[PW_SID:1156921] Add RISC-V RPMI device power service support

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>;
+    };
+...

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>;
+    };
+...

MAINTAINERS

@@ -23587,6 +23587,14 @@ F:	drivers/irqchip/irq-riscv-rpmi-sysmsi.c
 F:	drivers/mailbox/riscv-sbi-mpxy-mbox.c
 F:	include/linux/mailbox/riscv-rpmi-message.h
 
+RISC-V RPMI DEVICE POWER DRIVER
+M:	Joshua Yeong <joshua.yeong@starfivetech.com>
+L:	linux-riscv@lists.infradead.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/power/riscv,rpmi-device-power.yaml
+F:	Documentation/devicetree/bindings/power/riscv,rpmi-mpxy-device-power.yaml
+F:	drivers/pmdomain/riscv/
+
 RISC-V SPACEMIT SoC Support
 M:	Yixun Lan <dlan@kernel.org>
 L:	linux-riscv@lists.infradead.org

drivers/pmdomain/Kconfig

@@ -11,6 +11,7 @@ source "drivers/pmdomain/marvell/Kconfig"
 source "drivers/pmdomain/mediatek/Kconfig"
 source "drivers/pmdomain/qcom/Kconfig"
 source "drivers/pmdomain/renesas/Kconfig"
+source "drivers/pmdomain/riscv/Kconfig"
 source "drivers/pmdomain/rockchip/Kconfig"
 source "drivers/pmdomain/samsung/Kconfig"
 source "drivers/pmdomain/st/Kconfig"

drivers/pmdomain/Makefile

@@ -9,6 +9,7 @@ obj-y					+= marvell/
 obj-y					+= mediatek/
 obj-y					+= qcom/
 obj-y					+= renesas/
+obj-y					+= riscv/
 obj-y					+= rockchip/
 obj-y					+= samsung/
 obj-y					+= st/

drivers/pmdomain/riscv/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config RISCV_RPMI_DEVICE_POWER
+	bool "RISC-V RPMI Based Device Power driver"
+	depends on RISCV || COMPILE_TEST
+	depends on MAILBOX
+	depends on PM
+	default RISCV
+	select PM_GENERIC_DOMAINS
+	help
+	  Support for device power domains based on the device power service
+	  group defined by the RISC-V platform management interface (RPMI)
+	  specification. The power domains advertised by the platform
+	  microcontroller are registered as generic power domains, so that
+	  devices can reference them through the "power-domains" property.

drivers/pmdomain/riscv/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_RISCV_RPMI_DEVICE_POWER)	+= riscv-rpmi-device-power.o