[PATCH] max6875: new i2c device driver

This patch adds support for the MAX6875/MAX6874 chips.
Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/i2c/chips/max6875

+Kernel driver max6875
+=====================
+
+Supported chips:
+  * Maxim max6874, max6875
+    Prefixes: 'max6875'
+    Addresses scanned: 0x50, 0x52
+    Datasheets:
+        http://pdfserv.maxim-ic.com/en/ds/MAX6874-MAX6875.pdf
+
+Author: Ben Gardner <bgardner@wabtec.com>
+
+
+Module Parameters
+-----------------
+
+* allow_write int
+  Set to non-zero to enable write permission:
+  *0: Read only
+   1: Read and write
+
+
+Description
+-----------
+
+The MAXIM max6875 is a EEPROM-programmable power-supply sequencer/supervisor.
+It provides timed outputs that can be used as a watchdog, if properly wired.
+It also provides 512 bytes of user EEPROM.
+
+At reset, the max6875 reads the configuration eeprom into its configuration
+registers.  The chip then begins to operate according to the values in the
+registers.
+
+See the datasheet for details on how to program the EEPROM.
+
+
+Sysfs entries
+-------------
+
+eeprom_user   - 512 bytes of user-defined EEPROM space. Only writable if
+                allow_write was set and register 0x43 is 0.
+
+eeprom_config - 70 bytes of config EEPROM. Note that changes will not get
+                loaded into register space until a power cycle or device reset.
+
+reg_config    - 70 bytes of register space. Any changes take affect immediately.
+
+
+General Remarks
+---------------
+
+A typical application will require that the EEPROMs be programmed once and
+never altered afterwards.
+

drivers/i2c/chips/Kconfig

@@ -498,4 +498,16 @@ config SENSORS_M41T00
 	  This driver can also be built as a module.  If so, the module
 	  will be called m41t00.
 
+config SENSORS_MAX6875
+	tristate "MAXIM MAX6875 Power supply supervisor"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the MAX6875
+	  EEPROM-Programmable, Hex/Quad, Power-Suppy Sequencers/Supervisors.
+
+          This provides a interface to program the EEPROM and reset the chip.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called max6875.
+
 endmenu

drivers/i2c/chips/Makefile

@@ -32,6 +32,7 @@ obj-$(CONFIG_SENSORS_LM87)	+= lm87.o
 obj-$(CONFIG_SENSORS_LM90)	+= lm90.o
 obj-$(CONFIG_SENSORS_LM92)	+= lm92.o
 obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o
+obj-$(CONFIG_SENSORS_MAX6875)	+= max6875.o
 obj-$(CONFIG_SENSORS_M41T00)	+= m41t00.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PCF8574)	+= pcf8574.o