lcd-rgb-keypad.dts

// Definitions for MCP23017 Gpio Extender from Microchip Semiconductor

/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2708";

	fragment@0 {
		target = <&i2c_arm>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;

			status = "okay";
			
			mcp23017: mcp@20 {
				compatible = "microchip,mcp23017";
				reg = <0x20>;
				gpio-controller;
				#gpio-cells = <2>;
				//#interrupt-cells=<2>;
				//interrupt-parent = <&gpio>;
				//interrupts = <4 2>;
				//interrupt-controller;
				//microchip,irq-mirror;

				status = "okay";

				gpiokeys: pinmux0 {
				 	pins = "gpio0", "gpio1", "gpio2", "gpio3", "gpio4";
					bias-pull-up;
				};
				gpioleds: pinmux1 {
				 	pins = "gpio6", "gpio7", "gpio8";
					bias-pull-up;
				};
				gpiolcd: pinmux2 {
				 	pins = "gpio5", "gpio9", "gpio10", "gpio11", "gpio12", "gpio13", "gpio14", "gpio15";
					bias-pull-up;
				};
			};
		};
	};

	// Display
    fragment@1 {
        target-path = "/";
       	__overlay__ {
			auxdisplay: auxdisplay {
				compatible = "hit,hd44780";

				// 0->GPIO_ACTIVE_HIGH
				data-gpios =   <&mcp23017 12 0>, /*Port GPB4*/
					           <&mcp23017 11 0>, /*Port GPB3*/
					           <&mcp23017 10 0>, /*Port GPB2*/
					           <&mcp23017  9 0>; /*Port GPB1*/
				enable-gpios = <&mcp23017 13 0>; //Port GPB5
				rw-gpios =     <&mcp23017 14 0>; //Port GPB6
				rs-gpios =     <&mcp23017 15 0>; //Port GPB7
				backlight-gpios = <&mcp23017 5 1>; //Port GPA5 (invert command)
				
				display-height-chars = <2>;
				display-width-chars = <16>;		
				
				pinctrl-names = "default";
				pinctrl-0 = <&gpiolcd>;

				status = "okay";
			};
		};
	};

	// RGB Led
	// led R Port GPA6
	// led G Port GPA7
	// led B Port GPB0
	fragment@2 {
		target-path = "/";
		__overlay__ {
			expander_leds {
				compatible = "gpio-leds";

				pinctrl-names = "default";
				pinctrl-0 = <&gpioleds>;

				status = "okay";

				led0: red {
					label = "red";
					gpios = <&mcp23017 6 1>;
					default-state = "off";
				};

				led1: green {
					label = "green";
					gpios = <&mcp23017 7 1>;
					default-state = "off";
				};

				led2: blue {
					label = "blue";
					gpios = <&mcp23017 8 1>;
					default-state = "off";
				};
			};
		};
	};

	// TODO Buttons (need to be fixed and tested)
	// Button Select GPA0
	// Button Right  GPA1
	// Button Down   GPA2
	// Button Up     GPA3
	// Button Left   GPA4
	fragment@3 {
		target-path = "/";

		__overlay__ {
        	keypad: keypad {
				//compatible = "gpio-keys"; 	// NOT POSSIBLE BECAUSE Interrupt pins are not wired on my mcp23017 board
				compatible = "gpio-keys-polled";
				poll-interval = <100>;
                #address-cells = <1>;
                #size-cells = <0>;
				autorepeat;
				
				pinctrl-names = "default";
				pinctrl-0 = <&gpiokeys>;
				
				status = "okay";
				
				enter: enter {
        			label = "GPIO Key Select";
        			linux,code = <28>; // Enter
        			gpios = <&mcp23017 0 1>;
				};
				
				right: right {
        			label = "GPIO Key RIGHT";
        			linux,code = <106>;
        			gpios = <&mcp23017 1 1>;
				};
				
				down: down {
        			label = "GPIO Key DOWN";
        			linux,code = <108>;
        			gpios = <&mcp23017 2 1>;
				};
				
				up: up {
        			label = "GPIO Key UP";
        			linux,code = <103>;
        			gpios = <&mcp23017 3 1>;
				};
		
				left: left {
					label = "GPIO Key LEFT";
					linux,code = <105>;
					gpios = <&mcp23017 4 1>;
				};
        	};
		};
	};

};