Re: [PATCH 12/12] arm64: dts: exynos: Add Exynos850 SoC support

From: Krzysztof Kozlowski
Date: Fri Aug 06 2021 - 08:50:14 EST

On 06/08/2021 14:32, Krzysztof Kozlowski wrote:
> On 06/08/2021 14:07, Sam Protsenko wrote:
>> On Fri, 6 Aug 2021 at 10:49, Krzysztof Kozlowski
>> <krzysztof.kozlowski@xxxxxxxxxxxxx> wrote:
>>> On 06/08/2021 01:06, Sam Protsenko wrote:
>>>> On Sat, 31 Jul 2021 at 12:03, Krzysztof Kozlowski
>>>> <krzysztof.kozlowski@xxxxxxxxxxxxx> wrote:
>>>>>> This patch adds minimal SoC support. Particular board device tree files
>>>>>> can include exynos850.dtsi file to get SoC related nodes, and then
>>>>>> reference those nodes further as needed.
>>>>>> Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
>>>>>> ---
>>>>>> .../boot/dts/exynos/exynos850-pinctrl.dtsi | 782 ++++++++++++++++++
>>>>>> arch/arm64/boot/dts/exynos/exynos850-usi.dtsi | 30 +
>>>>>> arch/arm64/boot/dts/exynos/exynos850.dtsi | 245 ++++++
>>>>> Not buildable. Missing Makefile, missing DTS. Please submit with initial
>>>>> DTS, otherwise no one is able to verify it even compiles.
>>>> This device is not available for purchase yet. I'll send the patch for
>>>> board dts once it's announced. I can do all the testing for now, if
>>>> you have any specific requests. Would it be possible for us to review
>>>> and apply only SoC support for now? Will send v2 soon...
>>> What you propose is equal to adding a driver (C source code) without
>>> ability to compile it. What's the point of having it in the kernel? It's
>>> unverifiable, unbuildable and unusable.
>> Yes, I understand. That's adding code with no users, and it's not a
>> good practice.
>>> We can review the DTSI however merging has to be with a DTS. Usually the
>>> SoC vendor adds first an evalkit (e.g. SMDK board). Maybe you have one
>>> for Exynos850? Otherwise if you cannot disclose the actual board, the
>>> DTSI will have to wait. You can submit drivers, though.
>> Sure, let's go this way. I'll send v2 soon. Improving patches and
>> having Reviewed-by tag for those would good enough for me at this
>> point. I'll continue to prepare another Exynos850 related patches
>> until the actual board is announced, like proper clock driver, reset,
>> MMC, etc. Is it ok if I send those for a review too (so I can fix all
>> issues ahead)?
> Sure, prepare all necessary drivers earlier. I suspect clocks will be a
> real pain because of significant changes modeled in vendor kernel. I
> remember Paweł Chmiel (+Cc) was doing something for these:
> I mentioned before - you should also modify the chipid driver. Check
> also other drivers in drivers/soc/samsung, although some are needed only
> for suspend&resume.

You can also take a look at Exynos8895 efforts:

Since knowledge, datasheets and efforts are quite spread all over, I
keep track of some work here:

Best regards,