text: /*
   * Copyright (c) 2006-2009 Red Hat Inc.
   * Copyright (c) 2006-2008 Intel Corporation
   * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   *
   * DRM framebuffer helper functions
   *
   * 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.
   *
   * Authors:
   *      Dave Airlie <airlied@linux.ie>
   *      Jesse Barnes <jesse.barnes@intel.com>
   */
  #ifndef DRM_FB_HELPER_H
  #define DRM_FB_HELPER_H
  
  struct drm_fb_helper;
  
  #include <drm/drm_crtc.h>
  #include <linux/kgdb.h>
  
  enum mode_set_atomic {
  	LEAVE_ATOMIC_MODE_SET,
  	ENTER_ATOMIC_MODE_SET,
  };
  
  struct drm_fb_offset {
  	int x, y;
  };
  
  struct drm_fb_helper_crtc {
  	struct drm_mode_set mode_set;
  	struct drm_display_mode *desired_mode;
  	int x, y;
  };
  
  /**
   * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
   * @fb_width: fbdev width
   * @fb_height: fbdev height
   * @surface_width: scanout buffer width
   * @surface_height: scanout buffer height
   * @surface_bpp: scanout buffer bpp
   * @surface_depth: scanout buffer depth
   *
   * Note that the scanout surface width/height may be larger than the fbdev
   * width/height.  In case of multiple displays, the scanout surface is sized
   * according to the largest width/height (so it is large enough for all CRTCs
   * to scanout).  But the fbdev width/height is sized to the minimum width/
   * height of all the displays.  This ensures that fbcon fits on the smallest
   * of the attached displays.
   *
   * So what is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
   * rather than the surface size.
   */
  struct drm_fb_helper_surface_size {
  	u32 fb_width;
  	u32 fb_height;
  	u32 surface_width;
  	u32 surface_height;
  	u32 surface_bpp;
  	u32 surface_depth;
  };
  
  /**
   * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
   *
   * Driver callbacks used by the fbdev emulation helper library.
   */
  struct drm_fb_helper_funcs {
  	/**
  	 * @gamma_set:
  	 *
  	 * Set the given gamma LUT register on the given CRTC.
  	 *
  	 * This callback is optional.
  	 *
  	 * FIXME:
  	 *
  	 * This callback is functionally redundant with the core gamma table
  	 * support and simply exists because the fbdev hasn't yet been
  	 * refactored to use the core gamma table interfaces.
  	 */
  	void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
  			  u16 blue, int regno);
  	/**
  	 * @gamma_get:
  	 *
  	 * Read the given gamma LUT register on the given CRTC, used to save the
  	 * current LUT when force-restoring the fbdev for e.g. kdbg.
  	 *
  	 * This callback is optional.
  	 *
  	 * FIXME:
  	 *
  	 * This callback is functionally redundant with the core gamma table
  	 * support and simply exists because the fbdev hasn't yet been
  	 * refactored to use the core gamma table interfaces.
  	 */
  	void (*gamma_get)(struct drm_crtc *crtc, u16 *red, u16 *green,
  			  u16 *blue, int regno);
  
  	/**
  	 * @fb_probe:
  	 *
  	 * Driver callback to allocate and initialize the fbdev info structure.
  	 * Furthermore it also needs to allocate the DRM framebuffer used to
  	 * back the fbdev.
  	 *
  	 * This callback is mandatory.
  	 *
  	 * RETURNS:
  	 *
  	 * The driver should return 0 on success and a negative error code on
  	 * failure.
  	 */
  	int (*fb_probe)(struct drm_fb_helper *helper,
  			struct drm_fb_helper_surface_size *sizes);
  
  	/**
  	 * @initial_config:
  	 *
  	 * Driver callback to setup an initial fbdev display configuration.
  	 * Drivers can use this callback to tell the fbdev emulation what the
  	 * preferred initial configuration is. This is useful to implement
  	 * smooth booting where the fbdev (and subsequently all userspace) never
  	 * changes the mode, but always inherits the existing configuration.
  	 *
  	 * This callback is optional.
  	 *
  	 * RETURNS:
  	 *
  	 * The driver should return true if a suitable initial configuration has
  	 * been filled out and false when the fbdev helper should fall back to
  	 * the default probing logic.
  	 */
  	bool (*initial_config)(struct drm_fb_helper *fb_helper,
  			       struct drm_fb_helper_crtc **crtcs,
  			       struct drm_display_mode **modes,
  			       struct drm_fb_offset *offsets,
  			       bool *enabled, int width, int height);
  };
  
  struct drm_fb_helper_connector {
  	struct drm_connector *connector;
  };
  
  /**
   * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
   * @fb: Scanout framebuffer object
   * @dev: DRM device
   * @crtc_count: number of possible CRTCs
   * @crtc_info: per-CRTC helper state (mode, x/y offset, etc)
   * @connector_count: number of connected connectors
   * @connector_info_alloc_count: size of connector_info
   * @connector_info: array of per-connector information
   * @funcs: driver callbacks for fb helper
   * @fbdev: emulated fbdev device info struct
   * @pseudo_palette: fake palette of 16 colors
   * @dirty_clip: clip rectangle used with deferred_io to accumulate damage to
   *              the screen buffer
   * @dirty_lock: spinlock protecting @dirty_clip
   * @dirty_work: worker used to flush the framebuffer
   * @resume_work: worker used during resume if the console lock is already taken
   *
   * This is the main structure used by the fbdev helpers. Drivers supporting
   * fbdev emulation should embedded this into their overall driver structure.
   * Drivers must also fill out a struct &drm_fb_helper_funcs with a few
   * operations.
   */
  struct drm_fb_helper {
  	struct drm_framebuffer *fb;
  	struct drm_device *dev;
  	int crtc_count;
  	struct drm_fb_helper_crtc *crtc_info;
  	int connector_count;
  	int connector_info_alloc_count;
  	struct drm_fb_helper_connector **connector_info;
  	const struct drm_fb_helper_funcs *funcs;
  	struct fb_info *fbdev;
  	u32 pseudo_palette[17];
  	struct drm_clip_rect dirty_clip;
  	struct lock dirty_lock;
  	struct work_struct dirty_work;
  	struct work_struct resume_work;
  
  	/**
  	 * @kernel_fb_list:
  	 *
  	 * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
  	 */
  	struct list_head kernel_fb_list;
  
  	/**
  	 * @delayed_hotplug:
  	 *
  	 * A hotplug was received while fbdev wasn't in control of the DRM
  	 * device, i.e. another KMS master was active. The output configuration
  	 * needs to be reprobe when fbdev is in control again.
  	 */
  	bool delayed_hotplug;
  };
  
  /**
   * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
   *
   * Helper define to register default implementations of drm_fb_helper
   * functions. To be used in struct fb_ops of drm drivers.
   */
  #define DRM_FB_HELPER_DEFAULT_OPS \
  	.fb_check_var	= drm_fb_helper_check_var, \
  	.fb_set_par	= drm_fb_helper_set_par, \
  	.fb_setcmap	= drm_fb_helper_setcmap, \
  	.fb_blank	= drm_fb_helper_blank, \
  	.fb_pan_display	= drm_fb_helper_pan_display
  
  /**
   * @DRM_FB_HELPER_DEFAULT_OPS:
   *
   * Helper define to register default implementations of drm_fb_helper
   * functions. To be used in struct fb_ops of drm drivers.
   */
  #define DRM_FB_HELPER_DEFAULT_OPS \
  	.fb_check_var	= drm_fb_helper_check_var, \
  	.fb_set_par	= drm_fb_helper_set_par, \
  	.fb_setcmap	= drm_fb_helper_setcmap, \
  	.fb_blank	= drm_fb_helper_blank, \
  	.fb_pan_display	= drm_fb_helper_pan_display
  
  #ifdef CONFIG_DRM_FBDEV_EMULATION
  void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
  			   const struct drm_fb_helper_funcs *funcs);
  int drm_fb_helper_init(struct drm_device *dev,
  		       struct drm_fb_helper *helper, int crtc_count,
  		       int max_conn);
  void drm_fb_helper_fini(struct drm_fb_helper *helper);
  int drm_fb_helper_blank(int blank, struct fb_info *info);
  int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
  			      struct fb_info *info);
  int drm_fb_helper_set_par(struct fb_info *info);
  int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
  			    struct fb_info *info);
  
  int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
  
  struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
  void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
  void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper);
  void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
  			    uint32_t fb_width, uint32_t fb_height);
  void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
  			    uint32_t depth);
  
  void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
  
  void drm_fb_helper_deferred_io(struct fb_info *info,
  			       struct list_head *pagelist);
  
  ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
  			       size_t count, loff_t *ppos);
  ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
  				size_t count, loff_t *ppos);
  
  void drm_fb_helper_sys_fillrect(struct fb_info *info,
  				const struct fb_fillrect *rect);
  void drm_fb_helper_sys_copyarea(struct fb_info *info,
  				const struct fb_copyarea *area);
  void drm_fb_helper_sys_imageblit(struct fb_info *info,
  				 const struct fb_image *image);
  
  void drm_fb_helper_cfb_fillrect(struct fb_info *info,
  				const struct fb_fillrect *rect);
  void drm_fb_helper_cfb_copyarea(struct fb_info *info,
  				const struct fb_copyarea *area);
  void drm_fb_helper_cfb_imageblit(struct fb_info *info,
  				 const struct fb_image *image);
  
  void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
  void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
  					bool suspend);
  
  int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
  
  int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
  int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
  int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
  int drm_fb_helper_debug_enter(struct fb_info *info);
  int drm_fb_helper_debug_leave(struct fb_info *info);
  struct drm_display_mode *
  drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
  			int width, int height);
  struct drm_display_mode *
  drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
  		      int width, int height);
  
  int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
  int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
  				       struct drm_connector *connector);
  #else
  static inline void drm_fb_helper_prepare(struct drm_device *dev,
  					struct drm_fb_helper *helper,
  					const struct drm_fb_helper_funcs *funcs)
  {
  }
  
  static inline int drm_fb_helper_init(struct drm_device *dev,
  		       struct drm_fb_helper *helper, int crtc_count,
  		       int max_conn)
  {
  	return 0;
  }
  
  static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
  {
  }
  
  static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
  					    struct fb_info *info)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_set_par(struct fb_info *info)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
  					  struct fb_info *info)
  {
  	return 0;
  }
  
  static inline int
  drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
  {
  	return 0;
  }
  
  static inline struct fb_info *
  drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
  {
  	return NULL;
  }
  
  static inline void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
  {
  }
  static inline void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper)
  {
  }
  
  static inline void drm_fb_helper_fill_var(struct fb_info *info,
  					  struct drm_fb_helper *fb_helper,
  					  uint32_t fb_width, uint32_t fb_height)
  {
  }
  
  static inline void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
  					  uint32_t depth)
  {
  }
  
  static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
  					struct fb_info *info)
  {
  	return 0;
  }
  
  static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
  {
  }
  
  static inline void drm_fb_helper_deferred_io(struct fb_info *info,
  					     struct list_head *pagelist)
  {
  }
  
  static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
  					     char __user *buf, size_t count,
  					     loff_t *ppos)
  {
  	return -ENODEV;
  }
  
  static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
  					      const char __user *buf,
  					      size_t count, loff_t *ppos)
  {
  	return -ENODEV;
  }
  
  static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
  					      const struct fb_fillrect *rect)
  {
  }
  
  static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
  					      const struct fb_copyarea *area)
  {
  }
  
  static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
  					       const struct fb_image *image)
  {
  }
  
  static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
  					      const struct fb_fillrect *rect)
  {
  }
  
  static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
  					      const struct fb_copyarea *area)
  {
  }
  
  static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
  					       const struct fb_image *image)
  {
  }
  
  static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
  					     bool suspend)
  {
  }
  
  static inline void
  drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
  {
  }
  
  static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
  					       int bpp_sel)
  {
  	return 0;
  }
  
  static inline int
  drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_debug_enter(struct fb_info *info)
  {
  	return 0;
  }
  
  static inline int drm_fb_helper_debug_leave(struct fb_info *info)
  {
  	return 0;
  }
  
  static inline struct drm_display_mode *
  drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
  		       int width, int height)
  {
  	return NULL;
  }
  
  static inline struct drm_display_mode *
  drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
  		      int width, int height)
  {
  	return NULL;
  }
  
  static inline int
  drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
  				struct drm_connector *connector)
  {
  	return 0;
  }
  
  static inline int
  drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
  				   struct drm_connector *connector)
  {
  	return 0;
  }
  
  #endif
  
  static inline int
  drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
  					      const char *name, bool primary)
  {
  #if IS_ENABLED(CONFIG_FB)
  	return remove_conflicting_framebuffers(a, name, primary);
  #else
  	return 0;
  #endif
  }
  
  #endif
  