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Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -03001/*
Guennadi Liakhovetski07051352008-04-22 14:42:13 -03002 * helper functions for SG DMA video4linux capture buffers
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -03003 *
Magnus Damm5d6aaf52008-07-16 21:27:49 -03004 * The functions expect the hardware being able to scatter gather
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -03005 * (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.
8 *
9 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
10 *
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
15 *
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
19 */
20
21#include <media/videobuf-core.h>
22
23/* --------------------------------------------------------------------- */
24
25/*
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.
29 */
30struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
31
32/*
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.
36 */
37struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
38 int offset);
39
40/* --------------------------------------------------------------------- */
41
42/*
43 * A small set of helper functions to manage buffers (both userland
44 * and kernel) for DMA.
45 *
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().
50 *
51 * videobuf_dma_*()
Randy Dunlap5872fb92009-01-29 16:28:02 -080052 * see Documentation/PCI/PCI-DMA-mapping.txt, these functions to
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -030053 * basically the same. The map function does also build a
54 * scatterlist for the buffer (and unmap frees it ...)
55 *
56 * videobuf_dma_free()
57 * no comment ...
58 *
59 */
60
61struct videobuf_dmabuf {
62 u32 magic;
63
64 /* for userland buffer */
65 int offset;
66 struct page **pages;
67
68 /* for kernel buffers */
69 void *vmalloc;
70
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -030071 /* for overlay buffers (pci-pci dma) */
72 dma_addr_t bus_addr;
73
74 /* common */
75 struct scatterlist *sglist;
76 int sglen;
77 int nr_pages;
78 int direction;
79};
80
Guennadi Liakhovetski07051352008-04-22 14:42:13 -030081struct videobuf_dma_sg_memory
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -030082{
83 u32 magic;
84
85 /* for mmap'ed buffers */
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -030086 struct videobuf_dmabuf dma;
87};
88
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -030089void videobuf_dma_init(struct videobuf_dmabuf *dma);
90int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
91 unsigned long data, unsigned long size);
92int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
93 int nr_pages);
94int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
95 dma_addr_t addr, int nr_pages);
96int videobuf_dma_free(struct videobuf_dmabuf *dma);
97
98int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
99int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
100int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
101struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf);
102
Guennadi Liakhovetski07051352008-04-22 14:42:13 -0300103void *videobuf_sg_alloc(size_t size);
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -0300104
Guennadi Liakhovetski07051352008-04-22 14:42:13 -0300105void videobuf_queue_sg_init(struct videobuf_queue* q,
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -0300106 struct videobuf_queue_ops *ops,
Guennadi Liakhovetski07051352008-04-22 14:42:13 -0300107 struct device *dev,
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -0300108 spinlock_t *irqlock,
109 enum v4l2_buf_type type,
110 enum v4l2_field field,
111 unsigned int msize,
112 void *priv);
113
114 /*FIXME: these variants are used only on *-alsa code, where videobuf is
115 * used without queue
116 */
Guennadi Liakhovetski07051352008-04-22 14:42:13 -0300117int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma);
118int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma);
Mauro Carvalho Chehab7a7d9a82007-08-23 16:26:14 -0300119