xref: /freebsd/sys/contrib/device-tree/Bindings/leds/leds-lm36274.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)

* Texas Instruments LM36274 4-Channel LCD Backlight Driver w/Integrated Bias

The LM36274 is an integrated four-channel WLED driver and LCD bias supply.
The backlight boost provides the power to bias four parallel LED strings with
up to 29V total output voltage. The 11-bit LED current is programmable via
the I2C bus and/or controlled via a logic level PWM input from 60 uA to 30 mA.

Parent device properties are documented in
Documentation/devicetree/bindings/mfd/ti-lmu.txt

Regulator properties are documented in
Documentation/devicetree/bindings/regulator/lm363x-regulator.txt

Required backlight properties:
	- compatible:
		"ti,lm36274-backlight"
	- reg : 0
	- #address-cells : 1
	- #size-cells : 0
	- led-sources : Indicates which LED strings will be enabled.
			Values from 0-3, sources is 0 based so strings will be
			source value + 1.

Optional backlight properties:
	- label : see Documentation/devicetree/bindings/leds/common.txt
	- linux,default-trigger :
	   see Documentation/devicetree/bindings/leds/common.txt

Example:

HVLED string 1 and 3 are controlled by control bank A and HVLED 2 string is
controlled by control bank B.

lm36274@11 {
	compatible = "ti,lm36274";
	#address-cells = <1>;
	#size-cells = <0>;
	reg = <0x11>;

	enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;

	regulators {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "ti,lm363x-regulator";

		enable-gpios = <&pioC 0 GPIO_ACTIVE_HIGH>,
			       <&pioC 1 GPIO_ACTIVE_HIGH>;

		vboost {
			regulator-name = "lcd_boost";
			regulator-min-microvolt = <4000000>;
			regulator-max-microvolt = <7150000>;
			regulator-always-on;
		};

		vpos {
			regulator-name = "lcd_vpos";
			regulator-min-microvolt = <4000000>;
			regulator-max-microvolt = <6500000>;
		};

		vneg {
			regulator-name = "lcd_vneg";
			regulator-min-microvolt = <4000000>;
			regulator-max-microvolt = <6500000>;
		};
	};

	backlight {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "ti,lm36274-backlight";

		led@0 {
			reg = <0>;
			led-sources = <0 2>;
			label = "white:backlight_cluster";
			linux,default-trigger = "backlight";
		};
	};
};

For more product information please see the link below:
https://www.ti.com/lit/ds/symlink/lm36274.pdf