Some HW has static trace id which cannot be changed via software programming. For this case, configure the trace id in device tree with "arm,trace-id = <xxx>", and call coresight_trace_id_get_system_id with the trace id value in device probe function. The id will be reserved for the HW all the time if the device is probed. Changes since V2: 1. Change "trace-id" to "arm,trace-id". 2. Add trace id flag for getting preferred id or ODD id. Changes since V1: 1. Add argument to coresight_trace_id_get_system_id for preferred id instead of adding new function coresight_trace_id_reserve_system_id. 2. Add constraint to trace-id in dt-binding file. Mao Jinlong (3): dt-bindings: arm: Add arm,trace-id for coresight dummy source coresight: Add support to get preferred id for system trace sources coresight: dummy: Add reserve atid support for dummy source .../sysfs-bus-coresight-devices-dummy-source | 15 +++++ .../arm/arm,coresight-dummy-source.yaml | 6 ++ drivers/hwtracing/coresight/coresight-dummy.c | 59 +++++++++++++++++-- .../hwtracing/coresight/coresight-platform.c | 25 ++++++++ drivers/hwtracing/coresight/coresight-stm.c | 2 +- drivers/hwtracing/coresight/coresight-tpda.c | 2 +- .../hwtracing/coresight/coresight-trace-id.c | 35 +++++++---- .../hwtracing/coresight/coresight-trace-id.h | 11 +++- include/linux/coresight.h | 1 + 9 files changed, 137 insertions(+), 19 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source -- 2.41.0