Platform: add Samsung Laptop platform driver

This adds the samsung-laptop driver to the kernel.  It now supports
all known Samsung laptops that use the SABI interface.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Documentation/ABI/testing/sysfs-driver-samsung-laptop

+What:		/sys/devices/platform/samsung/performance_level
+Date:		January 1, 2010
+KernelVersion:	2.6.33
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:	Some Samsung laptops have different "performance levels"
+		that are can be modified by a function key, and by this
+		sysfs file.  These values don't always make a whole lot
+		of sense, but some users like to modify them to keep
+		their fans quiet at all costs.  Reading from this file
+		will show the current performance level.  Writing to the
+		file can change this value.
+			Valid options:
+				"silent"
+				"normal"
+				"overclock"
+		Note that not all laptops support all of these options.
+		Specifically, not all support the "overclock" option,
+		and it's still unknown if this value even changes
+		anything, other than making the user feel a bit better.

drivers/platform/x86/Kconfig

@@ -739,4 +739,17 @@ config XO15_EBOOK
 	  This switch is triggered as the screen is rotated and folded down to
 	  convert the device into ebook form.
 
+config SAMSUNG_LAPTOP
+	tristate "Samsung Laptop driver"
+	depends on RFKILL && BACKLIGHT_CLASS_DEVICE && X86
+	---help---
+	  This module implements a driver for a wide range of different
+	  Samsung laptops.  It offers control over the different
+	  function keys, wireless LED, LCD backlight level, and
+	  sometimes provides a "performance_control" sysfs file to allow
+	  the performance level of the laptop to be changed.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called samsung-laptop.
+
 endif # X86_PLATFORM_DEVICES

drivers/platform/x86/Makefile

@@ -40,4 +40,5 @@ obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
 obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 obj-$(CONFIG_XO15_EBOOK)	+= xo15-ebook.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
+obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop.o
 obj-$(CONFIG_INTEL_MFLD_THERMAL)	+= intel_mid_thermal.o