[PATCH v4 1/4] dt-bindings: soc: imx8m: add DT Binding doc for soc unique ID

[Alice Guo]

Add DT Binding doc for the Unique ID of i.MX 8M series.

v2: remove the subject prefix "LF-2571-1"
v3: put it into Documentation/devicetree/bindings/arm/fsl.yaml
    modify the description of nvmem-cells
    use "make ARCH=arm64 dtbs_check" to test it and fix errors
v4: use allOf to limit new version DTS files for i.MX8M to include
    "fsl,imx8mm/n/p/q-soc", nvmem-cells and nvmem-cells-names

Signed-off-by: Alice Guo <alice.guo@xxxxxxx>
---
 .../devicetree/bindings/arm/fsl.yaml          | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/fsl.yaml b/Documentation/devicetree/bindings/arm/fsl.yaml
index 67980dcef66d..d8048323a290 100644
--- a/Documentation/devicetree/bindings/arm/fsl.yaml
+++ b/Documentation/devicetree/bindings/arm/fsl.yaml
@@ -918,6 +918,57 @@ properties:
               - fsl,s32v234-evb           # S32V234-EVB2 Customer Evaluation Board
           - const: fsl,s32v234

+  soc:
+    type: object
+    properties:
+      compatible:
+        oneOf:
+          - description: new version compatible for i.MX8M SoCs
+            items:
+              - enum:
+                  - fsl,imx8mm-soc
+                  - fsl,imx8mn-soc
+                  - fsl,imx8mp-soc
+                  - fsl,imx8mq-soc
+              - const: simple-bus
+
+          - description: old version compatible for i.MX8M SoCs
+            items:
+              - const: simple-bus
+
+      nvmem-cells:
+        maxItems: 1
+        description: Phandle to the SOC Unique ID provided by a nvmem node
+
+      nvmem-cells-names:
+        const: soc_unique_id
+
+    allOf:
+      - if:
+          properties:
+            compatible:
+              contains:
+                enum:
+                  - fsl,imx8mm
+                  - fsl,imx8mn
+                  - fsl,imx8mp
+                  - fsl,imx8mq
+
+        then:
+          properties:
+            compatible:
+              items:
+                - enum:
+                    - fsl,imx8mm-soc
+                    - fsl,imx8mn-soc
+                    - fsl,imx8mp-soc
+                    - fsl,imx8mq-soc
+                - const: simple-bus
+
+          required:
+            - nvmem-cells
+            - nvmem-cells-names
+
 additionalProperties: true

 ...
--
2.17.1