Re: [PATCH V6 1/3] dt-bindings: sram: qcom,imem: Add Boot Stat region within IMEM

[Souradeep Chowdhury]

On 5/9/2023 6:35 PM, Dmitry Baryshkov wrote:
> On Tue, 9 May 2023 at 15:21, Souradeep Chowdhury
> <quic_schowdhu@xxxxxxxxxxx> wrote:
> > On 5/9/2023 5:05 PM, Dmitry Baryshkov wrote:
> > > On Tue, 9 May 2023 at 13:53, Souradeep Chowdhury
> > > <quic_schowdhu@xxxxxxxxxxx> wrote:
> > > > All Qualcomm bootloaders log useful timestamp information related
> > > > to bootloader stats in the IMEM region. Add the child node within
> > > > IMEM for the boot stat region containing register address and
> > > > compatible string.
> > >
> > > I might have a minor vote here. Is there any reason why you have to
> > > instantiate the device from DT?
> > > It looks like a software interface. Ideally software should not be
> > > described in DT (e.g. this can be instantiated from imem
> > > driver-to-be).
> > > Or we can follow the RPM master-stats approach, where the device is a
> > > top-level device, having handle pointers to the sram regions.
> >
> > This is a dedicated region of IMEM reserved for storing stats related
> > information. So it is represented as a child of IMEM, please
> > refer to Documentation/devicetree/bindings/sram/sram.yaml which
> > follows a similar philosophy. Also since this is a child of IMEM with
> > a specific purpose, does it not warrant a dedicated driver?
>
> I do not question a dedicated driver. I was asking about the DT node.
> Even the mentioned bindings file describes the SRAM regions inside the
> SRAM, rather than a proper device to be instantiated in the SRAM node.
> I'd point to the boot_stats discussions (present on the list in the
> last several months).

Ack. Will instantiate the device from the parent node in the driver and
access the stats region to print the boot_stats information.


> > > > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
> > > > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> > > > ---
> > > >    .../devicetree/bindings/sram/qcom,imem.yaml   | 22 +++++++++++++++++++
> > > >    1 file changed, 22 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/sram/qcom,imem.yaml b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
> > > > index 0548e8e0d30b..bb884c5c8952 100644
> > > > --- a/Documentation/devicetree/bindings/sram/qcom,imem.yaml
> > > > +++ b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
> > > > @@ -50,6 +50,28 @@ patternProperties:
> > > >        $ref: /schemas/remoteproc/qcom,pil-info.yaml#
> > > >        description: Peripheral image loader relocation region
> > > >
> > > > +  "^stats@[0-9a-f]+$":
> > > > +    type: object
> > > > +    description:
> > > > +      Imem region dedicated for storing timestamps related
> > > > +      information regarding bootstats.
> > > > +
> > > > +    additionalProperties: false
> > > > +
> > > > +    properties:
> > > > +      compatible:
> > > > +        items:
> > > > +          - enum:
> > > > +              - qcom,sm8450-bootstats
> > > > +          - const: qcom,imem-bootstats
> > > > +
> > > > +      reg:
> > > > +        maxItems: 1
> > > > +
> > > > +    required:
> > > > +      - compatible
> > > > +      - reg
> > > > +
> > > >    required:
> > > >      - compatible
> > > >      - reg
> > > > --
> > > > 2.17.1