hwmon: add generic GPIO fan driver

This patch adds hwmon support for fans connected to GPIO lines.

Platform specific information such as GPIO pinout and speed conversion array
(rpm from/to GPIO value) are passed to the driver via platform_data.

Signed-off-by: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index ec4295f..c357c83 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -399,6 +399,15 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called gl520sm.
 
+config SENSORS_GPIO_FAN
+	tristate "GPIO fan"
+	depends on GENERIC_GPIO
+	help
+	  If you say yes here you get support for fans connected to GPIO lines.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called gpio-fan.
+
 config SENSORS_CORETEMP
 	tristate "Intel Core/Core2/Atom temperature sensor"
 	depends on X86 && PCI && EXPERIMENTAL