[PATCH v3 03/23] dt-bindings: mailbox: Add bindings for RISC-V SBI MPXY extension

Anup Patel
2025-05-11T13:40:30Z

Add device tree bindings for the RISC-V SBI Message Proxy (MPXY)
extension as a mailbox controller.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
.../bindings/mailbox/riscv,sbi-mpxy-mbox.yaml | 51 +++++++++++++++++++
1 file changed, 51 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/riscv,sbi-mpxy-mbox.yaml

diff --git a/Documentation/devicetree/bindings/mailbox/riscv,sbi-mpxy-mbox.yaml b/Documentation/devicetree/bindings/mailbox/riscv,sbi-mpxy-mbox.yaml
new file mode 100644
index 000000000000..ad4c135e0510
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/riscv,sbi-mpxy-mbox.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/riscv,sbi-mpxy-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V SBI Message Proxy (MPXY) extension based mailbox
+
+maintainers:
+ - Anup Patel <anup@brainfault.org>
+
+description: |
+ The RISC-V SBI Message Proxy (MPXY) extension [1] allows supervisor
+ software to send messages through the SBI implementation (M-mode
+ firmware or HS-mode hypervisor). The underlying message protocol
+ and message format used by the supervisor software could be some
+ other standard protocol compatible with the SBI MPXY extension
+ (such as RISC-V Platform Management Interface (RPMI) [2]).
+
+ ===========================================
+ References
+ ===========================================
+
+ [1] RISC-V Supervisor Binary Interface (SBI)
+ https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+ [2] RISC-V Platform Management Interface (RPMI)
+ https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+properties:
+ compatible:
+ const: riscv,sbi-mpxy-mbox
+
+ "#mbox-cells":
+ const: 2
+ description:
+ The first cell specifies channel_id of the SBI MPXY channel,
+ the second cell specifies MSG_PROT_ID of the SBI MPXY channel
+
+required:
+ - compatible
+ - "#mbox-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ mailbox {
+ compatible = "riscv,sbi-mpxy-mbox";
+ #mbox-cells = <2>;
+ };
--
2.43.0