- int snd_soc_dai_set_channel_map(struct snd_soc_dai * dai, unsigned int tx_num, unsigned int * tx_slot, unsigned int rx_num, unsigned int * rx_slot);
- how many TX channels
- pointer to an array which imply the TX slot number channel 0~num-1 uses
- how many RX channels
- pointer to an array which imply the RX slot number channel 0~num-1 uses
configure the relationship between channel number and TDM slot number.