1 files changed, 41 insertions, 17 deletions

diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index ce8da64022b4..121f7aabccd1 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/list.h>
 
+struct backlight_device;
 struct device_node;
 struct drm_connector;
 struct drm_device;
@@ -59,12 +60,18 @@ struct display_timing;
  *
  * To save power when no video data is transmitted, a driver can power down
  * the panel. This is the job of the .unprepare() function.
+ *
+ * Backlight can be handled automatically if configured using
+ * drm_panel_of_backlight(). Then the driver does not need to implement the
+ * functionality to enable/disable backlight.
  */
 struct drm_panel_funcs {
 	/**
 	 * @prepare:
 	 *
 	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
 	 */
 	int (*prepare)(struct drm_panel *panel);
 
@@ -72,6 +79,8 @@ struct drm_panel_funcs {
 	 * @enable:
 	 *
 	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*enable)(struct drm_panel *panel);
 
@@ -79,6 +88,8 @@ struct drm_panel_funcs {
 	 * @disable:
 	 *
 	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
 	 */
 	int (*disable)(struct drm_panel *panel);
 
@@ -86,22 +97,29 @@ 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);
+	int (*get_modes)(struct drm_panel *panel,
+			 struct drm_connector *connector);
 
 	/**
 	 * @get_timings:
 	 *
 	 * 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);
@@ -112,25 +130,22 @@ struct drm_panel_funcs {
  */
 struct drm_panel {
 	/**
-	 * @drm:
-	 *
-	 * DRM device owning the panel.
-	 */
-	struct drm_device *drm;
-
-	/**
-	 * @connector:
+	 * @dev:
 	 *
-	 * DRM connector that the panel is attached to.
+	 * Parent device of the panel.
 	 */
-	struct drm_connector *connector;
+	struct device *dev;
 
 	/**
-	 * @dev:
+	 * @backlight:
 	 *
-	 * Parent device of the panel.
+	 * Backlight device, used to turn on backlight after the call
+	 * to enable(), and to turn off backlight before the call to
+	 * disable().
+	 * backlight is set by drm_panel_of_backlight() and drivers
+	 * shall not assign it.
 	 */
-	struct device *dev;
+	struct backlight_device *backlight;
 
 	/**
 	 * @funcs:
@@ -172,7 +187,7 @@ int drm_panel_unprepare(struct drm_panel *panel);
 int drm_panel_enable(struct drm_panel *panel);
 int drm_panel_disable(struct drm_panel *panel);
 
-int drm_panel_get_modes(struct drm_panel *panel);
+int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
 
 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 struct drm_panel *of_drm_find_panel(const struct device_node *np);
@@ -183,4 +198,13 @@ static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 }
 #endif
 
+#if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
+int drm_panel_of_backlight(struct drm_panel *panel);
+#else
+static inline int drm_panel_of_backlight(struct drm_panel *panel)
+{
+	return 0;
+}
+#endif
+
 #endif