dt-bindings: arm: scu: Convert to json-schema

Convert the ARM Snoop Control Unit (SCU) Device Tree binding
documentation to json-schema.

Document required properties.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/c5c36fb952675df4b9c9834d53a21fb58f391e86.1621522979.git.geert+renesas@glider.beSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/arm,scu.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,scu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Snoop Control Unit (SCU)
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  As part of the MPCore complex, Cortex-A5 and Cortex-A9 are provided
+  with a Snoop Control Unit. The register range is usually 256 (0x100)
+  bytes.
+
+  References:
+    - Cortex-A9: see DDI0407E Cortex-A9 MPCore Technical Reference Manual
+      Revision r2p0
+    - Cortex-A5: see DDI0434B Cortex-A5 MPCore Technical Reference Manual
+      Revision r0p1
+    - ARM11 MPCore: see DDI0360F ARM 11 MPCore Processor Technical Reference
+      Manial Revision r2p0
+
+properties:
+  compatible:
+    enum:
+      - arm,cortex-a9-scu
+      - arm,cortex-a5-scu
+      - arm,arm11mp-scu
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    scu@a0410000 {
+            compatible = "arm,cortex-a9-scu";
+            reg = <0xa0410000 0x100>;
+    };

Documentation/devicetree/bindings/arm/scu.txt

-* ARM Snoop Control Unit (SCU)
-
-As part of the MPCore complex, Cortex-A5 and Cortex-A9 are provided
-with a Snoop Control Unit. The register range is usually 256 (0x100)
-bytes.
-
-References:
-
-- Cortex-A9: see DDI0407E Cortex-A9 MPCore Technical Reference Manual
-  Revision r2p0
-- Cortex-A5: see DDI0434B Cortex-A5 MPCore Technical Reference Manual
-  Revision r0p1
-- ARM11 MPCore: see DDI0360F ARM 11 MPCore Processor Technical Reference
-  Manial Revision r2p0
-
-- compatible : Should be:
-	"arm,cortex-a9-scu"
-	"arm,cortex-a5-scu"
-	"arm,arm11mp-scu"
-
-- reg : Specify the base address and the size of the SCU register window.
-
-Example:
-
-scu@a0410000 {
-	compatible = "arm,cortex-a9-scu";
-	reg = <0xa0410000 0x100>;
-};

Documentation/devicetree/bindings/arm/ux500/boards.txt

@@ -20,7 +20,7 @@ during retention, system won't boot without this):
 	compatible = "ste,dbx500-backupram"
 
 scu:
-	see binding for arm/scu.txt
+	see binding for arm/arm,scu.yaml
 
 interrupt-controller:
 	see binding for interrupt-controller/arm,gic.txt