Re: [PATCH v8 09/13] arm64: dts: Add board DTS for Rpi5 which includes RP1 node

[Andrea della Porta <andrea.porta@suse.com>]

Hi Stefan,

On 13:48 Mon 14 Apr     , Stefan Wahren wrote:
> Hi Andrea,
> 
> Am 19.03.25 um 22:52 schrieb Andrea della Porta:
> > Add the board 'monolithic' DTS for RaspberryPi 5 which includes
> > the RP1 node definition.  The inclusion treeis as follow (the
> > arrow points to the includer):
> > 
> > rp1-common.dtsi ----> rp1-nexus.dtsi ----> bcm2712-rpi-5-b-monolithic.dts
> >                                                 ^
> >                                                 |
> >                                             bcm2712-rpi-5-b.dts
> sorry for the delay. I'm not happy with the monolithic appendix.
> 
> How about bcm2712-rpi-5-b-rp1.dts or something more self-explaining?Regards

Sure, good catch. I'd go even further saying that we can rename (or merge if
the destination file already exists) as:

bcm2712-rpi-5-b.dts             ->  bcm2712-rpi-5-b-norp1.dts (or some better suffix other than -norp1)
bcm2712-rpi-5-b-monolithic.dts  ->  bcm2712-rpi-5-b.dts

so the monolithic one, which seems to be the 'safest' option as of now,
would be the default dtb. Do you think it could be ok?

> > This is designed to maximize the compatibility with downstream DT
> > while ensuring that a fully defined DT (one which includes the RP1
> > node as opposed to load it from overlay at runtime) is present
> > since early boot stage.
> > 
> > Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
> > ---
> > Right now bcm2712-rpi-5-b.dts is the overlay-ready DT which will make
> > the RP1 driver to load the RP1 dtb overlay at runtime, while
> > bcm2712-rpi-5-b-monolithic.dts is the fully defined one (i.e. it
> > already contains RP1 node, so no overlay is loaded nor needed).
> > Depending on which one we want to be considered the default, we can
> > swap the file names to align with downstream naming convention that
> > has only the fully defined DT called bcm2712-rpi-5-b.dts.
> Could you please move some of this good explanation into this dts file as
> comment?

Sure.

Thanks,
Andrea

> > ---
> >   arch/arm64/boot/dts/broadcom/Makefile                     | 1 +
> >   .../boot/dts/broadcom/bcm2712-rpi-5-b-monolithic.dts      | 8 ++++++++
> >   2 files changed, 9 insertions(+)
> >   create mode 100644 arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-monolithic.dts
> > 
> > diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile
> > index 3d0efb93b06d..4836c6da5bee 100644
> > --- a/arch/arm64/boot/dts/broadcom/Makefile
> > +++ b/arch/arm64/boot/dts/broadcom/Makefile
> > @@ -7,6 +7,7 @@ dtb-$(CONFIG_ARCH_BCM2835) += bcm2711-rpi-400.dtb \
> >   			      bcm2711-rpi-4-b.dtb \
> >   			      bcm2711-rpi-cm4-io.dtb \
> >   			      bcm2712-rpi-5-b.dtb \
> > +			      bcm2712-rpi-5-b-monolithic.dtb \
> >   			      bcm2712-d-rpi-5-b.dtb \
> >   			      bcm2837-rpi-3-a-plus.dtb \
> >   			      bcm2837-rpi-3-b.dtb \
> > diff --git a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-monolithic.dts b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-monolithic.dts
> > new file mode 100644
> > index 000000000000..3aeee678b0bc
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-monolithic.dts
> > @@ -0,0 +1,8 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > +/dts-v1/;
> > +
> > +#include "bcm2712-rpi-5-b.dts"
> > +
> > +&pcie2 {
> > +	#include "rp1-nexus.dtsi"
> > +};
>