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authorHans Verkuil <hans.verkuil@cisco.com>2011-06-07 09:53:37 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-07-27 17:53:20 -0300
commit85724983c4d212c24116d45f6585a1c4ff845dd3 (patch)
treedf40b351ce71f73b99dad597e69b08c5ee1d5c35 /Documentation/DocBook/media/v4l
parentce7275747bd548e0da7425ba0b7edb6f2c7657a2 (diff)
[media] V4L2 spec: document control events
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook/media/v4l')
-rw-r--r--Documentation/DocBook/media/v4l/vidioc-dqevent.xml17
-rw-r--r--Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml142
2 files changed, 157 insertions, 2 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
index 4e0a7cc3081..b8c4f7657d6 100644
--- a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
@@ -81,6 +81,13 @@
</row>
<row>
<entry></entry>
+ <entry>&v4l2-event-ctrl;</entry>
+ <entry><structfield>ctrl</structfield></entry>
+ <entry>Event data for event V4L2_EVENT_CTRL.
+ </entry>
+ </row>
+ <row>
+ <entry></entry>
<entry>__u8</entry>
<entry><structfield>data</structfield>[64]</entry>
<entry>Event data. Defined by the event type. The union
@@ -110,8 +117,16 @@
<entry>Event timestamp.</entry>
</row>
<row>
+ <entry>u32</entry>
+ <entry><structfield>id</structfield></entry>
+ <entry></entry>
+ <entry>The ID associated with the event source. If the event does not
+ have an associated ID (this depends on the event type), then this
+ is 0.</entry>
+ </row>
+ <row>
<entry>__u32</entry>
- <entry><structfield>reserved</structfield>[9]</entry>
+ <entry><structfield>reserved</structfield>[8]</entry>
<entry></entry>
<entry>Reserved for future extensions. Drivers must set
the array to zero.</entry>
diff --git a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
index 8b501791aa6..975f603a42e 100644
--- a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
@@ -64,7 +64,19 @@
</row>
<row>
<entry>__u32</entry>
- <entry><structfield>reserved</structfield>[7]</entry>
+ <entry><structfield>id</structfield></entry>
+ <entry>ID of the event source. If there is no ID associated with
+ the event source, then set this to 0. Whether or not an event
+ needs an ID depends on the event type.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>flags</structfield></entry>
+ <entry>Event flags, see <xref linkend="event-flags" />.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>reserved</structfield>[5]</entry>
<entry>Reserved for future extensions. Drivers and applications
must set the array to zero.</entry>
</row>
@@ -100,6 +112,23 @@
</entry>
</row>
<row>
+ <entry><constant>V4L2_EVENT_CTRL</constant></entry>
+ <entry>3</entry>
+ <entry>This event requires that the <structfield>id</structfield>
+ matches the control ID from which you want to receive events.
+ This event is triggered if the control's value changes, if a
+ button control is pressed or if the control's flags change.
+ This event has &v4l2-event-ctrl; associated with it. This struct
+ contains much of the same information as &v4l2-queryctrl; and
+ &v4l2-control;.
+
+ If the event is generated due to a call to &VIDIOC-S-CTRL; or
+ &VIDIOC-S-EXT-CTRLS;, then the event will not be sent to
+ the file handle that called the ioctl function. This prevents
+ nasty feedback loops.
+ </entry>
+ </row>
+ <row>
<entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry>
<entry>0x08000000</entry>
<entry>Base event number for driver-private events.</entry>
@@ -108,6 +137,23 @@
</tgroup>
</table>
+ <table pgwide="1" frame="none" id="event-flags">
+ <title>Event Flags</title>
+ <tgroup cols="3">
+ &cs-def;
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_EVENT_SUB_FL_SEND_INITIAL</constant></entry>
+ <entry>0x0001</entry>
+ <entry>When this event is subscribed an initial event will be sent
+ containing the current status. This only makes sense for events
+ that are triggered by a status change. Other events will ignore
+ this flag.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
<table frame="none" pgwide="1" id="v4l2-event-vsync">
<title>struct <structname>v4l2_event_vsync</structname></title>
<tgroup cols="3">
@@ -122,6 +168,100 @@
</tgroup>
</table>
+ <table frame="none" pgwide="1" id="v4l2-event-ctrl">
+ <title>struct <structname>v4l2_event_ctrl</structname></title>
+ <tgroup cols="4">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>changes</structfield></entry>
+ <entry></entry>
+ <entry>A bitmask that tells what has changed. See <xref linkend="changes-flags" />.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>type</structfield></entry>
+ <entry></entry>
+ <entry>The type of the control. See &v4l2-ctrl-type;.</entry>
+ </row>
+ <row>
+ <entry>union (anonymous)</entry>
+ <entry></entry>
+ <entry></entry>
+ <entry></entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>__s32</entry>
+ <entry><structfield>value</structfield></entry>
+ <entry>The 32-bit value of the control for 32-bit control types.
+ This is 0 for string controls since the value of a string
+ cannot be passed using &VIDIOC-DQEVENT;.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>__s64</entry>
+ <entry><structfield>value64</structfield></entry>
+ <entry>The 64-bit value of the control for 64-bit control types.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>flags</structfield></entry>
+ <entry></entry>
+ <entry>The control flags. See <xref linkend="control-flags" />.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>minimum</structfield></entry>
+ <entry></entry>
+ <entry>The minimum value of the control. See &v4l2-queryctrl;.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>maximum</structfield></entry>
+ <entry></entry>
+ <entry>The maximum value of the control. See &v4l2-queryctrl;.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>step</structfield></entry>
+ <entry></entry>
+ <entry>The step value of the control. See &v4l2-queryctrl;.</entry>
+ </row>
+ <row>
+ <entry>__s32</entry>
+ <entry><structfield>default_value</structfield></entry>
+ <entry></entry>
+ <entry>The default value value of the control. See &v4l2-queryctrl;.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <table pgwide="1" frame="none" id="changes-flags">
+ <title>Changes</title>
+ <tgroup cols="3">
+ &cs-def;
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_EVENT_CTRL_CH_VALUE</constant></entry>
+ <entry>0x0001</entry>
+ <entry>This control event was triggered because the value of the control
+ changed. Special case: if a button control is pressed, then this
+ event is sent as well, even though there is not explicit value
+ associated with a button control.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_EVENT_CTRL_CH_FLAGS</constant></entry>
+ <entry>0x0002</entry>
+ <entry>This control event was triggered because the control flags
+ changed.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
</refsect1>
</refentry>
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