Overlay for Adafruit's OLED Bonnet https://www.adafruit.com/product/3531

bonnet.dts

//!/usr/bin/dtc -I dts -O dtb -o bonnet.dtbo bonnet.dts
// Overlay for Adafruit's OLED Bonnet https://www.adafruit.com/product/3531
// May need to add "fbcon=map:1" to /boot/cmdline.txt

/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";

	fragment@0 {
		target-path = "/";
		__overlay__ {
			keypad: keypad {
				compatible = "gpio-keys";

				a {
					label = "bonnet A";
					linux,code = <28>; // return
					gpios = <&gpio 5 0>;
				};

				b {
					label = "bonnet B";
					linux,code = <22>; // backspace
					gpios = <&gpio 6 0>;
				};

				up {
					label = "bonnet up";
					linux,code = <103>;
					gpios = <&gpio 17 0>;
				};
				down {
					label = "bonnet down";
					linux,code = <108>;
					gpios = <&gpio 22 0>;
				};
				left {
					label = "bonnet left";
					linux,code = <105>;
					gpios = <&gpio 27 0>;
				};

				right {
					label = "bonnet right";
					linux,code = <106>;
					gpios = <&gpio 23 0>;
				};

				center {
					label = "bonnet center";
					linux,code = <29>; // control
					gpios = <&gpio 4 0>;
				};
			};
		};
	};

	fragment@1 {
		target = <&i2c>;
		__overlay__ {
			status = "okay";
			#address-cells = <1>;
			#size-cells = <0>;			
			ssd1306: oled@3c {
				compatible = "solomon,ssd1306fb-i2c";
				reg = <0x3c>;
				solomon,prechargep1 = <0x1>;
				solomon,prechargep2 = <0xf>;
				solomon,width = <128>;
				solomon,height = <64>;
				solomon,page-offset = <0>;
				solomon,com-invdir;
			};
		};
	};
};