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/info.h>
43 #include <sound/initval.h>
45 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
46 MODULE_DESCRIPTION("A loopback soundcard");
47 MODULE_LICENSE("GPL");
48 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
50 #define MAX_PCM_SUBSTREAMS 8
52 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
53 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
54 static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
55 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
56 static int pcm_notify[SNDRV_CARDS];
58 module_param_array(index, int, NULL, 0444);
59 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
60 module_param_array(id, charp, NULL, 0444);
61 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
62 module_param_array(enable, bool, NULL, 0444);
63 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
64 module_param_array(pcm_substreams, int, NULL, 0444);
65 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
66 module_param_array(pcm_notify, int, NULL, 0444);
67 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
69 #define NO_PITCH 100000
73 struct loopback_cable {
75 struct loopback_pcm *streams[2];
76 struct snd_pcm_hardware hw;
83 struct loopback_setup {
84 unsigned int notify: 1;
85 unsigned int rate_shift;
88 unsigned int channels;
89 struct snd_ctl_elem_id active_id;
90 struct snd_ctl_elem_id format_id;
91 struct snd_ctl_elem_id rate_id;
92 struct snd_ctl_elem_id channels_id;
96 struct snd_card *card;
97 struct mutex cable_lock;
98 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
99 struct snd_pcm *pcm[2];
100 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
103 struct loopback_pcm {
104 struct loopback *loopback;
105 struct snd_pcm_substream *substream;
106 struct loopback_cable *cable;
107 unsigned int pcm_buffer_size;
108 unsigned int buf_pos; /* position in buffer */
109 unsigned int silent_size;
111 unsigned int pcm_period_size;
112 unsigned int pcm_bps; /* bytes per second */
113 unsigned int pcm_salign; /* bytes per sample * channels */
114 unsigned int pcm_rate_shift; /* rate shift value */
116 unsigned int period_update_pending :1;
118 unsigned int irq_pos; /* fractional IRQ position */
119 unsigned int period_size_frac;
120 unsigned long last_jiffies;
121 struct timer_list timer;
122 spinlock_t timer_lock;
125 static struct platform_device *devices[SNDRV_CARDS];
127 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
129 if (dpcm->pcm_rate_shift == NO_PITCH) {
132 x = div_u64(NO_PITCH * (unsigned long long)x,
133 HZ * (unsigned long long)dpcm->pcm_rate_shift);
135 return x - (x % dpcm->pcm_salign);
138 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
140 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
143 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
149 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
151 int device = dpcm->substream->pstr->pcm->device;
153 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
155 return &dpcm->loopback->setup[dpcm->substream->number][device];
158 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
160 return get_setup(dpcm)->notify;
163 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
165 return get_setup(dpcm)->rate_shift;
168 static void loopback_timer_start(struct loopback_pcm *dpcm)
171 unsigned int rate_shift = get_rate_shift(dpcm);
173 spin_lock(&dpcm->timer_lock);
174 if (rate_shift != dpcm->pcm_rate_shift) {
175 dpcm->pcm_rate_shift = rate_shift;
176 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
178 if (dpcm->period_size_frac <= dpcm->irq_pos) {
179 dpcm->irq_pos %= dpcm->period_size_frac;
180 dpcm->period_update_pending = 1;
182 tick = dpcm->period_size_frac - dpcm->irq_pos;
183 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
184 dpcm->timer.expires = jiffies + tick;
185 add_timer(&dpcm->timer);
186 spin_unlock(&dpcm->timer_lock);
189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
191 spin_lock(&dpcm->timer_lock);
192 del_timer(&dpcm->timer);
193 dpcm->timer.expires = 0;
194 spin_unlock(&dpcm->timer_lock);
197 #define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
198 #define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
199 #define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
201 static int loopback_check_format(struct loopback_cable *cable, int stream)
203 struct snd_pcm_runtime *runtime, *cruntime;
204 struct loopback_setup *setup;
205 struct snd_card *card;
208 if (cable->valid != CABLE_VALID_BOTH) {
209 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
213 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
215 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
217 check = runtime->format != cruntime->format ||
218 runtime->rate != cruntime->rate ||
219 runtime->channels != cruntime->channels;
222 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
225 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
226 substream, SNDRV_PCM_STATE_DRAINING);
228 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
230 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
231 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
232 if (setup->format != runtime->format) {
233 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
235 setup->format = runtime->format;
237 if (setup->rate != runtime->rate) {
238 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
240 setup->rate = runtime->rate;
242 if (setup->channels != runtime->channels) {
243 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
244 &setup->channels_id);
245 setup->channels = runtime->channels;
251 static void loopback_active_notify(struct loopback_pcm *dpcm)
253 snd_ctl_notify(dpcm->loopback->card,
254 SNDRV_CTL_EVENT_MASK_VALUE,
255 &get_setup(dpcm)->active_id);
258 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
260 struct snd_pcm_runtime *runtime = substream->runtime;
261 struct loopback_pcm *dpcm = runtime->private_data;
262 struct loopback_cable *cable = dpcm->cable;
263 int err, stream = 1 << substream->stream;
266 case SNDRV_PCM_TRIGGER_START:
267 err = loopback_check_format(cable, substream->stream);
270 dpcm->last_jiffies = jiffies;
271 dpcm->pcm_rate_shift = 0;
272 spin_lock(&cable->lock);
273 cable->running |= stream;
274 cable->pause &= ~stream;
275 spin_unlock(&cable->lock);
276 loopback_timer_start(dpcm);
277 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
278 loopback_active_notify(dpcm);
280 case SNDRV_PCM_TRIGGER_STOP:
281 spin_lock(&cable->lock);
282 cable->running &= ~stream;
283 cable->pause &= ~stream;
284 spin_unlock(&cable->lock);
285 loopback_timer_stop(dpcm);
286 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
287 loopback_active_notify(dpcm);
289 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
290 case SNDRV_PCM_TRIGGER_SUSPEND:
291 spin_lock(&cable->lock);
292 cable->pause |= stream;
293 spin_unlock(&cable->lock);
294 loopback_timer_stop(dpcm);
296 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
297 case SNDRV_PCM_TRIGGER_RESUME:
298 spin_lock(&cable->lock);
299 dpcm->last_jiffies = jiffies;
300 cable->pause &= ~stream;
301 spin_unlock(&cable->lock);
302 loopback_timer_start(dpcm);
310 static void params_change_substream(struct loopback_pcm *dpcm,
311 struct snd_pcm_runtime *runtime)
313 struct snd_pcm_runtime *dst_runtime;
315 if (dpcm == NULL || dpcm->substream == NULL)
317 dst_runtime = dpcm->substream->runtime;
318 if (dst_runtime == NULL)
320 dst_runtime->hw = dpcm->cable->hw;
323 static void params_change(struct snd_pcm_substream *substream)
325 struct snd_pcm_runtime *runtime = substream->runtime;
326 struct loopback_pcm *dpcm = runtime->private_data;
327 struct loopback_cable *cable = dpcm->cable;
329 cable->hw.formats = (1ULL << runtime->format);
330 cable->hw.rate_min = runtime->rate;
331 cable->hw.rate_max = runtime->rate;
332 cable->hw.channels_min = runtime->channels;
333 cable->hw.channels_max = runtime->channels;
334 params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
336 params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
340 static int loopback_prepare(struct snd_pcm_substream *substream)
342 struct snd_pcm_runtime *runtime = substream->runtime;
343 struct loopback_pcm *dpcm = runtime->private_data;
344 struct loopback_cable *cable = dpcm->cable;
347 salign = (snd_pcm_format_width(runtime->format) *
348 runtime->channels) / 8;
349 bps = salign * runtime->rate;
350 if (bps <= 0 || salign <= 0)
354 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
355 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
356 /* clear capture buffer */
357 dpcm->silent_size = dpcm->pcm_buffer_size;
358 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
359 runtime->buffer_size * runtime->channels);
363 dpcm->period_update_pending = 0;
365 dpcm->pcm_salign = salign;
366 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
368 mutex_lock(&dpcm->loopback->cable_lock);
369 if (!(cable->valid & ~(1 << substream->stream)) ||
370 (get_setup(dpcm)->notify &&
371 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
372 params_change(substream);
373 cable->valid |= 1 << substream->stream;
374 mutex_unlock(&dpcm->loopback->cable_lock);
379 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
381 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
382 char *dst = runtime->dma_area;
383 unsigned int dst_off = dpcm->buf_pos;
385 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
387 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
388 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
391 unsigned int size = bytes;
392 if (dst_off + size > dpcm->pcm_buffer_size)
393 size = dpcm->pcm_buffer_size - dst_off;
394 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
395 bytes_to_frames(runtime, size) *
397 dpcm->silent_size += size;
405 static void copy_play_buf(struct loopback_pcm *play,
406 struct loopback_pcm *capt,
409 struct snd_pcm_runtime *runtime = play->substream->runtime;
410 char *src = runtime->dma_area;
411 char *dst = capt->substream->runtime->dma_area;
412 unsigned int src_off = play->buf_pos;
413 unsigned int dst_off = capt->buf_pos;
414 unsigned int clear_bytes = 0;
416 /* check if playback is draining, trim the capture copy size
417 * when our pointer is at the end of playback ring buffer */
418 if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
419 snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
420 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
421 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
422 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
423 appl_ptr1 += play->buf_pos / play->pcm_salign;
424 if (appl_ptr < appl_ptr1)
425 appl_ptr1 -= runtime->buffer_size;
426 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
428 clear_bytes = bytes - diff;
434 unsigned int size = bytes;
435 if (src_off + size > play->pcm_buffer_size)
436 size = play->pcm_buffer_size - src_off;
437 if (dst_off + size > capt->pcm_buffer_size)
438 size = capt->pcm_buffer_size - dst_off;
439 memcpy(dst + dst_off, src + src_off, size);
440 capt->silent_size = 0;
444 src_off = (src_off + size) % play->pcm_buffer_size;
445 dst_off = (dst_off + size) % capt->pcm_buffer_size;
448 if (clear_bytes > 0) {
449 clear_capture_buf(capt, clear_bytes);
450 capt->silent_size = 0;
454 #define BYTEPOS_UPDATE_POSONLY 0
455 #define BYTEPOS_UPDATE_CLEAR 1
456 #define BYTEPOS_UPDATE_COPY 2
458 static void loopback_bytepos_update(struct loopback_pcm *dpcm,
463 unsigned long last_pos;
465 last_pos = byte_pos(dpcm, dpcm->irq_pos);
466 dpcm->irq_pos += delta * dpcm->pcm_bps;
467 count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
470 if (cmd == BYTEPOS_UPDATE_CLEAR)
471 clear_capture_buf(dpcm, count);
472 else if (cmd == BYTEPOS_UPDATE_COPY)
473 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
474 dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
476 dpcm->buf_pos += count;
477 dpcm->buf_pos %= dpcm->pcm_buffer_size;
478 if (dpcm->irq_pos >= dpcm->period_size_frac) {
479 dpcm->irq_pos %= dpcm->period_size_frac;
480 dpcm->period_update_pending = 1;
484 static unsigned int loopback_pos_update(struct loopback_cable *cable)
486 struct loopback_pcm *dpcm_play =
487 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
488 struct loopback_pcm *dpcm_capt =
489 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
490 unsigned long delta_play = 0, delta_capt = 0;
491 unsigned int running;
494 spin_lock_irqsave(&cable->lock, flags);
495 running = cable->running ^ cable->pause;
496 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
497 delta_play = jiffies - dpcm_play->last_jiffies;
498 dpcm_play->last_jiffies += delta_play;
501 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
502 delta_capt = jiffies - dpcm_capt->last_jiffies;
503 dpcm_capt->last_jiffies += delta_capt;
506 if (delta_play == 0 && delta_capt == 0)
509 if (delta_play > delta_capt) {
510 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
511 BYTEPOS_UPDATE_POSONLY);
512 delta_play = delta_capt;
513 } else if (delta_play < delta_capt) {
514 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
515 BYTEPOS_UPDATE_CLEAR);
516 delta_capt = delta_play;
519 if (delta_play == 0 && delta_capt == 0)
522 /* note delta_capt == delta_play at this moment */
523 loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
524 loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
526 spin_unlock_irqrestore(&cable->lock, flags);
530 static void loopback_timer_function(unsigned long data)
532 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
533 unsigned int running;
535 running = loopback_pos_update(dpcm->cable);
536 if (running & (1 << dpcm->substream->stream)) {
537 loopback_timer_start(dpcm);
538 if (dpcm->period_update_pending) {
539 dpcm->period_update_pending = 0;
540 snd_pcm_period_elapsed(dpcm->substream);
545 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
547 struct snd_pcm_runtime *runtime = substream->runtime;
548 struct loopback_pcm *dpcm = runtime->private_data;
550 loopback_pos_update(dpcm->cable);
551 return bytes_to_frames(runtime, dpcm->buf_pos);
554 static struct snd_pcm_hardware loopback_pcm_hardware =
556 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
557 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
558 SNDRV_PCM_INFO_RESUME),
559 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
560 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
561 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
562 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
567 .buffer_bytes_max = 2 * 1024 * 1024,
568 .period_bytes_min = 64,
569 /* note check overflow in frac_pos() using pcm_rate_shift before
570 changing period_bytes_max value */
571 .period_bytes_max = 1024 * 1024,
577 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
579 struct loopback_pcm *dpcm = runtime->private_data;
583 static int loopback_hw_params(struct snd_pcm_substream *substream,
584 struct snd_pcm_hw_params *params)
586 return snd_pcm_lib_alloc_vmalloc_buffer(substream,
587 params_buffer_bytes(params));
590 static int loopback_hw_free(struct snd_pcm_substream *substream)
592 struct snd_pcm_runtime *runtime = substream->runtime;
593 struct loopback_pcm *dpcm = runtime->private_data;
594 struct loopback_cable *cable = dpcm->cable;
596 mutex_lock(&dpcm->loopback->cable_lock);
597 cable->valid &= ~(1 << substream->stream);
598 mutex_unlock(&dpcm->loopback->cable_lock);
599 return snd_pcm_lib_free_vmalloc_buffer(substream);
602 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
604 if (!substream->pcm->device)
605 return substream->stream;
607 return !substream->stream;
610 static int rule_format(struct snd_pcm_hw_params *params,
611 struct snd_pcm_hw_rule *rule)
614 struct snd_pcm_hardware *hw = rule->private;
615 struct snd_mask *maskp = hw_param_mask(params, rule->var);
617 maskp->bits[0] &= (u_int32_t)hw->formats;
618 maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
619 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
620 if (! maskp->bits[0] && ! maskp->bits[1])
625 static int rule_rate(struct snd_pcm_hw_params *params,
626 struct snd_pcm_hw_rule *rule)
628 struct snd_pcm_hardware *hw = rule->private;
629 struct snd_interval t;
631 t.min = hw->rate_min;
632 t.max = hw->rate_max;
633 t.openmin = t.openmax = 0;
635 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
638 static int rule_channels(struct snd_pcm_hw_params *params,
639 struct snd_pcm_hw_rule *rule)
641 struct snd_pcm_hardware *hw = rule->private;
642 struct snd_interval t;
644 t.min = hw->channels_min;
645 t.max = hw->channels_max;
646 t.openmin = t.openmax = 0;
648 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
651 static int loopback_open(struct snd_pcm_substream *substream)
653 struct snd_pcm_runtime *runtime = substream->runtime;
654 struct loopback *loopback = substream->private_data;
655 struct loopback_pcm *dpcm;
656 struct loopback_cable *cable;
658 int dev = get_cable_index(substream);
660 mutex_lock(&loopback->cable_lock);
661 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
666 dpcm->loopback = loopback;
667 dpcm->substream = substream;
668 setup_timer(&dpcm->timer, loopback_timer_function,
669 (unsigned long)dpcm);
670 spin_lock_init(&dpcm->timer_lock);
672 cable = loopback->cables[substream->number][dev];
674 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
680 spin_lock_init(&cable->lock);
681 cable->hw = loopback_pcm_hardware;
682 loopback->cables[substream->number][dev] = cable;
685 cable->streams[substream->stream] = dpcm;
687 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
689 /* use dynamic rules based on actual runtime->hw values */
690 /* note that the default rules created in the PCM midlevel code */
691 /* are cached -> they do not reflect the actual state */
692 err = snd_pcm_hw_rule_add(runtime, 0,
693 SNDRV_PCM_HW_PARAM_FORMAT,
694 rule_format, &runtime->hw,
695 SNDRV_PCM_HW_PARAM_FORMAT, -1);
698 err = snd_pcm_hw_rule_add(runtime, 0,
699 SNDRV_PCM_HW_PARAM_RATE,
700 rule_rate, &runtime->hw,
701 SNDRV_PCM_HW_PARAM_RATE, -1);
704 err = snd_pcm_hw_rule_add(runtime, 0,
705 SNDRV_PCM_HW_PARAM_CHANNELS,
706 rule_channels, &runtime->hw,
707 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
711 runtime->private_data = dpcm;
712 runtime->private_free = loopback_runtime_free;
713 if (get_notify(dpcm))
714 runtime->hw = loopback_pcm_hardware;
716 runtime->hw = cable->hw;
718 mutex_unlock(&loopback->cable_lock);
722 static int loopback_close(struct snd_pcm_substream *substream)
724 struct loopback *loopback = substream->private_data;
725 struct loopback_pcm *dpcm = substream->runtime->private_data;
726 struct loopback_cable *cable;
727 int dev = get_cable_index(substream);
729 loopback_timer_stop(dpcm);
730 mutex_lock(&loopback->cable_lock);
731 cable = loopback->cables[substream->number][dev];
732 if (cable->streams[!substream->stream]) {
733 /* other stream is still alive */
734 cable->streams[substream->stream] = NULL;
737 loopback->cables[substream->number][dev] = NULL;
740 mutex_unlock(&loopback->cable_lock);
744 static struct snd_pcm_ops loopback_playback_ops = {
745 .open = loopback_open,
746 .close = loopback_close,
747 .ioctl = snd_pcm_lib_ioctl,
748 .hw_params = loopback_hw_params,
749 .hw_free = loopback_hw_free,
750 .prepare = loopback_prepare,
751 .trigger = loopback_trigger,
752 .pointer = loopback_pointer,
753 .page = snd_pcm_lib_get_vmalloc_page,
754 .mmap = snd_pcm_lib_mmap_vmalloc,
757 static struct snd_pcm_ops loopback_capture_ops = {
758 .open = loopback_open,
759 .close = loopback_close,
760 .ioctl = snd_pcm_lib_ioctl,
761 .hw_params = loopback_hw_params,
762 .hw_free = loopback_hw_free,
763 .prepare = loopback_prepare,
764 .trigger = loopback_trigger,
765 .pointer = loopback_pointer,
766 .page = snd_pcm_lib_get_vmalloc_page,
767 .mmap = snd_pcm_lib_mmap_vmalloc,
770 static int __devinit loopback_pcm_new(struct loopback *loopback,
771 int device, int substreams)
776 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
777 substreams, substreams, &pcm);
780 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
781 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
783 pcm->private_data = loopback;
785 strcpy(pcm->name, "Loopback PCM");
787 loopback->pcm[device] = pcm;
791 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
792 struct snd_ctl_elem_info *uinfo)
794 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
796 uinfo->value.integer.min = 80000;
797 uinfo->value.integer.max = 120000;
798 uinfo->value.integer.step = 1;
802 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
803 struct snd_ctl_elem_value *ucontrol)
805 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
807 ucontrol->value.integer.value[0] =
808 loopback->setup[kcontrol->id.subdevice]
809 [kcontrol->id.device].rate_shift;
813 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
814 struct snd_ctl_elem_value *ucontrol)
816 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
820 val = ucontrol->value.integer.value[0];
825 mutex_lock(&loopback->cable_lock);
826 if (val != loopback->setup[kcontrol->id.subdevice]
827 [kcontrol->id.device].rate_shift) {
828 loopback->setup[kcontrol->id.subdevice]
829 [kcontrol->id.device].rate_shift = val;
832 mutex_unlock(&loopback->cable_lock);
836 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
837 struct snd_ctl_elem_value *ucontrol)
839 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
841 ucontrol->value.integer.value[0] =
842 loopback->setup[kcontrol->id.subdevice]
843 [kcontrol->id.device].notify;
847 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
848 struct snd_ctl_elem_value *ucontrol)
850 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
854 val = ucontrol->value.integer.value[0] ? 1 : 0;
855 if (val != loopback->setup[kcontrol->id.subdevice]
856 [kcontrol->id.device].notify) {
857 loopback->setup[kcontrol->id.subdevice]
858 [kcontrol->id.device].notify = val;
864 static int loopback_active_get(struct snd_kcontrol *kcontrol,
865 struct snd_ctl_elem_value *ucontrol)
867 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
868 struct loopback_cable *cable = loopback->cables
869 [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
870 unsigned int val = 0;
873 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
875 ucontrol->value.integer.value[0] = val;
879 static int loopback_format_info(struct snd_kcontrol *kcontrol,
880 struct snd_ctl_elem_info *uinfo)
882 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
884 uinfo->value.integer.min = 0;
885 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
886 uinfo->value.integer.step = 1;
890 static int loopback_format_get(struct snd_kcontrol *kcontrol,
891 struct snd_ctl_elem_value *ucontrol)
893 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
895 ucontrol->value.integer.value[0] =
896 loopback->setup[kcontrol->id.subdevice]
897 [kcontrol->id.device].format;
901 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
902 struct snd_ctl_elem_info *uinfo)
904 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
906 uinfo->value.integer.min = 0;
907 uinfo->value.integer.max = 192000;
908 uinfo->value.integer.step = 1;
912 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
913 struct snd_ctl_elem_value *ucontrol)
915 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
917 ucontrol->value.integer.value[0] =
918 loopback->setup[kcontrol->id.subdevice]
919 [kcontrol->id.device].rate;
923 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
924 struct snd_ctl_elem_info *uinfo)
926 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
928 uinfo->value.integer.min = 1;
929 uinfo->value.integer.max = 1024;
930 uinfo->value.integer.step = 1;
934 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
935 struct snd_ctl_elem_value *ucontrol)
937 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
939 ucontrol->value.integer.value[0] =
940 loopback->setup[kcontrol->id.subdevice]
941 [kcontrol->id.device].channels;
945 static struct snd_kcontrol_new loopback_controls[] __devinitdata = {
947 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
948 .name = "PCM Rate Shift 100000",
949 .info = loopback_rate_shift_info,
950 .get = loopback_rate_shift_get,
951 .put = loopback_rate_shift_put,
954 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
955 .name = "PCM Notify",
956 .info = snd_ctl_boolean_mono_info,
957 .get = loopback_notify_get,
958 .put = loopback_notify_put,
962 .access = SNDRV_CTL_ELEM_ACCESS_READ,
963 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
964 .name = "PCM Slave Active",
965 .info = snd_ctl_boolean_mono_info,
966 .get = loopback_active_get,
970 .access = SNDRV_CTL_ELEM_ACCESS_READ,
971 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
972 .name = "PCM Slave Format",
973 .info = loopback_format_info,
974 .get = loopback_format_get
978 .access = SNDRV_CTL_ELEM_ACCESS_READ,
979 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
980 .name = "PCM Slave Rate",
981 .info = loopback_rate_info,
982 .get = loopback_rate_get
984 #define CHANNELS_IDX 5
986 .access = SNDRV_CTL_ELEM_ACCESS_READ,
987 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
988 .name = "PCM Slave Channels",
989 .info = loopback_channels_info,
990 .get = loopback_channels_get
994 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
996 struct snd_card *card = loopback->card;
998 struct snd_kcontrol *kctl;
999 struct loopback_setup *setup;
1000 int err, dev, substr, substr_count, idx;
1002 strcpy(card->mixername, "Loopback Mixer");
1003 for (dev = 0; dev < 2; dev++) {
1004 pcm = loopback->pcm[dev];
1006 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1007 for (substr = 0; substr < substr_count; substr++) {
1008 setup = &loopback->setup[substr][dev];
1009 setup->notify = notify;
1010 setup->rate_shift = NO_PITCH;
1011 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1012 setup->rate = 48000;
1013 setup->channels = 2;
1014 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1016 kctl = snd_ctl_new1(&loopback_controls[idx],
1020 kctl->id.device = dev;
1021 kctl->id.subdevice = substr;
1024 setup->active_id = kctl->id;
1027 setup->format_id = kctl->id;
1030 setup->rate_id = kctl->id;
1033 setup->channels_id = kctl->id;
1038 err = snd_ctl_add(card, kctl);
1047 #ifdef CONFIG_PROC_FS
1049 static void print_dpcm_info(struct snd_info_buffer *buffer,
1050 struct loopback_pcm *dpcm,
1053 snd_iprintf(buffer, " %s\n", id);
1055 snd_iprintf(buffer, " inactive\n");
1058 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1059 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1060 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1061 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1062 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1063 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1064 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1065 snd_iprintf(buffer, " update_pending:\t%u\n",
1066 dpcm->period_update_pending);
1067 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1068 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1069 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1070 dpcm->last_jiffies, jiffies);
1071 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1074 static void print_substream_info(struct snd_info_buffer *buffer,
1075 struct loopback *loopback,
1079 struct loopback_cable *cable = loopback->cables[sub][num];
1081 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1082 if (cable == NULL) {
1083 snd_iprintf(buffer, " inactive\n");
1086 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1087 snd_iprintf(buffer, " running: %u\n", cable->running);
1088 snd_iprintf(buffer, " pause: %u\n", cable->pause);
1089 print_dpcm_info(buffer, cable->streams[0], "Playback");
1090 print_dpcm_info(buffer, cable->streams[1], "Capture");
1093 static void print_cable_info(struct snd_info_entry *entry,
1094 struct snd_info_buffer *buffer)
1096 struct loopback *loopback = entry->private_data;
1099 mutex_lock(&loopback->cable_lock);
1100 num = entry->name[strlen(entry->name)-1];
1101 num = num == '0' ? 0 : 1;
1102 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1103 print_substream_info(buffer, loopback, sub, num);
1104 mutex_unlock(&loopback->cable_lock);
1107 static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1110 struct snd_info_entry *entry;
1113 snprintf(name, sizeof(name), "cable#%d", cidx);
1114 err = snd_card_proc_new(loopback->card, name, &entry);
1118 snd_info_set_text_ops(entry, loopback, print_cable_info);
1122 #else /* !CONFIG_PROC_FS */
1124 #define loopback_proc_new(loopback, cidx) do { } while (0)
1128 static int __devinit loopback_probe(struct platform_device *devptr)
1130 struct snd_card *card;
1131 struct loopback *loopback;
1132 int dev = devptr->id;
1135 err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1136 sizeof(struct loopback), &card);
1139 loopback = card->private_data;
1141 if (pcm_substreams[dev] < 1)
1142 pcm_substreams[dev] = 1;
1143 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1144 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1146 loopback->card = card;
1147 mutex_init(&loopback->cable_lock);
1149 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1152 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1155 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1158 loopback_proc_new(loopback, 0);
1159 loopback_proc_new(loopback, 1);
1160 strcpy(card->driver, "Loopback");
1161 strcpy(card->shortname, "Loopback");
1162 sprintf(card->longname, "Loopback %i", dev + 1);
1163 err = snd_card_register(card);
1165 platform_set_drvdata(devptr, card);
1169 snd_card_free(card);
1173 static int __devexit loopback_remove(struct platform_device *devptr)
1175 snd_card_free(platform_get_drvdata(devptr));
1176 platform_set_drvdata(devptr, NULL);
1181 static int loopback_suspend(struct platform_device *pdev,
1184 struct snd_card *card = platform_get_drvdata(pdev);
1185 struct loopback *loopback = card->private_data;
1187 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1189 snd_pcm_suspend_all(loopback->pcm[0]);
1190 snd_pcm_suspend_all(loopback->pcm[1]);
1194 static int loopback_resume(struct platform_device *pdev)
1196 struct snd_card *card = platform_get_drvdata(pdev);
1198 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1203 #define SND_LOOPBACK_DRIVER "snd_aloop"
1205 static struct platform_driver loopback_driver = {
1206 .probe = loopback_probe,
1207 .remove = __devexit_p(loopback_remove),
1209 .suspend = loopback_suspend,
1210 .resume = loopback_resume,
1213 .name = SND_LOOPBACK_DRIVER
1217 static void loopback_unregister_all(void)
1221 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1222 platform_device_unregister(devices[i]);
1223 platform_driver_unregister(&loopback_driver);
1226 static int __init alsa_card_loopback_init(void)
1230 err = platform_driver_register(&loopback_driver);
1236 for (i = 0; i < SNDRV_CARDS; i++) {
1237 struct platform_device *device;
1240 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1244 if (!platform_get_drvdata(device)) {
1245 platform_device_unregister(device);
1248 devices[i] = device;
1253 printk(KERN_ERR "aloop: No loopback enabled\n");
1255 loopback_unregister_all();
1261 static void __exit alsa_card_loopback_exit(void)
1263 loopback_unregister_all();
1266 module_init(alsa_card_loopback_init)
1267 module_exit(alsa_card_loopback_exit)