On Sat, Apr 22, 2023 at 03:37:14PM +0800, Hao Zhang wrote: > +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 The wording confuses me, so I have to make the improv: ---- >8 ---- diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst index 7cb59f080c8892..f0a92669288b0c 100644 --- a/Documentation/trace/coresight/coresight-dummy.rst +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -8,27 +8,25 @@ Coresight Dummy Trace Module :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. +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 (e.g, static links), 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. The nodes -should be observed at the below coresight path:: +There are two types of nodes, dummy sink and dummy source. These nodes +are available at ``/sys/bus/coresight/devices``. - ``/sys/bus/coresight/devices``. +Example output:: -e.g.:: - - / $ ls -l /sys/bus/coresight/devices | grep dummy + $ 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 Thanks. -- An old man doll... just what I always wanted! - Clara
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