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 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>
  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 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];
  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 long last_jiffies;
 121         struct timer_list timer;
 122 };
 123
 124 static struct platform_device *devices[SNDRV_CARDS];
 125
 126 static 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
 137 static 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
 148 static 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
 157 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 158 {
 159         return get_setup(dpcm)->notify;
 160 }
 161
 162 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 163 {
 164         return get_setup(dpcm)->rate_shift;
 165 }
 166
 167 static 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         }
 176         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 177                 dpcm->irq_pos %= dpcm->period_size_frac;
 178                 dpcm->period_update_pending = 1;
 179         }
 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
 186 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 187 {
 188         del_timer(&dpcm->timer);
 189         dpcm->timer.expires = 0;
 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
 196 static int loopback_check_format(struct loopback_cable *cable, int stream)
 197 {
 198         struct snd_pcm_runtime *runtime, *cruntime;
 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;
 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;
 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
 246 static 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
 253 static 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;
 258         int err, stream = 1 << substream->stream;
 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;
 267                 spin_lock(&cable->lock);
 268                 cable->running |= stream;
 269                 cable->pause &= ~stream;
 270                 spin_unlock(&cable->lock);
 271                 loopback_timer_start(dpcm);
 272                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 273                         loopback_active_notify(dpcm);
 274                 break;
 275         case SNDRV_PCM_TRIGGER_STOP:
 276                 spin_lock(&cable->lock);
 277                 cable->running &= ~stream;
 278                 cable->pause &= ~stream;
 279                 spin_unlock(&cable->lock);
 280                 loopback_timer_stop(dpcm);
 281                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 282                         loopback_active_notify(dpcm);
 283                 break;
 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;
 297         default:
 298                 return -EINVAL;
 299         }
 300         return 0;
 301 }
 302
 303 static 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
 316 static 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
 333 static 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;
 338         int bps, salign;
 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);
 362         if (!(cable->valid & ~(1 << substream->stream)) ||
 363             (get_setup(dpcm)->notify &&
 364              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 365                 params_change(substream);
 366         cable->valid |= 1 << substream->stream;
 367         mutex_unlock(&dpcm->loopback->cable_lock);
 368
 369         return 0;
 370 }
 371
 372 static 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
 398 static 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;
 403         char *src = runtime->dma_area;
 404         char *dst = capt->substream->runtime->dma_area;
 405         unsigned int src_off = play->buf_pos;
 406         unsigned int dst_off = capt->buf_pos;
 407         unsigned int clear_bytes = 0;
 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
 441         if (clear_bytes > 0) {
 442                 clear_capture_buf(capt, clear_bytes);
 443                 capt->silent_size = 0;
 444         }
 445 }
 446
 447 #define BYTEPOS_UPDATE_POSONLY  0
 448 #define BYTEPOS_UPDATE_CLEAR    1
 449 #define BYTEPOS_UPDATE_COPY     2
 450
 451 static 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
 477 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 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;
 484         unsigned int running;
 485         unsigned long flags;
 486
 487         spin_lock_irqsave(&cable->lock, flags);
 488         running = cable->running ^ cable->pause;
 489         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 490                 delta_play = jiffies - dpcm_play->last_jiffies;
 491                 dpcm_play->last_jiffies += delta_play;
 492         }
 493
 494         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 495                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 496                 dpcm_capt->last_jiffies += delta_capt;
 497         }
 498
 499         if (delta_play == 0 && delta_capt == 0)
 500                 goto unlock;
 501
 502         if (delta_play > delta_capt) {
 503                 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
 504                                         BYTEPOS_UPDATE_POSONLY);
 505                 delta_play = delta_capt;
 506         } else if (delta_play < delta_capt) {
 507                 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
 508                                         BYTEPOS_UPDATE_CLEAR);
 509                 delta_capt = delta_play;
 510         }
 511
 512         if (delta_play == 0 && delta_capt == 0)
 513                 goto unlock;
 514
 515         /* note delta_capt == delta_play at this moment */
 516         loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
 517         loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
 518  unlock:
 519         spin_unlock_irqrestore(&cable->lock, flags);
 520         return running;
 521 }
 522
 523 static void loopback_timer_function(unsigned long data)
 524 {
 525         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 526         unsigned int running;
 527
 528         running = loopback_pos_update(dpcm->cable);
 529         if (running & (1 << dpcm->substream->stream)) {
 530                 loopback_timer_start(dpcm);
 531                 if (dpcm->period_update_pending) {
 532                         dpcm->period_update_pending = 0;
 533                         snd_pcm_period_elapsed(dpcm->substream);
 534                 }
 535         }
 536 }
 537
 538 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 539 {
 540         struct snd_pcm_runtime *runtime = substream->runtime;
 541         struct loopback_pcm *dpcm = runtime->private_data;
 542
 543         loopback_pos_update(dpcm->cable);
 544         return bytes_to_frames(runtime, dpcm->buf_pos);
 545 }
 546
 547 static struct snd_pcm_hardware loopback_pcm_hardware =
 548 {
 549         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 550                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE),
 551         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 552                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 553                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 554         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 555         .rate_min =             8000,
 556         .rate_max =             192000,
 557         .channels_min =         1,
 558         .channels_max =         32,
 559         .buffer_bytes_max =     2 * 1024 * 1024,
 560         .period_bytes_min =     64,
 561         /* note check overflow in frac_pos() using pcm_rate_shift before
 562            changing period_bytes_max value */
 563         .period_bytes_max =     1024 * 1024,
 564         .periods_min =          1,
 565         .periods_max =          1024,
 566         .fifo_size =            0,
 567 };
 568
 569 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 570 {
 571         struct loopback_pcm *dpcm = runtime->private_data;
 572         kfree(dpcm);
 573 }
 574
 575 static int loopback_hw_params(struct snd_pcm_substream *substream,
 576                               struct snd_pcm_hw_params *params)
 577 {
 578         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 579                                                 params_buffer_bytes(params));
 580 }
 581
 582 static 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_vmalloc_buffer(substream);
 592 }
 593
 594 static 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
 602 static 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
 617 static 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
 630 static 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
 643 static 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
 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
 702         runtime->private_data = dpcm;
 703         runtime->private_free = loopback_runtime_free;
 704         if (get_notify(dpcm))
 705                 runtime->hw = loopback_pcm_hardware;
 706         else
 707                 runtime->hw = cable->hw;
 708  unlock:
 709         mutex_unlock(&loopback->cable_lock);
 710         return err;
 711 }
 712
 713 static 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
 735 static 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         .page =         snd_pcm_lib_get_vmalloc_page,
 745         .mmap =         snd_pcm_lib_mmap_vmalloc,
 746 };
 747
 748 static struct snd_pcm_ops loopback_capture_ops = {
 749         .open =         loopback_open,
 750         .close =        loopback_close,
 751         .ioctl =        snd_pcm_lib_ioctl,
 752         .hw_params =    loopback_hw_params,
 753         .hw_free =      loopback_hw_free,
 754         .prepare =      loopback_prepare,
 755         .trigger =      loopback_trigger,
 756         .pointer =      loopback_pointer,
 757         .page =         snd_pcm_lib_get_vmalloc_page,
 758         .mmap =         snd_pcm_lib_mmap_vmalloc,
 759 };
 760
 761 static int __devinit loopback_pcm_new(struct loopback *loopback,
 762                                       int device, int substreams)
 763 {
 764         struct snd_pcm *pcm;
 765         int err;
 766
 767         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 768                           substreams, substreams, &pcm);
 769         if (err < 0)
 770                 return err;
 771         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 772         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 773
 774         pcm->private_data = loopback;
 775         pcm->info_flags = 0;
 776         strcpy(pcm->name, "Loopback PCM");
 777
 778         loopback->pcm[device] = pcm;
 779         return 0;
 780 }
 781
 782 static 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
 793 static 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
 804 static 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
 827 static 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
 838 static 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
 855 static 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
 860                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 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
 870 static 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
 881 static 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
 892 static 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
 903 static 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
 914 static 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
 925 static 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]
 932                                [kcontrol->id.device].channels;
 933         return 0;
 934 }
 935
 936 static 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
 985 static 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
1038 #ifdef CONFIG_PROC_FS
1039
1040 static 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
1065 static 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);
1079         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1080         print_dpcm_info(buffer, cable->streams[0], "Playback");
1081         print_dpcm_info(buffer, cable->streams[1], "Capture");
1082 }
1083
1084 static 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
1098 static 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
1119 static 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;
1149         loopback_proc_new(loopback, 0);
1150         loopback_proc_new(loopback, 1);
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
1164 static 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
1172 static 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
1185 static 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
1196 static 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
1208 static 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
1217 static 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
1252 static void __exit alsa_card_loopback_exit(void)
1253 {
1254         loopback_unregister_all();
1255 }
1256
1257 module_init(alsa_card_loopback_init)
1258 module_exit(alsa_card_loopback_exit)