1 files changed, 291 insertions, 102 deletions

diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 14ac240a1f64..2407bfa60236 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -24,25 +24,24 @@
 #ifndef __DRM_PANEL_H__
 #define __DRM_PANEL_H__
 
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/kref.h>
 
+struct backlight_device;
+struct dentry;
 struct device_node;
 struct drm_connector;
-struct drm_device;
+struct drm_panel_follower;
 struct drm_panel;
 struct display_timing;
 
+enum drm_panel_orientation;
+
 /**
  * struct drm_panel_funcs - perform operations on a given panel
- * @disable: disable panel (turn off back light, etc.)
- * @unprepare: turn off panel
- * @prepare: turn on panel and perform set up
- * @enable: enable panel (turn on back light, etc.)
- * @get_modes: add modes to the connector that the panel is attached to and
- * return the number of modes added
- * @get_timings: copy display timings into the provided array and return
- * the number of display timings available
  *
  * The .prepare() function is typically called before the display controller
  * starts to transmit video data. Panel drivers can use this to turn the panel
@@ -66,140 +65,330 @@ 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() or drm_panel_dp_aux_backlight(). Then the driver
+ * does not need to implement the functionality to enable/disable backlight.
  */
 struct drm_panel_funcs {
-	int (*disable)(struct drm_panel *panel);
-	int (*unprepare)(struct drm_panel *panel);
+	/**
+	 * @prepare:
+	 *
+	 * Turn on panel and perform set up.
+	 *
+	 * This function is optional.
+	 */
 	int (*prepare)(struct drm_panel *panel);
+
+	/**
+	 * @enable:
+	 *
+	 * Enable panel (turn on back light, etc.).
+	 *
+	 * This function is optional.
+	 */
 	int (*enable)(struct drm_panel *panel);
-	int (*get_modes)(struct drm_panel *panel);
+
+	/**
+	 * @disable:
+	 *
+	 * Disable panel (turn off back light, etc.).
+	 *
+	 * This function is optional.
+	 */
+	int (*disable)(struct drm_panel *panel);
+
+	/**
+	 * @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 returns the number of modes added.
+	 *
+	 * This function is mandatory.
+	 */
+	int (*get_modes)(struct drm_panel *panel,
+			 struct drm_connector *connector);
+
+	/**
+	 * @get_orientation:
+	 *
+	 * Return the panel orientation set by device tree or EDID.
+	 *
+	 * This function is optional.
+	 */
+	enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);
+
+	/**
+	 * @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);
+
+	/**
+	 * @debugfs_init:
+	 *
+	 * Allows panels to create panels-specific debugfs files.
+	 */
+	void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);
+};
+
+struct drm_panel_follower_funcs {
+	/**
+	 * @panel_prepared:
+	 *
+	 * Called after the panel has been powered on.
+	 */
+	int (*panel_prepared)(struct drm_panel_follower *follower);
+
+	/**
+	 * @panel_unpreparing:
+	 *
+	 * Called before the panel is powered off.
+	 */
+	int (*panel_unpreparing)(struct drm_panel_follower *follower);
+
+	/**
+	 * @panel_enabled:
+	 *
+	 * Called after the panel and the backlight have been enabled.
+	 */
+	int (*panel_enabled)(struct drm_panel_follower *follower);
+
+	/**
+	 * @panel_disabling:
+	 *
+	 * Called before the panel and the backlight are disabled.
+	 */
+	int (*panel_disabling)(struct drm_panel_follower *follower);
+};
+
+struct drm_panel_follower {
+	/**
+	 * @funcs:
+	 *
+	 * Dependent device callbacks; should be initted by the caller.
+	 */
+	const struct drm_panel_follower_funcs *funcs;
+
+	/**
+	 * @list
+	 *
+	 * Used for linking into panel's list; set by drm_panel_add_follower().
+	 */
+	struct list_head list;
+
+	/**
+	 * @panel
+	 *
+	 * The panel we're dependent on; set by drm_panel_add_follower().
+	 */
+	struct drm_panel *panel;
 };
 
 /**
  * struct drm_panel - DRM panel object
- * @drm: DRM device owning the panel
- * @connector: DRM connector that the panel is attached to
- * @dev: parent device of the panel
- * @funcs: operations that can be performed on the panel
- * @list: panel entry in registry
  */
 struct drm_panel {
-	struct drm_device *drm;
-	struct drm_connector *connector;
+	/**
+	 * @dev:
+	 *
+	 * Parent device of the panel.
+	 */
 	struct device *dev;
 
+	/**
+	 * @backlight:
+	 *
+	 * 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() or
+	 * drm_panel_dp_aux_backlight() and drivers shall not assign it.
+	 */
+	struct backlight_device *backlight;
+
+	/**
+	 * @funcs:
+	 *
+	 * Operations that can be performed on the panel.
+	 */
 	const struct drm_panel_funcs *funcs;
 
+	/**
+	 * @connector_type:
+	 *
+	 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
+	 * initialise the drm_connector corresponding to the panel with the
+	 * correct connector type.
+	 */
+	int connector_type;
+
+	/**
+	 * @list:
+	 *
+	 * Panel entry in registry.
+	 */
 	struct list_head list;
-};
 
-/**
- * drm_disable_unprepare - power off a panel
- * @panel: DRM panel
- *
- * Calling this function will completely power off a panel (assert the panel's
- * reset, turn off power supplies, ...). After this function has completed, it
- * is usually no longer possible to communicate with the panel until another
- * call to drm_panel_prepare().
- *
- * Return: 0 on success or a negative error code on failure.
- */
-static inline int drm_panel_unprepare(struct drm_panel *panel)
-{
-	if (panel && panel->funcs && panel->funcs->unprepare)
-		return panel->funcs->unprepare(panel);
+	/**
+	 * @followers:
+	 *
+	 * A list of struct drm_panel_follower dependent on this panel.
+	 */
+	struct list_head followers;
 
-	return panel ? -ENOSYS : -EINVAL;
-}
+	/**
+	 * @follower_lock:
+	 *
+	 * Lock for followers list.
+	 */
+	struct mutex follower_lock;
 
-/**
- * drm_panel_disable - disable a panel
- * @panel: DRM panel
- *
- * This will typically turn off the panel's backlight or disable the display
- * drivers. For smart panels it should still be possible to communicate with
- * the integrated circuitry via any command bus after this call.
- *
- * Return: 0 on success or a negative error code on failure.
- */
-static inline int drm_panel_disable(struct drm_panel *panel)
-{
-	if (panel && panel->funcs && panel->funcs->disable)
-		return panel->funcs->disable(panel);
+	/**
+	 * @prepare_prev_first:
+	 *
+	 * The previous controller should be prepared first, before the prepare
+	 * for the panel is called. This is largely required for DSI panels
+	 * where the DSI host controller should be initialised to LP-11 before
+	 * the panel is powered up.
+	 */
+	bool prepare_prev_first;
 
-	return panel ? -ENOSYS : -EINVAL;
-}
+	/**
+	 * @prepared:
+	 *
+	 * If true then the panel has been prepared.
+	 */
+	bool prepared;
 
-/**
- * drm_panel_prepare - power on a panel
- * @panel: DRM panel
- *
- * Calling this function will enable power and deassert any reset signals to
- * the panel. After this has completed it is possible to communicate with any
- * integrated circuitry via a command bus.
- *
- * Return: 0 on success or a negative error code on failure.
- */
-static inline int drm_panel_prepare(struct drm_panel *panel)
-{
-	if (panel && panel->funcs && panel->funcs->prepare)
-		return panel->funcs->prepare(panel);
+	/**
+	 * @enabled:
+	 *
+	 * If true then the panel has been enabled.
+	 */
+	bool enabled;
 
-	return panel ? -ENOSYS : -EINVAL;
-}
+	/**
+	 * @container: Pointer to the private driver struct embedding this
+	 * @struct drm_panel.
+	 */
+	void *container;
 
-/**
- * drm_panel_enable - enable a panel
- * @panel: DRM panel
- *
- * Calling this function will cause the panel display drivers to be turned on
- * and the backlight to be enabled. Content will be visible on screen after
- * this call completes.
- *
- * Return: 0 on success or a negative error code on failure.
- */
-static inline int drm_panel_enable(struct drm_panel *panel)
-{
-	if (panel && panel->funcs && panel->funcs->enable)
-		return panel->funcs->enable(panel);
+	/**
+	 * @refcount: reference count of users referencing this panel.
+	 */
+	struct kref refcount;
+};
 
-	return panel ? -ENOSYS : -EINVAL;
-}
+void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset,
+			     const struct drm_panel_funcs *funcs,
+			     int connector_type);
 
 /**
- * drm_panel_get_modes - probe the available display modes of a panel
- * @panel: DRM panel
+ * devm_drm_panel_alloc - Allocate and initialize a refcounted panel.
  *
- * The modes probed from the panel are automatically added to the connector
- * that the panel is attached to.
+ * @dev: struct device of the panel device
+ * @type: the type of the struct which contains struct &drm_panel
+ * @member: the name of the &drm_panel within @type
+ * @funcs: callbacks for this panel
+ * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
+ * the panel interface
  *
- * Return: The number of modes available from the panel on success or a
- * negative error code on failure.
+ * The reference count of the returned panel is initialized to 1. This
+ * reference will be automatically dropped via devm (by calling
+ * drm_panel_put()) when @dev is removed.
+ *
+ * Returns:
+ * Pointer to container structure embedding the panel, ERR_PTR on failure.
  */
-static inline int drm_panel_get_modes(struct drm_panel *panel)
-{
-	if (panel && panel->funcs && panel->funcs->get_modes)
-		return panel->funcs->get_modes(panel);
+#define devm_drm_panel_alloc(dev, type, member, funcs, connector_type) \
+	((type *)__devm_drm_panel_alloc(dev, sizeof(type), \
+					offsetof(type, member), funcs, \
+					connector_type))
 
-	return panel ? -ENOSYS : -EINVAL;
-}
+void drm_panel_init(struct drm_panel *panel, struct device *dev,
+		    const struct drm_panel_funcs *funcs,
+		    int connector_type);
 
-void drm_panel_init(struct drm_panel *panel);
+struct drm_panel *drm_panel_get(struct drm_panel *panel);
+void drm_panel_put(struct drm_panel *panel);
 
-int drm_panel_add(struct drm_panel *panel);
+void drm_panel_add(struct drm_panel *panel);
 void drm_panel_remove(struct drm_panel *panel);
 
-int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
-int drm_panel_detach(struct drm_panel *panel);
+void drm_panel_prepare(struct drm_panel *panel);
+void drm_panel_unprepare(struct drm_panel *panel);
+
+void drm_panel_enable(struct drm_panel *panel);
+void drm_panel_disable(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);
+int of_drm_get_panel_orientation(const struct device_node *np,
+				 enum drm_panel_orientation *orientation);
 #else
 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 {
-	return NULL;
+	return ERR_PTR(-ENODEV);
+}
+
+static inline int of_drm_get_panel_orientation(const struct device_node *np,
+					       enum drm_panel_orientation *orientation)
+{
+	return -ENODEV;
+}
+#endif
+
+#if defined(CONFIG_DRM_PANEL)
+bool drm_is_panel_follower(struct device *dev);
+int drm_panel_add_follower(struct device *follower_dev,
+			   struct drm_panel_follower *follower);
+void drm_panel_remove_follower(struct drm_panel_follower *follower);
+int devm_drm_panel_add_follower(struct device *follower_dev,
+				struct drm_panel_follower *follower);
+#else
+static inline bool drm_is_panel_follower(struct device *dev)
+{
+	return false;
+}
+
+static inline int drm_panel_add_follower(struct device *follower_dev,
+					 struct drm_panel_follower *follower)
+{
+	return -ENODEV;
+}
+
+static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { }
+static inline int devm_drm_panel_add_follower(struct device *follower_dev,
+					      struct drm_panel_follower *follower)
+{
+	return -ENODEV;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
+	(IS_MODULE(CONFIG_DRM) && IS_MODULE(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