/* SPDX-License-Identifier: MIT */
  
  #ifndef _DRM_VBLANK_WORK_H_
  #define _DRM_VBLANK_WORK_H_
  
  #include <linux/kthread.h>
  
  struct drm_crtc;
  
  /**
   * struct drm_vblank_work - A delayed work item which delays until a target
   * vblank passes, and then executes at realtime priority outside of IRQ
   * context.
   *
   * See also:
   * drm_vblank_work_schedule()
   * drm_vblank_work_init()
   * drm_vblank_work_cancel_sync()
   * drm_vblank_work_flush()
   */
  struct drm_vblank_work {
  	/**
  	 * @base: The base &kthread_work item which will be executed by
  	 * &drm_vblank_crtc.worker. Drivers should not interact with this
  	 * directly, and instead rely on drm_vblank_work_init() to initialize
  	 * this.
  	 */
  	struct kthread_work base;
  
  	/**
  	 * @vblank: A pointer to &drm_vblank_crtc this work item belongs to.
  	 */
  	struct drm_vblank_crtc *vblank;
  
  	/**
  	 * @count: The target vblank this work will execute on. Drivers should
  	 * not modify this value directly, and instead use
  	 * drm_vblank_work_schedule()
  	 */
  	u64 count;
  
  	/**
  	 * @cancelling: The number of drm_vblank_work_cancel_sync() calls that
  	 * are currently running. A work item cannot be rescheduled until all
  	 * calls have finished.
  	 */
  	int cancelling;
  
  	/**
  	 * @node: The position of this work item in
  	 * &drm_vblank_crtc.pending_work.
  	 */
  	struct list_head node;
  };
  
  /**
   * to_drm_vblank_work - Retrieve the respective &drm_vblank_work item from a
   * &kthread_work
   * @_work: The &kthread_work embedded inside a &drm_vblank_work
   */
  #define to_drm_vblank_work(_work) \
  	container_of((_work), struct drm_vblank_work, base)
  
  int drm_vblank_work_schedule(struct drm_vblank_work *work,
  			     u64 count, bool nextonmiss);
  void drm_vblank_work_init(struct drm_vblank_work *work, struct drm_crtc *crtc,
  			  void (*func)(struct kthread_work *work));
  bool drm_vblank_work_cancel_sync(struct drm_vblank_work *work);
  void drm_vblank_work_flush(struct drm_vblank_work *work);
  
  #endif /* !_DRM_VBLANK_WORK_H_ */