HLK-7628N i2c connection

[Kaar3l]

Hello!

I designed a circuit with HILINK HLK-7628N. Connected I2C MCP27017 to i2c pins.

I did change mt7628an.dtsi file line 110 to status = "okay";

Now I get:

root@GateOpenerTEST:/dev# dmesg | grep i2c
[   89.513728] i2c_dev: i2c /dev entries driver
[   89.540343] rt2880-pinmux pinctrl: pin io4 already requested by pinctrl; cannot claim for 10000900.i2c
[   89.558911] rt2880-pinmux pinctrl: pin-4 (10000900.i2c) status -22
[   89.571166] rt2880-pinmux pinctrl: could not request pin 4 (io4) from group i2c  on device ralink-pinmux
[   89.589961] i2c-mt7621 10000900.i2c: Error applying setting, reverse things back

And there is no i2c device in /dev.

In dtsi file are also pin numbers.Do I need to define these separately? Is the io4 right pin in the dmesg?

			pinctrl-names = "default";
			pinctrl-0 = <&i2c_pins>;

[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.