HLK-7628N i2c connection

[Kaar3l]

Solved by this thread:

MT7621 : Enable I2C Driver

I think that something wrong here: If you want to use software i2c-gpio driver (instead of mediatek i2c-driver) you must remove these lines: pinctrl-names = "default"; pinctrl-0 = <&i2c_pins>; which implicitly request i2c mode for i2c_pins group and conflict with your explicit request for the same group to gpio mode: gpio { mtk,group = "i2c"; mtk,function = "gpio"; };

Commented out these lines in mt7628an_hilink_hlk-7628n.dts file

		gpio {
			mtk,group = "i2c";
			mtk,function = "gpio";
		};

And now dmesg shows:

root@GateOpenerTEST:~# dmesg | grep i2c
[   88.969126] i2c_dev: i2c /dev entries driver
[   88.994647] i2c-mt7621 10000900.i2c: clock 100 kHz

I also had hardware connections missing. The MCP23017 needs +3.3v to RESET pin.