summaryrefslogtreecommitdiff
path: root/sound/core/pcm_misc.c
blob: 257d412eac5ddb618074e662ad2b0346e19c12e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
/*
 *  PCM Interface - misc routines
 *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library General Public License as
 *   published by the Free Software Foundation; either version 2 of
 *   the License, or (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */
  
#include <linux/time.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>

#include "pcm_local.h"

#define SND_PCM_FORMAT_UNKNOWN (-1)

/* NOTE: "signed" prefix must be given below since the default char is
 *       unsigned on some architectures!
 */
struct pcm_format_data {
	unsigned char width;	/* bit width */
	unsigned char phys;	/* physical bit width */
	signed char le;	/* 0 = big-endian, 1 = little-endian, -1 = others */
	signed char signd;	/* 0 = unsigned, 1 = signed, -1 = others */
	unsigned char silence[8];	/* silence data to fill */
};

/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
#define INT	__force int

static bool valid_format(snd_pcm_format_t format)
{
	return (INT)format >= 0 && (INT)format <= (INT)SNDRV_PCM_FORMAT_LAST;
}

static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
	[SNDRV_PCM_FORMAT_S8] = {
		.width = 8, .phys = 8, .le = -1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U8] = {
		.width = 8, .phys = 8, .le = -1, .signd = 0,
		.silence = { 0x80 },
	},
	[SNDRV_PCM_FORMAT_S16_LE] = {
		.width = 16, .phys = 16, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S16_BE] = {
		.width = 16, .phys = 16, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U16_LE] = {
		.width = 16, .phys = 16, .le = 1, .signd = 0,
		.silence = { 0x00, 0x80 },
	},
	[SNDRV_PCM_FORMAT_U16_BE] = {
		.width = 16, .phys = 16, .le = 0, .signd = 0,
		.silence = { 0x80, 0x00 },
	},
	[SNDRV_PCM_FORMAT_S24_LE] = {
		.width = 24, .phys = 32, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S24_BE] = {
		.width = 24, .phys = 32, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U24_LE] = {
		.width = 24, .phys = 32, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x80 },
	},
	[SNDRV_PCM_FORMAT_U24_BE] = {
		.width = 24, .phys = 32, .le = 0, .signd = 0,
		.silence = { 0x00, 0x80, 0x00, 0x00 },
	},
	[SNDRV_PCM_FORMAT_S32_LE] = {
		.width = 32, .phys = 32, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S32_BE] = {
		.width = 32, .phys = 32, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U32_LE] = {
		.width = 32, .phys = 32, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x00, 0x80 },
	},
	[SNDRV_PCM_FORMAT_U32_BE] = {
		.width = 32, .phys = 32, .le = 0, .signd = 0,
		.silence = { 0x80, 0x00, 0x00, 0x00 },
	},
	[SNDRV_PCM_FORMAT_FLOAT_LE] = {
		.width = 32, .phys = 32, .le = 1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_FLOAT_BE] = {
		.width = 32, .phys = 32, .le = 0, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_FLOAT64_LE] = {
		.width = 64, .phys = 64, .le = 1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_FLOAT64_BE] = {
		.width = 64, .phys = 64, .le = 0, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
		.width = 32, .phys = 32, .le = 1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
		.width = 32, .phys = 32, .le = 0, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_MU_LAW] = {
		.width = 8, .phys = 8, .le = -1, .signd = -1,
		.silence = { 0x7f },
	},
	[SNDRV_PCM_FORMAT_A_LAW] = {
		.width = 8, .phys = 8, .le = -1, .signd = -1,
		.silence = { 0x55 },
	},
	[SNDRV_PCM_FORMAT_IMA_ADPCM] = {
		.width = 4, .phys = 4, .le = -1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_G723_24] = {
		.width = 3, .phys = 3, .le = -1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_G723_40] = {
		.width = 5, .phys = 5, .le = -1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_DSD_U8] = {
		.width = 8, .phys = 8, .le = 1, .signd = 0,
		.silence = { 0x69 },
	},
	[SNDRV_PCM_FORMAT_DSD_U16_LE] = {
		.width = 16, .phys = 16, .le = 1, .signd = 0,
		.silence = { 0x69, 0x69 },
	},
	[SNDRV_PCM_FORMAT_DSD_U32_LE] = {
		.width = 32, .phys = 32, .le = 1, .signd = 0,
		.silence = { 0x69, 0x69, 0x69, 0x69 },
	},
	[SNDRV_PCM_FORMAT_DSD_U16_BE] = {
		.width = 16, .phys = 16, .le = 0, .signd = 0,
		.silence = { 0x69, 0x69 },
	},
	[SNDRV_PCM_FORMAT_DSD_U32_BE] = {
		.width = 32, .phys = 32, .le = 0, .signd = 0,
		.silence = { 0x69, 0x69, 0x69, 0x69 },
	},
	/* FIXME: the following two formats are not defined properly yet */
	[SNDRV_PCM_FORMAT_MPEG] = {
		.le = -1, .signd = -1,
	},
	[SNDRV_PCM_FORMAT_GSM] = {
		.le = -1, .signd = -1,
	},
	[SNDRV_PCM_FORMAT_S20_LE] = {
		.width = 20, .phys = 32, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S20_BE] = {
		.width = 20, .phys = 32, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U20_LE] = {
		.width = 20, .phys = 32, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x08, 0x00 },
	},
	[SNDRV_PCM_FORMAT_U20_BE] = {
		.width = 20, .phys = 32, .le = 0, .signd = 0,
		.silence = { 0x00, 0x08, 0x00, 0x00 },
	},
	/* FIXME: the following format is not defined properly yet */
	[SNDRV_PCM_FORMAT_SPECIAL] = {
		.le = -1, .signd = -1,
	},
	[SNDRV_PCM_FORMAT_S24_3LE] = {
		.width = 24, .phys = 24, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S24_3BE] = {
		.width = 24, .phys = 24, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U24_3LE] = {
		.width = 24, .phys = 24, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x80 },
	},
	[SNDRV_PCM_FORMAT_U24_3BE] = {
		.width = 24, .phys = 24, .le = 0, .signd = 0,
		.silence = { 0x80, 0x00, 0x00 },
	},
	[SNDRV_PCM_FORMAT_S20_3LE] = {
		.width = 20, .phys = 24, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S20_3BE] = {
		.width = 20, .phys = 24, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U20_3LE] = {
		.width = 20, .phys = 24, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x08 },
	},
	[SNDRV_PCM_FORMAT_U20_3BE] = {
		.width = 20, .phys = 24, .le = 0, .signd = 0,
		.silence = { 0x08, 0x00, 0x00 },
	},
	[SNDRV_PCM_FORMAT_S18_3LE] = {
		.width = 18, .phys = 24, .le = 1, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_S18_3BE] = {
		.width = 18, .phys = 24, .le = 0, .signd = 1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_U18_3LE] = {
		.width = 18, .phys = 24, .le = 1, .signd = 0,
		.silence = { 0x00, 0x00, 0x02 },
	},
	[SNDRV_PCM_FORMAT_U18_3BE] = {
		.width = 18, .phys = 24, .le = 0, .signd = 0,
		.silence = { 0x02, 0x00, 0x00 },
	},
	[SNDRV_PCM_FORMAT_G723_24_1B] = {
		.width = 3, .phys = 8, .le = -1, .signd = -1,
		.silence = {},
	},
	[SNDRV_PCM_FORMAT_G723_40_1B] = {
		.width = 5, .phys = 8, .le = -1, .signd = -1,
		.silence = {},
	},
};


/**
 * snd_pcm_format_signed - Check the PCM format is signed linear
 * @format: the format to check
 *
 * Return: 1 if the given PCM format is signed linear, 0 if unsigned
 * linear, and a negative error code for non-linear formats.
 */
int snd_pcm_format_signed(snd_pcm_format_t format)
{
	int val;
	if (!valid_format(format))
		return -EINVAL;
	if ((val = pcm_formats[(INT)format].signd) < 0)
		return -EINVAL;
	return val;
}
EXPORT_SYMBOL(snd_pcm_format_signed);

/**
 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 * @format: the format to check
 *
 * Return: 1 if the given PCM format is unsigned linear, 0 if signed
 * linear, and a negative error code for non-linear formats.
 */
int snd_pcm_format_unsigned(snd_pcm_format_t format)
{
	int val;

	val = snd_pcm_format_signed(format);
	if (val < 0)
		return val;
	return !val;
}
EXPORT_SYMBOL(snd_pcm_format_unsigned);

/**
 * snd_pcm_format_linear - Check the PCM format is linear
 * @format: the format to check
 *
 * Return: 1 if the given PCM format is linear, 0 if not.
 */
int snd_pcm_format_linear(snd_pcm_format_t format)
{
	return snd_pcm_format_signed(format) >= 0;
}
EXPORT_SYMBOL(snd_pcm_format_linear);

/**
 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 * @format: the format to check
 *
 * Return: 1 if the given PCM format is little-endian, 0 if
 * big-endian, or a negative error code if endian not specified.
 */
int snd_pcm_format_little_endian(snd_pcm_format_t format)
{
	int val;
	if (!valid_format(format))
		return -EINVAL;
	if ((val = pcm_formats[(INT)format].le) < 0)
		return -EINVAL;
	return val;
}
EXPORT_SYMBOL(snd_pcm_format_little_endian);

/**
 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 * @format: the format to check
 *
 * Return: 1 if the given PCM format is big-endian, 0 if
 * little-endian, or a negative error code if endian not specified.
 */
int snd_pcm_format_big_endian(snd_pcm_format_t format)
{
	int val;

	val = snd_pcm_format_little_endian(format);
	if (val < 0)
		return val;
	return !val;
}
EXPORT_SYMBOL(snd_pcm_format_big_endian);

/**
 * snd_pcm_format_width - return the bit-width of the format
 * @format: the format to check
 *
 * Return: The bit-width of the format, or a negative error code
 * if unknown format.
 */
int snd_pcm_format_width(snd_pcm_format_t format)
{
	int val;
	if (!valid_format(format))
		return -EINVAL;
	if ((val = pcm_formats[(INT)format].width) == 0)
		return -EINVAL;
	return val;
}
EXPORT_SYMBOL(snd_pcm_format_width);

/**
 * snd_pcm_format_physical_width - return the physical bit-width of the format
 * @format: the format to check
 *
 * Return: The physical bit-width of the format, or a negative error code
 * if unknown format.
 */
int snd_pcm_format_physical_width(snd_pcm_format_t format)
{
	int val;
	if (!valid_format(format))
		return -EINVAL;
	if ((val = pcm_formats[(INT)format].phys) == 0)
		return -EINVAL;
	return val;
}
EXPORT_SYMBOL(snd_pcm_format_physical_width);

/**
 * snd_pcm_format_size - return the byte size of samples on the given format
 * @format: the format to check
 * @samples: sampling rate
 *
 * Return: The byte size of the given samples for the format, or a
 * negative error code if unknown format.
 */
ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
{
	int phys_width = snd_pcm_format_physical_width(format);
	if (phys_width < 0)
		return -EINVAL;
	return samples * phys_width / 8;
}
EXPORT_SYMBOL(snd_pcm_format_size);

/**
 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 * @format: the format to check
 *
 * Return: The format pattern to fill or %NULL if error.
 */
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
{
	if (!valid_format(format))
		return NULL;
	if (! pcm_formats[(INT)format].phys)
		return NULL;
	return pcm_formats[(INT)format].silence;
}
EXPORT_SYMBOL(snd_pcm_format_silence_64);

/**
 * snd_pcm_format_set_silence - set the silence data on the buffer
 * @format: the PCM format
 * @data: the buffer pointer
 * @samples: the number of samples to set silence
 *
 * Sets the silence data on the buffer for the given samples.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
{
	int width;
	unsigned char *dst;
	const unsigned char *pat;

	if (!valid_format(format))
		return -EINVAL;
	if (samples == 0)
		return 0;
	width = pcm_formats[(INT)format].phys; /* physical width */
	pat = pcm_formats[(INT)format].silence;
	if (! width)
		return -EINVAL;
	/* signed or 1 byte data */
	if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
		unsigned int bytes = samples * width / 8;
		memset(data, *pat, bytes);
		return 0;
	}
	/* non-zero samples, fill using a loop */
	width /= 8;
	dst = data;
#if 0
	while (samples--) {
		memcpy(dst, pat, width);
		dst += width;
	}
#else
	/* a bit optimization for constant width */
	switch (width) {
	case 2:
		while (samples--) {
			memcpy(dst, pat, 2);
			dst += 2;
		}
		break;
	case 3:
		while (samples--) {
			memcpy(dst, pat, 3);
			dst += 3;
		}
		break;
	case 4:
		while (samples--) {
			memcpy(dst, pat, 4);
			dst += 4;
		}
		break;
	case 8:
		while (samples--) {
			memcpy(dst, pat, 8);
			dst += 8;
		}
		break;
	}
#endif
	return 0;
}
EXPORT_SYMBOL(snd_pcm_format_set_silence);

/**
 * snd_pcm_hw_limit_rates - determine rate_min/rate_max fields
 * @hw: the pcm hw instance
 *
 * Determines the rate_min and rate_max fields from the rates bits of
 * the given hw.
 *
 * Return: Zero if successful.
 */
int snd_pcm_hw_limit_rates(struct snd_pcm_hardware *hw)
{
	int i;
	for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
		if (hw->rates & (1 << i)) {
			hw->rate_min = snd_pcm_known_rates.list[i];
			break;
		}
	}
	for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
		if (hw->rates & (1 << i)) {
			hw->rate_max = snd_pcm_known_rates.list[i];
			break;
		}
	}
	return 0;
}
EXPORT_SYMBOL(snd_pcm_hw_limit_rates);

/**
 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 * @rate: the sample rate to convert
 *
 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 * SNDRV_PCM_RATE_KNOT for an unknown rate.
 */
unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
{
	unsigned int i;

	for (i = 0; i < snd_pcm_known_rates.count; i++)
		if (snd_pcm_known_rates.list[i] == rate)
			return 1u << i;
	return SNDRV_PCM_RATE_KNOT;
}
EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);

/**
 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
 * @rate_bit: the rate bit to convert
 *
 * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
 * or 0 for an unknown rate bit.
 */
unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
{
	unsigned int i;

	for (i = 0; i < snd_pcm_known_rates.count; i++)
		if ((1u << i) == rate_bit)
			return snd_pcm_known_rates.list[i];
	return 0;
}
EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);

static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
{
	if (rates & SNDRV_PCM_RATE_CONTINUOUS)
		return SNDRV_PCM_RATE_CONTINUOUS;
	else if (rates & SNDRV_PCM_RATE_KNOT)
		return SNDRV_PCM_RATE_KNOT;
	return rates;
}

/**
 * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
 * @rates_a: The first rate mask
 * @rates_b: The second rate mask
 *
 * This function computes the rates that are supported by both rate masks passed
 * to the function. It will take care of the special handling of
 * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
 *
 * Return: A rate mask containing the rates that are supported by both rates_a
 * and rates_b.
 */
unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
	unsigned int rates_b)
{
	rates_a = snd_pcm_rate_mask_sanitize(rates_a);
	rates_b = snd_pcm_rate_mask_sanitize(rates_b);

	if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
		return rates_b;
	else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
		return rates_a;
	else if (rates_a & SNDRV_PCM_RATE_KNOT)
		return rates_b;
	else if (rates_b & SNDRV_PCM_RATE_KNOT)
		return rates_a;
	return rates_a & rates_b;
}
EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);

/**
 * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
 * @rate_min: the minimum sample rate
 * @rate_max: the maximum sample rate
 *
 * This function has an implicit assumption: the rates in the given range have
 * only the pre-defined rates like 44100 or 16000.
 *
 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
 * or SNDRV_PCM_RATE_KNOT for an unknown range.
 */
unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
	unsigned int rate_max)
{
	unsigned int rates = 0;
	int i;

	for (i = 0; i < snd_pcm_known_rates.count; i++) {
		if (snd_pcm_known_rates.list[i] >= rate_min
			&& snd_pcm_known_rates.list[i] <= rate_max)
			rates |= 1 << i;
	}

	if (!rates)
		rates = SNDRV_PCM_RATE_KNOT;

	return rates;
}
EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);