[PATCH 3/7] media: i2c: ov7251: Add control event support

[Antoine Pichot <antoine.pichot@gmail.com>]

The driver exposes writable controls on its subdev node but does not
support control events, so VIDIOC_SUBSCRIBE_EVENT fails and
v4l2-compliance reports:

  fail: v4l2-test-controls.cpp(1128): subscribe event for control
  'User Controls' failed
  test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: FAIL

Set V4L2_SUBDEV_FL_HAS_EVENTS and use the standard control event
helpers, as other sensor drivers do.

Signed-off-by: Antoine Pichot <antoine.pichot@gmail.com>
---
 drivers/media/i2c/ov7251.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
index 8dad747f77..917285a62d 100644
--- a/drivers/media/i2c/ov7251.c
+++ b/drivers/media/i2c/ov7251.c
@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
@@ -1471,6 +1472,11 @@ static int ov7251_set_frame_interval(struct v4l2_subdev *subdev,
 	return ret;
 }
 
+static const struct v4l2_subdev_core_ops ov7251_core_ops = {
+	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
 static const struct v4l2_subdev_video_ops ov7251_video_ops = {
 	.s_stream = ov7251_s_stream,
 };
@@ -1487,6 +1493,7 @@ static const struct v4l2_subdev_pad_ops ov7251_subdev_pad_ops = {
 };
 
 static const struct v4l2_subdev_ops ov7251_subdev_ops = {
+	.core = &ov7251_core_ops,
 	.video = &ov7251_video_ops,
 	.pad = &ov7251_subdev_pad_ops,
 };
@@ -1717,7 +1724,8 @@ static int ov7251_probe(struct i2c_client *client)
 
 	v4l2_i2c_subdev_init(&ov7251->sd, client, &ov7251_subdev_ops);
 	ov7251->sd.internal_ops = &ov7251_internal_ops;
-	ov7251->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	ov7251->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+			    V4L2_SUBDEV_FL_HAS_EVENTS;
 	ov7251->pad.flags = MEDIA_PAD_FL_SOURCE;
 	ov7251->sd.dev = &client->dev;
 	ov7251->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
-- 
2.53.0