backlight: Add GPIO-based backlight driver

The GPIO backlight driver controls the backlight in on/off mode through
a single GPIO.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index d5ab658..5ab6423 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -425,6 +425,13 @@
 	  If you have an Austrian Microsystems AS3711 say Y to enable the
 	  backlight driver.
 
+config BACKLIGHT_GPIO
+	tristate "Generic GPIO based Backlight Driver"
+	depends on GPIOLIB
+	help
+	  If you have a LCD backlight adjustable by GPIO, say Y to enable
+	  this driver.
+
 endif # BACKLIGHT_CLASS_DEVICE
 
 endif # BACKLIGHT_LCD_SUPPORT