1 /*
2 * generic helper functions for handling video4linux capture buffers
3 *
4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
5 *
6 * Highly based on video-buf written originally by:
7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
8 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
9 * (c) 2006 Ted Walther and John Sokol
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2
14 */
15
16 #ifndef _VIDEOBUF_CORE_H
17 #define _VIDEOBUF_CORE_H
18
19 #include <linux/poll.h>
20 #include <linux/videodev2.h>
21
22 #define UNSET (-1U)
23
24
25 struct videobuf_buffer;
26 struct videobuf_queue;
27
28 /* --------------------------------------------------------------------- */
29
30 /*
31 * A small set of helper functions to manage video4linux buffers.
32 *
33 * struct videobuf_buffer holds the data structures used by the helper
34 * functions, additionally some commonly used fields for v4l buffers
35 * (width, height, lists, waitqueue) are in there. That struct should
36 * be used as first element in the drivers buffer struct.
37 *
38 * about the mmap helpers (videobuf_mmap_*):
39 *
40 * The mmaper function allows to map any subset of contiguous buffers.
41 * This includes one mmap() call for all buffers (which the original
42 * video4linux API uses) as well as one mmap() for every single buffer
43 * (which v4l2 uses).
44 *
45 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
46 * userspace address + size which can be feeded into the
47 * videobuf_dma_init_user function listed above.
48 *
49 */
50
51 struct videobuf_mapping {
52 unsigned int count;
53 struct videobuf_queue *q;
54 };
55
56 enum videobuf_state {
57 VIDEOBUF_NEEDS_INIT = 0,
58 VIDEOBUF_PREPARED = 1,
59 VIDEOBUF_QUEUED = 2,
60 VIDEOBUF_ACTIVE = 3,
61 VIDEOBUF_DONE = 4,
62 VIDEOBUF_ERROR = 5,
63 VIDEOBUF_IDLE = 6,
64 };
65
66 struct videobuf_buffer {
67 unsigned int i;
68 u32 magic;
69
70 /* info about the buffer */
71 unsigned int width;
72 unsigned int height;
73 unsigned int bytesperline; /* use only if != 0 */
74 unsigned long size;
75 enum v4l2_field field;
76 enum videobuf_state state;
77 struct list_head stream; /* QBUF/DQBUF list */
78
79 /* touched by irq handler */
80 struct list_head queue;
81 wait_queue_head_t done;
82 unsigned int field_count;
83 struct timeval ts;
84
85 /* Memory type */
86 enum v4l2_memory memory;
87
88 /* buffer size */
89 size_t bsize;
90
91 /* buffer offset (mmap + overlay) */
92 size_t boff;
93
94 /* buffer addr (userland ptr!) */
95 unsigned long baddr;
96
97 /* for mmap'ed buffers */
98 struct videobuf_mapping *map;
99
100 /* Private pointer to allow specific methods to store their data */
101 int privsize;
102 void *priv;
103 };
104
105 struct videobuf_queue_ops {
106 int (*buf_setup)(struct videobuf_queue *q,
107 unsigned int *count, unsigned int *size);
108 int (*buf_prepare)(struct videobuf_queue *q,
109 struct videobuf_buffer *vb,
110 enum v4l2_field field);
111 void (*buf_queue)(struct videobuf_queue *q,
112 struct videobuf_buffer *vb);
113 void (*buf_release)(struct videobuf_queue *q,
114 struct videobuf_buffer *vb);
115 };
116
117 #define MAGIC_QTYPE_OPS 0x12261003
118
119 /* Helper operations - device type dependent */
120 struct videobuf_qtype_ops {
121 u32 magic;
122
123 struct videobuf_buffer *(*alloc_vb)(size_t size);
124 void *(*vaddr) (struct videobuf_buffer *buf);
125 int (*iolock) (struct videobuf_queue *q,
126 struct videobuf_buffer *vb,
127 struct v4l2_framebuffer *fbuf);
128 int (*sync) (struct videobuf_queue *q,
129 struct videobuf_buffer *buf);
130 int (*mmap_mapper) (struct videobuf_queue *q,
131 struct videobuf_buffer *buf,
132 struct vm_area_struct *vma);
133 };
134
135 struct videobuf_queue {
136 struct mutex vb_lock;
137 struct mutex *ext_lock;
138 spinlock_t *irqlock;
139 struct device *dev;
140
141 wait_queue_head_t wait; /* wait if queue is empty */
142
143 enum v4l2_buf_type type;
144 unsigned int msize;
145 enum v4l2_field field;
146 enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */
147 struct videobuf_buffer *bufs[VIDEO_MAX_FRAME];
148 const struct videobuf_queue_ops *ops;
149 struct videobuf_qtype_ops *int_ops;
150
151 unsigned int streaming:1;
152 unsigned int reading:1;
153
154 /* capture via mmap() + ioctl(QBUF/DQBUF) */
155 struct list_head stream;
156
157 /* capture via read() */
158 unsigned int read_off;
159 struct videobuf_buffer *read_buf;
160
161 /* driver private data */
162 void *priv_data;
163 };
164
videobuf_queue_lock(struct videobuf_queue * q)165 static inline void videobuf_queue_lock(struct videobuf_queue *q)
166 {
167 if (!q->ext_lock)
168 mutex_lock(&q->vb_lock);
169 }
170
videobuf_queue_unlock(struct videobuf_queue * q)171 static inline void videobuf_queue_unlock(struct videobuf_queue *q)
172 {
173 if (!q->ext_lock)
174 mutex_unlock(&q->vb_lock);
175 }
176
177 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
178 int non_blocking, int intr);
179 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
180 struct v4l2_framebuffer *fbuf);
181
182 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
183
184 /* Used on videobuf-dvb */
185 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
186 struct videobuf_buffer *buf);
187
188 void videobuf_queue_core_init(struct videobuf_queue *q,
189 const struct videobuf_queue_ops *ops,
190 struct device *dev,
191 spinlock_t *irqlock,
192 enum v4l2_buf_type type,
193 enum v4l2_field field,
194 unsigned int msize,
195 void *priv,
196 struct videobuf_qtype_ops *int_ops,
197 struct mutex *ext_lock);
198 int videobuf_queue_is_busy(struct videobuf_queue *q);
199 void videobuf_queue_cancel(struct videobuf_queue *q);
200
201 enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
202 int videobuf_reqbufs(struct videobuf_queue *q,
203 struct v4l2_requestbuffers *req);
204 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
205 int videobuf_qbuf(struct videobuf_queue *q,
206 struct v4l2_buffer *b);
207 int videobuf_dqbuf(struct videobuf_queue *q,
208 struct v4l2_buffer *b, int nonblocking);
209 int videobuf_streamon(struct videobuf_queue *q);
210 int videobuf_streamoff(struct videobuf_queue *q);
211
212 void videobuf_stop(struct videobuf_queue *q);
213
214 int videobuf_read_start(struct videobuf_queue *q);
215 void videobuf_read_stop(struct videobuf_queue *q);
216 ssize_t videobuf_read_stream(struct videobuf_queue *q,
217 char __user *data, size_t count, loff_t *ppos,
218 int vbihack, int nonblocking);
219 ssize_t videobuf_read_one(struct videobuf_queue *q,
220 char __user *data, size_t count, loff_t *ppos,
221 int nonblocking);
222 __poll_t videobuf_poll_stream(struct file *file,
223 struct videobuf_queue *q,
224 poll_table *wait);
225
226 int videobuf_mmap_setup(struct videobuf_queue *q,
227 unsigned int bcount, unsigned int bsize,
228 enum v4l2_memory memory);
229 int __videobuf_mmap_setup(struct videobuf_queue *q,
230 unsigned int bcount, unsigned int bsize,
231 enum v4l2_memory memory);
232 int videobuf_mmap_free(struct videobuf_queue *q);
233 int videobuf_mmap_mapper(struct videobuf_queue *q,
234 struct vm_area_struct *vma);
235
236 #endif
237
