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

[Inochi Amaoto]

On Sun, Apr 21, 2024 at 07:57:01AM GMT, Michael Opdenacker wrote:
> Hi Inochi
> 
> Thanks for your advice!
> 
> On 4/17/24 at 11:34, Inochi Amaoto wrote:
> > On Wed, Apr 17, 2024 at 08:53:11AM GMT, michael.opdenacker@xxxxxxxxxxx wrote:
> > > From: Michael Opdenacker <michael.opdenacker@xxxxxxxxxxx>
> > > 
> > > This adds initial support for the Milk-V Duo S board
> > > (https://milkv.io/duo-s), enabling the serial port,
> > > making it possible to boot Linux to the command line.
> > > 
> > > Link: https://lore.kernel.org/linux-riscv/171266958507.1032617.9460749136730849811.robh@xxxxxxxxxx/T/#t
> > > 
> > > Signed-off-by: Michael Opdenacker <michael.opdenacker@xxxxxxxxxxx>
> > > ---
> > >   arch/riscv/boot/dts/sophgo/Makefile           |  1 +
> > >   .../boot/dts/sophgo/sg2000-milkv-duos.dts     | 34 +++++++++++++++++++
> > >   2 files changed, 35 insertions(+)
> > >   create mode 100644 arch/riscv/boot/dts/sophgo/sg2000-milkv-duos.dts
> > > 
> > > diff --git a/arch/riscv/boot/dts/sophgo/Makefile b/arch/riscv/boot/dts/sophgo/Makefile
> > > index 57ad82a61ea6..e008acb5240f 100644
> > > --- a/arch/riscv/boot/dts/sophgo/Makefile
> > > +++ b/arch/riscv/boot/dts/sophgo/Makefile
> > > @@ -1,4 +1,5 @@
> > >   # SPDX-License-Identifier: GPL-2.0
> > >   dtb-$(CONFIG_ARCH_SOPHGO) += cv1800b-milkv-duo.dtb
> > >   dtb-$(CONFIG_ARCH_SOPHGO) += cv1812h-huashan-pi.dtb
> > > +dtb-$(CONFIG_ARCH_SOPHGO) += sg2000-milkv-duos.dtb
> > >   dtb-$(CONFIG_ARCH_SOPHGO) += sg2042-milkv-pioneer.dtb
> > > diff --git a/arch/riscv/boot/dts/sophgo/sg2000-milkv-duos.dts b/arch/riscv/boot/dts/sophgo/sg2000-milkv-duos.dts
> > > new file mode 100644
> > > index 000000000000..c1ecf97d5e93
> > > --- /dev/null
> > > +++ 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@xxxxxxxxxxx>
> > > + */
> > > +
> > > +/dts-v1/;
> > > +
> > > +#include "cv1812h.dtsi"
> > > +
> > > +/ {
> > > +	model = "Milk-V Duo S";
> > > +	compatible = "milkv,duos", "sophgo,cv1812h";
> > > +
> > > +	aliases {
> > > +		serial0 = &uart0;
> > > +	};
> > > +
> > > +	chosen {
> > > +		stdout-path = "serial0:115200n8";
> > > +	};
> > > +
> > > +	memory@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.

> > 
> > > +};
> > > +
> > > +&osc {
> > > +	clock-frequency = <25000000>;
> > > +};
> > > +
> > > +&uart0 {
> > > +	status = "okay";
> > > +};
> > > -- 
> > > 2.34.1
> > > 
> > Add necessary DT node in the cpu specific file. (clint,
> > plic and clk). You also need to rebase your patch based
> > on sophgo/for-next.
> 
> Same here, cv1812h.dtsi already configures &clint, &plic and &clk, so it
> seems to me I don't need to make changes again here. At least the board
> boots fine for me as it is.
> Cheers
> Michael.
> 
> 
> -- 
> 
> Michael Opdenacker, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>