Mathieu, Suzuki,
Fixed per you suggestions.
Thanks
Mike
On Mon, 2 Dec 2019 at 10:43, Suzuki Kuruppassery Poulose suzuki.poulose@arm.com wrote:
On 19/11/2019 23:19, Mike Leach wrote:
Add new document covering CTI / CTM usage in CoreSight.
Add section in coresight.rst introducing CTI and CTM modules with link to new document.
Signed-off-by: Mike Leach mike.leach@linaro.org
.../trace/coresight/coresight-ect.rst | 200 ++++++++++++++++++ Documentation/trace/coresight/coresight.rst | 13 ++ 2 files changed, 213 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-ect.rst
diff --git a/Documentation/trace/coresight/coresight-ect.rst b/Documentation/trace/coresight/coresight-ect.rst new file mode 100644 index 000000000000..6448cf910f20 --- /dev/null +++ b/Documentation/trace/coresight/coresight-ect.rst @@ -0,0 +1,200 @@ +============================================= +CoreSight Embedded Cross Trigger (CTI & CTM). +=============================================
- :Author: Mike Leach mike.leach@linaro.org
- :Date: November 2019
...
+Channels API Directory +~~~~~~~~~~~~~~~~~~~~~~
+This provides an easy way to attach triggers to channels, without needing +the multiple register operations that are required if manipluating the +'regs' sub-dir elements directly.
+A number of files provide this API::
- chan_clear chan_inuse chan_xtrigs_view trigin_detach
- chan_free chan_pulse chan_xtrigs_view_sel trigout_attach
- chan_gate_disable chan_set trig_filter_enable trigout_detach
- chan_gate_enable chan_xtrigs_reset trigin_attach trigout_filtered
+Most access to these elements take the form::
- echo <chan> [<trigger>] > /<device_path>/<operation>
+where the optional <trigger> is only needed for trigXX_attach | detach +operations.
+e.g.::
+Attaches trigout(1) to channel(0), then activates channel(0) generating a +set state on cti_sys0.trigout(1)
+*API operations*
- ``trigin_attach, trigout_attach``: Attach a channel to a trigger signal.
- ``trigin_detach, trigout_detach``: Detach a channel from a trigger signal.
- ``chan_set``: Set the channel - the set state will be propogated around
the CTM to other connected devices.
- ``chan_clear``: Clear the channel.
- ``chan_pulse``: Set the channel for a single CoreSight clock cycle.
- ``chan_gate_enable``: Write operation sets the CTI gate to propagate
(enable) the channel to other devices. This operation takes a channelnumber. CTI gate is enabled for all channels by default at power up. Readto list the currently enabled channels on the gate.
- ``chan_gate_disable``: Write channel number to disable gate for that
channel.
- ``chan_inuse``: Show the current channels attached to any signal
- ``chan_free``: Show channels with no attached signals.
- ``chan_xtrig_view``: write a channel number to select a channel to view,
read to show the cross triggers programmed for the selected channel.
- ``trig_filter_enable``: Defaults to enabled, disable to allow potentially
dangerous output signals to be set.
- ``trigout_filtered``: Trigger out signals that are prevented from being
set if filtering ``trig_filter_enable`` is enabled. One use is to preventaccidental ``EDBGREQ`` signals stopping a core.
- ``chan_xtrigs_reset``: Write 1 to clear all channel / trigger programming.
Resets device hardware to default state.+e.g.::
- .../cti_sys0/channels# echo 2 1 > trigin_attach
- .../cti_sys0/channels# echo 2 6 > trigout_attach
minor nit: It may be a good idea to add a comment to describe what you are doing with the above operations, to avoid looking up and mapping it for someone looking it up. I am not too keen, but it is definitely helpful.
- .../cti_sys0/channels# cat chan_free
- 0-1,3
- .../cti_sys0/channels# cat chan_inuse
- 2
- .../cti_sys0/channels# echo 2 > chan_xtrigs_view
- .../cti_sys0/channels# cat chan_xtrigs_view
- [2] IN: 1 OUT: 6
- .../cti_sys0/# echo 1 > enable
- .../cti_sys0/channels# echo 2 > chan_set
- .../cti_sys0/channels# cat ../regs/choutstatus
- 0x4
- .../cti_sys0/channels# cat ../regs/trigoutstatus
- 0x40
- .../cti_sys0/channels# echo 2 > chan_clear
- .../cti_sys0/channels# cat ../regs/trigoutstatus
- 0x0
- .../cti_sys0/channels# cat ../regs/trigoutstatus
- 0x0
nit: duplicate lines ?
Otherwise:
Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com