hwmon: Add NPCM7xx PWM and Fan driver

Add Nuvoton BMC NPCM750/730/715/705 Pulse Width Modulation (PWM)
and Fan tacho driver.

The Nuvoton BMC NPCM750/730/715/705 supports 8 PWM controller outputs
and 16 Fan controller inputs.

The driver provides a sysfs entries through which the user can
configure the duty-cycle value from 0(off) and 255(full speed)
and read the fan tacho rpm value.
Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/npcm750-pwm-fan

+Kernel driver npcm750-pwm-fan
+=============================
+
+Supported chips:
+	NUVOTON NPCM750/730/715/705
+
+Authors:
+	<tomer.maimon@nuvoton.com>
+
+Description:
+------------
+This driver implements support for NUVOTON NPCM7XX PWM and Fan Tacho
+controller. The PWM controller supports up to 8 PWM outputs. The Fan tacho
+controller supports up to 16 tachometer inputs.
+
+The driver provides the following sensor accesses in sysfs:
+
+fanX_input	ro	provide current fan rotation value in RPM as reported
+			by the fan to the device.
+
+pwmX		rw	get or set PWM fan control value. This is an integer
+			value between 0(off) and 255(full speed).

drivers/hwmon/Kconfig

@@ -1268,6 +1268,16 @@ config SENSORS_NCT7904
 	  This driver can also be built as a module.  If so, the module
 	  will be called nct7904.
 
+config SENSORS_NPCM7XX
+	tristate "Nuvoton NPCM750 and compatible PWM and Fan controllers"
+	imply THERMAL
+	help
+	  This driver provides support for Nuvoton NPCM750/730/715/705 PWM
+          and Fan controllers.
+
+          This driver can also be built as a module. If so, the module
+          will be called npcm750-pwm-fan.
+
 config SENSORS_NSA320
 	tristate "ZyXEL NSA320 and compatible fan speed and temperature sensors"
 	depends on GPIOLIB && OF

drivers/hwmon/Makefile

@@ -135,6 +135,7 @@ obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
 obj-$(CONFIG_SENSORS_NCT7802)	+= nct7802.o
 obj-$(CONFIG_SENSORS_NCT7904)	+= nct7904.o
+obj-$(CONFIG_SENSORS_NPCM7XX)	+= npcm750-pwm-fan.o
 obj-$(CONFIG_SENSORS_NSA320)	+= nsa320-hwmon.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o