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 * 323 * Returns the byte size of the given samples for the format, or a 324 * negative error code if unknown format. 325 */ 326 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples) 327 { 328 int phys_width = snd_pcm_format_physical_width(format); 329 if (phys_width < 0) 330 return -EINVAL; 331 return samples * phys_width / 8; 332 } 333 334 EXPORT_SYMBOL(snd_pcm_format_size); 335 336 /** 337 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array 338 * @format: the format to check 339 * 340 * Returns the format pattern to fill or NULL if error. 341 */ 342 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format) 343 { 344 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 345 return NULL; 346 if (! pcm_formats[format].phys) 347 return NULL; 348 return pcm_formats[format].silence; 349 } 350 351 EXPORT_SYMBOL(snd_pcm_format_silence_64); 352 353 /** 354 * snd_pcm_format_set_silence - set the silence data on the buffer 355 * @format: the PCM format 356 * @data: the buffer pointer 357 * @samples: the number of samples to set silence 358 * 359 * Sets the silence data on the buffer for the given samples. 360 * 361 * Returns zero if successful, or a negative error code on failure. 362 */ 363 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples) 364 { 365 int width; 366 unsigned char *dst, *pat; 367 368 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 369 return -EINVAL; 370 if (samples == 0) 371 return 0; 372 width = pcm_formats[format].phys; /* physical width */ 373 pat = pcm_formats[format].silence; 374 if (! width) 375 return -EINVAL; 376 /* signed or 1 byte data */ 377 if (pcm_formats[format].signd == 1 || width <= 8) { 378 unsigned int bytes = samples * width / 8; 379 memset(data, *pat, bytes); 380 return 0; 381 } 382 /* non-zero samples, fill using a loop */ 383 width /= 8; 384 dst = data; 385 #if 0 386 while (samples--) { 387 memcpy(dst, pat, width); 388 dst += width; 389 } 390 #else 391 /* a bit optimization for constant width */ 392 switch (width) { 393 case 2: 394 while (samples--) { 395 memcpy(dst, pat, 2); 396 dst += 2; 397 } 398 break; 399 case 3: 400 while (samples--) { 401 memcpy(dst, pat, 3); 402 dst += 3; 403 } 404 break; 405 case 4: 406 while (samples--) { 407 memcpy(dst, pat, 4); 408 dst += 4; 409 } 410 break; 411 case 8: 412 while (samples--) { 413 memcpy(dst, pat, 8); 414 dst += 8; 415 } 416 break; 417 } 418 #endif 419 return 0; 420 } 421 422 EXPORT_SYMBOL(snd_pcm_format_set_silence); 423 424 /** 425 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields 426 * @runtime: the runtime instance 427 * 428 * Determines the rate_min and rate_max fields from the rates bits of 429 * the given runtime->hw. 430 * 431 * Returns zero if successful. 432 */ 433 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime) 434 { 435 int i; 436 for (i = 0; i < (int)snd_pcm_known_rates.count; i++) { 437 if (runtime->hw.rates & (1 << i)) { 438 runtime->hw.rate_min = snd_pcm_known_rates.list[i]; 439 break; 440 } 441 } 442 for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) { 443 if (runtime->hw.rates & (1 << i)) { 444 runtime->hw.rate_max = snd_pcm_known_rates.list[i]; 445 break; 446 } 447 } 448 return 0; 449 } 450 451 EXPORT_SYMBOL(snd_pcm_limit_hw_rates); 452 453 /** 454 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit 455 * @rate: the sample rate to convert 456 * 457 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or 458 * SNDRV_PCM_RATE_KNOT for an unknown rate. 459 */ 460 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) 461 { 462 unsigned int i; 463 464 for (i = 0; i < snd_pcm_known_rates.count; i++) 465 if (snd_pcm_known_rates.list[i] == rate) 466 return 1u << i; 467 return SNDRV_PCM_RATE_KNOT; 468 } 469 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); 470