[PATCH v2 1/7] dt-bindings: dvfs: Add RPMI performance service message proxy bindings

[Joshua Yeong <joshua.yeong@starfivetech.com>]

Add device tree bindings for the RPMI performance service group based
message proxy implemented by the SBI implementation (machine mode
firmware or hypervisor).

The RPMI performance service group is defined by the RISC-V Platform
Management Interface (RPMI) specification.

Signed-off-by: Joshua Yeong <joshua.yeong@starfivetech.com>
---
 .../dvfs/riscv,rpmi-mpxy-performance.yaml     | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dvfs/riscv,rpmi-mpxy-performance.yaml

diff --git a/Documentation/devicetree/bindings/dvfs/riscv,rpmi-mpxy-performance.yaml b/Documentation/devicetree/bindings/dvfs/riscv,rpmi-mpxy-performance.yaml
new file mode 100644
index 000000000000..4a05c48c1e12
--- /dev/null
+++ b/Documentation/devicetree/bindings/dvfs/riscv,rpmi-mpxy-performance.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dvfs/riscv,rpmi-mpxy-performance.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI performance service group based message proxy
+
+maintainers:
+  - Joshua Yeong <joshua.yeong@starfivetech.com>
+
+description: |
+  The RISC-V Platform Management Interface (RPMI) [1] defines a modular and
+  extensible messaging protocol for platform management functions. The supervisor
+  software can send and receive RPMI messages via SBI MPXY extension [2]
+  or via a dedicated supervisor-mode RPMI transport.
+
+  The RPMI specification [1] defines performance service group (performance
+  domain) for accessing and controlling platform-managed performance-related
+  resources implemented by a platform microcontroller. The SBI implementation
+  (machine mode firmware or hypervisor) can implement an SBI MPXY channel
+  to allow supervisor software to access the RPMI performance service group.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+properties:
+  compatible:
+    description:
+      Intended for use by the SBI implementation.
+    const: riscv,rpmi-mpxy-performance
+
+  mboxes:
+    maxItems: 1
+    description:
+      Mailbox channel of the underlying RPMI transport.
+
+  riscv,sbi-mpxy-channel-id:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The SBI MPXY channel id to be used for providing RPMI access to
+      the supervisor software.
+
+required:
+  - compatible
+  - mboxes
+  - riscv,sbi-mpxy-channel-id
+
+additionalProperties: false
+
+examples:
+  - |
+    performance {
+        compatible = "riscv,rpmi-mpxy-performance";
+        mboxes = <&rpmi_shmem_mbox 0x0a>;
+        riscv,sbi-mpxy-channel-id = <0x1003>;
+    };
+...
-- 
2.43.0