[PATCH v2 1/2] dt-bindings: power: Add RPMI device power service bindings

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

Add device tree bindings for the RISC-V Platform Management Interface
(RPMI) device power service group, both for the supervisor-facing power
domain controller and for the SBI MPXY channel which the SBI
implementation uses to expose the service group.

Signed-off-by: Joshua Yeong <joshua.yeong@starfivetech.com>
---
 .../power/riscv,rpmi-device-power.yaml        | 65 +++++++++++++++++++
 .../power/riscv,rpmi-mpxy-device-power.yaml   | 65 +++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/riscv,rpmi-device-power.yaml
 create mode 100644 Documentation/devicetree/bindings/power/riscv,rpmi-mpxy-device-power.yaml

diff --git a/Documentation/devicetree/bindings/power/riscv,rpmi-device-power.yaml b/Documentation/devicetree/bindings/power/riscv,rpmi-device-power.yaml
new file mode 100644
index 000000000000..5afdc40df7e0
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/riscv,rpmi-device-power.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/riscv,rpmi-device-power.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI device power service group based power domain controller
+
+maintainers:
+  - Joshua Yeong <joshua.yeong@starfivetech.com>
+
+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 device power service group for
+  accessing and controlling the power state of platform devices managed
+  by a platform microcontroller. The supervisor software can access RPMI
+  device power service group via SBI MPXY channel or some dedicated
+  supervisor-mode RPMI transport.
+
+  ===========================================
+  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 supervisor software.
+    const: riscv,rpmi-device-power
+
+  mboxes:
+    maxItems: 1
+    description:
+      Mailbox channel of the underlying RPMI transport or SBI message proxy channel.
+
+  "#power-domain-cells":
+    const: 1
+    description:
+      Platform specific DOMAIN_ID as defined by the RISC-V Platform Management
+      Interface (RPMI) specification.
+
+required:
+  - compatible
+  - mboxes
+  - "#power-domain-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    power-controller {
+        compatible = "riscv,rpmi-device-power";
+        mboxes = <&mpxy_mbox 0x1002 0x0>;
+        #power-domain-cells = <1>;
+    };
+...
diff --git a/Documentation/devicetree/bindings/power/riscv,rpmi-mpxy-device-power.yaml b/Documentation/devicetree/bindings/power/riscv,rpmi-mpxy-device-power.yaml
new file mode 100644
index 000000000000..2b7df66ba172
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/riscv,rpmi-mpxy-device-power.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/riscv,rpmi-mpxy-device-power.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI device power service group based message proxy
+
+maintainers:
+  - Joshua Yeong <joshua.yeong@starfivetech.com>
+
+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 device power service group for
+  accessing and controlling the power state of platform devices managed
+  by a platform microcontroller. The SBI implementation (machine mode
+  firmware or hypervisor) can implement an SBI MPXY channel to allow RPMI
+  device power service group access to the supervisor software.
+
+  ===========================================
+  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-device-power
+
+  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:
+  - |
+    device-power-service {
+        compatible = "riscv,rpmi-mpxy-device-power";
+        mboxes = <&rpmi_shmem_mbox 0x9>;
+        riscv,sbi-mpxy-channel-id = <0x1002>;
+    };
+...
-- 
2.43.0