This event indicates that the video device has encountered
a source parameter change during runtime. This can typically be a
resolution change detected by a video decoder OR a format change
detected by an HDMI connector.
This needs to be nofified to the userspace and the application may
be expected to reallocate buffers before proceeding. The application
can subscribe to events on a specific pad or input port which
it is interested in.
Signed-off-by: Arun Kumar K <arun.kk@xxxxxxxxxxx>
---
Documentation/DocBook/media/v4l/vidioc-dqevent.xml | 32 +++++++++++++++++
.../DocBook/media/v4l/vidioc-subscribe-event.xml | 19 +++++++++++
drivers/media/v4l2-core/v4l2-event.c | 36 ++++++++++++++++++++
include/media/v4l2-event.h | 4 +++
include/uapi/linux/videodev2.h | 8 +++++
5 files changed, 99 insertions(+)
diff --git a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
index 89891ad..6afabaa 100644
--- a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
@@ -242,6 +242,22 @@
</tgroup>
</table>
+ <table frame="none" pgwide="1" id="v4l2-event-src-change">
+ <title>struct <structname>v4l2_event_src_change</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>changes</structfield></entry>
+ <entry>
+ A bitmask that tells what has changed. See <xref linkend="src-changes-flags" />.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
<table pgwide="1" frame="none" id="changes-flags">
<title>Changes</title>
<tgroup cols="3">
@@ -270,6 +286,22 @@
</tbody>
</tgroup>
</table>
+
+ <table pgwide="1" frame="none" id="src-changes-flags">
+ <title>Source Changes</title>
+ <tgroup cols="3">
+ &cs-def;
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_EVENT_SRC_CH_RESOLUTION</constant></entry>
+ <entry>0x0001</entry>
+ <entry>This event gets triggered when a resolution change is
+ detected at runtime. This can typically come from a video decoder.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
</refsect1>
<refsect1>
&return-value;
diff --git a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
index 5c70b61..067a0d5 100644
--- a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
@@ -155,6 +155,25 @@
</entry>
</row>
<row>
+ <entry><constant>V4L2_EVENT_SOURCE_CHANGE</constant></entry>
+ <entry>5</entry>
+ <entry>
+ <para>This event is triggered when a source parameter change is
+ detected during runtime by the video device. It can be a
+ runtime resolution change triggered by a video decoder or the
+ format change happening on an HDMI connector.
+ This event requires that the <structfield>id</structfield>
+ matches the pad / input index from which you want to receive
+ events.</para>
+
+ <para>This event has a &v4l2-event-source-change; associated
+ with it. The <structfield>changes</structfield> bitfield denotes
+ what has changed for the subscribed pad. If multiple events
+ occured before application could dequeue them, then the changes
+ will have the ORed value of all the events generated.</para>
+ </entry>
+ </row>
+ <row>
<entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry>
<entry>0x08000000</entry>
<entry>Base event number for driver-private events.</entry>
diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c
index 86dcb54..8761aab 100644
--- a/drivers/media/v4l2-core/v4l2-event.c
+++ b/drivers/media/v4l2-core/v4l2-event.c
@@ -318,3 +318,39 @@ int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
return v4l2_event_unsubscribe(fh, sub);
}
EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe);
+
+static void v4l2_event_src_replace(struct v4l2_event *old,
+ const struct v4l2_event *new)
+{
+ u32 old_changes = old->u.src_change.changes;
+
+ old->u.src_change = new->u.src_change;
+ old->u.src_change.changes |= old_changes;
+}
+
+static void v4l2_event_src_merge(const struct v4l2_event *old,
+ struct v4l2_event *new)
+{
+ new->u.src_change.changes |= old->u.src_change.changes;
+}
+
+static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = {
+ .replace = v4l2_event_src_replace,
+ .merge = v4l2_event_src_merge,
+};
+
+int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
+ const struct v4l2_event_subscription *sub)
+{
+ if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
+ return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe);
+
+int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
+ struct v4l2_fh *fh, struct v4l2_event_subscription *sub)
+{
+ return v4l2_src_change_event_subscribe(fh, sub);
+}
+EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);
diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
index be05d01..1ab9045 100644
--- a/include/media/v4l2-event.h
+++ b/include/media/v4l2-event.h
@@ -132,4 +132,8 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
struct v4l2_event_subscription *sub);
+int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
+ const struct v4l2_event_subscription *sub);
+int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
+ struct v4l2_fh *fh, struct v4l2_event_subscription *sub);
#endif /* V4L2_EVENT_H */
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index ea468ee..b923d91 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -1765,6 +1765,7 @@ struct v4l2_streamparm {
#define V4L2_EVENT_EOS 2
#define V4L2_EVENT_CTRL 3
#define V4L2_EVENT_FRAME_SYNC 4
+#define V4L2_EVENT_SOURCE_CHANGE 5
#define V4L2_EVENT_PRIVATE_START 0x08000000
/* Payload for V4L2_EVENT_VSYNC */
@@ -1796,12 +1797,19 @@ struct v4l2_event_frame_sync {
__u32 frame_sequence;
};
+#define V4L2_EVENT_SRC_CH_RESOLUTION (1 << 0)
+
+struct v4l2_event_src_change {
+ __u32 changes;
+};
+
struct v4l2_event {
__u32 type;
union {
struct v4l2_event_vsync vsync;
struct v4l2_event_ctrl ctrl;
struct v4l2_event_frame_sync frame_sync;
+ struct v4l2_event_src_change src_change;
__u8 data[64];
} u;
__u32 pending;
--
1.7.9.5
--
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