sound/drivers/dummy.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Dummy soundcard
   4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5  */
   6
   7 #include <linux/init.h>
   8 #include <linux/err.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/jiffies.h>
  11 #include <linux/slab.h>
  12 #include <linux/time.h>
  13 #include <linux/wait.h>
  14 #include <linux/hrtimer.h>
  15 #include <linux/math64.h>
  16 #include <linux/module.h>
  17 #include <sound/core.h>
  18 #include <sound/control.h>
  19 #include <sound/tlv.h>
  20 #include <sound/pcm.h>
  21 #include <sound/rawmidi.h>
  22 #include <sound/info.h>
  23 #include <sound/initval.h>
  24
  25 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  26 MODULE_DESCRIPTION("Dummy soundcard (/dev/null)");
  27 MODULE_LICENSE("GPL");
  28
  29 #define MAX_PCM_DEVICES         4
  30 #define MAX_PCM_SUBSTREAMS      128
  31 #define MAX_MIDI_DEVICES        2
  32
  33 /* defaults */
  34 #define MAX_BUFFER_SIZE         (64*1024)
  35 #define MIN_PERIOD_SIZE         64
  36 #define MAX_PERIOD_SIZE         MAX_BUFFER_SIZE
  37 #define USE_FORMATS             (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE)
  38 #define USE_RATE                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000
  39 #define USE_RATE_MIN            5500
  40 #define USE_RATE_MAX            48000
  41 #define USE_CHANNELS_MIN        1
  42 #define USE_CHANNELS_MAX        2
  43 #define USE_PERIODS_MIN         1
  44 #define USE_PERIODS_MAX         1024
  45 #define USE_MIXER_VOLUME_LEVEL_MIN      -50
  46 #define USE_MIXER_VOLUME_LEVEL_MAX      100
  47
  48 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  49 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  50 static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  51 static char *model[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = NULL};
  52 static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
  53 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  54 //static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
  55 static int mixer_volume_level_min = USE_MIXER_VOLUME_LEVEL_MIN;
  56 static int mixer_volume_level_max = USE_MIXER_VOLUME_LEVEL_MAX;
  57 #ifdef CONFIG_HIGH_RES_TIMERS
  58 static bool hrtimer = 1;
  59 #endif
  60 static bool fake_buffer = 1;
  61
  62 module_param_array(index, int, NULL, 0444);
  63 MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
  64 module_param_array(id, charp, NULL, 0444);
  65 MODULE_PARM_DESC(id, "ID string for dummy soundcard.");
  66 module_param_array(enable, bool, NULL, 0444);
  67 MODULE_PARM_DESC(enable, "Enable this dummy soundcard.");
  68 module_param_array(model, charp, NULL, 0444);
  69 MODULE_PARM_DESC(model, "Soundcard model.");
  70 module_param_array(pcm_devs, int, NULL, 0444);
  71 MODULE_PARM_DESC(pcm_devs, "PCM devices # (0-4) for dummy driver.");
  72 module_param_array(pcm_substreams, int, NULL, 0444);
  73 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
  74 //module_param_array(midi_devs, int, NULL, 0444);
  75 //MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
  76 module_param(mixer_volume_level_min, int, 0444);
  77 MODULE_PARM_DESC(mixer_volume_level_min, "Minimum mixer volume level for dummy driver. Default: -50");
  78 module_param(mixer_volume_level_max, int, 0444);
  79 MODULE_PARM_DESC(mixer_volume_level_max, "Maximum mixer volume level for dummy driver. Default: 100");
  80 module_param(fake_buffer, bool, 0444);
  81 MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
  82 #ifdef CONFIG_HIGH_RES_TIMERS
  83 module_param(hrtimer, bool, 0644);
  84 MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
  85 #endif
  86
  87 static struct platform_device *devices[SNDRV_CARDS];
  88
  89 #define MIXER_ADDR_MASTER       0
  90 #define MIXER_ADDR_LINE         1
  91 #define MIXER_ADDR_MIC          2
  92 #define MIXER_ADDR_SYNTH        3
  93 #define MIXER_ADDR_CD           4
  94 #define MIXER_ADDR_LAST         4
  95
  96 struct dummy_timer_ops {
  97         int (*create)(struct snd_pcm_substream *);
  98         void (*free)(struct snd_pcm_substream *);
  99         int (*prepare)(struct snd_pcm_substream *);
 100         int (*start)(struct snd_pcm_substream *);
 101         int (*stop)(struct snd_pcm_substream *);
 102         snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
 103 };
 104
 105 #define get_dummy_ops(substream) \
 106         (*(const struct dummy_timer_ops **)(substream)->runtime->private_data)
 107
 108 struct dummy_model {
 109         const char *name;
 110         int (*playback_constraints)(struct snd_pcm_runtime *runtime);
 111         int (*capture_constraints)(struct snd_pcm_runtime *runtime);
 112         u64 formats;
 113         size_t buffer_bytes_max;
 114         size_t period_bytes_min;
 115         size_t period_bytes_max;
 116         unsigned int periods_min;
 117         unsigned int periods_max;
 118         unsigned int rates;
 119         unsigned int rate_min;
 120         unsigned int rate_max;
 121         unsigned int channels_min;
 122         unsigned int channels_max;
 123 };
 124
 125 struct snd_dummy {
 126         struct snd_card *card;
 127         const struct dummy_model *model;
 128         struct snd_pcm *pcm;
 129         struct snd_pcm_hardware pcm_hw;
 130         spinlock_t mixer_lock;
 131         int mixer_volume[MIXER_ADDR_LAST+1][2];
 132         int capture_source[MIXER_ADDR_LAST+1][2];
 133         int iobox;
 134         struct snd_kcontrol *cd_volume_ctl;
 135         struct snd_kcontrol *cd_switch_ctl;
 136 };
 137
 138 /*
 139  * card models
 140  */
 141
 142 static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
 143 {
 144         int err;
 145         err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 146         if (err < 0)
 147                 return err;
 148         err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX);
 149         if (err < 0)
 150                 return err;
 151         return 0;
 152 }
 153
 154 static const struct dummy_model model_emu10k1 = {
 155         .name = "emu10k1",
 156         .playback_constraints = emu10k1_playback_constraints,
 157         .buffer_bytes_max = 128 * 1024,
 158 };
 159
 160 static const struct dummy_model model_rme9652 = {
 161         .name = "rme9652",
 162         .buffer_bytes_max = 26 * 64 * 1024,
 163         .formats = SNDRV_PCM_FMTBIT_S32_LE,
 164         .channels_min = 26,
 165         .channels_max = 26,
 166         .periods_min = 2,
 167         .periods_max = 2,
 168 };
 169
 170 static const struct dummy_model model_ice1712 = {
 171         .name = "ice1712",
 172         .buffer_bytes_max = 256 * 1024,
 173         .formats = SNDRV_PCM_FMTBIT_S32_LE,
 174         .channels_min = 10,
 175         .channels_max = 10,
 176         .periods_min = 1,
 177         .periods_max = 1024,
 178 };
 179
 180 static const struct dummy_model model_uda1341 = {
 181         .name = "uda1341",
 182         .buffer_bytes_max = 16380,
 183         .formats = SNDRV_PCM_FMTBIT_S16_LE,
 184         .channels_min = 2,
 185         .channels_max = 2,
 186         .periods_min = 2,
 187         .periods_max = 255,
 188 };
 189
 190 static const struct dummy_model model_ac97 = {
 191         .name = "ac97",
 192         .formats = SNDRV_PCM_FMTBIT_S16_LE,
 193         .channels_min = 2,
 194         .channels_max = 2,
 195         .rates = SNDRV_PCM_RATE_48000,
 196         .rate_min = 48000,
 197         .rate_max = 48000,
 198 };
 199
 200 static const struct dummy_model model_ca0106 = {
 201         .name = "ca0106",
 202         .formats = SNDRV_PCM_FMTBIT_S16_LE,
 203         .buffer_bytes_max = ((65536-64)*8),
 204         .period_bytes_max = (65536-64),
 205         .periods_min = 2,
 206         .periods_max = 8,
 207         .channels_min = 2,
 208         .channels_max = 2,
 209         .rates = SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_96000|SNDRV_PCM_RATE_192000,
 210         .rate_min = 48000,
 211         .rate_max = 192000,
 212 };
 213
 214 static const struct dummy_model *dummy_models[] = {
 215         &model_emu10k1,
 216         &model_rme9652,
 217         &model_ice1712,
 218         &model_uda1341,
 219         &model_ac97,
 220         &model_ca0106,
 221         NULL
 222 };
 223
 224 /*
 225  * system timer interface
 226  */
 227
 228 struct dummy_systimer_pcm {
 229         /* ops must be the first item */
 230         const struct dummy_timer_ops *timer_ops;
 231         spinlock_t lock;
 232         struct timer_list timer;
 233         unsigned long base_time;
 234         unsigned int frac_pos;  /* fractional sample position (based HZ) */
 235         unsigned int frac_period_rest;
 236         unsigned int frac_buffer_size;  /* buffer_size * HZ */
 237         unsigned int frac_period_size;  /* period_size * HZ */
 238         unsigned int rate;
 239         int elapsed;
 240         struct snd_pcm_substream *substream;
 241 };
 242
 243 static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
 244 {
 245         mod_timer(&dpcm->timer, jiffies +
 246                 DIV_ROUND_UP(dpcm->frac_period_rest, dpcm->rate));
 247 }
 248
 249 static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
 250 {
 251         unsigned long delta;
 252
 253         delta = jiffies - dpcm->base_time;
 254         if (!delta)
 255                 return;
 256         dpcm->base_time += delta;
 257         delta *= dpcm->rate;
 258         dpcm->frac_pos += delta;
 259         while (dpcm->frac_pos >= dpcm->frac_buffer_size)
 260                 dpcm->frac_pos -= dpcm->frac_buffer_size;
 261         while (dpcm->frac_period_rest <= delta) {
 262                 dpcm->elapsed++;
 263                 dpcm->frac_period_rest += dpcm->frac_period_size;
 264         }
 265         dpcm->frac_period_rest -= delta;
 266 }
 267
 268 static int dummy_systimer_start(struct snd_pcm_substream *substream)
 269 {
 270         struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 271         spin_lock(&dpcm->lock);
 272         dpcm->base_time = jiffies;
 273         dummy_systimer_rearm(dpcm);
 274         spin_unlock(&dpcm->lock);
 275         return 0;
 276 }
 277
 278 static int dummy_systimer_stop(struct snd_pcm_substream *substream)
 279 {
 280         struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 281         spin_lock(&dpcm->lock);
 282         del_timer(&dpcm->timer);
 283         spin_unlock(&dpcm->lock);
 284         return 0;
 285 }
 286
 287 static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
 288 {
 289         struct snd_pcm_runtime *runtime = substream->runtime;
 290         struct dummy_systimer_pcm *dpcm = runtime->private_data;
 291
 292         dpcm->frac_pos = 0;
 293         dpcm->rate = runtime->rate;
 294         dpcm->frac_buffer_size = runtime->buffer_size * HZ;
 295         dpcm->frac_period_size = runtime->period_size * HZ;
 296         dpcm->frac_period_rest = dpcm->frac_period_size;
 297         dpcm->elapsed = 0;
 298
 299         return 0;
 300 }
 301
 302 static void dummy_systimer_callback(struct timer_list *t)
 303 {
 304         struct dummy_systimer_pcm *dpcm = from_timer(dpcm, t, timer);
 305         unsigned long flags;
 306         int elapsed = 0;
 307
 308         spin_lock_irqsave(&dpcm->lock, flags);
 309         dummy_systimer_update(dpcm);
 310         dummy_systimer_rearm(dpcm);
 311         elapsed = dpcm->elapsed;
 312         dpcm->elapsed = 0;
 313         spin_unlock_irqrestore(&dpcm->lock, flags);
 314         if (elapsed)
 315                 snd_pcm_period_elapsed(dpcm->substream);
 316 }
 317
 318 static snd_pcm_uframes_t
 319 dummy_systimer_pointer(struct snd_pcm_substream *substream)
 320 {
 321         struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 322         snd_pcm_uframes_t pos;
 323
 324         spin_lock(&dpcm->lock);
 325         dummy_systimer_update(dpcm);
 326         pos = dpcm->frac_pos / HZ;
 327         spin_unlock(&dpcm->lock);
 328         return pos;
 329 }
 330
 331 static int dummy_systimer_create(struct snd_pcm_substream *substream)
 332 {
 333         struct dummy_systimer_pcm *dpcm;
 334
 335         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 336         if (!dpcm)
 337                 return -ENOMEM;
 338         substream->runtime->private_data = dpcm;
 339         timer_setup(&dpcm->timer, dummy_systimer_callback, 0);
 340         spin_lock_init(&dpcm->lock);
 341         dpcm->substream = substream;
 342         return 0;
 343 }
 344
 345 static void dummy_systimer_free(struct snd_pcm_substream *substream)
 346 {
 347         kfree(substream->runtime->private_data);
 348 }
 349
 350 static const struct dummy_timer_ops dummy_systimer_ops = {
 351         .create =       dummy_systimer_create,
 352         .free =         dummy_systimer_free,
 353         .prepare =      dummy_systimer_prepare,
 354         .start =        dummy_systimer_start,
 355         .stop =         dummy_systimer_stop,
 356         .pointer =      dummy_systimer_pointer,
 357 };
 358
 359 #ifdef CONFIG_HIGH_RES_TIMERS
 360 /*
 361  * hrtimer interface
 362  */
 363
 364 struct dummy_hrtimer_pcm {
 365         /* ops must be the first item */
 366         const struct dummy_timer_ops *timer_ops;
 367         ktime_t base_time;
 368         ktime_t period_time;
 369         atomic_t running;
 370         struct hrtimer timer;
 371         struct snd_pcm_substream *substream;
 372 };
 373
 374 static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
 375 {
 376         struct dummy_hrtimer_pcm *dpcm;
 377
 378         dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
 379         if (!atomic_read(&dpcm->running))
 380                 return HRTIMER_NORESTART;
 381         /*
 382          * In cases of XRUN and draining, this calls .trigger to stop PCM
 383          * substream.
 384          */
 385         snd_pcm_period_elapsed(dpcm->substream);
 386         if (!atomic_read(&dpcm->running))
 387                 return HRTIMER_NORESTART;
 388
 389         hrtimer_forward_now(timer, dpcm->period_time);
 390         return HRTIMER_RESTART;
 391 }
 392
 393 static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
 394 {
 395         struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 396
 397         dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
 398         hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL_SOFT);
 399         atomic_set(&dpcm->running, 1);
 400         return 0;
 401 }
 402
 403 static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
 404 {
 405         struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 406
 407         atomic_set(&dpcm->running, 0);
 408         if (!hrtimer_callback_running(&dpcm->timer))
 409                 hrtimer_cancel(&dpcm->timer);
 410         return 0;
 411 }
 412
 413 static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
 414 {
 415         hrtimer_cancel(&dpcm->timer);
 416 }
 417
 418 static snd_pcm_uframes_t
 419 dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
 420 {
 421         struct snd_pcm_runtime *runtime = substream->runtime;
 422         struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 423         u64 delta;
 424         u32 pos;
 425
 426         delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
 427                                dpcm->base_time);
 428         delta = div_u64(delta * runtime->rate + 999999, 1000000);
 429         div_u64_rem(delta, runtime->buffer_size, &pos);
 430         return pos;
 431 }
 432
 433 static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
 434 {
 435         struct snd_pcm_runtime *runtime = substream->runtime;
 436         struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 437         unsigned int period, rate;
 438         long sec;
 439         unsigned long nsecs;
 440
 441         dummy_hrtimer_sync(dpcm);
 442         period = runtime->period_size;
 443         rate = runtime->rate;
 444         sec = period / rate;
 445         period %= rate;
 446         nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
 447         dpcm->period_time = ktime_set(sec, nsecs);
 448
 449         return 0;
 450 }
 451
 452 static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
 453 {
 454         struct dummy_hrtimer_pcm *dpcm;
 455
 456         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 457         if (!dpcm)
 458                 return -ENOMEM;
 459         substream->runtime->private_data = dpcm;
 460         hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
 461         dpcm->timer.function = dummy_hrtimer_callback;
 462         dpcm->substream = substream;
 463         atomic_set(&dpcm->running, 0);
 464         return 0;
 465 }
 466
 467 static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
 468 {
 469         struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 470         dummy_hrtimer_sync(dpcm);
 471         kfree(dpcm);
 472 }
 473
 474 static const struct dummy_timer_ops dummy_hrtimer_ops = {
 475         .create =       dummy_hrtimer_create,
 476         .free =         dummy_hrtimer_free,
 477         .prepare =      dummy_hrtimer_prepare,
 478         .start =        dummy_hrtimer_start,
 479         .stop =         dummy_hrtimer_stop,
 480         .pointer =      dummy_hrtimer_pointer,
 481 };
 482
 483 #endif /* CONFIG_HIGH_RES_TIMERS */
 484
 485 /*
 486  * PCM interface
 487  */
 488
 489 static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 490 {
 491         switch (cmd) {
 492         case SNDRV_PCM_TRIGGER_START:
 493         case SNDRV_PCM_TRIGGER_RESUME:
 494                 return get_dummy_ops(substream)->start(substream);
 495         case SNDRV_PCM_TRIGGER_STOP:
 496         case SNDRV_PCM_TRIGGER_SUSPEND:
 497                 return get_dummy_ops(substream)->stop(substream);
 498         }
 499         return -EINVAL;
 500 }
 501
 502 static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
 503 {
 504         return get_dummy_ops(substream)->prepare(substream);
 505 }
 506
 507 static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
 508 {
 509         return get_dummy_ops(substream)->pointer(substream);
 510 }
 511
 512 static const struct snd_pcm_hardware dummy_pcm_hardware = {
 513         .info =                 (SNDRV_PCM_INFO_MMAP |
 514                                  SNDRV_PCM_INFO_INTERLEAVED |
 515                                  SNDRV_PCM_INFO_RESUME |
 516                                  SNDRV_PCM_INFO_MMAP_VALID),
 517         .formats =              USE_FORMATS,
 518         .rates =                USE_RATE,
 519         .rate_min =             USE_RATE_MIN,
 520         .rate_max =             USE_RATE_MAX,
 521         .channels_min =         USE_CHANNELS_MIN,
 522         .channels_max =         USE_CHANNELS_MAX,
 523         .buffer_bytes_max =     MAX_BUFFER_SIZE,
 524         .period_bytes_min =     MIN_PERIOD_SIZE,
 525         .period_bytes_max =     MAX_PERIOD_SIZE,
 526         .periods_min =          USE_PERIODS_MIN,
 527         .periods_max =          USE_PERIODS_MAX,
 528         .fifo_size =            0,
 529 };
 530
 531 static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
 532                                struct snd_pcm_hw_params *hw_params)
 533 {
 534         if (fake_buffer) {
 535                 /* runtime->dma_bytes has to be set manually to allow mmap */
 536                 substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
 537                 return 0;
 538         }
 539         return 0;
 540 }
 541
 542 static int dummy_pcm_open(struct snd_pcm_substream *substream)
 543 {
 544         struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 545         const struct dummy_model *model = dummy->model;
 546         struct snd_pcm_runtime *runtime = substream->runtime;
 547         const struct dummy_timer_ops *ops;
 548         int err;
 549
 550         ops = &dummy_systimer_ops;
 551 #ifdef CONFIG_HIGH_RES_TIMERS
 552         if (hrtimer)
 553                 ops = &dummy_hrtimer_ops;
 554 #endif
 555
 556         err = ops->create(substream);
 557         if (err < 0)
 558                 return err;
 559         get_dummy_ops(substream) = ops;
 560
 561         runtime->hw = dummy->pcm_hw;
 562         if (substream->pcm->device & 1) {
 563                 runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
 564                 runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
 565         }
 566         if (substream->pcm->device & 2)
 567                 runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
 568                                       SNDRV_PCM_INFO_MMAP_VALID);
 569
 570         if (model == NULL)
 571                 return 0;
 572
 573         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 574                 if (model->playback_constraints)
 575                         err = model->playback_constraints(substream->runtime);
 576         } else {
 577                 if (model->capture_constraints)
 578                         err = model->capture_constraints(substream->runtime);
 579         }
 580         if (err < 0) {
 581                 get_dummy_ops(substream)->free(substream);
 582                 return err;
 583         }
 584         return 0;
 585 }
 586
 587 static int dummy_pcm_close(struct snd_pcm_substream *substream)
 588 {
 589         get_dummy_ops(substream)->free(substream);
 590         return 0;
 591 }
 592
 593 /*
 594  * dummy buffer handling
 595  */
 596
 597 static void *dummy_page[2];
 598
 599 static void free_fake_buffer(void)
 600 {
 601         if (fake_buffer) {
 602                 int i;
 603                 for (i = 0; i < 2; i++)
 604                         if (dummy_page[i]) {
 605                                 free_page((unsigned long)dummy_page[i]);
 606                                 dummy_page[i] = NULL;
 607                         }
 608         }
 609 }
 610
 611 static int alloc_fake_buffer(void)
 612 {
 613         int i;
 614
 615         if (!fake_buffer)
 616                 return 0;
 617         for (i = 0; i < 2; i++) {
 618                 dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
 619                 if (!dummy_page[i]) {
 620                         free_fake_buffer();
 621                         return -ENOMEM;
 622                 }
 623         }
 624         return 0;
 625 }
 626
 627 static int dummy_pcm_copy(struct snd_pcm_substream *substream,
 628                           int channel, unsigned long pos,
 629                           void __user *dst, unsigned long bytes)
 630 {
 631         return 0; /* do nothing */
 632 }
 633
 634 static int dummy_pcm_copy_kernel(struct snd_pcm_substream *substream,
 635                                  int channel, unsigned long pos,
 636                                  void *dst, unsigned long bytes)
 637 {
 638         return 0; /* do nothing */
 639 }
 640
 641 static int dummy_pcm_silence(struct snd_pcm_substream *substream,
 642                              int channel, unsigned long pos,
 643                              unsigned long bytes)
 644 {
 645         return 0; /* do nothing */
 646 }
 647
 648 static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
 649                                    unsigned long offset)
 650 {
 651         return virt_to_page(dummy_page[substream->stream]); /* the same page */
 652 }
 653
 654 static const struct snd_pcm_ops dummy_pcm_ops = {
 655         .open =         dummy_pcm_open,
 656         .close =        dummy_pcm_close,
 657         .hw_params =    dummy_pcm_hw_params,
 658         .prepare =      dummy_pcm_prepare,
 659         .trigger =      dummy_pcm_trigger,
 660         .pointer =      dummy_pcm_pointer,
 661 };
 662
 663 static const struct snd_pcm_ops dummy_pcm_ops_no_buf = {
 664         .open =         dummy_pcm_open,
 665         .close =        dummy_pcm_close,
 666         .hw_params =    dummy_pcm_hw_params,
 667         .prepare =      dummy_pcm_prepare,
 668         .trigger =      dummy_pcm_trigger,
 669         .pointer =      dummy_pcm_pointer,
 670         .copy_user =    dummy_pcm_copy,
 671         .copy_kernel =  dummy_pcm_copy_kernel,
 672         .fill_silence = dummy_pcm_silence,
 673         .page =         dummy_pcm_page,
 674 };
 675
 676 static int snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
 677                               int substreams)
 678 {
 679         struct snd_pcm *pcm;
 680         const struct snd_pcm_ops *ops;
 681         int err;
 682
 683         err = snd_pcm_new(dummy->card, "Dummy PCM", device,
 684                                substreams, substreams, &pcm);
 685         if (err < 0)
 686                 return err;
 687         dummy->pcm = pcm;
 688         if (fake_buffer)
 689                 ops = &dummy_pcm_ops_no_buf;
 690         else
 691                 ops = &dummy_pcm_ops;
 692         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
 693         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
 694         pcm->private_data = dummy;
 695         pcm->info_flags = 0;
 696         strcpy(pcm->name, "Dummy PCM");
 697         if (!fake_buffer) {
 698                 snd_pcm_set_managed_buffer_all(pcm,
 699                         SNDRV_DMA_TYPE_CONTINUOUS,
 700                         NULL,
 701                         0, 64*1024);
 702         }
 703         return 0;
 704 }
 705
 706 /*
 707  * mixer interface
 708  */
 709
 710 #define DUMMY_VOLUME(xname, xindex, addr) \
 711 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
 712   .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
 713   .name = xname, .index = xindex, \
 714   .info = snd_dummy_volume_info, \
 715   .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
 716   .private_value = addr, \
 717   .tlv = { .p = db_scale_dummy } }
 718
 719 static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
 720                                  struct snd_ctl_elem_info *uinfo)
 721 {
 722         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 723         uinfo->count = 2;
 724         uinfo->value.integer.min = mixer_volume_level_min;
 725         uinfo->value.integer.max = mixer_volume_level_max;
 726         return 0;
 727 }
 728
 729 static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
 730                                 struct snd_ctl_elem_value *ucontrol)
 731 {
 732         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 733         int addr = kcontrol->private_value;
 734
 735         spin_lock_irq(&dummy->mixer_lock);
 736         ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
 737         ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
 738         spin_unlock_irq(&dummy->mixer_lock);
 739         return 0;
 740 }
 741
 742 static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
 743                                 struct snd_ctl_elem_value *ucontrol)
 744 {
 745         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 746         int change, addr = kcontrol->private_value;
 747         int left, right;
 748
 749         left = ucontrol->value.integer.value[0];
 750         if (left < mixer_volume_level_min)
 751                 left = mixer_volume_level_min;
 752         if (left > mixer_volume_level_max)
 753                 left = mixer_volume_level_max;
 754         right = ucontrol->value.integer.value[1];
 755         if (right < mixer_volume_level_min)
 756                 right = mixer_volume_level_min;
 757         if (right > mixer_volume_level_max)
 758                 right = mixer_volume_level_max;
 759         spin_lock_irq(&dummy->mixer_lock);
 760         change = dummy->mixer_volume[addr][0] != left ||
 761                  dummy->mixer_volume[addr][1] != right;
 762         dummy->mixer_volume[addr][0] = left;
 763         dummy->mixer_volume[addr][1] = right;
 764         spin_unlock_irq(&dummy->mixer_lock);
 765         return change;
 766 }
 767
 768 static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
 769
 770 #define DUMMY_CAPSRC(xname, xindex, addr) \
 771 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
 772   .info = snd_dummy_capsrc_info, \
 773   .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
 774   .private_value = addr }
 775
 776 #define snd_dummy_capsrc_info   snd_ctl_boolean_stereo_info
 777
 778 static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
 779                                 struct snd_ctl_elem_value *ucontrol)
 780 {
 781         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 782         int addr = kcontrol->private_value;
 783
 784         spin_lock_irq(&dummy->mixer_lock);
 785         ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
 786         ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
 787         spin_unlock_irq(&dummy->mixer_lock);
 788         return 0;
 789 }
 790
 791 static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 792 {
 793         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 794         int change, addr = kcontrol->private_value;
 795         int left, right;
 796
 797         left = ucontrol->value.integer.value[0] & 1;
 798         right = ucontrol->value.integer.value[1] & 1;
 799         spin_lock_irq(&dummy->mixer_lock);
 800         change = dummy->capture_source[addr][0] != left &&
 801                  dummy->capture_source[addr][1] != right;
 802         dummy->capture_source[addr][0] = left;
 803         dummy->capture_source[addr][1] = right;
 804         spin_unlock_irq(&dummy->mixer_lock);
 805         return change;
 806 }
 807
 808 static int snd_dummy_iobox_info(struct snd_kcontrol *kcontrol,
 809                                 struct snd_ctl_elem_info *info)
 810 {
 811         static const char *const names[] = { "None", "CD Player" };
 812
 813         return snd_ctl_enum_info(info, 1, 2, names);
 814 }
 815
 816 static int snd_dummy_iobox_get(struct snd_kcontrol *kcontrol,
 817                                struct snd_ctl_elem_value *value)
 818 {
 819         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 820
 821         value->value.enumerated.item[0] = dummy->iobox;
 822         return 0;
 823 }
 824
 825 static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
 826                                struct snd_ctl_elem_value *value)
 827 {
 828         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 829         int changed;
 830
 831         if (value->value.enumerated.item[0] > 1)
 832                 return -EINVAL;
 833
 834         changed = value->value.enumerated.item[0] != dummy->iobox;
 835         if (changed) {
 836                 dummy->iobox = value->value.enumerated.item[0];
 837
 838                 if (dummy->iobox) {
 839                         dummy->cd_volume_ctl->vd[0].access &=
 840                                 ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 841                         dummy->cd_switch_ctl->vd[0].access &=
 842                                 ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 843                 } else {
 844                         dummy->cd_volume_ctl->vd[0].access |=
 845                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 846                         dummy->cd_switch_ctl->vd[0].access |=
 847                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 848                 }
 849
 850                 snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 851                                &dummy->cd_volume_ctl->id);
 852                 snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 853                                &dummy->cd_switch_ctl->id);
 854         }
 855
 856         return changed;
 857 }
 858
 859 static const struct snd_kcontrol_new snd_dummy_controls[] = {
 860 DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
 861 DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
 862 DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
 863 DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
 864 DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
 865 DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
 866 DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
 867 DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
 868 DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
 869 DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD),
 870 {
 871         .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 872         .name  = "External I/O Box",
 873         .info  = snd_dummy_iobox_info,
 874         .get   = snd_dummy_iobox_get,
 875         .put   = snd_dummy_iobox_put,
 876 },
 877 };
 878
 879 static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
 880 {
 881         struct snd_card *card = dummy->card;
 882         struct snd_kcontrol *kcontrol;
 883         unsigned int idx;
 884         int err;
 885
 886         spin_lock_init(&dummy->mixer_lock);
 887         strcpy(card->mixername, "Dummy Mixer");
 888         dummy->iobox = 1;
 889
 890         for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
 891                 kcontrol = snd_ctl_new1(&snd_dummy_controls[idx], dummy);
 892                 err = snd_ctl_add(card, kcontrol);
 893                 if (err < 0)
 894                         return err;
 895                 if (!strcmp(kcontrol->id.name, "CD Volume"))
 896                         dummy->cd_volume_ctl = kcontrol;
 897                 else if (!strcmp(kcontrol->id.name, "CD Capture Switch"))
 898                         dummy->cd_switch_ctl = kcontrol;
 899
 900         }
 901         return 0;
 902 }
 903
 904 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_PROC_FS)
 905 /*
 906  * proc interface
 907  */
 908 static void print_formats(struct snd_dummy *dummy,
 909                           struct snd_info_buffer *buffer)
 910 {
 911         snd_pcm_format_t i;
 912
 913         pcm_for_each_format(i) {
 914                 if (dummy->pcm_hw.formats & pcm_format_to_bits(i))
 915                         snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
 916         }
 917 }
 918
 919 static void print_rates(struct snd_dummy *dummy,
 920                         struct snd_info_buffer *buffer)
 921 {
 922         static const int rates[] = {
 923                 5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
 924                 64000, 88200, 96000, 176400, 192000,
 925         };
 926         int i;
 927
 928         if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_CONTINUOUS)
 929                 snd_iprintf(buffer, " continuous");
 930         if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_KNOT)
 931                 snd_iprintf(buffer, " knot");
 932         for (i = 0; i < ARRAY_SIZE(rates); i++)
 933                 if (dummy->pcm_hw.rates & (1 << i))
 934                         snd_iprintf(buffer, " %d", rates[i]);
 935 }
 936
 937 #define get_dummy_int_ptr(dummy, ofs) \
 938         (unsigned int *)((char *)&((dummy)->pcm_hw) + (ofs))
 939 #define get_dummy_ll_ptr(dummy, ofs) \
 940         (unsigned long long *)((char *)&((dummy)->pcm_hw) + (ofs))
 941
 942 struct dummy_hw_field {
 943         const char *name;
 944         const char *format;
 945         unsigned int offset;
 946         unsigned int size;
 947 };
 948 #define FIELD_ENTRY(item, fmt) {                   \
 949         .name = #item,                             \
 950         .format = fmt,                             \
 951         .offset = offsetof(struct snd_pcm_hardware, item), \
 952         .size = sizeof(dummy_pcm_hardware.item) }
 953
 954 static const struct dummy_hw_field fields[] = {
 955         FIELD_ENTRY(formats, "%#llx"),
 956         FIELD_ENTRY(rates, "%#x"),
 957         FIELD_ENTRY(rate_min, "%d"),
 958         FIELD_ENTRY(rate_max, "%d"),
 959         FIELD_ENTRY(channels_min, "%d"),
 960         FIELD_ENTRY(channels_max, "%d"),
 961         FIELD_ENTRY(buffer_bytes_max, "%ld"),
 962         FIELD_ENTRY(period_bytes_min, "%ld"),
 963         FIELD_ENTRY(period_bytes_max, "%ld"),
 964         FIELD_ENTRY(periods_min, "%d"),
 965         FIELD_ENTRY(periods_max, "%d"),
 966 };
 967
 968 static void dummy_proc_read(struct snd_info_entry *entry,
 969                             struct snd_info_buffer *buffer)
 970 {
 971         struct snd_dummy *dummy = entry->private_data;
 972         int i;
 973
 974         for (i = 0; i < ARRAY_SIZE(fields); i++) {
 975                 snd_iprintf(buffer, "%s ", fields[i].name);
 976                 if (fields[i].size == sizeof(int))
 977                         snd_iprintf(buffer, fields[i].format,
 978                                 *get_dummy_int_ptr(dummy, fields[i].offset));
 979                 else
 980                         snd_iprintf(buffer, fields[i].format,
 981                                 *get_dummy_ll_ptr(dummy, fields[i].offset));
 982                 if (!strcmp(fields[i].name, "formats"))
 983                         print_formats(dummy, buffer);
 984                 else if (!strcmp(fields[i].name, "rates"))
 985                         print_rates(dummy, buffer);
 986                 snd_iprintf(buffer, "\n");
 987         }
 988 }
 989
 990 static void dummy_proc_write(struct snd_info_entry *entry,
 991                              struct snd_info_buffer *buffer)
 992 {
 993         struct snd_dummy *dummy = entry->private_data;
 994         char line[64];
 995
 996         while (!snd_info_get_line(buffer, line, sizeof(line))) {
 997                 char item[20];
 998                 const char *ptr;
 999                 unsigned long long val;
1000                 int i;
1001
1002                 ptr = snd_info_get_str(item, line, sizeof(item));
1003                 for (i = 0; i < ARRAY_SIZE(fields); i++) {
1004                         if (!strcmp(item, fields[i].name))
1005                                 break;
1006                 }
1007                 if (i >= ARRAY_SIZE(fields))
1008                         continue;
1009                 snd_info_get_str(item, ptr, sizeof(item));
1010                 if (kstrtoull(item, 0, &val))
1011                         continue;
1012                 if (fields[i].size == sizeof(int))
1013                         *get_dummy_int_ptr(dummy, fields[i].offset) = val;
1014                 else
1015                         *get_dummy_ll_ptr(dummy, fields[i].offset) = val;
1016         }
1017 }
1018
1019 static void dummy_proc_init(struct snd_dummy *chip)
1020 {
1021         snd_card_rw_proc_new(chip->card, "dummy_pcm", chip,
1022                              dummy_proc_read, dummy_proc_write);
1023 }
1024 #else
1025 #define dummy_proc_init(x)
1026 #endif /* CONFIG_SND_DEBUG && CONFIG_SND_PROC_FS */
1027
1028 static int snd_dummy_probe(struct platform_device *devptr)
1029 {
1030         struct snd_card *card;
1031         struct snd_dummy *dummy;
1032         const struct dummy_model *m = NULL, **mdl;
1033         int idx, err;
1034         int dev = devptr->id;
1035
1036         err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1037                                 sizeof(struct snd_dummy), &card);
1038         if (err < 0)
1039                 return err;
1040         dummy = card->private_data;
1041         dummy->card = card;
1042         for (mdl = dummy_models; *mdl && model[dev]; mdl++) {
1043                 if (strcmp(model[dev], (*mdl)->name) == 0) {
1044                         printk(KERN_INFO
1045                                 "snd-dummy: Using model '%s' for card %i\n",
1046                                 (*mdl)->name, card->number);
1047                         m = dummy->model = *mdl;
1048                         break;
1049                 }
1050         }
1051         for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
1052                 if (pcm_substreams[dev] < 1)
1053                         pcm_substreams[dev] = 1;
1054                 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1055                         pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1056                 err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
1057                 if (err < 0)
1058                         return err;
1059         }
1060
1061         dummy->pcm_hw = dummy_pcm_hardware;
1062         if (m) {
1063                 if (m->formats)
1064                         dummy->pcm_hw.formats = m->formats;
1065                 if (m->buffer_bytes_max)
1066                         dummy->pcm_hw.buffer_bytes_max = m->buffer_bytes_max;
1067                 if (m->period_bytes_min)
1068                         dummy->pcm_hw.period_bytes_min = m->period_bytes_min;
1069                 if (m->period_bytes_max)
1070                         dummy->pcm_hw.period_bytes_max = m->period_bytes_max;
1071                 if (m->periods_min)
1072                         dummy->pcm_hw.periods_min = m->periods_min;
1073                 if (m->periods_max)
1074                         dummy->pcm_hw.periods_max = m->periods_max;
1075                 if (m->rates)
1076                         dummy->pcm_hw.rates = m->rates;
1077                 if (m->rate_min)
1078                         dummy->pcm_hw.rate_min = m->rate_min;
1079                 if (m->rate_max)
1080                         dummy->pcm_hw.rate_max = m->rate_max;
1081                 if (m->channels_min)
1082                         dummy->pcm_hw.channels_min = m->channels_min;
1083                 if (m->channels_max)
1084                         dummy->pcm_hw.channels_max = m->channels_max;
1085         }
1086
1087         if (mixer_volume_level_min > mixer_volume_level_max) {
1088                 pr_warn("snd-dummy: Invalid mixer volume level: min=%d, max=%d. Fall back to default value.\n",
1089                 mixer_volume_level_min, mixer_volume_level_max);
1090                 mixer_volume_level_min = USE_MIXER_VOLUME_LEVEL_MIN;
1091                 mixer_volume_level_max = USE_MIXER_VOLUME_LEVEL_MAX;
1092         }
1093         err = snd_card_dummy_new_mixer(dummy);
1094         if (err < 0)
1095                 return err;
1096         strcpy(card->driver, "Dummy");
1097         strcpy(card->shortname, "Dummy");
1098         sprintf(card->longname, "Dummy %i", dev + 1);
1099
1100         dummy_proc_init(dummy);
1101
1102         err = snd_card_register(card);
1103         if (err < 0)
1104                 return err;
1105         platform_set_drvdata(devptr, card);
1106         return 0;
1107 }
1108
1109 #ifdef CONFIG_PM_SLEEP
1110 static int snd_dummy_suspend(struct device *pdev)
1111 {
1112         struct snd_card *card = dev_get_drvdata(pdev);
1113
1114         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1115         return 0;
1116 }
1117
1118 static int snd_dummy_resume(struct device *pdev)
1119 {
1120         struct snd_card *card = dev_get_drvdata(pdev);
1121
1122         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1123         return 0;
1124 }
1125
1126 static SIMPLE_DEV_PM_OPS(snd_dummy_pm, snd_dummy_suspend, snd_dummy_resume);
1127 #define SND_DUMMY_PM_OPS        &snd_dummy_pm
1128 #else
1129 #define SND_DUMMY_PM_OPS        NULL
1130 #endif
1131
1132 #define SND_DUMMY_DRIVER        "snd_dummy"
1133
1134 static struct platform_driver snd_dummy_driver = {
1135         .probe          = snd_dummy_probe,
1136         .driver         = {
1137                 .name   = SND_DUMMY_DRIVER,
1138                 .pm     = SND_DUMMY_PM_OPS,
1139         },
1140 };
1141
1142 static void snd_dummy_unregister_all(void)
1143 {
1144         int i;
1145
1146         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1147                 platform_device_unregister(devices[i]);
1148         platform_driver_unregister(&snd_dummy_driver);
1149         free_fake_buffer();
1150 }
1151
1152 static int __init alsa_card_dummy_init(void)
1153 {
1154         int i, cards, err;
1155
1156         err = platform_driver_register(&snd_dummy_driver);
1157         if (err < 0)
1158                 return err;
1159
1160         err = alloc_fake_buffer();
1161         if (err < 0) {
1162                 platform_driver_unregister(&snd_dummy_driver);
1163                 return err;
1164         }
1165
1166         cards = 0;
1167         for (i = 0; i < SNDRV_CARDS; i++) {
1168                 struct platform_device *device;
1169                 if (! enable[i])
1170                         continue;
1171                 device = platform_device_register_simple(SND_DUMMY_DRIVER,
1172                                                          i, NULL, 0);
1173                 if (IS_ERR(device))
1174                         continue;
1175                 if (!platform_get_drvdata(device)) {
1176                         platform_device_unregister(device);
1177                         continue;
1178                 }
1179                 devices[i] = device;
1180                 cards++;
1181         }
1182         if (!cards) {
1183 #ifdef MODULE
1184                 printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1185 #endif
1186                 snd_dummy_unregister_all();
1187                 return -ENODEV;
1188         }
1189         return 0;
1190 }
1191
1192 static void __exit alsa_card_dummy_exit(void)
1193 {
1194         snd_dummy_unregister_all();
1195 }
1196
1197 module_init(alsa_card_dummy_init)
1198 module_exit(alsa_card_dummy_exit)