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 bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  56 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  57 static int pcm_notify[SNDRV_CARDS];
  58
  59 module_param_array(index, int, NULL, 0444);
  60 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  61 module_param_array(id, charp, NULL, 0444);
  62 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  63 module_param_array(enable, bool, NULL, 0444);
  64 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  65 module_param_array(pcm_substreams, int, NULL, 0444);
  66 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  67 module_param_array(pcm_notify, int, NULL, 0444);
  68 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  69
  70 #define NO_PITCH 100000
  71
  72 struct loopback_pcm;
  73
  74 struct loopback_cable {
  75         spinlock_t lock;
  76         struct loopback_pcm *streams[2];
  77         struct snd_pcm_hardware hw;
  78         /* flags */
  79         unsigned int valid;
  80         unsigned int running;
  81         unsigned int pause;
  82 };
  83
  84 struct loopback_setup {
  85         unsigned int notify: 1;
  86         unsigned int rate_shift;
  87         unsigned int format;
  88         unsigned int rate;
  89         unsigned int channels;
  90         struct snd_ctl_elem_id active_id;
  91         struct snd_ctl_elem_id format_id;
  92         struct snd_ctl_elem_id rate_id;
  93         struct snd_ctl_elem_id channels_id;
  94 };
  95
  96 struct loopback {
  97         struct snd_card *card;
  98         struct mutex cable_lock;
  99         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
 100         struct snd_pcm *pcm[2];
 101         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 102 };
 103
 104 struct loopback_pcm {
 105         struct loopback *loopback;
 106         struct snd_pcm_substream *substream;
 107         struct loopback_cable *cable;
 108         unsigned int pcm_buffer_size;
 109         unsigned int buf_pos;   /* position in buffer */
 110         unsigned int silent_size;
 111         /* PCM parameters */
 112         unsigned int pcm_period_size;
 113         unsigned int pcm_bps;           /* bytes per second */
 114         unsigned int pcm_salign;        /* bytes per sample * channels */
 115         unsigned int pcm_rate_shift;    /* rate shift value */
 116         /* flags */
 117         unsigned int period_update_pending :1;
 118         /* timer stuff */
 119         unsigned int irq_pos;           /* fractional IRQ position */
 120         unsigned int period_size_frac;
 121         unsigned int last_drift;
 122         unsigned long last_jiffies;
 123         struct timer_list timer;
 124 };
 125
 126 static struct platform_device *devices[SNDRV_CARDS];
 127
 128 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 129 {
 130         if (dpcm->pcm_rate_shift == NO_PITCH) {
 131                 x /= HZ;
 132         } else {
 133                 x = div_u64(NO_PITCH * (unsigned long long)x,
 134                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 135         }
 136         return x - (x % dpcm->pcm_salign);
 137 }
 138
 139 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 140 {
 141         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 142                 return x * HZ;
 143         } else {
 144                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 145                             NO_PITCH);
 146         }
 147         return x;
 148 }
 149
 150 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 151 {
 152         int device = dpcm->substream->pstr->pcm->device;
 153
 154         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 155                 device ^= 1;
 156         return &dpcm->loopback->setup[dpcm->substream->number][device];
 157 }
 158
 159 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 160 {
 161         return get_setup(dpcm)->notify;
 162 }
 163
 164 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 165 {
 166         return get_setup(dpcm)->rate_shift;
 167 }
 168
 169 /* call in cable->lock */
 170 static void loopback_timer_start(struct loopback_pcm *dpcm)
 171 {
 172         unsigned long tick;
 173         unsigned int rate_shift = get_rate_shift(dpcm);
 174
 175         if (rate_shift != dpcm->pcm_rate_shift) {
 176                 dpcm->pcm_rate_shift = rate_shift;
 177                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 178         }
 179         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 180                 dpcm->irq_pos %= dpcm->period_size_frac;
 181                 dpcm->period_update_pending = 1;
 182         }
 183         tick = dpcm->period_size_frac - dpcm->irq_pos;
 184         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 185         mod_timer(&dpcm->timer, jiffies + tick);
 186 }
 187
 188 /* call in cable->lock */
 189 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 190 {
 191         del_timer(&dpcm->timer);
 192         dpcm->timer.expires = 0;
 193 }
 194
 195 static inline void loopback_timer_stop_sync(struct loopback_pcm *dpcm)
 196 {
 197         del_timer_sync(&dpcm->timer);
 198 }
 199
 200 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 201 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 202 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 203
 204 static int loopback_check_format(struct loopback_cable *cable, int stream)
 205 {
 206         struct snd_pcm_runtime *runtime, *cruntime;
 207         struct loopback_setup *setup;
 208         struct snd_card *card;
 209         int check;
 210
 211         if (cable->valid != CABLE_VALID_BOTH) {
 212                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 213                         goto __notify;
 214                 return 0;
 215         }
 216         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 217                                                         substream->runtime;
 218         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 219                                                         substream->runtime;
 220         check = runtime->format != cruntime->format ||
 221                 runtime->rate != cruntime->rate ||
 222                 runtime->channels != cruntime->channels;
 223         if (!check)
 224                 return 0;
 225         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 226                 return -EIO;
 227         } else {
 228                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 229                                         substream, SNDRV_PCM_STATE_DRAINING);
 230               __notify:
 231                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 232                                                         substream->runtime;
 233                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 234                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 235                 if (setup->format != runtime->format) {
 236                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 237                                                         &setup->format_id);
 238                         setup->format = runtime->format;
 239                 }
 240                 if (setup->rate != runtime->rate) {
 241                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 242                                                         &setup->rate_id);
 243                         setup->rate = runtime->rate;
 244                 }
 245                 if (setup->channels != runtime->channels) {
 246                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 247                                                         &setup->channels_id);
 248                         setup->channels = runtime->channels;
 249                 }
 250         }
 251         return 0;
 252 }
 253
 254 static void loopback_active_notify(struct loopback_pcm *dpcm)
 255 {
 256         snd_ctl_notify(dpcm->loopback->card,
 257                        SNDRV_CTL_EVENT_MASK_VALUE,
 258                        &get_setup(dpcm)->active_id);
 259 }
 260
 261 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 262 {
 263         struct snd_pcm_runtime *runtime = substream->runtime;
 264         struct loopback_pcm *dpcm = runtime->private_data;
 265         struct loopback_cable *cable = dpcm->cable;
 266         int err, stream = 1 << substream->stream;
 267
 268         switch (cmd) {
 269         case SNDRV_PCM_TRIGGER_START:
 270                 err = loopback_check_format(cable, substream->stream);
 271                 if (err < 0)
 272                         return err;
 273                 dpcm->last_jiffies = jiffies;
 274                 dpcm->pcm_rate_shift = 0;
 275                 dpcm->last_drift = 0;
 276                 spin_lock(&cable->lock);
 277                 cable->running |= stream;
 278                 cable->pause &= ~stream;
 279                 loopback_timer_start(dpcm);
 280                 spin_unlock(&cable->lock);
 281                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 282                         loopback_active_notify(dpcm);
 283                 break;
 284         case SNDRV_PCM_TRIGGER_STOP:
 285                 spin_lock(&cable->lock);
 286                 cable->running &= ~stream;
 287                 cable->pause &= ~stream;
 288                 loopback_timer_stop(dpcm);
 289                 spin_unlock(&cable->lock);
 290                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 291                         loopback_active_notify(dpcm);
 292                 break;
 293         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 294         case SNDRV_PCM_TRIGGER_SUSPEND:
 295                 spin_lock(&cable->lock);
 296                 cable->pause |= stream;
 297                 loopback_timer_stop(dpcm);
 298                 spin_unlock(&cable->lock);
 299                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 300                         loopback_active_notify(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                 loopback_timer_start(dpcm);
 308                 spin_unlock(&cable->lock);
 309                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 310                         loopback_active_notify(dpcm);
 311                 break;
 312         default:
 313                 return -EINVAL;
 314         }
 315         return 0;
 316 }
 317
 318 static void params_change(struct snd_pcm_substream *substream)
 319 {
 320         struct snd_pcm_runtime *runtime = substream->runtime;
 321         struct loopback_pcm *dpcm = runtime->private_data;
 322         struct loopback_cable *cable = dpcm->cable;
 323
 324         cable->hw.formats = pcm_format_to_bits(runtime->format);
 325         cable->hw.rate_min = runtime->rate;
 326         cable->hw.rate_max = runtime->rate;
 327         cable->hw.channels_min = runtime->channels;
 328         cable->hw.channels_max = runtime->channels;
 329 }
 330
 331 static int loopback_prepare(struct snd_pcm_substream *substream)
 332 {
 333         struct snd_pcm_runtime *runtime = substream->runtime;
 334         struct loopback_pcm *dpcm = runtime->private_data;
 335         struct loopback_cable *cable = dpcm->cable;
 336         int bps, salign;
 337
 338         loopback_timer_stop_sync(dpcm);
 339
 340         salign = (snd_pcm_format_physical_width(runtime->format) *
 341                                                 runtime->channels) / 8;
 342         bps = salign * runtime->rate;
 343         if (bps <= 0 || salign <= 0)
 344                 return -EINVAL;
 345
 346         dpcm->buf_pos = 0;
 347         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 348         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 349                 /* clear capture buffer */
 350                 dpcm->silent_size = dpcm->pcm_buffer_size;
 351                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 352                                            runtime->buffer_size * runtime->channels);
 353         }
 354
 355         dpcm->irq_pos = 0;
 356         dpcm->period_update_pending = 0;
 357         dpcm->pcm_bps = bps;
 358         dpcm->pcm_salign = salign;
 359         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 360
 361         mutex_lock(&dpcm->loopback->cable_lock);
 362         if (!(cable->valid & ~(1 << substream->stream)) ||
 363             (get_setup(dpcm)->notify &&
 364              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 365                 params_change(substream);
 366         cable->valid |= 1 << substream->stream;
 367         mutex_unlock(&dpcm->loopback->cable_lock);
 368
 369         return 0;
 370 }
 371
 372 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 373 {
 374         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 375         char *dst = runtime->dma_area;
 376         unsigned int dst_off = dpcm->buf_pos;
 377
 378         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 379                 return;
 380         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 381                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 382
 383         for (;;) {
 384                 unsigned int size = bytes;
 385                 if (dst_off + size > dpcm->pcm_buffer_size)
 386                         size = dpcm->pcm_buffer_size - dst_off;
 387                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 388                                            bytes_to_frames(runtime, size) *
 389                                                 runtime->channels);
 390                 dpcm->silent_size += size;
 391                 bytes -= size;
 392                 if (!bytes)
 393                         break;
 394                 dst_off = 0;
 395         }
 396 }
 397
 398 static void copy_play_buf(struct loopback_pcm *play,
 399                           struct loopback_pcm *capt,
 400                           unsigned int bytes)
 401 {
 402         struct snd_pcm_runtime *runtime = play->substream->runtime;
 403         char *src = runtime->dma_area;
 404         char *dst = capt->substream->runtime->dma_area;
 405         unsigned int src_off = play->buf_pos;
 406         unsigned int dst_off = capt->buf_pos;
 407         unsigned int clear_bytes = 0;
 408
 409         /* check if playback is draining, trim the capture copy size
 410          * when our pointer is at the end of playback ring buffer */
 411         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 412             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 413                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 414                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 415                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 416                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 417                 if (appl_ptr < appl_ptr1)
 418                         appl_ptr1 -= runtime->buffer_size;
 419                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 420                 if (diff < bytes) {
 421                         clear_bytes = bytes - diff;
 422                         bytes = diff;
 423                 }
 424         }
 425
 426         for (;;) {
 427                 unsigned int size = bytes;
 428                 if (src_off + size > play->pcm_buffer_size)
 429                         size = play->pcm_buffer_size - src_off;
 430                 if (dst_off + size > capt->pcm_buffer_size)
 431                         size = capt->pcm_buffer_size - dst_off;
 432                 memcpy(dst + dst_off, src + src_off, size);
 433                 capt->silent_size = 0;
 434                 bytes -= size;
 435                 if (!bytes)
 436                         break;
 437                 src_off = (src_off + size) % play->pcm_buffer_size;
 438                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 439         }
 440
 441         if (clear_bytes > 0) {
 442                 clear_capture_buf(capt, clear_bytes);
 443                 capt->silent_size = 0;
 444         }
 445 }
 446
 447 static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
 448                                          unsigned int jiffies_delta)
 449 {
 450         unsigned long last_pos;
 451         unsigned int delta;
 452
 453         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 454         dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
 455         delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 456         if (delta >= dpcm->last_drift)
 457                 delta -= dpcm->last_drift;
 458         dpcm->last_drift = 0;
 459         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 460                 dpcm->irq_pos %= dpcm->period_size_frac;
 461                 dpcm->period_update_pending = 1;
 462         }
 463         return delta;
 464 }
 465
 466 static inline void bytepos_finish(struct loopback_pcm *dpcm,
 467                                   unsigned int delta)
 468 {
 469         dpcm->buf_pos += delta;
 470         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 471 }
 472
 473 /* call in cable->lock */
 474 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 475 {
 476         struct loopback_pcm *dpcm_play =
 477                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 478         struct loopback_pcm *dpcm_capt =
 479                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 480         unsigned long delta_play = 0, delta_capt = 0;
 481         unsigned int running, count1, count2;
 482
 483         running = cable->running ^ cable->pause;
 484         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 485                 delta_play = jiffies - dpcm_play->last_jiffies;
 486                 dpcm_play->last_jiffies += delta_play;
 487         }
 488
 489         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 490                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 491                 dpcm_capt->last_jiffies += delta_capt;
 492         }
 493
 494         if (delta_play == 0 && delta_capt == 0)
 495                 goto unlock;
 496
 497         if (delta_play > delta_capt) {
 498                 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
 499                 bytepos_finish(dpcm_play, count1);
 500                 delta_play = delta_capt;
 501         } else if (delta_play < delta_capt) {
 502                 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
 503                 clear_capture_buf(dpcm_capt, count1);
 504                 bytepos_finish(dpcm_capt, count1);
 505                 delta_capt = delta_play;
 506         }
 507
 508         if (delta_play == 0 && delta_capt == 0)
 509                 goto unlock;
 510
 511         /* note delta_capt == delta_play at this moment */
 512         count1 = bytepos_delta(dpcm_play, delta_play);
 513         count2 = bytepos_delta(dpcm_capt, delta_capt);
 514         if (count1 < count2) {
 515                 dpcm_capt->last_drift = count2 - count1;
 516                 count1 = count2;
 517         } else if (count1 > count2) {
 518                 dpcm_play->last_drift = count1 - count2;
 519         }
 520         copy_play_buf(dpcm_play, dpcm_capt, count1);
 521         bytepos_finish(dpcm_play, count1);
 522         bytepos_finish(dpcm_capt, count1);
 523  unlock:
 524         return running;
 525 }
 526
 527 static void loopback_timer_function(struct timer_list *t)
 528 {
 529         struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
 530         unsigned long flags;
 531
 532         spin_lock_irqsave(&dpcm->cable->lock, flags);
 533         if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
 534                 loopback_timer_start(dpcm);
 535                 if (dpcm->period_update_pending) {
 536                         dpcm->period_update_pending = 0;
 537                         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 538                         /* need to unlock before calling below */
 539                         snd_pcm_period_elapsed(dpcm->substream);
 540                         return;
 541                 }
 542         }
 543         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 544 }
 545
 546 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 547 {
 548         struct snd_pcm_runtime *runtime = substream->runtime;
 549         struct loopback_pcm *dpcm = runtime->private_data;
 550         snd_pcm_uframes_t pos;
 551
 552         spin_lock(&dpcm->cable->lock);
 553         loopback_pos_update(dpcm->cable);
 554         pos = dpcm->buf_pos;
 555         spin_unlock(&dpcm->cable->lock);
 556         return bytes_to_frames(runtime, pos);
 557 }
 558
 559 static const struct snd_pcm_hardware loopback_pcm_hardware =
 560 {
 561         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 562                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
 563                          SNDRV_PCM_INFO_RESUME),
 564         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 565                          SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
 566                          SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |
 567                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 568                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 569         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 570         .rate_min =             8000,
 571         .rate_max =             192000,
 572         .channels_min =         1,
 573         .channels_max =         32,
 574         .buffer_bytes_max =     2 * 1024 * 1024,
 575         .period_bytes_min =     64,
 576         /* note check overflow in frac_pos() using pcm_rate_shift before
 577            changing period_bytes_max value */
 578         .period_bytes_max =     1024 * 1024,
 579         .periods_min =          1,
 580         .periods_max =          1024,
 581         .fifo_size =            0,
 582 };
 583
 584 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 585 {
 586         struct loopback_pcm *dpcm = runtime->private_data;
 587         kfree(dpcm);
 588 }
 589
 590 static int loopback_hw_params(struct snd_pcm_substream *substream,
 591                               struct snd_pcm_hw_params *params)
 592 {
 593         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 594                                                 params_buffer_bytes(params));
 595 }
 596
 597 static int loopback_hw_free(struct snd_pcm_substream *substream)
 598 {
 599         struct snd_pcm_runtime *runtime = substream->runtime;
 600         struct loopback_pcm *dpcm = runtime->private_data;
 601         struct loopback_cable *cable = dpcm->cable;
 602
 603         mutex_lock(&dpcm->loopback->cable_lock);
 604         cable->valid &= ~(1 << substream->stream);
 605         mutex_unlock(&dpcm->loopback->cable_lock);
 606         return snd_pcm_lib_free_vmalloc_buffer(substream);
 607 }
 608
 609 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 610 {
 611         if (!substream->pcm->device)
 612                 return substream->stream;
 613         else
 614                 return !substream->stream;
 615 }
 616
 617 static int rule_format(struct snd_pcm_hw_params *params,
 618                        struct snd_pcm_hw_rule *rule)
 619 {
 620         struct loopback_pcm *dpcm = rule->private;
 621         struct loopback_cable *cable = dpcm->cable;
 622         struct snd_mask m;
 623
 624         snd_mask_none(&m);
 625         mutex_lock(&dpcm->loopback->cable_lock);
 626         m.bits[0] = (u_int32_t)cable->hw.formats;
 627         m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
 628         mutex_unlock(&dpcm->loopback->cable_lock);
 629         return snd_mask_refine(hw_param_mask(params, rule->var), &m);
 630 }
 631
 632 static int rule_rate(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.rate_min;
 641         t.max = cable->hw.rate_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 int rule_channels(struct snd_pcm_hw_params *params,
 649                          struct snd_pcm_hw_rule *rule)
 650 {
 651         struct loopback_pcm *dpcm = rule->private;
 652         struct loopback_cable *cable = dpcm->cable;
 653         struct snd_interval t;
 654
 655         mutex_lock(&dpcm->loopback->cable_lock);
 656         t.min = cable->hw.channels_min;
 657         t.max = cable->hw.channels_max;
 658         mutex_unlock(&dpcm->loopback->cable_lock);
 659         t.openmin = t.openmax = 0;
 660         t.integer = 0;
 661         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 662 }
 663
 664 static void free_cable(struct snd_pcm_substream *substream)
 665 {
 666         struct loopback *loopback = substream->private_data;
 667         int dev = get_cable_index(substream);
 668         struct loopback_cable *cable;
 669
 670         cable = loopback->cables[substream->number][dev];
 671         if (!cable)
 672                 return;
 673         if (cable->streams[!substream->stream]) {
 674                 /* other stream is still alive */
 675                 spin_lock_irq(&cable->lock);
 676                 cable->streams[substream->stream] = NULL;
 677                 spin_unlock_irq(&cable->lock);
 678         } else {
 679                 /* free the cable */
 680                 loopback->cables[substream->number][dev] = NULL;
 681                 kfree(cable);
 682         }
 683 }
 684
 685 static int loopback_open(struct snd_pcm_substream *substream)
 686 {
 687         struct snd_pcm_runtime *runtime = substream->runtime;
 688         struct loopback *loopback = substream->private_data;
 689         struct loopback_pcm *dpcm;
 690         struct loopback_cable *cable = NULL;
 691         int err = 0;
 692         int dev = get_cable_index(substream);
 693
 694         mutex_lock(&loopback->cable_lock);
 695         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 696         if (!dpcm) {
 697                 err = -ENOMEM;
 698                 goto unlock;
 699         }
 700         dpcm->loopback = loopback;
 701         dpcm->substream = substream;
 702         timer_setup(&dpcm->timer, loopback_timer_function, 0);
 703
 704         cable = loopback->cables[substream->number][dev];
 705         if (!cable) {
 706                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 707                 if (!cable) {
 708                         err = -ENOMEM;
 709                         goto unlock;
 710                 }
 711                 spin_lock_init(&cable->lock);
 712                 cable->hw = loopback_pcm_hardware;
 713                 loopback->cables[substream->number][dev] = cable;
 714         }
 715         dpcm->cable = cable;
 716
 717         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 718
 719         /* use dynamic rules based on actual runtime->hw values */
 720         /* note that the default rules created in the PCM midlevel code */
 721         /* are cached -> they do not reflect the actual state */
 722         err = snd_pcm_hw_rule_add(runtime, 0,
 723                                   SNDRV_PCM_HW_PARAM_FORMAT,
 724                                   rule_format, dpcm,
 725                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 726         if (err < 0)
 727                 goto unlock;
 728         err = snd_pcm_hw_rule_add(runtime, 0,
 729                                   SNDRV_PCM_HW_PARAM_RATE,
 730                                   rule_rate, dpcm,
 731                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 732         if (err < 0)
 733                 goto unlock;
 734         err = snd_pcm_hw_rule_add(runtime, 0,
 735                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 736                                   rule_channels, dpcm,
 737                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 738         if (err < 0)
 739                 goto unlock;
 740
 741         runtime->private_data = dpcm;
 742         runtime->private_free = loopback_runtime_free;
 743         if (get_notify(dpcm))
 744                 runtime->hw = loopback_pcm_hardware;
 745         else
 746                 runtime->hw = cable->hw;
 747
 748         spin_lock_irq(&cable->lock);
 749         cable->streams[substream->stream] = dpcm;
 750         spin_unlock_irq(&cable->lock);
 751
 752  unlock:
 753         if (err < 0) {
 754                 free_cable(substream);
 755                 kfree(dpcm);
 756         }
 757         mutex_unlock(&loopback->cable_lock);
 758         return err;
 759 }
 760
 761 static int loopback_close(struct snd_pcm_substream *substream)
 762 {
 763         struct loopback *loopback = substream->private_data;
 764         struct loopback_pcm *dpcm = substream->runtime->private_data;
 765
 766         loopback_timer_stop_sync(dpcm);
 767         mutex_lock(&loopback->cable_lock);
 768         free_cable(substream);
 769         mutex_unlock(&loopback->cable_lock);
 770         return 0;
 771 }
 772
 773 static const struct snd_pcm_ops loopback_pcm_ops = {
 774         .open =         loopback_open,
 775         .close =        loopback_close,
 776         .ioctl =        snd_pcm_lib_ioctl,
 777         .hw_params =    loopback_hw_params,
 778         .hw_free =      loopback_hw_free,
 779         .prepare =      loopback_prepare,
 780         .trigger =      loopback_trigger,
 781         .pointer =      loopback_pointer,
 782         .page =         snd_pcm_lib_get_vmalloc_page,
 783 };
 784
 785 static int 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_pcm_ops);
 796         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_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         mutex_lock(&loopback->cable_lock);
 823         ucontrol->value.integer.value[0] =
 824                 loopback->setup[kcontrol->id.subdevice]
 825                                [kcontrol->id.device].rate_shift;
 826         mutex_unlock(&loopback->cable_lock);
 827         return 0;
 828 }
 829
 830 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 831                                    struct snd_ctl_elem_value *ucontrol)
 832 {
 833         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 834         unsigned int val;
 835         int change = 0;
 836
 837         val = ucontrol->value.integer.value[0];
 838         if (val < 80000)
 839                 val = 80000;
 840         if (val > 120000)
 841                 val = 120000;
 842         mutex_lock(&loopback->cable_lock);
 843         if (val != loopback->setup[kcontrol->id.subdevice]
 844                                   [kcontrol->id.device].rate_shift) {
 845                 loopback->setup[kcontrol->id.subdevice]
 846                                [kcontrol->id.device].rate_shift = val;
 847                 change = 1;
 848         }
 849         mutex_unlock(&loopback->cable_lock);
 850         return change;
 851 }
 852
 853 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 854                                struct snd_ctl_elem_value *ucontrol)
 855 {
 856         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 857
 858         mutex_lock(&loopback->cable_lock);
 859         ucontrol->value.integer.value[0] =
 860                 loopback->setup[kcontrol->id.subdevice]
 861                                [kcontrol->id.device].notify;
 862         mutex_unlock(&loopback->cable_lock);
 863         return 0;
 864 }
 865
 866 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 867                                struct snd_ctl_elem_value *ucontrol)
 868 {
 869         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 870         unsigned int val;
 871         int change = 0;
 872
 873         val = ucontrol->value.integer.value[0] ? 1 : 0;
 874         mutex_lock(&loopback->cable_lock);
 875         if (val != loopback->setup[kcontrol->id.subdevice]
 876                                 [kcontrol->id.device].notify) {
 877                 loopback->setup[kcontrol->id.subdevice]
 878                         [kcontrol->id.device].notify = val;
 879                 change = 1;
 880         }
 881         mutex_unlock(&loopback->cable_lock);
 882         return change;
 883 }
 884
 885 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 886                                struct snd_ctl_elem_value *ucontrol)
 887 {
 888         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 889         struct loopback_cable *cable;
 890
 891         unsigned int val = 0;
 892
 893         mutex_lock(&loopback->cable_lock);
 894         cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 895         if (cable != NULL) {
 896                 unsigned int running = cable->running ^ cable->pause;
 897
 898                 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
 899         }
 900         mutex_unlock(&loopback->cable_lock);
 901         ucontrol->value.integer.value[0] = val;
 902         return 0;
 903 }
 904
 905 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 906                                 struct snd_ctl_elem_info *uinfo)
 907 {
 908         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 909         uinfo->count = 1;
 910         uinfo->value.integer.min = 0;
 911         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 912         uinfo->value.integer.step = 1;
 913         return 0;
 914 }
 915
 916 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 917                                struct snd_ctl_elem_value *ucontrol)
 918 {
 919         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 920
 921         ucontrol->value.integer.value[0] =
 922                 loopback->setup[kcontrol->id.subdevice]
 923                                [kcontrol->id.device].format;
 924         return 0;
 925 }
 926
 927 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 928                               struct snd_ctl_elem_info *uinfo)
 929 {
 930         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 931         uinfo->count = 1;
 932         uinfo->value.integer.min = 0;
 933         uinfo->value.integer.max = 192000;
 934         uinfo->value.integer.step = 1;
 935         return 0;
 936 }
 937
 938 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 939                              struct snd_ctl_elem_value *ucontrol)
 940 {
 941         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 942
 943         mutex_lock(&loopback->cable_lock);
 944         ucontrol->value.integer.value[0] =
 945                 loopback->setup[kcontrol->id.subdevice]
 946                                [kcontrol->id.device].rate;
 947         mutex_unlock(&loopback->cable_lock);
 948         return 0;
 949 }
 950
 951 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 952                                   struct snd_ctl_elem_info *uinfo)
 953 {
 954         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 955         uinfo->count = 1;
 956         uinfo->value.integer.min = 1;
 957         uinfo->value.integer.max = 1024;
 958         uinfo->value.integer.step = 1;
 959         return 0;
 960 }
 961
 962 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 963                                  struct snd_ctl_elem_value *ucontrol)
 964 {
 965         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 966
 967         mutex_lock(&loopback->cable_lock);
 968         ucontrol->value.integer.value[0] =
 969                 loopback->setup[kcontrol->id.subdevice]
 970                                [kcontrol->id.device].channels;
 971         mutex_unlock(&loopback->cable_lock);
 972         return 0;
 973 }
 974
 975 static struct snd_kcontrol_new loopback_controls[]  = {
 976 {
 977         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 978         .name =         "PCM Rate Shift 100000",
 979         .info =         loopback_rate_shift_info,
 980         .get =          loopback_rate_shift_get,
 981         .put =          loopback_rate_shift_put,
 982 },
 983 {
 984         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 985         .name =         "PCM Notify",
 986         .info =         snd_ctl_boolean_mono_info,
 987         .get =          loopback_notify_get,
 988         .put =          loopback_notify_put,
 989 },
 990 #define ACTIVE_IDX 2
 991 {
 992         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 993         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 994         .name =         "PCM Slave Active",
 995         .info =         snd_ctl_boolean_mono_info,
 996         .get =          loopback_active_get,
 997 },
 998 #define FORMAT_IDX 3
 999 {
1000         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1001         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1002         .name =         "PCM Slave Format",
1003         .info =         loopback_format_info,
1004         .get =          loopback_format_get
1005 },
1006 #define RATE_IDX 4
1007 {
1008         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1009         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1010         .name =         "PCM Slave Rate",
1011         .info =         loopback_rate_info,
1012         .get =          loopback_rate_get
1013 },
1014 #define CHANNELS_IDX 5
1015 {
1016         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1017         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1018         .name =         "PCM Slave Channels",
1019         .info =         loopback_channels_info,
1020         .get =          loopback_channels_get
1021 }
1022 };
1023
1024 static int loopback_mixer_new(struct loopback *loopback, int notify)
1025 {
1026         struct snd_card *card = loopback->card;
1027         struct snd_pcm *pcm;
1028         struct snd_kcontrol *kctl;
1029         struct loopback_setup *setup;
1030         int err, dev, substr, substr_count, idx;
1031
1032         strcpy(card->mixername, "Loopback Mixer");
1033         for (dev = 0; dev < 2; dev++) {
1034                 pcm = loopback->pcm[dev];
1035                 substr_count =
1036                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1037                 for (substr = 0; substr < substr_count; substr++) {
1038                         setup = &loopback->setup[substr][dev];
1039                         setup->notify = notify;
1040                         setup->rate_shift = NO_PITCH;
1041                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1042                         setup->rate = 48000;
1043                         setup->channels = 2;
1044                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1045                                                                         idx++) {
1046                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1047                                                     loopback);
1048                                 if (!kctl)
1049                                         return -ENOMEM;
1050                                 kctl->id.device = dev;
1051                                 kctl->id.subdevice = substr;
1052                                 switch (idx) {
1053                                 case ACTIVE_IDX:
1054                                         setup->active_id = kctl->id;
1055                                         break;
1056                                 case FORMAT_IDX:
1057                                         setup->format_id = kctl->id;
1058                                         break;
1059                                 case RATE_IDX:
1060                                         setup->rate_id = kctl->id;
1061                                         break;
1062                                 case CHANNELS_IDX:
1063                                         setup->channels_id = kctl->id;
1064                                         break;
1065                                 default:
1066                                         break;
1067                                 }
1068                                 err = snd_ctl_add(card, kctl);
1069                                 if (err < 0)
1070                                         return err;
1071                         }
1072                 }
1073         }
1074         return 0;
1075 }
1076
1077 static void print_dpcm_info(struct snd_info_buffer *buffer,
1078                             struct loopback_pcm *dpcm,
1079                             const char *id)
1080 {
1081         snd_iprintf(buffer, "  %s\n", id);
1082         if (dpcm == NULL) {
1083                 snd_iprintf(buffer, "    inactive\n");
1084                 return;
1085         }
1086         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1087         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1088         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1089         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1090         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1091         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1092         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1093         snd_iprintf(buffer, "    update_pending:\t%u\n",
1094                                                 dpcm->period_update_pending);
1095         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1096         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1097         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1098                                         dpcm->last_jiffies, jiffies);
1099         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1100 }
1101
1102 static void print_substream_info(struct snd_info_buffer *buffer,
1103                                  struct loopback *loopback,
1104                                  int sub,
1105                                  int num)
1106 {
1107         struct loopback_cable *cable = loopback->cables[sub][num];
1108
1109         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1110         if (cable == NULL) {
1111                 snd_iprintf(buffer, "  inactive\n");
1112                 return;
1113         }
1114         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1115         snd_iprintf(buffer, "  running: %u\n", cable->running);
1116         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1117         print_dpcm_info(buffer, cable->streams[0], "Playback");
1118         print_dpcm_info(buffer, cable->streams[1], "Capture");
1119 }
1120
1121 static void print_cable_info(struct snd_info_entry *entry,
1122                              struct snd_info_buffer *buffer)
1123 {
1124         struct loopback *loopback = entry->private_data;
1125         int sub, num;
1126
1127         mutex_lock(&loopback->cable_lock);
1128         num = entry->name[strlen(entry->name)-1];
1129         num = num == '0' ? 0 : 1;
1130         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1131                 print_substream_info(buffer, loopback, sub, num);
1132         mutex_unlock(&loopback->cable_lock);
1133 }
1134
1135 static int loopback_proc_new(struct loopback *loopback, int cidx)
1136 {
1137         char name[32];
1138
1139         snprintf(name, sizeof(name), "cable#%d", cidx);
1140         return snd_card_ro_proc_new(loopback->card, name, loopback,
1141                                     print_cable_info);
1142 }
1143
1144 static int loopback_probe(struct platform_device *devptr)
1145 {
1146         struct snd_card *card;
1147         struct loopback *loopback;
1148         int dev = devptr->id;
1149         int err;
1150
1151         err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1152                            sizeof(struct loopback), &card);
1153         if (err < 0)
1154                 return err;
1155         loopback = card->private_data;
1156
1157         if (pcm_substreams[dev] < 1)
1158                 pcm_substreams[dev] = 1;
1159         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1160                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1161
1162         loopback->card = card;
1163         mutex_init(&loopback->cable_lock);
1164
1165         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1166         if (err < 0)
1167                 goto __nodev;
1168         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1169         if (err < 0)
1170                 goto __nodev;
1171         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1172         if (err < 0)
1173                 goto __nodev;
1174         loopback_proc_new(loopback, 0);
1175         loopback_proc_new(loopback, 1);
1176         strcpy(card->driver, "Loopback");
1177         strcpy(card->shortname, "Loopback");
1178         sprintf(card->longname, "Loopback %i", dev + 1);
1179         err = snd_card_register(card);
1180         if (!err) {
1181                 platform_set_drvdata(devptr, card);
1182                 return 0;
1183         }
1184       __nodev:
1185         snd_card_free(card);
1186         return err;
1187 }
1188
1189 static int loopback_remove(struct platform_device *devptr)
1190 {
1191         snd_card_free(platform_get_drvdata(devptr));
1192         return 0;
1193 }
1194
1195 #ifdef CONFIG_PM_SLEEP
1196 static int loopback_suspend(struct device *pdev)
1197 {
1198         struct snd_card *card = dev_get_drvdata(pdev);
1199
1200         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1201         return 0;
1202 }
1203
1204 static int loopback_resume(struct device *pdev)
1205 {
1206         struct snd_card *card = dev_get_drvdata(pdev);
1207
1208         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1209         return 0;
1210 }
1211
1212 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1213 #define LOOPBACK_PM_OPS &loopback_pm
1214 #else
1215 #define LOOPBACK_PM_OPS NULL
1216 #endif
1217
1218 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1219
1220 static struct platform_driver loopback_driver = {
1221         .probe          = loopback_probe,
1222         .remove         = loopback_remove,
1223         .driver         = {
1224                 .name   = SND_LOOPBACK_DRIVER,
1225                 .pm     = LOOPBACK_PM_OPS,
1226         },
1227 };
1228
1229 static void loopback_unregister_all(void)
1230 {
1231         int i;
1232
1233         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1234                 platform_device_unregister(devices[i]);
1235         platform_driver_unregister(&loopback_driver);
1236 }
1237
1238 static int __init alsa_card_loopback_init(void)
1239 {
1240         int i, err, cards;
1241
1242         err = platform_driver_register(&loopback_driver);
1243         if (err < 0)
1244                 return err;
1245
1246
1247         cards = 0;
1248         for (i = 0; i < SNDRV_CARDS; i++) {
1249                 struct platform_device *device;
1250                 if (!enable[i])
1251                         continue;
1252                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1253                                                          i, NULL, 0);
1254                 if (IS_ERR(device))
1255                         continue;
1256                 if (!platform_get_drvdata(device)) {
1257                         platform_device_unregister(device);
1258                         continue;
1259                 }
1260                 devices[i] = device;
1261                 cards++;
1262         }
1263         if (!cards) {
1264 #ifdef MODULE
1265                 printk(KERN_ERR "aloop: No loopback enabled\n");
1266 #endif
1267                 loopback_unregister_all();
1268                 return -ENODEV;
1269         }
1270         return 0;
1271 }
1272
1273 static void __exit alsa_card_loopback_exit(void)
1274 {
1275         loopback_unregister_all();
1276 }
1277
1278 module_init(alsa_card_loopback_init)
1279 module_exit(alsa_card_loopback_exit)