Not all supported chips support the entire I2C address range.
Only accept specific chips at the addresses supported by that chip.
Check for invalid values in conversion rate and status registers.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NJean Delvare <jdelvare@suse.de>

Add documentation for the tmp421 driver.
Signed-off-by: NAndre Prendel <andre.prendel@gmx.de>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NJean Delvare <khali@linux-fr.org>