/*
   * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sub license,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial portions
   * of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  #ifndef __DRM_PANEL_H__
  #define __DRM_PANEL_H__

  #include <linux/err.h>

  #include <linux/errno.h>

  #include <linux/list.h>

  struct backlight_device;

  struct device_node;

  struct drm_connector;
  struct drm_device;
  struct drm_panel;

  struct display_timing;

  enum drm_panel_orientation;

  /**
   * struct drm_panel_funcs - perform operations on a given panel

   *
   * The .prepare() function is typically called before the display controller
   * starts to transmit video data. Panel drivers can use this to turn the panel
   * on and wait for it to become ready. If additional configuration is required
   * (via a control bus such as I2C, SPI or DSI for example) this is a good time
   * to do that.
   *
   * After the display controller has started transmitting video data, it's safe
   * to call the .enable() function. This will typically enable the backlight to
   * make the image on screen visible. Some panels require a certain amount of
   * time or frames before the image is displayed. This function is responsible
   * for taking this into account before enabling the backlight to avoid visual
   * glitches.
   *
   * Before stopping video transmission from the display controller it can be
   * necessary to turn off the panel to avoid visual glitches. This is done in
   * the .disable() function. Analogously to .enable() this typically involves
   * turning off the backlight and waiting for some time to make sure no image
   * is visible on the panel. It is then safe for the display controller to
   * cease transmission of video data.
   *
   * 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);

  
  	/**
  	 * @enable:
  	 *
  	 * Enable panel (turn on back light, etc.).

  	 *
  	 * This function is optional.

  	 */

  	int (*enable)(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_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);

  };

  /**
   * struct drm_panel - DRM panel object

   */

  struct drm_panel {

  	/**

  	 * @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() 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;
  };

  void drm_panel_init(struct drm_panel *panel, struct device *dev,

  		    const struct drm_panel_funcs *funcs,
  		    int connector_type);

  void drm_panel_add(struct drm_panel *panel);

  void drm_panel_remove(struct drm_panel *panel);

  int drm_panel_prepare(struct drm_panel *panel);
  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, 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 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 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

  #endif