Re: [PATCH V4 1/3] dt-bindings: sram: qcom,imem: Add Boot Stat region within IMEM

[Dmitry Baryshkov]

On 04/05/2023 09:26, Krzysztof Kozlowski wrote:
> On 04/05/2023 00:10, Caleb Connolly wrote:
> > On 17/04/2023 16:08, Souradeep Chowdhury 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.
> > >
> > > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
> > > ---
> > >   .../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 ba694ce..d028bed 100644
> > > --- a/Documentation/devicetree/bindings/sram/qcom,imem.yaml
> > > +++ b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
> > > @@ -49,6 +49,28 @@ 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
> >
> > This region isn't exclusive to sm8450, it exists also on sdm845 and
> > presumably other platforms. Is there any need for an SoC specific
> > compatible?
>
> Yes.
> https://elixir.bootlin.com/linux/v6.1-rc1/source/Documentation/devicetree/bindings/writing-bindings.rst#L42
>
> Also see many discussions on LKML about this.

After taking another glance at the parent device (IMEM), I start to 
think that we should not be defining the device at all. The imem has the 
SoC name in it. So I think there should be a proper driver for IMEM. 
Then it will instantiate the ABL stats platform device depending on the 
SoC compat. Also this would allow us to rewrite qcom_pil_info_init() in 
a way to query IMEM instead of poking into DT directly.

--
With best wishes
Dmitry