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

From: Suzuki Kuruppassery Poulose
Date: Mon Nov 21 2022 - 05:21:46 EST


On 21/11/2022 08:21, 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 series applies to coresight/next
https://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git?h=next

Does it ?

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@xxxxxxxxxxx/


And the CoreSight Dynamice Trace ID series too.

Change log please

Suzuki