My First DTS

This tutorial walks you through creating your first device tree overlay using Analog Attach. By the end, you will have a working overlay that configures an AD7124-8 ADC on SPI, complete with clock and voltage regulator definitions.

The video below demonstrates the complete workflow for creating an AD7124 overlay using the Plug and Play editor.

Step by step guide to creating a dtso file with Analog Attach

Video

Step by step guide to creating a dtso file with Analog Attach

https://raw.githubusercontent.com/analogdevicesinc/analog-attach/doc_resources/resources/ad7124-overlay-creation-with-AA.mp4

Final Result

After following the steps in the video, your .dtso file should look like this:

/dts-v1/;
/plugin/;

&spi0 {
    status = "okay";
    ad7124-8@1 {
        status = "okay";
        compatible = "adi,ad7124-8";
        reg = <1>;
        clocks = <&ad7124_mclk>;
        clock-names = "mclk";
        interrupts = <25 2>;
        interrupt-parent = <&gpio>;
        refin1-supply = <&vref>;
        spi-max-frequency = <500000>;

        channel@0 {
            reg = <0>;
            diff-channels = <0 19>;
        };

        channel@1 {
            reg = <1>;
            diff-channels = <1 19>;
        };
    };
};

&{/clocks} {
    status = "okay";
    ad7124_mclk: fixed-clock {
        status = "okay";
        compatible = "fixed-clock";
        #clock-cells = <0>;
        clock-frequency = <614400>;
    };
};

&{/} {
    status = "okay";
    vref: regulator-fixed {
        status = "okay";
        compatible = "regulator-fixed";
        regulator-name = "fixed-supply";
        regulator-min-microvolt = <2500000>;
        regulator-max-microvolt = <2500000>;
        regulator-boot-on;
    };
};

This overlay:

• Attaches an AD7124-8 ADC to spi0 at chip select 1

• Configures two differential input channels

• Defines a fixed clock source for the ADC

• Creates a fixed voltage regulator for the reference input