linux/sound/drivers/dummy.c
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   1/*
   2 *  Dummy soundcard
   3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4 *
   5 *   This program is free software; you can redistribute it and/or modify
   6 *   it under the terms of the GNU General Public License as published by
   7 *   the Free Software Foundation; either version 2 of the License, or
   8 *   (at your option) any later version.
   9 *
  10 *   This program is distributed in the hope that it will be useful,
  11 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 *   GNU General Public License for more details.
  14 *
  15 *   You should have received a copy of the GNU General Public License
  16 *   along with this program; if not, write to the Free Software
  17 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18 *
  19 */
  20
  21#include <linux/init.h>
  22#include <linux/err.h>
  23#include <linux/platform_device.h>
  24#include <linux/jiffies.h>
  25#include <linux/slab.h>
  26#include <linux/time.h>
  27#include <linux/wait.h>
  28#include <linux/hrtimer.h>
  29#include <linux/math64.h>
  30#include <linux/module.h>
  31#include <sound/core.h>
  32#include <sound/control.h>
  33#include <sound/tlv.h>
  34#include <sound/pcm.h>
  35#include <sound/rawmidi.h>
  36#include <sound/info.h>
  37#include <sound/initval.h>
  38
  39MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  40MODULE_DESCRIPTION("Dummy soundcard (/dev/null)");
  41MODULE_LICENSE("GPL");
  42MODULE_SUPPORTED_DEVICE("{{ALSA,Dummy soundcard}}");
  43
  44#define MAX_PCM_DEVICES         4
  45#define MAX_PCM_SUBSTREAMS      128
  46#define MAX_MIDI_DEVICES        2
  47
  48/* defaults */
  49#define MAX_BUFFER_SIZE         (64*1024)
  50#define MIN_PERIOD_SIZE         64
  51#define MAX_PERIOD_SIZE         MAX_BUFFER_SIZE
  52#define USE_FORMATS             (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE)
  53#define USE_RATE                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000
  54#define USE_RATE_MIN            5500
  55#define USE_RATE_MAX            48000
  56#define USE_CHANNELS_MIN        1
  57#define USE_CHANNELS_MAX        2
  58#define USE_PERIODS_MIN         1
  59#define USE_PERIODS_MAX         1024
  60
  61static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  62static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  63static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  64static char *model[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = NULL};
  65static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
  66static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  67//static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
  68#ifdef CONFIG_HIGH_RES_TIMERS
  69static bool hrtimer = 1;
  70#endif
  71static bool fake_buffer = 1;
  72
  73module_param_array(index, int, NULL, 0444);
  74MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
  75module_param_array(id, charp, NULL, 0444);
  76MODULE_PARM_DESC(id, "ID string for dummy soundcard.");
  77module_param_array(enable, bool, NULL, 0444);
  78MODULE_PARM_DESC(enable, "Enable this dummy soundcard.");
  79module_param_array(model, charp, NULL, 0444);
  80MODULE_PARM_DESC(model, "Soundcard model.");
  81module_param_array(pcm_devs, int, NULL, 0444);
  82MODULE_PARM_DESC(pcm_devs, "PCM devices # (0-4) for dummy driver.");
  83module_param_array(pcm_substreams, int, NULL, 0444);
  84MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
  85//module_param_array(midi_devs, int, NULL, 0444);
  86//MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
  87module_param(fake_buffer, bool, 0444);
  88MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
  89#ifdef CONFIG_HIGH_RES_TIMERS
  90module_param(hrtimer, bool, 0644);
  91MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
  92#endif
  93
  94static struct platform_device *devices[SNDRV_CARDS];
  95
  96#define MIXER_ADDR_MASTER       0
  97#define MIXER_ADDR_LINE         1
  98#define MIXER_ADDR_MIC          2
  99#define MIXER_ADDR_SYNTH        3
 100#define MIXER_ADDR_CD           4
 101#define MIXER_ADDR_LAST         4
 102
 103struct dummy_timer_ops {
 104        int (*create)(struct snd_pcm_substream *);
 105        void (*free)(struct snd_pcm_substream *);
 106        int (*prepare)(struct snd_pcm_substream *);
 107        int (*start)(struct snd_pcm_substream *);
 108        int (*stop)(struct snd_pcm_substream *);
 109        snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
 110};
 111
 112#define get_dummy_ops(substream) \
 113        (*(const struct dummy_timer_ops **)(substream)->runtime->private_data)
 114
 115struct dummy_model {
 116        const char *name;
 117        int (*playback_constraints)(struct snd_pcm_runtime *runtime);
 118        int (*capture_constraints)(struct snd_pcm_runtime *runtime);
 119        u64 formats;
 120        size_t buffer_bytes_max;
 121        size_t period_bytes_min;
 122        size_t period_bytes_max;
 123        unsigned int periods_min;
 124        unsigned int periods_max;
 125        unsigned int rates;
 126        unsigned int rate_min;
 127        unsigned int rate_max;
 128        unsigned int channels_min;
 129        unsigned int channels_max;
 130};
 131
 132struct snd_dummy {
 133        struct snd_card *card;
 134        struct dummy_model *model;
 135        struct snd_pcm *pcm;
 136        struct snd_pcm_hardware pcm_hw;
 137        spinlock_t mixer_lock;
 138        int mixer_volume[MIXER_ADDR_LAST+1][2];
 139        int capture_source[MIXER_ADDR_LAST+1][2];
 140        int iobox;
 141        struct snd_kcontrol *cd_volume_ctl;
 142        struct snd_kcontrol *cd_switch_ctl;
 143};
 144
 145/*
 146 * card models
 147 */
 148
 149static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
 150{
 151        int err;
 152        err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 153        if (err < 0)
 154                return err;
 155        err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX);
 156        if (err < 0)
 157                return err;
 158        return 0;
 159}
 160
 161static struct dummy_model model_emu10k1 = {
 162        .name = "emu10k1",
 163        .playback_constraints = emu10k1_playback_constraints,
 164        .buffer_bytes_max = 128 * 1024,
 165};
 166
 167static struct dummy_model model_rme9652 = {
 168        .name = "rme9652",
 169        .buffer_bytes_max = 26 * 64 * 1024,
 170        .formats = SNDRV_PCM_FMTBIT_S32_LE,
 171        .channels_min = 26,
 172        .channels_max = 26,
 173        .periods_min = 2,
 174        .periods_max = 2,
 175};
 176
 177static struct dummy_model model_ice1712 = {
 178        .name = "ice1712",
 179        .buffer_bytes_max = 256 * 1024,
 180        .formats = SNDRV_PCM_FMTBIT_S32_LE,
 181        .channels_min = 10,
 182        .channels_max = 10,
 183        .periods_min = 1,
 184        .periods_max = 1024,
 185};
 186
 187static struct dummy_model model_uda1341 = {
 188        .name = "uda1341",
 189        .buffer_bytes_max = 16380,
 190        .formats = SNDRV_PCM_FMTBIT_S16_LE,
 191        .channels_min = 2,
 192        .channels_max = 2,
 193        .periods_min = 2,
 194        .periods_max = 255,
 195};
 196
 197static struct dummy_model model_ac97 = {
 198        .name = "ac97",
 199        .formats = SNDRV_PCM_FMTBIT_S16_LE,
 200        .channels_min = 2,
 201        .channels_max = 2,
 202        .rates = SNDRV_PCM_RATE_48000,
 203        .rate_min = 48000,
 204        .rate_max = 48000,
 205};
 206
 207static struct dummy_model model_ca0106 = {
 208        .name = "ca0106",
 209        .formats = SNDRV_PCM_FMTBIT_S16_LE,
 210        .buffer_bytes_max = ((65536-64)*8),
 211        .period_bytes_max = (65536-64),
 212        .periods_min = 2,
 213        .periods_max = 8,
 214        .channels_min = 2,
 215        .channels_max = 2,
 216        .rates = SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_96000|SNDRV_PCM_RATE_192000,
 217        .rate_min = 48000,
 218        .rate_max = 192000,
 219};
 220
 221static struct dummy_model *dummy_models[] = {
 222        &model_emu10k1,
 223        &model_rme9652,
 224        &model_ice1712,
 225        &model_uda1341,
 226        &model_ac97,
 227        &model_ca0106,
 228        NULL
 229};
 230
 231/*
 232 * system timer interface
 233 */
 234
 235struct dummy_systimer_pcm {
 236        /* ops must be the first item */
 237        const struct dummy_timer_ops *timer_ops;
 238        spinlock_t lock;
 239        struct timer_list timer;
 240        unsigned long base_time;
 241        unsigned int frac_pos;  /* fractional sample position (based HZ) */
 242        unsigned int frac_period_rest;
 243        unsigned int frac_buffer_size;  /* buffer_size * HZ */
 244        unsigned int frac_period_size;  /* period_size * HZ */
 245        unsigned int rate;
 246        int elapsed;
 247        struct snd_pcm_substream *substream;
 248};
 249
 250static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
 251{
 252        mod_timer(&dpcm->timer, jiffies +
 253                (dpcm->frac_period_rest + dpcm->rate - 1) / dpcm->rate);
 254}
 255
 256static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
 257{
 258        unsigned long delta;
 259
 260        delta = jiffies - dpcm->base_time;
 261        if (!delta)
 262                return;
 263        dpcm->base_time += delta;
 264        delta *= dpcm->rate;
 265        dpcm->frac_pos += delta;
 266        while (dpcm->frac_pos >= dpcm->frac_buffer_size)
 267                dpcm->frac_pos -= dpcm->frac_buffer_size;
 268        while (dpcm->frac_period_rest <= delta) {
 269                dpcm->elapsed++;
 270                dpcm->frac_period_rest += dpcm->frac_period_size;
 271        }
 272        dpcm->frac_period_rest -= delta;
 273}
 274
 275static int dummy_systimer_start(struct snd_pcm_substream *substream)
 276{
 277        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 278        spin_lock(&dpcm->lock);
 279        dpcm->base_time = jiffies;
 280        dummy_systimer_rearm(dpcm);
 281        spin_unlock(&dpcm->lock);
 282        return 0;
 283}
 284
 285static int dummy_systimer_stop(struct snd_pcm_substream *substream)
 286{
 287        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 288        spin_lock(&dpcm->lock);
 289        del_timer(&dpcm->timer);
 290        spin_unlock(&dpcm->lock);
 291        return 0;
 292}
 293
 294static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
 295{
 296        struct snd_pcm_runtime *runtime = substream->runtime;
 297        struct dummy_systimer_pcm *dpcm = runtime->private_data;
 298
 299        dpcm->frac_pos = 0;
 300        dpcm->rate = runtime->rate;
 301        dpcm->frac_buffer_size = runtime->buffer_size * HZ;
 302        dpcm->frac_period_size = runtime->period_size * HZ;
 303        dpcm->frac_period_rest = dpcm->frac_period_size;
 304        dpcm->elapsed = 0;
 305
 306        return 0;
 307}
 308
 309static void dummy_systimer_callback(unsigned long data)
 310{
 311        struct dummy_systimer_pcm *dpcm = (struct dummy_systimer_pcm *)data;
 312        unsigned long flags;
 313        int elapsed = 0;
 314        
 315        spin_lock_irqsave(&dpcm->lock, flags);
 316        dummy_systimer_update(dpcm);
 317        dummy_systimer_rearm(dpcm);
 318        elapsed = dpcm->elapsed;
 319        dpcm->elapsed = 0;
 320        spin_unlock_irqrestore(&dpcm->lock, flags);
 321        if (elapsed)
 322                snd_pcm_period_elapsed(dpcm->substream);
 323}
 324
 325static snd_pcm_uframes_t
 326dummy_systimer_pointer(struct snd_pcm_substream *substream)
 327{
 328        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 329        snd_pcm_uframes_t pos;
 330
 331        spin_lock(&dpcm->lock);
 332        dummy_systimer_update(dpcm);
 333        pos = dpcm->frac_pos / HZ;
 334        spin_unlock(&dpcm->lock);
 335        return pos;
 336}
 337
 338static int dummy_systimer_create(struct snd_pcm_substream *substream)
 339{
 340        struct dummy_systimer_pcm *dpcm;
 341
 342        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 343        if (!dpcm)
 344                return -ENOMEM;
 345        substream->runtime->private_data = dpcm;
 346        setup_timer(&dpcm->timer, dummy_systimer_callback,
 347                        (unsigned long) dpcm);
 348        spin_lock_init(&dpcm->lock);
 349        dpcm->substream = substream;
 350        return 0;
 351}
 352
 353static void dummy_systimer_free(struct snd_pcm_substream *substream)
 354{
 355        kfree(substream->runtime->private_data);
 356}
 357
 358static const struct dummy_timer_ops dummy_systimer_ops = {
 359        .create =       dummy_systimer_create,
 360        .free =         dummy_systimer_free,
 361        .prepare =      dummy_systimer_prepare,
 362        .start =        dummy_systimer_start,
 363        .stop =         dummy_systimer_stop,
 364        .pointer =      dummy_systimer_pointer,
 365};
 366
 367#ifdef CONFIG_HIGH_RES_TIMERS
 368/*
 369 * hrtimer interface
 370 */
 371
 372struct dummy_hrtimer_pcm {
 373        /* ops must be the first item */
 374        const struct dummy_timer_ops *timer_ops;
 375        ktime_t base_time;
 376        ktime_t period_time;
 377        atomic_t running;
 378        struct hrtimer timer;
 379        struct tasklet_struct tasklet;
 380        struct snd_pcm_substream *substream;
 381};
 382
 383static void dummy_hrtimer_pcm_elapsed(unsigned long priv)
 384{
 385        struct dummy_hrtimer_pcm *dpcm = (struct dummy_hrtimer_pcm *)priv;
 386        if (atomic_read(&dpcm->running))
 387                snd_pcm_period_elapsed(dpcm->substream);
 388}
 389
 390static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
 391{
 392        struct dummy_hrtimer_pcm *dpcm;
 393
 394        dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
 395        if (!atomic_read(&dpcm->running))
 396                return HRTIMER_NORESTART;
 397        tasklet_schedule(&dpcm->tasklet);
 398        hrtimer_forward_now(timer, dpcm->period_time);
 399        return HRTIMER_RESTART;
 400}
 401
 402static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
 403{
 404        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 405
 406        dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
 407        hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL);
 408        atomic_set(&dpcm->running, 1);
 409        return 0;
 410}
 411
 412static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
 413{
 414        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 415
 416        atomic_set(&dpcm->running, 0);
 417        hrtimer_cancel(&dpcm->timer);
 418        return 0;
 419}
 420
 421static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
 422{
 423        hrtimer_cancel(&dpcm->timer);
 424        tasklet_kill(&dpcm->tasklet);
 425}
 426
 427static snd_pcm_uframes_t
 428dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
 429{
 430        struct snd_pcm_runtime *runtime = substream->runtime;
 431        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 432        u64 delta;
 433        u32 pos;
 434
 435        delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
 436                               dpcm->base_time);
 437        delta = div_u64(delta * runtime->rate + 999999, 1000000);
 438        div_u64_rem(delta, runtime->buffer_size, &pos);
 439        return pos;
 440}
 441
 442static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
 443{
 444        struct snd_pcm_runtime *runtime = substream->runtime;
 445        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 446        unsigned int period, rate;
 447        long sec;
 448        unsigned long nsecs;
 449
 450        dummy_hrtimer_sync(dpcm);
 451        period = runtime->period_size;
 452        rate = runtime->rate;
 453        sec = period / rate;
 454        period %= rate;
 455        nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
 456        dpcm->period_time = ktime_set(sec, nsecs);
 457
 458        return 0;
 459}
 460
 461static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
 462{
 463        struct dummy_hrtimer_pcm *dpcm;
 464
 465        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 466        if (!dpcm)
 467                return -ENOMEM;
 468        substream->runtime->private_data = dpcm;
 469        hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 470        dpcm->timer.function = dummy_hrtimer_callback;
 471        dpcm->substream = substream;
 472        atomic_set(&dpcm->running, 0);
 473        tasklet_init(&dpcm->tasklet, dummy_hrtimer_pcm_elapsed,
 474                     (unsigned long)dpcm);
 475        return 0;
 476}
 477
 478static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
 479{
 480        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 481        dummy_hrtimer_sync(dpcm);
 482        kfree(dpcm);
 483}
 484
 485static const struct dummy_timer_ops dummy_hrtimer_ops = {
 486        .create =       dummy_hrtimer_create,
 487        .free =         dummy_hrtimer_free,
 488        .prepare =      dummy_hrtimer_prepare,
 489        .start =        dummy_hrtimer_start,
 490        .stop =         dummy_hrtimer_stop,
 491        .pointer =      dummy_hrtimer_pointer,
 492};
 493
 494#endif /* CONFIG_HIGH_RES_TIMERS */
 495
 496/*
 497 * PCM interface
 498 */
 499
 500static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 501{
 502        switch (cmd) {
 503        case SNDRV_PCM_TRIGGER_START:
 504        case SNDRV_PCM_TRIGGER_RESUME:
 505                return get_dummy_ops(substream)->start(substream);
 506        case SNDRV_PCM_TRIGGER_STOP:
 507        case SNDRV_PCM_TRIGGER_SUSPEND:
 508                return get_dummy_ops(substream)->stop(substream);
 509        }
 510        return -EINVAL;
 511}
 512
 513static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
 514{
 515        return get_dummy_ops(substream)->prepare(substream);
 516}
 517
 518static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
 519{
 520        return get_dummy_ops(substream)->pointer(substream);
 521}
 522
 523static struct snd_pcm_hardware dummy_pcm_hardware = {
 524        .info =                 (SNDRV_PCM_INFO_MMAP |
 525                                 SNDRV_PCM_INFO_INTERLEAVED |
 526                                 SNDRV_PCM_INFO_RESUME |
 527                                 SNDRV_PCM_INFO_MMAP_VALID),
 528        .formats =              USE_FORMATS,
 529        .rates =                USE_RATE,
 530        .rate_min =             USE_RATE_MIN,
 531        .rate_max =             USE_RATE_MAX,
 532        .channels_min =         USE_CHANNELS_MIN,
 533        .channels_max =         USE_CHANNELS_MAX,
 534        .buffer_bytes_max =     MAX_BUFFER_SIZE,
 535        .period_bytes_min =     MIN_PERIOD_SIZE,
 536        .period_bytes_max =     MAX_PERIOD_SIZE,
 537        .periods_min =          USE_PERIODS_MIN,
 538        .periods_max =          USE_PERIODS_MAX,
 539        .fifo_size =            0,
 540};
 541
 542static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
 543                               struct snd_pcm_hw_params *hw_params)
 544{
 545        if (fake_buffer) {
 546                /* runtime->dma_bytes has to be set manually to allow mmap */
 547                substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
 548                return 0;
 549        }
 550        return snd_pcm_lib_malloc_pages(substream,
 551                                        params_buffer_bytes(hw_params));
 552}
 553
 554static int dummy_pcm_hw_free(struct snd_pcm_substream *substream)
 555{
 556        if (fake_buffer)
 557                return 0;
 558        return snd_pcm_lib_free_pages(substream);
 559}
 560
 561static int dummy_pcm_open(struct snd_pcm_substream *substream)
 562{
 563        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 564        struct dummy_model *model = dummy->model;
 565        struct snd_pcm_runtime *runtime = substream->runtime;
 566        const struct dummy_timer_ops *ops;
 567        int err;
 568
 569        ops = &dummy_systimer_ops;
 570#ifdef CONFIG_HIGH_RES_TIMERS
 571        if (hrtimer)
 572                ops = &dummy_hrtimer_ops;
 573#endif
 574
 575        err = ops->create(substream);
 576        if (err < 0)
 577                return err;
 578        get_dummy_ops(substream) = ops;
 579
 580        runtime->hw = dummy->pcm_hw;
 581        if (substream->pcm->device & 1) {
 582                runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
 583                runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
 584        }
 585        if (substream->pcm->device & 2)
 586                runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
 587                                      SNDRV_PCM_INFO_MMAP_VALID);
 588
 589        if (model == NULL)
 590                return 0;
 591
 592        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 593                if (model->playback_constraints)
 594                        err = model->playback_constraints(substream->runtime);
 595        } else {
 596                if (model->capture_constraints)
 597                        err = model->capture_constraints(substream->runtime);
 598        }
 599        if (err < 0) {
 600                get_dummy_ops(substream)->free(substream);
 601                return err;
 602        }
 603        return 0;
 604}
 605
 606static int dummy_pcm_close(struct snd_pcm_substream *substream)
 607{
 608        get_dummy_ops(substream)->free(substream);
 609        return 0;
 610}
 611
 612/*
 613 * dummy buffer handling
 614 */
 615
 616static void *dummy_page[2];
 617
 618static void free_fake_buffer(void)
 619{
 620        if (fake_buffer) {
 621                int i;
 622                for (i = 0; i < 2; i++)
 623                        if (dummy_page[i]) {
 624                                free_page((unsigned long)dummy_page[i]);
 625                                dummy_page[i] = NULL;
 626                        }
 627        }
 628}
 629
 630static int alloc_fake_buffer(void)
 631{
 632        int i;
 633
 634        if (!fake_buffer)
 635                return 0;
 636        for (i = 0; i < 2; i++) {
 637                dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
 638                if (!dummy_page[i]) {
 639                        free_fake_buffer();
 640                        return -ENOMEM;
 641                }
 642        }
 643        return 0;
 644}
 645
 646static int dummy_pcm_copy(struct snd_pcm_substream *substream,
 647                          int channel, unsigned long pos,
 648                          void __user *dst, unsigned long bytes)
 649{
 650        return 0; /* do nothing */
 651}
 652
 653static int dummy_pcm_copy_kernel(struct snd_pcm_substream *substream,
 654                                 int channel, unsigned long pos,
 655                                 void *dst, unsigned long bytes)
 656{
 657        return 0; /* do nothing */
 658}
 659
 660static int dummy_pcm_silence(struct snd_pcm_substream *substream,
 661                             int channel, unsigned long pos,
 662                             unsigned long bytes)
 663{
 664        return 0; /* do nothing */
 665}
 666
 667static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
 668                                   unsigned long offset)
 669{
 670        return virt_to_page(dummy_page[substream->stream]); /* the same page */
 671}
 672
 673static struct snd_pcm_ops dummy_pcm_ops = {
 674        .open =         dummy_pcm_open,
 675        .close =        dummy_pcm_close,
 676        .ioctl =        snd_pcm_lib_ioctl,
 677        .hw_params =    dummy_pcm_hw_params,
 678        .hw_free =      dummy_pcm_hw_free,
 679        .prepare =      dummy_pcm_prepare,
 680        .trigger =      dummy_pcm_trigger,
 681        .pointer =      dummy_pcm_pointer,
 682};
 683
 684static struct snd_pcm_ops dummy_pcm_ops_no_buf = {
 685        .open =         dummy_pcm_open,
 686        .close =        dummy_pcm_close,
 687        .ioctl =        snd_pcm_lib_ioctl,
 688        .hw_params =    dummy_pcm_hw_params,
 689        .hw_free =      dummy_pcm_hw_free,
 690        .prepare =      dummy_pcm_prepare,
 691        .trigger =      dummy_pcm_trigger,
 692        .pointer =      dummy_pcm_pointer,
 693        .copy_user =    dummy_pcm_copy,
 694        .copy_kernel =  dummy_pcm_copy_kernel,
 695        .fill_silence = dummy_pcm_silence,
 696        .page =         dummy_pcm_page,
 697};
 698
 699static int snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
 700                              int substreams)
 701{
 702        struct snd_pcm *pcm;
 703        struct snd_pcm_ops *ops;
 704        int err;
 705
 706        err = snd_pcm_new(dummy->card, "Dummy PCM", device,
 707                               substreams, substreams, &pcm);
 708        if (err < 0)
 709                return err;
 710        dummy->pcm = pcm;
 711        if (fake_buffer)
 712                ops = &dummy_pcm_ops_no_buf;
 713        else
 714                ops = &dummy_pcm_ops;
 715        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
 716        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
 717        pcm->private_data = dummy;
 718        pcm->info_flags = 0;
 719        strcpy(pcm->name, "Dummy PCM");
 720        if (!fake_buffer) {
 721                snd_pcm_lib_preallocate_pages_for_all(pcm,
 722                        SNDRV_DMA_TYPE_CONTINUOUS,
 723                        snd_dma_continuous_data(GFP_KERNEL),
 724                        0, 64*1024);
 725        }
 726        return 0;
 727}
 728
 729/*
 730 * mixer interface
 731 */
 732
 733#define DUMMY_VOLUME(xname, xindex, addr) \
 734{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
 735  .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
 736  .name = xname, .index = xindex, \
 737  .info = snd_dummy_volume_info, \
 738  .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
 739  .private_value = addr, \
 740  .tlv = { .p = db_scale_dummy } }
 741
 742static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
 743                                 struct snd_ctl_elem_info *uinfo)
 744{
 745        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 746        uinfo->count = 2;
 747        uinfo->value.integer.min = -50;
 748        uinfo->value.integer.max = 100;
 749        return 0;
 750}
 751 
 752static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
 753                                struct snd_ctl_elem_value *ucontrol)
 754{
 755        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 756        int addr = kcontrol->private_value;
 757
 758        spin_lock_irq(&dummy->mixer_lock);
 759        ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
 760        ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
 761        spin_unlock_irq(&dummy->mixer_lock);
 762        return 0;
 763}
 764
 765static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
 766                                struct snd_ctl_elem_value *ucontrol)
 767{
 768        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 769        int change, addr = kcontrol->private_value;
 770        int left, right;
 771
 772        left = ucontrol->value.integer.value[0];
 773        if (left < -50)
 774                left = -50;
 775        if (left > 100)
 776                left = 100;
 777        right = ucontrol->value.integer.value[1];
 778        if (right < -50)
 779                right = -50;
 780        if (right > 100)
 781                right = 100;
 782        spin_lock_irq(&dummy->mixer_lock);
 783        change = dummy->mixer_volume[addr][0] != left ||
 784                 dummy->mixer_volume[addr][1] != right;
 785        dummy->mixer_volume[addr][0] = left;
 786        dummy->mixer_volume[addr][1] = right;
 787        spin_unlock_irq(&dummy->mixer_lock);
 788        return change;
 789}
 790
 791static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
 792
 793#define DUMMY_CAPSRC(xname, xindex, addr) \
 794{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
 795  .info = snd_dummy_capsrc_info, \
 796  .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
 797  .private_value = addr }
 798
 799#define snd_dummy_capsrc_info   snd_ctl_boolean_stereo_info
 800 
 801static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
 802                                struct snd_ctl_elem_value *ucontrol)
 803{
 804        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 805        int addr = kcontrol->private_value;
 806
 807        spin_lock_irq(&dummy->mixer_lock);
 808        ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
 809        ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
 810        spin_unlock_irq(&dummy->mixer_lock);
 811        return 0;
 812}
 813
 814static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 815{
 816        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 817        int change, addr = kcontrol->private_value;
 818        int left, right;
 819
 820        left = ucontrol->value.integer.value[0] & 1;
 821        right = ucontrol->value.integer.value[1] & 1;
 822        spin_lock_irq(&dummy->mixer_lock);
 823        change = dummy->capture_source[addr][0] != left &&
 824                 dummy->capture_source[addr][1] != right;
 825        dummy->capture_source[addr][0] = left;
 826        dummy->capture_source[addr][1] = right;
 827        spin_unlock_irq(&dummy->mixer_lock);
 828        return change;
 829}
 830
 831static int snd_dummy_iobox_info(struct snd_kcontrol *kcontrol,
 832                                struct snd_ctl_elem_info *info)
 833{
 834        const char *const names[] = { "None", "CD Player" };
 835
 836        return snd_ctl_enum_info(info, 1, 2, names);
 837}
 838
 839static int snd_dummy_iobox_get(struct snd_kcontrol *kcontrol,
 840                               struct snd_ctl_elem_value *value)
 841{
 842        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 843
 844        value->value.enumerated.item[0] = dummy->iobox;
 845        return 0;
 846}
 847
 848static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
 849                               struct snd_ctl_elem_value *value)
 850{
 851        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 852        int changed;
 853
 854        if (value->value.enumerated.item[0] > 1)
 855                return -EINVAL;
 856
 857        changed = value->value.enumerated.item[0] != dummy->iobox;
 858        if (changed) {
 859                dummy->iobox = value->value.enumerated.item[0];
 860
 861                if (dummy->iobox) {
 862                        dummy->cd_volume_ctl->vd[0].access &=
 863                                ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 864                        dummy->cd_switch_ctl->vd[0].access &=
 865                                ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 866                } else {
 867                        dummy->cd_volume_ctl->vd[0].access |=
 868                                SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 869                        dummy->cd_switch_ctl->vd[0].access |=
 870                                SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 871                }
 872
 873                snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 874                               &dummy->cd_volume_ctl->id);
 875                snd_ctl_notify(dummy->card, SNDRV_CTL_EVENT_MASK_INFO,
 876                               &dummy->cd_switch_ctl->id);
 877        }
 878
 879        return changed;
 880}
 881
 882static struct snd_kcontrol_new snd_dummy_controls[] = {
 883DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
 884DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
 885DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
 886DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
 887DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
 888DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
 889DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
 890DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
 891DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
 892DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD),
 893{
 894        .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 895        .name  = "External I/O Box",
 896        .info  = snd_dummy_iobox_info,
 897        .get   = snd_dummy_iobox_get,
 898        .put   = snd_dummy_iobox_put,
 899},
 900};
 901
 902static int snd_card_dummy_new_mixer(struct snd_dummy *dummy)
 903{
 904        struct snd_card *card = dummy->card;
 905        struct snd_kcontrol *kcontrol;
 906        unsigned int idx;
 907        int err;
 908
 909        spin_lock_init(&dummy->mixer_lock);
 910        strcpy(card->mixername, "Dummy Mixer");
 911        dummy->iobox = 1;
 912
 913        for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
 914                kcontrol = snd_ctl_new1(&snd_dummy_controls[idx], dummy);
 915                err = snd_ctl_add(card, kcontrol);
 916                if (err < 0)
 917                        return err;
 918                if (!strcmp(kcontrol->id.name, "CD Volume"))
 919                        dummy->cd_volume_ctl = kcontrol;
 920                else if (!strcmp(kcontrol->id.name, "CD Capture Switch"))
 921                        dummy->cd_switch_ctl = kcontrol;
 922
 923        }
 924        return 0;
 925}
 926
 927#if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_PROC_FS)
 928/*
 929 * proc interface
 930 */
 931static void print_formats(struct snd_dummy *dummy,
 932                          struct snd_info_buffer *buffer)
 933{
 934        int i;
 935
 936        for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
 937                if (dummy->pcm_hw.formats & (1ULL << i))
 938                        snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
 939        }
 940}
 941
 942static void print_rates(struct snd_dummy *dummy,
 943                        struct snd_info_buffer *buffer)
 944{
 945        static int rates[] = {
 946                5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
 947                64000, 88200, 96000, 176400, 192000,
 948        };
 949        int i;
 950
 951        if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_CONTINUOUS)
 952                snd_iprintf(buffer, " continuous");
 953        if (dummy->pcm_hw.rates & SNDRV_PCM_RATE_KNOT)
 954                snd_iprintf(buffer, " knot");
 955        for (i = 0; i < ARRAY_SIZE(rates); i++)
 956                if (dummy->pcm_hw.rates & (1 << i))
 957                        snd_iprintf(buffer, " %d", rates[i]);
 958}
 959
 960#define get_dummy_int_ptr(dummy, ofs) \
 961        (unsigned int *)((char *)&((dummy)->pcm_hw) + (ofs))
 962#define get_dummy_ll_ptr(dummy, ofs) \
 963        (unsigned long long *)((char *)&((dummy)->pcm_hw) + (ofs))
 964
 965struct dummy_hw_field {
 966        const char *name;
 967        const char *format;
 968        unsigned int offset;
 969        unsigned int size;
 970};
 971#define FIELD_ENTRY(item, fmt) {                   \
 972        .name = #item,                             \
 973        .format = fmt,                             \
 974        .offset = offsetof(struct snd_pcm_hardware, item), \
 975        .size = sizeof(dummy_pcm_hardware.item) }
 976
 977static struct dummy_hw_field fields[] = {
 978        FIELD_ENTRY(formats, "%#llx"),
 979        FIELD_ENTRY(rates, "%#x"),
 980        FIELD_ENTRY(rate_min, "%d"),
 981        FIELD_ENTRY(rate_max, "%d"),
 982        FIELD_ENTRY(channels_min, "%d"),
 983        FIELD_ENTRY(channels_max, "%d"),
 984        FIELD_ENTRY(buffer_bytes_max, "%ld"),
 985        FIELD_ENTRY(period_bytes_min, "%ld"),
 986        FIELD_ENTRY(period_bytes_max, "%ld"),
 987        FIELD_ENTRY(periods_min, "%d"),
 988        FIELD_ENTRY(periods_max, "%d"),
 989};
 990
 991static void dummy_proc_read(struct snd_info_entry *entry,
 992                            struct snd_info_buffer *buffer)
 993{
 994        struct snd_dummy *dummy = entry->private_data;
 995        int i;
 996
 997        for (i = 0; i < ARRAY_SIZE(fields); i++) {
 998                snd_iprintf(buffer, "%s ", fields[i].name);
 999                if (fields[i].size == sizeof(int))
1000                        snd_iprintf(buffer, fields[i].format,
1001                                *get_dummy_int_ptr(dummy, fields[i].offset));
1002                else
1003                        snd_iprintf(buffer, fields[i].format,
1004                                *get_dummy_ll_ptr(dummy, fields[i].offset));
1005                if (!strcmp(fields[i].name, "formats"))
1006                        print_formats(dummy, buffer);
1007                else if (!strcmp(fields[i].name, "rates"))
1008                        print_rates(dummy, buffer);
1009                snd_iprintf(buffer, "\n");
1010        }
1011}
1012
1013static void dummy_proc_write(struct snd_info_entry *entry,
1014                             struct snd_info_buffer *buffer)
1015{
1016        struct snd_dummy *dummy = entry->private_data;
1017        char line[64];
1018
1019        while (!snd_info_get_line(buffer, line, sizeof(line))) {
1020                char item[20];
1021                const char *ptr;
1022                unsigned long long val;
1023                int i;
1024
1025                ptr = snd_info_get_str(item, line, sizeof(item));
1026                for (i = 0; i < ARRAY_SIZE(fields); i++) {
1027                        if (!strcmp(item, fields[i].name))
1028                                break;
1029                }
1030                if (i >= ARRAY_SIZE(fields))
1031                        continue;
1032                snd_info_get_str(item, ptr, sizeof(item));
1033                if (kstrtoull(item, 0, &val))
1034                        continue;
1035                if (fields[i].size == sizeof(int))
1036                        *get_dummy_int_ptr(dummy, fields[i].offset) = val;
1037                else
1038                        *get_dummy_ll_ptr(dummy, fields[i].offset) = val;
1039        }
1040}
1041
1042static void dummy_proc_init(struct snd_dummy *chip)
1043{
1044        struct snd_info_entry *entry;
1045
1046        if (!snd_card_proc_new(chip->card, "dummy_pcm", &entry)) {
1047                snd_info_set_text_ops(entry, chip, dummy_proc_read);
1048                entry->c.text.write = dummy_proc_write;
1049                entry->mode |= S_IWUSR;
1050                entry->private_data = chip;
1051        }
1052}
1053#else
1054#define dummy_proc_init(x)
1055#endif /* CONFIG_SND_DEBUG && CONFIG_SND_PROC_FS */
1056
1057static int snd_dummy_probe(struct platform_device *devptr)
1058{
1059        struct snd_card *card;
1060        struct snd_dummy *dummy;
1061        struct dummy_model *m = NULL, **mdl;
1062        int idx, err;
1063        int dev = devptr->id;
1064
1065        err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
1066                           sizeof(struct snd_dummy), &card);
1067        if (err < 0)
1068                return err;
1069        dummy = card->private_data;
1070        dummy->card = card;
1071        for (mdl = dummy_models; *mdl && model[dev]; mdl++) {
1072                if (strcmp(model[dev], (*mdl)->name) == 0) {
1073                        printk(KERN_INFO
1074                                "snd-dummy: Using model '%s' for card %i\n",
1075                                (*mdl)->name, card->number);
1076                        m = dummy->model = *mdl;
1077                        break;
1078                }
1079        }
1080        for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
1081                if (pcm_substreams[dev] < 1)
1082                        pcm_substreams[dev] = 1;
1083                if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1084                        pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1085                err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
1086                if (err < 0)
1087                        goto __nodev;
1088        }
1089
1090        dummy->pcm_hw = dummy_pcm_hardware;
1091        if (m) {
1092                if (m->formats)
1093                        dummy->pcm_hw.formats = m->formats;
1094                if (m->buffer_bytes_max)
1095                        dummy->pcm_hw.buffer_bytes_max = m->buffer_bytes_max;
1096                if (m->period_bytes_min)
1097                        dummy->pcm_hw.period_bytes_min = m->period_bytes_min;
1098                if (m->period_bytes_max)
1099                        dummy->pcm_hw.period_bytes_max = m->period_bytes_max;
1100                if (m->periods_min)
1101                        dummy->pcm_hw.periods_min = m->periods_min;
1102                if (m->periods_max)
1103                        dummy->pcm_hw.periods_max = m->periods_max;
1104                if (m->rates)
1105                        dummy->pcm_hw.rates = m->rates;
1106                if (m->rate_min)
1107                        dummy->pcm_hw.rate_min = m->rate_min;
1108                if (m->rate_max)
1109                        dummy->pcm_hw.rate_max = m->rate_max;
1110                if (m->channels_min)
1111                        dummy->pcm_hw.channels_min = m->channels_min;
1112                if (m->channels_max)
1113                        dummy->pcm_hw.channels_max = m->channels_max;
1114        }
1115
1116        err = snd_card_dummy_new_mixer(dummy);
1117        if (err < 0)
1118                goto __nodev;
1119        strcpy(card->driver, "Dummy");
1120        strcpy(card->shortname, "Dummy");
1121        sprintf(card->longname, "Dummy %i", dev + 1);
1122
1123        dummy_proc_init(dummy);
1124
1125        err = snd_card_register(card);
1126        if (err == 0) {
1127                platform_set_drvdata(devptr, card);
1128                return 0;
1129        }
1130      __nodev:
1131        snd_card_free(card);
1132        return err;
1133}
1134
1135static int snd_dummy_remove(struct platform_device *devptr)
1136{
1137        snd_card_free(platform_get_drvdata(devptr));
1138        return 0;
1139}
1140
1141#ifdef CONFIG_PM_SLEEP
1142static int snd_dummy_suspend(struct device *pdev)
1143{
1144        struct snd_card *card = dev_get_drvdata(pdev);
1145        struct snd_dummy *dummy = card->private_data;
1146
1147        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1148        snd_pcm_suspend_all(dummy->pcm);
1149        return 0;
1150}
1151        
1152static int snd_dummy_resume(struct device *pdev)
1153{
1154        struct snd_card *card = dev_get_drvdata(pdev);
1155
1156        snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1157        return 0;
1158}
1159
1160static SIMPLE_DEV_PM_OPS(snd_dummy_pm, snd_dummy_suspend, snd_dummy_resume);
1161#define SND_DUMMY_PM_OPS        &snd_dummy_pm
1162#else
1163#define SND_DUMMY_PM_OPS        NULL
1164#endif
1165
1166#define SND_DUMMY_DRIVER        "snd_dummy"
1167
1168static struct platform_driver snd_dummy_driver = {
1169        .probe          = snd_dummy_probe,
1170        .remove         = snd_dummy_remove,
1171        .driver         = {
1172                .name   = SND_DUMMY_DRIVER,
1173                .pm     = SND_DUMMY_PM_OPS,
1174        },
1175};
1176
1177static void snd_dummy_unregister_all(void)
1178{
1179        int i;
1180
1181        for (i = 0; i < ARRAY_SIZE(devices); ++i)
1182                platform_device_unregister(devices[i]);
1183        platform_driver_unregister(&snd_dummy_driver);
1184        free_fake_buffer();
1185}
1186
1187static int __init alsa_card_dummy_init(void)
1188{
1189        int i, cards, err;
1190
1191        err = platform_driver_register(&snd_dummy_driver);
1192        if (err < 0)
1193                return err;
1194
1195        err = alloc_fake_buffer();
1196        if (err < 0) {
1197                platform_driver_unregister(&snd_dummy_driver);
1198                return err;
1199        }
1200
1201        cards = 0;
1202        for (i = 0; i < SNDRV_CARDS; i++) {
1203                struct platform_device *device;
1204                if (! enable[i])
1205                        continue;
1206                device = platform_device_register_simple(SND_DUMMY_DRIVER,
1207                                                         i, NULL, 0);
1208                if (IS_ERR(device))
1209                        continue;
1210                if (!platform_get_drvdata(device)) {
1211                        platform_device_unregister(device);
1212                        continue;
1213                }
1214                devices[i] = device;
1215                cards++;
1216        }
1217        if (!cards) {
1218#ifdef MODULE
1219                printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1220#endif
1221                snd_dummy_unregister_all();
1222                return -ENODEV;
1223        }
1224        return 0;
1225}
1226
1227static void __exit alsa_card_dummy_exit(void)
1228{
1229        snd_dummy_unregister_all();
1230}
1231
1232module_init(alsa_card_dummy_init)
1233module_exit(alsa_card_dummy_exit)
1234