// Overlay for the AB Electronics ADC DAC Pi Zero
// https://www.abelectronics.co.uk/p/74/adc-dac-pi-zero

/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2835";

	// Create a fictitious voltage regulator for the reference

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

	// Enable MCP3202 ADC on SPI chip 0 slave select 0 (GPIO8)

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

			mcp3202: mcp3202@0 {
				compatible = "mcp3202";
				reg = <0>;
				spi-max-frequency = <1000000>;
				vref-supply = <&ADC_DAC_Pi_Zero_vref>;
			};
		};
	};

	// Enable MCP4822 DAC on SPI chip 0 slave select 1 (GPIO7)

	fragment@2 {
		target = <&spi0>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;
			status = "okay";

			mcp4822: mcp4822@1 {
				compatible = "mcp4822";
				reg = <1>;
				spi-max-frequency = <1000000>;
			};
		};
	};

	// Define parameters to calibrate the reference voltage

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