TSC1641_VLOAD_LSB_MVOLT
*val = regval * TSC1641_VLOAD_LSB_MVOLT;
val = clamp_val(val, 0, TSC1641_VLOAD_LSB_MVOLT * USHRT_MAX);
regval = DIV_ROUND_CLOSEST(val, TSC1641_VLOAD_LSB_MVOLT);