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

[tanmay.shah]

On 6/1/22 5:22 AM, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> 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?

Ok. I misunderstood previous comment here in that case. I thought minIterms will be
1 by default. But, it is not that way. I will fix this in next revision.        

Thanks.

> Anyway rest looks good to me.
>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
>
> Best regards,
> Krzysztof