Re: [PATCH] PCI: imx6: Add support for MX6SX LDO PCIE domain regulator

[Lucas Stach <l.stach@pengutronix.de>]

Hi Fabio,

Am Sonntag, den 12.06.2016, 10:51 -0300 schrieb Fabio Estevam:
> Hi Christoph,
> 
> On Wed, Jun 8, 2016 at 6:35 AM, Christoph Fritz
> <chf.fritz@googlemail.com> wrote:
> 
> > There was a discussion doing the handling of the regulator inside the PM
> > backend:
> 
> Thanks for pointing me to this discussion.
> 
> >
> >> On Mon, 2016-02-15 at 07:24 +0000, Richard Zhu wrote:
> >> > As Lucas discussed with me before,  the GPC regulator operations should[n't] be touched in
> >> > Imx pcie driver at all.  These bits operations should be encapsulate into the PM system,
> >> >  for example, the regulator driver.
> >
> > On Thu, 2016-02-18 at 12:59 +0100, Christoph Fritz wrote:
> >> Ok, for an initial version, I'll just leave the regulator in my
> >> devicetree enabled. For further enhancements I suppose
> >> arch/arm/mach-imx/gpc.c needs to get touched?
> >>
> > @Richard and @Lucas: Any further hints on this?
> 
> Yes, would appreciate some hints or examples as to how to properly
> handle the PCI LDO regulator on mx6sx.
> 
It should be handled the same way as the PU domain regulator on mx6q.
This means the regulator is a supply of the PCIe PHY power domain and
should be en-/disabled through the GPC driver.

I already posted a series to rework the GPC driver to allow adding new
power domains easily, but it was rejected by Shawn on formal grounds, as
it's mostly a single big patch to do the rework. I don't have time to
split this up further at the moment, as this is really non-trivial, but
maybe Shawn is willing to take it if someone does a proper review of the
patch.

With this series applied it should be easy to add the required power
domains and regulator handling for mx6sx.

Regards,
Lucas