sound/drivers/aloop.c

   1 /*
   2  *  Loopback soundcard
   3  *
   4  *  Original code:
   5  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   6  *
   7  *  More accurate positioning and full-duplex support:
   8  *  Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
   9  *
  10  *  Major (almost complete) rewrite:
  11  *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
  12  *
  13  *  A next major update in 2010 (separate timers for playback and capture):
  14  *  Copyright (c) Jaroslav Kysela <perex@perex.cz>
  15  *
  16  *   This program is free software; you can redistribute it and/or modify
  17  *   it under the terms of the GNU General Public License as published by
  18  *   the Free Software Foundation; either version 2 of the License, or
  19  *   (at your option) any later version.
  20  *
  21  *   This program is distributed in the hope that it will be useful,
  22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   GNU General Public License for more details.
  25  *
  26  *   You should have received a copy of the GNU General Public License
  27  *   along with this program; if not, write to the Free Software
  28  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  29  *
  30  */
  31
  32 #include <linux/init.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/slab.h>
  35 #include <linux/time.h>
  36 #include <linux/wait.h>
  37 #include <linux/module.h>
  38 #include <linux/platform_device.h>
  39 #include <sound/core.h>
  40 #include <sound/control.h>
  41 #include <sound/pcm.h>
  42 #include <sound/pcm_params.h>
  43 #include <sound/info.h>
  44 #include <sound/initval.h>
  45
  46 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  47 MODULE_DESCRIPTION("A loopback soundcard");
  48 MODULE_LICENSE("GPL");
  49 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  50
  51 #define MAX_PCM_SUBSTREAMS      8
  52
  53 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  54 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  55 static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  57 static int pcm_notify[SNDRV_CARDS];
  58
  59 module_param_array(index, int, NULL, 0444);
  60 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  61 module_param_array(id, charp, NULL, 0444);
  62 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  63 module_param_array(enable, bool, NULL, 0444);
  64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  65 module_param_array(pcm_substreams, int, NULL, 0444);
  66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  67 module_param_array(pcm_notify, int, NULL, 0444);
  68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  69
  70 #define NO_PITCH 100000
  71
  72 struct loopback_pcm;
  73
  74 struct loopback_cable {
  75         spinlock_t lock;
  76         struct loopback_pcm *streams[2];
  77         struct snd_pcm_hardware hw;
  78         /* flags */
  79         unsigned int valid;
  80         unsigned int running;
  81         unsigned int pause;
  82 };
  83
  84 struct loopback_setup {
  85         unsigned int notify: 1;
  86         unsigned int rate_shift;
  87         unsigned int format;
  88         unsigned int rate;
  89         unsigned int channels;
  90         struct snd_ctl_elem_id active_id;
  91         struct snd_ctl_elem_id format_id;
  92         struct snd_ctl_elem_id rate_id;
  93         struct snd_ctl_elem_id channels_id;
  94 };
  95
  96 struct loopback {
  97         struct snd_card *card;
  98         struct mutex cable_lock;
  99         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
 100         struct snd_pcm *pcm[2];
 101         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 102 };
 103
 104 struct loopback_pcm {
 105         struct loopback *loopback;
 106         struct snd_pcm_substream *substream;
 107         struct loopback_cable *cable;
 108         unsigned int pcm_buffer_size;
 109         unsigned int buf_pos;   /* position in buffer */
 110         unsigned int silent_size;
 111         /* PCM parameters */
 112         unsigned int pcm_period_size;
 113         unsigned int pcm_bps;           /* bytes per second */
 114         unsigned int pcm_salign;        /* bytes per sample * channels */
 115         unsigned int pcm_rate_shift;    /* rate shift value */
 116         /* flags */
 117         unsigned int period_update_pending :1;
 118         /* timer stuff */
 119         unsigned int irq_pos;           /* fractional IRQ position */
 120         unsigned int period_size_frac;
 121         unsigned long last_jiffies;
 122         struct timer_list timer;
 123         spinlock_t timer_lock;
 124 };
 125
 126 static struct platform_device *devices[SNDRV_CARDS];
 127
 128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 129 {
 130         if (dpcm->pcm_rate_shift == NO_PITCH) {
 131                 x /= HZ;
 132         } else {
 133                 x = div_u64(NO_PITCH * (unsigned long long)x,
 134                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 135         }
 136         return x - (x % dpcm->pcm_salign);
 137 }
 138
 139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 140 {
 141         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 142                 return x * HZ;
 143         } else {
 144                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 145                             NO_PITCH);
 146         }
 147         return x;
 148 }
 149
 150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 151 {
 152         int device = dpcm->substream->pstr->pcm->device;
 153
 154         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 155                 device ^= 1;
 156         return &dpcm->loopback->setup[dpcm->substream->number][device];
 157 }
 158
 159 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 160 {
 161         return get_setup(dpcm)->notify;
 162 }
 163
 164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 165 {
 166         return get_setup(dpcm)->rate_shift;
 167 }
 168
 169 static void loopback_timer_start(struct loopback_pcm *dpcm)
 170 {
 171         unsigned long tick;
 172         unsigned int rate_shift = get_rate_shift(dpcm);
 173
 174         spin_lock(&dpcm->timer_lock);
 175         if (rate_shift != dpcm->pcm_rate_shift) {
 176                 dpcm->pcm_rate_shift = rate_shift;
 177                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 178         }
 179         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 180                 dpcm->irq_pos %= dpcm->period_size_frac;
 181                 dpcm->period_update_pending = 1;
 182         }
 183         tick = dpcm->period_size_frac - dpcm->irq_pos;
 184         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 185         dpcm->timer.expires = jiffies + tick;
 186         add_timer(&dpcm->timer);
 187         spin_unlock(&dpcm->timer_lock);
 188 }
 189
 190 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 191 {
 192         spin_lock(&dpcm->timer_lock);
 193         del_timer(&dpcm->timer);
 194         dpcm->timer.expires = 0;
 195         spin_unlock(&dpcm->timer_lock);
 196 }
 197
 198 static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm)
 199 {
 200         del_timer_sync(&dpcm->timer);
 201 }
 202
 203 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 204 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 205 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 206
 207 static int loopback_check_format(struct loopback_cable *cable, int stream)
 208 {
 209         struct snd_pcm_runtime *runtime, *cruntime;
 210         struct loopback_setup *setup;
 211         struct snd_card *card;
 212         int check;
 213
 214         if (cable->valid != CABLE_VALID_BOTH) {
 215                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 216                         goto __notify;
 217                 return 0;
 218         }
 219         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 220                                                         substream->runtime;
 221         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 222                                                         substream->runtime;
 223         check = runtime->format != cruntime->format ||
 224                 runtime->rate != cruntime->rate ||
 225                 runtime->channels != cruntime->channels;
 226         if (!check)
 227                 return 0;
 228         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 229                 return -EIO;
 230         } else {
 231                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 232                                         substream, SNDRV_PCM_STATE_DRAINING);
 233               __notify:
 234                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 235                                                         substream->runtime;
 236                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 237                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 238                 if (setup->format != runtime->format) {
 239                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 240                                                         &setup->format_id);
 241                         setup->format = runtime->format;
 242                 }
 243                 if (setup->rate != runtime->rate) {
 244                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 245                                                         &setup->rate_id);
 246                         setup->rate = runtime->rate;
 247                 }
 248                 if (setup->channels != runtime->channels) {
 249                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 250                                                         &setup->channels_id);
 251                         setup->channels = runtime->channels;
 252                 }
 253         }
 254         return 0;
 255 }
 256
 257 static void loopback_active_notify(struct loopback_pcm *dpcm)
 258 {
 259         snd_ctl_notify(dpcm->loopback->card,
 260                        SNDRV_CTL_EVENT_MASK_VALUE,
 261                        &get_setup(dpcm)->active_id);
 262 }
 263
 264 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 265 {
 266         struct snd_pcm_runtime *runtime = substream->runtime;
 267         struct loopback_pcm *dpcm = runtime->private_data;
 268         struct loopback_cable *cable = dpcm->cable;
 269         int err, stream = 1 << substream->stream;
 270
 271         switch (cmd) {
 272         case SNDRV_PCM_TRIGGER_START:
 273                 err = loopback_check_format(cable, substream->stream);
 274                 if (err < 0)
 275                         return err;
 276                 dpcm->last_jiffies = jiffies;
 277                 dpcm->pcm_rate_shift = 0;
 278                 spin_lock(&cable->lock);
 279                 cable->running |= stream;
 280                 cable->pause &= ~stream;
 281                 spin_unlock(&cable->lock);
 282                 loopback_timer_start(dpcm);
 283                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 284                         loopback_active_notify(dpcm);
 285                 break;
 286         case SNDRV_PCM_TRIGGER_STOP:
 287                 spin_lock(&cable->lock);
 288                 cable->running &= ~stream;
 289                 cable->pause &= ~stream;
 290                 spin_unlock(&cable->lock);
 291                 loopback_timer_stop(dpcm);
 292                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 293                         loopback_active_notify(dpcm);
 294                 break;
 295         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 296         case SNDRV_PCM_TRIGGER_SUSPEND:
 297                 spin_lock(&cable->lock);
 298                 cable->pause |= stream;
 299                 spin_unlock(&cable->lock);
 300                 loopback_timer_stop(dpcm);
 301                 break;
 302         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 303         case SNDRV_PCM_TRIGGER_RESUME:
 304                 spin_lock(&cable->lock);
 305                 dpcm->last_jiffies = jiffies;
 306                 cable->pause &= ~stream;
 307                 spin_unlock(&cable->lock);
 308                 loopback_timer_start(dpcm);
 309                 break;
 310         default:
 311                 return -EINVAL;
 312         }
 313         return 0;
 314 }
 315
 316 static void params_change(struct snd_pcm_substream *substream)
 317 {
 318         struct snd_pcm_runtime *runtime = substream->runtime;
 319         struct loopback_pcm *dpcm = runtime->private_data;
 320         struct loopback_cable *cable = dpcm->cable;
 321
 322         cable->hw.formats = (1ULL << runtime->format);
 323         cable->hw.rate_min = runtime->rate;
 324         cable->hw.rate_max = runtime->rate;
 325         cable->hw.channels_min = runtime->channels;
 326         cable->hw.channels_max = runtime->channels;
 327 }
 328
 329 static int loopback_prepare(struct snd_pcm_substream *substream)
 330 {
 331         struct snd_pcm_runtime *runtime = substream->runtime;
 332         struct loopback_pcm *dpcm = runtime->private_data;
 333         struct loopback_cable *cable = dpcm->cable;
 334         int bps, salign;
 335
 336         loopback_timer_stop_sync(dpcm);
 337
 338         salign = (snd_pcm_format_width(runtime->format) *
 339                                                 runtime->channels) / 8;
 340         bps = salign * runtime->rate;
 341         if (bps <= 0 || salign <= 0)
 342                 return -EINVAL;
 343
 344         dpcm->buf_pos = 0;
 345         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 346         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 347                 /* clear capture buffer */
 348                 dpcm->silent_size = dpcm->pcm_buffer_size;
 349                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 350                                            runtime->buffer_size * runtime->channels);
 351         }
 352
 353         dpcm->irq_pos = 0;
 354         dpcm->period_update_pending = 0;
 355         dpcm->pcm_bps = bps;
 356         dpcm->pcm_salign = salign;
 357         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 358
 359         mutex_lock(&dpcm->loopback->cable_lock);
 360         if (!(cable->valid & ~(1 << substream->stream)) ||
 361             (get_setup(dpcm)->notify &&
 362              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 363                 params_change(substream);
 364         cable->valid |= 1 << substream->stream;
 365         mutex_unlock(&dpcm->loopback->cable_lock);
 366
 367         return 0;
 368 }
 369
 370 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 371 {
 372         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 373         char *dst = runtime->dma_area;
 374         unsigned int dst_off = dpcm->buf_pos;
 375
 376         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 377                 return;
 378         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 379                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 380
 381         for (;;) {
 382                 unsigned int size = bytes;
 383                 if (dst_off + size > dpcm->pcm_buffer_size)
 384                         size = dpcm->pcm_buffer_size - dst_off;
 385                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 386                                            bytes_to_frames(runtime, size) *
 387                                                 runtime->channels);
 388                 dpcm->silent_size += size;
 389                 bytes -= size;
 390                 if (!bytes)
 391                         break;
 392                 dst_off = 0;
 393         }
 394 }
 395
 396 static void copy_play_buf(struct loopback_pcm *play,
 397                           struct loopback_pcm *capt,
 398                           unsigned int bytes)
 399 {
 400         struct snd_pcm_runtime *runtime = play->substream->runtime;
 401         char *src = runtime->dma_area;
 402         char *dst = capt->substream->runtime->dma_area;
 403         unsigned int src_off = play->buf_pos;
 404         unsigned int dst_off = capt->buf_pos;
 405         unsigned int clear_bytes = 0;
 406
 407         /* check if playback is draining, trim the capture copy size
 408          * when our pointer is at the end of playback ring buffer */
 409         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 410             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 411                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 412                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 413                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 414                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 415                 if (appl_ptr < appl_ptr1)
 416                         appl_ptr1 -= runtime->buffer_size;
 417                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 418                 if (diff < bytes) {
 419                         clear_bytes = bytes - diff;
 420                         bytes = diff;
 421                 }
 422         }
 423
 424         for (;;) {
 425                 unsigned int size = bytes;
 426                 if (src_off + size > play->pcm_buffer_size)
 427                         size = play->pcm_buffer_size - src_off;
 428                 if (dst_off + size > capt->pcm_buffer_size)
 429                         size = capt->pcm_buffer_size - dst_off;
 430                 memcpy(dst + dst_off, src + src_off, size);
 431                 capt->silent_size = 0;
 432                 bytes -= size;
 433                 if (!bytes)
 434                         break;
 435                 src_off = (src_off + size) % play->pcm_buffer_size;
 436                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 437         }
 438
 439         if (clear_bytes > 0) {
 440                 clear_capture_buf(capt, clear_bytes);
 441                 capt->silent_size = 0;
 442         }
 443 }
 444
 445 #define BYTEPOS_UPDATE_POSONLY  0
 446 #define BYTEPOS_UPDATE_CLEAR    1
 447 #define BYTEPOS_UPDATE_COPY     2
 448
 449 static void loopback_bytepos_update(struct loopback_pcm *dpcm,
 450                                     unsigned int delta,
 451                                     unsigned int cmd)
 452 {
 453         unsigned int count;
 454         unsigned long last_pos;
 455
 456         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 457         dpcm->irq_pos += delta * dpcm->pcm_bps;
 458         count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 459         if (!count)
 460                 return;
 461         if (cmd == BYTEPOS_UPDATE_CLEAR)
 462                 clear_capture_buf(dpcm, count);
 463         else if (cmd == BYTEPOS_UPDATE_COPY)
 464                 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 465                               dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 466                               count);
 467         dpcm->buf_pos += count;
 468         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 469         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 470                 dpcm->irq_pos %= dpcm->period_size_frac;
 471                 dpcm->period_update_pending = 1;
 472         }
 473 }
 474
 475 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 476 {
 477         struct loopback_pcm *dpcm_play =
 478                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 479         struct loopback_pcm *dpcm_capt =
 480                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 481         unsigned long delta_play = 0, delta_capt = 0;
 482         unsigned int running;
 483         unsigned long flags;
 484
 485         spin_lock_irqsave(&cable->lock, flags);
 486         running = cable->running ^ cable->pause;
 487         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 488                 delta_play = jiffies - dpcm_play->last_jiffies;
 489                 dpcm_play->last_jiffies += delta_play;
 490         }
 491
 492         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 493                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 494                 dpcm_capt->last_jiffies += delta_capt;
 495         }
 496
 497         if (delta_play == 0 && delta_capt == 0)
 498                 goto unlock;
 499
 500         if (delta_play > delta_capt) {
 501                 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
 502                                         BYTEPOS_UPDATE_POSONLY);
 503                 delta_play = delta_capt;
 504         } else if (delta_play < delta_capt) {
 505                 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
 506                                         BYTEPOS_UPDATE_CLEAR);
 507                 delta_capt = delta_play;
 508         }
 509
 510         if (delta_play == 0 && delta_capt == 0)
 511                 goto unlock;
 512
 513         /* note delta_capt == delta_play at this moment */
 514         loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
 515         loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
 516  unlock:
 517         spin_unlock_irqrestore(&cable->lock, flags);
 518         return running;
 519 }
 520
 521 static void loopback_timer_function(unsigned long data)
 522 {
 523         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 524         unsigned int running;
 525
 526         running = loopback_pos_update(dpcm->cable);
 527         if (running & (1 << dpcm->substream->stream)) {
 528                 loopback_timer_start(dpcm);
 529                 if (dpcm->period_update_pending) {
 530                         dpcm->period_update_pending = 0;
 531                         snd_pcm_period_elapsed(dpcm->substream);
 532                 }
 533         }
 534 }
 535
 536 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 537 {
 538         struct snd_pcm_runtime *runtime = substream->runtime;
 539         struct loopback_pcm *dpcm = runtime->private_data;
 540
 541         loopback_pos_update(dpcm->cable);
 542         return bytes_to_frames(runtime, dpcm->buf_pos);
 543 }
 544
 545 static struct snd_pcm_hardware loopback_pcm_hardware =
 546 {
 547         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 548                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
 549                          SNDRV_PCM_INFO_RESUME),
 550         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 551                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 552                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 553         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 554         .rate_min =             8000,
 555         .rate_max =             192000,
 556         .channels_min =         1,
 557         .channels_max =         32,
 558         .buffer_bytes_max =     2 * 1024 * 1024,
 559         .period_bytes_min =     64,
 560         /* note check overflow in frac_pos() using pcm_rate_shift before
 561            changing period_bytes_max value */
 562         .period_bytes_max =     1024 * 1024,
 563         .periods_min =          1,
 564         .periods_max =          1024,
 565         .fifo_size =            0,
 566 };
 567
 568 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 569 {
 570         struct loopback_pcm *dpcm = runtime->private_data;
 571         kfree(dpcm);
 572 }
 573
 574 static int loopback_hw_params(struct snd_pcm_substream *substream,
 575                               struct snd_pcm_hw_params *params)
 576 {
 577         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 578                                                 params_buffer_bytes(params));
 579 }
 580
 581 static int loopback_hw_free(struct snd_pcm_substream *substream)
 582 {
 583         struct snd_pcm_runtime *runtime = substream->runtime;
 584         struct loopback_pcm *dpcm = runtime->private_data;
 585         struct loopback_cable *cable = dpcm->cable;
 586
 587         mutex_lock(&dpcm->loopback->cable_lock);
 588         cable->valid &= ~(1 << substream->stream);
 589         mutex_unlock(&dpcm->loopback->cable_lock);
 590         return snd_pcm_lib_free_vmalloc_buffer(substream);
 591 }
 592
 593 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 594 {
 595         if (!substream->pcm->device)
 596                 return substream->stream;
 597         else
 598                 return !substream->stream;
 599 }
 600
 601 static int rule_format(struct snd_pcm_hw_params *params,
 602                        struct snd_pcm_hw_rule *rule)
 603 {
 604         struct loopback_pcm *dpcm = rule->private;
 605         struct loopback_cable *cable = dpcm->cable;
 606         struct snd_mask m;
 607
 608         snd_mask_none(&m);
 609         mutex_lock(&dpcm->loopback->cable_lock);
 610         m.bits[0] = (u_int32_t)cable->hw.formats;
 611         m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
 612         mutex_unlock(&dpcm->loopback->cable_lock);
 613         return snd_mask_refine(hw_param_mask(params, rule->var), &m);
 614 }
 615
 616 static int rule_rate(struct snd_pcm_hw_params *params,
 617                      struct snd_pcm_hw_rule *rule)
 618 {
 619         struct loopback_pcm *dpcm = rule->private;
 620         struct loopback_cable *cable = dpcm->cable;
 621         struct snd_interval t;
 622
 623         mutex_lock(&dpcm->loopback->cable_lock);
 624         t.min = cable->hw.rate_min;
 625         t.max = cable->hw.rate_max;
 626         mutex_unlock(&dpcm->loopback->cable_lock);
 627         t.openmin = t.openmax = 0;
 628         t.integer = 0;
 629         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 630 }
 631
 632 static int rule_channels(struct snd_pcm_hw_params *params,
 633                          struct snd_pcm_hw_rule *rule)
 634 {
 635         struct loopback_pcm *dpcm = rule->private;
 636         struct loopback_cable *cable = dpcm->cable;
 637         struct snd_interval t;
 638
 639         mutex_lock(&dpcm->loopback->cable_lock);
 640         t.min = cable->hw.channels_min;
 641         t.max = cable->hw.channels_max;
 642         mutex_unlock(&dpcm->loopback->cable_lock);
 643         t.openmin = t.openmax = 0;
 644         t.integer = 0;
 645         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 646 }
 647
 648 static void free_cable(struct snd_pcm_substream *substream)
 649 {
 650         struct loopback *loopback = substream->private_data;
 651         int dev = get_cable_index(substream);
 652         struct loopback_cable *cable;
 653
 654         cable = loopback->cables[substream->number][dev];
 655         if (!cable)
 656                 return;
 657         if (cable->streams[!substream->stream]) {
 658                 /* other stream is still alive */
 659                 cable->streams[substream->stream] = NULL;
 660         } else {
 661                 /* free the cable */
 662                 loopback->cables[substream->number][dev] = NULL;
 663                 kfree(cable);
 664         }
 665 }
 666
 667 static int loopback_open(struct snd_pcm_substream *substream)
 668 {
 669         struct snd_pcm_runtime *runtime = substream->runtime;
 670         struct loopback *loopback = substream->private_data;
 671         struct loopback_pcm *dpcm;
 672         struct loopback_cable *cable = NULL;
 673         int err = 0;
 674         int dev = get_cable_index(substream);
 675
 676         mutex_lock(&loopback->cable_lock);
 677         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 678         if (!dpcm) {
 679                 err = -ENOMEM;
 680                 goto unlock;
 681         }
 682         dpcm->loopback = loopback;
 683         dpcm->substream = substream;
 684         setup_timer(&dpcm->timer, loopback_timer_function,
 685                     (unsigned long)dpcm);
 686         spin_lock_init(&dpcm->timer_lock);
 687
 688         cable = loopback->cables[substream->number][dev];
 689         if (!cable) {
 690                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 691                 if (!cable) {
 692                         err = -ENOMEM;
 693                         goto unlock;
 694                 }
 695                 spin_lock_init(&cable->lock);
 696                 cable->hw = loopback_pcm_hardware;
 697                 loopback->cables[substream->number][dev] = cable;
 698         }
 699         dpcm->cable = cable;
 700         cable->streams[substream->stream] = dpcm;
 701
 702         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 703
 704         /* use dynamic rules based on actual runtime->hw values */
 705         /* note that the default rules created in the PCM midlevel code */
 706         /* are cached -> they do not reflect the actual state */
 707         err = snd_pcm_hw_rule_add(runtime, 0,
 708                                   SNDRV_PCM_HW_PARAM_FORMAT,
 709                                   rule_format, dpcm,
 710                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 711         if (err < 0)
 712                 goto unlock;
 713         err = snd_pcm_hw_rule_add(runtime, 0,
 714                                   SNDRV_PCM_HW_PARAM_RATE,
 715                                   rule_rate, dpcm,
 716                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 717         if (err < 0)
 718                 goto unlock;
 719         err = snd_pcm_hw_rule_add(runtime, 0,
 720                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 721                                   rule_channels, dpcm,
 722                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 723         if (err < 0)
 724                 goto unlock;
 725
 726         runtime->private_data = dpcm;
 727         runtime->private_free = loopback_runtime_free;
 728         if (get_notify(dpcm))
 729                 runtime->hw = loopback_pcm_hardware;
 730         else
 731                 runtime->hw = cable->hw;
 732  unlock:
 733         if (err < 0) {
 734                 free_cable(substream);
 735                 kfree(dpcm);
 736         }
 737         mutex_unlock(&loopback->cable_lock);
 738         return err;
 739 }
 740
 741 static int loopback_close(struct snd_pcm_substream *substream)
 742 {
 743         struct loopback *loopback = substream->private_data;
 744         struct loopback_pcm *dpcm = substream->runtime->private_data;
 745
 746         loopback_timer_stop_sync(dpcm);
 747         mutex_lock(&loopback->cable_lock);
 748         free_cable(substream);
 749         mutex_unlock(&loopback->cable_lock);
 750         return 0;
 751 }
 752
 753 static struct snd_pcm_ops loopback_playback_ops = {
 754         .open =         loopback_open,
 755         .close =        loopback_close,
 756         .ioctl =        snd_pcm_lib_ioctl,
 757         .hw_params =    loopback_hw_params,
 758         .hw_free =      loopback_hw_free,
 759         .prepare =      loopback_prepare,
 760         .trigger =      loopback_trigger,
 761         .pointer =      loopback_pointer,
 762         .page =         snd_pcm_lib_get_vmalloc_page,
 763         .mmap =         snd_pcm_lib_mmap_vmalloc,
 764 };
 765
 766 static struct snd_pcm_ops loopback_capture_ops = {
 767         .open =         loopback_open,
 768         .close =        loopback_close,
 769         .ioctl =        snd_pcm_lib_ioctl,
 770         .hw_params =    loopback_hw_params,
 771         .hw_free =      loopback_hw_free,
 772         .prepare =      loopback_prepare,
 773         .trigger =      loopback_trigger,
 774         .pointer =      loopback_pointer,
 775         .page =         snd_pcm_lib_get_vmalloc_page,
 776         .mmap =         snd_pcm_lib_mmap_vmalloc,
 777 };
 778
 779 static int __devinit loopback_pcm_new(struct loopback *loopback,
 780                                       int device, int substreams)
 781 {
 782         struct snd_pcm *pcm;
 783         int err;
 784
 785         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 786                           substreams, substreams, &pcm);
 787         if (err < 0)
 788                 return err;
 789         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 790         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 791
 792         pcm->private_data = loopback;
 793         pcm->info_flags = 0;
 794         strcpy(pcm->name, "Loopback PCM");
 795
 796         loopback->pcm[device] = pcm;
 797         return 0;
 798 }
 799
 800 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 801                                     struct snd_ctl_elem_info *uinfo)
 802 {
 803         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 804         uinfo->count = 1;
 805         uinfo->value.integer.min = 80000;
 806         uinfo->value.integer.max = 120000;
 807         uinfo->value.integer.step = 1;
 808         return 0;
 809 }
 810
 811 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 812                                    struct snd_ctl_elem_value *ucontrol)
 813 {
 814         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 815
 816         ucontrol->value.integer.value[0] =
 817                 loopback->setup[kcontrol->id.subdevice]
 818                                [kcontrol->id.device].rate_shift;
 819         return 0;
 820 }
 821
 822 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 823                                    struct snd_ctl_elem_value *ucontrol)
 824 {
 825         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 826         unsigned int val;
 827         int change = 0;
 828
 829         val = ucontrol->value.integer.value[0];
 830         if (val < 80000)
 831                 val = 80000;
 832         if (val > 120000)
 833                 val = 120000;
 834         mutex_lock(&loopback->cable_lock);
 835         if (val != loopback->setup[kcontrol->id.subdevice]
 836                                   [kcontrol->id.device].rate_shift) {
 837                 loopback->setup[kcontrol->id.subdevice]
 838                                [kcontrol->id.device].rate_shift = val;
 839                 change = 1;
 840         }
 841         mutex_unlock(&loopback->cable_lock);
 842         return change;
 843 }
 844
 845 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 846                                struct snd_ctl_elem_value *ucontrol)
 847 {
 848         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 849
 850         ucontrol->value.integer.value[0] =
 851                 loopback->setup[kcontrol->id.subdevice]
 852                                [kcontrol->id.device].notify;
 853         return 0;
 854 }
 855
 856 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 857                                struct snd_ctl_elem_value *ucontrol)
 858 {
 859         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 860         unsigned int val;
 861         int change = 0;
 862
 863         val = ucontrol->value.integer.value[0] ? 1 : 0;
 864         if (val != loopback->setup[kcontrol->id.subdevice]
 865                                 [kcontrol->id.device].notify) {
 866                 loopback->setup[kcontrol->id.subdevice]
 867                         [kcontrol->id.device].notify = val;
 868                 change = 1;
 869         }
 870         return change;
 871 }
 872
 873 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 874                                struct snd_ctl_elem_value *ucontrol)
 875 {
 876         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 877         struct loopback_cable *cable = loopback->cables
 878                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 879         unsigned int val = 0;
 880
 881         if (cable != NULL)
 882                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 883                                                                         1 : 0;
 884         ucontrol->value.integer.value[0] = val;
 885         return 0;
 886 }
 887
 888 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 889                                 struct snd_ctl_elem_info *uinfo)
 890 {
 891         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 892         uinfo->count = 1;
 893         uinfo->value.integer.min = 0;
 894         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 895         uinfo->value.integer.step = 1;
 896         return 0;
 897 }
 898
 899 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 900                                struct snd_ctl_elem_value *ucontrol)
 901 {
 902         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 903
 904         ucontrol->value.integer.value[0] =
 905                 loopback->setup[kcontrol->id.subdevice]
 906                                [kcontrol->id.device].format;
 907         return 0;
 908 }
 909
 910 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 911                               struct snd_ctl_elem_info *uinfo)
 912 {
 913         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 914         uinfo->count = 1;
 915         uinfo->value.integer.min = 0;
 916         uinfo->value.integer.max = 192000;
 917         uinfo->value.integer.step = 1;
 918         return 0;
 919 }
 920
 921 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 922                              struct snd_ctl_elem_value *ucontrol)
 923 {
 924         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 925
 926         ucontrol->value.integer.value[0] =
 927                 loopback->setup[kcontrol->id.subdevice]
 928                                [kcontrol->id.device].rate;
 929         return 0;
 930 }
 931
 932 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 933                                   struct snd_ctl_elem_info *uinfo)
 934 {
 935         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 936         uinfo->count = 1;
 937         uinfo->value.integer.min = 1;
 938         uinfo->value.integer.max = 1024;
 939         uinfo->value.integer.step = 1;
 940         return 0;
 941 }
 942
 943 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 944                                  struct snd_ctl_elem_value *ucontrol)
 945 {
 946         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 947
 948         ucontrol->value.integer.value[0] =
 949                 loopback->setup[kcontrol->id.subdevice]
 950                                [kcontrol->id.device].channels;
 951         return 0;
 952 }
 953
 954 static struct snd_kcontrol_new loopback_controls[]  __devinitdata = {
 955 {
 956         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 957         .name =         "PCM Rate Shift 100000",
 958         .info =         loopback_rate_shift_info,
 959         .get =          loopback_rate_shift_get,
 960         .put =          loopback_rate_shift_put,
 961 },
 962 {
 963         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 964         .name =         "PCM Notify",
 965         .info =         snd_ctl_boolean_mono_info,
 966         .get =          loopback_notify_get,
 967         .put =          loopback_notify_put,
 968 },
 969 #define ACTIVE_IDX 2
 970 {
 971         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 972         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 973         .name =         "PCM Slave Active",
 974         .info =         snd_ctl_boolean_mono_info,
 975         .get =          loopback_active_get,
 976 },
 977 #define FORMAT_IDX 3
 978 {
 979         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 980         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 981         .name =         "PCM Slave Format",
 982         .info =         loopback_format_info,
 983         .get =          loopback_format_get
 984 },
 985 #define RATE_IDX 4
 986 {
 987         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 988         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 989         .name =         "PCM Slave Rate",
 990         .info =         loopback_rate_info,
 991         .get =          loopback_rate_get
 992 },
 993 #define CHANNELS_IDX 5
 994 {
 995         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 996         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 997         .name =         "PCM Slave Channels",
 998         .info =         loopback_channels_info,
 999         .get =          loopback_channels_get
1000 }
1001 };
1002
1003 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
1004 {
1005         struct snd_card *card = loopback->card;
1006         struct snd_pcm *pcm;
1007         struct snd_kcontrol *kctl;
1008         struct loopback_setup *setup;
1009         int err, dev, substr, substr_count, idx;
1010
1011         strcpy(card->mixername, "Loopback Mixer");
1012         for (dev = 0; dev < 2; dev++) {
1013                 pcm = loopback->pcm[dev];
1014                 substr_count =
1015                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1016                 for (substr = 0; substr < substr_count; substr++) {
1017                         setup = &loopback->setup[substr][dev];
1018                         setup->notify = notify;
1019                         setup->rate_shift = NO_PITCH;
1020                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1021                         setup->rate = 48000;
1022                         setup->channels = 2;
1023                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1024                                                                         idx++) {
1025                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1026                                                     loopback);
1027                                 if (!kctl)
1028                                         return -ENOMEM;
1029                                 kctl->id.device = dev;
1030                                 kctl->id.subdevice = substr;
1031                                 switch (idx) {
1032                                 case ACTIVE_IDX:
1033                                         setup->active_id = kctl->id;
1034                                         break;
1035                                 case FORMAT_IDX:
1036                                         setup->format_id = kctl->id;
1037                                         break;
1038                                 case RATE_IDX:
1039                                         setup->rate_id = kctl->id;
1040                                         break;
1041                                 case CHANNELS_IDX:
1042                                         setup->channels_id = kctl->id;
1043                                         break;
1044                                 default:
1045                                         break;
1046                                 }
1047                                 err = snd_ctl_add(card, kctl);
1048                                 if (err < 0)
1049                                         return err;
1050                         }
1051                 }
1052         }
1053         return 0;
1054 }
1055
1056 #ifdef CONFIG_PROC_FS
1057
1058 static void print_dpcm_info(struct snd_info_buffer *buffer,
1059                             struct loopback_pcm *dpcm,
1060                             const char *id)
1061 {
1062         snd_iprintf(buffer, "  %s\n", id);
1063         if (dpcm == NULL) {
1064                 snd_iprintf(buffer, "    inactive\n");
1065                 return;
1066         }
1067         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1068         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1069         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1070         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1071         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1072         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1073         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1074         snd_iprintf(buffer, "    update_pending:\t%u\n",
1075                                                 dpcm->period_update_pending);
1076         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1077         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1078         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1079                                         dpcm->last_jiffies, jiffies);
1080         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1081 }
1082
1083 static void print_substream_info(struct snd_info_buffer *buffer,
1084                                  struct loopback *loopback,
1085                                  int sub,
1086                                  int num)
1087 {
1088         struct loopback_cable *cable = loopback->cables[sub][num];
1089
1090         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1091         if (cable == NULL) {
1092                 snd_iprintf(buffer, "  inactive\n");
1093                 return;
1094         }
1095         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1096         snd_iprintf(buffer, "  running: %u\n", cable->running);
1097         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1098         print_dpcm_info(buffer, cable->streams[0], "Playback");
1099         print_dpcm_info(buffer, cable->streams[1], "Capture");
1100 }
1101
1102 static void print_cable_info(struct snd_info_entry *entry,
1103                              struct snd_info_buffer *buffer)
1104 {
1105         struct loopback *loopback = entry->private_data;
1106         int sub, num;
1107
1108         mutex_lock(&loopback->cable_lock);
1109         num = entry->name[strlen(entry->name)-1];
1110         num = num == '0' ? 0 : 1;
1111         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1112                 print_substream_info(buffer, loopback, sub, num);
1113         mutex_unlock(&loopback->cable_lock);
1114 }
1115
1116 static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1117 {
1118         char name[32];
1119         struct snd_info_entry *entry;
1120         int err;
1121
1122         snprintf(name, sizeof(name), "cable#%d", cidx);
1123         err = snd_card_proc_new(loopback->card, name, &entry);
1124         if (err < 0)
1125                 return err;
1126
1127         snd_info_set_text_ops(entry, loopback, print_cable_info);
1128         return 0;
1129 }
1130
1131 #else /* !CONFIG_PROC_FS */
1132
1133 #define loopback_proc_new(loopback, cidx) do { } while (0)
1134
1135 #endif
1136
1137 static int __devinit loopback_probe(struct platform_device *devptr)
1138 {
1139         struct snd_card *card;
1140         struct loopback *loopback;
1141         int dev = devptr->id;
1142         int err;
1143
1144         err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1145                               sizeof(struct loopback), &card);
1146         if (err < 0)
1147                 return err;
1148         loopback = card->private_data;
1149
1150         if (pcm_substreams[dev] < 1)
1151                 pcm_substreams[dev] = 1;
1152         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1153                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1154
1155         loopback->card = card;
1156         mutex_init(&loopback->cable_lock);
1157
1158         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1159         if (err < 0)
1160                 goto __nodev;
1161         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1162         if (err < 0)
1163                 goto __nodev;
1164         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1165         if (err < 0)
1166                 goto __nodev;
1167         loopback_proc_new(loopback, 0);
1168         loopback_proc_new(loopback, 1);
1169         strcpy(card->driver, "Loopback");
1170         strcpy(card->shortname, "Loopback");
1171         sprintf(card->longname, "Loopback %i", dev + 1);
1172         err = snd_card_register(card);
1173         if (!err) {
1174                 platform_set_drvdata(devptr, card);
1175                 return 0;
1176         }
1177       __nodev:
1178         snd_card_free(card);
1179         return err;
1180 }
1181
1182 static int __devexit loopback_remove(struct platform_device *devptr)
1183 {
1184         snd_card_free(platform_get_drvdata(devptr));
1185         platform_set_drvdata(devptr, NULL);
1186         return 0;
1187 }
1188
1189 #ifdef CONFIG_PM
1190 static int loopback_suspend(struct platform_device *pdev,
1191                                 pm_message_t state)
1192 {
1193         struct snd_card *card = platform_get_drvdata(pdev);
1194         struct loopback *loopback = card->private_data;
1195
1196         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1197
1198         snd_pcm_suspend_all(loopback->pcm[0]);
1199         snd_pcm_suspend_all(loopback->pcm[1]);
1200         return 0;
1201 }
1202
1203 static int loopback_resume(struct platform_device *pdev)
1204 {
1205         struct snd_card *card = platform_get_drvdata(pdev);
1206
1207         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1208         return 0;
1209 }
1210 #endif
1211
1212 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1213
1214 static struct platform_driver loopback_driver = {
1215         .probe          = loopback_probe,
1216         .remove         = __devexit_p(loopback_remove),
1217 #ifdef CONFIG_PM
1218         .suspend        = loopback_suspend,
1219         .resume         = loopback_resume,
1220 #endif
1221         .driver         = {
1222                 .name   = SND_LOOPBACK_DRIVER
1223         },
1224 };
1225
1226 static void loopback_unregister_all(void)
1227 {
1228         int i;
1229
1230         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1231                 platform_device_unregister(devices[i]);
1232         platform_driver_unregister(&loopback_driver);
1233 }
1234
1235 static int __init alsa_card_loopback_init(void)
1236 {
1237         int i, err, cards;
1238
1239         err = platform_driver_register(&loopback_driver);
1240         if (err < 0)
1241                 return err;
1242
1243
1244         cards = 0;
1245         for (i = 0; i < SNDRV_CARDS; i++) {
1246                 struct platform_device *device;
1247                 if (!enable[i])
1248                         continue;
1249                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1250                                                          i, NULL, 0);
1251                 if (IS_ERR(device))
1252                         continue;
1253                 if (!platform_get_drvdata(device)) {
1254                         platform_device_unregister(device);
1255                         continue;
1256                 }
1257                 devices[i] = device;
1258                 cards++;
1259         }
1260         if (!cards) {
1261 #ifdef MODULE
1262                 printk(KERN_ERR "aloop: No loopback enabled\n");
1263 #endif
1264                 loopback_unregister_all();
1265                 return -ENODEV;
1266         }
1267         return 0;
1268 }
1269
1270 static void __exit alsa_card_loopback_exit(void)
1271 {
1272         loopback_unregister_all();
1273 }
1274
1275 module_init(alsa_card_loopback_init)
1276 module_exit(alsa_card_loopback_exit)