dt-bindings: power: supply: max17040: Add DT bindings for max17040 fuel gauge

max17040_battery

~~~~~~~~~~~~~~~~

Required properties :

 - compatible : "maxim,max17040" or "maxim,max77836-battery"

 - reg: i2c slave address

Optional properties :

- maxim,alert-low-soc-level :	The alert threshold that sets the state of

				charge level (%) where an interrupt is

				generated. Can be configured from 1 up to 32

				(%). If skipped the power up default value of

				4 (%) will be used.

- interrupts : 			Interrupt line see Documentation/devicetree/

				bindings/interrupt-controller/interrupts.txt

- wakeup-source :		This device has wakeup capabilities. Use this

				property to use alert low SOC level interrupt

				as wake up source.

Optional properties support interrupt functionality for alert low state of

charge level, present in some ICs in the same family, and should be used with

compatible "maxim,max77836-battery".

Example:

	battery-fuel-gauge@36 {

		compatible = "maxim,max77836-battery";

		reg = <0x36>;

		maxim,alert-low-soc-level = <10>;

		interrupt-parent = <&gpio7>;

		interrupts = <2 IRQ_TYPE_EDGE_FALLING>;

		wakeup-source;

	};