On Saturday 28 June 2014 22:40:26 Thierry Reding wrote: > > > pmc.c implements various routines to access the power management > > > controller, some of which is needed by suspend/resume, some of it is > > > needed by SMP. powergate.c implements a subset of the PMC that needs to > > > be exported to drivers to enable power partitions on the SoC. I'm not > > > aware of subsystems that deal with this kind of driver. > > > > > Please see above. > > Like I said, I don't see what business suspend/resume related code has > in drivers/power. What we're talking about here really is functionality > very specific to Tegra. Also some of that code needs to be run at very > early points in the boot process, so we can't reasonably turn it into a > proper driver anyway. I believe the powergate.c stuff can be changed into pm_domain code, but we don't have a good subsystem with generic DT bindings yet, so that may need some more groundwork first. drivers/power or a subdirectory of that may end up being the right place though. > Also, the real win we get from moving code out into drivers/ is if we > can provide a common framework for them. I don't see how we can possibly > do that for this code since there simply isn't enough commonality > between SoCs. At the same time we now have a situation where both 32-bit > and 64-bit variants of some SoCs share some of the same hardware at the > very low level and since we don't have mach-* directories for 64-bit ARM > and shouldn't be duplicating code either, we need to find a new home for > this type of code. drivers/soc seemed to fit perfectly well. For the low-level stuff yes, but I agree with Santosh there needs to be some more work trying to split out individual high-level drivers. There are two common patterns for the interface between the low-level register access and the more high-level stuff: you can either use a "syscon" driver that just exports a struct regmap and that gets referenced from other drivers using a phandle in their device nodes, or you have a driver in drivers/soc that exports a somewhat higher-level interface and comes with its own header file that gets included by other drivers. At the moment, the syscon/regmap variant can only be used once device drivers are loaded, but there is some broad agreement that it should be changed to allow calling syscon_regmap_lookup_by_phandle() at early boot using just DT accessors. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
