[PATCH 9/9] sunxi: Add support for Anbernic RG35XX-2024

[Chris Morgan]

On Fri, Aug 02, 2024 at 04:08:39PM +0530, Sumit Garg wrote:
> Hi Andre,
> 
> On Fri, 2 Aug 2024 at 15:27, Andre Przywara <andre.przywara at arm.com> wrote:
> >
> > On Fri, 2 Aug 2024 12:24:56 +0530
> > Sumit Garg <sumit.garg at linaro.org> wrote:
> >
> > Hi Sumit,
> >
> > > Hi Chris,
> > >
> > > On Fri, 2 Aug 2024 at 04:29, Chris Morgan <macroalpha82 at gmail.com> wrote:
> > > >
> > > > From: Chris Morgan <macromorgan at hotmail.com>
> > > >
> > > > The Anbernic RG35XX series of devices are based around an Allwinner
> > > > H700 SoC with 1GB of RAM, 2 SD cards, and multiple input buttons.
> > > >
> > > > This bootloader has been tested on the Anbernic RG35XX-2024 and
> > > > RG35XX-H, but should be suitable for the entire lineup of H700 based
> > > > devices.
> > > >
> > > > A future series of updates will add board selection logic to identify
> > > > and load the correct device tree automatically, and will switch to
> > > > utilizing a mainline device tree.
> > >
> > > I can already see the upstream DT subtree containing DTS for this board as:
> > >
> > > ./dts/upstream/src/arm64/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts
> > >
> > > Are there any major differences that won't allow you to switch to
> > > OF_UPSTREAM for this board?
> >
> > In this case there are no differences between the DT in the kernel repo
> > and what we put in U-Boot. The main reason for me holding back the switch
> > to OF_UPSTREAM for the H616 was indeed the rather slow update cadence,
> > which somewhat slows down upstreaming of new boards like this. Doing this
> > separately gives us a bit more control and freedom to take DT patches
> > early, for instance when they appear in some Linux -rc1, or even before
> > that (linux-next).
> > I explained my position in more detail here:
> > https://lore.kernel.org/u-boot/191A0F66-E2AE-4D1B-ACBE-E411E135BB61@arm.com/
> >
> 
> I can see the reasoning, thanks.
> 
> > I think Tom partly convinced me that regular updates together with
> > cherry-picking should solve most of those problems, so I will probably do
> > the switch for the next cycle.
> >
> 
> Glad to hear that. Cherry-picking has been working really well for
> Rockchip platforms [1] [2] [3] as the changes appear in Linux -rc1.
> Also, it pretty much avoids maintainers to review the DT changes
> unless there are some bits added via *-u-boot.dtsi.
> 
> [1] https://patchwork.ozlabs.org/project/uboot/list/?series=417233
> [2] https://patchwork.ozlabs.org/project/uboot/list/?series=417377
> [3] https://patchwork.ozlabs.org/project/uboot/list/?series=417353
> 
> -Sumit

The specific differences between this and the upstream tree is that the
upstream tree is missing the switch from rsb to i2c for the PMIC. That
said, if we can cherry pick the change (it was just accepted and should
end up in 6.12) that would work and I can start from the get-go with an
upstream tree. There may be other differences, but they are ultimately
superficial for U-Boot. I'll still make this for the RK35XX-2024 only
for now, because I need to finish some stuff in the detection logic.

Thank you.
Chris