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android-review.linaro.org / kernel / hikey-linaro / 7a7d9a89d0307b1743d782197e2c5fc5ddf183f3 / . / include / media / videobuf-dma-sg.h
blob: 62a3709905f341798a04691e28123610157d7318 [file] [log] [blame]
Mauro Carvalho Chehab7a7d9a892007-08-23 16:26:14 -0300[diff] [blame^]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 */
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_*()
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
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
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
84struct videbuf_pci_sg_memory
85{
86 u32 magic;
87
88 /* for mmap'ed buffers */
89 struct videobuf_mapping *map;
90 struct videobuf_dmabuf dma;
91};
92
93/* FIXME: To be removed soon */
94typedef int (vb_map_sg_t)(void *dev, struct scatterlist *sglist, int nr_pages,
95 int direction);
96
97/* FIXME: To be removed soon */
98struct videobuf_dma_sg_ops
99{
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;
103
104};
105
106void videobuf_dma_init(struct videobuf_dmabuf *dma);
107int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
108 unsigned long data, unsigned long size);
109int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
110 int nr_pages);
111int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
112 dma_addr_t addr, int nr_pages);
113int videobuf_dma_free(struct videobuf_dmabuf *dma);
114
115int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
116int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
117int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
118struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf);
119
120void *videobuf_pci_alloc (size_t size);
121
122void videobuf_queue_pci_init(struct videobuf_queue* q,
123 struct videobuf_queue_ops *ops,
124 void *dev,
125 spinlock_t *irqlock,
126 enum v4l2_buf_type type,
127 enum v4l2_field field,
128 unsigned int msize,
129 void *priv);
130
131 /*FIXME: these variants are used only on *-alsa code, where videobuf is
132 * used without queue
133 */
134int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma);
135int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma);
136
137/* FIXME: temporary routine for vivi and tm6000, while lacking implementation
138 * of videobuf-vmalloc
139 */
140void videobuf_set_pci_ops (struct videobuf_queue* q,
141 struct videobuf_dma_sg_ops *ops);
142