LN2_PWR_UNITS
power = 5 * LN2_PWR_UNITS;
ret = read_sensor(dev, chan, LN2_VOLT, 1, LN2_PWR_UNITS, val);
ret = read_sensor(dev, chan, LN2_CURR, nsamples, LN2_PWR_UNITS, val);
power = DIV_ROUND_CLOSEST_ULL(power, LN2_PWR_UNITS);