/*
   * Copyright (c) 2016 Intel Corporation
   *
   * Permission to use, copy, modify, distribute, and sell this software and its
   * documentation for any purpose is hereby granted without fee, provided that
   * the above copyright notice appear in all copies and that both that copyright
   * notice and this permission notice appear in supporting documentation, and
   * that the name of the copyright holders not be used in advertising or
   * publicity pertaining to distribution of the software without specific,
   * written prior permission.  The copyright holders make no representations
   * about the suitability of this software for any purpose.  It is provided "as
   * is" without express or implied warranty.
   *
   * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
   * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
   * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
   * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
   * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   * OF THIS SOFTWARE.
   */
  
  #ifndef __DRM_FRAMEBUFFER_H__
  #define __DRM_FRAMEBUFFER_H__

  #include <linux/ctype.h>

  #include <linux/list.h>
  #include <linux/sched.h>

  #include <drm/drm_mode_object.h>

  struct drm_clip_rect;

  struct drm_device;

  struct drm_file;

  struct drm_format_info;

  struct drm_framebuffer;
  struct drm_gem_object;

  
  /**
   * struct drm_framebuffer_funcs - framebuffer hooks
   */
  struct drm_framebuffer_funcs {
  	/**
  	 * @destroy:
  	 *
  	 * Clean up framebuffer resources, specifically also unreference the
  	 * backing storage. The core guarantees to call this function for every

  	 * framebuffer successfully created by calling
  	 * &drm_mode_config_funcs.fb_create. Drivers must also call

  	 * drm_framebuffer_cleanup() to release DRM core resources for this
  	 * framebuffer.
  	 */
  	void (*destroy)(struct drm_framebuffer *framebuffer);
  
  	/**
  	 * @create_handle:
  	 *
  	 * Create a buffer handle in the driver-specific buffer manager (either

  	 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by

  	 * the core to implement the GETFB IOCTL, which returns (for
  	 * sufficiently priviledged user) also a native buffer handle. This can
  	 * be used for seamless transitions between modesetting clients by
  	 * copying the current screen contents to a private buffer and blending
  	 * between that and the new contents.
  	 *
  	 * GEM based drivers should call drm_gem_handle_create() to create the
  	 * handle.
  	 *
  	 * RETURNS:
  	 *
  	 * 0 on success or a negative error code on failure.
  	 */
  	int (*create_handle)(struct drm_framebuffer *fb,
  			     struct drm_file *file_priv,
  			     unsigned int *handle);
  	/**
  	 * @dirty:
  	 *
  	 * Optional callback for the dirty fb IOCTL.
  	 *
  	 * Userspace can notify the driver via this callback that an area of the
  	 * framebuffer has changed and should be flushed to the display
  	 * hardware. This can also be used internally, e.g. by the fbdev
  	 * emulation, though that's not the case currently.
  	 *
  	 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
  	 * for more information as all the semantics and arguments have a one to
  	 * one mapping on this function.
  	 *

  	 * Atomic drivers should use drm_atomic_helper_dirtyfb() to implement
  	 * this hook.
  	 *

  	 * RETURNS:
  	 *
  	 * 0 on success or a negative error code on failure.
  	 */
  	int (*dirty)(struct drm_framebuffer *framebuffer,
  		     struct drm_file *file_priv, unsigned flags,
  		     unsigned color, struct drm_clip_rect *clips,
  		     unsigned num_clips);
  };

  /**
   * struct drm_framebuffer - frame buffer object
   *
   * Note that the fb is refcounted for the benefit of driver internals,
   * for example some hw, disabling a CRTC/plane is asynchronous, and
   * scanout does not actually complete until the next vblank.  So some
   * cleanup (like releasing the reference(s) on the backing GEM bo(s))
   * should be deferred.  In cases like this, the driver would like to
   * hold a ref to the fb even though it has already been removed from

   * userspace perspective. See drm_framebuffer_get() and
   * drm_framebuffer_put().

   *
   * The refcount is stored inside the mode object @base.
   */

  struct drm_framebuffer {

  	/**
  	 * @dev: DRM device this framebuffer belongs to
  	 */

  	struct drm_device *dev;

  	/**

  	 * @head: Place on the &drm_mode_config.fb_list, access protected by
  	 * &drm_mode_config.fb_lock.

  	 */
  	struct list_head head;

  
  	/**
  	 * @base: base modeset object structure, contains the reference count.
  	 */

  	struct drm_mode_object base;

  
  	/**
  	 * @comm: Name of the process allocating the fb, used for fb dumping.
  	 */
  	char comm[TASK_COMM_LEN];

  	/**

  	 * @format: framebuffer format information
  	 */
  	const struct drm_format_info *format;
  	/**

  	 * @funcs: framebuffer vfunc table
  	 */

  	const struct drm_framebuffer_funcs *funcs;

  	/**
  	 * @pitches: Line stride per buffer. For userspace created object this
  	 * is copied from drm_mode_fb_cmd2.
  	 */

  	unsigned int pitches[4];

  	/**
  	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
  	 * per buffer. For userspace created object this is copied from
  	 * drm_mode_fb_cmd2.
  	 *
  	 * Note that this is a linear offset and does not take into account
  	 * tiling or buffer laytou per @modifier. It meant to be used when the
  	 * actual pixel data for this framebuffer plane starts at an offset,
  	 * e.g.  when multiple planes are allocated within the same backing
  	 * storage buffer object. For tiled layouts this generally means it
  	 * @offsets must at least be tile-size aligned, but hardware often has
  	 * stricter requirements.
  	 *
  	 * This should not be used to specifiy x/y pixel offsets into the buffer
  	 * data (even for linear buffers). Specifying an x/y pixel offset is

  	 * instead done through the source rectangle in &struct drm_plane_state.

  	 */

  	unsigned int offsets[4];

  	/**

  	 * @modifier: Data layout modifier. This is used to describe

  	 * tiling, or also special layouts (like compression) of auxiliary
  	 * buffers. For userspace created object this is copied from
  	 * drm_mode_fb_cmd2.
  	 */

  	uint64_t modifier;

  	/**
  	 * @width: Logical width of the visible area of the framebuffer, in
  	 * pixels.
  	 */

  	unsigned int width;

  	/**
  	 * @height: Logical height of the visible area of the framebuffer, in
  	 * pixels.
  	 */

  	unsigned int height;

  	/**

  	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
  	 * DRM_MODE_FB_MODIFIERS.
  	 */

  	int flags;

  	/**

  	 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
  	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
  	 * universal plane.
  	 */

  	int hot_x;

  	/**
  	 * @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor
  	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
  	 * universal plane.
  	 */

  	int hot_y;

  	/**

  	 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.

  	 */

  	struct list_head filp_head;

  	/**
  	 * @obj: GEM objects backing the framebuffer, one per plane (optional).
  	 *
  	 * This is used by the GEM framebuffer helpers, see e.g.
  	 * drm_gem_fb_create().
  	 */
  	struct drm_gem_object *obj[4];

  };

  #define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)

  int drm_framebuffer_init(struct drm_device *dev,
  			 struct drm_framebuffer *fb,
  			 const struct drm_framebuffer_funcs *funcs);
  struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,

  					       struct drm_file *file_priv,

  					       uint32_t id);
  void drm_framebuffer_remove(struct drm_framebuffer *fb);
  void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
  void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
  
  /**

   * drm_framebuffer_get - acquire a framebuffer reference
   * @fb: DRM framebuffer
   *
   * This function increments the framebuffer's reference count.
   */
  static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
  {
  	drm_mode_object_get(&fb->base);
  }
  
  /**
   * drm_framebuffer_put - release a framebuffer reference
   * @fb: DRM framebuffer
   *
   * This function decrements the framebuffer's reference count and frees the
   * framebuffer if the reference count drops to zero.
   */
  static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
  {
  	drm_mode_object_put(&fb->base);
  }
  
  /**

   * drm_framebuffer_read_refcount - read the framebuffer reference count.
   * @fb: framebuffer
   *
   * This functions returns the framebuffer's reference count.
   */

  static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)

  {

  	return kref_read(&fb->base.refcount);

  }

  
  /**

   * drm_framebuffer_assign - store a reference to the fb
   * @p: location to store framebuffer
   * @fb: new framebuffer (maybe NULL)
   *
   * This functions sets the location to store a reference to the framebuffer,
   * unreferencing the framebuffer that was previously stored in that location.
   */
  static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
  					  struct drm_framebuffer *fb)
  {
  	if (fb)

  		drm_framebuffer_get(fb);

  	if (*p)

  		drm_framebuffer_put(*p);

  	*p = fb;
  }
  
  /*

   * drm_for_each_fb - iterate over all framebuffers
   * @fb: the loop cursor
   * @dev: the DRM device
   *

   * Iterate over all framebuffers of @dev. User must hold
   * &drm_mode_config.fb_lock.

   */
  #define drm_for_each_fb(fb, dev) \
  	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
  	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
  					  struct drm_framebuffer, head);	\
  	     &fb->head != (&(dev)->mode_config.fb_list);			\
  	     fb = list_next_entry(fb, head))

  
  int drm_framebuffer_plane_width(int width,
  				const struct drm_framebuffer *fb, int plane);
  int drm_framebuffer_plane_height(int height,
  				 const struct drm_framebuffer *fb, int plane);

  /**
   * struct drm_afbc_framebuffer - a special afbc frame buffer object
   *
   * A derived class of struct drm_framebuffer, dedicated for afbc use cases.
   */
  struct drm_afbc_framebuffer {
  	/**
  	 * @base: base framebuffer structure.
  	 */
  	struct drm_framebuffer base;
  	/**

  	 * @block_width: width of a single afbc block

  	 */
  	u32 block_width;
  	/**

  	 * @block_height: height of a single afbc block

  	 */
  	u32 block_height;
  	/**
  	 * @aligned_width: aligned frame buffer width
  	 */
  	u32 aligned_width;
  	/**
  	 * @aligned_height: aligned frame buffer height
  	 */
  	u32 aligned_height;
  	/**
  	 * @offset: offset of the first afbc header
  	 */
  	u32 offset;
  	/**
  	 * @afbc_size: minimum size of afbc buffer
  	 */
  	u32 afbc_size;

  };
  
  #define fb_to_afbc_fb(x) container_of(x, struct drm_afbc_framebuffer, base)

  #endif