[PATCH v2] v4l: Add source event change for bit-depth

[Stanimir Varbanov]

This event indicate that the source bit-depth is changed during
run-time. The client must get the new format and re-allocate buffers
for it. This can usually happens with video decoder (encoders) when
the bit-stream depth is changed from 8 to 10bits or vice versa.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
---
Change since v1: s/BITDEPTH/BIT_DEPTH

 Documentation/media/uapi/v4l/vidioc-dqevent.rst | 7 +++++++
 Documentation/media/videodev2.h.rst.exceptions  | 1 +
 include/uapi/linux/videodev2.h                  | 1 +
 3 files changed, 9 insertions(+)

diff --git a/Documentation/media/uapi/v4l/vidioc-dqevent.rst b/Documentation/media/uapi/v4l/vidioc-dqevent.rst
index dea9c0cc00ab..f7782cbddc5f 100644
--- a/Documentation/media/uapi/v4l/vidioc-dqevent.rst
+++ b/Documentation/media/uapi/v4l/vidioc-dqevent.rst
@@ -397,6 +397,13 @@ call.
 	that many devices are not able to recover from a temporary loss of
 	signal and so restarting streaming I/O is required in order for the
 	hardware to synchronize to the video signal.
+    * - ``V4L2_EVENT_SRC_CH_BIT_DEPTH``
+      - 0x0002
+      - This event gets triggered when bit-depth change is detected from a
+	video decoder. Applications will have to query the new pixel format
+	and re-negotiate the queue. In most cases the streaming must be stopped
+	and restarted (:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` followed by
+	:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>`).
 
 
 Return Value
diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
index 64d348e67df9..68ae00d7450f 100644
--- a/Documentation/media/videodev2.h.rst.exceptions
+++ b/Documentation/media/videodev2.h.rst.exceptions
@@ -478,6 +478,7 @@ replace define V4L2_EVENT_CTRL_CH_FLAGS ctrl-changes-flags
 replace define V4L2_EVENT_CTRL_CH_RANGE ctrl-changes-flags
 
 replace define V4L2_EVENT_SRC_CH_RESOLUTION src-changes-flags
+replace define V4L2_EVENT_SRC_CH_BIT_DEPTH src-changes-flags
 
 replace define V4L2_EVENT_MD_FL_HAVE_FRAME_SEQ :c:type:`v4l2_event_motion_det`
 
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 1050a75fb7ef..ecfdbaa60b05 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -2287,6 +2287,7 @@ struct v4l2_event_frame_sync {
 };
 
 #define V4L2_EVENT_SRC_CH_RESOLUTION		(1 << 0)
+#define V4L2_EVENT_SRC_CH_BIT_DEPTH		(1 << 1)
 
 struct v4l2_event_src_change {
 	__u32 changes;
-- 
2.17.1