[ODROID n2] Power off and wake up using GPIO key button and heartbeat LED action

[dieneuser]

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• [ ] ODROID [N2(+)]

I installed a switch with LED in the odroid n2+ and was able to use it under Ubuntu from hardkernel: (https://wiki.odroid.com/odroid-n2/application_note/gpio/gpio_key_wakeup) Is it possible to use this function under Home Assistant OS too? A configuration of the gpiopower flag in the boot.scr did nothing - Doesn't the kernel support that? (argument gpiopower=479 for power button on PIN 11+9) And a look in the dtb file from home assistant os shows that the parameter and value for the blue LED pin are different to the solution from hardkernel. (PIN 8+6)

thx

[agners]

Hm, Raspberry Pi solves such kind of hardware modification using device tree overlays. I'd rather prefer not to add/support overlays for ODROID-N2(+). But we could just declare those pins as "power button pins" by default.

We use upstream/mainline Linux, whereas ODROID's Ubuntu uses something downstream. The gpiopower kernel argument is a downstream/custom kernel argument. But I think its not required to have such an argument if we would just declare it as default function of those pins.

[agners]

And a look in the dtb file from home assistant os shows that the parameter and value for the blue LED pin are different to the solution from hardkernel. (PIN 8+6)

Looks pretty much the same to me:

Home Assistant OS/upstream kernel:

	leds {
		compatible = "gpio-leds";

		blue {
			label = "n2:blue";
			gpios = <&gpio_ao GPIOAO_11 GPIO_ACTIVE_HIGH>;
			linux,default-trigger = "heartbeat";
		};
	};

Hardkernel 4.9 kernel

	leds {
		compatible = "gpio-leds";
		blueled {
			label = "blue:heartbeat";
			gpios = <&gpio_ao GPIOAO_11 GPIO_ACTIVE_HIGH>;
			linux,default-trigger = "heartbeat";
		};
	};

Any problems with the pulse led?

[dieneuser]

Hm, Raspberry Pi solves such kind of hardware modification using device tree overlays. I'd rather prefer not to add/support overlays for ODROID-N2(+). But we could just declare those pins as "power button pins" by default.

This sounds good, i prefer the same PINs like in the Odroid Wiki (9+11).

Home Assistant OS/upstream kernel:

  leds {
  	compatible = "gpio-leds";

  	blue {
  		label = "n2:blue";
  		gpios = <&gpio_ao GPIOAO_11 GPIO_ACTIVE_HIGH>;
  		linux,default-trigger = "heartbeat";
  	};
  };

In my installation it looks different: Home Assistant OS 5.10: meson-odroid-n2-plus.dtb:

	leds {
		compatible = "gpio-leds";

		blue {
			label = "n2:blue";
			gpios = < 0x48 0x0b 0x00 >;
			linux,default-trigger = "heartbeat";
		};

Values: 72 11 0

Hardkernel: meson64_odroidn2_plus.dtb:

	leds {
		compatible = "gpio-leds";

		blueled {
			label = "blue:heartbeat";
			gpios = < 0x18 0x0b 0x00 >;
			linux,default-trigger = "heartbeat";
		};

Values: 24 11 0

And for the LED on PINs 8+9 I need 26 78 0

The big question is, when the first value 72 is the onboard GIPO_AO from Home Assistant OS, what value is for the GPIO header?

Then I can simply rewrite the file with the command: fdtput meson-g12b-odroid-n2-plus.dtb /leds/blue gpios ?? 78 0 for the button LED.

[agners]

Oh I see you are trying to use the LED on the pin header pin number 8, which is GPIOX_12. The button is GPIOX_3, so in theory it should work by just using what the button is using (fdtget buildroot/output_odroid_n2/images/meson-g12b-odroid-n2.dtb /gpio-keys-polled/power-button gpios) as GPIO reference shifted by 9.

Btw, the first number is device tree internal reference (think of it as pointer), and this can be different every time a device tree gets compiled. In other words, a new Home Assistant OS release might have different numbers... The second number (GPIO number within that controller) is stable in upstream/mainline Linux, but it can be different between downstream/vendor specific kernels and upstream Linux.

[dieneuser]

Thank you for the explanations and implementation.

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[jasonmp85]

Hey, this seems to have had some work done for it (updating the dtb files, etc.) but my ODROID N2+ isn't responding to the button press. Are there changes needed in the boot script?

[jasonmp85]

Ok, power off works for me, but wake-up does not. What is the expected behavior here for you all?