Question about supply-gpios specification in dts file

[BertL]

I'm currently writing a zephyr device driver for an accelerometer (ST lis2dux12). In our design this accelerometer is powered using a gpio port to make hard reboots of the sensor possible. The corresponding gpio is specified using supply-gpios:

	lis2dux12: lis2dux12@0 {
		compatible = "st,lis2dux12";
		reg = <0>;
		spi-max-frequency = <10000000>;
		irq-gpios =  <&gpio0 29 GPIO_ACTIVE_HIGH>, <&gpio0 30 GPIO_ACTIVE_HIGH>;
		range = <2>;
		power-mode = <0>;
		odr = <2>;
		supply-gpios = <&gpio0 24 GPIO_ACTIVE_HIGH>;
	};

My question: Is Zephyr power management already doing something with this supply-gpios parameter, like setting it high during the boot of the device? Or should all the power-up logic be implemented in the driver itself? I could not find any documentation about this.

[Sigurd Hellesvik]

Hi,

Searching through the nRF Connect SDK for supply-gpios, I see that they are not used much, and that only by one of the boards (efr32mg...).

EDIT: Added image from search

From this, it looks like it is up to the sensor drivers to handle the supply-gpios.

See https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/pm/device_runtime.html#implementation-guidelines.

I also recommend searching for CONFIG_PM in other sensor drivers to learn how they implement power management.

Does this answer your questions?

Regards,
Sigurd Hellesvik

[BertL]

Hi Sigurd, thanks, this is useful information!