[PATCH] drivers: CCI: add ARM CCI PMU support
Stephen Warren
swarren at wwwdotorg.org
Wed Aug 14 17:06:26 EDT 2013
On 07/23/2013 03:19 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.
> diff --git a/Documentation/devicetree/bindings/arm/cci.txt b/Documentation/devicetree/bindings/arm/cci.txt
> + - CCI PMU node
> +
> + Node name must be "pmu".
I don't think the binding should require the node to have a particular
name; node names shouldn't be interpret/used/relied-upon by drivers.
> + 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"
What is the first entry in this list for; why wouldn't you always use
one of the two versioned compatible values?
The use of , before revN is a little unusual; I would have expected
arm,cci-400-pmu-rev0, but this isn't a big deal.
> + - interrupts:
> + Usage: required
> + Value type: <prop-encoded-array>
> + Definition: comma-separated list of unique PMU
> + interrupts
Is there more than one interrupt? The text seems to imply that. If so,
what are they, and which order must they appear?
More information about the linux-arm-kernel
mailing list