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                 spin_lock_irq(&cable->lock);
 660                 cable->streams[substream->stream] = NULL;
 661                 spin_unlock_irq(&cable->lock);
 662         } else {
 663                 /* free the cable */
 664                 loopback->cables[substream->number][dev] = NULL;
 665                 kfree(cable);
 666         }
 667 }
 668
 669 static int loopback_open(struct snd_pcm_substream *substream)
 670 {
 671         struct snd_pcm_runtime *runtime = substream->runtime;
 672         struct loopback *loopback = substream->private_data;
 673         struct loopback_pcm *dpcm;
 674         struct loopback_cable *cable = NULL;
 675         int err = 0;
 676         int dev = get_cable_index(substream);
 677
 678         mutex_lock(&loopback->cable_lock);
 679         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 680         if (!dpcm) {
 681                 err = -ENOMEM;
 682                 goto unlock;
 683         }
 684         dpcm->loopback = loopback;
 685         dpcm->substream = substream;
 686         setup_timer(&dpcm->timer, loopback_timer_function,
 687                     (unsigned long)dpcm);
 688         spin_lock_init(&dpcm->timer_lock);
 689
 690         cable = loopback->cables[substream->number][dev];
 691         if (!cable) {
 692                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 693                 if (!cable) {
 694                         err = -ENOMEM;
 695                         goto unlock;
 696                 }
 697                 spin_lock_init(&cable->lock);
 698                 cable->hw = loopback_pcm_hardware;
 699                 loopback->cables[substream->number][dev] = cable;
 700         }
 701         dpcm->cable = cable;
 702
 703         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 704
 705         /* use dynamic rules based on actual runtime->hw values */
 706         /* note that the default rules created in the PCM midlevel code */
 707         /* are cached -> they do not reflect the actual state */
 708         err = snd_pcm_hw_rule_add(runtime, 0,
 709                                   SNDRV_PCM_HW_PARAM_FORMAT,
 710                                   rule_format, dpcm,
 711                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 712         if (err < 0)
 713                 goto unlock;
 714         err = snd_pcm_hw_rule_add(runtime, 0,
 715                                   SNDRV_PCM_HW_PARAM_RATE,
 716                                   rule_rate, dpcm,
 717                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 718         if (err < 0)
 719                 goto unlock;
 720         err = snd_pcm_hw_rule_add(runtime, 0,
 721                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 722                                   rule_channels, dpcm,
 723                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 724         if (err < 0)
 725                 goto unlock;
 726
 727         runtime->private_data = dpcm;
 728         runtime->private_free = loopback_runtime_free;
 729         if (get_notify(dpcm))
 730                 runtime->hw = loopback_pcm_hardware;
 731         else
 732                 runtime->hw = cable->hw;
 733
 734         spin_lock_irq(&cable->lock);
 735         cable->streams[substream->stream] = dpcm;
 736         spin_unlock_irq(&cable->lock);
 737
 738  unlock:
 739         if (err < 0) {
 740                 free_cable(substream);
 741                 kfree(dpcm);
 742         }
 743         mutex_unlock(&loopback->cable_lock);
 744         return err;
 745 }
 746
 747 static int loopback_close(struct snd_pcm_substream *substream)
 748 {
 749         struct loopback *loopback = substream->private_data;
 750         struct loopback_pcm *dpcm = substream->runtime->private_data;
 751
 752         loopback_timer_stop_sync(dpcm);
 753         mutex_lock(&loopback->cable_lock);
 754         free_cable(substream);
 755         mutex_unlock(&loopback->cable_lock);
 756         return 0;
 757 }
 758
 759 static struct snd_pcm_ops loopback_playback_ops = {
 760         .open =         loopback_open,
 761         .close =        loopback_close,
 762         .ioctl =        snd_pcm_lib_ioctl,
 763         .hw_params =    loopback_hw_params,
 764         .hw_free =      loopback_hw_free,
 765         .prepare =      loopback_prepare,
 766         .trigger =      loopback_trigger,
 767         .pointer =      loopback_pointer,
 768         .page =         snd_pcm_lib_get_vmalloc_page,
 769         .mmap =         snd_pcm_lib_mmap_vmalloc,
 770 };
 771
 772 static struct snd_pcm_ops loopback_capture_ops = {
 773         .open =         loopback_open,
 774         .close =        loopback_close,
 775         .ioctl =        snd_pcm_lib_ioctl,
 776         .hw_params =    loopback_hw_params,
 777         .hw_free =      loopback_hw_free,
 778         .prepare =      loopback_prepare,
 779         .trigger =      loopback_trigger,
 780         .pointer =      loopback_pointer,
 781         .page =         snd_pcm_lib_get_vmalloc_page,
 782         .mmap =         snd_pcm_lib_mmap_vmalloc,
 783 };
 784
 785 static int __devinit loopback_pcm_new(struct loopback *loopback,
 786                                       int device, int substreams)
 787 {
 788         struct snd_pcm *pcm;
 789         int err;
 790
 791         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 792                           substreams, substreams, &pcm);
 793         if (err < 0)
 794                 return err;
 795         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 796         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 797
 798         pcm->private_data = loopback;
 799         pcm->info_flags = 0;
 800         strcpy(pcm->name, "Loopback PCM");
 801
 802         loopback->pcm[device] = pcm;
 803         return 0;
 804 }
 805
 806 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 807                                     struct snd_ctl_elem_info *uinfo)
 808 {
 809         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 810         uinfo->count = 1;
 811         uinfo->value.integer.min = 80000;
 812         uinfo->value.integer.max = 120000;
 813         uinfo->value.integer.step = 1;
 814         return 0;
 815 }
 816
 817 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 818                                    struct snd_ctl_elem_value *ucontrol)
 819 {
 820         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 821
 822         ucontrol->value.integer.value[0] =
 823                 loopback->setup[kcontrol->id.subdevice]
 824                                [kcontrol->id.device].rate_shift;
 825         return 0;
 826 }
 827
 828 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 829                                    struct snd_ctl_elem_value *ucontrol)
 830 {
 831         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 832         unsigned int val;
 833         int change = 0;
 834
 835         val = ucontrol->value.integer.value[0];
 836         if (val < 80000)
 837                 val = 80000;
 838         if (val > 120000)
 839                 val = 120000;
 840         mutex_lock(&loopback->cable_lock);
 841         if (val != loopback->setup[kcontrol->id.subdevice]
 842                                   [kcontrol->id.device].rate_shift) {
 843                 loopback->setup[kcontrol->id.subdevice]
 844                                [kcontrol->id.device].rate_shift = val;
 845                 change = 1;
 846         }
 847         mutex_unlock(&loopback->cable_lock);
 848         return change;
 849 }
 850
 851 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 852                                struct snd_ctl_elem_value *ucontrol)
 853 {
 854         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 855
 856         ucontrol->value.integer.value[0] =
 857                 loopback->setup[kcontrol->id.subdevice]
 858                                [kcontrol->id.device].notify;
 859         return 0;
 860 }
 861
 862 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 863                                struct snd_ctl_elem_value *ucontrol)
 864 {
 865         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 866         unsigned int val;
 867         int change = 0;
 868
 869         val = ucontrol->value.integer.value[0] ? 1 : 0;
 870         if (val != loopback->setup[kcontrol->id.subdevice]
 871                                 [kcontrol->id.device].notify) {
 872                 loopback->setup[kcontrol->id.subdevice]
 873                         [kcontrol->id.device].notify = val;
 874                 change = 1;
 875         }
 876         return change;
 877 }
 878
 879 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 880                                struct snd_ctl_elem_value *ucontrol)
 881 {
 882         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 883         struct loopback_cable *cable = loopback->cables
 884                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 885         unsigned int val = 0;
 886
 887         if (cable != NULL)
 888                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 889                                                                         1 : 0;
 890         ucontrol->value.integer.value[0] = val;
 891         return 0;
 892 }
 893
 894 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 895                                 struct snd_ctl_elem_info *uinfo)
 896 {
 897         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 898         uinfo->count = 1;
 899         uinfo->value.integer.min = 0;
 900         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 901         uinfo->value.integer.step = 1;
 902         return 0;
 903 }
 904
 905 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 906                                struct snd_ctl_elem_value *ucontrol)
 907 {
 908         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 909
 910         ucontrol->value.integer.value[0] =
 911                 loopback->setup[kcontrol->id.subdevice]
 912                                [kcontrol->id.device].format;
 913         return 0;
 914 }
 915
 916 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 917                               struct snd_ctl_elem_info *uinfo)
 918 {
 919         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 920         uinfo->count = 1;
 921         uinfo->value.integer.min = 0;
 922         uinfo->value.integer.max = 192000;
 923         uinfo->value.integer.step = 1;
 924         return 0;
 925 }
 926
 927 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 928                              struct snd_ctl_elem_value *ucontrol)
 929 {
 930         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 931
 932         ucontrol->value.integer.value[0] =
 933                 loopback->setup[kcontrol->id.subdevice]
 934                                [kcontrol->id.device].rate;
 935         return 0;
 936 }
 937
 938 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 939                                   struct snd_ctl_elem_info *uinfo)
 940 {
 941         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 942         uinfo->count = 1;
 943         uinfo->value.integer.min = 1;
 944         uinfo->value.integer.max = 1024;
 945         uinfo->value.integer.step = 1;
 946         return 0;
 947 }
 948
 949 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 950                                  struct snd_ctl_elem_value *ucontrol)
 951 {
 952         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 953
 954         ucontrol->value.integer.value[0] =
 955                 loopback->setup[kcontrol->id.subdevice]
 956                                [kcontrol->id.device].channels;
 957         return 0;
 958 }
 959
 960 static struct snd_kcontrol_new loopback_controls[]  __devinitdata = {
 961 {
 962         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 963         .name =         "PCM Rate Shift 100000",
 964         .info =         loopback_rate_shift_info,
 965         .get =          loopback_rate_shift_get,
 966         .put =          loopback_rate_shift_put,
 967 },
 968 {
 969         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 970         .name =         "PCM Notify",
 971         .info =         snd_ctl_boolean_mono_info,
 972         .get =          loopback_notify_get,
 973         .put =          loopback_notify_put,
 974 },
 975 #define ACTIVE_IDX 2
 976 {
 977         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 978         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 979         .name =         "PCM Slave Active",
 980         .info =         snd_ctl_boolean_mono_info,
 981         .get =          loopback_active_get,
 982 },
 983 #define FORMAT_IDX 3
 984 {
 985         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 986         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 987         .name =         "PCM Slave Format",
 988         .info =         loopback_format_info,
 989         .get =          loopback_format_get
 990 },
 991 #define RATE_IDX 4
 992 {
 993         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 994         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 995         .name =         "PCM Slave Rate",
 996         .info =         loopback_rate_info,
 997         .get =          loopback_rate_get
 998 },
 999 #define CHANNELS_IDX 5
1000 {
1001         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1002         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1003         .name =         "PCM Slave Channels",
1004         .info =         loopback_channels_info,
1005         .get =          loopback_channels_get
1006 }
1007 };
1008
1009 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
1010 {
1011         struct snd_card *card = loopback->card;
1012         struct snd_pcm *pcm;
1013         struct snd_kcontrol *kctl;
1014         struct loopback_setup *setup;
1015         int err, dev, substr, substr_count, idx;
1016
1017         strcpy(card->mixername, "Loopback Mixer");
1018         for (dev = 0; dev < 2; dev++) {
1019                 pcm = loopback->pcm[dev];
1020                 substr_count =
1021                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1022                 for (substr = 0; substr < substr_count; substr++) {
1023                         setup = &loopback->setup[substr][dev];
1024                         setup->notify = notify;
1025                         setup->rate_shift = NO_PITCH;
1026                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1027                         setup->rate = 48000;
1028                         setup->channels = 2;
1029                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1030                                                                         idx++) {
1031                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1032                                                     loopback);
1033                                 if (!kctl)
1034                                         return -ENOMEM;
1035                                 kctl->id.device = dev;
1036                                 kctl->id.subdevice = substr;
1037                                 switch (idx) {
1038                                 case ACTIVE_IDX:
1039                                         setup->active_id = kctl->id;
1040                                         break;
1041                                 case FORMAT_IDX:
1042                                         setup->format_id = kctl->id;
1043                                         break;
1044                                 case RATE_IDX:
1045                                         setup->rate_id = kctl->id;
1046                                         break;
1047                                 case CHANNELS_IDX:
1048                                         setup->channels_id = kctl->id;
1049                                         break;
1050                                 default:
1051                                         break;
1052                                 }
1053                                 err = snd_ctl_add(card, kctl);
1054                                 if (err < 0)
1055                                         return err;
1056                         }
1057                 }
1058         }
1059         return 0;
1060 }
1061
1062 #ifdef CONFIG_PROC_FS
1063
1064 static void print_dpcm_info(struct snd_info_buffer *buffer,
1065                             struct loopback_pcm *dpcm,
1066                             const char *id)
1067 {
1068         snd_iprintf(buffer, "  %s\n", id);
1069         if (dpcm == NULL) {
1070                 snd_iprintf(buffer, "    inactive\n");
1071                 return;
1072         }
1073         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1074         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1075         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1076         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1077         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1078         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1079         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1080         snd_iprintf(buffer, "    update_pending:\t%u\n",
1081                                                 dpcm->period_update_pending);
1082         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1083         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1084         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1085                                         dpcm->last_jiffies, jiffies);
1086         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1087 }
1088
1089 static void print_substream_info(struct snd_info_buffer *buffer,
1090                                  struct loopback *loopback,
1091                                  int sub,
1092                                  int num)
1093 {
1094         struct loopback_cable *cable = loopback->cables[sub][num];
1095
1096         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1097         if (cable == NULL) {
1098                 snd_iprintf(buffer, "  inactive\n");
1099                 return;
1100         }
1101         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1102         snd_iprintf(buffer, "  running: %u\n", cable->running);
1103         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1104         print_dpcm_info(buffer, cable->streams[0], "Playback");
1105         print_dpcm_info(buffer, cable->streams[1], "Capture");
1106 }
1107
1108 static void print_cable_info(struct snd_info_entry *entry,
1109                              struct snd_info_buffer *buffer)
1110 {
1111         struct loopback *loopback = entry->private_data;
1112         int sub, num;
1113
1114         mutex_lock(&loopback->cable_lock);
1115         num = entry->name[strlen(entry->name)-1];
1116         num = num == '0' ? 0 : 1;
1117         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1118                 print_substream_info(buffer, loopback, sub, num);
1119         mutex_unlock(&loopback->cable_lock);
1120 }
1121
1122 static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1123 {
1124         char name[32];
1125         struct snd_info_entry *entry;
1126         int err;
1127
1128         snprintf(name, sizeof(name), "cable#%d", cidx);
1129         err = snd_card_proc_new(loopback->card, name, &entry);
1130         if (err < 0)
1131                 return err;
1132
1133         snd_info_set_text_ops(entry, loopback, print_cable_info);
1134         return 0;
1135 }
1136
1137 #else /* !CONFIG_PROC_FS */
1138
1139 #define loopback_proc_new(loopback, cidx) do { } while (0)
1140
1141 #endif
1142
1143 static int __devinit 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_create(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 __devexit loopback_remove(struct platform_device *devptr)
1189 {
1190         snd_card_free(platform_get_drvdata(devptr));
1191         platform_set_drvdata(devptr, NULL);
1192         return 0;
1193 }
1194
1195 #ifdef CONFIG_PM
1196 static int loopback_suspend(struct platform_device *pdev,
1197                                 pm_message_t state)
1198 {
1199         struct snd_card *card = platform_get_drvdata(pdev);
1200         struct loopback *loopback = card->private_data;
1201
1202         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1203
1204         snd_pcm_suspend_all(loopback->pcm[0]);
1205         snd_pcm_suspend_all(loopback->pcm[1]);
1206         return 0;
1207 }
1208
1209 static int loopback_resume(struct platform_device *pdev)
1210 {
1211         struct snd_card *card = platform_get_drvdata(pdev);
1212
1213         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1214         return 0;
1215 }
1216 #endif
1217
1218 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1219
1220 static struct platform_driver loopback_driver = {
1221         .probe          = loopback_probe,
1222         .remove         = __devexit_p(loopback_remove),
1223 #ifdef CONFIG_PM
1224         .suspend        = loopback_suspend,
1225         .resume         = loopback_resume,
1226 #endif
1227         .driver         = {
1228                 .name   = SND_LOOPBACK_DRIVER
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)