[RFC PATCH 7/8] dt-bindings: clock: Add bindings for RISC-V RPMI clock service group

[Anup Patel <apatel@ventanamicro.com>]

Add device tree bindings for the clock service group defined by the
RISC-V platform management interface (RPMI) specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 .../bindings/clock/riscv,rpmi-clock.yaml      | 78 +++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml

diff --git a/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml b/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml
new file mode 100644
index 000000000000..9dd98e390708
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/riscv,rpmi-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI clock service group based clock controller
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description: |
+  The RISC-V Platform Management Interface (RPMI) [1] defines a
+  messaging protocol which is modular and extensible. The supervisor
+  software can send/receive RPMI messages via SBI MPXY extension [2]
+  or some dedicated supervisor-mode RPMI transport.
+
+  The RPMI specification [1] defines clock service group for accessing
+  system clocks managed by a platform microcontroller.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+properties:
+  compatible:
+    oneOf:
+      - description:
+          Intended for use by the SBI implementation in machine mode or
+          software in supervisor mode.
+        const: riscv,rpmi-clock
+
+      - description:
+          Intended for use by the SBI implementation in machine mode.
+        const: riscv,rpmi-mpxy-clock
+
+  mboxes:
+    minItems: 1
+    maxItems: 1
+    description: |
+      Mailbox channel of the underlying RPMI transport or SBI message proxy.
+
+  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. This property is mandatory when using
+      riscv,rpmi-mpxy-clock compatible string.
+
+  "#clock-cells":
+    const: 1
+    description:
+      This property is mandatory when using riscv,rpmi-clock compatible string.
+
+required:
+  - compatible
+  - mboxes
+
+additionalProperties: false
+
+examples:
+  - |
+    mpxy_mbox: sbi-mpxy-mbox {
+          compatible = "riscv,sbi-mpxy-mbox";
+          #mbox-cells = <2>;
+    };
+    rpmi-clk {
+        compatible = "riscv,rpmi-clock";
+        mboxes = <&mpxy_mbox 0x1000 0x0>;
+        #clock-cells = <1>;
+    };
+...
-- 
2.43.0