summaryrefslogtreecommitdiffstats
path: root/include/media/video-buf.h
blob: ae8d7a0004402715d015e2962287a9a9c9161f00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 *
 * 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:
 */
OpenPOWER on IntegriCloud