dt-bindings: watchdog: renesas-wdt: Convert to json-schema

Convert the Renesas Watchdog Timer (WDT) Controller Device Tree binding
documentation to json-schema.

Add missing "renesas,r8a77980-wdt" compatible value.
Document missing properties.
Update the example to match reality.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/watchdog/renesas,wdt.txt

-Renesas Watchdog Timer (WDT) Controller
-
-Required properties:
- - compatible : Must be "renesas,<soctype>-wdt", followed by a generic
-		fallback compatible string when compatible with the generic
-		version.
-	       Examples with soctypes are:
-		 - "renesas,r8a7743-wdt" (RZ/G1M)
-		 - "renesas,r8a7744-wdt" (RZ/G1N)
-		 - "renesas,r8a7745-wdt" (RZ/G1E)
-		 - "renesas,r8a77470-wdt" (RZ/G1C)
-		 - "renesas,r8a774a1-wdt" (RZ/G2M)
-		 - "renesas,r8a774b1-wdt" (RZ/G2N)
-		 - "renesas,r8a774c0-wdt" (RZ/G2E)
-	         - "renesas,r8a7790-wdt" (R-Car H2)
-	         - "renesas,r8a7791-wdt" (R-Car M2-W)
-	         - "renesas,r8a7792-wdt" (R-Car V2H)
-	         - "renesas,r8a7793-wdt" (R-Car M2-N)
-	         - "renesas,r8a7794-wdt" (R-Car E2)
-	         - "renesas,r8a7795-wdt" (R-Car H3)
-	         - "renesas,r8a7796-wdt" (R-Car M3-W)
-	         - "renesas,r8a77961-wdt" (R-Car M3-W+)
-		 - "renesas,r8a77965-wdt" (R-Car M3-N)
-	         - "renesas,r8a77970-wdt" (R-Car V3M)
-	         - "renesas,r8a77990-wdt" (R-Car E3)
-	         - "renesas,r8a77995-wdt" (R-Car D3)
-	         - "renesas,r7s72100-wdt" (RZ/A1)
-	         - "renesas,r7s9210-wdt"  (RZ/A2)
-		The generic compatible string must be:
-		 - "renesas,rza-wdt" for RZ/A
-		 - "renesas,rcar-gen2-wdt" for R-Car Gen2 and RZ/G1
-		 - "renesas,rcar-gen3-wdt" for R-Car Gen3 and RZ/G2
-
-- reg : Should contain WDT registers location and length
-- clocks : the clock feeding the watchdog timer.
-
-Optional properties:
-- timeout-sec : Contains the watchdog timeout in seconds
-- power-domains : the power domain the WDT belongs to
-- interrupts: Some WDTs have an interrupt when used in interval timer mode
-
-Examples:
-
-	wdt0: watchdog@e6020000 {
-		compatible = "renesas,r8a7795-wdt", "renesas,rcar-gen3-wdt";
-		reg = <0 0xe6020000 0 0x0c>;
-		clocks = <&cpg CPG_MOD 402>;
-		power-domains = <&cpg>;
-		timeout-sec = <60>;
-	};

Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/renesas,wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Watchdog Timer (WDT) Controller
+
+maintainers:
+  - Wolfram Sang <wsa+renesas@sang-engineering.com>
+  - Geert Uytterhoeven <geert+renesas@glider.be>
+
+allOf:
+  - $ref: "watchdog.yaml#"
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - renesas,r7s72100-wdt     # RZ/A1
+              - renesas,r7s9210-wdt      # RZ/A2
+          - const: renesas,rza-wdt       # RZ/A
+
+      - items:
+          - enum:
+              - renesas,r8a7743-wdt      # RZ/G1M
+              - renesas,r8a7744-wdt      # RZ/G1N
+              - renesas,r8a7745-wdt      # RZ/G1E
+              - renesas,r8a77470-wdt     # RZ/G1C
+              - renesas,r8a7790-wdt      # R-Car H2
+              - renesas,r8a7791-wdt      # R-Car M2-W
+              - renesas,r8a7792-wdt      # R-Car V2H
+              - renesas,r8a7793-wdt      # R-Car M2-N
+              - renesas,r8a7794-wdt      # R-Car E2
+          - const: renesas,rcar-gen2-wdt # R-Car Gen2 and RZ/G1
+
+      - items:
+          - enum:
+              - renesas,r8a774a1-wdt     # RZ/G2M
+              - renesas,r8a774b1-wdt     # RZ/G2N
+              - renesas,r8a774c0-wdt     # RZ/G2E
+              - renesas,r8a7795-wdt      # R-Car H3
+              - renesas,r8a7796-wdt      # R-Car M3-W
+              - renesas,r8a77961-wdt     # R-Car M3-W+
+              - renesas,r8a77965-wdt     # R-Car M3-N
+              - renesas,r8a77970-wdt     # R-Car V3M
+              - renesas,r8a77980-wdt     # R-Car V3H
+              - renesas,r8a77990-wdt     # R-Car E3
+              - renesas,r8a77995-wdt     # R-Car D3
+          - const: renesas,rcar-gen3-wdt # R-Car Gen3 and RZ/G2
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  timeout-sec: true
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+if:
+  not:
+    properties:
+      compatible:
+        contains:
+          enum:
+            - renesas,rza-wdt
+then:
+  required:
+    - power-domains
+    - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r8a7795-cpg-mssr.h>
+    #include <dt-bindings/power/r8a7795-sysc.h>
+    wdt0: watchdog@e6020000 {
+            compatible = "renesas,r8a7795-wdt", "renesas,rcar-gen3-wdt";
+            reg = <0xe6020000 0x0c>;
+            clocks = <&cpg CPG_MOD 402>;
+            power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
+            resets = <&cpg 402>;
+            timeout-sec = <60>;
+    };