260 lines
8.3 KiB
C
260 lines
8.3 KiB
C
/*
|
|
*
|
|
* generic helper functions for video4linux capture buffers, to handle
|
|
* memory management and PCI DMA. Right now bttv + saa7134 use it.
|
|
*
|
|
* The functions expect the hardware being able to scatter gatter
|
|
* (i.e. the buffers are not linear in physical memory, but fragmented
|
|
* into PAGE_SIZE chunks). They also assume the driver does not need
|
|
* to touch the video data (thus it is probably not useful for USB as
|
|
* data often must be uncompressed by the drivers).
|
|
*
|
|
* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
|
|
*
|
|
* 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; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/videodev2.h>
|
|
|
|
#define UNSET (-1U)
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Return a scatterlist for some page-aligned vmalloc()'ed memory
|
|
* block (NULL on errors). Memory for the scatterlist is allocated
|
|
* using kmalloc. The caller must free the memory.
|
|
*/
|
|
struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
|
|
|
|
/*
|
|
* Return a scatterlist for a an array of userpages (NULL on errors).
|
|
* Memory for the scatterlist is allocated using kmalloc. The caller
|
|
* must free the memory.
|
|
*/
|
|
struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
|
|
int offset);
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* A small set of helper functions to manage buffers (both userland
|
|
* and kernel) for DMA.
|
|
*
|
|
* videobuf_dma_init_*()
|
|
* creates a buffer. The userland version takes a userspace
|
|
* pointer + length. The kernel version just wants the size and
|
|
* does memory allocation too using vmalloc_32().
|
|
*
|
|
* videobuf_dma_pci_*()
|
|
* see Documentation/DMA-mapping.txt, these functions to
|
|
* basically the same. The map function does also build a
|
|
* scatterlist for the buffer (and unmap frees it ...)
|
|
*
|
|
* videobuf_dma_free()
|
|
* no comment ...
|
|
*
|
|
*/
|
|
|
|
struct videobuf_dmabuf {
|
|
u32 magic;
|
|
|
|
/* for userland buffer */
|
|
int offset;
|
|
struct page **pages;
|
|
|
|
/* for kernel buffers */
|
|
void *vmalloc;
|
|
|
|
/* for overlay buffers (pci-pci dma) */
|
|
dma_addr_t bus_addr;
|
|
|
|
/* common */
|
|
struct scatterlist *sglist;
|
|
int sglen;
|
|
int nr_pages;
|
|
int direction;
|
|
};
|
|
|
|
void videobuf_dma_init(struct videobuf_dmabuf *dma);
|
|
int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
|
|
unsigned long data, unsigned long size);
|
|
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
|
|
int nr_pages);
|
|
int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
|
|
dma_addr_t addr, int nr_pages);
|
|
int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma);
|
|
int videobuf_dma_pci_sync(struct pci_dev *dev,
|
|
struct videobuf_dmabuf *dma);
|
|
int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma);
|
|
int videobuf_dma_free(struct videobuf_dmabuf *dma);
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* A small set of helper functions to manage video4linux buffers.
|
|
*
|
|
* struct videobuf_buffer holds the data structures used by the helper
|
|
* functions, additionally some commonly used fields for v4l buffers
|
|
* (width, height, lists, waitqueue) are in there. That struct should
|
|
* be used as first element in the drivers buffer struct.
|
|
*
|
|
* about the mmap helpers (videobuf_mmap_*):
|
|
*
|
|
* The mmaper function allows to map any subset of contingous buffers.
|
|
* This includes one mmap() call for all buffers (which the original
|
|
* video4linux API uses) as well as one mmap() for every single buffer
|
|
* (which v4l2 uses).
|
|
*
|
|
* If there is a valid mapping for a buffer, buffer->baddr/bsize holds
|
|
* userspace address + size which can be feeded into the
|
|
* videobuf_dma_init_user function listed above.
|
|
*
|
|
*/
|
|
|
|
struct videobuf_buffer;
|
|
struct videobuf_queue;
|
|
|
|
struct videobuf_mapping {
|
|
unsigned int count;
|
|
unsigned long start;
|
|
unsigned long end;
|
|
struct videobuf_queue *q;
|
|
};
|
|
|
|
enum videobuf_state {
|
|
STATE_NEEDS_INIT = 0,
|
|
STATE_PREPARED = 1,
|
|
STATE_QUEUED = 2,
|
|
STATE_ACTIVE = 3,
|
|
STATE_DONE = 4,
|
|
STATE_ERROR = 5,
|
|
STATE_IDLE = 6,
|
|
};
|
|
|
|
struct videobuf_buffer {
|
|
unsigned int i;
|
|
u32 magic;
|
|
|
|
/* info about the buffer */
|
|
unsigned int width;
|
|
unsigned int height;
|
|
unsigned int bytesperline; /* use only if != 0 */
|
|
unsigned long size;
|
|
unsigned int input;
|
|
enum v4l2_field field;
|
|
enum videobuf_state state;
|
|
struct videobuf_dmabuf dma;
|
|
struct list_head stream; /* QBUF/DQBUF list */
|
|
|
|
/* for mmap'ed buffers */
|
|
enum v4l2_memory memory;
|
|
size_t boff; /* buffer offset (mmap + overlay) */
|
|
size_t bsize; /* buffer size */
|
|
unsigned long baddr; /* buffer addr (userland ptr!) */
|
|
struct videobuf_mapping *map;
|
|
|
|
/* touched by irq handler */
|
|
struct list_head queue;
|
|
wait_queue_head_t done;
|
|
unsigned int field_count;
|
|
struct timeval ts;
|
|
};
|
|
|
|
struct videobuf_queue_ops {
|
|
int (*buf_setup)(struct videobuf_queue *q,
|
|
unsigned int *count, unsigned int *size);
|
|
int (*buf_prepare)(struct videobuf_queue *q,
|
|
struct videobuf_buffer *vb,
|
|
enum v4l2_field field);
|
|
void (*buf_queue)(struct videobuf_queue *q,
|
|
struct videobuf_buffer *vb);
|
|
void (*buf_release)(struct videobuf_queue *q,
|
|
struct videobuf_buffer *vb);
|
|
};
|
|
|
|
struct videobuf_queue {
|
|
struct semaphore lock;
|
|
spinlock_t *irqlock;
|
|
struct pci_dev *pci;
|
|
|
|
enum v4l2_buf_type type;
|
|
unsigned int inputs; /* for V4L2_BUF_FLAG_INPUT */
|
|
unsigned int msize;
|
|
enum v4l2_field field;
|
|
enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */
|
|
struct videobuf_buffer *bufs[VIDEO_MAX_FRAME];
|
|
struct videobuf_queue_ops *ops;
|
|
|
|
/* capture via mmap() + ioctl(QBUF/DQBUF) */
|
|
unsigned int streaming;
|
|
struct list_head stream;
|
|
|
|
/* capture via read() */
|
|
unsigned int reading;
|
|
unsigned int read_off;
|
|
struct videobuf_buffer *read_buf;
|
|
|
|
/* driver private data */
|
|
void *priv_data;
|
|
};
|
|
|
|
void* videobuf_alloc(unsigned int size);
|
|
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
|
|
int videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
|
|
struct v4l2_framebuffer *fbuf);
|
|
|
|
void videobuf_queue_init(struct videobuf_queue *q,
|
|
struct videobuf_queue_ops *ops,
|
|
struct pci_dev *pci,
|
|
spinlock_t *irqlock,
|
|
enum v4l2_buf_type type,
|
|
enum v4l2_field field,
|
|
unsigned int msize,
|
|
void *priv);
|
|
int videobuf_queue_is_busy(struct videobuf_queue *q);
|
|
void videobuf_queue_cancel(struct videobuf_queue *q);
|
|
|
|
enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
|
|
void videobuf_status(struct v4l2_buffer *b, struct videobuf_buffer *vb,
|
|
enum v4l2_buf_type type);
|
|
int videobuf_reqbufs(struct videobuf_queue *q,
|
|
struct v4l2_requestbuffers *req);
|
|
int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
|
|
int videobuf_qbuf(struct videobuf_queue *q,
|
|
struct v4l2_buffer *b);
|
|
int videobuf_dqbuf(struct videobuf_queue *q,
|
|
struct v4l2_buffer *b, int nonblocking);
|
|
int videobuf_streamon(struct videobuf_queue *q);
|
|
int videobuf_streamoff(struct videobuf_queue *q);
|
|
|
|
int videobuf_read_start(struct videobuf_queue *q);
|
|
void videobuf_read_stop(struct videobuf_queue *q);
|
|
ssize_t videobuf_read_stream(struct videobuf_queue *q,
|
|
char __user *data, size_t count, loff_t *ppos,
|
|
int vbihack, int nonblocking);
|
|
ssize_t videobuf_read_one(struct videobuf_queue *q,
|
|
char __user *data, size_t count, loff_t *ppos,
|
|
int nonblocking);
|
|
unsigned int videobuf_poll_stream(struct file *file,
|
|
struct videobuf_queue *q,
|
|
poll_table *wait);
|
|
|
|
int videobuf_mmap_setup(struct videobuf_queue *q,
|
|
unsigned int bcount, unsigned int bsize,
|
|
enum v4l2_memory memory);
|
|
int videobuf_mmap_free(struct videobuf_queue *q);
|
|
int videobuf_mmap_mapper(struct videobuf_queue *q,
|
|
struct vm_area_struct *vma);
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Local variables:
|
|
* c-basic-offset: 8
|
|
* End:
|
|
*/
|