[PATCH RFC v2 2/3] dt-bindings: mailbox: Add thead,th1520-mailbox bindings

[Michal Wilczynski]

Add bindings for the mailbox controller. This work is based on the vendor
kernel. [1]

Link: https://github.com/revyos/thead-kernel.git [1]

Signed-off-by: Michal Wilczynski <m.wilczynski at samsung.com>
---
 .../bindings/mailbox/thead,th1520-mbox.yaml   | 84 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 85 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml

diff --git a/Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml b/Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml
new file mode 100644
index 000000000000..b517d0c6eb12
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml
@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/thead,th1520-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: T-head TH1520 Mailbox Controller
+
+description:
+  The T-head mailbox controller enables communication and coordination between
+  cores within the SoC by passing messages (e.g., data, status, and control)
+  through mailbox channels. It also allows one core to signal another processor
+  using interrupts via the Interrupt Controller Unit (ICU).
+
+maintainers:
+  - Michal Wilczynski <m.wilczynski at samsung.com>
+
+properties:
+  compatible:
+    const: thead,th1520-mbox
+
+  reg:
+    items:
+      - description: Mailbox local base address
+      - description: Remote ICU 0 base address
+      - description: Remote ICU 1 base address
+      - description: Remote ICU 2 base address
+
+  reg-names:
+    items:
+      - const: local
+      - const: remote-icu0
+      - const: remote-icu1
+      - const: remote-icu2
+
+  interrupts:
+    maxItems: 1
+
+  thead,icu-cpu-id:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      CPU ID associated with the Interrupt Controller Unit (ICU). This ID should
+      correspond to a valid CPU core in the system. The value must be between 0
+      and (N - 1), where N is the total number of CPU cores in the SoC.
+    minimum: 0
+    maximum: 3
+
+  '#mbox-cells':
+    const: 2
+    description: |
+      Specifies the number of cells needed to encode the mailbox specifier.
+      The mailbox specifier consists of two cells:
+        - The first cell is the destination CPU ID.
+        - The second cell is the mailbox channel ID.
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - thead,icu-cpu-id
+  - '#mbox-cells'
+
+examples:
+  - |
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+      mailbox at ffffc38000 {
+        compatible = "thead,th1520-mbox";
+        reg = <0xff 0xffc38000 0x0 0x4000>,
+              <0xff 0xffc44000 0x0 0x1000>,
+              <0xff 0xffc4c000 0x0 0x1000>,
+              <0xff 0xffc54000 0x0 0x1000>;
+        reg-names = "local", "remote-icu0", "remote-icu1", "remote-icu2";
+        interrupts = <28>;
+        thead,icu-cpu-id = <0>;
+        #mbox-cells = <2>;
+      };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index df4d7be6cf35..a6028f850a25 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19943,6 +19943,7 @@ L:	linux-riscv at lists.infradead.org
 S:	Maintained
 T:	git https://github.com/pdp7/linux.git
 F:	Documentation/devicetree/bindings/clock/thead,th1520-clk-ap.yaml
+F:	Documentation/devicetree/bindings/mailbox/thead,th1520-mbox.yaml
 F:	arch/riscv/boot/dts/thead/
 F:	drivers/clk/thead/clk-th1520-ap.c
 F:	drivers/mailbox/mailbox-th1520.c
-- 
2.34.1