reg2temp
out = reg2temp(data, data->temp[THERM][sattr->index]) -
out = reg2temp(data, data->temp[sattr->nr][sattr->index]);
temp = reg2temp(data, data->temp[THERM][sattr->index]);
val = reg2temp(data, data->temp[AUTOMIN][sattr->index]);
temp = reg2temp(data, data->temp[AUTOMIN][sattr->index]);