Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/sound/drivers/aloop.c

  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 ─░nan <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/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>
 44 
 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}}");
 49 
 50 #define MAX_PCM_SUBSTREAMS      8
 51 
 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 bool 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];
 57 
 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.");
 68 
 69 #define NO_PITCH 100000
 70 
 71 struct loopback_pcm;
 72 
 73 struct 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;
 80         unsigned int pause;
 81 };
 82 
 83 struct 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 
 95 struct 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 
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;
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 int last_drift;
121         unsigned long last_jiffies;
122         struct timer_list timer;
123 };
124 
125 static struct platform_device *devices[SNDRV_CARDS];
126 
127 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
128 {
129         if (dpcm->pcm_rate_shift == NO_PITCH) {
130                 x /= HZ;
131         } else {
132                 x = div_u64(NO_PITCH * (unsigned long long)x,
133                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
134         }
135         return x - (x % dpcm->pcm_salign);
136 }
137 
138 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
139 {
140         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
141                 return x * HZ;
142         } else {
143                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
144                             NO_PITCH);
145         }
146         return x;
147 }
148 
149 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
150 {
151         int device = dpcm->substream->pstr->pcm->device;
152         
153         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
154                 device ^= 1;
155         return &dpcm->loopback->setup[dpcm->substream->number][device];
156 }
157 
158 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
159 {
160         return get_setup(dpcm)->notify;
161 }
162 
163 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
164 {
165         return get_setup(dpcm)->rate_shift;
166 }
167 
168 /* call in cable->lock */
169 static void loopback_timer_start(struct loopback_pcm *dpcm)
170 {
171         unsigned long tick;
172         unsigned int rate_shift = get_rate_shift(dpcm);
173 
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);
177         }
178         if (dpcm->period_size_frac <= dpcm->irq_pos) {
179                 dpcm->irq_pos %= dpcm->period_size_frac;
180                 dpcm->period_update_pending = 1;
181         }
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 }
187 
188 /* call in cable->lock */
189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
190 {
191         del_timer(&dpcm->timer);
192         dpcm->timer.expires = 0;
193 }
194 
195 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
196 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
197 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
198 
199 static int loopback_check_format(struct loopback_cable *cable, int stream)
200 {
201         struct snd_pcm_runtime *runtime, *cruntime;
202         struct loopback_setup *setup;
203         struct snd_card *card;
204         int check;
205 
206         if (cable->valid != CABLE_VALID_BOTH) {
207                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
208                         goto __notify;
209                 return 0;
210         }
211         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
212                                                         substream->runtime;
213         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
214                                                         substream->runtime;
215         check = runtime->format != cruntime->format ||
216                 runtime->rate != cruntime->rate ||
217                 runtime->channels != cruntime->channels;
218         if (!check)
219                 return 0;
220         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
221                 return -EIO;
222         } else {
223                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
224                                         substream, SNDRV_PCM_STATE_DRAINING);
225               __notify:
226                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
227                                                         substream->runtime;
228                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
229                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
230                 if (setup->format != runtime->format) {
231                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
232                                                         &setup->format_id);
233                         setup->format = runtime->format;
234                 }
235                 if (setup->rate != runtime->rate) {
236                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
237                                                         &setup->rate_id);
238                         setup->rate = runtime->rate;
239                 }
240                 if (setup->channels != runtime->channels) {
241                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
242                                                         &setup->channels_id);
243                         setup->channels = runtime->channels;
244                 }
245         }
246         return 0;
247 }
248 
249 static void loopback_active_notify(struct loopback_pcm *dpcm)
250 {
251         snd_ctl_notify(dpcm->loopback->card,
252                        SNDRV_CTL_EVENT_MASK_VALUE,
253                        &get_setup(dpcm)->active_id);
254 }
255 
256 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
257 {
258         struct snd_pcm_runtime *runtime = substream->runtime;
259         struct loopback_pcm *dpcm = runtime->private_data;
260         struct loopback_cable *cable = dpcm->cable;
261         int err, stream = 1 << substream->stream;
262 
263         switch (cmd) {
264         case SNDRV_PCM_TRIGGER_START:
265                 err = loopback_check_format(cable, substream->stream);
266                 if (err < 0)
267                         return err;
268                 dpcm->last_jiffies = jiffies;
269                 dpcm->pcm_rate_shift = 0;
270                 dpcm->last_drift = 0;
271                 spin_lock(&cable->lock);        
272                 cable->running |= stream;
273                 cable->pause &= ~stream;
274                 loopback_timer_start(dpcm);
275                 spin_unlock(&cable->lock);
276                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
277                         loopback_active_notify(dpcm);
278                 break;
279         case SNDRV_PCM_TRIGGER_STOP:
280                 spin_lock(&cable->lock);        
281                 cable->running &= ~stream;
282                 cable->pause &= ~stream;
283                 loopback_timer_stop(dpcm);
284                 spin_unlock(&cable->lock);
285                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
286                         loopback_active_notify(dpcm);
287                 break;
288         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
289         case SNDRV_PCM_TRIGGER_SUSPEND:
290                 spin_lock(&cable->lock);        
291                 cable->pause |= stream;
292                 loopback_timer_stop(dpcm);
293                 spin_unlock(&cable->lock);
294                 break;
295         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
296         case SNDRV_PCM_TRIGGER_RESUME:
297                 spin_lock(&cable->lock);
298                 dpcm->last_jiffies = jiffies;
299                 cable->pause &= ~stream;
300                 loopback_timer_start(dpcm);
301                 spin_unlock(&cable->lock);
302                 break;
303         default:
304                 return -EINVAL;
305         }
306         return 0;
307 }
308 
309 static void params_change_substream(struct loopback_pcm *dpcm,
310                                     struct snd_pcm_runtime *runtime)
311 {
312         struct snd_pcm_runtime *dst_runtime;
313 
314         if (dpcm == NULL || dpcm->substream == NULL)
315                 return;
316         dst_runtime = dpcm->substream->runtime;
317         if (dst_runtime == NULL)
318                 return;
319         dst_runtime->hw = dpcm->cable->hw;
320 }
321 
322 static void params_change(struct snd_pcm_substream *substream)
323 {
324         struct snd_pcm_runtime *runtime = substream->runtime;
325         struct loopback_pcm *dpcm = runtime->private_data;
326         struct loopback_cable *cable = dpcm->cable;
327 
328         cable->hw.formats = pcm_format_to_bits(runtime->format);
329         cable->hw.rate_min = runtime->rate;
330         cable->hw.rate_max = runtime->rate;
331         cable->hw.channels_min = runtime->channels;
332         cable->hw.channels_max = runtime->channels;
333         params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
334                                 runtime);
335         params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
336                                 runtime);
337 }
338 
339 static int loopback_prepare(struct snd_pcm_substream *substream)
340 {
341         struct snd_pcm_runtime *runtime = substream->runtime;
342         struct loopback_pcm *dpcm = runtime->private_data;
343         struct loopback_cable *cable = dpcm->cable;
344         int bps, salign;
345 
346         salign = (snd_pcm_format_width(runtime->format) *
347                                                 runtime->channels) / 8;
348         bps = salign * runtime->rate;
349         if (bps <= 0 || salign <= 0)
350                 return -EINVAL;
351 
352         dpcm->buf_pos = 0;
353         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
354         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
355                 /* clear capture buffer */
356                 dpcm->silent_size = dpcm->pcm_buffer_size;
357                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
358                                            runtime->buffer_size * runtime->channels);
359         }
360 
361         dpcm->irq_pos = 0;
362         dpcm->period_update_pending = 0;
363         dpcm->pcm_bps = bps;
364         dpcm->pcm_salign = salign;
365         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
366 
367         mutex_lock(&dpcm->loopback->cable_lock);
368         if (!(cable->valid & ~(1 << substream->stream)) ||
369             (get_setup(dpcm)->notify &&
370              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
371                 params_change(substream);
372         cable->valid |= 1 << substream->stream;
373         mutex_unlock(&dpcm->loopback->cable_lock);
374 
375         return 0;
376 }
377 
378 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
379 {
380         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
381         char *dst = runtime->dma_area;
382         unsigned int dst_off = dpcm->buf_pos;
383 
384         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
385                 return;
386         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
387                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
388 
389         for (;;) {
390                 unsigned int size = bytes;
391                 if (dst_off + size > dpcm->pcm_buffer_size)
392                         size = dpcm->pcm_buffer_size - dst_off;
393                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
394                                            bytes_to_frames(runtime, size) *
395                                                 runtime->channels);
396                 dpcm->silent_size += size;
397                 bytes -= size;
398                 if (!bytes)
399                         break;
400                 dst_off = 0;
401         }
402 }
403 
404 static void copy_play_buf(struct loopback_pcm *play,
405                           struct loopback_pcm *capt,
406                           unsigned int bytes)
407 {
408         struct snd_pcm_runtime *runtime = play->substream->runtime;
409         char *src = runtime->dma_area;
410         char *dst = capt->substream->runtime->dma_area;
411         unsigned int src_off = play->buf_pos;
412         unsigned int dst_off = capt->buf_pos;
413         unsigned int clear_bytes = 0;
414 
415         /* check if playback is draining, trim the capture copy size
416          * when our pointer is at the end of playback ring buffer */
417         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
418             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { 
419                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
420                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
421                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
422                 appl_ptr1 += play->buf_pos / play->pcm_salign;
423                 if (appl_ptr < appl_ptr1)
424                         appl_ptr1 -= runtime->buffer_size;
425                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
426                 if (diff < bytes) {
427                         clear_bytes = bytes - diff;
428                         bytes = diff;
429                 }
430         }
431 
432         for (;;) {
433                 unsigned int size = bytes;
434                 if (src_off + size > play->pcm_buffer_size)
435                         size = play->pcm_buffer_size - src_off;
436                 if (dst_off + size > capt->pcm_buffer_size)
437                         size = capt->pcm_buffer_size - dst_off;
438                 memcpy(dst + dst_off, src + src_off, size);
439                 capt->silent_size = 0;
440                 bytes -= size;
441                 if (!bytes)
442                         break;
443                 src_off = (src_off + size) % play->pcm_buffer_size;
444                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
445         }
446 
447         if (clear_bytes > 0) {
448                 clear_capture_buf(capt, clear_bytes);
449                 capt->silent_size = 0;
450         }
451 }
452 
453 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
454                                          unsigned int jiffies_delta)
455 {
456         unsigned long last_pos;
457         unsigned int delta;
458 
459         last_pos = byte_pos(dpcm, dpcm->irq_pos);
460         dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
461         delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
462         if (delta >= dpcm->last_drift)
463                 delta -= dpcm->last_drift;
464         dpcm->last_drift = 0;
465         if (dpcm->irq_pos >= dpcm->period_size_frac) {
466                 dpcm->irq_pos %= dpcm->period_size_frac;
467                 dpcm->period_update_pending = 1;
468         }
469         return delta;
470 }
471 
472 static inline void bytepos_finish(struct loopback_pcm *dpcm,
473                                   unsigned int delta)
474 {
475         dpcm->buf_pos += delta;
476         dpcm->buf_pos %= dpcm->pcm_buffer_size;
477 }
478 
479 /* call in cable->lock */
480 static unsigned int loopback_pos_update(struct loopback_cable *cable)
481 {
482         struct loopback_pcm *dpcm_play =
483                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
484         struct loopback_pcm *dpcm_capt =
485                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
486         unsigned long delta_play = 0, delta_capt = 0;
487         unsigned int running, count1, count2;
488 
489         running = cable->running ^ cable->pause;
490         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
491                 delta_play = jiffies - dpcm_play->last_jiffies;
492                 dpcm_play->last_jiffies += delta_play;
493         }
494 
495         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
496                 delta_capt = jiffies - dpcm_capt->last_jiffies;
497                 dpcm_capt->last_jiffies += delta_capt;
498         }
499 
500         if (delta_play == 0 && delta_capt == 0)
501                 goto unlock;
502                 
503         if (delta_play > delta_capt) {
504                 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
505                 bytepos_finish(dpcm_play, count1);
506                 delta_play = delta_capt;
507         } else if (delta_play < delta_capt) {
508                 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
509                 clear_capture_buf(dpcm_capt, count1);
510                 bytepos_finish(dpcm_capt, count1);
511                 delta_capt = delta_play;
512         }
513 
514         if (delta_play == 0 && delta_capt == 0)
515                 goto unlock;
516 
517         /* note delta_capt == delta_play at this moment */
518         count1 = bytepos_delta(dpcm_play, delta_play);
519         count2 = bytepos_delta(dpcm_capt, delta_capt);
520         if (count1 < count2) {
521                 dpcm_capt->last_drift = count2 - count1;
522                 count1 = count2;
523         } else if (count1 > count2) {
524                 dpcm_play->last_drift = count1 - count2;
525         }
526         copy_play_buf(dpcm_play, dpcm_capt, count1);
527         bytepos_finish(dpcm_play, count1);
528         bytepos_finish(dpcm_capt, count1);
529  unlock:
530         return running;
531 }
532 
533 static void loopback_timer_function(unsigned long data)
534 {
535         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
536         unsigned long flags;
537 
538         spin_lock_irqsave(&dpcm->cable->lock, flags);
539         if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
540                 loopback_timer_start(dpcm);
541                 if (dpcm->period_update_pending) {
542                         dpcm->period_update_pending = 0;
543                         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
544                         /* need to unlock before calling below */
545                         snd_pcm_period_elapsed(dpcm->substream);
546                         return;
547                 }
548         }
549         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
550 }
551 
552 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
553 {
554         struct snd_pcm_runtime *runtime = substream->runtime;
555         struct loopback_pcm *dpcm = runtime->private_data;
556         snd_pcm_uframes_t pos;
557 
558         spin_lock(&dpcm->cable->lock);
559         loopback_pos_update(dpcm->cable);
560         pos = dpcm->buf_pos;
561         spin_unlock(&dpcm->cable->lock);
562         return bytes_to_frames(runtime, pos);
563 }
564 
565 static struct snd_pcm_hardware loopback_pcm_hardware =
566 {
567         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
568                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
569                          SNDRV_PCM_INFO_RESUME),
570         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
571                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
572                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
573         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
574         .rate_min =             8000,
575         .rate_max =             192000,
576         .channels_min =         1,
577         .channels_max =         32,
578         .buffer_bytes_max =     2 * 1024 * 1024,
579         .period_bytes_min =     64,
580         /* note check overflow in frac_pos() using pcm_rate_shift before
581            changing period_bytes_max value */
582         .period_bytes_max =     1024 * 1024,
583         .periods_min =          1,
584         .periods_max =          1024,
585         .fifo_size =            0,
586 };
587 
588 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
589 {
590         struct loopback_pcm *dpcm = runtime->private_data;
591         kfree(dpcm);
592 }
593 
594 static int loopback_hw_params(struct snd_pcm_substream *substream,
595                               struct snd_pcm_hw_params *params)
596 {
597         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
598                                                 params_buffer_bytes(params));
599 }
600 
601 static int loopback_hw_free(struct snd_pcm_substream *substream)
602 {
603         struct snd_pcm_runtime *runtime = substream->runtime;
604         struct loopback_pcm *dpcm = runtime->private_data;
605         struct loopback_cable *cable = dpcm->cable;
606 
607         mutex_lock(&dpcm->loopback->cable_lock);
608         cable->valid &= ~(1 << substream->stream);
609         mutex_unlock(&dpcm->loopback->cable_lock);
610         return snd_pcm_lib_free_vmalloc_buffer(substream);
611 }
612 
613 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
614 {
615         if (!substream->pcm->device)
616                 return substream->stream;
617         else
618                 return !substream->stream;
619 }
620 
621 static int rule_format(struct snd_pcm_hw_params *params,
622                        struct snd_pcm_hw_rule *rule)
623 {
624 
625         struct snd_pcm_hardware *hw = rule->private;
626         struct snd_mask *maskp = hw_param_mask(params, rule->var);
627 
628         maskp->bits[0] &= (u_int32_t)hw->formats;
629         maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
630         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
631         if (! maskp->bits[0] && ! maskp->bits[1])
632                 return -EINVAL;
633         return 0;
634 }
635 
636 static int rule_rate(struct snd_pcm_hw_params *params,
637                      struct snd_pcm_hw_rule *rule)
638 {
639         struct snd_pcm_hardware *hw = rule->private;
640         struct snd_interval t;
641 
642         t.min = hw->rate_min;
643         t.max = hw->rate_max;
644         t.openmin = t.openmax = 0;
645         t.integer = 0;
646         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
647 }
648 
649 static int rule_channels(struct snd_pcm_hw_params *params,
650                          struct snd_pcm_hw_rule *rule)
651 {
652         struct snd_pcm_hardware *hw = rule->private;
653         struct snd_interval t;
654 
655         t.min = hw->channels_min;
656         t.max = hw->channels_max;
657         t.openmin = t.openmax = 0;
658         t.integer = 0;
659         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
660 }
661 
662 static int loopback_open(struct snd_pcm_substream *substream)
663 {
664         struct snd_pcm_runtime *runtime = substream->runtime;
665         struct loopback *loopback = substream->private_data;
666         struct loopback_pcm *dpcm;
667         struct loopback_cable *cable;
668         int err = 0;
669         int dev = get_cable_index(substream);
670 
671         mutex_lock(&loopback->cable_lock);
672         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
673         if (!dpcm) {
674                 err = -ENOMEM;
675                 goto unlock;
676         }
677         dpcm->loopback = loopback;
678         dpcm->substream = substream;
679         setup_timer(&dpcm->timer, loopback_timer_function,
680                     (unsigned long)dpcm);
681 
682         cable = loopback->cables[substream->number][dev];
683         if (!cable) {
684                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
685                 if (!cable) {
686                         kfree(dpcm);
687                         err = -ENOMEM;
688                         goto unlock;
689                 }
690                 spin_lock_init(&cable->lock);
691                 cable->hw = loopback_pcm_hardware;
692                 loopback->cables[substream->number][dev] = cable;
693         }
694         dpcm->cable = cable;
695         cable->streams[substream->stream] = dpcm;
696 
697         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
698 
699         /* use dynamic rules based on actual runtime->hw values */
700         /* note that the default rules created in the PCM midlevel code */
701         /* are cached -> they do not reflect the actual state */
702         err = snd_pcm_hw_rule_add(runtime, 0,
703                                   SNDRV_PCM_HW_PARAM_FORMAT,
704                                   rule_format, &runtime->hw,
705                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
706         if (err < 0)
707                 goto unlock;
708         err = snd_pcm_hw_rule_add(runtime, 0,
709                                   SNDRV_PCM_HW_PARAM_RATE,
710                                   rule_rate, &runtime->hw,
711                                   SNDRV_PCM_HW_PARAM_RATE, -1);
712         if (err < 0)
713                 goto unlock;
714         err = snd_pcm_hw_rule_add(runtime, 0,
715                                   SNDRV_PCM_HW_PARAM_CHANNELS,
716                                   rule_channels, &runtime->hw,
717                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
718         if (err < 0)
719                 goto unlock;
720 
721         runtime->private_data = dpcm;
722         runtime->private_free = loopback_runtime_free;
723         if (get_notify(dpcm))
724                 runtime->hw = loopback_pcm_hardware;
725         else
726                 runtime->hw = cable->hw;
727  unlock:
728         mutex_unlock(&loopback->cable_lock);
729         return err;
730 }
731 
732 static int loopback_close(struct snd_pcm_substream *substream)
733 {
734         struct loopback *loopback = substream->private_data;
735         struct loopback_pcm *dpcm = substream->runtime->private_data;
736         struct loopback_cable *cable;
737         int dev = get_cable_index(substream);
738 
739         loopback_timer_stop(dpcm);
740         mutex_lock(&loopback->cable_lock);
741         cable = loopback->cables[substream->number][dev];
742         if (cable->streams[!substream->stream]) {
743                 /* other stream is still alive */
744                 cable->streams[substream->stream] = NULL;
745         } else {
746                 /* free the cable */
747                 loopback->cables[substream->number][dev] = NULL;
748                 kfree(cable);
749         }
750         mutex_unlock(&loopback->cable_lock);
751         return 0;
752 }
753 
754 static struct snd_pcm_ops loopback_playback_ops = {
755         .open =         loopback_open,
756         .close =        loopback_close,
757         .ioctl =        snd_pcm_lib_ioctl,
758         .hw_params =    loopback_hw_params,
759         .hw_free =      loopback_hw_free,
760         .prepare =      loopback_prepare,
761         .trigger =      loopback_trigger,
762         .pointer =      loopback_pointer,
763         .page =         snd_pcm_lib_get_vmalloc_page,
764         .mmap =         snd_pcm_lib_mmap_vmalloc,
765 };
766 
767 static struct snd_pcm_ops loopback_capture_ops = {
768         .open =         loopback_open,
769         .close =        loopback_close,
770         .ioctl =        snd_pcm_lib_ioctl,
771         .hw_params =    loopback_hw_params,
772         .hw_free =      loopback_hw_free,
773         .prepare =      loopback_prepare,
774         .trigger =      loopback_trigger,
775         .pointer =      loopback_pointer,
776         .page =         snd_pcm_lib_get_vmalloc_page,
777         .mmap =         snd_pcm_lib_mmap_vmalloc,
778 };
779 
780 static int loopback_pcm_new(struct loopback *loopback,
781                             int device, int substreams)
782 {
783         struct snd_pcm *pcm;
784         int err;
785 
786         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
787                           substreams, substreams, &pcm);
788         if (err < 0)
789                 return err;
790         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
791         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
792 
793         pcm->private_data = loopback;
794         pcm->info_flags = 0;
795         strcpy(pcm->name, "Loopback PCM");
796 
797         loopback->pcm[device] = pcm;
798         return 0;
799 }
800 
801 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,   
802                                     struct snd_ctl_elem_info *uinfo) 
803 {
804         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
805         uinfo->count = 1;
806         uinfo->value.integer.min = 80000;
807         uinfo->value.integer.max = 120000;
808         uinfo->value.integer.step = 1;
809         return 0;
810 }                                  
811 
812 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
813                                    struct snd_ctl_elem_value *ucontrol)
814 {
815         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
816         
817         ucontrol->value.integer.value[0] =
818                 loopback->setup[kcontrol->id.subdevice]
819                                [kcontrol->id.device].rate_shift;
820         return 0;
821 }
822 
823 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
824                                    struct snd_ctl_elem_value *ucontrol)
825 {
826         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
827         unsigned int val;
828         int change = 0;
829 
830         val = ucontrol->value.integer.value[0];
831         if (val < 80000)
832                 val = 80000;
833         if (val > 120000)
834                 val = 120000;   
835         mutex_lock(&loopback->cable_lock);
836         if (val != loopback->setup[kcontrol->id.subdevice]
837                                   [kcontrol->id.device].rate_shift) {
838                 loopback->setup[kcontrol->id.subdevice]
839                                [kcontrol->id.device].rate_shift = val;
840                 change = 1;
841         }
842         mutex_unlock(&loopback->cable_lock);
843         return change;
844 }
845 
846 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
847                                struct snd_ctl_elem_value *ucontrol)
848 {
849         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
850         
851         ucontrol->value.integer.value[0] =
852                 loopback->setup[kcontrol->id.subdevice]
853                                [kcontrol->id.device].notify;
854         return 0;
855 }
856 
857 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
858                                struct snd_ctl_elem_value *ucontrol)
859 {
860         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
861         unsigned int val;
862         int change = 0;
863 
864         val = ucontrol->value.integer.value[0] ? 1 : 0;
865         if (val != loopback->setup[kcontrol->id.subdevice]
866                                 [kcontrol->id.device].notify) {
867                 loopback->setup[kcontrol->id.subdevice]
868                         [kcontrol->id.device].notify = val;
869                 change = 1;
870         }
871         return change;
872 }
873 
874 static int loopback_active_get(struct snd_kcontrol *kcontrol,
875                                struct snd_ctl_elem_value *ucontrol)
876 {
877         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
878         struct loopback_cable *cable = loopback->cables
879                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
880         unsigned int val = 0;
881 
882         if (cable != NULL)
883                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
884                                                                         1 : 0;
885         ucontrol->value.integer.value[0] = val;
886         return 0;
887 }
888 
889 static int loopback_format_info(struct snd_kcontrol *kcontrol,   
890                                 struct snd_ctl_elem_info *uinfo) 
891 {
892         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
893         uinfo->count = 1;
894         uinfo->value.integer.min = 0;
895         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
896         uinfo->value.integer.step = 1;
897         return 0;
898 }                                  
899 
900 static int loopback_format_get(struct snd_kcontrol *kcontrol,
901                                struct snd_ctl_elem_value *ucontrol)
902 {
903         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
904         
905         ucontrol->value.integer.value[0] =
906                 loopback->setup[kcontrol->id.subdevice]
907                                [kcontrol->id.device].format;
908         return 0;
909 }
910 
911 static int loopback_rate_info(struct snd_kcontrol *kcontrol,   
912                               struct snd_ctl_elem_info *uinfo) 
913 {
914         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
915         uinfo->count = 1;
916         uinfo->value.integer.min = 0;
917         uinfo->value.integer.max = 192000;
918         uinfo->value.integer.step = 1;
919         return 0;
920 }                                  
921 
922 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
923                              struct snd_ctl_elem_value *ucontrol)
924 {
925         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
926         
927         ucontrol->value.integer.value[0] =
928                 loopback->setup[kcontrol->id.subdevice]
929                                [kcontrol->id.device].rate;
930         return 0;
931 }
932 
933 static int loopback_channels_info(struct snd_kcontrol *kcontrol,   
934                                   struct snd_ctl_elem_info *uinfo) 
935 {
936         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
937         uinfo->count = 1;
938         uinfo->value.integer.min = 1;
939         uinfo->value.integer.max = 1024;
940         uinfo->value.integer.step = 1;
941         return 0;
942 }                                  
943 
944 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
945                                  struct snd_ctl_elem_value *ucontrol)
946 {
947         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
948         
949         ucontrol->value.integer.value[0] =
950                 loopback->setup[kcontrol->id.subdevice]
951                                [kcontrol->id.device].channels;
952         return 0;
953 }
954 
955 static struct snd_kcontrol_new loopback_controls[]  = {
956 {
957         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
958         .name =         "PCM Rate Shift 100000",
959         .info =         loopback_rate_shift_info,
960         .get =          loopback_rate_shift_get,
961         .put =          loopback_rate_shift_put,
962 },
963 {
964         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
965         .name =         "PCM Notify",
966         .info =         snd_ctl_boolean_mono_info,
967         .get =          loopback_notify_get,
968         .put =          loopback_notify_put,
969 },
970 #define ACTIVE_IDX 2
971 {
972         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
973         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
974         .name =         "PCM Slave Active",
975         .info =         snd_ctl_boolean_mono_info,
976         .get =          loopback_active_get,
977 },
978 #define FORMAT_IDX 3
979 {
980         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
981         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
982         .name =         "PCM Slave Format",
983         .info =         loopback_format_info,
984         .get =          loopback_format_get
985 },
986 #define RATE_IDX 4
987 {
988         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
989         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
990         .name =         "PCM Slave Rate",
991         .info =         loopback_rate_info,
992         .get =          loopback_rate_get
993 },
994 #define CHANNELS_IDX 5
995 {
996         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
997         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
998         .name =         "PCM Slave Channels",
999         .info =         loopback_channels_info,
1000         .get =          loopback_channels_get
1001 }
1002 };
1003 
1004 static int loopback_mixer_new(struct loopback *loopback, int notify)
1005 {
1006         struct snd_card *card = loopback->card;
1007         struct snd_pcm *pcm;
1008         struct snd_kcontrol *kctl;
1009         struct loopback_setup *setup;
1010         int err, dev, substr, substr_count, idx;
1011 
1012         strcpy(card->mixername, "Loopback Mixer");
1013         for (dev = 0; dev < 2; dev++) {
1014                 pcm = loopback->pcm[dev];
1015                 substr_count =
1016                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1017                 for (substr = 0; substr < substr_count; substr++) {
1018                         setup = &loopback->setup[substr][dev];
1019                         setup->notify = notify;
1020                         setup->rate_shift = NO_PITCH;
1021                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1022                         setup->rate = 48000;
1023                         setup->channels = 2;
1024                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1025                                                                         idx++) {
1026                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1027                                                     loopback);
1028                                 if (!kctl)
1029                                         return -ENOMEM;
1030                                 kctl->id.device = dev;
1031                                 kctl->id.subdevice = substr;
1032                                 switch (idx) {
1033                                 case ACTIVE_IDX:
1034                                         setup->active_id = kctl->id;
1035                                         break;
1036                                 case FORMAT_IDX:
1037                                         setup->format_id = kctl->id;
1038                                         break;
1039                                 case RATE_IDX:
1040                                         setup->rate_id = kctl->id;
1041                                         break;
1042                                 case CHANNELS_IDX:
1043                                         setup->channels_id = kctl->id;
1044                                         break;
1045                                 default:
1046                                         break;
1047                                 }
1048                                 err = snd_ctl_add(card, kctl);
1049                                 if (err < 0)
1050                                         return err;
1051                         }
1052                 }
1053         }
1054         return 0;
1055 }
1056 
1057 #ifdef CONFIG_PROC_FS
1058 
1059 static void print_dpcm_info(struct snd_info_buffer *buffer,
1060                             struct loopback_pcm *dpcm,
1061                             const char *id)
1062 {
1063         snd_iprintf(buffer, "  %s\n", id);
1064         if (dpcm == NULL) {
1065                 snd_iprintf(buffer, "    inactive\n");
1066                 return;
1067         }
1068         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1069         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1070         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1071         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1072         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1073         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1074         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1075         snd_iprintf(buffer, "    update_pending:\t%u\n",
1076                                                 dpcm->period_update_pending);
1077         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1078         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1079         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1080                                         dpcm->last_jiffies, jiffies);
1081         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1082 }
1083 
1084 static void print_substream_info(struct snd_info_buffer *buffer,
1085                                  struct loopback *loopback,
1086                                  int sub,
1087                                  int num)
1088 {
1089         struct loopback_cable *cable = loopback->cables[sub][num];
1090 
1091         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1092         if (cable == NULL) {
1093                 snd_iprintf(buffer, "  inactive\n");
1094                 return;
1095         }
1096         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1097         snd_iprintf(buffer, "  running: %u\n", cable->running);
1098         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1099         print_dpcm_info(buffer, cable->streams[0], "Playback");
1100         print_dpcm_info(buffer, cable->streams[1], "Capture");
1101 }
1102 
1103 static void print_cable_info(struct snd_info_entry *entry,
1104                              struct snd_info_buffer *buffer)
1105 {
1106         struct loopback *loopback = entry->private_data;
1107         int sub, num;
1108 
1109         mutex_lock(&loopback->cable_lock);
1110         num = entry->name[strlen(entry->name)-1];
1111         num = num == '' ? 0 : 1;
1112         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1113                 print_substream_info(buffer, loopback, sub, num);
1114         mutex_unlock(&loopback->cable_lock);
1115 }
1116 
1117 static int loopback_proc_new(struct loopback *loopback, int cidx)
1118 {
1119         char name[32];
1120         struct snd_info_entry *entry;
1121         int err;
1122 
1123         snprintf(name, sizeof(name), "cable#%d", cidx);
1124         err = snd_card_proc_new(loopback->card, name, &entry);
1125         if (err < 0)
1126                 return err;
1127 
1128         snd_info_set_text_ops(entry, loopback, print_cable_info);
1129         return 0;
1130 }
1131 
1132 #else /* !CONFIG_PROC_FS */
1133 
1134 #define loopback_proc_new(loopback, cidx) do { } while (0)
1135 
1136 #endif
1137 
1138 static int loopback_probe(struct platform_device *devptr)
1139 {
1140         struct snd_card *card;
1141         struct loopback *loopback;
1142         int dev = devptr->id;
1143         int err;
1144 
1145         err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1146                            sizeof(struct loopback), &card);
1147         if (err < 0)
1148                 return err;
1149         loopback = card->private_data;
1150 
1151         if (pcm_substreams[dev] < 1)
1152                 pcm_substreams[dev] = 1;
1153         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1154                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1155         
1156         loopback->card = card;
1157         mutex_init(&loopback->cable_lock);
1158 
1159         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1160         if (err < 0)
1161                 goto __nodev;
1162         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1163         if (err < 0)
1164                 goto __nodev;
1165         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1166         if (err < 0)
1167                 goto __nodev;
1168         loopback_proc_new(loopback, 0);
1169         loopback_proc_new(loopback, 1);
1170         strcpy(card->driver, "Loopback");
1171         strcpy(card->shortname, "Loopback");
1172         sprintf(card->longname, "Loopback %i", dev + 1);
1173         err = snd_card_register(card);
1174         if (!err) {
1175                 platform_set_drvdata(devptr, card);
1176                 return 0;
1177         }
1178       __nodev:
1179         snd_card_free(card);
1180         return err;
1181 }
1182 
1183 static int loopback_remove(struct platform_device *devptr)
1184 {
1185         snd_card_free(platform_get_drvdata(devptr));
1186         return 0;
1187 }
1188 
1189 #ifdef CONFIG_PM_SLEEP
1190 static int loopback_suspend(struct device *pdev)
1191 {
1192         struct snd_card *card = dev_get_drvdata(pdev);
1193         struct loopback *loopback = card->private_data;
1194 
1195         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1196 
1197         snd_pcm_suspend_all(loopback->pcm[0]);
1198         snd_pcm_suspend_all(loopback->pcm[1]);
1199         return 0;
1200 }
1201         
1202 static int loopback_resume(struct device *pdev)
1203 {
1204         struct snd_card *card = dev_get_drvdata(pdev);
1205 
1206         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1207         return 0;
1208 }
1209 
1210 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1211 #define LOOPBACK_PM_OPS &loopback_pm
1212 #else
1213 #define LOOPBACK_PM_OPS NULL
1214 #endif
1215 
1216 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1217 
1218 static struct platform_driver loopback_driver = {
1219         .probe          = loopback_probe,
1220         .remove         = loopback_remove,
1221         .driver         = {
1222                 .name   = SND_LOOPBACK_DRIVER,
1223                 .owner  = THIS_MODULE,
1224                 .pm     = LOOPBACK_PM_OPS,
1225         },
1226 };
1227 
1228 static void loopback_unregister_all(void)
1229 {
1230         int i;
1231 
1232         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1233                 platform_device_unregister(devices[i]);
1234         platform_driver_unregister(&loopback_driver);
1235 }
1236 
1237 static int __init alsa_card_loopback_init(void)
1238 {
1239         int i, err, cards;
1240 
1241         err = platform_driver_register(&loopback_driver);
1242         if (err < 0)
1243                 return err;
1244 
1245 
1246         cards = 0;
1247         for (i = 0; i < SNDRV_CARDS; i++) {
1248                 struct platform_device *device;
1249                 if (!enable[i])
1250                         continue;
1251                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1252                                                          i, NULL, 0);
1253                 if (IS_ERR(device))
1254                         continue;
1255                 if (!platform_get_drvdata(device)) {
1256                         platform_device_unregister(device);
1257                         continue;
1258                 }
1259                 devices[i] = device;
1260                 cards++;
1261         }
1262         if (!cards) {
1263 #ifdef MODULE
1264                 printk(KERN_ERR "aloop: No loopback enabled\n");
1265 #endif
1266                 loopback_unregister_all();
1267                 return -ENODEV;
1268         }
1269         return 0;
1270 }
1271 
1272 static void __exit alsa_card_loopback_exit(void)
1273 {
1274         loopback_unregister_all();
1275 }
1276 
1277 module_init(alsa_card_loopback_init)
1278 module_exit(alsa_card_loopback_exit)
1279 

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