Loading...
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. The size argument to this function
58 * shall be *page aligned*.
59 * @put: inform the allocator that the buffer will no longer be used;
60 * usually will result in the allocator freeing the buffer (if
61 * no other users of this buffer are present); the @buf_priv
62 * argument is the allocator private per-buffer structure
63 * previously returned from the alloc callback.
64 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
65 * DMABUF memory types.
66 * @get_userptr: acquire userspace memory for a hardware operation; used for
67 * USERPTR memory types; vaddr is the address passed to the
68 * videobuf layer when queuing a video buffer of USERPTR type;
69 * should return an allocator private per-buffer structure
70 * associated with the buffer on success, ERR_PTR() on failure;
71 * the returned private structure will then be passed as @buf_priv
72 * argument to other ops in this structure.
73 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
74 * be used.
75 * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
76 * used for DMABUF memory types; dev is the alloc device
77 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
78 * allocator private per-buffer structure on success;
79 * this needs to be used for further accesses to the buffer.
80 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
81 * buffer is no longer used; the @buf_priv argument is the
82 * allocator private per-buffer structure previously returned
83 * from the attach_dmabuf callback.
84 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
85 * of dmabuf is informed that this driver is going to use the
86 * dmabuf.
87 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
88 * that this driver is done using the dmabuf for now.
89 * @prepare: called every time the buffer is passed from userspace to the
90 * driver, useful for cache synchronisation, optional.
91 * @finish: called every time the buffer is passed back from the driver
92 * to the userspace, also optional.
93 * @vaddr: return a kernel virtual address to a given memory buffer
94 * associated with the passed private structure or NULL if no
95 * such mapping exists.
96 * @cookie: return allocator specific cookie for a given memory buffer
97 * associated with the passed private structure or NULL if not
98 * available.
99 * @num_users: return the current number of users of a memory buffer;
100 * return 1 if the videobuf layer (or actually the driver using
101 * it) is the only user.
102 * @mmap: setup a userspace mapping for a given memory buffer under
103 * the provided virtual memory region.
104 *
105 * Those operations are used by the videobuf2 core to implement the memory
106 * handling/memory allocators for each type of supported streaming I/O method.
107 *
108 * .. note::
109 * #) Required ops for USERPTR types: get_userptr, put_userptr.
110 *
111 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
112 *
113 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
114 *
115 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
116 * map_dmabuf, unmap_dmabuf.
117 */
118struct vb2_mem_ops {
119 void *(*alloc)(struct device *dev, unsigned long attrs,
120 unsigned long size,
121 enum dma_data_direction dma_dir,
122 gfp_t gfp_flags);
123 void (*put)(void *buf_priv);
124 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
125
126 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
127 unsigned long size,
128 enum dma_data_direction dma_dir);
129 void (*put_userptr)(void *buf_priv);
130
131 void (*prepare)(void *buf_priv);
132 void (*finish)(void *buf_priv);
133
134 void *(*attach_dmabuf)(struct device *dev,
135 struct dma_buf *dbuf,
136 unsigned long size,
137 enum dma_data_direction dma_dir);
138 void (*detach_dmabuf)(void *buf_priv);
139 int (*map_dmabuf)(void *buf_priv);
140 void (*unmap_dmabuf)(void *buf_priv);
141
142 void *(*vaddr)(void *buf_priv);
143 void *(*cookie)(void *buf_priv);
144
145 unsigned int (*num_users)(void *buf_priv);
146
147 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
148};
149
150/**
151 * struct vb2_plane - plane information.
152 * @mem_priv: private data with this plane.
153 * @dbuf: dma_buf - shared buffer object.
154 * @dbuf_mapped: flag to show whether dbuf is mapped or not
155 * @bytesused: number of bytes occupied by data in the plane (payload).
156 * @length: size of this plane (NOT the payload) in bytes.
157 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
158 * @length is always greater or equal to @min_length.
159 * @m: Union with memtype-specific data.
160 * @m.offset: when memory in the associated struct vb2_buffer is
161 * %VB2_MEMORY_MMAP, equals the offset from the start of
162 * the device memory for this plane (or is a "cookie" that
163 * should be passed to mmap() called on the video node).
164 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer
165 * pointing to this plane.
166 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file
167 * descriptor associated with this plane.
168 * @data_offset: offset in the plane to the start of data; usually 0,
169 * unless there is a header in front of the data.
170 *
171 * Should contain enough information to be able to cover all the fields
172 * of &struct v4l2_plane at videodev2.h.
173 */
174struct vb2_plane {
175 void *mem_priv;
176 struct dma_buf *dbuf;
177 unsigned int dbuf_mapped;
178 unsigned int bytesused;
179 unsigned int length;
180 unsigned int min_length;
181 union {
182 unsigned int offset;
183 unsigned long userptr;
184 int fd;
185 } m;
186 unsigned int data_offset;
187};
188
189/**
190 * enum vb2_io_modes - queue access methods.
191 * @VB2_MMAP: driver supports MMAP with streaming API.
192 * @VB2_USERPTR: driver supports USERPTR with streaming API.
193 * @VB2_READ: driver supports read() style access.
194 * @VB2_WRITE: driver supports write() style access.
195 * @VB2_DMABUF: driver supports DMABUF with streaming API.
196 */
197enum vb2_io_modes {
198 VB2_MMAP = BIT(0),
199 VB2_USERPTR = BIT(1),
200 VB2_READ = BIT(2),
201 VB2_WRITE = BIT(3),
202 VB2_DMABUF = BIT(4),
203};
204
205/**
206 * enum vb2_buffer_state - current video buffer state.
207 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control.
208 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request.
209 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf.
210 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver.
211 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
212 * in a hardware operation.
213 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
214 * not yet dequeued to userspace.
215 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
216 * has ended with an error, which will be reported
217 * to the userspace when it is dequeued.
218 */
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_ACTIVE,
225 VB2_BUF_STATE_DONE,
226 VB2_BUF_STATE_ERROR,
227};
228
229struct vb2_queue;
230
231/**
232 * struct vb2_buffer - represents a video buffer.
233 * @vb2_queue: pointer to &struct vb2_queue with the queue to
234 * which this driver belongs.
235 * @index: id number of the buffer.
236 * @type: buffer type.
237 * @memory: the method, in which the actual data is passed.
238 * @num_planes: number of planes in the buffer
239 * on an internal driver queue.
240 * @timestamp: frame timestamp in ns.
241 * @request: the request this buffer is associated with.
242 * @req_obj: used to bind this buffer to a request. This
243 * request object has a refcount.
244 */
245struct vb2_buffer {
246 struct vb2_queue *vb2_queue;
247 unsigned int index;
248 unsigned int type;
249 unsigned int memory;
250 unsigned int num_planes;
251 u64 timestamp;
252 struct media_request *request;
253 struct media_request_object req_obj;
254
255 /* private: internal use only
256 *
257 * state: current buffer state; do not change
258 * synced: this buffer has been synced for DMA, i.e. the
259 * 'prepare' memop was called. It is cleared again
260 * after the 'finish' memop is called.
261 * prepared: this buffer has been prepared, i.e. the
262 * buf_prepare op was called. It is cleared again
263 * after the 'buf_finish' op is called.
264 * copied_timestamp: the timestamp of this capture buffer was copied
265 * from an output buffer.
266 * need_cache_sync_on_prepare: when set buffer's ->prepare() function
267 * performs cache sync/invalidation.
268 * need_cache_sync_on_finish: when set buffer's ->finish() function
269 * performs cache sync/invalidation.
270 * queued_entry: entry on the queued buffers list, which holds
271 * all buffers queued from userspace
272 * done_entry: entry on the list that stores all buffers ready
273 * to be dequeued to userspace
274 * vb2_plane: per-plane information; do not change
275 */
276 enum vb2_buffer_state state;
277 unsigned int synced:1;
278 unsigned int prepared:1;
279 unsigned int copied_timestamp:1;
280 unsigned int need_cache_sync_on_prepare:1;
281 unsigned int need_cache_sync_on_finish:1;
282
283 struct vb2_plane planes[VB2_MAX_PLANES];
284 struct list_head queued_entry;
285 struct list_head done_entry;
286#ifdef CONFIG_VIDEO_ADV_DEBUG
287 /*
288 * Counters for how often these buffer-related ops are
289 * called. Used to check for unbalanced ops.
290 */
291 u32 cnt_mem_alloc;
292 u32 cnt_mem_put;
293 u32 cnt_mem_get_dmabuf;
294 u32 cnt_mem_get_userptr;
295 u32 cnt_mem_put_userptr;
296 u32 cnt_mem_prepare;
297 u32 cnt_mem_finish;
298 u32 cnt_mem_attach_dmabuf;
299 u32 cnt_mem_detach_dmabuf;
300 u32 cnt_mem_map_dmabuf;
301 u32 cnt_mem_unmap_dmabuf;
302 u32 cnt_mem_vaddr;
303 u32 cnt_mem_cookie;
304 u32 cnt_mem_num_users;
305 u32 cnt_mem_mmap;
306
307 u32 cnt_buf_out_validate;
308 u32 cnt_buf_init;
309 u32 cnt_buf_prepare;
310 u32 cnt_buf_finish;
311 u32 cnt_buf_cleanup;
312 u32 cnt_buf_queue;
313 u32 cnt_buf_request_complete;
314
315 /* This counts the number of calls to vb2_buffer_done() */
316 u32 cnt_buf_done;
317#endif
318};
319
320/**
321 * struct vb2_ops - driver-specific callbacks.
322 *
323 * These operations are not called from interrupt context except where
324 * mentioned specifically.
325 *
326 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
327 * handlers before memory allocation. It can be called
328 * twice: if the original number of requested buffers
329 * could not be allocated, then it will be called a
330 * second time with the actually allocated number of
331 * buffers to verify if that is OK.
332 * The driver should return the required number of buffers
333 * in \*num_buffers, the required number of planes per
334 * buffer in \*num_planes, the size of each plane should be
335 * set in the sizes\[\] array and optional per-plane
336 * allocator specific device in the alloc_devs\[\] array.
337 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
338 * the driver has to use the currently configured format to
339 * determine the plane sizes and \*num_buffers is the total
340 * number of buffers that are being allocated. When called
341 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
342 * describes the requested number of planes and sizes\[\]
343 * contains the requested plane sizes. In this case
344 * \*num_buffers are being allocated additionally to
345 * q->num_buffers. If either \*num_planes or the requested
346 * sizes are invalid callback must return %-EINVAL.
347 * @wait_prepare: release any locks taken while calling vb2 functions;
348 * it is called before an ioctl needs to wait for a new
349 * buffer to arrive; required to avoid a deadlock in
350 * blocking access type.
351 * @wait_finish: reacquire all locks released in the previous callback;
352 * required to continue operation after sleeping while
353 * waiting for a new buffer to arrive.
354 * @buf_out_validate: called when the output buffer is prepared or queued
355 * to a request; drivers can use this to validate
356 * userspace-provided information; this is required only
357 * for OUTPUT queues.
358 * @buf_init: called once after allocating a buffer (in MMAP case)
359 * or after acquiring a new USERPTR buffer; drivers may
360 * perform additional buffer-related initialization;
361 * initialization failure (return != 0) will prevent
362 * queue setup from completing successfully; optional.
363 * @buf_prepare: called every time the buffer is queued from userspace
364 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
365 * perform any initialization required before each
366 * hardware operation in this callback; drivers can
367 * access/modify the buffer here as it is still synced for
368 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
369 * also validate the buffer size; if an error is returned,
370 * the buffer will not be queued in driver; optional.
371 * @buf_finish: called before every dequeue of the buffer back to
372 * userspace; the buffer is synced for the CPU, so drivers
373 * can access/modify the buffer contents; drivers may
374 * perform any operations required before userspace
375 * accesses the buffer; optional. The buffer state can be
376 * one of the following: %DONE and %ERROR occur while
377 * streaming is in progress, and the %PREPARED state occurs
378 * when the queue has been canceled and all pending
379 * buffers are being returned to their default %DEQUEUED
380 * state. Typically you only have to do something if the
381 * state is %VB2_BUF_STATE_DONE, since in all other cases
382 * the buffer contents will be ignored anyway.
383 * @buf_cleanup: called once before the buffer is freed; drivers may
384 * perform any additional cleanup; optional.
385 * @start_streaming: called once to enter 'streaming' state; the driver may
386 * receive buffers with @buf_queue callback
387 * before @start_streaming is called; the driver gets the
388 * number of already queued buffers in count parameter;
389 * driver can return an error if hardware fails, in that
390 * case all buffers that have been already given by
391 * the @buf_queue callback are to be returned by the driver
392 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
393 * If you need a minimum number of buffers before you can
394 * start streaming, then set
395 * &vb2_queue->min_buffers_needed. If that is non-zero
396 * then @start_streaming won't be called until at least
397 * that many buffers have been queued up by userspace.
398 * @stop_streaming: called when 'streaming' state must be disabled; driver
399 * should stop any DMA transactions or wait until they
400 * finish and give back all buffers it got from &buf_queue
401 * callback by calling vb2_buffer_done() with either
402 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
403 * vb2_wait_for_all_buffers() function
404 * @buf_queue: passes buffer vb to the driver; driver may start
405 * hardware operation on this buffer; driver should give
406 * the buffer back by calling vb2_buffer_done() function;
407 * it is always called after calling VIDIOC_STREAMON()
408 * ioctl; might be called before @start_streaming callback
409 * if user pre-queued buffers before calling
410 * VIDIOC_STREAMON().
411 * @buf_request_complete: a buffer that was never queued to the driver but is
412 * associated with a queued request was canceled.
413 * The driver will have to mark associated objects in the
414 * request as completed; required if requests are
415 * supported.
416 */
417struct vb2_ops {
418 int (*queue_setup)(struct vb2_queue *q,
419 unsigned int *num_buffers, unsigned int *num_planes,
420 unsigned int sizes[], struct device *alloc_devs[]);
421
422 void (*wait_prepare)(struct vb2_queue *q);
423 void (*wait_finish)(struct vb2_queue *q);
424
425 int (*buf_out_validate)(struct vb2_buffer *vb);
426 int (*buf_init)(struct vb2_buffer *vb);
427 int (*buf_prepare)(struct vb2_buffer *vb);
428 void (*buf_finish)(struct vb2_buffer *vb);
429 void (*buf_cleanup)(struct vb2_buffer *vb);
430
431 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
432 void (*stop_streaming)(struct vb2_queue *q);
433
434 void (*buf_queue)(struct vb2_buffer *vb);
435
436 void (*buf_request_complete)(struct vb2_buffer *vb);
437};
438
439/**
440 * struct vb2_buf_ops - driver-specific callbacks.
441 *
442 * @verify_planes_array: Verify that a given user space structure contains
443 * enough planes for the buffer. This is called
444 * for each dequeued buffer.
445 * @init_buffer: given a &vb2_buffer initialize the extra data after
446 * struct vb2_buffer.
447 * For V4L2 this is a &struct vb2_v4l2_buffer.
448 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
449 * For V4L2 this is a &struct v4l2_buffer.
450 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer.
451 * If the userspace structure is invalid, then this op
452 * will return an error.
453 * @copy_timestamp: copy the timestamp from a userspace structure to
454 * the &struct vb2_buffer.
455 */
456struct vb2_buf_ops {
457 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
458 void (*init_buffer)(struct vb2_buffer *vb);
459 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
460 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
461 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
462};
463
464/**
465 * struct vb2_queue - a videobuf queue.
466 *
467 * @type: private buffer type whose content is defined by the vb2-core
468 * caller. For example, for V4L2, it should match
469 * the types defined on &enum v4l2_buf_type.
470 * @io_modes: supported io methods (see &enum vb2_io_modes).
471 * @alloc_devs: &struct device memory type/allocator-specific per-plane device
472 * @dev: device to use for the default allocation context if the driver
473 * doesn't fill in the @alloc_devs array.
474 * @dma_attrs: DMA attributes to use for the DMA.
475 * @bidirectional: when this flag is set the DMA direction for the buffers of
476 * this queue will be overridden with %DMA_BIDIRECTIONAL direction.
477 * This is useful in cases where the hardware (firmware) writes to
478 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
479 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order
480 * to satisfy some internal hardware restrictions or adds a padding
481 * needed by the processing algorithm. In case the DMA mapping is
482 * not bidirectional but the hardware (firmware) trying to access
483 * the buffer (in the opposite direction) this could lead to an
484 * IOMMU protection faults.
485 * @fileio_read_once: report EOF after reading the first buffer
486 * @fileio_write_immediately: queue buffer after each write() call
487 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
488 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
489 * has not been called. This is a vb1 idiom that has been adopted
490 * also by vb2.
491 * @supports_requests: this queue supports the Request API.
492 * @requires_requests: this queue requires the Request API. If this is set to 1,
493 * then supports_requests must be set to 1 as well.
494 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first
495 * time this is called. Set to 0 when the queue is canceled.
496 * If this is 1, then you cannot queue buffers from a request.
497 * @uses_requests: requests are used for this queue. Set to 1 the first time
498 * a request is queued. Set to 0 when the queue is canceled.
499 * If this is 1, then you cannot queue buffers directly.
500 * @allow_cache_hints: when set user-space can pass cache management hints in
501 * order to skip cache flush/invalidation on ->prepare() or/and
502 * ->finish().
503 * @lock: pointer to a mutex that protects the &struct vb2_queue. The
504 * driver can set this to a mutex to let the v4l2 core serialize
505 * the queuing ioctls. If the driver wants to handle locking
506 * itself, then this should be set to NULL. This lock is not used
507 * by the videobuf2 core API.
508 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
509 * that called reqbufs, create_buffers or started fileio.
510 * This field is not used by the videobuf2 core API, but it allows
511 * drivers to easily associate an owner filehandle with the queue.
512 * @ops: driver-specific callbacks
513 * @mem_ops: memory allocator specific callbacks
514 * @buf_ops: callbacks to deliver buffer information.
515 * between user-space and kernel-space.
516 * @drv_priv: driver private data.
517 * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used
518 * by the vb2 core.
519 * @buf_struct_size: size of the driver-specific buffer structure;
520 * "0" indicates the driver doesn't want to use a custom buffer
521 * structure type. In that case a subsystem-specific struct
522 * will be used (in the case of V4L2 that is
523 * ``sizeof(struct vb2_v4l2_buffer)``). The first field of the
524 * driver-specific buffer structure must be the subsystem-specific
525 * struct (vb2_v4l2_buffer in the case of V4L2).
526 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
527 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*``
528 * @gfp_flags: additional gfp flags used when allocating the buffers.
529 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
530 * to force the buffer allocation to a specific memory zone.
531 * @min_buffers_needed: the minimum number of buffers needed before
532 * @start_streaming can be called. Used when a DMA engine
533 * cannot be started unless at least this number of buffers
534 * have been queued into the driver.
535 */
536/*
537 * Private elements (won't appear at the uAPI book):
538 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
539 * @memory: current memory type used
540 * @dma_dir: DMA mapping direction.
541 * @bufs: videobuf buffer structures
542 * @num_buffers: number of allocated/used buffers
543 * @queued_list: list of buffers currently queued from userspace
544 * @queued_count: number of buffers queued and ready for streaming.
545 * @owned_by_drv_count: number of buffers owned by the driver
546 * @done_list: list of buffers ready to be dequeued to userspace
547 * @done_lock: lock to protect done_list list
548 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
549 * @streaming: current streaming state
550 * @start_streaming_called: @start_streaming was called successfully and we
551 * started streaming.
552 * @error: a fatal error occurred on the queue
553 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
554 * buffers. Only set for capture queues if qbuf has not yet been
555 * called since poll() needs to return %EPOLLERR in that situation.
556 * @is_multiplanar: set if buffer type is multiplanar
557 * @is_output: set if buffer type is output
558 * @copy_timestamp: set if vb2-core should set timestamps
559 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
560 * last decoded buffer was already dequeued. Set for capture queues
561 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
562 * @fileio: file io emulator internal data, used only if emulator is active
563 * @threadio: thread io internal data, used only if thread is active
564 * @name: queue name, used for logging purpose. Initialized automatically
565 * if left empty by drivers.
566 */
567struct vb2_queue {
568 unsigned int type;
569 unsigned int io_modes;
570 struct device *dev;
571 unsigned long dma_attrs;
572 unsigned int bidirectional:1;
573 unsigned int fileio_read_once:1;
574 unsigned int fileio_write_immediately:1;
575 unsigned int allow_zero_bytesused:1;
576 unsigned int quirk_poll_must_check_waiting_for_buffers:1;
577 unsigned int supports_requests:1;
578 unsigned int requires_requests:1;
579 unsigned int uses_qbuf:1;
580 unsigned int uses_requests:1;
581 unsigned int allow_cache_hints:1;
582
583 struct mutex *lock;
584 void *owner;
585
586 const struct vb2_ops *ops;
587 const struct vb2_mem_ops *mem_ops;
588 const struct vb2_buf_ops *buf_ops;
589
590 void *drv_priv;
591 u32 subsystem_flags;
592 unsigned int buf_struct_size;
593 u32 timestamp_flags;
594 gfp_t gfp_flags;
595 u32 min_buffers_needed;
596
597 struct device *alloc_devs[VB2_MAX_PLANES];
598
599 /* private: internal use only */
600 struct mutex mmap_lock;
601 unsigned int memory;
602 enum dma_data_direction dma_dir;
603 struct vb2_buffer *bufs[VB2_MAX_FRAME];
604 unsigned int num_buffers;
605
606 struct list_head queued_list;
607 unsigned int queued_count;
608
609 atomic_t owned_by_drv_count;
610 struct list_head done_list;
611 spinlock_t done_lock;
612 wait_queue_head_t done_wq;
613
614 unsigned int streaming:1;
615 unsigned int start_streaming_called:1;
616 unsigned int error:1;
617 unsigned int waiting_for_buffers:1;
618 unsigned int waiting_in_dqbuf:1;
619 unsigned int is_multiplanar:1;
620 unsigned int is_output:1;
621 unsigned int copy_timestamp:1;
622 unsigned int last_buffer_dequeued:1;
623
624 struct vb2_fileio_data *fileio;
625 struct vb2_threadio_data *threadio;
626
627 char name[32];
628
629#ifdef CONFIG_VIDEO_ADV_DEBUG
630 /*
631 * Counters for how often these queue-related ops are
632 * called. Used to check for unbalanced ops.
633 */
634 u32 cnt_queue_setup;
635 u32 cnt_wait_prepare;
636 u32 cnt_wait_finish;
637 u32 cnt_start_streaming;
638 u32 cnt_stop_streaming;
639#endif
640};
641
642/**
643 * vb2_queue_allows_cache_hints() - Return true if the queue allows cache
644 * and memory consistency hints.
645 *
646 * @q: pointer to &struct vb2_queue with videobuf2 queue
647 */
648static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q)
649{
650 return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP;
651}
652
653/**
654 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
655 * @vb: pointer to &struct vb2_buffer to which the plane in
656 * question belongs to.
657 * @plane_no: plane number for which the address is to be returned.
658 *
659 * This function returns a kernel virtual address of a given plane if
660 * such a mapping exist, NULL otherwise.
661 */
662void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
663
664/**
665 * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
666 * @vb: pointer to &struct vb2_buffer to which the plane in
667 * question belongs to.
668 * @plane_no: plane number for which the cookie is to be returned.
669 *
670 * This function returns an allocator specific cookie for a given plane if
671 * available, NULL otherwise. The allocator should provide some simple static
672 * inline function, which would convert this cookie to the allocator specific
673 * type that can be used directly by the driver to access the buffer. This can
674 * be for example physical address, pointer to scatter list or IOMMU mapping.
675 */
676void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
677
678/**
679 * vb2_buffer_done() - inform videobuf that an operation on a buffer
680 * is finished.
681 * @vb: pointer to &struct vb2_buffer to be used.
682 * @state: state of the buffer, as defined by &enum vb2_buffer_state.
683 * Either %VB2_BUF_STATE_DONE if the operation finished
684 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
685 * with an error or %VB2_BUF_STATE_QUEUED.
686 *
687 * This function should be called by the driver after a hardware operation on
688 * a buffer is finished and the buffer may be returned to userspace. The driver
689 * cannot use this buffer anymore until it is queued back to it by videobuf
690 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
691 * to the driver by &vb2_ops->buf_queue can be passed to this function.
692 *
693 * While streaming a buffer can only be returned in state DONE or ERROR.
694 * The &vb2_ops->start_streaming op can also return them in case the DMA engine
695 * cannot be started for some reason. In that case the buffers should be
696 * returned with state QUEUED to put them back into the queue.
697 */
698void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
699
700/**
701 * vb2_discard_done() - discard all buffers marked as DONE.
702 * @q: pointer to &struct vb2_queue with videobuf2 queue.
703 *
704 * This function is intended to be used with suspend/resume operations. It
705 * discards all 'done' buffers as they would be too old to be requested after
706 * resume.
707 *
708 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
709 * delayed works before calling this function to make sure no buffer will be
710 * touched by the driver and/or hardware.
711 */
712void vb2_discard_done(struct vb2_queue *q);
713
714/**
715 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
716 * @q: pointer to &struct vb2_queue with videobuf2 queue.
717 *
718 * This function will wait until all buffers that have been given to the driver
719 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
720 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
721 * It is intended to be called with all locks taken, for example from
722 * &vb2_ops->stop_streaming callback.
723 */
724int vb2_wait_for_all_buffers(struct vb2_queue *q);
725
726/**
727 * vb2_core_querybuf() - query video buffer information.
728 * @q: pointer to &struct vb2_queue with videobuf2 queue.
729 * @index: id number of the buffer.
730 * @pb: buffer struct passed from userspace.
731 *
732 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
733 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
734 *
735 * The passed buffer should have been verified.
736 *
737 * This function fills the relevant information for the userspace.
738 *
739 * Return: returns zero on success; an error code otherwise.
740 */
741void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
742
743/**
744 * vb2_core_reqbufs() - Initiate streaming.
745 * @q: pointer to &struct vb2_queue with videobuf2 queue.
746 * @memory: memory type, as defined by &enum vb2_memory.
747 * @count: requested buffer count.
748 *
749 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
750 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
751 *
752 * This function:
753 *
754 * #) verifies streaming parameters passed from the userspace;
755 * #) sets up the queue;
756 * #) negotiates number of buffers and planes per buffer with the driver
757 * to be used during streaming;
758 * #) allocates internal buffer structures (&struct vb2_buffer), according to
759 * the agreed parameters;
760 * #) for MMAP memory type, allocates actual video memory, using the
761 * memory handling/allocation routines provided during queue initialization.
762 *
763 * If req->count is 0, all the memory will be freed instead.
764 *
765 * If the queue has been allocated previously by a previous vb2_core_reqbufs()
766 * call and the queue is not busy, memory will be reallocated.
767 *
768 * Return: returns zero on success; an error code otherwise.
769 */
770int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
771 unsigned int *count);
772
773/**
774 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
775 * @q: pointer to &struct vb2_queue with videobuf2 queue.
776 * @memory: memory type, as defined by &enum vb2_memory.
777 * @count: requested buffer count.
778 * @requested_planes: number of planes requested.
779 * @requested_sizes: array with the size of the planes.
780 *
781 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
782 * called internally by VB2 by an API-specific handler, like
783 * ``videobuf2-v4l2.h``.
784 *
785 * This function:
786 *
787 * #) verifies parameter sanity;
788 * #) calls the &vb2_ops->queue_setup queue operation;
789 * #) performs any necessary memory allocations.
790 *
791 * Return: returns zero on success; an error code otherwise.
792 */
793int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
794 unsigned int *count,
795 unsigned int requested_planes,
796 const unsigned int requested_sizes[]);
797
798/**
799 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
800 * to the kernel.
801 * @q: pointer to &struct vb2_queue with videobuf2 queue.
802 * @index: id number of the buffer.
803 * @pb: buffer structure passed from userspace to
804 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
805 *
806 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
807 * called internally by VB2 by an API-specific handler, like
808 * ``videobuf2-v4l2.h``.
809 *
810 * The passed buffer should have been verified.
811 *
812 * This function calls vb2_ops->buf_prepare callback in the driver
813 * (if provided), in which driver-specific buffer initialization can
814 * be performed.
815 *
816 * Return: returns zero on success; an error code otherwise.
817 */
818int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
819
820/**
821 * vb2_core_qbuf() - Queue a buffer from userspace
822 *
823 * @q: pointer to &struct vb2_queue with videobuf2 queue.
824 * @index: id number of the buffer
825 * @pb: buffer structure passed from userspace to
826 * v4l2_ioctl_ops->vidioc_qbuf handler in driver
827 * @req: pointer to &struct media_request, may be NULL.
828 *
829 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
830 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
831 *
832 * This function:
833 *
834 * #) If @req is non-NULL, then the buffer will be bound to this
835 * media request and it returns. The buffer will be prepared and
836 * queued to the driver (i.e. the next two steps) when the request
837 * itself is queued.
838 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
839 * (if provided), in which driver-specific buffer initialization can
840 * be performed;
841 * #) if streaming is on, queues the buffer in driver by the means of
842 * &vb2_ops->buf_queue callback for processing.
843 *
844 * Return: returns zero on success; an error code otherwise.
845 */
846int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
847 struct media_request *req);
848
849/**
850 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
851 * @q: pointer to &struct vb2_queue with videobuf2 queue
852 * @pindex: pointer to the buffer index. May be NULL
853 * @pb: buffer structure passed from userspace to
854 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
855 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
856 * buffers ready for dequeuing are present. Normally the driver
857 * would be passing (file->f_flags & O_NONBLOCK) here.
858 *
859 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
860 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
861 *
862 * This function:
863 *
864 * #) calls buf_finish callback in the driver (if provided), in which
865 * driver can perform any additional operations that may be required before
866 * returning the buffer to userspace, such as cache sync,
867 * #) the buffer struct members are filled with relevant information for
868 * the userspace.
869 *
870 * Return: returns zero on success; an error code otherwise.
871 */
872int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
873 bool nonblocking);
874
875/**
876 * vb2_core_streamon() - Implements VB2 stream ON logic
877 *
878 * @q: pointer to &struct vb2_queue with videobuf2 queue
879 * @type: type of the queue to be started.
880 * For V4L2, this is defined by &enum v4l2_buf_type type.
881 *
882 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
883 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
884 *
885 * Return: returns zero on success; an error code otherwise.
886 */
887int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
888
889/**
890 * vb2_core_streamoff() - Implements VB2 stream OFF logic
891 *
892 * @q: pointer to &struct vb2_queue with videobuf2 queue
893 * @type: type of the queue to be started.
894 * For V4L2, this is defined by &enum v4l2_buf_type type.
895 *
896 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
897 * called internally by VB2 by an API-specific handler, like
898 * ``videobuf2-v4l2.h``.
899 *
900 * Return: returns zero on success; an error code otherwise.
901 */
902int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
903
904/**
905 * vb2_core_expbuf() - Export a buffer as a file descriptor.
906 * @q: pointer to &struct vb2_queue with videobuf2 queue.
907 * @fd: pointer to the file descriptor associated with DMABUF
908 * (set by driver).
909 * @type: buffer type.
910 * @index: id number of the buffer.
911 * @plane: index of the plane to be exported, 0 for single plane queues
912 * @flags: file flags for newly created file, as defined at
913 * include/uapi/asm-generic/fcntl.h.
914 * Currently, the only used flag is %O_CLOEXEC.
915 * is supported, refer to manual of open syscall for more details.
916 *
917 *
918 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
919 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
920 *
921 * Return: returns zero on success; an error code otherwise.
922 */
923int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
924 unsigned int index, unsigned int plane, unsigned int flags);
925
926/**
927 * vb2_core_queue_init() - initialize a videobuf2 queue
928 * @q: pointer to &struct vb2_queue with videobuf2 queue.
929 * This structure should be allocated in driver
930 *
931 * The &vb2_queue structure should be allocated by the driver. The driver is
932 * responsible of clearing it's content and setting initial values for some
933 * required entries before calling this function.
934 *
935 * .. note::
936 *
937 * The following fields at @q should be set before calling this function:
938 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
939 */
940int vb2_core_queue_init(struct vb2_queue *q);
941
942/**
943 * vb2_core_queue_release() - stop streaming, release the queue and free memory
944 * @q: pointer to &struct vb2_queue with videobuf2 queue.
945 *
946 * This function stops streaming and performs necessary clean ups, including
947 * freeing video buffer memory. The driver is responsible for freeing
948 * the &struct vb2_queue itself.
949 */
950void vb2_core_queue_release(struct vb2_queue *q);
951
952/**
953 * vb2_queue_error() - signal a fatal error on the queue
954 * @q: pointer to &struct vb2_queue with videobuf2 queue.
955 *
956 * Flag that a fatal unrecoverable error has occurred and wake up all processes
957 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
958 * buffers will return %-EIO.
959 *
960 * The error flag will be cleared when canceling the queue, either from
961 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
962 * function before starting the stream, otherwise the error flag will remain set
963 * until the queue is released when closing the device node.
964 */
965void vb2_queue_error(struct vb2_queue *q);
966
967/**
968 * vb2_mmap() - map video buffers into application address space.
969 * @q: pointer to &struct vb2_queue with videobuf2 queue.
970 * @vma: pointer to &struct vm_area_struct with the vma passed
971 * to the mmap file operation handler in the driver.
972 *
973 * Should be called from mmap file operation handler of a driver.
974 * This function maps one plane of one of the available video buffers to
975 * userspace. To map whole video memory allocated on reqbufs, this function
976 * has to be called once per each plane per each buffer previously allocated.
977 *
978 * When the userspace application calls mmap, it passes to it an offset returned
979 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
980 * That offset acts as a "cookie", which is then used to identify the plane
981 * to be mapped.
982 *
983 * This function finds a plane with a matching offset and a mapping is performed
984 * by the means of a provided memory operation.
985 *
986 * The return values from this function are intended to be directly returned
987 * from the mmap handler in driver.
988 */
989int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
990
991#ifndef CONFIG_MMU
992/**
993 * vb2_get_unmapped_area - map video buffers into application address space.
994 * @q: pointer to &struct vb2_queue with videobuf2 queue.
995 * @addr: memory address.
996 * @len: buffer size.
997 * @pgoff: page offset.
998 * @flags: memory flags.
999 *
1000 * This function is used in noMMU platforms to propose address mapping
1001 * for a given buffer. It's intended to be used as a handler for the
1002 * &file_operations->get_unmapped_area operation.
1003 *
1004 * This is called by the mmap() syscall routines will call this
1005 * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
1006 */
1007unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1008 unsigned long addr,
1009 unsigned long len,
1010 unsigned long pgoff,
1011 unsigned long flags);
1012#endif
1013
1014/**
1015 * vb2_core_poll() - implements poll syscall() logic.
1016 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1017 * @file: &struct file argument passed to the poll
1018 * file operation handler.
1019 * @wait: &poll_table wait argument passed to the poll
1020 * file operation handler.
1021 *
1022 * This function implements poll file operation handler for a driver.
1023 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
1024 * be informed that the file descriptor of a video device is available for
1025 * reading.
1026 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
1027 * will be reported as available for writing.
1028 *
1029 * The return values from this function are intended to be directly returned
1030 * from poll handler in driver.
1031 */
1032__poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
1033 poll_table *wait);
1034
1035/**
1036 * vb2_read() - implements read() syscall logic.
1037 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1038 * @data: pointed to target userspace buffer
1039 * @count: number of bytes to read
1040 * @ppos: file handle position tracking pointer
1041 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1042 */
1043size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
1044 loff_t *ppos, int nonblock);
1045/**
1046 * vb2_read() - implements write() syscall logic.
1047 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1048 * @data: pointed to target userspace buffer
1049 * @count: number of bytes to write
1050 * @ppos: file handle position tracking pointer
1051 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1052 */
1053size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
1054 loff_t *ppos, int nonblock);
1055
1056/**
1057 * typedef vb2_thread_fnc - callback function for use with vb2_thread.
1058 *
1059 * @vb: pointer to struct &vb2_buffer.
1060 * @priv: pointer to a private data.
1061 *
1062 * This is called whenever a buffer is dequeued in the thread.
1063 */
1064typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
1065
1066/**
1067 * vb2_thread_start() - start a thread for the given queue.
1068 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1069 * @fnc: &vb2_thread_fnc callback function.
1070 * @priv: priv pointer passed to the callback function.
1071 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
1072 *
1073 * This starts a thread that will queue and dequeue until an error occurs
1074 * or vb2_thread_stop() is called.
1075 *
1076 * .. attention::
1077 *
1078 * This function should not be used for anything else but the videobuf2-dvb
1079 * support. If you think you have another good use-case for this, then please
1080 * contact the linux-media mailing list first.
1081 */
1082int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1083 const char *thread_name);
1084
1085/**
1086 * vb2_thread_stop() - stop the thread for the given queue.
1087 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1088 */
1089int vb2_thread_stop(struct vb2_queue *q);
1090
1091/**
1092 * vb2_is_streaming() - return streaming status of the queue.
1093 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1094 */
1095static inline bool vb2_is_streaming(struct vb2_queue *q)
1096{
1097 return q->streaming;
1098}
1099
1100/**
1101 * vb2_fileio_is_active() - return true if fileio is active.
1102 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1103 *
1104 * This returns true if read() or write() is used to stream the data
1105 * as opposed to stream I/O. This is almost never an important distinction,
1106 * except in rare cases. One such case is that using read() or write() to
1107 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1108 * is no way you can pass the field information of each buffer to/from
1109 * userspace. A driver that supports this field format should check for
1110 * this in the &vb2_ops->queue_setup op and reject it if this function returns
1111 * true.
1112 */
1113static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1114{
1115 return q->fileio;
1116}
1117
1118/**
1119 * vb2_is_busy() - return busy status of the queue.
1120 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1121 *
1122 * This function checks if queue has any buffers allocated.
1123 */
1124static inline bool vb2_is_busy(struct vb2_queue *q)
1125{
1126 return (q->num_buffers > 0);
1127}
1128
1129/**
1130 * vb2_get_drv_priv() - return driver private data associated with the queue.
1131 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1132 */
1133static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1134{
1135 return q->drv_priv;
1136}
1137
1138/**
1139 * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1140 * @vb: pointer to &struct vb2_buffer to which the plane in
1141 * question belongs to.
1142 * @plane_no: plane number for which payload should be set.
1143 * @size: payload in bytes.
1144 */
1145static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1146 unsigned int plane_no, unsigned long size)
1147{
1148 if (plane_no < vb->num_planes)
1149 vb->planes[plane_no].bytesused = size;
1150}
1151
1152/**
1153 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1154 * @vb: pointer to &struct vb2_buffer to which the plane in
1155 * question belongs to.
1156 * @plane_no: plane number for which payload should be set.
1157 */
1158static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1159 unsigned int plane_no)
1160{
1161 if (plane_no < vb->num_planes)
1162 return vb->planes[plane_no].bytesused;
1163 return 0;
1164}
1165
1166/**
1167 * vb2_plane_size() - return plane size in bytes.
1168 * @vb: pointer to &struct vb2_buffer to which the plane in
1169 * question belongs to.
1170 * @plane_no: plane number for which size should be returned.
1171 */
1172static inline unsigned long
1173vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1174{
1175 if (plane_no < vb->num_planes)
1176 return vb->planes[plane_no].length;
1177 return 0;
1178}
1179
1180/**
1181 * vb2_start_streaming_called() - return streaming status of driver.
1182 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1183 */
1184static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1185{
1186 return q->start_streaming_called;
1187}
1188
1189/**
1190 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1191 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1192 */
1193static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1194{
1195 q->last_buffer_dequeued = false;
1196}
1197
1198/**
1199 * vb2_get_buffer() - get a buffer from a queue
1200 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1201 * @index: buffer index
1202 *
1203 * This function obtains a buffer from a queue, by its index.
1204 * Keep in mind that there is no refcounting involved in this
1205 * operation, so the buffer lifetime should be taken into
1206 * consideration.
1207 */
1208static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
1209 unsigned int index)
1210{
1211 if (index < q->num_buffers)
1212 return q->bufs[index];
1213 return NULL;
1214}
1215
1216/*
1217 * The following functions are not part of the vb2 core API, but are useful
1218 * functions for videobuf2-*.
1219 */
1220
1221/**
1222 * vb2_buffer_in_use() - return true if the buffer is in use and
1223 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1224 *
1225 * @vb: buffer for which plane size should be returned.
1226 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1227 */
1228bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1229
1230/**
1231 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1232 * passed to a buffer operation are compatible with the queue.
1233 *
1234 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1235 * @memory: memory model, as defined by enum &vb2_memory.
1236 * @type: private buffer type whose content is defined by the vb2-core
1237 * caller. For example, for V4L2, it should match
1238 * the types defined on enum &v4l2_buf_type.
1239 */
1240int vb2_verify_memory_type(struct vb2_queue *q,
1241 enum vb2_memory memory, unsigned int type);
1242
1243/**
1244 * vb2_request_object_is_buffer() - return true if the object is a buffer
1245 *
1246 * @obj: the request object.
1247 */
1248bool vb2_request_object_is_buffer(struct media_request_object *obj);
1249
1250/**
1251 * vb2_request_buffer_cnt() - return the number of buffers in the request
1252 *
1253 * @req: the request.
1254 */
1255unsigned int vb2_request_buffer_cnt(struct media_request *req);
1256
1257#endif /* _MEDIA_VIDEOBUF2_CORE_H */
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. The size argument to this function
58 * shall be *page aligned*.
59 * @put: inform the allocator that the buffer will no longer be used;
60 * usually will result in the allocator freeing the buffer (if
61 * no other users of this buffer are present); the @buf_priv
62 * argument is the allocator private per-buffer structure
63 * previously returned from the alloc callback.
64 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
65 * DMABUF memory types.
66 * @get_userptr: acquire userspace memory for a hardware operation; used for
67 * USERPTR memory types; vaddr is the address passed to the
68 * videobuf layer when queuing a video buffer of USERPTR type;
69 * should return an allocator private per-buffer structure
70 * associated with the buffer on success, ERR_PTR() on failure;
71 * the returned private structure will then be passed as @buf_priv
72 * argument to other ops in this structure.
73 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
74 * be used.
75 * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
76 * used for DMABUF memory types; dev is the alloc device
77 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
78 * allocator private per-buffer structure on success;
79 * this needs to be used for further accesses to the buffer.
80 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
81 * buffer is no longer used; the @buf_priv argument is the
82 * allocator private per-buffer structure previously returned
83 * from the attach_dmabuf callback.
84 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
85 * of dmabuf is informed that this driver is going to use the
86 * dmabuf.
87 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
88 * that this driver is done using the dmabuf for now.
89 * @prepare: called every time the buffer is passed from userspace to the
90 * driver, useful for cache synchronisation, optional.
91 * @finish: called every time the buffer is passed back from the driver
92 * to the userspace, also optional.
93 * @vaddr: return a kernel virtual address to a given memory buffer
94 * associated with the passed private structure or NULL if no
95 * such mapping exists.
96 * @cookie: return allocator specific cookie for a given memory buffer
97 * associated with the passed private structure or NULL if not
98 * available.
99 * @num_users: return the current number of users of a memory buffer;
100 * return 1 if the videobuf layer (or actually the driver using
101 * it) is the only user.
102 * @mmap: setup a userspace mapping for a given memory buffer under
103 * the provided virtual memory region.
104 *
105 * Those operations are used by the videobuf2 core to implement the memory
106 * handling/memory allocators for each type of supported streaming I/O method.
107 *
108 * .. note::
109 * #) Required ops for USERPTR types: get_userptr, put_userptr.
110 *
111 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
112 *
113 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
114 *
115 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
116 * map_dmabuf, unmap_dmabuf.
117 */
118struct vb2_mem_ops {
119 void *(*alloc)(struct device *dev, unsigned long attrs,
120 unsigned long size,
121 enum dma_data_direction dma_dir,
122 gfp_t gfp_flags);
123 void (*put)(void *buf_priv);
124 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
125
126 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
127 unsigned long size,
128 enum dma_data_direction dma_dir);
129 void (*put_userptr)(void *buf_priv);
130
131 void (*prepare)(void *buf_priv);
132 void (*finish)(void *buf_priv);
133
134 void *(*attach_dmabuf)(struct device *dev,
135 struct dma_buf *dbuf,
136 unsigned long size,
137 enum dma_data_direction dma_dir);
138 void (*detach_dmabuf)(void *buf_priv);
139 int (*map_dmabuf)(void *buf_priv);
140 void (*unmap_dmabuf)(void *buf_priv);
141
142 void *(*vaddr)(void *buf_priv);
143 void *(*cookie)(void *buf_priv);
144
145 unsigned int (*num_users)(void *buf_priv);
146
147 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
148};
149
150/**
151 * struct vb2_plane - plane information.
152 * @mem_priv: private data with this plane.
153 * @dbuf: dma_buf - shared buffer object.
154 * @dbuf_mapped: flag to show whether dbuf is mapped or not
155 * @bytesused: number of bytes occupied by data in the plane (payload).
156 * @length: size of this plane (NOT the payload) in bytes.
157 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
158 * @length is always greater or equal to @min_length.
159 * @m: Union with memtype-specific data.
160 * @m.offset: when memory in the associated struct vb2_buffer is
161 * %VB2_MEMORY_MMAP, equals the offset from the start of
162 * the device memory for this plane (or is a "cookie" that
163 * should be passed to mmap() called on the video node).
164 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer
165 * pointing to this plane.
166 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file
167 * descriptor associated with this plane.
168 * @data_offset: offset in the plane to the start of data; usually 0,
169 * unless there is a header in front of the data.
170 *
171 * Should contain enough information to be able to cover all the fields
172 * of &struct v4l2_plane at videodev2.h.
173 */
174struct vb2_plane {
175 void *mem_priv;
176 struct dma_buf *dbuf;
177 unsigned int dbuf_mapped;
178 unsigned int bytesused;
179 unsigned int length;
180 unsigned int min_length;
181 union {
182 unsigned int offset;
183 unsigned long userptr;
184 int fd;
185 } m;
186 unsigned int data_offset;
187};
188
189/**
190 * enum vb2_io_modes - queue access methods.
191 * @VB2_MMAP: driver supports MMAP with streaming API.
192 * @VB2_USERPTR: driver supports USERPTR with streaming API.
193 * @VB2_READ: driver supports read() style access.
194 * @VB2_WRITE: driver supports write() style access.
195 * @VB2_DMABUF: driver supports DMABUF with streaming API.
196 */
197enum vb2_io_modes {
198 VB2_MMAP = BIT(0),
199 VB2_USERPTR = BIT(1),
200 VB2_READ = BIT(2),
201 VB2_WRITE = BIT(3),
202 VB2_DMABUF = BIT(4),
203};
204
205/**
206 * enum vb2_buffer_state - current video buffer state.
207 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control.
208 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request.
209 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf.
210 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver.
211 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
212 * in a hardware operation.
213 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
214 * not yet dequeued to userspace.
215 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
216 * has ended with an error, which will be reported
217 * to the userspace when it is dequeued.
218 */
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_ACTIVE,
225 VB2_BUF_STATE_DONE,
226 VB2_BUF_STATE_ERROR,
227};
228
229struct vb2_queue;
230
231/**
232 * struct vb2_buffer - represents a video buffer.
233 * @vb2_queue: pointer to &struct vb2_queue with the queue to
234 * which this driver belongs.
235 * @index: id number of the buffer.
236 * @type: buffer type.
237 * @memory: the method, in which the actual data is passed.
238 * @num_planes: number of planes in the buffer
239 * on an internal driver queue.
240 * @timestamp: frame timestamp in ns.
241 * @request: the request this buffer is associated with.
242 * @req_obj: used to bind this buffer to a request. This
243 * request object has a refcount.
244 */
245struct vb2_buffer {
246 struct vb2_queue *vb2_queue;
247 unsigned int index;
248 unsigned int type;
249 unsigned int memory;
250 unsigned int num_planes;
251 u64 timestamp;
252 struct media_request *request;
253 struct media_request_object req_obj;
254
255 /* private: internal use only
256 *
257 * state: current buffer state; do not change
258 * synced: this buffer has been synced for DMA, i.e. the
259 * 'prepare' memop was called. It is cleared again
260 * after the 'finish' memop is called.
261 * prepared: this buffer has been prepared, i.e. the
262 * buf_prepare op was called. It is cleared again
263 * after the 'buf_finish' op is called.
264 * copied_timestamp: the timestamp of this capture buffer was copied
265 * from an output buffer.
266 * queued_entry: entry on the queued buffers list, which holds
267 * all buffers queued from userspace
268 * done_entry: entry on the list that stores all buffers ready
269 * to be dequeued to userspace
270 * vb2_plane: per-plane information; do not change
271 */
272 enum vb2_buffer_state state;
273 unsigned int synced:1;
274 unsigned int prepared:1;
275 unsigned int copied_timestamp:1;
276
277 struct vb2_plane planes[VB2_MAX_PLANES];
278 struct list_head queued_entry;
279 struct list_head done_entry;
280#ifdef CONFIG_VIDEO_ADV_DEBUG
281 /*
282 * Counters for how often these buffer-related ops are
283 * called. Used to check for unbalanced ops.
284 */
285 u32 cnt_mem_alloc;
286 u32 cnt_mem_put;
287 u32 cnt_mem_get_dmabuf;
288 u32 cnt_mem_get_userptr;
289 u32 cnt_mem_put_userptr;
290 u32 cnt_mem_prepare;
291 u32 cnt_mem_finish;
292 u32 cnt_mem_attach_dmabuf;
293 u32 cnt_mem_detach_dmabuf;
294 u32 cnt_mem_map_dmabuf;
295 u32 cnt_mem_unmap_dmabuf;
296 u32 cnt_mem_vaddr;
297 u32 cnt_mem_cookie;
298 u32 cnt_mem_num_users;
299 u32 cnt_mem_mmap;
300
301 u32 cnt_buf_out_validate;
302 u32 cnt_buf_init;
303 u32 cnt_buf_prepare;
304 u32 cnt_buf_finish;
305 u32 cnt_buf_cleanup;
306 u32 cnt_buf_queue;
307 u32 cnt_buf_request_complete;
308
309 /* This counts the number of calls to vb2_buffer_done() */
310 u32 cnt_buf_done;
311#endif
312};
313
314/**
315 * struct vb2_ops - driver-specific callbacks.
316 *
317 * These operations are not called from interrupt context except where
318 * mentioned specifically.
319 *
320 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
321 * handlers before memory allocation. It can be called
322 * twice: if the original number of requested buffers
323 * could not be allocated, then it will be called a
324 * second time with the actually allocated number of
325 * buffers to verify if that is OK.
326 * The driver should return the required number of buffers
327 * in \*num_buffers, the required number of planes per
328 * buffer in \*num_planes, the size of each plane should be
329 * set in the sizes\[\] array and optional per-plane
330 * allocator specific device in the alloc_devs\[\] array.
331 * When called from VIDIOC_REQBUFS(), \*num_planes == 0,
332 * the driver has to use the currently configured format to
333 * determine the plane sizes and \*num_buffers is the total
334 * number of buffers that are being allocated. When called
335 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
336 * describes the requested number of planes and sizes\[\]
337 * contains the requested plane sizes. In this case
338 * \*num_buffers are being allocated additionally to
339 * q->num_buffers. If either \*num_planes or the requested
340 * sizes are invalid callback must return %-EINVAL.
341 * @wait_prepare: release any locks taken while calling vb2 functions;
342 * it is called before an ioctl needs to wait for a new
343 * buffer to arrive; required to avoid a deadlock in
344 * blocking access type.
345 * @wait_finish: reacquire all locks released in the previous callback;
346 * required to continue operation after sleeping while
347 * waiting for a new buffer to arrive.
348 * @buf_out_validate: called when the output buffer is prepared or queued
349 * to a request; drivers can use this to validate
350 * userspace-provided information; this is required only
351 * for OUTPUT queues.
352 * @buf_init: called once after allocating a buffer (in MMAP case)
353 * or after acquiring a new USERPTR buffer; drivers may
354 * perform additional buffer-related initialization;
355 * initialization failure (return != 0) will prevent
356 * queue setup from completing successfully; optional.
357 * @buf_prepare: called every time the buffer is queued from userspace
358 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
359 * perform any initialization required before each
360 * hardware operation in this callback; drivers can
361 * access/modify the buffer here as it is still synced for
362 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
363 * also validate the buffer size; if an error is returned,
364 * the buffer will not be queued in driver; optional.
365 * @buf_finish: called before every dequeue of the buffer back to
366 * userspace; the buffer is synced for the CPU, so drivers
367 * can access/modify the buffer contents; drivers may
368 * perform any operations required before userspace
369 * accesses the buffer; optional. The buffer state can be
370 * one of the following: %DONE and %ERROR occur while
371 * streaming is in progress, and the %PREPARED state occurs
372 * when the queue has been canceled and all pending
373 * buffers are being returned to their default %DEQUEUED
374 * state. Typically you only have to do something if the
375 * state is %VB2_BUF_STATE_DONE, since in all other cases
376 * the buffer contents will be ignored anyway.
377 * @buf_cleanup: called once before the buffer is freed; drivers may
378 * perform any additional cleanup; optional.
379 * @start_streaming: called once to enter 'streaming' state; the driver may
380 * receive buffers with @buf_queue callback
381 * before @start_streaming is called; the driver gets the
382 * number of already queued buffers in count parameter;
383 * driver can return an error if hardware fails, in that
384 * case all buffers that have been already given by
385 * the @buf_queue callback are to be returned by the driver
386 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
387 * If you need a minimum number of buffers before you can
388 * start streaming, then set
389 * &vb2_queue->min_buffers_needed. If that is non-zero
390 * then @start_streaming won't be called until at least
391 * that many buffers have been queued up by userspace.
392 * @stop_streaming: called when 'streaming' state must be disabled; driver
393 * should stop any DMA transactions or wait until they
394 * finish and give back all buffers it got from &buf_queue
395 * callback by calling vb2_buffer_done() with either
396 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
397 * vb2_wait_for_all_buffers() function
398 * @buf_queue: passes buffer vb to the driver; driver may start
399 * hardware operation on this buffer; driver should give
400 * the buffer back by calling vb2_buffer_done() function;
401 * it is always called after calling VIDIOC_STREAMON()
402 * ioctl; might be called before @start_streaming callback
403 * if user pre-queued buffers before calling
404 * VIDIOC_STREAMON().
405 * @buf_request_complete: a buffer that was never queued to the driver but is
406 * associated with a queued request was canceled.
407 * The driver will have to mark associated objects in the
408 * request as completed; required if requests are
409 * supported.
410 */
411struct vb2_ops {
412 int (*queue_setup)(struct vb2_queue *q,
413 unsigned int *num_buffers, unsigned int *num_planes,
414 unsigned int sizes[], struct device *alloc_devs[]);
415
416 void (*wait_prepare)(struct vb2_queue *q);
417 void (*wait_finish)(struct vb2_queue *q);
418
419 int (*buf_out_validate)(struct vb2_buffer *vb);
420 int (*buf_init)(struct vb2_buffer *vb);
421 int (*buf_prepare)(struct vb2_buffer *vb);
422 void (*buf_finish)(struct vb2_buffer *vb);
423 void (*buf_cleanup)(struct vb2_buffer *vb);
424
425 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
426 void (*stop_streaming)(struct vb2_queue *q);
427
428 void (*buf_queue)(struct vb2_buffer *vb);
429
430 void (*buf_request_complete)(struct vb2_buffer *vb);
431};
432
433/**
434 * struct vb2_buf_ops - driver-specific callbacks.
435 *
436 * @verify_planes_array: Verify that a given user space structure contains
437 * enough planes for the buffer. This is called
438 * for each dequeued buffer.
439 * @init_buffer: given a &vb2_buffer initialize the extra data after
440 * struct vb2_buffer.
441 * For V4L2 this is a &struct vb2_v4l2_buffer.
442 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
443 * For V4L2 this is a &struct v4l2_buffer.
444 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer.
445 * If the userspace structure is invalid, then this op
446 * will return an error.
447 * @copy_timestamp: copy the timestamp from a userspace structure to
448 * the &struct vb2_buffer.
449 */
450struct vb2_buf_ops {
451 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
452 void (*init_buffer)(struct vb2_buffer *vb);
453 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
454 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
455 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
456};
457
458/**
459 * struct vb2_queue - a videobuf queue.
460 *
461 * @type: private buffer type whose content is defined by the vb2-core
462 * caller. For example, for V4L2, it should match
463 * the types defined on &enum v4l2_buf_type.
464 * @io_modes: supported io methods (see &enum vb2_io_modes).
465 * @alloc_devs: &struct device memory type/allocator-specific per-plane device
466 * @dev: device to use for the default allocation context if the driver
467 * doesn't fill in the @alloc_devs array.
468 * @dma_attrs: DMA attributes to use for the DMA.
469 * @bidirectional: when this flag is set the DMA direction for the buffers of
470 * this queue will be overridden with %DMA_BIDIRECTIONAL direction.
471 * This is useful in cases where the hardware (firmware) writes to
472 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
473 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order
474 * to satisfy some internal hardware restrictions or adds a padding
475 * needed by the processing algorithm. In case the DMA mapping is
476 * not bidirectional but the hardware (firmware) trying to access
477 * the buffer (in the opposite direction) this could lead to an
478 * IOMMU protection faults.
479 * @fileio_read_once: report EOF after reading the first buffer
480 * @fileio_write_immediately: queue buffer after each write() call
481 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
482 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
483 * has not been called. This is a vb1 idiom that has been adopted
484 * also by vb2.
485 * @supports_requests: this queue supports the Request API.
486 * @requires_requests: this queue requires the Request API. If this is set to 1,
487 * then supports_requests must be set to 1 as well.
488 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first
489 * time this is called. Set to 0 when the queue is canceled.
490 * If this is 1, then you cannot queue buffers from a request.
491 * @uses_requests: requests are used for this queue. Set to 1 the first time
492 * a request is queued. Set to 0 when the queue is canceled.
493 * If this is 1, then you cannot queue buffers directly.
494 * @lock: pointer to a mutex that protects the &struct vb2_queue. The
495 * driver can set this to a mutex to let the v4l2 core serialize
496 * the queuing ioctls. If the driver wants to handle locking
497 * itself, then this should be set to NULL. This lock is not used
498 * by the videobuf2 core API.
499 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
500 * that called reqbufs, create_buffers or started fileio.
501 * This field is not used by the videobuf2 core API, but it allows
502 * drivers to easily associate an owner filehandle with the queue.
503 * @ops: driver-specific callbacks
504 * @mem_ops: memory allocator specific callbacks
505 * @buf_ops: callbacks to deliver buffer information.
506 * between user-space and kernel-space.
507 * @drv_priv: driver private data.
508 * @buf_struct_size: size of the driver-specific buffer structure;
509 * "0" indicates the driver doesn't want to use a custom buffer
510 * structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
511 * will be used for v4l2.
512 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
513 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*``
514 * @gfp_flags: additional gfp flags used when allocating the buffers.
515 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
516 * to force the buffer allocation to a specific memory zone.
517 * @min_buffers_needed: the minimum number of buffers needed before
518 * @start_streaming can be called. Used when a DMA engine
519 * cannot be started unless at least this number of buffers
520 * have been queued into the driver.
521 */
522/*
523 * Private elements (won't appear at the uAPI book):
524 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
525 * @memory: current memory type used
526 * @dma_dir: DMA mapping direction.
527 * @bufs: videobuf buffer structures
528 * @num_buffers: number of allocated/used buffers
529 * @queued_list: list of buffers currently queued from userspace
530 * @queued_count: number of buffers queued and ready for streaming.
531 * @owned_by_drv_count: number of buffers owned by the driver
532 * @done_list: list of buffers ready to be dequeued to userspace
533 * @done_lock: lock to protect done_list list
534 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
535 * @streaming: current streaming state
536 * @start_streaming_called: @start_streaming was called successfully and we
537 * started streaming.
538 * @error: a fatal error occurred on the queue
539 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
540 * buffers. Only set for capture queues if qbuf has not yet been
541 * called since poll() needs to return %EPOLLERR in that situation.
542 * @is_multiplanar: set if buffer type is multiplanar
543 * @is_output: set if buffer type is output
544 * @copy_timestamp: set if vb2-core should set timestamps
545 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
546 * last decoded buffer was already dequeued. Set for capture queues
547 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
548 * @fileio: file io emulator internal data, used only if emulator is active
549 * @threadio: thread io internal data, used only if thread is active
550 */
551struct vb2_queue {
552 unsigned int type;
553 unsigned int io_modes;
554 struct device *dev;
555 unsigned long dma_attrs;
556 unsigned bidirectional:1;
557 unsigned fileio_read_once:1;
558 unsigned fileio_write_immediately:1;
559 unsigned allow_zero_bytesused:1;
560 unsigned quirk_poll_must_check_waiting_for_buffers:1;
561 unsigned supports_requests:1;
562 unsigned requires_requests:1;
563 unsigned uses_qbuf:1;
564 unsigned uses_requests:1;
565
566 struct mutex *lock;
567 void *owner;
568
569 const struct vb2_ops *ops;
570 const struct vb2_mem_ops *mem_ops;
571 const struct vb2_buf_ops *buf_ops;
572
573 void *drv_priv;
574 unsigned int buf_struct_size;
575 u32 timestamp_flags;
576 gfp_t gfp_flags;
577 u32 min_buffers_needed;
578
579 struct device *alloc_devs[VB2_MAX_PLANES];
580
581 /* private: internal use only */
582 struct mutex mmap_lock;
583 unsigned int memory;
584 enum dma_data_direction dma_dir;
585 struct vb2_buffer *bufs[VB2_MAX_FRAME];
586 unsigned int num_buffers;
587
588 struct list_head queued_list;
589 unsigned int queued_count;
590
591 atomic_t owned_by_drv_count;
592 struct list_head done_list;
593 spinlock_t done_lock;
594 wait_queue_head_t done_wq;
595
596 unsigned int streaming:1;
597 unsigned int start_streaming_called:1;
598 unsigned int error:1;
599 unsigned int waiting_for_buffers:1;
600 unsigned int waiting_in_dqbuf:1;
601 unsigned int is_multiplanar:1;
602 unsigned int is_output:1;
603 unsigned int copy_timestamp:1;
604 unsigned int last_buffer_dequeued:1;
605
606 struct vb2_fileio_data *fileio;
607 struct vb2_threadio_data *threadio;
608
609#ifdef CONFIG_VIDEO_ADV_DEBUG
610 /*
611 * Counters for how often these queue-related ops are
612 * called. Used to check for unbalanced ops.
613 */
614 u32 cnt_queue_setup;
615 u32 cnt_wait_prepare;
616 u32 cnt_wait_finish;
617 u32 cnt_start_streaming;
618 u32 cnt_stop_streaming;
619#endif
620};
621
622/**
623 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
624 * @vb: pointer to &struct vb2_buffer to which the plane in
625 * question belongs to.
626 * @plane_no: plane number for which the address is to be returned.
627 *
628 * This function returns a kernel virtual address of a given plane if
629 * such a mapping exist, NULL otherwise.
630 */
631void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
632
633/**
634 * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
635 * @vb: pointer to &struct vb2_buffer to which the plane in
636 * question belongs to.
637 * @plane_no: plane number for which the cookie is to be returned.
638 *
639 * This function returns an allocator specific cookie for a given plane if
640 * available, NULL otherwise. The allocator should provide some simple static
641 * inline function, which would convert this cookie to the allocator specific
642 * type that can be used directly by the driver to access the buffer. This can
643 * be for example physical address, pointer to scatter list or IOMMU mapping.
644 */
645void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
646
647/**
648 * vb2_buffer_done() - inform videobuf that an operation on a buffer
649 * is finished.
650 * @vb: pointer to &struct vb2_buffer to be used.
651 * @state: state of the buffer, as defined by &enum vb2_buffer_state.
652 * Either %VB2_BUF_STATE_DONE if the operation finished
653 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
654 * with an error or %VB2_BUF_STATE_QUEUED.
655 *
656 * This function should be called by the driver after a hardware operation on
657 * a buffer is finished and the buffer may be returned to userspace. The driver
658 * cannot use this buffer anymore until it is queued back to it by videobuf
659 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
660 * to the driver by &vb2_ops->buf_queue can be passed to this function.
661 *
662 * While streaming a buffer can only be returned in state DONE or ERROR.
663 * The &vb2_ops->start_streaming op can also return them in case the DMA engine
664 * cannot be started for some reason. In that case the buffers should be
665 * returned with state QUEUED to put them back into the queue.
666 */
667void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
668
669/**
670 * vb2_discard_done() - discard all buffers marked as DONE.
671 * @q: pointer to &struct vb2_queue with videobuf2 queue.
672 *
673 * This function is intended to be used with suspend/resume operations. It
674 * discards all 'done' buffers as they would be too old to be requested after
675 * resume.
676 *
677 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
678 * delayed works before calling this function to make sure no buffer will be
679 * touched by the driver and/or hardware.
680 */
681void vb2_discard_done(struct vb2_queue *q);
682
683/**
684 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
685 * @q: pointer to &struct vb2_queue with videobuf2 queue.
686 *
687 * This function will wait until all buffers that have been given to the driver
688 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
689 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
690 * It is intended to be called with all locks taken, for example from
691 * &vb2_ops->stop_streaming callback.
692 */
693int vb2_wait_for_all_buffers(struct vb2_queue *q);
694
695/**
696 * vb2_core_querybuf() - query video buffer information.
697 * @q: pointer to &struct vb2_queue with videobuf2 queue.
698 * @index: id number of the buffer.
699 * @pb: buffer struct passed from userspace.
700 *
701 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
702 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
703 *
704 * The passed buffer should have been verified.
705 *
706 * This function fills the relevant information for the userspace.
707 *
708 * Return: returns zero on success; an error code otherwise.
709 */
710void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
711
712/**
713 * vb2_core_reqbufs() - Initiate streaming.
714 * @q: pointer to &struct vb2_queue with videobuf2 queue.
715 * @memory: memory type, as defined by &enum vb2_memory.
716 * @count: requested buffer count.
717 *
718 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
719 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
720 *
721 * This function:
722 *
723 * #) verifies streaming parameters passed from the userspace;
724 * #) sets up the queue;
725 * #) negotiates number of buffers and planes per buffer with the driver
726 * to be used during streaming;
727 * #) allocates internal buffer structures (&struct vb2_buffer), according to
728 * the agreed parameters;
729 * #) for MMAP memory type, allocates actual video memory, using the
730 * memory handling/allocation routines provided during queue initialization.
731 *
732 * If req->count is 0, all the memory will be freed instead.
733 *
734 * If the queue has been allocated previously by a previous vb2_core_reqbufs()
735 * call and the queue is not busy, memory will be reallocated.
736 *
737 * Return: returns zero on success; an error code otherwise.
738 */
739int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
740 unsigned int *count);
741
742/**
743 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
744 * @q: pointer to &struct vb2_queue with videobuf2 queue.
745 * @memory: memory type, as defined by &enum vb2_memory.
746 * @count: requested buffer count.
747 * @requested_planes: number of planes requested.
748 * @requested_sizes: array with the size of the planes.
749 *
750 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
751 * called internally by VB2 by an API-specific handler, like
752 * ``videobuf2-v4l2.h``.
753 *
754 * This function:
755 *
756 * #) verifies parameter sanity;
757 * #) calls the &vb2_ops->queue_setup queue operation;
758 * #) performs any necessary memory allocations.
759 *
760 * Return: returns zero on success; an error code otherwise.
761 */
762int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
763 unsigned int *count, unsigned int requested_planes,
764 const unsigned int requested_sizes[]);
765
766/**
767 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
768 * to the kernel.
769 * @q: pointer to &struct vb2_queue with videobuf2 queue.
770 * @index: id number of the buffer.
771 * @pb: buffer structure passed from userspace to
772 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
773 *
774 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
775 * called internally by VB2 by an API-specific handler, like
776 * ``videobuf2-v4l2.h``.
777 *
778 * The passed buffer should have been verified.
779 *
780 * This function calls vb2_ops->buf_prepare callback in the driver
781 * (if provided), in which driver-specific buffer initialization can
782 * be performed.
783 *
784 * Return: returns zero on success; an error code otherwise.
785 */
786int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
787
788/**
789 * vb2_core_qbuf() - Queue a buffer from userspace
790 *
791 * @q: pointer to &struct vb2_queue with videobuf2 queue.
792 * @index: id number of the buffer
793 * @pb: buffer structure passed from userspace to
794 * v4l2_ioctl_ops->vidioc_qbuf handler in driver
795 * @req: pointer to &struct media_request, may be NULL.
796 *
797 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
798 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
799 *
800 * This function:
801 *
802 * #) If @req is non-NULL, then the buffer will be bound to this
803 * media request and it returns. The buffer will be prepared and
804 * queued to the driver (i.e. the next two steps) when the request
805 * itself is queued.
806 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
807 * (if provided), in which driver-specific buffer initialization can
808 * be performed;
809 * #) if streaming is on, queues the buffer in driver by the means of
810 * &vb2_ops->buf_queue callback for processing.
811 *
812 * Return: returns zero on success; an error code otherwise.
813 */
814int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
815 struct media_request *req);
816
817/**
818 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
819 * @q: pointer to &struct vb2_queue with videobuf2 queue
820 * @pindex: pointer to the buffer index. May be NULL
821 * @pb: buffer structure passed from userspace to
822 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
823 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
824 * buffers ready for dequeuing are present. Normally the driver
825 * would be passing (file->f_flags & O_NONBLOCK) here.
826 *
827 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
828 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
829 *
830 * This function:
831 *
832 * #) calls buf_finish callback in the driver (if provided), in which
833 * driver can perform any additional operations that may be required before
834 * returning the buffer to userspace, such as cache sync,
835 * #) the buffer struct members are filled with relevant information for
836 * the userspace.
837 *
838 * Return: returns zero on success; an error code otherwise.
839 */
840int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
841 bool nonblocking);
842
843/**
844 * vb2_core_streamon() - Implements VB2 stream ON logic
845 *
846 * @q: pointer to &struct vb2_queue with videobuf2 queue
847 * @type: type of the queue to be started.
848 * For V4L2, this is defined by &enum v4l2_buf_type type.
849 *
850 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
851 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
852 *
853 * Return: returns zero on success; an error code otherwise.
854 */
855int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
856
857/**
858 * vb2_core_streamoff() - Implements VB2 stream OFF logic
859 *
860 * @q: pointer to &struct vb2_queue with videobuf2 queue
861 * @type: type of the queue to be started.
862 * For V4L2, this is defined by &enum v4l2_buf_type type.
863 *
864 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
865 * called internally by VB2 by an API-specific handler, like
866 * ``videobuf2-v4l2.h``.
867 *
868 * Return: returns zero on success; an error code otherwise.
869 */
870int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
871
872/**
873 * vb2_core_expbuf() - Export a buffer as a file descriptor.
874 * @q: pointer to &struct vb2_queue with videobuf2 queue.
875 * @fd: pointer to the file descriptor associated with DMABUF
876 * (set by driver).
877 * @type: buffer type.
878 * @index: id number of the buffer.
879 * @plane: index of the plane to be exported, 0 for single plane queues
880 * @flags: file flags for newly created file, as defined at
881 * include/uapi/asm-generic/fcntl.h.
882 * Currently, the only used flag is %O_CLOEXEC.
883 * is supported, refer to manual of open syscall for more details.
884 *
885 *
886 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
887 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
888 *
889 * Return: returns zero on success; an error code otherwise.
890 */
891int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
892 unsigned int index, unsigned int plane, unsigned int flags);
893
894/**
895 * vb2_core_queue_init() - initialize a videobuf2 queue
896 * @q: pointer to &struct vb2_queue with videobuf2 queue.
897 * This structure should be allocated in driver
898 *
899 * The &vb2_queue structure should be allocated by the driver. The driver is
900 * responsible of clearing it's content and setting initial values for some
901 * required entries before calling this function.
902 *
903 * .. note::
904 *
905 * The following fields at @q should be set before calling this function:
906 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
907 */
908int vb2_core_queue_init(struct vb2_queue *q);
909
910/**
911 * vb2_core_queue_release() - stop streaming, release the queue and free memory
912 * @q: pointer to &struct vb2_queue with videobuf2 queue.
913 *
914 * This function stops streaming and performs necessary clean ups, including
915 * freeing video buffer memory. The driver is responsible for freeing
916 * the &struct vb2_queue itself.
917 */
918void vb2_core_queue_release(struct vb2_queue *q);
919
920/**
921 * vb2_queue_error() - signal a fatal error on the queue
922 * @q: pointer to &struct vb2_queue with videobuf2 queue.
923 *
924 * Flag that a fatal unrecoverable error has occurred and wake up all processes
925 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
926 * buffers will return %-EIO.
927 *
928 * The error flag will be cleared when canceling the queue, either from
929 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
930 * function before starting the stream, otherwise the error flag will remain set
931 * until the queue is released when closing the device node.
932 */
933void vb2_queue_error(struct vb2_queue *q);
934
935/**
936 * vb2_mmap() - map video buffers into application address space.
937 * @q: pointer to &struct vb2_queue with videobuf2 queue.
938 * @vma: pointer to &struct vm_area_struct with the vma passed
939 * to the mmap file operation handler in the driver.
940 *
941 * Should be called from mmap file operation handler of a driver.
942 * This function maps one plane of one of the available video buffers to
943 * userspace. To map whole video memory allocated on reqbufs, this function
944 * has to be called once per each plane per each buffer previously allocated.
945 *
946 * When the userspace application calls mmap, it passes to it an offset returned
947 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
948 * That offset acts as a "cookie", which is then used to identify the plane
949 * to be mapped.
950 *
951 * This function finds a plane with a matching offset and a mapping is performed
952 * by the means of a provided memory operation.
953 *
954 * The return values from this function are intended to be directly returned
955 * from the mmap handler in driver.
956 */
957int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
958
959#ifndef CONFIG_MMU
960/**
961 * vb2_get_unmapped_area - map video buffers into application address space.
962 * @q: pointer to &struct vb2_queue with videobuf2 queue.
963 * @addr: memory address.
964 * @len: buffer size.
965 * @pgoff: page offset.
966 * @flags: memory flags.
967 *
968 * This function is used in noMMU platforms to propose address mapping
969 * for a given buffer. It's intended to be used as a handler for the
970 * &file_operations->get_unmapped_area operation.
971 *
972 * This is called by the mmap() syscall routines will call this
973 * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
974 */
975unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
976 unsigned long addr,
977 unsigned long len,
978 unsigned long pgoff,
979 unsigned long flags);
980#endif
981
982/**
983 * vb2_core_poll() - implements poll syscall() logic.
984 * @q: pointer to &struct vb2_queue with videobuf2 queue.
985 * @file: &struct file argument passed to the poll
986 * file operation handler.
987 * @wait: &poll_table wait argument passed to the poll
988 * file operation handler.
989 *
990 * This function implements poll file operation handler for a driver.
991 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
992 * be informed that the file descriptor of a video device is available for
993 * reading.
994 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
995 * will be reported as available for writing.
996 *
997 * The return values from this function are intended to be directly returned
998 * from poll handler in driver.
999 */
1000__poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
1001 poll_table *wait);
1002
1003/**
1004 * vb2_read() - implements read() syscall logic.
1005 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1006 * @data: pointed to target userspace buffer
1007 * @count: number of bytes to read
1008 * @ppos: file handle position tracking pointer
1009 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1010 */
1011size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
1012 loff_t *ppos, int nonblock);
1013/**
1014 * vb2_read() - implements write() syscall logic.
1015 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1016 * @data: pointed to target userspace buffer
1017 * @count: number of bytes to write
1018 * @ppos: file handle position tracking pointer
1019 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1020 */
1021size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
1022 loff_t *ppos, int nonblock);
1023
1024/**
1025 * typedef vb2_thread_fnc - callback function for use with vb2_thread.
1026 *
1027 * @vb: pointer to struct &vb2_buffer.
1028 * @priv: pointer to a private data.
1029 *
1030 * This is called whenever a buffer is dequeued in the thread.
1031 */
1032typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
1033
1034/**
1035 * vb2_thread_start() - start a thread for the given queue.
1036 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1037 * @fnc: &vb2_thread_fnc callback function.
1038 * @priv: priv pointer passed to the callback function.
1039 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
1040 *
1041 * This starts a thread that will queue and dequeue until an error occurs
1042 * or vb2_thread_stop() is called.
1043 *
1044 * .. attention::
1045 *
1046 * This function should not be used for anything else but the videobuf2-dvb
1047 * support. If you think you have another good use-case for this, then please
1048 * contact the linux-media mailing list first.
1049 */
1050int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1051 const char *thread_name);
1052
1053/**
1054 * vb2_thread_stop() - stop the thread for the given queue.
1055 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1056 */
1057int vb2_thread_stop(struct vb2_queue *q);
1058
1059/**
1060 * vb2_is_streaming() - return streaming status of the queue.
1061 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1062 */
1063static inline bool vb2_is_streaming(struct vb2_queue *q)
1064{
1065 return q->streaming;
1066}
1067
1068/**
1069 * vb2_fileio_is_active() - return true if fileio is active.
1070 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1071 *
1072 * This returns true if read() or write() is used to stream the data
1073 * as opposed to stream I/O. This is almost never an important distinction,
1074 * except in rare cases. One such case is that using read() or write() to
1075 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1076 * is no way you can pass the field information of each buffer to/from
1077 * userspace. A driver that supports this field format should check for
1078 * this in the &vb2_ops->queue_setup op and reject it if this function returns
1079 * true.
1080 */
1081static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1082{
1083 return q->fileio;
1084}
1085
1086/**
1087 * vb2_is_busy() - return busy status of the queue.
1088 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1089 *
1090 * This function checks if queue has any buffers allocated.
1091 */
1092static inline bool vb2_is_busy(struct vb2_queue *q)
1093{
1094 return (q->num_buffers > 0);
1095}
1096
1097/**
1098 * vb2_get_drv_priv() - return driver private data associated with the queue.
1099 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1100 */
1101static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1102{
1103 return q->drv_priv;
1104}
1105
1106/**
1107 * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1108 * @vb: pointer to &struct vb2_buffer to which the plane in
1109 * question belongs to.
1110 * @plane_no: plane number for which payload should be set.
1111 * @size: payload in bytes.
1112 */
1113static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1114 unsigned int plane_no, unsigned long size)
1115{
1116 if (plane_no < vb->num_planes)
1117 vb->planes[plane_no].bytesused = size;
1118}
1119
1120/**
1121 * vb2_get_plane_payload() - get bytesused for the plane plane_no
1122 * @vb: pointer to &struct vb2_buffer to which the plane in
1123 * question belongs to.
1124 * @plane_no: plane number for which payload should be set.
1125 */
1126static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1127 unsigned int plane_no)
1128{
1129 if (plane_no < vb->num_planes)
1130 return vb->planes[plane_no].bytesused;
1131 return 0;
1132}
1133
1134/**
1135 * vb2_plane_size() - return plane size in bytes.
1136 * @vb: pointer to &struct vb2_buffer to which the plane in
1137 * question belongs to.
1138 * @plane_no: plane number for which size should be returned.
1139 */
1140static inline unsigned long
1141vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1142{
1143 if (plane_no < vb->num_planes)
1144 return vb->planes[plane_no].length;
1145 return 0;
1146}
1147
1148/**
1149 * vb2_start_streaming_called() - return streaming status of driver.
1150 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1151 */
1152static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1153{
1154 return q->start_streaming_called;
1155}
1156
1157/**
1158 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1159 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1160 */
1161static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1162{
1163 q->last_buffer_dequeued = false;
1164}
1165
1166/**
1167 * vb2_get_buffer() - get a buffer from a queue
1168 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1169 * @index: buffer index
1170 *
1171 * This function obtains a buffer from a queue, by its index.
1172 * Keep in mind that there is no refcounting involved in this
1173 * operation, so the buffer lifetime should be taken into
1174 * consideration.
1175 */
1176static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q,
1177 unsigned int index)
1178{
1179 if (index < q->num_buffers)
1180 return q->bufs[index];
1181 return NULL;
1182}
1183
1184/*
1185 * The following functions are not part of the vb2 core API, but are useful
1186 * functions for videobuf2-*.
1187 */
1188
1189/**
1190 * vb2_buffer_in_use() - return true if the buffer is in use and
1191 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1192 *
1193 * @vb: buffer for which plane size should be returned.
1194 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1195 */
1196bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1197
1198/**
1199 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1200 * passed to a buffer operation are compatible with the queue.
1201 *
1202 * @q: pointer to &struct vb2_queue with videobuf2 queue.
1203 * @memory: memory model, as defined by enum &vb2_memory.
1204 * @type: private buffer type whose content is defined by the vb2-core
1205 * caller. For example, for V4L2, it should match
1206 * the types defined on enum &v4l2_buf_type.
1207 */
1208int vb2_verify_memory_type(struct vb2_queue *q,
1209 enum vb2_memory memory, unsigned int type);
1210
1211/**
1212 * vb2_request_object_is_buffer() - return true if the object is a buffer
1213 *
1214 * @obj: the request object.
1215 */
1216bool vb2_request_object_is_buffer(struct media_request_object *obj);
1217
1218/**
1219 * vb2_request_buffer_cnt() - return the number of buffers in the request
1220 *
1221 * @req: the request.
1222 */
1223unsigned int vb2_request_buffer_cnt(struct media_request *req);
1224
1225#endif /* _MEDIA_VIDEOBUF2_CORE_H */