Re: [PATCH v3 5/9] ARM: dts: stm32: add Hardware debug port (HDP) on stm32mp13

[Clement LE GOFFIC]

On 6/11/25 08:35, Krzysztof Kozlowski wrote:
> On 10/06/2025 15:33, Clement LE GOFFIC wrote:
> > On 6/10/25 14:38, Krzysztof Kozlowski wrote:
> > > On 10/06/2025 14:02, Clement LE GOFFIC wrote:
> > > > On 5/29/25 11:01, Krzysztof Kozlowski wrote:
> > > > > On 28/05/2025 14:14, Clement LE GOFFIC wrote:
> > > > > > > > +		};
> > > > > > > > +
> > > > > > > > +		hdp: pinctrl@5002a000 {
> > > > > > > > +			compatible = "st,stm32mp131-hdp";
> > > > > > > > +			reg = <0x5002a000 0x400>;
> > > > > > > > +			clocks = <&rcc HDP>;
> > > > > > > >      			status = "disabled";
> > > > > > >
> > > > > > > Why are you disabling it? What is missing?
> > > > > >
> > > > > > Nothing is missing just disabled by default.
> > > > > > The node is then enabled when needed in board's dts file.
> > > > > Nodes should not be disabled by default if they are complete. That's why
> > > > > I asked what is missing. Drop.
> > > >
> > > > Hi Krzysztof, OK I better understand now.
> > > > So yes the 'pinctrl-*' properties which are board dependent are lacking.
> > >
> > > These are not properties of this node.
> >
> > Does this mean I should add 'pinctrl-*' properties in bindings yaml file ?
> > I don't get it..
>
> These properties have no meaning here, so the hardware description is
> complete. You claim that you miss them thus device is incomplete is just
> not correct: these properties do not belong here! They belong to the
> board but even there they are totally optional. Why would they be a
> required resource?
>
> To remind: we talk here ONLY about required resources.

Yes, 'pinctrl-*' properties belongs to the board and are not required.
So nothing is missing.

This hdp node in the SoC dtsi file can be enabled by default.
But the hdp driver will probe and do nothing because without the 
'pinctrl-*' properties from the board files it would not be able to 
access to any pin.
I consider enabling this driver by default in SoC dtsi file as just 
increasing the boot time on "every" board.
It's the board dts that requires the hdp and provides the 'pinctrl-*' 
properties to connect the hdp to some SoC pin and then to some signal on 
the board. For me it's natural to have the status okay only in the board 
dts file.

> > > > In the last patch of my serie I add them (only for stm32mp157f-dk2) but
> > > > keep it disabled because the pin is on an external connector (the
> > > > Arduino connector of the board).
> > > > This prevent any issue with a possible connected module.
> > >
> > > Not relevant. Pin control for connector are board specific, but pinctrl
> > > SoC part is SoC.
> >
> > I think we don't understand each other here too. I don't understand the
> > end of your sentence "pinctrl SoC part is SoC".
>
> Please read first how DTS is organized.
>
> The pin controller device is part of SoC not part of a board.
>
> Pins configuration for devices on the board are not part of the SoC.
> What is not clear here? We talk here in terms how DTS is supposed to be
> organized.

Now everything is clear, you want me to just set status enable in soc 
dtsi file but I disagree, keep discussing.

> > Maybe some informations that could help:
> > The 'pinctrl-*' properties are used in the HDP case to select the
> > internal signal to output AND the alternate function on the pin to
> > output the HDP function.
>
> We all know this.

Ok fine

Best regards,

Clément

> > > Best regards,
> > > Krzysztof
>
>
> Best regards,
> Krzysztof