Re: [PATCH 3/3] firmware: scpi: add device power domain support using genpd

[Sudeep Holla]

On 15/06/16 14:29, Ulf Hansson wrote:
> [...]
>
> > > > +static const struct of_device_id scpi_power_domain_ids[] = {
> > > > +       { .compatible = "arm,scpi-power-domains", },
> > > > +       { /* sentinel */ }
> > > > +};
> > >
> > >
> > > Actually I think you shouldn't implement this a standalone driver and
> > > thus you can remove this compatible.
> >
> > While I tend to agree, I did this to keep it aligned with other SCPI
> > users(clocks, sensors,.. for example).
> >
> > I assume remove compatible just from driver ? IMO, it doesn't make sense
> > to add power domain provider without a compatible.
> >
> > > Instead, I think it's better if you let the arm_scpi driver to also
> > > initialize the PM domain.
> >
> > OK, I can do that.
> >
> > > If you still want the PM domain code to be maintained in a separate
> > > file, just provide a header file which declares an
> > > "scpi_pm_domain_init()" function (and a stub when not supported),
> > > which the arm_scpi driver should call during ->probe().
> >
> > I am fine with that, just that it deviates from the approach taken in
> > other subsystems as I mentioned above.
>
> If DT maintainers are happy with you adding a compatible for this,
> don't let me stop you from implementing this as standalone driver.

I assume compatibles are always preferred even if they are not used to
make it future proof and may be that's why the binding was accepted. We
need to have a node to specify phandle in the consumers anyways, it's
always better to have separate node for each of the SCPI users/provider
(like clock, sensors, power domains) instead of pointing all to the one
SCPI node. Again that's just my view.

> I have no strong opinions about it, so perhaps it's then better to not
> deviate from other cases!?

OK, thanks. I will respin with Kconfig changes and retain the file in
drivers/firmware for now.

--
Regards,
Sudeep