// Device tree overlay for the RasPio Analog Zero ADC board
// https://rasp.io/analogzero

/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2835";

	// Create a fictitious voltage regulator for the MCP3008 reference

	fragment@0 {
		target-path = "/";
		__overlay__ {
			mcp3008_vref: mcp3008-vref {
				compatible = "regulator-fixed";
				regulator-name = "MCP3008";
				regulator-min-microvolt = <3300000>;
				regulator-max-microvolt = <3300000>;
				regulator-always-on;
				status = "okay";
 			};
		};
	};

	// Enable MCP3008 on SPI chip 0 slave select 0 (GPIO8)

	fragment@1 {
		target = <&spi0>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;
			status = "okay";

			mcp3008_00: mcp3008@0 {
				compatible = "mcp3008";
				reg = <0>;
				spi-max-frequency = <1000000>;
				vref-supply = <&mcp3008_vref>;
			};
		};
	};

	// Define parameters to calibrate the MCP3008 reference voltage

	__overrides__ {
		min = <&mcp3008_vref>, "regulator-min-microvolt:0";
		max = <&mcp3008_vref>, "regulator-max-microvolt:0";
	};
};