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/dma-fence.h>
21 #define VB2_MAX_FRAME (32)
22 #define VB2_MAX_PLANES (8)
25 * enum vb2_memory - type of memory model used to make the buffers visible
28 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on
30 * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is
31 * memory mapped via mmap() ioctl. This model is
32 * also used when the user is using the buffers via
33 * read() or write() system calls.
34 * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is
35 * memory mapped via mmap() ioctl.
36 * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer.
39 VB2_MEMORY_UNKNOWN
= 0,
41 VB2_MEMORY_USERPTR
= 2,
42 VB2_MEMORY_DMABUF
= 4,
45 struct vb2_fileio_data
;
46 struct vb2_threadio_data
;
49 * struct vb2_mem_ops - memory handling/memory allocator operations
50 * @alloc: allocate video memory and, optionally, allocator private data,
51 * return ERR_PTR() on failure or a pointer to allocator private,
52 * per-buffer data on success; the returned private structure
53 * will then be passed as @buf_priv argument to other ops in this
54 * structure. Additional gfp_flags to use when allocating the
55 * are also passed to this operation. These flags are from the
56 * gfp_flags field of vb2_queue.
57 * @put: inform the allocator that the buffer will no longer be used;
58 * usually will result in the allocator freeing the buffer (if
59 * no other users of this buffer are present); the @buf_priv
60 * argument is the allocator private per-buffer structure
61 * previously returned from the alloc callback.
62 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
63 * DMABUF memory types.
64 * @get_userptr: acquire userspace memory for a hardware operation; used for
65 * USERPTR memory types; vaddr is the address passed to the
66 * videobuf layer when queuing a video buffer of USERPTR type;
67 * should return an allocator private per-buffer structure
68 * associated with the buffer on success, ERR_PTR() on failure;
69 * the returned private structure will then be passed as @buf_priv
70 * argument to other ops in this structure.
71 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
73 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
74 * used for DMABUF memory types; dev is the alloc device
75 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
76 * allocator private per-buffer structure on success;
77 * this needs to be used for further accesses to the buffer.
78 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
79 * buffer is no longer used; the @buf_priv argument is the
80 * allocator private per-buffer structure previously returned
81 * from the attach_dmabuf callback.
82 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
83 * of dmabuf is informed that this driver is going to use the
85 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
86 * that this driver is done using the dmabuf for now.
87 * @prepare: called every time the buffer is passed from userspace to the
88 * driver, useful for cache synchronisation, optional.
89 * @finish: called every time the buffer is passed back from the driver
90 * to the userspace, also optional.
91 * @vaddr: return a kernel virtual address to a given memory buffer
92 * associated with the passed private structure or NULL if no
93 * such mapping exists.
94 * @cookie: return allocator specific cookie for a given memory buffer
95 * associated with the passed private structure or NULL if not
97 * @num_users: return the current number of users of a memory buffer;
98 * return 1 if the videobuf layer (or actually the driver using
99 * it) is the only user.
100 * @mmap: setup a userspace mapping for a given memory buffer under
101 * the provided virtual memory region.
103 * Those operations are used by the videobuf2 core to implement the memory
104 * handling/memory allocators for each type of supported streaming I/O method.
107 * #) Required ops for USERPTR types: get_userptr, put_userptr.
109 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
111 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
113 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
114 * map_dmabuf, unmap_dmabuf.
117 void *(*alloc
)(struct device
*dev
, unsigned long attrs
,
119 enum dma_data_direction dma_dir
,
120 gfp_t gfp_flags
, int memflags
);
121 void (*put
)(void *buf_priv
);
122 struct dma_buf
*(*get_dmabuf
)(void *buf_priv
, unsigned long flags
);
124 void *(*get_userptr
)(struct device
*dev
, unsigned long vaddr
,
126 enum dma_data_direction dma_dir
,
128 void (*put_userptr
)(void *buf_priv
);
130 void (*prepare
)(void *buf_priv
, size_t size
, int memflags
);
131 void (*finish
)(void *buf_priv
, size_t size
, int memflags
);
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
, size_t size
,
140 void (*unmap_dmabuf
)(void *buf_priv
, size_t size
);
142 void *(*vaddr
)(void *buf_priv
);
143 void *(*cookie
)(void *buf_priv
);
145 unsigned int (*num_users
)(void *buf_priv
);
147 int (*mmap
)(void *buf_priv
, struct vm_area_struct
*vma
);
151 * struct vb2_plane - plane information
152 * @mem_priv: private data with this plane
153 * @dbuf: dma_buf - shared buffer object
154 * @dbuf_mapped: flag to show whether dbuf is mapped or not
155 * @bytesused: number of bytes occupied by data in the plane (payload)
156 * @length: size of this plane (NOT the payload) in bytes
157 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
158 * @length is always greater or equal to @min_length.
159 * @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 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
164 * pointing to this plane
165 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
166 * descriptor associated with this plane
167 * @m: Union with memtype-specific data (@offset, @userptr or
169 * @data_offset: offset in the plane to the start of data; usually 0,
170 * unless there is a header in front of the data
171 * Should contain enough information to be able to cover all the fields
172 * of struct v4l2_plane at videodev2.h
176 struct dma_buf
*dbuf
;
177 unsigned int dbuf_mapped
;
178 unsigned int bytesused
;
180 unsigned int min_length
;
183 unsigned long userptr
;
186 unsigned int data_offset
;
190 * enum vb2_io_modes - queue access methods
191 * @VB2_MMAP: driver supports MMAP with streaming API
192 * @VB2_USERPTR: driver supports USERPTR with streaming API
193 * @VB2_READ: driver supports read() style access
194 * @VB2_WRITE: driver supports write() style access
195 * @VB2_DMABUF: driver supports DMABUF with streaming API
199 VB2_USERPTR
= (1 << 1),
201 VB2_WRITE
= (1 << 3),
202 VB2_DMABUF
= (1 << 4),
206 * enum vb2_buffer_state - current video buffer state
207 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
208 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
209 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
210 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
211 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
212 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
213 * in a hardware operation
214 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
215 * not yet dequeued to userspace
216 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
217 * has ended with an error, which will be reported
218 * to the userspace when it is dequeued
220 enum vb2_buffer_state
{
221 VB2_BUF_STATE_DEQUEUED
,
222 VB2_BUF_STATE_PREPARING
,
223 VB2_BUF_STATE_PREPARED
,
224 VB2_BUF_STATE_QUEUED
,
225 VB2_BUF_STATE_REQUEUEING
,
226 VB2_BUF_STATE_ACTIVE
,
234 * struct vb2_buffer - represents a video buffer
235 * @vb2_queue: the queue to which this driver belongs
236 * @index: id number of the buffer
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 * @planes: private per-plane information; do not change
242 * @timestamp: frame timestamp in ns
245 struct vb2_queue
*vb2_queue
;
249 unsigned int num_planes
;
250 struct vb2_plane planes
[VB2_MAX_PLANES
];
253 /* private: internal use only
255 * state: current buffer state; do not change
256 * queued_entry: entry on the queued buffers list, which holds
257 * all buffers queued from userspace
258 * done_entry: entry on the list that stores all buffers ready
259 * to be dequeued to userspace
260 * in_fence: fence received from vb2 client to wait on before
261 * using the buffer (queueing to the driver)
262 * fence_cb: fence callback information
263 * fence_cb_lock: protect callback signal/remove
264 * out_fence_fd: the out_fence_fd to be shared with userspace.
265 * out_fence: the out-fence associated with the buffer once
266 * it is queued to the driver.
267 * sync_file: the sync file to wrap the out fence
269 enum vb2_buffer_state state
;
271 struct list_head queued_entry
;
272 struct list_head done_entry
;
274 struct dma_fence
*in_fence
;
275 struct dma_fence_cb fence_cb
;
276 struct work_struct qbuf_work
;
277 spinlock_t fence_cb_lock
;
279 struct timer_list fence_timer
;
282 struct dma_fence
*out_fence
;
283 struct sync_file
*sync_file
;
285 #ifdef CONFIG_VIDEO_ADV_DEBUG
287 * Counters for how often these buffer-related ops are
288 * called. Used to check for unbalanced ops.
292 u32 cnt_mem_get_dmabuf
;
293 u32 cnt_mem_get_userptr
;
294 u32 cnt_mem_put_userptr
;
297 u32 cnt_mem_attach_dmabuf
;
298 u32 cnt_mem_detach_dmabuf
;
299 u32 cnt_mem_map_dmabuf
;
300 u32 cnt_mem_unmap_dmabuf
;
303 u32 cnt_mem_num_users
;
312 /* This counts the number of calls to vb2_buffer_done() */
318 * struct vb2_ops - driver-specific callbacks
320 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
321 * handlers before memory allocation. It can be called
322 * twice: if the original number of requested buffers
323 * could not be allocated, then it will be called a
324 * second time with the actually allocated number of
325 * buffers to verify if that is OK.
326 * The driver should return the required number of buffers
327 * in \*num_buffers, the required number of planes per
328 * buffer in \*num_planes, the size of each plane should be
329 * set in the sizes\[\] array and optional per-plane
330 * allocator specific device in the alloc_devs\[\] array.
331 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
332 * the driver has to use the currently configured format to
333 * determine the plane sizes and \*num_buffers is the total
334 * number of buffers that are being allocated. When called
335 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
336 * describes the requested number of planes and sizes\[\]
337 * contains the requested plane sizes. In this case
338 * \*num_buffers are being allocated additionally to
339 * q->num_buffers. If either \*num_planes or the requested
340 * sizes are invalid callback must return %-EINVAL.
341 * @wait_prepare: release any locks taken while calling vb2 functions;
342 * it is called before an ioctl needs to wait for a new
343 * buffer to arrive; required to avoid a deadlock in
344 * blocking access type.
345 * @wait_finish: reacquire all locks released in the previous callback;
346 * required to continue operation after sleeping while
347 * waiting for a new buffer to arrive.
348 * @buf_init: called once after allocating a buffer (in MMAP case)
349 * or after acquiring a new USERPTR buffer; drivers may
350 * perform additional buffer-related initialization;
351 * initialization failure (return != 0) will prevent
352 * queue setup from completing successfully; optional.
353 * @buf_prepare: called every time the buffer is queued from userspace
354 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
355 * perform any initialization required before each
356 * hardware operation in this callback; drivers can
357 * access/modify the buffer here as it is still synced for
358 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
359 * also validate the buffer size; if an error is returned,
360 * the buffer will not be queued in driver; optional.
361 * @buf_finish: called before every dequeue of the buffer back to
362 * userspace; the buffer is synced for the CPU, so drivers
363 * can access/modify the buffer contents; drivers may
364 * perform any operations required before userspace
365 * accesses the buffer; optional. The buffer state can be
366 * one of the following: %DONE and %ERROR occur while
367 * streaming is in progress, and the %PREPARED state occurs
368 * when the queue has been canceled and all pending
369 * buffers are being returned to their default %DEQUEUED
370 * state. Typically you only have to do something if the
371 * state is %VB2_BUF_STATE_DONE, since in all other cases
372 * the buffer contents will be ignored anyway.
373 * @buf_cleanup: called once before the buffer is freed; drivers may
374 * perform any additional cleanup; optional.
375 * @start_streaming: called once to enter 'streaming' state; the driver may
376 * receive buffers with @buf_queue callback
377 * before @start_streaming is called; the driver gets the
378 * number of already queued buffers in count parameter;
379 * driver can return an error if hardware fails, in that
380 * case all buffers that have been already given by
381 * the @buf_queue callback are to be returned by the driver
382 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
383 * If you need a minimum number of buffers before you can
384 * start streaming, then set @min_buffers_needed in the
385 * vb2_queue structure. If that is non-zero then
386 * @start_streaming won't be called until at least that
387 * many buffers have been queued up by userspace.
388 * @stop_streaming: called when 'streaming' state must be disabled; driver
389 * should stop any DMA transactions or wait until they
390 * finish and give back all buffers it got from &buf_queue
391 * callback by calling vb2_buffer_done() with either
392 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
393 * vb2_wait_for_all_buffers() function
394 * @is_unordered: tell if the queue is unordered, i.e. buffers can be
395 * dequeued in a different order from how they were queued.
396 * The default is assumed to be ordered and this function
397 * only needs to be implemented for unordered queues.
398 * @buf_queue: passes buffer vb to the driver; driver may start
399 * hardware operation on this buffer; driver should give
400 * the buffer back by calling vb2_buffer_done() function;
401 * it is allways called after calling VIDIOC_STREAMON()
402 * ioctl; might be called before @start_streaming callback
403 * if user pre-queued buffers before calling
405 * @mem_flags: called before events of buffer manipulations including
406 * buffer acquisition and mappin to study extra information
407 * vb2 mem implementations. The return values of
408 * @mem_flags are implementation specific.
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_init
)(struct vb2_buffer
*vb
);
419 int (*buf_prepare
)(struct vb2_buffer
*vb
);
420 void (*buf_finish
)(struct vb2_buffer
*vb
);
421 void (*buf_cleanup
)(struct vb2_buffer
*vb
);
423 int (*start_streaming
)(struct vb2_queue
*q
, unsigned int count
);
424 void (*stop_streaming
)(struct vb2_queue
*q
);
425 bool (*is_unordered
)(struct vb2_queue
*q
);
427 void (*buf_queue
)(struct vb2_buffer
*vb
);
428 int (*mem_flags
)(struct vb2_buffer
*vb
);
432 * struct vb2_buf_ops - driver-specific callbacks
434 * @verify_planes_array: Verify that a given user space structure contains
435 * enough planes for the buffer. This is called
436 * for each dequeued buffer.
437 * @fill_user_buffer: given a vb2_buffer fill in the userspace structure.
438 * For V4L2 this is a struct v4l2_buffer.
439 * @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer.
440 * If the userspace structure is invalid, then this op
441 * will return an error.
442 * @copy_timestamp: copy the timestamp from a userspace structure to
443 * the vb2_buffer struct.
446 int (*verify_planes_array
)(struct vb2_buffer
*vb
, const void *pb
);
447 void (*fill_user_buffer
)(struct vb2_buffer
*vb
, void *pb
);
448 int (*fill_vb2_buffer
)(struct vb2_buffer
*vb
, const void *pb
,
449 struct vb2_plane
*planes
);
450 void (*copy_timestamp
)(struct vb2_buffer
*vb
, const void *pb
);
454 * struct vb2_queue - a videobuf queue
456 * @type: private buffer type whose content is defined by the vb2-core
457 * caller. For example, for V4L2, it should match
458 * the types defined on enum &v4l2_buf_type
459 * @io_modes: supported io methods (see vb2_io_modes enum)
460 * @dev: device to use for the default allocation context if the driver
461 * doesn't fill in the @alloc_devs array.
462 * @dma_attrs: DMA attributes to use for the DMA.
463 * @bidirectional: when this flag is set the DMA direction for the buffers of
464 * this queue will be overridden with DMA_BIDIRECTIONAL direction.
465 * This is useful in cases where the hardware (firmware) writes to
466 * a buffer which is mapped as read (DMA_TO_DEVICE), or reads from
467 * buffer which is mapped for write (DMA_FROM_DEVICE) in order
468 * to satisfy some internal hardware restrictions or adds a padding
469 * needed by the processing algorithm. In case the DMA mapping is
470 * not bidirectional but the hardware (firmware) trying to access
471 * the buffer (in the opposite direction) this could lead to an
472 * IOMMU protection faults.
473 * @fileio_read_once: report EOF after reading the first buffer
474 * @fileio_write_immediately: queue buffer after each write() call
475 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
476 * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
477 * has not been called. This is a vb1 idiom that has been adopted
479 * @lock: pointer to a mutex that protects the vb2_queue struct. The
480 * driver can set this to a mutex to let the v4l2 core serialize
481 * the queuing ioctls. If the driver wants to handle locking
482 * itself, then this should be set to NULL. This lock is not used
483 * by the videobuf2 core API.
484 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
485 * that called reqbufs, create_buffers or started fileio.
486 * This field is not used by the videobuf2 core API, but it allows
487 * drivers to easily associate an owner filehandle with the queue.
488 * @ops: driver-specific callbacks
489 * @mem_ops: memory allocator specific callbacks
490 * @buf_ops: callbacks to deliver buffer information
491 * between user-space and kernel-space
492 * @drv_priv: driver private data
493 * @buf_struct_size: size of the driver-specific buffer structure;
494 * "0" indicates the driver doesn't want to use a custom buffer
495 * structure type. for example, sizeof(struct vb2_v4l2_buffer)
496 * will be used for v4l2.
497 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
498 * V4L2_BUF_FLAG_TSTAMP_SRC_*
499 * @gfp_flags: additional gfp flags used when allocating the buffers.
500 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
501 * to force the buffer allocation to a specific memory zone.
502 * @min_buffers_needed: the minimum number of buffers needed before
503 * @start_streaming can be called. Used when a DMA engine
504 * cannot be started unless at least this number of buffers
505 * have been queued into the driver.
508 * Private elements (won't appear at the uAPI book):
509 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
510 * @memory: current memory type used
511 * @dma_dir: DMA mapping direction.
512 * @bufs: videobuf buffer structures
513 * @num_buffers: number of allocated/used buffers
514 * @queued_list: list of buffers currently queued from userspace
515 * @queued_count: number of buffers queued and ready for streaming.
516 * @owned_by_drv_count: number of buffers owned by the driver
517 * @done_list: list of buffers ready to be dequeued to userspace
518 * @done_lock: lock to protect done_list list
519 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
520 * @alloc_devs: memory type/allocator-specific per-plane device
521 * @streaming: current streaming state
522 * @start_streaming_called: @start_streaming was called successfully and we
524 * @error: a fatal error occurred on the queue
525 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
526 * buffers. Only set for capture queues if qbuf has not yet been
527 * called since poll() needs to return POLLERR in that situation.
528 * @is_multiplanar: set if buffer type is multiplanar
529 * @is_output: set if buffer type is output
530 * @copy_timestamp: set if vb2-core should set timestamps
531 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
532 * last decoded buffer was already dequeued. Set for capture queues
533 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
534 * @fileio: file io emulator internal data, used only if emulator is active
535 * @threadio: thread io internal data, used only if thread is active
539 unsigned int io_modes
;
541 unsigned long dma_attrs
;
542 unsigned bidirectional
:1;
543 unsigned fileio_read_once
:1;
544 unsigned fileio_write_immediately
:1;
545 unsigned allow_zero_bytesused
:1;
546 unsigned quirk_poll_must_check_waiting_for_buffers
:1;
551 const struct vb2_ops
*ops
;
552 const struct vb2_mem_ops
*mem_ops
;
553 const struct vb2_buf_ops
*buf_ops
;
556 unsigned int buf_struct_size
;
559 u32 min_buffers_needed
;
561 /* private: internal use only */
562 struct mutex mmap_lock
;
564 enum dma_data_direction dma_dir
;
565 struct vb2_buffer
*bufs
[VB2_MAX_FRAME
];
566 unsigned int num_buffers
;
568 struct list_head queued_list
;
569 unsigned int queued_count
;
571 atomic_t owned_by_drv_count
;
572 struct list_head done_list
;
573 spinlock_t done_lock
;
574 wait_queue_head_t done_wq
;
576 struct device
*alloc_devs
[VB2_MAX_PLANES
];
578 unsigned int streaming
:1;
579 unsigned int start_streaming_called
:1;
580 unsigned int error
:1;
581 unsigned int waiting_for_buffers
:1;
582 unsigned int is_multiplanar
:1;
583 unsigned int is_output
:1;
584 unsigned int copy_timestamp
:1;
585 unsigned int last_buffer_dequeued
:1;
586 unsigned int queueing_started
:1;
588 u64 out_fence_context
;
589 spinlock_t out_fence_lock
;
591 struct vb2_fileio_data
*fileio
;
592 struct vb2_threadio_data
*threadio
;
594 #ifdef CONFIG_VIDEO_ADV_DEBUG
596 * Counters for how often these queue-related ops are
597 * called. Used to check for unbalanced ops.
600 u32 cnt_wait_prepare
;
602 u32 cnt_start_streaming
;
603 u32 cnt_stop_streaming
;
604 u32 cnt_is_unordered
;
610 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
611 * @vb: vb2_buffer to which the plane in question belongs to
612 * @plane_no: plane number for which the address is to be returned
614 * This function returns a kernel virtual address of a given plane if
615 * such a mapping exist, NULL otherwise.
617 void *vb2_plane_vaddr(struct vb2_buffer
*vb
, unsigned int plane_no
);
620 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
621 * @vb: vb2_buffer to which the plane in question belongs to
622 * @plane_no: plane number for which the cookie is to be returned
624 * This function returns an allocator specific cookie for a given plane if
625 * available, NULL otherwise. The allocator should provide some simple static
626 * inline function, which would convert this cookie to the allocator specific
627 * type that can be used directly by the driver to access the buffer. This can
628 * be for example physical address, pointer to scatter list or IOMMU mapping.
630 void *vb2_plane_cookie(struct vb2_buffer
*vb
, unsigned int plane_no
);
633 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
634 * @vb: vb2_buffer returned from the driver
635 * @state: either %VB2_BUF_STATE_DONE if the operation finished
636 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
637 * with an error or %VB2_BUF_STATE_QUEUED if the driver wants to
638 * requeue buffers. If start_streaming fails then it should return
639 * buffers with state %VB2_BUF_STATE_QUEUED to put them back into
642 * This function should be called by the driver after a hardware operation on
643 * a buffer is finished and the buffer may be returned to userspace. The driver
644 * cannot use this buffer anymore until it is queued back to it by videobuf
645 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
646 * to the driver by &vb2_ops->buf_queue can be passed to this function.
648 * While streaming a buffer can only be returned in state DONE or ERROR.
649 * The start_streaming op can also return them in case the DMA engine cannot
650 * be started for some reason. In that case the buffers should be returned with
653 void vb2_buffer_done(struct vb2_buffer
*vb
, enum vb2_buffer_state state
);
656 * vb2_discard_done() - discard all buffers marked as DONE
657 * @q: videobuf2 queue
659 * This function is intended to be used with suspend/resume operations. It
660 * discards all 'done' buffers as they would be too old to be requested after
663 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
664 * delayed works before calling this function to make sure no buffer will be
665 * touched by the driver and/or hardware.
667 void vb2_discard_done(struct vb2_queue
*q
);
670 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
671 * @q: videobuf2 queue
673 * This function will wait until all buffers that have been given to the driver
674 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
675 * doesn't call wait_prepare()/wait_finish() pair. It is intended to be called
676 * with all locks taken, for example from &vb2_ops->stop_streaming callback.
678 int vb2_wait_for_all_buffers(struct vb2_queue
*q
);
681 * vb2_core_querybuf() - query video buffer information
683 * @index: id number of the buffer
684 * @pb: buffer struct passed from userspace
686 * Should be called from vidioc_querybuf ioctl handler in driver.
687 * The passed buffer should have been verified.
688 * This function fills the relevant information for the userspace.
690 void vb2_core_querybuf(struct vb2_queue
*q
, unsigned int index
, void *pb
);
693 * vb2_core_reqbufs() - Initiate streaming
694 * @q: videobuf2 queue
695 * @memory: memory type
696 * @count: requested buffer count
698 * Should be called from vidioc_reqbufs ioctl handler of a driver.
702 * #) verifies streaming parameters passed from the userspace,
703 * #) sets up the queue,
704 * #) negotiates number of buffers and planes per buffer with the driver
705 * to be used during streaming,
706 * #) allocates internal buffer structures (struct vb2_buffer), according to
707 * the agreed parameters,
708 * #) for MMAP memory type, allocates actual video memory, using the
709 * memory handling/allocation routines provided during queue initialization
711 * If req->count is 0, all the memory will be freed instead.
712 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
713 * and the queue is not busy, memory will be reallocated.
715 * The return values from this function are intended to be directly returned
716 * from vidioc_reqbufs handler in driver.
718 int vb2_core_reqbufs(struct vb2_queue
*q
, enum vb2_memory memory
,
719 unsigned int *count
);
722 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
723 * @q: videobuf2 queue
724 * @memory: memory type
725 * @count: requested buffer count
726 * @requested_planes: number of planes requested
727 * @requested_sizes: array with the size of the planes
729 * Should be called from VIDIOC_CREATE_BUFS() ioctl handler of a driver.
732 * #) verifies parameter sanity
733 * #) calls the .queue_setup() queue operation
734 * #) performs any necessary memory allocations
736 * Return: the return values from this function are intended to be directly
737 * returned from VIDIOC_CREATE_BUFS() handler in driver.
739 int vb2_core_create_bufs(struct vb2_queue
*q
, enum vb2_memory memory
,
740 unsigned int *count
, unsigned int requested_planes
,
741 const unsigned int requested_sizes
[]);
744 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
746 * @q: videobuf2 queue
747 * @index: id number of the buffer
748 * @pb: buffer structure passed from userspace to vidioc_prepare_buf
751 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
752 * The passed buffer should have been verified.
753 * This function calls buf_prepare callback in the driver (if provided),
754 * in which driver-specific buffer initialization can be performed,
756 * The return values from this function are intended to be directly returned
757 * from vidioc_prepare_buf handler in driver.
759 int vb2_core_prepare_buf(struct vb2_queue
*q
, unsigned int index
, void *pb
);
762 * vb2_setup_out_fence() - setup new out-fence
763 * @q: The vb2_queue where to setup it
764 * @index: index of the buffer
766 * Setup the file descriptor, the fence and the sync_file for the next
767 * buffer to be queued and add everything to the tail of the q->out_fence_list.
769 int vb2_setup_out_fence(struct vb2_queue
*q
, unsigned int index
);
772 * vb2_core_qbuf() - Queue a buffer from userspace
774 * @q: videobuf2 queue
775 * @index: id number of the buffer
776 * @pb: buffer structure passed from userspace to vidioc_qbuf handler
778 * @in_fence: in-fence to wait on before queueing the buffer
780 * Should be called from vidioc_qbuf ioctl handler of a driver.
781 * The passed buffer should have been verified.
785 * #) if necessary, calls buf_prepare callback in the driver (if provided), in
786 * which driver-specific buffer initialization can be performed,
787 * #) if streaming is on, queues the buffer in driver by the means of
788 * &vb2_ops->buf_queue callback for processing.
790 * The return values from this function are intended to be directly returned
791 * from vidioc_qbuf handler in driver.
793 int vb2_core_qbuf(struct vb2_queue
*q
, unsigned int index
, void *pb
,
794 struct dma_fence
*in_fence
);
797 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
798 * @q: videobuf2 queue
799 * @pindex: pointer to the buffer index. May be NULL
800 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler
802 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
803 * buffers ready for dequeuing are present. Normally the driver
804 * would be passing (file->f_flags & O_NONBLOCK) here
806 * Should be called from vidioc_dqbuf ioctl handler of a driver.
807 * The passed buffer should have been verified.
811 * #) calls buf_finish callback in the driver (if provided), in which
812 * driver can perform any additional operations that may be required before
813 * returning the buffer to userspace, such as cache sync,
814 * #) the buffer struct members are filled with relevant information for
817 * The return values from this function are intended to be directly returned
818 * from vidioc_dqbuf handler in driver.
820 int vb2_core_dqbuf(struct vb2_queue
*q
, unsigned int *pindex
, void *pb
,
823 int vb2_core_streamon(struct vb2_queue
*q
, unsigned int type
);
824 int vb2_core_streamoff(struct vb2_queue
*q
, unsigned int type
);
827 * vb2_core_expbuf() - Export a buffer as a file descriptor
828 * @q: videobuf2 queue
829 * @fd: file descriptor associated with DMABUF (set by driver) *
831 * @index: id number of the buffer
832 * @plane: index of the plane to be exported, 0 for single plane queues
833 * @flags: flags for newly created file, currently only O_CLOEXEC is
834 * supported, refer to manual of open syscall for more details
836 * The return values from this function are intended to be directly returned
837 * from vidioc_expbuf handler in driver.
839 int vb2_core_expbuf(struct vb2_queue
*q
, int *fd
, unsigned int type
,
840 unsigned int index
, unsigned int plane
, unsigned int flags
);
843 * vb2_core_queue_init() - initialize a videobuf2 queue
844 * @q: videobuf2 queue; this structure should be allocated in driver
846 * The vb2_queue structure should be allocated by the driver. The driver is
847 * responsible of clearing it's content and setting initial values for some
848 * required entries before calling this function.
849 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
850 * to the struct vb2_queue description in include/media/videobuf2-core.h
851 * for more information.
853 int vb2_core_queue_init(struct vb2_queue
*q
);
856 * vb2_core_queue_release() - stop streaming, release the queue and free memory
857 * @q: videobuf2 queue
859 * This function stops streaming and performs necessary clean ups, including
860 * freeing video buffer memory. The driver is responsible for freeing
861 * the vb2_queue structure itself.
863 void vb2_core_queue_release(struct vb2_queue
*q
);
866 * vb2_queue_error() - signal a fatal error on the queue
867 * @q: videobuf2 queue
869 * Flag that a fatal unrecoverable error has occurred and wake up all processes
870 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
871 * buffers will return -EIO.
873 * The error flag will be cleared when cancelling the queue, either from
874 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
875 * function before starting the stream, otherwise the error flag will remain set
876 * until the queue is released when closing the device node.
878 void vb2_queue_error(struct vb2_queue
*q
);
881 * vb2_mmap() - map video buffers into application address space
882 * @q: videobuf2 queue
883 * @vma: vma passed to the mmap file operation handler in the driver
885 * Should be called from mmap file operation handler of a driver.
886 * This function maps one plane of one of the available video buffers to
887 * userspace. To map whole video memory allocated on reqbufs, this function
888 * has to be called once per each plane per each buffer previously allocated.
890 * When the userspace application calls mmap, it passes to it an offset returned
891 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
892 * a "cookie", which is then used to identify the plane to be mapped.
893 * This function finds a plane with a matching offset and a mapping is performed
894 * by the means of a provided memory operation.
896 * The return values from this function are intended to be directly returned
897 * from the mmap handler in driver.
899 int vb2_mmap(struct vb2_queue
*q
, struct vm_area_struct
*vma
);
902 unsigned long vb2_get_unmapped_area(struct vb2_queue
*q
,
906 unsigned long flags
);
910 * vb2_core_poll() - implements poll userspace operation
911 * @q: videobuf2 queue
912 * @file: file argument passed to the poll file operation handler
913 * @wait: wait argument passed to the poll file operation handler
915 * This function implements poll file operation handler for a driver.
916 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
917 * be informed that the file descriptor of a video device is available for
919 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
920 * will be reported as available for writing.
922 * The return values from this function are intended to be directly returned
923 * from poll handler in driver.
925 unsigned int vb2_core_poll(struct vb2_queue
*q
, struct file
*file
,
928 size_t vb2_read(struct vb2_queue
*q
, char __user
*data
, size_t count
,
929 loff_t
*ppos
, int nonblock
);
930 size_t vb2_write(struct vb2_queue
*q
, const char __user
*data
, size_t count
,
931 loff_t
*ppos
, int nonblock
);
934 * typedef vb2_thread_fnc - callback function for use with vb2_thread
936 * @vb: pointer to struct &vb2_buffer
937 * @priv: pointer to a private pointer
939 * This is called whenever a buffer is dequeued in the thread.
941 typedef int (*vb2_thread_fnc
)(struct vb2_buffer
*vb
, void *priv
);
944 * vb2_thread_start() - start a thread for the given queue.
946 * @fnc: callback function
947 * @priv: priv pointer passed to the callback function
948 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
950 * This starts a thread that will queue and dequeue until an error occurs
951 * or @vb2_thread_stop is called.
955 * This function should not be used for anything else but the videobuf2-dvb
956 * support. If you think you have another good use-case for this, then please
957 * contact the linux-media mailing list first.
959 int vb2_thread_start(struct vb2_queue
*q
, vb2_thread_fnc fnc
, void *priv
,
960 const char *thread_name
);
963 * vb2_thread_stop() - stop the thread for the given queue.
966 int vb2_thread_stop(struct vb2_queue
*q
);
969 * vb2_is_streaming() - return streaming status of the queue
972 static inline bool vb2_is_streaming(struct vb2_queue
*q
)
978 * vb2_fileio_is_active() - return true if fileio is active.
981 * This returns true if read() or write() is used to stream the data
982 * as opposed to stream I/O. This is almost never an important distinction,
983 * except in rare cases. One such case is that using read() or write() to
984 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
985 * is no way you can pass the field information of each buffer to/from
986 * userspace. A driver that supports this field format should check for
987 * this in the queue_setup op and reject it if this function returns true.
989 static inline bool vb2_fileio_is_active(struct vb2_queue
*q
)
995 * vb2_is_busy() - return busy status of the queue
998 * This function checks if queue has any buffers allocated.
1000 static inline bool vb2_is_busy(struct vb2_queue
*q
)
1002 return (q
->num_buffers
> 0);
1006 * vb2_get_drv_priv() - return driver private data associated with the queue
1007 * @q: videobuf queue
1009 static inline void *vb2_get_drv_priv(struct vb2_queue
*q
)
1015 * vb2_set_plane_payload() - set bytesused for the plane plane_no
1016 * @vb: buffer for which plane payload should be set
1017 * @plane_no: plane number for which payload should be set
1018 * @size: payload in bytes
1020 static inline void vb2_set_plane_payload(struct vb2_buffer
*vb
,
1021 unsigned int plane_no
, unsigned long size
)
1023 if (plane_no
< vb
->num_planes
)
1024 vb
->planes
[plane_no
].bytesused
= size
;
1028 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1029 * @vb: buffer for which plane payload should be set
1030 * @plane_no: plane number for which payload should be set
1032 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer
*vb
,
1033 unsigned int plane_no
)
1035 if (plane_no
< vb
->num_planes
)
1036 return vb
->planes
[plane_no
].bytesused
;
1041 * vb2_plane_size() - return plane size in bytes
1042 * @vb: buffer for which plane size should be returned
1043 * @plane_no: plane number for which size should be returned
1045 static inline unsigned long
1046 vb2_plane_size(struct vb2_buffer
*vb
, unsigned int plane_no
)
1048 if (plane_no
< vb
->num_planes
)
1049 return vb
->planes
[plane_no
].length
;
1054 * vb2_start_streaming_called() - return streaming status of driver
1055 * @q: videobuf queue
1057 static inline bool vb2_start_streaming_called(struct vb2_queue
*q
)
1059 return q
->start_streaming_called
;
1063 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
1064 * @q: videobuf queue
1066 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue
*q
)
1068 q
->last_buffer_dequeued
= false;
1072 * The following functions are not part of the vb2 core API, but are useful
1073 * functions for videobuf2-*.
1077 * vb2_buffer_in_use() - return true if the buffer is in use and
1078 * the queue cannot be freed (by the means of REQBUFS(0)) call
1080 * @vb: buffer for which plane size should be returned
1081 * @q: videobuf queue
1083 bool vb2_buffer_in_use(struct vb2_queue
*q
, struct vb2_buffer
*vb
);
1086 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1087 * passed to a buffer operation are compatible with the queue.
1089 * @q: videobuf queue
1090 * @memory: memory model, as defined by enum &vb2_memory.
1091 * @type: private buffer type whose content is defined by the vb2-core
1092 * caller. For example, for V4L2, it should match
1093 * the types defined on enum &v4l2_buf_type
1095 int vb2_verify_memory_type(struct vb2_queue
*q
,
1096 enum vb2_memory memory
, unsigned int type
);
1097 #endif /* _MEDIA_VIDEOBUF2_CORE_H */