return 0;
 }
 
+static int ar0521_enum_frame_size(struct v4l2_subdev *sd,
+                                 struct v4l2_subdev_state *sd_state,
+                                 struct v4l2_subdev_frame_size_enum *fse)
+{
+       if (fse->index)
+               return -EINVAL;
+
+       if (fse->code != MEDIA_BUS_FMT_SGRBG8_1X8)
+               return -EINVAL;
+
+       fse->min_width = AR0521_WIDTH_MIN;
+       fse->max_width = AR0521_WIDTH_MAX;
+       fse->min_height = AR0521_HEIGHT_MIN;
+       fse->max_height = AR0521_HEIGHT_MAX;
+
+       return 0;
+}
+
 static int ar0521_pre_streamon(struct v4l2_subdev *sd, u32 flags)
 {
        struct ar0521_dev *sensor = to_ar0521_dev(sd);
 
 static const struct v4l2_subdev_pad_ops ar0521_pad_ops = {
        .enum_mbus_code = ar0521_enum_mbus_code,
+       .enum_frame_size = ar0521_enum_frame_size,
        .get_fmt = ar0521_get_fmt,
        .set_fmt = ar0521_set_fmt,
 };