media: add V4L2_CTRL_TYPE_AREA control type

This type contains the width and the height of a rectangular area.

Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Ricardo Ribalda Delgado <ribalda@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index fb08838..c9ca867 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -50,6 +50,7 @@ struct poll_table_struct;
  * @p_h264_slice_params:	Pointer to a struct v4l2_ctrl_h264_slice_params.
  * @p_h264_decode_params:	Pointer to a struct v4l2_ctrl_h264_decode_params.
  * @p_vp8_frame_header:		Pointer to a VP8 frame header structure.
+ * @p_area:			Pointer to an area.
  * @p:				Pointer to a compound value.
  */
 union v4l2_ctrl_ptr {
@@ -68,6 +69,7 @@ union v4l2_ctrl_ptr {
 	struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
 	struct v4l2_ctrl_h264_decode_params *p_h264_decode_params;
 	struct v4l2_ctrl_vp8_frame_header *p_vp8_frame_header;
+	struct v4l2_area *p_area;
 	void *p;
 };
 
@@ -1087,6 +1089,46 @@ static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 	return rval;
 }
 
+/**
+ * __v4l2_ctrl_s_ctrl_area() - Unlocked variant of v4l2_ctrl_s_ctrl_area().
+ *
+ * @ctrl:	The control.
+ * @area:	The new area.
+ *
+ * This sets the control's new area safely by going through the control
+ * framework. This function assumes the control's handler is already locked,
+ * allowing it to be used from within the &v4l2_ctrl_ops functions.
+ *
+ * This function is for area type controls only.
+ */
+int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
+			    const struct v4l2_area *area);
+
+/**
+ * v4l2_ctrl_s_ctrl_area() - Helper function to set a control's area value
+ *	 from within a driver.
+ *
+ * @ctrl:	The control.
+ * @area:	The new area.
+ *
+ * This sets the control's new area safely by going through the control
+ * framework. This function will lock the control's handler, so it cannot be
+ * used from within the &v4l2_ctrl_ops functions.
+ *
+ * This function is for area type controls only.
+ */
+static inline int v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
+					const struct v4l2_area *area)
+{
+	int rval;
+
+	v4l2_ctrl_lock(ctrl);
+	rval = __v4l2_ctrl_s_ctrl_area(ctrl, area);
+	v4l2_ctrl_unlock(ctrl);
+
+	return rval;
+}
+
 /* Internal helper functions that deal with control events. */
 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;