[PATCH v5 0/5] coresight: Add remote etm support

Mao Jinlong quic_jinlmao at quicinc.com
Thu Apr 24 04:58:49 PDT 2025


The system on chip (SoC) consists of main APSS(Applications processor
subsytem) and additional processors like modem, lpass. There is
coresight-etm driver for etm trace of APSS. Coresight remote etm driver
is for enabling and disabling the etm trace of remote processors.
It uses QMI interface to communicate with remote processors' software
and uses coresight framework to configure the connection from remote
etm source to TMC sinks.

Example to capture the remote etm trace:

Enable source:
echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
echo 1 > /sys/bus/coresight/devices/remote_etm0/enable_source

Capture the trace:
cat /dev/tmc_etf0 > /data/remote_etm.bin

Disable source:
echo 0 > /sys/bus/coresight/devices/remote_etm0/enable_source

Changes since V4:
1. Add coresight QMI driver
2. Add coresight qmi node and qcom,qmi-id of modem-etm in msm8996 dtsi

Changes since V3:
1. Use different compatible for different remote etms in dt.
2. Get qmi instance id from the match table data in driver.

Change since V2:
1. Change qcom,inst-id to qcom,qmi-id
2. Fix the error in code for type of remote_etm_remove
3. Depend on QMI helper in Kconfig

Changes since V1:
1. Remove unused content
2. Use CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS as remote etm source type.
3. Use enabled instead of enable in driver data.
4. Validate instance id value where it's read from the DT.

Mao Jinlong (5):
  dt-bindings: arm: Add CoreSight QMI component description
  coresight: Add coresight QMI driver
  dt-bindings: arm: Add qcom,qmi-id for remote etm
  coresight: Add remote etm support
  arm64: dts: qcom: msm8996: Add coresight qmi node

 .../bindings/arm/qcom,coresight-qmi.yaml      |  65 +++++
 .../arm/qcom,coresight-remote-etm.yaml        |  10 +
 arch/arm64/boot/dts/qcom/msm8996.dtsi         |  11 +
 drivers/hwtracing/coresight/Kconfig           |  24 ++
 drivers/hwtracing/coresight/Makefile          |   2 +
 drivers/hwtracing/coresight/coresight-qmi.c   | 209 +++++++++++++++
 drivers/hwtracing/coresight/coresight-qmi.h   | 107 ++++++++
 .../coresight/coresight-remote-etm.c          | 252 ++++++++++++++++++
 8 files changed, 680 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.c
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h
 create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c

-- 
2.25.1




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