[U-Boot] [PATCH v2 0/7] mmc: sunxi: Enable DM_MMC

[Jagan Teki]

On Fri, Jan 18, 2019 at 6:00 PM Andre Przywara <andre.przywara at arm.com> wrote:
>
> On Fri, 18 Jan 2019 07:17:41 -0500
> Tom Rini <trini at konsulko.com> wrote:
>
> > On Fri, Jan 18, 2019 at 11:53:49AM +0000, Andre Przywara wrote:
> > > On Thu, 17 Jan 2019 22:39:44 +0530
> > > Jagan Teki <jagan at amarulasolutions.com> wrote:
> > >
> > > > V2 for previous version[1] changes, for enabling DM_MMC
> > > > on Allwinner platform.
> > >
> > > So this is a neat and simple solution to the DM_MMC problem, to the
> > > point where I am wondering why we actually need all those DT driven
> > > clock and reset drivers in the first place.
> > > But as I understand using plat data in this way is somewhat frowned
> > > upon and considered deprecated (although it makes a lot of sense in
> > > this context).
> > >
> > > Also, isn't this series independent from the clock gates/reset
> > > patches? So why do you pile them on top of each other in sunxi/next?
> > >
> > > If we really want to have the full featured DT driven clock and
> > > reset support, why not use it together:
> > > We keep the current mod clock support in the MMC driver, but use the
> > > newly introduced clock gates and reset support via the new clock
> > > driver, mostly replacing this series. This would give us some test
> > > coverage of the new clock driver, while still avoiding to rush the
> > > MMC mod clock implementation.
> > >
> > > Does that make sense? Happy to bake some patches for that on the
> > > weekend.
> > >
> > > Btw: After talking to Tom on IRC, the DM_MMC deadline is actually
> > > _after_ the 2019.04 release, so we don't need to have DM_MMC
> > > support in this merge window.
> >
> > To be clearer, I plan to mark as BROKEN and start saying we're going
> > to remove stuff that isn't migrated, after the release.  So it would
> > be good to get things moved this release that can be moved this
> > release. Trying to use sunxi w/o MMC isn't going to be fun :)
>
> Understood. I just gave it a quick try and it is actually quite easy: We
> are pretty good already regarding gate clocks and resets, with the new
> DM_CLK driver (v2 on the list). And using them in sunxi_mmc.c is a piece
> of cake and very clean.
> We just need to keep the MMC mod clock hack in (which this series here
> does as well), but can still enable DM_MMC.
> And for the next merge window we can tackle this by implementing the
> MMC mod clock properly in the clock driver, then replacing the hack
> with the normal clk_get_by_name(); clk_set_rate(); sequence.

I tried with ahb clock and reset, with v2 version of CLK series and
it's straightforward. but mmc clock may take some time along with
series of testing. So I just windup this, instead of making some noise
at last minute.