2 * helper functions for PCI DMA video4linux capture buffers
4 * The functions expect the hardware being able to scatter gatter
5 * (i.e. the buffers are not linear in physical memory, but fragmented
6 * into PAGE_SIZE chunks). They also assume the driver does not need
7 * to touch the video data.
9 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
11 * Highly based on video-buf written originally by:
12 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
13 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
14 * (c) 2006 Ted Walther and John Sokol
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2
21 #include <media/videobuf-core.h>
23 /* --------------------------------------------------------------------- */
26 * Return a scatterlist for some page-aligned vmalloc()'ed memory
27 * block (NULL on errors). Memory for the scatterlist is allocated
28 * using kmalloc. The caller must free the memory.
30 struct scatterlist
* videobuf_vmalloc_to_sg(unsigned char *virt
, int nr_pages
);
33 * Return a scatterlist for a an array of userpages (NULL on errors).
34 * Memory for the scatterlist is allocated using kmalloc. The caller
35 * must free the memory.
37 struct scatterlist
* videobuf_pages_to_sg(struct page
**pages
, int nr_pages
,
40 /* --------------------------------------------------------------------- */
43 * A small set of helper functions to manage buffers (both userland
44 * and kernel) for DMA.
46 * videobuf_dma_init_*()
47 * creates a buffer. The userland version takes a userspace
48 * pointer + length. The kernel version just wants the size and
49 * does memory allocation too using vmalloc_32().
52 * see Documentation/DMA-mapping.txt, these functions to
53 * basically the same. The map function does also build a
54 * scatterlist for the buffer (and unmap frees it ...)
61 struct videobuf_dmabuf
{
64 /* for userland buffer */
68 /* for kernel buffers */
71 /* Stores the userspace pointer to vmalloc area */
74 /* for overlay buffers (pci-pci dma) */
78 struct scatterlist
*sglist
;
84 struct videbuf_pci_sg_memory
88 /* for mmap'ed buffers */
89 struct videobuf_mapping
*map
;
90 struct videobuf_dmabuf dma
;
93 /* FIXME: To be removed soon */
94 typedef int (vb_map_sg_t
)(void *dev
, struct scatterlist
*sglist
, int nr_pages
,
97 /* FIXME: To be removed soon */
98 struct videobuf_dma_sg_ops
100 vb_map_sg_t
*vb_map_sg
;
101 vb_map_sg_t
*vb_dma_sync_sg
;
102 vb_map_sg_t
*vb_unmap_sg
;
106 void videobuf_dma_init(struct videobuf_dmabuf
*dma
);
107 int videobuf_dma_init_user(struct videobuf_dmabuf
*dma
, int direction
,
108 unsigned long data
, unsigned long size
);
109 int videobuf_dma_init_kernel(struct videobuf_dmabuf
*dma
, int direction
,
111 int videobuf_dma_init_overlay(struct videobuf_dmabuf
*dma
, int direction
,
112 dma_addr_t addr
, int nr_pages
);
113 int videobuf_dma_free(struct videobuf_dmabuf
*dma
);
115 int videobuf_dma_map(struct videobuf_queue
* q
,struct videobuf_dmabuf
*dma
);
116 int videobuf_dma_sync(struct videobuf_queue
* q
,struct videobuf_dmabuf
*dma
);
117 int videobuf_dma_unmap(struct videobuf_queue
* q
,struct videobuf_dmabuf
*dma
);
118 struct videobuf_dmabuf
*videobuf_to_dma (struct videobuf_buffer
*buf
);
120 void *videobuf_pci_alloc (size_t size
);
122 void videobuf_queue_pci_init(struct videobuf_queue
* q
,
123 struct videobuf_queue_ops
*ops
,
126 enum v4l2_buf_type type
,
127 enum v4l2_field field
,
131 /*FIXME: these variants are used only on *-alsa code, where videobuf is
134 int videobuf_pci_dma_map(struct pci_dev
*pci
,struct videobuf_dmabuf
*dma
);
135 int videobuf_pci_dma_unmap(struct pci_dev
*pci
,struct videobuf_dmabuf
*dma
);
137 /* FIXME: temporary routine for vivi and tm6000, while lacking implementation
138 * of videobuf-vmalloc
140 void videobuf_set_pci_ops (struct videobuf_queue
* q
,
141 struct videobuf_dma_sg_ops
*ops
);
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