xref: /linux/sound/core/pcm_misc.c (revision 95db3b255fde4e830e5f8cc011eb404023f669d4)
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 #define SND_PCM_FORMAT_UNKNOWN (-1)
27 
28 /* NOTE: "signed" prefix must be given below since the default char is
29  *       unsigned on some architectures!
30  */
31 struct pcm_format_data {
32 	unsigned char width;	/* bit width */
33 	unsigned char phys;	/* physical bit width */
34 	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
35 	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
36 	unsigned char silence[8];	/* silence data to fill */
37 };
38 
39 /* we do lots of calculations on snd_pcm_format_t; shut up sparse */
40 #define INT	__force int
41 
42 static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
43 	[SNDRV_PCM_FORMAT_S8] = {
44 		.width = 8, .phys = 8, .le = -1, .signd = 1,
45 		.silence = {},
46 	},
47 	[SNDRV_PCM_FORMAT_U8] = {
48 		.width = 8, .phys = 8, .le = -1, .signd = 0,
49 		.silence = { 0x80 },
50 	},
51 	[SNDRV_PCM_FORMAT_S16_LE] = {
52 		.width = 16, .phys = 16, .le = 1, .signd = 1,
53 		.silence = {},
54 	},
55 	[SNDRV_PCM_FORMAT_S16_BE] = {
56 		.width = 16, .phys = 16, .le = 0, .signd = 1,
57 		.silence = {},
58 	},
59 	[SNDRV_PCM_FORMAT_U16_LE] = {
60 		.width = 16, .phys = 16, .le = 1, .signd = 0,
61 		.silence = { 0x00, 0x80 },
62 	},
63 	[SNDRV_PCM_FORMAT_U16_BE] = {
64 		.width = 16, .phys = 16, .le = 0, .signd = 0,
65 		.silence = { 0x80, 0x00 },
66 	},
67 	[SNDRV_PCM_FORMAT_S24_LE] = {
68 		.width = 24, .phys = 32, .le = 1, .signd = 1,
69 		.silence = {},
70 	},
71 	[SNDRV_PCM_FORMAT_S24_BE] = {
72 		.width = 24, .phys = 32, .le = 0, .signd = 1,
73 		.silence = {},
74 	},
75 	[SNDRV_PCM_FORMAT_U24_LE] = {
76 		.width = 24, .phys = 32, .le = 1, .signd = 0,
77 		.silence = { 0x00, 0x00, 0x80 },
78 	},
79 	[SNDRV_PCM_FORMAT_U24_BE] = {
80 		.width = 24, .phys = 32, .le = 0, .signd = 0,
81 		.silence = { 0x00, 0x80, 0x00, 0x00 },
82 	},
83 	[SNDRV_PCM_FORMAT_S32_LE] = {
84 		.width = 32, .phys = 32, .le = 1, .signd = 1,
85 		.silence = {},
86 	},
87 	[SNDRV_PCM_FORMAT_S32_BE] = {
88 		.width = 32, .phys = 32, .le = 0, .signd = 1,
89 		.silence = {},
90 	},
91 	[SNDRV_PCM_FORMAT_U32_LE] = {
92 		.width = 32, .phys = 32, .le = 1, .signd = 0,
93 		.silence = { 0x00, 0x00, 0x00, 0x80 },
94 	},
95 	[SNDRV_PCM_FORMAT_U32_BE] = {
96 		.width = 32, .phys = 32, .le = 0, .signd = 0,
97 		.silence = { 0x80, 0x00, 0x00, 0x00 },
98 	},
99 	[SNDRV_PCM_FORMAT_FLOAT_LE] = {
100 		.width = 32, .phys = 32, .le = 1, .signd = -1,
101 		.silence = {},
102 	},
103 	[SNDRV_PCM_FORMAT_FLOAT_BE] = {
104 		.width = 32, .phys = 32, .le = 0, .signd = -1,
105 		.silence = {},
106 	},
107 	[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
108 		.width = 64, .phys = 64, .le = 1, .signd = -1,
109 		.silence = {},
110 	},
111 	[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
112 		.width = 64, .phys = 64, .le = 0, .signd = -1,
113 		.silence = {},
114 	},
115 	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
116 		.width = 32, .phys = 32, .le = 1, .signd = -1,
117 		.silence = {},
118 	},
119 	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
120 		.width = 32, .phys = 32, .le = 0, .signd = -1,
121 		.silence = {},
122 	},
123 	[SNDRV_PCM_FORMAT_MU_LAW] = {
124 		.width = 8, .phys = 8, .le = -1, .signd = -1,
125 		.silence = { 0x7f },
126 	},
127 	[SNDRV_PCM_FORMAT_A_LAW] = {
128 		.width = 8, .phys = 8, .le = -1, .signd = -1,
129 		.silence = { 0x55 },
130 	},
131 	[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
132 		.width = 4, .phys = 4, .le = -1, .signd = -1,
133 		.silence = {},
134 	},
135 	[SNDRV_PCM_FORMAT_G723_24] = {
136 		.width = 3, .phys = 3, .le = -1, .signd = -1,
137 		.silence = {},
138 	},
139 	[SNDRV_PCM_FORMAT_G723_40] = {
140 		.width = 5, .phys = 5, .le = -1, .signd = -1,
141 		.silence = {},
142 	},
143 	[SNDRV_PCM_FORMAT_DSD_U8] = {
144 		.width = 8, .phys = 8, .le = 1, .signd = 0,
145 		.silence = { 0x69 },
146 	},
147 	[SNDRV_PCM_FORMAT_DSD_U16_LE] = {
148 		.width = 16, .phys = 16, .le = 1, .signd = 0,
149 		.silence = { 0x69, 0x69 },
150 	},
151 	[SNDRV_PCM_FORMAT_DSD_U32_LE] = {
152 		.width = 32, .phys = 32, .le = 1, .signd = 0,
153 		.silence = { 0x69, 0x69, 0x69, 0x69 },
154 	},
155 	[SNDRV_PCM_FORMAT_DSD_U16_BE] = {
156 		.width = 16, .phys = 16, .le = 0, .signd = 0,
157 		.silence = { 0x69, 0x69 },
158 	},
159 	[SNDRV_PCM_FORMAT_DSD_U32_BE] = {
160 		.width = 32, .phys = 32, .le = 0, .signd = 0,
161 		.silence = { 0x69, 0x69, 0x69, 0x69 },
162 	},
163 	/* FIXME: the following three formats are not defined properly yet */
164 	[SNDRV_PCM_FORMAT_MPEG] = {
165 		.le = -1, .signd = -1,
166 	},
167 	[SNDRV_PCM_FORMAT_GSM] = {
168 		.le = -1, .signd = -1,
169 	},
170 	[SNDRV_PCM_FORMAT_SPECIAL] = {
171 		.le = -1, .signd = -1,
172 	},
173 	[SNDRV_PCM_FORMAT_S24_3LE] = {
174 		.width = 24, .phys = 24, .le = 1, .signd = 1,
175 		.silence = {},
176 	},
177 	[SNDRV_PCM_FORMAT_S24_3BE] = {
178 		.width = 24, .phys = 24, .le = 0, .signd = 1,
179 		.silence = {},
180 	},
181 	[SNDRV_PCM_FORMAT_U24_3LE] = {
182 		.width = 24, .phys = 24, .le = 1, .signd = 0,
183 		.silence = { 0x00, 0x00, 0x80 },
184 	},
185 	[SNDRV_PCM_FORMAT_U24_3BE] = {
186 		.width = 24, .phys = 24, .le = 0, .signd = 0,
187 		.silence = { 0x80, 0x00, 0x00 },
188 	},
189 	[SNDRV_PCM_FORMAT_S20_3LE] = {
190 		.width = 20, .phys = 24, .le = 1, .signd = 1,
191 		.silence = {},
192 	},
193 	[SNDRV_PCM_FORMAT_S20_3BE] = {
194 		.width = 20, .phys = 24, .le = 0, .signd = 1,
195 		.silence = {},
196 	},
197 	[SNDRV_PCM_FORMAT_U20_3LE] = {
198 		.width = 20, .phys = 24, .le = 1, .signd = 0,
199 		.silence = { 0x00, 0x00, 0x08 },
200 	},
201 	[SNDRV_PCM_FORMAT_U20_3BE] = {
202 		.width = 20, .phys = 24, .le = 0, .signd = 0,
203 		.silence = { 0x08, 0x00, 0x00 },
204 	},
205 	[SNDRV_PCM_FORMAT_S18_3LE] = {
206 		.width = 18, .phys = 24, .le = 1, .signd = 1,
207 		.silence = {},
208 	},
209 	[SNDRV_PCM_FORMAT_S18_3BE] = {
210 		.width = 18, .phys = 24, .le = 0, .signd = 1,
211 		.silence = {},
212 	},
213 	[SNDRV_PCM_FORMAT_U18_3LE] = {
214 		.width = 18, .phys = 24, .le = 1, .signd = 0,
215 		.silence = { 0x00, 0x00, 0x02 },
216 	},
217 	[SNDRV_PCM_FORMAT_U18_3BE] = {
218 		.width = 18, .phys = 24, .le = 0, .signd = 0,
219 		.silence = { 0x02, 0x00, 0x00 },
220 	},
221 	[SNDRV_PCM_FORMAT_G723_24_1B] = {
222 		.width = 3, .phys = 8, .le = -1, .signd = -1,
223 		.silence = {},
224 	},
225 	[SNDRV_PCM_FORMAT_G723_40_1B] = {
226 		.width = 5, .phys = 8, .le = -1, .signd = -1,
227 		.silence = {},
228 	},
229 };
230 
231 
232 /**
233  * snd_pcm_format_signed - Check the PCM format is signed linear
234  * @format: the format to check
235  *
236  * Return: 1 if the given PCM format is signed linear, 0 if unsigned
237  * linear, and a negative error code for non-linear formats.
238  */
239 int snd_pcm_format_signed(snd_pcm_format_t format)
240 {
241 	int val;
242 	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
243 		return -EINVAL;
244 	if ((val = pcm_formats[(INT)format].signd) < 0)
245 		return -EINVAL;
246 	return val;
247 }
248 
249 EXPORT_SYMBOL(snd_pcm_format_signed);
250 
251 /**
252  * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
253  * @format: the format to check
254  *
255  * Return: 1 if the given PCM format is unsigned linear, 0 if signed
256  * linear, and a negative error code for non-linear formats.
257  */
258 int snd_pcm_format_unsigned(snd_pcm_format_t format)
259 {
260 	int val;
261 
262 	val = snd_pcm_format_signed(format);
263 	if (val < 0)
264 		return val;
265 	return !val;
266 }
267 
268 EXPORT_SYMBOL(snd_pcm_format_unsigned);
269 
270 /**
271  * snd_pcm_format_linear - Check the PCM format is linear
272  * @format: the format to check
273  *
274  * Return: 1 if the given PCM format is linear, 0 if not.
275  */
276 int snd_pcm_format_linear(snd_pcm_format_t format)
277 {
278 	return snd_pcm_format_signed(format) >= 0;
279 }
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 
300 EXPORT_SYMBOL(snd_pcm_format_little_endian);
301 
302 /**
303  * snd_pcm_format_big_endian - Check the PCM format is big-endian
304  * @format: the format to check
305  *
306  * Return: 1 if the given PCM format is big-endian, 0 if
307  * little-endian, or a negative error code if endian not specified.
308  */
309 int snd_pcm_format_big_endian(snd_pcm_format_t format)
310 {
311 	int val;
312 
313 	val = snd_pcm_format_little_endian(format);
314 	if (val < 0)
315 		return val;
316 	return !val;
317 }
318 
319 EXPORT_SYMBOL(snd_pcm_format_big_endian);
320 
321 /**
322  * snd_pcm_format_width - return the bit-width of the format
323  * @format: the format to check
324  *
325  * Return: The bit-width of the format, or a negative error code
326  * if unknown format.
327  */
328 int snd_pcm_format_width(snd_pcm_format_t format)
329 {
330 	int val;
331 	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
332 		return -EINVAL;
333 	if ((val = pcm_formats[(INT)format].width) == 0)
334 		return -EINVAL;
335 	return val;
336 }
337 
338 EXPORT_SYMBOL(snd_pcm_format_width);
339 
340 /**
341  * snd_pcm_format_physical_width - return the physical bit-width of the format
342  * @format: the format to check
343  *
344  * Return: The physical bit-width of the format, or a negative error code
345  * if unknown format.
346  */
347 int snd_pcm_format_physical_width(snd_pcm_format_t format)
348 {
349 	int val;
350 	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
351 		return -EINVAL;
352 	if ((val = pcm_formats[(INT)format].phys) == 0)
353 		return -EINVAL;
354 	return val;
355 }
356 
357 EXPORT_SYMBOL(snd_pcm_format_physical_width);
358 
359 /**
360  * snd_pcm_format_size - return the byte size of samples on the given format
361  * @format: the format to check
362  * @samples: sampling rate
363  *
364  * Return: The byte size of the given samples for the format, or a
365  * negative error code if unknown format.
366  */
367 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
368 {
369 	int phys_width = snd_pcm_format_physical_width(format);
370 	if (phys_width < 0)
371 		return -EINVAL;
372 	return samples * phys_width / 8;
373 }
374 
375 EXPORT_SYMBOL(snd_pcm_format_size);
376 
377 /**
378  * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
379  * @format: the format to check
380  *
381  * Return: The format pattern to fill or %NULL if error.
382  */
383 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
384 {
385 	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
386 		return NULL;
387 	if (! pcm_formats[(INT)format].phys)
388 		return NULL;
389 	return pcm_formats[(INT)format].silence;
390 }
391 
392 EXPORT_SYMBOL(snd_pcm_format_silence_64);
393 
394 /**
395  * snd_pcm_format_set_silence - set the silence data on the buffer
396  * @format: the PCM format
397  * @data: the buffer pointer
398  * @samples: the number of samples to set silence
399  *
400  * Sets the silence data on the buffer for the given samples.
401  *
402  * Return: Zero if successful, or a negative error code on failure.
403  */
404 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
405 {
406 	int width;
407 	unsigned char *dst, *pat;
408 
409 	if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
410 		return -EINVAL;
411 	if (samples == 0)
412 		return 0;
413 	width = pcm_formats[(INT)format].phys; /* physical width */
414 	pat = pcm_formats[(INT)format].silence;
415 	if (! width)
416 		return -EINVAL;
417 	/* signed or 1 byte data */
418 	if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
419 		unsigned int bytes = samples * width / 8;
420 		memset(data, *pat, bytes);
421 		return 0;
422 	}
423 	/* non-zero samples, fill using a loop */
424 	width /= 8;
425 	dst = data;
426 #if 0
427 	while (samples--) {
428 		memcpy(dst, pat, width);
429 		dst += width;
430 	}
431 #else
432 	/* a bit optimization for constant width */
433 	switch (width) {
434 	case 2:
435 		while (samples--) {
436 			memcpy(dst, pat, 2);
437 			dst += 2;
438 		}
439 		break;
440 	case 3:
441 		while (samples--) {
442 			memcpy(dst, pat, 3);
443 			dst += 3;
444 		}
445 		break;
446 	case 4:
447 		while (samples--) {
448 			memcpy(dst, pat, 4);
449 			dst += 4;
450 		}
451 		break;
452 	case 8:
453 		while (samples--) {
454 			memcpy(dst, pat, 8);
455 			dst += 8;
456 		}
457 		break;
458 	}
459 #endif
460 	return 0;
461 }
462 
463 EXPORT_SYMBOL(snd_pcm_format_set_silence);
464 
465 /**
466  * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
467  * @runtime: the runtime instance
468  *
469  * Determines the rate_min and rate_max fields from the rates bits of
470  * the given runtime->hw.
471  *
472  * Return: Zero if successful.
473  */
474 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
475 {
476 	int i;
477 	for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
478 		if (runtime->hw.rates & (1 << i)) {
479 			runtime->hw.rate_min = snd_pcm_known_rates.list[i];
480 			break;
481 		}
482 	}
483 	for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
484 		if (runtime->hw.rates & (1 << i)) {
485 			runtime->hw.rate_max = snd_pcm_known_rates.list[i];
486 			break;
487 		}
488 	}
489 	return 0;
490 }
491 
492 EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
493 
494 /**
495  * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
496  * @rate: the sample rate to convert
497  *
498  * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
499  * SNDRV_PCM_RATE_KNOT for an unknown rate.
500  */
501 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
502 {
503 	unsigned int i;
504 
505 	for (i = 0; i < snd_pcm_known_rates.count; i++)
506 		if (snd_pcm_known_rates.list[i] == rate)
507 			return 1u << i;
508 	return SNDRV_PCM_RATE_KNOT;
509 }
510 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
511 
512 /**
513  * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
514  * @rate_bit: the rate bit to convert
515  *
516  * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
517  * or 0 for an unknown rate bit.
518  */
519 unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
520 {
521 	unsigned int i;
522 
523 	for (i = 0; i < snd_pcm_known_rates.count; i++)
524 		if ((1u << i) == rate_bit)
525 			return snd_pcm_known_rates.list[i];
526 	return 0;
527 }
528 EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
529 
530 static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
531 {
532 	if (rates & SNDRV_PCM_RATE_CONTINUOUS)
533 		return SNDRV_PCM_RATE_CONTINUOUS;
534 	else if (rates & SNDRV_PCM_RATE_KNOT)
535 		return SNDRV_PCM_RATE_KNOT;
536 	return rates;
537 }
538 
539 /**
540  * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
541  * @rates_a: The first rate mask
542  * @rates_b: The second rate mask
543  *
544  * This function computes the rates that are supported by both rate masks passed
545  * to the function. It will take care of the special handling of
546  * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
547  *
548  * Return: A rate mask containing the rates that are supported by both rates_a
549  * and rates_b.
550  */
551 unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
552 	unsigned int rates_b)
553 {
554 	rates_a = snd_pcm_rate_mask_sanitize(rates_a);
555 	rates_b = snd_pcm_rate_mask_sanitize(rates_b);
556 
557 	if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
558 		return rates_b;
559 	else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
560 		return rates_a;
561 	else if (rates_a & SNDRV_PCM_RATE_KNOT)
562 		return rates_b;
563 	else if (rates_b & SNDRV_PCM_RATE_KNOT)
564 		return rates_a;
565 	return rates_a & rates_b;
566 }
567 EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
568 
569 /**
570  * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
571  * @rate_min: the minimum sample rate
572  * @rate_max: the maximum sample rate
573  *
574  * This function has an implicit assumption: the rates in the given range have
575  * only the pre-defined rates like 44100 or 16000.
576  *
577  * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
578  * or SNDRV_PCM_RATE_KNOT for an unknown range.
579  */
580 unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
581 	unsigned int rate_max)
582 {
583 	unsigned int rates = 0;
584 	int i;
585 
586 	for (i = 0; i < snd_pcm_known_rates.count; i++) {
587 		if (snd_pcm_known_rates.list[i] >= rate_min
588 			&& snd_pcm_known_rates.list[i] <= rate_max)
589 			rates |= 1 << i;
590 	}
591 
592 	if (!rates)
593 		rates = SNDRV_PCM_RATE_KNOT;
594 
595 	return rates;
596 }
597 EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);
598