adc_src_4020_bits
adc_src_4020_bits(devpriv->calibration_source);
devpriv->i2c_cal_range_bits |= adc_src_4020_bits(4);
devpriv->i2c_cal_range_bits |= adc_src_4020_bits(4);
devpriv->i2c_cal_range_bits = adc_src_4020_bits(4);