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linux/sound/core/pcm_misc.c
Clemens Ladisch fea952e5cc ALSA: core: sparse cleanups 
Change the core code where sparse complains.  In most cases, this means
just adding annotations to confirm that we indeed want to do the dirty
things we're doing.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-02-14 17:10:11 +01:00

490 lines
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/*
* 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 <sound/core.h>
#include <sound/pcm.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 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 = {},
},
/* FIXME: the following three 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_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
*
* Returns 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 ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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
*
* Returns 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
*
* Returns 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
*
* Returns 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 ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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
*
* Returns 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
*
* Returns 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 ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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
*
* Returns 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 ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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
*
* Returns 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
*
* Returns the format pattern to fill or NULL if error.
*/
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
{
if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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.
*
* Returns 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, *pat;
if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
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_limit_hw_rates - determine rate_min/rate_max fields
* @runtime: the runtime instance
*
* Determines the rate_min and rate_max fields from the rates bits of
* the given runtime->hw.
*
* Returns zero if successful.
*/
int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
{
int i;
for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
if (runtime->hw.rates & (1 << i)) {
runtime->hw.rate_min = snd_pcm_known_rates.list[i];
break;
}
}
for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
if (runtime->hw.rates & (1 << i)) {
runtime->hw.rate_max = snd_pcm_known_rates.list[i];
break;
}
}
return 0;
}
EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
/**
* snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
* @rate: the sample rate to convert
*
* Returns 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);
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