On 28-02-17, 09:52, Rob Herring wrote: > On Tue, Feb 28, 2017 at 9:14 AM, Ulf Hansson <ulf.hans...@linaro.org> wrote: > > This comes from the early design of the generic PM domain, thus I > > assume we have some HW with such complex PM topology. However, I don't > > know if it is actually being used. > > > > Moreover, the corresponding DT bindings for "power-domains" parents, > > can easily be extended to cover more than one parent. See more in > > Documentation/devicetree/bindings/power/power_domain.txt > > I could easily see device having 2 power domains. For example a cpu > may have separate domains for RAM/caches and logic.
An important thing here is that PM domain doesn't support such devices. i.e. a device isn't allowed to have multiple PM domains today. So a way to support such devices can be to create a virtual PM domain, that has two parents and device as its child. -- viresh
