[PATCH 2/2] coresight: etm4x: docs: Add documentation for 'ts_source' sysfs interface

German Gomez
2022-04-29T12:33:25Z

Sync sysfs documentation pages to include the new ts_source (timestamp
source) interface.

Signed-off-by: German Gomez <german.gomez@arm.com>
---
.../ABI/testing/sysfs-bus-coresight-devices-etm4x | 8 ++++++++
.../trace/coresight/coresight-etm4x-reference.rst | 14 ++++++++++++++
2 files changed, 22 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index 8e53a32f81505..19ac9d6d2f504 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
@@ -516,3 +516,11 @@ Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (Read) Returns the number of special conditional P1 right-hand keys
that the trace unit can use (0x194). The value is taken
directly from the HW.
+
+What: /sys/bus/coresight/devices/etm<N>/ts_source
+Date: April 2022
+KernelVersion: 5.18
+Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
+Description: (Read) When FEAT_TRF is implemented, value of TRFCR_ELx.TS used for
+ trace session. Otherwise -1 indicates an unknown time source. Check
+ trcidr0.tssize to see if a global timestamp is available.
diff --git a/Documentation/trace/coresight/coresight-etm4x-reference.rst b/Documentation/trace/coresight/coresight-etm4x-reference.rst
index d25dfe86af9bf..f016c7c29429b 100644
--- a/Documentation/trace/coresight/coresight-etm4x-reference.rst
+++ b/Documentation/trace/coresight/coresight-etm4x-reference.rst
@@ -71,6 +71,20 @@ the ‘TRC’ prefix.

----

+:File: ``ts_source`` (ro)
+:Trace Registers: None.
+:Notes:
+ When FEAT_TRF is implemented, value of TRFCR_ELx.TS used for trace session. Otherwise -1
+ indicates an unknown time source. Check trcidr0.tssize to see if a global timestamp is
+ available.
+
+:Example:
+ ``$> cat ts_source``
+
+ ``$> 1``
+
+----
+
:File: ``addr_idx`` (rw)
:Trace Registers: None.