[alsa-devel] ASOC: For SND_SOC_DAIFMT_IB_IF what is invert baseed on?

Hi,

include/sound/soc.h /* * DAI hardware signal inversions */ #define SND_SOC_DAIFMT_NB_NF (0 << 8) /* normal bclk + frm */ #define SND_SOC_DAIFMT_NB_IF (1 << 8) /* normal bclk + inv frm */ #define SND_SOC_DAIFMT_IB_NF (2 << 8) /* invert bclk + nor frm */ #define SND_SOC_DAIFMT_IB_IF (3 << 8) /* invert bclk + frm */

What are frame cock and bit clock invert based on? I2S, PCM or some else bus protocols? Or just high level voltage or low level voltage?

Thanks Richard