SOUND_MIXER_VOLUME
#define SOUND_MASK_VOLUME (1 << SOUND_MIXER_VOLUME)
#define SOUND_MIXER_READ_VOLUME MIXER_READ(SOUND_MIXER_VOLUME)
#define SOUND_MIXER_WRITE_VOLUME MIXER_WRITE(SOUND_MIXER_VOLUME)
{ SOUND_MIXER_VOLUME, "Master", 0 },
{ SOUND_MIXER_VOLUME, "Front", 0 }, /* fallback */