Input: add support for key scan interface of the LPC32xx SoC

This is a driver for the key scan interface of the LPC32xx SoC
Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/lpc32xx-key.txt

+NXP LPC32xx Key Scan Interface
+
+Required Properties:
+- compatible: Should be "nxp,lpc3220-key"
+- reg: Physical base address of the controller and length of memory mapped
+  region.
+- interrupts: The interrupt number to the cpu.
+- keypad,num-rows: Number of rows and columns, e.g. 1: 1x1, 6: 6x6
+- keypad,num-columns: Must be equal to keypad,num-rows since LPC32xx only
+  supports square matrices
+- nxp,debounce-delay-ms: Debounce delay in ms
+- nxp,scan-delay-ms: Repeated scan period in ms
+- linux,keymap: the key-code to be reported when the key is pressed
+  and released, see also
+  Documentation/devicetree/bindings/input/matrix-keymap.txt
+
+Example:
+
+	key@40050000 {
+		compatible = "nxp,lpc3220-key";
+		reg = <0x40050000 0x1000>;
+		interrupts = <54 0>;
+		keypad,num-rows = <1>;
+		keypad,num-columns = <1>;
+		nxp,debounce-delay-ms = <3>;
+		nxp,scan-delay-ms = <34>;
+		linux,keymap = <0x00000002>;
+	};

drivers/input/keyboard/Kconfig

@@ -332,6 +332,16 @@ config KEYBOARD_LOCOMO
 	  To compile this driver as a module, choose M here: the
 	  module will be called locomokbd.
 
+config KEYBOARD_LPC32XX
+	tristate "LPC32XX matrix key scanner support"
+	depends on ARCH_LPC32XX && OF
+	help
+	  Say Y here if you want to use NXP LPC32XX SoC key scanner interface,
+	  connected to a key matrix.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called lpc32xx-keys.
+
 config KEYBOARD_MAPLE
 	tristate "Maple bus keyboard"
 	depends on SH_DREAMCAST && MAPLE

drivers/input/keyboard/Makefile

@@ -26,6 +26,7 @@ obj-$(CONFIG_KEYBOARD_LKKBD)		+= lkkbd.o
 obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o
 obj-$(CONFIG_KEYBOARD_LM8333)		+= lm8333.o
 obj-$(CONFIG_KEYBOARD_LOCOMO)		+= locomokbd.o
+obj-$(CONFIG_KEYBOARD_LPC32XX)		+= lpc32xx-keys.o
 obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
 obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
 obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o