);
308 spin_unlock(&cable->lock);
309 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
310 loopback_active_notify(dpcm);
311 break;
312 default:
313 return -EINVAL;
314 }
315 return 0;
316}
317
318static void params_change(struct snd_pcm_substream *substream)
319{
320 struct snd_pcm_runtime *runtime = substream->runtime;
321 struct loopback_pcm *dpcm = runtime->private_data;
322 struct loopback_cable *cable = dpcm->cable;
323
324 cable->hw.formats = pcm_format_to_bits(runtime->format);
325 cable->hw.rate_min = runtime->rate;
326 cable->hw.rate_max = runtime->rate;
327 cable->hw.channels_min = runtime->channels;
328 cable->hw.channels_max = runtime->channels;
329}
330
331static int loopback_prepare(struct snd_pcm_substream *substream)
332{
333 struct snd_pcm_runtime *runtime = substream->runtime;
334 struct loopback_pcm *dpcm = runtime->private_data;
335 struct loopback_cable *cable = dpcm->cable;
336 int bps, salign;
337
338 loopback_timer_stop_sync(dpcm);
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
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
410
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
447static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
448 unsigned int jiffies_delta)
449{
450 unsigned long last_pos;
451 unsigned int delta;
452
453 last_pos = byte_pos(dpcm, dpcm->irq_pos);
454 dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
455 delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
456 if (delta >= dpcm->last_drift)
457 delta -= dpcm->last_drift;
458 dpcm->last_drift = 0;
459 if (dpcm->irq_pos >= dpcm->period_size_frac) {
460 dpcm->irq_pos %= dpcm->period_size_frac;
461 dpcm->period_update_pending = 1;
462 }
463 return delta;
464}
465
466static inline void bytepos_finish(struct loopback_pcm *dpcm,
467 unsigned int delta)
468{
469 dpcm->buf_pos += delta;
470 dpcm->buf_pos %= dpcm->pcm_buffer_size;
471}
472
473
474static unsigned int loopback_pos_update(struct loopback_cable *cable)
475{
476 struct loopback_pcm *dpcm_play =
477 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
478 struct loopback_pcm *dpcm_capt =
479 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
480 unsigned long delta_play = 0, delta_capt = 0;
481 unsigned int running, count1, count2;
482
483 running = cable->running ^ cable->pause;
484 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
485 delta_play = jiffies - dpcm_play->last_jiffies;
486 dpcm_play->last_jiffies += delta_play;
487 }
488
489 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
490 delta_capt = jiffies - dpcm_capt->last_jiffies;
491 dpcm_capt->last_jiffies += delta_capt;
492 }
493
494 if (delta_play == 0 && delta_capt == 0)
495 goto unlock;
496
497 if (delta_play > delta_capt) {
498 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
499 bytepos_finish(dpcm_play, count1);
500 delta_play = delta_capt;
501 } else if (delta_play < delta_capt) {
502 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
503 clear_capture_buf(dpcm_capt, count1);
504 bytepos_finish(dpcm_capt, count1);
505 delta_capt = delta_play;
506 }
507
508 if (delta_play == 0 && delta_capt == 0)
509 goto unlock;
510
511
512 count1 = bytepos_delta(dpcm_play, delta_play);
513 count2 = bytepos_delta(dpcm_capt, delta_capt);
514 if (count1 < count2) {
515 dpcm_capt->last_drift = count2 - count1;
516 count1 = count2;
517 } else if (count1 > count2) {
518 dpcm_play->last_drift = count1 - count2;
519 }
520 copy_play_buf(dpcm_play, dpcm_capt, count1);
521 bytepos_finish(dpcm_play, count1);
522 bytepos_finish(dpcm_capt, count1);
523 unlock:
524 return running;
525}
526
527static void loopback_timer_function(struct timer_list *t)
528{
529 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
530 unsigned long flags;
531
532 spin_lock_irqsave(&dpcm->cable->lock, flags);
533 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
534 loopback_timer_start(dpcm);
535 if (dpcm->period_update_pending) {
536 dpcm->period_update_pending = 0;
537 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
538
539 snd_pcm_period_elapsed(dpcm->substream);
540 return;
541 }
542 }
543 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
544}
545
546static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
547{
548 struct snd_pcm_runtime *runtime = substream->runtime;
549 struct loopback_pcm *dpcm = runtime->private_data;
550 snd_pcm_uframes_t pos;
551
552 spin_lock(&dpcm->cable->lock);
553 loopback_pos_update(dpcm->cable);
554 pos = dpcm->buf_pos;
555 spin_unlock(&dpcm->cable->lock);
556 return bytes_to_frames(runtime, pos);
557}
558
559static const struct snd_pcm_hardware loopback_pcm_hardware =
560{
561 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
562 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
563 SNDRV_PCM_INFO_RESUME),
564 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
565 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
566 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
567 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
568 .rate_min = 8000,
569 .rate_max = 192000,
570 .channels_min = 1,
571 .channels_max = 32,
572 .buffer_bytes_max = 2 * 1024 * 1024,
573 .period_bytes_min = 64,
574
575
576 .period_bytes_max = 1024 * 1024,
577 .periods_min = 1,
578 .periods_max = 1024,
579 .fifo_size = 0,
580};
581
582static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
583{
584 struct loopback_pcm *dpcm = runtime->private_data;
585 kfree(dpcm);
586}
587
588static int loopback_hw_params(struct snd_pcm_substream *substream,
589 struct snd_pcm_hw_params *params)
590{
591 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
592 params_buffer_bytes(params));
593}
594
595static int loopback_hw_free(struct snd_pcm_substream *substream)
596{
597 struct snd_pcm_runtime *runtime = substream->runtime;
598 struct loopback_pcm *dpcm = runtime->private_data;
599 struct loopback_cable *cable = dpcm->cable;
600
601 mutex_lock(&dpcm->loopback->cable_lock);
602 cable->valid &= ~(1 << substream->stream);
603 mutex_unlock(&dpcm->loopback->cable_lock);
604 return snd_pcm_lib_free_vmalloc_buffer(substream);
605}
606
607static unsigned int get_cable_index(struct snd_pcm_substream *substream)
608{
609 if (!substream->pcm->device)
610 return substream->stream;
611 else
612 return !substream->stream;
613}
614
615static int rule_format(struct snd_pcm_hw_params *params,
616 struct snd_pcm_hw_rule *rule)
617{
618 struct loopback_pcm *dpcm = rule->private;
619 struct loopback_cable *cable = dpcm->cable;
620 struct snd_mask m;
621
622 snd_mask_none(&m);
623 mutex_lock(&dpcm->loopback->cable_lock);
624 m.bits[0] = (u_int32_t)cable->hw.formats;
625 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
626 mutex_unlock(&dpcm->loopback->cable_lock);
627 return snd_mask_refine(hw_param_mask(params, rule->var), &m);
628}
629
630static int rule_rate(struct snd_pcm_hw_params *params,
631 struct snd_pcm_hw_rule *rule)
632{
633 struct loopback_pcm *dpcm = rule->private;
634 struct loopback_cable *cable = dpcm->cable;
635 struct snd_interval t;
636
637 mutex_lock(&dpcm->loopback->cable_lock);
638 t.min = cable->hw.rate_min;
639 t.max = cable->hw.rate_max;
640 mutex_unlock(&dpcm->loopback->cable_lock);
641 t.openmin = t.openmax = 0;
642 t.integer = 0;
643 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
644}
645
646static int rule_channels(struct snd_pcm_hw_params *params,
647 struct snd_pcm_hw_rule *rule)
648{
649 struct loopback_pcm *dpcm = rule->private;
650 struct loopback_cable *cable = dpcm->cable;
651 struct snd_interval t;
652
653 mutex_lock(&dpcm->loopback->cable_lock);
654 t.min = cable->hw.channels_min;
655 t.max = cable->hw.channels_max;
656 mutex_unlock(&dpcm->loopback->cable_lock);
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 void free_cable(struct snd_pcm_substream *substream)
663{
664 struct loopback *loopback = substream->private_data;
665 int dev = get_cable_index(substream);
666 struct loopback_cable *cable;
667
668 cable = loopback->cables[substream->number][dev];
669 if (!cable)
670 return;
671 if (cable->streams[!substream->stream]) {
672
673 spin_lock_irq(&cable->lock);
674 cable->streams[substream->stream] = NULL;
675 spin_unlock_irq(&cable->lock);
676 } else {
677
678 loopback->cables[substream->number][dev] = NULL;
679 kfree(cable);
680 }
681}
682
683static int loopback_open(struct snd_pcm_substream *substream)
684{
685 struct snd_pcm_runtime *runtime = substream->runtime;
686 struct loopback *loopback = substream->private_data;
687 struct loopback_pcm *dpcm;
688 struct loopback_cable *cable = NULL;
689 int err = 0;
690 int dev = get_cable_index(substream);
691
692 mutex_lock(&loopback->cable_lock);
693 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
694 if (!dpcm) {
695 err = -ENOMEM;
696 goto unlock;
697 }
698 dpcm->loopback = loopback;
699 dpcm->substream = substream;
700 timer_setup(&dpcm->timer, loopback_timer_function, 0);
701
702 cable = loopback->cables[substream->number][dev];
703 if (!cable) {
704 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
705 if (!cable) {
706 err = -ENOMEM;
707 goto unlock;
708 }
709 spin_lock_init(&cable->lock);
710 cable->hw = loopback_pcm_hardware;
711 loopback->cables[substream->number][dev] = cable;
712 }
713 dpcm->cable = cable;
714
715 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
716
717
718
719
720 err = snd_pcm_hw_rule_add(runtime, 0,
721 SNDRV_PCM_HW_PARAM_FORMAT,
722 rule_format, dpcm,
723 SNDRV_PCM_HW_PARAM_FORMAT, -1);
724 if (err < 0)
725 goto unlock;
726 err = snd_pcm_hw_rule_add(runtime, 0,
727 SNDRV_PCM_HW_PARAM_RATE,
728 rule_rate, dpcm,
729 SNDRV_PCM_HW_PARAM_RATE, -1);
730 if (err < 0)
731 goto unlock;
732 err = snd_pcm_hw_rule_add(runtime, 0,
733 SNDRV_PCM_HW_PARAM_CHANNELS,
734 rule_channels, dpcm,
735 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
736 if (err < 0)
737 goto unlock;
738
739 runtime->private_data = dpcm;
740 runtime->private_free = loopback_runtime_free;
741 if (get_notify(dpcm))
742 runtime->hw = loopback_pcm_hardware;
743 else
744 runtime->hw = cable->hw;
745
746 spin_lock_irq(&cable->lock);
747 cable->streams[substream->stream] = dpcm;
748 spin_unlock_irq(&cable->lock);
749
750 unlock:
751 if (err < 0) {
752 free_cable(substream);
753 kfree(dpcm);
754 }
755 mutex_unlock(&loopback->cable_lock);
756 return err;
757}
758
759static int loopback_close(struct snd_pcm_substream *substream)
760{
761 struct loopback *loopback = substream->private_data;
762 struct loopback_pcm *dpcm = substream->runtime->private_data;
763
764 loopback_timer_stop_sync(dpcm);
765 mutex_lock(&loopback->cable_lock);
766 free_cable(substream);
767 mutex_unlock(&loopback->cable_lock);
768 return 0;
769}
770
771static const struct snd_pcm_ops loopback_playback_ops = {
772 .open = loopback_open,
773 .close = loopback_close,
774 .ioctl = snd_pcm_lib_ioctl,
775 .hw_params = loopback_hw_params,
776 .hw_free = loopback_hw_free,
777 .prepare = loopback_prepare,
778 .trigger = loopback_trigger,
779 .pointer = loopback_pointer,
780 .page = snd_pcm_lib_get_vmalloc_page,
781 .mmap = snd_pcm_lib_mmap_vmalloc,
782};
783
784static const struct snd_pcm_ops loopback_capture_ops = {
785 .open = loopback_open,
786 .close = loopback_close,
787 .ioctl = snd_pcm_lib_ioctl,
788 .hw_params = loopback_hw_params,
789 .hw_free = loopback_hw_free,
790 .prepare = loopback_prepare,
791 .trigger = loopback_trigger,
792 .pointer = loopback_pointer,
793 .page = snd_pcm_lib_get_vmalloc_page,
794 .mmap = snd_pcm_lib_mmap_vmalloc,
795};
796
797static int loopback_pcm_new(struct loopback *loopback,
798 int device, int substreams)
799{
800 struct snd_pcm *pcm;
801 int err;
802
803 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
804 substreams, substreams, &pcm);
805 if (err < 0)
806 return err;
807 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
808 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
809
810 pcm->private_data = loopback;
811 pcm->info_flags = 0;
812 strcpy(pcm->name, "Loopback PCM");
813
814 loopback->pcm[device] = pcm;
815 return 0;
816}
817
818static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
819 struct snd_ctl_elem_info *uinfo)
820{
821 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
822 uinfo->count = 1;
823 uinfo->value.integer.min = 80000;
824 uinfo->value.integer.max = 120000;
825 uinfo->value.integer.step = 1;
826 return 0;
827}
828
829static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
830 struct snd_ctl_elem_value *ucontrol)
831{
832 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
833
834 mutex_lock(&loopback->cable_lock);
835 ucontrol->value.integer.value[0] =
836 loopback->setup[kcontrol->id.subdevice]
837 [kcontrol->id.device].rate_shift;
838 mutex_unlock(&loopback->cable_lock);
839 return 0;
840}
841
842static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
843 struct snd_ctl_elem_value *ucontrol)
844{
845 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
846 unsigned int val;
847 int change = 0;
848
849 val = ucontrol->value.integer.value[0];
850 if (val < 80000)
851 val = 80000;
852 if (val > 120000)
853 val = 120000;
854 mutex_lock(&loopback->cable_lock);
855 if (val != loopback->setup[kcontrol->id.subdevice]
856 [kcontrol->id.device].rate_shift) {
857 loopback->setup[kcontrol->id.subdevice]
858 [kcontrol->id.device].rate_shift = val;
859 change = 1;
860 }
861 mutex_unlock(&loopback->cable_lock);
862 return change;
863}
864
865static int loopback_notify_get(struct snd_kcontrol *kcontrol,
866 struct snd_ctl_elem_value *ucontrol)
867{
868 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
869
870 mutex_lock(&loopback->cable_lock);
871 ucontrol->value.integer.value[0] =
872 loopback->setup[kcontrol->id.subdevice]
873 [kcontrol->id.device].notify;
874 mutex_unlock(&loopback->cable_lock);
875 return 0;
876}
877
878static int loopback_notify_put(struct snd_kcontrol *kcontrol,
879 struct snd_ctl_elem_value *ucontrol)
880{
881 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
882 unsigned int val;
883 int change = 0;
884
885 val = ucontrol->value.integer.value[0] ? 1 : 0;
886 mutex_lock(&loopback->cable_lock);
887 if (val != loopback->setup[kcontrol->id.subdevice]
888 [kcontrol->id.device].notify) {
889 loopback->setup[kcontrol->id.subdevice]
890 [kcontrol->id.device].notify = val;
891 change = 1;
892 }
893 mutex_unlock(&loopback->cable_lock);
894 return change;
895}
896
897static int loopback_active_get(struct snd_kcontrol *kcontrol,
898 struct snd_ctl_elem_value *ucontrol)
899{
900 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
901 struct loopback_cable *cable;
902
903 unsigned int val = 0;
904
905 mutex_lock(&loopback->cable_lock);
906 cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
907 if (cable != NULL) {
908 unsigned int running = cable->running ^ cable->pause;
909
910 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
911 }
912 mutex_unlock(&loopback->cable_lock);
913 ucontrol->value.integer.value[0] = val;
914 return 0;
915}
916
917static int loopback_format_info(struct snd_kcontrol *kcontrol,
918 struct snd_ctl_elem_info *uinfo)
919{
920 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
921 uinfo->count = 1;
922 uinfo->value.integer.min = 0;
923 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
924 uinfo->value.integer.step = 1;
925 return 0;
926}
927
928static int loopback_format_get(struct snd_kcontrol *kcontrol,
929 struct snd_ctl_elem_value *ucontrol)
930{
931 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
932
933 ucontrol->value.integer.value[0] =
934 loopback->setup[kcontrol->id.subdevice]
935 [kcontrol->id.device].format;
936 return 0;
937}
938
939static int loopback_rate_info(struct snd_kcontrol *kcontrol,
940 struct snd_ctl_elem_info *uinfo)
941{
942 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
943 uinfo->count = 1;
944 uinfo->value.integer.min = 0;
945 uinfo->value.integer.max = 192000;
946 uinfo->value.integer.step = 1;
947 return 0;
948}
949
950static int loopback_rate_get(struct snd_kcontrol *kcontrol,
951 struct snd_ctl_elem_value *ucontrol)
952{
953 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
954
955 mutex_lock(&loopback->cable_lock);
956 ucontrol->value.integer.value[0] =
957 loopback->setup[kcontrol->id.subdevice]
958 [kcontrol->id.device].rate;
959 mutex_unlock(&loopback->cable_lock);
960 return 0;
961}
962
963static int loopback_channels_info(struct snd_kcontrol *kcontrol,
964 struct snd_ctl_elem_info *uinfo)
965{
966 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
967 uinfo->count = 1;
968 uinfo->value.integer.min = 1;
969 uinfo->value.integer.max = 1024;
970 uinfo->value.integer.step = 1;
971 return 0;
972}
973
974static int loopback_channels_get(struct snd_kcontrol *kcontrol,
975 struct snd_ctl_elem_value *ucontrol)
976{
977 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
978
979 mutex_lock(&loopback->cable_lock);
980 ucontrol->value.integer.value[0] =
981 loopback->setup[kcontrol->id.subdevice]
982 [kcontrol->id.device].channels;
983 mutex_unlock(&loopback->cable_lock);
984 return 0;
985}
986
987static struct snd_kcontrol_new loopback_controls[] = {
988{
989 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
990 .name = "PCM Rate Shift 100000",
991 .info = loopback_rate_shift_info,
992 .get = loopback_rate_shift_get,
993 .put = loopback_rate_shift_put,
994},
995{
996 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
997 .name = "PCM Notify",
998 .info = snd_ctl_boolean_mono_info,
999 .get = loopback_notify_get,
1000 .put = loopback_notify_put,
1001},
1002#define ACTIVE_IDX 2
1003{
1004 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1005 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1006 .name = "PCM Slave Active",
1007 .info = snd_ctl_boolean_mono_info,
1008 .get = loopback_active_get,
1009},
1010#define FORMAT_IDX 3
1011{
1012 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1013 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1014 .name = "PCM Slave Format",
1015 .info = loopback_format_info,
1016 .get = loopback_format_get
1017},
1018#define RATE_IDX 4
1019{
1020 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1021 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1022 .name = "PCM Slave Rate",
1023 .info = loopback_rate_info,
1024 .get = loopback_rate_get
1025},
1026#define CHANNELS_IDX 5
1027{
1028 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1029 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1030 .name = "PCM Slave Channels",
1031 .info = loopback_channels_info,
1032 .get = loopback_channels_get
1033}
1034};
1035
1036static int loopback_mixer_new(struct loopback *loopback, int notify)
1037{
1038 struct snd_card *card = loopback->card;
1039 struct snd_pcm *pcm;
1040 struct snd_kcontrol *kctl;
1041 struct loopback_setup *setup;
1042 int err, dev, substr, substr_count, idx;
1043
1044 strcpy(card->mixername, "Loopback Mixer");
1045 for (dev = 0; dev < 2; dev++) {
1046 pcm = loopback->pcm[dev];
1047 substr_count =
1048 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1049 for (substr = 0; substr < substr_count; substr++) {
1050 setup = &loopback->setup[substr][dev];
1051 setup->notify = notify;
1052 setup->rate_shift = NO_PITCH;
1053 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1054 setup->rate = 48000;
1055 setup->channels = 2;
1056 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1057 idx++) {
1058 kctl = snd_ctl_new1(&loopback_controls[idx],
1059 loopback);
1060 if (!kctl)
1061 return -ENOMEM;
1062 kctl->id.device = dev;
1063 kctl->id.subdevice = substr;
1064 switch (idx) {
1065 case ACTIVE_IDX:
1066 setup->active_id = kctl->id;
1067 break;
1068 case FORMAT_IDX:
1069 setup->format_id = kctl->id;
1070 break;
1071 case RATE_IDX:
1072 setup->rate_id = kctl->id;
1073 break;
1074 case CHANNELS_IDX:
1075 setup->channels_id = kctl->id;
1076 break;
1077 default:
1078 break;
1079 }
1080 err = snd_ctl_add(card, kctl);
1081 if (err < 0)
1082 return err;
1083 }
1084 }
1085 }
1086 return 0;
1087}
1088
1089static void print_dpcm_info(struct snd_info_buffer *buffer,
1090 struct loopback_pcm *dpcm,
1091 const char *id)
1092{
1093 snd_iprintf(buffer, " %s\n", id);
1094 if (dpcm == NULL) {
1095 snd_iprintf(buffer, " inactive\n");
1096 return;
1097 }
1098 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1099 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1100 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1101 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1102 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1103 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1104 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1105 snd_iprintf(buffer, " update_pending:\t%u\n",
1106 dpcm->period_update_pending);
1107 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1108 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1109 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1110 dpcm->last_jiffies, jiffies);
1111 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1112}
1113
1114static void print_substream_info(struct snd_info_buffer *buffer,
1115 struct loopback *loopback,
1116 int sub,
1117 int num)
1118{
1119 struct loopback_cable *cable = loopback->cables[sub][num];
1120
1121 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1122 if (cable == NULL) {
1123 snd_iprintf(buffer, " inactive\n");
1124 return;
1125 }
1126 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1127 snd_iprintf(buffer, " running: %u\n", cable->running);
1128 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1129 print_dpcm_info(buffer, cable->streams[0], "Playback");
1130 print_dpcm_info(buffer, cable->streams[1], "Capture");
1131}
1132
1133static void print_cable_info(struct snd_info_entry *entry,
1134 struct snd_info_buffer *buffer)
1135{
1136 struct loopback *loopback = entry->private_data;
1137 int sub, num;
1138
1139 mutex_lock(&loopback->cable_lock);
1140 num = entry->name[strlen(entry->name)-1];
1141 num = num == '0' ? 0 : 1;
1142 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1143 print_substream_info(buffer, loopback, sub, num);
1144 mutex_unlock(&loopback->cable_lock);
1145}
1146
1147static int loopback_proc_new(struct loopback *loopback, int cidx)
1148{
1149 char name[32];
1150 struct snd_info_entry *entry;
1151 int err;
1152
1153 snprintf(name, sizeof(name), "cable#%d", cidx);
1154 err = snd_card_proc_new(loopback->card, name, &entry);
1155 if (err < 0)
1156 return err;
1157
1158 snd_info_set_text_ops(entry, loopback, print_cable_info);
1159 return 0;
1160}
1161
1162static int loopback_probe(struct platform_device *devptr)
1163{
1164 struct snd_card *card;
1165 struct loopback *loopback;
1166 int dev = devptr->id;
1167 int err;
1168
1169 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1170 sizeof(struct loopback), &card);
1171 if (err < 0)
1172 return err;
1173 loopback = card->private_data;
1174
1175 if (pcm_substreams[dev] < 1)
1176 pcm_substreams[dev] = 1;
1177 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1178 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1179
1180 loopback->card = card;
1181 mutex_init(&loopback->cable_lock);
1182
1183 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1184 if (err < 0)
1185 goto __nodev;
1186 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1187 if (err < 0)
1188 goto __nodev;
1189 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1190 if (err < 0)
1191 goto __nodev;
1192 loopback_proc_new(loopback, 0);
1193 loopback_proc_new(loopback, 1);
1194 strcpy(card->driver, "Loopback");
1195 strcpy(card->shortname, "Loopback");
1196 sprintf(card->longname, "Loopback %i", dev + 1);
1197 err = snd_card_register(card);
1198 if (!err) {
1199 platform_set_drvdata(devptr, card);
1200 return 0;
1201 }
1202 __nodev:
1203 snd_card_free(card);
1204 return err;
1205}
1206
1207static int loopback_remove(struct platform_device *devptr)
1208{
1209 snd_card_free(platform_get_drvdata(devptr));
1210 return 0;
1211}
1212
1213#ifdef CONFIG_PM_SLEEP
1214static int loopback_suspend(struct device *pdev)
1215{
1216 struct snd_card *card = dev_get_drvdata(pdev);
1217 struct loopback *loopback = card->private_data;
1218
1219 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1220
1221 snd_pcm_suspend_all(loopback->pcm[0]);
1222 snd_pcm_suspend_all(loopback->pcm[1]);
1223 return 0;
1224}
1225
1226static int loopback_resume(struct device *pdev)
1227{
1228 struct snd_card *card = dev_get_drvdata(pdev);
1229
1230 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1231 return 0;
1232}
1233
1234static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1235#define LOOPBACK_PM_OPS &loopback_pm
1236#else
1237#define LOOPBACK_PM_OPS NULL
1238#endif
1239
1240#define SND_LOOPBACK_DRIVER "snd_aloop"
1241
1242static struct platform_driver loopback_driver = {
1243 .probe = loopback_probe,
1244 .remove = loopback_remove,
1245 .driver = {
1246 .name = SND_LOOPBACK_DRIVER,
1247 .pm = LOOPBACK_PM_OPS,
1248 },
1249};
1250
1251static void loopback_unregister_all(void)
1252{
1253 int i;
1254
1255 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1256 platform_device_unregister(devices[i]);
1257 platform_driver_unregister(&loopback_driver);
1258}
1259
1260static int __init alsa_card_loopback_init(void)
1261{
1262 int i, err, cards;
1263
1264 err = platform_driver_register(&loopback_driver);
1265 if (err < 0)
1266 return err;
1267
1268
1269 cards = 0;
1270 for (i = 0; i < SNDRV_CARDS; i++) {
1271 struct platform_device *device;
1272 if (!enable[i])
1273 continue;
1274 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1275 i, NULL, 0);
1276 if (IS_ERR(device))
1277 continue;
1278 if (!platform_get_drvdata(device)) {
1279 platform_device_unregister(device);
1280 continue;
1281 }
1282 devices[i] = device;
1283 cards++;
1284 }
1285 if (!cards) {
1286#ifdef MODULE
1287 printk(KERN_ERR "aloop: No loopback enabled\n");
1288#endif
1289 loopback_unregister_all();
1290 return -ENODEV;
1291 }
1292 return 0;
1293}
1294
1295static void __exit alsa_card_loopback_exit(void)
1296{
1297 loopback_unregister_all();
1298}
1299
1300module_init(alsa_card_loopback_init)
1301module_exit(alsa_card_loopback_exit)
1302
