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Commit 95b0137f authored by Noralf Trønnes's avatar Noralf Trønnes
Browse files

drm/fb-helper: Update DOC with new helpers 



Promote new helpers for dealing with fbdev emulation.

Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171215175119.36181-5-noralf@tronnes.org
parent ee05baa0

drivers/gpu/drm/drm_fb_helper.c

+16 −12
Original line number Diff line number Diff line
@@ -66,19 +66,23 @@ static DEFINE_MUTEX(kernel_fb_helper_lock); 
 * helper functions used by many drivers to implement the kernel mode setting

 * interfaces.

 *

 * Initialization is done as a four-step process with drm_fb_helper_prepare(),

 * drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and

 * drm_fb_helper_initial_config(). Drivers with fancier requirements than the

 * default behaviour can override the third step with their own code.

 * Teardown is done with drm_fb_helper_fini() after the fbdev device is

 * unregisters using drm_fb_helper_unregister_fbi().

 *

 * At runtime drivers should restore the fbdev console by calling

 * drm_fb_helper_restore_fbdev_mode_unlocked() from their &drm_driver.lastclose

 * callback.  They should also notify the fb helper code from updates to the

 * output configuration by calling drm_fb_helper_hotplug_event(). For easier

 * integration with the output polling code in drm_crtc_helper.c the modeset

 * code provides a &drm_mode_config_funcs.output_poll_changed callback.

 * Setup fbdev emulation by calling drm_fb_helper_fbdev_setup() and tear it

 * down by calling drm_fb_helper_fbdev_teardown().

 *

 * Drivers that need to handle connector hotplugging (e.g. dp mst) can't use

 * the setup helper and will need to do the whole four-step setup process with

 * drm_fb_helper_prepare(), drm_fb_helper_init(),

 * drm_fb_helper_single_add_all_connectors(), enable hotplugging and

 * drm_fb_helper_initial_config() to avoid a possible race window.

 *

 * At runtime drivers should restore the fbdev console by using

 * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.

 * They should also notify the fb helper code from updates to the output

 * configuration by using drm_fb_helper_output_poll_changed() as their

 * &drm_mode_config_funcs.output_poll_changed callback.

 *

 * For suspend/resume consider using drm_mode_config_helper_suspend() and

 * drm_mode_config_helper_resume() which takes care of fbdev as well.

 *

 * All other functions exported by the fb helper library can be used to

 * implement the fbdev driver interface by the driver.