[PATCH v4 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace
From: Hao Zhang <hidden>
Date: 2023-05-05 09:25:48
Also in:
linux-arm-msm, linux-devicetree, linux-doc, lkml
Subsystem:
arm/coresight framework and drivers, documentation, the rest, tracing · Maintainers:
Suzuki K Poulose, Jonathan Corbet, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Add documentation for Coresight Dummy Trace under trace/coresight. Signed-off-by: Hao Zhang <redacted> --- .../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..7cb59f080c88
--- /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@quicinc.com> + :Date: May 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 + dummy_sink0 -> ../../../devices/platform/soc@0/soc@0:sink/dummy_sink0 + dummy_source0 -> ../../../devices/platform/soc@0/soc@0:source/dummy_source0
--
2.17.1
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