[PATCH v1 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace
From: Hao Zhang <hidden>
Date: 2023-03-16 03:24:19
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 | 58 +++++++++++++++++++ 1 file changed, 58 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..819cabab8623
--- /dev/null
+++ b/Documentation/trace/coresight/coresight-dummy.rst@@ -0,0 +1,58 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang <quic_hazha@quicinc.com> + :Date: March 2023 + +Introduction +--------------------------- + +Coresight Dummy Trace Module is for the specific devices that HLOS don't +have permission to access or configure. Such as Coresight sink EUD, some +TPDMs etc. So there need driver to register dummy devices as Coresight +devices. 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. + +Sysfs files and directories +--------------------------- + +Root: ``/sys/bus/coresight/devices/dummy<N>`` + +---- + +:File: ``enable_source`` (RW) +:Notes: + - > 0 : enable the datasets of dummy source. + + - = 0 : disable the datasets of dummy source. + +:Syntax: + ``echo 1 > enable_source`` + +---- + +:File: ``enable_sink`` (RW) +:Notes: + - > 0 : enable the datasets of dummy sink. + + - = 0 : disable the datasets of dummy sink. + +:Syntax: + ``echo 1 > enable_sink`` + +---- + +Config details +--------------------------- + +There are two types of nodes, dummy sink and dummy source. The nodes +should be observed at the coresight path +"/sys/bus/coresight/devices". +e.g. +/sys/bus/coresight/devices # ls -l | 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
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