2 * videobuf2-core.h - Video Buffer 2 Core Framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
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.
12 #ifndef _MEDIA_VIDEOBUF2_CORE_H
13 #define _MEDIA_VIDEOBUF2_CORE_H
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>
22 #define VB2_MAX_FRAME (32)
23 #define VB2_MAX_PLANES (8)
26 * enum vb2_memory - type of memory model used to make the buffers visible
29 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on
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.
40 VB2_MEMORY_UNKNOWN = 0,
42 VB2_MEMORY_USERPTR = 2,
43 VB2_MEMORY_DMABUF = 4,
46 struct vb2_fileio_data;
47 struct vb2_threadio_data;
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
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
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
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.
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.
108 * #) Required ops for USERPTR types: get_userptr, put_userptr.
110 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
112 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
114 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
115 * map_dmabuf, unmap_dmabuf.
118 void *(*alloc)(struct device *dev, unsigned long attrs,
120 enum dma_data_direction dma_dir,
122 void (*put)(void *buf_priv);
123 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
125 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
127 enum dma_data_direction dma_dir);
128 void (*put_userptr)(void *buf_priv);
130 void (*prepare)(void *buf_priv);
131 void (*finish)(void *buf_priv);
133 void *(*attach_dmabuf)(struct device *dev,
134 struct dma_buf *dbuf,
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);
141 void *(*vaddr)(void *buf_priv);
142 void *(*cookie)(void *buf_priv);
144 unsigned int (*num_users)(void *buf_priv);
146 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
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.
170 * Should contain enough information to be able to cover all the fields
171 * of &struct v4l2_plane at videodev2.h.
175 struct dma_buf *dbuf;
176 unsigned int dbuf_mapped;
177 unsigned int bytesused;
179 unsigned int min_length;
182 unsigned long userptr;
185 unsigned int data_offset;
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.
198 VB2_USERPTR = BIT(1),
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_ACTIVE: buffer queued in driver and possibly used
211 * in a hardware operation.
212 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
213 * not yet dequeued to userspace.
214 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
215 * has ended with an error, which will be reported
216 * to the userspace when it is dequeued.
218 enum vb2_buffer_state {
219 VB2_BUF_STATE_DEQUEUED,
220 VB2_BUF_STATE_IN_REQUEST,
221 VB2_BUF_STATE_PREPARING,
222 VB2_BUF_STATE_QUEUED,
223 VB2_BUF_STATE_ACTIVE,
231 * struct vb2_buffer - represents a video buffer.
232 * @vb2_queue: pointer to &struct vb2_queue with the queue to
233 * which this driver belongs.
234 * @index: id number of the buffer.
235 * @type: buffer type.
236 * @memory: the method, in which the actual data is passed.
237 * @num_planes: number of planes in the buffer
238 * on an internal driver queue.
239 * @timestamp: frame timestamp in ns.
240 * @request: the request this buffer is associated with.
241 * @req_obj: used to bind this buffer to a request. This
242 * request object has a refcount.
245 struct vb2_queue *vb2_queue;
249 unsigned int num_planes;
251 struct media_request *request;
252 struct media_request_object req_obj;
254 /* private: internal use only
256 * state: current buffer state; do not change
257 * synced: this buffer has been synced for DMA, i.e. the
258 * 'prepare' memop was called. It is cleared again
259 * after the 'finish' memop is called.
260 * prepared: this buffer has been prepared, i.e. the
261 * buf_prepare op was called. It is cleared again
262 * after the 'buf_finish' op is called.
263 * copied_timestamp: the timestamp of this capture buffer was copied
264 * from an output buffer.
265 * queued_entry: entry on the queued buffers list, which holds
266 * all buffers queued from userspace
267 * done_entry: entry on the list that stores all buffers ready
268 * to be dequeued to userspace
269 * vb2_plane: per-plane information; do not change
271 enum vb2_buffer_state state;
272 unsigned int synced:1;
273 unsigned int prepared:1;
274 unsigned int copied_timestamp:1;
276 struct vb2_plane planes[VB2_MAX_PLANES];
277 struct list_head queued_entry;
278 struct list_head done_entry;
279 #ifdef CONFIG_VIDEO_ADV_DEBUG
281 * Counters for how often these buffer-related ops are
282 * called. Used to check for unbalanced ops.
286 u32 cnt_mem_get_dmabuf;
287 u32 cnt_mem_get_userptr;
288 u32 cnt_mem_put_userptr;
291 u32 cnt_mem_attach_dmabuf;
292 u32 cnt_mem_detach_dmabuf;
293 u32 cnt_mem_map_dmabuf;
294 u32 cnt_mem_unmap_dmabuf;
297 u32 cnt_mem_num_users;
300 u32 cnt_buf_out_validate;
306 u32 cnt_buf_request_complete;
308 /* This counts the number of calls to vb2_buffer_done() */
314 * struct vb2_ops - driver-specific callbacks.
316 * These operations are not called from interrupt context except where
317 * mentioned specifically.
319 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
320 * handlers before memory allocation. It can be called
321 * twice: if the original number of requested buffers
322 * could not be allocated, then it will be called a
323 * second time with the actually allocated number of
324 * buffers to verify if that is OK.
325 * The driver should return the required number of buffers
326 * in \*num_buffers, the required number of planes per
327 * buffer in \*num_planes, the size of each plane should be
328 * set in the sizes\[\] array and optional per-plane
329 * allocator specific device in the alloc_devs\[\] array.
330 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
331 * the driver has to use the currently configured format to
332 * determine the plane sizes and \*num_buffers is the total
333 * number of buffers that are being allocated. When called
334 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
335 * describes the requested number of planes and sizes\[\]
336 * contains the requested plane sizes. In this case
337 * \*num_buffers are being allocated additionally to
338 * q->num_buffers. If either \*num_planes or the requested
339 * sizes are invalid callback must return %-EINVAL.
340 * @wait_prepare: release any locks taken while calling vb2 functions;
341 * it is called before an ioctl needs to wait for a new
342 * buffer to arrive; required to avoid a deadlock in
343 * blocking access type.
344 * @wait_finish: reacquire all locks released in the previous callback;
345 * required to continue operation after sleeping while
346 * waiting for a new buffer to arrive.
347 * @buf_out_validate: called when the output buffer is prepared or queued
348 * to a request; drivers can use this to validate
349 * userspace-provided information; this is required only
351 * @buf_init: called once after allocating a buffer (in MMAP case)
352 * or after acquiring a new USERPTR buffer; drivers may
353 * perform additional buffer-related initialization;
354 * initialization failure (return != 0) will prevent
355 * queue setup from completing successfully; optional.
356 * @buf_prepare: called every time the buffer is queued from userspace
357 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
358 * perform any initialization required before each
359 * hardware operation in this callback; drivers can
360 * access/modify the buffer here as it is still synced for
361 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
362 * also validate the buffer size; if an error is returned,
363 * the buffer will not be queued in driver; optional.
364 * @buf_finish: called before every dequeue of the buffer back to
365 * userspace; the buffer is synced for the CPU, so drivers
366 * can access/modify the buffer contents; drivers may
367 * perform any operations required before userspace
368 * accesses the buffer; optional. The buffer state can be
369 * one of the following: %DONE and %ERROR occur while
370 * streaming is in progress, and the %PREPARED state occurs
371 * when the queue has been canceled and all pending
372 * buffers are being returned to their default %DEQUEUED
373 * state. Typically you only have to do something if the
374 * state is %VB2_BUF_STATE_DONE, since in all other cases
375 * the buffer contents will be ignored anyway.
376 * @buf_cleanup: called once before the buffer is freed; drivers may
377 * perform any additional cleanup; optional.
378 * @start_streaming: called once to enter 'streaming' state; the driver may
379 * receive buffers with @buf_queue callback
380 * before @start_streaming is called; the driver gets the
381 * number of already queued buffers in count parameter;
382 * driver can return an error if hardware fails, in that
383 * case all buffers that have been already given by
384 * the @buf_queue callback are to be returned by the driver
385 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
386 * If you need a minimum number of buffers before you can
387 * start streaming, then set
388 * &vb2_queue->min_buffers_needed. If that is non-zero
389 * then @start_streaming won't be called until at least
390 * that many buffers have been queued up by userspace.
391 * @stop_streaming: called when 'streaming' state must be disabled; driver
392 * should stop any DMA transactions or wait until they
393 * finish and give back all buffers it got from &buf_queue
394 * callback by calling vb2_buffer_done() with either
395 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
396 * vb2_wait_for_all_buffers() function
397 * @buf_queue: passes buffer vb to the driver; driver may start
398 * hardware operation on this buffer; driver should give
399 * the buffer back by calling vb2_buffer_done() function;
400 * it is always called after calling VIDIOC_STREAMON()
401 * ioctl; might be called before @start_streaming callback
402 * if user pre-queued buffers before calling
404 * @buf_request_complete: a buffer that was never queued to the driver but is
405 * associated with a queued request was canceled.
406 * The driver will have to mark associated objects in the
407 * request as completed; required if requests are
411 int (*queue_setup)(struct vb2_queue *q,
412 unsigned int *num_buffers, unsigned int *num_planes,
413 unsigned int sizes[], struct device *alloc_devs[]);
415 void (*wait_prepare)(struct vb2_queue *q);
416 void (*wait_finish)(struct vb2_queue *q);
418 int (*buf_out_validate)(struct vb2_buffer *vb);
419 int (*buf_init)(struct vb2_buffer *vb);
420 int (*buf_prepare)(struct vb2_buffer *vb);
421 void (*buf_finish)(struct vb2_buffer *vb);
422 void (*buf_cleanup)(struct vb2_buffer *vb);
424 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
425 void (*stop_streaming)(struct vb2_queue *q);
427 void (*buf_queue)(struct vb2_buffer *vb);
429 void (*buf_request_complete)(struct vb2_buffer *vb);
433 * struct vb2_buf_ops - driver-specific callbacks.
435 * @verify_planes_array: Verify that a given user space structure contains
436 * enough planes for the buffer. This is called
437 * for each dequeued buffer.
438 * @init_buffer: given a &vb2_buffer initialize the extra data after
440 * For V4L2 this is a &struct vb2_v4l2_buffer.
441 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
442 * For V4L2 this is a &struct v4l2_buffer.
443 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer.
444 * If the userspace structure is invalid, then this op
445 * will return an error.
446 * @copy_timestamp: copy the timestamp from a userspace structure to
447 * the &struct vb2_buffer.
450 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
451 void (*init_buffer)(struct vb2_buffer *vb);
452 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
453 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
454 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
458 * struct vb2_queue - a videobuf queue.
460 * @type: private buffer type whose content is defined by the vb2-core
461 * caller. For example, for V4L2, it should match
462 * the types defined on &enum v4l2_buf_type.
463 * @io_modes: supported io methods (see &enum vb2_io_modes).
464 * @alloc_devs: &struct device memory type/allocator-specific per-plane device
465 * @dev: device to use for the default allocation context if the driver
466 * doesn't fill in the @alloc_devs array.
467 * @dma_attrs: DMA attributes to use for the DMA.
468 * @bidirectional: when this flag is set the DMA direction for the buffers of
469 * this queue will be overridden with %DMA_BIDIRECTIONAL direction.
470 * This is useful in cases where the hardware (firmware) writes to
471 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
472 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order
473 * to satisfy some internal hardware restrictions or adds a padding
474 * needed by the processing algorithm. In case the DMA mapping is
475 * not bidirectional but the hardware (firmware) trying to access
476 * the buffer (in the opposite direction) this could lead to an
477 * IOMMU protection faults.
478 * @fileio_read_once: report EOF after reading the first buffer
479 * @fileio_write_immediately: queue buffer after each write() call
480 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
481 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
482 * has not been called. This is a vb1 idiom that has been adopted
484 * @supports_requests: this queue supports the Request API.
485 * @requires_requests: this queue requires the Request API. If this is set to 1,
486 * then supports_requests must be set to 1 as well.
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.
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
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
552 unsigned int io_modes;
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 requires_requests:1;
562 unsigned uses_qbuf:1;
563 unsigned uses_requests:1;
568 const struct vb2_ops *ops;
569 const struct vb2_mem_ops *mem_ops;
570 const struct vb2_buf_ops *buf_ops;
573 unsigned int buf_struct_size;
576 u32 min_buffers_needed;
578 struct device *alloc_devs[VB2_MAX_PLANES];
580 /* private: internal use only */
581 struct mutex mmap_lock;
583 enum dma_data_direction dma_dir;
584 struct vb2_buffer *bufs[VB2_MAX_FRAME];
585 unsigned int num_buffers;
587 struct list_head queued_list;
588 unsigned int queued_count;
590 atomic_t owned_by_drv_count;
591 struct list_head done_list;
592 spinlock_t done_lock;
593 wait_queue_head_t done_wq;
595 unsigned int streaming:1;
596 unsigned int start_streaming_called:1;
597 unsigned int error:1;
598 unsigned int waiting_for_buffers:1;
599 unsigned int waiting_in_dqbuf:1;
600 unsigned int is_multiplanar:1;
601 unsigned int is_output:1;
602 unsigned int copy_timestamp:1;
603 unsigned int last_buffer_dequeued:1;
605 struct vb2_fileio_data *fileio;
606 struct vb2_threadio_data *threadio;
608 #ifdef CONFIG_VIDEO_ADV_DEBUG
610 * Counters for how often these queue-related ops are
611 * called. Used to check for unbalanced ops.
614 u32 cnt_wait_prepare;
616 u32 cnt_start_streaming;
617 u32 cnt_stop_streaming;
622 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
623 * @vb: pointer to &struct vb2_buffer to which the plane in
624 * question belongs to.
625 * @plane_no: plane number for which the address is to be returned.
627 * This function returns a kernel virtual address of a given plane if
628 * such a mapping exist, NULL otherwise.
630 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
633 * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
634 * @vb: pointer to &struct vb2_buffer to which the plane in
635 * question belongs to.
636 * @plane_no: plane number for which the cookie is to be returned.
638 * This function returns an allocator specific cookie for a given plane if
639 * available, NULL otherwise. The allocator should provide some simple static
640 * inline function, which would convert this cookie to the allocator specific
641 * type that can be used directly by the driver to access the buffer. This can
642 * be for example physical address, pointer to scatter list or IOMMU mapping.
644 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
647 * vb2_buffer_done() - inform videobuf that an operation on a buffer
649 * @vb: pointer to &struct vb2_buffer to be used.
650 * @state: state of the buffer, as defined by &enum vb2_buffer_state.
651 * Either %VB2_BUF_STATE_DONE if the operation finished
652 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
653 * with an error or %VB2_BUF_STATE_QUEUED.
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.
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 to put them back into the queue.
666 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
669 * vb2_discard_done() - discard all buffers marked as DONE.
670 * @q: pointer to &struct vb2_queue with videobuf2 queue.
672 * This function is intended to be used with suspend/resume operations. It
673 * discards all 'done' buffers as they would be too old to be requested after
676 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
677 * delayed works before calling this function to make sure no buffer will be
678 * touched by the driver and/or hardware.
680 void vb2_discard_done(struct vb2_queue *q);
683 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
684 * @q: pointer to &struct vb2_queue with videobuf2 queue.
686 * This function will wait until all buffers that have been given to the driver
687 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
688 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
689 * It is intended to be called with all locks taken, for example from
690 * &vb2_ops->stop_streaming callback.
692 int vb2_wait_for_all_buffers(struct vb2_queue *q);
695 * vb2_core_querybuf() - query video buffer information.
696 * @q: pointer to &struct vb2_queue with videobuf2 queue.
697 * @index: id number of the buffer.
698 * @pb: buffer struct passed from userspace.
700 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
701 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
703 * The passed buffer should have been verified.
705 * This function fills the relevant information for the userspace.
707 * Return: returns zero on success; an error code otherwise.
709 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
712 * vb2_core_reqbufs() - Initiate streaming.
713 * @q: pointer to &struct vb2_queue with videobuf2 queue.
714 * @memory: memory type, as defined by &enum vb2_memory.
715 * @count: requested buffer count.
717 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
718 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
722 * #) verifies streaming parameters passed from the userspace;
723 * #) sets up the queue;
724 * #) negotiates number of buffers and planes per buffer with the driver
725 * to be used during streaming;
726 * #) allocates internal buffer structures (&struct vb2_buffer), according to
727 * the agreed parameters;
728 * #) for MMAP memory type, allocates actual video memory, using the
729 * memory handling/allocation routines provided during queue initialization.
731 * If req->count is 0, all the memory will be freed instead.
733 * If the queue has been allocated previously by a previous vb2_core_reqbufs()
734 * call and the queue is not busy, memory will be reallocated.
736 * Return: returns zero on success; an error code otherwise.
738 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
739 unsigned int *count);
742 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
743 * @q: pointer to &struct vb2_queue with videobuf2 queue.
744 * @memory: memory type, as defined by &enum vb2_memory.
745 * @count: requested buffer count.
746 * @requested_planes: number of planes requested.
747 * @requested_sizes: array with the size of the planes.
749 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
750 * called internally by VB2 by an API-specific handler, like
751 * ``videobuf2-v4l2.h``.
755 * #) verifies parameter sanity;
756 * #) calls the &vb2_ops->queue_setup queue operation;
757 * #) performs any necessary memory allocations.
759 * Return: returns zero on success; an error code otherwise.
761 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
762 unsigned int *count, unsigned int requested_planes,
763 const unsigned int requested_sizes[]);
766 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
768 * @q: pointer to &struct vb2_queue with videobuf2 queue.
769 * @index: id number of the buffer.
770 * @pb: buffer structure passed from userspace to
771 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
773 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
774 * called internally by VB2 by an API-specific handler, like
775 * ``videobuf2-v4l2.h``.
777 * The passed buffer should have been verified.
779 * This function calls vb2_ops->buf_prepare callback in the driver
780 * (if provided), in which driver-specific buffer initialization can
783 * Return: returns zero on success; an error code otherwise.
785 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
788 * vb2_core_qbuf() - Queue a buffer from userspace
790 * @q: pointer to &struct vb2_queue with videobuf2 queue.
791 * @index: id number of the buffer
792 * @pb: buffer structure passed from userspace to
793 * v4l2_ioctl_ops->vidioc_qbuf handler in driver
794 * @req: pointer to &struct media_request, may be NULL.
796 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
797 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
801 * #) If @req is non-NULL, then the buffer will be bound to this
802 * media request and it returns. The buffer will be prepared and
803 * queued to the driver (i.e. the next two steps) when the request
805 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
806 * (if provided), in which driver-specific buffer initialization can
808 * #) if streaming is on, queues the buffer in driver by the means of
809 * &vb2_ops->buf_queue callback for processing.
811 * Return: returns zero on success; an error code otherwise.
813 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
814 struct media_request *req);
817 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
818 * @q: pointer to &struct vb2_queue with videobuf2 queue
819 * @pindex: pointer to the buffer index. May be NULL
820 * @pb: buffer structure passed from userspace to
821 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
822 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
823 * buffers ready for dequeuing are present. Normally the driver
824 * would be passing (file->f_flags & O_NONBLOCK) here.
826 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
827 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
831 * #) calls buf_finish callback in the driver (if provided), in which
832 * driver can perform any additional operations that may be required before
833 * returning the buffer to userspace, such as cache sync,
834 * #) the buffer struct members are filled with relevant information for
837 * Return: returns zero on success; an error code otherwise.
839 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
843 * vb2_core_streamon() - Implements VB2 stream ON logic
845 * @q: pointer to &struct vb2_queue with videobuf2 queue
846 * @type: type of the queue to be started.
847 * For V4L2, this is defined by &enum v4l2_buf_type type.
849 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
850 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
852 * Return: returns zero on success; an error code otherwise.
854 int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
857 * vb2_core_streamoff() - Implements VB2 stream OFF logic
859 * @q: pointer to &struct vb2_queue with videobuf2 queue
860 * @type: type of the queue to be started.
861 * For V4L2, this is defined by &enum v4l2_buf_type type.
863 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
864 * called internally by VB2 by an API-specific handler, like
865 * ``videobuf2-v4l2.h``.
867 * Return: returns zero on success; an error code otherwise.
869 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
872 * vb2_core_expbuf() - Export a buffer as a file descriptor.
873 * @q: pointer to &struct vb2_queue with videobuf2 queue.
874 * @fd: pointer to the file descriptor associated with DMABUF
876 * @type: buffer type.
877 * @index: id number of the buffer.
878 * @plane: index of the plane to be exported, 0 for single plane queues
879 * @flags: file flags for newly created file, as defined at
880 * include/uapi/asm-generic/fcntl.h.
881 * Currently, the only used flag is %O_CLOEXEC.
882 * is supported, refer to manual of open syscall for more details.
885 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
886 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
888 * Return: returns zero on success; an error code otherwise.
890 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
891 unsigned int index, unsigned int plane, unsigned int flags);
894 * vb2_core_queue_init() - initialize a videobuf2 queue
895 * @q: pointer to &struct vb2_queue with videobuf2 queue.
896 * This structure should be allocated in driver
898 * The &vb2_queue structure should be allocated by the driver. The driver is
899 * responsible of clearing it's content and setting initial values for some
900 * required entries before calling this function.
904 * The following fields at @q should be set before calling this function:
905 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
907 int vb2_core_queue_init(struct vb2_queue *q);
910 * vb2_core_queue_release() - stop streaming, release the queue and free memory
911 * @q: pointer to &struct vb2_queue with videobuf2 queue.
913 * This function stops streaming and performs necessary clean ups, including
914 * freeing video buffer memory. The driver is responsible for freeing
915 * the &struct vb2_queue itself.
917 void vb2_core_queue_release(struct vb2_queue *q);
920 * vb2_queue_error() - signal a fatal error on the queue
921 * @q: pointer to &struct vb2_queue with videobuf2 queue.
923 * Flag that a fatal unrecoverable error has occurred and wake up all processes
924 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
925 * buffers will return %-EIO.
927 * The error flag will be cleared when canceling the queue, either from
928 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
929 * function before starting the stream, otherwise the error flag will remain set
930 * until the queue is released when closing the device node.
932 void vb2_queue_error(struct vb2_queue *q);
935 * vb2_mmap() - map video buffers into application address space.
936 * @q: pointer to &struct vb2_queue with videobuf2 queue.
937 * @vma: pointer to &struct vm_area_struct with the vma passed
938 * to the mmap file operation handler in the driver.
940 * Should be called from mmap file operation handler of a driver.
941 * This function maps one plane of one of the available video buffers to
942 * userspace. To map whole video memory allocated on reqbufs, this function
943 * has to be called once per each plane per each buffer previously allocated.
945 * When the userspace application calls mmap, it passes to it an offset returned
946 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
947 * That offset acts as a "cookie", which is then used to identify the plane
950 * This function finds a plane with a matching offset and a mapping is performed
951 * by the means of a provided memory operation.
953 * The return values from this function are intended to be directly returned
954 * from the mmap handler in driver.
956 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
960 * vb2_get_unmapped_area - map video buffers into application address space.
961 * @q: pointer to &struct vb2_queue with videobuf2 queue.
962 * @addr: memory address.
964 * @pgoff: page offset.
965 * @flags: memory flags.
967 * This function is used in noMMU platforms to propose address mapping
968 * for a given buffer. It's intended to be used as a handler for the
969 * &file_operations->get_unmapped_area operation.
971 * This is called by the mmap() syscall routines will call this
972 * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
974 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
978 unsigned long flags);
982 * vb2_core_poll() - implements poll syscall() logic.
983 * @q: pointer to &struct vb2_queue with videobuf2 queue.
984 * @file: &struct file argument passed to the poll
985 * file operation handler.
986 * @wait: &poll_table wait argument passed to the poll
987 * file operation handler.
989 * This function implements poll file operation handler for a driver.
990 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
991 * be informed that the file descriptor of a video device is available for
993 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
994 * will be reported as available for writing.
996 * The return values from this function are intended to be directly returned
997 * from poll handler in driver.
999 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
1003 * vb2_read() - implements read() syscall logic.
1004 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1005 * @data: pointed to target userspace buffer
1006 * @count: number of bytes to read
1007 * @ppos: file handle position tracking pointer
1008 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1010 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
1011 loff_t *ppos, int nonblock);
1013 * vb2_read() - implements write() syscall logic.
1014 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1015 * @data: pointed to target userspace buffer
1016 * @count: number of bytes to write
1017 * @ppos: file handle position tracking pointer
1018 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1020 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
1021 loff_t *ppos, int nonblock);
1024 * typedef vb2_thread_fnc - callback function for use with vb2_thread.
1026 * @vb: pointer to struct &vb2_buffer.
1027 * @priv: pointer to a private data.
1029 * This is called whenever a buffer is dequeued in the thread.
1031 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
1034 * vb2_thread_start() - start a thread for the given queue.
1035 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1036 * @fnc: &vb2_thread_fnc callback function.
1037 * @priv: priv pointer passed to the callback function.
1038 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
1040 * This starts a thread that will queue and dequeue until an error occurs
1041 * or vb2_thread_stop() is called.
1045 * This function should not be used for anything else but the videobuf2-dvb
1046 * support. If you think you have another good use-case for this, then please
1047 * contact the linux-media mailing list first.
1049 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1050 const char *thread_name);
1053 * vb2_thread_stop() - stop the thread for the given queue.
1054 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1056 int vb2_thread_stop(struct vb2_queue *q);
1059 * vb2_is_streaming() - return streaming status of the queue.
1060 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1062 static inline bool vb2_is_streaming(struct vb2_queue *q)
1064 return q->streaming;
1068 * vb2_fileio_is_active() - return true if fileio is active.
1069 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1071 * This returns true if read() or write() is used to stream the data
1072 * as opposed to stream I/O. This is almost never an important distinction,
1073 * except in rare cases. One such case is that using read() or write() to
1074 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1075 * is no way you can pass the field information of each buffer to/from
1076 * userspace. A driver that supports this field format should check for
1077 * this in the &vb2_ops->queue_setup op and reject it if this function returns
1080 static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1086 * vb2_is_busy() - return busy status of the queue.
1087 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1089 * This function checks if queue has any buffers allocated.
1091 static inline bool vb2_is_busy(struct vb2_queue *q)
1093 return (q->num_buffers > 0);
1097 * vb2_get_drv_priv() - return driver private data associated with the queue.
1098 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1100 static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1106 * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1107 * @vb: pointer to &struct vb2_buffer to which the plane in
1108 * question belongs to.
1109 * @plane_no: plane number for which payload should be set.
1110 * @size: payload in bytes.
1112 static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1113 unsigned int plane_no, unsigned long size)
1115 if (plane_no < vb->num_planes)
1116 vb->planes[plane_no].bytesused = size;
1120 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1121 * @vb: pointer to &struct vb2_buffer to which the plane in
1122 * question belongs to.
1123 * @plane_no: plane number for which payload should be set.
1125 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1126 unsigned int plane_no)
1128 if (plane_no < vb->num_planes)
1129 return vb->planes[plane_no].bytesused;
1134 * vb2_plane_size() - return plane size in bytes.
1135 * @vb: pointer to &struct vb2_buffer to which the plane in
1136 * question belongs to.
1137 * @plane_no: plane number for which size should be returned.
1139 static inline unsigned long
1140 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1142 if (plane_no < vb->num_planes)
1143 return vb->planes[plane_no].length;
1148 * vb2_start_streaming_called() - return streaming status of driver.
1149 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1151 static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1153 return q->start_streaming_called;
1157 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1158 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1160 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1162 q->last_buffer_dequeued = false;
1166 * The following functions are not part of the vb2 core API, but are useful
1167 * functions for videobuf2-*.
1171 * vb2_buffer_in_use() - return true if the buffer is in use and
1172 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1174 * @vb: buffer for which plane size should be returned.
1175 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1177 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1180 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1181 * passed to a buffer operation are compatible with the queue.
1183 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1184 * @memory: memory model, as defined by enum &vb2_memory.
1185 * @type: private buffer type whose content is defined by the vb2-core
1186 * caller. For example, for V4L2, it should match
1187 * the types defined on enum &v4l2_buf_type.
1189 int vb2_verify_memory_type(struct vb2_queue *q,
1190 enum vb2_memory memory, unsigned int type);
1193 * vb2_request_object_is_buffer() - return true if the object is a buffer
1195 * @obj: the request object.
1197 bool vb2_request_object_is_buffer(struct media_request_object *obj);
1200 * vb2_request_buffer_cnt() - return the number of buffers in the request
1202 * @req: the request.
1204 unsigned int vb2_request_buffer_cnt(struct media_request *req);
1206 #endif /* _MEDIA_VIDEOBUF2_CORE_H */