* general function
  */
 
-static struct ov772x_priv *to_ov772x(const struct i2c_client *client)
+static struct ov772x_priv *to_ov772x(struct v4l2_subdev *sd)
 {
-       return container_of(i2c_get_clientdata(client), struct ov772x_priv,
-                           subdev);
+       return container_of(sd, struct ov772x_priv, subdev);
 }
 
 static int ov772x_write_array(struct i2c_client        *client,
 static int ov772x_s_stream(struct v4l2_subdev *sd, int enable)
 {
        struct i2c_client *client = v4l2_get_subdevdata(sd);
-       struct ov772x_priv *priv = container_of(sd, struct ov772x_priv, subdev);
+       struct ov772x_priv *priv = to_ov772x(sd);
 
        if (!enable) {
                ov772x_mask_set(client, COM2, SOFT_SLEEP_MODE, SOFT_SLEEP_MODE);
 static int ov772x_g_chip_ident(struct v4l2_subdev *sd,
                               struct v4l2_dbg_chip_ident *id)
 {
-       struct ov772x_priv *priv = container_of(sd, struct ov772x_priv, subdev);
+       struct ov772x_priv *priv = to_ov772x(sd);
 
        id->ident    = priv->model;
        id->revision = 0;
 static int ov772x_g_fmt(struct v4l2_subdev *sd,
                        struct v4l2_mbus_framefmt *mf)
 {
-       struct ov772x_priv *priv = container_of(sd, struct ov772x_priv, subdev);
+       struct ov772x_priv *priv = to_ov772x(sd);
 
        mf->width       = priv->win->width;
        mf->height      = priv->win->height;
 
 static int ov772x_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf)
 {
-       struct ov772x_priv *priv = container_of(sd, struct ov772x_priv, subdev);
+       struct ov772x_priv *priv = to_ov772x(sd);
        const struct ov772x_color_format *cfmt;
        const struct ov772x_win_size *win;
        int ret;
        return 0;
 }
 
-static int ov772x_video_probe(struct i2c_client *client)
+static int ov772x_video_probe(struct ov772x_priv *priv)
 {
-       struct ov772x_priv *priv = to_ov772x(client);
+       struct i2c_client  *client = v4l2_get_subdevdata(&priv->subdev);
        u8                  pid, ver;
        const char         *devname;
        int                 ret;
                goto done;
        }
 
-       ret = ov772x_video_probe(client);
+       ret = ov772x_video_probe(priv);
        if (ret < 0)
                goto done;
 
 
 static int ov772x_remove(struct i2c_client *client)
 {
-       struct ov772x_priv *priv = to_ov772x(client);
+       struct ov772x_priv *priv = to_ov772x(i2c_get_clientdata(client));
 
        v4l2_device_unregister_subdev(&priv->subdev);
        v4l2_ctrl_handler_free(&priv->hdl);