dt-bindings: timer: arm,twd: Convert to json-schema

Convert the ARM Timer-Watchdog Device Tree binding documentation to
json-schema.  As the old binding document actually contained two
bindings, it is split in two document: one for the timer part, and one
for the watchdog part.

Document missing properties.
Update examples to match reality.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/3ccc0cf5319f56e230ee3b8a009f8d63afb114c1.1621521847.git.geert+renesas@glider.be
[robh: Fix up node names]
Signed-off-by: Rob Herring <robh@kernel.org>

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

@@ -26,7 +26,7 @@ interrupt-controller:
 	see binding for interrupt-controller/arm,gic.txt
 
 timer:
-	see binding for timer/arm,twd.txt
+	see binding for timer/arm,twd-timer.yaml
 
 clocks:
 	see binding for clocks/ux500.txt

Documentation/devicetree/bindings/timer/arm,twd-timer.yaml

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/arm,twd-timer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Timer-Watchdog Timer
+
+maintainers:
+  - Rob Herring <robh@kernel.org>
+
+description:
+  ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
+  Timer-Watchdog (aka TWD), which provides both a per-cpu local timer
+  and watchdog.
+
+  The TWD is usually attached to a GIC to deliver its two per-processor
+  interrupts.
+
+properties:
+  compatible:
+    enum:
+      - arm,cortex-a9-twd-timer
+      - arm,cortex-a5-twd-timer
+      - arm,arm11mp-twd-timer
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  always-on:
+    description:
+      If present, the timer is powered through an always-on power domain,
+      therefore it never loses context.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    timer@2c000600 {
+            compatible = "arm,arm11mp-twd-timer";
+            reg = <0x2c000600 0x20>;
+            interrupts = <GIC_PPI 13 0xf01>;
+    };

Documentation/devicetree/bindings/timer/arm,twd.txt

@@ -1,53 +0,0 @@
-* ARM Timer Watchdog
-
-ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
-Timer-Watchdog (aka TWD), which provides both a per-cpu local timer
-and watchdog.
-
-The TWD is usually attached to a GIC to deliver its two per-processor
-interrupts.
-
-** Timer node required properties:
-
-- compatible : Should be one of:
-	"arm,cortex-a9-twd-timer"
-	"arm,cortex-a5-twd-timer"
-	"arm,arm11mp-twd-timer"
-
-- interrupts : One interrupt to each core
-
-- reg : Specify the base address and the size of the TWD timer
-	register window.
-
-Optional
-
-- always-on : a boolean property. If present, the timer is powered through
-  an always-on power domain, therefore it never loses context.
-
-Example:
-
-	twd-timer@2c000600 {
-		compatible = "arm,arm11mp-twd-timer"";
-		reg = <0x2c000600 0x20>;
-		interrupts = <1 13 0xf01>;
-	};
-
-** Watchdog node properties:
-
-- compatible : Should be one of:
-	"arm,cortex-a9-twd-wdt"
-	"arm,cortex-a5-twd-wdt"
-	"arm,arm11mp-twd-wdt"
-
-- interrupts : One interrupt to each core
-
-- reg : Specify the base address and the size of the TWD watchdog
-	register window.
-
-Example:
-
-	twd-watchdog@2c000620 {
-		compatible = "arm,arm11mp-twd-wdt";
-		reg = <0x2c000620 0x20>;
-		interrupts = <1 14 0xf01>;
-	};

Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yaml

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/arm,twd-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Timer-Watchdog Watchdog
+
+maintainers:
+  - Rob Herring <robh@kernel.org>
+
+description:
+  ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
+  Timer-Watchdog (aka TWD), which provides both a per-cpu local timer
+  and watchdog.
+
+  The TWD is usually attached to a GIC to deliver its two per-processor
+  interrupts.
+
+properties:
+  compatible:
+    enum:
+      - arm,cortex-a9-twd-wdt
+      - arm,cortex-a5-twd-wdt
+      - arm,arm11mp-twd-wdt
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    watchdog@2c000620 {
+            compatible = "arm,arm11mp-twd-wdt";
+            reg = <0x2c000620 0x20>;
+            interrupts = <GIC_PPI 14 0xf01>;
+    };