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_physical_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;
481 unsigned int running, count1, count2;
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;
489 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
490 delta_capt = jiffies - dpcm_capt->last_jiffies;
491 dpcm_capt->last_jiffies += delta_capt;
494 if (delta_play == 0 && delta_capt == 0)
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;
508 if (delta_play == 0 && delta_capt == 0)
511 /* note delta_capt == delta_play at this moment */
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;
517 } else if (count1 > count2) {
518 dpcm_play->last_drift = count1 - count2;
520 copy_play_buf(dpcm_play, dpcm_capt, count1);
521 bytepos_finish(dpcm_play, count1);
522 bytepos_finish(dpcm_capt, count1);
527 static void loopback_timer_function(struct timer_list *t)
529 struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
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 /* need to unlock before calling below */
539 snd_pcm_period_elapsed(dpcm->substream);
543 spin_unlock_irqrestore(&dpcm->cable->lock, flags);
546 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
548 struct snd_pcm_runtime *runtime = substream->runtime;
549 struct loopback_pcm *dpcm = runtime->private_data;
550 snd_pcm_uframes_t pos;
552 spin_lock(&dpcm->cable->lock);
553 loopback_pos_update(dpcm->cable);
555 spin_unlock(&dpcm->cable->lock);
556 return bytes_to_frames(runtime, pos);
559 static const struct snd_pcm_hardware loopback_pcm_hardware =
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_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
566 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |
567 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
568 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
569 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
574 .buffer_bytes_max = 2 * 1024 * 1024,
575 .period_bytes_min = 64,
576 /* note check overflow in frac_pos() using pcm_rate_shift before
577 changing period_bytes_max value */
578 .period_bytes_max = 1024 * 1024,
584 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
586 struct loopback_pcm *dpcm = runtime->private_data;
590 static int loopback_hw_params(struct snd_pcm_substream *substream,
591 struct snd_pcm_hw_params *params)
593 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
594 params_buffer_bytes(params));
597 static int loopback_hw_free(struct snd_pcm_substream *substream)
599 struct snd_pcm_runtime *runtime = substream->runtime;
600 struct loopback_pcm *dpcm = runtime->private_data;
601 struct loopback_cable *cable = dpcm->cable;
603 mutex_lock(&dpcm->loopback->cable_lock);
604 cable->valid &= ~(1 << substream->stream);
605 mutex_unlock(&dpcm->loopback->cable_lock);
606 return snd_pcm_lib_free_vmalloc_buffer(substream);
609 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
611 if (!substream->pcm->device)
612 return substream->stream;
614 return !substream->stream;
617 static int rule_format(struct snd_pcm_hw_params *params,
618 struct snd_pcm_hw_rule *rule)
620 struct loopback_pcm *dpcm = rule->private;
621 struct loopback_cable *cable = dpcm->cable;
625 mutex_lock(&dpcm->loopback->cable_lock);
626 m.bits[0] = (u_int32_t)cable->hw.formats;
627 m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
628 mutex_unlock(&dpcm->loopback->cable_lock);
629 return snd_mask_refine(hw_param_mask(params, rule->var), &m);
632 static int rule_rate(struct snd_pcm_hw_params *params,
633 struct snd_pcm_hw_rule *rule)
635 struct loopback_pcm *dpcm = rule->private;
636 struct loopback_cable *cable = dpcm->cable;
637 struct snd_interval t;
639 mutex_lock(&dpcm->loopback->cable_lock);
640 t.min = cable->hw.rate_min;
641 t.max = cable->hw.rate_max;
642 mutex_unlock(&dpcm->loopback->cable_lock);
643 t.openmin = t.openmax = 0;
645 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
648 static int rule_channels(struct snd_pcm_hw_params *params,
649 struct snd_pcm_hw_rule *rule)
651 struct loopback_pcm *dpcm = rule->private;
652 struct loopback_cable *cable = dpcm->cable;
653 struct snd_interval t;
655 mutex_lock(&dpcm->loopback->cable_lock);
656 t.min = cable->hw.channels_min;
657 t.max = cable->hw.channels_max;
658 mutex_unlock(&dpcm->loopback->cable_lock);
659 t.openmin = t.openmax = 0;
661 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
664 static void free_cable(struct snd_pcm_substream *substream)
666 struct loopback *loopback = substream->private_data;
667 int dev = get_cable_index(substream);
668 struct loopback_cable *cable;
670 cable = loopback->cables[substream->number][dev];
673 if (cable->streams[!substream->stream]) {
674 /* other stream is still alive */
675 spin_lock_irq(&cable->lock);
676 cable->streams[substream->stream] = NULL;
677 spin_unlock_irq(&cable->lock);
680 loopback->cables[substream->number][dev] = NULL;
685 static int loopback_open(struct snd_pcm_substream *substream)
687 struct snd_pcm_runtime *runtime = substream->runtime;
688 struct loopback *loopback = substream->private_data;
689 struct loopback_pcm *dpcm;
690 struct loopback_cable *cable = NULL;
692 int dev = get_cable_index(substream);
694 mutex_lock(&loopback->cable_lock);
695 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
700 dpcm->loopback = loopback;
701 dpcm->substream = substream;
702 timer_setup(&dpcm->timer, loopback_timer_function, 0);
704 cable = loopback->cables[substream->number][dev];
706 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
711 spin_lock_init(&cable->lock);
712 cable->hw = loopback_pcm_hardware;
713 loopback->cables[substream->number][dev] = cable;
717 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
719 /* use dynamic rules based on actual runtime->hw values */
720 /* note that the default rules created in the PCM midlevel code */
721 /* are cached -> they do not reflect the actual state */
722 err = snd_pcm_hw_rule_add(runtime, 0,
723 SNDRV_PCM_HW_PARAM_FORMAT,
725 SNDRV_PCM_HW_PARAM_FORMAT, -1);
728 err = snd_pcm_hw_rule_add(runtime, 0,
729 SNDRV_PCM_HW_PARAM_RATE,
731 SNDRV_PCM_HW_PARAM_RATE, -1);
734 err = snd_pcm_hw_rule_add(runtime, 0,
735 SNDRV_PCM_HW_PARAM_CHANNELS,
737 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
741 runtime->private_data = dpcm;
742 runtime->private_free = loopback_runtime_free;
743 if (get_notify(dpcm))
744 runtime->hw = loopback_pcm_hardware;
746 runtime->hw = cable->hw;
748 spin_lock_irq(&cable->lock);
749 cable->streams[substream->stream] = dpcm;
750 spin_unlock_irq(&cable->lock);
754 free_cable(substream);
757 mutex_unlock(&loopback->cable_lock);
761 static int loopback_close(struct snd_pcm_substream *substream)
763 struct loopback *loopback = substream->private_data;
764 struct loopback_pcm *dpcm = substream->runtime->private_data;
766 loopback_timer_stop_sync(dpcm);
767 mutex_lock(&loopback->cable_lock);
768 free_cable(substream);
769 mutex_unlock(&loopback->cable_lock);
773 static const struct snd_pcm_ops loopback_pcm_ops = {
774 .open = loopback_open,
775 .close = loopback_close,
776 .ioctl = snd_pcm_lib_ioctl,
777 .hw_params = loopback_hw_params,
778 .hw_free = loopback_hw_free,
779 .prepare = loopback_prepare,
780 .trigger = loopback_trigger,
781 .pointer = loopback_pointer,
782 .page = snd_pcm_lib_get_vmalloc_page,
785 static int loopback_pcm_new(struct loopback *loopback,
786 int device, int substreams)
791 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
792 substreams, substreams, &pcm);
795 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops);
796 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops);
798 pcm->private_data = loopback;
800 strcpy(pcm->name, "Loopback PCM");
802 loopback->pcm[device] = pcm;
806 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
807 struct snd_ctl_elem_info *uinfo)
809 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
811 uinfo->value.integer.min = 80000;
812 uinfo->value.integer.max = 120000;
813 uinfo->value.integer.step = 1;
817 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
818 struct snd_ctl_elem_value *ucontrol)
820 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
822 mutex_lock(&loopback->cable_lock);
823 ucontrol->value.integer.value[0] =
824 loopback->setup[kcontrol->id.subdevice]
825 [kcontrol->id.device].rate_shift;
826 mutex_unlock(&loopback->cable_lock);
830 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
831 struct snd_ctl_elem_value *ucontrol)
833 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
837 val = ucontrol->value.integer.value[0];
842 mutex_lock(&loopback->cable_lock);
843 if (val != loopback->setup[kcontrol->id.subdevice]
844 [kcontrol->id.device].rate_shift) {
845 loopback->setup[kcontrol->id.subdevice]
846 [kcontrol->id.device].rate_shift = val;
849 mutex_unlock(&loopback->cable_lock);
853 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
854 struct snd_ctl_elem_value *ucontrol)
856 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
858 mutex_lock(&loopback->cable_lock);
859 ucontrol->value.integer.value[0] =
860 loopback->setup[kcontrol->id.subdevice]
861 [kcontrol->id.device].notify;
862 mutex_unlock(&loopback->cable_lock);
866 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
867 struct snd_ctl_elem_value *ucontrol)
869 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
873 val = ucontrol->value.integer.value[0] ? 1 : 0;
874 mutex_lock(&loopback->cable_lock);
875 if (val != loopback->setup[kcontrol->id.subdevice]
876 [kcontrol->id.device].notify) {
877 loopback->setup[kcontrol->id.subdevice]
878 [kcontrol->id.device].notify = val;
881 mutex_unlock(&loopback->cable_lock);
885 static int loopback_active_get(struct snd_kcontrol *kcontrol,
886 struct snd_ctl_elem_value *ucontrol)
888 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
889 struct loopback_cable *cable;
891 unsigned int val = 0;
893 mutex_lock(&loopback->cable_lock);
894 cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
896 unsigned int running = cable->running ^ cable->pause;
898 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
900 mutex_unlock(&loopback->cable_lock);
901 ucontrol->value.integer.value[0] = val;
905 static int loopback_format_info(struct snd_kcontrol *kcontrol,
906 struct snd_ctl_elem_info *uinfo)
908 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
910 uinfo->value.integer.min = 0;
911 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
912 uinfo->value.integer.step = 1;
916 static int loopback_format_get(struct snd_kcontrol *kcontrol,
917 struct snd_ctl_elem_value *ucontrol)
919 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
921 ucontrol->value.integer.value[0] =
922 loopback->setup[kcontrol->id.subdevice]
923 [kcontrol->id.device].format;
927 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
928 struct snd_ctl_elem_info *uinfo)
930 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
932 uinfo->value.integer.min = 0;
933 uinfo->value.integer.max = 192000;
934 uinfo->value.integer.step = 1;
938 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
939 struct snd_ctl_elem_value *ucontrol)
941 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
943 mutex_lock(&loopback->cable_lock);
944 ucontrol->value.integer.value[0] =
945 loopback->setup[kcontrol->id.subdevice]
946 [kcontrol->id.device].rate;
947 mutex_unlock(&loopback->cable_lock);
951 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
952 struct snd_ctl_elem_info *uinfo)
954 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
956 uinfo->value.integer.min = 1;
957 uinfo->value.integer.max = 1024;
958 uinfo->value.integer.step = 1;
962 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
963 struct snd_ctl_elem_value *ucontrol)
965 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
967 mutex_lock(&loopback->cable_lock);
968 ucontrol->value.integer.value[0] =
969 loopback->setup[kcontrol->id.subdevice]
970 [kcontrol->id.device].channels;
971 mutex_unlock(&loopback->cable_lock);
975 static struct snd_kcontrol_new loopback_controls[] = {
977 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
978 .name = "PCM Rate Shift 100000",
979 .info = loopback_rate_shift_info,
980 .get = loopback_rate_shift_get,
981 .put = loopback_rate_shift_put,
984 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
985 .name = "PCM Notify",
986 .info = snd_ctl_boolean_mono_info,
987 .get = loopback_notify_get,
988 .put = loopback_notify_put,
992 .access = SNDRV_CTL_ELEM_ACCESS_READ,
993 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
994 .name = "PCM Slave Active",
995 .info = snd_ctl_boolean_mono_info,
996 .get = loopback_active_get,
1000 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1001 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1002 .name = "PCM Slave Format",
1003 .info = loopback_format_info,
1004 .get = loopback_format_get
1008 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1009 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1010 .name = "PCM Slave Rate",
1011 .info = loopback_rate_info,
1012 .get = loopback_rate_get
1014 #define CHANNELS_IDX 5
1016 .access = SNDRV_CTL_ELEM_ACCESS_READ,
1017 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
1018 .name = "PCM Slave Channels",
1019 .info = loopback_channels_info,
1020 .get = loopback_channels_get
1024 static int loopback_mixer_new(struct loopback *loopback, int notify)
1026 struct snd_card *card = loopback->card;
1027 struct snd_pcm *pcm;
1028 struct snd_kcontrol *kctl;
1029 struct loopback_setup *setup;
1030 int err, dev, substr, substr_count, idx;
1032 strcpy(card->mixername, "Loopback Mixer");
1033 for (dev = 0; dev < 2; dev++) {
1034 pcm = loopback->pcm[dev];
1036 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1037 for (substr = 0; substr < substr_count; substr++) {
1038 setup = &loopback->setup[substr][dev];
1039 setup->notify = notify;
1040 setup->rate_shift = NO_PITCH;
1041 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1042 setup->rate = 48000;
1043 setup->channels = 2;
1044 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1046 kctl = snd_ctl_new1(&loopback_controls[idx],
1050 kctl->id.device = dev;
1051 kctl->id.subdevice = substr;
1054 setup->active_id = kctl->id;
1057 setup->format_id = kctl->id;
1060 setup->rate_id = kctl->id;
1063 setup->channels_id = kctl->id;
1068 err = snd_ctl_add(card, kctl);
1077 static void print_dpcm_info(struct snd_info_buffer *buffer,
1078 struct loopback_pcm *dpcm,
1081 snd_iprintf(buffer, " %s\n", id);
1083 snd_iprintf(buffer, " inactive\n");
1086 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1087 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1088 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1089 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1090 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1091 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1092 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1093 snd_iprintf(buffer, " update_pending:\t%u\n",
1094 dpcm->period_update_pending);
1095 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1096 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1097 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1098 dpcm->last_jiffies, jiffies);
1099 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1102 static void print_substream_info(struct snd_info_buffer *buffer,
1103 struct loopback *loopback,
1107 struct loopback_cable *cable = loopback->cables[sub][num];
1109 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1110 if (cable == NULL) {
1111 snd_iprintf(buffer, " inactive\n");
1114 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1115 snd_iprintf(buffer, " running: %u\n", cable->running);
1116 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1117 print_dpcm_info(buffer, cable->streams[0], "Playback");
1118 print_dpcm_info(buffer, cable->streams[1], "Capture");
1121 static void print_cable_info(struct snd_info_entry *entry,
1122 struct snd_info_buffer *buffer)
1124 struct loopback *loopback = entry->private_data;
1127 mutex_lock(&loopback->cable_lock);
1128 num = entry->name[strlen(entry->name)-1];
1129 num = num == '0' ? 0 : 1;
1130 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1131 print_substream_info(buffer, loopback, sub, num);
1132 mutex_unlock(&loopback->cable_lock);
1135 static int loopback_proc_new(struct loopback *loopback, int cidx)
1139 snprintf(name, sizeof(name), "cable#%d", cidx);
1140 return snd_card_ro_proc_new(loopback->card, name, loopback,
1144 static int loopback_probe(struct platform_device *devptr)
1146 struct snd_card *card;
1147 struct loopback *loopback;
1148 int dev = devptr->id;
1151 err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1152 sizeof(struct loopback), &card);
1155 loopback = card->private_data;
1157 if (pcm_substreams[dev] < 1)
1158 pcm_substreams[dev] = 1;
1159 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1160 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1162 loopback->card = card;
1163 mutex_init(&loopback->cable_lock);
1165 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1168 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1171 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1174 loopback_proc_new(loopback, 0);
1175 loopback_proc_new(loopback, 1);
1176 strcpy(card->driver, "Loopback");
1177 strcpy(card->shortname, "Loopback");
1178 sprintf(card->longname, "Loopback %i", dev + 1);
1179 err = snd_card_register(card);
1181 platform_set_drvdata(devptr, card);
1185 snd_card_free(card);
1189 static int loopback_remove(struct platform_device *devptr)
1191 snd_card_free(platform_get_drvdata(devptr));
1195 #ifdef CONFIG_PM_SLEEP
1196 static int loopback_suspend(struct device *pdev)
1198 struct snd_card *card = dev_get_drvdata(pdev);
1200 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1204 static int loopback_resume(struct device *pdev)
1206 struct snd_card *card = dev_get_drvdata(pdev);
1208 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1212 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1213 #define LOOPBACK_PM_OPS &loopback_pm
1215 #define LOOPBACK_PM_OPS NULL
1218 #define SND_LOOPBACK_DRIVER "snd_aloop"
1220 static struct platform_driver loopback_driver = {
1221 .probe = loopback_probe,
1222 .remove = loopback_remove,
1224 .name = SND_LOOPBACK_DRIVER,
1225 .pm = LOOPBACK_PM_OPS,
1229 static void loopback_unregister_all(void)
1233 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1234 platform_device_unregister(devices[i]);
1235 platform_driver_unregister(&loopback_driver);
1238 static int __init alsa_card_loopback_init(void)
1242 err = platform_driver_register(&loopback_driver);
1248 for (i = 0; i < SNDRV_CARDS; i++) {
1249 struct platform_device *device;
1252 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1256 if (!platform_get_drvdata(device)) {
1257 platform_device_unregister(device);
1260 devices[i] = device;
1265 printk(KERN_ERR "aloop: No loopback enabled\n");
1267 loopback_unregister_all();
1273 static void __exit alsa_card_loopback_exit(void)
1275 loopback_unregister_all();
1278 module_init(alsa_card_loopback_init)
1279 module_exit(alsa_card_loopback_exit)