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 bool valid_format(snd_pcm_format_t format)
46{
47 return (INT)format >= 0 && (INT)format <= (INT)SNDRV_PCM_FORMAT_LAST;
48}
49
50static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
51 [SNDRV_PCM_FORMAT_S8] = {
52 .width = 8, .phys = 8, .le = -1, .signd = 1,
53 .silence = {},
54 },
55 [SNDRV_PCM_FORMAT_U8] = {
56 .width = 8, .phys = 8, .le = -1, .signd = 0,
57 .silence = { 0x80 },
58 },
59 [SNDRV_PCM_FORMAT_S16_LE] = {
60 .width = 16, .phys = 16, .le = 1, .signd = 1,
61 .silence = {},
62 },
63 [SNDRV_PCM_FORMAT_S16_BE] = {
64 .width = 16, .phys = 16, .le = 0, .signd = 1,
65 .silence = {},
66 },
67 [SNDRV_PCM_FORMAT_U16_LE] = {
68 .width = 16, .phys = 16, .le = 1, .signd = 0,
69 .silence = { 0x00, 0x80 },
70 },
71 [SNDRV_PCM_FORMAT_U16_BE] = {
72 .width = 16, .phys = 16, .le = 0, .signd = 0,
73 .silence = { 0x80, 0x00 },
74 },
75 [SNDRV_PCM_FORMAT_S24_LE] = {
76 .width = 24, .phys = 32, .le = 1, .signd = 1,
77 .silence = {},
78 },
79 [SNDRV_PCM_FORMAT_S24_BE] = {
80 .width = 24, .phys = 32, .le = 0, .signd = 1,
81 .silence = {},
82 },
83 [SNDRV_PCM_FORMAT_U24_LE] = {
84 .width = 24, .phys = 32, .le = 1, .signd = 0,
85 .silence = { 0x00, 0x00, 0x80 },
86 },
87 [SNDRV_PCM_FORMAT_U24_BE] = {
88 .width = 24, .phys = 32, .le = 0, .signd = 0,
89 .silence = { 0x00, 0x80, 0x00, 0x00 },
90 },
91 [SNDRV_PCM_FORMAT_S32_LE] = {
92 .width = 32, .phys = 32, .le = 1, .signd = 1,
93 .silence = {},
94 },
95 [SNDRV_PCM_FORMAT_S32_BE] = {
96 .width = 32, .phys = 32, .le = 0, .signd = 1,
97 .silence = {},
98 },
99 [SNDRV_PCM_FORMAT_U32_LE] = {
100 .width = 32, .phys = 32, .le = 1, .signd = 0,
101 .silence = { 0x00, 0x00, 0x00, 0x80 },
102 },
103 [SNDRV_PCM_FORMAT_U32_BE] = {
104 .width = 32, .phys = 32, .le = 0, .signd = 0,
105 .silence = { 0x80, 0x00, 0x00, 0x00 },
106 },
107 [SNDRV_PCM_FORMAT_FLOAT_LE] = {
108 .width = 32, .phys = 32, .le = 1, .signd = -1,
109 .silence = {},
110 },
111 [SNDRV_PCM_FORMAT_FLOAT_BE] = {
112 .width = 32, .phys = 32, .le = 0, .signd = -1,
113 .silence = {},
114 },
115 [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
116 .width = 64, .phys = 64, .le = 1, .signd = -1,
117 .silence = {},
118 },
119 [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
120 .width = 64, .phys = 64, .le = 0, .signd = -1,
121 .silence = {},
122 },
123 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
124 .width = 32, .phys = 32, .le = 1, .signd = -1,
125 .silence = {},
126 },
127 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
128 .width = 32, .phys = 32, .le = 0, .signd = -1,
129 .silence = {},
130 },
131 [SNDRV_PCM_FORMAT_MU_LAW] = {
132 .width = 8, .phys = 8, .le = -1, .signd = -1,
133 .silence = { 0x7f },
134 },
135 [SNDRV_PCM_FORMAT_A_LAW] = {
136 .width = 8, .phys = 8, .le = -1, .signd = -1,
137 .silence = { 0x55 },
138 },
139 [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
140 .width = 4, .phys = 4, .le = -1, .signd = -1,
141 .silence = {},
142 },
143 [SNDRV_PCM_FORMAT_G723_24] = {
144 .width = 3, .phys = 3, .le = -1, .signd = -1,
145 .silence = {},
146 },
147 [SNDRV_PCM_FORMAT_G723_40] = {
148 .width = 5, .phys = 5, .le = -1, .signd = -1,
149 .silence = {},
150 },
151 [SNDRV_PCM_FORMAT_DSD_U8] = {
152 .width = 8, .phys = 8, .le = 1, .signd = 0,
153 .silence = { 0x69 },
154 },
155 [SNDRV_PCM_FORMAT_DSD_U16_LE] = {
156 .width = 16, .phys = 16, .le = 1, .signd = 0,
157 .silence = { 0x69, 0x69 },
158 },
159 [SNDRV_PCM_FORMAT_DSD_U32_LE] = {
160 .width = 32, .phys = 32, .le = 1, .signd = 0,
161 .silence = { 0x69, 0x69, 0x69, 0x69 },
162 },
163 [SNDRV_PCM_FORMAT_DSD_U16_BE] = {
164 .width = 16, .phys = 16, .le = 0, .signd = 0,
165 .silence = { 0x69, 0x69 },
166 },
167 [SNDRV_PCM_FORMAT_DSD_U32_BE] = {
168 .width = 32, .phys = 32, .le = 0, .signd = 0,
169 .silence = { 0x69, 0x69, 0x69, 0x69 },
170 },
171 /* FIXME: the following two formats are not defined properly yet */
172 [SNDRV_PCM_FORMAT_MPEG] = {
173 .le = -1, .signd = -1,
174 },
175 [SNDRV_PCM_FORMAT_GSM] = {
176 .le = -1, .signd = -1,
177 },
178 [SNDRV_PCM_FORMAT_S20_LE] = {
179 .width = 20, .phys = 32, .le = 1, .signd = 1,
180 .silence = {},
181 },
182 [SNDRV_PCM_FORMAT_S20_BE] = {
183 .width = 20, .phys = 32, .le = 0, .signd = 1,
184 .silence = {},
185 },
186 [SNDRV_PCM_FORMAT_U20_LE] = {
187 .width = 20, .phys = 32, .le = 1, .signd = 0,
188 .silence = { 0x00, 0x00, 0x08, 0x00 },
189 },
190 [SNDRV_PCM_FORMAT_U20_BE] = {
191 .width = 20, .phys = 32, .le = 0, .signd = 0,
192 .silence = { 0x00, 0x08, 0x00, 0x00 },
193 },
194 /* FIXME: the following format is not defined properly yet */
195 [SNDRV_PCM_FORMAT_SPECIAL] = {
196 .le = -1, .signd = -1,
197 },
198 [SNDRV_PCM_FORMAT_S24_3LE] = {
199 .width = 24, .phys = 24, .le = 1, .signd = 1,
200 .silence = {},
201 },
202 [SNDRV_PCM_FORMAT_S24_3BE] = {
203 .width = 24, .phys = 24, .le = 0, .signd = 1,
204 .silence = {},
205 },
206 [SNDRV_PCM_FORMAT_U24_3LE] = {
207 .width = 24, .phys = 24, .le = 1, .signd = 0,
208 .silence = { 0x00, 0x00, 0x80 },
209 },
210 [SNDRV_PCM_FORMAT_U24_3BE] = {
211 .width = 24, .phys = 24, .le = 0, .signd = 0,
212 .silence = { 0x80, 0x00, 0x00 },
213 },
214 [SNDRV_PCM_FORMAT_S20_3LE] = {
215 .width = 20, .phys = 24, .le = 1, .signd = 1,
216 .silence = {},
217 },
218 [SNDRV_PCM_FORMAT_S20_3BE] = {
219 .width = 20, .phys = 24, .le = 0, .signd = 1,
220 .silence = {},
221 },
222 [SNDRV_PCM_FORMAT_U20_3LE] = {
223 .width = 20, .phys = 24, .le = 1, .signd = 0,
224 .silence = { 0x00, 0x00, 0x08 },
225 },
226 [SNDRV_PCM_FORMAT_U20_3BE] = {
227 .width = 20, .phys = 24, .le = 0, .signd = 0,
228 .silence = { 0x08, 0x00, 0x00 },
229 },
230 [SNDRV_PCM_FORMAT_S18_3LE] = {
231 .width = 18, .phys = 24, .le = 1, .signd = 1,
232 .silence = {},
233 },
234 [SNDRV_PCM_FORMAT_S18_3BE] = {
235 .width = 18, .phys = 24, .le = 0, .signd = 1,
236 .silence = {},
237 },
238 [SNDRV_PCM_FORMAT_U18_3LE] = {
239 .width = 18, .phys = 24, .le = 1, .signd = 0,
240 .silence = { 0x00, 0x00, 0x02 },
241 },
242 [SNDRV_PCM_FORMAT_U18_3BE] = {
243 .width = 18, .phys = 24, .le = 0, .signd = 0,
244 .silence = { 0x02, 0x00, 0x00 },
245 },
246 [SNDRV_PCM_FORMAT_G723_24_1B] = {
247 .width = 3, .phys = 8, .le = -1, .signd = -1,
248 .silence = {},
249 },
250 [SNDRV_PCM_FORMAT_G723_40_1B] = {
251 .width = 5, .phys = 8, .le = -1, .signd = -1,
252 .silence = {},
253 },
254};
255
256
257/**
258 * snd_pcm_format_signed - Check the PCM format is signed linear
259 * @format: the format to check
260 *
261 * Return: 1 if the given PCM format is signed linear, 0 if unsigned
262 * linear, and a negative error code for non-linear formats.
263 */
264int snd_pcm_format_signed(snd_pcm_format_t format)
265{
266 int val;
267 if (!valid_format(format))
268 return -EINVAL;
269 val = pcm_formats[(INT)format].signd;
270 if (val < 0)
271 return -EINVAL;
272 return val;
273}
274EXPORT_SYMBOL(snd_pcm_format_signed);
275
276/**
277 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
278 * @format: the format to check
279 *
280 * Return: 1 if the given PCM format is unsigned linear, 0 if signed
281 * linear, and a negative error code for non-linear formats.
282 */
283int snd_pcm_format_unsigned(snd_pcm_format_t format)
284{
285 int val;
286
287 val = snd_pcm_format_signed(format);
288 if (val < 0)
289 return val;
290 return !val;
291}
292EXPORT_SYMBOL(snd_pcm_format_unsigned);
293
294/**
295 * snd_pcm_format_linear - Check the PCM format is linear
296 * @format: the format to check
297 *
298 * Return: 1 if the given PCM format is linear, 0 if not.
299 */
300int snd_pcm_format_linear(snd_pcm_format_t format)
301{
302 return snd_pcm_format_signed(format) >= 0;
303}
304EXPORT_SYMBOL(snd_pcm_format_linear);
305
306/**
307 * snd_pcm_format_little_endian - Check the PCM format is little-endian
308 * @format: the format to check
309 *
310 * Return: 1 if the given PCM format is little-endian, 0 if
311 * big-endian, or a negative error code if endian not specified.
312 */
313int snd_pcm_format_little_endian(snd_pcm_format_t format)
314{
315 int val;
316 if (!valid_format(format))
317 return -EINVAL;
318 val = pcm_formats[(INT)format].le;
319 if (val < 0)
320 return -EINVAL;
321 return val;
322}
323EXPORT_SYMBOL(snd_pcm_format_little_endian);
324
325/**
326 * snd_pcm_format_big_endian - Check the PCM format is big-endian
327 * @format: the format to check
328 *
329 * Return: 1 if the given PCM format is big-endian, 0 if
330 * little-endian, or a negative error code if endian not specified.
331 */
332int snd_pcm_format_big_endian(snd_pcm_format_t format)
333{
334 int val;
335
336 val = snd_pcm_format_little_endian(format);
337 if (val < 0)
338 return val;
339 return !val;
340}
341EXPORT_SYMBOL(snd_pcm_format_big_endian);
342
343/**
344 * snd_pcm_format_width - return the bit-width of the format
345 * @format: the format to check
346 *
347 * Return: The bit-width of the format, or a negative error code
348 * if unknown format.
349 */
350int snd_pcm_format_width(snd_pcm_format_t format)
351{
352 int val;
353 if (!valid_format(format))
354 return -EINVAL;
355 val = pcm_formats[(INT)format].width;
356 if (!val)
357 return -EINVAL;
358 return val;
359}
360EXPORT_SYMBOL(snd_pcm_format_width);
361
362/**
363 * snd_pcm_format_physical_width - return the physical bit-width of the format
364 * @format: the format to check
365 *
366 * Return: The physical bit-width of the format, or a negative error code
367 * if unknown format.
368 */
369int snd_pcm_format_physical_width(snd_pcm_format_t format)
370{
371 int val;
372 if (!valid_format(format))
373 return -EINVAL;
374 val = pcm_formats[(INT)format].phys;
375 if (!val)
376 return -EINVAL;
377 return val;
378}
379EXPORT_SYMBOL(snd_pcm_format_physical_width);
380
381/**
382 * snd_pcm_format_size - return the byte size of samples on the given format
383 * @format: the format to check
384 * @samples: sampling rate
385 *
386 * Return: The byte size of the given samples for the format, or a
387 * negative error code if unknown format.
388 */
389ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
390{
391 int phys_width = snd_pcm_format_physical_width(format);
392 if (phys_width < 0)
393 return -EINVAL;
394 return samples * phys_width / 8;
395}
396EXPORT_SYMBOL(snd_pcm_format_size);
397
398/**
399 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
400 * @format: the format to check
401 *
402 * Return: The format pattern to fill or %NULL if error.
403 */
404const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
405{
406 if (!valid_format(format))
407 return NULL;
408 if (! pcm_formats[(INT)format].phys)
409 return NULL;
410 return pcm_formats[(INT)format].silence;
411}
412EXPORT_SYMBOL(snd_pcm_format_silence_64);
413
414/**
415 * snd_pcm_format_set_silence - set the silence data on the buffer
416 * @format: the PCM format
417 * @data: the buffer pointer
418 * @samples: the number of samples to set silence
419 *
420 * Sets the silence data on the buffer for the given samples.
421 *
422 * Return: Zero if successful, or a negative error code on failure.
423 */
424int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
425{
426 int width;
427 unsigned char *dst;
428 const unsigned char *pat;
429
430 if (!valid_format(format))
431 return -EINVAL;
432 if (samples == 0)
433 return 0;
434 width = pcm_formats[(INT)format].phys; /* physical width */
435 pat = pcm_formats[(INT)format].silence;
436 if (!width || !pat)
437 return -EINVAL;
438 /* signed or 1 byte data */
439 if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
440 unsigned int bytes = samples * width / 8;
441 memset(data, *pat, bytes);
442 return 0;
443 }
444 /* non-zero samples, fill using a loop */
445 width /= 8;
446 dst = data;
447#if 0
448 while (samples--) {
449 memcpy(dst, pat, width);
450 dst += width;
451 }
452#else
453 /* a bit optimization for constant width */
454 switch (width) {
455 case 2:
456 while (samples--) {
457 memcpy(dst, pat, 2);
458 dst += 2;
459 }
460 break;
461 case 3:
462 while (samples--) {
463 memcpy(dst, pat, 3);
464 dst += 3;
465 }
466 break;
467 case 4:
468 while (samples--) {
469 memcpy(dst, pat, 4);
470 dst += 4;
471 }
472 break;
473 case 8:
474 while (samples--) {
475 memcpy(dst, pat, 8);
476 dst += 8;
477 }
478 break;
479 }
480#endif
481 return 0;
482}
483EXPORT_SYMBOL(snd_pcm_format_set_silence);
484
485/**
486 * snd_pcm_hw_limit_rates - determine rate_min/rate_max fields
487 * @hw: the pcm hw instance
488 *
489 * Determines the rate_min and rate_max fields from the rates bits of
490 * the given hw.
491 *
492 * Return: Zero if successful.
493 */
494int snd_pcm_hw_limit_rates(struct snd_pcm_hardware *hw)
495{
496 int i;
497 for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
498 if (hw->rates & (1 << i)) {
499 hw->rate_min = snd_pcm_known_rates.list[i];
500 break;
501 }
502 }
503 for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
504 if (hw->rates & (1 << i)) {
505 hw->rate_max = snd_pcm_known_rates.list[i];
506 break;
507 }
508 }
509 return 0;
510}
511EXPORT_SYMBOL(snd_pcm_hw_limit_rates);
512
513/**
514 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
515 * @rate: the sample rate to convert
516 *
517 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
518 * SNDRV_PCM_RATE_KNOT for an unknown rate.
519 */
520unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
521{
522 unsigned int i;
523
524 for (i = 0; i < snd_pcm_known_rates.count; i++)
525 if (snd_pcm_known_rates.list[i] == rate)
526 return 1u << i;
527 return SNDRV_PCM_RATE_KNOT;
528}
529EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
530
531/**
532 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
533 * @rate_bit: the rate bit to convert
534 *
535 * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
536 * or 0 for an unknown rate bit.
537 */
538unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
539{
540 unsigned int i;
541
542 for (i = 0; i < snd_pcm_known_rates.count; i++)
543 if ((1u << i) == rate_bit)
544 return snd_pcm_known_rates.list[i];
545 return 0;
546}
547EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
548
549static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
550{
551 if (rates & SNDRV_PCM_RATE_CONTINUOUS)
552 return SNDRV_PCM_RATE_CONTINUOUS;
553 else if (rates & SNDRV_PCM_RATE_KNOT)
554 return SNDRV_PCM_RATE_KNOT;
555 return rates;
556}
557
558/**
559 * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
560 * @rates_a: The first rate mask
561 * @rates_b: The second rate mask
562 *
563 * This function computes the rates that are supported by both rate masks passed
564 * to the function. It will take care of the special handling of
565 * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
566 *
567 * Return: A rate mask containing the rates that are supported by both rates_a
568 * and rates_b.
569 */
570unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
571 unsigned int rates_b)
572{
573 rates_a = snd_pcm_rate_mask_sanitize(rates: rates_a);
574 rates_b = snd_pcm_rate_mask_sanitize(rates: rates_b);
575
576 if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
577 return rates_b;
578 else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
579 return rates_a;
580 else if (rates_a & SNDRV_PCM_RATE_KNOT)
581 return rates_b;
582 else if (rates_b & SNDRV_PCM_RATE_KNOT)
583 return rates_a;
584 return rates_a & rates_b;
585}
586EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
587
588/**
589 * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
590 * @rate_min: the minimum sample rate
591 * @rate_max: the maximum sample rate
592 *
593 * This function has an implicit assumption: the rates in the given range have
594 * only the pre-defined rates like 44100 or 16000.
595 *
596 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
597 * or SNDRV_PCM_RATE_KNOT for an unknown range.
598 */
599unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
600 unsigned int rate_max)
601{
602 unsigned int rates = 0;
603 int i;
604
605 for (i = 0; i < snd_pcm_known_rates.count; i++) {
606 if (snd_pcm_known_rates.list[i] >= rate_min
607 && snd_pcm_known_rates.list[i] <= rate_max)
608 rates |= 1 << i;
609 }
610
611 if (!rates)
612 rates = SNDRV_PCM_RATE_KNOT;
613
614 return rates;
615}
616EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);
617

source code of linux/sound/core/pcm_misc.c