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From: Mike Leach <mike.leach@linaro.org>
To: Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>
Cc: Coresight ML <coresight@lists.linaro.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	devicetree@vger.kernel.org,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>
Subject: Re: [PATCH v5 13/14] docs: coresight: Update documentation for CoreSight to cover CTI.
Date: Fri, 6 Dec 2019 17:39:27 +0000	[thread overview]
Message-ID: <CAJ9a7VjUmDA6Sx2CQzttXnptSJDVhobiSj_8z5ez_SFMC7L14Q@mail.gmail.com> (raw)
In-Reply-To: <1076b0e3-6b50-7be9-0a25-cb003bd77674@arm.com>

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::
> > +
> > +   >$ ls ./cti_sys0/channels/
> > +   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.::
> > +
> > +   >$ echo 0 1 > ./cti_sys0/channels/trigout_attach
> > +   >$ echo 0 > ./cti_sys0/channels/chan_set
> > +
> > +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 channel
> > +     number. CTI gate is enabled for all channels by default at power up. Read
> > +     to 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 prevent
> > +     accidental ``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>



-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK

  reply	other threads:[~2019-12-06 17:39 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-19 23:18 [PATCH v5 00/14] CoreSight CTI Driver Mike Leach
2019-11-19 23:18 ` [PATCH v5 01/14] coresight: cti: Initial " Mike Leach
2019-11-21 20:21   ` Mathieu Poirier
2019-11-29 12:05     ` Mike Leach
2019-12-03 16:53       ` Mathieu Poirier
2019-11-25 19:03   ` Suzuki Kuruppassery Poulose
2019-11-29 12:06     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 02/14] coresight: cti: Add sysfs coresight mgmt reg access Mike Leach
2019-11-22 17:19   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 03/14] coresight: cti: Add sysfs access to program function regs Mike Leach
2019-11-27 18:26   ` Suzuki Kuruppassery Poulose
2019-11-29 12:47     ` Mike Leach
2019-11-28 10:54   ` Suzuki Kuruppassery Poulose
2019-11-28 17:20     ` Mathieu Poirier
2019-11-28 18:00       ` Suzuki Kuruppassery Poulose
2019-11-29 12:50     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 04/14] coresight: cti: Add sysfs trigger / channel programming API Mike Leach
2019-11-22 18:40   ` Mathieu Poirier
2019-11-27 18:40   ` Suzuki Kuruppassery Poulose
2019-11-29 13:01     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 05/14] dt-bindings: arm: Adds CoreSight CTI hardware definitions Mike Leach
2019-11-20 19:06   ` Mathieu Poirier
2019-11-20 22:39     ` Mike Leach
2019-11-22 23:33   ` Rob Herring
2019-11-29 13:50     ` Mike Leach
2019-11-29 14:12       ` Suzuki Kuruppassery Poulose
2019-11-28 18:38   ` Suzuki Kuruppassery Poulose
2019-11-29 13:57     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 06/14] coresight: cti: Add device tree support for v8 arch CTI Mike Leach
2019-11-25 19:00   ` Mathieu Poirier
2019-11-29 11:33   ` Suzuki Kuruppassery Poulose
2019-12-03 10:59     ` Mike Leach
2019-12-03 11:28       ` Suzuki Kuruppassery Poulose
2019-12-03 12:25         ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 07/14] coresight: cti: Add device tree support for custom CTI Mike Leach
2019-11-25 21:22   ` Mathieu Poirier
2019-11-29 14:16     ` Suzuki Kuruppassery Poulose
2019-11-29 21:11       ` Mathieu Poirier
2019-11-29 14:18   ` Suzuki Kuruppassery Poulose
2019-12-03 14:05     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 08/14] coresight: cti: Enable CTI associated with devices Mike Leach
2019-11-25 22:45   ` Mathieu Poirier
2019-12-05 16:33     ` Mike Leach
2019-11-29 18:28   ` Suzuki Kuruppassery Poulose
2019-11-29 21:25     ` Mathieu Poirier
2019-12-05 16:33     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 09/14] coresight: cti: Add connection information to sysfs Mike Leach
2019-11-27 18:09   ` Mathieu Poirier
2019-12-06 16:24     ` Mike Leach
2019-12-02  9:47   ` Suzuki Kuruppassery Poulose
2019-12-06 16:24     ` Mike Leach
2019-11-19 23:19 ` [PATCH v5 10/14] dt-bindings: qcom: Add CTI options for qcom msm8916 Mike Leach
2019-11-27 18:18   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 11/14] dt-bindings: arm: Juno platform - add CTI entries to device tree Mike Leach
2019-11-27 18:25   ` Mathieu Poirier
2019-11-19 23:19 ` [PATCH v5 12/14] dt-bindings: hisilicon: Add CTI bindings for hi-6220 Mike Leach
2019-11-19 23:19 ` [PATCH v5 13/14] docs: coresight: Update documentation for CoreSight to cover CTI Mike Leach
2019-11-27 19:00   ` Mathieu Poirier
2019-12-02 10:43   ` Suzuki Kuruppassery Poulose
2019-12-06 17:39     ` Mike Leach [this message]
2019-11-19 23:19 ` [PATCH v5 14/14] docs: sysfs: coresight: Add sysfs ABI documentation for CTI Mike Leach
2019-11-27 19:08   ` Mathieu Poirier

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