On Aug 15, 2013, at 4:10 AM, Punit Agrawal wrote: > Hi Kumar, > > Thanks for a review of the bindings. > > On 14/08/13 22:03, Kumar Gala wrote: >> >> On Jul 23, 2013, at 4:19 AM, Punit Agrawal wrote: >> >>> The CCI PMU can profile bus transactions at the master and slave >>> interfaces of the CCI. The PMU can be used to observe an aggregated view >>> of the bus traffic between the various components connected to the CCI. >>> >>> Extend the existing CCI driver to support the PMU by registering a perf >>> backend for it. >>> >>> Document the device tree binding to describe the CCI PMU. >>> >>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> >>> Cc: Nicolas Pitre <nico@xxxxxxxxxx> >>> Cc: Dave Martin <dave.martin@xxxxxxxxxx> >>> Cc: Rob Herring <rob.herring@xxxxxxxxxxx> >>> Cc: Will Deacon <will.deacon@xxxxxxx> >>> Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx> >>> Reviewed-by: Will Deacon <will.deacon@xxxxxxx> >>> --- >>> Documentation/devicetree/bindings/arm/cci.txt | 38 ++ >>> drivers/bus/arm-cci.c | 642 +++++++++++++++++++++++++ >>> 2 files changed, 680 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/arm/cci.txt b/Documentation/devicetree/bindings/arm/cci.txt >>> index 92d36e2..5bc95e5 100644 >>> --- a/Documentation/devicetree/bindings/arm/cci.txt >>> +++ b/Documentation/devicetree/bindings/arm/cci.txt >>> @@ -79,6 +79,34 @@ specific to ARM. >>> corresponding interface programming >>> registers. >>> >>> + - CCI PMU node >>> + >>> + Node name must be "pmu". >>> + Parent node must be CCI interconnect node. >>> + >>> + A CCI pmu node must contain the following properties: >>> + >>> + - compatible >>> + Usage: required >>> + Value type: <string> >>> + Definition: must be set to one of >>> + "arm,cci-400-pmu" >>> + "arm,cci-400-pmu,rev0" >>> + "arm,cci-400-pmu,rev1" >> >> Do you really mean only one? Seems like ""arm,cci-400-pmu,rev0", "arm,cci-400-pmu" would be valid. >> > > Hmm... yes both would be valid. But... > > The event numbering scheme changed between Rev 0 and Rev 1 of the CCI. If the revision is specified then it is used to get the event ranges to validate the events. If not, i.e., "arm,cci-400-pmu" is used, then the driver tries to find the the revision by reading the peripheral id registers. > > I was trying to make the bindings robust in the face of change in behaviour between different revisons of the IP. If there is a periph id register why bother with the device tree having different version info in it? - k -- Employee of Qualcomm Innovation Center, Inc. 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
