dt-bindings: leds: Convert leds-lm3692x to YAML format

Additional changes:

 - Add ref to common.yaml for child node.
 - Add I2C node at example.

Fix below warning:
  arch/arm64/boot/dts/freescale/imx8mq-librem5-r2.dtb: /soc@0/bus@30800000/i2c@30a40000/backlight@36:
	failed to match any schema with compatible: ['ti,lm36922']

Signed-off-by: Frank Li <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

Author: nxpfrankli

Documentation/devicetree/bindings/leds/leds-lm3692x.txt

@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/ti.lm36922.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments - LM3692x Highly Efficient White LED Driver
+
+maintainers:
+  - Dan Murphy <[email protected]>
+
+description: |
+  The LM3692x is an ultra-compact, highly efficient,
+  white-LED driver designed for LCD display backlighting.
+
+  The main difference between the LM36922 and LM36923 is the number of
+  LED strings it supports. The LM36922 supports two strings while the LM36923
+  supports three strings.
+
+  For more product information please see the link below:
+  https://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
+
+properties:
+  compatible:
+    enum:
+      - ti,lm36922
+      - ti,lm36923
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  enable-gpios:
+    description: gpio pin to enable/disable the device.
+
+  vled-supply:
+    description: LED supply
+
+  ti,ovp-microvolt:
+    description: Overvoltage protection.
+    default: 29000000
+    enum: [17000000, 21000000, 25000000, 29000000]
+
+patternProperties:
+  '^led@[0-3]$':
+    type: object
+    $ref: common.yaml
+    properties:
+      reg:
+        enum: [0, 1, 2, 3]
+        description: |
+          0 - Will enable all LED sync paths
+          1 - Will enable the LED1 sync
+          2 - Will enable the LED2 sync
+          3 - Will enable the LED3 sync (LM36923 only)
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: ti,lm36922
+    then:
+      properties:
+        led@3: false
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@36 {
+            compatible = "ti,lm36922";
+            reg = <0x36>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+            vled-supply = <&vbatt>;
+            ti,ovp-microvolt = <29000000>;
+
+            led@0 {
+                reg = <0>;
+                function = LED_FUNCTION_BACKLIGHT;
+                color = <LED_COLOR_ID_WHITE>;
+                linux,default-trigger = "backlight";
+                led-max-microamp = <20000>;
+            };
+        };
+    };
+