dt-bindings: mailbox: Convert mtk-gce to DT schema

Convert the mtk-gce mailbox binding to DT schema format.

During the conversion, the examples for client device/mutex nodes
were removed, as these are found in their respective bindings:
arm/mediatek/mediatek,mmsys.yaml for "mediatek,mt8173-mmsys"
soc/mediatek/mediatek,mutex.yaml for "mediatek,mt8173-disp-mutex"

Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Rob Herring <[email protected]>

Author: AngeloGioacchino Del Regno

Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml

@@ -52,7 +52,8 @@ properties:
     description:
       Using mailbox to communicate with GCE, it should have this
       property and list of phandle, mailbox specifiers. See
-      Documentation/devicetree/bindings/mailbox/mtk-gce.txt for details.
+      Documentation/devicetree/bindings/mailbox/mediatek,gce-mailbox.yaml
+      for details.
     $ref: /schemas/types.yaml#/definitions/phandle-array
 
   mediatek,gce-client-reg:

Documentation/devicetree/bindings/mailbox/mediatek,gce-mailbox.yaml

@@ -0,0 +1,85 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/mediatek,gce-mailbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek Global Command Engine Mailbox
+
+maintainers:
+  - Houlong Wei <[email protected]>
+
+description:
+  The Global Command Engine (GCE) is used to help read/write registers with
+  critical time limitation, such as updating display configuration during the
+  vblank. The GCE can be used to implement the Command Queue (CMDQ) driver.
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt6779-gce
+      - mediatek,mt8173-gce
+      - mediatek,mt8183-gce
+      - mediatek,mt8186-gce
+      - mediatek,mt8192-gce
+      - mediatek,mt8195-gce
+
+  "#mbox-cells":
+    const: 2
+    description:
+      The first cell describes the Thread ID of the GCE,
+      the second cell describes the priority of the GCE thread
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: Global Command Engine clock
+
+  clock-names:
+    items:
+      - const: gce
+
+required:
+  - compatible
+  - "#mbox-cells"
+  - reg
+  - interrupts
+  - clocks
+
+allOf:
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              const: mediatek,mt8195-gce
+    then:
+      required:
+        - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/mt8173-clk.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        gce: mailbox@10212000 {
+            compatible = "mediatek,mt8173-gce";
+            reg = <0 0x10212000 0 0x1000>;
+            interrupts = <GIC_SPI 135 IRQ_TYPE_LEVEL_LOW>;
+            #mbox-cells = <2>;
+            clocks = <&infracfg CLK_INFRA_GCE>;
+            clock-names = "gce";
+        };
+    };