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
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 (2): dt-bindings: arm: Add qcom,qmi-id for remote etm coresight: Add remote etm support
.../arm/qcom,coresight-remote-etm.yaml | 10 + drivers/hwtracing/coresight/Kconfig | 13 + drivers/hwtracing/coresight/Makefile | 1 + drivers/hwtracing/coresight/coresight-qmi.h | 89 +++++ .../coresight/coresight-remote-etm.c | 307 ++++++++++++++++++ 5 files changed, 420 insertions(+) create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c