dt-bindings: mailbox: sti-mailbox: convert to DT schema

Convert the sti-mailbox.txt file into st,sti-mailbox.yaml

Signed-off-by: Alain Volmat <avolmat@me.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Documentation/devicetree/bindings/mailbox/st,sti-mailbox.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/st,sti-mailbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics Mailbox Driver for STi platform
+
+description:
+  Each ST Mailbox IP currently consists of 4 instances of 32 channels.
+  Messages are passed between Application and Remote processors using
+  shared memory.
+
+maintainers:
+  - Patrice Chotard <patrice.chotard@foss.st.com>
+
+properties:
+  compatible:
+    const: st,stih407-mailbox
+
+  reg:
+    maxItems: 1
+
+  mbox-name:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: name of the mailbox IP
+
+  interrupts:
+    description: the irq line for the RX mailbox
+    maxItems: 1
+
+  "#mbox-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - "#mbox-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    mailbox0: mailbox@8f00000  {
+        compatible = "st,stih407-mailbox";
+        reg = <0x8f00000 0x1000>;
+        interrupts = <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>;
+        #mbox-cells = <2>;
+        mbox-name = "a9";
+    };
+
+...

Documentation/devicetree/bindings/mailbox/sti-mailbox.txt

-ST Microelectronics Mailbox Driver
-
-Each ST Mailbox IP currently consists of 4 instances of 32 channels.  Messages
-are passed between Application and Remote processors using shared memory.
-
-Controller
-----------
-
-Required properties:
-- compatible		: Should be "st,stih407-mailbox"
-- reg			: Offset and length of the device's register set
-- mbox-name		: Name of the mailbox
-- #mbox-cells:		: Must be 2
-			  <&phandle instance channel direction>
-			    phandle   : Label name of controller
-			    instance  : Instance number
-			    channel   : Channel number
-
-Optional properties
-- interrupts		: Contains the IRQ line for a Rx mailbox
-
-Example:
-
-mailbox0: mailbox@0  {
-	compatible	= "st,stih407-mailbox";
-	reg		= <0x08f00000 0x1000>;
-	interrupts	= <GIC_SPI 1 IRQ_TYPE_NONE>;
-	#mbox-cells	= <2>;
-	mbox-name	= "a9";
-};
-
-Client
-------
-
-Required properties:
-- compatible		: Many (See the client docs)
-- reg			: Shared (between Application and Remote) memory address
-- mboxes		: Standard property to specify a Mailbox (See ./mailbox.txt)
-			  Cells must match 'mbox-cells' (See Controller docs above)
-
-Optional properties
-- mbox-names		: Name given to channels seen in the 'mboxes' property.
-
-Example:
-
-mailbox_test {
-	compatible	= "mailbox-test";
-	reg		= <0x[shared_memory_address], [shared_memory_size]>;
-	mboxes		= <&mailbox2 0 1>, <&mailbox0 2 1>;
-	mbox-names	= "tx",	"rx";
-};