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/*

 * 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>

/* --------------------------------------------------------------------- */

/*

 * 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);

int videobuf_lock(struct page **pages, int nr_pages);

int videobuf_unlock(struct page **pages, int nr_pages);

/* --------------------------------------------------------------------- */

/*

 * 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 {

        /* 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;

};

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;

        int highmem_ok;

        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;

        /* info about the buffer */

        unsigned int            width;

        unsigned int            height;

        unsigned int            bytesperline; /* use only if != 0 */

        unsigned long           size;

        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 file *file,

                         unsigned int *count, unsigned int *size);

        int (*buf_prepare)(struct file *file,struct videobuf_buffer *vb,

                           enum v4l2_field field);

        void (*buf_queue)(struct file *file,struct videobuf_buffer *vb);

        void (*buf_release)(struct file *file,struct videobuf_buffer *vb);

};

struct videobuf_queue {

        struct semaphore           lock;

        spinlock_t                 *irqlock;

        struct pci_dev             *pci;

        enum v4l2_buf_type         type;

        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;

};

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);

int  videobuf_queue_is_busy(struct videobuf_queue *q);

void videobuf_queue_cancel(struct file *file, 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 file *file, struct videobuf_queue *q,

                     struct v4l2_requestbuffers *req);

int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);

int videobuf_qbuf(struct file *file, struct videobuf_queue *q,

                  struct v4l2_buffer *b);

int videobuf_dqbuf(struct file *file, struct videobuf_queue *q,

                   struct v4l2_buffer *b);

int videobuf_streamon(struct file *file, struct videobuf_queue *q);

int videobuf_streamoff(struct file *file, struct videobuf_queue *q);

int videobuf_read_start(struct file *file, struct videobuf_queue *q);

void videobuf_read_stop(struct file *file, struct videobuf_queue *q);

ssize_t videobuf_read_stream(struct file *file, struct videobuf_queue *q,

                             char *data, size_t count, loff_t *ppos,

                             int vbihack);

ssize_t videobuf_read_one(struct file *file, struct videobuf_queue *q,

                          char *data, size_t count, loff_t *ppos);

unsigned int videobuf_poll_stream(struct file *file,

                                  struct videobuf_queue *q,

                                  poll_table *wait);

int videobuf_mmap_setup(struct file *file, struct videobuf_queue *q,

                        unsigned int bcount, unsigned int bsize,

                        enum v4l2_memory memory);

int videobuf_mmap_free(struct file *file, struct videobuf_queue *q);

int videobuf_mmap_mapper(struct vm_area_struct *vma,

                         struct videobuf_queue *q);

/* --------------------------------------------------------------------- */

/*

 * Local variables:

 * c-basic-offset: 8

 * End:

 */