struct drm_mode_config_funcs — basic driver provided mode setting functions
struct drm_mode_config_funcs {
  struct drm_framebuffer *(* fb_create) (struct drm_device *dev,struct drm_file *file_priv,struct drm_mode_fb_cmd2 *mode_cmd);
  void (* output_poll_changed) (struct drm_device *dev);
  int (* atomic_check) (struct drm_device *dev,struct drm_atomic_state *a);
  int (* atomic_commit) (struct drm_device *dev,struct drm_atomic_state *a,bool async);
  struct drm_atomic_state *(* atomic_state_alloc) (struct drm_device *dev);
  void (* atomic_state_clear) (struct drm_atomic_state *state);
  void (* atomic_state_free) (struct drm_atomic_state *state);
};  create a new framebuffer object
function to handle output configuration changes
check whether a given atomic state update is possible
   commit an atomic state update previously verified with
   atomic_check
      
allocate a new atomic state
clear the atomic state
free the atomic state