include/media/videobuf2-v4l2.h - arm/linux - Git at Google

 /*
  * videobuf2-v4l2.h - V4L2 driver helper 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_V4L2_H
 #define _MEDIA_VIDEOBUF2_V4L2_H

 #include <linux/videodev2.h>
 #include <media/videobuf2-core.h>

 #if VB2_MAX_FRAME != VIDEO_MAX_FRAME
 #error VB2_MAX_FRAME != VIDEO_MAX_FRAME
 #endif

 #if VB2_MAX_PLANES != VIDEO_MAX_PLANES
 #error VB2_MAX_PLANES != VIDEO_MAX_PLANES
 #endif

 /**
  * struct vb2_v4l2_buffer - video buffer information for v4l2
  *
  * @vb2_buf:	video buffer 2
  * @flags:	buffer informational flags
  * @field:	enum v4l2_field; field order of the image in the buffer
  * @timecode:	frame timecode
  * @sequence:	sequence count of this frame
  *
  * Should contain enough information to be able to cover all the fields
  * of struct v4l2_buffer at videodev2.h
  */
 struct vb2_v4l2_buffer {
 	struct vb2_buffer	vb2_buf;

 	__u32			flags;
 	__u32			field;
 	struct v4l2_timecode	timecode;
 	__u32			sequence;
 };

 /*
  * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
  */
 #define to_vb2_v4l2_buffer(vb) \
 	container_of(vb, struct vb2_v4l2_buffer, vb2_buf)

 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);

 /**
  * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
  * the memory and type values.
  *
  * @q:		videobuf2 queue
  * @req:	struct passed from userspace to vidioc_reqbufs handler
  *		in driver
  */
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);

 /**
  * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
  * the memory and type values.
  *
  * @q:		videobuf2 queue
  * @create:	creation parameters, passed from userspace to vidioc_create_bufs
  *		handler in driver
  */
 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);

 /**
  * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
  *
  * @q:		videobuf2 queue
  * @b:		buffer structure passed from userspace to vidioc_prepare_buf
  *		handler in driver
  *
  * Should be called from vidioc_prepare_buf ioctl handler of a driver.
  * This function:
  *
  * #) verifies the passed buffer,
  * #) calls buf_prepare callback in the driver (if provided), in which
  *    driver-specific buffer initialization can be performed.
  *
  * The return values from this function are intended to be directly returned
  * from vidioc_prepare_buf handler in driver.
  */
 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);

 /**
  * vb2_qbuf() - Queue a buffer from userspace
  * @q:		videobuf2 queue
  * @b:		buffer structure passed from userspace to VIDIOC_QBUF() handler
  *		in driver
  *
  * Should be called from VIDIOC_QBUF() ioctl handler of a driver.
  *
  * This function:
  *
  * #) verifies the passed buffer,
  * #) if necessary, calls buf_prepare callback in the driver (if provided), in
  *    which driver-specific buffer initialization can be performed,
  * #) if streaming is on, queues the buffer in driver by the means of buf_queue
  *    callback for processing.
  *
  * The return values from this function are intended to be directly returned
  * from VIDIOC_QBUF() handler in driver.
  */
 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);

 /**
  * vb2_expbuf() - Export a buffer as a file descriptor
  * @q:		videobuf2 queue
  * @eb:		export buffer structure passed from userspace to VIDIOC_EXPBUF()
  *		handler in driver
  *
  * The return values from this function are intended to be directly returned
  * from VIDIOC_EXPBUF() handler in driver.
  */
 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);

 /**
  * vb2_dqbuf() - Dequeue a buffer to the userspace
  * @q:		videobuf2 queue
  * @b:		buffer structure passed from userspace to VIDIOC_DQBUF() handler
  *		in driver
  * @nonblocking: if true, this call will not sleep waiting for a buffer if no
  *		 buffers ready for dequeuing are present. Normally the driver
  *		 would be passing (file->f_flags & O_NONBLOCK) here
  *
  * Should be called from VIDIOC_DQBUF() ioctl handler of a driver.
  *
  * This function:
  *
  * #) verifies the passed buffer,
  * #) calls buf_finish callback in the driver (if provided), in which
  *    driver can perform any additional operations that may be required before
  *    returning the buffer to userspace, such as cache sync,
  * #) the buffer struct members are filled with relevant information for
  *    the userspace.
  *
  * The return values from this function are intended to be directly returned
  * from VIDIOC_DQBUF() handler in driver.
  */
 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);

 /**
  * vb2_streamon - start streaming
  * @q:		videobuf2 queue
  * @type:	type argument passed from userspace to vidioc_streamon handler
  *
  * Should be called from vidioc_streamon handler of a driver.
  *
  * This function:
  *
  * 1) verifies current state
  * 2) passes any previously queued buffers to the driver and starts streaming
  *
  * The return values from this function are intended to be directly returned
  * from vidioc_streamon handler in the driver.
  */
 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);

 /**
  * vb2_streamoff - stop streaming
  * @q:		videobuf2 queue
  * @type:	type argument passed from userspace to vidioc_streamoff handler
  *
  * Should be called from vidioc_streamoff handler of a driver.
  *
  * This function:
  *
  * #) verifies current state,
  * #) stop streaming and dequeues any queued buffers, including those previously
  *    passed to the driver (after waiting for the driver to finish).
  *
  * This call can be used for pausing playback.
  * The return values from this function are intended to be directly returned
  * from vidioc_streamoff handler in the driver
  */
 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);

 /**
  * vb2_queue_init() - initialize a videobuf2 queue
  * @q:		videobuf2 queue; this structure should be allocated in driver
  *
  * The vb2_queue structure should be allocated by the driver. The driver is
  * responsible of clearing it's content and setting initial values for some
  * required entries before calling this function.
  * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
  * to the struct vb2_queue description in include/media/videobuf2-core.h
  * for more information.
  */
 int __must_check vb2_queue_init(struct vb2_queue *q);

 /**
  * vb2_queue_release() - stop streaming, release the queue and free memory
  * @q:		videobuf2 queue
  *
  * This function stops streaming and performs necessary clean ups, including
  * freeing video buffer memory. The driver is responsible for freeing
  * the vb2_queue structure itself.
  */
 void vb2_queue_release(struct vb2_queue *q);

 /**
  * vb2_poll() - implements poll userspace operation
  * @q:		videobuf2 queue
  * @file:	file argument passed to the poll file operation handler
  * @wait:	wait argument passed to the poll file operation handler
  *
  * This function implements poll file operation handler for a driver.
  * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
  * be informed that the file descriptor of a video device is available for
  * reading.
  * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
  * will be reported as available for writing.
  *
  * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
  * pending events.
  *
  * The return values from this function are intended to be directly returned
  * from poll handler in driver.
  */
 unsigned int vb2_poll(struct vb2_queue *q, struct file *file,
 		      poll_table *wait);

 /*
  * The following functions are not part of the vb2 core API, but are simple
  * helper functions that you can use in your struct v4l2_file_operations,
  * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
  * or video_device->lock is set, and they will set and test vb2_queue->owner
  * to check if the calling filehandle is permitted to do the queuing operation.
  */

 /* struct v4l2_ioctl_ops helpers */

 int vb2_ioctl_reqbufs(struct file *file, void *priv,
 			  struct v4l2_requestbuffers *p);
 int vb2_ioctl_create_bufs(struct file *file, void *priv,
 			  struct v4l2_create_buffers *p);
 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
 			  struct v4l2_buffer *p);
 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
 int vb2_ioctl_expbuf(struct file *file, void *priv,
 	struct v4l2_exportbuffer *p);

 /* struct v4l2_file_operations helpers */

 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
 int vb2_fop_release(struct file *file);
 int _vb2_fop_release(struct file *file, struct mutex *lock);
 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
 		size_t count, loff_t *ppos);
 ssize_t vb2_fop_read(struct file *file, char __user *buf,
 		size_t count, loff_t *ppos);
 unsigned int vb2_fop_poll(struct file *file, poll_table *wait);
 #ifndef CONFIG_MMU
 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags);
 #endif

 /**
  * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
  *
  * @vq: pointer to struct vb2_queue
  *
  * ..note:: only use if vq->lock is non-NULL.
  */
 void vb2_ops_wait_prepare(struct vb2_queue *vq);

 /**
  * vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
  *
  * @vq: pointer to struct vb2_queue
  *
  * ..note:: only use if vq->lock is non-NULL.
  */
 void vb2_ops_wait_finish(struct vb2_queue *vq);

 #endif /* _MEDIA_VIDEOBUF2_V4L2_H */
	/*
	* videobuf2-v4l2.h - V4L2 driver helper 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_V4L2_H
	#define _MEDIA_VIDEOBUF2_V4L2_H

	#include <linux/videodev2.h>
	#include <media/videobuf2-core.h>

	#if VB2_MAX_FRAME != VIDEO_MAX_FRAME
	#error VB2_MAX_FRAME != VIDEO_MAX_FRAME
	#endif

	#if VB2_MAX_PLANES != VIDEO_MAX_PLANES
	#error VB2_MAX_PLANES != VIDEO_MAX_PLANES
	#endif

	/**
	* struct vb2_v4l2_buffer - video buffer information for v4l2
	*
	* @vb2_buf: video buffer 2
	* @flags: buffer informational flags
	* @field: enum v4l2_field; field order of the image in the buffer
	* @timecode: frame timecode
	* @sequence: sequence count of this frame
	*
	* Should contain enough information to be able to cover all the fields
	* of struct v4l2_buffer at videodev2.h
	*/
	struct vb2_v4l2_buffer {
	struct vb2_buffer vb2_buf;

	__u32 flags;
	__u32 field;
	struct v4l2_timecode timecode;
	__u32 sequence;
	};

	/*
	* to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
	*/
	#define to_vb2_v4l2_buffer(vb) \
	container_of(vb, struct vb2_v4l2_buffer, vb2_buf)

	int vb2_querybuf(struct vb2_queue q, struct v4l2_buffer b);

	/**
	* vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
	* the memory and type values.
	*
	* @q: videobuf2 queue
	* @req: struct passed from userspace to vidioc_reqbufs handler
	* in driver
	*/
	int vb2_reqbufs(struct vb2_queue q, struct v4l2_requestbuffers req);

	/**
	* vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
	* the memory and type values.
	*
	* @q: videobuf2 queue
	* @create: creation parameters, passed from userspace to vidioc_create_bufs
	* handler in driver
	*/
	int vb2_create_bufs(struct vb2_queue q, struct v4l2_create_buffers create);

	/**
	* vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
	*
	* @q: videobuf2 queue
	* @b: buffer structure passed from userspace to vidioc_prepare_buf
	* handler in driver
	*
	* Should be called from vidioc_prepare_buf ioctl handler of a driver.
	* This function:
	*
	* #) verifies the passed buffer,
	* #) calls buf_prepare callback in the driver (if provided), in which
	* driver-specific buffer initialization can be performed.
	*
	* The return values from this function are intended to be directly returned
	* from vidioc_prepare_buf handler in driver.
	*/
	int vb2_prepare_buf(struct vb2_queue q, struct v4l2_buffer b);

	/**
	* vb2_qbuf() - Queue a buffer from userspace
	* @q: videobuf2 queue
	* @b: buffer structure passed from userspace to VIDIOC_QBUF() handler
	* in driver
	*
	* Should be called from VIDIOC_QBUF() ioctl handler of a driver.
	*
	* This function:
	*
	* #) verifies the passed buffer,
	* #) if necessary, calls buf_prepare callback in the driver (if provided), in
	* which driver-specific buffer initialization can be performed,
	* #) if streaming is on, queues the buffer in driver by the means of buf_queue
	* callback for processing.
	*
	* The return values from this function are intended to be directly returned
	* from VIDIOC_QBUF() handler in driver.
	*/
	int vb2_qbuf(struct vb2_queue q, struct v4l2_buffer b);

	/**
	* vb2_expbuf() - Export a buffer as a file descriptor
	* @q: videobuf2 queue
	* @eb: export buffer structure passed from userspace to VIDIOC_EXPBUF()
	* handler in driver
	*
	* The return values from this function are intended to be directly returned
	* from VIDIOC_EXPBUF() handler in driver.
	*/
	int vb2_expbuf(struct vb2_queue q, struct v4l2_exportbuffer eb);

	/**
	* vb2_dqbuf() - Dequeue a buffer to the userspace
	* @q: videobuf2 queue
	* @b: buffer structure passed from userspace to VIDIOC_DQBUF() handler
	* in driver
	* @nonblocking: if true, this call will not sleep waiting for a buffer if no
	* buffers ready for dequeuing are present. Normally the driver
	* would be passing (file->f_flags & O_NONBLOCK) here
	*
	* Should be called from VIDIOC_DQBUF() ioctl handler of a driver.
	*
	* This function:
	*
	* #) verifies the passed buffer,
	* #) calls buf_finish callback in the driver (if provided), in which
	* driver can perform any additional operations that may be required before
	* returning the buffer to userspace, such as cache sync,
	* #) the buffer struct members are filled with relevant information for
	* the userspace.
	*
	* The return values from this function are intended to be directly returned
	* from VIDIOC_DQBUF() handler in driver.
	*/
	int vb2_dqbuf(struct vb2_queue q, struct v4l2_buffer b, bool nonblocking);

	/**
	* vb2_streamon - start streaming
	* @q: videobuf2 queue
	* @type: type argument passed from userspace to vidioc_streamon handler
	*
	* Should be called from vidioc_streamon handler of a driver.
	*
	* This function:
	*
	* 1) verifies current state
	* 2) passes any previously queued buffers to the driver and starts streaming
	*
	* The return values from this function are intended to be directly returned
	* from vidioc_streamon handler in the driver.
	*/
	int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);

	/**
	* vb2_streamoff - stop streaming
	* @q: videobuf2 queue
	* @type: type argument passed from userspace to vidioc_streamoff handler
	*
	* Should be called from vidioc_streamoff handler of a driver.
	*
	* This function:
	*
	* #) verifies current state,
	* #) stop streaming and dequeues any queued buffers, including those previously
	* passed to the driver (after waiting for the driver to finish).
	*
	* This call can be used for pausing playback.
	* The return values from this function are intended to be directly returned
	* from vidioc_streamoff handler in the driver
	*/
	int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);

	/**
	* vb2_queue_init() - initialize a videobuf2 queue
	* @q: videobuf2 queue; this structure should be allocated in driver
	*
	* The vb2_queue structure should be allocated by the driver. The driver is
	* responsible of clearing it's content and setting initial values for some
	* required entries before calling this function.
	* q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
	* to the struct vb2_queue description in include/media/videobuf2-core.h
	* for more information.
	*/
	int __must_check vb2_queue_init(struct vb2_queue *q);

	/**
	* vb2_queue_release() - stop streaming, release the queue and free memory
	* @q: videobuf2 queue
	*
	* This function stops streaming and performs necessary clean ups, including
	* freeing video buffer memory. The driver is responsible for freeing
	* the vb2_queue structure itself.
	*/
	void vb2_queue_release(struct vb2_queue *q);

	/**
	* vb2_poll() - implements poll userspace operation
	* @q: videobuf2 queue
	* @file: file argument passed to the poll file operation handler
	* @wait: wait argument passed to the poll file operation handler
	*
	* This function implements poll file operation handler for a driver.
	* For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
	* be informed that the file descriptor of a video device is available for
	* reading.
	* For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
	* will be reported as available for writing.
	*
	* If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
	* pending events.
	*
	* The return values from this function are intended to be directly returned
	* from poll handler in driver.
	*/
	unsigned int vb2_poll(struct vb2_queue q, struct file file,
	poll_table *wait);

	/*
	* The following functions are not part of the vb2 core API, but are simple
	* helper functions that you can use in your struct v4l2_file_operations,
	* struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
	* or video_device->lock is set, and they will set and test vb2_queue->owner
	* to check if the calling filehandle is permitted to do the queuing operation.
	*/

	/* struct v4l2_ioctl_ops helpers */

	int vb2_ioctl_reqbufs(struct file file, void priv,
	struct v4l2_requestbuffers *p);
	int vb2_ioctl_create_bufs(struct file file, void priv,
	struct v4l2_create_buffers *p);
	int vb2_ioctl_prepare_buf(struct file file, void priv,
	struct v4l2_buffer *p);
	int vb2_ioctl_querybuf(struct file file, void priv, struct v4l2_buffer *p);
	int vb2_ioctl_qbuf(struct file file, void priv, struct v4l2_buffer *p);
	int vb2_ioctl_dqbuf(struct file file, void priv, struct v4l2_buffer *p);
	int vb2_ioctl_streamon(struct file file, void priv, enum v4l2_buf_type i);
	int vb2_ioctl_streamoff(struct file file, void priv, enum v4l2_buf_type i);
	int vb2_ioctl_expbuf(struct file file, void priv,
	struct v4l2_exportbuffer *p);

	/* struct v4l2_file_operations helpers */

	int vb2_fop_mmap(struct file file, struct vm_area_struct vma);
	int vb2_fop_release(struct file *file);
	int _vb2_fop_release(struct file file, struct mutex lock);
	ssize_t vb2_fop_write(struct file file, const char __user buf,
	size_t count, loff_t *ppos);
	ssize_t vb2_fop_read(struct file file, char __user buf,
	size_t count, loff_t *ppos);
	unsigned int vb2_fop_poll(struct file file, poll_table wait);
	#ifndef CONFIG_MMU
	unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
	unsigned long len, unsigned long pgoff, unsigned long flags);
	#endif

	/**
	* vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
	*
	* @vq: pointer to struct vb2_queue
	*
	* ..note:: only use if vq->lock is non-NULL.
	*/
	void vb2_ops_wait_prepare(struct vb2_queue *vq);

	/**
	* vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
	*
	* @vq: pointer to struct vb2_queue
	*
	* ..note:: only use if vq->lock is non-NULL.
	*/
	void vb2_ops_wait_finish(struct vb2_queue *vq);

	#endif /* _MEDIA_VIDEOBUF2_V4L2_H */