Re: [RFC PATCH 14/14] dts: bindings: coresight: ETMv4.4 system register access only units

From: Mathieu Poirier
Date: Mon Aug 10 2020 - 16:14:35 EST


On Thu, Jul 30, 2020 at 05:38:37PM +0100, Suzuki K Poulose wrote:
> On 07/29/2020 06:20 PM, Mathieu Poirier wrote:
> > On Wed, Jul 22, 2020 at 06:20:40PM +0100, Suzuki K Poulose wrote:
> > > Document the bindings for ETMv4.4 and later with only system register
> > > access.
> > >
> > > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > > Cc: devicetree@xxxxxxxxxxxxxxx
> > > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > > Cc: Mike Leach <mike.leach@xxxxxxxxxx>
> > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > > ---
> > > 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";
> >
> > I would rather call this "arm,coresight-etm-v4.4+" so that the binding's
> > semantic is still relevant when dealing with ETM v4.5 and onward.
>
> AFAIUC, "compatible" stands for something that is compatible with v4.4.
> All v4.4+ versions that are compatible with v4.4 are covered here.

Your position is valid - let's to with what you had.

> Having said that I am fine with "arm,coresight-etm-v4.4+" , if it
> is fine by the DT conventions.
>
> Cheers
> Suzuki