Brooklyn/arch/arm/boot/dts/overlays/i2c-gpio-overlay.dts

// Overlay for i2c_gpio bitbanging host bus.
/dts-v1/;
/plugin/;

#include <dt-bindings/gpio/gpio.h>

/ {
	compatible = "brcm,bcm2835";

	fragment@0 {
		target-path = "/";

		__overlay__ {
			i2c_gpio: i2c@0 {
				reg = <0xffffffff>;
				compatible = "i2c-gpio";
				gpios = <&gpio 23 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN) /* sda */
					 &gpio 24 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN) /* scl */
					>;
				i2c-gpio,delay-us = <2>;        /* ~100 kHz */
				#address-cells = <1>;
				#size-cells = <0>;
			};
		};
	};

	fragment@1 {
		target-path = "/aliases";
		__overlay__ {
			i2c_gpio = "/i2c@0";
		};
	};

	fragment@2 {
		target-path = "/__symbols__";
		__overlay__ {
			i2c_gpio = "/i2c@0";
		};
	};

	__overrides__ {
		i2c_gpio_sda = <&i2c_gpio>,"gpios:4";
		i2c_gpio_scl = <&i2c_gpio>,"gpios:16";
		i2c_gpio_delay_us = <&i2c_gpio>,"i2c-gpio,delay-us:0";
		bus = <&i2c_gpio>, "reg:0";
	};
};