On 29 April 2015 at 13:30, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > Hi Rajendra, > > On Wed, Apr 29, 2015 at 11:49 AM, Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> wrote: >>>> I guess I can also control the rest of the devices the same way, just >>>> that the genpd on/off for them would do nothing. >>>> That way I don't have to use pm_clk_add_notifier() and can also >>>> associate the power domain (with no on/off control) to devices >>>> through DT (and there isn;t any duplication of code in the drivers) >>> >>> >>> That looks similar to what we have on R-Mobile: some devices are in >>> controllable power areas, other are in an "always on" power area. All >>> (most) >>> devices have controllable clocks, which we also control through the PM >>> domain. "git grep sysc-rmobile" will point you to the related code and >>> DTS. >> >> Geert, thanks, I was wondering how you handle the !CONFIG_PM case for >> rmobile. I mean who turns the clocks on for the devices when you build >> with CONFIG_PM disabled? > > We still use pm_clk_add_notifier() in drivers/sh/pm_runtime.c if > CONFIG_PM_GENERIC_DOMAINS_OF=n. Hence the second instance of > pm_clk_notify() will enable the clocks at driver binding time. > Hardware power domains are assumed enabled by reset state/the boot > loader. Yes, it a bit tricky - but I guess that's the current only viable solution if we have when using the pm_clk API. > > Given the amount of PM infrastructure involved when hardware power and > clock domains are involved, I think at one point we'll have to start restricting > our builds to CONFIG_PM=y. I don't think that would solve the problem, since you may still have cross SoC drivers which may be used without CONFIG_PM. So all SoC that uses a driver which expects clocks to be managed using PM clocks from a PM domain, will need the above "trick". Right? Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
