CS42L51_MIC_POWER_CTL_SPEED
power_ctl &= ~(CS42L51_MIC_POWER_CTL_SPEED(3)
power_ctl |= CS42L51_MIC_POWER_CTL_SPEED(mode);
power_ctl |= CS42L51_MIC_POWER_CTL_SPEED(ratios[i].speed_mode);