[PATCH v7 0/5] Fix traceNoC probe issue on multiple QCOM platforms

[Jie Gan]

The CoreSight TNOC (Trace Network-On-Chip) binding so far only allowed the
two-string AMBA form "qcom,coresight-tnoc", "arm,primecell". That form
forces the device onto the AMBA bus, where the driver must read the
peripheral ID from the device registers during probe. On several QCOM
platforms this AMBA peripheral-ID probing fails, so the traceNoC device
never probes and its trace path is unavailable.

This series drops the "arm,primecell" entry and turns "qcom,coresight-tnoc"
into a standalone platform compatible. Without "arm,primecell" the device
is created on the platform bus and probes through the platform driver by
compatible string, bypassing the AMBA peripheral-ID read while remaining a
fully functional Aggregator TNOC that allocates a system trace ID (ATID).

The series is organized as: binding first, then the driver support for the
platform-bus compatible, followed by the per-platform DT fixes that switch
the affected nodes over to it.

- Patch 1 (dt-bindings) drops "arm,primecell" and makes
"qcom,coresight-tnoc" a single standalone compatible, and updates the
example node accordingly.
- Patch 2 (driver) adds "qcom,coresight-tnoc" to the platform driver's
match table and renames the itnoc-specific names to generic tnoc names,
since the platform driver now serves both the Interconnect and Aggregator
TNOC. It also restricts the ATID-unsupported handling to
"qcom,coresight-itnoc" only, so the Aggregator TNOC on the platform bus is
no longer wrongly covered and correctly allocates a trace ID.
- Patches 3-4 (kaanapali, sm8750) drop the "arm,primecell" entry on the
traceNoC nodes and use the standalone "qcom,coresight-tnoc" compatible,
fixing the probe failure on those platforms.
- Patch 5 (glymur) switches the node from "qcom,coresight-itnoc" to
"qcom,coresight-tnoc". This node is actually an Aggregator TNOC (its
tn_ag_* endpoints show aggregation), so it should expose a system trace
ID rather than being treated as an Interconnect TNOC.

Signed-off-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
---
Changes in v7:
- rebased on next-20261109 
- collect reviewed-by tags.
- Link to v6: https://lore.kernel.org/all/20260710-fix-tracenoc-probe-issue-v6-0-41eb36fef8d9@xxxxxxxxxxxxxxxx/

Changes in v6:
- update commit message for all commits to focus on describe the
  hardware itself and the hardware issue we are facing on.
- Link to v5: https://lore.kernel.org/r/20260707-fix-tracenoc-probe-issue-v5-0-bf733ed9ebd0@xxxxxxxxxxxxxxxx

Changes in v5:
- Drop the separate "qcom,coresight-agtnoc" compatible. Instead drop the
  "arm,primecell" entry and reuse the existing "qcom,coresight-tnoc" as a
  standalone platform compatible.
- Update the binding, driver match table, and per-platform DT nodes to the
  standalone "qcom,coresight-tnoc" compatible accordingly.
- Rewrite the commit messages to describe dropping "arm,primecell" and
  binding on the platform bus.
- Link to v4: https://lore.kernel.org/r/20260701-fix-tracenoc-probe-issue-v4-0-aefab449a470@xxxxxxxxxxxxxxxx

Changes in v4:
- rewrite the commit message for the patch 3 - patch 5.
- free the allocated ATID in remove path.
- Link to v3: https://lore.kernel.org/r/20260630-fix-tracenoc-probe-issue-v3-0-7201e1841e94@xxxxxxxxxxxxxxxx

Changes in v3:
- add standalone compatible for AG traceNoC device, allow it to be
  probed with platform driver.
- add fix patches for sm8750 and Glymur platforms
- Link to v2: https://lore.kernel.org/r/20260624-fix-tracenoc-probe-issue-v2-0-786520f62f21@xxxxxxxxxxxxxxxx

Changes in v2:
- address the ATID issue reported by Sashiko.
- update binding to accept arm,primecell-periphid property.
- Link to v1: https://lore.kernel.org/r/20260624-fix-tracenoc-probe-issue-v1-1-bcc785198fc5@xxxxxxxxxxxxxxxx

To: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
To: Mike Leach <mike.leach@xxxxxxx>
To: James Clark <james.clark@xxxxxxxxxx>
To: Leo Yan <leo.yan@xxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Tingwei Zhang <tingwei.zhang@xxxxxxxxxxxxxxxx>
To: Yuanfang Zhang <yuanfang.zhang@xxxxxxxxxxxxxxxx>
To: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
To: Bjorn Andersson <andersson@xxxxxxxxxx>
To: Konrad Dybcio <konradybcio@xxxxxxxxxx>
To: Abel Vesa <abelvesa@xxxxxxxxxx>
To: Jingyi Wang <jingyi.wang@xxxxxxxxxxxxxxxx>
Cc: linux-arm-msm@xxxxxxxxxxxxxxx
Cc: coresight@xxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
Signed-off-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>

---
Jie Gan (5):
      dt-bindings: arm: coresight-tnoc: Bind on platform bus instead of AMBA
      coresight: tnoc: Bind Aggregator TNOC on the platform bus
      arm64: dts: qcom: kaanapali: bind traceNoC on the platform bus
      arm64: dts: qcom: sm8750: bind traceNoC on the platform bus
      arm64: dts: qcom: glymur: use Aggregator TNOC compatible

 .../bindings/arm/qcom,coresight-tnoc.yaml          | 16 ++--------
 arch/arm64/boot/dts/qcom/glymur.dtsi               |  6 ++--
 arch/arm64/boot/dts/qcom/kaanapali.dtsi            |  2 +-
 arch/arm64/boot/dts/qcom/sm8750.dtsi               |  2 +-
 drivers/hwtracing/coresight/coresight-tnoc.c       | 37 ++++++++++++----------
 5 files changed, 27 insertions(+), 36 deletions(-)
---
base-commit: 630059a5a632377b9b7b487baccde92b7ae1dd47
change-id: 20261110-fix-trace-noc-probe-issue-e75c5a649fd9

Best regards,
-- 
Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>