LXR linux/sound/core/pcm

   1/*
   2 *  PCM Interface - misc routines
   3 *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
   4 *
   5 *
   6 *   This library is free software; you can redistribute it and/or modify
   7 *   it under the terms of the GNU Library General Public License as
   8 *   published by the Free Software Foundation; either version 2 of
   9 *   the License, or (at your option) any later version.
  10 *
  11 *   This program is distributed in the hope that it will be useful,
  12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *   GNU Library General Public License for more details.
  15 *
  16 *   You should have received a copy of the GNU Library General Public
  17 *   License along with this library; if not, write to the Free Software
  18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19 *
  20 */
  21  
  22#include <linux/time.h>
  23#include <linux/export.h>
  24#include <sound/core.h>
  25#include <sound/pcm.h>
  26#define SND_PCM_FORMAT_UNKNOWN (-1)
  27
  28/* NOTE: "signed" prefix must be given below since the default char is
  29 *       unsigned on some architectures!
  30 */
  31struct pcm_format_data {
  32        unsigned char width;    /* bit width */
  33        unsigned char phys;     /* physical bit width */
  34        signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
  35        signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
  36        unsigned char silence[8];       /* silence data to fill */
  37};
  38
  39/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
  40#define INT     __force int
  41
  42static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
  43        [SNDRV_PCM_FORMAT_S8] = {
  44                .width = 8, .phys = 8, .le = -1, .signd = 1,
  45                .silence = {},
  46        },
  47        [SNDRV_PCM_FORMAT_U8] = {
  48                .width = 8, .phys = 8, .le = -1, .signd = 0,
  49                .silence = { 0x80 },
  50        },
  51        [SNDRV_PCM_FORMAT_S16_LE] = {
  52                .width = 16, .phys = 16, .le = 1, .signd = 1,
  53                .silence = {},
  54        },
  55        [SNDRV_PCM_FORMAT_S16_BE] = {
  56                .width = 16, .phys = 16, .le = 0, .signd = 1,
  57                .silence = {},
  58        },
  59        [SNDRV_PCM_FORMAT_U16_LE] = {
  60                .width = 16, .phys = 16, .le = 1, .signd = 0,
  61                .silence = { 0x00, 0x80 },
  62        },
  63        [SNDRV_PCM_FORMAT_U16_BE] = {
  64                .width = 16, .phys = 16, .le = 0, .signd = 0,
  65                .silence = { 0x80, 0x00 },
  66        },
  67        [SNDRV_PCM_FORMAT_S24_LE] = {
  68                .width = 24, .phys = 32, .le = 1, .signd = 1,
  69                .silence = {},
  70        },
  71        [SNDRV_PCM_FORMAT_S24_BE] = {
  72                .width = 24, .phys = 32, .le = 0, .signd = 1,
  73                .silence = {},
  74        },
  75        [SNDRV_PCM_FORMAT_U24_LE] = {
  76                .width = 24, .phys = 32, .le = 1, .signd = 0,
  77                .silence = { 0x00, 0x00, 0x80 },
  78        },
  79        [SNDRV_PCM_FORMAT_U24_BE] = {
  80                .width = 24, .phys = 32, .le = 0, .signd = 0,
  81                .silence = { 0x00, 0x80, 0x00, 0x00 },
  82        },
  83        [SNDRV_PCM_FORMAT_S32_LE] = {
  84                .width = 32, .phys = 32, .le = 1, .signd = 1,
  85                .silence = {},
  86        },
  87        [SNDRV_PCM_FORMAT_S32_BE] = {
  88                .width = 32, .phys = 32, .le = 0, .signd = 1,
  89                .silence = {},
  90        },
  91        [SNDRV_PCM_FORMAT_U32_LE] = {
  92                .width = 32, .phys = 32, .le = 1, .signd = 0,
  93                .silence = { 0x00, 0x00, 0x00, 0x80 },
  94        },
  95        [SNDRV_PCM_FORMAT_U32_BE] = {
  96                .width = 32, .phys = 32, .le = 0, .signd = 0,
  97                .silence = { 0x80, 0x00, 0x00, 0x00 },
  98        },
  99        [SNDRV_PCM_FORMAT_FLOAT_LE] = {
 100                .width = 32, .phys = 32, .le = 1, .signd = -1,
 101                .silence = {},
 102        },
 103        [SNDRV_PCM_FORMAT_FLOAT_BE] = {
 104                .width = 32, .phys = 32, .le = 0, .signd = -1,
 105                .silence = {},
 106        },
 107        [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
 108                .width = 64, .phys = 64, .le = 1, .signd = -1,
 109                .silence = {},
 110        },
 111        [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
 112                .width = 64, .phys = 64, .le = 0, .signd = -1,
 113                .silence = {},
 114        },
 115        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
 116                .width = 32, .phys = 32, .le = 1, .signd = -1,
 117                .silence = {},
 118        },
 119        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
 120                .width = 32, .phys = 32, .le = 0, .signd = -1,
 121                .silence = {},
 122        },
 123        [SNDRV_PCM_FORMAT_MU_LAW] = {
 124                .width = 8, .phys = 8, .le = -1, .signd = -1,
 125                .silence = { 0x7f },
 126        },
 127        [SNDRV_PCM_FORMAT_A_LAW] = {
 128                .width = 8, .phys = 8, .le = -1, .signd = -1,
 129                .silence = { 0x55 },
 130        },
 131        [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
 132                .width = 4, .phys = 4, .le = -1, .signd = -1,
 133                .silence = {},
 134        },
 135        [SNDRV_PCM_FORMAT_G723_24] = {
 136                .width = 3, .phys = 3, .le = -1, .signd = -1,
 137                .silence = {},
 138        },
 139        [SNDRV_PCM_FORMAT_G723_40] = {
 140                .width = 5, .phys = 5, .le = -1, .signd = -1,
 141                .silence = {},
 142        },
 143        [SNDRV_PCM_FORMAT_DSD_U8] = {
 144                .width = 8, .phys = 8, .le = 1, .signd = 0,
 145                .silence = {},
 146        },
 147        [SNDRV_PCM_FORMAT_DSD_U16_LE] = {
 148                .width = 16, .phys = 16, .le = 1, .signd = 0,
 149                .silence = {},
 150        },
 151        /* FIXME: the following three formats are not defined properly yet */
 152        [SNDRV_PCM_FORMAT_MPEG] = {
 153                .le = -1, .signd = -1,
 154        },
 155        [SNDRV_PCM_FORMAT_GSM] = {
 156                .le = -1, .signd = -1,
 157        },
 158        [SNDRV_PCM_FORMAT_SPECIAL] = {
 159                .le = -1, .signd = -1,
 160        },
 161        [SNDRV_PCM_FORMAT_S24_3LE] = {
 162                .width = 24, .phys = 24, .le = 1, .signd = 1,
 163                .silence = {},
 164        },
 165        [SNDRV_PCM_FORMAT_S24_3BE] = {
 166                .width = 24, .phys = 24, .le = 0, .signd = 1,
 167                .silence = {},
 168        },
 169        [SNDRV_PCM_FORMAT_U24_3LE] = {
 170                .width = 24, .phys = 24, .le = 1, .signd = 0,
 171                .silence = { 0x00, 0x00, 0x80 },
 172        },
 173        [SNDRV_PCM_FORMAT_U24_3BE] = {
 174                .width = 24, .phys = 24, .le = 0, .signd = 0,
 175                .silence = { 0x80, 0x00, 0x00 },
 176        },
 177        [SNDRV_PCM_FORMAT_S20_3LE] = {
 178                .width = 20, .phys = 24, .le = 1, .signd = 1,
 179                .silence = {},
 180        },
 181        [SNDRV_PCM_FORMAT_S20_3BE] = {
 182                .width = 20, .phys = 24, .le = 0, .signd = 1,
 183                .silence = {},
 184        },
 185        [SNDRV_PCM_FORMAT_U20_3LE] = {
 186                .width = 20, .phys = 24, .le = 1, .signd = 0,
 187                .silence = { 0x00, 0x00, 0x08 },
 188        },
 189        [SNDRV_PCM_FORMAT_U20_3BE] = {
 190                .width = 20, .phys = 24, .le = 0, .signd = 0,
 191                .silence = { 0x08, 0x00, 0x00 },
 192        },
 193        [SNDRV_PCM_FORMAT_S18_3LE] = {
 194                .width = 18, .phys = 24, .le = 1, .signd = 1,
 195                .silence = {},
 196        },
 197        [SNDRV_PCM_FORMAT_S18_3BE] = {
 198                .width = 18, .phys = 24, .le = 0, .signd = 1,
 199                .silence = {},
 200        },
 201        [SNDRV_PCM_FORMAT_U18_3LE] = {
 202                .width = 18, .phys = 24, .le = 1, .signd = 0,
 203                .silence = { 0x00, 0x00, 0x02 },
 204        },
 205        [SNDRV_PCM_FORMAT_U18_3BE] = {
 206                .width = 18, .phys = 24, .le = 0, .signd = 0,
 207                .silence = { 0x02, 0x00, 0x00 },
 208        },
 209        [SNDRV_PCM_FORMAT_G723_24_1B] = {
 210                .width = 3, .phys = 8, .le = -1, .signd = -1,
 211                .silence = {},
 212        },
 213        [SNDRV_PCM_FORMAT_G723_40_1B] = {
 214                .width = 5, .phys = 8, .le = -1, .signd = -1,
 215                .silence = {},
 216        },
 217};
 218
 219
 220/**
 221 * snd_pcm_format_signed - Check the PCM format is signed linear
 222 * @format: the format to check
 223 *
 224 * Return: 1 if the given PCM format is signed linear, 0 if unsigned
 225 * linear, and a negative error code for non-linear formats.
 226 */
 227int snd_pcm_format_signed(snd_pcm_format_t format)
 228{
 229        int val;
 230        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 231                return -EINVAL;
 232        if ((val = pcm_formats[(INT)format].signd) < 0)
 233                return -EINVAL;
 234        return val;
 235}
 236
 237EXPORT_SYMBOL(snd_pcm_format_signed);
 238
 239/**
 240 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 241 * @format: the format to check
 242 *
 243 * Return: 1 if the given PCM format is unsigned linear, 0 if signed
 244 * linear, and a negative error code for non-linear formats.
 245 */
 246int snd_pcm_format_unsigned(snd_pcm_format_t format)
 247{
 248        int val;
 249
 250        val = snd_pcm_format_signed(format);
 251        if (val < 0)
 252                return val;
 253        return !val;
 254}
 255
 256EXPORT_SYMBOL(snd_pcm_format_unsigned);
 257
 258/**
 259 * snd_pcm_format_linear - Check the PCM format is linear
 260 * @format: the format to check
 261 *
 262 * Return: 1 if the given PCM format is linear, 0 if not.
 263 */
 264int snd_pcm_format_linear(snd_pcm_format_t format)
 265{
 266        return snd_pcm_format_signed(format) >= 0;
 267}
 268
 269EXPORT_SYMBOL(snd_pcm_format_linear);
 270
 271/**
 272 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 273 * @format: the format to check
 274 *
 275 * Return: 1 if the given PCM format is little-endian, 0 if
 276 * big-endian, or a negative error code if endian not specified.
 277 */
 278int snd_pcm_format_little_endian(snd_pcm_format_t format)
 279{
 280        int val;
 281        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 282                return -EINVAL;
 283        if ((val = pcm_formats[(INT)format].le) < 0)
 284                return -EINVAL;
 285        return val;
 286}
 287
 288EXPORT_SYMBOL(snd_pcm_format_little_endian);
 289
 290/**
 291 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 292 * @format: the format to check
 293 *
 294 * Return: 1 if the given PCM format is big-endian, 0 if
 295 * little-endian, or a negative error code if endian not specified.
 296 */
 297int snd_pcm_format_big_endian(snd_pcm_format_t format)
 298{
 299        int val;
 300
 301        val = snd_pcm_format_little_endian(format);
 302        if (val < 0)
 303                return val;
 304        return !val;
 305}
 306
 307EXPORT_SYMBOL(snd_pcm_format_big_endian);
 308
 309/**
 310 * snd_pcm_format_width - return the bit-width of the format
 311 * @format: the format to check
 312 *
 313 * Return: The bit-width of the format, or a negative error code
 314 * if unknown format.
 315 */
 316int snd_pcm_format_width(snd_pcm_format_t format)
 317{
 318        int val;
 319        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 320                return -EINVAL;
 321        if ((val = pcm_formats[(INT)format].width) == 0)
 322                return -EINVAL;
 323        return val;
 324}
 325
 326EXPORT_SYMBOL(snd_pcm_format_width);
 327
 328/**
 329 * snd_pcm_format_physical_width - return the physical bit-width of the format
 330 * @format: the format to check
 331 *
 332 * Return: The physical bit-width of the format, or a negative error code
 333 * if unknown format.
 334 */
 335int snd_pcm_format_physical_width(snd_pcm_format_t format)
 336{
 337        int val;
 338        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 339                return -EINVAL;
 340        if ((val = pcm_formats[(INT)format].phys) == 0)
 341                return -EINVAL;
 342        return val;
 343}
 344
 345EXPORT_SYMBOL(snd_pcm_format_physical_width);
 346
 347/**
 348 * snd_pcm_format_size - return the byte size of samples on the given format
 349 * @format: the format to check
 350 * @samples: sampling rate
 351 *
 352 * Return: The byte size of the given samples for the format, or a
 353 * negative error code if unknown format.
 354 */
 355ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 356{
 357        int phys_width = snd_pcm_format_physical_width(format);
 358        if (phys_width < 0)
 359                return -EINVAL;
 360        return samples * phys_width / 8;
 361}
 362
 363EXPORT_SYMBOL(snd_pcm_format_size);
 364
 365/**
 366 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 367 * @format: the format to check
 368 *
 369 * Return: The format pattern to fill or %NULL if error.
 370 */
 371const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 372{
 373        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 374                return NULL;
 375        if (! pcm_formats[(INT)format].phys)
 376                return NULL;
 377        return pcm_formats[(INT)format].silence;
 378}
 379
 380EXPORT_SYMBOL(snd_pcm_format_silence_64);
 381
 382/**
 383 * snd_pcm_format_set_silence - set the silence data on the buffer
 384 * @format: the PCM format
 385 * @data: the buffer pointer
 386 * @samples: the number of samples to set silence
 387 *
 388 * Sets the silence data on the buffer for the given samples.
 389 *
 390 * Return: Zero if successful, or a negative error code on failure.
 391 */
 392int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 393{
 394        int width;
 395        unsigned char *dst, *pat;
 396
 397        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 398                return -EINVAL;
 399        if (samples == 0)
 400                return 0;
 401        width = pcm_formats[(INT)format].phys; /* physical width */
 402        pat = pcm_formats[(INT)format].silence;
 403        if (! width)
 404                return -EINVAL;
 405        /* signed or 1 byte data */
 406        if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
 407                unsigned int bytes = samples * width / 8;
 408                memset(data, *pat, bytes);
 409                return 0;
 410        }
 411        /* non-zero samples, fill using a loop */
 412        width /= 8;
 413        dst = data;
 414#if 0
 415        while (samples--) {
 416                memcpy(dst, pat, width);
 417                dst += width;
 418        }
 419#else
 420        /* a bit optimization for constant width */
 421        switch (width) {
 422        case 2:
 423                while (samples--) {
 424                        memcpy(dst, pat, 2);
 425                        dst += 2;
 426                }
 427                break;
 428        case 3:
 429                while (samples--) {
 430                        memcpy(dst, pat, 3);
 431                        dst += 3;
 432                }
 433                break;
 434        case 4:
 435                while (samples--) {
 436                        memcpy(dst, pat, 4);
 437                        dst += 4;
 438                }
 439                break;
 440        case 8:
 441                while (samples--) {
 442                        memcpy(dst, pat, 8);
 443                        dst += 8;
 444                }
 445                break;
 446        }
 447#endif
 448        return 0;
 449}
 450
 451EXPORT_SYMBOL(snd_pcm_format_set_silence);
 452
 453/**
 454 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 455 * @runtime: the runtime instance
 456 *
 457 * Determines the rate_min and rate_max fields from the rates bits of
 458 * the given runtime->hw.
 459 *
 460 * Return: Zero if successful.
 461 */
 462int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
 463{
 464        int i;
 465        for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
 466                if (runtime->hw.rates & (1 << i)) {
 467                        runtime->hw.rate_min = snd_pcm_known_rates.list[i];
 468                        break;
 469                }
 470        }
 471        for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
 472                if (runtime->hw.rates & (1 << i)) {
 473                        runtime->hw.rate_max = snd_pcm_known_rates.list[i];
 474                        break;
 475                }
 476        }
 477        return 0;
 478}
 479
 480EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
 481
 482/**
 483 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 484 * @rate: the sample rate to convert
 485 *
 486 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 487 * SNDRV_PCM_RATE_KNOT for an unknown rate.
 488 */
 489unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
 490{
 491        unsigned int i;
 492
 493        for (i = 0; i < snd_pcm_known_rates.count; i++)
 494                if (snd_pcm_known_rates.list[i] == rate)
 495                        return 1u << i;
 496        return SNDRV_PCM_RATE_KNOT;
 497}
 498EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
 499
 500/**
 501 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
 502 * @rate_bit: the rate bit to convert
 503 *
 504 * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
 505 * or 0 for an unknown rate bit.
 506 */
 507unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
 508{
 509        unsigned int i;
 510
 511        for (i = 0; i < snd_pcm_known_rates.count; i++)
 512                if ((1u << i) == rate_bit)
 513                        return snd_pcm_known_rates.list[i];
 514        return 0;
 515}
 516EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
 517