Re: [PATCH v2 3/3] dt-bindings: arm: msm: Convert kpss-gcc driver Documentation to yaml

From: Bjorn Andersson
Date: Mon Jun 27 2022 - 16:55:03 EST


On Sat 30 Apr 02:42 CDT 2022, Ansuel Smith wrote:

> On Sat, Apr 30, 2022 at 04:40:54PM +0200, Krzysztof Kozlowski wrote:
> > On 30/04/2022 08:01, Ansuel Smith wrote:
> > > Convert kpss-gcc driver Documentation to yaml.
> > > Add #clock-cells additional binding to required bindings and example
> > > as it's a required binding for clock-output-names.
> > >
> > > Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
> >
> >
> > (...)
> >
> > > +properties:
> > > + compatible:
> > > + items:
> > > + - enum:
> > > + - qcom,kpss-gcc-ipq8064
> > > + - qcom,kpss-gcc-apq8064
> > > + - qcom,kpss-gcc-msm8974
> > > + - qcom,kpss-gcc-msm8960
> > > + - const: qcom,kpss-gcc
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + clocks:
> > > + items:
> > > + - description: phandle to pll8_vote
> > > + - description: phandle to pxo_board
> > > +
> > > + clock-names:
> > > + items:
> > > + - const: pll8_vote
> > > + - const: pxo
> > > +
> > > + clock-output-names:
> > > + const: acpu_l2_aux
> >
> > It does not make sense having a constant output name. What is the
> > meaning this property in such case? The original binding did not enforce it.
> >
> >
> >
> > Best regards,
> > Krzysztof
>
> Mh. Should I just drop the const and put a description referring to an
> advised name? The driver with the kpss-gcc hardcode the name to
> acpu_l2_aux that's why I thought it was a correct conversion using a
> const but I assume this is another problem of not making a correct 1:1
> conversion and adding fixes on pure conversion.
> Think I should drop it and put a description to it. (and then later fix
> it when I will push the other series with all the tweaks)
>
> What do you think?
>

The typical reason for using clock-output-names is that we have some
consumer that finds the clock based on global name lookup. Over time
we've been moving these to use .fw_name or .index based lookup, which
removes this problem.

But I don't see that being the case here. So my suggestion is that you
just drop clock-output-names from the binding, which will solve
Krzysztof's objection.


>From there we can review what needs to be done in the Linux driver to
work with the improved binding.

Regards,
Bjorn