234 lines
6.8 KiB
C
234 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* generic helper functions for handling video4linux capture buffers
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*
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* (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
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*
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* Highly based on video-buf written originally by:
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* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
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* (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
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* (c) 2006 Ted Walther and John Sokol
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*/
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#ifndef _VIDEOBUF_CORE_H
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#define _VIDEOBUF_CORE_H
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#include <linux/poll.h>
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#include <linux/videodev2.h>
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#define UNSET (-1U)
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struct videobuf_buffer;
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struct videobuf_queue;
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/* --------------------------------------------------------------------- */
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/*
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* A small set of helper functions to manage video4linux buffers.
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*
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* struct videobuf_buffer holds the data structures used by the helper
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* functions, additionally some commonly used fields for v4l buffers
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* (width, height, lists, waitqueue) are in there. That struct should
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* be used as first element in the drivers buffer struct.
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*
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* about the mmap helpers (videobuf_mmap_*):
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*
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* The mmaper function allows to map any subset of contiguous buffers.
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* This includes one mmap() call for all buffers (which the original
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* video4linux API uses) as well as one mmap() for every single buffer
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* (which v4l2 uses).
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*
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* If there is a valid mapping for a buffer, buffer->baddr/bsize holds
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* userspace address + size which can be fed into the
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* videobuf_dma_init_user function listed above.
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*
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*/
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struct videobuf_mapping {
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unsigned int count;
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struct videobuf_queue *q;
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};
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enum videobuf_state {
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VIDEOBUF_NEEDS_INIT = 0,
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VIDEOBUF_PREPARED = 1,
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VIDEOBUF_QUEUED = 2,
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VIDEOBUF_ACTIVE = 3,
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VIDEOBUF_DONE = 4,
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VIDEOBUF_ERROR = 5,
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VIDEOBUF_IDLE = 6,
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};
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struct videobuf_buffer {
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unsigned int i;
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u32 magic;
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/* info about the buffer */
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unsigned int width;
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unsigned int height;
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unsigned int bytesperline; /* use only if != 0 */
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unsigned long size;
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enum v4l2_field field;
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enum videobuf_state state;
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struct list_head stream; /* QBUF/DQBUF list */
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/* touched by irq handler */
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struct list_head queue;
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wait_queue_head_t done;
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unsigned int field_count;
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u64 ts;
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/* Memory type */
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enum v4l2_memory memory;
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/* buffer size */
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size_t bsize;
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/* buffer offset (mmap + overlay) */
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size_t boff;
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/* buffer addr (userland ptr!) */
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unsigned long baddr;
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/* for mmap'ed buffers */
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struct videobuf_mapping *map;
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/* Private pointer to allow specific methods to store their data */
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int privsize;
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void *priv;
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};
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struct videobuf_queue_ops {
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int (*buf_setup)(struct videobuf_queue *q,
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unsigned int *count, unsigned int *size);
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int (*buf_prepare)(struct videobuf_queue *q,
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struct videobuf_buffer *vb,
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enum v4l2_field field);
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void (*buf_queue)(struct videobuf_queue *q,
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struct videobuf_buffer *vb);
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void (*buf_release)(struct videobuf_queue *q,
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struct videobuf_buffer *vb);
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};
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#define MAGIC_QTYPE_OPS 0x12261003
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/* Helper operations - device type dependent */
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struct videobuf_qtype_ops {
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u32 magic;
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struct videobuf_buffer *(*alloc_vb)(size_t size);
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void *(*vaddr) (struct videobuf_buffer *buf);
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int (*iolock) (struct videobuf_queue *q,
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struct videobuf_buffer *vb,
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struct v4l2_framebuffer *fbuf);
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int (*sync) (struct videobuf_queue *q,
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struct videobuf_buffer *buf);
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int (*mmap_mapper) (struct videobuf_queue *q,
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struct videobuf_buffer *buf,
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struct vm_area_struct *vma);
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};
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struct videobuf_queue {
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struct mutex vb_lock;
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struct mutex *ext_lock;
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spinlock_t *irqlock;
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struct device *dev;
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wait_queue_head_t wait; /* wait if queue is empty */
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enum v4l2_buf_type type;
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unsigned int msize;
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enum v4l2_field field;
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enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */
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struct videobuf_buffer *bufs[VIDEO_MAX_FRAME];
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const struct videobuf_queue_ops *ops;
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struct videobuf_qtype_ops *int_ops;
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unsigned int streaming:1;
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unsigned int reading:1;
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/* capture via mmap() + ioctl(QBUF/DQBUF) */
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struct list_head stream;
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/* capture via read() */
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unsigned int read_off;
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struct videobuf_buffer *read_buf;
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/* driver private data */
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void *priv_data;
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};
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static inline void videobuf_queue_lock(struct videobuf_queue *q)
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{
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if (!q->ext_lock)
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mutex_lock(&q->vb_lock);
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}
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static inline void videobuf_queue_unlock(struct videobuf_queue *q)
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{
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if (!q->ext_lock)
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mutex_unlock(&q->vb_lock);
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}
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int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
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int non_blocking, int intr);
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int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
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struct v4l2_framebuffer *fbuf);
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struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
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/* Used on videobuf-dvb */
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void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
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struct videobuf_buffer *buf);
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void videobuf_queue_core_init(struct videobuf_queue *q,
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const struct videobuf_queue_ops *ops,
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struct device *dev,
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spinlock_t *irqlock,
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enum v4l2_buf_type type,
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enum v4l2_field field,
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unsigned int msize,
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void *priv,
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struct videobuf_qtype_ops *int_ops,
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struct mutex *ext_lock);
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int videobuf_queue_is_busy(struct videobuf_queue *q);
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void videobuf_queue_cancel(struct videobuf_queue *q);
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enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
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int videobuf_reqbufs(struct videobuf_queue *q,
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struct v4l2_requestbuffers *req);
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int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
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int videobuf_qbuf(struct videobuf_queue *q,
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struct v4l2_buffer *b);
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int videobuf_dqbuf(struct videobuf_queue *q,
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struct v4l2_buffer *b, int nonblocking);
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int videobuf_streamon(struct videobuf_queue *q);
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int videobuf_streamoff(struct videobuf_queue *q);
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void videobuf_stop(struct videobuf_queue *q);
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int videobuf_read_start(struct videobuf_queue *q);
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void videobuf_read_stop(struct videobuf_queue *q);
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ssize_t videobuf_read_stream(struct videobuf_queue *q,
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char __user *data, size_t count, loff_t *ppos,
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int vbihack, int nonblocking);
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ssize_t videobuf_read_one(struct videobuf_queue *q,
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char __user *data, size_t count, loff_t *ppos,
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int nonblocking);
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__poll_t videobuf_poll_stream(struct file *file,
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struct videobuf_queue *q,
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poll_table *wait);
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int videobuf_mmap_setup(struct videobuf_queue *q,
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unsigned int bcount, unsigned int bsize,
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enum v4l2_memory memory);
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int __videobuf_mmap_setup(struct videobuf_queue *q,
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unsigned int bcount, unsigned int bsize,
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enum v4l2_memory memory);
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int videobuf_mmap_free(struct videobuf_queue *q);
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int videobuf_mmap_mapper(struct videobuf_queue *q,
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struct vm_area_struct *vma);
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#endif
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