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 */
39enum vb2_memory {
40 VB2_MEMORY_UNKNOWN = 0,
41 VB2_MEMORY_MMAP = 1,
42 VB2_MEMORY_USERPTR = 2,
43 VB2_MEMORY_DMABUF = 4,
44};
45
46struct vb2_fileio_data;
47struct 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.
58 * @put: inform the allocator that the buffer will no longer be used;
59 * usually will result in the allocator freeing the buffer (if
60 * no other users of this buffer are present); the @buf_priv
61 * argument is the allocator private per-buffer structure
62 * previously returned from the alloc callback.
63 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
64 * DMABUF memory types.
65 * @get_userptr: acquire userspace memory for a hardware operation; used for
66 * USERPTR memory types; vaddr is the address passed to the
67 * videobuf layer when queuing a video buffer of USERPTR type;
68 * should return an allocator private per-buffer structure
69 * associated with the buffer on success, ERR_PTR() on failure;
70 * the returned private structure will then be passed as @buf_priv
71 * argument to other ops in this structure.
72 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
73 * be used.
74 * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
75 * used for DMABUF memory types; dev is the alloc device
76 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
77 * allocator private per-buffer structure on success;
78 * this needs to be used for further accesses to the buffer.
79 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
80 * buffer is no longer used; the @buf_priv argument is the
81 * allocator private per-buffer structure previously returned
82 * from the attach_dmabuf callback.
83 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
84 * of dmabuf is informed that this driver is going to use the
85 * dmabuf.
86 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
87 * that this driver is done using the dmabuf for now.
88 * @prepare: called every time the buffer is passed from userspace to the
89 * driver, useful for cache synchronisation, optional.
90 * @finish: called every time the buffer is passed back from the driver
91 * to the userspace, also optional.
92 * @vaddr: return a kernel virtual address to a given memory buffer
93 * associated with the passed private structure or NULL if no
94 * such mapping exists.
95 * @cookie: return allocator specific cookie for a given memory buffer
96 * associated with the passed private structure or NULL if not
97 * available.
98 * @num_users: return the current number of users of a memory buffer;
99 * return 1 if the videobuf layer (or actually the driver using
100 * it) is the only user.
101 * @mmap: setup a userspace mapping for a given memory buffer under
102 * the provided virtual memory region.
103 *
104 * Those operations are used by the videobuf2 core to implement the memory
105 * handling/memory allocators for each type of supported streaming I/O method.
106 *
107 * .. note::
108 * #) Required ops for USERPTR types: get_userptr, put_userptr.
109 *
110 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
111 *
112 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
113 *
114 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
115 * map_dmabuf, unmap_dmabuf.
116 */
117struct vb2_mem_ops {
118 void *(*alloc)(struct device *dev, unsigned long attrs,
119 unsigned long size,
120 enum dma_data_direction dma_dir,
121 gfp_t gfp_flags);
122 void (*put)(void *buf_priv);
123 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
124
125 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
126 unsigned long size,
127 enum dma_data_direction dma_dir);
128 void (*put_userptr)(void *buf_priv);
129
130 void (*prepare)(void *buf_priv);
131 void (*finish)(void *buf_priv);
132
133 void *(*attach_dmabuf)(struct device *dev,
134 struct dma_buf *dbuf,
135 unsigned long size,
136 enum dma_data_direction dma_dir);
137 void (*detach_dmabuf)(void *buf_priv);
138 int (*map_dmabuf)(void *buf_priv);
139 void (*unmap_dmabuf)(void *buf_priv);
140
141 void *(*vaddr)(void *buf_priv);
142 void *(*cookie)(void *buf_priv);
143
144 unsigned int (*num_users)(void *buf_priv);
145
146 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
147};
148
149/**
150 * struct vb2_plane - plane information.
151 * @mem_priv: private data with this plane.
152 * @dbuf: dma_buf - shared buffer object.
153 * @dbuf_mapped: flag to show whether dbuf is mapped or not
154 * @bytesused: number of bytes occupied by data in the plane (payload).
155 * @length: size of this plane (NOT the payload) in bytes.
156 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
157 * @length is always greater or equal to @min_length.
158 * @m: Union with memtype-specific data.
159 * @m.offset: when memory in the associated struct vb2_buffer is
160 * %VB2_MEMORY_MMAP, equals the offset from the start of
161 * the device memory for this plane (or is a "cookie" that
162 * should be passed to mmap() called on the video node).
163 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer
164 * pointing to this plane.
165 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file
166 * descriptor associated with this plane.
167 * @data_offset: offset in the plane to the start of data; usually 0,
168 * unless there is a header in front of the data.
169 *
170 * Should contain enough information to be able to cover all the fields
171 * of &struct v4l2_plane at videodev2.h.
172 */
173struct vb2_plane {
174 void *mem_priv;
175 struct dma_buf *dbuf;
176 unsigned int dbuf_mapped;
177 unsigned int bytesused;
178 unsigned int length;
179 unsigned int min_length;
180 union {
181 unsigned int offset;
182 unsigned long userptr;
183 int fd;
184 } m;
185 unsigned int data_offset;
186};
187
188/**
189 * enum vb2_io_modes - queue access methods.
190 * @VB2_MMAP: driver supports MMAP with streaming API.
191 * @VB2_USERPTR: driver supports USERPTR with streaming API.
192 * @VB2_READ: driver supports read() style access.
193 * @VB2_WRITE: driver supports write() style access.
194 * @VB2_DMABUF: driver supports DMABUF with streaming API.
195 */
196enum vb2_io_modes {
197 VB2_MMAP = BIT(0),
198 VB2_USERPTR = BIT(1),
199 VB2_READ = BIT(2),
200 VB2_WRITE = BIT(3),
201 VB2_DMABUF = BIT(4),
202};
203
204/**
205 * enum vb2_buffer_state - current video buffer state.
206 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control.
207 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request.
208 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf.
209 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver.
210 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the 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 */
219enum 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_REQUEUEING,
225 VB2_BUF_STATE_ACTIVE,
226 VB2_BUF_STATE_DONE,
227 VB2_BUF_STATE_ERROR,
228};
229
230struct vb2_queue;
231
232/**
233 * struct vb2_buffer - represents a video buffer.
234 * @vb2_queue: pointer to &struct vb2_queue with the queue to
235 * which this driver belongs.
236 * @index: id number of the buffer.
237 * @type: buffer type.
238 * @memory: the method, in which the actual data is passed.
239 * @num_planes: number of planes in the buffer
240 * on an internal driver queue.
241 * @timestamp: frame timestamp in ns.
242 * @request: the request this buffer is associated with.
243 * @req_obj: used to bind this buffer to a request. This
244 * request object has a refcount.
245 */
246struct vb2_buffer {
247 struct vb2_queue *vb2_queue;
248 unsigned int index;
249 unsigned int type;
250 unsigned int memory;
251 unsigned int num_planes;
252 u64 timestamp;
253 struct media_request *request;
254 struct media_request_object req_obj;
255
256 /* private: internal use only
257 *
258 * state: current buffer state; do not change
259 * synced: this buffer has been synced for DMA, i.e. the
260 * 'prepare' memop was called. It is cleared again
261 * after the 'finish' memop is called.
262 * prepared: this buffer has been prepared, i.e. the
263 * buf_prepare op was called. It is cleared again
264 * after the 'buf_finish' op is called.
265 * copied_timestamp: the timestamp of this capture buffer was copied
266 * from an output buffer.
267 * queued_entry: entry on the queued buffers list, which holds
268 * all buffers queued from userspace
269 * done_entry: entry on the list that stores all buffers ready
270 * to be dequeued to userspace
271 * vb2_plane: per-plane information; do not change
272 */
273 enum vb2_buffer_state state;
274 unsigned int synced:1;
275 unsigned int prepared:1;
276 unsigned int copied_timestamp:1;
277
278 struct vb2_plane planes[VB2_MAX_PLANES];
279 struct list_head queued_entry;
280 struct list_head done_entry;
281#ifdef CONFIG_VIDEO_ADV_DEBUG
282 /*
283 * Counters for how often these buffer-related ops are
284 * called. Used to check for unbalanced ops.
285 */
286 u32 cnt_mem_alloc;
287 u32 cnt_mem_put;
288 u32 cnt_mem_get_dmabuf;
289 u32 cnt_mem_get_userptr;
290 u32 cnt_mem_put_userptr;
291 u32 cnt_mem_prepare;
292 u32 cnt_mem_finish;
293 u32 cnt_mem_attach_dmabuf;
294 u32 cnt_mem_detach_dmabuf;
295 u32 cnt_mem_map_dmabuf;
296 u32 cnt_mem_unmap_dmabuf;
297 u32 cnt_mem_vaddr;
298 u32 cnt_mem_cookie;
299 u32 cnt_mem_num_users;
300 u32 cnt_mem_mmap;
301
302 u32 cnt_buf_out_validate;
303 u32 cnt_buf_init;
304 u32 cnt_buf_prepare;
305 u32 cnt_buf_finish;
306 u32 cnt_buf_cleanup;
307 u32 cnt_buf_queue;
308 u32 cnt_buf_request_complete;
309
310 /* This counts the number of calls to vb2_buffer_done() */
311 u32 cnt_buf_done;
312#endif
313};
314
315/**
316 * struct vb2_ops - driver-specific callbacks.
317 *
318 * These operations are not called from interrupt context except where
319 * mentioned specifically.
320 *
321 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
322 * handlers before memory allocation. It can be called
323 * twice: if the original number of requested buffers
324 * could not be allocated, then it will be called a
325 * second time with the actually allocated number of
326 * buffers to verify if that is OK.
327 * The driver should return the required number of buffers
328 * in \*num_buffers, the required number of planes per
329 * buffer in \*num_planes, the size of each plane should be
330 * set in the sizes\[\] array and optional per-plane
331 * allocator specific device in the alloc_devs\[\] array.
332 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
333 * the driver has to use the currently configured format to
334 * determine the plane sizes and \*num_buffers is the total
335 * number of buffers that are being allocated. When called
336 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
337 * describes the requested number of planes and sizes\[\]
338 * contains the requested plane sizes. In this case
339 * \*num_buffers are being allocated additionally to
340 * q->num_buffers. If either \*num_planes or the requested
341 * sizes are invalid callback must return %-EINVAL.
342 * @wait_prepare: release any locks taken while calling vb2 functions;
343 * it is called before an ioctl needs to wait for a new
344 * buffer to arrive; required to avoid a deadlock in
345 * blocking access type.
346 * @wait_finish: reacquire all locks released in the previous callback;
347 * required to continue operation after sleeping while
348 * waiting for a new buffer to arrive.
349 * @buf_out_validate: called when the output buffer is prepared or queued
350 * to a request; drivers can use this to validate
351 * userspace-provided information; this is required only
352 * for OUTPUT queues.
353 * @buf_init: called once after allocating a buffer (in MMAP case)
354 * or after acquiring a new USERPTR buffer; drivers may
355 * perform additional buffer-related initialization;
356 * initialization failure (return != 0) will prevent
357 * queue setup from completing successfully; optional.
358 * @buf_prepare: called every time the buffer is queued from userspace
359 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
360 * perform any initialization required before each
361 * hardware operation in this callback; drivers can
362 * access/modify the buffer here as it is still synced for
363 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
364 * also validate the buffer size; if an error is returned,
365 * the buffer will not be queued in driver; optional.
366 * @buf_finish: called before every dequeue of the buffer back to
367 * userspace; the buffer is synced for the CPU, so drivers
368 * can access/modify the buffer contents; drivers may
369 * perform any operations required before userspace
370 * accesses the buffer; optional. The buffer state can be
371 * one of the following: %DONE and %ERROR occur while
372 * streaming is in progress, and the %PREPARED state occurs
373 * when the queue has been canceled and all pending
374 * buffers are being returned to their default %DEQUEUED
375 * state. Typically you only have to do something if the
376 * state is %VB2_BUF_STATE_DONE, since in all other cases
377 * the buffer contents will be ignored anyway.
378 * @buf_cleanup: called once before the buffer is freed; drivers may
379 * perform any additional cleanup; optional.
380 * @start_streaming: called once to enter 'streaming' state; the driver may
381 * receive buffers with @buf_queue callback
382 * before @start_streaming is called; the driver gets the
383 * number of already queued buffers in count parameter;
384 * driver can return an error if hardware fails, in that
385 * case all buffers that have been already given by
386 * the @buf_queue callback are to be returned by the driver
387 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED
388 * or %VB2_BUF_STATE_REQUEUEING. If you need a minimum
389 * number of buffers before you can start streaming, then
390 * set &vb2_queue->min_buffers_needed. If that is non-zero
391 * then @start_streaming won't be called until at least
392 * that many buffers have been queued up by userspace.
393 * @stop_streaming: called when 'streaming' state must be disabled; driver
394 * should stop any DMA transactions or wait until they
395 * finish and give back all buffers it got from &buf_queue
396 * callback by calling vb2_buffer_done() with either
397 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
398 * vb2_wait_for_all_buffers() function
399 * @buf_queue: passes buffer vb to the driver; driver may start
400 * hardware operation on this buffer; driver should give
401 * the buffer back by calling vb2_buffer_done() function;
402 * it is always called after calling VIDIOC_STREAMON()
403 * ioctl; might be called before @start_streaming callback
404 * if user pre-queued buffers before calling
405 * VIDIOC_STREAMON().
406 * @buf_request_complete: a buffer that was never queued to the driver but is
407 * associated with a queued request was canceled.
408 * The driver will have to mark associated objects in the
409 * request as completed; required if requests are
410 * supported.
411 */
412struct vb2_ops {
413 int (*queue_setup)(struct vb2_queue *q,
414 unsigned int *num_buffers, unsigned int *num_planes,
415 unsigned int sizes[], struct device *alloc_devs[]);
416
417 void (*wait_prepare)(struct vb2_queue *q);
418 void (*wait_finish)(struct vb2_queue *q);
419
420 int (*buf_out_validate)(struct vb2_buffer *vb);
421 int (*buf_init)(struct vb2_buffer *vb);
422 int (*buf_prepare)(struct vb2_buffer *vb);
423 void (*buf_finish)(struct vb2_buffer *vb);
424 void (*buf_cleanup)(struct vb2_buffer *vb);
425
426 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
427 void (*stop_streaming)(struct vb2_queue *q);
428
429 void (*buf_queue)(struct vb2_buffer *vb);
430
431 void (*buf_request_complete)(struct vb2_buffer *vb);
432};
433
434/**
435 * struct vb2_buf_ops - driver-specific callbacks.
436 *
437 * @verify_planes_array: Verify that a given user space structure contains
438 * enough planes for the buffer. This is called
439 * for each dequeued buffer.
440 * @init_buffer: given a &vb2_buffer initialize the extra data after
441 * struct vb2_buffer.
442 * For V4L2 this is a &struct vb2_v4l2_buffer.
443 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
444 * For V4L2 this is a &struct v4l2_buffer.
445 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer.
446 * If the userspace structure is invalid, then this op
447 * will return an error.
448 * @copy_timestamp: copy the timestamp from a userspace structure to
449 * the &struct vb2_buffer.
450 */
451struct vb2_buf_ops {
452 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
453 void (*init_buffer)(struct vb2_buffer *vb);
454 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
455 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
456 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
457};
458
459/**
460 * struct vb2_queue - a videobuf queue.
461 *
462 * @type: private buffer type whose content is defined by the vb2-core
463 * caller. For example, for V4L2, it should match
464 * the types defined on &enum v4l2_buf_type.
465 * @io_modes: supported io methods (see &enum vb2_io_modes).
466 * @alloc_devs: &struct device memory type/allocator-specific per-plane device
467 * @dev: device to use for the default allocation context if the driver
468 * doesn't fill in the @alloc_devs array.
469 * @dma_attrs: DMA attributes to use for the DMA.
470 * @bidirectional: when this flag is set the DMA direction for the buffers of
471 * this queue will be overridden with %DMA_BIDIRECTIONAL direction.
472 * This is useful in cases where the hardware (firmware) writes to
473 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
474 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order
475 * to satisfy some internal hardware restrictions or adds a padding
476 * needed by the processing algorithm. In case the DMA mapping is
477 * not bidirectional but the hardware (firmware) trying to access
478 * the buffer (in the opposite direction) this could lead to an
479 * IOMMU protection faults.
480 * @fileio_read_once: report EOF after reading the first buffer
481 * @fileio_write_immediately: queue buffer after each write() call
482 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
483 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
484 * has not been called. This is a vb1 idiom that has been adopted
485 * also by vb2.
486 * @supports_requests: this queue supports the Request API.
487 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first
488 * time this is called. Set to 0 when the queue is canceled.
489 * If this is 1, then you cannot queue buffers from a request.
490 * @uses_requests: requests are used for this queue. Set to 1 the first time
491 * a request is queued. Set to 0 when the queue is canceled.
492 * If this is 1, then you cannot queue buffers directly.
493 * @lock: pointer to a mutex that protects the &struct vb2_queue. The
494 * driver can set this to a mutex to let the v4l2 core serialize
495 * the queuing ioctls. If the driver wants to handle locking
496 * itself, then this should be set to NULL. This lock is not used
497 * by the videobuf2 core API.
498 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
499 * that called reqbufs, create_buffers or started fileio.
500 * This field is not used by the videobuf2 core API, but it allows
501 * drivers to easily associate an owner filehandle with the queue.
502 * @ops: driver-specific callbacks
503 * @mem_ops: memory allocator specific callbacks
504 * @buf_ops: callbacks to deliver buffer information.
505 * between user-space and kernel-space.
506 * @drv_priv: driver private data.
507 * @buf_struct_size: size of the driver-specific buffer structure;
508 * "0" indicates the driver doesn't want to use a custom buffer
509 * structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
510 * will be used for v4l2.
511 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
512 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*``
513 * @gfp_flags: additional gfp flags used when allocating the buffers.
514 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
515 * to force the buffer allocation to a specific memory zone.
516 * @min_buffers_needed: the minimum number of buffers needed before
517 * @start_streaming can be called. Used when a DMA engine
518 * cannot be started unless at least this number of buffers
519 * have been queued into the driver.
520 */
521/*
522 * Private elements (won't appear at the uAPI book):
523 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
524 * @memory: current memory type used
525 * @dma_dir: DMA mapping direction.
526 * @bufs: videobuf buffer structures
527 * @num_buffers: number of allocated/used buffers
528 * @queued_list: list of buffers currently queued from userspace
529 * @queued_count: number of buffers queued and ready for streaming.
530 * @owned_by_drv_count: number of buffers owned by the driver
531 * @done_list: list of buffers ready to be dequeued to userspace
532 * @done_lock: lock to protect done_list list
533 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
534 * @streaming: current streaming state
535 * @start_streaming_called: @start_streaming was called successfully and we
536 * started streaming.
537 * @error: a fatal error occurred on the queue
538 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
539 * buffers. Only set for capture queues if qbuf has not yet been
540 * called since poll() needs to return %EPOLLERR in that situation.
541 * @is_multiplanar: set if buffer type is multiplanar
542 * @is_output: set if buffer type is output
543 * @copy_timestamp: set if vb2-core should set timestamps
544 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
545 * last decoded buffer was already dequeued. Set for capture queues
546 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
547 * @fileio: file io emulator internal data, used only if emulator is active
548 * @threadio: thread io internal data, used only if thread is active
549 */
550struct vb2_queue {
551 unsigned int type;
552 unsigned int io_modes;
553 struct device *dev;
554 unsigned long dma_attrs;
555 unsigned bidirectional:1;
556 unsigned fileio_read_once:1;
557 unsigned fileio_write_immediately:1;
558 unsigned allow_zero_bytesused:1;
559 unsigned quirk_poll_must_check_waiting_for_buffers:1;
560 unsigned supports_requests:1;
561 unsigned uses_qbuf:1;
562 unsigned uses_requests:1;
563
564 struct mutex *lock;
565 void *owner;
566
567 const struct vb2_ops *ops;
568 const struct vb2_mem_ops *mem_ops;
569 const struct vb2_buf_ops *buf_ops;
570
571 void *drv_priv;
572 unsigned int buf_struct_size;
573 u32 timestamp_flags;
574 gfp_t gfp_flags;
575 u32 min_buffers_needed;
576
577 struct device *alloc_devs[VB2_MAX_PLANES];
578
579 /* private: internal use only */
580 struct mutex mmap_lock;
581 unsigned int memory;
582 enum dma_data_direction dma_dir;
583 struct vb2_buffer *bufs[VB2_MAX_FRAME];
584 unsigned int num_buffers;
585
586 struct list_head queued_list;
587 unsigned int queued_count;
588
589 atomic_t owned_by_drv_count;
590 struct list_head done_list;
591 spinlock_t done_lock;
592 wait_queue_head_t done_wq;
593
594 unsigned int streaming:1;
595 unsigned int start_streaming_called:1;
596 unsigned int error:1;
597 unsigned int waiting_for_buffers:1;
598 unsigned int is_multiplanar:1;
599 unsigned int is_output:1;
600 unsigned int copy_timestamp:1;
601 unsigned int last_buffer_dequeued:1;
602
603 struct vb2_fileio_data *fileio;
604 struct vb2_threadio_data *threadio;
605
606#ifdef CONFIG_VIDEO_ADV_DEBUG
607 /*
608 * Counters for how often these queue-related ops are
609 * called. Used to check for unbalanced ops.
610 */
611 u32 cnt_queue_setup;
612 u32 cnt_wait_prepare;
613 u32 cnt_wait_finish;
614 u32 cnt_start_streaming;
615 u32 cnt_stop_streaming;
616#endif
617};
618
619/**
620 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
621 * @vb: pointer to &struct vb2_buffer to which the plane in
622 * question belongs to.
623 * @plane_no: plane number for which the address is to be returned.
624 *
625 * This function returns a kernel virtual address of a given plane if
626 * such a mapping exist, NULL otherwise.
627 */
628void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
629
630/**
631 * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
632 * @vb: pointer to &struct vb2_buffer to which the plane in
633 * question belongs to.
634 * @plane_no: plane number for which the cookie is to be returned.
635 *
636 * This function returns an allocator specific cookie for a given plane if
637 * available, NULL otherwise. The allocator should provide some simple static
638 * inline function, which would convert this cookie to the allocator specific
639 * type that can be used directly by the driver to access the buffer. This can
640 * be for example physical address, pointer to scatter list or IOMMU mapping.
641 */
642void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
643
644/**
645 * vb2_buffer_done() - inform videobuf that an operation on a buffer
646 * is finished.
647 * @vb: pointer to &struct vb2_buffer to be used.
648 * @state: state of the buffer, as defined by &enum vb2_buffer_state.
649 * Either %VB2_BUF_STATE_DONE if the operation finished
650 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
651 * with an error or any of %VB2_BUF_STATE_QUEUED or
652 * %VB2_BUF_STATE_REQUEUEING if the driver wants to
653 * requeue buffers (see below).
654 *
655 * This function should be called by the driver after a hardware operation on
656 * a buffer is finished and the buffer may be returned to userspace. The driver
657 * cannot use this buffer anymore until it is queued back to it by videobuf
658 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
659 * to the driver by &vb2_ops->buf_queue can be passed to this function.
660 *
661 * While streaming a buffer can only be returned in state DONE or ERROR.
662 * The &vb2_ops->start_streaming op can also return them in case the DMA engine
663 * cannot be started for some reason. In that case the buffers should be
664 * returned with state QUEUED or REQUEUEING to put them back into the queue.
665 *
666 * %VB2_BUF_STATE_REQUEUEING is like %VB2_BUF_STATE_QUEUED, but it also calls
667 * &vb2_ops->buf_queue to queue buffers back to the driver. Note that calling
668 * vb2_buffer_done(..., VB2_BUF_STATE_REQUEUEING) from interrupt context will
669 * result in &vb2_ops->buf_queue being called in interrupt context as well.
670 */
671void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
672
673/**
674 * vb2_discard_done() - discard all buffers marked as DONE.
675 * @q: pointer to &struct vb2_queue with videobuf2 queue.
676 *
677 * This function is intended to be used with suspend/resume operations. It
678 * discards all 'done' buffers as they would be too old to be requested after
679 * resume.
680 *
681 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
682 * delayed works before calling this function to make sure no buffer will be
683 * touched by the driver and/or hardware.
684 */
685void vb2_discard_done(struct vb2_queue *q);
686
687/**
688 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
689 * @q: pointer to &struct vb2_queue with videobuf2 queue.
690 *
691 * This function will wait until all buffers that have been given to the driver
692 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
693 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
694 * It is intended to be called with all locks taken, for example from
695 * &vb2_ops->stop_streaming callback.
696 */
697int vb2_wait_for_all_buffers(struct vb2_queue *q);
698
699/**
700 * vb2_core_querybuf() - query video buffer information.
701 * @q: pointer to &struct vb2_queue with videobuf2 queue.
702 * @index: id number of the buffer.
703 * @pb: buffer struct passed from userspace.
704 *
705 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
706 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
707 *
708 * The passed buffer should have been verified.
709 *
710 * This function fills the relevant information for the userspace.
711 *
712 * Return: returns zero on success; an error code otherwise.
713 */
714void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
715
716/**
717 * vb2_core_reqbufs() - Initiate streaming.
718 * @q: pointer to &struct vb2_queue with videobuf2 queue.
719 * @memory: memory type, as defined by &enum vb2_memory.
720 * @count: requested buffer count.
721 *
722 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
723 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
724 *
725 * This function:
726 *
727 * #) verifies streaming parameters passed from the userspace;
728 * #) sets up the queue;
729 * #) negotiates number of buffers and planes per buffer with the driver
730 * to be used during streaming;
731 * #) allocates internal buffer structures (&struct vb2_buffer), according to
732 * the agreed parameters;
733 * #) for MMAP memory type, allocates actual video memory, using the
734 * memory handling/allocation routines provided during queue initialization.
735 *
736 * If req->count is 0, all the memory will be freed instead.
737 *
738 * If the queue has been allocated previously by a previous vb2_core_reqbufs()
739 * call and the queue is not busy, memory will be reallocated.
740 *
741 * Return: returns zero on success; an error code otherwise.
742 */
743int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
744 unsigned int *count);
745
746/**
747 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
748 * @q: pointer to &struct vb2_queue with videobuf2 queue.
749 * @memory: memory type, as defined by &enum vb2_memory.
750 * @count: requested buffer count.
751 * @requested_planes: number of planes requested.
752 * @requested_sizes: array with the size of the planes.
753 *
754 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
755 * called internally by VB2 by an API-specific handler, like
756 * ``videobuf2-v4l2.h``.
757 *
758 * This function:
759 *
760 * #) verifies parameter sanity;
761 * #) calls the &vb2_ops->queue_setup queue operation;
762 * #) performs any necessary memory allocations.
763 *
764 * Return: returns zero on success; an error code otherwise.
765 */
766int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
767 unsigned int *count, unsigned int requested_planes,
768 const unsigned int requested_sizes[]);
769
770/**
771 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
772 * to the kernel.
773 * @q: pointer to &struct vb2_queue with videobuf2 queue.
774 * @index: id number of the buffer.
775 * @pb: buffer structure passed from userspace to
776 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
777 *
778 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
779 * called internally by VB2 by an API-specific handler, like
780 * ``videobuf2-v4l2.h``.
781 *
782 * The passed buffer should have been verified.
783 *
784 * This function calls vb2_ops->buf_prepare callback in the driver
785 * (if provided), in which driver-specific buffer initialization can
786 * be performed.
787 *
788 * Return: returns zero on success; an error code otherwise.
789 */
790int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
791
792/**
793 * vb2_core_qbuf() - Queue a buffer from userspace
794 *
795 * @q: pointer to &struct vb2_queue with videobuf2 queue.
796 * @index: id number of the buffer
797 * @pb: buffer structure passed from userspace to
798 * v4l2_ioctl_ops->vidioc_qbuf handler in driver
799 * @req: pointer to &struct media_request, may be NULL.
800 *
801 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
802 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
803 *
804 * This function:
805 *
806 * #) If @req is non-NULL, then the buffer will be bound to this
807 * media request and it returns. The buffer will be prepared and
808 * queued to the driver (i.e. the next two steps) when the request
809 * itself is queued.
810 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
811 * (if provided), in which driver-specific buffer initialization can
812 * be performed;
813 * #) if streaming is on, queues the buffer in driver by the means of
814 * &vb2_ops->buf_queue callback for processing.
815 *
816 * Return: returns zero on success; an error code otherwise.
817 */
818int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
819 struct media_request *req);
820
821/**
822 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
823 * @q: pointer to &struct vb2_queue with videobuf2 queue
824 * @pindex: pointer to the buffer index. May be NULL
825 * @pb: buffer structure passed from userspace to
826 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
827 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
828 * buffers ready for dequeuing are present. Normally the driver
829 * would be passing (file->f_flags & O_NONBLOCK) here.
830 *
831 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
832 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
833 *
834 * This function:
835 *
836 * #) calls buf_finish callback in the driver (if provided), in which
837 * driver can perform any additional operations that may be required before
838 * returning the buffer to userspace, such as cache sync,
839 * #) the buffer struct members are filled with relevant information for
840 * the userspace.
841 *
842 * Return: returns zero on success; an error code otherwise.
843 */
844int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
845 bool nonblocking);
846
847/**
848 * vb2_core_streamon() - Implements VB2 stream ON logic
849 *
850 * @q: pointer to &struct vb2_queue with videobuf2 queue
851 * @type: type of the queue to be started.
852 * For V4L2, this is defined by &enum v4l2_buf_type type.
853 *
854 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
855 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
856 *
857 * Return: returns zero on success; an error code otherwise.
858 */
859int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
860
861/**
862 * vb2_core_streamoff() - Implements VB2 stream OFF logic
863 *
864 * @q: pointer to &struct vb2_queue with videobuf2 queue
865 * @type: type of the queue to be started.
866 * For V4L2, this is defined by &enum v4l2_buf_type type.
867 *
868 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
869 * called internally by VB2 by an API-specific handler, like
870 * ``videobuf2-v4l2.h``.
871 *
872 * Return: returns zero on success; an error code otherwise.
873 */
874int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
875
876/**
877 * vb2_core_expbuf() - Export a buffer as a file descriptor.
878 * @q: pointer to &struct vb2_queue with videobuf2 queue.
879 * @fd: pointer to the file descriptor associated with DMABUF
880 * (set by driver).
881 * @type: buffer type.
882 * @index: id number of the buffer.
883 * @plane: index of the plane to be exported, 0 for single plane queues
884 * @flags: file flags for newly created file, as defined at
885 * include/uapi/asm-generic/fcntl.h.
886 * Currently, the only used flag is %O_CLOEXEC.
887 * is supported, refer to manual of open syscall for more details.
888 *
889 *
890 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
891 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
892 *
893 * Return: returns zero on success; an error code otherwise.
894 */
895int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
896 unsigned int index, unsigned int plane, unsigned int flags);
897
898/**
899 * vb2_core_queue_init() - initialize a videobuf2 queue
900 * @q: pointer to &struct vb2_queue with videobuf2 queue.
901 * This structure should be allocated in driver
902 *
903 * The &vb2_queue structure should be allocated by the driver. The driver is
904 * responsible of clearing it's content and setting initial values for some
905 * required entries before calling this function.
906 *
907 * .. note::
908 *
909 * The following fields at @q should be set before calling this function:
910 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
911 */
912int vb2_core_queue_init(struct vb2_queue *q);
913
914/**
915 * vb2_core_queue_release() - stop streaming, release the queue and free memory
916 * @q: pointer to &struct vb2_queue with videobuf2 queue.
917 *
918 * This function stops streaming and performs necessary clean ups, including
919 * freeing video buffer memory. The driver is responsible for freeing
920 * the &struct vb2_queue itself.
921 */
922void vb2_core_queue_release(struct vb2_queue *q);
923
924/**
925 * vb2_queue_error() - signal a fatal error on the queue
926 * @q: pointer to &struct vb2_queue with videobuf2 queue.
927 *
928 * Flag that a fatal unrecoverable error has occurred and wake up all processes
929 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
930 * buffers will return %-EIO.
931 *
932 * The error flag will be cleared when canceling the queue, either from
933 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
934 * function before starting the stream, otherwise the error flag will remain set
935 * until the queue is released when closing the device node.
936 */
937void vb2_queue_error(struct vb2_queue *q);
938
939/**
940 * vb2_mmap() - map video buffers into application address space.
941 * @q: pointer to &struct vb2_queue with videobuf2 queue.
942 * @vma: pointer to &struct vm_area_struct with the vma passed
943 * to the mmap file operation handler in the driver.
944 *
945 * Should be called from mmap file operation handler of a driver.
946 * This function maps one plane of one of the available video buffers to
947 * userspace. To map whole video memory allocated on reqbufs, this function
948 * has to be called once per each plane per each buffer previously allocated.
949 *
950 * When the userspace application calls mmap, it passes to it an offset returned
951 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
952 * That offset acts as a "cookie", which is then used to identify the plane
953 * to be mapped.
954 *
955 * This function finds a plane with a matching offset and a mapping is performed
956 * by the means of a provided memory operation.
957 *
958 * The return values from this function are intended to be directly returned
959 * from the mmap handler in driver.
960 */
961int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
962
963#ifndef CONFIG_MMU
964/**
965 * vb2_get_unmapped_area - map video buffers into application address space.
966 * @q: pointer to &struct vb2_queue with videobuf2 queue.
967 * @addr: memory address.
968 * @len: buffer size.
969 * @pgoff: page offset.
970 * @flags: memory flags.
971 *
972 * This function is used in noMMU platforms to propose address mapping
973 * for a given buffer. It's intended to be used as a handler for the
974 * &file_operations->get_unmapped_area operation.
975 *
976 * This is called by the mmap() syscall routines will call this
977 * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
978 */
979unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
980 unsigned long addr,
981 unsigned long len,
982 unsigned long pgoff,
983 unsigned long flags);
984#endif
985
986/**
987 * vb2_core_poll() - implements poll syscall() logic.
988 * @q: pointer to &struct vb2_queue with videobuf2 queue.
989 * @file: &struct file argument passed to the poll
990 * file operation handler.
991 * @wait: &poll_table wait argument passed to the poll
992 * file operation handler.
993 *
994 * This function implements poll file operation handler for a driver.
995 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
996 * be informed that the file descriptor of a video device is available for
997 * reading.
998 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
999 * will be reported as available for writing.
1000 *
1001 * The return values from this function are intended to be directly returned
1002 * from poll handler in driver.
1003 */
1004__poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
1005 poll_table *wait);
1006
1007/**
1008 * vb2_read() - implements read() syscall logic.
1009 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1010 * @data: pointed to target userspace buffer
1011 * @count: number of bytes to read
1012 * @ppos: file handle position tracking pointer
1013 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1014 */
1015size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
1016 loff_t *ppos, int nonblock);
1017/**
1018 * vb2_read() - implements write() syscall logic.
1019 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1020 * @data: pointed to target userspace buffer
1021 * @count: number of bytes to write
1022 * @ppos: file handle position tracking pointer
1023 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1024 */
1025size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
1026 loff_t *ppos, int nonblock);
1027
1028/**
1029 * typedef vb2_thread_fnc - callback function for use with vb2_thread.
1030 *
1031 * @vb: pointer to struct &vb2_buffer.
1032 * @priv: pointer to a private data.
1033 *
1034 * This is called whenever a buffer is dequeued in the thread.
1035 */
1036typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
1037
1038/**
1039 * vb2_thread_start() - start a thread for the given queue.
1040 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1041 * @fnc: &vb2_thread_fnc callback function.
1042 * @priv: priv pointer passed to the callback function.
1043 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
1044 *
1045 * This starts a thread that will queue and dequeue until an error occurs
1046 * or vb2_thread_stop() is called.
1047 *
1048 * .. attention::
1049 *
1050 * This function should not be used for anything else but the videobuf2-dvb
1051 * support. If you think you have another good use-case for this, then please
1052 * contact the linux-media mailing list first.
1053 */
1054int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1055 const char *thread_name);
1056
1057/**
1058 * vb2_thread_stop() - stop the thread for the given queue.
1059 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1060 */
1061int vb2_thread_stop(struct vb2_queue *q);
1062
1063/**
1064 * vb2_is_streaming() - return streaming status of the queue.
1065 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1066 */
1067static inline bool vb2_is_streaming(struct vb2_queue *q)
1068{
1069 return q->streaming;
1070}
1071
1072/**
1073 * vb2_fileio_is_active() - return true if fileio is active.
1074 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1075 *
1076 * This returns true if read() or write() is used to stream the data
1077 * as opposed to stream I/O. This is almost never an important distinction,
1078 * except in rare cases. One such case is that using read() or write() to
1079 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1080 * is no way you can pass the field information of each buffer to/from
1081 * userspace. A driver that supports this field format should check for
1082 * this in the &vb2_ops->queue_setup op and reject it if this function returns
1083 * true.
1084 */
1085static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1086{
1087 return q->fileio;
1088}
1089
1090/**
1091 * vb2_is_busy() - return busy status of the queue.
1092 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1093 *
1094 * This function checks if queue has any buffers allocated.
1095 */
1096static inline bool vb2_is_busy(struct vb2_queue *q)
1097{
1098 return (q->num_buffers > 0);
1099}
1100
1101/**
1102 * vb2_get_drv_priv() - return driver private data associated with the queue.
1103 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1104 */
1105static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1106{
1107 return q->drv_priv;
1108}
1109
1110/**
1111 * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1112 * @vb: pointer to &struct vb2_buffer to which the plane in
1113 * question belongs to.
1114 * @plane_no: plane number for which payload should be set.
1115 * @size: payload in bytes.
1116 */
1117static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1118 unsigned int plane_no, unsigned long size)
1119{
1120 if (plane_no < vb->num_planes)
1121 vb->planes[plane_no].bytesused = size;
1122}
1123
1124/**
1125 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1126 * @vb: pointer to &struct vb2_buffer to which the plane in
1127 * question belongs to.
1128 * @plane_no: plane number for which payload should be set.
1129 */
1130static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1131 unsigned int plane_no)
1132{
1133 if (plane_no < vb->num_planes)
1134 return vb->planes[plane_no].bytesused;
1135 return 0;
1136}
1137
1138/**
1139 * vb2_plane_size() - return plane size in bytes.
1140 * @vb: pointer to &struct vb2_buffer to which the plane in
1141 * question belongs to.
1142 * @plane_no: plane number for which size should be returned.
1143 */
1144static inline unsigned long
1145vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1146{
1147 if (plane_no < vb->num_planes)
1148 return vb->planes[plane_no].length;
1149 return 0;
1150}
1151
1152/**
1153 * vb2_start_streaming_called() - return streaming status of driver.
1154 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1155 */
1156static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1157{
1158 return q->start_streaming_called;
1159}
1160
1161/**
1162 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1163 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1164 */
1165static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1166{
1167 q->last_buffer_dequeued = false;
1168}
1169
1170/*
1171 * The following functions are not part of the vb2 core API, but are useful
1172 * functions for videobuf2-*.
1173 */
1174
1175/**
1176 * vb2_buffer_in_use() - return true if the buffer is in use and
1177 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1178 *
1179 * @vb: buffer for which plane size should be returned.
1180 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1181 */
1182bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1183
1184/**
1185 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1186 * passed to a buffer operation are compatible with the queue.
1187 *
1188 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1189 * @memory: memory model, as defined by enum &vb2_memory.
1190 * @type: private buffer type whose content is defined by the vb2-core
1191 * caller. For example, for V4L2, it should match
1192 * the types defined on enum &v4l2_buf_type.
1193 */
1194int vb2_verify_memory_type(struct vb2_queue *q,
1195 enum vb2_memory memory, unsigned int type);
1196
1197/**
1198 * vb2_request_object_is_buffer() - return true if the object is a buffer
1199 *
1200 * @obj: the request object.
1201 */
1202bool vb2_request_object_is_buffer(struct media_request_object *obj);
1203
1204/**
1205 * vb2_request_buffer_cnt() - return the number of buffers in the request
1206 *
1207 * @req: the request.
1208 */
1209unsigned int vb2_request_buffer_cnt(struct media_request *req);
1210
1211#endif /* _MEDIA_VIDEOBUF2_CORE_H */
1212