391 строка
14 KiB
C
391 строка
14 KiB
C
/*
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* videobuf2-v4l2.h - V4L2 driver helper framework
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*
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* Copyright (C) 2010 Samsung Electronics
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*
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* Author: Pawel Osciak <pawel@osciak.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation.
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*/
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#ifndef _MEDIA_VIDEOBUF2_V4L2_H
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#define _MEDIA_VIDEOBUF2_V4L2_H
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#include <linux/videodev2.h>
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#include <media/videobuf2-core.h>
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#if VB2_MAX_FRAME != VIDEO_MAX_FRAME
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#error VB2_MAX_FRAME != VIDEO_MAX_FRAME
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#endif
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#if VB2_MAX_PLANES != VIDEO_MAX_PLANES
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#error VB2_MAX_PLANES != VIDEO_MAX_PLANES
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#endif
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struct video_device;
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/**
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* struct vb2_v4l2_buffer - video buffer information for v4l2.
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*
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* @vb2_buf: embedded struct &vb2_buffer.
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* @flags: buffer informational flags.
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* @field: field order of the image in the buffer, as defined by
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* &enum v4l2_field.
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* @timecode: frame timecode.
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* @sequence: sequence count of this frame.
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* @request_fd: the request_fd associated with this buffer
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* @is_held: if true, then this capture buffer was held
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* @planes: plane information (userptr/fd, length, bytesused, data_offset).
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*
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* Should contain enough information to be able to cover all the fields
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* of &struct v4l2_buffer at ``videodev2.h``.
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*/
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struct vb2_v4l2_buffer {
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struct vb2_buffer vb2_buf;
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__u32 flags;
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__u32 field;
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struct v4l2_timecode timecode;
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__u32 sequence;
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__s32 request_fd;
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bool is_held;
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struct vb2_plane planes[VB2_MAX_PLANES];
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};
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/* VB2 V4L2 flags as set in vb2_queue.subsystem_flags */
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#define VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 0)
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/*
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* to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
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*/
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#define to_vb2_v4l2_buffer(vb) \
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container_of(vb, struct vb2_v4l2_buffer, vb2_buf)
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/**
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* vb2_find_buffer() - Find a buffer with given timestamp
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*
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @timestamp: the timestamp to find.
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*
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* Returns the buffer with the given @timestamp, or NULL if not found.
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*/
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struct vb2_buffer *vb2_find_buffer(struct vb2_queue *q, u64 timestamp);
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int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
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/**
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* vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
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* the memory and type values.
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*
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @req: &struct v4l2_requestbuffers passed from userspace to
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* &v4l2_ioctl_ops->vidioc_reqbufs handler in driver.
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*/
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int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
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/**
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* vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
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* the memory and type values.
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*
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @create: creation parameters, passed from userspace to
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* &v4l2_ioctl_ops->vidioc_create_bufs handler in driver
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*/
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int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
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/**
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* vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
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*
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @mdev: pointer to &struct media_device, may be NULL.
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* @b: buffer structure passed from userspace to
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* &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver
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*
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* Should be called from &v4l2_ioctl_ops->vidioc_prepare_buf ioctl handler
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* of a driver.
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*
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* This function:
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*
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* #) verifies the passed buffer,
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* #) calls &vb2_ops->buf_prepare callback in the driver (if provided),
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* in which driver-specific buffer initialization can be performed.
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* #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
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* then bind the prepared buffer to the request.
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*
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* The return values from this function are intended to be directly returned
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* from &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
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*/
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int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
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struct v4l2_buffer *b);
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/**
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* vb2_qbuf() - Queue a buffer from userspace
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @mdev: pointer to &struct media_device, may be NULL.
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* @b: buffer structure passed from userspace to
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* &v4l2_ioctl_ops->vidioc_qbuf handler in driver
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*
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* Should be called from &v4l2_ioctl_ops->vidioc_qbuf handler of a driver.
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*
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* This function:
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*
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* #) verifies the passed buffer;
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* #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
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* then bind the buffer to the request.
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* #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
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* (if provided), in which driver-specific buffer initialization can
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* be performed;
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* #) if streaming is on, queues the buffer in driver by the means of
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* &vb2_ops->buf_queue callback for processing.
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*
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* The return values from this function are intended to be directly returned
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* from &v4l2_ioctl_ops->vidioc_qbuf handler in driver.
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*/
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int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
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struct v4l2_buffer *b);
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/**
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* vb2_expbuf() - Export a buffer as a file descriptor
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @eb: export buffer structure passed from userspace to
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* &v4l2_ioctl_ops->vidioc_expbuf handler in driver
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*
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* The return values from this function are intended to be directly returned
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* from &v4l2_ioctl_ops->vidioc_expbuf handler in driver.
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*/
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int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
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/**
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* vb2_dqbuf() - Dequeue a buffer to the userspace
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @b: buffer structure passed from userspace to
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* &v4l2_ioctl_ops->vidioc_dqbuf handler in driver
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* @nonblocking: if true, this call will not sleep waiting for a buffer if no
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* buffers ready for dequeuing are present. Normally the driver
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* would be passing (&file->f_flags & %O_NONBLOCK) here
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*
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* Should be called from &v4l2_ioctl_ops->vidioc_dqbuf ioctl handler
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* of a driver.
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*
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* This function:
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*
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* #) verifies the passed buffer;
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* #) calls &vb2_ops->buf_finish callback in the driver (if provided), in which
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* driver can perform any additional operations that may be required before
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* returning the buffer to userspace, such as cache sync;
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* #) the buffer struct members are filled with relevant information for
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* the userspace.
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*
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* The return values from this function are intended to be directly returned
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* from &v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
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*/
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int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
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/**
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* vb2_streamon - start streaming
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @type: type argument passed from userspace to vidioc_streamon handler,
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* as defined by &enum v4l2_buf_type.
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*
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* Should be called from &v4l2_ioctl_ops->vidioc_streamon handler of a driver.
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*
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* This function:
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*
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* 1) verifies current state
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* 2) passes any previously queued buffers to the driver and starts streaming
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*
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* The return values from this function are intended to be directly returned
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* from &v4l2_ioctl_ops->vidioc_streamon handler in the driver.
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*/
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int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
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/**
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* vb2_streamoff - stop streaming
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @type: type argument passed from userspace to vidioc_streamoff handler
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*
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* Should be called from vidioc_streamoff handler of a driver.
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*
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* This function:
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*
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* #) verifies current state,
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* #) stop streaming and dequeues any queued buffers, including those previously
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* passed to the driver (after waiting for the driver to finish).
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*
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* This call can be used for pausing playback.
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* The return values from this function are intended to be directly returned
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* from vidioc_streamoff handler in the driver
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*/
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int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
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/**
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* vb2_queue_init() - initialize a videobuf2 queue
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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*
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* The vb2_queue structure should be allocated by the driver. The driver is
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* responsible of clearing it's content and setting initial values for some
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* required entries before calling this function.
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* q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
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* to the struct vb2_queue description in include/media/videobuf2-core.h
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* for more information.
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*/
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int __must_check vb2_queue_init(struct vb2_queue *q);
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/**
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* vb2_queue_init_name() - initialize a videobuf2 queue with a name
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @name: the queue name
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*
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* This function initializes the vb2_queue exactly like vb2_queue_init(),
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* and additionally sets the queue name. The queue name is used for logging
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* purpose, and should uniquely identify the queue within the context of the
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* device it belongs to. This is useful to attribute kernel log messages to the
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* right queue for m2m devices or other devices that handle multiple queues.
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*/
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int __must_check vb2_queue_init_name(struct vb2_queue *q, const char *name);
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/**
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* vb2_queue_release() - stop streaming, release the queue and free memory
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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*
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* This function stops streaming and performs necessary clean ups, including
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* freeing video buffer memory. The driver is responsible for freeing
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* the vb2_queue structure itself.
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*/
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void vb2_queue_release(struct vb2_queue *q);
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/**
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* vb2_queue_change_type() - change the type of an inactive vb2_queue
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @type: the type to change to (V4L2_BUF_TYPE_VIDEO_*)
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*
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* This function changes the type of the vb2_queue. This is only possible
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* if the queue is not busy (i.e. no buffers have been allocated).
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*
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* vb2_queue_change_type() can be used to support multiple buffer types using
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* the same queue. The driver can implement v4l2_ioctl_ops.vidioc_reqbufs and
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* v4l2_ioctl_ops.vidioc_create_bufs functions and call vb2_queue_change_type()
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* before calling vb2_ioctl_reqbufs() or vb2_ioctl_create_bufs(), and thus
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* "lock" the buffer type until the buffers have been released.
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*/
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int vb2_queue_change_type(struct vb2_queue *q, unsigned int type);
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/**
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* vb2_poll() - implements poll userspace operation
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @file: file argument passed to the poll file operation handler
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* @wait: wait argument passed to the poll file operation handler
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*
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* This function implements poll file operation handler for a driver.
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* For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
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* be informed that the file descriptor of a video device is available for
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* reading.
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* For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
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* will be reported as available for writing.
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*
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* If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
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* pending events.
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*
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* The return values from this function are intended to be directly returned
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* from poll handler in driver.
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*/
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__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
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/*
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* The following functions are not part of the vb2 core API, but are simple
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* helper functions that you can use in your struct v4l2_file_operations,
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* struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
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* or video_device->lock is set, and they will set and test the queue owner
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* (vb2_queue->owner) to check if the calling filehandle is permitted to do the
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* queuing operation.
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*/
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/**
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* vb2_queue_is_busy() - check if the queue is busy
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* @q: pointer to &struct vb2_queue with videobuf2 queue.
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* @file: file through which the vb2 queue access is performed
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*
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* The queue is considered busy if it has an owner and the owner is not the
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* @file.
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*
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* Queue ownership is acquired and checked by some of the v4l2_ioctl_ops helpers
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* below. Drivers can also use this function directly when they need to
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* open-code ioctl handlers, for instance to add additional checks between the
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* queue ownership test and the call to the corresponding vb2 operation.
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*/
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static inline bool vb2_queue_is_busy(struct vb2_queue *q, struct file *file)
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{
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return q->owner && q->owner != file->private_data;
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}
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/* struct v4l2_ioctl_ops helpers */
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int vb2_ioctl_reqbufs(struct file *file, void *priv,
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struct v4l2_requestbuffers *p);
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int vb2_ioctl_create_bufs(struct file *file, void *priv,
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struct v4l2_create_buffers *p);
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int vb2_ioctl_prepare_buf(struct file *file, void *priv,
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struct v4l2_buffer *p);
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int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
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int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
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int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
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int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
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int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
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int vb2_ioctl_expbuf(struct file *file, void *priv,
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struct v4l2_exportbuffer *p);
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/* struct v4l2_file_operations helpers */
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int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
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int vb2_fop_release(struct file *file);
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int _vb2_fop_release(struct file *file, struct mutex *lock);
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ssize_t vb2_fop_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos);
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ssize_t vb2_fop_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos);
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__poll_t vb2_fop_poll(struct file *file, poll_table *wait);
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#ifndef CONFIG_MMU
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unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags);
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#endif
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/**
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* vb2_video_unregister_device - unregister the video device and release queue
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*
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* @vdev: pointer to &struct video_device
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*
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* If the driver uses vb2_fop_release()/_vb2_fop_release(), then it should use
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* vb2_video_unregister_device() instead of video_unregister_device().
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*
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* This function will call video_unregister_device() and then release the
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* vb2_queue if streaming is in progress. This will stop streaming and
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* this will simplify the unbind sequence since after this call all subdevs
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* will have stopped streaming as well.
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*/
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void vb2_video_unregister_device(struct video_device *vdev);
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/**
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* vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
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*
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* @vq: pointer to &struct vb2_queue
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*
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* ..note:: only use if vq->lock is non-NULL.
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*/
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void vb2_ops_wait_prepare(struct vb2_queue *vq);
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/**
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* vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
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*
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* @vq: pointer to &struct vb2_queue
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*
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* ..note:: only use if vq->lock is non-NULL.
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*/
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void vb2_ops_wait_finish(struct vb2_queue *vq);
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struct media_request;
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int vb2_request_validate(struct media_request *req);
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void vb2_request_queue(struct media_request *req);
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#endif /* _MEDIA_VIDEOBUF2_V4L2_H */
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