current-sense-shunt.txt

Current Sense Shunt
===================

When an io-channel measures the voltage over a current sense shunt,
the interesting measurement is almost always the current through the
shunt, not the voltage over it. This binding describes such a current
sense circuit.

Required properties:
- compatible : "current-sense-shunt"
- io-channels : Channel node of a voltage io-channel.
- shunt-resistor-micro-ohms : The shunt resistance in microohms.

Example:
The system current is measured by measuring the voltage over a
3.3 ohms shunt resistor.

sysi {
	compatible = "current-sense-shunt";
	io-channels = <&tiadc 0>;

	/* Divide the voltage by 3300000/1000000 (or 3.3) for the current. */
	shunt-resistor-micro-ohms = <3300000>;
};

&i2c {
	tiadc: adc@48 {
		compatible = "ti,ads1015";
		reg = <0x48>;
		#io-channel-cells = <1>;

		#address-cells = <1>;
		#size-cells = <0>;

		channel@0 { /* IN0,IN1 differential */
			reg = <0>;
			ti,gain = <1>;
			ti,datarate = <4>;
		};
	};
};