Re: [PATCH v5 7/7] dt-bindings: Document devicetree binding for ARM SPE

From: Mark Rutland
Date: Mon Oct 02 2017 - 06:08:37 EST


On Thu, Sep 28, 2017 at 03:09:51PM +0100, Will Deacon wrote:
> This patch documents the devicetree binding in use for ARM SPE.
>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
> ---
> Documentation/devicetree/bindings/arm/spe-pmu.txt | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/spe-pmu.txt
>
> diff --git a/Documentation/devicetree/bindings/arm/spe-pmu.txt b/Documentation/devicetree/bindings/arm/spe-pmu.txt
> new file mode 100644
> index 000000000000..93372f2a7df9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/spe-pmu.txt
> @@ -0,0 +1,20 @@
> +* ARMv8.2 Statistical Profiling Extension (SPE) Performance Monitor Units (PMU)
> +
> +ARMv8.2 introduces the optional Statistical Profiling Extension for collecting
> +performance sample data using an in-memory trace buffer.

It might make sense to comment that even if described in the DT, a
higher exception level may disallow access (discoverable via
PMBIDR_EL1).

Either way:

Acked-by: Mark Rutland <mark.rutland@xxxxxxx>

As a nit, this should've come before the driver, as per
Documentation/devicetree/bindings/submitting-patches.txt, but thanks for
splitting as its own patch.

Thanks,
Mark.

> +
> +** SPE Required properties:
> +
> +- compatible : should be one of:
> + "arm,statistical-profiling-extension-v1"
> +
> +- interrupts : Exactly 1 PPI must be listed. For heterogeneous systems where
> + SPE is only supported on a subset of the CPUs, please consult
> + the arm,gic-v3 binding for details on describing a PPI partition.
> +
> +** Example:
> +
> +spe-pmu {
> + compatible = "arm,statistical-profiling-extension-v1";
> + interrupts = <GIC_PPI 05 IRQ_TYPE_LEVEL_HIGH &part1>;
> +};
> --
> 2.1.4
>