> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Sent: Friday, May 5, 2023 5:27 PM
> To: Bharat Bhushan <bbhushan2@xxxxxxxxxxx>; wim@xxxxxxxxxxxxxxxxxx;
> linux@xxxxxxxxxxxx; robh+dt@xxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx;
> linux-watchdog@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
> Subject: Re: [EXT] Re: [PATCH 1/2 v5] dt-bindings: watchdog: marvell GTI system
> watchdog driver
>
> On 05/05/2023 13:15, Bharat Bhushan wrote:
> >
> >
> >> -----Original Message-----
> >> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> >> Sent: Friday, May 5, 2023 4:27 PM
> >> To: Bharat Bhushan <bbhushan2@xxxxxxxxxxx>; wim@xxxxxxxxxxxxxxxxxx;
> >> linux@xxxxxxxxxxxx; robh+dt@xxxxxxxxxx;
> >> krzysztof.kozlowski+dt@xxxxxxxxxx;
> >> linux-watchdog@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
> >> Subject: Re: [EXT] Re: [PATCH 1/2 v5] dt-bindings: watchdog: marvell
> >> GTI system watchdog driver
> >>
> >> On 05/05/2023 12:41, Bharat Bhushan wrote:
> >>>>>>
> >>>>>> You need anyway SoC specific compatibles. Once you add proper
> >>>>>> compatibles, you will see that property is not needed.
> >>>>>
> >>>>> Also on a given soc, firmware can configure one of 64 timer to be
> >>>>> used as
> >>>> system watchdog time then compatible will not work.
> >>>>
> >>>> Can't you query the firmware for that? Or can't you just choose
> >>>> first unused timer? DT is for non-discoverable properties.
> >>>
> >>> Query to firmware required arm SMC call, to me that does not look
> >>> correct
> >> approach. Thought of using first one but that is already used and
> >> moving that is as same as this.
> >>>
> >>> Hardcoding to 63 will make it work on some SoCs but not all.
> >>
> >> But you know which one is started or is not. GTI_CWD_WDOG tells you this.
> >
> > On a given SoC, Firmware can reserve and/or use one or more timer for some
> other use case (customer use) and configure one of the timer as watchdog timer.
> Linux have to use the configured timer only and cannot decide by its own.
>
> Then the SoCs which have such firmware could use proposed property.
> Provide some rationale property description in your next version (adding
> necessary compatibles).
Will add compatible as below:
properties:
compatible:
enum:
- marvell,cn10k-wdt
- marvell,octeontx2-wdt
And define this as optional property
marvell,wdt-timer-index:
$ref: /schemas/types.yaml#/definitions/uint32
minimum: 0
maximum: 63
description:
An SoC have many timers (up to 64), firmware can reserve one or more timer
for some other use case and configures one of the global timer as watchdog
timer. Firmware will update this field with the timer number configured
as watchdog timer.
Let me know if this looks good.
Thanks
-Bharat
>
> Best regards,
> Krzysztof
