xref: /linux/sound/core/pcm_misc.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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);
590