290 lines
9.2 KiB
C
290 lines
9.2 KiB
C
/*
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*
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* generic helper functions for video4linux capture buffers, to handle
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* memory management and PCI DMA.
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* Right now, bttv, saa7134, saa7146 and cx88 use it.
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*
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* The functions expect the hardware being able to scatter gatter
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* (i.e. the buffers are not linear in physical memory, but fragmented
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* into PAGE_SIZE chunks). They also assume the driver does not need
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* to touch the video data.
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*
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* device specific map/unmap/sync stuff now are mapped as file operations
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* to allow its usage by USB and virtual devices.
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*
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* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
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* (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
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* (c) 2006 Ted Walther and John Sokol
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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; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/videodev2.h>
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#include <linux/poll.h>
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#define UNSET (-1U)
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/* --------------------------------------------------------------------- */
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/*
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* Return a scatterlist for some page-aligned vmalloc()'ed memory
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* block (NULL on errors). Memory for the scatterlist is allocated
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* using kmalloc. The caller must free the memory.
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*/
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struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
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/*
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* Return a scatterlist for a an array of userpages (NULL on errors).
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* Memory for the scatterlist is allocated using kmalloc. The caller
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* must free the memory.
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*/
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struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
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int offset);
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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 buffers (both userland
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* and kernel) for DMA.
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*
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* videobuf_dma_init_*()
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* creates a buffer. The userland version takes a userspace
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* pointer + length. The kernel version just wants the size and
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* does memory allocation too using vmalloc_32().
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*
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* videobuf_dma_*()
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* see Documentation/DMA-mapping.txt, these functions to
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* basically the same. The map function does also build a
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* scatterlist for the buffer (and unmap frees it ...)
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*
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* videobuf_dma_free()
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* no comment ...
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*
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*/
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struct videobuf_dmabuf {
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u32 magic;
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/* for userland buffer */
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int offset;
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struct page **pages;
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/* for kernel buffers */
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void *vmalloc;
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/* Stores the userspace pointer to vmalloc area */
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void *varea;
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/* for overlay buffers (pci-pci dma) */
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dma_addr_t bus_addr;
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/* common */
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struct scatterlist *sglist;
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int sglen;
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int nr_pages;
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int direction;
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};
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void videobuf_dma_init(struct videobuf_dmabuf *dma);
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int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
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unsigned long data, unsigned long size);
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int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
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int nr_pages);
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int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
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dma_addr_t addr, int nr_pages);
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int videobuf_dma_free(struct videobuf_dmabuf *dma);
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int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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/*FIXME: these variants are used only on *-alsa code, where videobuf is
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* used without queue
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*/
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int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma);
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int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma);
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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 contingous 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 feeded 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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unsigned long start;
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unsigned long end;
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struct videobuf_queue *q;
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};
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enum videobuf_state {
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STATE_NEEDS_INIT = 0,
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STATE_PREPARED = 1,
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STATE_QUEUED = 2,
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STATE_ACTIVE = 3,
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STATE_DONE = 4,
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STATE_ERROR = 5,
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STATE_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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unsigned int input;
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enum v4l2_field field;
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enum videobuf_state state;
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struct videobuf_dmabuf dma;
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struct list_head stream; /* QBUF/DQBUF list */
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/* for mmap'ed buffers */
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enum v4l2_memory memory;
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size_t boff; /* buffer offset (mmap + overlay) */
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size_t bsize; /* buffer size */
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unsigned long baddr; /* buffer addr (userland ptr!) */
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struct videobuf_mapping *map;
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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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struct timeval ts;
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};
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typedef int (vb_map_sg_t)(void *dev,struct scatterlist *sglist,int nr_pages,
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int direction);
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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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/* Helper operations - device dependent.
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* If null, videobuf_init defaults all to PCI handling
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*/
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vb_map_sg_t *vb_map_sg;
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vb_map_sg_t *vb_dma_sync_sg;
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vb_map_sg_t *vb_unmap_sg;
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};
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struct videobuf_queue {
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struct mutex lock;
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spinlock_t *irqlock;
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void *dev; /* on pci, points to struct pci_dev */
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enum v4l2_buf_type type;
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unsigned int inputs; /* for V4L2_BUF_FLAG_INPUT */
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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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struct videobuf_queue_ops *ops;
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/* capture via mmap() + ioctl(QBUF/DQBUF) */
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unsigned int streaming;
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struct list_head stream;
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/* capture via read() */
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unsigned int reading;
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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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void* videobuf_alloc(unsigned int size);
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int videobuf_waiton(struct videobuf_buffer *vb, 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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/* Maps fops to PCI stuff */
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void videobuf_queue_pci(struct videobuf_queue* q);
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void videobuf_queue_init(struct videobuf_queue *q,
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struct videobuf_queue_ops *ops,
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void *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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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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void videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
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enum v4l2_buf_type type);
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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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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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unsigned int 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_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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/* --------------------------------------------------------------------- */
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/*
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* Local variables:
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* c-basic-offset: 8
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* End:
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*/
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