dt: bindings: lp50xx: Introduce the lp50xx family of RGB drivers

Introduce the bindings for the Texas Instruments LP5036, LP5030, LP5024,
LP5018, LP5012 and LP5009 RGB LED device driver.  The LP5036/30/24/18/12/9
can control RGB LEDs individually or as part of a control bank group.
These devices have the ability to adjust the mixing control for the RGB
LEDs to obtain different colors independent of the overall brightness of
the LED grouping.

Datasheet:
http://www.ti.com/lit/ds/symlink/lp5012.pdf
http://www.ti.com/lit/ds/symlink/lp5024.pdf
http://www.ti.com/lit/ds/symlink/lp5036.pdfReviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NJacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Signed-off-by: NPavel Machek <pavel@ucw.cz>

Documentation/devicetree/bindings/leds/leds-lp50xx.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-lp50xx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LED driver for LP50XX RGB LED from Texas Instruments.
+
+maintainers:
+  - Dan Murphy <dmurphy@ti.com>
+
+description: |
+  The LP50XX is multi-channel, I2C RGB LED Drivers that can group RGB LEDs into
+  a LED group or control them individually.
+
+  The difference in these RGB LED drivers is the number of supported RGB
+  modules.
+
+  For more product information please see the link below:
+  https://www.ti.com/lit/ds/symlink/lp5012.pdf
+  https://www.ti.com/lit/ds/symlink/lp5024.pdf
+  https://www.ti.com/lit/ds/symlink/lp5036.pdf
+
+properties:
+  compatible:
+    enum:
+      - ti,lp5009
+      - ti,lp5012
+      - ti,lp5018
+      - ti,lp5024
+      - ti,lp5030
+      - ti,lp5036
+
+  reg:
+    maxItems: 1
+    description:
+      I2C slave address
+      lp5009/12 - 0x14, 0x15, 0x16, 0x17
+      lp5018/24 - 0x28, 0x29, 0x2a, 0x2b
+      lp5030/36 - 0x30, 0x31, 0x32, 0x33
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO pin to enable/disable the device.
+
+  vled-supply:
+    description: LED supply.
+
+patternProperties:
+  '^multi-led@[0-9a-f]$':
+    type: object
+    allOf:
+      - $ref: leds-class-multicolor.yaml#
+    properties:
+      reg:
+        minItems: 1
+        maxItems: 12
+        description:
+          This property denotes the LED module number(s) that is used on the
+          for the child node.  The LED modules can either be used stand alone
+          or grouped into a module bank.
+
+    patternProperties:
+      "(^led-[0-9a-f]$|led)":
+        type: object
+        $ref: common.yaml#
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+   #include <dt-bindings/gpio/gpio.h>
+   #include <dt-bindings/leds/common.h>
+
+   i2c {
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       led-controller@14 {
+           compatible = "ti,lp5009";
+           reg = <0x14>;
+           #address-cells = <1>;
+           #size-cells = <0>;
+           enable-gpios = <&gpio1 16>;
+
+           multi-led@1 {
+               #address-cells = <1>;
+               #size-cells = <0>;
+               reg = <0x1>;
+               color = <LED_COLOR_ID_RGB>;
+               function = LED_FUNCTION_CHARGING;
+
+               led-0 {
+                   color = <LED_COLOR_ID_RED>;
+               };
+
+               led-1 {
+                   color = <LED_COLOR_ID_GREEN>;
+               };
+
+               led-2 {
+                   color = <LED_COLOR_ID_BLUE>;
+               };
+          };
+
+          multi-led@2 {
+            #address-cells = <1>;
+            #size-cells = <2>;
+            reg = <0x2 0x3 0x5>;
+            color = <LED_COLOR_ID_RGB>;
+            function = LED_FUNCTION_STANDBY;
+
+            led-6 {
+              color = <LED_COLOR_ID_RED>;
+            };
+
+            led-7 {
+              color = <LED_COLOR_ID_GREEN>;
+            };
+
+            led-8 {
+              color = <LED_COLOR_ID_BLUE>;
+            };
+         };
+       };
+    };
+
+...