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