alistair23-linux/include/media/video-buf.h
Mauro Carvalho Chehab 401998fa96 V4L/DVB (4065): Several improvements at videodev.c
Videodev now is capable of better handling V4L2 api, by
processing V4L2 ioctls and using callbacks to the driver.
The drivers should be migrated to the newer way and the older
one will be obsoleted soon.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-25 02:05:04 -03:00

287 lines
9.1 KiB
C

/*
*
* generic helper functions for video4linux capture buffers, to handle
* memory management and PCI DMA.
* Right now, bttv, saa7134, saa7146 and cx88 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.
*
* device specific map/unmap/sync stuff now are mapped as file operations
* to allow its usage by USB and virtual devices.
*
* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
* (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
* (c) 2006 Ted Walther and John Sokol
*
* 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>
#include <linux/poll.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);
struct videobuf_buffer;
struct videobuf_queue;
/* --------------------------------------------------------------------- */
/*
* 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_*()
* 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_free(struct videobuf_dmabuf *dma);
int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
/*FIXME: these variants are used only on *-alsa code, where videobuf is
* used without queue
*/
int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma);
int videobuf_pci_dma_unmap(struct pci_dev *pci,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_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;
};
typedef int (vb_map_sg_t)(void *dev,struct scatterlist *sglist,int nr_pages,
int direction);
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);
/* Helper operations - device dependent.
* If null, videobuf_init defaults all to PCI handling
*/
vb_map_sg_t *vb_map_sg;
vb_map_sg_t *vb_dma_sync_sg;
vb_map_sg_t *vb_unmap_sg;
};
struct videobuf_queue {
struct mutex lock;
spinlock_t *irqlock;
void *dev; /* on pci, points to struct pci_dev */
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 videobuf_queue* q, struct videobuf_buffer *vb,
struct v4l2_framebuffer *fbuf);
/* Maps fops to PCI stuff */
void videobuf_queue_pci(struct videobuf_queue* q);
void videobuf_queue_init(struct videobuf_queue *q,
struct videobuf_queue_ops *ops,
void *dev,
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:
*/