hwmon: Add driver for LM95234

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/lm95234

+Kernel driver lm95234
+=====================
+
+Supported chips:
+  * National Semiconductor / Texas Instruments LM95234
+    Addresses scanned: I2C 0x18, 0x4d, 0x4e
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/product/lm95234
+
+
+Author: Guenter Roeck <linux@roeck-us.net>
+
+Description
+-----------
+
+LM95234 is an 11-bit digital temperature sensor with a 2-wire System Management
+Bus (SMBus) interface and TrueTherm technology that can very accurately monitor
+the temperature of four remote diodes as well as its own temperature.
+The four remote diodes can be external devices such as microprocessors,
+graphics processors or diode-connected 2N3904s. The LM95234's TruTherm
+beta compensation technology allows sensing of 90 nm or 65 nm process
+thermal diodes accurately.
+
+All temperature values are given in millidegrees Celsius. Temperature
+is provided within a range of -127 to +255 degrees (+127.875 degrees for
+the internal sensor). Resolution depends on temperature input and range.
+
+Each sensor has its own maximum limit, but the hysteresis is common to all
+channels. The hysteresis is configurable with the tem1_max_hyst attribute and
+affects the hysteresis on all channels. The first two external sensors also
+have a critical limit.
+
+The lm95234 driver can change its update interval to a fixed set of values.
+It will round up to the next selectable interval. See the datasheet for exact
+values. Reading sensor values more often will do no harm, but will return
+'old' values.

drivers/hwmon/Kconfig

@@ -771,6 +771,16 @@ config SENSORS_LTC4261
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc4261.
 
+config SENSORS_LM95234
+	tristate "National Semiconductor LM95234"
+	depends on I2C
+	help
+	  If you say yes here you get support for the LM95234 temperature
+	  sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called lm95234.
+
 config SENSORS_LM95241
 	tristate "National Semiconductor LM95241 and compatibles"
 	depends on I2C

drivers/hwmon/Makefile

@@ -88,6 +88,7 @@ obj-$(CONFIG_SENSORS_LM87)	+= lm87.o
 obj-$(CONFIG_SENSORS_LM90)	+= lm90.o
 obj-$(CONFIG_SENSORS_LM92)	+= lm92.o
 obj-$(CONFIG_SENSORS_LM93)	+= lm93.o
+obj-$(CONFIG_SENSORS_LM95234)	+= lm95234.o
 obj-$(CONFIG_SENSORS_LM95241)	+= lm95241.o
 obj-$(CONFIG_SENSORS_LM95245)	+= lm95245.o
 obj-$(CONFIG_SENSORS_LTC4151)	+= ltc4151.o