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/module.h>
  38 #include <linux/platform_device.h>
  39 #include <sound/core.h>
  40 #include <sound/control.h>
  41 #include <sound/pcm.h>
  42 #include <sound/pcm_params.h>
  43 #include <sound/info.h>
  44 #include <sound/initval.h>
  45
  46 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  47 MODULE_DESCRIPTION("A loopback soundcard");
  48 MODULE_LICENSE("GPL");
  49 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  50
  51 #define MAX_PCM_SUBSTREAMS      8
  52
  53 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  54 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  55 static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  57 static int pcm_notify[SNDRV_CARDS];
  58
  59 module_param_array(index, int, NULL, 0444);
  60 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  61 module_param_array(id, charp, NULL, 0444);
  62 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  63 module_param_array(enable, bool, NULL, 0444);
  64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  65 module_param_array(pcm_substreams, int, NULL, 0444);
  66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  67 module_param_array(pcm_notify, int, NULL, 0444);
  68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  69
  70 #define NO_PITCH 100000
  71
  72 struct loopback_pcm;
  73
  74 struct loopback_cable {
  75         spinlock_t lock;
  76         struct loopback_pcm *streams[2];
  77         struct snd_pcm_hardware hw;
  78         /* flags */
  79         unsigned int valid;
  80         unsigned int running;
  81         unsigned int pause;
  82 };
  83
  84 struct loopback_setup {
  85         unsigned int notify: 1;
  86         unsigned int rate_shift;
  87         unsigned int format;
  88         unsigned int rate;
  89         unsigned int channels;
  90         struct snd_ctl_elem_id active_id;
  91         struct snd_ctl_elem_id format_id;
  92         struct snd_ctl_elem_id rate_id;
  93         struct snd_ctl_elem_id channels_id;
  94 };
  95
  96 struct loopback {
  97         struct snd_card *card;
  98         struct mutex cable_lock;
  99         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
 100         struct snd_pcm *pcm[2];
 101         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 102 };
 103
 104 struct loopback_pcm {
 105         struct loopback *loopback;
 106         struct snd_pcm_substream *substream;
 107         struct loopback_cable *cable;
 108         unsigned int pcm_buffer_size;
 109         unsigned int buf_pos;   /* position in buffer */
 110         unsigned int silent_size;
 111         /* PCM parameters */
 112         unsigned int pcm_period_size;
 113         unsigned int pcm_bps;           /* bytes per second */
 114         unsigned int pcm_salign;        /* bytes per sample * channels */
 115         unsigned int pcm_rate_shift;    /* rate shift value */
 116         /* flags */
 117         unsigned int period_update_pending :1;
 118         /* timer stuff */
 119         unsigned int irq_pos;           /* fractional IRQ position */
 120         unsigned int period_size_frac;
 121         unsigned long last_jiffies;
 122         struct timer_list timer;
 123         spinlock_t timer_lock;
 124 };
 125
 126 static struct platform_device *devices[SNDRV_CARDS];
 127
 128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 129 {
 130         if (dpcm->pcm_rate_shift == NO_PITCH) {
 131                 x /= HZ;
 132         } else {
 133                 x = div_u64(NO_PITCH * (unsigned long long)x,
 134                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 135         }
 136         return x - (x % dpcm->pcm_salign);
 137 }
 138
 139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 140 {
 141         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 142                 return x * HZ;
 143         } else {
 144                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 145                             NO_PITCH);
 146         }
 147         return x;
 148 }
 149
 150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 151 {
 152         int device = dpcm->substream->pstr->pcm->device;
 153
 154         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 155                 device ^= 1;
 156         return &dpcm->loopback->setup[dpcm->substream->number][device];
 157 }
 158
 159 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 160 {
 161         return get_setup(dpcm)->notify;
 162 }
 163
 164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 165 {
 166         return get_setup(dpcm)->rate_shift;
 167 }
 168
 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         spin_lock(&dpcm->timer_lock);
 175         if (rate_shift != dpcm->pcm_rate_shift) {
 176                 dpcm->pcm_rate_shift = rate_shift;
 177                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 178         }
 179         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 180                 dpcm->irq_pos %= dpcm->period_size_frac;
 181                 dpcm->period_update_pending = 1;
 182         }
 183         tick = dpcm->period_size_frac - dpcm->irq_pos;
 184         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 185         dpcm->timer.expires = jiffies + tick;
 186         add_timer(&dpcm->timer);
 187         spin_unlock(&dpcm->timer_lock);
 188 }
 189
 190 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 191 {
 192         spin_lock(&dpcm->timer_lock);
 193         del_timer(&dpcm->timer);
 194         dpcm->timer.expires = 0;
 195         spin_unlock(&dpcm->timer_lock);
 196 }
 197
 198 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 199 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 200 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 201
 202 static int loopback_check_format(struct loopback_cable *cable, int stream)
 203 {
 204         struct snd_pcm_runtime *runtime, *cruntime;
 205         struct loopback_setup *setup;
 206         struct snd_card *card;
 207         int check;
 208
 209         if (cable->valid != CABLE_VALID_BOTH) {
 210                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 211                         goto __notify;
 212                 return 0;
 213         }
 214         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 215                                                         substream->runtime;
 216         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 217                                                         substream->runtime;
 218         check = runtime->format != cruntime->format ||
 219                 runtime->rate != cruntime->rate ||
 220                 runtime->channels != cruntime->channels;
 221         if (!check)
 222                 return 0;
 223         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 224                 return -EIO;
 225         } else {
 226                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 227                                         substream, SNDRV_PCM_STATE_DRAINING);
 228               __notify:
 229                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 230                                                         substream->runtime;
 231                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 232                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 233                 if (setup->format != runtime->format) {
 234                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 235                                                         &setup->format_id);
 236                         setup->format = runtime->format;
 237                 }
 238                 if (setup->rate != runtime->rate) {
 239                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 240                                                         &setup->rate_id);
 241                         setup->rate = runtime->rate;
 242                 }
 243                 if (setup->channels != runtime->channels) {
 244                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 245                                                         &setup->channels_id);
 246                         setup->channels = runtime->channels;
 247                 }
 248         }
 249         return 0;
 250 }
 251
 252 static void loopback_active_notify(struct loopback_pcm *dpcm)
 253 {
 254         snd_ctl_notify(dpcm->loopback->card,
 255                        SNDRV_CTL_EVENT_MASK_VALUE,
 256                        &get_setup(dpcm)->active_id);
 257 }
 258
 259 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 260 {
 261         struct snd_pcm_runtime *runtime = substream->runtime;
 262         struct loopback_pcm *dpcm = runtime->private_data;
 263         struct loopback_cable *cable = dpcm->cable;
 264         int err, stream = 1 << substream->stream;
 265
 266         switch (cmd) {
 267         case SNDRV_PCM_TRIGGER_START:
 268                 err = loopback_check_format(cable, substream->stream);
 269                 if (err < 0)
 270                         return err;
 271                 dpcm->last_jiffies = jiffies;
 272                 dpcm->pcm_rate_shift = 0;
 273                 spin_lock(&cable->lock);
 274                 cable->running |= stream;
 275                 cable->pause &= ~stream;
 276                 spin_unlock(&cable->lock);
 277                 loopback_timer_start(dpcm);
 278                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 279                         loopback_active_notify(dpcm);
 280                 break;
 281         case SNDRV_PCM_TRIGGER_STOP:
 282                 spin_lock(&cable->lock);
 283                 cable->running &= ~stream;
 284                 cable->pause &= ~stream;
 285                 spin_unlock(&cable->lock);
 286                 loopback_timer_stop(dpcm);
 287                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 288                         loopback_active_notify(dpcm);
 289                 break;
 290         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 291         case SNDRV_PCM_TRIGGER_SUSPEND:
 292                 spin_lock(&cable->lock);
 293                 cable->pause |= stream;
 294                 spin_unlock(&cable->lock);
 295                 loopback_timer_stop(dpcm);
 296                 break;
 297         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 298         case SNDRV_PCM_TRIGGER_RESUME:
 299                 spin_lock(&cable->lock);
 300                 dpcm->last_jiffies = jiffies;
 301                 cable->pause &= ~stream;
 302                 spin_unlock(&cable->lock);
 303                 loopback_timer_start(dpcm);
 304                 break;
 305         default:
 306                 return -EINVAL;
 307         }
 308         return 0;
 309 }
 310
 311 static void params_change(struct snd_pcm_substream *substream)
 312 {
 313         struct snd_pcm_runtime *runtime = substream->runtime;
 314         struct loopback_pcm *dpcm = runtime->private_data;
 315         struct loopback_cable *cable = dpcm->cable;
 316
 317         cable->hw.formats = (1ULL << runtime->format);
 318         cable->hw.rate_min = runtime->rate;
 319         cable->hw.rate_max = runtime->rate;
 320         cable->hw.channels_min = runtime->channels;
 321         cable->hw.channels_max = runtime->channels;
 322 }
 323
 324 static int loopback_prepare(struct snd_pcm_substream *substream)
 325 {
 326         struct snd_pcm_runtime *runtime = substream->runtime;
 327         struct loopback_pcm *dpcm = runtime->private_data;
 328         struct loopback_cable *cable = dpcm->cable;
 329         int bps, salign;
 330
 331         salign = (snd_pcm_format_width(runtime->format) *
 332                                                 runtime->channels) / 8;
 333         bps = salign * runtime->rate;
 334         if (bps <= 0 || salign <= 0)
 335                 return -EINVAL;
 336
 337         dpcm->buf_pos = 0;
 338         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 339         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 340                 /* clear capture buffer */
 341                 dpcm->silent_size = dpcm->pcm_buffer_size;
 342                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 343                                            runtime->buffer_size * runtime->channels);
 344         }
 345
 346         dpcm->irq_pos = 0;
 347         dpcm->period_update_pending = 0;
 348         dpcm->pcm_bps = bps;
 349         dpcm->pcm_salign = salign;
 350         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 351
 352         mutex_lock(&dpcm->loopback->cable_lock);
 353         if (!(cable->valid & ~(1 << substream->stream)) ||
 354             (get_setup(dpcm)->notify &&
 355              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 356                 params_change(substream);
 357         cable->valid |= 1 << substream->stream;
 358         mutex_unlock(&dpcm->loopback->cable_lock);
 359
 360         return 0;
 361 }
 362
 363 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 364 {
 365         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 366         char *dst = runtime->dma_area;
 367         unsigned int dst_off = dpcm->buf_pos;
 368
 369         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 370                 return;
 371         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 372                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 373
 374         for (;;) {
 375                 unsigned int size = bytes;
 376                 if (dst_off + size > dpcm->pcm_buffer_size)
 377                         size = dpcm->pcm_buffer_size - dst_off;
 378                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 379                                            bytes_to_frames(runtime, size) *
 380                                                 runtime->channels);
 381                 dpcm->silent_size += size;
 382                 bytes -= size;
 383                 if (!bytes)
 384                         break;
 385                 dst_off = 0;
 386         }
 387 }
 388
 389 static void copy_play_buf(struct loopback_pcm *play,
 390                           struct loopback_pcm *capt,
 391                           unsigned int bytes)
 392 {
 393         struct snd_pcm_runtime *runtime = play->substream->runtime;
 394         char *src = runtime->dma_area;
 395         char *dst = capt->substream->runtime->dma_area;
 396         unsigned int src_off = play->buf_pos;
 397         unsigned int dst_off = capt->buf_pos;
 398         unsigned int clear_bytes = 0;
 399
 400         /* check if playback is draining, trim the capture copy size
 401          * when our pointer is at the end of playback ring buffer */
 402         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 403             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 404                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 405                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 406                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 407                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 408                 if (appl_ptr < appl_ptr1)
 409                         appl_ptr1 -= runtime->buffer_size;
 410                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 411                 if (diff < bytes) {
 412                         clear_bytes = bytes - diff;
 413                         bytes = diff;
 414                 }
 415         }
 416
 417         for (;;) {
 418                 unsigned int size = bytes;
 419                 if (src_off + size > play->pcm_buffer_size)
 420                         size = play->pcm_buffer_size - src_off;
 421                 if (dst_off + size > capt->pcm_buffer_size)
 422                         size = capt->pcm_buffer_size - dst_off;
 423                 memcpy(dst + dst_off, src + src_off, size);
 424                 capt->silent_size = 0;
 425                 bytes -= size;
 426                 if (!bytes)
 427                         break;
 428                 src_off = (src_off + size) % play->pcm_buffer_size;
 429                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 430         }
 431
 432         if (clear_bytes > 0) {
 433                 clear_capture_buf(capt, clear_bytes);
 434                 capt->silent_size = 0;
 435         }
 436 }
 437
 438 #define BYTEPOS_UPDATE_POSONLY  0
 439 #define BYTEPOS_UPDATE_CLEAR    1
 440 #define BYTEPOS_UPDATE_COPY     2
 441
 442 static void loopback_bytepos_update(struct loopback_pcm *dpcm,
 443                                     unsigned int delta,
 444                                     unsigned int cmd)
 445 {
 446         unsigned int count;
 447         unsigned long last_pos;
 448
 449         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 450         dpcm->irq_pos += delta * dpcm->pcm_bps;
 451         count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 452         if (!count)
 453                 return;
 454         if (cmd == BYTEPOS_UPDATE_CLEAR)
 455                 clear_capture_buf(dpcm, count);
 456         else if (cmd == BYTEPOS_UPDATE_COPY)
 457                 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 458                               dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 459                               count);
 460         dpcm->buf_pos += count;
 461         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 462         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 463                 dpcm->irq_pos %= dpcm->period_size_frac;
 464                 dpcm->period_update_pending = 1;
 465         }
 466 }
 467
 468 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 469 {
 470         struct loopback_pcm *dpcm_play =
 471                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 472         struct loopback_pcm *dpcm_capt =
 473                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 474         unsigned long delta_play = 0, delta_capt = 0;
 475         unsigned int running;
 476         unsigned long flags;
 477
 478         spin_lock_irqsave(&cable->lock, flags);
 479         running = cable->running ^ cable->pause;
 480         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 481                 delta_play = jiffies - dpcm_play->last_jiffies;
 482                 dpcm_play->last_jiffies += delta_play;
 483         }
 484
 485         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 486                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 487                 dpcm_capt->last_jiffies += delta_capt;
 488         }
 489
 490         if (delta_play == 0 && delta_capt == 0)
 491                 goto unlock;
 492
 493         if (delta_play > delta_capt) {
 494                 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
 495                                         BYTEPOS_UPDATE_POSONLY);
 496                 delta_play = delta_capt;
 497         } else if (delta_play < delta_capt) {
 498                 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
 499                                         BYTEPOS_UPDATE_CLEAR);
 500                 delta_capt = delta_play;
 501         }
 502
 503         if (delta_play == 0 && delta_capt == 0)
 504                 goto unlock;
 505
 506         /* note delta_capt == delta_play at this moment */
 507         loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
 508         loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
 509  unlock:
 510         spin_unlock_irqrestore(&cable->lock, flags);
 511         return running;
 512 }
 513
 514 static void loopback_timer_function(unsigned long data)
 515 {
 516         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 517         unsigned int running;
 518
 519         running = loopback_pos_update(dpcm->cable);
 520         if (running & (1 << dpcm->substream->stream)) {
 521                 loopback_timer_start(dpcm);
 522                 if (dpcm->period_update_pending) {
 523                         dpcm->period_update_pending = 0;
 524                         snd_pcm_period_elapsed(dpcm->substream);
 525                 }
 526         }
 527 }
 528
 529 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 530 {
 531         struct snd_pcm_runtime *runtime = substream->runtime;
 532         struct loopback_pcm *dpcm = runtime->private_data;
 533
 534         loopback_pos_update(dpcm->cable);
 535         return bytes_to_frames(runtime, dpcm->buf_pos);
 536 }
 537
 538 static struct snd_pcm_hardware loopback_pcm_hardware =
 539 {
 540         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 541                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
 542                          SNDRV_PCM_INFO_RESUME),
 543         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 544                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 545                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 546         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 547         .rate_min =             8000,
 548         .rate_max =             192000,
 549         .channels_min =         1,
 550         .channels_max =         32,
 551         .buffer_bytes_max =     2 * 1024 * 1024,
 552         .period_bytes_min =     64,
 553         /* note check overflow in frac_pos() using pcm_rate_shift before
 554            changing period_bytes_max value */
 555         .period_bytes_max =     1024 * 1024,
 556         .periods_min =          1,
 557         .periods_max =          1024,
 558         .fifo_size =            0,
 559 };
 560
 561 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 562 {
 563         struct loopback_pcm *dpcm = runtime->private_data;
 564         kfree(dpcm);
 565 }
 566
 567 static int loopback_hw_params(struct snd_pcm_substream *substream,
 568                               struct snd_pcm_hw_params *params)
 569 {
 570         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 571                                                 params_buffer_bytes(params));
 572 }
 573
 574 static int loopback_hw_free(struct snd_pcm_substream *substream)
 575 {
 576         struct snd_pcm_runtime *runtime = substream->runtime;
 577         struct loopback_pcm *dpcm = runtime->private_data;
 578         struct loopback_cable *cable = dpcm->cable;
 579
 580         mutex_lock(&dpcm->loopback->cable_lock);
 581         cable->valid &= ~(1 << substream->stream);
 582         mutex_unlock(&dpcm->loopback->cable_lock);
 583         return snd_pcm_lib_free_vmalloc_buffer(substream);
 584 }
 585
 586 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 587 {
 588         if (!substream->pcm->device)
 589                 return substream->stream;
 590         else
 591                 return !substream->stream;
 592 }
 593
 594 static int rule_format(struct snd_pcm_hw_params *params,
 595                        struct snd_pcm_hw_rule *rule)
 596 {
 597         struct loopback_pcm *dpcm = rule->private;
 598         struct loopback_cable *cable = dpcm->cable;
 599         struct snd_mask m;
 600
 601         snd_mask_none(&m);
 602         mutex_lock(&dpcm->loopback->cable_lock);
 603         m.bits[0] = (u_int32_t)cable->hw.formats;
 604         m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
 605         mutex_unlock(&dpcm->loopback->cable_lock);
 606         return snd_mask_refine(hw_param_mask(params, rule->var), &m);
 607 }
 608
 609 static int rule_rate(struct snd_pcm_hw_params *params,
 610                      struct snd_pcm_hw_rule *rule)
 611 {
 612         struct loopback_pcm *dpcm = rule->private;
 613         struct loopback_cable *cable = dpcm->cable;
 614         struct snd_interval t;
 615
 616         mutex_lock(&dpcm->loopback->cable_lock);
 617         t.min = cable->hw.rate_min;
 618         t.max = cable->hw.rate_max;
 619         mutex_unlock(&dpcm->loopback->cable_lock);
 620         t.openmin = t.openmax = 0;
 621         t.integer = 0;
 622         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 623 }
 624
 625 static int rule_channels(struct snd_pcm_hw_params *params,
 626                          struct snd_pcm_hw_rule *rule)
 627 {
 628         struct loopback_pcm *dpcm = rule->private;
 629         struct loopback_cable *cable = dpcm->cable;
 630         struct snd_interval t;
 631
 632         mutex_lock(&dpcm->loopback->cable_lock);
 633         t.min = cable->hw.channels_min;
 634         t.max = cable->hw.channels_max;
 635         mutex_unlock(&dpcm->loopback->cable_lock);
 636         t.openmin = t.openmax = 0;
 637         t.integer = 0;
 638         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 639 }
 640
 641 static void free_cable(struct snd_pcm_substream *substream)
 642 {
 643         struct loopback *loopback = substream->private_data;
 644         int dev = get_cable_index(substream);
 645         struct loopback_cable *cable;
 646
 647         cable = loopback->cables[substream->number][dev];
 648         if (!cable)
 649                 return;
 650         if (cable->streams[!substream->stream]) {
 651                 /* other stream is still alive */
 652                 cable->streams[substream->stream] = NULL;
 653         } else {
 654                 /* free the cable */
 655                 loopback->cables[substream->number][dev] = NULL;
 656                 kfree(cable);
 657         }
 658 }
 659
 660 static int loopback_open(struct snd_pcm_substream *substream)
 661 {
 662         struct snd_pcm_runtime *runtime = substream->runtime;
 663         struct loopback *loopback = substream->private_data;
 664         struct loopback_pcm *dpcm;
 665         struct loopback_cable *cable = NULL;
 666         int err = 0;
 667         int dev = get_cable_index(substream);
 668
 669         mutex_lock(&loopback->cable_lock);
 670         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 671         if (!dpcm) {
 672                 err = -ENOMEM;
 673                 goto unlock;
 674         }
 675         dpcm->loopback = loopback;
 676         dpcm->substream = substream;
 677         setup_timer(&dpcm->timer, loopback_timer_function,
 678                     (unsigned long)dpcm);
 679         spin_lock_init(&dpcm->timer_lock);
 680
 681         cable = loopback->cables[substream->number][dev];
 682         if (!cable) {
 683                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 684                 if (!cable) {
 685                         err = -ENOMEM;
 686                         goto unlock;
 687                 }
 688                 spin_lock_init(&cable->lock);
 689                 cable->hw = loopback_pcm_hardware;
 690                 loopback->cables[substream->number][dev] = cable;
 691         }
 692         dpcm->cable = cable;
 693         cable->streams[substream->stream] = dpcm;
 694
 695         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 696
 697         /* use dynamic rules based on actual runtime->hw values */
 698         /* note that the default rules created in the PCM midlevel code */
 699         /* are cached -> they do not reflect the actual state */
 700         err = snd_pcm_hw_rule_add(runtime, 0,
 701                                   SNDRV_PCM_HW_PARAM_FORMAT,
 702                                   rule_format, dpcm,
 703                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 704         if (err < 0)
 705                 goto unlock;
 706         err = snd_pcm_hw_rule_add(runtime, 0,
 707                                   SNDRV_PCM_HW_PARAM_RATE,
 708                                   rule_rate, dpcm,
 709                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 710         if (err < 0)
 711                 goto unlock;
 712         err = snd_pcm_hw_rule_add(runtime, 0,
 713                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 714                                   rule_channels, dpcm,
 715                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 716         if (err < 0)
 717                 goto unlock;
 718
 719         runtime->private_data = dpcm;
 720         runtime->private_free = loopback_runtime_free;
 721         if (get_notify(dpcm))
 722                 runtime->hw = loopback_pcm_hardware;
 723         else
 724                 runtime->hw = cable->hw;
 725  unlock:
 726         if (err < 0) {
 727                 free_cable(substream);
 728                 kfree(dpcm);
 729         }
 730         mutex_unlock(&loopback->cable_lock);
 731         return err;
 732 }
 733
 734 static int loopback_close(struct snd_pcm_substream *substream)
 735 {
 736         struct loopback *loopback = substream->private_data;
 737         struct loopback_pcm *dpcm = substream->runtime->private_data;
 738
 739         loopback_timer_stop(dpcm);
 740         mutex_lock(&loopback->cable_lock);
 741         free_cable(substream);
 742         mutex_unlock(&loopback->cable_lock);
 743         return 0;
 744 }
 745
 746 static struct snd_pcm_ops loopback_playback_ops = {
 747         .open =         loopback_open,
 748         .close =        loopback_close,
 749         .ioctl =        snd_pcm_lib_ioctl,
 750         .hw_params =    loopback_hw_params,
 751         .hw_free =      loopback_hw_free,
 752         .prepare =      loopback_prepare,
 753         .trigger =      loopback_trigger,
 754         .pointer =      loopback_pointer,
 755         .page =         snd_pcm_lib_get_vmalloc_page,
 756         .mmap =         snd_pcm_lib_mmap_vmalloc,
 757 };
 758
 759 static struct snd_pcm_ops loopback_capture_ops = {
 760         .open =         loopback_open,
 761         .close =        loopback_close,
 762         .ioctl =        snd_pcm_lib_ioctl,
 763         .hw_params =    loopback_hw_params,
 764         .hw_free =      loopback_hw_free,
 765         .prepare =      loopback_prepare,
 766         .trigger =      loopback_trigger,
 767         .pointer =      loopback_pointer,
 768         .page =         snd_pcm_lib_get_vmalloc_page,
 769         .mmap =         snd_pcm_lib_mmap_vmalloc,
 770 };
 771
 772 static int __devinit loopback_pcm_new(struct loopback *loopback,
 773                                       int device, int substreams)
 774 {
 775         struct snd_pcm *pcm;
 776         int err;
 777
 778         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 779                           substreams, substreams, &pcm);
 780         if (err < 0)
 781                 return err;
 782         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 783         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 784
 785         pcm->private_data = loopback;
 786         pcm->info_flags = 0;
 787         strcpy(pcm->name, "Loopback PCM");
 788
 789         loopback->pcm[device] = pcm;
 790         return 0;
 791 }
 792
 793 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 794                                     struct snd_ctl_elem_info *uinfo)
 795 {
 796         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 797         uinfo->count = 1;
 798         uinfo->value.integer.min = 80000;
 799         uinfo->value.integer.max = 120000;
 800         uinfo->value.integer.step = 1;
 801         return 0;
 802 }
 803
 804 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 805                                    struct snd_ctl_elem_value *ucontrol)
 806 {
 807         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 808
 809         ucontrol->value.integer.value[0] =
 810                 loopback->setup[kcontrol->id.subdevice]
 811                                [kcontrol->id.device].rate_shift;
 812         return 0;
 813 }
 814
 815 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 816                                    struct snd_ctl_elem_value *ucontrol)
 817 {
 818         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 819         unsigned int val;
 820         int change = 0;
 821
 822         val = ucontrol->value.integer.value[0];
 823         if (val < 80000)
 824                 val = 80000;
 825         if (val > 120000)
 826                 val = 120000;
 827         mutex_lock(&loopback->cable_lock);
 828         if (val != loopback->setup[kcontrol->id.subdevice]
 829                                   [kcontrol->id.device].rate_shift) {
 830                 loopback->setup[kcontrol->id.subdevice]
 831                                [kcontrol->id.device].rate_shift = val;
 832                 change = 1;
 833         }
 834         mutex_unlock(&loopback->cable_lock);
 835         return change;
 836 }
 837
 838 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 839                                struct snd_ctl_elem_value *ucontrol)
 840 {
 841         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 842
 843         ucontrol->value.integer.value[0] =
 844                 loopback->setup[kcontrol->id.subdevice]
 845                                [kcontrol->id.device].notify;
 846         return 0;
 847 }
 848
 849 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 850                                struct snd_ctl_elem_value *ucontrol)
 851 {
 852         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 853         unsigned int val;
 854         int change = 0;
 855
 856         val = ucontrol->value.integer.value[0] ? 1 : 0;
 857         if (val != loopback->setup[kcontrol->id.subdevice]
 858                                 [kcontrol->id.device].notify) {
 859                 loopback->setup[kcontrol->id.subdevice]
 860                         [kcontrol->id.device].notify = val;
 861                 change = 1;
 862         }
 863         return change;
 864 }
 865
 866 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 867                                struct snd_ctl_elem_value *ucontrol)
 868 {
 869         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 870         struct loopback_cable *cable = loopback->cables
 871                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 872         unsigned int val = 0;
 873
 874         if (cable != NULL)
 875                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 876                                                                         1 : 0;
 877         ucontrol->value.integer.value[0] = val;
 878         return 0;
 879 }
 880
 881 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 882                                 struct snd_ctl_elem_info *uinfo)
 883 {
 884         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 885         uinfo->count = 1;
 886         uinfo->value.integer.min = 0;
 887         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 888         uinfo->value.integer.step = 1;
 889         return 0;
 890 }
 891
 892 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 893                                struct snd_ctl_elem_value *ucontrol)
 894 {
 895         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 896
 897         ucontrol->value.integer.value[0] =
 898                 loopback->setup[kcontrol->id.subdevice]
 899                                [kcontrol->id.device].format;
 900         return 0;
 901 }
 902
 903 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 904                               struct snd_ctl_elem_info *uinfo)
 905 {
 906         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 907         uinfo->count = 1;
 908         uinfo->value.integer.min = 0;
 909         uinfo->value.integer.max = 192000;
 910         uinfo->value.integer.step = 1;
 911         return 0;
 912 }
 913
 914 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 915                              struct snd_ctl_elem_value *ucontrol)
 916 {
 917         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 918
 919         ucontrol->value.integer.value[0] =
 920                 loopback->setup[kcontrol->id.subdevice]
 921                                [kcontrol->id.device].rate;
 922         return 0;
 923 }
 924
 925 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 926                                   struct snd_ctl_elem_info *uinfo)
 927 {
 928         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 929         uinfo->count = 1;
 930         uinfo->value.integer.min = 1;
 931         uinfo->value.integer.max = 1024;
 932         uinfo->value.integer.step = 1;
 933         return 0;
 934 }
 935
 936 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 937                                  struct snd_ctl_elem_value *ucontrol)
 938 {
 939         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 940
 941         ucontrol->value.integer.value[0] =
 942                 loopback->setup[kcontrol->id.subdevice]
 943                                [kcontrol->id.device].channels;
 944         return 0;
 945 }
 946
 947 static struct snd_kcontrol_new loopback_controls[]  __devinitdata = {
 948 {
 949         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 950         .name =         "PCM Rate Shift 100000",
 951         .info =         loopback_rate_shift_info,
 952         .get =          loopback_rate_shift_get,
 953         .put =          loopback_rate_shift_put,
 954 },
 955 {
 956         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 957         .name =         "PCM Notify",
 958         .info =         snd_ctl_boolean_mono_info,
 959         .get =          loopback_notify_get,
 960         .put =          loopback_notify_put,
 961 },
 962 #define ACTIVE_IDX 2
 963 {
 964         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 965         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 966         .name =         "PCM Slave Active",
 967         .info =         snd_ctl_boolean_mono_info,
 968         .get =          loopback_active_get,
 969 },
 970 #define FORMAT_IDX 3
 971 {
 972         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 973         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 974         .name =         "PCM Slave Format",
 975         .info =         loopback_format_info,
 976         .get =          loopback_format_get
 977 },
 978 #define RATE_IDX 4
 979 {
 980         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 981         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 982         .name =         "PCM Slave Rate",
 983         .info =         loopback_rate_info,
 984         .get =          loopback_rate_get
 985 },
 986 #define CHANNELS_IDX 5
 987 {
 988         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 989         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 990         .name =         "PCM Slave Channels",
 991         .info =         loopback_channels_info,
 992         .get =          loopback_channels_get
 993 }
 994 };
 995
 996 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
 997 {
 998         struct snd_card *card = loopback->card;
 999         struct snd_pcm *pcm;
1000         struct snd_kcontrol *kctl;
1001         struct loopback_setup *setup;
1002         int err, dev, substr, substr_count, idx;
1003
1004         strcpy(card->mixername, "Loopback Mixer");
1005         for (dev = 0; dev < 2; dev++) {
1006                 pcm = loopback->pcm[dev];
1007                 substr_count =
1008                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1009                 for (substr = 0; substr < substr_count; substr++) {
1010                         setup = &loopback->setup[substr][dev];
1011                         setup->notify = notify;
1012                         setup->rate_shift = NO_PITCH;
1013                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1014                         setup->rate = 48000;
1015                         setup->channels = 2;
1016                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1017                                                                         idx++) {
1018                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1019                                                     loopback);
1020                                 if (!kctl)
1021                                         return -ENOMEM;
1022                                 kctl->id.device = dev;
1023                                 kctl->id.subdevice = substr;
1024                                 switch (idx) {
1025                                 case ACTIVE_IDX:
1026                                         setup->active_id = kctl->id;
1027                                         break;
1028                                 case FORMAT_IDX:
1029                                         setup->format_id = kctl->id;
1030                                         break;
1031                                 case RATE_IDX:
1032                                         setup->rate_id = kctl->id;
1033                                         break;
1034                                 case CHANNELS_IDX:
1035                                         setup->channels_id = kctl->id;
1036                                         break;
1037                                 default:
1038                                         break;
1039                                 }
1040                                 err = snd_ctl_add(card, kctl);
1041                                 if (err < 0)
1042                                         return err;
1043                         }
1044                 }
1045         }
1046         return 0;
1047 }
1048
1049 #ifdef CONFIG_PROC_FS
1050
1051 static void print_dpcm_info(struct snd_info_buffer *buffer,
1052                             struct loopback_pcm *dpcm,
1053                             const char *id)
1054 {
1055         snd_iprintf(buffer, "  %s\n", id);
1056         if (dpcm == NULL) {
1057                 snd_iprintf(buffer, "    inactive\n");
1058                 return;
1059         }
1060         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1061         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1062         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1063         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1064         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1065         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1066         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1067         snd_iprintf(buffer, "    update_pending:\t%u\n",
1068                                                 dpcm->period_update_pending);
1069         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1070         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1071         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1072                                         dpcm->last_jiffies, jiffies);
1073         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1074 }
1075
1076 static void print_substream_info(struct snd_info_buffer *buffer,
1077                                  struct loopback *loopback,
1078                                  int sub,
1079                                  int num)
1080 {
1081         struct loopback_cable *cable = loopback->cables[sub][num];
1082
1083         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1084         if (cable == NULL) {
1085                 snd_iprintf(buffer, "  inactive\n");
1086                 return;
1087         }
1088         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1089         snd_iprintf(buffer, "  running: %u\n", cable->running);
1090         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1091         print_dpcm_info(buffer, cable->streams[0], "Playback");
1092         print_dpcm_info(buffer, cable->streams[1], "Capture");
1093 }
1094
1095 static void print_cable_info(struct snd_info_entry *entry,
1096                              struct snd_info_buffer *buffer)
1097 {
1098         struct loopback *loopback = entry->private_data;
1099         int sub, num;
1100
1101         mutex_lock(&loopback->cable_lock);
1102         num = entry->name[strlen(entry->name)-1];
1103         num = num == '0' ? 0 : 1;
1104         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1105                 print_substream_info(buffer, loopback, sub, num);
1106         mutex_unlock(&loopback->cable_lock);
1107 }
1108
1109 static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1110 {
1111         char name[32];
1112         struct snd_info_entry *entry;
1113         int err;
1114
1115         snprintf(name, sizeof(name), "cable#%d", cidx);
1116         err = snd_card_proc_new(loopback->card, name, &entry);
1117         if (err < 0)
1118                 return err;
1119
1120         snd_info_set_text_ops(entry, loopback, print_cable_info);
1121         return 0;
1122 }
1123
1124 #else /* !CONFIG_PROC_FS */
1125
1126 #define loopback_proc_new(loopback, cidx) do { } while (0)
1127
1128 #endif
1129
1130 static int __devinit loopback_probe(struct platform_device *devptr)
1131 {
1132         struct snd_card *card;
1133         struct loopback *loopback;
1134         int dev = devptr->id;
1135         int err;
1136
1137         err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1138                               sizeof(struct loopback), &card);
1139         if (err < 0)
1140                 return err;
1141         loopback = card->private_data;
1142
1143         if (pcm_substreams[dev] < 1)
1144                 pcm_substreams[dev] = 1;
1145         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1146                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1147
1148         loopback->card = card;
1149         mutex_init(&loopback->cable_lock);
1150
1151         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1152         if (err < 0)
1153                 goto __nodev;
1154         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1155         if (err < 0)
1156                 goto __nodev;
1157         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1158         if (err < 0)
1159                 goto __nodev;
1160         loopback_proc_new(loopback, 0);
1161         loopback_proc_new(loopback, 1);
1162         strcpy(card->driver, "Loopback");
1163         strcpy(card->shortname, "Loopback");
1164         sprintf(card->longname, "Loopback %i", dev + 1);
1165         err = snd_card_register(card);
1166         if (!err) {
1167                 platform_set_drvdata(devptr, card);
1168                 return 0;
1169         }
1170       __nodev:
1171         snd_card_free(card);
1172         return err;
1173 }
1174
1175 static int __devexit loopback_remove(struct platform_device *devptr)
1176 {
1177         snd_card_free(platform_get_drvdata(devptr));
1178         platform_set_drvdata(devptr, NULL);
1179         return 0;
1180 }
1181
1182 #ifdef CONFIG_PM
1183 static int loopback_suspend(struct platform_device *pdev,
1184                                 pm_message_t state)
1185 {
1186         struct snd_card *card = platform_get_drvdata(pdev);
1187         struct loopback *loopback = card->private_data;
1188
1189         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1190
1191         snd_pcm_suspend_all(loopback->pcm[0]);
1192         snd_pcm_suspend_all(loopback->pcm[1]);
1193         return 0;
1194 }
1195
1196 static int loopback_resume(struct platform_device *pdev)
1197 {
1198         struct snd_card *card = platform_get_drvdata(pdev);
1199
1200         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1201         return 0;
1202 }
1203 #endif
1204
1205 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1206
1207 static struct platform_driver loopback_driver = {
1208         .probe          = loopback_probe,
1209         .remove         = __devexit_p(loopback_remove),
1210 #ifdef CONFIG_PM
1211         .suspend        = loopback_suspend,
1212         .resume         = loopback_resume,
1213 #endif
1214         .driver         = {
1215                 .name   = SND_LOOPBACK_DRIVER
1216         },
1217 };
1218
1219 static void loopback_unregister_all(void)
1220 {
1221         int i;
1222
1223         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1224                 platform_device_unregister(devices[i]);
1225         platform_driver_unregister(&loopback_driver);
1226 }
1227
1228 static int __init alsa_card_loopback_init(void)
1229 {
1230         int i, err, cards;
1231
1232         err = platform_driver_register(&loopback_driver);
1233         if (err < 0)
1234                 return err;
1235
1236
1237         cards = 0;
1238         for (i = 0; i < SNDRV_CARDS; i++) {
1239                 struct platform_device *device;
1240                 if (!enable[i])
1241                         continue;
1242                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1243                                                          i, NULL, 0);
1244                 if (IS_ERR(device))
1245                         continue;
1246                 if (!platform_get_drvdata(device)) {
1247                         platform_device_unregister(device);
1248                         continue;
1249                 }
1250                 devices[i] = device;
1251                 cards++;
1252         }
1253         if (!cards) {
1254 #ifdef MODULE
1255                 printk(KERN_ERR "aloop: No loopback enabled\n");
1256 #endif
1257                 loopback_unregister_all();
1258                 return -ENODEV;
1259         }
1260         return 0;
1261 }
1262
1263 static void __exit alsa_card_loopback_exit(void)
1264 {
1265         loopback_unregister_all();
1266 }
1267
1268 module_init(alsa_card_loopback_init)
1269 module_exit(alsa_card_loopback_exit)