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 static struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = { 39 [SNDRV_PCM_FORMAT_S8] = { 40 .width = 8, .phys = 8, .le = -1, .signd = 1, 41 .silence = {}, 42 }, 43 [SNDRV_PCM_FORMAT_U8] = { 44 .width = 8, .phys = 8, .le = -1, .signd = 0, 45 .silence = { 0x80 }, 46 }, 47 [SNDRV_PCM_FORMAT_S16_LE] = { 48 .width = 16, .phys = 16, .le = 1, .signd = 1, 49 .silence = {}, 50 }, 51 [SNDRV_PCM_FORMAT_S16_BE] = { 52 .width = 16, .phys = 16, .le = 0, .signd = 1, 53 .silence = {}, 54 }, 55 [SNDRV_PCM_FORMAT_U16_LE] = { 56 .width = 16, .phys = 16, .le = 1, .signd = 0, 57 .silence = { 0x00, 0x80 }, 58 }, 59 [SNDRV_PCM_FORMAT_U16_BE] = { 60 .width = 16, .phys = 16, .le = 0, .signd = 0, 61 .silence = { 0x80, 0x00 }, 62 }, 63 [SNDRV_PCM_FORMAT_S24_LE] = { 64 .width = 24, .phys = 32, .le = 1, .signd = 1, 65 .silence = {}, 66 }, 67 [SNDRV_PCM_FORMAT_S24_BE] = { 68 .width = 24, .phys = 32, .le = 0, .signd = 1, 69 .silence = {}, 70 }, 71 [SNDRV_PCM_FORMAT_U24_LE] = { 72 .width = 24, .phys = 32, .le = 1, .signd = 0, 73 .silence = { 0x00, 0x00, 0x80 }, 74 }, 75 [SNDRV_PCM_FORMAT_U24_BE] = { 76 .width = 24, .phys = 32, .le = 0, .signd = 0, 77 .silence = { 0x00, 0x80, 0x00, 0x00 }, 78 }, 79 [SNDRV_PCM_FORMAT_S32_LE] = { 80 .width = 32, .phys = 32, .le = 1, .signd = 1, 81 .silence = {}, 82 }, 83 [SNDRV_PCM_FORMAT_S32_BE] = { 84 .width = 32, .phys = 32, .le = 0, .signd = 1, 85 .silence = {}, 86 }, 87 [SNDRV_PCM_FORMAT_U32_LE] = { 88 .width = 32, .phys = 32, .le = 1, .signd = 0, 89 .silence = { 0x00, 0x00, 0x00, 0x80 }, 90 }, 91 [SNDRV_PCM_FORMAT_U32_BE] = { 92 .width = 32, .phys = 32, .le = 0, .signd = 0, 93 .silence = { 0x80, 0x00, 0x00, 0x00 }, 94 }, 95 [SNDRV_PCM_FORMAT_FLOAT_LE] = { 96 .width = 32, .phys = 32, .le = 1, .signd = -1, 97 .silence = {}, 98 }, 99 [SNDRV_PCM_FORMAT_FLOAT_BE] = { 100 .width = 32, .phys = 32, .le = 0, .signd = -1, 101 .silence = {}, 102 }, 103 [SNDRV_PCM_FORMAT_FLOAT64_LE] = { 104 .width = 64, .phys = 64, .le = 1, .signd = -1, 105 .silence = {}, 106 }, 107 [SNDRV_PCM_FORMAT_FLOAT64_BE] = { 108 .width = 64, .phys = 64, .le = 0, .signd = -1, 109 .silence = {}, 110 }, 111 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = { 112 .width = 32, .phys = 32, .le = 1, .signd = -1, 113 .silence = {}, 114 }, 115 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = { 116 .width = 32, .phys = 32, .le = 0, .signd = -1, 117 .silence = {}, 118 }, 119 [SNDRV_PCM_FORMAT_MU_LAW] = { 120 .width = 8, .phys = 8, .le = -1, .signd = -1, 121 .silence = { 0x7f }, 122 }, 123 [SNDRV_PCM_FORMAT_A_LAW] = { 124 .width = 8, .phys = 8, .le = -1, .signd = -1, 125 .silence = { 0x55 }, 126 }, 127 [SNDRV_PCM_FORMAT_IMA_ADPCM] = { 128 .width = 4, .phys = 4, .le = -1, .signd = -1, 129 .silence = {}, 130 }, 131 /* FIXME: the following three formats are not defined properly yet */ 132 [SNDRV_PCM_FORMAT_MPEG] = { 133 .le = -1, .signd = -1, 134 }, 135 [SNDRV_PCM_FORMAT_GSM] = { 136 .le = -1, .signd = -1, 137 }, 138 [SNDRV_PCM_FORMAT_SPECIAL] = { 139 .le = -1, .signd = -1, 140 }, 141 [SNDRV_PCM_FORMAT_S24_3LE] = { 142 .width = 24, .phys = 24, .le = 1, .signd = 1, 143 .silence = {}, 144 }, 145 [SNDRV_PCM_FORMAT_S24_3BE] = { 146 .width = 24, .phys = 24, .le = 0, .signd = 1, 147 .silence = {}, 148 }, 149 [SNDRV_PCM_FORMAT_U24_3LE] = { 150 .width = 24, .phys = 24, .le = 1, .signd = 0, 151 .silence = { 0x00, 0x00, 0x80 }, 152 }, 153 [SNDRV_PCM_FORMAT_U24_3BE] = { 154 .width = 24, .phys = 24, .le = 0, .signd = 0, 155 .silence = { 0x80, 0x00, 0x00 }, 156 }, 157 [SNDRV_PCM_FORMAT_S20_3LE] = { 158 .width = 20, .phys = 24, .le = 1, .signd = 1, 159 .silence = {}, 160 }, 161 [SNDRV_PCM_FORMAT_S20_3BE] = { 162 .width = 20, .phys = 24, .le = 0, .signd = 1, 163 .silence = {}, 164 }, 165 [SNDRV_PCM_FORMAT_U20_3LE] = { 166 .width = 20, .phys = 24, .le = 1, .signd = 0, 167 .silence = { 0x00, 0x00, 0x08 }, 168 }, 169 [SNDRV_PCM_FORMAT_U20_3BE] = { 170 .width = 20, .phys = 24, .le = 0, .signd = 0, 171 .silence = { 0x08, 0x00, 0x00 }, 172 }, 173 [SNDRV_PCM_FORMAT_S18_3LE] = { 174 .width = 18, .phys = 24, .le = 1, .signd = 1, 175 .silence = {}, 176 }, 177 [SNDRV_PCM_FORMAT_S18_3BE] = { 178 .width = 18, .phys = 24, .le = 0, .signd = 1, 179 .silence = {}, 180 }, 181 [SNDRV_PCM_FORMAT_U18_3LE] = { 182 .width = 18, .phys = 24, .le = 1, .signd = 0, 183 .silence = { 0x00, 0x00, 0x02 }, 184 }, 185 [SNDRV_PCM_FORMAT_U18_3BE] = { 186 .width = 18, .phys = 24, .le = 0, .signd = 0, 187 .silence = { 0x02, 0x00, 0x00 }, 188 }, 189 }; 190 191 192 /** 193 * snd_pcm_format_signed - Check the PCM format is signed linear 194 * @format: the format to check 195 * 196 * Returns 1 if the given PCM format is signed linear, 0 if unsigned 197 * linear, and a negative error code for non-linear formats. 198 */ 199 int snd_pcm_format_signed(snd_pcm_format_t format) 200 { 201 int val; 202 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 203 return -EINVAL; 204 if ((val = pcm_formats[format].signd) < 0) 205 return -EINVAL; 206 return val; 207 } 208 209 EXPORT_SYMBOL(snd_pcm_format_signed); 210 211 /** 212 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear 213 * @format: the format to check 214 * 215 * Returns 1 if the given PCM format is unsigned linear, 0 if signed 216 * linear, and a negative error code for non-linear formats. 217 */ 218 int snd_pcm_format_unsigned(snd_pcm_format_t format) 219 { 220 int val; 221 222 val = snd_pcm_format_signed(format); 223 if (val < 0) 224 return val; 225 return !val; 226 } 227 228 EXPORT_SYMBOL(snd_pcm_format_unsigned); 229 230 /** 231 * snd_pcm_format_linear - Check the PCM format is linear 232 * @format: the format to check 233 * 234 * Returns 1 if the given PCM format is linear, 0 if not. 235 */ 236 int snd_pcm_format_linear(snd_pcm_format_t format) 237 { 238 return snd_pcm_format_signed(format) >= 0; 239 } 240 241 EXPORT_SYMBOL(snd_pcm_format_linear); 242 243 /** 244 * snd_pcm_format_little_endian - Check the PCM format is little-endian 245 * @format: the format to check 246 * 247 * Returns 1 if the given PCM format is little-endian, 0 if 248 * big-endian, or a negative error code if endian not specified. 249 */ 250 int snd_pcm_format_little_endian(snd_pcm_format_t format) 251 { 252 int val; 253 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 254 return -EINVAL; 255 if ((val = pcm_formats[format].le) < 0) 256 return -EINVAL; 257 return val; 258 } 259 260 EXPORT_SYMBOL(snd_pcm_format_little_endian); 261 262 /** 263 * snd_pcm_format_big_endian - Check the PCM format is big-endian 264 * @format: the format to check 265 * 266 * Returns 1 if the given PCM format is big-endian, 0 if 267 * little-endian, or a negative error code if endian not specified. 268 */ 269 int snd_pcm_format_big_endian(snd_pcm_format_t format) 270 { 271 int val; 272 273 val = snd_pcm_format_little_endian(format); 274 if (val < 0) 275 return val; 276 return !val; 277 } 278 279 EXPORT_SYMBOL(snd_pcm_format_big_endian); 280 281 /** 282 * snd_pcm_format_width - return the bit-width of the format 283 * @format: the format to check 284 * 285 * Returns the bit-width of the format, or a negative error code 286 * if unknown format. 287 */ 288 int snd_pcm_format_width(snd_pcm_format_t format) 289 { 290 int val; 291 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 292 return -EINVAL; 293 if ((val = pcm_formats[format].width) == 0) 294 return -EINVAL; 295 return val; 296 } 297 298 EXPORT_SYMBOL(snd_pcm_format_width); 299 300 /** 301 * snd_pcm_format_physical_width - return the physical bit-width of the format 302 * @format: the format to check 303 * 304 * Returns the physical bit-width of the format, or a negative error code 305 * if unknown format. 306 */ 307 int snd_pcm_format_physical_width(snd_pcm_format_t format) 308 { 309 int val; 310 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 311 return -EINVAL; 312 if ((val = pcm_formats[format].phys) == 0) 313 return -EINVAL; 314 return val; 315 } 316 317 EXPORT_SYMBOL(snd_pcm_format_physical_width); 318 319 /** 320 * snd_pcm_format_size - return the byte size of samples on the given format 321 * @format: the format to check 322 * @samples: sampling rate 323 * 324 * Returns the byte size of the given samples for the format, or a 325 * negative error code if unknown format. 326 */ 327 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples) 328 { 329 int phys_width = snd_pcm_format_physical_width(format); 330 if (phys_width < 0) 331 return -EINVAL; 332 return samples * phys_width / 8; 333 } 334 335 EXPORT_SYMBOL(snd_pcm_format_size); 336 337 /** 338 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array 339 * @format: the format to check 340 * 341 * Returns the format pattern to fill or NULL if error. 342 */ 343 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format) 344 { 345 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 346 return NULL; 347 if (! pcm_formats[format].phys) 348 return NULL; 349 return pcm_formats[format].silence; 350 } 351 352 EXPORT_SYMBOL(snd_pcm_format_silence_64); 353 354 /** 355 * snd_pcm_format_set_silence - set the silence data on the buffer 356 * @format: the PCM format 357 * @data: the buffer pointer 358 * @samples: the number of samples to set silence 359 * 360 * Sets the silence data on the buffer for the given samples. 361 * 362 * Returns zero if successful, or a negative error code on failure. 363 */ 364 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples) 365 { 366 int width; 367 unsigned char *dst, *pat; 368 369 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 370 return -EINVAL; 371 if (samples == 0) 372 return 0; 373 width = pcm_formats[format].phys; /* physical width */ 374 pat = pcm_formats[format].silence; 375 if (! width) 376 return -EINVAL; 377 /* signed or 1 byte data */ 378 if (pcm_formats[format].signd == 1 || width <= 8) { 379 unsigned int bytes = samples * width / 8; 380 memset(data, *pat, bytes); 381 return 0; 382 } 383 /* non-zero samples, fill using a loop */ 384 width /= 8; 385 dst = data; 386 #if 0 387 while (samples--) { 388 memcpy(dst, pat, width); 389 dst += width; 390 } 391 #else 392 /* a bit optimization for constant width */ 393 switch (width) { 394 case 2: 395 while (samples--) { 396 memcpy(dst, pat, 2); 397 dst += 2; 398 } 399 break; 400 case 3: 401 while (samples--) { 402 memcpy(dst, pat, 3); 403 dst += 3; 404 } 405 break; 406 case 4: 407 while (samples--) { 408 memcpy(dst, pat, 4); 409 dst += 4; 410 } 411 break; 412 case 8: 413 while (samples--) { 414 memcpy(dst, pat, 8); 415 dst += 8; 416 } 417 break; 418 } 419 #endif 420 return 0; 421 } 422 423 EXPORT_SYMBOL(snd_pcm_format_set_silence); 424 425 /** 426 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields 427 * @runtime: the runtime instance 428 * 429 * Determines the rate_min and rate_max fields from the rates bits of 430 * the given runtime->hw. 431 * 432 * Returns zero if successful. 433 */ 434 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime) 435 { 436 int i; 437 for (i = 0; i < (int)snd_pcm_known_rates.count; i++) { 438 if (runtime->hw.rates & (1 << i)) { 439 runtime->hw.rate_min = snd_pcm_known_rates.list[i]; 440 break; 441 } 442 } 443 for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) { 444 if (runtime->hw.rates & (1 << i)) { 445 runtime->hw.rate_max = snd_pcm_known_rates.list[i]; 446 break; 447 } 448 } 449 return 0; 450 } 451 452 EXPORT_SYMBOL(snd_pcm_limit_hw_rates); 453 454 /** 455 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit 456 * @rate: the sample rate to convert 457 * 458 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or 459 * SNDRV_PCM_RATE_KNOT for an unknown rate. 460 */ 461 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) 462 { 463 unsigned int i; 464 465 for (i = 0; i < snd_pcm_known_rates.count; i++) 466 if (snd_pcm_known_rates.list[i] == rate) 467 return 1u << i; 468 return SNDRV_PCM_RATE_KNOT; 469 } 470 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); 471