dts: bindings: led_strip: Add common binding

Adds a common binding with a chain length and colour ordering
property

Signed-off-by: Jamie McCrae <spam@helper3000.net>

dts/bindings/led_strip/led-strip.yaml

@@ -0,0 +1,24 @@
+# Copyright (c) 2019, Linaro Limited
+# Copyright (c) 2019, Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+# Common fields for LED strips
+
+properties:
+  chain-length:
+    type: int
+    required: true
+    description: |
+      The number of devices in the daisy-chain.
+
+  color-mapping:
+    type: array
+    required: true
+    description: |
+      Channel to color mapping (or pixel order).
+
+      For example a GRB channel to color mapping would be
+
+         color-mapping = <LED_COLOR_ID_GREEN
+                          LED_COLOR_ID_RED
+                          LED_COLOR_ID_BLUE>;

dts/bindings/led_strip/ti,tlc5971.yaml

@@ -6,7 +6,8 @@ description: |
 
   Driver bindings for daisy chains of a TLC5971 devices using a single device
   tree node. Length of daisy chains in pixels is defined by the chain-length
-  property.
+  property. Note: chain-length must be a multiple of 4. A single TLC5971 device
+  supports 4 RGB LEDs.
 
   The color order of the TLC5971 is BGR. Applications can provide custom mappings
   using the color-mapping property.
@@ -28,23 +29,4 @@ description: |
 
 compatible: "ti,tlc5971"
 
-include: spi-device.yaml
+include: [spi-device.yaml, led-strip.yaml]
-
-properties:
-  chain-length:
-    type: int
-    required: true
-    description: |
-      The number of RGB LEDs in the daisy-chain.
-      Must be multiple of 4. A single TLC5971 device supports 4 RGB LEDs.
-
-  color-mapping:
-    type: array
-    required: true
-    description: |
-      Channel to color mapping (or pixel order).
-      For example a BGR channel to color mapping would be
-
-         color-mapping = <LED_COLOR_ID_BLUE
-                          LED_COLOR_ID_GREEN
-                          LED_COLOR_ID_RED>;

dts/bindings/led_strip/ws2812.yaml

@@ -34,25 +34,9 @@ description: |
   property. The pixel order depends on the model and it can be configured
   using the color-mapping property.
 
+include: led-strip.yaml
+
 properties:
-  chain-length:
-    type: int
-    required: true
-    description: |
-      The number of devices in the daisy-chain.
-
-  color-mapping:
-    type: array
-    required: true
-    description: |
-      Channel to color mapping (or pixel order).
-
-      For example a GRB channel to color mapping would be
-
-         color-mapping = <LED_COLOR_ID_GREEN
-                          LED_COLOR_ID_RED
-                          LED_COLOR_ID_BLUE>;
-
   reset-delay:
     type: int
     default: 8