Re: [PATCH v3 4/4] watchdog: qcom: add support to read the restart reason from IMEM

[Kathiravan Thirumoorthy]

On 5/2/2025 7:33 PM, Konrad Dybcio wrote:
> > +static int  qcom_wdt_get_restart_reason(struct qcom_wdt *wdt,
> > +					const struct qcom_wdt_match_data *data)
> > +{
> > +	struct regmap *imem;
> > +	unsigned int val;
> > +	int ret;
> > +
> > +	imem = syscon_regmap_lookup_by_compatible(data->imem_compatible);
> Try syscon_regmap_lookup_by_phandle_args() and pass a phandle, see e.g.
> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c & phy@1bfc000 in x1e80100.dtsi
>
> That way all platform specifics will live in the DT, requiring no
> hardcode-y driver changes on similar platforms


Thanks. I thought about this API but it didn't strike that I can use the 
args to fetch and match the value.

I need a suggestion here. There is a plan to extend this feature to 
other IPQ targets and also support WDIOF_POWERUNDER and WDIOF_OVERHEAT 
cause as well. For IPQ5424, all 3 cause will support and for other IPQ 
platforms, we are exploring how to integrate WDIOF_OVERHEAT. In any 
case, can I define the DT entry like below

        imem,phandle = <&imem 0x7b0 <Non secure WDT value> <Power Under 
value> <Overheat value>>;

and store these in values args[1], args[2] and args[3] respectively and 
use it for manipulation? If any of the platform doesn't support all 3, I 
can update the bindings and define the number of args as required.

Is this approach fine. Please let me know your comments.


> Konrad