sound/core/pcm_misc.c

   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  */
  34 struct 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
  45 static 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  */
 242 int 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 }
 251 EXPORT_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  */
 260 int 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 }
 269 EXPORT_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  */
 277 int snd_pcm_format_linear(snd_pcm_format_t format)
 278 {
 279         return snd_pcm_format_signed(format) >= 0;
 280 }
 281 EXPORT_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  */
 290 int 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 }
 299 EXPORT_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  */
 308 int 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 }
 317 EXPORT_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  */
 326 int 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 }
 335 EXPORT_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  */
 344 int 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 }
 353 EXPORT_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  */
 363 ssize_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 }
 370 EXPORT_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  */
 378 const 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 }
 386 EXPORT_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  */
 398 int 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 }
 456 EXPORT_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  */
 467 int 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 }
 484 EXPORT_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  */
 493 unsigned 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 }
 502 EXPORT_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  */
 511 unsigned 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 }
 520 EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
 521
 522 static 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  */
 543 unsigned 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 }
 559 EXPORT_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  */
 572 unsigned 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 }
 589 EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);