1.. SPDX-License-Identifier: GPL-2.0
2
3=================================================================
4The trace performance monitoring and diagnostics aggregator(TPDA)
5=================================================================
6
7    :Author:   Jinlong Mao <quic_jinlmao@quicinc.com>
8    :Date:     January 2023
9
10Hardware Description
11--------------------
12
13TPDA - The trace performance monitoring and diagnostics aggregator or
14TPDA in short serves as an arbitration and packetization engine for the
15performance monitoring and diagnostics network specification.
16The primary use case of the TPDA is to provide packetization, funneling
17and timestamping of Monitor data.
18
19
20Sysfs files and directories
21---------------------------
22Root: ``/sys/bus/coresight/devices/tpda<N>``
23
24Config details
25---------------------------
26
27The tpdm and tpda nodes should be observed at the coresight path
28"/sys/bus/coresight/devices".
29e.g.
30/sys/bus/coresight/devices # ls -l | grep tpd
31tpda0 -> ../../../devices/platform/soc@0/6004000.tpda/tpda0
32tpdm0 -> ../../../devices/platform/soc@0/6c08000.mm.tpdm/tpdm0
33
34We can use the commands are similar to the below to validate TPDMs.
35Enable coresight sink first. The port of tpda which is connected to
36the tpdm will be enabled after commands below.
37
38echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
39echo 1 > /sys/bus/coresight/devices/tpdm0/enable_source
40echo 1 > /sys/bus/coresight/devices/tpdm0/integration_test
41echo 2 > /sys/bus/coresight/devices/tpdm0/integration_test
42
43The test data will be collected in the coresight sink which is enabled.
44If rwp register of the sink is keeping updating when do
45integration_test (by cat tmc_etf0/mgmt/rwp), it means there is data
46generated from TPDM to sink.
47
48There must be a tpda between tpdm and the sink. When there are some
49other trace event hw components in the same HW block with tpdm, tpdm
50and these hw components will connect to the coresight funnel. When
51there is only tpdm trace hw in the HW block, tpdm will connect to
52tpda directly.
53