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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 *
29 * @vb2_buf: embedded struct &vb2_buffer.
30 * @flags: buffer informational flags.
31 * @field: field order of the image in the buffer, as defined by
32 * &enum v4l2_field.
33 * @timecode: frame timecode.
34 * @sequence: sequence count of this frame.
35 * @request_fd: the request_fd associated with this buffer
36 * @is_held: if true, then this capture buffer was held
37 * @planes: plane information (userptr/fd, length, bytesused, data_offset).
38 *
39 * Should contain enough information to be able to cover all the fields
40 * of &struct v4l2_buffer at ``videodev2.h``.
41 */
42struct vb2_v4l2_buffer {
43 struct vb2_buffer vb2_buf;
44
45 __u32 flags;
46 __u32 field;
47 struct v4l2_timecode timecode;
48 __u32 sequence;
49 __s32 request_fd;
50 bool is_held;
51 struct vb2_plane planes[VB2_MAX_PLANES];
52};
53
54/* VB2 V4L2 flags as set in vb2_queue.subsystem_flags */
55#define VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 0)
56
57/*
58 * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
59 */
60#define to_vb2_v4l2_buffer(vb) \
61 container_of(vb, struct vb2_v4l2_buffer, vb2_buf)
62
63/**
64 * vb2_find_timestamp() - Find buffer with given timestamp in the queue
65 *
66 * @q: pointer to &struct vb2_queue with videobuf2 queue.
67 * @timestamp: the timestamp to find.
68 * @start_idx: the start index (usually 0) in the buffer array to start
69 * searching from. Note that there may be multiple buffers
70 * with the same timestamp value, so you can restart the search
71 * by setting @start_idx to the previously found index + 1.
72 *
73 * Returns the buffer index of the buffer with the given @timestamp, or
74 * -1 if no buffer with @timestamp was found.
75 */
76int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
77 unsigned int start_idx);
78
79int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
80
81/**
82 * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
83 * the memory and type values.
84 *
85 * @q: pointer to &struct vb2_queue with videobuf2 queue.
86 * @req: &struct v4l2_requestbuffers passed from userspace to
87 * &v4l2_ioctl_ops->vidioc_reqbufs handler in driver.
88 */
89int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
90
91/**
92 * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
93 * the memory and type values.
94 *
95 * @q: pointer to &struct vb2_queue with videobuf2 queue.
96 * @create: creation parameters, passed from userspace to
97 * &v4l2_ioctl_ops->vidioc_create_bufs handler in driver
98 */
99int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
100
101/**
102 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
103 *
104 * @q: pointer to &struct vb2_queue with videobuf2 queue.
105 * @mdev: pointer to &struct media_device, may be NULL.
106 * @b: buffer structure passed from userspace to
107 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver
108 *
109 * Should be called from &v4l2_ioctl_ops->vidioc_prepare_buf ioctl handler
110 * of a driver.
111 *
112 * This function:
113 *
114 * #) verifies the passed buffer,
115 * #) calls &vb2_ops->buf_prepare callback in the driver (if provided),
116 * in which driver-specific buffer initialization can be performed.
117 * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
118 * then bind the prepared buffer to the request.
119 *
120 * The return values from this function are intended to be directly returned
121 * from &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
122 */
123int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
124 struct v4l2_buffer *b);
125
126/**
127 * vb2_qbuf() - Queue a buffer from userspace
128 * @q: pointer to &struct vb2_queue with videobuf2 queue.
129 * @mdev: pointer to &struct media_device, may be NULL.
130 * @b: buffer structure passed from userspace to
131 * &v4l2_ioctl_ops->vidioc_qbuf handler in driver
132 *
133 * Should be called from &v4l2_ioctl_ops->vidioc_qbuf handler of a driver.
134 *
135 * This function:
136 *
137 * #) verifies the passed buffer;
138 * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
139 * then bind the buffer to the request.
140 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
141 * (if provided), in which driver-specific buffer initialization can
142 * be performed;
143 * #) if streaming is on, queues the buffer in driver by the means of
144 * &vb2_ops->buf_queue callback for processing.
145 *
146 * The return values from this function are intended to be directly returned
147 * from &v4l2_ioctl_ops->vidioc_qbuf handler in driver.
148 */
149int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
150 struct v4l2_buffer *b);
151
152/**
153 * vb2_expbuf() - Export a buffer as a file descriptor
154 * @q: pointer to &struct vb2_queue with videobuf2 queue.
155 * @eb: export buffer structure passed from userspace to
156 * &v4l2_ioctl_ops->vidioc_expbuf handler in driver
157 *
158 * The return values from this function are intended to be directly returned
159 * from &v4l2_ioctl_ops->vidioc_expbuf handler in driver.
160 */
161int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
162
163/**
164 * vb2_dqbuf() - Dequeue a buffer to the userspace
165 * @q: pointer to &struct vb2_queue with videobuf2 queue.
166 * @b: buffer structure passed from userspace to
167 * &v4l2_ioctl_ops->vidioc_dqbuf handler in driver
168 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
169 * buffers ready for dequeuing are present. Normally the driver
170 * would be passing (&file->f_flags & %O_NONBLOCK) here
171 *
172 * Should be called from &v4l2_ioctl_ops->vidioc_dqbuf ioctl handler
173 * of a driver.
174 *
175 * This function:
176 *
177 * #) verifies the passed buffer;
178 * #) calls &vb2_ops->buf_finish callback in the driver (if provided), in which
179 * driver can perform any additional operations that may be required before
180 * returning the buffer to userspace, such as cache sync;
181 * #) the buffer struct members are filled with relevant information for
182 * the userspace.
183 *
184 * The return values from this function are intended to be directly returned
185 * from &v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
186 */
187int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
188
189/**
190 * vb2_streamon - start streaming
191 * @q: pointer to &struct vb2_queue with videobuf2 queue.
192 * @type: type argument passed from userspace to vidioc_streamon handler,
193 * as defined by &enum v4l2_buf_type.
194 *
195 * Should be called from &v4l2_ioctl_ops->vidioc_streamon handler of a driver.
196 *
197 * This function:
198 *
199 * 1) verifies current state
200 * 2) passes any previously queued buffers to the driver and starts streaming
201 *
202 * The return values from this function are intended to be directly returned
203 * from &v4l2_ioctl_ops->vidioc_streamon handler in the driver.
204 */
205int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
206
207/**
208 * vb2_streamoff - stop streaming
209 * @q: pointer to &struct vb2_queue with videobuf2 queue.
210 * @type: type argument passed from userspace to vidioc_streamoff handler
211 *
212 * Should be called from vidioc_streamoff handler of a driver.
213 *
214 * This function:
215 *
216 * #) verifies current state,
217 * #) stop streaming and dequeues any queued buffers, including those previously
218 * passed to the driver (after waiting for the driver to finish).
219 *
220 * This call can be used for pausing playback.
221 * The return values from this function are intended to be directly returned
222 * from vidioc_streamoff handler in the driver
223 */
224int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
225
226/**
227 * vb2_queue_init() - initialize a videobuf2 queue
228 * @q: pointer to &struct vb2_queue with videobuf2 queue.
229 *
230 * The vb2_queue structure should be allocated by the driver. The driver is
231 * responsible of clearing it's content and setting initial values for some
232 * required entries before calling this function.
233 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
234 * to the struct vb2_queue description in include/media/videobuf2-core.h
235 * for more information.
236 */
237int __must_check vb2_queue_init(struct vb2_queue *q);
238
239/**
240 * vb2_queue_init_name() - initialize a videobuf2 queue with a name
241 * @q: pointer to &struct vb2_queue with videobuf2 queue.
242 * @name: the queue name
243 *
244 * This function initializes the vb2_queue exactly like vb2_queue_init(),
245 * and additionally sets the queue name. The queue name is used for logging
246 * purpose, and should uniquely identify the queue within the context of the
247 * device it belongs to. This is useful to attribute kernel log messages to the
248 * right queue for m2m devices or other devices that handle multiple queues.
249 */
250int __must_check vb2_queue_init_name(struct vb2_queue *q, const char *name);
251
252/**
253 * vb2_queue_release() - stop streaming, release the queue and free memory
254 * @q: pointer to &struct vb2_queue with videobuf2 queue.
255 *
256 * This function stops streaming and performs necessary clean ups, including
257 * freeing video buffer memory. The driver is responsible for freeing
258 * the vb2_queue structure itself.
259 */
260void vb2_queue_release(struct vb2_queue *q);
261
262/**
263 * vb2_poll() - implements poll userspace operation
264 * @q: pointer to &struct vb2_queue with videobuf2 queue.
265 * @file: file argument passed to the poll file operation handler
266 * @wait: wait argument passed to the poll file operation handler
267 *
268 * This function implements poll file operation handler for a driver.
269 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
270 * be informed that the file descriptor of a video device is available for
271 * reading.
272 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
273 * will be reported as available for writing.
274 *
275 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
276 * pending events.
277 *
278 * The return values from this function are intended to be directly returned
279 * from poll handler in driver.
280 */
281__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
282
283/*
284 * The following functions are not part of the vb2 core API, but are simple
285 * helper functions that you can use in your struct v4l2_file_operations,
286 * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
287 * or video_device->lock is set, and they will set and test vb2_queue->owner
288 * to check if the calling filehandle is permitted to do the queuing operation.
289 */
290
291/* struct v4l2_ioctl_ops helpers */
292
293int vb2_ioctl_reqbufs(struct file *file, void *priv,
294 struct v4l2_requestbuffers *p);
295int vb2_ioctl_create_bufs(struct file *file, void *priv,
296 struct v4l2_create_buffers *p);
297int vb2_ioctl_prepare_buf(struct file *file, void *priv,
298 struct v4l2_buffer *p);
299int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
300int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
301int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
302int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
303int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
304int vb2_ioctl_expbuf(struct file *file, void *priv,
305 struct v4l2_exportbuffer *p);
306
307/* struct v4l2_file_operations helpers */
308
309int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
310int vb2_fop_release(struct file *file);
311int _vb2_fop_release(struct file *file, struct mutex *lock);
312ssize_t vb2_fop_write(struct file *file, const char __user *buf,
313 size_t count, loff_t *ppos);
314ssize_t vb2_fop_read(struct file *file, char __user *buf,
315 size_t count, loff_t *ppos);
316__poll_t vb2_fop_poll(struct file *file, poll_table *wait);
317#ifndef CONFIG_MMU
318unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
319 unsigned long len, unsigned long pgoff, unsigned long flags);
320#endif
321
322/**
323 * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
324 *
325 * @vq: pointer to &struct vb2_queue
326 *
327 * ..note:: only use if vq->lock is non-NULL.
328 */
329void vb2_ops_wait_prepare(struct vb2_queue *vq);
330
331/**
332 * vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
333 *
334 * @vq: pointer to &struct vb2_queue
335 *
336 * ..note:: only use if vq->lock is non-NULL.
337 */
338void vb2_ops_wait_finish(struct vb2_queue *vq);
339
340struct media_request;
341int vb2_request_validate(struct media_request *req);
342void vb2_request_queue(struct media_request *req);
343
344#endif /* _MEDIA_VIDEOBUF2_V4L2_H */
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
26struct video_device;
27
28/**
29 * struct vb2_v4l2_buffer - video buffer information for v4l2.
30 *
31 * @vb2_buf: embedded struct &vb2_buffer.
32 * @flags: buffer informational flags.
33 * @field: field order of the image in the buffer, as defined by
34 * &enum v4l2_field.
35 * @timecode: frame timecode.
36 * @sequence: sequence count of this frame.
37 * @request_fd: the request_fd associated with this buffer
38 * @is_held: if true, then this capture buffer was held
39 * @planes: plane information (userptr/fd, length, bytesused, data_offset).
40 *
41 * Should contain enough information to be able to cover all the fields
42 * of &struct v4l2_buffer at ``videodev2.h``.
43 */
44struct vb2_v4l2_buffer {
45 struct vb2_buffer vb2_buf;
46
47 __u32 flags;
48 __u32 field;
49 struct v4l2_timecode timecode;
50 __u32 sequence;
51 __s32 request_fd;
52 bool is_held;
53 struct vb2_plane planes[VB2_MAX_PLANES];
54};
55
56/* VB2 V4L2 flags as set in vb2_queue.subsystem_flags */
57#define VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 0)
58
59/*
60 * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *
61 */
62#define to_vb2_v4l2_buffer(vb) \
63 container_of(vb, struct vb2_v4l2_buffer, vb2_buf)
64
65/**
66 * vb2_find_timestamp() - Find buffer with given timestamp in the queue
67 *
68 * @q: pointer to &struct vb2_queue with videobuf2 queue.
69 * @timestamp: the timestamp to find.
70 * @start_idx: the start index (usually 0) in the buffer array to start
71 * searching from. Note that there may be multiple buffers
72 * with the same timestamp value, so you can restart the search
73 * by setting @start_idx to the previously found index + 1.
74 *
75 * Returns the buffer index of the buffer with the given @timestamp, or
76 * -1 if no buffer with @timestamp was found.
77 */
78int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
79 unsigned int start_idx);
80
81int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
82
83/**
84 * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
85 * the memory and type values.
86 *
87 * @q: pointer to &struct vb2_queue with videobuf2 queue.
88 * @req: &struct v4l2_requestbuffers passed from userspace to
89 * &v4l2_ioctl_ops->vidioc_reqbufs handler in driver.
90 */
91int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
92
93/**
94 * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
95 * the memory and type values.
96 *
97 * @q: pointer to &struct vb2_queue with videobuf2 queue.
98 * @create: creation parameters, passed from userspace to
99 * &v4l2_ioctl_ops->vidioc_create_bufs handler in driver
100 */
101int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
102
103/**
104 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
105 *
106 * @q: pointer to &struct vb2_queue with videobuf2 queue.
107 * @mdev: pointer to &struct media_device, may be NULL.
108 * @b: buffer structure passed from userspace to
109 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver
110 *
111 * Should be called from &v4l2_ioctl_ops->vidioc_prepare_buf ioctl handler
112 * of a driver.
113 *
114 * This function:
115 *
116 * #) verifies the passed buffer,
117 * #) calls &vb2_ops->buf_prepare callback in the driver (if provided),
118 * in which driver-specific buffer initialization can be performed.
119 * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
120 * then bind the prepared buffer to the request.
121 *
122 * The return values from this function are intended to be directly returned
123 * from &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
124 */
125int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
126 struct v4l2_buffer *b);
127
128/**
129 * vb2_qbuf() - Queue a buffer from userspace
130 * @q: pointer to &struct vb2_queue with videobuf2 queue.
131 * @mdev: pointer to &struct media_device, may be NULL.
132 * @b: buffer structure passed from userspace to
133 * &v4l2_ioctl_ops->vidioc_qbuf handler in driver
134 *
135 * Should be called from &v4l2_ioctl_ops->vidioc_qbuf handler of a driver.
136 *
137 * This function:
138 *
139 * #) verifies the passed buffer;
140 * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
141 * then bind the buffer to the request.
142 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
143 * (if provided), in which driver-specific buffer initialization can
144 * be performed;
145 * #) if streaming is on, queues the buffer in driver by the means of
146 * &vb2_ops->buf_queue callback for processing.
147 *
148 * The return values from this function are intended to be directly returned
149 * from &v4l2_ioctl_ops->vidioc_qbuf handler in driver.
150 */
151int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
152 struct v4l2_buffer *b);
153
154/**
155 * vb2_expbuf() - Export a buffer as a file descriptor
156 * @q: pointer to &struct vb2_queue with videobuf2 queue.
157 * @eb: export buffer structure passed from userspace to
158 * &v4l2_ioctl_ops->vidioc_expbuf handler in driver
159 *
160 * The return values from this function are intended to be directly returned
161 * from &v4l2_ioctl_ops->vidioc_expbuf handler in driver.
162 */
163int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
164
165/**
166 * vb2_dqbuf() - Dequeue a buffer to the userspace
167 * @q: pointer to &struct vb2_queue with videobuf2 queue.
168 * @b: buffer structure passed from userspace to
169 * &v4l2_ioctl_ops->vidioc_dqbuf handler in driver
170 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
171 * buffers ready for dequeuing are present. Normally the driver
172 * would be passing (&file->f_flags & %O_NONBLOCK) here
173 *
174 * Should be called from &v4l2_ioctl_ops->vidioc_dqbuf ioctl handler
175 * of a driver.
176 *
177 * This function:
178 *
179 * #) verifies the passed buffer;
180 * #) calls &vb2_ops->buf_finish callback in the driver (if provided), in which
181 * driver can perform any additional operations that may be required before
182 * returning the buffer to userspace, such as cache sync;
183 * #) the buffer struct members are filled with relevant information for
184 * the userspace.
185 *
186 * The return values from this function are intended to be directly returned
187 * from &v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
188 */
189int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
190
191/**
192 * vb2_streamon - start streaming
193 * @q: pointer to &struct vb2_queue with videobuf2 queue.
194 * @type: type argument passed from userspace to vidioc_streamon handler,
195 * as defined by &enum v4l2_buf_type.
196 *
197 * Should be called from &v4l2_ioctl_ops->vidioc_streamon handler of a driver.
198 *
199 * This function:
200 *
201 * 1) verifies current state
202 * 2) passes any previously queued buffers to the driver and starts streaming
203 *
204 * The return values from this function are intended to be directly returned
205 * from &v4l2_ioctl_ops->vidioc_streamon handler in the driver.
206 */
207int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
208
209/**
210 * vb2_streamoff - stop streaming
211 * @q: pointer to &struct vb2_queue with videobuf2 queue.
212 * @type: type argument passed from userspace to vidioc_streamoff handler
213 *
214 * Should be called from vidioc_streamoff handler of a driver.
215 *
216 * This function:
217 *
218 * #) verifies current state,
219 * #) stop streaming and dequeues any queued buffers, including those previously
220 * passed to the driver (after waiting for the driver to finish).
221 *
222 * This call can be used for pausing playback.
223 * The return values from this function are intended to be directly returned
224 * from vidioc_streamoff handler in the driver
225 */
226int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
227
228/**
229 * vb2_queue_init() - initialize a videobuf2 queue
230 * @q: pointer to &struct vb2_queue with videobuf2 queue.
231 *
232 * The vb2_queue structure should be allocated by the driver. The driver is
233 * responsible of clearing it's content and setting initial values for some
234 * required entries before calling this function.
235 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
236 * to the struct vb2_queue description in include/media/videobuf2-core.h
237 * for more information.
238 */
239int __must_check vb2_queue_init(struct vb2_queue *q);
240
241/**
242 * vb2_queue_init_name() - initialize a videobuf2 queue with a name
243 * @q: pointer to &struct vb2_queue with videobuf2 queue.
244 * @name: the queue name
245 *
246 * This function initializes the vb2_queue exactly like vb2_queue_init(),
247 * and additionally sets the queue name. The queue name is used for logging
248 * purpose, and should uniquely identify the queue within the context of the
249 * device it belongs to. This is useful to attribute kernel log messages to the
250 * right queue for m2m devices or other devices that handle multiple queues.
251 */
252int __must_check vb2_queue_init_name(struct vb2_queue *q, const char *name);
253
254/**
255 * vb2_queue_release() - stop streaming, release the queue and free memory
256 * @q: pointer to &struct vb2_queue with videobuf2 queue.
257 *
258 * This function stops streaming and performs necessary clean ups, including
259 * freeing video buffer memory. The driver is responsible for freeing
260 * the vb2_queue structure itself.
261 */
262void vb2_queue_release(struct vb2_queue *q);
263
264/**
265 * vb2_queue_change_type() - change the type of an inactive vb2_queue
266 * @q: pointer to &struct vb2_queue with videobuf2 queue.
267 * @type: the type to change to (V4L2_BUF_TYPE_VIDEO_*)
268 *
269 * This function changes the type of the vb2_queue. This is only possible
270 * if the queue is not busy (i.e. no buffers have been allocated).
271 *
272 * vb2_queue_change_type() can be used to support multiple buffer types using
273 * the same queue. The driver can implement v4l2_ioctl_ops.vidioc_reqbufs and
274 * v4l2_ioctl_ops.vidioc_create_bufs functions and call vb2_queue_change_type()
275 * before calling vb2_ioctl_reqbufs() or vb2_ioctl_create_bufs(), and thus
276 * "lock" the buffer type until the buffers have been released.
277 */
278int vb2_queue_change_type(struct vb2_queue *q, unsigned int type);
279
280/**
281 * vb2_poll() - implements poll userspace operation
282 * @q: pointer to &struct vb2_queue with videobuf2 queue.
283 * @file: file argument passed to the poll file operation handler
284 * @wait: wait argument passed to the poll file operation handler
285 *
286 * This function implements poll file operation handler for a driver.
287 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
288 * be informed that the file descriptor of a video device is available for
289 * reading.
290 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
291 * will be reported as available for writing.
292 *
293 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
294 * pending events.
295 *
296 * The return values from this function are intended to be directly returned
297 * from poll handler in driver.
298 */
299__poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
300
301/*
302 * The following functions are not part of the vb2 core API, but are simple
303 * helper functions that you can use in your struct v4l2_file_operations,
304 * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
305 * or video_device->lock is set, and they will set and test vb2_queue->owner
306 * to check if the calling filehandle is permitted to do the queuing operation.
307 */
308
309/* struct v4l2_ioctl_ops helpers */
310
311int vb2_ioctl_reqbufs(struct file *file, void *priv,
312 struct v4l2_requestbuffers *p);
313int vb2_ioctl_create_bufs(struct file *file, void *priv,
314 struct v4l2_create_buffers *p);
315int vb2_ioctl_prepare_buf(struct file *file, void *priv,
316 struct v4l2_buffer *p);
317int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
318int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
319int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
320int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
321int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
322int vb2_ioctl_expbuf(struct file *file, void *priv,
323 struct v4l2_exportbuffer *p);
324
325/* struct v4l2_file_operations helpers */
326
327int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
328int vb2_fop_release(struct file *file);
329int _vb2_fop_release(struct file *file, struct mutex *lock);
330ssize_t vb2_fop_write(struct file *file, const char __user *buf,
331 size_t count, loff_t *ppos);
332ssize_t vb2_fop_read(struct file *file, char __user *buf,
333 size_t count, loff_t *ppos);
334__poll_t vb2_fop_poll(struct file *file, poll_table *wait);
335#ifndef CONFIG_MMU
336unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
337 unsigned long len, unsigned long pgoff, unsigned long flags);
338#endif
339
340/**
341 * vb2_video_unregister_device - unregister the video device and release queue
342 *
343 * @vdev: pointer to &struct video_device
344 *
345 * If the driver uses vb2_fop_release()/_vb2_fop_release(), then it should use
346 * vb2_video_unregister_device() instead of video_unregister_device().
347 *
348 * This function will call video_unregister_device() and then release the
349 * vb2_queue if streaming is in progress. This will stop streaming and
350 * this will simplify the unbind sequence since after this call all subdevs
351 * will have stopped streaming as well.
352 */
353void vb2_video_unregister_device(struct video_device *vdev);
354
355/**
356 * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
357 *
358 * @vq: pointer to &struct vb2_queue
359 *
360 * ..note:: only use if vq->lock is non-NULL.
361 */
362void vb2_ops_wait_prepare(struct vb2_queue *vq);
363
364/**
365 * vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
366 *
367 * @vq: pointer to &struct vb2_queue
368 *
369 * ..note:: only use if vq->lock is non-NULL.
370 */
371void vb2_ops_wait_finish(struct vb2_queue *vq);
372
373struct media_request;
374int vb2_request_validate(struct media_request *req);
375void vb2_request_queue(struct media_request *req);
376
377#endif /* _MEDIA_VIDEOBUF2_V4L2_H */