[PATCH v3 0/11] Add support to configure TPDM DSB subunit

[Tao Zhang]

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 patch series depends on patch series "[PATCH v2 0/9] coresight:
Fix CTI module refcount leak by making it a helper device"
https://patchwork.kernel.org/project/linux-arm-kernel/cover/20230310160610.742382-1-james.clark@arm.com/

TPDM_DSB commit tree:
https://git.codelinaro.org/clo/linux-kernel/coresight/-/tree/tpdm-dsb-v3
https://git.codelinaro.org/clo/linux-kernel/coresight/-/commits/tpdm-dsb-v3

Changes in V3:
1. Move the property "qcom,dsb-element-size" to TPDM
devicetree and update the TPDM yaml file for this item.
-- Suzuki K Poulose
2. Add the error message when the DSB element size is not set to
32-bit or 64-bit. -- Suzuki K Poulose
3. Add more information to the comments of patch #3
-- Suzuki K Poulose
4. Combine the value updates to the TPDM_DSB_CR for TPDM.
-- Suzuki K Poulose
5. Remove the function "tpdm_datasets_alloc", and fold its code
to a new function "tpdm_init_datasets". It will complete the
initialization of TPDM.  -- Suzuki K Poulose
6. Change the method of qualifying input values.
-- Suzuki K Poulose
7. Add the documentation of the new sysfs handles.
-- Suzuki K Poulose
8. Provide the separate handles for the "mode bits".
-- Suzuki K Poulose

Changes in V2:
1. Change the name of the property "qcom,dsb-elem-size" to
"qcom,dsb-element-size" -- Suzuki K Poulose
2. Update the TPDA yaml file for the item "qcom,dsb-elem-size".
-- Krzysztof Kozlowski
3. Add the full name of DSB in the description of the item
"qcom,dsb-elem-size". -- Rob Herring

Changes in V1:
1. Change the definition of the property "qcom,dsb-elem-size" from
"uint32-array" to "uint32-matrix". -- Krzysztof Kozlowski
2. Add the full name of DSB. -- Rob Herring
3. Deal with 2 entries in an iteration in TPDA driver. -- Suzuki K Poulose
4. Divide the function "tpdm_datasets_alloc" into two functions,
"tpdm_datasets_setup" and "tpdm_datasets_alloc".
5. Detecte the input string with the conventional semantics automatically,
and constrain the size of the input value. -- Suzuki K Poulose
6. Use the hook function "is_visible()" to hide the DSB related knobs if
the data sets are missing. -- Suzuki K Poulose
7. Use the macros "FIELD_GET" and "FIELD_PREP" to set the values.
-- Suzuki K Poulose
8. Update the definition of the macros in TPDM driver.
9. Update the comments of the values for the nodes which are for DSB
element creation and onfigure pattern match output. -- Suzuki K Poulose
10. Use API "sysfs_emit" to "replace scnprintf". -- Suzuki K Poulose

Tao Zhang (10):
  dt-bindings: arm: Add support for DSB element size
  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 edge control
  coresight-tpdm: Add nodes to configure pattern match output
  coresight-tpdm: Add nodes for timestamp request
  dt-bindings: arm: Add support for DSB MSR register
  coresight-tpdm: Add nodes for dsb msr support

 .../ABI/testing/sysfs-bus-coresight-devices-tpdm   | 144 +++++
 .../bindings/arm/qcom,coresight-tpdm.yaml          |  21 +
 drivers/hwtracing/coresight/coresight-tpda.c       |  58 ++
 drivers/hwtracing/coresight/coresight-tpda.h       |   4 +
 drivers/hwtracing/coresight/coresight-tpdm.c       | 694 ++++++++++++++++++++-
 drivers/hwtracing/coresight/coresight-tpdm.h       |  69 ++
 6 files changed, 984 insertions(+), 6 deletions(-)

-- 
2.7.4