How to get zephyr to use a new .yaml file and .overlay

[Yury Morgunov]

I am trying to create a description of my peripherals in the device tree.
For example, I want to describe the pins that will control the input type for the ADC. Current input or not.

To do this, I created the gpio-sensors.yaml file and put it along the path ncs\zephyr\dts\bindings\gpio

Here are its contents:

description: GPIO Sensors parent node

include: base.yaml
compatible: "gpio-sensors"

child-binding:
   description: Enabling current input for sensors
   properties:
      sensor1-type:
         type: int
         required: true
      sensor2-type:
         type: int
         required: true
      sensor3-type:
         type: int
         required: true
      sensor4-type:
         type: int
         required: true

In the nrf9160dk_nrf9160ns.overlay file, I added the following:

/ {
	chosen {
		zephyr,bt-uart=&uart2;
	};

	extperipheral {
		compatible = "gpio-sensors";
		sensors-type {
			sensor1-type = <0>;
			sensor2-type = <29>;
			sensor3-type = <28>;
			sensor4-type = <27>;
		};
	};
};

In this configuration, everything works fine. In devicetree_unfixed.h, I see everything that is described in .overlay

But there is a problem when I want to transfer gpio-sensors.yaml to the root of the project. In the devicetree_unfixed.h file, my description of sensor(x)_type disappears. I understand this is due to the fact that the collector can not find gpio-sensors.yaml

The question is, how do I indicate the location of this file in CMakeLists? The documentation found a mention of DTS_ROOT.
adding a line to CmakeLists

set (DTS_ROOT $ {CMAKE_CURRENT_SOURCE_DIR} /)

in devicetree_unfixed.h sensor(x)_type did not appear.
How do I get the build system to use my yaml?

Here is the structure of my project:

firmware:
- ncs
- CMakeLists.txt
- gpio-sensors.yaml
- nrf9160dk_nrf9160ns.overlay
- prj.conf

Thank!

[Simonr]

Hi

Please check out the DeviceTree Guide in the Zephyr documentation here for more information on .yaml files. For information on how to do overlays and read them, please check out our nRFConnect SDK tutorial (Part 3) which describes that.

I also suggest checking out the Zephyr documentation on DeviceTree Definitions for information on out-of-tree DTS. Please note that the structure proposed here has to be located right after the CMakeLists that describes your project.

Best regards,

Simon

[Yury Morgunov]

Yes indeed, you need to create a directory of the form:

firmware:
- ncs
- CMakeLists.txt
- nrf9160dk_nrf9160ns.overlay
- prj.conf
- dts/common/
- dts/arm/
- dts/
- dts/bindings/gpio-sensors.yaml

Then it works. I used to try to do so, but apparently I was mistaken somewhere.

Here's what you need when creating a project:

cmake -B eclipse_project -GNinja -DBOARD=nrf9160dk_nrf9160ns -DDTS_ROOT=dts -G"Eclipse CDT4 - Ninja"

Or in Cmakelist:

set(DTS_ROOT "dts")

However, I could not specify DTS_ROOT through "west"
this is how I tried:

west build -d eclipse_project -b nrf9160dk_nrf9160ns -- -DDTS_ROOT=dts -- -G"Eclipse CDT4 - Ninja" 

Something is wrong with the syntax.

Many thanks for the help!