[PATCH v5 2/2] riscv: dts: sophgo: add initial Milk-V Duo S board support

[Inochi Amaoto]

On Tue, Apr 23, 2024 at 08:11:29AM GMT, Michael Opdenacker wrote:
> Hi Inochi,
> 
> Thanks for the advice.
> 
> On 4/21/24 at 08:30, Inochi Amaoto wrote:
> > On Sun, Apr 21, 2024 at 07:57:01AM GMT, Michael Opdenacker wrote:
> > +++ b/arch/riscv/boot/dts/sophgo/sg2000-milkv-duos.dts
> > @@ -0,0 +1,34 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > +/*
> > + * Copyright (C) 2024 Michael Opdenacker <michael.opdenacker at bootlin.com>
> > + */
> > +
> > +/dts-v1/;
> > +
> > +#include "cv1812h.dtsi"
> > +
> > +/ {
> > +	model = "Milk-V Duo S";
> > +	compatible = "milkv,duos", "sophgo,cv1812h";
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory at 80000000 {
> > +		device_type = "memory";
> > +		reg = <0x80000000 0x20000000>;
> > +	};
> > > > Add a cpu specific file, and move this to it.
> > > Now that I'm including "cv1812h.dtsi", which has the same structure, all I
> > > need is to change the reg setting to have 512 MB of RAM instead of 256MB,
> > > right? See the V6 I'm sending soon.
> > > 
> > No, Duo S does not use cv1812h, in any means. I just told you to use
> > cv1812h for local test. If you want to upstream Duo S, you must add
> > the right cpu compatibles and necessary nodes. These two are different
> > things.
> 
> So, do you mean I should create a new "sophgo,sg2000" compatible, together
> with  a new "sg2000.dtsi" (or "sg200x.dtsi"?) file? Could this file include
> "cv18xx.dtsi"?
> 

Right. For the second question, it must. "cv18xx.dtsi" is the common file
for the whole series. You can check the existed cpu file in sophgo upstream 
repository: https://github.com/sophgo/linux/tree/for-next.

> By the way, where's the best source of information about the Sophgo sg2000
> and sg2002 processors? Even the Sophgo website doesn't seem to have them :-/
> . It just mentions the CV18xx ones.
> 

In additional to the doc mentioned by Thomas, I think you may need to
check Duo docs from milkv: https://github.com/milkv-duo/duo-files. It
contains all you need for Duo S.

> Thanks again
> Cheers
> Michael.
> 
> -- 
> Michael Opdenacker, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>