Re: [linux-sunxi] Re: [PATCH 0/6] ARM: sunxi: Introduce Allwinner H3 support

From: Hans de Goede
Date: Thu Oct 22 2015 - 04:49:26 EST


Hi,

On 22-10-15 09:49, Jens Kuske wrote:
Hi,

On 21/10/15 21:18, Hans de Goede wrote:

Great to see that you've started working on this again. Last weekend I
ended up working on this too together with Reinder E.N. de Haan <reinder@xxxxxxxxx>
(added to the Cc).

We took a slightly different approach for the gates clocks, see:

https://github.com/jwrdegoede/linux-sunxi/commits/sunxi-wip

And specifically:

https://github.com/jwrdegoede/linux-sunxi/commit/80a1afe319d5d1a0c426d42e75d37f0c64e8ea0b

Combined with:

https://github.com/jwrdegoede/linux-sunxi/commit/d508da5feb5048f6674d6b24b58ac9058fb9d877

This deals with the per gate parents the same way the rockchip
clock code does, and it seems to be quite a bit less code then your solution.

So now we've two solutions to chose from :) Since you seem to be back to
working on this I'll refrain from doing any further work, at least
without coordinating. Maxime, can you let us know which solution for the
gates clock parents is best, or tell us if you think both solutions are
no good :)

I'd actually prefer your solution. I duplicated the simple-gates code
when trying a different approach and never revisited that decision.

Ok, note then when you switch to my solution (or the improved version of it
or the improved version Jean-Francois Moine suggests) the dtsi now has a list
of clocks with one per gate, rather then clock indices. You can save yourself
some time by taking that list from the dtsi patch in my tree, rather then
building it yourself manually.

(I wanted to get in touch with you about the work done this weekend,
but your posting of this v3 has sorta pre-empted that).

Other then the slightly different solution for the gates, the code in my tree
is a straight forward port of your v2.

Thanks for your work on this!

Regards,

Hans


p.s.

I'm teaching a kernel driver course at my local hackerspace in the netherlands:

https://revspace.nl/KernelDriverProgrammingCourse2015

Which is where our work on this this weekend originated. The next planned
course day is November 1st and I expect Reinder to be working on the H3
again then. I think the plan was to tackle USB next. Reinder can you confirm
this ? If you (Jens) want to work on USB before then, that is fine, but please
coordinate their is plenty to do, so no need for us to be doing (more) double
work.


I don't plan to work on USB soon, my next step would have been Ethernet
and finishing the basic u-boot support. You know my u-boot H3 wip tree I
hope? Before we duplicate our work there too...
https://github.com/jemk/u-boot-sunxi/tree/sunxi/h3

I was not aware of that work, at a first glance it looks good. Can you rebase
this on top of current u-boot/master (or v2015.10) and then submit it upstream ?

2 questions which come to mind immediately:

1) Where does the dram init logic come from, AFAIK Allwinner has not provided
any H3 dram init code ?

2) I see no pmic code in there. I know these boards do not use an axp pmic,
but according to my info at least the Orange Pi 2 (which I have) uses a
sy8106a pmic, it is not entirely clear to me yet if this one needs any
init though, I've mailed the Orange Pi people about this.

Regards,

Hans



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