/*
   * videobuf2-core.h - Video Buffer 2 Core Framework
   *
   * Copyright (C) 2010 Samsung Electronics
   *
   * Author: Pawel Osciak <pawel@osciak.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation.
   */
  #ifndef _MEDIA_VIDEOBUF2_CORE_H
  #define _MEDIA_VIDEOBUF2_CORE_H
  
  #include <linux/mm_types.h>
  #include <linux/mutex.h>
  #include <linux/poll.h>
  #include <linux/dma-buf.h>
  
  #define VB2_MAX_FRAME	(128)
  #define VB2_MAX_PLANES	(8)
  
  enum vb2_memory {
  	VB2_MEMORY_UNKNOWN	= 0,
  	VB2_MEMORY_MMAP		= 1,
  	VB2_MEMORY_USERPTR	= 2,
  	VB2_MEMORY_DMABUF	= 4,
  };
  
  struct vb2_alloc_ctx;
  struct vb2_fileio_data;
  struct vb2_threadio_data;
  
  /**
   * struct vb2_mem_ops - memory handling/memory allocator operations
   * @alloc:	allocate video memory and, optionally, allocator private data,
   *		return NULL on failure or a pointer to allocator private,
   *		per-buffer data on success; the returned private structure
   *		will then be passed as buf_priv argument to other ops in this
   *		structure. Additional gfp_flags to use when allocating the
   *		are also passed to this operation. These flags are from the
   *		gfp_flags field of vb2_queue.
   * @put:	inform the allocator that the buffer will no longer be used;
   *		usually will result in the allocator freeing the buffer (if
   *		no other users of this buffer are present); the buf_priv
   *		argument is the allocator private per-buffer structure
   *		previously returned from the alloc callback.
   * @get_dmabuf: acquire userspace memory for a hardware operation; used for
   *		 DMABUF memory types.
   * @get_userptr: acquire userspace memory for a hardware operation; used for
   *		 USERPTR memory types; vaddr is the address passed to the
   *		 videobuf layer when queuing a video buffer of USERPTR type;
   *		 should return an allocator private per-buffer structure
   *		 associated with the buffer on success, NULL on failure;
   *		 the returned private structure will then be passed as buf_priv
   *		 argument to other ops in this structure.
   * @put_userptr: inform the allocator that a USERPTR buffer will no longer
   *		 be used.
   * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
   *		   used for DMABUF memory types; alloc_ctx is the alloc context
   *		   dbuf is the shared dma_buf; returns NULL on failure;
   *		   allocator private per-buffer structure on success;
   *		   this needs to be used for further accesses to the buffer.
   * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
   *		   buffer is no longer used; the buf_priv argument is the
   *		   allocator private per-buffer structure previously returned
   *		   from the attach_dmabuf callback.
   * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
   *		of dmabuf is informed that this driver is going to use the
   *		dmabuf.
   * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
   *		  that this driver is done using the dmabuf for now.
   * @prepare:	called every time the buffer is passed from userspace to the
   *		driver, useful for cache synchronisation, optional.
   * @finish:	called every time the buffer is passed back from the driver
   *		to the userspace, also optional.
   * @vaddr:	return a kernel virtual address to a given memory buffer
   *		associated with the passed private structure or NULL if no
   *		such mapping exists.
   * @cookie:	return allocator specific cookie for a given memory buffer
   *		associated with the passed private structure or NULL if not
   *		available.
   * @num_users:	return the current number of users of a memory buffer;
   *		return 1 if the videobuf layer (or actually the driver using
   *		it) is the only user.
   * @mmap:	setup a userspace mapping for a given memory buffer under
   *		the provided virtual memory region.
   *
   * Required ops for USERPTR types: get_userptr, put_userptr.
   * Required ops for MMAP types: alloc, put, num_users, mmap.
   * Required ops for read/write access types: alloc, put, num_users, vaddr.
   * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
   *				  unmap_dmabuf.
   */
  struct vb2_mem_ops {
  	void		*(*alloc)(void *alloc_ctx, unsigned long size,
  				  enum dma_data_direction dma_dir,
  				  gfp_t gfp_flags);
  	void		(*put)(void *buf_priv);
  	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
  
  	void		*(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
  					unsigned long size,
  					enum dma_data_direction dma_dir);
  	void		(*put_userptr)(void *buf_priv);
  
  	void		(*prepare)(void *buf_priv);
  	void		(*finish)(void *buf_priv);
  
  	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
  					  unsigned long size,
  					  enum dma_data_direction dma_dir);
  	void		(*detach_dmabuf)(void *buf_priv);
  	int		(*map_dmabuf)(void *buf_priv);
  	void		(*unmap_dmabuf)(void *buf_priv);
  
  	void		*(*vaddr)(void *buf_priv);
  	void		*(*cookie)(void *buf_priv);
  
  	unsigned int	(*num_users)(void *buf_priv);
  
  	int		(*mmap)(void *buf_priv, struct vm_area_struct *vma);
  };
  
  /**
   * struct vb2_plane - plane information
   * @mem_priv:	private data with this plane
   * @dbuf:	dma_buf - shared buffer object
   * @dbuf_mapped:	flag to show whether dbuf is mapped or not
   * @bytesused:	number of bytes occupied by data in the plane (payload)
   * @length:	size of this plane (NOT the payload) in bytes
   * @offset:	when memory in the associated struct vb2_buffer is
   *		VB2_MEMORY_MMAP, equals the offset from the start of
   *		the device memory for this plane (or is a "cookie" that
   *		should be passed to mmap() called on the video node)
   * @userptr:	when memory is VB2_MEMORY_USERPTR, a userspace pointer
   *		pointing to this plane
   * @fd:		when memory is VB2_MEMORY_DMABUF, a userspace file
   *		descriptor associated with this plane
   * @m:		Union with memtype-specific data (@offset, @userptr or
   *		@fd).
   * @data_offset:	offset in the plane to the start of data; usually 0,
   *		unless there is a header in front of the data
   * Should contain enough information to be able to cover all the fields
   * of struct v4l2_plane at videodev2.h
   */
  struct vb2_plane {
  	void			*mem_priv;
  	struct dma_buf		*dbuf;
  	unsigned int		dbuf_mapped;
  	unsigned int		bytesused;
  	unsigned int		length;
  	union {
  		unsigned int	offset;
  		unsigned long	userptr;
  		int		fd;
  	} m;
  	unsigned int		data_offset;
  };
  
  /**
   * enum vb2_io_modes - queue access methods
   * @VB2_MMAP:		driver supports MMAP with streaming API
   * @VB2_USERPTR:	driver supports USERPTR with streaming API
   * @VB2_READ:		driver supports read() style access
   * @VB2_WRITE:		driver supports write() style access
   * @VB2_DMABUF:		driver supports DMABUF with streaming API
   */
  enum vb2_io_modes {
  	VB2_MMAP	= (1 << 0),
  	VB2_USERPTR	= (1 << 1),
  	VB2_READ	= (1 << 2),
  	VB2_WRITE	= (1 << 3),
  	VB2_DMABUF	= (1 << 4),
  };
  
  /**
   * enum vb2_buffer_state - current video buffer state
   * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control
   * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf
   * @VB2_BUF_STATE_PREPARED:	buffer prepared in videobuf and by the driver
   * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver
   * @VB2_BUF_STATE_REQUEUEING:	re-queue a buffer to the driver
   * @VB2_BUF_STATE_ACTIVE:	buffer queued in driver and possibly used
   *				in a hardware operation
   * @VB2_BUF_STATE_DONE:		buffer returned from driver to videobuf, but
   *				not yet dequeued to userspace
   * @VB2_BUF_STATE_ERROR:	same as above, but the operation on the buffer
   *				has ended with an error, which will be reported
   *				to the userspace when it is dequeued
   */
  enum vb2_buffer_state {
  	VB2_BUF_STATE_DEQUEUED,
  	VB2_BUF_STATE_PREPARING,
  	VB2_BUF_STATE_PREPARED,
  	VB2_BUF_STATE_QUEUED,
  	VB2_BUF_STATE_REQUEUEING,
  	VB2_BUF_STATE_ACTIVE,
  	VB2_BUF_STATE_DONE,
  	VB2_BUF_STATE_ERROR,
  };
  
  struct vb2_queue;
  
  /**
   * struct vb2_buffer - represents a video buffer
   * @vb2_queue:		the queue to which this driver belongs
   * @index:		id number of the buffer
   * @type:		buffer type
   * @memory:		the method, in which the actual data is passed
   * @num_planes:		number of planes in the buffer
   *			on an internal driver queue
   * @planes:		private per-plane information; do not change
   */
  struct vb2_buffer {
  	struct vb2_queue	*vb2_queue;
  	unsigned int		index;
  	unsigned int		type;
  	unsigned int		memory;
  	unsigned int		num_planes;
  	struct vb2_plane	planes[VB2_MAX_PLANES];
  
  	/* private: internal use only
  	 *
  	 * state:		current buffer state; do not change
  	 * queued_entry:	entry on the queued buffers list, which holds
  	 *			all buffers queued from userspace
  	 * done_entry:		entry on the list that stores all buffers ready
  	 *			to be dequeued to userspace
  	 */
  	enum vb2_buffer_state	state;
  
  	struct list_head	queued_entry;
  	struct list_head	done_entry;
  #ifdef CONFIG_VIDEO_ADV_DEBUG
  	/*
  	 * Counters for how often these buffer-related ops are
  	 * called. Used to check for unbalanced ops.
  	 */
  	u32		cnt_mem_alloc;
  	u32		cnt_mem_put;
  	u32		cnt_mem_get_dmabuf;
  	u32		cnt_mem_get_userptr;
  	u32		cnt_mem_put_userptr;
  	u32		cnt_mem_prepare;
  	u32		cnt_mem_finish;
  	u32		cnt_mem_attach_dmabuf;
  	u32		cnt_mem_detach_dmabuf;
  	u32		cnt_mem_map_dmabuf;
  	u32		cnt_mem_unmap_dmabuf;
  	u32		cnt_mem_vaddr;
  	u32		cnt_mem_cookie;
  	u32		cnt_mem_num_users;
  	u32		cnt_mem_mmap;
  
  	u32		cnt_buf_init;
  	u32		cnt_buf_prepare;
  	u32		cnt_buf_finish;
  	u32		cnt_buf_cleanup;
  	u32		cnt_buf_queue;
  
  	/* This counts the number of calls to vb2_buffer_done() */
  	u32		cnt_buf_done;
  #endif
  };
  
  /**
   * struct vb2_ops - driver-specific callbacks
   *
   * @queue_setup:	called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
   *			handlers before memory allocation, or, if
   *			*num_planes != 0, after the allocation to verify a
   *			smaller number of buffers. Driver should return
   *			the required number of buffers in *num_buffers, the
   *			required number of planes per buffer in *num_planes; the
   *			size of each plane should be set in the sizes[] array
   *			and optional per-plane allocator specific context in the
   *			alloc_ctxs[] array. When called from VIDIOC_REQBUFS,
   *			fmt == NULL, the driver has to use the currently
   *			configured format and *num_buffers is the total number
   *			of buffers, that are being allocated. When called from
   *			VIDIOC_CREATE_BUFS, fmt != NULL and it describes the
   *			target frame format (if the format isn't valid the
   *			callback must return -EINVAL). In this case *num_buffers
   *			are being allocated additionally to q->num_buffers.
   * @wait_prepare:	release any locks taken while calling vb2 functions;
   *			it is called before an ioctl needs to wait for a new
   *			buffer to arrive; required to avoid a deadlock in
   *			blocking access type.
   * @wait_finish:	reacquire all locks released in the previous callback;
   *			required to continue operation after sleeping while
   *			waiting for a new buffer to arrive.
   * @buf_init:		called once after allocating a buffer (in MMAP case)
   *			or after acquiring a new USERPTR buffer; drivers may
   *			perform additional buffer-related initialization;
   *			initialization failure (return != 0) will prevent
   *			queue setup from completing successfully; optional.
   * @buf_prepare:	called every time the buffer is queued from userspace
   *			and from the VIDIOC_PREPARE_BUF ioctl; drivers may
   *			perform any initialization required before each
   *			hardware operation in this callback; drivers can
   *			access/modify the buffer here as it is still synced for
   *			the CPU; drivers that support VIDIOC_CREATE_BUFS must
   *			also validate the buffer size; if an error is returned,
   *			the buffer will not be queued in driver; optional.
   * @buf_finish:		called before every dequeue of the buffer back to
   *			userspace; the buffer is synced for the CPU, so drivers
   *			can access/modify the buffer contents; drivers may
   *			perform any operations required before userspace
   *			accesses the buffer; optional. The buffer state can be
   *			one of the following: DONE and ERROR occur while
   *			streaming is in progress, and the PREPARED state occurs
   *			when the queue has been canceled and all pending
   *			buffers are being returned to their default DEQUEUED
   *			state. Typically you only have to do something if the
   *			state is VB2_BUF_STATE_DONE, since in all other cases
   *			the buffer contents will be ignored anyway.
   * @buf_cleanup:	called once before the buffer is freed; drivers may
   *			perform any additional cleanup; optional.
   * @start_streaming:	called once to enter 'streaming' state; the driver may
   *			receive buffers with @buf_queue callback before
   *			@start_streaming is called; the driver gets the number
   *			of already queued buffers in count parameter; driver
   *			can return an error if hardware fails, in that case all
   *			buffers that have been already given by the @buf_queue
   *			callback are to be returned by the driver by calling
   *			@vb2_buffer_done(VB2_BUF_STATE_QUEUED).
   *			If you need a minimum number of buffers before you can
   *			start streaming, then set @min_buffers_needed in the
   *			vb2_queue structure. If that is non-zero then
   *			start_streaming won't be called until at least that
   *			many buffers have been queued up by userspace.
   * @stop_streaming:	called when 'streaming' state must be disabled; driver
   *			should stop any DMA transactions or wait until they
   *			finish and give back all buffers it got from buf_queue()
   *			callback by calling @vb2_buffer_done() with either
   *			VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use
   *			vb2_wait_for_all_buffers() function
   * @buf_queue:		passes buffer vb to the driver; driver may start
   *			hardware operation on this buffer; driver should give
   *			the buffer back by calling vb2_buffer_done() function;
   *			it is allways called after calling STREAMON ioctl;
   *			might be called before start_streaming callback if user
   *			pre-queued buffers before calling STREAMON.
   */
  struct vb2_ops {
  	int (*queue_setup)(struct vb2_queue *q, const void *parg,
  			   unsigned int *num_buffers, unsigned int *num_planes,
  			   unsigned int sizes[], void *alloc_ctxs[]);
  
  	void (*wait_prepare)(struct vb2_queue *q);
  	void (*wait_finish)(struct vb2_queue *q);
  
  	int (*buf_init)(struct vb2_buffer *vb);
  	int (*buf_prepare)(struct vb2_buffer *vb);
  	void (*buf_finish)(struct vb2_buffer *vb);
  	void (*buf_cleanup)(struct vb2_buffer *vb);
  
  	int (*start_streaming)(struct vb2_queue *q, unsigned int count);
  	void (*stop_streaming)(struct vb2_queue *q);
  
  	void (*buf_queue)(struct vb2_buffer *vb);
  };
  
  struct vb2_buf_ops {
  	int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
  	int (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
  	int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
  				struct vb2_plane *planes);
  	int (*set_timestamp)(struct vb2_buffer *vb, const void *pb);
  };
  
  /**
   * struct vb2_queue - a videobuf queue
   *
   * @type:	private buffer type whose content is defined by the vb2-core
   *		caller. For example, for V4L2, it should match
   *		the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h
   * @io_modes:	supported io methods (see vb2_io_modes enum)
   * @fileio_read_once:		report EOF after reading the first buffer
   * @fileio_write_immediately:	queue buffer after each write() call
   * @allow_zero_bytesused:	allow bytesused == 0 to be passed to the driver
   * @lock:	pointer to a mutex that protects the vb2_queue struct. The
   *		driver can set this to a mutex to let the v4l2 core serialize
   *		the queuing ioctls. If the driver wants to handle locking
   *		itself, then this should be set to NULL. This lock is not used
   *		by the videobuf2 core API.
   * @owner:	The filehandle that 'owns' the buffers, i.e. the filehandle
   *		that called reqbufs, create_buffers or started fileio.
   *		This field is not used by the videobuf2 core API, but it allows
   *		drivers to easily associate an owner filehandle with the queue.
   * @ops:	driver-specific callbacks
   * @mem_ops:	memory allocator specific callbacks
   * @buf_ops:	callbacks to deliver buffer information
   *		between user-space and kernel-space
   * @drv_priv:	driver private data
   * @buf_struct_size: size of the driver-specific buffer structure;
   *		"0" indicates the driver doesn't want to use a custom buffer
   *		structure type. for example, sizeof(struct vb2_v4l2_buffer)
   *		will be used for v4l2.
   * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
   *		V4L2_BUF_FLAG_TSTAMP_SRC_*
   * @gfp_flags:	additional gfp flags used when allocating the buffers.
   *		Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
   *		to force the buffer allocation to a specific memory zone.
   * @min_buffers_needed: the minimum number of buffers needed before
   *		start_streaming() can be called. Used when a DMA engine
   *		cannot be started unless at least this number of buffers
   *		have been queued into the driver.
   */
  /*
   * Private elements (won't appear at the DocBook):
   * @mmap_lock:	private mutex used when buffers are allocated/freed/mmapped
   * @memory:	current memory type used
   * @bufs:	videobuf buffer structures
   * @num_buffers: number of allocated/used buffers
   * @queued_list: list of buffers currently queued from userspace
   * @queued_count: number of buffers queued and ready for streaming.
   * @owned_by_drv_count: number of buffers owned by the driver
   * @done_list:	list of buffers ready to be dequeued to userspace
   * @done_lock:	lock to protect done_list list
   * @done_wq:	waitqueue for processes waiting for buffers ready to be dequeued
   * @alloc_ctx:	memory type/allocator-specific contexts for each plane
   * @streaming:	current streaming state
   * @start_streaming_called: start_streaming() was called successfully and we
   *		started streaming.
   * @error:	a fatal error occurred on the queue
   * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
   *		buffers. Only set for capture queues if qbuf has not yet been
   *		called since poll() needs to return POLLERR in that situation.
   * @is_multiplanar: set if buffer type is multiplanar
   * @is_output:	set if buffer type is output
   * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
   *		last decoded buffer was already dequeued. Set for capture queues
   *		when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
   * @fileio:	file io emulator internal data, used only if emulator is active
   * @threadio:	thread io internal data, used only if thread is active
   */
  struct vb2_queue {
  	unsigned int			type;
  	unsigned int			io_modes;
  	unsigned			fileio_read_once:1;
  	unsigned			fileio_write_immediately:1;
  	unsigned			allow_zero_bytesused:1;
  
  	struct mutex			*lock;
  	void				*owner;
  
  	const struct vb2_ops		*ops;
  	const struct vb2_mem_ops	*mem_ops;
  	const struct vb2_buf_ops	*buf_ops;
  
  	void				*drv_priv;
  	unsigned int			buf_struct_size;
  	u32				timestamp_flags;
  	gfp_t				gfp_flags;
  	u32				min_buffers_needed;
  
  	/* private: internal use only */
  	struct mutex			mmap_lock;
  	unsigned int			memory;
  	struct vb2_buffer		*bufs[VB2_MAX_FRAME];
  	unsigned int			num_buffers;
  
  	struct list_head		queued_list;
  	unsigned int			queued_count;
  
  	atomic_t			owned_by_drv_count;
  	struct list_head		done_list;
  	spinlock_t			done_lock;
  	wait_queue_head_t		done_wq;
  
  	void				*alloc_ctx[VB2_MAX_PLANES];
  	unsigned int			plane_sizes[VB2_MAX_PLANES];
  
  	unsigned int			streaming:1;
  	unsigned int			start_streaming_called:1;
  	unsigned int			error:1;
  	unsigned int			waiting_for_buffers:1;
  	unsigned int			is_multiplanar:1;
  	unsigned int			is_output:1;
  	unsigned int			last_buffer_dequeued:1;
  
  	struct vb2_fileio_data		*fileio;
  	struct vb2_threadio_data	*threadio;
  
  #ifdef CONFIG_VIDEO_ADV_DEBUG
  	/*
  	 * Counters for how often these queue-related ops are
  	 * called. Used to check for unbalanced ops.
  	 */
  	u32				cnt_queue_setup;
  	u32				cnt_wait_prepare;
  	u32				cnt_wait_finish;
  	u32				cnt_start_streaming;
  	u32				cnt_stop_streaming;
  #endif
  };
  
  void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
  void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
  
  void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
  void vb2_discard_done(struct vb2_queue *q);
  int vb2_wait_for_all_buffers(struct vb2_queue *q);
  
  int vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
  int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
  		unsigned int *count);
  int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
  		unsigned int *count, const void *parg);
  int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
  int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
  int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking);
  
  int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
  int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
  
  int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
  		unsigned int index, unsigned int plane, unsigned int flags);
  
  int vb2_core_queue_init(struct vb2_queue *q);
  void vb2_core_queue_release(struct vb2_queue *q);
  
  void vb2_queue_error(struct vb2_queue *q);
  
  int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
  #ifndef CONFIG_MMU
  unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
  				    unsigned long addr,
  				    unsigned long len,
  				    unsigned long pgoff,
  				    unsigned long flags);
  #endif
  
  /**
   * vb2_is_streaming() - return streaming status of the queue
   * @q:		videobuf queue
   */
  static inline bool vb2_is_streaming(struct vb2_queue *q)
  {
  	return q->streaming;
  }
  
  /**
   * vb2_fileio_is_active() - return true if fileio is active.
   * @q:		videobuf queue
   *
   * This returns true if read() or write() is used to stream the data
   * as opposed to stream I/O. This is almost never an important distinction,
   * except in rare cases. One such case is that using read() or write() to
   * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
   * is no way you can pass the field information of each buffer to/from
   * userspace. A driver that supports this field format should check for
   * this in the queue_setup op and reject it if this function returns true.
   */
  static inline bool vb2_fileio_is_active(struct vb2_queue *q)
  {
  	return q->fileio;
  }
  
  /**
   * vb2_is_busy() - return busy status of the queue
   * @q:		videobuf queue
   *
   * This function checks if queue has any buffers allocated.
   */
  static inline bool vb2_is_busy(struct vb2_queue *q)
  {
  	return (q->num_buffers > 0);
  }
  
  /**
   * vb2_get_drv_priv() - return driver private data associated with the queue
   * @q:		videobuf queue
   */
  static inline void *vb2_get_drv_priv(struct vb2_queue *q)
  {
  	return q->drv_priv;
  }
  
  /**
   * vb2_set_plane_payload() - set bytesused for the plane plane_no
   * @vb:		buffer for which plane payload should be set
   * @plane_no:	plane number for which payload should be set
   * @size:	payload in bytes
   */
  static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
  				 unsigned int plane_no, unsigned long size)
  {
  	if (plane_no < vb->num_planes)
  		vb->planes[plane_no].bytesused = size;
  }
  
  /**
   * vb2_get_plane_payload() - get bytesused for the plane plane_no
   * @vb:		buffer for which plane payload should be set
   * @plane_no:	plane number for which payload should be set
   */
  static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
  				 unsigned int plane_no)
  {
  	if (plane_no < vb->num_planes)
  		return vb->planes[plane_no].bytesused;
  	return 0;
  }
  
  /**
   * vb2_plane_size() - return plane size in bytes
   * @vb:		buffer for which plane size should be returned
   * @plane_no:	plane number for which size should be returned
   */
  static inline unsigned long
  vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
  {
  	if (plane_no < vb->num_planes)
  		return vb->planes[plane_no].length;
  	return 0;
  }
  
  /**
   * vb2_start_streaming_called() - return streaming status of driver
   * @q:		videobuf queue
   */
  static inline bool vb2_start_streaming_called(struct vb2_queue *q)
  {
  	return q->start_streaming_called;
  }
  
  /**
   * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
   * @q:		videobuf queue
   */
  static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
  {
  	q->last_buffer_dequeued = false;
  }
  
  #endif /* _MEDIA_VIDEOBUF2_CORE_H */