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-rw-r--r--include/media/video-buf.h260
1 files changed, 260 insertions, 0 deletions
diff --git a/include/media/video-buf.h b/include/media/video-buf.h
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+/*
+ * $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:
+ */