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From:   Dmitry Baryshkov <dbaryshkov@gmail.com>
Date:   Fri, 6 Jan 2023 12:06:06 +0200
Message-ID: <CALT56yN9aBn+s5rFB1yBdhGtYa6t=c0JeNmy0T=ckh3bNPgh2Q@mail.gmail.com>
Subject: Re: [PATCH 01/27] ARM: pxa: remove unused board files
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Richard Purdie <richard.purdie@linuxfoundation.org>,
        Arnd Bergmann <arnd@kernel.org>,
        Robert Jarzmik <robert.jarzmik@free.fr>,
        Daniel Mack <daniel@zonque.org>,
        Haojian Zhuang <haojian.zhuang@gmail.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Ales Bardorfer <ales@i-tech.si>,
        Ales Snuparek <snuparek@atlas.cz>,
        Alex Osborne <ato@meshy.org>,
        Alex Osborne <bobofdoom@gmail.com>,
        Dirk Opfer <dirk@opfer-online.de>, Ian Molton <spyro@f2s.com>,
        Lennert Buytenhek <kernel@wantstofly.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Michael Petchkovsky <mkpetch@internode.on.net>,
        Nick Bane <nick@cecomputing.co.uk>,
        Paul Parsons <lost.distance@yahoo.com>,
        Philipp Zabel <philipp.zabel@gmail.com>,
        Sergey Lapin <slapin@ossfans.org>,
        Tomas Cech <sleep_walker@suse.cz>,
        Linus Walleij <linusw@kernel.org>,
        Marc Zyngier <maz@kernel.org>
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=D0=BF=D1=82, 6 =D1=8F=D0=BD=D0=B2. 2023 =D0=B3. =D0=B2 11:47, Arnd Bergman=
n <arnd@arndb.de>:
>
> On Thu, Jan 5, 2023, at 23:45, Richard Purdie wrote:
> > On Thu, 2023-01-05 at 23:16 +0100, Arnd Bergmann wrote:
> >> On Thu, Jan 5, 2023, at 18:05, Richard Purdie wrote:
> >> > On Thu, 2023-01-05 at 17:50 +0200, Dmitry Baryshkov wrote:
> >>
> >> In the long run, I expect we will remove all the remaining
> >> legacy boardfiles and only keep the DT support. Ideally
> >> if someone is motivated to convert spitz to DT, supporting
> >> corgi the same way is also easy.
> >
> > Personally, I'm not that interested in tosa (or poodle/collie).

I think I was one of the last devs having interest in tosa. It worked
mostly fine except the offline charging.

> >
> > The other zaurus devices are interesting for me as I know the platform,
> > they have qemu emulation, there are set of devices which are similar
> > but also have differences and there were one of the original targets
> > for OpenEmbedded and Yocto Project. I did quite a bit of work to get
> > one kernel which could run on multiple devices, as best you could at
> > the time! I'd actually forgotten about the qemu emulation.
> >
> > There is a need for better automated testing around DT in OE/YP and
> > this is making me wonder about a few potential ideas.
>
> Ok
>
> > Is there any conversion to DT you can easily point at as an example of
> > the kinds of changes needed?
>
> Robert Jarzmik and Daniel Mack worked on the conversion of the
> PXA platform to DT. Daniel contributed the port for Raumfeld,
> which should be complete, while Robert worked on more driver
> conversions and mentioned[1] that he had converted additional
> boards in the past but did not merge it upstream. They
> can probably point you to whatever is missing. I would expect
> the generic PXA drivers (spi, mmc, nand, i2c, audio, fb, gpio,
> keypad) to  basically work work a correct DT description,
> while the machine specific drivers (scoop and pcmcia mainly)
> will need DT support in the driver.
>
> In addition, Linus Walleij and Marc Zyngier have both expressed
> interest in keeping sa1100 (h3600, collie, assabet, jornada720)
> alive, but those don't have any DT support yet and require
> much more work. Also note that while you can now build a kernel
> that includes support for all little-endian ARMv4T and ARMv5
> machines, StrongARM machine still require a separate kernel
> build.

I looked into converting collie to use DT several years ago. The major
problem was not in the StrongARM itself , but rather in the locomo
(platform-specific ASIC) and PCMCIA. Unfortunately I abandoned that
work ages ago. RMK didn't seem to be very interested, if I remember
correclty.

I suspect that the platforms might need to be rebootstrapped from the
ground up. This sounds like a fun project for the next Connect demo :D

BTW: collie is also supported by the qemu (in fact at some point I
mostly used qemu for debugging collie). I don't think that the LCD
emulation works, but the rest should be mostly good.

>
>      Arnd
>
> [1] https://lore.kernel.org/all/803778517.2279639.1667493436959.JavaMail.=
open-xchange@opme11oxm02aub.pom.fr.intraorange/

--=20
With best wishes
Dmitry