sound/drivers/aloop.c

   1 /*
   2  *  Loopback soundcard
   3  *
   4  *  Original code:
   5  *  Copyright (c) by Jaroslav Kysela <[email protected]>
   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 <[email protected]>
  12  *
  13  *  A next major update in 2010 (separate timers for playback and capture):
  14  *  Copyright (c) Jaroslav Kysela <[email protected]>
  15  *
  16  *   This program is free software; you can redistribute it and/or modify
  17  *   it under the terms of the GNU General Public License as published by
  18  *   the Free Software Foundation; either version 2 of the License, or
  19  *   (at your option) any later version.
  20  *
  21  *   This program is distributed in the hope that it will be useful,
  22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   GNU General Public License for more details.
  25  *
  26  *   You should have received a copy of the GNU General Public License
  27  *   along with this program; if not, write to the Free Software
  28  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  29  *
  30  */
  31
  32 #include <linux/init.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/slab.h>
  35 #include <linux/time.h>
  36 #include <linux/wait.h>
  37 #include <linux/module.h>
  38 #include <linux/platform_device.h>
  39 #include <sound/core.h>
  40 #include <sound/control.h>
  41 #include <sound/pcm.h>
  42 #include <sound/pcm_params.h>
  43 #include <sound/info.h>
  44 #include <sound/initval.h>
  45
  46 MODULE_AUTHOR("Jaroslav Kysela <[email protected]>");
  47 MODULE_DESCRIPTION("A loopback soundcard");
  48 MODULE_LICENSE("GPL");
  49 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  50
  51 #define MAX_PCM_SUBSTREAMS      8
  52
  53 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  54 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  55 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  57 static int pcm_notify[SNDRV_CARDS];
  58
  59 module_param_array(index, int, NULL, 0444);
  60 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  61 module_param_array(id, charp, NULL, 0444);
  62 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  63 module_param_array(enable, bool, NULL, 0444);
  64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  65 module_param_array(pcm_substreams, int, NULL, 0444);
  66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  67 module_param_array(pcm_notify, int, NULL, 0444);
  68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  69
  70 #define NO_PITCH 100000
  71
  72 struct loopback_pcm;
  73
  74 struct loopback_cable {
  75         spinlock_t lock;
  76         struct loopback_pcm *streams[2];
  77         struct snd_pcm_hardware hw;
  78         /* flags */
  79         unsigned int valid;
  80         unsigned int running;
  81         unsigned int pause;
  82 };
  83
  84 struct loopback_setup {
  85         unsigned int notify: 1;
  86         unsigned int rate_shift;
  87         unsigned int format;
  88         unsigned int rate;
  89         unsigned int channels;
  90         struct snd_ctl_elem_id active_id;
  91         struct snd_ctl_elem_id format_id;
  92         struct snd_ctl_elem_id rate_id;
  93         struct snd_ctl_elem_id channels_id;
  94 };
  95
  96 struct loopback {
  97         struct snd_card *card;
  98         struct mutex cable_lock;
  99         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
 100         struct snd_pcm *pcm[2];
 101         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 102 };
 103
 104 struct loopback_pcm {
 105         struct loopback *loopback;
 106         struct snd_pcm_substream *substream;
 107         struct loopback_cable *cable;
 108         unsigned int pcm_buffer_size;
 109         unsigned int buf_pos;   /* position in buffer */
 110         unsigned int silent_size;
 111         /* PCM parameters */
 112         unsigned int pcm_period_size;
 113         unsigned int pcm_bps;           /* bytes per second */
 114         unsigned int pcm_salign;        /* bytes per sample * channels */
 115         unsigned int pcm_rate_shift;    /* rate shift value */
 116         /* flags */
 117         unsigned int period_update_pending :1;
 118         /* timer stuff */
 119         unsigned int irq_pos;           /* fractional IRQ position */
 120         unsigned int period_size_frac;
 121         unsigned int last_drift;
 122         unsigned long last_jiffies;
 123         struct timer_list timer;
 124 };
 125
 126 static struct platform_device *devices[SNDRV_CARDS];
 127
 128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 129 {
 130         if (dpcm->pcm_rate_shift == NO_PITCH) {
 131                 x /= HZ;
 132         } else {
 133                 x = div_u64(NO_PITCH * (unsigned long long)x,
 134                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 135         }
 136         return x - (x % dpcm->pcm_salign);
 137 }
 138
 139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 140 {
 141         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 142                 return x * HZ;
 143         } else {
 144                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 145                             NO_PITCH);
 146         }
 147         return x;
 148 }
 149
 150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 151 {
 152         int device = dpcm->substream->pstr->pcm->device;
 153
 154         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 155                 device ^= 1;
 156         return &dpcm->loopback->setup[dpcm->substream->number][device];
 157 }
 158
 159 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 160 {
 161         return get_setup(dpcm)->notify;
 162 }
 163
 164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 165 {
 166         return get_setup(dpcm)->rate_shift;
 167 }
 168
 169 /* call in cable->lock */
 170 static void loopback_timer_start(struct loopback_pcm *dpcm)
 171 {
 172         unsigned long tick;
 173         unsigned int rate_shift = get_rate_shift(dpcm);
 174
 175         if (rate_shift != dpcm->pcm_rate_shift) {
 176                 dpcm->pcm_rate_shift = rate_shift;
 177                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 178         }
 179         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 180                 dpcm->irq_pos %= dpcm->period_size_frac;
 181                 dpcm->period_update_pending = 1;
 182         }
 183         tick = dpcm->period_size_frac - dpcm->irq_pos;
 184         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 185         mod_timer(&dpcm->timer, jiffies + tick);
 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 static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm)
 196 {
 197         del_timer_sync(&dpcm->timer);
 198 }
 199
 200 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 201 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 202 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 203
 204 static int loopback_check_format(struct loopback_cable *cable, int stream)
 205 {
 206         struct snd_pcm_runtime *runtime, *cruntime;
 207         struct loopback_setup *setup;
 208         struct snd_card *card;
 209         int check;
 210
 211         if (cable->valid != CABLE_VALID_BOTH) {
 212                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 213                         goto __notify;
 214                 return 0;
 215         }
 216         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 217                                                         substream->runtime;
 218         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 219                                                         substream->runtime;
 220         check = runtime->format != cruntime->format ||
 221                 runtime->rate != cruntime->rate ||
 222                 runtime->channels != cruntime->channels;
 223         if (!check)
 224                 return 0;
 225         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 226                 return -EIO;
 227         } else {
 228                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 229                                         substream, SNDRV_PCM_STATE_DRAINING);
 230               __notify:
 231                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 232                                                         substream->runtime;
 233                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 234                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 235                 if (setup->format != runtime->format) {
 236                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 237                                                         &setup->format_id);
 238                         setup->format = runtime->format;
 239                 }
 240                 if (setup->rate != runtime->rate) {
 241                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 242                                                         &setup->rate_id);
 243                         setup->rate = runtime->rate;
 244                 }
 245                 if (setup->channels != runtime->channels) {
 246                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 247                                                         &setup->channels_id);
 248                         setup->channels = runtime->channels;
 249                 }
 250         }
 251         return 0;
 252 }
 253
 254 static void loopback_active_notify(struct loopback_pcm *dpcm)
 255 {
 256         snd_ctl_notify(dpcm->loopback->card,
 257                        SNDRV_CTL_EVENT_MASK_VALUE,
 258                        &get_setup(dpcm)->active_id);
 259 }
 260
 261 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 262 {
 263         struct snd_pcm_runtime *runtime = substream->runtime;
 264         struct loopback_pcm *dpcm = runtime->private_data;
 265         struct loopback_cable *cable = dpcm->cable;
 266         int err, stream = 1 << substream->stream;
 267
 268         switch (cmd) {
 269         case SNDRV_PCM_TRIGGER_START:
 270                 err = loopback_check_format(cable, substream->stream);
 271                 if (err < 0)
 272                         return err;
 273                 dpcm->last_jiffies = jiffies;
 274                 dpcm->pcm_rate_shift = 0;
 275                 dpcm->last_drift = 0;
 276                 spin_lock(&cable->lock);
 277                 cable->running |= stream;
 278                 cable->pause &= ~stream;
 279                 loopback_timer_start(dpcm);
 280                 spin_unlock(&cable->lock);
 281                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 282                         loopback_active_notify(dpcm);
 283                 break;
 284         case SNDRV_PCM_TRIGGER_STOP:
 285                 spin_lock(&cable->lock);
 286                 cable->running &= ~stream;
 287                 cable->pause &= ~stream;
 288                 loopback_timer_stop(dpcm);
 289                 spin_unlock(&cable->lock);
 290                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 291                         loopback_active_notify(dpcm);
 292                 break;
 293         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 294         case SNDRV_PCM_TRIGGER_SUSPEND:
 295                 spin_lock(&cable->lock);
 296                 cable->pause |= stream;
 297                 loopback_timer_stop(dpcm);
 298                 spin_unlock(&cable->lock);
 299                 break;
 300         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 301         case SNDRV_PCM_TRIGGER_RESUME:
 302                 spin_lock(&cable->lock);
 303                 dpcm->last_jiffies = jiffies;
 304                 cable->pause &= ~stream;
 305                 loopback_timer_start(dpcm);
 306                 spin_unlock(&cable->lock);
 307                 break;
 308         default:
 309                 return -EINVAL;
 310         }
 311         return 0;
 312 }
 313
 314 static void params_change(struct snd_pcm_substream *substream)
 315 {
 316         struct snd_pcm_runtime *runtime = substream->runtime;
 317         struct loopback_pcm *dpcm = runtime->private_data;
 318         struct loopback_cable *cable = dpcm->cable;
 319
 320         cable->hw.formats = pcm_format_to_bits(runtime->format);
 321         cable->hw.rate_min = runtime->rate;
 322         cable->hw.rate_max = runtime->rate;
 323         cable->hw.channels_min = runtime->channels;
 324         cable->hw.channels_max = runtime->channels;
 325 }
 326
 327 static int loopback_prepare(struct snd_pcm_substream *substream)
 328 {
 329         struct snd_pcm_runtime *runtime = substream->runtime;
 330         struct loopback_pcm *dpcm = runtime->private_data;
 331         struct loopback_cable *cable = dpcm->cable;
 332         int bps, salign;
 333
 334         loopback_timer_stop_sync(dpcm);
 335
 336         salign = (snd_pcm_format_width(runtime->format) *
 337                                                 runtime->channels) / 8;
 338         bps = salign * runtime->rate;
 339         if (bps <= 0 || salign <= 0)
 340                 return -EINVAL;
 341
 342         dpcm->buf_pos = 0;
 343         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 344         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 345                 /* clear capture buffer */
 346                 dpcm->silent_size = dpcm->pcm_buffer_size;
 347                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 348                                            runtime->buffer_size * runtime->channels);
 349         }
 350
 351         dpcm->irq_pos = 0;
 352         dpcm->period_update_pending = 0;
 353         dpcm->pcm_bps = bps;
 354         dpcm->pcm_salign = salign;
 355         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 356
 357         mutex_lock(&dpcm->loopback->cable_lock);
 358         if (!(cable->valid & ~(1 << substream->stream)) ||
 359             (get_setup(dpcm)->notify &&
 360              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 361                 params_change(substream);
 362         cable->valid |= 1 << substream->stream;
 363         mutex_unlock(&dpcm->loopback->cable_lock);
 364
 365         return 0;
 366 }
 367
 368 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 369 {
 370         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 371         char *dst = runtime->dma_area;
 372         unsigned int dst_off = dpcm->buf_pos;
 373
 374         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 375                 return;
 376         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 377                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 378
 379         for (;;) {
 380                 unsigned int size = bytes;
 381                 if (dst_off + size > dpcm->pcm_buffer_size)
 382                         size = dpcm->pcm_buffer_size - dst_off;
 383                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 384                                            bytes_to_frames(runtime, size) *
 385                                                 runtime->channels);
 386                 dpcm->silent_size += size;
 387                 bytes -= size;
 388                 if (!bytes)
 389                         break;
 390                 dst_off = 0;
 391         }
 392 }
 393
 394 static void copy_play_buf(struct loopback_pcm *play,
 395                           struct loopback_pcm *capt,
 396                           unsigned int bytes)
 397 {
 398         struct snd_pcm_runtime *runtime = play->substream->runtime;
 399         char *src = runtime->dma_area;
 400         char *dst = capt->substream->runtime->dma_area;
 401         unsigned int src_off = play->buf_pos;
 402         unsigned int dst_off = capt->buf_pos;
 403         unsigned int clear_bytes = 0;
 404
 405         /* check if playback is draining, trim the capture copy size
 406          * when our pointer is at the end of playback ring buffer */
 407         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 408             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 409                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 410                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 411                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 412                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 413                 if (appl_ptr < appl_ptr1)
 414                         appl_ptr1 -= runtime->buffer_size;
 415                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 416                 if (diff < bytes) {
 417                         clear_bytes = bytes - diff;
 418                         bytes = diff;
 419                 }
 420         }
 421
 422         for (;;) {
 423                 unsigned int size = bytes;
 424                 if (src_off + size > play->pcm_buffer_size)
 425                         size = play->pcm_buffer_size - src_off;
 426                 if (dst_off + size > capt->pcm_buffer_size)
 427                         size = capt->pcm_buffer_size - dst_off;
 428                 memcpy(dst + dst_off, src + src_off, size);
 429                 capt->silent_size = 0;
 430                 bytes -= size;
 431                 if (!bytes)
 432                         break;
 433                 src_off = (src_off + size) % play->pcm_buffer_size;
 434                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 435         }
 436
 437         if (clear_bytes > 0) {
 438                 clear_capture_buf(capt, clear_bytes);
 439                 capt->silent_size = 0;
 440         }
 441 }
 442
 443 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
 444                                          unsigned int jiffies_delta)
 445 {
 446         unsigned long last_pos;
 447         unsigned int delta;
 448
 449         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 450         dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
 451         delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 452         if (delta >= dpcm->last_drift)
 453                 delta -= dpcm->last_drift;
 454         dpcm->last_drift = 0;
 455         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 456                 dpcm->irq_pos %= dpcm->period_size_frac;
 457                 dpcm->period_update_pending = 1;
 458         }
 459         return delta;
 460 }
 461
 462 static inline void bytepos_finish(struct loopback_pcm *dpcm,
 463                                   unsigned int delta)
 464 {
 465         dpcm->buf_pos += delta;
 466         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 467 }
 468
 469 /* call in cable->lock */
 470 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 471 {
 472         struct loopback_pcm *dpcm_play =
 473                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 474         struct loopback_pcm *dpcm_capt =
 475                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 476         unsigned long delta_play = 0, delta_capt = 0;
 477         unsigned int running, count1, count2;
 478
 479         running = cable->running ^ cable->pause;
 480         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 481                 delta_play = jiffies - dpcm_play->last_jiffies;
 482                 dpcm_play->last_jiffies += delta_play;
 483         }
 484
 485         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 486                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 487                 dpcm_capt->last_jiffies += delta_capt;
 488         }
 489
 490         if (delta_play == 0 && delta_capt == 0)
 491                 goto unlock;
 492
 493         if (delta_play > delta_capt) {
 494                 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
 495                 bytepos_finish(dpcm_play, count1);
 496                 delta_play = delta_capt;
 497         } else if (delta_play < delta_capt) {
 498                 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
 499                 clear_capture_buf(dpcm_capt, count1);
 500                 bytepos_finish(dpcm_capt, count1);
 501                 delta_capt = delta_play;
 502         }
 503
 504         if (delta_play == 0 && delta_capt == 0)
 505                 goto unlock;
 506
 507         /* note delta_capt == delta_play at this moment */
 508         count1 = bytepos_delta(dpcm_play, delta_play);
 509         count2 = bytepos_delta(dpcm_capt, delta_capt);
 510         if (count1 < count2) {
 511                 dpcm_capt->last_drift = count2 - count1;
 512                 count1 = count2;
 513         } else if (count1 > count2) {
 514                 dpcm_play->last_drift = count1 - count2;
 515         }
 516         copy_play_buf(dpcm_play, dpcm_capt, count1);
 517         bytepos_finish(dpcm_play, count1);
 518         bytepos_finish(dpcm_capt, count1);
 519  unlock:
 520         return running;
 521 }
 522
 523 static void loopback_timer_function(struct timer_list *t)
 524 {
 525         struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
 526         unsigned long flags;
 527
 528         spin_lock_irqsave(&dpcm->cable->lock, flags);
 529         if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
 530                 loopback_timer_start(dpcm);
 531                 if (dpcm->period_update_pending) {
 532                         dpcm->period_update_pending = 0;
 533                         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 534                         /* need to unlock before calling below */
 535                         snd_pcm_period_elapsed(dpcm->substream);
 536                         return;
 537                 }
 538         }
 539         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 540 }
 541
 542 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 543 {
 544         struct snd_pcm_runtime *runtime = substream->runtime;
 545         struct loopback_pcm *dpcm = runtime->private_data;
 546         snd_pcm_uframes_t pos;
 547
 548         spin_lock(&dpcm->cable->lock);
 549         loopback_pos_update(dpcm->cable);
 550         pos = dpcm->buf_pos;
 551         spin_unlock(&dpcm->cable->lock);
 552         return bytes_to_frames(runtime, pos);
 553 }
 554
 555 static const struct snd_pcm_hardware loopback_pcm_hardware =
 556 {
 557         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 558                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
 559                          SNDRV_PCM_INFO_RESUME),
 560         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 561                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 562                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 563         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 564         .rate_min =             8000,
 565         .rate_max =             192000,
 566         .channels_min =         1,
 567         .channels_max =         32,
 568         .buffer_bytes_max =     2 * 1024 * 1024,
 569         .period_bytes_min =     64,
 570         /* note check overflow in frac_pos() using pcm_rate_shift before
 571            changing period_bytes_max value */
 572         .period_bytes_max =     1024 * 1024,
 573         .periods_min =          1,
 574         .periods_max =          1024,
 575         .fifo_size =            0,
 576 };
 577
 578 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 579 {
 580         struct loopback_pcm *dpcm = runtime->private_data;
 581         kfree(dpcm);
 582 }
 583
 584 static int loopback_hw_params(struct snd_pcm_substream *substream,
 585                               struct snd_pcm_hw_params *params)
 586 {
 587         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 588                                                 params_buffer_bytes(params));
 589 }
 590
 591 static int loopback_hw_free(struct snd_pcm_substream *substream)
 592 {
 593         struct snd_pcm_runtime *runtime = substream->runtime;
 594         struct loopback_pcm *dpcm = runtime->private_data;
 595         struct loopback_cable *cable = dpcm->cable;
 596
 597         mutex_lock(&dpcm->loopback->cable_lock);
 598         cable->valid &= ~(1 << substream->stream);
 599         mutex_unlock(&dpcm->loopback->cable_lock);
 600         return snd_pcm_lib_free_vmalloc_buffer(substream);
 601 }
 602
 603 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 604 {
 605         if (!substream->pcm->device)
 606                 return substream->stream;
 607         else
 608                 return !substream->stream;
 609 }
 610
 611 static int rule_format(struct snd_pcm_hw_params *params,
 612                        struct snd_pcm_hw_rule *rule)
 613 {
 614         struct loopback_pcm *dpcm = rule->private;
 615         struct loopback_cable *cable = dpcm->cable;
 616         struct snd_mask m;
 617
 618         snd_mask_none(&m);
 619         mutex_lock(&dpcm->loopback->cable_lock);
 620         m.bits[0] = (u_int32_t)cable->hw.formats;
 621         m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
 622         mutex_unlock(&dpcm->loopback->cable_lock);
 623         return snd_mask_refine(hw_param_mask(params, rule->var), &m);
 624 }
 625
 626 static int rule_rate(struct snd_pcm_hw_params *params,
 627                      struct snd_pcm_hw_rule *rule)
 628 {
 629         struct loopback_pcm *dpcm = rule->private;
 630         struct loopback_cable *cable = dpcm->cable;
 631         struct snd_interval t;
 632
 633         mutex_lock(&dpcm->loopback->cable_lock);
 634         t.min = cable->hw.rate_min;
 635         t.max = cable->hw.rate_max;
 636         mutex_unlock(&dpcm->loopback->cable_lock);
 637         t.openmin = t.openmax = 0;
 638         t.integer = 0;
 639         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 640 }
 641
 642 static int rule_channels(struct snd_pcm_hw_params *params,
 643                          struct snd_pcm_hw_rule *rule)
 644 {
 645         struct loopback_pcm *dpcm = rule->private;
 646         struct loopback_cable *cable = dpcm->cable;
 647         struct snd_interval t;
 648
 649         mutex_lock(&dpcm->loopback->cable_lock);
 650         t.min = cable->hw.channels_min;
 651         t.max = cable->hw.channels_max;
 652         mutex_unlock(&dpcm->loopback->cable_lock);
 653         t.openmin = t.openmax = 0;
 654         t.integer = 0;
 655         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 656 }
 657
 658 static void free_cable(struct snd_pcm_substream *substream)
 659 {
 660         struct loopback *loopback = substream->private_data;
 661         int dev = get_cable_index(substream);
 662         struct loopback_cable *cable;
 663
 664         cable = loopback->cables[substream->number][dev];
 665         if (!cable)
 666                 return;
 667         if (cable->streams[!substream->stream]) {
 668                 /* other stream is still alive */
 669                 spin_lock_irq(&cable->lock);
 670                 cable->streams[substream->stream] = NULL;
 671                 spin_unlock_irq(&cable->lock);
 672         } else {
 673                 /* free the cable */
 674                 loopback->cables[substream->number][dev] = NULL;
 675                 kfree(cable);
 676         }
 677 }
 678
 679 static int loopback_open(struct snd_pcm_substream *substream)
 680 {
 681         struct snd_pcm_runtime *runtime = substream->runtime;
 682         struct loopback *loopback = substream->private_data;
 683         struct loopback_pcm *dpcm;
 684         struct loopback_cable *cable = NULL;
 685         int err = 0;
 686         int dev = get_cable_index(substream);
 687
 688         mutex_lock(&loopback->cable_lock);
 689         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 690         if (!dpcm) {
 691                 err = -ENOMEM;
 692                 goto unlock;
 693         }
 694         dpcm->loopback = loopback;
 695         dpcm->substream = substream;
 696         timer_setup(&dpcm->timer, loopback_timer_function, 0);
 697
 698         cable = loopback->cables[substream->number][dev];
 699         if (!cable) {
 700                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 701                 if (!cable) {
 702                         err = -ENOMEM;
 703                         goto unlock;
 704                 }
 705                 spin_lock_init(&cable->lock);
 706                 cable->hw = loopback_pcm_hardware;
 707                 loopback->cables[substream->number][dev] = cable;
 708         }
 709         dpcm->cable = cable;
 710
 711         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 712
 713         /* use dynamic rules based on actual runtime->hw values */
 714         /* note that the default rules created in the PCM midlevel code */
 715         /* are cached -> they do not reflect the actual state */
 716         err = snd_pcm_hw_rule_add(runtime, 0,
 717                                   SNDRV_PCM_HW_PARAM_FORMAT,
 718                                   rule_format, dpcm,
 719                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 720         if (err < 0)
 721                 goto unlock;
 722         err = snd_pcm_hw_rule_add(runtime, 0,
 723                                   SNDRV_PCM_HW_PARAM_RATE,
 724                                   rule_rate, dpcm,
 725                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 726         if (err < 0)
 727                 goto unlock;
 728         err = snd_pcm_hw_rule_add(runtime, 0,
 729                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 730                                   rule_channels, dpcm,
 731                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 732         if (err < 0)
 733                 goto unlock;
 734
 735         runtime->private_data = dpcm;
 736         runtime->private_free = loopback_runtime_free;
 737         if (get_notify(dpcm))
 738                 runtime->hw = loopback_pcm_hardware;
 739         else
 740                 runtime->hw = cable->hw;
 741
 742         spin_lock_irq(&cable->lock);
 743         cable->streams[substream->stream] = dpcm;
 744         spin_unlock_irq(&cable->lock);
 745
 746  unlock:
 747         if (err < 0) {
 748                 free_cable(substream);
 749                 kfree(dpcm);
 750         }
 751         mutex_unlock(&loopback->cable_lock);
 752         return err;
 753 }
 754
 755 static int loopback_close(struct snd_pcm_substream *substream)
 756 {
 757         struct loopback *loopback = substream->private_data;
 758         struct loopback_pcm *dpcm = substream->runtime->private_data;
 759
 760         loopback_timer_stop_sync(dpcm);
 761         mutex_lock(&loopback->cable_lock);
 762         free_cable(substream);
 763         mutex_unlock(&loopback->cable_lock);
 764         return 0;
 765 }
 766
 767 static const struct snd_pcm_ops loopback_playback_ops = {
 768         .open =         loopback_open,
 769         .close =        loopback_close,
 770         .ioctl =        snd_pcm_lib_ioctl,
 771         .hw_params =    loopback_hw_params,
 772         .hw_free =      loopback_hw_free,
 773         .prepare =      loopback_prepare,
 774         .trigger =      loopback_trigger,
 775         .pointer =      loopback_pointer,
 776         .page =         snd_pcm_lib_get_vmalloc_page,
 777         .mmap =         snd_pcm_lib_mmap_vmalloc,
 778 };
 779
 780 static const struct snd_pcm_ops loopback_capture_ops = {
 781         .open =         loopback_open,
 782         .close =        loopback_close,
 783         .ioctl =        snd_pcm_lib_ioctl,
 784         .hw_params =    loopback_hw_params,
 785         .hw_free =      loopback_hw_free,
 786         .prepare =      loopback_prepare,
 787         .trigger =      loopback_trigger,
 788         .pointer =      loopback_pointer,
 789         .page =         snd_pcm_lib_get_vmalloc_page,
 790         .mmap =         snd_pcm_lib_mmap_vmalloc,
 791 };
 792
 793 static int loopback_pcm_new(struct loopback *loopback,
 794                             int device, int substreams)
 795 {
 796         struct snd_pcm *pcm;
 797         int err;
 798
 799         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 800                           substreams, substreams, &pcm);
 801         if (err < 0)
 802                 return err;
 803         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 804         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 805
 806         pcm->private_data = loopback;
 807         pcm->info_flags = 0;
 808         strcpy(pcm->name, "Loopback PCM");
 809
 810         loopback->pcm[device] = pcm;
 811         return 0;
 812 }
 813
 814 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 815                                     struct snd_ctl_elem_info *uinfo)
 816 {
 817         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 818         uinfo->count = 1;
 819         uinfo->value.integer.min = 80000;
 820         uinfo->value.integer.max = 120000;
 821         uinfo->value.integer.step = 1;
 822         return 0;
 823 }
 824
 825 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 826                                    struct snd_ctl_elem_value *ucontrol)
 827 {
 828         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 829
 830         ucontrol->value.integer.value[0] =
 831                 loopback->setup[kcontrol->id.subdevice]
 832                                [kcontrol->id.device].rate_shift;
 833         return 0;
 834 }
 835
 836 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 837                                    struct snd_ctl_elem_value *ucontrol)
 838 {
 839         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 840         unsigned int val;
 841         int change = 0;
 842
 843         val = ucontrol->value.integer.value[0];
 844         if (val < 80000)
 845                 val = 80000;
 846         if (val > 120000)
 847                 val = 120000;
 848         mutex_lock(&loopback->cable_lock);
 849         if (val != loopback->setup[kcontrol->id.subdevice]
 850                                   [kcontrol->id.device].rate_shift) {
 851                 loopback->setup[kcontrol->id.subdevice]
 852                                [kcontrol->id.device].rate_shift = val;
 853                 change = 1;
 854         }
 855         mutex_unlock(&loopback->cable_lock);
 856         return change;
 857 }
 858
 859 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 860                                struct snd_ctl_elem_value *ucontrol)
 861 {
 862         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 863
 864         ucontrol->value.integer.value[0] =
 865                 loopback->setup[kcontrol->id.subdevice]
 866                                [kcontrol->id.device].notify;
 867         return 0;
 868 }
 869
 870 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 871                                struct snd_ctl_elem_value *ucontrol)
 872 {
 873         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 874         unsigned int val;
 875         int change = 0;
 876
 877         val = ucontrol->value.integer.value[0] ? 1 : 0;
 878         if (val != loopback->setup[kcontrol->id.subdevice]
 879                                 [kcontrol->id.device].notify) {
 880                 loopback->setup[kcontrol->id.subdevice]
 881                         [kcontrol->id.device].notify = val;
 882                 change = 1;
 883         }
 884         return change;
 885 }
 886
 887 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 888                                struct snd_ctl_elem_value *ucontrol)
 889 {
 890         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 891         struct loopback_cable *cable = loopback->cables
 892                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 893         unsigned int val = 0;
 894
 895         if (cable != NULL)
 896                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 897                                                                         1 : 0;
 898         ucontrol->value.integer.value[0] = val;
 899         return 0;
 900 }
 901
 902 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 903                                 struct snd_ctl_elem_info *uinfo)
 904 {
 905         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 906         uinfo->count = 1;
 907         uinfo->value.integer.min = 0;
 908         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 909         uinfo->value.integer.step = 1;
 910         return 0;
 911 }
 912
 913 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 914                                struct snd_ctl_elem_value *ucontrol)
 915 {
 916         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 917
 918         ucontrol->value.integer.value[0] =
 919                 loopback->setup[kcontrol->id.subdevice]
 920                                [kcontrol->id.device].format;
 921         return 0;
 922 }
 923
 924 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 925                               struct snd_ctl_elem_info *uinfo)
 926 {
 927         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 928         uinfo->count = 1;
 929         uinfo->value.integer.min = 0;
 930         uinfo->value.integer.max = 192000;
 931         uinfo->value.integer.step = 1;
 932         return 0;
 933 }
 934
 935 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 936                              struct snd_ctl_elem_value *ucontrol)
 937 {
 938         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 939
 940         ucontrol->value.integer.value[0] =
 941                 loopback->setup[kcontrol->id.subdevice]
 942                                [kcontrol->id.device].rate;
 943         return 0;
 944 }
 945
 946 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 947                                   struct snd_ctl_elem_info *uinfo)
 948 {
 949         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 950         uinfo->count = 1;
 951         uinfo->value.integer.min = 1;
 952         uinfo->value.integer.max = 1024;
 953         uinfo->value.integer.step = 1;
 954         return 0;
 955 }
 956
 957 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 958                                  struct snd_ctl_elem_value *ucontrol)
 959 {
 960         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 961
 962         ucontrol->value.integer.value[0] =
 963                 loopback->setup[kcontrol->id.subdevice]
 964                                [kcontrol->id.device].channels;
 965         return 0;
 966 }
 967
 968 static struct snd_kcontrol_new loopback_controls[]  = {
 969 {
 970         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 971         .name =         "PCM Rate Shift 100000",
 972         .info =         loopback_rate_shift_info,
 973         .get =          loopback_rate_shift_get,
 974         .put =          loopback_rate_shift_put,
 975 },
 976 {
 977         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 978         .name =         "PCM Notify",
 979         .info =         snd_ctl_boolean_mono_info,
 980         .get =          loopback_notify_get,
 981         .put =          loopback_notify_put,
 982 },
 983 #define ACTIVE_IDX 2
 984 {
 985         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 986         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 987         .name =         "PCM Slave Active",
 988         .info =         snd_ctl_boolean_mono_info,
 989         .get =          loopback_active_get,
 990 },
 991 #define FORMAT_IDX 3
 992 {
 993         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 994         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 995         .name =         "PCM Slave Format",
 996         .info =         loopback_format_info,
 997         .get =          loopback_format_get
 998 },
 999 #define RATE_IDX 4
1000 {
1001         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1002         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1003         .name =         "PCM Slave Rate",
1004         .info =         loopback_rate_info,
1005         .get =          loopback_rate_get
1006 },
1007 #define CHANNELS_IDX 5
1008 {
1009         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1010         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1011         .name =         "PCM Slave Channels",
1012         .info =         loopback_channels_info,
1013         .get =          loopback_channels_get
1014 }
1015 };
1016
1017 static int loopback_mixer_new(struct loopback *loopback, int notify)
1018 {
1019         struct snd_card *card = loopback->card;
1020         struct snd_pcm *pcm;
1021         struct snd_kcontrol *kctl;
1022         struct loopback_setup *setup;
1023         int err, dev, substr, substr_count, idx;
1024
1025         strcpy(card->mixername, "Loopback Mixer");
1026         for (dev = 0; dev < 2; dev++) {
1027                 pcm = loopback->pcm[dev];
1028                 substr_count =
1029                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1030                 for (substr = 0; substr < substr_count; substr++) {
1031                         setup = &loopback->setup[substr][dev];
1032                         setup->notify = notify;
1033                         setup->rate_shift = NO_PITCH;
1034                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1035                         setup->rate = 48000;
1036                         setup->channels = 2;
1037                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1038                                                                         idx++) {
1039                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1040                                                     loopback);
1041                                 if (!kctl)
1042                                         return -ENOMEM;
1043                                 kctl->id.device = dev;
1044                                 kctl->id.subdevice = substr;
1045                                 switch (idx) {
1046                                 case ACTIVE_IDX:
1047                                         setup->active_id = kctl->id;
1048                                         break;
1049                                 case FORMAT_IDX:
1050                                         setup->format_id = kctl->id;
1051                                         break;
1052                                 case RATE_IDX:
1053                                         setup->rate_id = kctl->id;
1054                                         break;
1055                                 case CHANNELS_IDX:
1056                                         setup->channels_id = kctl->id;
1057                                         break;
1058                                 default:
1059                                         break;
1060                                 }
1061                                 err = snd_ctl_add(card, kctl);
1062                                 if (err < 0)
1063                                         return err;
1064                         }
1065                 }
1066         }
1067         return 0;
1068 }
1069
1070 static void print_dpcm_info(struct snd_info_buffer *buffer,
1071                             struct loopback_pcm *dpcm,
1072                             const char *id)
1073 {
1074         snd_iprintf(buffer, "  %s\n", id);
1075         if (dpcm == NULL) {
1076                 snd_iprintf(buffer, "    inactive\n");
1077                 return;
1078         }
1079         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1080         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1081         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1082         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1083         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1084         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1085         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1086         snd_iprintf(buffer, "    update_pending:\t%u\n",
1087                                                 dpcm->period_update_pending);
1088         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1089         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1090         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1091                                         dpcm->last_jiffies, jiffies);
1092         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1093 }
1094
1095 static void print_substream_info(struct snd_info_buffer *buffer,
1096                                  struct loopback *loopback,
1097                                  int sub,
1098                                  int num)
1099 {
1100         struct loopback_cable *cable = loopback->cables[sub][num];
1101
1102         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1103         if (cable == NULL) {
1104                 snd_iprintf(buffer, "  inactive\n");
1105                 return;
1106         }
1107         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1108         snd_iprintf(buffer, "  running: %u\n", cable->running);
1109         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1110         print_dpcm_info(buffer, cable->streams[0], "Playback");
1111         print_dpcm_info(buffer, cable->streams[1], "Capture");
1112 }
1113
1114 static void print_cable_info(struct snd_info_entry *entry,
1115                              struct snd_info_buffer *buffer)
1116 {
1117         struct loopback *loopback = entry->private_data;
1118         int sub, num;
1119
1120         mutex_lock(&loopback->cable_lock);
1121         num = entry->name[strlen(entry->name)-1];
1122         num = num == '0' ? 0 : 1;
1123         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1124                 print_substream_info(buffer, loopback, sub, num);
1125         mutex_unlock(&loopback->cable_lock);
1126 }
1127
1128 static int loopback_proc_new(struct loopback *loopback, int cidx)
1129 {
1130         char name[32];
1131         struct snd_info_entry *entry;
1132         int err;
1133
1134         snprintf(name, sizeof(name), "cable#%d", cidx);
1135         err = snd_card_proc_new(loopback->card, name, &entry);
1136         if (err < 0)
1137                 return err;
1138
1139         snd_info_set_text_ops(entry, loopback, print_cable_info);
1140         return 0;
1141 }
1142
1143 static int loopback_probe(struct platform_device *devptr)
1144 {
1145         struct snd_card *card;
1146         struct loopback *loopback;
1147         int dev = devptr->id;
1148         int err;
1149
1150         err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1151                            sizeof(struct loopback), &card);
1152         if (err < 0)
1153                 return err;
1154         loopback = card->private_data;
1155
1156         if (pcm_substreams[dev] < 1)
1157                 pcm_substreams[dev] = 1;
1158         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1159                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1160
1161         loopback->card = card;
1162         mutex_init(&loopback->cable_lock);
1163
1164         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1165         if (err < 0)
1166                 goto __nodev;
1167         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1168         if (err < 0)
1169                 goto __nodev;
1170         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1171         if (err < 0)
1172                 goto __nodev;
1173         loopback_proc_new(loopback, 0);
1174         loopback_proc_new(loopback, 1);
1175         strcpy(card->driver, "Loopback");
1176         strcpy(card->shortname, "Loopback");
1177         sprintf(card->longname, "Loopback %i", dev + 1);
1178         err = snd_card_register(card);
1179         if (!err) {
1180                 platform_set_drvdata(devptr, card);
1181                 return 0;
1182         }
1183       __nodev:
1184         snd_card_free(card);
1185         return err;
1186 }
1187
1188 static int loopback_remove(struct platform_device *devptr)
1189 {
1190         snd_card_free(platform_get_drvdata(devptr));
1191         return 0;
1192 }
1193
1194 #ifdef CONFIG_PM_SLEEP
1195 static int loopback_suspend(struct device *pdev)
1196 {
1197         struct snd_card *card = dev_get_drvdata(pdev);
1198         struct loopback *loopback = card->private_data;
1199
1200         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1201
1202         snd_pcm_suspend_all(loopback->pcm[0]);
1203         snd_pcm_suspend_all(loopback->pcm[1]);
1204         return 0;
1205 }
1206
1207 static int loopback_resume(struct device *pdev)
1208 {
1209         struct snd_card *card = dev_get_drvdata(pdev);
1210
1211         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1212         return 0;
1213 }
1214
1215 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1216 #define LOOPBACK_PM_OPS &loopback_pm
1217 #else
1218 #define LOOPBACK_PM_OPS NULL
1219 #endif
1220
1221 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1222
1223 static struct platform_driver loopback_driver = {
1224         .probe          = loopback_probe,
1225         .remove         = loopback_remove,
1226         .driver         = {
1227                 .name   = SND_LOOPBACK_DRIVER,
1228                 .pm     = LOOPBACK_PM_OPS,
1229         },
1230 };
1231
1232 static void loopback_unregister_all(void)
1233 {
1234         int i;
1235
1236         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1237                 platform_device_unregister(devices[i]);
1238         platform_driver_unregister(&loopback_driver);
1239 }
1240
1241 static int __init alsa_card_loopback_init(void)
1242 {
1243         int i, err, cards;
1244
1245         err = platform_driver_register(&loopback_driver);
1246         if (err < 0)
1247                 return err;
1248
1249
1250         cards = 0;
1251         for (i = 0; i < SNDRV_CARDS; i++) {
1252                 struct platform_device *device;
1253                 if (!enable[i])
1254                         continue;
1255                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1256                                                          i, NULL, 0);
1257                 if (IS_ERR(device))
1258                         continue;
1259                 if (!platform_get_drvdata(device)) {
1260                         platform_device_unregister(device);
1261                         continue;
1262                 }
1263                 devices[i] = device;
1264                 cards++;
1265         }
1266         if (!cards) {
1267 #ifdef MODULE
1268                 printk(KERN_ERR "aloop: No loopback enabled\n");
1269 #endif
1270                 loopback_unregister_all();
1271                 return -ENODEV;
1272         }
1273         return 0;
1274 }
1275
1276 static void __exit alsa_card_loopback_exit(void)
1277 {
1278         loopback_unregister_all();
1279 }
1280
1281 module_init(alsa_card_loopback_init)
1282 module_exit(alsa_card_loopback_exit)