[PATCH v1 0/9] Add support to configure TPDM DSB subunit

Tao Zhang quic_taozha at quicinc.com
Mon Nov 21 00:21:04 PST 2022


Introduction of TPDM DSB subunit
DSB subunit is responsible for creating a dataset element, and is also
optionally responsible for packing it to fit multiple elements on a
single ATB transfer if possible in the configuration. The TPDM Core
Datapath requests timestamps be stored by the TPDA and then delivering
ATB sized data (depending on ATB width and element size, this could
be smaller or larger than a dataset element) to the ATB Mast FSM.

The DSB subunit must be configured prior to enablement. This series
adds support for TPDM to configure the configure DSB subunit.

Once this series patches are applied properly, the new tpdm nodes for
should be observed at the tpdm path /sys/bus/coresight/devices/tpdm*
which supports DSB subunit.
e.g.
/sys/devices/platform/soc at 0/69d0000.tpdm/tpdm0#ls -l | grep dsb
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_edge_ctrl
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_edge_ctrl_mask
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_mode
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_patt_mask
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_patt_ts
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_patt_type
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_patt_val
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_trig_patt_mask
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_trig_patt_val
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_trig_ts
-rw-r--r--    1 root     root      4096 Jan  1 00:01 dsb_trig_type

We can use the commands are similar to the below to configure the
TPDMs which support DSB subunit. Enable coresight sink first.
echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
echo 1 > /sys/bus/coresight/devices/tpdm0/reset
echo 0x3 0x3 0x1 > /sys/bus/coresight/devices/tpdm0/dsb_edge_ctrl_mask
echo 0x6d 0x6d 0 > /sys/bus/coresight/devices/tpdm0/dsb_edge_ctrl
echo 1 > /sys/bus/coresight/devices/tpdm0/dsb_patt_ts
echo 1 > /sys/bus/coresight/devices/tpdm0/dsb_patt_type
echo 0 > /sys/bus/coresight/devices/tpdm0/dsb_trig_ts
echo 0 0xFFFFFFFF > /sys/bus/coresight/devices/tpdm0/dsb_patt_mask
echo 0 0xFFFFFFFF > /sys/bus/coresight/devices/tpdm0/dsb_trig_patt_val

This series applies to coresight/next
https://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git?h=next

This patch series depends on patch series "[v12,0/9] Coresight: Add
support for TPDM and TPDA"
https://patchwork.kernel.org/project/linux-arm-kernel/cover/20221114144027.14365-1-quic_jinlmao@quicinc.com/

Tao Zhang (9):
  dt-bindings: arm: Add support for DSB element
  coresight-tpda: Add DSB dataset support
  coresight-tpdm: Initialize DSB subunit configuration
  coresight-tpdm: Add reset node to TPDM node
  coresight-tpdm: Add nodes to set trigger timestamp and type
  coresight-tpdm: Add node to set dsb programming mode
  coresight-tpdm: Add nodes for dsb element creation
  coresight-tpdm: Add nodes to configure pattern match output
  coresight-tpdm: Add nodes for timestamp request

 .../bindings/arm/qcom,coresight-tpda.yaml          |   9 +
 drivers/hwtracing/coresight/coresight-tpda.c       |  62 ++
 drivers/hwtracing/coresight/coresight-tpda.h       |   4 +
 drivers/hwtracing/coresight/coresight-tpdm.c       | 630 ++++++++++++++++++++-
 drivers/hwtracing/coresight/coresight-tpdm.h       |  65 +++
 5 files changed, 765 insertions(+), 5 deletions(-)

-- 
2.7.4




More information about the linux-arm-kernel mailing list