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