Microchip RISC-V SoCs typically contain one or more clusters. Clusters can operate in Asymmetric Multi-Processing (AMP) mode, where individual cores or groups of cores run as independent software contexts.
The compatible is intentionally generic, representing a “generic” SBI ecall interface to a set of remote processors, with the platform abstracted via SBI ecalls. The IPC/IHC (named differently depending on whether it is RTL for the FPGA fabric or a hardened version) is intended for Asymmetric Multiprocessing, where a set of cores or clusters can run other firmware, such as Zephyr. Unlike platforms with a fixed DSP, the configuration here is variable even for a single SoC. For example, which memory regions are used for the remote cluster or which mailbox channel is selected. This binding documents that firmware interface. Signed-off-by: Valentina Fernandez <[email protected]> --- .../microchip,ipc-sbi-remoteproc.yaml | 131 ++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 Documentation/devicetree/bindings/remoteproc/microchip,ipc-sbi-remoteproc.yaml diff --git a/Documentation/devicetree/bindings/remoteproc/microchip,ipc-sbi-remoteproc.yaml b/Documentation/devicetree/bindings/remoteproc/microchip,ipc-sbi-remoteproc.yaml new file mode 100644 index 000000000000..6fc0ab7f3ffb --- /dev/null +++ b/Documentation/devicetree/bindings/remoteproc/microchip,ipc-sbi-remoteproc.yaml @@ -0,0 +1,131 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/remoteproc/microchip,ipc-sbi-remoteproc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Microchip IPC Remote Processor + +description: + Microchip RISC-V SoCs typically contain one or more clusters. Clusters can + operate in Asymmetric Multi-Processing (AMP) mode, where individual cores + or groups of cores run as independent software contexts. + + The configuration is flexible, as the set of cores or clusters that can be + controlled as remote processors may vary, and memory regions used for + firmware as well as mailbox assignments depend on the system design. + + Communication with remote cores or clusters is abstracted using ecalls + to the platform's Supervisor Binary Interface (SBI) firmware, through + which the state of remote cores or clusters are controlled. This binding + documents that firmware interface. + +maintainers: + - Valentina Fernandez <[email protected]> + +properties: + compatible: + const: microchip,ipc-sbi-remoteproc + + cpu: + description: + phandles to the CPUs comprising the remote cluster + $ref: /schemas/types.yaml#/definitions/phandle-array + + mboxes: + description: + Microchip IPC mailbox specifier. Used for communication with + a remote cluster. For HSS versions prior to v2026.04, it is also + used for controlling the life cycle of a remote cluster. The + specifier format is as per the bindings in + Documentation/devicetree/bindings/mailbox/microchip,sbi-ipc.yaml + maxItems: 1 + + memory-region: + minItems: 1 + maxItems: 5 + description: + List of phandles to the reserved memory regions associated wih the + remoteproc device. This is variable and describes the memories shared + with the remote cluster (e.g. firmware, resource table, rpmsg vrings) + items: + anyOf: + - description: resource table when firmware is started by the bootloader + - description: remote cluster firmware image section + - description: virtio device (vdev) buffer + - description: vring0 + - description: vring1 + + memory-region-names: + minItems: 1 + maxItems: 5 + items: + anyOf: + - const: rsc-table + - const: firmware + - const: buffer + - const: vring0 + - const: vring1 + +required: + - compatible + +# Remote Cluster ID is derived either from the CPU phandle or +# from the mailbox specifier prior to HSS v2026.04 +anyOf: + - required: + - cpu + - required: + - mboxes + +allOf: + - if: + properties: + memory-region-names: + contains: + enum: + - vring0 + - vring1 + then: + properties: + memory-region-names: + contains: + const: buffer + +additionalProperties: false + +examples: + - | + // Early boot mode example - firmware started by bootloader + soc { + #address-cells = <2>; + #size-cells = <2>; + + remoteproc { + compatible = "microchip,ipc-sbi-remoteproc"; + cpu = <&cpu4>; + mboxes= <&ihc 8>; + memory-region = <&rsctable>, <&vdev0buffer>, + <&vdev0vring0>, <&vdev0vring1>; + memory-region-names = "rsc-table", "buffer", + "vring0", "vring1"; + }; + }; + + - | + // Late boot mode example - firmware started by Linux (remoteproc) + soc { + #address-cells = <2>; + #size-cells = <2>; + + remoteproc { + compatible = "microchip,ipc-sbi-remoteproc"; + cpu = <&cpu4>; + mboxes= <&ihc 8>; + memory-region = <&cluster_firmware>, <&vdev0buffer>, + <&vdev0vring0>, <&vdev0vring1>; + memory-region-names = "firmware", "buffer", + "vring0", "vring1"; + }; + }; +... -- 2.34.1
