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