On Fri, Aug 04, 2017 at 11:34:51AM +0200, Marek Szyprowski wrote: > Registers for some clocks might be located in the SOC area, which are under the > power domain. To enable access to those registers respective domain has to be > turned on. Additionally, registers for such clocks will usually loose its > contents when power domain is turned off, so additional saving and restoring of > them might be needed in the clock controller driver. > > This patch adds basic infrastructure in the clocks core to allow implementing > driver for such clocks under power domains. Clock provider can supply a > struct device pointer, which is the used by clock core for tracking and managing > clock's controller runtime pm state. Each clk_prepare() operation > will first call pm_runtime_get_sync() on the supplied device, while > clk_unprepare() will do pm_runtime_put_sync() at the end. > > Additional calls to pm_runtime_get/put functions are required to ensure that any > register access (like calculating/changing clock rates and unpreparing/disabling > unused clocks on boot) will be done with clock controller in runtime resumend > state. > > When one wants to register clock controller, which make use of this feature, he > has to: > 1. Provide a struct device to the core when registering the provider. > 2. Ensure to enable runtime PM for that device before registering clocks. > 3. Make sure that the runtime PM status of the controller device reflects > the HW state. > > Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > --- > drivers/clk/clk.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 114 insertions(+), 15 deletions(-) > Acked-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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