diff options
| author | Jaroslav Kysela <perex@perex.cz> | 2023-11-17 13:05:55 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2023-11-27 17:24:26 +0100 |
| commit | 2112aa034907c428785e1a5730927181276ee45b (patch) | |
| tree | c75e6907ab964064ba449d4b716109fcfce1d597 /include/uapi/sound/asound.h | |
| parent | 26257869672fd4a06a60c2da841e15fb2cb47bbe (diff) | |
ALSA: pcm: Introduce MSBITS subformat interface
Improve granularity of format selection for S32/U32 formats by adding
constants representing 20, 24 and MAX most significant bits.
The MAX means the maximum number of significant bits which can
the physical format hold. For 32-bit formats, MAX is related
to 32 bits. For 8-bit formats, MAX is related to 8 bits etc.
As there is only one user currently (format S32_LE), subformat is
represented by a simple u32 and stores flags only for that one user
alone. The approach of subformat being part of struct snd_pcm_hardware
is a compromise between ALSA and ASoC allowing for
hw_params-intersection code to be alloc/free-less while not adding any
new responsibilities to ASoC runtime structures.
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Co-developed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20231117120610.1755254-2-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/uapi/sound/asound.h')
| -rw-r--r-- | include/uapi/sound/asound.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index f9939da41122..d5b9cfbd9cea 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -142,7 +142,7 @@ struct snd_hwdep_dsp_image { * * *****************************************************************************/ -#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 15) +#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 16) typedef unsigned long snd_pcm_uframes_t; typedef signed long snd_pcm_sframes_t; @@ -267,7 +267,10 @@ typedef int __bitwise snd_pcm_format_t; typedef int __bitwise snd_pcm_subformat_t; #define SNDRV_PCM_SUBFORMAT_STD ((__force snd_pcm_subformat_t) 0) -#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_STD +#define SNDRV_PCM_SUBFORMAT_MSBITS_MAX ((__force snd_pcm_subformat_t) 1) +#define SNDRV_PCM_SUBFORMAT_MSBITS_20 ((__force snd_pcm_subformat_t) 2) +#define SNDRV_PCM_SUBFORMAT_MSBITS_24 ((__force snd_pcm_subformat_t) 3) +#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_MSBITS_24 #define SNDRV_PCM_INFO_MMAP 0x00000001 /* hardware supports mmap */ #define SNDRV_PCM_INFO_MMAP_VALID 0x00000002 /* period data are valid during transfer */ |