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

[Andre Przywara <andre.przywara@arm.com>]

On Fri, 18 Jan 2019 07:17:41 -0500
Tom Rini <trini@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@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.

Will send a patch later.

Cheers,
Andre