dt-bindings: mailbox: Convert hisilicon,hi6220-mbox to DT schema

Convert the hisilicon,hi6220-mbox binding to DT schema format. It's a
straight forward conversion.

Assisted-by: LLM
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mailbox.txt

@@ -1,74 +0,0 @@
-Hisilicon Hi6220 Mailbox Driver
-===============================
-
-Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
-is unidirectional with a maximum message size of 8 words. I/O is
-performed using register access (there is no DMA) and the cell
-raises an interrupt when messages are received.
-
-Mailbox Device Node:
-====================
-
-Required properties:
---------------------
-- compatible:		Shall be "hisilicon,hi6220-mbox"
-- reg:			Contains the mailbox register address range (base
-			address and length); the first item is for IPC
-			registers, the second item is shared buffer for
-			slots.
-- #mbox-cells:		Common mailbox binding property to identify the number
-			of cells required for the mailbox specifier. Must be 3.
-			<&phandle slot_id dst_irq ack_irq>
-			  phandle: Label name of mailbox controller
-			  slot_id: Slot id used either for TX or RX
-			  dst_irq: IRQ identifier index number which used by MCU
-			  ack_irq: IRQ identifier index number with generating a
-			           TX/RX interrupt to application processor,
-				   mailbox driver uses it to acknowledge interrupt
-- interrupts:		Contains the interrupt information for the mailbox
-			device. The format is dependent on which interrupt
-			controller the SoCs use.
-
-Optional Properties:
---------------------
-- hi6220,mbox-tx-noirq: Property of MCU firmware's feature, so mailbox driver
-			use this flag to ask MCU to enable "automatic idle
-			flag" mode or IRQ generated mode to acknowledge a TX
-			completion.
-
-Example:
---------
-
-	mailbox: mailbox@f7510000 {
-		compatible = "hisilicon,hi6220-mbox";
-		reg = <0x0 0xf7510000 0x0 0x1000>, /* IPC_S */
-		      <0x0 0x06dff800 0x0 0x0800>; /* Mailbox */
-		interrupt-parent = <&gic>;
-		interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
-		#mbox-cells = <3>;
-	};
-
-
-Mailbox client
-===============
-
-Required properties:
---------------------
-- compatible:		Many (See the client docs).
-- mboxes:		Standard property to specify a Mailbox (See ./mailbox.txt)
-			Cells must match 'mbox-cells' (See Mailbox Device Node above).
-
-Optional Properties:
---------------------
-- mbox-names:		Name given to channels seen in the 'mboxes' property.
-
-Example:
---------
-
-	stub_clock: stub_clock {
-		compatible = "hisilicon,hi6220-stub-clk";
-		hisilicon,hi6220-clk-sram = <&sram>;
-		#clock-cells = <1>;
-		mbox-names = "mbox-tx", "mbox-rx";
-		mboxes = <&mailbox 1 0 11>, <&mailbox 0 1 10>;
-	};

Documentation/devicetree/bindings/mailbox/hisilicon,hi6220-mbox.yaml

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/hisilicon,hi6220-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Hisilicon Hi6220 Mailbox Controller
+
+maintainers:
+  - Wei Xu <xuwei5@hisilicon.com>
+
+description:
+  Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel is
+  unidirectional with a maximum message size of 8 words. I/O is performed using
+  register access (there is no DMA) and the cell raises an interrupt when
+  messages are received.
+
+properties:
+  compatible:
+    const: hisilicon,hi6220-mbox
+
+  reg:
+    items:
+      - description: IPC registers
+      - description: Shared buffer for mailbox slots
+
+  interrupts:
+    maxItems: 1
+
+  "#mbox-cells":
+    const: 3
+    description: >
+      The cells content are as follows:
+        - Slot number
+        - Remote destination interrupt vector
+        - Local ack interrupt vector
+
+  hi6220,mbox-tx-noirq:
+    description:
+      Flag to request MCU to enable automatic idle flag mode instead of IRQ for
+      TX completion.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - "#mbox-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    mailbox@f7510000 {
+        compatible = "hisilicon,hi6220-mbox";
+        reg = <0xf7510000 0x1000>,
+              <0x06dff800 0x0800>;
+        interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
+        #mbox-cells = <3>;
+    };