dt-bindings: rtc: Convert and update jz4740-rtc doc to YAML

Convert the jz4740-rtc doc to YAML, and update it to reflect the new
changes in the driver:
- More compatible strings are specified, with fallbacks if needed,
- The vendor-specific properties are now properly prefixed with the
  'ingenic,' prefix.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200311182318.22154-3-paul@crapouillou.netSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/rtc/ingenic,jz4740-rtc.txt

-JZ4740 and similar SoCs real-time clock driver
-
-Required properties:
-
-- compatible: One of:
-  - "ingenic,jz4740-rtc" - for use with the JZ4740 SoC
-  - "ingenic,jz4780-rtc" - for use with the JZ4780 SoC
-- reg: Address range of rtc register set
-- interrupts: IRQ number for the alarm interrupt
-- clocks: phandle to the "rtc" clock
-- clock-names: must be "rtc"
-
-Optional properties:
-- system-power-controller: To use this component as the
-  system power controller
-- reset-pin-assert-time-ms: Reset pin low-level assertion
-  time after wakeup (default 60ms; range 0-125ms if RTC clock
-  at 32 kHz)
-- min-wakeup-pin-assert-time-ms: Minimum wakeup pin assertion
-  time (default 100ms; range 0-2s if RTC clock at 32 kHz)
-
-Example:
-
-rtc@10003000 {
-	compatible = "ingenic,jz4740-rtc";
-	reg = <0x10003000 0x40>;
-
-	interrupt-parent = <&intc>;
-	interrupts = <32>;
-
-	clocks = <&rtc_clock>;
-	clock-names = "rtc";
-
-	system-power-controller;
-	reset-pin-assert-time-ms = <60>;
-	min-wakeup-pin-assert-time-ms = <100>;
-};

Documentation/devicetree/bindings/rtc/ingenic,rtc.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/ingenic,rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ingenic SoCs Real-Time Clock DT bindings
+
+maintainers:
+  - Paul Cercueil <paul@crapouillou.net>
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+        - ingenic,jz4740-rtc
+        - ingenic,jz4760-rtc
+      - items:
+        - const: ingenic,jz4725b-rtc
+        - const: ingenic,jz4740-rtc
+      - items:
+        - enum:
+          - ingenic,jz4770-rtc
+          - ingenic,jz4780-rtc
+        - const: ingenic,jz4760-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: rtc
+
+  system-power-controller:
+    description: |
+      Indicates that the RTC is responsible for powering OFF
+      the system.
+    type: boolean
+
+  ingenic,reset-pin-assert-time-ms:
+    minimum: 0
+    maximum: 125
+    default: 60
+    description: |
+      Reset pin low-level assertion time after wakeup
+      (assuming RTC clock at 32 kHz)
+
+  ingenic,min-wakeup-pin-assert-time-ms:
+    minimum: 0
+    maximum: 2000
+    default: 100
+    description: |
+      Minimum wakeup pin assertion time
+      (assuming RTC clock at 32 kHz)
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+examples:
+  - |
+    #include <dt-bindings/clock/jz4740-cgu.h>
+    rtc_dev: rtc@10003000 {
+      compatible = "ingenic,jz4740-rtc";
+      reg = <0x10003000 0x40>;
+
+      interrupt-parent = <&intc>;
+      interrupts = <15>;
+
+      clocks = <&cgu JZ4740_CLK_RTC>;
+      clock-names = "rtc";
+    };