[PATCH 19/19] dts: bindings: coresight: ETMv4.4 system register access only units
Suzuki K Poulose
suzuki.poulose at arm.com
Thu Sep 24 05:48:10 EDT 2020
On 09/18/2020 04:35 PM, Mike Leach wrote:
> 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
>> 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.
You're right. I got it confused with the v8.4 SelfHosted Extensions, which
mandates the sysreg access and makes the mem I/O obsolete. How about :
> 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?
I will take a look, haven't played with the yaml.
Thanks for the review !
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