[PATCH 19/19] dts: bindings: coresight: ETMv4.4 system register access only units

Mike Leach mike.leach at linaro.org
Fri Sep 18 11:35:57 EDT 2020


On Fri, 11 Sep 2020 at 09:41, Suzuki K Poulose <suzuki.poulose at arm.com> wrote:
>
> Document the bindings for ETMv4.4 and later with only system register
> access.
>
> Cc: devicetree at vger.kernel.org
> Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
> Cc: Mike Leach <mike.leach at linaro.org>
> Reviewed-by: Rob Herring <robh at kernel.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
> ---
>  Documentation/devicetree/bindings/arm/coresight.txt | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
> index d711676b4a51..cfe47bdda728 100644
> --- a/Documentation/devicetree/bindings/arm/coresight.txt
> +++ b/Documentation/devicetree/bindings/arm/coresight.txt
> @@ -34,9 +34,13 @@ its hardware characteristcs.
>                                         Program Flow Trace Macrocell:
>                         "arm,coresight-etm3x", "arm,primecell";
>
> -               - Embedded Trace Macrocell (version 4.x):
> +               - Embedded Trace Macrocell (version 4.x), with memory mapped access.
>                         "arm,coresight-etm4x", "arm,primecell";
>
> +               - Embedded Trace Macrocell (version 4.4 and later) with system
> +                 register access only.
> +                       "arm,coresight-etm-v4.4";

Any version of ETM can implement register access - including those pre
ETM 4.4. Perhaps the new name should simply reflect sys reg access
rather than a version.

Given that the two compatibility strings should be mutually exclusive
for a given device, should the bindings doc (or at least the etm4x
component part) be re-written into the .yaml format so that this can
be enforced?

Regards

Mike


> +
>                 - Coresight programmable Replicator :
>                         "arm,coresight-dynamic-replicator", "arm,primecell";
>
> --
> 2.24.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK



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