1 /*
2 * videobuf2-core.h - Video Buffer 2 Core 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_CORE_H
13 #define _MEDIA_VIDEOBUF2_CORE_H
14
15 #include <linux/mm_types.h>
16 #include <linux/mutex.h>
17 #include <linux/poll.h>
18 #include <linux/dma-buf.h>
19 #include <linux/bitops.h>
20 #include <media/media-request.h>
21
22 #define VB2_MAX_FRAME (32)
23 #define VB2_MAX_PLANES (8)
24
25 /**
26 * enum vb2_memory - type of memory model used to make the buffers visible
27 * on userspace.
28 *
29 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on
30 * userspace.
31 * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is
32 * memory mapped via mmap() ioctl. This model is
33 * also used when the user is using the buffers via
34 * read() or write() system calls.
35 * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is
36 * memory mapped via mmap() ioctl.
37 * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer.
38 */
39 enum vb2_memory {
40 VB2_MEMORY_UNKNOWN = 0,
41 VB2_MEMORY_MMAP = 1,
42 VB2_MEMORY_USERPTR = 2,
43 VB2_MEMORY_DMABUF = 4,
44 };
45
46 struct vb2_fileio_data;
47 struct vb2_threadio_data;
48
49 /**
50 * struct vb2_mem_ops - memory handling/memory allocator operations.
51 * @alloc: allocate video memory and, optionally, allocator private data,
52 * return ERR_PTR() on failure or a pointer to allocator private,
53 * per-buffer data on success; the returned private structure
54 * will then be passed as @buf_priv argument to other ops in this
55 * structure. Additional gfp_flags to use when allocating the
56 * are also passed to this operation. These flags are from the
57 * gfp_flags field of vb2_queue. The size argument to this function
58 * shall be *page aligned*.
59 * @put: inform the allocator that the buffer will no longer be used;
60 * usually will result in the allocator freeing the buffer (if
61 * no other users of this buffer are present); the @buf_priv
62 * argument is the allocator private per-buffer structure
63 * previously returned from the alloc callback.
64 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
65 * DMABUF memory types.
66 * @get_userptr: acquire userspace memory for a hardware operation; used for
67 * USERPTR memory types; vaddr is the address passed to the
68 * videobuf layer when queuing a video buffer of USERPTR type;
69 * should return an allocator private per-buffer structure
70 * associated with the buffer on success, ERR_PTR() on failure;
71 * the returned private structure will then be passed as @buf_priv
72 * argument to other ops in this structure.
73 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
74 * be used.
75 * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
76 * used for DMABUF memory types; dev is the alloc device
77 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
78 * allocator private per-buffer structure on success;
79 * this needs to be used for further accesses to the buffer.
80 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
81 * buffer is no longer used; the @buf_priv argument is the
82 * allocator private per-buffer structure previously returned
83 * from the attach_dmabuf callback.
84 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
85 * of dmabuf is informed that this driver is going to use the
86 * dmabuf.
87 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
88 * that this driver is done using the dmabuf for now.
89 * @prepare: called every time the buffer is passed from userspace to the
90 * driver, useful for cache synchronisation, optional.
91 * @finish: called every time the buffer is passed back from the driver
92 * to the userspace, also optional.
93 * @vaddr: return a kernel virtual address to a given memory buffer
94 * associated with the passed private structure or NULL if no
95 * such mapping exists.
96 * @cookie: return allocator specific cookie for a given memory buffer
97 * associated with the passed private structure or NULL if not
98 * available.
99 * @num_users: return the current number of users of a memory buffer;
100 * return 1 if the videobuf layer (or actually the driver using
101 * it) is the only user.
102 * @mmap: setup a userspace mapping for a given memory buffer under
103 * the provided virtual memory region.
104 *
105 * Those operations are used by the videobuf2 core to implement the memory
106 * handling/memory allocators for each type of supported streaming I/O method.
107 *
108 * .. note::
109 * #) Required ops for USERPTR types: get_userptr, put_userptr.
110 *
111 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
112 *
113 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
114 *
115 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
116 * map_dmabuf, unmap_dmabuf.
117 */
118 struct vb2_mem_ops {
119 void *(*alloc)(struct device *dev, unsigned long attrs,
120 unsigned long size,
121 enum dma_data_direction dma_dir,
122 gfp_t gfp_flags);
123 void (*put)(void *buf_priv);
124 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
125
126 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
127 unsigned long size,
128 enum dma_data_direction dma_dir);
129 void (*put_userptr)(void *buf_priv);
130
131 void (*prepare)(void *buf_priv);
132 void (*finish)(void *buf_priv);
133
134 void *(*attach_dmabuf)(struct device *dev,
135 struct dma_buf *dbuf,
136 unsigned long size,
137 enum dma_data_direction dma_dir);
138 void (*detach_dmabuf)(void *buf_priv);
139 int (*map_dmabuf)(void *buf_priv);
140 void (*unmap_dmabuf)(void *buf_priv);
141
142 void *(*vaddr)(void *buf_priv);
143 void *(*cookie)(void *buf_priv);
144
145 unsigned int (*num_users)(void *buf_priv);
146
147 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
148 };
149
150 /**
151 * struct vb2_plane - plane information.
152 * @mem_priv: private data with this plane.
153 * @dbuf: dma_buf - shared buffer object.
154 * @dbuf_mapped: flag to show whether dbuf is mapped or not
155 * @bytesused: number of bytes occupied by data in the plane (payload).
156 * @length: size of this plane (NOT the payload) in bytes.
157 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
158 * @length is always greater or equal to @min_length.
159 * @m: Union with memtype-specific data.
160 * @m.offset: when memory in the associated struct vb2_buffer is
161 * %VB2_MEMORY_MMAP, equals the offset from the start of
162 * the device memory for this plane (or is a "cookie" that
163 * should be passed to mmap() called on the video node).
164 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer
165 * pointing to this plane.
166 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file
167 * descriptor associated with this plane.
168 * @data_offset: offset in the plane to the start of data; usually 0,
169 * unless there is a header in front of the data.
170 *
171 * Should contain enough information to be able to cover all the fields
172 * of &struct v4l2_plane at videodev2.h.
173 */
174 struct vb2_plane {
175 void *mem_priv;
176 struct dma_buf *dbuf;
177 unsigned int dbuf_mapped;
178 unsigned int bytesused;
179 unsigned int length;
180 unsigned int min_length;
181 union {
182 unsigned int offset;
183 unsigned long userptr;
184 int fd;
185 } m;
186 unsigned int data_offset;
187 };
188
189 /**
190 * enum vb2_io_modes - queue access methods.
191 * @VB2_MMAP: driver supports MMAP with streaming API.
192 * @VB2_USERPTR: driver supports USERPTR with streaming API.
193 * @VB2_READ: driver supports read() style access.
194 * @VB2_WRITE: driver supports write() style access.
195 * @VB2_DMABUF: driver supports DMABUF with streaming API.
196 */
197 enum vb2_io_modes {
198 VB2_MMAP = BIT(0),
199 VB2_USERPTR = BIT(1),
200 VB2_READ = BIT(2),
201 VB2_WRITE = BIT(3),
202 VB2_DMABUF = BIT(4),
203 };
204
205 /**
206 * enum vb2_buffer_state - current video buffer state.
207 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control.
208 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request.
209 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf.
210 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver.
211 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
212 * in a hardware operation.
213 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
214 * not yet dequeued to userspace.
215 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
216 * has ended with an error, which will be reported
217 * to the userspace when it is dequeued.
218 */
219 enum vb2_buffer_state {
220 VB2_BUF_STATE_DEQUEUED,
221 VB2_BUF_STATE_IN_REQUEST,
222 VB2_BUF_STATE_PREPARING,
223 VB2_BUF_STATE_QUEUED,
224 VB2_BUF_STATE_ACTIVE,
225 VB2_BUF_STATE_DONE,
226 VB2_BUF_STATE_ERROR,
227 };
228
229 struct vb2_queue;
230
231 /**
232 * struct vb2_buffer - represents a video buffer.
233 * @vb2_queue: pointer to &struct vb2_queue with the queue to
234 * which this driver belongs.
235 * @index: id number of the buffer.
236 * @type: buffer type.
237 * @memory: the method, in which the actual data is passed.
238 * @num_planes: number of planes in the buffer
239 * on an internal driver queue.
240 * @timestamp: frame timestamp in ns.
241 * @request: the request this buffer is associated with.
242 * @req_obj: used to bind this buffer to a request. This
243 * request object has a refcount.
244 */
245 struct vb2_buffer {
246 struct vb2_queue *vb2_queue;
247 unsigned int index;
248 unsigned int type;
249 unsigned int memory;
250 unsigned int num_planes;
251 u64 timestamp;
252 struct media_request *request;
253 struct media_request_object req_obj;
254
255 /* private: internal use only
256 *
257 * state: current buffer state; do not change
258 * synced: this buffer has been synced for DMA, i.e. the
259 * 'prepare' memop was called. It is cleared again
260 * after the 'finish' memop is called.
261 * prepared: this buffer has been prepared, i.e. the
262 * buf_prepare op was called. It is cleared again
263 * after the 'buf_finish' op is called.
264 * copied_timestamp: the timestamp of this capture buffer was copied
265 * from an output buffer.
266 * queued_entry: entry on the queued buffers list, which holds
267 * all buffers queued from userspace
268 * done_entry: entry on the list that stores all buffers ready
269 * to be dequeued to userspace
270 * vb2_plane: per-plane information; do not change
271 */
272 enum vb2_buffer_state state;
273 unsigned int synced:1;
274 unsigned int prepared:1;
275 unsigned int copied_timestamp:1;
276
277 struct vb2_plane planes[VB2_MAX_PLANES];
278 struct list_head queued_entry;
279 struct list_head done_entry;
280 #ifdef CONFIG_VIDEO_ADV_DEBUG
281 /*
282 * Counters for how often these buffer-related ops are
283 * called. Used to check for unbalanced ops.
284 */
285 u32 cnt_mem_alloc;
286 u32 cnt_mem_put;
287 u32 cnt_mem_get_dmabuf;
288 u32 cnt_mem_get_userptr;
289 u32 cnt_mem_put_userptr;
290 u32 cnt_mem_prepare;
291 u32 cnt_mem_finish;
292 u32 cnt_mem_attach_dmabuf;
293 u32 cnt_mem_detach_dmabuf;
294 u32 cnt_mem_map_dmabuf;
295 u32 cnt_mem_unmap_dmabuf;
296 u32 cnt_mem_vaddr;
297 u32 cnt_mem_cookie;
298 u32 cnt_mem_num_users;
299 u32 cnt_mem_mmap;
300
301 u32 cnt_buf_out_validate;
302 u32 cnt_buf_init;
303 u32 cnt_buf_prepare;
304 u32 cnt_buf_finish;
305 u32 cnt_buf_cleanup;
306 u32 cnt_buf_queue;
307 u32 cnt_buf_request_complete;
308
309 /* This counts the number of calls to vb2_buffer_done() */
310 u32 cnt_buf_done;
311 #endif
312 };
313
314 /**
315 * struct vb2_ops - driver-specific callbacks.
316 *
317 * These operations are not called from interrupt context except where
318 * mentioned specifically.
319 *
320 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
321 * handlers before memory allocation. It can be called
322 * twice: if the original number of requested buffers
323 * could not be allocated, then it will be called a
324 * second time with the actually allocated number of
325 * buffers to verify if that is OK.
326 * The driver should return the required number of buffers
327 * in \*num_buffers, the required number of planes per
328 * buffer in \*num_planes, the size of each plane should be
329 * set in the sizes\[\] array and optional per-plane
330 * allocator specific device in the alloc_devs\[\] array.
331 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
332 * the driver has to use the currently configured format to
333 * determine the plane sizes and \*num_buffers is the total
334 * number of buffers that are being allocated. When called
335 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
336 * describes the requested number of planes and sizes\[\]
337 * contains the requested plane sizes. In this case
338 * \*num_buffers are being allocated additionally to
339 * q->num_buffers. If either \*num_planes or the requested
340 * sizes are invalid callback must return %-EINVAL.
341 * @wait_prepare: release any locks taken while calling vb2 functions;
342 * it is called before an ioctl needs to wait for a new
343 * buffer to arrive; required to avoid a deadlock in
344 * blocking access type.
345 * @wait_finish: reacquire all locks released in the previous callback;
346 * required to continue operation after sleeping while
347 * waiting for a new buffer to arrive.
348 * @buf_out_validate: called when the output buffer is prepared or queued
349 * to a request; drivers can use this to validate
350 * userspace-provided information; this is required only
351 * for OUTPUT queues.
352 * @buf_init: called once after allocating a buffer (in MMAP case)
353 * or after acquiring a new USERPTR buffer; drivers may
354 * perform additional buffer-related initialization;
355 * initialization failure (return != 0) will prevent
356 * queue setup from completing successfully; optional.
357 * @buf_prepare: called every time the buffer is queued from userspace
358 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
359 * perform any initialization required before each
360 * hardware operation in this callback; drivers can
361 * access/modify the buffer here as it is still synced for
362 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
363 * also validate the buffer size; if an error is returned,
364 * the buffer will not be queued in driver; optional.
365 * @buf_finish: called before every dequeue of the buffer back to
366 * userspace; the buffer is synced for the CPU, so drivers
367 * can access/modify the buffer contents; drivers may
368 * perform any operations required before userspace
369 * accesses the buffer; optional. The buffer state can be
370 * one of the following: %DONE and %ERROR occur while
371 * streaming is in progress, and the %PREPARED state occurs
372 * when the queue has been canceled and all pending
373 * buffers are being returned to their default %DEQUEUED
374 * state. Typically you only have to do something if the
375 * state is %VB2_BUF_STATE_DONE, since in all other cases
376 * the buffer contents will be ignored anyway.
377 * @buf_cleanup: called once before the buffer is freed; drivers may
378 * perform any additional cleanup; optional.
379 * @start_streaming: called once to enter 'streaming' state; the driver may
380 * receive buffers with @buf_queue callback
381 * before @start_streaming is called; the driver gets the
382 * number of already queued buffers in count parameter;
383 * driver can return an error if hardware fails, in that
384 * case all buffers that have been already given by
385 * the @buf_queue callback are to be returned by the driver
386 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
387 * If you need a minimum number of buffers before you can
388 * start streaming, then set
389 * &vb2_queue->min_buffers_needed. If that is non-zero
390 * then @start_streaming won't be called until at least
391 * that many buffers have been queued up by userspace.
392 * @stop_streaming: called when 'streaming' state must be disabled; driver
393 * should stop any DMA transactions or wait until they
394 * finish and give back all buffers it got from &buf_queue
395 * callback by calling vb2_buffer_done() with either
396 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
397 * vb2_wait_for_all_buffers() function
398 * @buf_queue: passes buffer vb to the driver; driver may start
399 * hardware operation on this buffer; driver should give
400 * the buffer back by calling vb2_buffer_done() function;
401 * it is always called after calling VIDIOC_STREAMON()
402 * ioctl; might be called before @start_streaming callback
403 * if user pre-queued buffers before calling
404 * VIDIOC_STREAMON().
405 * @buf_request_complete: a buffer that was never queued to the driver but is
406 * associated with a queued request was canceled.
407 * The driver will have to mark associated objects in the
408 * request as completed; required if requests are
409 * supported.
410 */
411 struct vb2_ops {
412 int (*queue_setup)(struct vb2_queue *q,
413 unsigned int *num_buffers, unsigned int *num_planes,
414 unsigned int sizes[], struct device *alloc_devs[]);
415
416 void (*wait_prepare)(struct vb2_queue *q);
417 void (*wait_finish)(struct vb2_queue *q);
418
419 int (*buf_out_validate)(struct vb2_buffer *vb);
420 int (*buf_init)(struct vb2_buffer *vb);
421 int (*buf_prepare)(struct vb2_buffer *vb);
422 void (*buf_finish)(struct vb2_buffer *vb);
423 void (*buf_cleanup)(struct vb2_buffer *vb);
424
425 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
426 void (*stop_streaming)(struct vb2_queue *q);
427
428 void (*buf_queue)(struct vb2_buffer *vb);
429
430 void (*buf_request_complete)(struct vb2_buffer *vb);
431 };
432
433 /**
434 * struct vb2_buf_ops - driver-specific callbacks.
435 *
436 * @verify_planes_array: Verify that a given user space structure contains
437 * enough planes for the buffer. This is called
438 * for each dequeued buffer.
439 * @init_buffer: given a &vb2_buffer initialize the extra data after
440 * struct vb2_buffer.
441 * For V4L2 this is a &struct vb2_v4l2_buffer.
442 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
443 * For V4L2 this is a &struct v4l2_buffer.
444 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer.
445 * If the userspace structure is invalid, then this op
446 * will return an error.
447 * @copy_timestamp: copy the timestamp from a userspace structure to
448 * the &struct vb2_buffer.
449 */
450 struct vb2_buf_ops {
451 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
452 void (*init_buffer)(struct vb2_buffer *vb);
453 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
454 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
455 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
456 };
457
458 /**
459 * struct vb2_queue - a videobuf queue.
460 *
461 * @type: private buffer type whose content is defined by the vb2-core
462 * caller. For example, for V4L2, it should match
463 * the types defined on &enum v4l2_buf_type.
464 * @io_modes: supported io methods (see &enum vb2_io_modes).
465 * @alloc_devs: &struct device memory type/allocator-specific per-plane device
466 * @dev: device to use for the default allocation context if the driver
467 * doesn't fill in the @alloc_devs array.
468 * @dma_attrs: DMA attributes to use for the DMA.
469 * @bidirectional: when this flag is set the DMA direction for the buffers of
470 * this queue will be overridden with %DMA_BIDIRECTIONAL direction.
471 * This is useful in cases where the hardware (firmware) writes to
472 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
473 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order
474 * to satisfy some internal hardware restrictions or adds a padding
475 * needed by the processing algorithm. In case the DMA mapping is
476 * not bidirectional but the hardware (firmware) trying to access
477 * the buffer (in the opposite direction) this could lead to an
478 * IOMMU protection faults.
479 * @fileio_read_once: report EOF after reading the first buffer
480 * @fileio_write_immediately: queue buffer after each write() call
481 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
482 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
483 * has not been called. This is a vb1 idiom that has been adopted
484 * also by vb2.
485 * @supports_requests: this queue supports the Request API.
486 * @requires_requests: this queue requires the Request API. If this is set to 1,
487 * then supports_requests must be set to 1 as well.
488 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first
489 * time this is called. Set to 0 when the queue is canceled.
490 * If this is 1, then you cannot queue buffers from a request.
491 * @uses_requests: requests are used for this queue. Set to 1 the first time
492 * a request is queued. Set to 0 when the queue is canceled.
493 * If this is 1, then you cannot queue buffers directly.
494 * @lock: pointer to a mutex that protects the &struct vb2_queue. The
495 * driver can set this to a mutex to let the v4l2 core serialize
496 * the queuing ioctls. If the driver wants to handle locking
497 * itself, then this should be set to NULL. This lock is not used
498 * by the videobuf2 core API.
499 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
500 * that called reqbufs, create_buffers or started fileio.
501 * This field is not used by the videobuf2 core API, but it allows
502 * drivers to easily associate an owner filehandle with the queue.
503 * @ops: driver-specific callbacks
504 * @mem_ops: memory allocator specific callbacks
505 * @buf_ops: callbacks to deliver buffer information.
506 * between user-space and kernel-space.
507 * @drv_priv: driver private data.
508 * @buf_struct_size: size of the driver-specific buffer structure;
509 * "0" indicates the driver doesn't want to use a custom buffer
510 * structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
511 * will be used for v4l2.
512 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
513 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*``
514 * @gfp_flags: additional gfp flags used when allocating the buffers.
515 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
516 * to force the buffer allocation to a specific memory zone.
517 * @min_buffers_needed: the minimum number of buffers needed before
518 * @start_streaming can be called. Used when a DMA engine
519 * cannot be started unless at least this number of buffers
520 * have been queued into the driver.
521 */
522 /*
523 * Private elements (won't appear at the uAPI book):
524 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
525 * @memory: current memory type used
526 * @dma_dir: DMA mapping direction.
527 * @bufs: videobuf buffer structures
528 * @num_buffers: number of allocated/used buffers
529 * @queued_list: list of buffers currently queued from userspace
530 * @queued_count: number of buffers queued and ready for streaming.
531 * @owned_by_drv_count: number of buffers owned by the driver
532 * @done_list: list of buffers ready to be dequeued to userspace
533 * @done_lock: lock to protect done_list list
534 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
535 * @streaming: current streaming state
536 * @start_streaming_called: @start_streaming was called successfully and we
537 * started streaming.
538 * @error: a fatal error occurred on the queue
539 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
540 * buffers. Only set for capture queues if qbuf has not yet been
541 * called since poll() needs to return %EPOLLERR in that situation.
542 * @is_multiplanar: set if buffer type is multiplanar
543 * @is_output: set if buffer type is output
544 * @copy_timestamp: set if vb2-core should set timestamps
545 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
546 * last decoded buffer was already dequeued. Set for capture queues
547 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
548 * @fileio: file io emulator internal data, used only if emulator is active
549 * @threadio: thread io internal data, used only if thread is active
550 */
551 struct vb2_queue {
552 unsigned int type;
553 unsigned int io_modes;
554 struct device *dev;
555 unsigned long dma_attrs;
556 unsigned bidirectional:1;
557 unsigned fileio_read_once:1;
558 unsigned fileio_write_immediately:1;
559 unsigned allow_zero_bytesused:1;
560 unsigned quirk_poll_must_check_waiting_for_buffers:1;
561 unsigned supports_requests:1;
562 unsigned requires_requests:1;
563 unsigned uses_qbuf:1;
564 unsigned uses_requests:1;
565
566 struct mutex *lock;
567 void *owner;
568
569 const struct vb2_ops *ops;
570 const struct vb2_mem_ops *mem_ops;
571 const struct vb2_buf_ops *buf_ops;
572
573 void *drv_priv;
574 unsigned int buf_struct_size;
575 u32 timestamp_flags;
576 gfp_t gfp_flags;
577 u32 min_buffers_needed;
578
579 struct device *alloc_devs[VB2_MAX_PLANES];
580
581 /* private: internal use only */
582 struct mutex mmap_lock;
583 unsigned int memory;
584 enum dma_data_direction dma_dir;
585 struct vb2_buffer *bufs[VB2_MAX_FRAME];
586 unsigned int num_buffers;
587
588 struct list_head queued_list;
589 unsigned int queued_count;
590
591 atomic_t owned_by_drv_count;
592 struct list_head done_list;
593 spinlock_t done_lock;
594 wait_queue_head_t done_wq;
595
596 unsigned int streaming:1;
597 unsigned int start_streaming_called:1;
598 unsigned int error:1;
599 unsigned int waiting_for_buffers:1;
600 unsigned int waiting_in_dqbuf:1;
601 unsigned int is_multiplanar:1;
602 unsigned int is_output:1;
603 unsigned int copy_timestamp:1;
604 unsigned int last_buffer_dequeued:1;
605
606 struct vb2_fileio_data *fileio;
607 struct vb2_threadio_data *threadio;
608
609 #ifdef CONFIG_VIDEO_ADV_DEBUG
610 /*
611 * Counters for how often these queue-related ops are
612 * called. Used to check for unbalanced ops.
613 */
614 u32 cnt_queue_setup;
615 u32 cnt_wait_prepare;
616 u32 cnt_wait_finish;
617 u32 cnt_start_streaming;
618 u32 cnt_stop_streaming;
619 #endif
620 };
621
622 /**
623 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
624 * @vb: pointer to &struct vb2_buffer to which the plane in
625 * question belongs to.
626 * @plane_no: plane number for which the address is to be returned.
627 *
628 * This function returns a kernel virtual address of a given plane if
629 * such a mapping exist, NULL otherwise.
630 */
631 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
632
633 /**
634 * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
635 * @vb: pointer to &struct vb2_buffer to which the plane in
636 * question belongs to.
637 * @plane_no: plane number for which the cookie is to be returned.
638 *
639 * This function returns an allocator specific cookie for a given plane if
640 * available, NULL otherwise. The allocator should provide some simple static
641 * inline function, which would convert this cookie to the allocator specific
642 * type that can be used directly by the driver to access the buffer. This can
643 * be for example physical address, pointer to scatter list or IOMMU mapping.
644 */
645 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
646
647 /**
648 * vb2_buffer_done() - inform videobuf that an operation on a buffer
649 * is finished.
650 * @vb: pointer to &struct vb2_buffer to be used.
651 * @state: state of the buffer, as defined by &enum vb2_buffer_state.
652 * Either %VB2_BUF_STATE_DONE if the operation finished
653 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
654 * with an error or %VB2_BUF_STATE_QUEUED.
655 *
656 * This function should be called by the driver after a hardware operation on
657 * a buffer is finished and the buffer may be returned to userspace. The driver
658 * cannot use this buffer anymore until it is queued back to it by videobuf
659 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
660 * to the driver by &vb2_ops->buf_queue can be passed to this function.
661 *
662 * While streaming a buffer can only be returned in state DONE or ERROR.
663 * The &vb2_ops->start_streaming op can also return them in case the DMA engine
664 * cannot be started for some reason. In that case the buffers should be
665 * returned with state QUEUED to put them back into the queue.
666 */
667 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
668
669 /**
670 * vb2_discard_done() - discard all buffers marked as DONE.
671 * @q: pointer to &struct vb2_queue with videobuf2 queue.
672 *
673 * This function is intended to be used with suspend/resume operations. It
674 * discards all 'done' buffers as they would be too old to be requested after
675 * resume.
676 *
677 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
678 * delayed works before calling this function to make sure no buffer will be
679 * touched by the driver and/or hardware.
680 */
681 void vb2_discard_done(struct vb2_queue *q);
682
683 /**
684 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
685 * @q: pointer to &struct vb2_queue with videobuf2 queue.
686 *
687 * This function will wait until all buffers that have been given to the driver
688 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
689 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
690 * It is intended to be called with all locks taken, for example from
691 * &vb2_ops->stop_streaming callback.
692 */
693 int vb2_wait_for_all_buffers(struct vb2_queue *q);
694
695 /**
696 * vb2_core_querybuf() - query video buffer information.
697 * @q: pointer to &struct vb2_queue with videobuf2 queue.
698 * @index: id number of the buffer.
699 * @pb: buffer struct passed from userspace.
700 *
701 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
702 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
703 *
704 * The passed buffer should have been verified.
705 *
706 * This function fills the relevant information for the userspace.
707 *
708 * Return: returns zero on success; an error code otherwise.
709 */
710 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
711
712 /**
713 * vb2_core_reqbufs() - Initiate streaming.
714 * @q: pointer to &struct vb2_queue with videobuf2 queue.
715 * @memory: memory type, as defined by &enum vb2_memory.
716 * @count: requested buffer count.
717 *
718 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
719 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
720 *
721 * This function:
722 *
723 * #) verifies streaming parameters passed from the userspace;
724 * #) sets up the queue;
725 * #) negotiates number of buffers and planes per buffer with the driver
726 * to be used during streaming;
727 * #) allocates internal buffer structures (&struct vb2_buffer), according to
728 * the agreed parameters;
729 * #) for MMAP memory type, allocates actual video memory, using the
730 * memory handling/allocation routines provided during queue initialization.
731 *
732 * If req->count is 0, all the memory will be freed instead.
733 *
734 * If the queue has been allocated previously by a previous vb2_core_reqbufs()
735 * call and the queue is not busy, memory will be reallocated.
736 *
737 * Return: returns zero on success; an error code otherwise.
738 */
739 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
740 unsigned int *count);
741
742 /**
743 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
744 * @q: pointer to &struct vb2_queue with videobuf2 queue.
745 * @memory: memory type, as defined by &enum vb2_memory.
746 * @count: requested buffer count.
747 * @requested_planes: number of planes requested.
748 * @requested_sizes: array with the size of the planes.
749 *
750 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
751 * called internally by VB2 by an API-specific handler, like
752 * ``videobuf2-v4l2.h``.
753 *
754 * This function:
755 *
756 * #) verifies parameter sanity;
757 * #) calls the &vb2_ops->queue_setup queue operation;
758 * #) performs any necessary memory allocations.
759 *
760 * Return: returns zero on success; an error code otherwise.
761 */
762 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
763 unsigned int *count, unsigned int requested_planes,
764 const unsigned int requested_sizes[]);
765
766 /**
767 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
768 * to the kernel.
769 * @q: pointer to &struct vb2_queue with videobuf2 queue.
770 * @index: id number of the buffer.
771 * @pb: buffer structure passed from userspace to
772 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
773 *
774 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
775 * called internally by VB2 by an API-specific handler, like
776 * ``videobuf2-v4l2.h``.
777 *
778 * The passed buffer should have been verified.
779 *
780 * This function calls vb2_ops->buf_prepare callback in the driver
781 * (if provided), in which driver-specific buffer initialization can
782 * be performed.
783 *
784 * Return: returns zero on success; an error code otherwise.
785 */
786 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
787
788 /**
789 * vb2_core_qbuf() - Queue a buffer from userspace
790 *
791 * @q: pointer to &struct vb2_queue with videobuf2 queue.
792 * @index: id number of the buffer
793 * @pb: buffer structure passed from userspace to
794 * v4l2_ioctl_ops->vidioc_qbuf handler in driver
795 * @req: pointer to &struct media_request, may be NULL.
796 *
797 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
798 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
799 *
800 * This function:
801 *
802 * #) If @req is non-NULL, then the buffer will be bound to this
803 * media request and it returns. The buffer will be prepared and
804 * queued to the driver (i.e. the next two steps) when the request
805 * itself is queued.
806 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
807 * (if provided), in which driver-specific buffer initialization can
808 * be performed;
809 * #) if streaming is on, queues the buffer in driver by the means of
810 * &vb2_ops->buf_queue callback for processing.
811 *
812 * Return: returns zero on success; an error code otherwise.
813 */
814 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
815 struct media_request *req);
816
817 /**
818 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
819 * @q: pointer to &struct vb2_queue with videobuf2 queue
820 * @pindex: pointer to the buffer index. May be NULL
821 * @pb: buffer structure passed from userspace to
822 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
823 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
824 * buffers ready for dequeuing are present. Normally the driver
825 * would be passing (file->f_flags & O_NONBLOCK) here.
826 *
827 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
828 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
829 *
830 * This function:
831 *
832 * #) calls buf_finish callback in the driver (if provided), in which
833 * driver can perform any additional operations that may be required before
834 * returning the buffer to userspace, such as cache sync,
835 * #) the buffer struct members are filled with relevant information for
836 * the userspace.
837 *
838 * Return: returns zero on success; an error code otherwise.
839 */
840 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
841 bool nonblocking);
842
843 /**
844 * vb2_core_streamon() - Implements VB2 stream ON logic
845 *
846 * @q: pointer to &struct vb2_queue with videobuf2 queue
847 * @type: type of the queue to be started.
848 * For V4L2, this is defined by &enum v4l2_buf_type type.
849 *
850 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
851 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
852 *
853 * Return: returns zero on success; an error code otherwise.
854 */
855 int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
856
857 /**
858 * vb2_core_streamoff() - Implements VB2 stream OFF logic
859 *
860 * @q: pointer to &struct vb2_queue with videobuf2 queue
861 * @type: type of the queue to be started.
862 * For V4L2, this is defined by &enum v4l2_buf_type type.
863 *
864 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
865 * called internally by VB2 by an API-specific handler, like
866 * ``videobuf2-v4l2.h``.
867 *
868 * Return: returns zero on success; an error code otherwise.
869 */
870 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
871
872 /**
873 * vb2_core_expbuf() - Export a buffer as a file descriptor.
874 * @q: pointer to &struct vb2_queue with videobuf2 queue.
875 * @fd: pointer to the file descriptor associated with DMABUF
876 * (set by driver).
877 * @type: buffer type.
878 * @index: id number of the buffer.
879 * @plane: index of the plane to be exported, 0 for single plane queues
880 * @flags: file flags for newly created file, as defined at
881 * include/uapi/asm-generic/fcntl.h.
882 * Currently, the only used flag is %O_CLOEXEC.
883 * is supported, refer to manual of open syscall for more details.
884 *
885 *
886 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
887 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
888 *
889 * Return: returns zero on success; an error code otherwise.
890 */
891 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
892 unsigned int index, unsigned int plane, unsigned int flags);
893
894 /**
895 * vb2_core_queue_init() - initialize a videobuf2 queue
896 * @q: pointer to &struct vb2_queue with videobuf2 queue.
897 * This structure should be allocated in driver
898 *
899 * The &vb2_queue structure should be allocated by the driver. The driver is
900 * responsible of clearing it's content and setting initial values for some
901 * required entries before calling this function.
902 *
903 * .. note::
904 *
905 * The following fields at @q should be set before calling this function:
906 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
907 */
908 int vb2_core_queue_init(struct vb2_queue *q);
909
910 /**
911 * vb2_core_queue_release() - stop streaming, release the queue and free memory
912 * @q: pointer to &struct vb2_queue with videobuf2 queue.
913 *
914 * This function stops streaming and performs necessary clean ups, including
915 * freeing video buffer memory. The driver is responsible for freeing
916 * the &struct vb2_queue itself.
917 */
918 void vb2_core_queue_release(struct vb2_queue *q);
919
920 /**
921 * vb2_queue_error() - signal a fatal error on the queue
922 * @q: pointer to &struct vb2_queue with videobuf2 queue.
923 *
924 * Flag that a fatal unrecoverable error has occurred and wake up all processes
925 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
926 * buffers will return %-EIO.
927 *
928 * The error flag will be cleared when canceling the queue, either from
929 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
930 * function before starting the stream, otherwise the error flag will remain set
931 * until the queue is released when closing the device node.
932 */
933 void vb2_queue_error(struct vb2_queue *q);
934
935 /**
936 * vb2_mmap() - map video buffers into application address space.
937 * @q: pointer to &struct vb2_queue with videobuf2 queue.
938 * @vma: pointer to &struct vm_area_struct with the vma passed
939 * to the mmap file operation handler in the driver.
940 *
941 * Should be called from mmap file operation handler of a driver.
942 * This function maps one plane of one of the available video buffers to
943 * userspace. To map whole video memory allocated on reqbufs, this function
944 * has to be called once per each plane per each buffer previously allocated.
945 *
946 * When the userspace application calls mmap, it passes to it an offset returned
947 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
948 * That offset acts as a "cookie", which is then used to identify the plane
949 * to be mapped.
950 *
951 * This function finds a plane with a matching offset and a mapping is performed
952 * by the means of a provided memory operation.
953 *
954 * The return values from this function are intended to be directly returned
955 * from the mmap handler in driver.
956 */
957 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
958
959 #ifndef CONFIG_MMU
960 /**
961 * vb2_get_unmapped_area - map video buffers into application address space.
962 * @q: pointer to &struct vb2_queue with videobuf2 queue.
963 * @addr: memory address.
964 * @len: buffer size.
965 * @pgoff: page offset.
966 * @flags: memory flags.
967 *
968 * This function is used in noMMU platforms to propose address mapping
969 * for a given buffer. It's intended to be used as a handler for the
970 * &file_operations->get_unmapped_area operation.
971 *
972 * This is called by the mmap() syscall routines will call this
973 * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
974 */
975 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
976 unsigned long addr,
977 unsigned long len,
978 unsigned long pgoff,
979 unsigned long flags);
980 #endif
981
982 /**
983 * vb2_core_poll() - implements poll syscall() logic.
984 * @q: pointer to &struct vb2_queue with videobuf2 queue.
985 * @file: &struct file argument passed to the poll
986 * file operation handler.
987 * @wait: &poll_table wait argument passed to the poll
988 * file operation handler.
989 *
990 * This function implements poll file operation handler for a driver.
991 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
992 * be informed that the file descriptor of a video device is available for
993 * reading.
994 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
995 * will be reported as available for writing.
996 *
997 * The return values from this function are intended to be directly returned
998 * from poll handler in driver.
999 */
1000 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
1001 poll_table *wait);
1002
1003 /**
1004 * vb2_read() - implements read() syscall logic.
1005 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1006 * @data: pointed to target userspace buffer
1007 * @count: number of bytes to read
1008 * @ppos: file handle position tracking pointer
1009 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1010 */
1011 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
1012 loff_t *ppos, int nonblock);
1013 /**
1014 * vb2_read() - implements write() syscall logic.
1015 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1016 * @data: pointed to target userspace buffer
1017 * @count: number of bytes to write
1018 * @ppos: file handle position tracking pointer
1019 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1020 */
1021 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
1022 loff_t *ppos, int nonblock);
1023
1024 /**
1025 * typedef vb2_thread_fnc - callback function for use with vb2_thread.
1026 *
1027 * @vb: pointer to struct &vb2_buffer.
1028 * @priv: pointer to a private data.
1029 *
1030 * This is called whenever a buffer is dequeued in the thread.
1031 */
1032 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
1033
1034 /**
1035 * vb2_thread_start() - start a thread for the given queue.
1036 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1037 * @fnc: &vb2_thread_fnc callback function.
1038 * @priv: priv pointer passed to the callback function.
1039 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
1040 *
1041 * This starts a thread that will queue and dequeue until an error occurs
1042 * or vb2_thread_stop() is called.
1043 *
1044 * .. attention::
1045 *
1046 * This function should not be used for anything else but the videobuf2-dvb
1047 * support. If you think you have another good use-case for this, then please
1048 * contact the linux-media mailing list first.
1049 */
1050 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1051 const char *thread_name);
1052
1053 /**
1054 * vb2_thread_stop() - stop the thread for the given queue.
1055 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1056 */
1057 int vb2_thread_stop(struct vb2_queue *q);
1058
1059 /**
1060 * vb2_is_streaming() - return streaming status of the queue.
1061 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1062 */
1063 static inline bool vb2_is_streaming(struct vb2_queue *q)
1064 {
1065 return q->streaming;
1066 }
1067
1068 /**
1069 * vb2_fileio_is_active() - return true if fileio is active.
1070 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1071 *
1072 * This returns true if read() or write() is used to stream the data
1073 * as opposed to stream I/O. This is almost never an important distinction,
1074 * except in rare cases. One such case is that using read() or write() to
1075 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1076 * is no way you can pass the field information of each buffer to/from
1077 * userspace. A driver that supports this field format should check for
1078 * this in the &vb2_ops->queue_setup op and reject it if this function returns
1079 * true.
1080 */
1081 static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1082 {
1083 return q->fileio;
1084 }
1085
1086 /**
1087 * vb2_is_busy() - return busy status of the queue.
1088 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1089 *
1090 * This function checks if queue has any buffers allocated.
1091 */
1092 static inline bool vb2_is_busy(struct vb2_queue *q)
1093 {
1094 return (q->num_buffers > 0);
1095 }
1096
1097 /**
1098 * vb2_get_drv_priv() - return driver private data associated with the queue.
1099 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1100 */
1101 static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1102 {
1103 return q->drv_priv;
1104 }
1105
1106 /**
1107 * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1108 * @vb: pointer to &struct vb2_buffer to which the plane in
1109 * question belongs to.
1110 * @plane_no: plane number for which payload should be set.
1111 * @size: payload in bytes.
1112 */
1113 static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1114 unsigned int plane_no, unsigned long size)
1115 {
1116 if (plane_no < vb->num_planes)
1117 vb->planes[plane_no].bytesused = size;
1118 }
1119
1120 /**
1121 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1122 * @vb: pointer to &struct vb2_buffer to which the plane in
1123 * question belongs to.
1124 * @plane_no: plane number for which payload should be set.
1125 */
1126 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1127 unsigned int plane_no)
1128 {
1129 if (plane_no < vb->num_planes)
1130 return vb->planes[plane_no].bytesused;
1131 return 0;
1132 }
1133
1134 /**
1135 * vb2_plane_size() - return plane size in bytes.
1136 * @vb: pointer to &struct vb2_buffer to which the plane in
1137 * question belongs to.
1138 * @plane_no: plane number for which size should be returned.
1139 */
1140 static inline unsigned long
1141 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1142 {
1143 if (plane_no < vb->num_planes)
1144 return vb->planes[plane_no].length;
1145 return 0;
1146 }
1147
1148 /**
1149 * vb2_start_streaming_called() - return streaming status of driver.
1150 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1151 */
1152 static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1153 {
1154 return q->start_streaming_called;
1155 }
1156
1157 /**
1158 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1159 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1160 */
1161 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1162 {
1163 q->last_buffer_dequeued = false;
1164 }
1165
1166 /**
1167 * vb2_get_buffer() - get a buffer from a queue
1168 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1169 * @index: buffer index
1170 *
1171 * This function obtains a buffer from a queue, by its index.
1172 * Keep in mind that there is no refcounting involved in this
1173 * operation, so the buffer lifetime should be taken into
1174 * consideration.
1175 */
1176 static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
1177 unsigned int index)
1178 {
1179 if (index < q->num_buffers)
1180 return q->bufs[index];
1181 return NULL;
1182 }
1183
1184 /*
1185 * The following functions are not part of the vb2 core API, but are useful
1186 * functions for videobuf2-*.
1187 */
1188
1189 /**
1190 * vb2_buffer_in_use() - return true if the buffer is in use and
1191 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1192 *
1193 * @vb: buffer for which plane size should be returned.
1194 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1195 */
1196 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1197
1198 /**
1199 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1200 * passed to a buffer operation are compatible with the queue.
1201 *
1202 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1203 * @memory: memory model, as defined by enum &vb2_memory.
1204 * @type: private buffer type whose content is defined by the vb2-core
1205 * caller. For example, for V4L2, it should match
1206 * the types defined on enum &v4l2_buf_type.
1207 */
1208 int vb2_verify_memory_type(struct vb2_queue *q,
1209 enum vb2_memory memory, unsigned int type);
1210
1211 /**
1212 * vb2_request_object_is_buffer() - return true if the object is a buffer
1213 *
1214 * @obj: the request object.
1215 */
1216 bool vb2_request_object_is_buffer(struct media_request_object *obj);
1217
1218 /**
1219 * vb2_request_buffer_cnt() - return the number of buffers in the request
1220 *
1221 * @req: the request.
1222 */
1223 unsigned int vb2_request_buffer_cnt(struct media_request *req);
1224
1225 #endif /* _MEDIA_VIDEOBUF2_CORE_H */