5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
7 * More accurate positioning and full-duplex support:
8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
10 * Major (almost complete) rewrite:
11 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
13 * A next major update in 2010 (separate timers for playback and capture):
14 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
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.
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.
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
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>
46 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
47 MODULE_DESCRIPTION("A loopback soundcard");
48 MODULE_LICENSE("GPL");
49 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
51 #define MAX_PCM_SUBSTREAMS 8
53 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
54 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
55 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
57 static int pcm_notify[SNDRV_CARDS];
59 module_param_array(index, int, NULL, 0444);
60 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
61 module_param_array(id, charp, NULL, 0444);
62 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
63 module_param_array(enable, bool, NULL, 0444);
64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
65 module_param_array(pcm_substreams, int, NULL, 0444);
66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
67 module_param_array(pcm_notify, int, NULL, 0444);
68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
70 #define NO_PITCH 100000
74 struct loopback_cable {
76 struct loopback_pcm *streams[2];
77 struct snd_pcm_hardware hw;
84 struct loopback_setup {
85 unsigned int notify: 1;
86 unsigned int rate_shift;
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;
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];
104 struct 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; /* position in buffer */
110 unsigned int silent_size;
112 unsigned int pcm_period_size;
113 unsigned int pcm_bps; /* bytes per second */
114 unsigned int pcm_salign; /* bytes per sample * channels */
115 unsigned int pcm_rate_shift; /* rate shift value */
117 unsigned int period_update_pending :1;
119 unsigned int irq_pos; /* fractional IRQ position */
120 unsigned int period_size_frac;
121 unsigned int last_drift;
122 unsigned long last_jiffies;
123 struct timer_list timer;
126 static struct platform_device *devices[SNDRV_CARDS];
128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
130 if (dpcm->pcm_rate_shift == NO_PITCH) {
133 x = div_u64(NO_PITCH * (unsigned long long)x,
134 HZ * (unsigned long long)dpcm->pcm_rate_shift);
136 return x - (x % dpcm->pcm_salign);
139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
141 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
144 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
152 int device = dpcm->substream->pstr->pcm->device;
154 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
156 return &dpcm->loopback->setup[dpcm->substream->number][device];
159 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
161 return get_setup(dpcm)->notify;
164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
166 return get_setup(dpcm)->rate_shift;
169 /* call in cable->lock */
170 static void loopback_timer_start(struct loopback_pcm *dpcm)
173 unsigned int rate_shift = get_rate_shift(dpcm);
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);
179 if (dpcm->period_size_frac <= dpcm->irq_pos) {
180 dpcm->irq_pos %= dpcm->period_size_frac;
181 dpcm->period_update_pending = 1;
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);
188 /* call in cable->lock */
189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
191 del_timer(&dpcm->timer);
192 dpcm->timer.expires = 0;
195 static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm)
197 del_timer_sync(&dpcm->timer);
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)
204 static int loopback_check_format(struct loopback_cable *cable, int stream)
206 struct snd_pcm_runtime *runtime, *cruntime;
207 struct loopback_setup *setup;
208 struct snd_card *card;
211 if (cable->valid != CABLE_VALID_BOTH) {
212 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
216 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
218 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
220 check = runtime->format != cruntime->format ||
221 runtime->rate != cruntime->rate ||
222 runtime->channels != cruntime->channels;
225 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
228 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
229 substream, SNDRV_PCM_STATE_DRAINING);
231 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
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,
238 setup->format = runtime->format;
240 if (setup->rate != runtime->rate) {
241 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
243 setup->rate = runtime->rate;
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;
254 static void loopback_active_notify(struct loopback_pcm *dpcm)
256 snd_ctl_notify(dpcm->loopback->card,
257 SNDRV_CTL_EVENT_MASK_VALUE,
258 &get_setup(dpcm)->active_id);
261 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
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;
269 case SNDRV_PCM_TRIGGER_START:
270 err = loopback_check_format(cable, substream->stream);
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);
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);
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);
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);
318 static void params_change(struct snd_pcm_substream *substream)
320 struct snd_pcm_runtime *runtime = substream->runtime;
321 struct loopback_pcm *dpcm = runtime->private_data;
322 struct loopback_cable *cable = dpcm->cable;
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;
331 static int loopback_prepare(struct snd_pcm_substream *substream)
333 struct snd_pcm_runtime *runtime = substream->runtime;
334 struct loopback_pcm *dpcm = runtime->private_data;
335 struct loopback_cable *cable = dpcm->cable;
338 loopback_timer_stop_sync(dpcm);
340 salign = (snd_pcm_format_width(runtime->format) *
341 runtime->channels) / 8;
342 bps = salign * runtime->rate;
343 if (bps <= 0 || salign <= 0)
347 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
348 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
349 /* clear capture buffer */
350 dpcm->silent_size = dpcm->pcm_buffer_size;
351 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
352 runtime->buffer_size * runtime->channels);
356 dpcm->period_update_pending = 0;
358 dpcm->pcm_salign = salign;
359 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
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);
372 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
374 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
375 char *dst = runtime->dma_area;
376 unsigned int dst_off = dpcm->buf_pos;
378 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
380 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
381 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
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) *
390 dpcm->silent_size += size;
398 static void copy_play_buf(struct loopback_pcm *play,
399 struct loopback_pcm *capt,
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;
409 /* check if playback is draining, trim the capture copy size
410 * when our pointer is at the end of playback ring buffer */
411 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
412 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
413 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
414 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
415 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
416 appl_ptr1 += play->buf_pos / play->pcm_salign;
417 if (appl_ptr < appl_ptr1)
418 appl_ptr1 -= runtime->buffer_size;
419 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
421 clear_bytes = bytes - diff;
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;
437 src_off = (src_off + size) % play->pcm_buffer_size;
438 dst_off = (dst_off + size) % capt->pcm_buffer_size;
441 if (clear_bytes > 0) {
442 clear_capture_buf(capt, clear_bytes);
443 capt->silent_size = 0;
447 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
448 unsigned int jiffies_delta)
450 unsigned long last_pos;
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;
466 static inline void bytepos_finish(struct loopback_pcm *dpcm,
469 dpcm->buf_pos += delta;
470 dpcm->buf_pos %= dpcm->pcm_buffer_size;
473 /* call in cable->lock */
474 static unsigned int loopback_pos_update(struct loopback_cable *cable)
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, cur_jiffies;
481 unsigned int running, count1, count2;
483 cur_jiffies = jiffies;
484 running = cable->running ^ cable->pause;
485 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
486 delta_play = cur_jiffies - dpcm_play->last_jiffies;
487 dpcm_play->last_jiffies += delta_play;
490 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
491 delta_capt = cur_jiffies - dpcm_capt->last_jiffies;
492 dpcm_capt->last_jiffies += delta_capt;
495 if (delta_play == 0 && delta_capt == 0)
498 if (delta_play > delta_capt) {
499 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
500 bytepos_finish(dpcm_play, count1);
501 delta_play = delta_capt;
502 } else if (delta_play < delta_capt) {
503 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
504 clear_capture_buf(dpcm_capt, count1);
505 bytepos_finish(dpcm_capt, count1);
506 delta_capt = delta_play;
509 if (delta_play == 0 && delta_capt == 0)
512 /* note delta_capt == delta_play at this moment */
513 count1 = bytepos_delta(dpcm_play, delta_play);
514 count2 = bytepos_delta(dpcm_capt, delta_capt);
515 if (count1 < count2) {
516 dpcm_capt->last_drift = count2 - count1;
518 } else if (count1 > count2) {
519 dpcm_play->last_drift = count1 - count2;
521 copy_play_buf(dpcm_play, dpcm_capt, count1);
522 bytepos_finish(dpcm_play, count1);
523 bytepos_finish(dpcm_capt, count1);
528 static void loopback_timer_function(struct timer_list *t)
530 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
533 spin_lock_irqsave(&dpcm->cable->lock, flags);
534 if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
535 loopback_timer_start(dpcm);
536 if (dpcm->period_update_pending) {
537 dpcm->period_update_pending = 0;
538 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
539 /* need to unlock before calling below */
540 snd_pcm_period_elapsed(dpcm->substream);
544 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
547 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
549 struct snd_pcm_runtime *runtime = substream->runtime;
550 struct loopback_pcm *dpcm = runtime->private_data;
551 snd_pcm_uframes_t pos;
553 spin_lock(&dpcm->cable->lock);
554 loopback_pos_update(dpcm->cable);
556 spin_unlock(&dpcm->cable->lock);
557 return bytes_to_frames(runtime, pos);
560 static const struct snd_pcm_hardware loopback_pcm_hardware =
562 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
563 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
564 SNDRV_PCM_INFO_RESUME),
565 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
566 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
567 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
568 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
573 .buffer_bytes_max = 2 * 1024 * 1024,
574 .period_bytes_min = 64,
575 /* note check overflow in frac_pos() using pcm_rate_shift before
576 changing period_bytes_max value */
577 .period_bytes_max = 1024 * 1024,
583 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
585 struct loopback_pcm *dpcm = runtime->private_data;
589 static int loopback_hw_params(struct snd_pcm_substream *substream,
590 struct snd_pcm_hw_params *params)
592 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
593 params_buffer_bytes(params));
596 static int loopback_hw_free(struct snd_pcm_substream *substream)
598 struct snd_pcm_runtime *runtime = substream->runtime;
599 struct loopback_pcm *dpcm = runtime->private_data;
600 struct loopback_cable *cable = dpcm->cable;
602 mutex_lock(&dpcm->loopback->cable_lock);
603 cable->valid &= ~(1 << substream->stream);
604 mutex_unlock(&dpcm->loopback->cable_lock);
605 return snd_pcm_lib_free_vmalloc_buffer(substream);
608 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
610 if (!substream->pcm->device)
611 return substream->stream;
613 return !substream->stream;
616 static int rule_format(struct snd_pcm_hw_params *params,
617 struct snd_pcm_hw_rule *rule)
619 struct loopback_pcm *dpcm = rule->private;
620 struct loopback_cable *cable = dpcm->cable;
624 mutex_lock(&dpcm->loopback->cable_lock);
625 m.bits[0] = (u_int32_t)cable->hw.formats;
626 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
627 mutex_unlock(&dpcm->loopback->cable_lock);
628 return snd_mask_refine(hw_param_mask(params, rule->var), &m);
631 static int rule_rate(struct snd_pcm_hw_params *params,
632 struct snd_pcm_hw_rule *rule)
634 struct loopback_pcm *dpcm = rule->private;
635 struct loopback_cable *cable = dpcm->cable;
636 struct snd_interval t;
638 mutex_lock(&dpcm->loopback->cable_lock);
639 t.min = cable->hw.rate_min;
640 t.max = cable->hw.rate_max;
641 mutex_unlock(&dpcm->loopback->cable_lock);
642 t.openmin = t.openmax = 0;
644 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
647 static int rule_channels(struct snd_pcm_hw_params *params,
648 struct snd_pcm_hw_rule *rule)
650 struct loopback_pcm *dpcm = rule->private;
651 struct loopback_cable *cable = dpcm->cable;
652 struct snd_interval t;
654 mutex_lock(&dpcm->loopback->cable_lock);
655 t.min = cable->hw.channels_min;
656 t.max = cable->hw.channels_max;
657 mutex_unlock(&dpcm->loopback->cable_lock);
658 t.openmin = t.openmax = 0;
660 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
663 static void free_cable(struct snd_pcm_substream *substream)
665 struct loopback *loopback = substream->private_data;
666 int dev = get_cable_index(substream);
667 struct loopback_cable *cable;
669 cable = loopback->cables[substream->number][dev];
672 if (cable->streams[!substream->stream]) {
673 /* other stream is still alive */
674 spin_lock_irq(&cable->lock);
675 cable->streams[substream->stream] = NULL;
676 spin_unlock_irq(&cable->lock);
679 loopback->cables[substream->number][dev] = NULL;
684 static int loopback_open(struct snd_pcm_substream *substream)
686 struct snd_pcm_runtime *runtime = substream->runtime;
687 struct loopback *loopback = substream->private_data;
688 struct loopback_pcm *dpcm;
689 struct loopback_cable *cable = NULL;
691 int dev = get_cable_index(substream);
693 mutex_lock(&loopback->cable_lock);
694 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
699 dpcm->loopback = loopback;
700 dpcm->substream = substream;
701 timer_setup(&dpcm->timer, loopback_timer_function, 0);
703 cable = loopback->cables[substream->number][dev];
705 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
710 spin_lock_init(&cable->lock);
711 cable->hw = loopback_pcm_hardware;
712 loopback->cables[substream->number][dev] = cable;
716 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
718 /* use dynamic rules based on actual runtime->hw values */
719 /* note that the default rules created in the PCM midlevel code */
720 /* are cached -> they do not reflect the actual state */
721 err = snd_pcm_hw_rule_add(runtime, 0,
722 SNDRV_PCM_HW_PARAM_FORMAT,
724 SNDRV_PCM_HW_PARAM_FORMAT, -1);
727 err = snd_pcm_hw_rule_add(runtime, 0,
728 SNDRV_PCM_HW_PARAM_RATE,
730 SNDRV_PCM_HW_PARAM_RATE, -1);
733 err = snd_pcm_hw_rule_add(runtime, 0,
734 SNDRV_PCM_HW_PARAM_CHANNELS,
736 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
740 runtime->private_data = dpcm;
741 runtime->private_free = loopback_runtime_free;
742 if (get_notify(dpcm))
743 runtime->hw = loopback_pcm_hardware;
745 runtime->hw = cable->hw;
747 spin_lock_irq(&cable->lock);
748 cable->streams[substream->stream] = dpcm;
749 spin_unlock_irq(&cable->lock);
753 free_cable(substream);
756 mutex_unlock(&loopback->cable_lock);
760 static int loopback_close(struct snd_pcm_substream *substream)
762 struct loopback *loopback = substream->private_data;
763 struct loopback_pcm *dpcm = substream->runtime->private_data;
765 loopback_timer_stop_sync(dpcm);
766 mutex_lock(&loopback->cable_lock);
767 free_cable(substream);
768 mutex_unlock(&loopback->cable_lock);
772 static const struct snd_pcm_ops loopback_pcm_ops = {
773 .open = loopback_open,
774 .close = loopback_close,
775 .ioctl = snd_pcm_lib_ioctl,
776 .hw_params = loopback_hw_params,
777 .hw_free = loopback_hw_free,
778 .prepare = loopback_prepare,
779 .trigger = loopback_trigger,
780 .pointer = loopback_pointer,
781 .page = snd_pcm_lib_get_vmalloc_page,
784 static int loopback_pcm_new(struct loopback *loopback,
785 int device, int substreams)
790 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
791 substreams, substreams, &pcm);
794 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops);
795 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops);
797 pcm->private_data = loopback;
799 strcpy(pcm->name, "Loopback PCM");
801 loopback->pcm[device] = pcm;
805 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
806 struct snd_ctl_elem_info *uinfo)
808 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
810 uinfo->value.integer.min = 80000;
811 uinfo->value.integer.max = 120000;
812 uinfo->value.integer.step = 1;
816 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
817 struct snd_ctl_elem_value *ucontrol)
819 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
821 mutex_lock(&loopback->cable_lock);
822 ucontrol->value.integer.value[0] =
823 loopback->setup[kcontrol->id.subdevice]
824 [kcontrol->id.device].rate_shift;
825 mutex_unlock(&loopback->cable_lock);
829 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
830 struct snd_ctl_elem_value *ucontrol)
832 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
836 val = ucontrol->value.integer.value[0];
841 mutex_lock(&loopback->cable_lock);
842 if (val != loopback->setup[kcontrol->id.subdevice]
843 [kcontrol->id.device].rate_shift) {
844 loopback->setup[kcontrol->id.subdevice]
845 [kcontrol->id.device].rate_shift = val;
848 mutex_unlock(&loopback->cable_lock);
852 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
853 struct snd_ctl_elem_value *ucontrol)
855 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
857 mutex_lock(&loopback->cable_lock);
858 ucontrol->value.integer.value[0] =
859 loopback->setup[kcontrol->id.subdevice]
860 [kcontrol->id.device].notify;
861 mutex_unlock(&loopback->cable_lock);
865 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
866 struct snd_ctl_elem_value *ucontrol)
868 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
872 val = ucontrol->value.integer.value[0] ? 1 : 0;
873 mutex_lock(&loopback->cable_lock);
874 if (val != loopback->setup[kcontrol->id.subdevice]
875 [kcontrol->id.device].notify) {
876 loopback->setup[kcontrol->id.subdevice]
877 [kcontrol->id.device].notify = val;
880 mutex_unlock(&loopback->cable_lock);
884 static int loopback_active_get(struct snd_kcontrol *kcontrol,
885 struct snd_ctl_elem_value *ucontrol)
887 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
888 struct loopback_cable *cable;
890 unsigned int val = 0;
892 mutex_lock(&loopback->cable_lock);
893 cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
895 unsigned int running = cable->running ^ cable->pause;
897 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
899 mutex_unlock(&loopback->cable_lock);
900 ucontrol->value.integer.value[0] = val;
904 static int loopback_format_info(struct snd_kcontrol *kcontrol,
905 struct snd_ctl_elem_info *uinfo)
907 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
909 uinfo->value.integer.min = 0;
910 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
911 uinfo->value.integer.step = 1;
915 static int loopback_format_get(struct snd_kcontrol *kcontrol,
916 struct snd_ctl_elem_value *ucontrol)
918 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
920 ucontrol->value.integer.value[0] =
921 loopback->setup[kcontrol->id.subdevice]
922 [kcontrol->id.device].format;
926 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
927 struct snd_ctl_elem_info *uinfo)
929 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
931 uinfo->value.integer.min = 0;
932 uinfo->value.integer.max = 192000;
933 uinfo->value.integer.step = 1;
937 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
938 struct snd_ctl_elem_value *ucontrol)
940 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
942 mutex_lock(&loopback->cable_lock);
943 ucontrol->value.integer.value[0] =
944 loopback->setup[kcontrol->id.subdevice]
945 [kcontrol->id.device].rate;
946 mutex_unlock(&loopback->cable_lock);
950 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
951 struct snd_ctl_elem_info *uinfo)
953 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
955 uinfo->value.integer.min = 1;
956 uinfo->value.integer.max = 1024;
957 uinfo->value.integer.step = 1;
961 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
962 struct snd_ctl_elem_value *ucontrol)
964 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
966 mutex_lock(&loopback->cable_lock);
967 ucontrol->value.integer.value[0] =
968 loopback->setup[kcontrol->id.subdevice]
969 [kcontrol->id.device].channels;
970 mutex_unlock(&loopback->cable_lock);
974 static struct snd_kcontrol_new loopback_controls[] = {
976 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
977 .name = "PCM Rate Shift 100000",
978 .info = loopback_rate_shift_info,
979 .get = loopback_rate_shift_get,
980 .put = loopback_rate_shift_put,
983 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
984 .name = "PCM Notify",
985 .info = snd_ctl_boolean_mono_info,
986 .get = loopback_notify_get,
987 .put = loopback_notify_put,
991 .access = SNDRV_CTL_ELEM_ACCESS_READ,
992 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
993 .name = "PCM Slave Active",
994 .info = snd_ctl_boolean_mono_info,
995 .get = loopback_active_get,
999 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1000 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1001 .name = "PCM Slave Format",
1002 .info = loopback_format_info,
1003 .get = loopback_format_get
1007 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1008 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1009 .name = "PCM Slave Rate",
1010 .info = loopback_rate_info,
1011 .get = loopback_rate_get
1013 #define CHANNELS_IDX 5
1015 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1016 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1017 .name = "PCM Slave Channels",
1018 .info = loopback_channels_info,
1019 .get = loopback_channels_get
1023 static int loopback_mixer_new(struct loopback *loopback, int notify)
1025 struct snd_card *card = loopback->card;
1026 struct snd_pcm *pcm;
1027 struct snd_kcontrol *kctl;
1028 struct loopback_setup *setup;
1029 int err, dev, substr, substr_count, idx;
1031 strcpy(card->mixername, "Loopback Mixer");
1032 for (dev = 0; dev < 2; dev++) {
1033 pcm = loopback->pcm[dev];
1035 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1036 for (substr = 0; substr < substr_count; substr++) {
1037 setup = &loopback->setup[substr][dev];
1038 setup->notify = notify;
1039 setup->rate_shift = NO_PITCH;
1040 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1041 setup->rate = 48000;
1042 setup->channels = 2;
1043 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1045 kctl = snd_ctl_new1(&loopback_controls[idx],
1049 kctl->id.device = dev;
1050 kctl->id.subdevice = substr;
1052 /* Add the control before copying the id so that
1053 * the numid field of the id is set in the copy.
1055 err = snd_ctl_add(card, kctl);
1061 setup->active_id = kctl->id;
1064 setup->format_id = kctl->id;
1067 setup->rate_id = kctl->id;
1070 setup->channels_id = kctl->id;
1081 static void print_dpcm_info(struct snd_info_buffer *buffer,
1082 struct loopback_pcm *dpcm,
1085 snd_iprintf(buffer, " %s\n", id);
1087 snd_iprintf(buffer, " inactive\n");
1090 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1091 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1092 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1093 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1094 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1095 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1096 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1097 snd_iprintf(buffer, " update_pending:\t%u\n",
1098 dpcm->period_update_pending);
1099 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1100 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1101 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1102 dpcm->last_jiffies, jiffies);
1103 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1106 static void print_substream_info(struct snd_info_buffer *buffer,
1107 struct loopback *loopback,
1111 struct loopback_cable *cable = loopback->cables[sub][num];
1113 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1114 if (cable == NULL) {
1115 snd_iprintf(buffer, " inactive\n");
1118 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1119 snd_iprintf(buffer, " running: %u\n", cable->running);
1120 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1121 print_dpcm_info(buffer, cable->streams[0], "Playback");
1122 print_dpcm_info(buffer, cable->streams[1], "Capture");
1125 static void print_cable_info(struct snd_info_entry *entry,
1126 struct snd_info_buffer *buffer)
1128 struct loopback *loopback = entry->private_data;
1131 mutex_lock(&loopback->cable_lock);
1132 num = entry->name[strlen(entry->name)-1];
1133 num = num == '0' ? 0 : 1;
1134 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1135 print_substream_info(buffer, loopback, sub, num);
1136 mutex_unlock(&loopback->cable_lock);
1139 static int loopback_proc_new(struct loopback *loopback, int cidx)
1142 struct snd_info_entry *entry;
1145 snprintf(name, sizeof(name), "cable#%d", cidx);
1146 err = snd_card_proc_new(loopback->card, name, &entry);
1150 snd_info_set_text_ops(entry, loopback, print_cable_info);
1154 static int loopback_probe(struct platform_device *devptr)
1156 struct snd_card *card;
1157 struct loopback *loopback;
1158 int dev = devptr->id;
1161 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1162 sizeof(struct loopback), &card);
1165 loopback = card->private_data;
1167 if (pcm_substreams[dev] < 1)
1168 pcm_substreams[dev] = 1;
1169 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1170 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1172 loopback->card = card;
1173 mutex_init(&loopback->cable_lock);
1175 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1178 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1181 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1184 loopback_proc_new(loopback, 0);
1185 loopback_proc_new(loopback, 1);
1186 strcpy(card->driver, "Loopback");
1187 strcpy(card->shortname, "Loopback");
1188 sprintf(card->longname, "Loopback %i", dev + 1);
1189 err = snd_card_register(card);
1191 platform_set_drvdata(devptr, card);
1195 snd_card_free(card);
1199 static int loopback_remove(struct platform_device *devptr)
1201 snd_card_free(platform_get_drvdata(devptr));
1205 #ifdef CONFIG_PM_SLEEP
1206 static int loopback_suspend(struct device *pdev)
1208 struct snd_card *card = dev_get_drvdata(pdev);
1209 struct loopback *loopback = card->private_data;
1211 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1213 snd_pcm_suspend_all(loopback->pcm[0]);
1214 snd_pcm_suspend_all(loopback->pcm[1]);
1218 static int loopback_resume(struct device *pdev)
1220 struct snd_card *card = dev_get_drvdata(pdev);
1222 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1226 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1227 #define LOOPBACK_PM_OPS &loopback_pm
1229 #define LOOPBACK_PM_OPS NULL
1232 #define SND_LOOPBACK_DRIVER "snd_aloop"
1234 static struct platform_driver loopback_driver = {
1235 .probe = loopback_probe,
1236 .remove = loopback_remove,
1238 .name = SND_LOOPBACK_DRIVER,
1239 .pm = LOOPBACK_PM_OPS,
1243 static void loopback_unregister_all(void)
1247 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1248 platform_device_unregister(devices[i]);
1249 platform_driver_unregister(&loopback_driver);
1252 static int __init alsa_card_loopback_init(void)
1256 err = platform_driver_register(&loopback_driver);
1262 for (i = 0; i < SNDRV_CARDS; i++) {
1263 struct platform_device *device;
1266 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1270 if (!platform_get_drvdata(device)) {
1271 platform_device_unregister(device);
1274 devices[i] = device;
1279 printk(KERN_ERR "aloop: No loopback enabled\n");
1281 loopback_unregister_all();
1287 static void __exit alsa_card_loopback_exit(void)
1289 loopback_unregister_all();
1292 module_init(alsa_card_loopback_init)
1293 module_exit(alsa_card_loopback_exit)