Re: [PATCH RFC 3/6] dt-bindings: watchdog: Add Qualcomm restart reason binding

[Kathiravan Thirumoorthy]

On 4/9/2025 12:30 PM, Krzysztof Kozlowski wrote:
> On 08/04/2025 10:49, Kathiravan Thirumoorthy wrote:
> > Add a devicetree binding for the Qualcomm IPQ SOCs restart reason
> > information region found in the IMEM, allowing the system to identify
> > the cause of a restart.
> >
> > Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
> > ---
> >   .../bindings/watchdog/qcom,restart-reason.yaml     | 46 ++++++++++++++++++++++
> >   1 file changed, 46 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/watchdog/qcom,restart-reason.yaml b/Documentation/devicetree/bindings/watchdog/qcom,restart-reason.yaml
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..babbaa70b114f9691018ed6cb10bfa78e18fad64
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/watchdog/qcom,restart-reason.yaml
> > @@ -0,0 +1,46 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/watchdog/qcom,restart-reason.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Qualcomm IPQ SoC restart reason location
> > +
> > +maintainers:
> > +  - Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
> > +
> > +description:
> > +  The Qualcomm IPQ SoC restart reason memory region, in IMEM, is used to
> > +  identify the cause of the system restart. This will be helpful to identify
> > +  the cause when the RAM dump collection is disabled.
> > +
> > +properties:
> > +  compatible:
> > +    const: qcom,restart-reason-info
> No generic compatibles.
>
> OTOH, I don't see much of a value of this being a separate node.

I leveraged this based on the qcom,pil-info.yaml [1]. I guess, I see the 
point. I will drop all these. Just define IMEM node and in the watchdog 
driver, I will get the regmap of the syscon / IMEM node and do 
regmap_read at the desired offset. Please let me know if this approach 
is fine.

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/remoteproc/qcom,pil-info.yaml