On Tue, Mar 17, 2026 at 07:03:23PM +0100, Arnaud Pouliquen wrote:
> Add a Device Tree binding for the STM32 remote processor controlled
> via a Trusted Application running in OP-TEE.
> This binding describes the interface and properties required for STM32MP
> remoteproc instances managed by the TEE rproc service, including a
> linkage to the TEE backend through the property "rproc-tee-phandle".
>
> Signed-off-by: Arnaud Pouliquen <[email protected]>
> ---
> V21 updates:
> - the m4 node is no more declared as a child of the optee-rproc node
> - "rproc-tee-phandle" property is introduced to reference the optee-rproc
> ---
> .../remoteproc/st,stm32-rproc-tee.yaml | 108 ++++++++++++++++++
> 1 file changed, 108 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/remoteproc/st,stm32-rproc-tee.yaml
>
> diff --git
> a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc-tee.yaml
> b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc-tee.yaml
> new file mode 100644
> index 000000000000..ca4dd1c8e7b0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc-tee.yaml
> @@ -0,0 +1,108 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/remoteproc/st,stm32-rproc-tee.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: STMicroelectronics STM32 remote processor controlled via TEE
> +
> +maintainers:
> + - Arnaud Pouliquen <[email protected]>
> +
> +description: |
> + STM32MP remote processor controlled by a Trusted Application
> + running in OP-TEE. This node is a child of the TEE remoteproc service
> + (UUID 80a4c275-0a47-4905-8285-1486a9771a08) and exposes a remoteproc
> + instance managed by the Linux remoteproc core via the TEE rproc service.
> +
> + Firmware loading, authentication and remote processor start/stop are
> managed
> + by the TEE application. The STM32-specific driver handles platform
> resources
> + such as the mailboxes and reserved-memory.
> +
> +properties:
> + compatible:
> + const: st,stm32mp1-m4-tee
Drop "tee", it suggests that compatible is tied to implementation of FW
you put there.
> +
> + reg:
> + description: |
Do not need '|' unless you need to preserve formatting.
> + Remote processor identifier used by the TEE service. The <0> value
> + in the example denotes a single instance with ID 0.
> + maxItems: 1
> +
> + mboxes:
> + description: |
> + Mailbox channels used for rpmsg/virtio functionality and processor
> + shutdown.
> + maxItems: 3
> +
> + mbox-names:
> + items:
> + - const: vq0
> + - const: vq1
> + - const: shutdown
> +
> + memory-region:
> + description: |
> + List of phandles to reserved-memory nodes describing the memory layout
> + for the interprocessors communication.
Drop description. You miss maxItems, though.
> +
> + interrupts:
> + description: |
Same comments...
> + Optional watchdog / status interrupt line used to detect crashes
> + and optionally wake up the system.
> + maxItems: 1
> +
> + st,auto-boot:
> + type: boolean
> + description: |
> + If present, the remote processor will be automatically started by
> + the remoteproc core at boot.
That's policy, not DT property.
> +
> + wakeup-source:
> + type: boolean
> + description: |
> + Indicates that the watchdog interrupt can be used as a wakeup source.
> +
> + rproc-tee-phandle:
Missing vendor prefix, drop phandle. You do not say that "st,auto-boot"
is "st,auto-boot-boolean"
> + description: |
> + Phandle to the remote processor backend node and its identifier. This
> property
> + is used to link the TEE remoteproc service to the remote processor
> instance
> + it controls. The value is a phandle reference to the remote processor
> node,
> + followed by a cell specifying the remote processor identifier used by
> the TEE.
> + $ref: /schemas/types.yaml#/definitions/phandle-array
Missing constraints.
I also do not understand which bus node this is being child, if not
remote proc.
> +
> +required:
> + - compatible
> + - reg
> + - rproc-tee-phandle
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + firmware {
> + tee_rproc: optee-rproc {
> + compatible = "80a4c275-0a47-4905-8285-1486a9771a08";
> + };
> + };
Drop
> +
> + m4: m4@0 {
Drop unused label.
Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
If you cannot find a name matching your device, please check in kernel
sources for similar cases or you can grow the spec (via pull request to
DT spec repo).
e.g. mcu, because m4 feels like given model (Cortex M4?).
> + compatible = "st,stm32mp1-m4-tee";
> + reg = <0 0>;
> +
> + mboxes = <&ipcc 0>, <&ipcc 1>, <&ipcc 2>;
> + mbox-names = "vq0", "vq1", "shutdown";
> +
> + memory-region = <&vdev0vring0>, <&m_ipc_shm>, <&mcuram2>,
> + <&vdev0vring1>, <&vdev0buffer>, <&retram>;
> +
> + interrupt-parent = <&exti>;
> + interrupts = <68 1>;
> +
> + rproc-tee-phandle = <&tee_rproc 0>;
> + st,auto-boot;
> + wakeup-source;
> +
> + status = "okay";
Drop
Best regards,
Krzysztof
