Many panel drivers duplicate logic to prevent prepare to be called for a panel that is already prepared. Likewise for enable.
Implement this logic in drm_panel so the individual drivers no longer needs this. A panel is considered prepared/enabled only if the prepare/enable call succeeds. For disable/unprepare it is unconditionally considered disabled/unprepared.
This allows calls to prepare/enable again, even if there were some issue disabling a regulator or similar during disable/unprepare.
Signed-off-by: Sam Ravnborg sam@ravnborg.org Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard maxime.ripard@bootlin.com Cc: Sean Paul sean@poorly.run 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 --- drivers/gpu/drm/drm_panel.c | 66 ++++++++++++++++++++++++++++++------- include/drm/drm_panel.h | 21 ++++++++++++ 2 files changed, 75 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index da19d5b4a2f4..0853764040de 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -66,10 +66,21 @@ EXPORT_SYMBOL(drm_panel_init); */ int drm_panel_prepare(struct drm_panel *panel) { - if (panel && panel->funcs && panel->funcs->prepare) - return panel->funcs->prepare(panel); + int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL; + if (!panel) + return -EINVAL; + + if (panel->prepared) + return 0; + + if (panel->funcs && panel->funcs->prepare) + ret = panel->funcs->prepare(panel); + + if (ret >= 0) + panel->prepared = true; + + return ret; } EXPORT_SYMBOL(drm_panel_prepare);
@@ -85,10 +96,21 @@ EXPORT_SYMBOL(drm_panel_prepare); */ int drm_panel_enable(struct drm_panel *panel) { - if (panel && panel->funcs && panel->funcs->enable) - return panel->funcs->enable(panel); + int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL; + if (!panel) + return -EINVAL; + + if (panel->enabled) + return 0; + + if (panel->funcs && panel->funcs->enable) + ret = panel->funcs->enable(panel); + + if (ret >= 0) + panel->enabled = true; + + return ret; } EXPORT_SYMBOL(drm_panel_enable);
@@ -104,10 +126,20 @@ EXPORT_SYMBOL(drm_panel_enable); */ int drm_panel_disable(struct drm_panel *panel) { - if (panel && panel->funcs && panel->funcs->disable) - return panel->funcs->disable(panel); + int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL; + if (!panel) + return -EINVAL; + + if (!panel->enabled) + return 0; + + if (panel->funcs && panel->funcs->disable) + ret = panel->funcs->disable(panel); + + panel->enabled = false; + + return ret; } EXPORT_SYMBOL(drm_panel_disable);
@@ -124,10 +156,20 @@ EXPORT_SYMBOL(drm_panel_disable); */ int drm_panel_unprepare(struct drm_panel *panel) { - if (panel && panel->funcs && panel->funcs->unprepare) - return panel->funcs->unprepare(panel); + int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL; + if (!panel) + return -EINVAL; + + if (!panel->prepared) + return 0; + + if (panel->funcs && panel->funcs->unprepare) + ret = panel->funcs->unprepare(panel); + + panel->prepared = false; + + return ret; } EXPORT_SYMBOL(drm_panel_unprepare);
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 624bd15ecfab..7493500fc9bd 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -65,6 +65,9 @@ struct drm_panel_funcs { * @prepare: * * Turn on panel and perform set up. + * When the panel is successfully prepared the prepare() function + * will not be called again until the panel has been unprepared. + * */ int (*prepare)(struct drm_panel *panel);
@@ -72,6 +75,8 @@ struct drm_panel_funcs { * @enable: * * Enable panel (turn on back light, etc.). + * When the panel is successfully enabled the enable() function + * will not be called again until the panel has been disabled. */ int (*enable)(struct drm_panel *panel);
@@ -79,6 +84,7 @@ struct drm_panel_funcs { * @disable: * * Disable panel (turn off back light, etc.). + * If the panel is already disabled the disable() function is not called. */ int (*disable)(struct drm_panel *panel);
@@ -86,6 +92,7 @@ struct drm_panel_funcs { * @unprepare: * * Turn off panel. + * If the panel is already unprepared the unprepare() function is not called. */ int (*unprepare)(struct drm_panel *panel);
@@ -145,6 +152,20 @@ struct drm_panel { * Panel entry in registry. */ struct list_head list; + + /** + * @prepared: + * + * Set to true when the panel is successfully prepared. + */ + bool prepared; + + /** + * @enabled: + * + * Set to true when the panel is successfully enabled. + */ + bool enabled; };
void drm_panel_init(struct drm_panel *panel);