On Thursday 12 February 2015 14:17:41 Arun Ramamurthy wrote: > Hi Arnd > > My apologies for the late reply, I was moved to other work items. I > wanted to get more clarification on the syscon issue so that I can > submit the next patch set. If I understand correctly, you would like > me to move the CRMU logic to a new driver under mfd/ and use the syscon > api calls in my rtc driver? Thanks It depends a lot on what's in there, I can best advise you if you have some form of register list. A common approach would be to not have a driver for the crmu at all, but just mark it as syscon, and have the other drivers either reference the syscon node through a phandle, or create them as childrem of the syscon node. The latter case makes most sense if all uses of the crmu have no other MMIO registers. > On 14-12-17 06:31 AM, Arnd Bergmann wrote: > > On Tuesday 16 December 2014 13:54:04 Arun Ramamurthy wrote: > >> On 14-12-16 12:27 PM, Ray Jui wrote: > >>> On 12/16/2014 12:19 PM, Arnd Bergmann wrote: > >>>> > >>>> It sounds like CRMU is some other unit aside from the RTC. Could this > >>>> be something like a generic system controller? I think it should > >>>> either have its own driver or use the syscon logic if that is what > >>>> this is. > >>>> > >>> Giving that CRMU has scattered, miscellaneous control logic for multiple > >>> different peripherals, it probably makes more sense to use the syscon > >>> logic here. > >>> > >> Arnd, thanks for the feedback. If I was to write a separate driver for > >> the CRMU, I would have to export certain functions and create an api > >> that only this RTC driver would use. I am not sure that is efficient or > >> required. What is your opinion? > >> Would it be better if I use the syson api in my current driver and move > >> the CRMU registers to separate syscon device tree entry? > >> > > > > This is something that's normally up to the platform maintainers, depending > > on what works best for a given SoC. If you have a control block that > > wants to export the same high-level API for multiple drivers, that's > > fine, but if literally every register does something different, a syscon > > driver works best. > > > > It's also possible that some of the functions of the CRMU already have > > abstractions, like system-reset, device-reset, regulator or clock support. > > In that case, you can still use syscon but have the more other drivers > > use that for accessing the registers. > > > > Arnd > > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
