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pcm: softvol: add support for S24_LE

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Tested with the Wolfson WM8524 DAC on a i.MX6UL board and the following
ALSA configuration file using the pcm test utility from alsa-lib:

"""
$ cat /etc/asound.conf
pcm.!default {
    type plug
    slave.pcm "softvol"
}
pcm.softvol {
    type softvol
    slave {
        pcm "hw:0"
    }
    control {
        name "Master"
        card 0
    }
}
ctl.!default {
    type hw
    card 0
}
ctl.softvol {
    type hw
    card 0
}

$ pcm -D softvol -o S24_LE -c 2 -r 48000
"""

The data in the Synchronous Audio Interface (SAI) of the i.MX6UL is
aligned the following way:

"""
31 30 29 28 | 27 26 25 24 | 23 22 21 20 | .. | 3 2 1 0
## ## ## ##   ## ## ## ## [           DATA[23:0]       ]
"""

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Jörg Krause 2017-09-13 16:21:10 +02:00 • committed by Takashi Iwai
parent 8d61695145
commit 6a617cc719
1 changed files with 53 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

56
src/pcm/pcm_softvol.c
View file

@ -252,6 +252,44 @@ static inline short MULTI_DIV_short(short a, unsigned int b, int swap)
} \
} while (0)
#define CONVERT_AREA_S24_LE() do { \
unsigned int ch, fr; \
int *src, *dst; \
int tmp; \
for (ch = 0; ch < channels; ch++) { \
src_area = &src_areas[ch]; \
dst_area = &dst_areas[ch]; \
src = snd_pcm_channel_area_addr(src_area, src_offset); \
dst = snd_pcm_channel_area_addr(dst_area, dst_offset); \
src_step = snd_pcm_channel_area_step(src_area) \
/ sizeof(int); \
dst_step = snd_pcm_channel_area_step(dst_area) \
/ sizeof(int); \
GET_VOL_SCALE; \
fr = frames; \
if (! vol_scale) { \
while (fr--) { \
*dst = 0; \
dst += dst_step; \
} \
} else if (vol_scale == 0xffff) { \
while (fr--) { \
*dst = *src; \
src += dst_step; \
dst += src_step; \
} \
} else { \
while (fr--) { \
tmp = *src << 8; \
tmp = (signed int) tmp >> 8; \
*dst = MULTI_DIV_24(tmp, vol_scale); \
src += dst_step; \
dst += src_step; \
} \
} \
} \
} while (0)
#define GET_VOL_SCALE \
switch (ch) { \
case 0: \
@ -315,6 +353,10 @@ static void softvol_convert_stereo_vol(snd_pcm_softvol_t *svol,
CONVERT_AREA(int,
!snd_pcm_format_cpu_endian(svol->sformat));
break;
case SND_PCM_FORMAT_S24_LE:
/* 24bit samples */
CONVERT_AREA_S24_LE();
break;
case SND_PCM_FORMAT_S24_3LE:
CONVERT_AREA_S24_3LE();
break;
@ -366,6 +408,10 @@ static void softvol_convert_mono_vol(snd_pcm_softvol_t *svol,
CONVERT_AREA(int,
!snd_pcm_format_cpu_endian(svol->sformat));
break;
case SND_PCM_FORMAT_S24_LE:
/* 24bit samples */
CONVERT_AREA_S24_LE();
break;
case SND_PCM_FORMAT_S24_3LE:
CONVERT_AREA_S24_3LE();
break;
@ -422,6 +468,7 @@ static int snd_pcm_softvol_hw_refine_cprepare(snd_pcm_t *pcm,
{
(1ULL << SND_PCM_FORMAT_S16_LE) |
(1ULL << SND_PCM_FORMAT_S16_BE) |
(1ULL << SND_PCM_FORMAT_S24_LE) |
(1ULL << SND_PCM_FORMAT_S32_LE) |
(1ULL << SND_PCM_FORMAT_S32_BE),
(1ULL << (SND_PCM_FORMAT_S24_3LE - 32))
@ -577,10 +624,11 @@ static int snd_pcm_softvol_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * param
if (slave->format != SND_PCM_FORMAT_S16_LE &&
slave->format != SND_PCM_FORMAT_S16_BE &&
slave->format != SND_PCM_FORMAT_S24_3LE &&
slave->format != SND_PCM_FORMAT_S24_LE &&
slave->format != SND_PCM_FORMAT_S32_LE &&
slave->format != SND_PCM_FORMAT_S32_BE) {
SNDERR("softvol supports only S16_LE, S16_BE, S24_3LE, S32_LE "
" or S32_BE");
SNDERR("softvol supports only S16_LE, S16_BE, S24_LE, S24_3LE, "
"S32_LE or S32_BE");
return -EINVAL;
}
svol->sformat = slave->format;
@ -863,6 +911,7 @@ int snd_pcm_softvol_open(snd_pcm_t **pcmp, const char *name,
sformat != SND_PCM_FORMAT_S16_LE &&
sformat != SND_PCM_FORMAT_S16_BE &&
sformat != SND_PCM_FORMAT_S24_3LE &&
sformat != SND_PCM_FORMAT_S24_LE &&
sformat != SND_PCM_FORMAT_S32_LE &&
sformat != SND_PCM_FORMAT_S32_BE)
return -EINVAL;
@ -1082,9 +1131,10 @@ int _snd_pcm_softvol_open(snd_pcm_t **pcmp, const char *name,
sformat != SND_PCM_FORMAT_S16_LE &&
sformat != SND_PCM_FORMAT_S16_BE &&
sformat != SND_PCM_FORMAT_S24_3LE &&
sformat != SND_PCM_FORMAT_S24_LE &&
sformat != SND_PCM_FORMAT_S32_LE &&
sformat != SND_PCM_FORMAT_S32_BE) {
SNDERR("only S16_LE, S16_BE, S24_3LE, S32_LE or S32_BE format is supported");
SNDERR("only S16_LE, S16_BE, S24_LE, S24_3LE, S32_LE or S32_BE format is supported");
snd_config_delete(sconf);
return -EINVAL;
}