I2S_CSR_SHIFT
#define I2S_CHN_2 (0 << I2S_CSR_SHIFT)
#define I2S_CHN_4 (1 << I2S_CSR_SHIFT)
#define I2S_CHN_6 (2 << I2S_CSR_SHIFT)
#define I2S_CHN_8 (3 << I2S_CSR_SHIFT)
#define I2S_CHN_2 (0 << I2S_CSR_SHIFT)
#define I2S_CHN_4 (1 << I2S_CSR_SHIFT)
#define I2S_CHN_6 (2 << I2S_CSR_SHIFT)
#define I2S_CHN_8 (3 << I2S_CSR_SHIFT)