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/moduleparam.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#if 0 /* emu10k1 emulation */
  49#define MAX_BUFFER_SIZE         (128 * 1024)
  50static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
  51{
  52        int err;
  53        err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
  54        if (err < 0)
  55                return err;
  56        err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256, UINT_MAX);
  57        if (err < 0)
  58                return err;
  59        return 0;
  60}
  61#define add_playback_constraints emu10k1_playback_constraints
  62#endif
  63
  64#if 0 /* RME9652 emulation */
  65#define MAX_BUFFER_SIZE         (26 * 64 * 1024)
  66#define USE_FORMATS             SNDRV_PCM_FMTBIT_S32_LE
  67#define USE_CHANNELS_MIN        26
  68#define USE_CHANNELS_MAX        26
  69#define USE_PERIODS_MIN         2
  70#define USE_PERIODS_MAX         2
  71#endif
  72
  73#if 0 /* ICE1712 emulation */
  74#define MAX_BUFFER_SIZE         (256 * 1024)
  75#define USE_FORMATS             SNDRV_PCM_FMTBIT_S32_LE
  76#define USE_CHANNELS_MIN        10
  77#define USE_CHANNELS_MAX        10
  78#define USE_PERIODS_MIN         1
  79#define USE_PERIODS_MAX         1024
  80#endif
  81
  82#if 0 /* UDA1341 emulation */
  83#define MAX_BUFFER_SIZE         (16380)
  84#define USE_FORMATS             SNDRV_PCM_FMTBIT_S16_LE
  85#define USE_CHANNELS_MIN        2
  86#define USE_CHANNELS_MAX        2
  87#define USE_PERIODS_MIN         2
  88#define USE_PERIODS_MAX         255
  89#endif
  90
  91#if 0 /* simple AC97 bridge (intel8x0) with 48kHz AC97 only codec */
  92#define USE_FORMATS             SNDRV_PCM_FMTBIT_S16_LE
  93#define USE_CHANNELS_MIN        2
  94#define USE_CHANNELS_MAX        2
  95#define USE_RATE                SNDRV_PCM_RATE_48000
  96#define USE_RATE_MIN            48000
  97#define USE_RATE_MAX            48000
  98#endif
  99
 100#if 0 /* CA0106 */
 101#define USE_FORMATS             SNDRV_PCM_FMTBIT_S16_LE
 102#define USE_CHANNELS_MIN        2
 103#define USE_CHANNELS_MAX        2
 104#define USE_RATE                (SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_96000|SNDRV_PCM_RATE_192000) 
 105#define USE_RATE_MIN            48000 
 106#define USE_RATE_MAX            192000
 107#define MAX_BUFFER_SIZE         ((65536-64)*8)
 108#define MAX_PERIOD_SIZE         (65536-64)
 109#define USE_PERIODS_MIN         2
 110#define USE_PERIODS_MAX         8
 111#endif
 112
 113
 114/* defaults */
 115#ifndef MAX_BUFFER_SIZE
 116#define MAX_BUFFER_SIZE         (64*1024)
 117#endif
 118#ifndef MAX_PERIOD_SIZE
 119#define MAX_PERIOD_SIZE         MAX_BUFFER_SIZE
 120#endif
 121#ifndef USE_FORMATS
 122#define USE_FORMATS             (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE)
 123#endif
 124#ifndef USE_RATE
 125#define USE_RATE                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000
 126#define USE_RATE_MIN            5500
 127#define USE_RATE_MAX            48000
 128#endif
 129#ifndef USE_CHANNELS_MIN
 130#define USE_CHANNELS_MIN        1
 131#endif
 132#ifndef USE_CHANNELS_MAX
 133#define USE_CHANNELS_MAX        2
 134#endif
 135#ifndef USE_PERIODS_MIN
 136#define USE_PERIODS_MIN         1
 137#endif
 138#ifndef USE_PERIODS_MAX
 139#define USE_PERIODS_MAX         1024
 140#endif
 141#ifndef add_playback_constraints
 142#define add_playback_constraints(x) 0
 143#endif
 144#ifndef add_capture_constraints
 145#define add_capture_constraints(x) 0
 146#endif
 147
 148static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
 149static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
 150static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
 151static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
 152static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
 153//static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
 154#ifdef CONFIG_HIGH_RES_TIMERS
 155static int hrtimer = 1;
 156#endif
 157static int fake_buffer = 1;
 158
 159module_param_array(index, int, NULL, 0444);
 160MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
 161module_param_array(id, charp, NULL, 0444);
 162MODULE_PARM_DESC(id, "ID string for dummy soundcard.");
 163module_param_array(enable, bool, NULL, 0444);
 164MODULE_PARM_DESC(enable, "Enable this dummy soundcard.");
 165module_param_array(pcm_devs, int, NULL, 0444);
 166MODULE_PARM_DESC(pcm_devs, "PCM devices # (0-4) for dummy driver.");
 167module_param_array(pcm_substreams, int, NULL, 0444);
 168MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-128) for dummy driver.");
 169//module_param_array(midi_devs, int, NULL, 0444);
 170//MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
 171module_param(fake_buffer, bool, 0444);
 172MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
 173#ifdef CONFIG_HIGH_RES_TIMERS
 174module_param(hrtimer, bool, 0644);
 175MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
 176#endif
 177
 178static struct platform_device *devices[SNDRV_CARDS];
 179
 180#define MIXER_ADDR_MASTER       0
 181#define MIXER_ADDR_LINE         1
 182#define MIXER_ADDR_MIC          2
 183#define MIXER_ADDR_SYNTH        3
 184#define MIXER_ADDR_CD           4
 185#define MIXER_ADDR_LAST         4
 186
 187struct dummy_timer_ops {
 188        int (*create)(struct snd_pcm_substream *);
 189        void (*free)(struct snd_pcm_substream *);
 190        int (*prepare)(struct snd_pcm_substream *);
 191        int (*start)(struct snd_pcm_substream *);
 192        int (*stop)(struct snd_pcm_substream *);
 193        snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
 194};
 195
 196struct snd_dummy {
 197        struct snd_card *card;
 198        struct snd_pcm *pcm;
 199        spinlock_t mixer_lock;
 200        int mixer_volume[MIXER_ADDR_LAST+1][2];
 201        int capture_source[MIXER_ADDR_LAST+1][2];
 202        const struct dummy_timer_ops *timer_ops;
 203};
 204
 205/*
 206 * system timer interface
 207 */
 208
 209struct dummy_systimer_pcm {
 210        spinlock_t lock;
 211        struct timer_list timer;
 212        unsigned long base_time;
 213        unsigned int frac_pos;  /* fractional sample position (based HZ) */
 214        unsigned int frac_period_rest;
 215        unsigned int frac_buffer_size;  /* buffer_size * HZ */
 216        unsigned int frac_period_size;  /* period_size * HZ */
 217        unsigned int rate;
 218        int elapsed;
 219        struct snd_pcm_substream *substream;
 220};
 221
 222static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
 223{
 224        dpcm->timer.expires = jiffies +
 225                (dpcm->frac_period_rest + dpcm->rate - 1) / dpcm->rate;
 226        add_timer(&dpcm->timer);
 227}
 228
 229static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
 230{
 231        unsigned long delta;
 232
 233        delta = jiffies - dpcm->base_time;
 234        if (!delta)
 235                return;
 236        dpcm->base_time += delta;
 237        delta *= dpcm->rate;
 238        dpcm->frac_pos += delta;
 239        while (dpcm->frac_pos >= dpcm->frac_buffer_size)
 240                dpcm->frac_pos -= dpcm->frac_buffer_size;
 241        while (dpcm->frac_period_rest <= delta) {
 242                dpcm->elapsed++;
 243                dpcm->frac_period_rest += dpcm->frac_period_size;
 244        }
 245        dpcm->frac_period_rest -= delta;
 246}
 247
 248static int dummy_systimer_start(struct snd_pcm_substream *substream)
 249{
 250        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 251        spin_lock(&dpcm->lock);
 252        dpcm->base_time = jiffies;
 253        dummy_systimer_rearm(dpcm);
 254        spin_unlock(&dpcm->lock);
 255        return 0;
 256}
 257
 258static int dummy_systimer_stop(struct snd_pcm_substream *substream)
 259{
 260        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 261        spin_lock(&dpcm->lock);
 262        del_timer(&dpcm->timer);
 263        spin_unlock(&dpcm->lock);
 264        return 0;
 265}
 266
 267static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
 268{
 269        struct snd_pcm_runtime *runtime = substream->runtime;
 270        struct dummy_systimer_pcm *dpcm = runtime->private_data;
 271
 272        dpcm->frac_pos = 0;
 273        dpcm->rate = runtime->rate;
 274        dpcm->frac_buffer_size = runtime->buffer_size * HZ;
 275        dpcm->frac_period_size = runtime->period_size * HZ;
 276        dpcm->frac_period_rest = dpcm->frac_period_size;
 277        dpcm->elapsed = 0;
 278
 279        return 0;
 280}
 281
 282static void dummy_systimer_callback(unsigned long data)
 283{
 284        struct dummy_systimer_pcm *dpcm = (struct dummy_systimer_pcm *)data;
 285        unsigned long flags;
 286        int elapsed = 0;
 287        
 288        spin_lock_irqsave(&dpcm->lock, flags);
 289        dummy_systimer_update(dpcm);
 290        dummy_systimer_rearm(dpcm);
 291        elapsed = dpcm->elapsed;
 292        dpcm->elapsed = 0;
 293        spin_unlock_irqrestore(&dpcm->lock, flags);
 294        if (elapsed)
 295                snd_pcm_period_elapsed(dpcm->substream);
 296}
 297
 298static snd_pcm_uframes_t
 299dummy_systimer_pointer(struct snd_pcm_substream *substream)
 300{
 301        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
 302        snd_pcm_uframes_t pos;
 303
 304        spin_lock(&dpcm->lock);
 305        dummy_systimer_update(dpcm);
 306        pos = dpcm->frac_pos / HZ;
 307        spin_unlock(&dpcm->lock);
 308        return pos;
 309}
 310
 311static int dummy_systimer_create(struct snd_pcm_substream *substream)
 312{
 313        struct dummy_systimer_pcm *dpcm;
 314
 315        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 316        if (!dpcm)
 317                return -ENOMEM;
 318        substream->runtime->private_data = dpcm;
 319        init_timer(&dpcm->timer);
 320        dpcm->timer.data = (unsigned long) dpcm;
 321        dpcm->timer.function = dummy_systimer_callback;
 322        spin_lock_init(&dpcm->lock);
 323        dpcm->substream = substream;
 324        return 0;
 325}
 326
 327static void dummy_systimer_free(struct snd_pcm_substream *substream)
 328{
 329        kfree(substream->runtime->private_data);
 330}
 331
 332static struct dummy_timer_ops dummy_systimer_ops = {
 333        .create =       dummy_systimer_create,
 334        .free =         dummy_systimer_free,
 335        .prepare =      dummy_systimer_prepare,
 336        .start =        dummy_systimer_start,
 337        .stop =         dummy_systimer_stop,
 338        .pointer =      dummy_systimer_pointer,
 339};
 340
 341#ifdef CONFIG_HIGH_RES_TIMERS
 342/*
 343 * hrtimer interface
 344 */
 345
 346struct dummy_hrtimer_pcm {
 347        ktime_t base_time;
 348        ktime_t period_time;
 349        atomic_t running;
 350        struct hrtimer timer;
 351        struct tasklet_struct tasklet;
 352        struct snd_pcm_substream *substream;
 353};
 354
 355static void dummy_hrtimer_pcm_elapsed(unsigned long priv)
 356{
 357        struct dummy_hrtimer_pcm *dpcm = (struct dummy_hrtimer_pcm *)priv;
 358        if (atomic_read(&dpcm->running))
 359                snd_pcm_period_elapsed(dpcm->substream);
 360}
 361
 362static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
 363{
 364        struct dummy_hrtimer_pcm *dpcm;
 365
 366        dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
 367        if (!atomic_read(&dpcm->running))
 368                return HRTIMER_NORESTART;
 369        tasklet_schedule(&dpcm->tasklet);
 370        hrtimer_forward_now(timer, dpcm->period_time);
 371        return HRTIMER_RESTART;
 372}
 373
 374static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
 375{
 376        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 377
 378        dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
 379        hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL);
 380        atomic_set(&dpcm->running, 1);
 381        return 0;
 382}
 383
 384static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
 385{
 386        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 387
 388        atomic_set(&dpcm->running, 0);
 389        hrtimer_cancel(&dpcm->timer);
 390        return 0;
 391}
 392
 393static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
 394{
 395        tasklet_kill(&dpcm->tasklet);
 396}
 397
 398static snd_pcm_uframes_t
 399dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
 400{
 401        struct snd_pcm_runtime *runtime = substream->runtime;
 402        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 403        u64 delta;
 404        u32 pos;
 405
 406        delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
 407                               dpcm->base_time);
 408        delta = div_u64(delta * runtime->rate + 999999, 1000000);
 409        div_u64_rem(delta, runtime->buffer_size, &pos);
 410        return pos;
 411}
 412
 413static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
 414{
 415        struct snd_pcm_runtime *runtime = substream->runtime;
 416        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
 417        unsigned int period, rate;
 418        long sec;
 419        unsigned long nsecs;
 420
 421        dummy_hrtimer_sync(dpcm);
 422        period = runtime->period_size;
 423        rate = runtime->rate;
 424        sec = period / rate;
 425        period %= rate;
 426        nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
 427        dpcm->period_time = ktime_set(sec, nsecs);
 428
 429        return 0;
 430}
 431
 432static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
 433{
 434        struct dummy_hrtimer_pcm *dpcm;
 435
 436        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 437        if (!dpcm)
 438                return -ENOMEM;
 439        substream->runtime->private_data = dpcm;
 440        hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 441        dpcm->timer.function = dummy_hrtimer_callback;
 442        dpcm->substream = substream;
 443        atomic_set(&dpcm->running, 0);
 444        tasklet_init(&dpcm->tasklet, dummy_hrtimer_pcm_elapsed,
 445                     (unsigned long)dpcm);
 446        return 0;
 447}
 448
 449static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
 450{
 451        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
 452        dummy_hrtimer_sync(dpcm);
 453        kfree(dpcm);
 454}
 455
 456static struct dummy_timer_ops dummy_hrtimer_ops = {
 457        .create =       dummy_hrtimer_create,
 458        .free =         dummy_hrtimer_free,
 459        .prepare =      dummy_hrtimer_prepare,
 460        .start =        dummy_hrtimer_start,
 461        .stop =         dummy_hrtimer_stop,
 462        .pointer =      dummy_hrtimer_pointer,
 463};
 464
 465#endif /* CONFIG_HIGH_RES_TIMERS */
 466
 467/*
 468 * PCM interface
 469 */
 470
 471static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 472{
 473        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 474
 475        switch (cmd) {
 476        case SNDRV_PCM_TRIGGER_START:
 477        case SNDRV_PCM_TRIGGER_RESUME:
 478                return dummy->timer_ops->start(substream);
 479        case SNDRV_PCM_TRIGGER_STOP:
 480        case SNDRV_PCM_TRIGGER_SUSPEND:
 481                return dummy->timer_ops->stop(substream);
 482        }
 483        return -EINVAL;
 484}
 485
 486static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
 487{
 488        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 489
 490        return dummy->timer_ops->prepare(substream);
 491}
 492
 493static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
 494{
 495        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 496
 497        return dummy->timer_ops->pointer(substream);
 498}
 499
 500static struct snd_pcm_hardware dummy_pcm_hardware = {
 501        .info =                 (SNDRV_PCM_INFO_MMAP |
 502                                 SNDRV_PCM_INFO_INTERLEAVED |
 503                                 SNDRV_PCM_INFO_RESUME |
 504                                 SNDRV_PCM_INFO_MMAP_VALID),
 505        .formats =              USE_FORMATS,
 506        .rates =                USE_RATE,
 507        .rate_min =             USE_RATE_MIN,
 508        .rate_max =             USE_RATE_MAX,
 509        .channels_min =         USE_CHANNELS_MIN,
 510        .channels_max =         USE_CHANNELS_MAX,
 511        .buffer_bytes_max =     MAX_BUFFER_SIZE,
 512        .period_bytes_min =     64,
 513        .period_bytes_max =     MAX_PERIOD_SIZE,
 514        .periods_min =          USE_PERIODS_MIN,
 515        .periods_max =          USE_PERIODS_MAX,
 516        .fifo_size =            0,
 517};
 518
 519static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
 520                               struct snd_pcm_hw_params *hw_params)
 521{
 522        if (fake_buffer) {
 523                /* runtime->dma_bytes has to be set manually to allow mmap */
 524                substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
 525                return 0;
 526        }
 527        return snd_pcm_lib_malloc_pages(substream,
 528                                        params_buffer_bytes(hw_params));
 529}
 530
 531static int dummy_pcm_hw_free(struct snd_pcm_substream *substream)
 532{
 533        if (fake_buffer)
 534                return 0;
 535        return snd_pcm_lib_free_pages(substream);
 536}
 537
 538static int dummy_pcm_open(struct snd_pcm_substream *substream)
 539{
 540        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 541        struct snd_pcm_runtime *runtime = substream->runtime;
 542        int err;
 543
 544        dummy->timer_ops = &dummy_systimer_ops;
 545#ifdef CONFIG_HIGH_RES_TIMERS
 546        if (hrtimer)
 547                dummy->timer_ops = &dummy_hrtimer_ops;
 548#endif
 549
 550        err = dummy->timer_ops->create(substream);
 551        if (err < 0)
 552                return err;
 553
 554        runtime->hw = dummy_pcm_hardware;
 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 (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 564                err = add_playback_constraints(substream->runtime);
 565        else
 566                err = add_capture_constraints(substream->runtime);
 567        if (err < 0) {
 568                dummy->timer_ops->free(substream);
 569                return err;
 570        }
 571        return 0;
 572}
 573
 574static int dummy_pcm_close(struct snd_pcm_substream *substream)
 575{
 576        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
 577        dummy->timer_ops->free(substream);
 578        return 0;
 579}
 580
 581/*
 582 * dummy buffer handling
 583 */
 584
 585static void *dummy_page[2];
 586
 587static void free_fake_buffer(void)
 588{
 589        if (fake_buffer) {
 590                int i;
 591                for (i = 0; i < 2; i++)
 592                        if (dummy_page[i]) {
 593                                free_page((unsigned long)dummy_page[i]);
 594                                dummy_page[i] = NULL;
 595                        }
 596        }
 597}
 598
 599static int alloc_fake_buffer(void)
 600{
 601        int i;
 602
 603        if (!fake_buffer)
 604                return 0;
 605        for (i = 0; i < 2; i++) {
 606                dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
 607                if (!dummy_page[i]) {
 608                        free_fake_buffer();
 609                        return -ENOMEM;
 610                }
 611        }
 612        return 0;
 613}
 614
 615static int dummy_pcm_copy(struct snd_pcm_substream *substream,
 616                          int channel, snd_pcm_uframes_t pos,
 617                          void __user *dst, snd_pcm_uframes_t count)
 618{
 619        return 0; /* do nothing */
 620}
 621
 622static int dummy_pcm_silence(struct snd_pcm_substream *substream,
 623                             int channel, snd_pcm_uframes_t pos,
 624                             snd_pcm_uframes_t count)
 625{
 626        return 0; /* do nothing */
 627}
 628
 629static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
 630                                   unsigned long offset)
 631{
 632        return virt_to_page(dummy_page[substream->stream]); /* the same page */
 633}
 634
 635static struct snd_pcm_ops dummy_pcm_ops = {
 636        .open =         dummy_pcm_open,
 637        .close =        dummy_pcm_close,
 638        .ioctl =        snd_pcm_lib_ioctl,
 639        .hw_params =    dummy_pcm_hw_params,
 640        .hw_free =      dummy_pcm_hw_free,
 641        .prepare =      dummy_pcm_prepare,
 642        .trigger =      dummy_pcm_trigger,
 643        .pointer =      dummy_pcm_pointer,
 644};
 645
 646static struct snd_pcm_ops dummy_pcm_ops_no_buf = {
 647        .open =         dummy_pcm_open,
 648        .close =        dummy_pcm_close,
 649        .ioctl =        snd_pcm_lib_ioctl,
 650        .hw_params =    dummy_pcm_hw_params,
 651        .hw_free =      dummy_pcm_hw_free,
 652        .prepare =      dummy_pcm_prepare,
 653        .trigger =      dummy_pcm_trigger,
 654        .pointer =      dummy_pcm_pointer,
 655        .copy =         dummy_pcm_copy,
 656        .silence =      dummy_pcm_silence,
 657        .page =         dummy_pcm_page,
 658};
 659
 660static int __devinit snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
 661                                        int substreams)
 662{
 663        struct snd_pcm *pcm;
 664        struct snd_pcm_ops *ops;
 665        int err;
 666
 667        err = snd_pcm_new(dummy->card, "Dummy PCM", device,
 668                               substreams, substreams, &pcm);
 669        if (err < 0)
 670                return err;
 671        dummy->pcm = pcm;
 672        if (fake_buffer)
 673                ops = &dummy_pcm_ops_no_buf;
 674        else
 675                ops = &dummy_pcm_ops;
 676        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
 677        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
 678        pcm->private_data = dummy;
 679        pcm->info_flags = 0;
 680        strcpy(pcm->name, "Dummy PCM");
 681        if (!fake_buffer) {
 682                snd_pcm_lib_preallocate_pages_for_all(pcm,
 683                        SNDRV_DMA_TYPE_CONTINUOUS,
 684                        snd_dma_continuous_data(GFP_KERNEL),
 685                        0, 64*1024);
 686        }
 687        return 0;
 688}
 689
 690/*
 691 * mixer interface
 692 */
 693
 694#define DUMMY_VOLUME(xname, xindex, addr) \
 695{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
 696  .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
 697  .name = xname, .index = xindex, \
 698  .info = snd_dummy_volume_info, \
 699  .get = snd_dummy_volume_get, .put = snd_dummy_volume_put, \
 700  .private_value = addr, \
 701  .tlv = { .p = db_scale_dummy } }
 702
 703static int snd_dummy_volume_info(struct snd_kcontrol *kcontrol,
 704                                 struct snd_ctl_elem_info *uinfo)
 705{
 706        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 707        uinfo->count = 2;
 708        uinfo->value.integer.min = -50;
 709        uinfo->value.integer.max = 100;
 710        return 0;
 711}
 712 
 713static int snd_dummy_volume_get(struct snd_kcontrol *kcontrol,
 714                                struct snd_ctl_elem_value *ucontrol)
 715{
 716        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 717        int addr = kcontrol->private_value;
 718
 719        spin_lock_irq(&dummy->mixer_lock);
 720        ucontrol->value.integer.value[0] = dummy->mixer_volume[addr][0];
 721        ucontrol->value.integer.value[1] = dummy->mixer_volume[addr][1];
 722        spin_unlock_irq(&dummy->mixer_lock);
 723        return 0;
 724}
 725
 726static int snd_dummy_volume_put(struct snd_kcontrol *kcontrol,
 727                                struct snd_ctl_elem_value *ucontrol)
 728{
 729        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 730        int change, addr = kcontrol->private_value;
 731        int left, right;
 732
 733        left = ucontrol->value.integer.value[0];
 734        if (left < -50)
 735                left = -50;
 736        if (left > 100)
 737                left = 100;
 738        right = ucontrol->value.integer.value[1];
 739        if (right < -50)
 740                right = -50;
 741        if (right > 100)
 742                right = 100;
 743        spin_lock_irq(&dummy->mixer_lock);
 744        change = dummy->mixer_volume[addr][0] != left ||
 745                 dummy->mixer_volume[addr][1] != right;
 746        dummy->mixer_volume[addr][0] = left;
 747        dummy->mixer_volume[addr][1] = right;
 748        spin_unlock_irq(&dummy->mixer_lock);
 749        return change;
 750}
 751
 752static const DECLARE_TLV_DB_SCALE(db_scale_dummy, -4500, 30, 0);
 753
 754#define DUMMY_CAPSRC(xname, xindex, addr) \
 755{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
 756  .info = snd_dummy_capsrc_info, \
 757  .get = snd_dummy_capsrc_get, .put = snd_dummy_capsrc_put, \
 758  .private_value = addr }
 759
 760#define snd_dummy_capsrc_info   snd_ctl_boolean_stereo_info
 761 
 762static int snd_dummy_capsrc_get(struct snd_kcontrol *kcontrol,
 763                                struct snd_ctl_elem_value *ucontrol)
 764{
 765        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 766        int addr = kcontrol->private_value;
 767
 768        spin_lock_irq(&dummy->mixer_lock);
 769        ucontrol->value.integer.value[0] = dummy->capture_source[addr][0];
 770        ucontrol->value.integer.value[1] = dummy->capture_source[addr][1];
 771        spin_unlock_irq(&dummy->mixer_lock);
 772        return 0;
 773}
 774
 775static int snd_dummy_capsrc_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
 776{
 777        struct snd_dummy *dummy = snd_kcontrol_chip(kcontrol);
 778        int change, addr = kcontrol->private_value;
 779        int left, right;
 780
 781        left = ucontrol->value.integer.value[0] & 1;
 782        right = ucontrol->value.integer.value[1] & 1;
 783        spin_lock_irq(&dummy->mixer_lock);
 784        change = dummy->capture_source[addr][0] != left &&
 785                 dummy->capture_source[addr][1] != right;
 786        dummy->capture_source[addr][0] = left;
 787        dummy->capture_source[addr][1] = right;
 788        spin_unlock_irq(&dummy->mixer_lock);
 789        return change;
 790}
 791
 792static struct snd_kcontrol_new snd_dummy_controls[] = {
 793DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
 794DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
 795DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),
 796DUMMY_CAPSRC("Synth Capture Switch", 0, MIXER_ADDR_SYNTH),
 797DUMMY_VOLUME("Line Volume", 0, MIXER_ADDR_LINE),
 798DUMMY_CAPSRC("Line Capture Switch", 0, MIXER_ADDR_LINE),
 799DUMMY_VOLUME("Mic Volume", 0, MIXER_ADDR_MIC),
 800DUMMY_CAPSRC("Mic Capture Switch", 0, MIXER_ADDR_MIC),
 801DUMMY_VOLUME("CD Volume", 0, MIXER_ADDR_CD),
 802DUMMY_CAPSRC("CD Capture Switch", 0, MIXER_ADDR_CD)
 803};
 804
 805static int __devinit snd_card_dummy_new_mixer(struct snd_dummy *dummy)
 806{
 807        struct snd_card *card = dummy->card;
 808        unsigned int idx;
 809        int err;
 810
 811        spin_lock_init(&dummy->mixer_lock);
 812        strcpy(card->mixername, "Dummy Mixer");
 813
 814        for (idx = 0; idx < ARRAY_SIZE(snd_dummy_controls); idx++) {
 815                err = snd_ctl_add(card, snd_ctl_new1(&snd_dummy_controls[idx], dummy));
 816                if (err < 0)
 817                        return err;
 818        }
 819        return 0;
 820}
 821
 822#if defined(CONFIG_SND_DEBUG) && defined(CONFIG_PROC_FS)
 823/*
 824 * proc interface
 825 */
 826static void print_formats(struct snd_info_buffer *buffer)
 827{
 828        int i;
 829
 830        for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
 831                if (dummy_pcm_hardware.formats & (1ULL << i))
 832                        snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
 833        }
 834}
 835
 836static void print_rates(struct snd_info_buffer *buffer)
 837{
 838        static int rates[] = {
 839                5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
 840                64000, 88200, 96000, 176400, 192000,
 841        };
 842        int i;
 843
 844        if (dummy_pcm_hardware.rates & SNDRV_PCM_RATE_CONTINUOUS)
 845                snd_iprintf(buffer, " continuous");
 846        if (dummy_pcm_hardware.rates & SNDRV_PCM_RATE_KNOT)
 847                snd_iprintf(buffer, " knot");
 848        for (i = 0; i < ARRAY_SIZE(rates); i++)
 849                if (dummy_pcm_hardware.rates & (1 << i))
 850                        snd_iprintf(buffer, " %d", rates[i]);
 851}
 852
 853#define get_dummy_int_ptr(ofs) \
 854        (unsigned int *)((char *)&dummy_pcm_hardware + (ofs))
 855#define get_dummy_ll_ptr(ofs) \
 856        (unsigned long long *)((char *)&dummy_pcm_hardware + (ofs))
 857
 858struct dummy_hw_field {
 859        const char *name;
 860        const char *format;
 861        unsigned int offset;
 862        unsigned int size;
 863};
 864#define FIELD_ENTRY(item, fmt) {                   \
 865        .name = #item,                             \
 866        .format = fmt,                             \
 867        .offset = offsetof(struct snd_pcm_hardware, item), \
 868        .size = sizeof(dummy_pcm_hardware.item) }
 869
 870static struct dummy_hw_field fields[] = {
 871        FIELD_ENTRY(formats, "%#llx"),
 872        FIELD_ENTRY(rates, "%#x"),
 873        FIELD_ENTRY(rate_min, "%d"),
 874        FIELD_ENTRY(rate_max, "%d"),
 875        FIELD_ENTRY(channels_min, "%d"),
 876        FIELD_ENTRY(channels_max, "%d"),
 877        FIELD_ENTRY(buffer_bytes_max, "%ld"),
 878        FIELD_ENTRY(period_bytes_min, "%ld"),
 879        FIELD_ENTRY(period_bytes_max, "%ld"),
 880        FIELD_ENTRY(periods_min, "%d"),
 881        FIELD_ENTRY(periods_max, "%d"),
 882};
 883
 884static void dummy_proc_read(struct snd_info_entry *entry,
 885                            struct snd_info_buffer *buffer)
 886{
 887        int i;
 888
 889        for (i = 0; i < ARRAY_SIZE(fields); i++) {
 890                snd_iprintf(buffer, "%s ", fields[i].name);
 891                if (fields[i].size == sizeof(int))
 892                        snd_iprintf(buffer, fields[i].format,
 893                                    *get_dummy_int_ptr(fields[i].offset));
 894                else
 895                        snd_iprintf(buffer, fields[i].format,
 896                                    *get_dummy_ll_ptr(fields[i].offset));
 897                if (!strcmp(fields[i].name, "formats"))
 898                        print_formats(buffer);
 899                else if (!strcmp(fields[i].name, "rates"))
 900                        print_rates(buffer);
 901                snd_iprintf(buffer, "\n");
 902        }
 903}
 904
 905static void dummy_proc_write(struct snd_info_entry *entry,
 906                             struct snd_info_buffer *buffer)
 907{
 908        char line[64];
 909
 910        while (!snd_info_get_line(buffer, line, sizeof(line))) {
 911                char item[20];
 912                const char *ptr;
 913                unsigned long long val;
 914                int i;
 915
 916                ptr = snd_info_get_str(item, line, sizeof(item));
 917                for (i = 0; i < ARRAY_SIZE(fields); i++) {
 918                        if (!strcmp(item, fields[i].name))
 919                                break;
 920                }
 921                if (i >= ARRAY_SIZE(fields))
 922                        continue;
 923                snd_info_get_str(item, ptr, sizeof(item));
 924                if (strict_strtoull(item, 0, &val))
 925                        continue;
 926                if (fields[i].size == sizeof(int))
 927                        *get_dummy_int_ptr(fields[i].offset) = val;
 928                else
 929                        *get_dummy_ll_ptr(fields[i].offset) = val;
 930        }
 931}
 932
 933static void __devinit dummy_proc_init(struct snd_dummy *chip)
 934{
 935        struct snd_info_entry *entry;
 936
 937        if (!snd_card_proc_new(chip->card, "dummy_pcm", &entry)) {
 938                snd_info_set_text_ops(entry, chip, dummy_proc_read);
 939                entry->c.text.write = dummy_proc_write;
 940                entry->mode |= S_IWUSR;
 941        }
 942}
 943#else
 944#define dummy_proc_init(x)
 945#endif /* CONFIG_SND_DEBUG && CONFIG_PROC_FS */
 946
 947static int __devinit snd_dummy_probe(struct platform_device *devptr)
 948{
 949        struct snd_card *card;
 950        struct snd_dummy *dummy;
 951        int idx, err;
 952        int dev = devptr->id;
 953
 954        err = snd_card_create(index[dev], id[dev], THIS_MODULE,
 955                              sizeof(struct snd_dummy), &card);
 956        if (err < 0)
 957                return err;
 958        dummy = card->private_data;
 959        dummy->card = card;
 960        for (idx = 0; idx < MAX_PCM_DEVICES && idx < pcm_devs[dev]; idx++) {
 961                if (pcm_substreams[dev] < 1)
 962                        pcm_substreams[dev] = 1;
 963                if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
 964                        pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
 965                err = snd_card_dummy_pcm(dummy, idx, pcm_substreams[dev]);
 966                if (err < 0)
 967                        goto __nodev;
 968        }
 969        err = snd_card_dummy_new_mixer(dummy);
 970        if (err < 0)
 971                goto __nodev;
 972        strcpy(card->driver, "Dummy");
 973        strcpy(card->shortname, "Dummy");
 974        sprintf(card->longname, "Dummy %i", dev + 1);
 975
 976        dummy_proc_init(dummy);
 977
 978        snd_card_set_dev(card, &devptr->dev);
 979
 980        err = snd_card_register(card);
 981        if (err == 0) {
 982                platform_set_drvdata(devptr, card);
 983                return 0;
 984        }
 985      __nodev:
 986        snd_card_free(card);
 987        return err;
 988}
 989
 990static int __devexit snd_dummy_remove(struct platform_device *devptr)
 991{
 992        snd_card_free(platform_get_drvdata(devptr));
 993        platform_set_drvdata(devptr, NULL);
 994        return 0;
 995}
 996
 997#ifdef CONFIG_PM
 998static int snd_dummy_suspend(struct platform_device *pdev, pm_message_t state)
 999{
1000        struct snd_card *card = platform_get_drvdata(pdev);
1001        struct snd_dummy *dummy = card->private_data;
1002
1003        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1004        snd_pcm_suspend_all(dummy->pcm);
1005        return 0;
1006}
1007        
1008static int snd_dummy_resume(struct platform_device *pdev)
1009{
1010        struct snd_card *card = platform_get_drvdata(pdev);
1011
1012        snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1013        return 0;
1014}
1015#endif
1016
1017#define SND_DUMMY_DRIVER        "snd_dummy"
1018
1019static struct platform_driver snd_dummy_driver = {
1020        .probe          = snd_dummy_probe,
1021        .remove         = __devexit_p(snd_dummy_remove),
1022#ifdef CONFIG_PM
1023        .suspend        = snd_dummy_suspend,
1024        .resume         = snd_dummy_resume,
1025#endif
1026        .driver         = {
1027                .name   = SND_DUMMY_DRIVER
1028        },
1029};
1030
1031static void snd_dummy_unregister_all(void)
1032{
1033        int i;
1034
1035        for (i = 0; i < ARRAY_SIZE(devices); ++i)
1036                platform_device_unregister(devices[i]);
1037        platform_driver_unregister(&snd_dummy_driver);
1038        free_fake_buffer();
1039}
1040
1041static int __init alsa_card_dummy_init(void)
1042{
1043        int i, cards, err;
1044
1045        err = platform_driver_register(&snd_dummy_driver);
1046        if (err < 0)
1047                return err;
1048
1049        err = alloc_fake_buffer();
1050        if (err < 0) {
1051                platform_driver_unregister(&snd_dummy_driver);
1052                return err;
1053        }
1054
1055        cards = 0;
1056        for (i = 0; i < SNDRV_CARDS; i++) {
1057                struct platform_device *device;
1058                if (! enable[i])
1059                        continue;
1060                device = platform_device_register_simple(SND_DUMMY_DRIVER,
1061                                                         i, NULL, 0);
1062                if (IS_ERR(device))
1063                        continue;
1064                if (!platform_get_drvdata(device)) {
1065                        platform_device_unregister(device);
1066                        continue;
1067                }
1068                devices[i] = device;
1069                cards++;
1070        }
1071        if (!cards) {
1072#ifdef MODULE
1073                printk(KERN_ERR "Dummy soundcard not found or device busy\n");
1074#endif
1075                snd_dummy_unregister_all();
1076                return -ENODEV;
1077        }
1078        return 0;
1079}
1080
1081static void __exit alsa_card_dummy_exit(void)
1082{
1083        snd_dummy_unregister_all();
1084}
1085
1086module_init(alsa_card_dummy_init)
1087module_exit(alsa_card_dummy_exit)
1088