RK_I2S_SAMPLE_RATE
const u_int bclk_rate = 2 * 32 * RK_I2S_SAMPLE_RATE;
const u_int lrck_div = bclk_rate / RK_I2S_SAMPLE_RATE;
sc->sc_format.frequency[0] = RK_I2S_SAMPLE_RATE;