dt-bindings: rtc: s3c: Convert S3C/Exynos RTC bindings to json-schema

Convert Samsung S3C/Exynos Real Time Clock bindings to DT schema format
using json-schema.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/rtc/s3c-rtc.txt

-* Samsung's S3C Real Time Clock controller
-
-Required properties:
-- compatible: should be one of the following.
-    * "samsung,s3c2410-rtc" - for controllers compatible with s3c2410 rtc.
-    * "samsung,s3c2416-rtc" - for controllers compatible with s3c2416 rtc.
-    * "samsung,s3c2443-rtc" - for controllers compatible with s3c2443 rtc.
-    * "samsung,s3c6410-rtc" - for controllers compatible with s3c6410 rtc.
-    * "samsung,exynos3250-rtc" - (deprecated) for controllers compatible with
-                                 exynos3250 rtc (use "samsung,s3c6410-rtc").
-- reg: physical base address of the controller and length of memory mapped
-  region.
-- interrupts: Two interrupt numbers to the cpu should be specified. First
-  interrupt number is the rtc alarm interrupt and second interrupt number
-  is the rtc tick interrupt. The number of cells representing a interrupt
-  depends on the parent interrupt controller.
-- clocks: Must contain a list of phandle and clock specifier for the rtc
-          clock and in the case of a s3c6410 compatible controller, also
-          a source clock.
-- clock-names: Must contain "rtc" and for a s3c6410 compatible controller,
-               a "rtc_src" sorted in the same order as the clocks property.
-
-Example:
-
-	rtc@10070000 {
-		compatible = "samsung,s3c6410-rtc";
-		reg = <0x10070000 0x100>;
-		interrupts = <44 0 45 0>;
-		clocks = <&clock CLK_RTC>, <&s2mps11_osc S2MPS11_CLK_AP>;
-		clock-names = "rtc", "rtc_src";
-	};

Documentation/devicetree/bindings/rtc/s3c-rtc.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/s3c-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung S3C, S5P and Exynos Real Time Clock controller
+
+maintainers:
+  - Krzysztof Kozlowski <krzk@kernel.org>
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - samsung,s3c2410-rtc
+          - samsung,s3c2416-rtc
+          - samsung,s3c2443-rtc
+          - samsung,s3c6410-rtc
+      - const: samsung,exynos3250-rtc
+        deprecated: true
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description:
+      Must contain a list of phandle and clock specifier for the rtc
+      clock and in the case of a s3c6410 compatible controller, also
+      a source clock.
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    description:
+      Must contain "rtc" and for a s3c6410 compatible controller
+      also "rtc_src".
+    minItems: 1
+    maxItems: 2
+
+  interrupts:
+    description:
+      Two interrupt numbers to the cpu should be specified. First
+      interrupt number is the rtc alarm interrupt and second interrupt number
+      is the rtc tick interrupt. The number of cells representing a interrupt
+      depends on the parent interrupt controller.
+    minItems: 2
+    maxItems: 2
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - samsung,s3c6410-rtc
+              - samsung,exynos3250-rtc
+    then:
+      properties:
+        clocks:
+          minItems: 2
+          maxItems: 2
+        clock-names:
+          items:
+            - const: rtc
+            - const: rtc_src
+    else:
+      properties:
+        clocks:
+          minItems: 1
+          maxItems: 1
+        clock-names:
+          items:
+            - const: rtc
+
+examples:
+  - |
+    rtc@10070000 {
+      compatible = "samsung,s3c6410-rtc";
+      reg = <0x10070000 0x100>;
+      interrupts = <0 44 4>, <0 45 4>;
+      clocks = <&clock 0>, // CLK_RTC
+               <&s2mps11_osc 0>; // S2MPS11_CLK_AP
+      clock-names = "rtc", "rtc_src";
+    };