Re: [PATCH v6 1/6] dt-bindings: remoteproc: Add Xilinx RPU subsystem bindings

[Krzysztof Kozlowski]

On 01/06/2022 01:43, Tanmay Shah wrote:
> Xilinx ZynqMP platform has dual-core ARM Cortex R5 Realtime Processing
> Unit(RPU) subsystem. This patch adds dt-bindings for RPU subsystem
> (cluster).
> 
> Signed-off-by: Tanmay Shah <tanmay.shah@xxxxxxxxxx>
> ---
> 
> Changes in v6:
>   - Add maxItems to sram and memory-region property
> 
> Changes in v5:
> - Add constraints of the possible values of xlnx,cluster-mode property
> - fix description of power-domains property for r5 core
> - Remove reg, address-cells and size-cells properties as it is not required
> - Fix description of mboxes property
> - Add description of each memory-region and remove old .txt binding link
>   reference in the description
> 
> Changes in v4:
>   - Add memory-region, mboxes and mbox-names properties in example
> 
> Changes in v3:
>   - None
> 
> 
>  .../bindings/remoteproc/xlnx,r5f-rproc.yaml   | 129 ++++++++++++++++++
>  include/dt-bindings/power/xlnx-zynqmp-power.h |   6 +
>  2 files changed, 135 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
> new file mode 100644
> index 000000000000..cbff1c201a89
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/xlnx,r5f-rproc.yaml
> @@ -0,0 +1,129 @@
> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/remoteproc/xlnx,r5f-rproc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Xilinx R5F processor subsystem
> +
> +maintainers:
> +  - Ben Levinsky <ben.levinsky@xxxxxxxxxx>
> +  - Tanmay Shah <tanmay.shah@xxxxxxxxxx>
> +
> +description: |
> +  The Xilinx platforms include a pair of Cortex-R5F processors (RPU) for
> +  real-time processing based on the Cortex-R5F processor core from ARM.
> +  The Cortex-R5F processor implements the Arm v7-R architecture and includes a
> +  floating-point unit that implements the Arm VFPv3 instruction set.
> +
> +properties:
> +  compatible:
> +    const: xlnx,zynqmp-r5fss
> +
> +  xlnx,cluster-mode:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [0, 1, 2]
> +    description: |
> +      The RPU MPCore can operate in split mode(Dual-processor performance), Safety
> +      lock-step mode(Both RPU cores execute the same code in lock-step,
> +      clock-for-clock) or Single CPU mode (RPU core 0 can be held in reset while
> +      core 1 runs normally). The processor does not support dynamic configuration.
> +      Switching between modes is only permitted immediately after a processor reset.
> +      If set to  1 then lockstep mode and if 0 then split mode.
> +      If set to  2 then single CPU mode. When not defined, default will be lockstep mode.
> +
> +patternProperties:
> +  "^r5f-[a-f0-9]+$":
> +    type: object
> +    description: |
> +      The RPU is located in the Low Power Domain of the Processor Subsystem.
> +      Each processor includes separate L1 instruction and data caches and
> +      tightly coupled memories (TCM). System memory is cacheable, but the TCM
> +      memory space is non-cacheable.
> +
> +      Each RPU contains one 64KB memory and two 32KB memories that
> +      are accessed via the TCM A and B port interfaces, for a total of 128KB
> +      per processor. In lock-step mode, the processor has access to 256KB of
> +      TCM memory.
> +
> +    properties:
> +      compatible:
> +        const: xlnx,zynqmp-r5f
> +
> +      power-domains:
> +        description: RPU core PM domain specifier
> +        maxItems: 1
> +
> +      mboxes:
> +        minItems: 1
> +        items:
> +          - description: mailbox channel to send data to RPU
> +          - description: mailbox channel to receive data from RPU
> +
> +      mbox-names:
> +        minItems: 1
> +        items:
> +          - const: tx
> +          - const: rx
> +
> +      sram:
> +        $ref: /schemas/types.yaml#/definitions/phandle-array
> +        maxItems: 8

Without minItems, this means maxItems=minItems and previously you had
here "minItems:1", so is it really what you want?

Anyway rest looks good to me.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

Best regards,
Krzysztof