1 /*
2  * videobuf2-v4l2.h - V4L2 driver helper framework
3  *
4  * Copyright (C) 2010 Samsung Electronics
5  *
6  * Author: Pawel Osciak <pawel@osciak.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation.
11  */
12 #ifndef _MEDIA_VIDEOBUF2_V4L2_H
13 #define _MEDIA_VIDEOBUF2_V4L2_H
14 
15 #include <linux/videodev2.h>
16 #include <media/videobuf2-core.h>
17 
18 #if VB2_MAX_FRAME != VIDEO_MAX_FRAME
19 #error VB2_MAX_FRAME != VIDEO_MAX_FRAME
20 #endif
21 
22 #if VB2_MAX_PLANES != VIDEO_MAX_PLANES
23 #error VB2_MAX_PLANES != VIDEO_MAX_PLANES
24 #endif
25 
26 /**
27  * struct vb2_v4l2_buffer - video buffer information for v4l2
28  * @vb2_buf:	video buffer 2
29  * @flags:	buffer informational flags
30  * @field:	enum v4l2_field; field order of the image in the buffer
31  * @timestamp:	frame timestamp
32  * @timecode:	frame timecode
33  * @sequence:	sequence count of this frame
34  * Should contain enough information to be able to cover all the fields
35  * of struct v4l2_buffer at videodev2.h
36  */
37 struct vb2_v4l2_buffer {
38 	struct vb2_buffer	vb2_buf;
39 
40 	__u32			flags;
41 	__u32			field;
42 	struct timeval		timestamp;
43 	struct v4l2_timecode	timecode;
44 	__u32			sequence;
45 };
46 
47 /*
48  * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
49  */
50 #define to_vb2_v4l2_buffer(vb) \
51 	container_of(vb, struct vb2_v4l2_buffer, vb2_buf)
52 
53 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
54 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
55 
56 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
57 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
58 
59 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
60 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
61 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
62 
63 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
64 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
65 
66 int __must_check vb2_queue_init(struct vb2_queue *q);
67 void vb2_queue_release(struct vb2_queue *q);
68 
69 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
70 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
71 		loff_t *ppos, int nonblock);
72 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
73 		loff_t *ppos, int nonblock);
74 
75 /*
76  * vb2_thread_fnc - callback function for use with vb2_thread
77  *
78  * This is called whenever a buffer is dequeued in the thread.
79  */
80 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
81 
82 /**
83  * vb2_thread_start() - start a thread for the given queue.
84  * @q:		videobuf queue
85  * @fnc:	callback function
86  * @priv:	priv pointer passed to the callback function
87  * @thread_name:the name of the thread. This will be prefixed with "vb2-".
88  *
89  * This starts a thread that will queue and dequeue until an error occurs
90  * or @vb2_thread_stop is called.
91  *
92  * This function should not be used for anything else but the videobuf2-dvb
93  * support. If you think you have another good use-case for this, then please
94  * contact the linux-media mailinglist first.
95  */
96 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
97 		     const char *thread_name);
98 
99 /**
100  * vb2_thread_stop() - stop the thread for the given queue.
101  * @q:		videobuf queue
102  */
103 int vb2_thread_stop(struct vb2_queue *q);
104 
105 /*
106  * The following functions are not part of the vb2 core API, but are simple
107  * helper functions that you can use in your struct v4l2_file_operations,
108  * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
109  * or video_device->lock is set, and they will set and test vb2_queue->owner
110  * to check if the calling filehandle is permitted to do the queuing operation.
111  */
112 
113 /* struct v4l2_ioctl_ops helpers */
114 
115 int vb2_ioctl_reqbufs(struct file *file, void *priv,
116 			  struct v4l2_requestbuffers *p);
117 int vb2_ioctl_create_bufs(struct file *file, void *priv,
118 			  struct v4l2_create_buffers *p);
119 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
120 			  struct v4l2_buffer *p);
121 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
122 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
123 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
124 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
125 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
126 int vb2_ioctl_expbuf(struct file *file, void *priv,
127 	struct v4l2_exportbuffer *p);
128 
129 /* struct v4l2_file_operations helpers */
130 
131 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
132 int vb2_fop_release(struct file *file);
133 int _vb2_fop_release(struct file *file, struct mutex *lock);
134 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
135 		size_t count, loff_t *ppos);
136 ssize_t vb2_fop_read(struct file *file, char __user *buf,
137 		size_t count, loff_t *ppos);
138 unsigned int vb2_fop_poll(struct file *file, poll_table *wait);
139 #ifndef CONFIG_MMU
140 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
141 		unsigned long len, unsigned long pgoff, unsigned long flags);
142 #endif
143 
144 /* struct vb2_ops helpers, only use if vq->lock is non-NULL. */
145 
146 void vb2_ops_wait_prepare(struct vb2_queue *vq);
147 void vb2_ops_wait_finish(struct vb2_queue *vq);
148 
149 #endif /* _MEDIA_VIDEOBUF2_V4L2_H */
150