[PATCH v4 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 introduces a standalone "qcom,coresight-agtnoc" compatible
that describes the Aggregator TNOC as a plain platform device. Without
"arm,primecell" the device is created on the platform bus and probes
through the platform driver, 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
new compatible, followed by the per-platform DT fixes that switch the
affected nodes over to it.

- Patch 1 (dt-bindings) converts the compatible to a oneOf and adds the
standalone qcom,coresight-agtnoc form alongside the existing AMBA form,
updates the select block, and adds an example node.
- Patch 2 (driver) adds qcom,coresight-agtnoc 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 standalone Aggregator TNOC is no longer
wrongly covered and correctly allocates a trace ID.
- Patches 3-4 (kaanapali, sm8750) switch the traceNoC nodes from the AMBA
form to the standalone qcom,coresight-agtnoc compatible, fixing the probe
failure on those platforms.
- Patch 5 (glymur) switches the node from qcom,coresight-itnoc to
qcom,coresight-agtnoc. 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 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

---
Jie Gan (5):
      dt-bindings: arm: coresight-tnoc: Add standalone qcom,coresight-agtnoc compatible
      coresight: tnoc: add AG tnoc standalone compatible to the platform driver
      arm64: dts: qcom: kaanapali: fix traceNoC probe issue
      arm64: dts: qcom: sm8750: fix traceNoC probe issue
      arm64: dts: qcom: glymur: use Aggregator TNOC compatible

 .../bindings/arm/qcom,coresight-tnoc.yaml          | 39 ++++++++++++++++++++--
 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, 61 insertions(+), 25 deletions(-)
---
base-commit: 4e5dfb7c84012007c3c7061126491bbc92d71bf1
change-id: 20260624-fix-tracenoc-probe-issue-c6429da28df4

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