Commit 5dce87a9 authored by Sam Ravnborg's avatar Sam Ravnborg
Browse files

drm/drm_panel: no error when no callback 



The callbacks in drm_panel_funcs are optional, so do not
return an error just because no callback is assigned.

v2:
- Document what functions in drm_panel_funcs are optional (Laurent)
- Return -EOPNOTSUPP if get_modes() is not assigned (Laurent)
  (Sam: -EOPNOTSUPP seems to best error code in this situation)

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191207140353.23967-2-sam@ravnborg.org
parent 4286dc07

drivers/gpu/drm/drm_panel.c

+25 −10
Original line number Diff line number Diff line
@@ -151,10 +151,13 @@ EXPORT_SYMBOL(drm_panel_detach); 
 */

int drm_panel_prepare(struct drm_panel *panel)

{

	if (panel && panel->funcs && panel->funcs->prepare)

	if (!panel)

		return -EINVAL;



	if (panel->funcs && panel->funcs->prepare)

		return panel->funcs->prepare(panel);



	return panel ? -ENOSYS : -EINVAL;

	return 0;

}

EXPORT_SYMBOL(drm_panel_prepare);
@@ -171,10 +174,13 @@ EXPORT_SYMBOL(drm_panel_prepare); 
 */

int drm_panel_unprepare(struct drm_panel *panel)

{

	if (panel && panel->funcs && panel->funcs->unprepare)

	if (!panel)

		return -EINVAL;



	if (panel->funcs && panel->funcs->unprepare)

		return panel->funcs->unprepare(panel);



	return panel ? -ENOSYS : -EINVAL;

	return 0;

}

EXPORT_SYMBOL(drm_panel_unprepare);
@@ -190,10 +196,13 @@ EXPORT_SYMBOL(drm_panel_unprepare); 
 */

int drm_panel_enable(struct drm_panel *panel)

{

	if (panel && panel->funcs && panel->funcs->enable)

	if (!panel)

		return -EINVAL;



	if (panel->funcs && panel->funcs->enable)

		return panel->funcs->enable(panel);



	return panel ? -ENOSYS : -EINVAL;

	return 0;

}

EXPORT_SYMBOL(drm_panel_enable);
@@ -209,10 +218,13 @@ EXPORT_SYMBOL(drm_panel_enable); 
 */

int drm_panel_disable(struct drm_panel *panel)

{

	if (panel && panel->funcs && panel->funcs->disable)

	if (!panel)

		return -EINVAL;



	if (panel->funcs && panel->funcs->disable)

		return panel->funcs->disable(panel);



	return panel ? -ENOSYS : -EINVAL;

	return 0;

}

EXPORT_SYMBOL(drm_panel_disable);
@@ -228,10 +240,13 @@ EXPORT_SYMBOL(drm_panel_disable); 
 */

int drm_panel_get_modes(struct drm_panel *panel)

{

	if (panel && panel->funcs && panel->funcs->get_modes)

	if (!panel)

		return -EINVAL;



	if (panel->funcs && panel->funcs->get_modes)

		return panel->funcs->get_modes(panel);



	return panel ? -ENOSYS : -EINVAL;

	return -EOPNOTSUPP;

}

EXPORT_SYMBOL(drm_panel_get_modes);

include/drm/drm_panel.h

+14 −2
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ struct drm_panel_funcs { 
	 * @prepare:

	 *

	 * Turn on panel and perform set up.

	 *

	 * This function is optional.

	 */

	int (*prepare)(struct drm_panel *panel);
@@ -72,6 +74,8 @@ struct drm_panel_funcs { 
	 * @enable:

	 *

	 * Enable panel (turn on back light, etc.).

	 *

	 * This function is optional.

	 */

	int (*enable)(struct drm_panel *panel);
@@ -79,6 +83,8 @@ struct drm_panel_funcs { 
	 * @disable:

	 *

	 * Disable panel (turn off back light, etc.).

	 *

	 * This function is optional.

	 */

	int (*disable)(struct drm_panel *panel);
@@ -86,14 +92,18 @@ struct drm_panel_funcs { 
	 * @unprepare:

	 *

	 * Turn off panel.

	 *

	 * This function is optional.

	 */

	int (*unprepare)(struct drm_panel *panel);



	/**

	 * @get_modes:

	 *

	 * Add modes to the connector that the panel is attached to and

	 * return the number of modes added.

	 * Add modes to the connector that the panel is attached to

	 * and returns the number of modes added.

	 *

	 * This function is mandatory.

	 */

	int (*get_modes)(struct drm_panel *panel);
@@ -102,6 +112,8 @@ struct drm_panel_funcs { 
	 *

	 * Copy display timings into the provided array and return

	 * the number of display timings available.

	 *

	 * This function is optional.

	 */

	int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,

			   struct display_timing *timings);

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