Hi Mark, On Fri, Apr 1, 2016 at 5:30 AM, Mark Rutland <mark.rutl...@arm.com> wrote: > Hi, > > As per Documentation/devicetree/bindings/submitting-patches.txt, please > put binding patches earlier in a series than the code using them. > > On Thu, Mar 31, 2016 at 04:37:50PM -0700, Tai Nguyen wrote: >> Documentation: Add documentation for APM X-Gene SoC PMU DTS binding >> >> Signed-off-by: Tai Nguyen <ttngu...@apm.com> >> --- >> .../devicetree/bindings/perf/apm-xgene-pmu.txt | 116 >> +++++++++++++++++++++ >> 1 file changed, 116 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/perf/apm-xgene-pmu.txt >> >> diff --git a/Documentation/devicetree/bindings/perf/apm-xgene-pmu.txt >> b/Documentation/devicetree/bindings/perf/apm-xgene-pmu.txt >> new file mode 100644 >> index 0000000..40dfd4e >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/perf/apm-xgene-pmu.txt >> @@ -0,0 +1,116 @@ >> +* APM X-Gene SoC PMU bindings >> + >> +This is APM X-Gene SoC PMU (Performance Monitoring Unit) module. >> +The following PMU devices are supported: >> + >> + L3C - L3 cache controller >> + IOB - IO bridge >> + MCB - Memory controller bridge >> + MC - Memory controller > > These sound like separate units. How do these relate? > > Is there an SOC-wide PMU that aggregates counters, or are these actually > independent? >
Yes, they are independent, but sharing the same top level status interrupt. There's no SOC-wide PMU which aggregates these counters. >> + >> +The following section describes the SoC PMU DT node binding. >> + >> +Required properties: >> +- compatible : Shall be "apm,xgene-pmu" for revision 1 or >> + "apm,xgene-pmu-v2" for revision 2. > > That name is very general. Is there not a more specific name for the SOC > PMU? > Beside the ARMv8 core PMU which has the compatible name "arm,armv8-pmuv3", these are all the PMUs in X-Gene SoCs. Also, we are using the same PMU driver across our platforms. I think a general name is what it should be. >> +Required properties for L3C subnode: >> +- compatible : Shall be "apm,xgene-pmu-l3c". >> +- reg : First resource shall be the L3C PMU resource. >> +- index : Instance number of the L3C PMU. >> + >> +Required properties for IOB subnode: >> +- compatible : Shall be "apm,xgene-pmu-iob". >> +- reg : First resource shall be the IOB PMU resource. >> +- index : Instance number of the IOB PMU. >> + >> +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. > > What's the index property useful for? > The index property is used for indicating the physical hardware PMU id. For example, on X-Gene1 there are 4 memory controllers (MC), each of them has its own PMU. The index property tells us which MC a PMU belongs to. The same for MCB/L3C and IOB. > Thanks, > Mark. Thanks, Tai
