Documentation: trace: Add documentation for TPDM and TPDA

Add documentation for the TPDM and TPDA under trace/coresight.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-9-quic_jinlmao@quicinc.com

Documentation/trace/coresight/coresight-tpda.rst

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+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+The trace performance monitoring and diagnostics aggregator(TPDA).
+==============================
+
+    :Author:   Jinlong Mao <quic_jinlmao@quicinc.com>
+    :Date:     January 2023
+
+Hardware Description
+--------------------
+
+TPDA - The trace performance monitoring and diagnostics aggregator or
+TPDA in short serves as an arbitration and packetization engine for the
+performance monitoring and diagnostics network specification.
+The primary use case of the TPDA is to provide packetization, funneling
+and timestamping of Monitor data.
+
+
+Sysfs files and directories
+---------------------------
+Root: ``/sys/bus/coresight/devices/tpda<N>``
+
+Config details
+---------------------------
+
+The tpdm and tpda nodes should be observed at the coresight path
+"/sys/bus/coresight/devices".
+e.g.
+/sys/bus/coresight/devices # ls -l | grep tpd
+tpda0 -> ../../../devices/platform/soc@0/6004000.tpda/tpda0
+tpdm0 -> ../../../devices/platform/soc@0/6c08000.mm.tpdm/tpdm0
+
+We can use the commands are similar to the below to validate TPDMs.
+Enable coresight sink first. The port of tpda which is connected to
+the tpdm will be enabled after commands below.
+
+echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
+echo 1 > /sys/bus/coresight/devices/tpdm0/enable_source
+echo 1 > /sys/bus/coresight/devices/tpdm0/integration_test
+echo 2 > /sys/bus/coresight/devices/tpdm0/integration_test
+
+The test data will be collected in the coresight sink which is enabled.
+If rwp register of the sink is keeping updating when do
+integration_test (by cat tmc_etf0/mgmt/rwp), it means there is data
+generated from TPDM to sink.
+
+There must be a tpda between tpdm and the sink. When there are some
+other trace event hw components in the same HW block with tpdm, tpdm
+and these hw components will connect to the coresight funnel. When
+there is only tpdm trace hw in the HW block, tpdm will connect to
+tpda directly.

Documentation/trace/coresight/coresight-tpdm.rst

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+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+Trace performance monitoring and diagnostics monitor(TPDM).
+==============================
+
+    :Author:   Jinlong Mao <quic_jinlmao@quicinc.com>
+    :Date:     January 2023
+
+Hardware Description
+--------------------
+TPDM - The trace performance monitoring and diagnostics monitor or TPDM in
+short serves as data collection component for various dataset types.
+The primary use case of the TPDM is to collect data from different data
+sources and send it to a TPDA for packetization, timestamping and funneling.
+
+Sysfs files and directories
+---------------------------
+Root: ``/sys/bus/coresight/devices/tpdm<N>``
+
+----
+
+:File:            ``enable_source`` (RW)
+:Notes:
+    - > 0 : enable the datasets of TPDM.
+
+    - = 0 : disable the datasets of TPDM.
+
+:Syntax:
+    ``echo 1 > enable_source``
+
+----
+
+:File:            ``integration_test`` (wo)
+:Notes:
+    Integration test will generate test data for tpdm.
+
+:Syntax:
+    ``echo value > integration_test``
+
+    value -  1 or 2.
+
+----