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Diffstat (limited to 'include/media/video-buf.h')
| -rw-r--r-- | include/media/video-buf.h | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/include/media/video-buf.h b/include/media/video-buf.h new file mode 100644 index 00000000000..ae6da6de98d --- /dev/null +++ b/include/media/video-buf.h @@ -0,0 +1,260 @@ +/* + * $Id: video-buf.h,v 1.9 2004/11/07 13:17:15 kraxel Exp $ + * + * 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/videodev.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: + */ |