git.itanic.dy.fi Git - linux-stable/blob - 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_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, cur_jiffies;
 481         unsigned int running, count1, count2;
 482
 483         cur_jiffies = jiffies;
 484         running = cable->running ^ cable->pause;
 485         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 486                 delta_play = cur_jiffies - dpcm_play->last_jiffies;
 487                 dpcm_play->last_jiffies += delta_play;
 488         }
 489
 490         if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 491                 delta_capt = cur_jiffies - dpcm_capt->last_jiffies;
 492                 dpcm_capt->last_jiffies += delta_capt;
 493         }
 494
 495         if (delta_play == 0 && delta_capt == 0)
 496                 goto unlock;
 497
 498         if (delta_play > delta_capt) {
 499                 count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
 500                 bytepos_finish(dpcm_play, count1);
 501                 delta_play = delta_capt;
 502         } else if (delta_play < delta_capt) {
 503                 count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
 504                 clear_capture_buf(dpcm_capt, count1);
 505                 bytepos_finish(dpcm_capt, count1);
 506                 delta_capt = delta_play;
 507         }
 508
 509         if (delta_play == 0 && delta_capt == 0)
 510                 goto unlock;
 511
 512         /* note delta_capt == delta_play at this moment */
 513         count1 = bytepos_delta(dpcm_play, delta_play);
 514         count2 = bytepos_delta(dpcm_capt, delta_capt);
 515         if (count1 < count2) {
 516                 dpcm_capt->last_drift = count2 - count1;
 517                 count1 = count2;
 518         } else if (count1 > count2) {
 519                 dpcm_play->last_drift = count1 - count2;
 520         }
 521         copy_play_buf(dpcm_play, dpcm_capt, count1);
 522         bytepos_finish(dpcm_play, count1);
 523         bytepos_finish(dpcm_capt, count1);
 524  unlock:
 525         return running;
 526 }
 527
 528 static void loopback_timer_function(struct timer_list *t)
 529 {
 530         struct loopback_pcm *dpcm = from_timer(dpcm, t, timer);
 531         unsigned long flags;
 532
 533         spin_lock_irqsave(&dpcm->cable->lock, flags);
 534         if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
 535                 loopback_timer_start(dpcm);
 536                 if (dpcm->period_update_pending) {
 537                         dpcm->period_update_pending = 0;
 538                         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 539                         /* need to unlock before calling below */
 540                         snd_pcm_period_elapsed(dpcm->substream);
 541                         return;
 542                 }
 543         }
 544         spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 545 }
 546
 547 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 548 {
 549         struct snd_pcm_runtime *runtime = substream->runtime;
 550         struct loopback_pcm *dpcm = runtime->private_data;
 551         snd_pcm_uframes_t pos;
 552
 553         spin_lock(&dpcm->cable->lock);
 554         loopback_pos_update(dpcm->cable);
 555         pos = dpcm->buf_pos;
 556         spin_unlock(&dpcm->cable->lock);
 557         return bytes_to_frames(runtime, pos);
 558 }
 559
 560 static const struct snd_pcm_hardware loopback_pcm_hardware =
 561 {
 562         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 563                          SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE |
 564                          SNDRV_PCM_INFO_RESUME),
 565         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 566                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 567                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 568         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 569         .rate_min =             8000,
 570         .rate_max =             192000,
 571         .channels_min =         1,
 572         .channels_max =         32,
 573         .buffer_bytes_max =     2 * 1024 * 1024,
 574         .period_bytes_min =     64,
 575         /* note check overflow in frac_pos() using pcm_rate_shift before
 576            changing period_bytes_max value */
 577         .period_bytes_max =     1024 * 1024,
 578         .periods_min =          1,
 579         .periods_max =          1024,
 580         .fifo_size =            0,
 581 };
 582
 583 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 584 {
 585         struct loopback_pcm *dpcm = runtime->private_data;
 586         kfree(dpcm);
 587 }
 588
 589 static int loopback_hw_params(struct snd_pcm_substream *substream,
 590                               struct snd_pcm_hw_params *params)
 591 {
 592         return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 593                                                 params_buffer_bytes(params));
 594 }
 595
 596 static int loopback_hw_free(struct snd_pcm_substream *substream)
 597 {
 598         struct snd_pcm_runtime *runtime = substream->runtime;
 599         struct loopback_pcm *dpcm = runtime->private_data;
 600         struct loopback_cable *cable = dpcm->cable;
 601
 602         mutex_lock(&dpcm->loopback->cable_lock);
 603         cable->valid &= ~(1 << substream->stream);
 604         mutex_unlock(&dpcm->loopback->cable_lock);
 605         return snd_pcm_lib_free_vmalloc_buffer(substream);
 606 }
 607
 608 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 609 {
 610         if (!substream->pcm->device)
 611                 return substream->stream;
 612         else
 613                 return !substream->stream;
 614 }
 615
 616 static int rule_format(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_mask m;
 622
 623         snd_mask_none(&m);
 624         mutex_lock(&dpcm->loopback->cable_lock);
 625         m.bits[0] = (u_int32_t)cable->hw.formats;
 626         m.bits[1] = (u_int32_t)(cable->hw.formats >> 32);
 627         mutex_unlock(&dpcm->loopback->cable_lock);
 628         return snd_mask_refine(hw_param_mask(params, rule->var), &m);
 629 }
 630
 631 static int rule_rate(struct snd_pcm_hw_params *params,
 632                      struct snd_pcm_hw_rule *rule)
 633 {
 634         struct loopback_pcm *dpcm = rule->private;
 635         struct loopback_cable *cable = dpcm->cable;
 636         struct snd_interval t;
 637
 638         mutex_lock(&dpcm->loopback->cable_lock);
 639         t.min = cable->hw.rate_min;
 640         t.max = cable->hw.rate_max;
 641         mutex_unlock(&dpcm->loopback->cable_lock);
 642         t.openmin = t.openmax = 0;
 643         t.integer = 0;
 644         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 645 }
 646
 647 static int rule_channels(struct snd_pcm_hw_params *params,
 648                          struct snd_pcm_hw_rule *rule)
 649 {
 650         struct loopback_pcm *dpcm = rule->private;
 651         struct loopback_cable *cable = dpcm->cable;
 652         struct snd_interval t;
 653
 654         mutex_lock(&dpcm->loopback->cable_lock);
 655         t.min = cable->hw.channels_min;
 656         t.max = cable->hw.channels_max;
 657         mutex_unlock(&dpcm->loopback->cable_lock);
 658         t.openmin = t.openmax = 0;
 659         t.integer = 0;
 660         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 661 }
 662
 663 static void free_cable(struct snd_pcm_substream *substream)
 664 {
 665         struct loopback *loopback = substream->private_data;
 666         int dev = get_cable_index(substream);
 667         struct loopback_cable *cable;
 668
 669         cable = loopback->cables[substream->number][dev];
 670         if (!cable)
 671                 return;
 672         if (cable->streams[!substream->stream]) {
 673                 /* other stream is still alive */
 674                 spin_lock_irq(&cable->lock);
 675                 cable->streams[substream->stream] = NULL;
 676                 spin_unlock_irq(&cable->lock);
 677         } else {
 678                 /* free the cable */
 679                 loopback->cables[substream->number][dev] = NULL;
 680                 kfree(cable);
 681         }
 682 }
 683
 684 static int loopback_open(struct snd_pcm_substream *substream)
 685 {
 686         struct snd_pcm_runtime *runtime = substream->runtime;
 687         struct loopback *loopback = substream->private_data;
 688         struct loopback_pcm *dpcm;
 689         struct loopback_cable *cable = NULL;
 690         int err = 0;
 691         int dev = get_cable_index(substream);
 692
 693         mutex_lock(&loopback->cable_lock);
 694         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 695         if (!dpcm) {
 696                 err = -ENOMEM;
 697                 goto unlock;
 698         }
 699         dpcm->loopback = loopback;
 700         dpcm->substream = substream;
 701         timer_setup(&dpcm->timer, loopback_timer_function, 0);
 702
 703         cable = loopback->cables[substream->number][dev];
 704         if (!cable) {
 705                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 706                 if (!cable) {
 707                         err = -ENOMEM;
 708                         goto unlock;
 709                 }
 710                 spin_lock_init(&cable->lock);
 711                 cable->hw = loopback_pcm_hardware;
 712                 loopback->cables[substream->number][dev] = cable;
 713         }
 714         dpcm->cable = cable;
 715
 716         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 717
 718         /* use dynamic rules based on actual runtime->hw values */
 719         /* note that the default rules created in the PCM midlevel code */
 720         /* are cached -> they do not reflect the actual state */
 721         err = snd_pcm_hw_rule_add(runtime, 0,
 722                                   SNDRV_PCM_HW_PARAM_FORMAT,
 723                                   rule_format, dpcm,
 724                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 725         if (err < 0)
 726                 goto unlock;
 727         err = snd_pcm_hw_rule_add(runtime, 0,
 728                                   SNDRV_PCM_HW_PARAM_RATE,
 729                                   rule_rate, dpcm,
 730                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 731         if (err < 0)
 732                 goto unlock;
 733         err = snd_pcm_hw_rule_add(runtime, 0,
 734                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 735                                   rule_channels, dpcm,
 736                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 737         if (err < 0)
 738                 goto unlock;
 739
 740         runtime->private_data = dpcm;
 741         runtime->private_free = loopback_runtime_free;
 742         if (get_notify(dpcm))
 743                 runtime->hw = loopback_pcm_hardware;
 744         else
 745                 runtime->hw = cable->hw;
 746
 747         spin_lock_irq(&cable->lock);
 748         cable->streams[substream->stream] = dpcm;
 749         spin_unlock_irq(&cable->lock);
 750
 751  unlock:
 752         if (err < 0) {
 753                 free_cable(substream);
 754                 kfree(dpcm);
 755         }
 756         mutex_unlock(&loopback->cable_lock);
 757         return err;
 758 }
 759
 760 static int loopback_close(struct snd_pcm_substream *substream)
 761 {
 762         struct loopback *loopback = substream->private_data;
 763         struct loopback_pcm *dpcm = substream->runtime->private_data;
 764
 765         loopback_timer_stop_sync(dpcm);
 766         mutex_lock(&loopback->cable_lock);
 767         free_cable(substream);
 768         mutex_unlock(&loopback->cable_lock);
 769         return 0;
 770 }
 771
 772 static const struct snd_pcm_ops loopback_pcm_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 };
 783
 784 static int loopback_pcm_new(struct loopback *loopback,
 785                             int device, int substreams)
 786 {
 787         struct snd_pcm *pcm;
 788         int err;
 789
 790         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 791                           substreams, substreams, &pcm);
 792         if (err < 0)
 793                 return err;
 794         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_pcm_ops);
 795         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_pcm_ops);
 796
 797         pcm->private_data = loopback;
 798         pcm->info_flags = 0;
 799         strcpy(pcm->name, "Loopback PCM");
 800
 801         loopback->pcm[device] = pcm;
 802         return 0;
 803 }
 804
 805 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 806                                     struct snd_ctl_elem_info *uinfo)
 807 {
 808         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 809         uinfo->count = 1;
 810         uinfo->value.integer.min = 80000;
 811         uinfo->value.integer.max = 120000;
 812         uinfo->value.integer.step = 1;
 813         return 0;
 814 }
 815
 816 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 817                                    struct snd_ctl_elem_value *ucontrol)
 818 {
 819         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 820
 821         mutex_lock(&loopback->cable_lock);
 822         ucontrol->value.integer.value[0] =
 823                 loopback->setup[kcontrol->id.subdevice]
 824                                [kcontrol->id.device].rate_shift;
 825         mutex_unlock(&loopback->cable_lock);
 826         return 0;
 827 }
 828
 829 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 830                                    struct snd_ctl_elem_value *ucontrol)
 831 {
 832         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 833         unsigned int val;
 834         int change = 0;
 835
 836         val = ucontrol->value.integer.value[0];
 837         if (val < 80000)
 838                 val = 80000;
 839         if (val > 120000)
 840                 val = 120000;
 841         mutex_lock(&loopback->cable_lock);
 842         if (val != loopback->setup[kcontrol->id.subdevice]
 843                                   [kcontrol->id.device].rate_shift) {
 844                 loopback->setup[kcontrol->id.subdevice]
 845                                [kcontrol->id.device].rate_shift = val;
 846                 change = 1;
 847         }
 848         mutex_unlock(&loopback->cable_lock);
 849         return change;
 850 }
 851
 852 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 853                                struct snd_ctl_elem_value *ucontrol)
 854 {
 855         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 856
 857         mutex_lock(&loopback->cable_lock);
 858         ucontrol->value.integer.value[0] =
 859                 loopback->setup[kcontrol->id.subdevice]
 860                                [kcontrol->id.device].notify;
 861         mutex_unlock(&loopback->cable_lock);
 862         return 0;
 863 }
 864
 865 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 866                                struct snd_ctl_elem_value *ucontrol)
 867 {
 868         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 869         unsigned int val;
 870         int change = 0;
 871
 872         val = ucontrol->value.integer.value[0] ? 1 : 0;
 873         mutex_lock(&loopback->cable_lock);
 874         if (val != loopback->setup[kcontrol->id.subdevice]
 875                                 [kcontrol->id.device].notify) {
 876                 loopback->setup[kcontrol->id.subdevice]
 877                         [kcontrol->id.device].notify = val;
 878                 change = 1;
 879         }
 880         mutex_unlock(&loopback->cable_lock);
 881         return change;
 882 }
 883
 884 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 885                                struct snd_ctl_elem_value *ucontrol)
 886 {
 887         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 888         struct loopback_cable *cable;
 889
 890         unsigned int val = 0;
 891
 892         mutex_lock(&loopback->cable_lock);
 893         cable = loopback->cables[kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 894         if (cable != NULL) {
 895                 unsigned int running = cable->running ^ cable->pause;
 896
 897                 val = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? 1 : 0;
 898         }
 899         mutex_unlock(&loopback->cable_lock);
 900         ucontrol->value.integer.value[0] = val;
 901         return 0;
 902 }
 903
 904 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 905                                 struct snd_ctl_elem_info *uinfo)
 906 {
 907         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 908         uinfo->count = 1;
 909         uinfo->value.integer.min = 0;
 910         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 911         uinfo->value.integer.step = 1;
 912         return 0;
 913 }
 914
 915 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 916                                struct snd_ctl_elem_value *ucontrol)
 917 {
 918         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 919
 920         ucontrol->value.integer.value[0] =
 921                 loopback->setup[kcontrol->id.subdevice]
 922                                [kcontrol->id.device].format;
 923         return 0;
 924 }
 925
 926 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 927                               struct snd_ctl_elem_info *uinfo)
 928 {
 929         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 930         uinfo->count = 1;
 931         uinfo->value.integer.min = 0;
 932         uinfo->value.integer.max = 192000;
 933         uinfo->value.integer.step = 1;
 934         return 0;
 935 }
 936
 937 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 938                              struct snd_ctl_elem_value *ucontrol)
 939 {
 940         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 941
 942         mutex_lock(&loopback->cable_lock);
 943         ucontrol->value.integer.value[0] =
 944                 loopback->setup[kcontrol->id.subdevice]
 945                                [kcontrol->id.device].rate;
 946         mutex_unlock(&loopback->cable_lock);
 947         return 0;
 948 }
 949
 950 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 951                                   struct snd_ctl_elem_info *uinfo)
 952 {
 953         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 954         uinfo->count = 1;
 955         uinfo->value.integer.min = 1;
 956         uinfo->value.integer.max = 1024;
 957         uinfo->value.integer.step = 1;
 958         return 0;
 959 }
 960
 961 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 962                                  struct snd_ctl_elem_value *ucontrol)
 963 {
 964         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 965
 966         mutex_lock(&loopback->cable_lock);
 967         ucontrol->value.integer.value[0] =
 968                 loopback->setup[kcontrol->id.subdevice]
 969                                [kcontrol->id.device].channels;
 970         mutex_unlock(&loopback->cable_lock);
 971         return 0;
 972 }
 973
 974 static struct snd_kcontrol_new loopback_controls[]  = {
 975 {
 976         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 977         .name =         "PCM Rate Shift 100000",
 978         .info =         loopback_rate_shift_info,
 979         .get =          loopback_rate_shift_get,
 980         .put =          loopback_rate_shift_put,
 981 },
 982 {
 983         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 984         .name =         "PCM Notify",
 985         .info =         snd_ctl_boolean_mono_info,
 986         .get =          loopback_notify_get,
 987         .put =          loopback_notify_put,
 988 },
 989 #define ACTIVE_IDX 2
 990 {
 991         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 992         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 993         .name =         "PCM Slave Active",
 994         .info =         snd_ctl_boolean_mono_info,
 995         .get =          loopback_active_get,
 996 },
 997 #define FORMAT_IDX 3
 998 {
 999         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1000         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1001         .name =         "PCM Slave Format",
1002         .info =         loopback_format_info,
1003         .get =          loopback_format_get
1004 },
1005 #define RATE_IDX 4
1006 {
1007         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1008         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1009         .name =         "PCM Slave Rate",
1010         .info =         loopback_rate_info,
1011         .get =          loopback_rate_get
1012 },
1013 #define CHANNELS_IDX 5
1014 {
1015         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
1016         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1017         .name =         "PCM Slave Channels",
1018         .info =         loopback_channels_info,
1019         .get =          loopback_channels_get
1020 }
1021 };
1022
1023 static int loopback_mixer_new(struct loopback *loopback, int notify)
1024 {
1025         struct snd_card *card = loopback->card;
1026         struct snd_pcm *pcm;
1027         struct snd_kcontrol *kctl;
1028         struct loopback_setup *setup;
1029         int err, dev, substr, substr_count, idx;
1030
1031         strcpy(card->mixername, "Loopback Mixer");
1032         for (dev = 0; dev < 2; dev++) {
1033                 pcm = loopback->pcm[dev];
1034                 substr_count =
1035                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1036                 for (substr = 0; substr < substr_count; substr++) {
1037                         setup = &loopback->setup[substr][dev];
1038                         setup->notify = notify;
1039                         setup->rate_shift = NO_PITCH;
1040                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
1041                         setup->rate = 48000;
1042                         setup->channels = 2;
1043                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1044                                                                         idx++) {
1045                                 kctl = snd_ctl_new1(&loopback_controls[idx],
1046                                                     loopback);
1047                                 if (!kctl)
1048                                         return -ENOMEM;
1049                                 kctl->id.device = dev;
1050                                 kctl->id.subdevice = substr;
1051
1052                                 /* Add the control before copying the id so that
1053                                  * the numid field of the id is set in the copy.
1054                                  */
1055                                 err = snd_ctl_add(card, kctl);
1056                                 if (err < 0)
1057                                         return err;
1058
1059                                 switch (idx) {
1060                                 case ACTIVE_IDX:
1061                                         setup->active_id = kctl->id;
1062                                         break;
1063                                 case FORMAT_IDX:
1064                                         setup->format_id = kctl->id;
1065                                         break;
1066                                 case RATE_IDX:
1067                                         setup->rate_id = kctl->id;
1068                                         break;
1069                                 case CHANNELS_IDX:
1070                                         setup->channels_id = kctl->id;
1071                                         break;
1072                                 default:
1073                                         break;
1074                                 }
1075                         }
1076                 }
1077         }
1078         return 0;
1079 }
1080
1081 static void print_dpcm_info(struct snd_info_buffer *buffer,
1082                             struct loopback_pcm *dpcm,
1083                             const char *id)
1084 {
1085         snd_iprintf(buffer, "  %s\n", id);
1086         if (dpcm == NULL) {
1087                 snd_iprintf(buffer, "    inactive\n");
1088                 return;
1089         }
1090         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1091         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1092         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1093         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1094         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1095         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1096         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1097         snd_iprintf(buffer, "    update_pending:\t%u\n",
1098                                                 dpcm->period_update_pending);
1099         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1100         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1101         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1102                                         dpcm->last_jiffies, jiffies);
1103         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1104 }
1105
1106 static void print_substream_info(struct snd_info_buffer *buffer,
1107                                  struct loopback *loopback,
1108                                  int sub,
1109                                  int num)
1110 {
1111         struct loopback_cable *cable = loopback->cables[sub][num];
1112
1113         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1114         if (cable == NULL) {
1115                 snd_iprintf(buffer, "  inactive\n");
1116                 return;
1117         }
1118         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1119         snd_iprintf(buffer, "  running: %u\n", cable->running);
1120         snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1121         print_dpcm_info(buffer, cable->streams[0], "Playback");
1122         print_dpcm_info(buffer, cable->streams[1], "Capture");
1123 }
1124
1125 static void print_cable_info(struct snd_info_entry *entry,
1126                              struct snd_info_buffer *buffer)
1127 {
1128         struct loopback *loopback = entry->private_data;
1129         int sub, num;
1130
1131         mutex_lock(&loopback->cable_lock);
1132         num = entry->name[strlen(entry->name)-1];
1133         num = num == '0' ? 0 : 1;
1134         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1135                 print_substream_info(buffer, loopback, sub, num);
1136         mutex_unlock(&loopback->cable_lock);
1137 }
1138
1139 static int loopback_proc_new(struct loopback *loopback, int cidx)
1140 {
1141         char name[32];
1142         struct snd_info_entry *entry;
1143         int err;
1144
1145         snprintf(name, sizeof(name), "cable#%d", cidx);
1146         err = snd_card_proc_new(loopback->card, name, &entry);
1147         if (err < 0)
1148                 return err;
1149
1150         snd_info_set_text_ops(entry, loopback, print_cable_info);
1151         return 0;
1152 }
1153
1154 static int loopback_probe(struct platform_device *devptr)
1155 {
1156         struct snd_card *card;
1157         struct loopback *loopback;
1158         int dev = devptr->id;
1159         int err;
1160
1161         err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1162                            sizeof(struct loopback), &card);
1163         if (err < 0)
1164                 return err;
1165         loopback = card->private_data;
1166
1167         if (pcm_substreams[dev] < 1)
1168                 pcm_substreams[dev] = 1;
1169         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1170                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1171
1172         loopback->card = card;
1173         mutex_init(&loopback->cable_lock);
1174
1175         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1176         if (err < 0)
1177                 goto __nodev;
1178         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1179         if (err < 0)
1180                 goto __nodev;
1181         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1182         if (err < 0)
1183                 goto __nodev;
1184         loopback_proc_new(loopback, 0);
1185         loopback_proc_new(loopback, 1);
1186         strcpy(card->driver, "Loopback");
1187         strcpy(card->shortname, "Loopback");
1188         sprintf(card->longname, "Loopback %i", dev + 1);
1189         err = snd_card_register(card);
1190         if (!err) {
1191                 platform_set_drvdata(devptr, card);
1192                 return 0;
1193         }
1194       __nodev:
1195         snd_card_free(card);
1196         return err;
1197 }
1198
1199 static int loopback_remove(struct platform_device *devptr)
1200 {
1201         snd_card_free(platform_get_drvdata(devptr));
1202         return 0;
1203 }
1204
1205 #ifdef CONFIG_PM_SLEEP
1206 static int loopback_suspend(struct device *pdev)
1207 {
1208         struct snd_card *card = dev_get_drvdata(pdev);
1209         struct loopback *loopback = card->private_data;
1210
1211         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1212
1213         snd_pcm_suspend_all(loopback->pcm[0]);
1214         snd_pcm_suspend_all(loopback->pcm[1]);
1215         return 0;
1216 }
1217
1218 static int loopback_resume(struct device *pdev)
1219 {
1220         struct snd_card *card = dev_get_drvdata(pdev);
1221
1222         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1223         return 0;
1224 }
1225
1226 static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1227 #define LOOPBACK_PM_OPS &loopback_pm
1228 #else
1229 #define LOOPBACK_PM_OPS NULL
1230 #endif
1231
1232 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1233
1234 static struct platform_driver loopback_driver = {
1235         .probe          = loopback_probe,
1236         .remove         = loopback_remove,
1237         .driver         = {
1238                 .name   = SND_LOOPBACK_DRIVER,
1239                 .pm     = LOOPBACK_PM_OPS,
1240         },
1241 };
1242
1243 static void loopback_unregister_all(void)
1244 {
1245         int i;
1246
1247         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1248                 platform_device_unregister(devices[i]);
1249         platform_driver_unregister(&loopback_driver);
1250 }
1251
1252 static int __init alsa_card_loopback_init(void)
1253 {
1254         int i, err, cards;
1255
1256         err = platform_driver_register(&loopback_driver);
1257         if (err < 0)
1258                 return err;
1259
1260
1261         cards = 0;
1262         for (i = 0; i < SNDRV_CARDS; i++) {
1263                 struct platform_device *device;
1264                 if (!enable[i])
1265                         continue;
1266                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1267                                                          i, NULL, 0);
1268                 if (IS_ERR(device))
1269                         continue;
1270                 if (!platform_get_drvdata(device)) {
1271                         platform_device_unregister(device);
1272                         continue;
1273                 }
1274                 devices[i] = device;
1275                 cards++;
1276         }
1277         if (!cards) {
1278 #ifdef MODULE
1279                 printk(KERN_ERR "aloop: No loopback enabled\n");
1280 #endif
1281                 loopback_unregister_all();
1282                 return -ENODEV;
1283         }
1284         return 0;
1285 }
1286
1287 static void __exit alsa_card_loopback_exit(void)
1288 {
1289         loopback_unregister_all();
1290 }
1291
1292 module_init(alsa_card_loopback_init)
1293 module_exit(alsa_card_loopback_exit)