Add documentation for Coresight Dummy Trace under trace/coresight. Signed-off-by: Hao Zhang <quic_hazha@xxxxxxxxxxx> --- .../trace/coresight/coresight-dummy.rst | 34 +++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-dummy.rst diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst new file mode 100644 index 000000000000..d0f73253f694 --- /dev/null +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -0,0 +1,34 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang <quic_hazha@xxxxxxxxxxx> + :Date: April 2023 + +Introduction +--------------------------- + +Coresight Dummy Trace Module is for the specific devices that kernel +don't have permission to access or configure, e.g., CoreSight TPDMs +on Qualcomm platforms. So there need driver to register dummy devices +as Coresight devices. It may also be used to define components that +may not have any programming interfaces (e.g, static links), so that +paths can be established in the driver. Provide Coresight API for +dummy device operations, such as enabling and disabling dummy devices. +Build the Coresight path for dummy sink or dummy source for debugging. + +Config details +--------------------------- + +There are two types of nodes, dummy sink and dummy source. The nodes +should be observed at the below coresight path:: + + ``/sys/bus/coresight/devices``. + +e.g.:: + + / $ ls -l /sys/bus/coresight/devices | grep dummy + dummy0 -> ../../../devices/platform/soc@0/soc@0:dummy_source/dummy0 + dummy1 -> ../../../devices/platform/soc@0/soc@0:dummy_sink/dummy1 -- 2.17.1
