linux/sound/core/pcm_misc.c
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   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
  27#include "pcm_local.h"
  28
  29#define SND_PCM_FORMAT_UNKNOWN (-1)
  30
  31/* NOTE: "signed" prefix must be given below since the default char is
  32 *       unsigned on some architectures!
  33 */
  34struct pcm_format_data {
  35        unsigned char width;    /* bit width */
  36        unsigned char phys;     /* physical bit width */
  37        signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
  38        signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
  39        unsigned char silence[8];       /* silence data to fill */
  40};
  41
  42/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
  43#define INT     __force int
  44
  45static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
  46        [SNDRV_PCM_FORMAT_S8] = {
  47                .width = 8, .phys = 8, .le = -1, .signd = 1,
  48                .silence = {},
  49        },
  50        [SNDRV_PCM_FORMAT_U8] = {
  51                .width = 8, .phys = 8, .le = -1, .signd = 0,
  52                .silence = { 0x80 },
  53        },
  54        [SNDRV_PCM_FORMAT_S16_LE] = {
  55                .width = 16, .phys = 16, .le = 1, .signd = 1,
  56                .silence = {},
  57        },
  58        [SNDRV_PCM_FORMAT_S16_BE] = {
  59                .width = 16, .phys = 16, .le = 0, .signd = 1,
  60                .silence = {},
  61        },
  62        [SNDRV_PCM_FORMAT_U16_LE] = {
  63                .width = 16, .phys = 16, .le = 1, .signd = 0,
  64                .silence = { 0x00, 0x80 },
  65        },
  66        [SNDRV_PCM_FORMAT_U16_BE] = {
  67                .width = 16, .phys = 16, .le = 0, .signd = 0,
  68                .silence = { 0x80, 0x00 },
  69        },
  70        [SNDRV_PCM_FORMAT_S24_LE] = {
  71                .width = 24, .phys = 32, .le = 1, .signd = 1,
  72                .silence = {},
  73        },
  74        [SNDRV_PCM_FORMAT_S24_BE] = {
  75                .width = 24, .phys = 32, .le = 0, .signd = 1,
  76                .silence = {},
  77        },
  78        [SNDRV_PCM_FORMAT_U24_LE] = {
  79                .width = 24, .phys = 32, .le = 1, .signd = 0,
  80                .silence = { 0x00, 0x00, 0x80 },
  81        },
  82        [SNDRV_PCM_FORMAT_U24_BE] = {
  83                .width = 24, .phys = 32, .le = 0, .signd = 0,
  84                .silence = { 0x00, 0x80, 0x00, 0x00 },
  85        },
  86        [SNDRV_PCM_FORMAT_S32_LE] = {
  87                .width = 32, .phys = 32, .le = 1, .signd = 1,
  88                .silence = {},
  89        },
  90        [SNDRV_PCM_FORMAT_S32_BE] = {
  91                .width = 32, .phys = 32, .le = 0, .signd = 1,
  92                .silence = {},
  93        },
  94        [SNDRV_PCM_FORMAT_U32_LE] = {
  95                .width = 32, .phys = 32, .le = 1, .signd = 0,
  96                .silence = { 0x00, 0x00, 0x00, 0x80 },
  97        },
  98        [SNDRV_PCM_FORMAT_U32_BE] = {
  99                .width = 32, .phys = 32, .le = 0, .signd = 0,
 100                .silence = { 0x80, 0x00, 0x00, 0x00 },
 101        },
 102        [SNDRV_PCM_FORMAT_FLOAT_LE] = {
 103                .width = 32, .phys = 32, .le = 1, .signd = -1,
 104                .silence = {},
 105        },
 106        [SNDRV_PCM_FORMAT_FLOAT_BE] = {
 107                .width = 32, .phys = 32, .le = 0, .signd = -1,
 108                .silence = {},
 109        },
 110        [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
 111                .width = 64, .phys = 64, .le = 1, .signd = -1,
 112                .silence = {},
 113        },
 114        [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
 115                .width = 64, .phys = 64, .le = 0, .signd = -1,
 116                .silence = {},
 117        },
 118        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
 119                .width = 32, .phys = 32, .le = 1, .signd = -1,
 120                .silence = {},
 121        },
 122        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
 123                .width = 32, .phys = 32, .le = 0, .signd = -1,
 124                .silence = {},
 125        },
 126        [SNDRV_PCM_FORMAT_MU_LAW] = {
 127                .width = 8, .phys = 8, .le = -1, .signd = -1,
 128                .silence = { 0x7f },
 129        },
 130        [SNDRV_PCM_FORMAT_A_LAW] = {
 131                .width = 8, .phys = 8, .le = -1, .signd = -1,
 132                .silence = { 0x55 },
 133        },
 134        [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
 135                .width = 4, .phys = 4, .le = -1, .signd = -1,
 136                .silence = {},
 137        },
 138        [SNDRV_PCM_FORMAT_G723_24] = {
 139                .width = 3, .phys = 3, .le = -1, .signd = -1,
 140                .silence = {},
 141        },
 142        [SNDRV_PCM_FORMAT_G723_40] = {
 143                .width = 5, .phys = 5, .le = -1, .signd = -1,
 144                .silence = {},
 145        },
 146        [SNDRV_PCM_FORMAT_DSD_U8] = {
 147                .width = 8, .phys = 8, .le = 1, .signd = 0,
 148                .silence = { 0x69 },
 149        },
 150        [SNDRV_PCM_FORMAT_DSD_U16_LE] = {
 151                .width = 16, .phys = 16, .le = 1, .signd = 0,
 152                .silence = { 0x69, 0x69 },
 153        },
 154        [SNDRV_PCM_FORMAT_DSD_U32_LE] = {
 155                .width = 32, .phys = 32, .le = 1, .signd = 0,
 156                .silence = { 0x69, 0x69, 0x69, 0x69 },
 157        },
 158        [SNDRV_PCM_FORMAT_DSD_U16_BE] = {
 159                .width = 16, .phys = 16, .le = 0, .signd = 0,
 160                .silence = { 0x69, 0x69 },
 161        },
 162        [SNDRV_PCM_FORMAT_DSD_U32_BE] = {
 163                .width = 32, .phys = 32, .le = 0, .signd = 0,
 164                .silence = { 0x69, 0x69, 0x69, 0x69 },
 165        },
 166        /* FIXME: the following three formats are not defined properly yet */
 167        [SNDRV_PCM_FORMAT_MPEG] = {
 168                .le = -1, .signd = -1,
 169        },
 170        [SNDRV_PCM_FORMAT_GSM] = {
 171                .le = -1, .signd = -1,
 172        },
 173        [SNDRV_PCM_FORMAT_SPECIAL] = {
 174                .le = -1, .signd = -1,
 175        },
 176        [SNDRV_PCM_FORMAT_S24_3LE] = {
 177                .width = 24, .phys = 24, .le = 1, .signd = 1,
 178                .silence = {},
 179        },
 180        [SNDRV_PCM_FORMAT_S24_3BE] = {
 181                .width = 24, .phys = 24, .le = 0, .signd = 1,
 182                .silence = {},
 183        },
 184        [SNDRV_PCM_FORMAT_U24_3LE] = {
 185                .width = 24, .phys = 24, .le = 1, .signd = 0,
 186                .silence = { 0x00, 0x00, 0x80 },
 187        },
 188        [SNDRV_PCM_FORMAT_U24_3BE] = {
 189                .width = 24, .phys = 24, .le = 0, .signd = 0,
 190                .silence = { 0x80, 0x00, 0x00 },
 191        },
 192        [SNDRV_PCM_FORMAT_S20_3LE] = {
 193                .width = 20, .phys = 24, .le = 1, .signd = 1,
 194                .silence = {},
 195        },
 196        [SNDRV_PCM_FORMAT_S20_3BE] = {
 197                .width = 20, .phys = 24, .le = 0, .signd = 1,
 198                .silence = {},
 199        },
 200        [SNDRV_PCM_FORMAT_U20_3LE] = {
 201                .width = 20, .phys = 24, .le = 1, .signd = 0,
 202                .silence = { 0x00, 0x00, 0x08 },
 203        },
 204        [SNDRV_PCM_FORMAT_U20_3BE] = {
 205                .width = 20, .phys = 24, .le = 0, .signd = 0,
 206                .silence = { 0x08, 0x00, 0x00 },
 207        },
 208        [SNDRV_PCM_FORMAT_S18_3LE] = {
 209                .width = 18, .phys = 24, .le = 1, .signd = 1,
 210                .silence = {},
 211        },
 212        [SNDRV_PCM_FORMAT_S18_3BE] = {
 213                .width = 18, .phys = 24, .le = 0, .signd = 1,
 214                .silence = {},
 215        },
 216        [SNDRV_PCM_FORMAT_U18_3LE] = {
 217                .width = 18, .phys = 24, .le = 1, .signd = 0,
 218                .silence = { 0x00, 0x00, 0x02 },
 219        },
 220        [SNDRV_PCM_FORMAT_U18_3BE] = {
 221                .width = 18, .phys = 24, .le = 0, .signd = 0,
 222                .silence = { 0x02, 0x00, 0x00 },
 223        },
 224        [SNDRV_PCM_FORMAT_G723_24_1B] = {
 225                .width = 3, .phys = 8, .le = -1, .signd = -1,
 226                .silence = {},
 227        },
 228        [SNDRV_PCM_FORMAT_G723_40_1B] = {
 229                .width = 5, .phys = 8, .le = -1, .signd = -1,
 230                .silence = {},
 231        },
 232};
 233
 234
 235/**
 236 * snd_pcm_format_signed - Check the PCM format is signed linear
 237 * @format: the format to check
 238 *
 239 * Return: 1 if the given PCM format is signed linear, 0 if unsigned
 240 * linear, and a negative error code for non-linear formats.
 241 */
 242int snd_pcm_format_signed(snd_pcm_format_t format)
 243{
 244        int val;
 245        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 246                return -EINVAL;
 247        if ((val = pcm_formats[(INT)format].signd) < 0)
 248                return -EINVAL;
 249        return val;
 250}
 251EXPORT_SYMBOL(snd_pcm_format_signed);
 252
 253/**
 254 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 255 * @format: the format to check
 256 *
 257 * Return: 1 if the given PCM format is unsigned linear, 0 if signed
 258 * linear, and a negative error code for non-linear formats.
 259 */
 260int snd_pcm_format_unsigned(snd_pcm_format_t format)
 261{
 262        int val;
 263
 264        val = snd_pcm_format_signed(format);
 265        if (val < 0)
 266                return val;
 267        return !val;
 268}
 269EXPORT_SYMBOL(snd_pcm_format_unsigned);
 270
 271/**
 272 * snd_pcm_format_linear - Check the PCM format is linear
 273 * @format: the format to check
 274 *
 275 * Return: 1 if the given PCM format is linear, 0 if not.
 276 */
 277int snd_pcm_format_linear(snd_pcm_format_t format)
 278{
 279        return snd_pcm_format_signed(format) >= 0;
 280}
 281EXPORT_SYMBOL(snd_pcm_format_linear);
 282
 283/**
 284 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 285 * @format: the format to check
 286 *
 287 * Return: 1 if the given PCM format is little-endian, 0 if
 288 * big-endian, or a negative error code if endian not specified.
 289 */
 290int snd_pcm_format_little_endian(snd_pcm_format_t format)
 291{
 292        int val;
 293        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 294                return -EINVAL;
 295        if ((val = pcm_formats[(INT)format].le) < 0)
 296                return -EINVAL;
 297        return val;
 298}
 299EXPORT_SYMBOL(snd_pcm_format_little_endian);
 300
 301/**
 302 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 303 * @format: the format to check
 304 *
 305 * Return: 1 if the given PCM format is big-endian, 0 if
 306 * little-endian, or a negative error code if endian not specified.
 307 */
 308int snd_pcm_format_big_endian(snd_pcm_format_t format)
 309{
 310        int val;
 311
 312        val = snd_pcm_format_little_endian(format);
 313        if (val < 0)
 314                return val;
 315        return !val;
 316}
 317EXPORT_SYMBOL(snd_pcm_format_big_endian);
 318
 319/**
 320 * snd_pcm_format_width - return the bit-width of the format
 321 * @format: the format to check
 322 *
 323 * Return: The bit-width of the format, or a negative error code
 324 * if unknown format.
 325 */
 326int snd_pcm_format_width(snd_pcm_format_t format)
 327{
 328        int val;
 329        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 330                return -EINVAL;
 331        if ((val = pcm_formats[(INT)format].width) == 0)
 332                return -EINVAL;
 333        return val;
 334}
 335EXPORT_SYMBOL(snd_pcm_format_width);
 336
 337/**
 338 * snd_pcm_format_physical_width - return the physical bit-width of the format
 339 * @format: the format to check
 340 *
 341 * Return: The physical bit-width of the format, or a negative error code
 342 * if unknown format.
 343 */
 344int snd_pcm_format_physical_width(snd_pcm_format_t format)
 345{
 346        int val;
 347        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 348                return -EINVAL;
 349        if ((val = pcm_formats[(INT)format].phys) == 0)
 350                return -EINVAL;
 351        return val;
 352}
 353EXPORT_SYMBOL(snd_pcm_format_physical_width);
 354
 355/**
 356 * snd_pcm_format_size - return the byte size of samples on the given format
 357 * @format: the format to check
 358 * @samples: sampling rate
 359 *
 360 * Return: The byte size of the given samples for the format, or a
 361 * negative error code if unknown format.
 362 */
 363ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 364{
 365        int phys_width = snd_pcm_format_physical_width(format);
 366        if (phys_width < 0)
 367                return -EINVAL;
 368        return samples * phys_width / 8;
 369}
 370EXPORT_SYMBOL(snd_pcm_format_size);
 371
 372/**
 373 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 374 * @format: the format to check
 375 *
 376 * Return: The format pattern to fill or %NULL if error.
 377 */
 378const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 379{
 380        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 381                return NULL;
 382        if (! pcm_formats[(INT)format].phys)
 383                return NULL;
 384        return pcm_formats[(INT)format].silence;
 385}
 386EXPORT_SYMBOL(snd_pcm_format_silence_64);
 387
 388/**
 389 * snd_pcm_format_set_silence - set the silence data on the buffer
 390 * @format: the PCM format
 391 * @data: the buffer pointer
 392 * @samples: the number of samples to set silence
 393 *
 394 * Sets the silence data on the buffer for the given samples.
 395 *
 396 * Return: Zero if successful, or a negative error code on failure.
 397 */
 398int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 399{
 400        int width;
 401        unsigned char *dst, *pat;
 402
 403        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 404                return -EINVAL;
 405        if (samples == 0)
 406                return 0;
 407        width = pcm_formats[(INT)format].phys; /* physical width */
 408        pat = pcm_formats[(INT)format].silence;
 409        if (! width)
 410                return -EINVAL;
 411        /* signed or 1 byte data */
 412        if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
 413                unsigned int bytes = samples * width / 8;
 414                memset(data, *pat, bytes);
 415                return 0;
 416        }
 417        /* non-zero samples, fill using a loop */
 418        width /= 8;
 419        dst = data;
 420#if 0
 421        while (samples--) {
 422                memcpy(dst, pat, width);
 423                dst += width;
 424        }
 425#else
 426        /* a bit optimization for constant width */
 427        switch (width) {
 428        case 2:
 429                while (samples--) {
 430                        memcpy(dst, pat, 2);
 431                        dst += 2;
 432                }
 433                break;
 434        case 3:
 435                while (samples--) {
 436                        memcpy(dst, pat, 3);
 437                        dst += 3;
 438                }
 439                break;
 440        case 4:
 441                while (samples--) {
 442                        memcpy(dst, pat, 4);
 443                        dst += 4;
 444                }
 445                break;
 446        case 8:
 447                while (samples--) {
 448                        memcpy(dst, pat, 8);
 449                        dst += 8;
 450                }
 451                break;
 452        }
 453#endif
 454        return 0;
 455}
 456EXPORT_SYMBOL(snd_pcm_format_set_silence);
 457
 458/**
 459 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 460 * @runtime: the runtime instance
 461 *
 462 * Determines the rate_min and rate_max fields from the rates bits of
 463 * the given runtime->hw.
 464 *
 465 * Return: Zero if successful.
 466 */
 467int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
 468{
 469        int i;
 470        for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
 471                if (runtime->hw.rates & (1 << i)) {
 472                        runtime->hw.rate_min = snd_pcm_known_rates.list[i];
 473                        break;
 474                }
 475        }
 476        for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
 477                if (runtime->hw.rates & (1 << i)) {
 478                        runtime->hw.rate_max = snd_pcm_known_rates.list[i];
 479                        break;
 480                }
 481        }
 482        return 0;
 483}
 484EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
 485
 486/**
 487 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 488 * @rate: the sample rate to convert
 489 *
 490 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 491 * SNDRV_PCM_RATE_KNOT for an unknown rate.
 492 */
 493unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
 494{
 495        unsigned int i;
 496
 497        for (i = 0; i < snd_pcm_known_rates.count; i++)
 498                if (snd_pcm_known_rates.list[i] == rate)
 499                        return 1u << i;
 500        return SNDRV_PCM_RATE_KNOT;
 501}
 502EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
 503
 504/**
 505 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
 506 * @rate_bit: the rate bit to convert
 507 *
 508 * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
 509 * or 0 for an unknown rate bit.
 510 */
 511unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
 512{
 513        unsigned int i;
 514
 515        for (i = 0; i < snd_pcm_known_rates.count; i++)
 516                if ((1u << i) == rate_bit)
 517                        return snd_pcm_known_rates.list[i];
 518        return 0;
 519}
 520EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
 521
 522static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
 523{
 524        if (rates & SNDRV_PCM_RATE_CONTINUOUS)
 525                return SNDRV_PCM_RATE_CONTINUOUS;
 526        else if (rates & SNDRV_PCM_RATE_KNOT)
 527                return SNDRV_PCM_RATE_KNOT;
 528        return rates;
 529}
 530
 531/**
 532 * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
 533 * @rates_a: The first rate mask
 534 * @rates_b: The second rate mask
 535 *
 536 * This function computes the rates that are supported by both rate masks passed
 537 * to the function. It will take care of the special handling of
 538 * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
 539 *
 540 * Return: A rate mask containing the rates that are supported by both rates_a
 541 * and rates_b.
 542 */
 543unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
 544        unsigned int rates_b)
 545{
 546        rates_a = snd_pcm_rate_mask_sanitize(rates_a);
 547        rates_b = snd_pcm_rate_mask_sanitize(rates_b);
 548
 549        if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
 550                return rates_b;
 551        else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
 552                return rates_a;
 553        else if (rates_a & SNDRV_PCM_RATE_KNOT)
 554                return rates_b;
 555        else if (rates_b & SNDRV_PCM_RATE_KNOT)
 556                return rates_a;
 557        return rates_a & rates_b;
 558}
 559EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
 560
 561/**
 562 * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
 563 * @rate_min: the minimum sample rate
 564 * @rate_max: the maximum sample rate
 565 *
 566 * This function has an implicit assumption: the rates in the given range have
 567 * only the pre-defined rates like 44100 or 16000.
 568 *
 569 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
 570 * or SNDRV_PCM_RATE_KNOT for an unknown range.
 571 */
 572unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
 573        unsigned int rate_max)
 574{
 575        unsigned int rates = 0;
 576        int i;
 577
 578        for (i = 0; i < snd_pcm_known_rates.count; i++) {
 579                if (snd_pcm_known_rates.list[i] >= rate_min
 580                        && snd_pcm_known_rates.list[i] <= rate_max)
 581                        rates |= 1 << i;
 582        }
 583
 584        if (!rates)
 585                rates = SNDRV_PCM_RATE_KNOT;
 586
 587        return rates;
 588}
 589EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);
 590
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