linux-arkmicro/linux/Documentation/devicetree/bindings/iio/adc/max1118.txt

* MAX1117/MAX1118/MAX1119 8-bit, dual-channel ADCs

Required properties:
 - compatible: Should be one of
	* "maxim,max1117"
	* "maxim,max1118"
	* "maxim,max1119"
 - reg: spi chip select number for the device
 - (max1118 only) vref-supply: The regulator supply for ADC reference voltage

Recommended properties:
 - spi-max-frequency: Definition as per
		Documentation/devicetree/bindings/spi/spi-bus.txt

Example:
adc@0 {
	compatible = "maxim,max1118";
	reg = <0>;
	vref-supply = <&vdd_supply>;
	spi-max-frequency = <1000000>;
};