wcd_measure_adc_once
output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
output_mv = wcd_measure_adc_once(mbhc, MUX_CTL_IN2P);
hphl_adc_res = wcd_measure_adc_once(mbhc, MUX_CTL_HPH_L);
hphr_adc_res = wcd_measure_adc_once(mbhc, MUX_CTL_HPH_R);