dt-bindings: mailbox : arm,mhu: Convert to Json-schema

Convert the DT binding over to Json-schema.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Documentation/devicetree/bindings/mailbox/arm,mhu.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHU Mailbox Controller
+
+maintainers:
+  - Jassi Brar <jaswinder.singh@linaro.org>
+
+description: |
+  The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has 3
+  independent channels/links to communicate with remote processor(s).  MHU links
+  are hardwired on a platform. A link raises interrupt for any received data.
+  However, there is no specified way of knowing if the sent data has been read
+  by the remote. This driver assumes the sender polls STAT register and the
+  remote clears it after having read the data.  The last channel is specified to
+  be a 'Secure' resource, hence can't be used by Linux running NS.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+  properties:
+    compatible:
+      contains:
+        const: arm,mhu
+  required:
+    - compatible
+
+properties:
+  compatible:
+    items:
+      - const: arm,mhu
+      - const: arm,primecell
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: low-priority non-secure
+      - description: high-priority non-secure
+      - description: Secure
+    maxItems: 3
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: apb_pclk
+
+  '#mbox-cells':
+    description: Index of the channel.
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - '#mbox-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        mhuA: mailbox@2b1f0000 {
+            #mbox-cells = <1>;
+            compatible = "arm,mhu", "arm,primecell";
+            reg = <0 0x2b1f0000 0 0x1000>;
+            interrupts = <0 36 4>, /* LP-NonSecure */
+                         <0 35 4>, /* HP-NonSecure */
+                         <0 37 4>; /* Secure */
+            clocks = <&clock 0 2 1>;
+            clock-names = "apb_pclk";
+        };
+
+        mhu_client_scb: scb@2e000000 {
+            compatible = "fujitsu,mb86s70-scb-1.0";
+            reg = <0 0x2e000000 0 0x4000>;
+            mboxes = <&mhuA 1>; /* HP-NonSecure */
+        };
+    };

Documentation/devicetree/bindings/mailbox/arm-mhu.txt

-ARM MHU Mailbox Driver
-======================
-
-The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has
-3 independent channels/links to communicate with remote processor(s).
- MHU links are hardwired on a platform. A link raises interrupt for any
-received data. However, there is no specified way of knowing if the sent
-data has been read by the remote. This driver assumes the sender polls
-STAT register and the remote clears it after having read the data.
-The last channel is specified to be a 'Secure' resource, hence can't be
-used by Linux running NS.
-
-Mailbox Device Node:
-====================
-
-Required properties:
---------------------
-- compatible:		Shall be "arm,mhu" & "arm,primecell"
-- reg:			Contains the mailbox register address range (base
-			address and length)
-- #mbox-cells		Shall be 1 - the index of the channel needed.
-- interrupts:		Contains the interrupt information corresponding to
-			each of the 3 links of MHU.
-
-Example:
---------
-
-	mhu: mailbox@2b1f0000 {
-		#mbox-cells = <1>;
-		compatible = "arm,mhu", "arm,primecell";
-		reg = <0 0x2b1f0000 0x1000>;
-		interrupts = <0 36 4>, /* LP-NonSecure */
-			     <0 35 4>, /* HP-NonSecure */
-			     <0 37 4>; /* Secure */
-		clocks = <&clock 0 2 1>;
-		clock-names = "apb_pclk";
-	};
-
-	mhu_client: scb@2e000000 {
-		compatible = "fujitsu,mb86s70-scb-1.0";
-		reg = <0 0x2e000000 0x4000>;
-		mboxes = <&mhu 1>; /* HP-NonSecure */
-	};