On 03/02/2017 04:43 AM, Rob Herring wrote: > On Wed, Mar 1, 2017 at 12:27 AM, Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> wrote: >> >> >> On 02/28/2017 09:22 PM, Rob Herring wrote: >>> On Tue, Feb 28, 2017 at 9:14 AM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: >>>> [...] >>>> >>>>>> ---> Parent domain-2 (Contains Perfomance states) >>>>>> | >>>>>> | >>>>>> C.) DeviceX ---> Parent-domain-1 | >>>>>> | >>>>>> | >>>>>> ---> Parent domain-3 (Contains Perfomance states) >>>>> >>>>> I'm a bit confused. How does a domain have 2 parent domains? >>>> >>>> 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. And nesting of >> >> yet the bindings for power-domains (for consumer devices) only allows for >> one powerdomain to be associated with a device. > > There's nothing in the binding only allowing that. If that was true, > then #powerdomain-cells would be pointless Is't #powerdomain-cells a powerdomain provider property? and used to specify if a powerdomain provider supports providing 1 or many powerdomains? I was talking about the power domain consumer property. Looking at Documentation/devicetree/bindings/power/power_domain.txt.. ==PM domain consumers== Required properties: - power-domains : A phandle and PM domain specifier as defined by bindings of the power controller specified by phandle. It clearly says 'A phandle'. If there was a way to specify multiple power-domains for a consumer device should it not be saying a list of phandles? Like we do for clocks and regulators? > as the property size would > tell you the number of cells. Now it may be that we simply don't have > any cases with more than 1. Hopefully that's not because bindings are > working around PM domain limitations/requirements. > > Rob > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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