Re: [PATCH v2 1/6] dt-bindings: ti, sci: Add property for partial-io-wakeup-sources

Markus Schneider-Pargmann
2024-09-05T09:14:59Z

On Tue, Aug 06, 2024 at 10:03:00AM GMT, Krzysztof Kozlowski wrote:
> On 06/08/2024 09:11, Markus Schneider-Pargmann wrote:
> > Hi Krzysztof,
> >
> > On Tue, Aug 06, 2024 at 08:18:01AM GMT, Krzysztof Kozlowski wrote:
> >> On 29/07/2024 10:00, Markus Schneider-Pargmann wrote:
> >>> Partial-IO is a very low power mode in which nearly everything is
> >>> powered off. Only pins of a few hardware units are kept sensitive and
> >>> are capable to wakeup the SoC. The device nodes are marked as
> >>> 'wakeup-source' but so are a lot of other device nodes as well that are
> >>> not able to do a wakeup from Partial-IO. This creates the need to
> >>> describe the device nodes that are capable of wakeup from Partial-IO.
> >>>
> >>> This patch adds a property with a list of these nodes defining which
> >>> devices can be used as wakeup sources in Partial-IO.
> >>>
> >>
> >>
> >> This is a friendly reminder during the review process.
> >>
> >> It seems my or other reviewer's previous comments were not fully
> >> addressed. Maybe the feedback got lost between the quotes, maybe you
> >> just forgot to apply it. Please go back to the previous discussion and
> >> either implement all requested changes or keep discussing them.
> >>
> >> Thank you.
> >>
> >
> > I tried to address your comment from last version by explaining more
> > thoroughly what the binding is for as it seemed that my previous
> > explanation wasn't really good.
> >
> > You are suggesting to use 'wakeup-source' exclusively. Unfortunately
> > wakeup-source is a boolean property which covers two states. I have at
> > least three states I need to describe:
> >
> > - wakeup-source for suspend to memory and other low power modes
> > - wakeup-source for Partial-IO
> > - no wakeup-source
>
> Maybe we need generic property or maybe custom TI would be fine, but in
> any case - whether device is wakeup and what sort of wakeup it is, is a
> property of the device.

To continue on this, I currently only know of this Partial-IO mode that
would require a special flag like this. So I think a custom TI property
would work. For example a bool property like

ti,partial-io-wakeup-source;

in the device nodes for which it is relevant? This would be in addition
to the 'wakeup-source' property.

Best
Markus

>
> >
> > If something is a wakeup-source for Partial-IO it usually is a
> > wakeup-source for suspend to memory as well but not the other way
> > around.
>
> I understand, makes sense. The trouble is that your driver code does not
> indicate any of this.
>
> >
> > This is the reason why I added a property that lists the devicenodes
> > that are capable of wakeup from Partial-IO.
>
> This property looks purely to satisfy your driver design.
>
> Best regards,
> Krzysztof
>