5 files changed, 101 insertions, 0 deletions

diff --git a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
index 89891adb928a..820f86e8744b 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 +286,23 @@
         </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 an input. This can come from an input connector or
+            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 5c70b616d818..f016254377aa 100644
--- a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
@@ -155,6 +155,26 @@
             </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 input connector.
+               This event requires that the <structfield>id</structfield>
+               matches the input index (when used with a video device node)
+               or the pad index (when used with a subdevice node) 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
+              occurred 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 86dcb5483c42..8761aab99de9 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 be05d019de25..1ab9045e52e3 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 db4aebd8baba..00259d2baa10 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -1764,6 +1764,7 @@ 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 */
@@ -1795,12 +1796,19 @@ 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;