On Tue, Jun 20, 2017 at 11:44 AM, Mathieu Poirier
[off-list ref] wrote:

On 18 June 2017 at 08:04, Rob Herring [off-list ref] wrote:

quoted

On Tue, Jun 13, 2017 at 10:55:28AM -0600, Mathieu Poirier wrote:

quoted

On Mon, Jun 12, 2017 at 03:36:40PM +0100, Suzuki K Poulose wrote:

quoted

The Linux coresight drivers define the programmable ATB replicator as
Qualcom replicator, while this is designed by ARM. This can cause confusion
to a user selecting the driver. Cleanup all references to make it
 explicitly clear. This patch :

 1) Adds a new compatible string for the same, retaining the old one for
    compatibility.
 2) Changes the Kconfig symbol (since this is not part of any defconfigs)
     CORESIGHT_QCOM_REPLICATOR => CORESIGHT_DYNAMIC_REPLICATOR
 3) Improves the help message in the Kconfig.
 4) Changes the name of the driver :
    coresight-replicator-qcom => coresight-dynamic-replicator

Cc: Pratik Patel <redacted>
Cc: Ivan T. Ivanov <redacted>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: devicetree at vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Hi Suzuki,

quoted

---
 Documentation/devicetree/bindings/arm/coresight.txt     |  4 +++-
 drivers/hwtracing/coresight/Kconfig                     | 10 +++++-----
 drivers/hwtracing/coresight/Makefile                    |  2 +-
 drivers/hwtracing/coresight/coresight-replicator-qcom.c |  2 +-
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
index fcbae6a..f77329f 100644
--- a/Documentation/devicetree/bindings/arm/coresight.txt
+++ b/Documentation/devicetree/bindings/arm/coresight.txt

@@ -34,7 +34,9 @@ its hardware characteristcs.
            - Embedded Trace Macrocell (version 4.x):
                    "arm,coresight-etm4x", "arm,primecell";

-           - Qualcomm Configurable Replicator (version 1.x):
+           - Coresight programmable Replicator (version 1.x):
+                   "arm,coresight-dynamic-replicator", "arm,primecell";
+                           OR
                    "qcom,coresight-replicator1x", "arm,primecell";

Rob, what's your view on keeping the old binding around?  We could simply change
the two occurences we find in the DTs (Juno and 410c) to the new name and be
done with the old one.

Juno uses the Qcom string? We should keep the old string. You can switch
the dts files, but the driver should support the old name.

When we first started working on CoreSight programmable replicators
were available but the documentation wasn't public.  As such when I
saw Qualcomm's design I mistakenly thought it was a custom IP block
and came up with a compatible string that reflected that reality.
Fast forward 3 years the documentation is available and Juno has used
the same IP block in their design.  Suzuki's patch rectifies history
by changing the programmable replicator naming convention to what it
should have been from the start.

That being said, we can keep the old compatible string around but it
won't change anything.  CoreSight devices are discovered on the AMBA
bus and don't use the compatible string - drivers are probed based on
AMBA IDs laid out in the drivers and device IDs found in HW ID
registers.

In light of the above let me know what you want to do.

Well, if drivers don't use the string, then there is nothing to keep around.

Rob