BCM2708: Add core Device Tree support, ilitek251x

Signed-off-by: Samuel Hsu <[email protected]>

Author: samhsuism

arch/arm/boot/dts/overlays/Makefile

@@ -65,6 +65,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	i2c0-bcm2708.dtbo \
 	i2c1-bcm2708.dtbo \
 	i2s-gpio28-31.dtbo \
+	ilitek251x.dtbo \
 	iqaudio-dac.dtbo \
 	iqaudio-dacplus.dtbo \
 	iqaudio-digi-wm8804-audio.dtbo \

arch/arm/boot/dts/overlays/README

@@ -1123,6 +1123,17 @@ Load:   dtoverlay=i2s-gpio28-31
 Params: <None>
 
 
+Name:   ilitek251x
+Info:   Enables I2C connected Ilitek 251x multiple touch controller using
+        GPIO 4 (pin 7 on GPIO header) for interrupt.
+Load:   dtoverlay=ilitek251x,<param>=<val>
+Params: interrupt               GPIO used for interrupt (default 4)
+        sizex                   Touchscreen size x, horizontal resolution of
+                                touchscreen (in pixels)
+        sizey                   Touchscreen size y, vertical resolution of
+                                touchscreen (in pixels)
+
+
 Name:   iqaudio-dac
 Info:   Configures the IQaudio DAC audio card
 Load:   dtoverlay=iqaudio-dac,<param>

arch/arm/boot/dts/overlays/ilitek251x-overlay.dts

@@ -0,0 +1,45 @@
+// Device tree overlay for I2C connected Ilitek multiple touch controller
+/dts-v1/;
+/plugin/;
+
+ / {
+	compatible = "brcm,bcm2708";
+
+ 	fragment@0 {
+		target = <&gpio>;
+		__overlay__ {		
+			ili251x_pins: ili251x_pins {
+				brcm,pins = <4>; // interrupt
+				brcm,function = <0>; // in
+				brcm,pull = <2>; // pull-up //
+			};
+		};
+	};
+
+ 	fragment@1 {
+		target = <&i2c1>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "okay";
+
+ 			ili251x: ili251x@41 {
+				compatible = "ilitek,ili251x";
+				reg = <0x41>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&ili251x_pins>;
+				interrupt-parent = <&gpio>;
+				interrupts = <4 8>; // high-to-low edge triggered
+				touchscreen-size-x = <16384>;
+				touchscreen-size-y = <9600>;
+			};
+		};
+	};
+
+ 	__overrides__ {
+		interrupt = <&ili251x_pins>,"brcm,pins:0",
+			<&ili251x>,"interrupts:0";
+		sizex = <&ili251x>,"touchscreen-size-x:0";
+		sizey = <&ili251x>,"touchscreen-size-y:0";
+	};
+};