/*
   *
   *	V 4 L 2   D R I V E R   H E L P E R   A P I
   *
   * Moved from videodev2.h
   *
   *	Some commonly needed functions for drivers (v4l2-common.o module)
   */
  #ifndef _V4L2_DEV_H
  #define _V4L2_DEV_H
  
  #include <linux/poll.h>
  #include <linux/fs.h>
  #include <linux/device.h>
  #include <linux/cdev.h>
  #include <linux/mutex.h>
  #include <linux/videodev2.h>
  
  #include <media/media-entity.h>
  
  #define VIDEO_MAJOR	81
  
  #define VFL_TYPE_GRABBER	0
  #define VFL_TYPE_VBI		1
  #define VFL_TYPE_RADIO		2
  #define VFL_TYPE_SUBDEV		3
  #define VFL_TYPE_MAX		4
  
  /* Is this a receiver, transmitter or mem-to-mem? */
  /* Ignored for VFL_TYPE_SUBDEV. */
  #define VFL_DIR_RX		0
  #define VFL_DIR_TX		1
  #define VFL_DIR_M2M		2
  
  struct v4l2_ioctl_callbacks;
  struct video_device;
  struct v4l2_device;
  struct v4l2_ctrl_handler;
  
  /* Flag to mark the video_device struct as registered.
     Drivers can clear this flag if they want to block all future
     device access. It is cleared by video_unregister_device. */
  #define V4L2_FL_REGISTERED	(0)
  /* file->private_data points to struct v4l2_fh */
  #define V4L2_FL_USES_V4L2_FH	(1)
  /* Use the prio field of v4l2_fh for core priority checking */
  #define V4L2_FL_USE_FH_PRIO	(2)
  
  /* Priority helper functions */
  
  struct v4l2_prio_state {
  	atomic_t prios[4];
  };
  
  void v4l2_prio_init(struct v4l2_prio_state *global);
  int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  		     enum v4l2_priority new);
  void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  
  
  struct v4l2_file_operations {
  	struct module *owner;
  	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  	unsigned int (*poll) (struct file *, struct poll_table_struct *);
  	long (*ioctl) (struct file *, unsigned int, unsigned long);
  	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  #ifdef CONFIG_COMPAT
  	long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
  #endif
  	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  				unsigned long, unsigned long, unsigned long);
  	int (*mmap) (struct file *, struct vm_area_struct *);
  	int (*open) (struct file *);
  	int (*release) (struct file *);
  };
  
  /*
   * Newer version of video_device, handled by videodev2.c
   * 	This version moves redundant code from video device code to
   *	the common handler
   */
  
  struct video_device
  {
  #if defined(CONFIG_MEDIA_CONTROLLER)
  	struct media_entity entity;
  #endif
  	/* device ops */
  	const struct v4l2_file_operations *fops;
  
  	/* sysfs */
  	struct device dev;		/* v4l device */
  	struct cdev *cdev;		/* character device */
  
  	struct v4l2_device *v4l2_dev;	/* v4l2_device parent */
  	/* Only set parent if that can't be deduced from v4l2_dev */
  	struct device *dev_parent;	/* device parent */
  
  	/* Control handler associated with this device node. May be NULL. */
  	struct v4l2_ctrl_handler *ctrl_handler;
  
  	/* vb2_queue associated with this device node. May be NULL. */
  	struct vb2_queue *queue;
  
  	/* Priority state. If NULL, then v4l2_dev->prio will be used. */
  	struct v4l2_prio_state *prio;
  
  	/* device info */
  	char name[32];
  	int vfl_type;	/* device type */
  	int vfl_dir;	/* receiver, transmitter or m2m */
  	/* 'minor' is set to -1 if the registration failed */
  	int minor;
  	u16 num;
  	/* use bitops to set/clear/test flags */
  	unsigned long flags;
  	/* attribute to differentiate multiple indices on one physical device */
  	int index;
  
  	/* V4L2 file handles */
  	spinlock_t		fh_lock; /* Lock for all v4l2_fhs */
  	struct list_head	fh_list; /* List of struct v4l2_fh */
  
  	int debug;			/* Activates debug level*/
  
  	/* Video standard vars */
  	v4l2_std_id tvnorms;		/* Supported tv norms */
  
  	/* callbacks */
  	void (*release)(struct video_device *vdev);
  
  	/* ioctl callbacks */
  	const struct v4l2_ioctl_ops *ioctl_ops;
  	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
  
  	/* serialization lock */
  	DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
  	struct mutex *lock;
  };
  
  #define media_entity_to_video_device(__e) \
  	container_of(__e, struct video_device, entity)
  /* dev to video-device */
  #define to_video_device(cd) container_of(cd, struct video_device, dev)
  
  int __must_check __video_register_device(struct video_device *vdev, int type,
  		int nr, int warn_if_nr_in_use, struct module *owner);
  
  /* Register video devices. Note that if video_register_device fails,
     the release() callback of the video_device structure is *not* called, so
     the caller is responsible for freeing any data. Usually that means that
     you call video_device_release() on failure. */
  static inline int __must_check video_register_device(struct video_device *vdev,
  		int type, int nr)
  {
  	return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
  }
  
  /* Same as video_register_device, but no warning is issued if the desired
     device node number was already in use. */
  static inline int __must_check video_register_device_no_warn(
  		struct video_device *vdev, int type, int nr)
  {
  	return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
  }
  
  /* Unregister video devices. Will do nothing if vdev == NULL or
     video_is_registered() returns false. */
  void video_unregister_device(struct video_device *vdev);
  
  /* helper functions to alloc/release struct video_device, the
     latter can also be used for video_device->release(). */
  struct video_device * __must_check video_device_alloc(void);
  
  /* this release function frees the vdev pointer */
  void video_device_release(struct video_device *vdev);
  
  /* this release function does nothing, use when the video_device is a
     static global struct. Note that having a static video_device is
     a dubious construction at best. */
  void video_device_release_empty(struct video_device *vdev);
  
  /* returns true if cmd is a known V4L2 ioctl */
  bool v4l2_is_known_ioctl(unsigned int cmd);
  
  /* mark that this command shouldn't use core locking */
  static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
  {
  	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
  		set_bit(_IOC_NR(cmd), vdev->disable_locking);
  }
  
  /* Mark that this command isn't implemented. This must be called before
     video_device_register. See also the comments in determine_valid_ioctls().
     This function allows drivers to provide just one v4l2_ioctl_ops struct, but
     disable ioctls based on the specific card that is actually found. */
  static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
  {
  	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
  		set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
  }
  
  /* helper functions to access driver private data. */
  static inline void *video_get_drvdata(struct video_device *vdev)
  {
  	return dev_get_drvdata(&vdev->dev);
  }
  
  static inline void video_set_drvdata(struct video_device *vdev, void *data)
  {
  	dev_set_drvdata(&vdev->dev, data);
  }
  
  struct video_device *video_devdata(struct file *file);
  
  /* Combine video_get_drvdata and video_devdata as this is
     used very often. */
  static inline void *video_drvdata(struct file *file)
  {
  	return video_get_drvdata(video_devdata(file));
  }
  
  static inline const char *video_device_node_name(struct video_device *vdev)
  {
  	return dev_name(&vdev->dev);
  }
  
  static inline int video_is_registered(struct video_device *vdev)
  {
  	return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
  }
  
  #endif /* _V4L2_DEV_H */