xref: /openbmc/linux/Documentation/devicetree/bindings/regulator/ltc3676.txt (revision 0cce284537fb42d9c28b9b31038ffc9b464555f5)

Linear Technology LTC3676 8-output regulators

Required properties:
- compatible: "lltc,ltc3676"
- reg: I2C slave address

Required child node:
- regulators: Contains eight regulator child nodes sw1, sw2, sw3, sw4,
  ldo1, ldo2, ldo3, and ldo4, specifying the initialization data as
  documented in Documentation/devicetree/bindings/regulator/regulator.txt.

Each regulator is defined using the standard binding for regulators. The
nodes for sw1, sw2, sw3, sw4, ldo1, ldo2 and ldo4 additionally need to specify
the resistor values of their external feedback voltage dividers:

Required properties (not on ldo3):
- lltc,fb-voltage-divider: An array of two integers containing the resistor
  values R1 and R2 of the feedback voltage divider in ohms.

Regulators sw1, sw2, sw3, sw4 can regulate the feedback reference from:
412.5mV to 800mV in 12.5 mV steps. The output voltage thus ranges between
0.4125 * (1 + R1/R2) V and 0.8 * (1 + R1/R2) V.

Regulators ldo1, ldo2, and ldo4 have a fixed 0.725 V reference and thus output
0.725 * (1 + R1/R2) V. The ldo3 regulator is fixed to 1.8 V.  The ldo1 standby
regulator can not be disabled and thus should have the regulator-always-on
property set.

Example:

	ltc3676: pmic@3c {
		compatible = "lltc,ltc3676";
		reg = <0x3c>;

		regulators {
			sw1_reg: sw1 {
				regulator-min-microvolt = <674400>;
				regulator-max-microvolt = <1308000>;
				lltc,fb-voltage-divider = <127000 200000>;
				regulator-ramp-delay = <7000>;
				regulator-boot-on;
				regulator-always-on;
			};

			sw2_reg: sw2 {
				regulator-min-microvolt = <1033310>;
				regulator-max-microvolt = <200400>;
				lltc,fb-voltage-divider = <301000 200000>;
				regulator-ramp-delay = <7000>;
				regulator-boot-on;
				regulator-always-on;
			};

			sw3_reg: sw3 {
				regulator-min-microvolt = <674400>;
				regulator-max-microvolt = <130800>;
				lltc,fb-voltage-divider = <127000 200000>;
				regulator-ramp-delay = <7000>;
				regulator-boot-on;
				regulator-always-on;
			};

			sw4_reg: sw4 {
				regulator-min-microvolt = <868310>;
				regulator-max-microvolt = <168400>;
				lltc,fb-voltage-divider = <221000 200000>;
				regulator-ramp-delay = <7000>;
				regulator-boot-on;
				regulator-always-on;
			};

			ldo2_reg: ldo2 {
				regulator-min-microvolt = <2490375>;
				regulator-max-microvolt = <2490375>;
				lltc,fb-voltage-divider = <487000 200000>;
				regulator-boot-on;
				regulator-always-on;
			};

			ldo3_reg: ldo3 {
				regulator-min-microvolt = <1800000>;
				regulator-max-microvolt = <1800000>;
				regulator-boot-on;
			};

			ldo4_reg: ldo4 {
				regulator-min-microvolt = <3023250>;
				regulator-max-microvolt = <3023250>;
				lltc,fb-voltage-divider = <634000 200000>;
				regulator-boot-on;
				regulator-always-on;
			};
		};
	};