Loading...
Note: File does not exist in v6.9.4.
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * generic helper functions for handling video4linux capture buffers
4 *
5 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
6 *
7 * Highly based on video-buf written originally by:
8 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
9 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
10 * (c) 2006 Ted Walther and John Sokol
11 */
12
13#ifndef _VIDEOBUF_CORE_H
14#define _VIDEOBUF_CORE_H
15
16#include <linux/poll.h>
17#include <linux/videodev2.h>
18
19#define UNSET (-1U)
20
21
22struct videobuf_buffer;
23struct videobuf_queue;
24
25/* --------------------------------------------------------------------- */
26
27/*
28 * A small set of helper functions to manage video4linux buffers.
29 *
30 * struct videobuf_buffer holds the data structures used by the helper
31 * functions, additionally some commonly used fields for v4l buffers
32 * (width, height, lists, waitqueue) are in there. That struct should
33 * be used as first element in the drivers buffer struct.
34 *
35 * about the mmap helpers (videobuf_mmap_*):
36 *
37 * The mmaper function allows to map any subset of contiguous buffers.
38 * This includes one mmap() call for all buffers (which the original
39 * video4linux API uses) as well as one mmap() for every single buffer
40 * (which v4l2 uses).
41 *
42 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
43 * userspace address + size which can be fed into the
44 * videobuf_dma_init_user function listed above.
45 *
46 */
47
48struct videobuf_mapping {
49 unsigned int count;
50 struct videobuf_queue *q;
51};
52
53enum videobuf_state {
54 VIDEOBUF_NEEDS_INIT = 0,
55 VIDEOBUF_PREPARED = 1,
56 VIDEOBUF_QUEUED = 2,
57 VIDEOBUF_ACTIVE = 3,
58 VIDEOBUF_DONE = 4,
59 VIDEOBUF_ERROR = 5,
60 VIDEOBUF_IDLE = 6,
61};
62
63struct videobuf_buffer {
64 unsigned int i;
65 u32 magic;
66
67 /* info about the buffer */
68 unsigned int width;
69 unsigned int height;
70 unsigned int bytesperline; /* use only if != 0 */
71 unsigned long size;
72 enum v4l2_field field;
73 enum videobuf_state state;
74 struct list_head stream; /* QBUF/DQBUF list */
75
76 /* touched by irq handler */
77 struct list_head queue;
78 wait_queue_head_t done;
79 unsigned int field_count;
80 u64 ts;
81
82 /* Memory type */
83 enum v4l2_memory memory;
84
85 /* buffer size */
86 size_t bsize;
87
88 /* buffer offset (mmap + overlay) */
89 size_t boff;
90
91 /* buffer addr (userland ptr!) */
92 unsigned long baddr;
93
94 /* for mmap'ed buffers */
95 struct videobuf_mapping *map;
96
97 /* Private pointer to allow specific methods to store their data */
98 int privsize;
99 void *priv;
100};
101
102struct videobuf_queue_ops {
103 int (*buf_setup)(struct videobuf_queue *q,
104 unsigned int *count, unsigned int *size);
105 int (*buf_prepare)(struct videobuf_queue *q,
106 struct videobuf_buffer *vb,
107 enum v4l2_field field);
108 void (*buf_queue)(struct videobuf_queue *q,
109 struct videobuf_buffer *vb);
110 void (*buf_release)(struct videobuf_queue *q,
111 struct videobuf_buffer *vb);
112};
113
114#define MAGIC_QTYPE_OPS 0x12261003
115
116/* Helper operations - device type dependent */
117struct videobuf_qtype_ops {
118 u32 magic;
119
120 struct videobuf_buffer *(*alloc_vb)(size_t size);
121 void *(*vaddr) (struct videobuf_buffer *buf);
122 int (*iolock) (struct videobuf_queue *q,
123 struct videobuf_buffer *vb,
124 struct v4l2_framebuffer *fbuf);
125 int (*sync) (struct videobuf_queue *q,
126 struct videobuf_buffer *buf);
127 int (*mmap_mapper) (struct videobuf_queue *q,
128 struct videobuf_buffer *buf,
129 struct vm_area_struct *vma);
130};
131
132struct videobuf_queue {
133 struct mutex vb_lock;
134 struct mutex *ext_lock;
135 spinlock_t *irqlock;
136 struct device *dev;
137
138 wait_queue_head_t wait; /* wait if queue is empty */
139
140 enum v4l2_buf_type type;
141 unsigned int msize;
142 enum v4l2_field field;
143 enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */
144 struct videobuf_buffer *bufs[VIDEO_MAX_FRAME];
145 const struct videobuf_queue_ops *ops;
146 struct videobuf_qtype_ops *int_ops;
147
148 unsigned int streaming:1;
149 unsigned int reading:1;
150
151 /* capture via mmap() + ioctl(QBUF/DQBUF) */
152 struct list_head stream;
153
154 /* capture via read() */
155 unsigned int read_off;
156 struct videobuf_buffer *read_buf;
157
158 /* driver private data */
159 void *priv_data;
160};
161
162static inline void videobuf_queue_lock(struct videobuf_queue *q)
163{
164 if (!q->ext_lock)
165 mutex_lock(&q->vb_lock);
166}
167
168static inline void videobuf_queue_unlock(struct videobuf_queue *q)
169{
170 if (!q->ext_lock)
171 mutex_unlock(&q->vb_lock);
172}
173
174int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
175 int non_blocking, int intr);
176int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
177 struct v4l2_framebuffer *fbuf);
178
179struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
180
181/* Used on videobuf-dvb */
182void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
183 struct videobuf_buffer *buf);
184
185void videobuf_queue_core_init(struct videobuf_queue *q,
186 const struct videobuf_queue_ops *ops,
187 struct device *dev,
188 spinlock_t *irqlock,
189 enum v4l2_buf_type type,
190 enum v4l2_field field,
191 unsigned int msize,
192 void *priv,
193 struct videobuf_qtype_ops *int_ops,
194 struct mutex *ext_lock);
195int videobuf_queue_is_busy(struct videobuf_queue *q);
196void videobuf_queue_cancel(struct videobuf_queue *q);
197
198enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
199int videobuf_reqbufs(struct videobuf_queue *q,
200 struct v4l2_requestbuffers *req);
201int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
202int videobuf_qbuf(struct videobuf_queue *q,
203 struct v4l2_buffer *b);
204int videobuf_dqbuf(struct videobuf_queue *q,
205 struct v4l2_buffer *b, int nonblocking);
206int videobuf_streamon(struct videobuf_queue *q);
207int videobuf_streamoff(struct videobuf_queue *q);
208
209void videobuf_stop(struct videobuf_queue *q);
210
211int videobuf_read_start(struct videobuf_queue *q);
212void videobuf_read_stop(struct videobuf_queue *q);
213ssize_t videobuf_read_stream(struct videobuf_queue *q,
214 char __user *data, size_t count, loff_t *ppos,
215 int vbihack, int nonblocking);
216ssize_t videobuf_read_one(struct videobuf_queue *q,
217 char __user *data, size_t count, loff_t *ppos,
218 int nonblocking);
219__poll_t videobuf_poll_stream(struct file *file,
220 struct videobuf_queue *q,
221 poll_table *wait);
222
223int videobuf_mmap_setup(struct videobuf_queue *q,
224 unsigned int bcount, unsigned int bsize,
225 enum v4l2_memory memory);
226int __videobuf_mmap_setup(struct videobuf_queue *q,
227 unsigned int bcount, unsigned int bsize,
228 enum v4l2_memory memory);
229int videobuf_mmap_free(struct videobuf_queue *q);
230int videobuf_mmap_mapper(struct videobuf_queue *q,
231 struct vm_area_struct *vma);
232
233#endif