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/info.h>
  43 #include <sound/initval.h>
  44
  45 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  46 MODULE_DESCRIPTION("A loopback soundcard");
  47 MODULE_LICENSE("GPL");
  48 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  49
  50 #define MAX_PCM_SUBSTREAMS      8
  51
  52 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  53 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  54 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  55 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  56 static int pcm_notify[SNDRV_CARDS];
  57
  58 module_param_array(index, int, NULL, 0444);
  59 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  60 module_param_array(id, charp, NULL, 0444);
  61 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  62 module_param_array(enable, bool, NULL, 0444);
  63 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  64 module_param_array(pcm_substreams, int, NULL, 0444);
  65 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  66 module_param_array(pcm_notify, int, NULL, 0444);
  67 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  68
  69 #define NO_PITCH 100000
  70
  71 struct loopback_pcm;
  72
  73 struct loopback_cable {
  74         spinlock_t lock;
  75         struct loopback_pcm *streams[2];
  76         struct snd_pcm_hardware hw;
  77         /* flags */
  78         unsigned int valid;
  79         unsigned int running;
  80         unsigned int pause;
  81 };
  82
  83 struct loopback_setup {
  84         unsigned int notify: 1;
  85         unsigned int rate_shift;
  86         unsigned int format;
  87         unsigned int rate;
  88         unsigned int channels;
  89         struct snd_ctl_elem_id active_id;
  90         struct snd_ctl_elem_id format_id;
  91         struct snd_ctl_elem_id rate_id;
  92         struct snd_ctl_elem_id channels_id;
  93 };
  94
  95 struct loopback {
  96         struct snd_card *card;
  97         struct mutex cable_lock;
  98         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
  99         struct snd_pcm *pcm[2];
 100         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 101 };
 102
 103 struct loopback_pcm {
 104         struct loopback *loopback;
 105         struct snd_pcm_substream *substream;
 106         struct loopback_cable *cable;
 107         unsigned int pcm_buffer_size;
 108         unsigned int buf_pos;   /* position in buffer */
 109         unsigned int silent_size;
 110         /* PCM parameters */
 111         unsigned int pcm_period_size;
 112         unsigned int pcm_bps;           /* bytes per second */
 113         unsigned int pcm_salign;        /* bytes per sample * channels */
 114         unsigned int pcm_rate_shift;    /* rate shift value */
 115         /* flags */
 116         unsigned int period_update_pending :1;
 117         /* timer stuff */
 118         unsigned int irq_pos;           /* fractional IRQ position */
 119         unsigned int period_size_frac;
 120         unsigned int last_drift;
 121         unsigned long last_jiffies;
 122         struct timer_list timer;
 123 };
 124
 125 static struct platform_device *devices[SNDRV_CARDS];
 126
 127 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 128 {
 129         if (dpcm->pcm_rate_shift == NO_PITCH) {
 130                 x /= HZ;
 131         } else {
 132                 x = div_u64(NO_PITCH * (unsigned long long)x,
 133                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 134         }
 135         return x - (x % dpcm->pcm_salign);
 136 }
 137
 138 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 139 {
 140         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 141                 return x * HZ;
 142         } else {
 143                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 144                             NO_PITCH);
 145         }
 146         return x;
 147 }
 148
 149 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 150 {
 151         int device = dpcm->substream->pstr->pcm->device;
 152
 153         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 154                 device ^= 1;
 155         return &dpcm->loopback->setup[dpcm->substream->number][device];
 156 }
 157
 158 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 159 {
 160         return get_setup(dpcm)->notify;
 161 }
 162
 163 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 164 {
 165         return get_setup(dpcm)->rate_shift;
 166 }
 167
 168 /* call in cable->lock */
 169 static void loopback_timer_start(struct loopback_pcm *dpcm)
 170 {
 171         unsigned long tick;
 172         unsigned int rate_shift = get_rate_shift(dpcm);
 173
 174         if (rate_shift != dpcm->pcm_rate_shift) {
 175                 dpcm->pcm_rate_shift = rate_shift;
 176                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 177         }
 178         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 179                 dpcm->irq_pos %= dpcm->period_size_frac;
 180                 dpcm->period_update_pending = 1;
 181         }
 182         tick = dpcm->period_size_frac - dpcm->irq_pos;
 183         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 184         dpcm->timer.expires = jiffies + tick;
 185         add_timer(&dpcm->timer);
 186 }
 187
 188 /* call in cable->lock */
 189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 190 {
 191         del_timer(&dpcm->timer);
 192         dpcm->timer.expires = 0;
 193 }
 194
 195 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 196 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 197 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 198
 199 static int loopback_check_format(struct loopback_cable *cable, int stream)
 200 {
 201         struct snd_pcm_runtime *runtime, *cruntime;
 202         struct loopback_setup *setup;
 203         struct snd_card *card;
 204         int check;
 205
 206         if (cable->valid != CABLE_VALID_BOTH) {
 207                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 208                         goto __notify;
 209                 return 0;
 210         }
 211         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 212                                                         substream->runtime;
 213         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 214                                                         substream->runtime;
 215         check = runtime->format != cruntime->format ||
 216                 runtime->rate != cruntime->rate ||
 217                 runtime->channels != cruntime->channels;
 218         if (!check)
 219                 return 0;
 220         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 221                 return -EIO;
 222         } else {
 223                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 224                                         substream, SNDRV_PCM_STATE_DRAINING);
 225               __notify:
 226                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 227                                                         substream->runtime;
 228                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 229                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 230                 if (setup->format != runtime->format) {
 231                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 232                                                         &setup->format_id);
 233                         setup->format = runtime->format;
 234                 }
 235                 if (setup->rate != runtime->rate) {
 236                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 237                                                         &setup->rate_id);
 238                         setup->rate = runtime->rate;
 239                 }
 240                 if (setup->channels != runtime->channels) {
 241                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 242                                                         &setup->channels_id);
 243                         setup->channels = runtime->channels;
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 static void loopback_active_notify(struct loopback_pcm *dpcm)
 250 {
 251         snd_ctl_notify(dpcm->loopback->card,
 252                        SNDRV_CTL_EVENT_MASK_VALUE,
 253                        &get_setup(dpcm)->active_id);
 254 }
 255
 256 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 257 {
 258         struct snd_pcm_runtime *runtime = substream->runtime;
 259         struct loopback_pcm *dpcm = runtime->private_data;
 260         struct loopback_cable *cable = dpcm->cable;
 261         int err, stream = 1 << substream->stream;
 262
 263         switch (cmd) {
 264         case SNDRV_PCM_TRIGGER_START:
 265                 err = loopback_check_format(cable, substream->stream);
 266                 if (err < 0)
 267                         return err;
 268                 dpcm->last_jiffies = jiffies;
 269                 dpcm->pcm_rate_shift = 0;
 270                 dpcm->last_drift = 0;
 271                 spin_lock(&cable->lock);
 272                 cable->running |= stream;
 273                 cable->pause &= ~stream;
 274                 loopback_timer_start(dpcm);
 275                 spin_unlock(&cable->lock);
 276                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 277                         loopback_active_notify(dpcm);
 278                 break;
 279         case SNDRV_PCM_TRIGGER_STOP:
 280                 spin_lock(&cable->lock);
 281                 cable->running &= ~stream;
 282                 cable->pause &= ~stream;
 283                 loopback_timer_stop(dpcm);
 284                 spin_unlock(&cable->lock);
 285                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 286                         loopback_active_notify(dpcm);
 287                 break;
 288         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 289                 spin_lock(&cable->lock);
 290                 cable->pause |= stream;
 291                 loopback_timer_stop(dpcm);
 292                 spin_unlock(&cable->lock);
 293                 break;
 294         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 295                 spin_lock(&cable->lock);
 296                 dpcm->last_jiffies = jiffies;
 297                 cable->pause &= ~stream;
 298                 loopback_timer_start(dpcm);
 299                 spin_unlock(&cable->lock);
 300                 break;
 301         default:
 302                 return -EINVAL;
 303         }
 304         return 0;
 305 }
 306
 307 static void params_change_substream(struct loopback_pcm *dpcm,
 308                                     struct snd_pcm_runtime *runtime)
 309 {
 310         struct snd_pcm_runtime *dst_runtime;
 311
 312         if (dpcm == NULL || dpcm->substream == NULL)
 313                 return;
 314         dst_runtime = dpcm->substream->runtime;
 315         if (dst_runtime == NULL)
 316                 return;
 317         dst_runtime->hw = dpcm->cable->hw;
 318 }
 319
 320 static void params_change(struct snd_pcm_substream *substream)
 321 {
 322         struct snd_pcm_runtime *runtime = substream->runtime;
 323         struct loopback_pcm *dpcm = runtime->private_data;
 324         struct loopback_cable *cable = dpcm->cable;
 325
 326         cable->hw.formats = (1ULL << runtime->format);
 327         cable->hw.rate_min = runtime->rate;
 328         cable->hw.rate_max = runtime->rate;
 329         cable->hw.channels_min = runtime->channels;
 330         cable->hw.channels_max = runtime->channels;
 331         params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 332                                 runtime);
 333         params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 334                                 runtime);
 335 }
 336
 337 static int loopback_prepare(struct snd_pcm_substream *substream)
 338 {
 339         struct snd_pcm_runtime *runtime = substream->runtime;
 340         struct loopback_pcm *dpcm = runtime->private_data;
 341         struct loopback_cable *cable = dpcm->cable;
 342         int bps, salign;
 343
 344         salign = (snd_pcm_format_width(runtime->format) *
 345                                                 runtime->channels) / 8;
 346         bps = salign * runtime->rate;
 347         if (bps <= 0 || salign <= 0)
 348                 return -EINVAL;
 349
 350         dpcm->buf_pos = 0;
 351         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 352         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 353                 /* clear capture buffer */
 354                 dpcm->silent_size = dpcm->pcm_buffer_size;
 355                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 356                                            runtime->buffer_size * runtime->channels);
 357         }
 358
 359         dpcm->irq_pos = 0;
 360         dpcm->period_update_pending = 0;
 361         dpcm->pcm_bps = bps;
 362         dpcm->pcm_salign = salign;
 363         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 364
 365         mutex_lock(&dpcm->loopback->cable_lock);
 366         if (!(cable->valid & ~(1 << substream->stream)) ||
 367             (get_setup(dpcm)->notify &&
 368              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 369                 params_change(substream);
 370         cable->valid |= 1 << substream->stream;
 371         mutex_unlock(&dpcm->loopback->cable_lock);
 372
 373         return 0;
 374 }
 375
 376 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 377 {
 378         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 379         char *dst = runtime->dma_area;
 380         unsigned int dst_off = dpcm->buf_pos;
 381
 382         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 383                 return;
 384         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 385                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 386
 387         for (;;) {
 388                 unsigned int size = bytes;
 389                 if (dst_off + size > dpcm->pcm_buffer_size)
 390                         size = dpcm->pcm_buffer_size - dst_off;
 391                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 392                                            bytes_to_frames(runtime, size) *
 393                                                 runtime->channels);
 394                 dpcm->silent_size += size;
 395                 bytes -= size;
 396                 if (!bytes)
 397                         break;
 398                 dst_off = 0;
 399         }
 400 }
 401
 402 static void copy_play_buf(struct loopback_pcm *play,
 403                           struct loopback_pcm *capt,
 404                           unsigned int bytes)
 405 {
 406         struct snd_pcm_runtime *runtime = play->substream->runtime;
 407         char *src = runtime->dma_area;
 408         char *dst = capt->substream->runtime->dma_area;
 409         unsigned int src_off = play->buf_pos;
 410         unsigned int dst_off = capt->buf_pos;
 411         unsigned int clear_bytes = 0;
 412
 413         /* check if playback is draining, trim the capture copy size
 414          * when our pointer is at the end of playback ring buffer */
 415         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 416             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 417                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 418                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 419                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 420                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 421                 if (appl_ptr < appl_ptr1)
 422                         appl_ptr1 -= runtime->buffer_size;
 423                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 424                 if (diff < bytes) {
 425                         clear_bytes = bytes - diff;
 426                         bytes = diff;
 427                 }
 428         }
 429
 430         for (;;) {
 431                 unsigned int size = bytes;
 432                 if (src_off + size > play->pcm_buffer_size)
 433                         size = play->pcm_buffer_size - src_off;
 434                 if (dst_off + size > capt->pcm_buffer_size)
 435                         size = capt->pcm_buffer_size - dst_off;
 436                 memcpy(dst + dst_off, src + src_off, size);
 437                 capt->silent_size = 0;
 438                 bytes -= size;
 439                 if (!bytes)
 440                         break;
 441                 src_off = (src_off + size) % play->pcm_buffer_size;
 442                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 443         }
 444
 445         if (clear_bytes > 0) {
 446                 clear_capture_buf(capt, clear_bytes);
 447                 capt->silent_size = 0;
 448         }
 449 }
 450
 451 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
 452                                          unsigned int jiffies_delta)
 453 {
 454         unsigned long last_pos;
 455         unsigned int delta;
 456
 457         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 458         dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
 459         delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 460         if (delta >= dpcm->last_drift)
 461                 delta -= dpcm->last_drift;
 462         dpcm->last_drift = 0;
 463         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 464                 dpcm->irq_pos %= dpcm->period_size_frac;
 465                 dpcm->period_update_pending = 1;
 466         }
 467         return delta;
 468 }
 469
 470 static inline void bytepos_finish(struct loopback_pcm *dpcm,
 471                                   unsigned int delta)
 472 {
 473         dpcm->buf_pos += delta;
 474         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 475 }
 476
 477 /* call in cable->lock */
 478 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 479 {
 480         struct loopback_pcm *dpcm_play =
 481                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 482         struct loopback_pcm *dpcm_capt =
 483                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 484         unsigned long delta_play = 0, delta_capt = 0;
 485         unsigned int running, count1, count2;
 486
 487         running = cable->running ^ cable->pause;
 488         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 489                 delta_play = jiffies - dpcm_play->last_jiffies;
 490                 dpcm_play->last_jiffies += delta_play;
 491         }
 492
 493         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 494                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 495                 dpcm_capt->last_jiffies += delta_capt;
 496         }
 497
 498         if (delta_play == 0 && delta_capt == 0)
 499                 goto unlock;
 500
 501         if (delta_play > delta_capt) {
 502                 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
 503                 bytepos_finish(dpcm_play, count1);
 504                 delta_play = delta_capt;
 505         } else if (delta_play < delta_capt) {
 506                 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
 507                 clear_capture_buf(dpcm_capt, count1);
 508                 bytepos_finish(dpcm_capt, count1);
 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         count1 = bytepos_delta(dpcm_play, delta_play);
 517         count2 = bytepos_delta(dpcm_capt, delta_capt);
 518         if (count1 < count2) {
 519                 dpcm_capt->last_drift = count2 - count1;
 520                 count1 = count2;
 521         } else if (count1 > count2) {
 522                 dpcm_play->last_drift = count1 - count2;
 523         }
 524         copy_play_buf(dpcm_play, dpcm_capt, count1);
 525         bytepos_finish(dpcm_play, count1);
 526         bytepos_finish(dpcm_capt, count1);
 527  unlock:
 528         return running;
 529 }
 530
 531 static void loopback_timer_function(unsigned long data)
 532 {
 533         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 534         unsigned long flags;
 535
 536         spin_lock_irqsave(&dpcm->cable->lock, flags);
 537         if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
 538                 loopback_timer_start(dpcm);
 539                 if (dpcm->period_update_pending) {
 540                         dpcm->period_update_pending = 0;
 541                         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 542                         /* need to unlock before calling below */
 543                         snd_pcm_period_elapsed(dpcm->substream);
 544                         return;
 545                 }
 546         }
 547         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 548 }
 549
 550 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 551 {
 552         struct snd_pcm_runtime *runtime = substream->runtime;
 553         struct loopback_pcm *dpcm = runtime->private_data;
 554         snd_pcm_uframes_t pos;
 555
 556         spin_lock(&dpcm->cable->lock);
 557         loopback_pos_update(dpcm->cable);
 558         pos = dpcm->buf_pos;
 559         spin_unlock(&dpcm->cable->lock);
 560         return bytes_to_frames(runtime, pos);
 561 }
 562
 563 static struct snd_pcm_hardware loopback_pcm_hardware =
 564 {
 565         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 566                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE),
 567         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 568                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 569                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 570         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 571         .rate_min =             8000,
 572         .rate_max =             192000,
 573         .channels_min =         1,
 574         .channels_max =         32,
 575         .buffer_bytes_max =     2 * 1024 * 1024,
 576         .period_bytes_min =     64,
 577         /* note check overflow in frac_pos() using pcm_rate_shift before
 578            changing period_bytes_max value */
 579         .period_bytes_max =     1024 * 1024,
 580         .periods_min =          1,
 581         .periods_max =          1024,
 582         .fifo_size =            0,
 583 };
 584
 585 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 586 {
 587         struct loopback_pcm *dpcm = runtime->private_data;
 588         kfree(dpcm);
 589 }
 590
 591 static int loopback_hw_params(struct snd_pcm_substream *substream,
 592                               struct snd_pcm_hw_params *params)
 593 {
 594         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 595                                                 params_buffer_bytes(params));
 596 }
 597
 598 static int loopback_hw_free(struct snd_pcm_substream *substream)
 599 {
 600         struct snd_pcm_runtime *runtime = substream->runtime;
 601         struct loopback_pcm *dpcm = runtime->private_data;
 602         struct loopback_cable *cable = dpcm->cable;
 603
 604         mutex_lock(&dpcm->loopback->cable_lock);
 605         cable->valid &= ~(1 << substream->stream);
 606         mutex_unlock(&dpcm->loopback->cable_lock);
 607         return snd_pcm_lib_free_vmalloc_buffer(substream);
 608 }
 609
 610 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 611 {
 612         if (!substream->pcm->device)
 613                 return substream->stream;
 614         else
 615                 return !substream->stream;
 616 }
 617
 618 static int rule_format(struct snd_pcm_hw_params *params,
 619                        struct snd_pcm_hw_rule *rule)
 620 {
 621
 622         struct snd_pcm_hardware *hw = rule->private;
 623         struct snd_mask *maskp = hw_param_mask(params, rule->var);
 624
 625         maskp->bits[0] &= (u_int32_t)hw->formats;
 626         maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
 627         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
 628         if (! maskp->bits[0] && ! maskp->bits[1])
 629                 return -EINVAL;
 630         return 0;
 631 }
 632
 633 static int rule_rate(struct snd_pcm_hw_params *params,
 634                      struct snd_pcm_hw_rule *rule)
 635 {
 636         struct snd_pcm_hardware *hw = rule->private;
 637         struct snd_interval t;
 638
 639         t.min = hw->rate_min;
 640         t.max = hw->rate_max;
 641         t.openmin = t.openmax = 0;
 642         t.integer = 0;
 643         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 644 }
 645
 646 static int rule_channels(struct snd_pcm_hw_params *params,
 647                          struct snd_pcm_hw_rule *rule)
 648 {
 649         struct snd_pcm_hardware *hw = rule->private;
 650         struct snd_interval t;
 651
 652         t.min = hw->channels_min;
 653         t.max = hw->channels_max;
 654         t.openmin = t.openmax = 0;
 655         t.integer = 0;
 656         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 657 }
 658
 659 static int loopback_open(struct snd_pcm_substream *substream)
 660 {
 661         struct snd_pcm_runtime *runtime = substream->runtime;
 662         struct loopback *loopback = substream->private_data;
 663         struct loopback_pcm *dpcm;
 664         struct loopback_cable *cable;
 665         int err = 0;
 666         int dev = get_cable_index(substream);
 667
 668         mutex_lock(&loopback->cable_lock);
 669         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 670         if (!dpcm) {
 671                 err = -ENOMEM;
 672                 goto unlock;
 673         }
 674         dpcm->loopback = loopback;
 675         dpcm->substream = substream;
 676         setup_timer(&dpcm->timer, loopback_timer_function,
 677                     (unsigned long)dpcm);
 678
 679         cable = loopback->cables[substream->number][dev];
 680         if (!cable) {
 681                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 682                 if (!cable) {
 683                         kfree(dpcm);
 684                         err = -ENOMEM;
 685                         goto unlock;
 686                 }
 687                 spin_lock_init(&cable->lock);
 688                 cable->hw = loopback_pcm_hardware;
 689                 loopback->cables[substream->number][dev] = cable;
 690         }
 691         dpcm->cable = cable;
 692         cable->streams[substream->stream] = dpcm;
 693
 694         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 695
 696         /* use dynamic rules based on actual runtime->hw values */
 697         /* note that the default rules created in the PCM midlevel code */
 698         /* are cached -> they do not reflect the actual state */
 699         err = snd_pcm_hw_rule_add(runtime, 0,
 700                                   SNDRV_PCM_HW_PARAM_FORMAT,
 701                                   rule_format, &runtime->hw,
 702                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 703         if (err < 0)
 704                 goto unlock;
 705         err = snd_pcm_hw_rule_add(runtime, 0,
 706                                   SNDRV_PCM_HW_PARAM_RATE,
 707                                   rule_rate, &runtime->hw,
 708                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 709         if (err < 0)
 710                 goto unlock;
 711         err = snd_pcm_hw_rule_add(runtime, 0,
 712                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 713                                   rule_channels, &runtime->hw,
 714                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 715         if (err < 0)
 716                 goto unlock;
 717
 718         runtime->private_data = dpcm;
 719         runtime->private_free = loopback_runtime_free;
 720         if (get_notify(dpcm))
 721                 runtime->hw = loopback_pcm_hardware;
 722         else
 723                 runtime->hw = cable->hw;
 724  unlock:
 725         mutex_unlock(&loopback->cable_lock);
 726         return err;
 727 }
 728
 729 static int loopback_close(struct snd_pcm_substream *substream)
 730 {
 731         struct loopback *loopback = substream->private_data;
 732         struct loopback_pcm *dpcm = substream->runtime->private_data;
 733         struct loopback_cable *cable;
 734         int dev = get_cable_index(substream);
 735
 736         loopback_timer_stop(dpcm);
 737         mutex_lock(&loopback->cable_lock);
 738         cable = loopback->cables[substream->number][dev];
 739         if (cable->streams[!substream->stream]) {
 740                 /* other stream is still alive */
 741                 cable->streams[substream->stream] = NULL;
 742         } else {
 743                 /* free the cable */
 744                 loopback->cables[substream->number][dev] = NULL;
 745                 kfree(cable);
 746         }
 747         mutex_unlock(&loopback->cable_lock);
 748         return 0;
 749 }
 750
 751 static struct snd_pcm_ops loopback_playback_ops = {
 752         .open =         loopback_open,
 753         .close =        loopback_close,
 754         .ioctl =        snd_pcm_lib_ioctl,
 755         .hw_params =    loopback_hw_params,
 756         .hw_free =      loopback_hw_free,
 757         .prepare =      loopback_prepare,
 758         .trigger =      loopback_trigger,
 759         .pointer =      loopback_pointer,
 760         .page =         snd_pcm_lib_get_vmalloc_page,
 761         .mmap =         snd_pcm_lib_mmap_vmalloc,
 762 };
 763
 764 static struct snd_pcm_ops loopback_capture_ops = {
 765         .open =         loopback_open,
 766         .close =        loopback_close,
 767         .ioctl =        snd_pcm_lib_ioctl,
 768         .hw_params =    loopback_hw_params,
 769         .hw_free =      loopback_hw_free,
 770         .prepare =      loopback_prepare,
 771         .trigger =      loopback_trigger,
 772         .pointer =      loopback_pointer,
 773         .page =         snd_pcm_lib_get_vmalloc_page,
 774         .mmap =         snd_pcm_lib_mmap_vmalloc,
 775 };
 776
 777 static int loopback_pcm_new(struct loopback *loopback,
 778                             int device, int substreams)
 779 {
 780         struct snd_pcm *pcm;
 781         int err;
 782
 783         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 784                           substreams, substreams, &pcm);
 785         if (err < 0)
 786                 return err;
 787         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 788         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 789
 790         pcm->private_data = loopback;
 791         pcm->info_flags = 0;
 792         strcpy(pcm->name, "Loopback PCM");
 793
 794         loopback->pcm[device] = pcm;
 795         return 0;
 796 }
 797
 798 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 799                                     struct snd_ctl_elem_info *uinfo)
 800 {
 801         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 802         uinfo->count = 1;
 803         uinfo->value.integer.min = 80000;
 804         uinfo->value.integer.max = 120000;
 805         uinfo->value.integer.step = 1;
 806         return 0;
 807 }
 808
 809 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 810                                    struct snd_ctl_elem_value *ucontrol)
 811 {
 812         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 813
 814         ucontrol->value.integer.value[0] =
 815                 loopback->setup[kcontrol->id.subdevice]
 816                                [kcontrol->id.device].rate_shift;
 817         return 0;
 818 }
 819
 820 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 821                                    struct snd_ctl_elem_value *ucontrol)
 822 {
 823         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 824         unsigned int val;
 825         int change = 0;
 826
 827         val = ucontrol->value.integer.value[0];
 828         if (val < 80000)
 829                 val = 80000;
 830         if (val > 120000)
 831                 val = 120000;
 832         mutex_lock(&loopback->cable_lock);
 833         if (val != loopback->setup[kcontrol->id.subdevice]
 834                                   [kcontrol->id.device].rate_shift) {
 835                 loopback->setup[kcontrol->id.subdevice]
 836                                [kcontrol->id.device].rate_shift = val;
 837                 change = 1;
 838         }
 839         mutex_unlock(&loopback->cable_lock);
 840         return change;
 841 }
 842
 843 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 844                                struct snd_ctl_elem_value *ucontrol)
 845 {
 846         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 847
 848         ucontrol->value.integer.value[0] =
 849                 loopback->setup[kcontrol->id.subdevice]
 850                                [kcontrol->id.device].notify;
 851         return 0;
 852 }
 853
 854 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 855                                struct snd_ctl_elem_value *ucontrol)
 856 {
 857         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 858         unsigned int val;
 859         int change = 0;
 860
 861         val = ucontrol->value.integer.value[0] ? 1 : 0;
 862         if (val != loopback->setup[kcontrol->id.subdevice]
 863                                 [kcontrol->id.device].notify) {
 864                 loopback->setup[kcontrol->id.subdevice]
 865                         [kcontrol->id.device].notify = val;
 866                 change = 1;
 867         }
 868         return change;
 869 }
 870
 871 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 872                                struct snd_ctl_elem_value *ucontrol)
 873 {
 874         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 875         struct loopback_cable *cable = loopback->cables
 876                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 877         unsigned int val = 0;
 878
 879         if (cable != NULL)
 880                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 881                                                                         1 : 0;
 882         ucontrol->value.integer.value[0] = val;
 883         return 0;
 884 }
 885
 886 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 887                                 struct snd_ctl_elem_info *uinfo)
 888 {
 889         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 890         uinfo->count = 1;
 891         uinfo->value.integer.min = 0;
 892         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 893         uinfo->value.integer.step = 1;
 894         return 0;
 895 }
 896
 897 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 898                                struct snd_ctl_elem_value *ucontrol)
 899 {
 900         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 901
 902         ucontrol->value.integer.value[0] =
 903                 loopback->setup[kcontrol->id.subdevice]
 904                                [kcontrol->id.device].format;
 905         return 0;
 906 }
 907
 908 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 909                               struct snd_ctl_elem_info *uinfo)
 910 {
 911         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 912         uinfo->count = 1;
 913         uinfo->value.integer.min = 0;
 914         uinfo->value.integer.max = 192000;
 915         uinfo->value.integer.step = 1;
 916         return 0;
 917 }
 918
 919 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 920                              struct snd_ctl_elem_value *ucontrol)
 921 {
 922         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 923
 924         ucontrol->value.integer.value[0] =
 925                 loopback->setup[kcontrol->id.subdevice]
 926                                [kcontrol->id.device].rate;
 927         return 0;
 928 }
 929
 930 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 931                                   struct snd_ctl_elem_info *uinfo)
 932 {
 933         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 934         uinfo->count = 1;
 935         uinfo->value.integer.min = 1;
 936         uinfo->value.integer.max = 1024;
 937         uinfo->value.integer.step = 1;
 938         return 0;
 939 }
 940
 941 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 942                                  struct snd_ctl_elem_value *ucontrol)
 943 {
 944         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 945
 946         ucontrol->value.integer.value[0] =
 947                 loopback->setup[kcontrol->id.subdevice]
 948                                [kcontrol->id.device].channels;
 949         return 0;
 950 }
 951
 952 static struct snd_kcontrol_new loopback_controls[]  = {
 953 {
 954         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 955         .name =         "PCM Rate Shift 100000",
 956         .info =         loopback_rate_shift_info,
 957         .get =          loopback_rate_shift_get,
 958         .put =          loopback_rate_shift_put,
 959 },
 960 {
 961         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 962         .name =         "PCM Notify",
 963         .info =         snd_ctl_boolean_mono_info,
 964         .get =          loopback_notify_get,
 965         .put =          loopback_notify_put,
 966 },
 967 #define ACTIVE_IDX 2
 968 {
 969         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 970         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 971         .name =         "PCM Slave Active",
 972         .info =         snd_ctl_boolean_mono_info,
 973         .get =          loopback_active_get,
 974 },
 975 #define FORMAT_IDX 3
 976 {
 977         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 978         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 979         .name =         "PCM Slave Format",
 980         .info =         loopback_format_info,
 981         .get =          loopback_format_get
 982 },
 983 #define RATE_IDX 4
 984 {
 985         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 986         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 987         .name =         "PCM Slave Rate",
 988         .info =         loopback_rate_info,
 989         .get =          loopback_rate_get
 990 },
 991 #define CHANNELS_IDX 5
 992 {
 993         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 994         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 995         .name =         "PCM Slave Channels",
 996         .info =         loopback_channels_info,
 997         .get =          loopback_channels_get
 998 }
 999 };
1000
1001 static int loopback_mixer_new(struct loopback *loopback, int notify)
1002 {
1003         struct snd_card *card = loopback->card;
1004         struct snd_pcm *pcm;
1005         struct snd_kcontrol *kctl;
1006         struct loopback_setup *setup;
1007         int err, dev, substr, substr_count, idx;
1008
1009         strcpy(card->mixername, "Loopback Mixer");
1010         for (dev = 0; dev < 2; dev++) {
1011                 pcm = loopback->pcm[dev];
1012                 substr_count =
1013                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1014                 for (substr = 0; substr < substr_count; substr++) {
1015                         setup = &loopback->setup[substr][dev];
1016                         setup->notify = notify;
1017                         setup->rate_shift = NO_PITCH;
1018                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1019                         setup->rate = 48000;
1020                         setup->channels = 2;
1021                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1022                                                                         idx++) {
1023                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1024                                                     loopback);
1025                                 if (!kctl)
1026                                         return -ENOMEM;
1027                                 kctl->id.device = dev;
1028                                 kctl->id.subdevice = substr;
1029                                 switch (idx) {
1030                                 case ACTIVE_IDX:
1031                                         setup->active_id = kctl->id;
1032                                         break;
1033                                 case FORMAT_IDX:
1034                                         setup->format_id = kctl->id;
1035                                         break;
1036                                 case RATE_IDX:
1037                                         setup->rate_id = kctl->id;
1038                                         break;
1039                                 case CHANNELS_IDX:
1040                                         setup->channels_id = kctl->id;
1041                                         break;
1042                                 default:
1043                                         break;
1044                                 }
1045                                 err = snd_ctl_add(card, kctl);
1046                                 if (err < 0)
1047                                         return err;
1048                         }
1049                 }
1050         }
1051         return 0;
1052 }
1053
1054 #ifdef CONFIG_PROC_FS
1055
1056 static void print_dpcm_info(struct snd_info_buffer *buffer,
1057                             struct loopback_pcm *dpcm,
1058                             const char *id)
1059 {
1060         snd_iprintf(buffer, "  %s\n", id);
1061         if (dpcm == NULL) {
1062                 snd_iprintf(buffer, "    inactive\n");
1063                 return;
1064         }
1065         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1066         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1067         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1068         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1069         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1070         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1071         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1072         snd_iprintf(buffer, "    update_pending:\t%u\n",
1073                                                 dpcm->period_update_pending);
1074         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1075         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1076         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1077                                         dpcm->last_jiffies, jiffies);
1078         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1079 }
1080
1081 static void print_substream_info(struct snd_info_buffer *buffer,
1082                                  struct loopback *loopback,
1083                                  int sub,
1084                                  int num)
1085 {
1086         struct loopback_cable *cable = loopback->cables[sub][num];
1087
1088         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1089         if (cable == NULL) {
1090                 snd_iprintf(buffer, "  inactive\n");
1091                 return;
1092         }
1093         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1094         snd_iprintf(buffer, "  running: %u\n", cable->running);
1095         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1096         print_dpcm_info(buffer, cable->streams[0], "Playback");
1097         print_dpcm_info(buffer, cable->streams[1], "Capture");
1098 }
1099
1100 static void print_cable_info(struct snd_info_entry *entry,
1101                              struct snd_info_buffer *buffer)
1102 {
1103         struct loopback *loopback = entry->private_data;
1104         int sub, num;
1105
1106         mutex_lock(&loopback->cable_lock);
1107         num = entry->name[strlen(entry->name)-1];
1108         num = num == '0' ? 0 : 1;
1109         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1110                 print_substream_info(buffer, loopback, sub, num);
1111         mutex_unlock(&loopback->cable_lock);
1112 }
1113
1114 static int loopback_proc_new(struct loopback *loopback, int cidx)
1115 {
1116         char name[32];
1117         struct snd_info_entry *entry;
1118         int err;
1119
1120         snprintf(name, sizeof(name), "cable#%d", cidx);
1121         err = snd_card_proc_new(loopback->card, name, &entry);
1122         if (err < 0)
1123                 return err;
1124
1125         snd_info_set_text_ops(entry, loopback, print_cable_info);
1126         return 0;
1127 }
1128
1129 #else /* !CONFIG_PROC_FS */
1130
1131 #define loopback_proc_new(loopback, cidx) do { } while (0)
1132
1133 #endif
1134
1135 static int loopback_probe(struct platform_device *devptr)
1136 {
1137         struct snd_card *card;
1138         struct loopback *loopback;
1139         int dev = devptr->id;
1140         int err;
1141
1142         err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1143                               sizeof(struct loopback), &card);
1144         if (err < 0)
1145                 return err;
1146         loopback = card->private_data;
1147
1148         if (pcm_substreams[dev] < 1)
1149                 pcm_substreams[dev] = 1;
1150         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1151                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1152
1153         loopback->card = card;
1154         mutex_init(&loopback->cable_lock);
1155
1156         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1157         if (err < 0)
1158                 goto __nodev;
1159         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1160         if (err < 0)
1161                 goto __nodev;
1162         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1163         if (err < 0)
1164                 goto __nodev;
1165         loopback_proc_new(loopback, 0);
1166         loopback_proc_new(loopback, 1);
1167         strcpy(card->driver, "Loopback");
1168         strcpy(card->shortname, "Loopback");
1169         sprintf(card->longname, "Loopback %i", dev + 1);
1170         err = snd_card_register(card);
1171         if (!err) {
1172                 platform_set_drvdata(devptr, card);
1173                 return 0;
1174         }
1175       __nodev:
1176         snd_card_free(card);
1177         return err;
1178 }
1179
1180 static int loopback_remove(struct platform_device *devptr)
1181 {
1182         snd_card_free(platform_get_drvdata(devptr));
1183         platform_set_drvdata(devptr, NULL);
1184         return 0;
1185 }
1186
1187 #ifdef CONFIG_PM_SLEEP
1188 static int loopback_suspend(struct device *pdev)
1189 {
1190         struct snd_card *card = dev_get_drvdata(pdev);
1191         struct loopback *loopback = card->private_data;
1192
1193         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1194
1195         snd_pcm_suspend_all(loopback->pcm[0]);
1196         snd_pcm_suspend_all(loopback->pcm[1]);
1197         return 0;
1198 }
1199
1200 static int loopback_resume(struct device *pdev)
1201 {
1202         struct snd_card *card = dev_get_drvdata(pdev);
1203
1204         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1205         return 0;
1206 }
1207
1208 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1209 #define LOOPBACK_PM_OPS &loopback_pm
1210 #else
1211 #define LOOPBACK_PM_OPS NULL
1212 #endif
1213
1214 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1215
1216 static struct platform_driver loopback_driver = {
1217         .probe          = loopback_probe,
1218         .remove         = loopback_remove,
1219         .driver         = {
1220                 .name   = SND_LOOPBACK_DRIVER,
1221                 .owner  = THIS_MODULE,
1222                 .pm     = LOOPBACK_PM_OPS,
1223         },
1224 };
1225
1226 static void loopback_unregister_all(void)
1227 {
1228         int i;
1229
1230         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1231                 platform_device_unregister(devices[i]);
1232         platform_driver_unregister(&loopback_driver);
1233 }
1234
1235 static int __init alsa_card_loopback_init(void)
1236 {
1237         int i, err, cards;
1238
1239         err = platform_driver_register(&loopback_driver);
1240         if (err < 0)
1241                 return err;
1242
1243
1244         cards = 0;
1245         for (i = 0; i < SNDRV_CARDS; i++) {
1246                 struct platform_device *device;
1247                 if (!enable[i])
1248                         continue;
1249                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1250                                                          i, NULL, 0);
1251                 if (IS_ERR(device))
1252                         continue;
1253                 if (!platform_get_drvdata(device)) {
1254                         platform_device_unregister(device);
1255                         continue;
1256                 }
1257                 devices[i] = device;
1258                 cards++;
1259         }
1260         if (!cards) {
1261 #ifdef MODULE
1262                 printk(KERN_ERR "aloop: No loopback enabled\n");
1263 #endif
1264                 loopback_unregister_all();
1265                 return -ENODEV;
1266         }
1267         return 0;
1268 }
1269
1270 static void __exit alsa_card_loopback_exit(void)
1271 {
1272         loopback_unregister_all();
1273 }
1274
1275 module_init(alsa_card_loopback_init)
1276 module_exit(alsa_card_loopback_exit)