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

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

[FUKAUMI Naoki]

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.

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.

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
---
 arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e-v3.dts | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e-v3.dts

diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e-v3.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e-v3.dts
new file mode 100644
index 000000000000..956345274c12
--- /dev/null
+++ b/arch/arm64/boot/dts/rockchip/rk3328-rock-pi-e-v3.dts
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+#include "rk3328-rock-pi-e.dts"
-- 
2.43.0

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

[Krzysztof Kozlowski]

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?

> 
> 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.

This change really lacks proper explanation or is just unnecessary. If
change is proven as necessary, then you also miss compatible and model.


Best regards,
Krzysztof

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

[FUKAUMI Naoki]

Hi,

thank you very much for your comment!

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 latest U-Boot uses upstream device tree for some targets.

> This change really lacks proper explanation or is just unnecessary. If
> change is proven as necessary, then you also miss compatible and model.

sorry, I should write proper explanation.

Best regards,

--
FUKAUMI Naoki
Radxa Computer (Shenzhen) Co., Ltd.

> Best regards,
> Krzysztof
> 
> 

Re: [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

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

[Dragan Simic]

Hello Heiko,

On 2024-06-23 12:43, Heiko Stübner wrote:
> 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.

Please see the U-Boot patch submission [1] for more details.  Anyway,
I think in this case we'll need a rather full-fledged support for a new
board version, because that's what it actually is.

[1] 
https://lore.kernel.org/u-boot/20240623041542.50137-1-naoki@radxa.com/