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597603d6
JK		 1/*
2 * Loopback soundcard
3 *
4 * Original code:
5 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
6 *
7 * More accurate positioning and full-duplex support:
8 * Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
9 *
10 * Major (almost complete) rewrite:
11 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
12 *
13 * A next major update in 2010 (separate timers for playback and capture):
14 * Copyright (c) Jaroslav Kysela <perex@perex.cz>
15 *
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.
20 *
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.
25 *
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
29 *
30 */
31
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/moduleparam.h>
38#include <linux/platform_device.h>
39#include <sound/core.h>
40#include <sound/control.h>
41#include <sound/pcm.h>
e74670b6 42#include <sound/info.h>
597603d6
JK		 43#include <sound/initval.h>
44
45MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
46MODULE_DESCRIPTION("A loopback soundcard");
47MODULE_LICENSE("GPL");
48MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
49
50#define MAX_PCM_SUBSTREAMS 8
51
52static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
53static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
54static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
55static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
56static int pcm_notify[SNDRV_CARDS];
57
58module_param_array(index, int, NULL, 0444);
59MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
60module_param_array(id, charp, NULL, 0444);
61MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
62module_param_array(enable, bool, NULL, 0444);
63MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
64module_param_array(pcm_substreams, int, NULL, 0444);
65MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
66module_param_array(pcm_notify, int, NULL, 0444);
67MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
68
69#define NO_PITCH 100000
70
71struct loopback_pcm;
72
73struct loopback_cable {
74 spinlock_t lock;
75 struct loopback_pcm *streams[2];
76 struct snd_pcm_hardware hw;
77 /* flags */
78 unsigned int valid;
79 unsigned int running;
5de9e45f 80 unsigned int pause;
597603d6
JK		 81};
82
83struct loopback_setup {
84 unsigned int notify: 1;
85 unsigned int rate_shift;
86 unsigned int format;
87 unsigned int rate;
88 unsigned int channels;
89 struct snd_ctl_elem_id active_id;
90 struct snd_ctl_elem_id format_id;
91 struct snd_ctl_elem_id rate_id;
92 struct snd_ctl_elem_id channels_id;
93};
94
95struct loopback {
96 struct snd_card *card;
97 struct mutex cable_lock;
98 struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
99 struct snd_pcm *pcm[2];
100 struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
101};
102
103struct loopback_pcm {
104 struct loopback *loopback;
105 struct snd_pcm_substream *substream;
106 struct loopback_cable *cable;
107 unsigned int pcm_buffer_size;
108 unsigned int buf_pos; /* position in buffer */
109 unsigned int silent_size;
110 /* PCM parameters */
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 */
115 /* flags */
116 unsigned int period_update_pending :1;
117 /* timer stuff */
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};
123
124static struct platform_device *devices[SNDRV_CARDS];
125
126static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
127{
128 if (dpcm->pcm_rate_shift == NO_PITCH) {
129 x /= HZ;
130 } else {
131 x = div_u64(NO_PITCH * (unsigned long long)x,
132 HZ * (unsigned long long)dpcm->pcm_rate_shift);
133 }
134 return x - (x % dpcm->pcm_salign);
135}
136
137static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
138{
139 if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
140 return x * HZ;
141 } else {
142 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
143 NO_PITCH);
144 }
145 return x;
146}
147
148static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
149{
150 int device = dpcm->substream->pstr->pcm->device;
151
152 if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
153 device ^= 1;
154 return &dpcm->loopback->setup[dpcm->substream->number][device];
155}
156
157static inline unsigned int get_notify(struct loopback_pcm *dpcm)
158{
159 return get_setup(dpcm)->notify;
160}
161
162static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
163{
164 return get_setup(dpcm)->rate_shift;
165}
166
167static void loopback_timer_start(struct loopback_pcm *dpcm)
168{
169 unsigned long tick;
170 unsigned int rate_shift = get_rate_shift(dpcm);
171
172 if (rate_shift != dpcm->pcm_rate_shift) {
173 dpcm->pcm_rate_shift = rate_shift;
174 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
175 }
0db71023
JK		 176 if (dpcm->period_size_frac <= dpcm->irq_pos) {
177 dpcm->irq_pos %= dpcm->period_size_frac;
178 dpcm->period_update_pending = 1;
179 }
597603d6
JK		 180 tick = dpcm->period_size_frac - dpcm->irq_pos;
181 tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
182 dpcm->timer.expires = jiffies + tick;
183 add_timer(&dpcm->timer);
184}
185
186static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
187{
188 del_timer(&dpcm->timer);
e74670b6 189 dpcm->timer.expires = 0;
597603d6
JK		 190}
191
192#define CABLE_VALID_PLAYBACK (1 << SNDRV_PCM_STREAM_PLAYBACK)
193#define CABLE_VALID_CAPTURE (1 << SNDRV_PCM_STREAM_CAPTURE)
194#define CABLE_VALID_BOTH (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
195
196static int loopback_check_format(struct loopback_cable *cable, int stream)
197{
b1c73fc8 198 struct snd_pcm_runtime *runtime, *cruntime;
597603d6
JK		 199 struct loopback_setup *setup;
200 struct snd_card *card;
201 int check;
202
203 if (cable->valid != CABLE_VALID_BOTH) {
204 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
205 goto __notify;
206 return 0;
207 }
208 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
209 substream->runtime;
b1c73fc8
JK		 210 cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
211 substream->runtime;
212 check = runtime->format != cruntime->format ||
213 runtime->rate != cruntime->rate ||
214 runtime->channels != cruntime->channels;
597603d6
JK		 215 if (!check)
216 return 0;
217 if (stream == SNDRV_PCM_STREAM_CAPTURE) {
218 return -EIO;
219 } else {
220 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
221 substream, SNDRV_PCM_STATE_DRAINING);
222 __notify:
223 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
224 substream->runtime;
225 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
226 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
227 if (setup->format != runtime->format) {
228 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
229 &setup->format_id);
230 setup->format = runtime->format;
231 }
232 if (setup->rate != runtime->rate) {
233 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
234 &setup->rate_id);
235 setup->rate = runtime->rate;
236 }
237 if (setup->channels != runtime->channels) {
238 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
239 &setup->channels_id);
240 setup->channels = runtime->channels;
241 }
242 }
243 return 0;
244}
245
246static void loopback_active_notify(struct loopback_pcm *dpcm)
247{
248 snd_ctl_notify(dpcm->loopback->card,
249 SNDRV_CTL_EVENT_MASK_VALUE,
250 &get_setup(dpcm)->active_id);
251}
252
253static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
254{
255 struct snd_pcm_runtime *runtime = substream->runtime;
256 struct loopback_pcm *dpcm = runtime->private_data;
257 struct loopback_cable *cable = dpcm->cable;
5de9e45f 258 int err, stream = 1 << substream->stream;
597603d6
JK		 259
260 switch (cmd) {
261 case SNDRV_PCM_TRIGGER_START:
262 err = loopback_check_format(cable, substream->stream);
263 if (err < 0)
264 return err;
265 dpcm->last_jiffies = jiffies;
266 dpcm->pcm_rate_shift = 0;
dd04bb12 267 spin_lock(&cable->lock);
5de9e45f
JK		 268 cable->running |= stream;
269 cable->pause &= ~stream;
dd04bb12
JK		 270 spin_unlock(&cable->lock);
271 loopback_timer_start(dpcm);
597603d6
JK		 272 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
273 loopback_active_notify(dpcm);
274 break;
275 case SNDRV_PCM_TRIGGER_STOP:
dd04bb12 276 spin_lock(&cable->lock);
5de9e45f
JK		 277 cable->running &= ~stream;
278 cable->pause &= ~stream;
dd04bb12 279 spin_unlock(&cable->lock);
597603d6
JK		 280 loopback_timer_stop(dpcm);
281 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
282 loopback_active_notify(dpcm);
283 break;
5de9e45f
JK		 284 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
285 spin_lock(&cable->lock);
286 cable->pause |= stream;
287 spin_unlock(&cable->lock);
288 loopback_timer_stop(dpcm);
289 break;
290 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
291 spin_lock(&cable->lock);
292 dpcm->last_jiffies = jiffies;
293 cable->pause &= ~stream;
294 spin_unlock(&cable->lock);
295 loopback_timer_start(dpcm);
296 break;
597603d6
JK		 297 default:
298 return -EINVAL;
299 }
300 return 0;
301}
302
b1c73fc8
JK		 303static void params_change_substream(struct loopback_pcm *dpcm,
304 struct snd_pcm_runtime *runtime)
305{
306 struct snd_pcm_runtime *dst_runtime;
307
308 if (dpcm == NULL || dpcm->substream == NULL)
309 return;
310 dst_runtime = dpcm->substream->runtime;
311 if (dst_runtime == NULL)
312 return;
313 dst_runtime->hw = dpcm->cable->hw;
314}
315
316static void params_change(struct snd_pcm_substream *substream)
317{
318 struct snd_pcm_runtime *runtime = substream->runtime;
319 struct loopback_pcm *dpcm = runtime->private_data;
320 struct loopback_cable *cable = dpcm->cable;
321
322 cable->hw.formats = (1ULL << runtime->format);
323 cable->hw.rate_min = runtime->rate;
324 cable->hw.rate_max = runtime->rate;
325 cable->hw.channels_min = runtime->channels;
326 cable->hw.channels_max = runtime->channels;
327 params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
328 runtime);
329 params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
330 runtime);
331}
332
597603d6
JK		 333static int loopback_prepare(struct snd_pcm_substream *substream)
334{
335 struct snd_pcm_runtime *runtime = substream->runtime;
336 struct loopback_pcm *dpcm = runtime->private_data;
337 struct loopback_cable *cable = dpcm->cable;
b1c73fc8 338 int bps, salign;
597603d6
JK		 339
340 salign = (snd_pcm_format_width(runtime->format) *
341 runtime->channels) / 8;
342 bps = salign * runtime->rate;
343 if (bps <= 0 || salign <= 0)
344 return -EINVAL;
345
346 dpcm->buf_pos = 0;
347 dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
348 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
349 /* 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);
353 }
354
355 dpcm->irq_pos = 0;
356 dpcm->period_update_pending = 0;
357 dpcm->pcm_bps = bps;
358 dpcm->pcm_salign = salign;
359 dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
360
361 mutex_lock(&dpcm->loopback->cable_lock);
b1c73fc8
JK		 362 if (!(cable->valid & ~(1 << substream->stream)) ||
363 (get_setup(dpcm)->notify &&
364 substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
365 params_change(substream);
597603d6
JK		 366 cable->valid |= 1 << substream->stream;
367 mutex_unlock(&dpcm->loopback->cable_lock);
368
369 return 0;
370}
371
372static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
373{
374 struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
375 char *dst = runtime->dma_area;
376 unsigned int dst_off = dpcm->buf_pos;
377
378 if (dpcm->silent_size >= dpcm->pcm_buffer_size)
379 return;
380 if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
381 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
382
383 for (;;) {
384 unsigned int size = bytes;
385 if (dst_off + size > dpcm->pcm_buffer_size)
386 size = dpcm->pcm_buffer_size - dst_off;
387 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
388 bytes_to_frames(runtime, size) *
389 runtime->channels);
390 dpcm->silent_size += size;
391 bytes -= size;
392 if (!bytes)
393 break;
394 dst_off = 0;
395 }
396}
397
398static void copy_play_buf(struct loopback_pcm *play,
399 struct loopback_pcm *capt,
400 unsigned int bytes)
401{
402 struct snd_pcm_runtime *runtime = play->substream->runtime;
20d9a26d 403 char *src = runtime->dma_area;
597603d6
JK		 404 char *dst = capt->substream->runtime->dma_area;
405 unsigned int src_off = play->buf_pos;
406 unsigned int dst_off = capt->buf_pos;
407 unsigned int clear_bytes = 0;
408
409 /* 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;
420 if (diff < bytes) {
421 clear_bytes = bytes - diff;
422 bytes = diff;
423 }
424 }
425
426 for (;;) {
427 unsigned int size = bytes;
428 if (src_off + size > play->pcm_buffer_size)
429 size = play->pcm_buffer_size - src_off;
430 if (dst_off + size > capt->pcm_buffer_size)
431 size = capt->pcm_buffer_size - dst_off;
432 memcpy(dst + dst_off, src + src_off, size);
433 capt->silent_size = 0;
434 bytes -= size;
435 if (!bytes)
436 break;
437 src_off = (src_off + size) % play->pcm_buffer_size;
438 dst_off = (dst_off + size) % capt->pcm_buffer_size;
439 }
440
20d9a26d 441 if (clear_bytes > 0) {
597603d6 442 clear_capture_buf(capt, clear_bytes);
20d9a26d
JK		 443 capt->silent_size = 0;
444 }
597603d6
JK		 445}
446
447#define BYTEPOS_UPDATE_POSONLY 0
448#define BYTEPOS_UPDATE_CLEAR 1
449#define BYTEPOS_UPDATE_COPY 2
450
451static void loopback_bytepos_update(struct loopback_pcm *dpcm,
452 unsigned int delta,
453 unsigned int cmd)
454{
455 unsigned int count;
456 unsigned long last_pos;
457
458 last_pos = byte_pos(dpcm, dpcm->irq_pos);
459 dpcm->irq_pos += delta * dpcm->pcm_bps;
460 count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
461 if (!count)
462 return;
463 if (cmd == BYTEPOS_UPDATE_CLEAR)
464 clear_capture_buf(dpcm, count);
465 else if (cmd == BYTEPOS_UPDATE_COPY)
466 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
467 dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
468 count);
469 dpcm->buf_pos += count;
470 dpcm->buf_pos %= dpcm->pcm_buffer_size;
471 if (dpcm->irq_pos >= dpcm->period_size_frac) {
472 dpcm->irq_pos %= dpcm->period_size_frac;
473 dpcm->period_update_pending = 1;
474 }
475}
476
dd04bb12 477static unsigned int loopback_pos_update(struct loopback_cable *cable)
597603d6
JK		 478{
479 struct loopback_pcm *dpcm_play =
480 cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
481 struct loopback_pcm *dpcm_capt =
482 cable->streams[SNDRV_PCM_STREAM_CAPTURE];
483 unsigned long delta_play = 0, delta_capt = 0;
dd04bb12 484 unsigned int running;
597603d6
JK		 485
486 spin_lock(&cable->lock);
5de9e45f 487 running = cable->running ^ cable->pause;
dd04bb12 488 if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
597603d6
JK		 489 delta_play = jiffies - dpcm_play->last_jiffies;
490 dpcm_play->last_jiffies += delta_play;
491 }
492
dd04bb12 493 if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
597603d6
JK		 494 delta_capt = jiffies - dpcm_capt->last_jiffies;
495 dpcm_capt->last_jiffies += delta_capt;
496 }
497
498 if (delta_play == 0 && delta_capt == 0) {
499 spin_unlock(&cable->lock);
dd04bb12 500 return running;
597603d6
JK		 501 }
502
503 if (delta_play > delta_capt) {
504 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
505 BYTEPOS_UPDATE_POSONLY);
506 delta_play = delta_capt;
507 } else if (delta_play < delta_capt) {
508 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
509 BYTEPOS_UPDATE_CLEAR);
510 delta_capt = delta_play;
511 }
512
513 if (delta_play == 0 && delta_capt == 0) {
514 spin_unlock(&cable->lock);
dd04bb12 515 return running;
597603d6
JK		 516 }
517 /* note delta_capt == delta_play at this moment */
518 loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
519 loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
520 spin_unlock(&cable->lock);
dd04bb12 521 return running;
597603d6
JK		 522}
523
524static void loopback_timer_function(unsigned long data)
525{
526 struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
dd04bb12 527 unsigned int running;
597603d6 528
dd04bb12
JK		 529 running = loopback_pos_update(dpcm->cable);
530 if (running & (1 << dpcm->substream->stream)) {
597603d6 531 loopback_timer_start(dpcm);
dd04bb12
JK		 532 if (dpcm->period_update_pending) {
533 dpcm->period_update_pending = 0;
597603d6 534 snd_pcm_period_elapsed(dpcm->substream);
dd04bb12 535 }
597603d6
JK		 536 }
537}
538
539static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
540{
541 struct snd_pcm_runtime *runtime = substream->runtime;
542 struct loopback_pcm *dpcm = runtime->private_data;
543
544 loopback_pos_update(dpcm->cable);
545 return bytes_to_frames(runtime, dpcm->buf_pos);
546}
547
548static struct snd_pcm_hardware loopback_pcm_hardware =
549{
550 .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
5de9e45f 551 SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE),
597603d6
JK		 552 .formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
553 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
554 SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
555 .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
556 .rate_min = 8000,
557 .rate_max = 192000,
558 .channels_min = 1,
559 .channels_max = 32,
560 .buffer_bytes_max = 2 * 1024 * 1024,
561 .period_bytes_min = 64,
0db71023
JK		 562 /* note check overflow in frac_pos() using pcm_rate_shift before
563 changing period_bytes_max value */
564 .period_bytes_max = 1024 * 1024,
597603d6
JK		 565 .periods_min = 1,
566 .periods_max = 1024,
567 .fifo_size = 0,
568};
569
570static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
571{
572 struct loopback_pcm *dpcm = runtime->private_data;
573 kfree(dpcm);
574}
575
576static int loopback_hw_params(struct snd_pcm_substream *substream,
577 struct snd_pcm_hw_params *params)
578{
579 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
580}
581
582static int loopback_hw_free(struct snd_pcm_substream *substream)
583{
584 struct snd_pcm_runtime *runtime = substream->runtime;
585 struct loopback_pcm *dpcm = runtime->private_data;
586 struct loopback_cable *cable = dpcm->cable;
587
588 mutex_lock(&dpcm->loopback->cable_lock);
589 cable->valid &= ~(1 << substream->stream);
590 mutex_unlock(&dpcm->loopback->cable_lock);
591 return snd_pcm_lib_free_pages(substream);
592}
593
594static unsigned int get_cable_index(struct snd_pcm_substream *substream)
595{
596 if (!substream->pcm->device)
597 return substream->stream;
598 else
599 return !substream->stream;
600}
601
b1c73fc8
JK		 602static int rule_format(struct snd_pcm_hw_params *params,
603 struct snd_pcm_hw_rule *rule)
604{
605
606 struct snd_pcm_hardware *hw = rule->private;
607 struct snd_mask *maskp = hw_param_mask(params, rule->var);
608
609 maskp->bits[0] &= (u_int32_t)hw->formats;
610 maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
611 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
612 if (! maskp->bits[0] && ! maskp->bits[1])
613 return -EINVAL;
614 return 0;
615}
616
617static int rule_rate(struct snd_pcm_hw_params *params,
618 struct snd_pcm_hw_rule *rule)
619{
620 struct snd_pcm_hardware *hw = rule->private;
621 struct snd_interval t;
622
623 t.min = hw->rate_min;
624 t.max = hw->rate_max;
625 t.openmin = t.openmax = 0;
626 t.integer = 0;
627 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
628}
629
630static int rule_channels(struct snd_pcm_hw_params *params,
631 struct snd_pcm_hw_rule *rule)
632{
633 struct snd_pcm_hardware *hw = rule->private;
634 struct snd_interval t;
635
636 t.min = hw->channels_min;
637 t.max = hw->channels_max;
638 t.openmin = t.openmax = 0;
639 t.integer = 0;
640 return snd_interval_refine(hw_param_interval(params, rule->var), &t);
641}
642
597603d6
JK		 643static int loopback_open(struct snd_pcm_substream *substream)
644{
645 struct snd_pcm_runtime *runtime = substream->runtime;
646 struct loopback *loopback = substream->private_data;
647 struct loopback_pcm *dpcm;
648 struct loopback_cable *cable;
649 int err = 0;
650 int dev = get_cable_index(substream);
651
652 mutex_lock(&loopback->cable_lock);
653 dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
654 if (!dpcm) {
655 err = -ENOMEM;
656 goto unlock;
657 }
658 dpcm->loopback = loopback;
659 dpcm->substream = substream;
660 setup_timer(&dpcm->timer, loopback_timer_function,
661 (unsigned long)dpcm);
662
663 cable = loopback->cables[substream->number][dev];
664 if (!cable) {
665 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
666 if (!cable) {
667 kfree(dpcm);
668 err = -ENOMEM;
669 goto unlock;
670 }
671 spin_lock_init(&cable->lock);
672 cable->hw = loopback_pcm_hardware;
673 loopback->cables[substream->number][dev] = cable;
674 }
675 dpcm->cable = cable;
676 cable->streams[substream->stream] = dpcm;
677
678 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
679
b1c73fc8
JK		 680 /* use dynamic rules based on actual runtime->hw values */
681 /* note that the default rules created in the PCM midlevel code */
682 /* are cached -> they do not reflect the actual state */
683 err = snd_pcm_hw_rule_add(runtime, 0,
684 SNDRV_PCM_HW_PARAM_FORMAT,
685 rule_format, &runtime->hw,
686 SNDRV_PCM_HW_PARAM_FORMAT, -1);
687 if (err < 0)
688 goto unlock;
689 err = snd_pcm_hw_rule_add(runtime, 0,
690 SNDRV_PCM_HW_PARAM_RATE,
691 rule_rate, &runtime->hw,
692 SNDRV_PCM_HW_PARAM_RATE, -1);
693 if (err < 0)
694 goto unlock;
695 err = snd_pcm_hw_rule_add(runtime, 0,
696 SNDRV_PCM_HW_PARAM_CHANNELS,
697 rule_channels, &runtime->hw,
698 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
699 if (err < 0)
700 goto unlock;
701
597603d6
JK		 702 runtime->private_data = dpcm;
703 runtime->private_free = loopback_runtime_free;
b1c73fc8 704 if (get_notify(dpcm))
597603d6 705 runtime->hw = loopback_pcm_hardware;
b1c73fc8 706 else
597603d6 707 runtime->hw = cable->hw;
597603d6
JK		 708 unlock:
709 mutex_unlock(&loopback->cable_lock);
710 return err;
711}
712
713static int loopback_close(struct snd_pcm_substream *substream)
714{
715 struct loopback *loopback = substream->private_data;
716 struct loopback_pcm *dpcm = substream->runtime->private_data;
717 struct loopback_cable *cable;
718 int dev = get_cable_index(substream);
719
720 loopback_timer_stop(dpcm);
721 mutex_lock(&loopback->cable_lock);
722 cable = loopback->cables[substream->number][dev];
723 if (cable->streams[!substream->stream]) {
724 /* other stream is still alive */
725 cable->streams[substream->stream] = NULL;
726 } else {
727 /* free the cable */
728 loopback->cables[substream->number][dev] = NULL;
729 kfree(cable);
730 }
731 mutex_unlock(&loopback->cable_lock);
732 return 0;
733}
734
735static struct snd_pcm_ops loopback_playback_ops = {
736 .open = loopback_open,
737 .close = loopback_close,
738 .ioctl = snd_pcm_lib_ioctl,
739 .hw_params = loopback_hw_params,
740 .hw_free = loopback_hw_free,
741 .prepare = loopback_prepare,
742 .trigger = loopback_trigger,
743 .pointer = loopback_pointer,
744};
745
746static struct snd_pcm_ops loopback_capture_ops = {
747 .open = loopback_open,
748 .close = loopback_close,
749 .ioctl = snd_pcm_lib_ioctl,
750 .hw_params = loopback_hw_params,
751 .hw_free = loopback_hw_free,
752 .prepare = loopback_prepare,
753 .trigger = loopback_trigger,
754 .pointer = loopback_pointer,
755};
756
757static int __devinit loopback_pcm_new(struct loopback *loopback,
758 int device, int substreams)
759{
760 struct snd_pcm *pcm;
761 int err;
762
763 err = snd_pcm_new(loopback->card, "Loopback PCM", device,
764 substreams, substreams, &pcm);
765 if (err < 0)
766 return err;
767 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
768 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
769
770 pcm->private_data = loopback;
771 pcm->info_flags = 0;
772 strcpy(pcm->name, "Loopback PCM");
773
774 loopback->pcm[device] = pcm;
775
776 snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
777 snd_dma_continuous_data(GFP_KERNEL),
778 0, 2 * 1024 * 1024);
779 return 0;
780}
781
782static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
783 struct snd_ctl_elem_info *uinfo)
784{
785 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
786 uinfo->count = 1;
787 uinfo->value.integer.min = 80000;
788 uinfo->value.integer.max = 120000;
789 uinfo->value.integer.step = 1;
790 return 0;
791}
792
793static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
794 struct snd_ctl_elem_value *ucontrol)
795{
796 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
797
798 ucontrol->value.integer.value[0] =
799 loopback->setup[kcontrol->id.subdevice]
800 [kcontrol->id.device].rate_shift;
801 return 0;
802}
803
804static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
805 struct snd_ctl_elem_value *ucontrol)
806{
807 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
808 unsigned int val;
809 int change = 0;
810
811 val = ucontrol->value.integer.value[0];
812 if (val < 80000)
813 val = 80000;
814 if (val > 120000)
815 val = 120000;
816 mutex_lock(&loopback->cable_lock);
817 if (val != loopback->setup[kcontrol->id.subdevice]
818 [kcontrol->id.device].rate_shift) {
819 loopback->setup[kcontrol->id.subdevice]
820 [kcontrol->id.device].rate_shift = val;
821 change = 1;
822 }
823 mutex_unlock(&loopback->cable_lock);
824 return change;
825}
826
827static int loopback_notify_get(struct snd_kcontrol *kcontrol,
828 struct snd_ctl_elem_value *ucontrol)
829{
830 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
831
832 ucontrol->value.integer.value[0] =
833 loopback->setup[kcontrol->id.subdevice]
834 [kcontrol->id.device].notify;
835 return 0;
836}
837
838static int loopback_notify_put(struct snd_kcontrol *kcontrol,
839 struct snd_ctl_elem_value *ucontrol)
840{
841 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
842 unsigned int val;
843 int change = 0;
844
845 val = ucontrol->value.integer.value[0] ? 1 : 0;
846 if (val != loopback->setup[kcontrol->id.subdevice]
847 [kcontrol->id.device].notify) {
848 loopback->setup[kcontrol->id.subdevice]
849 [kcontrol->id.device].notify = val;
850 change = 1;
851 }
852 return change;
853}
854
855static int loopback_active_get(struct snd_kcontrol *kcontrol,
856 struct snd_ctl_elem_value *ucontrol)
857{
858 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
859 struct loopback_cable *cable = loopback->cables
ac446fb7 860 [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
597603d6
JK		 861 unsigned int val = 0;
862
863 if (cable != NULL)
864 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
865 1 : 0;
866 ucontrol->value.integer.value[0] = val;
867 return 0;
868}
869
870static int loopback_format_info(struct snd_kcontrol *kcontrol,
871 struct snd_ctl_elem_info *uinfo)
872{
873 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
874 uinfo->count = 1;
875 uinfo->value.integer.min = 0;
876 uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
877 uinfo->value.integer.step = 1;
878 return 0;
879}
880
881static int loopback_format_get(struct snd_kcontrol *kcontrol,
882 struct snd_ctl_elem_value *ucontrol)
883{
884 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
885
886 ucontrol->value.integer.value[0] =
887 loopback->setup[kcontrol->id.subdevice]
888 [kcontrol->id.device].format;
889 return 0;
890}
891
892static int loopback_rate_info(struct snd_kcontrol *kcontrol,
893 struct snd_ctl_elem_info *uinfo)
894{
895 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
896 uinfo->count = 1;
897 uinfo->value.integer.min = 0;
898 uinfo->value.integer.max = 192000;
899 uinfo->value.integer.step = 1;
900 return 0;
901}
902
903static int loopback_rate_get(struct snd_kcontrol *kcontrol,
904 struct snd_ctl_elem_value *ucontrol)
905{
906 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
907
908 ucontrol->value.integer.value[0] =
909 loopback->setup[kcontrol->id.subdevice]
910 [kcontrol->id.device].rate;
911 return 0;
912}
913
914static int loopback_channels_info(struct snd_kcontrol *kcontrol,
915 struct snd_ctl_elem_info *uinfo)
916{
917 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
918 uinfo->count = 1;
919 uinfo->value.integer.min = 1;
920 uinfo->value.integer.max = 1024;
921 uinfo->value.integer.step = 1;
922 return 0;
923}
924
925static int loopback_channels_get(struct snd_kcontrol *kcontrol,
926 struct snd_ctl_elem_value *ucontrol)
927{
928 struct loopback *loopback = snd_kcontrol_chip(kcontrol);
929
930 ucontrol->value.integer.value[0] =
931 loopback->setup[kcontrol->id.subdevice]
1446c5fb 932 [kcontrol->id.device].channels;
597603d6
JK		 933 return 0;
934}
935
936static struct snd_kcontrol_new loopback_controls[] __devinitdata = {
937{
938 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
939 .name = "PCM Rate Shift 100000",
940 .info = loopback_rate_shift_info,
941 .get = loopback_rate_shift_get,
942 .put = loopback_rate_shift_put,
943},
944{
945 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
946 .name = "PCM Notify",
947 .info = snd_ctl_boolean_mono_info,
948 .get = loopback_notify_get,
949 .put = loopback_notify_put,
950},
951#define ACTIVE_IDX 2
952{
953 .access = SNDRV_CTL_ELEM_ACCESS_READ,
954 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
955 .name = "PCM Slave Active",
956 .info = snd_ctl_boolean_mono_info,
957 .get = loopback_active_get,
958},
959#define FORMAT_IDX 3
960{
961 .access = SNDRV_CTL_ELEM_ACCESS_READ,
962 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
963 .name = "PCM Slave Format",
964 .info = loopback_format_info,
965 .get = loopback_format_get
966},
967#define RATE_IDX 4
968{
969 .access = SNDRV_CTL_ELEM_ACCESS_READ,
970 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
971 .name = "PCM Slave Rate",
972 .info = loopback_rate_info,
973 .get = loopback_rate_get
974},
975#define CHANNELS_IDX 5
976{
977 .access = SNDRV_CTL_ELEM_ACCESS_READ,
978 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
979 .name = "PCM Slave Channels",
980 .info = loopback_channels_info,
981 .get = loopback_channels_get
982}
983};
984
985static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
986{
987 struct snd_card *card = loopback->card;
988 struct snd_pcm *pcm;
989 struct snd_kcontrol *kctl;
990 struct loopback_setup *setup;
991 int err, dev, substr, substr_count, idx;
992
993 strcpy(card->mixername, "Loopback Mixer");
994 for (dev = 0; dev < 2; dev++) {
995 pcm = loopback->pcm[dev];
996 substr_count =
997 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
998 for (substr = 0; substr < substr_count; substr++) {
999 setup = &loopback->setup[substr][dev];
1000 setup->notify = notify;
1001 setup->rate_shift = NO_PITCH;
1002 setup->format = SNDRV_PCM_FORMAT_S16_LE;
1003 setup->rate = 48000;
1004 setup->channels = 2;
1005 for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1006 idx++) {
1007 kctl = snd_ctl_new1(&loopback_controls[idx],
1008 loopback);
1009 if (!kctl)
1010 return -ENOMEM;
1011 kctl->id.device = dev;
1012 kctl->id.subdevice = substr;
1013 switch (idx) {
1014 case ACTIVE_IDX:
1015 setup->active_id = kctl->id;
1016 break;
1017 case FORMAT_IDX:
1018 setup->format_id = kctl->id;
1019 break;
1020 case RATE_IDX:
1021 setup->rate_id = kctl->id;
1022 break;
1023 case CHANNELS_IDX:
1024 setup->channels_id = kctl->id;
1025 break;
1026 default:
1027 break;
1028 }
1029 err = snd_ctl_add(card, kctl);
1030 if (err < 0)
1031 return err;
1032 }
1033 }
1034 }
1035 return 0;
1036}
1037
e74670b6
JK		 1038#ifdef CONFIG_PROC_FS
1039
1040static void print_dpcm_info(struct snd_info_buffer *buffer,
1041 struct loopback_pcm *dpcm,
1042 const char *id)
1043{
1044 snd_iprintf(buffer, " %s\n", id);
1045 if (dpcm == NULL) {
1046 snd_iprintf(buffer, " inactive\n");
1047 return;
1048 }
1049 snd_iprintf(buffer, " buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1050 snd_iprintf(buffer, " buffer_pos:\t\t%u\n", dpcm->buf_pos);
1051 snd_iprintf(buffer, " silent_size:\t%u\n", dpcm->silent_size);
1052 snd_iprintf(buffer, " period_size:\t%u\n", dpcm->pcm_period_size);
1053 snd_iprintf(buffer, " bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1054 snd_iprintf(buffer, " sample_align:\t%u\n", dpcm->pcm_salign);
1055 snd_iprintf(buffer, " rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1056 snd_iprintf(buffer, " update_pending:\t%u\n",
1057 dpcm->period_update_pending);
1058 snd_iprintf(buffer, " irq_pos:\t\t%u\n", dpcm->irq_pos);
1059 snd_iprintf(buffer, " period_frac:\t%u\n", dpcm->period_size_frac);
1060 snd_iprintf(buffer, " last_jiffies:\t%lu (%lu)\n",
1061 dpcm->last_jiffies, jiffies);
1062 snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires);
1063}
1064
1065static void print_substream_info(struct snd_info_buffer *buffer,
1066 struct loopback *loopback,
1067 int sub,
1068 int num)
1069{
1070 struct loopback_cable *cable = loopback->cables[sub][num];
1071
1072 snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1073 if (cable == NULL) {
1074 snd_iprintf(buffer, " inactive\n");
1075 return;
1076 }
1077 snd_iprintf(buffer, " valid: %u\n", cable->valid);
1078 snd_iprintf(buffer, " running: %u\n", cable->running);
5de9e45f 1079 snd_iprintf(buffer, " pause: %u\n", cable->pause);
e74670b6
JK		 1080 print_dpcm_info(buffer, cable->streams[0], "Playback");
1081 print_dpcm_info(buffer, cable->streams[1], "Capture");
1082}
1083
1084static void print_cable_info(struct snd_info_entry *entry,
1085 struct snd_info_buffer *buffer)
1086{
1087 struct loopback *loopback = entry->private_data;
1088 int sub, num;
1089
1090 mutex_lock(&loopback->cable_lock);
1091 num = entry->name[strlen(entry->name)-1];
1092 num = num == '0' ? 0 : 1;
1093 for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1094 print_substream_info(buffer, loopback, sub, num);
1095 mutex_unlock(&loopback->cable_lock);
1096}
1097
1098static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1099{
1100 char name[32];
1101 struct snd_info_entry *entry;
1102 int err;
1103
1104 snprintf(name, sizeof(name), "cable#%d", cidx);
1105 err = snd_card_proc_new(loopback->card, name, &entry);
1106 if (err < 0)
1107 return err;
1108
1109 snd_info_set_text_ops(entry, loopback, print_cable_info);
1110 return 0;
1111}
1112
1113#else /* !CONFIG_PROC_FS */
1114
1115#define loopback_proc_new(loopback, cidx) do { } while (0)
1116
1117#endif
1118
597603d6
JK		 1119static int __devinit loopback_probe(struct platform_device *devptr)
1120{
1121 struct snd_card *card;
1122 struct loopback *loopback;
1123 int dev = devptr->id;
1124 int err;
1125
1126 err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1127 sizeof(struct loopback), &card);
1128 if (err < 0)
1129 return err;
1130 loopback = card->private_data;
1131
1132 if (pcm_substreams[dev] < 1)
1133 pcm_substreams[dev] = 1;
1134 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1135 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1136
1137 loopback->card = card;
1138 mutex_init(&loopback->cable_lock);
1139
1140 err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1141 if (err < 0)
1142 goto __nodev;
1143 err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1144 if (err < 0)
1145 goto __nodev;
1146 err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1147 if (err < 0)
1148 goto __nodev;
e74670b6
JK		 1149 loopback_proc_new(loopback, 0);
1150 loopback_proc_new(loopback, 1);
597603d6
JK		 1151 strcpy(card->driver, "Loopback");
1152 strcpy(card->shortname, "Loopback");
1153 sprintf(card->longname, "Loopback %i", dev + 1);
1154 err = snd_card_register(card);
1155 if (!err) {
1156 platform_set_drvdata(devptr, card);
1157 return 0;
1158 }
1159 __nodev:
1160 snd_card_free(card);
1161 return err;
1162}
1163
1164static int __devexit loopback_remove(struct platform_device *devptr)
1165{
1166 snd_card_free(platform_get_drvdata(devptr));
1167 platform_set_drvdata(devptr, NULL);
1168 return 0;
1169}
1170
1171#ifdef CONFIG_PM
1172static int loopback_suspend(struct platform_device *pdev,
1173 pm_message_t state)
1174{
1175 struct snd_card *card = platform_get_drvdata(pdev);
1176 struct loopback *loopback = card->private_data;
1177
1178 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1179
1180 snd_pcm_suspend_all(loopback->pcm[0]);
1181 snd_pcm_suspend_all(loopback->pcm[1]);
1182 return 0;
1183}
1184
1185static int loopback_resume(struct platform_device *pdev)
1186{
1187 struct snd_card *card = platform_get_drvdata(pdev);
1188
1189 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1190 return 0;
1191}
1192#endif
1193
1194#define SND_LOOPBACK_DRIVER "snd_aloop"
1195
1196static struct platform_driver loopback_driver = {
1197 .probe = loopback_probe,
1198 .remove = __devexit_p(loopback_remove),
1199#ifdef CONFIG_PM
1200 .suspend = loopback_suspend,
1201 .resume = loopback_resume,
1202#endif
1203 .driver = {
1204 .name = SND_LOOPBACK_DRIVER
1205 },
1206};
1207
1208static void loopback_unregister_all(void)
1209{
1210 int i;
1211
1212 for (i = 0; i < ARRAY_SIZE(devices); ++i)
1213 platform_device_unregister(devices[i]);
1214 platform_driver_unregister(&loopback_driver);
1215}
1216
1217static int __init alsa_card_loopback_init(void)
1218{
1219 int i, err, cards;
1220
1221 err = platform_driver_register(&loopback_driver);
1222 if (err < 0)
1223 return err;
1224
1225
1226 cards = 0;
1227 for (i = 0; i < SNDRV_CARDS; i++) {
1228 struct platform_device *device;
1229 if (!enable[i])
1230 continue;
1231 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1232 i, NULL, 0);
1233 if (IS_ERR(device))
1234 continue;
1235 if (!platform_get_drvdata(device)) {
1236 platform_device_unregister(device);
1237 continue;
1238 }
1239 devices[i] = device;
1240 cards++;
1241 }
1242 if (!cards) {
1243#ifdef MODULE
1244 printk(KERN_ERR "aloop: No loopback enabled\n");
1245#endif
1246 loopback_unregister_all();
1247 return -ENODEV;
1248 }
1249 return 0;
1250}
1251
1252static void __exit alsa_card_loopback_exit(void)
1253{
1254 loopback_unregister_all();
1255}
1256
1257module_init(alsa_card_loopback_init)
1258module_exit(alsa_card_loopback_exit)
Clone of davem's net-next-2.6 tree