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