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7a7d9a89 MCC |
1 | /* |
2 | * helper functions for PCI DMA video4linux capture buffers | |
3 | * | |
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. | |
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 | */ | |
30 | struct 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 | */ | |
37 | struct 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_*() | |
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 ...) | |
55 | * | |
56 | * videobuf_dma_free() | |
57 | * no comment ... | |
58 | * | |
59 | */ | |
60 | ||
61 | struct 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 | ||
71 | /* Stores the userspace pointer to vmalloc area */ | |
72 | void *varea; | |
73 | ||
74 | /* for overlay buffers (pci-pci dma) */ | |
75 | dma_addr_t bus_addr; | |
76 | ||
77 | /* common */ | |
78 | struct scatterlist *sglist; | |
79 | int sglen; | |
80 | int nr_pages; | |
81 | int direction; | |
82 | }; | |
83 | ||
84 | struct videbuf_pci_sg_memory | |
85 | { | |
86 | u32 magic; | |
87 | ||
88 | /* for mmap'ed buffers */ | |
7a7d9a89 MCC |
89 | struct videobuf_dmabuf dma; |
90 | }; | |
91 | ||
7a7d9a89 MCC |
92 | void videobuf_dma_init(struct videobuf_dmabuf *dma); |
93 | int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction, | |
94 | unsigned long data, unsigned long size); | |
95 | int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction, | |
96 | int nr_pages); | |
97 | int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction, | |
98 | dma_addr_t addr, int nr_pages); | |
99 | int videobuf_dma_free(struct videobuf_dmabuf *dma); | |
100 | ||
101 | int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma); | |
102 | int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma); | |
103 | int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma); | |
104 | struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf); | |
105 | ||
106 | void *videobuf_pci_alloc (size_t size); | |
107 | ||
108 | void videobuf_queue_pci_init(struct videobuf_queue* q, | |
109 | struct videobuf_queue_ops *ops, | |
110 | void *dev, | |
111 | spinlock_t *irqlock, | |
112 | enum v4l2_buf_type type, | |
113 | enum v4l2_field field, | |
114 | unsigned int msize, | |
115 | void *priv); | |
116 | ||
117 | /*FIXME: these variants are used only on *-alsa code, where videobuf is | |
118 | * used without queue | |
119 | */ | |
120 | int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma); | |
121 | int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma); | |
122 |