How to activate i2c pins 3 and 5 on the board?

theophile · January 18, 2023, 8:59pm

Here’s the .dts for that particular overlay:

arch/arm64/boot/dts/amlogic/overlay/meson-g12a-i2c-ee-m3-gpioa-14-gpioa-15.dts

linux-5.10.y-radxa-zero

/dts-v1/;
/plugin/;

/ {
	compatible = "radxa,zero", "amlogic,g12a";

	fragment@0 {
		target = <&i2c3>;
		__overlay__ {
			status = "okay";
			pinctrl-0 = <&i2c3_sck_a_pins &i2c3_sda_a_pins>;
			pinctrl-names = "default";
		};
	};
};

You should be able to compile it with sudo dtc -@ -I dts -O dtb -o meson-g12a-i2c-ee-m3-gpioa-14-gpioa-15.dtbo meson-g12a-i2c-ee-m3-gpioa-14-gpioa-15.dts

Then you move the resulting meson-g12a-i2c-ee-m3-gpioa-14-gpioa-15.dtbo to wherever other overlays are stored, usually somewhere in /boot. Then you can add the appropriate line in uEnv.txt or whatever boot script your system uses.