Re: [PATCH v4 00/11] Add support to configure TPDM DSB subunit

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 27/04/2023 10:00, Tao Zhang wrote:
> 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@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/patch/20230425143542.2305069-14-james.clark@arm.com/

There is v6 available for the above and there may be changes in the data
structures. But the series is stable now, and may be you could cordinate
with James and repost the series at rc1 ?

Suzuki