xref: /linux/sound/core/pcm_misc.c (revision e5c91aac491def6ab3f90c4cc246e3fcb0f8f058)
1 // SPDX-License-Identifier: LGPL-2.0+
2 /*
3  *  PCM Interface - misc routines
4  *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/time.h>
8 #include <linux/export.h>
9 #include <sound/core.h>
10 #include <sound/pcm.h>
11 
12 #include "pcm_local.h"
13 
14 #define SND_PCM_FORMAT_UNKNOWN (-1)
15 
16 /* NOTE: "signed" prefix must be given below since the default char is
17  *       unsigned on some architectures!
18  */
19 struct pcm_format_data {
20 	unsigned char width;	/* bit width */
21 	unsigned char phys;	/* physical bit width */
22 	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
23 	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
24 	unsigned char silence[8];	/* silence data to fill */
25 };
26 
27 static bool valid_format(snd_pcm_format_t format)
28 {
29 	return format >= 0 && format <= SNDRV_PCM_FORMAT_LAST;
30 }
31 
32 static const struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = {
33 	[SNDRV_PCM_FORMAT_S8] = {
34 		.width = 8, .phys = 8, .le = -1, .signd = 1,
35 		.silence = {},
36 	},
37 	[SNDRV_PCM_FORMAT_U8] = {
38 		.width = 8, .phys = 8, .le = -1, .signd = 0,
39 		.silence = { 0x80 },
40 	},
41 	[SNDRV_PCM_FORMAT_S16_LE] = {
42 		.width = 16, .phys = 16, .le = 1, .signd = 1,
43 		.silence = {},
44 	},
45 	[SNDRV_PCM_FORMAT_S16_BE] = {
46 		.width = 16, .phys = 16, .le = 0, .signd = 1,
47 		.silence = {},
48 	},
49 	[SNDRV_PCM_FORMAT_U16_LE] = {
50 		.width = 16, .phys = 16, .le = 1, .signd = 0,
51 		.silence = { 0x00, 0x80 },
52 	},
53 	[SNDRV_PCM_FORMAT_U16_BE] = {
54 		.width = 16, .phys = 16, .le = 0, .signd = 0,
55 		.silence = { 0x80, 0x00 },
56 	},
57 	[SNDRV_PCM_FORMAT_S24_LE] = {
58 		.width = 24, .phys = 32, .le = 1, .signd = 1,
59 		.silence = {},
60 	},
61 	[SNDRV_PCM_FORMAT_S24_BE] = {
62 		.width = 24, .phys = 32, .le = 0, .signd = 1,
63 		.silence = {},
64 	},
65 	[SNDRV_PCM_FORMAT_U24_LE] = {
66 		.width = 24, .phys = 32, .le = 1, .signd = 0,
67 		.silence = { 0x00, 0x00, 0x80 },
68 	},
69 	[SNDRV_PCM_FORMAT_U24_BE] = {
70 		.width = 24, .phys = 32, .le = 0, .signd = 0,
71 		.silence = { 0x00, 0x80, 0x00, 0x00 },
72 	},
73 	[SNDRV_PCM_FORMAT_S32_LE] = {
74 		.width = 32, .phys = 32, .le = 1, .signd = 1,
75 		.silence = {},
76 	},
77 	[SNDRV_PCM_FORMAT_S32_BE] = {
78 		.width = 32, .phys = 32, .le = 0, .signd = 1,
79 		.silence = {},
80 	},
81 	[SNDRV_PCM_FORMAT_U32_LE] = {
82 		.width = 32, .phys = 32, .le = 1, .signd = 0,
83 		.silence = { 0x00, 0x00, 0x00, 0x80 },
84 	},
85 	[SNDRV_PCM_FORMAT_U32_BE] = {
86 		.width = 32, .phys = 32, .le = 0, .signd = 0,
87 		.silence = { 0x80, 0x00, 0x00, 0x00 },
88 	},
89 	[SNDRV_PCM_FORMAT_FLOAT_LE] = {
90 		.width = 32, .phys = 32, .le = 1, .signd = -1,
91 		.silence = {},
92 	},
93 	[SNDRV_PCM_FORMAT_FLOAT_BE] = {
94 		.width = 32, .phys = 32, .le = 0, .signd = -1,
95 		.silence = {},
96 	},
97 	[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
98 		.width = 64, .phys = 64, .le = 1, .signd = -1,
99 		.silence = {},
100 	},
101 	[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
102 		.width = 64, .phys = 64, .le = 0, .signd = -1,
103 		.silence = {},
104 	},
105 	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
106 		.width = 32, .phys = 32, .le = 1, .signd = -1,
107 		.silence = {},
108 	},
109 	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
110 		.width = 32, .phys = 32, .le = 0, .signd = -1,
111 		.silence = {},
112 	},
113 	[SNDRV_PCM_FORMAT_MU_LAW] = {
114 		.width = 8, .phys = 8, .le = -1, .signd = -1,
115 		.silence = { 0x7f },
116 	},
117 	[SNDRV_PCM_FORMAT_A_LAW] = {
118 		.width = 8, .phys = 8, .le = -1, .signd = -1,
119 		.silence = { 0x55 },
120 	},
121 	[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
122 		.width = 4, .phys = 4, .le = -1, .signd = -1,
123 		.silence = {},
124 	},
125 	[SNDRV_PCM_FORMAT_G723_24] = {
126 		.width = 3, .phys = 3, .le = -1, .signd = -1,
127 		.silence = {},
128 	},
129 	[SNDRV_PCM_FORMAT_G723_40] = {
130 		.width = 5, .phys = 5, .le = -1, .signd = -1,
131 		.silence = {},
132 	},
133 	[SNDRV_PCM_FORMAT_DSD_U8] = {
134 		.width = 8, .phys = 8, .le = 1, .signd = 0,
135 		.silence = { 0x69 },
136 	},
137 	[SNDRV_PCM_FORMAT_DSD_U16_LE] = {
138 		.width = 16, .phys = 16, .le = 1, .signd = 0,
139 		.silence = { 0x69, 0x69 },
140 	},
141 	[SNDRV_PCM_FORMAT_DSD_U32_LE] = {
142 		.width = 32, .phys = 32, .le = 1, .signd = 0,
143 		.silence = { 0x69, 0x69, 0x69, 0x69 },
144 	},
145 	[SNDRV_PCM_FORMAT_DSD_U16_BE] = {
146 		.width = 16, .phys = 16, .le = 0, .signd = 0,
147 		.silence = { 0x69, 0x69 },
148 	},
149 	[SNDRV_PCM_FORMAT_DSD_U32_BE] = {
150 		.width = 32, .phys = 32, .le = 0, .signd = 0,
151 		.silence = { 0x69, 0x69, 0x69, 0x69 },
152 	},
153 	/* FIXME: the following two formats are not defined properly yet */
154 	[SNDRV_PCM_FORMAT_MPEG] = {
155 		.le = -1, .signd = -1,
156 	},
157 	[SNDRV_PCM_FORMAT_GSM] = {
158 		.le = -1, .signd = -1,
159 	},
160 	[SNDRV_PCM_FORMAT_S20_LE] = {
161 		.width = 20, .phys = 32, .le = 1, .signd = 1,
162 		.silence = {},
163 	},
164 	[SNDRV_PCM_FORMAT_S20_BE] = {
165 		.width = 20, .phys = 32, .le = 0, .signd = 1,
166 		.silence = {},
167 	},
168 	[SNDRV_PCM_FORMAT_U20_LE] = {
169 		.width = 20, .phys = 32, .le = 1, .signd = 0,
170 		.silence = { 0x00, 0x00, 0x08, 0x00 },
171 	},
172 	[SNDRV_PCM_FORMAT_U20_BE] = {
173 		.width = 20, .phys = 32, .le = 0, .signd = 0,
174 		.silence = { 0x00, 0x08, 0x00, 0x00 },
175 	},
176 	/* FIXME: the following format is not defined properly yet */
177 	[SNDRV_PCM_FORMAT_SPECIAL] = {
178 		.le = -1, .signd = -1,
179 	},
180 	[SNDRV_PCM_FORMAT_S24_3LE] = {
181 		.width = 24, .phys = 24, .le = 1, .signd = 1,
182 		.silence = {},
183 	},
184 	[SNDRV_PCM_FORMAT_S24_3BE] = {
185 		.width = 24, .phys = 24, .le = 0, .signd = 1,
186 		.silence = {},
187 	},
188 	[SNDRV_PCM_FORMAT_U24_3LE] = {
189 		.width = 24, .phys = 24, .le = 1, .signd = 0,
190 		.silence = { 0x00, 0x00, 0x80 },
191 	},
192 	[SNDRV_PCM_FORMAT_U24_3BE] = {
193 		.width = 24, .phys = 24, .le = 0, .signd = 0,
194 		.silence = { 0x80, 0x00, 0x00 },
195 	},
196 	[SNDRV_PCM_FORMAT_S20_3LE] = {
197 		.width = 20, .phys = 24, .le = 1, .signd = 1,
198 		.silence = {},
199 	},
200 	[SNDRV_PCM_FORMAT_S20_3BE] = {
201 		.width = 20, .phys = 24, .le = 0, .signd = 1,
202 		.silence = {},
203 	},
204 	[SNDRV_PCM_FORMAT_U20_3LE] = {
205 		.width = 20, .phys = 24, .le = 1, .signd = 0,
206 		.silence = { 0x00, 0x00, 0x08 },
207 	},
208 	[SNDRV_PCM_FORMAT_U20_3BE] = {
209 		.width = 20, .phys = 24, .le = 0, .signd = 0,
210 		.silence = { 0x08, 0x00, 0x00 },
211 	},
212 	[SNDRV_PCM_FORMAT_S18_3LE] = {
213 		.width = 18, .phys = 24, .le = 1, .signd = 1,
214 		.silence = {},
215 	},
216 	[SNDRV_PCM_FORMAT_S18_3BE] = {
217 		.width = 18, .phys = 24, .le = 0, .signd = 1,
218 		.silence = {},
219 	},
220 	[SNDRV_PCM_FORMAT_U18_3LE] = {
221 		.width = 18, .phys = 24, .le = 1, .signd = 0,
222 		.silence = { 0x00, 0x00, 0x02 },
223 	},
224 	[SNDRV_PCM_FORMAT_U18_3BE] = {
225 		.width = 18, .phys = 24, .le = 0, .signd = 0,
226 		.silence = { 0x02, 0x00, 0x00 },
227 	},
228 	[SNDRV_PCM_FORMAT_G723_24_1B] = {
229 		.width = 3, .phys = 8, .le = -1, .signd = -1,
230 		.silence = {},
231 	},
232 	[SNDRV_PCM_FORMAT_G723_40_1B] = {
233 		.width = 5, .phys = 8, .le = -1, .signd = -1,
234 		.silence = {},
235 	},
236 };
237 
238 
239 /**
240  * snd_pcm_format_signed - Check the PCM format is signed linear
241  * @format: the format to check
242  *
243  * Return: 1 if the given PCM format is signed linear, 0 if unsigned
244  * linear, and a negative error code for non-linear formats.
245  */
246 int snd_pcm_format_signed(snd_pcm_format_t format)
247 {
248 	int val;
249 	if (!valid_format(format))
250 		return -EINVAL;
251 	val = pcm_formats[format].signd;
252 	if (val < 0)
253 		return -EINVAL;
254 	return val;
255 }
256 EXPORT_SYMBOL(snd_pcm_format_signed);
257 
258 /**
259  * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
260  * @format: the format to check
261  *
262  * Return: 1 if the given PCM format is unsigned linear, 0 if signed
263  * linear, and a negative error code for non-linear formats.
264  */
265 int snd_pcm_format_unsigned(snd_pcm_format_t format)
266 {
267 	int val;
268 
269 	val = snd_pcm_format_signed(format);
270 	if (val < 0)
271 		return val;
272 	return !val;
273 }
274 EXPORT_SYMBOL(snd_pcm_format_unsigned);
275 
276 /**
277  * snd_pcm_format_linear - Check the PCM format is linear
278  * @format: the format to check
279  *
280  * Return: 1 if the given PCM format is linear, 0 if not.
281  */
282 int snd_pcm_format_linear(snd_pcm_format_t format)
283 {
284 	return snd_pcm_format_signed(format) >= 0;
285 }
286 EXPORT_SYMBOL(snd_pcm_format_linear);
287 
288 /**
289  * snd_pcm_format_little_endian - Check the PCM format is little-endian
290  * @format: the format to check
291  *
292  * Return: 1 if the given PCM format is little-endian, 0 if
293  * big-endian, or a negative error code if endian not specified.
294  */
295 int snd_pcm_format_little_endian(snd_pcm_format_t format)
296 {
297 	int val;
298 	if (!valid_format(format))
299 		return -EINVAL;
300 	val = pcm_formats[format].le;
301 	if (val < 0)
302 		return -EINVAL;
303 	return val;
304 }
305 EXPORT_SYMBOL(snd_pcm_format_little_endian);
306 
307 /**
308  * snd_pcm_format_big_endian - Check the PCM format is big-endian
309  * @format: the format to check
310  *
311  * Return: 1 if the given PCM format is big-endian, 0 if
312  * little-endian, or a negative error code if endian not specified.
313  */
314 int snd_pcm_format_big_endian(snd_pcm_format_t format)
315 {
316 	int val;
317 
318 	val = snd_pcm_format_little_endian(format);
319 	if (val < 0)
320 		return val;
321 	return !val;
322 }
323 EXPORT_SYMBOL(snd_pcm_format_big_endian);
324 
325 /**
326  * snd_pcm_format_width - return the bit-width of the format
327  * @format: the format to check
328  *
329  * Return: The bit-width of the format, or a negative error code
330  * if unknown format.
331  */
332 int snd_pcm_format_width(snd_pcm_format_t format)
333 {
334 	int val;
335 	if (!valid_format(format))
336 		return -EINVAL;
337 	val = pcm_formats[format].width;
338 	if (!val)
339 		return -EINVAL;
340 	return val;
341 }
342 EXPORT_SYMBOL(snd_pcm_format_width);
343 
344 /**
345  * snd_pcm_format_physical_width - return the physical bit-width of the format
346  * @format: the format to check
347  *
348  * Return: The physical bit-width of the format, or a negative error code
349  * if unknown format.
350  */
351 int snd_pcm_format_physical_width(snd_pcm_format_t format)
352 {
353 	int val;
354 	if (!valid_format(format))
355 		return -EINVAL;
356 	val = pcm_formats[format].phys;
357 	if (!val)
358 		return -EINVAL;
359 	return val;
360 }
361 EXPORT_SYMBOL(snd_pcm_format_physical_width);
362 
363 /**
364  * snd_pcm_format_size - return the byte size of samples on the given format
365  * @format: the format to check
366  * @samples: sampling rate
367  *
368  * Return: The byte size of the given samples for the format, or a
369  * negative error code if unknown format.
370  */
371 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
372 {
373 	int phys_width = snd_pcm_format_physical_width(format);
374 	if (phys_width < 0)
375 		return -EINVAL;
376 	return samples * phys_width / 8;
377 }
378 EXPORT_SYMBOL(snd_pcm_format_size);
379 
380 /**
381  * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
382  * @format: the format to check
383  *
384  * Return: The format pattern to fill or %NULL if error.
385  */
386 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
387 {
388 	if (!valid_format(format))
389 		return NULL;
390 	if (! pcm_formats[format].phys)
391 		return NULL;
392 	return pcm_formats[format].silence;
393 }
394 EXPORT_SYMBOL(snd_pcm_format_silence_64);
395 
396 /**
397  * snd_pcm_format_set_silence - set the silence data on the buffer
398  * @format: the PCM format
399  * @data: the buffer pointer
400  * @samples: the number of samples to set silence
401  *
402  * Sets the silence data on the buffer for the given samples.
403  *
404  * Return: Zero if successful, or a negative error code on failure.
405  */
406 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
407 {
408 	int width;
409 	unsigned char *dst;
410 	const unsigned char *pat;
411 
412 	if (!valid_format(format))
413 		return -EINVAL;
414 	if (samples == 0)
415 		return 0;
416 	width = pcm_formats[format].phys; /* physical width */
417 	if (!width)
418 		return -EINVAL;
419 	pat = pcm_formats[format].silence;
420 	/* signed or 1 byte data */
421 	if (pcm_formats[format].signd == 1 || width <= 8) {
422 		unsigned int bytes = samples * width / 8;
423 		memset(data, *pat, bytes);
424 		return 0;
425 	}
426 	/* non-zero samples, fill using a loop */
427 	width /= 8;
428 	dst = data;
429 #if 0
430 	while (samples--) {
431 		memcpy(dst, pat, width);
432 		dst += width;
433 	}
434 #else
435 	/* a bit optimization for constant width */
436 	switch (width) {
437 	case 2:
438 		while (samples--) {
439 			memcpy(dst, pat, 2);
440 			dst += 2;
441 		}
442 		break;
443 	case 3:
444 		while (samples--) {
445 			memcpy(dst, pat, 3);
446 			dst += 3;
447 		}
448 		break;
449 	case 4:
450 		while (samples--) {
451 			memcpy(dst, pat, 4);
452 			dst += 4;
453 		}
454 		break;
455 	case 8:
456 		while (samples--) {
457 			memcpy(dst, pat, 8);
458 			dst += 8;
459 		}
460 		break;
461 	}
462 #endif
463 	return 0;
464 }
465 EXPORT_SYMBOL(snd_pcm_format_set_silence);
466 
467 /**
468  * snd_pcm_hw_limit_rates - determine rate_min/rate_max fields
469  * @hw: the pcm hw instance
470  *
471  * Determines the rate_min and rate_max fields from the rates bits of
472  * the given hw.
473  *
474  * Return: Zero if successful.
475  */
476 int snd_pcm_hw_limit_rates(struct snd_pcm_hardware *hw)
477 {
478 	int i;
479 	unsigned int rmin, rmax;
480 
481 	rmin = UINT_MAX;
482 	rmax = 0;
483 	for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
484 		if (hw->rates & (1 << i)) {
485 			rmin = min(rmin, snd_pcm_known_rates.list[i]);
486 			rmax = max(rmax, snd_pcm_known_rates.list[i]);
487 		}
488 	}
489 	if (rmin > rmax)
490 		return -EINVAL;
491 	hw->rate_min = rmin;
492 	hw->rate_max = rmax;
493 	return 0;
494 }
495 EXPORT_SYMBOL(snd_pcm_hw_limit_rates);
496 
497 /**
498  * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
499  * @rate: the sample rate to convert
500  *
501  * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
502  * SNDRV_PCM_RATE_KNOT for an unknown rate.
503  */
504 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
505 {
506 	unsigned int i;
507 
508 	for (i = 0; i < snd_pcm_known_rates.count; i++)
509 		if (snd_pcm_known_rates.list[i] == rate)
510 			return 1u << i;
511 	return SNDRV_PCM_RATE_KNOT;
512 }
513 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
514 
515 /**
516  * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
517  * @rate_bit: the rate bit to convert
518  *
519  * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
520  * or 0 for an unknown rate bit.
521  */
522 unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
523 {
524 	unsigned int i;
525 
526 	for (i = 0; i < snd_pcm_known_rates.count; i++)
527 		if ((1u << i) == rate_bit)
528 			return snd_pcm_known_rates.list[i];
529 	return 0;
530 }
531 EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
532 
533 static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
534 {
535 	if (rates & SNDRV_PCM_RATE_CONTINUOUS)
536 		return SNDRV_PCM_RATE_CONTINUOUS;
537 	else if (rates & SNDRV_PCM_RATE_KNOT)
538 		return SNDRV_PCM_RATE_KNOT;
539 	return rates;
540 }
541 
542 /**
543  * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
544  * @rates_a: The first rate mask
545  * @rates_b: The second rate mask
546  *
547  * This function computes the rates that are supported by both rate masks passed
548  * to the function. It will take care of the special handling of
549  * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
550  *
551  * Return: A rate mask containing the rates that are supported by both rates_a
552  * and rates_b.
553  */
554 unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
555 	unsigned int rates_b)
556 {
557 	rates_a = snd_pcm_rate_mask_sanitize(rates_a);
558 	rates_b = snd_pcm_rate_mask_sanitize(rates_b);
559 
560 	if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
561 		return rates_b;
562 	else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
563 		return rates_a;
564 	else if (rates_a & SNDRV_PCM_RATE_KNOT)
565 		return rates_b;
566 	else if (rates_b & SNDRV_PCM_RATE_KNOT)
567 		return rates_a;
568 	return rates_a & rates_b;
569 }
570 EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
571