[media] v4l2-ctrls: Use v4l2_subscribed_event_ops

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[hans.verkuil@cisco.com: Fix a locking bug]
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 91b1978..ae544d8 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -2424,9 +2424,13 @@
 }
 EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);
 
-void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
-				struct v4l2_subscribed_event *sev)
+static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev)
 {
+	struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
+
+	if (ctrl == NULL)
+		return -EINVAL;
+
 	v4l2_ctrl_lock(ctrl);
 	list_add_tail(&sev->node, &ctrl->ev_subs);
 	if (ctrl->type != V4L2_CTRL_TYPE_CTRL_CLASS &&
@@ -2440,17 +2444,40 @@
 		v4l2_event_queue_fh(sev->fh, &ev);
 	}
 	v4l2_ctrl_unlock(ctrl);
+	return 0;
 }
-EXPORT_SYMBOL(v4l2_ctrl_add_event);
 
-void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
-				struct v4l2_subscribed_event *sev)
+static void v4l2_ctrl_del_event(struct v4l2_subscribed_event *sev)
 {
+	struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
+
 	v4l2_ctrl_lock(ctrl);
 	list_del(&sev->node);
 	v4l2_ctrl_unlock(ctrl);
 }
-EXPORT_SYMBOL(v4l2_ctrl_del_event);
+
+void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new)
+{
+	u32 old_changes = old->u.ctrl.changes;
+
+	old->u.ctrl = new->u.ctrl;
+	old->u.ctrl.changes |= old_changes;
+}
+EXPORT_SYMBOL(v4l2_ctrl_replace);
+
+void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new)
+{
+	new->u.ctrl.changes |= old->u.ctrl.changes;
+}
+EXPORT_SYMBOL(v4l2_ctrl_merge);
+
+const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops = {
+	.add = v4l2_ctrl_add_event,
+	.del = v4l2_ctrl_del_event,
+	.replace = v4l2_ctrl_replace,
+	.merge = v4l2_ctrl_merge,
+};
+EXPORT_SYMBOL(v4l2_ctrl_sub_ev_ops);
 
 int v4l2_ctrl_log_status(struct file *file, void *fh)
 {
@@ -2468,7 +2495,7 @@
 				struct v4l2_event_subscription *sub)
 {
 	if (sub->type == V4L2_EVENT_CTRL)
-		return v4l2_event_subscribe(fh, sub, 0, NULL);
+		return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
 	return -EINVAL;
 }
 EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);