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| author | Hao Zhang <quic_hazha@quicinc.com> | 2023-06-02 16:41:49 +0800 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2023-06-15 08:50:23 +0100 |
| commit | 3b79104f80036231a40ba5d15c3e329985029a0f (patch) | |
| tree | 054a8127fc981778c7bf8293e2992688157ece78 | |
| parent | 5911ff4559e45532c1f67257c5731b5e13f5e7a3 (diff) | |
Documentation: trace: Add documentation for Coresight Dummy Trace
Add documentation for Coresight Dummy Trace under trace/coresight.
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230602084149.40031-4-quic_hazha@quicinc.com
| -rw-r--r-- | Documentation/trace/coresight/coresight-dummy.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst new file mode 100644 index 000000000000..eff7c553ee6c --- /dev/null +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang <quic_hazha@quicinc.com> + :Date: June 2023 + +Introduction +------------ + +The 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. For these devices, a dummy driver is needed to register them as +Coresight devices. The module may also be used to define components that may +not have any programming interfaces, so that paths can be created in the driver. +It provides Coresight API for operations on dummy devices, such as enabling and +disabling them. It also provides the Coresight dummy sink/source paths for +debugging. + +Config details +-------------- + +There are two types of nodes, dummy sink and dummy source. These nodes +are available at ``/sys/bus/coresight/devices``. + +Example output:: + + $ 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 |