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                           struct iov_iter *iter, unsigned long bytes)
 630 {
 631         return 0; /* do nothing */
 632 }
 633
 634 static int dummy_pcm_silence(struct snd_pcm_substream *substream,
 635                              int channel, unsigned long pos,
 636                              unsigned long bytes)
 637 {
 638         return 0; /* do nothing */
 639 }
 640
 641 static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
 642                                    unsigned long offset)
 643 {
 644         return virt_to_page(dummy_page[substream->stream]); /* the same page */
 645 }
 646
 647 static const struct snd_pcm_ops dummy_pcm_ops = {
 648         .open =         dummy_pcm_open,
 649         .close =        dummy_pcm_close,
 650         .hw_params =    dummy_pcm_hw_params,
 651         .prepare =      dummy_pcm_prepare,
 652         .trigger =      dummy_pcm_trigger,
 653         .pointer =      dummy_pcm_pointer,
 654 };
 655
 656 static const struct snd_pcm_ops dummy_pcm_ops_no_buf = {
 657         .open =         dummy_pcm_open,
 658         .close =        dummy_pcm_close,
 659         .hw_params =    dummy_pcm_hw_params,
 660         .prepare =      dummy_pcm_prepare,
 661         .trigger =      dummy_pcm_trigger,
 662         .pointer =      dummy_pcm_pointer,
 663         .copy =         dummy_pcm_copy,
 664         .fill_silence = dummy_pcm_silence,
 665         .page =         dummy_pcm_page,
 666 };
 667
 668 static int snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
 669                               int substreams)
 670 {
 671         struct snd_pcm *pcm;
 672         const struct snd_pcm_ops *ops;
 673         int err;
 674
 675         err = snd_pcm_new(dummy->card, "Dummy PCM", device,
 676                                substreams, substreams, &pcm);
 677         if (err < 0)
 678                 return err;
 679         dummy->pcm = pcm;
 680         if (fake_buffer)
 681                 ops = &dummy_pcm_ops_no_buf;
 682         else
 683                 ops = &dummy_pcm_ops;
 684         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
 685         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
 686         pcm->private_data = dummy;
 687         pcm->info_flags = 0;
 688         strcpy(pcm->name, "Dummy PCM");
 689         if (!fake_buffer) {
 690                 snd_pcm_set_managed_buffer_all(pcm,
 691                         SNDRV_DMA_TYPE_CONTINUOUS,
 692                         NULL,
 693                         0, 64*1024);
 694         }
 695         return 0;
 696 }
 697
 698 /*
 699  * mixer interface
 700  */
 701
 702 #define DUMMY_VOLUME(xname, xindex, addr) \
 703 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
 704   .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
 705   .name = xname, .index = xindex, \
 706   .info = snd_dummy_volume_info, \
 707   .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
 708   .private_value = addr, \
 709   .tlv = { .p = db_scale_dummy } }
 710
 711 static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
 712                                  struct snd_ctl_elem_info *uinfo)
 713 {
 714         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 715         uinfo->count = 2;
 716         uinfo->value.integer.min = mixer_volume_level_min;
 717         uinfo->value.integer.max = mixer_volume_level_max;
 718         return 0;
 719 }
 720
 721 static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
 722                                 struct snd_ctl_elem_value *ucontrol)
 723 {
 724         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 725         int addr = kcontrol->private_value;
 726
 727         spin_lock_irq(&dummy->mixer_lock);
 728         ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
 729         ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
 730         spin_unlock_irq(&dummy->mixer_lock);
 731         return 0;
 732 }
 733
 734 static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
 735                                 struct snd_ctl_elem_value *ucontrol)
 736 {
 737         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 738         int change, addr = kcontrol->private_value;
 739         int left, right;
 740
 741         left = ucontrol->value.integer.value[0];
 742         if (left < mixer_volume_level_min)
 743                 left = mixer_volume_level_min;
 744         if (left > mixer_volume_level_max)
 745                 left = mixer_volume_level_max;
 746         right = ucontrol->value.integer.value[1];
 747         if (right < mixer_volume_level_min)
 748                 right = mixer_volume_level_min;
 749         if (right > mixer_volume_level_max)
 750                 right = mixer_volume_level_max;
 751         spin_lock_irq(&dummy->mixer_lock);
 752         change = dummy->mixer_volume[addr][0] != left ||
 753                  dummy->mixer_volume[addr][1] != right;
 754         dummy->mixer_volume[addr][0] = left;
 755         dummy->mixer_volume[addr][1] = right;
 756         spin_unlock_irq(&dummy->mixer_lock);
 757         return change;
 758 }
 759
 760 static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
 761
 762 #define DUMMY_CAPSRC(xname, xindex, addr) \
 763 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
 764   .info = snd_dummy_capsrc_info, \
 765   .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
 766   .private_value = addr }
 767
 768 #define snd_dummy_capsrc_info   snd_ctl_boolean_stereo_info
 769
 770 static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
 771                                 struct snd_ctl_elem_value *ucontrol)
 772 {
 773         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 774         int addr = kcontrol->private_value;
 775
 776         spin_lock_irq(&dummy->mixer_lock);
 777         ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
 778         ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
 779         spin_unlock_irq(&dummy->mixer_lock);
 780         return 0;
 781 }
 782
 783 static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 784 {
 785         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 786         int change, addr = kcontrol->private_value;
 787         int left, right;
 788
 789         left = ucontrol->value.integer.value[0] & 1;
 790         right = ucontrol->value.integer.value[1] & 1;
 791         spin_lock_irq(&dummy->mixer_lock);
 792         change = dummy->capture_source[addr][0] != left &&
 793                  dummy->capture_source[addr][1] != right;
 794         dummy->capture_source[addr][0] = left;
 795         dummy->capture_source[addr][1] = right;
 796         spin_unlock_irq(&dummy->mixer_lock);
 797         return change;
 798 }
 799
 800 static int snd_dummy_iobox_info(struct snd_kcontrol *kcontrol,
 801                                 struct snd_ctl_elem_info *info)
 802 {
 803         static const char *const names[] = { "None", "CD Player" };
 804
 805         return snd_ctl_enum_info(info, 1, 2, names);
 806 }
 807
 808 static int snd_dummy_iobox_get(struct snd_kcontrol *kcontrol,
 809                                struct snd_ctl_elem_value *value)
 810 {
 811         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 812
 813         value->value.enumerated.item[0] = dummy->iobox;
 814         return 0;
 815 }
 816
 817 static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
 818                                struct snd_ctl_elem_value *value)
 819 {
 820         struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 821         int changed;
 822
 823         if (value->value.enumerated.item[0] > 1)
 824                 return -EINVAL;
 825
 826         changed = value->value.enumerated.item[0] != dummy->iobox;
 827         if (changed) {
 828                 dummy->iobox = value->value.enumerated.item[0];
 829
 830                 if (dummy->iobox) {
 831                         dummy->cd_volume_ctl->vd[0].access &=
 832                                 ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 833                         dummy->cd_switch_ctl->vd[0].access &=
 834                                 ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 835                 } else {
 836                         dummy->cd_volume_ctl->vd[0].access |=
 837                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 838                         dummy->cd_switch_ctl->vd[0].access |=
 839                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 840                 }
 841
 842                 snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 843                                &dummy->cd_volume_ctl->id);
 844                 snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 845                                &dummy->cd_switch_ctl->id);
 846         }
 847
 848         return changed;
 849 }
 850
 851 static const struct snd_kcontrol_new snd_dummy_controls[] = {
 852 DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
 853 DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
 854 DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
 855 DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
 856 DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
 857 DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
 858 DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
 859 DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
 860 DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
 861 DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD),
 862 {
 863         .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 864         .name  = "External I/O Box",
 865         .info  = snd_dummy_iobox_info,
 866         .get   = snd_dummy_iobox_get,
 867         .put   = snd_dummy_iobox_put,
 868 },
 869 };
 870
 871 static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
 872 {
 873         struct snd_card *card = dummy->card;
 874         struct snd_kcontrol *kcontrol;
 875         unsigned int idx;
 876         int err;
 877
 878         spin_lock_init(&dummy->mixer_lock);
 879         strcpy(card->mixername, "Dummy Mixer");
 880         dummy->iobox = 1;
 881
 882         for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
 883                 kcontrol = snd_ctl_new1(&snd_dummy_controls[idx], dummy);
 884                 err = snd_ctl_add(card, kcontrol);
 885                 if (err < 0)
 886                         return err;
 887                 if (!strcmp(kcontrol->id.name, "CD Volume"))
 888                         dummy->cd_volume_ctl = kcontrol;
 889                 else if (!strcmp(kcontrol->id.name, "CD Capture Switch"))
 890                         dummy->cd_switch_ctl = kcontrol;
 891
 892         }
 893         return 0;
 894 }
 895
 896 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_PROC_FS)
 897 /*
 898  * proc interface
 899  */
 900 static void print_formats(struct snd_dummy *dummy,
 901                           struct snd_info_buffer *buffer)
 902 {
 903         snd_pcm_format_t i;
 904
 905         pcm_for_each_format(i) {
 906                 if (dummy->pcm_hw.formats & pcm_format_to_bits(i))
 907                         snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
 908         }
 909 }
 910
 911 static void print_rates(struct snd_dummy *dummy,
 912                         struct snd_info_buffer *buffer)
 913 {
 914         static const int rates[] = {
 915                 5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
 916                 64000, 88200, 96000, 176400, 192000,
 917         };
 918         int i;
 919
 920         if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_CONTINUOUS)
 921                 snd_iprintf(buffer, " continuous");
 922         if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_KNOT)
 923                 snd_iprintf(buffer, " knot");
 924         for (i = 0; i < ARRAY_SIZE(rates); i++)
 925                 if (dummy->pcm_hw.rates & (1 << i))
 926                         snd_iprintf(buffer, " %d", rates[i]);
 927 }
 928
 929 #define get_dummy_int_ptr(dummy, ofs) \
 930         (unsigned int *)((char *)&((dummy)->pcm_hw) + (ofs))
 931 #define get_dummy_ll_ptr(dummy, ofs) \
 932         (unsigned long long *)((char *)&((dummy)->pcm_hw) + (ofs))
 933
 934 struct dummy_hw_field {
 935         const char *name;
 936         const char *format;
 937         unsigned int offset;
 938         unsigned int size;
 939 };
 940 #define FIELD_ENTRY(item, fmt) {                   \
 941         .name = #item,                             \
 942         .format = fmt,                             \
 943         .offset = offsetof(struct snd_pcm_hardware, item), \
 944         .size = sizeof(dummy_pcm_hardware.item) }
 945
 946 static const struct dummy_hw_field fields[] = {
 947         FIELD_ENTRY(formats, "%#llx"),
 948         FIELD_ENTRY(rates, "%#x"),
 949         FIELD_ENTRY(rate_min, "%d"),
 950         FIELD_ENTRY(rate_max, "%d"),
 951         FIELD_ENTRY(channels_min, "%d"),
 952         FIELD_ENTRY(channels_max, "%d"),
 953         FIELD_ENTRY(buffer_bytes_max, "%ld"),
 954         FIELD_ENTRY(period_bytes_min, "%ld"),
 955         FIELD_ENTRY(period_bytes_max, "%ld"),
 956         FIELD_ENTRY(periods_min, "%d"),
 957         FIELD_ENTRY(periods_max, "%d"),
 958 };
 959
 960 static void dummy_proc_read(struct snd_info_entry *entry,
 961                             struct snd_info_buffer *buffer)
 962 {
 963         struct snd_dummy *dummy = entry->private_data;
 964         int i;
 965
 966         for (i = 0; i < ARRAY_SIZE(fields); i++) {
 967                 snd_iprintf(buffer, "%s ", fields[i].name);
 968                 if (fields[i].size == sizeof(int))
 969                         snd_iprintf(buffer, fields[i].format,
 970                                 *get_dummy_int_ptr(dummy, fields[i].offset));
 971                 else
 972                         snd_iprintf(buffer, fields[i].format,
 973                                 *get_dummy_ll_ptr(dummy, fields[i].offset));
 974                 if (!strcmp(fields[i].name, "formats"))
 975                         print_formats(dummy, buffer);
 976                 else if (!strcmp(fields[i].name, "rates"))
 977                         print_rates(dummy, buffer);
 978                 snd_iprintf(buffer, "\n");
 979         }
 980 }
 981
 982 static void dummy_proc_write(struct snd_info_entry *entry,
 983                              struct snd_info_buffer *buffer)
 984 {
 985         struct snd_dummy *dummy = entry->private_data;
 986         char line[64];
 987
 988         while (!snd_info_get_line(buffer, line, sizeof(line))) {
 989                 char item[20];
 990                 const char *ptr;
 991                 unsigned long long val;
 992                 int i;
 993
 994                 ptr = snd_info_get_str(item, line, sizeof(item));
 995                 for (i = 0; i < ARRAY_SIZE(fields); i++) {
 996                         if (!strcmp(item, fields[i].name))
 997                                 break;
 998                 }
 999                 if (i >= ARRAY_SIZE(fields))
1000                         continue;
1001                 snd_info_get_str(item, ptr, sizeof(item));
1002                 if (kstrtoull(item, 0, &val))
1003                         continue;
1004                 if (fields[i].size == sizeof(int))
1005                         *get_dummy_int_ptr(dummy, fields[i].offset) = val;
1006                 else
1007                         *get_dummy_ll_ptr(dummy, fields[i].offset) = val;
1008         }
1009 }
1010
1011 static void dummy_proc_init(struct snd_dummy *chip)
1012 {
1013         snd_card_rw_proc_new(chip->card, "dummy_pcm", chip,
1014                              dummy_proc_read, dummy_proc_write);
1015 }
1016 #else
1017 #define dummy_proc_init(x)
1018 #endif /* CONFIG_SND_DEBUG && CONFIG_SND_PROC_FS */
1019
1020 static int snd_dummy_probe(struct platform_device *devptr)
1021 {
1022         struct snd_card *card;
1023         struct snd_dummy *dummy;
1024         const struct dummy_model *m = NULL, **mdl;
1025         int idx, err;
1026         int dev = devptr->id;
1027
1028         err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1029                                 sizeof(struct snd_dummy), &card);
1030         if (err < 0)
1031                 return err;
1032         dummy = card->private_data;
1033         dummy->card = card;
1034         for (mdl = dummy_models; *mdl && model[dev]; mdl++) {
1035                 if (strcmp(model[dev], (*mdl)->name) == 0) {
1036                         printk(KERN_INFO
1037                                 "snd-dummy: Using model '%s' for card %i\n",
1038                                 (*mdl)->name, card->number);
1039                         m = dummy->model = *mdl;
1040                         break;
1041                 }
1042         }
1043         for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
1044                 if (pcm_substreams[dev] < 1)
1045                         pcm_substreams[dev] = 1;
1046                 if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1047                         pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1048                 err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
1049                 if (err < 0)
1050                         return err;
1051         }
1052
1053         dummy->pcm_hw = dummy_pcm_hardware;
1054         if (m) {
1055                 if (m->formats)
1056                         dummy->pcm_hw.formats = m->formats;
1057                 if (m->buffer_bytes_max)
1058                         dummy->pcm_hw.buffer_bytes_max = m->buffer_bytes_max;
1059                 if (m->period_bytes_min)
1060                         dummy->pcm_hw.period_bytes_min = m->period_bytes_min;
1061                 if (m->period_bytes_max)
1062                         dummy->pcm_hw.period_bytes_max = m->period_bytes_max;
1063                 if (m->periods_min)
1064                         dummy->pcm_hw.periods_min = m->periods_min;
1065                 if (m->periods_max)
1066                         dummy->pcm_hw.periods_max = m->periods_max;
1067                 if (m->rates)
1068                         dummy->pcm_hw.rates = m->rates;
1069                 if (m->rate_min)
1070                         dummy->pcm_hw.rate_min = m->rate_min;
1071                 if (m->rate_max)
1072                         dummy->pcm_hw.rate_max = m->rate_max;
1073                 if (m->channels_min)
1074                         dummy->pcm_hw.channels_min = m->channels_min;
1075                 if (m->channels_max)
1076                         dummy->pcm_hw.channels_max = m->channels_max;
1077         }
1078
1079         if (mixer_volume_level_min > mixer_volume_level_max) {
1080                 pr_warn("snd-dummy: Invalid mixer volume level: min=%d, max=%d. Fall back to default value.\n",
1081                 mixer_volume_level_min, mixer_volume_level_max);
1082                 mixer_volume_level_min = USE_MIXER_VOLUME_LEVEL_MIN;
1083                 mixer_volume_level_max = USE_MIXER_VOLUME_LEVEL_MAX;
1084         }
1085         err = snd_card_dummy_new_mixer(dummy);
1086         if (err < 0)
1087                 return err;
1088         strcpy(card->driver, "Dummy");
1089         strcpy(card->shortname, "Dummy");
1090         sprintf(card->longname, "Dummy %i", dev + 1);
1091
1092         dummy_proc_init(dummy);
1093
1094         err = snd_card_register(card);
1095         if (err < 0)
1096                 return err;
1097         platform_set_drvdata(devptr, card);
1098         return 0;
1099 }
1100
1101 static int snd_dummy_suspend(struct device *pdev)
1102 {
1103         struct snd_card *card = dev_get_drvdata(pdev);
1104
1105         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1106         return 0;
1107 }
1108
1109 static int snd_dummy_resume(struct device *pdev)
1110 {
1111         struct snd_card *card = dev_get_drvdata(pdev);
1112
1113         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1114         return 0;
1115 }
1116
1117 static DEFINE_SIMPLE_DEV_PM_OPS(snd_dummy_pm, snd_dummy_suspend, snd_dummy_resume);
1118
1119 #define SND_DUMMY_DRIVER        "snd_dummy"
1120
1121 static struct platform_driver snd_dummy_driver = {
1122         .probe          = snd_dummy_probe,
1123         .driver         = {
1124                 .name   = SND_DUMMY_DRIVER,
1125                 .pm     = &snd_dummy_pm,
1126         },
1127 };
1128
1129 static void snd_dummy_unregister_all(void)
1130 {
1131         int i;
1132
1133         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1134                 platform_device_unregister(devices[i]);
1135         platform_driver_unregister(&snd_dummy_driver);
1136         free_fake_buffer();
1137 }
1138
1139 static int __init alsa_card_dummy_init(void)
1140 {
1141         int i, cards, err;
1142
1143         err = platform_driver_register(&snd_dummy_driver);
1144         if (err < 0)
1145                 return err;
1146
1147         err = alloc_fake_buffer();
1148         if (err < 0) {
1149                 platform_driver_unregister(&snd_dummy_driver);
1150                 return err;
1151         }
1152
1153         cards = 0;
1154         for (i = 0; i < SNDRV_CARDS; i++) {
1155                 struct platform_device *device;
1156                 if (! enable[i])
1157                         continue;
1158                 device = platform_device_register_simple(SND_DUMMY_DRIVER,
1159                                                          i, NULL, 0);
1160                 if (IS_ERR(device))
1161                         continue;
1162                 if (!platform_get_drvdata(device)) {
1163                         platform_device_unregister(device);
1164                         continue;
1165                 }
1166                 devices[i] = device;
1167                 cards++;
1168         }
1169         if (!cards) {
1170 #ifdef MODULE
1171                 printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1172 #endif
1173                 snd_dummy_unregister_all();
1174                 return -ENODEV;
1175         }
1176         return 0;
1177 }
1178
1179 static void __exit alsa_card_dummy_exit(void)
1180 {
1181         snd_dummy_unregister_all();
1182 }
1183
1184 module_init(alsa_card_dummy_init)
1185 module_exit(alsa_card_dummy_exit)