>-----Original Message----- >From: Krzysztof Kozlowski [mailto:krzysztof.kozlowski@xxxxxxxxxx] >Sent: Friday, November 25, 2022 8:31 PM >To: Sam Protsenko <semen.protsenko@xxxxxxxxxx> >Cc: Lee Jones <lee@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; >Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Alim Akhtar ><alim.akhtar@xxxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux- >kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- >samsung-soc@xxxxxxxxxxxxxxx; Sriranjani P <sriranjani.p@xxxxxxxxxxx>; >Chanho Park <chanho61.park@xxxxxxxxxxx> >Subject: Re: [PATCH 3/4] dt-bindings: soc: samsung: exynos-sysreg: add >dedicated SYSREG compatibles to Exynos5433 > >On 25/11/2022 15:57, Sam Protsenko wrote: >> On Fri, 25 Nov 2022 at 08:47, Krzysztof Kozlowski >> <krzysztof.kozlowski@xxxxxxxxxx> wrote: >>> >>> On 25/11/2022 15:22, Sam Protsenko wrote: >>>> On Fri, 25 Nov 2022 at 05:22, Krzysztof Kozlowski >>>> <krzysztof.kozlowski@xxxxxxxxxx> wrote: >>>>> >>>>> Exynos5433 has several different SYSREGs, so use dedicated >>>>> compatibles for them. >>>>> >>>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >>>>> >>>>> --- >>>>> >>>>> Cc: Sriranjani P <sriranjani.p@xxxxxxxxxxx> >>>>> Cc: Chanho Park <chanho61.park@xxxxxxxxxxx> >>>>> Cc: Sam Protsenko <semen.protsenko@xxxxxxxxxx> >>>>> --- >>>> >>>> Hi Krzysztof, >>>> >>>> Just curious: what is the rationale for adding those more specific >>>> sysregs? AFAIR, e.g. in Exynos850, different SysReg instances have >>>> pretty much the same register layout. >>>> >>> >>> On Exynos5433 all these blocks have different registers. Are you >>> saying that Exynos850 has four (or more) sysregs which are exactly the >same? >>> Same registers? Why would they duplicate it? >>> >> >> Ah, no, you are right. Just checked it, they are different. Just first >> couple of registers are similar between blocks, that's why I memorized >> it wrong. >> >> So as I understand, adding those new compatibles follows "describe HW, >> not a driver" rule? Because AFAIU, right now it'll fallback to >> "syscon" compatible anyway. > >Yes, they describe hardware. Of course all of these sysregs are similar as they >are just bunch of SFR/MMIO-region, but they have different roles/features. >For example some other devices (users) of syscon/sysreg should reference >specific device, not any sysreg. > Yes, these are dedicated / extended SFR region to provide IP/Block specific side-band signals / configurations. >On several other architectures we use specific compatibles, so I think for >Samsung we should do the same. > Yes, most of the SoC's sysreg are dedicated/included in the IP block itself now a day, so make sense to have a dedicated compatible. >Different case was for Exynos 3/4/5 where there was only one SYSREG. > AFAIR, this is correct. >Best regards, >Krzysztof
