On Fri, 6 Aug 2021 at 15:48, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx> wrote: > > 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: > > https://github.com/PabloPL/linux/tree/exynos7420 > > > > 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. > > Yes, in due course... There won't be much problems with chip-id driver. But pretty much all platform drivers depend on clk, and that one I'm afraid I'll have to implement from scratch. Will take me a while, as vendor's codebase for clk driver is huge and depend on another huge non-upstreamable abstraction layer framework they have, and also they have kind of strange home brewed composite clocks... Anyway, that's what I'm going to look into next. Btw, I just sent v2 :) > > You can also take a look at Exynos8895 efforts: > https://github.com/ivoszbg/linux/commits/for-upstream/exynos8895 > > Since knowledge, datasheets and efforts are quite spread all over, I > keep track of some work here: > https://exynos.wiki.kernel.org/community > Thanks, Krzysztof! I'm sure that info will help a lot with further work, like clock driver. > > Best regards, > Krzysztof
