[PATCH] arm64: dts: rockchip: add dts for Radxa ROCK Pi E v3.0

[Heiko Stübner]

Hi,

Am Sonntag, 23. Juni 2024, 10:18:58 CEST schrieb FUKAUMI Naoki:
> On 6/23/24 17:07, Krzysztof Kozlowski wrote:
> > On 23/06/2024 09:53, FUKAUMI Naoki wrote:
> >> Radxa ROCK Pi E v3.0 has DDR4 SDRAM instead of DDR3 SDRAM.
> >>
> >> for Linux, this change doesn't make any difference from a device tree
> >> POV. but, for bootloader (U-Boot TPL), it makes a difference.
> > 
> > What difference?
> 
> U-Boot TPL initialize DDR SDRAM.
> 
> https://github.com/RadxaNaoki/u-boot/commit/16d823eb95fe311c82a8ebb31570b59b1c59c43b#diff-03ce6c241f5db74ae87d4d8654bfef5eeb5bc42a9f1ff3cc828b70b3b2ac51d2R4
> https://github.com/RadxaNaoki/u-boot/commit/16d823eb95fe311c82a8ebb31570b59b1c59c43b#diff-31b80303774e7c10b527fb2dbc704b82e6c5ccdc6d53dd4f65861309ce0e7413R4
> 
> there is 1 letter difference, ddr"3" and ddr"4".
> 
> >> bootloader needs a separeted dts for v3, so I add new dts for it.
> >> dtb can be shared between v3 and prior, so I don't touch Makefile.
> > 
> > I don't understand. If you have the same DTB then you do not need second
> > DTS.
> 
> 2nd dts is for bootloader. it's not needed for Linux.

but _what_ is this different dt needed for. If it is unchanged from the
first one, why can't you reference that one in u-boot?

Similar to Krzysztof, I don't see _why_ you need a separate devicetree
at all.


Heiko