[PATCH v6 1/4] dt-bindings: remoteproc: k3-m4f: Add K3 AM64x SoCs

[Rob Herring]

On Wed, Sep 13, 2023 at 6:17 AM Hari Nagalla <hnagalla at ti.com> wrote:
>
> K3 AM64x SoC has a Cortex M4F subsystem in the MCU voltage domain.
> The remote processor's life cycle management and IPC mechanisms are
> similar across the R5F and M4F cores from remote processor driver
> point of view. However, there are subtle differences in image loading
> and starting the M4F subsystems.
>
> The YAML binding document provides the various node properties to be
> configured by the consumers of the M4F subsystem.
>
> Signed-off-by: Martyn Welch <martyn.welch at collabora.com>
> Signed-off-by: Hari Nagalla <hnagalla at ti.com>
> ---
> Changes since v1:
>  - Spelling corrections
>  - Corrected to pass DT checks
>
> Changes since v2:
>  - Missed spelling correction to commit message
>
> Changes since v3:
>  - Removed unnecessary descriptions and used generic memory region names
>  - Made mboxes and memory-region optional
>  - Removed unrelated items from examples
>
> Changes since v4:
>  - Rebased to the latest kernel-next tree
>  - Added optional sram memory region for m4f device node
>
> Changes since v5:
>  - None
>
>  .../bindings/remoteproc/ti,k3-m4f-rproc.yaml  | 136 ++++++++++++++++++
>  1 file changed, 136 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml
>
> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml
> new file mode 100644
> index 000000000000..21b7f14d9dc4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-m4f-rproc.yaml
> @@ -0,0 +1,136 @@
> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/remoteproc/ti,k3-m4f-rproc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI K3 M4F processor subsystems
> +
> +maintainers:
> +  - Hari Nagalla <hnagalla at ti.com>
> +  - Mathieu Poirier <mathieu.poirier at linaro.org>
> +
> +description: |
> +  Some K3 family SoCs have Arm Cortex M4F cores. AM64x is a SoC in K3
> +  family with a M4F core. Typically safety oriented applications may use
> +  the M4F core in isolation without an IPC. Where as some industrial and
> +  home automation applications, may use the M4F core as a remote processor
> +  with IPC communications.
> +
> +$ref: /schemas/arm/keystone/ti,k3-sci-common.yaml#
> +
> +properties:
> +
> +  compatible:
> +    enum:
> +      - ti,am64-m4fss
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 2
> +
> +  "#size-cells":
> +    const: 2
> +
> +  reg:
> +    items:
> +      - description: IRAM internal memory region
> +      - description: DRAM internal memory region
> +
> +  reg-names:
> +    items:
> +      - const: iram
> +      - const: dram
> +
> +  resets:
> +    maxItems: 1
> +
> +  firmware-name:
> +    $ref: /schemas/types.yaml#/definitions/string
> +    description: Name of firmware to load for the M4F core
> +
> +  mboxes:
> +    description: |
> +      Mailbox specifier denoting the sub-mailbox, to be used for communication
> +      with the remote processor. This property should match with the
> +      sub-mailbox node used in the firmware image.
> +    maxItems: 2
> +
> +  memory-region:
> +    description: |
> +      phandle to the reserved memory nodes to be associated with the
> +      remoteproc device. The reserved memory nodes should be carveout nodes,
> +      and should be defined with a "no-map" property as per the bindings in
> +      Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml
> +      Optional memory regions available for firmware specific purposes.
> +    maxItems: 8
> +    items:
> +      - description: regions used for DMA allocations like vrings, vring buffers
> +                     and memory dedicated to firmware's specific purposes.
> +    additionalItems: true
> +
> +  sram:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    minItems: 1
> +    maxItems: 4
> +    items:
> +      maxItems: 4

You are saying there are 1-4 entries and each entry is 4 cells. What's
in the 4 cells?

>From the description and example, looks like you only have 1 cell (a
phandle) so maxItems should be 1.

Your example should fail, but I'm not sure why it doesn't.

Rob