hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips

Add support for Texas Instruments TMP421/422/423 temperature sensor IC.

TI's TMP421/422/423 are I2C temperature sensor chips. These chips are
similar to TI's TMP401/411 chips, but with reduced functionality (only
temperature measurement). The chips have one local sensor and up to
three (TMP423) remote sensors.

Signed-off-by: Andre Prendel <andre.prendel@gmx.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 2e25b7a..ee57a4a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -814,6 +814,16 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called tmp401.
 
+config SENSORS_TMP421
+	tristate "Texas Instruments TMP421 and compatible"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for Texas Instruments TMP421,
+	  TMP422 and TMP423 temperature sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tmp421.
+
 config SENSORS_VIA686A
 	tristate "VIA686A"
 	depends on PCI