Re: [PATCH v2 2/4] Documentation: Add documentation for APM X-Gene SoC PMU DTS binding
From: Will Deacon
Date: Wed Apr 20 2016 - 07:31:30 EST
On Mon, Apr 18, 2016 at 01:04:53PM -0700, Tai Tri Nguyen wrote:
> >> +Required properties for MCB subnode:
> >> +- compatible : Shall be "apm,xgene-pmu-mcb".
> >> +- reg : First resource shall be the MCB PMU resource.
> >> +- index : Instance number of the MCB PMU.
> >> +
> >> +Required properties for MC subnode:
> >> +- compatible : Shall be "apm,xgene-pmu-mc".
> >> +- reg : First resource shall be the MC PMU resource.
> >> +- index : Instance number of the MC PMU.
> > Don't use indexes. You probably need phandles to the nodes these are
> > related to.
> > How many variations of child nodes do you expect to have? 2, 10, 50? You
> > might want to just collapse all this down to a single node and put this
> > information in the driver if it is fixed for each SoC and there's only a
> > handful.
> For each kind of PMU, for example memory controller PMU, I expect to
> have the number of instances up to 8.
> They are actually all independent PMU nodes and have their own CSR memory bases.
> The indexes are used for exposing the devices to perf user only. It
> doesn't have an impact on the programming model.
> Mark also had the same concern.
Regardless, I'll need an ack from Rob or Mark before I can merge this.