[PATCH v5 2/2] arm64: dts: rockchip: add support for Radxa ROCK Pi E v3.0

[FUKAUMI Naoki]

Hi,

On 8/26/24 20:25, Dragan Simic wrote:
> Hello Naoki,
> 
> On 2024-08-18 00:30, Dragan Simic wrote:
>> On 2024-08-17 22:28, FUKAUMI Naoki wrote:
>>> On 8/18/24 05:12, Dragan Simic wrote:
>>>> On 2024-08-17 22:04, FUKAUMI Naoki wrote:
>>>>> On 8/18/24 04:51, Dragan Simic wrote:
>>>>>> On 2024-08-17 21:28, Dragan Simic wrote:
>>>>>>> On 2024-08-17 00:20, FUKAUMI Naoki wrote:
>>>>>>>> On 8/17/24 07:11, Heiko Stübner wrote:
>>>>>>>>> Am Freitag, 16. August 2024, 23:34:29 CEST schrieb FUKAUMI Naoki:
>>>>>>>>>> Radxa ROCK Pi E v3.0 is a compact networking SBC[1] using the 
>>>>>>>>>> Rockchip
>>>>>>>>>> RK3328 chip that ships in a number of RAM/eMMC/WiFi/BT 
>>>>>>>>>> configurations:
>>>>>>>>>>
>>>>>>>>>> - Rockchip RK3328 SoC
>>>>>>>>>> - Quad A53 CPU
>>>>>>>>>> - 512MB/1GB/2GB DDR4 RAM
>>>>>>>> (snip)
>>>>>>>>> can you please describe what is different in that v3 board?
>>>>>>>>> Describing what is different to require a separate board 
>>>>>>>>> should've been
>>>>>>>>> part of the commit message.
>>>>>>>>>
>>>>>>>>> Because from those changes, the bottom line currently seems to be
>>>>>>>>> the same board with swapped mmc aliases?
>>>>>>>>
>>>>>>>> it's new board which uses DDR4 RAM (instead of DDR3 RAM on Pi E).
>>>>>>>> different bootloader (U-Boot) is required.
>>>>>>>>
>>>>>>>> adding v3 dts seems not to be so important for Linux, but it's very
>>>>>>>> important for U-Boot and OpenWrt(it includes bootloader for
>>>>>>>> distributed binary).
>>>>>>>
>>>>>>> Aren't there different methods that allow such board variants to be
>>>>>>> supported in U-Boot, with no need for a separate DT in the kernel?
>>>>>>> IIRC, there are already more than a few examples of such board 
>>>>>>> variants,
>>>>>>> which require different DRAM initialization, which is covered in 
>>>>>>> U-Boot
>>>>>>> by providing different builds that use the same DT.
>>>>>>
>>>>>> As an example, please have a look at the following files in U-Boot:
>>>>>>
>>>>>> - arch/arm/dts/rk3399-nanopi-m4-u-boot.dtsi
>>>>>> - arch/arm/dts/rk3399-nanopi-m4-2gb-u-boot.dtsi
>>>>>> - configs/nanopi-m4-rk3399_defconfig
>>>>>> - configs/nanopi-m4-2gb-rk3399_defconfig
>>>>>>
>>>>>> Basically, there's no need for separate DTs in the kernel, just to 
>>>>>> support
>>>>>> board variants with different DRAM types in U-Boot.
>>>>>
>>>>> OpenWrt firmware upgrading tool (sysupgrade) refers "compatible"
>>>>> string to validate new firmware file is surely "for this board".
>>>>>
>>>>> currently both Pi E dts have "radxa,rockpi-e", it makes flashing wrong
>>>>> firmware (include bootloaer, U-Boot) possible.
>>>>
>>>> Could you, please, explain what's the actual issue with OpenWrt?  I did
>>>> read some GitHub issue that described it, IIRC, but I was unable to 
>>>> fully
>>>> understand what's the underlying issue.
>>>
>>> $ wget
>>> https://downloads.openwrt.org/snapshots/targets/rockchip/armv8/openwrt-rockchip-armv8-radxa_rock-pi-e-ext4-sysupgrade.img.gz
>>> $ strings
>>> openwrt-rockchip-armv8-radxa_rock-pi-e-ext4-sysupgrade.img.gz | grep
>>> metadata
>>> {  "metadata_version": "1.1", "compat_version": "1.0",
>>> "supported_devices":["radxa,rock-pi-e"], "version": { "dist":
>>> "OpenWrt", "version": "SNAPSHOT", "revision": "r27160-b72c4b5386",
>>> "target": "rockchip/armv8", "board": "radxa_rock-pi-e" } }
>>>
>>> $ wget
>>> https://downloads.openwrt.org/snapshots/targets/rockchip/armv8/openwrt-rockchip-armv8-radxa_rock-pi-e-v3-ext4-sysupgrade.img.gz
>>> $ strings
>>> openwrt-rockchip-armv8-radxa_rock-pi-e-v3-ext4-sysupgrade.img.gz |
>>> grep metadata
>>> {  "metadata_version": "1.1", "compat_version": "1.0",
>>> "supported_devices":["radxa,rock-pi-e-v3"], "version": { "dist":
>>> "OpenWrt", "version": "SNAPSHOT", "revision": "r27160-b72c4b5386",
>>> "target": "rockchip/armv8", "board": "radxa_rock-pi-e-v3" } }
>>>
>>> since they are incompatible firmware, it needs to have different
>>> "supported_devices" string. if both are "radxa,rockpi-e", firmware
>>> validation will not work correctly.
>>>
>>> (currently both values are wrong, it needs to be fixed, but it's 
>>> another story)
>>>
>>>>> Radxa ROCK Pi E v1.x(DDR3) and ROCK Pi E v3(DDR4) are different
>>>>> incompatible boards, it must have different "compatible" string.
>>>>
>>>> Well, the above-mentioned Nano Pi M4 boards share the same DT and 
>>>> the same
>>>> "compatible" value, because for all consumers of the DT, except for 
>>>> U-Boot
>>>> that can already handle the differences, they are the same boards.
>>>
>>> (un)fortunately Nano Pi M4 boards seems not to be supported by OpenWrt
>>>
>>>  https://downloads.openwrt.org/snapshots/targets/rockchip/armv8/
>>
>> Thanks for the explanations.  As discussed further in #linux-rockchip
>> on Libera.Chat, we do need a general solution for this issue, which would
>> get us covered for all the board variants that use different DRAM chips,
>> which are currently known to U-Boot only.
>>
>> I'll keep thinking about this in the next couple of days, and I'll come
>> back with an update.
> 
> As a separate thought, is there some way to detect the actual ROCK Pi E
> board variant at runtime, using some GPIO line, ADC readout, or something
> similar?  That would help with making it possible to have a single U-Boot
> build for both board variants.

as far as I know, no difference. (I asked my colleague)
I will compare schematics.

but, if there is difference, is it possible to replace RAM 
initialization on u-boot?

btw, RFC:
 
https://github.com/RadxaNaoki/u-boot/commit/ff1aa39ffb725d10fbb1608062debe6657f40acc

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