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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
20#define VB2_MAX_FRAME (32)
21#define VB2_MAX_PLANES (8)
22
23/**
24 * enum vb2_memory - type of memory model used to make the buffers visible
25 * on userspace.
26 *
27 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on
28 * userspace.
29 * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is
30 * memory mapped via mmap() ioctl. This model is
31 * also used when the user is using the buffers via
32 * read() or write() system calls.
33 * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is
34 * memory mapped via mmap() ioctl.
35 * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer.
36 */
37enum vb2_memory {
38 VB2_MEMORY_UNKNOWN = 0,
39 VB2_MEMORY_MMAP = 1,
40 VB2_MEMORY_USERPTR = 2,
41 VB2_MEMORY_DMABUF = 4,
42};
43
44struct vb2_fileio_data;
45struct vb2_threadio_data;
46
47/**
48 * struct vb2_mem_ops - memory handling/memory allocator operations
49 * @alloc: allocate video memory and, optionally, allocator private data,
50 * return ERR_PTR() on failure or a pointer to allocator private,
51 * per-buffer data on success; the returned private structure
52 * will then be passed as @buf_priv argument to other ops in this
53 * structure. Additional gfp_flags to use when allocating the
54 * are also passed to this operation. These flags are from the
55 * gfp_flags field of vb2_queue.
56 * @put: inform the allocator that the buffer will no longer be used;
57 * usually will result in the allocator freeing the buffer (if
58 * no other users of this buffer are present); the @buf_priv
59 * argument is the allocator private per-buffer structure
60 * previously returned from the alloc callback.
61 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
62 * DMABUF memory types.
63 * @get_userptr: acquire userspace memory for a hardware operation; used for
64 * USERPTR memory types; vaddr is the address passed to the
65 * videobuf layer when queuing a video buffer of USERPTR type;
66 * should return an allocator private per-buffer structure
67 * associated with the buffer on success, ERR_PTR() on failure;
68 * the returned private structure will then be passed as @buf_priv
69 * argument to other ops in this structure.
70 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
71 * be used.
72 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
73 * used for DMABUF memory types; dev is the alloc device
74 * dbuf is the shared dma_buf; returns ERR_PTR() on failure;
75 * allocator private per-buffer structure on success;
76 * this needs to be used for further accesses to the buffer.
77 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
78 * buffer is no longer used; the @buf_priv argument is the
79 * allocator private per-buffer structure previously returned
80 * from the attach_dmabuf callback.
81 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
82 * of dmabuf is informed that this driver is going to use the
83 * dmabuf.
84 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
85 * that this driver is done using the dmabuf for now.
86 * @prepare: called every time the buffer is passed from userspace to the
87 * driver, useful for cache synchronisation, optional.
88 * @finish: called every time the buffer is passed back from the driver
89 * to the userspace, also optional.
90 * @vaddr: return a kernel virtual address to a given memory buffer
91 * associated with the passed private structure or NULL if no
92 * such mapping exists.
93 * @cookie: return allocator specific cookie for a given memory buffer
94 * associated with the passed private structure or NULL if not
95 * available.
96 * @num_users: return the current number of users of a memory buffer;
97 * return 1 if the videobuf layer (or actually the driver using
98 * it) is the only user.
99 * @mmap: setup a userspace mapping for a given memory buffer under
100 * the provided virtual memory region.
101 *
102 * Those operations are used by the videobuf2 core to implement the memory
103 * handling/memory allocators for each type of supported streaming I/O method.
104 *
105 * .. note::
106 * #) Required ops for USERPTR types: get_userptr, put_userptr.
107 *
108 * #) Required ops for MMAP types: alloc, put, num_users, mmap.
109 *
110 * #) Required ops for read/write access types: alloc, put, num_users, vaddr.
111 *
112 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
113 * map_dmabuf, unmap_dmabuf.
114 */
115struct vb2_mem_ops {
116 void *(*alloc)(struct device *dev, unsigned long attrs,
117 unsigned long size,
118 enum dma_data_direction dma_dir,
119 gfp_t gfp_flags);
120 void (*put)(void *buf_priv);
121 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
122
123 void *(*get_userptr)(struct device *dev, unsigned long vaddr,
124 unsigned long size,
125 enum dma_data_direction dma_dir);
126 void (*put_userptr)(void *buf_priv);
127
128 void (*prepare)(void *buf_priv);
129 void (*finish)(void *buf_priv);
130
131 void *(*attach_dmabuf)(struct device *dev,
132 struct dma_buf *dbuf,
133 unsigned long size,
134 enum dma_data_direction dma_dir);
135 void (*detach_dmabuf)(void *buf_priv);
136 int (*map_dmabuf)(void *buf_priv);
137 void (*unmap_dmabuf)(void *buf_priv);
138
139 void *(*vaddr)(void *buf_priv);
140 void *(*cookie)(void *buf_priv);
141
142 unsigned int (*num_users)(void *buf_priv);
143
144 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
145};
146
147/**
148 * struct vb2_plane - plane information
149 * @mem_priv: private data with this plane
150 * @dbuf: dma_buf - shared buffer object
151 * @dbuf_mapped: flag to show whether dbuf is mapped or not
152 * @bytesused: number of bytes occupied by data in the plane (payload)
153 * @length: size of this plane (NOT the payload) in bytes
154 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
155 * @length is always greater or equal to @min_length.
156 * @offset: when memory in the associated struct vb2_buffer is
157 * VB2_MEMORY_MMAP, equals the offset from the start of
158 * the device memory for this plane (or is a "cookie" that
159 * should be passed to mmap() called on the video node)
160 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
161 * pointing to this plane
162 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
163 * descriptor associated with this plane
164 * @m: Union with memtype-specific data (@offset, @userptr or
165 * @fd).
166 * @data_offset: offset in the plane to the start of data; usually 0,
167 * unless there is a header in front of the data
168 * Should contain enough information to be able to cover all the fields
169 * of struct v4l2_plane at videodev2.h
170 */
171struct vb2_plane {
172 void *mem_priv;
173 struct dma_buf *dbuf;
174 unsigned int dbuf_mapped;
175 unsigned int bytesused;
176 unsigned int length;
177 unsigned int min_length;
178 union {
179 unsigned int offset;
180 unsigned long userptr;
181 int fd;
182 } m;
183 unsigned int data_offset;
184};
185
186/**
187 * enum vb2_io_modes - queue access methods
188 * @VB2_MMAP: driver supports MMAP with streaming API
189 * @VB2_USERPTR: driver supports USERPTR with streaming API
190 * @VB2_READ: driver supports read() style access
191 * @VB2_WRITE: driver supports write() style access
192 * @VB2_DMABUF: driver supports DMABUF with streaming API
193 */
194enum vb2_io_modes {
195 VB2_MMAP = (1 << 0),
196 VB2_USERPTR = (1 << 1),
197 VB2_READ = (1 << 2),
198 VB2_WRITE = (1 << 3),
199 VB2_DMABUF = (1 << 4),
200};
201
202/**
203 * enum vb2_buffer_state - current video buffer state
204 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
205 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
206 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
207 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
208 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
209 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
210 * in a hardware operation
211 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
212 * not yet dequeued to userspace
213 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
214 * has ended with an error, which will be reported
215 * to the userspace when it is dequeued
216 */
217enum vb2_buffer_state {
218 VB2_BUF_STATE_DEQUEUED,
219 VB2_BUF_STATE_PREPARING,
220 VB2_BUF_STATE_PREPARED,
221 VB2_BUF_STATE_QUEUED,
222 VB2_BUF_STATE_REQUEUEING,
223 VB2_BUF_STATE_ACTIVE,
224 VB2_BUF_STATE_DONE,
225 VB2_BUF_STATE_ERROR,
226};
227
228struct vb2_queue;
229
230/**
231 * struct vb2_buffer - represents a video buffer
232 * @vb2_queue: the queue to which this driver belongs
233 * @index: id number of the buffer
234 * @type: buffer type
235 * @memory: the method, in which the actual data is passed
236 * @num_planes: number of planes in the buffer
237 * on an internal driver queue
238 * @planes: private per-plane information; do not change
239 * @timestamp: frame timestamp in ns
240 */
241struct vb2_buffer {
242 struct vb2_queue *vb2_queue;
243 unsigned int index;
244 unsigned int type;
245 unsigned int memory;
246 unsigned int num_planes;
247 struct vb2_plane planes[VB2_MAX_PLANES];
248 u64 timestamp;
249
250 /* private: internal use only
251 *
252 * state: current buffer state; do not change
253 * queued_entry: entry on the queued buffers list, which holds
254 * all buffers queued from userspace
255 * done_entry: entry on the list that stores all buffers ready
256 * to be dequeued to userspace
257 */
258 enum vb2_buffer_state state;
259
260 struct list_head queued_entry;
261 struct list_head done_entry;
262#ifdef CONFIG_VIDEO_ADV_DEBUG
263 /*
264 * Counters for how often these buffer-related ops are
265 * called. Used to check for unbalanced ops.
266 */
267 u32 cnt_mem_alloc;
268 u32 cnt_mem_put;
269 u32 cnt_mem_get_dmabuf;
270 u32 cnt_mem_get_userptr;
271 u32 cnt_mem_put_userptr;
272 u32 cnt_mem_prepare;
273 u32 cnt_mem_finish;
274 u32 cnt_mem_attach_dmabuf;
275 u32 cnt_mem_detach_dmabuf;
276 u32 cnt_mem_map_dmabuf;
277 u32 cnt_mem_unmap_dmabuf;
278 u32 cnt_mem_vaddr;
279 u32 cnt_mem_cookie;
280 u32 cnt_mem_num_users;
281 u32 cnt_mem_mmap;
282
283 u32 cnt_buf_init;
284 u32 cnt_buf_prepare;
285 u32 cnt_buf_finish;
286 u32 cnt_buf_cleanup;
287 u32 cnt_buf_queue;
288
289 /* This counts the number of calls to vb2_buffer_done() */
290 u32 cnt_buf_done;
291#endif
292};
293
294/**
295 * struct vb2_ops - driver-specific callbacks
296 *
297 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
298 * handlers before memory allocation. It can be called
299 * twice: if the original number of requested buffers
300 * could not be allocated, then it will be called a
301 * second time with the actually allocated number of
302 * buffers to verify if that is OK.
303 * The driver should return the required number of buffers
304 * in \*num_buffers, the required number of planes per
305 * buffer in \*num_planes, the size of each plane should be
306 * set in the sizes\[\] array and optional per-plane
307 * allocator specific device in the alloc_devs\[\] array.
308 * When called from VIDIOC_REQBUFS,() \*num_planes == 0,
309 * the driver has to use the currently configured format to
310 * determine the plane sizes and \*num_buffers is the total
311 * number of buffers that are being allocated. When called
312 * from VIDIOC_CREATE_BUFS,() \*num_planes != 0 and it
313 * describes the requested number of planes and sizes\[\]
314 * contains the requested plane sizes. If either
315 * \*num_planes or the requested sizes are invalid callback
316 * must return %-EINVAL. In this case \*num_buffers are
317 * being allocated additionally to q->num_buffers.
318 * @wait_prepare: release any locks taken while calling vb2 functions;
319 * it is called before an ioctl needs to wait for a new
320 * buffer to arrive; required to avoid a deadlock in
321 * blocking access type.
322 * @wait_finish: reacquire all locks released in the previous callback;
323 * required to continue operation after sleeping while
324 * waiting for a new buffer to arrive.
325 * @buf_init: called once after allocating a buffer (in MMAP case)
326 * or after acquiring a new USERPTR buffer; drivers may
327 * perform additional buffer-related initialization;
328 * initialization failure (return != 0) will prevent
329 * queue setup from completing successfully; optional.
330 * @buf_prepare: called every time the buffer is queued from userspace
331 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
332 * perform any initialization required before each
333 * hardware operation in this callback; drivers can
334 * access/modify the buffer here as it is still synced for
335 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must
336 * also validate the buffer size; if an error is returned,
337 * the buffer will not be queued in driver; optional.
338 * @buf_finish: called before every dequeue of the buffer back to
339 * userspace; the buffer is synced for the CPU, so drivers
340 * can access/modify the buffer contents; drivers may
341 * perform any operations required before userspace
342 * accesses the buffer; optional. The buffer state can be
343 * one of the following: %DONE and %ERROR occur while
344 * streaming is in progress, and the %PREPARED state occurs
345 * when the queue has been canceled and all pending
346 * buffers are being returned to their default %DEQUEUED
347 * state. Typically you only have to do something if the
348 * state is %VB2_BUF_STATE_DONE, since in all other cases
349 * the buffer contents will be ignored anyway.
350 * @buf_cleanup: called once before the buffer is freed; drivers may
351 * perform any additional cleanup; optional.
352 * @start_streaming: called once to enter 'streaming' state; the driver may
353 * receive buffers with @buf_queue callback
354 * before @start_streaming is called; the driver gets the
355 * number of already queued buffers in count parameter;
356 * driver can return an error if hardware fails, in that
357 * case all buffers that have been already given by
358 * the @buf_queue callback are to be returned by the driver
359 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
360 * If you need a minimum number of buffers before you can
361 * start streaming, then set @min_buffers_needed in the
362 * vb2_queue structure. If that is non-zero then
363 * @start_streaming won't be called until at least that
364 * many buffers have been queued up by userspace.
365 * @stop_streaming: called when 'streaming' state must be disabled; driver
366 * should stop any DMA transactions or wait until they
367 * finish and give back all buffers it got from &buf_queue
368 * callback by calling vb2_buffer_done() with either
369 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
370 * vb2_wait_for_all_buffers() function
371 * @buf_queue: passes buffer vb to the driver; driver may start
372 * hardware operation on this buffer; driver should give
373 * the buffer back by calling vb2_buffer_done() function;
374 * it is allways called after calling VIDIOC_STREAMON()
375 * ioctl; might be called before @start_streaming callback
376 * if user pre-queued buffers before calling
377 * VIDIOC_STREAMON().
378 */
379struct vb2_ops {
380 int (*queue_setup)(struct vb2_queue *q,
381 unsigned int *num_buffers, unsigned int *num_planes,
382 unsigned int sizes[], struct device *alloc_devs[]);
383
384 void (*wait_prepare)(struct vb2_queue *q);
385 void (*wait_finish)(struct vb2_queue *q);
386
387 int (*buf_init)(struct vb2_buffer *vb);
388 int (*buf_prepare)(struct vb2_buffer *vb);
389 void (*buf_finish)(struct vb2_buffer *vb);
390 void (*buf_cleanup)(struct vb2_buffer *vb);
391
392 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
393 void (*stop_streaming)(struct vb2_queue *q);
394
395 void (*buf_queue)(struct vb2_buffer *vb);
396};
397
398/**
399 * struct vb2_buf_ops - driver-specific callbacks
400 *
401 * @verify_planes_array: Verify that a given user space structure contains
402 * enough planes for the buffer. This is called
403 * for each dequeued buffer.
404 * @fill_user_buffer: given a vb2_buffer fill in the userspace structure.
405 * For V4L2 this is a struct v4l2_buffer.
406 * @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer.
407 * If the userspace structure is invalid, then this op
408 * will return an error.
409 * @copy_timestamp: copy the timestamp from a userspace structure to
410 * the vb2_buffer struct.
411 */
412struct vb2_buf_ops {
413 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
414 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
415 int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
416 struct vb2_plane *planes);
417 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
418};
419
420/**
421 * struct vb2_queue - a videobuf queue
422 *
423 * @type: private buffer type whose content is defined by the vb2-core
424 * caller. For example, for V4L2, it should match
425 * the types defined on enum &v4l2_buf_type
426 * @io_modes: supported io methods (see vb2_io_modes enum)
427 * @dev: device to use for the default allocation context if the driver
428 * doesn't fill in the @alloc_devs array.
429 * @dma_attrs: DMA attributes to use for the DMA.
430 * @fileio_read_once: report EOF after reading the first buffer
431 * @fileio_write_immediately: queue buffer after each write() call
432 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
433 * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
434 * has not been called. This is a vb1 idiom that has been adopted
435 * also by vb2.
436 * @lock: pointer to a mutex that protects the vb2_queue struct. The
437 * driver can set this to a mutex to let the v4l2 core serialize
438 * the queuing ioctls. If the driver wants to handle locking
439 * itself, then this should be set to NULL. This lock is not used
440 * by the videobuf2 core API.
441 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
442 * that called reqbufs, create_buffers or started fileio.
443 * This field is not used by the videobuf2 core API, but it allows
444 * drivers to easily associate an owner filehandle with the queue.
445 * @ops: driver-specific callbacks
446 * @mem_ops: memory allocator specific callbacks
447 * @buf_ops: callbacks to deliver buffer information
448 * between user-space and kernel-space
449 * @drv_priv: driver private data
450 * @buf_struct_size: size of the driver-specific buffer structure;
451 * "0" indicates the driver doesn't want to use a custom buffer
452 * structure type. for example, sizeof(struct vb2_v4l2_buffer)
453 * will be used for v4l2.
454 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
455 * V4L2_BUF_FLAG_TSTAMP_SRC_*
456 * @gfp_flags: additional gfp flags used when allocating the buffers.
457 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
458 * to force the buffer allocation to a specific memory zone.
459 * @min_buffers_needed: the minimum number of buffers needed before
460 * @start_streaming can be called. Used when a DMA engine
461 * cannot be started unless at least this number of buffers
462 * have been queued into the driver.
463 */
464/*
465 * Private elements (won't appear at the uAPI book):
466 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
467 * @memory: current memory type used
468 * @bufs: videobuf buffer structures
469 * @num_buffers: number of allocated/used buffers
470 * @queued_list: list of buffers currently queued from userspace
471 * @queued_count: number of buffers queued and ready for streaming.
472 * @owned_by_drv_count: number of buffers owned by the driver
473 * @done_list: list of buffers ready to be dequeued to userspace
474 * @done_lock: lock to protect done_list list
475 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
476 * @alloc_devs: memory type/allocator-specific per-plane device
477 * @streaming: current streaming state
478 * @start_streaming_called: @start_streaming was called successfully and we
479 * started streaming.
480 * @error: a fatal error occurred on the queue
481 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
482 * buffers. Only set for capture queues if qbuf has not yet been
483 * called since poll() needs to return POLLERR in that situation.
484 * @is_multiplanar: set if buffer type is multiplanar
485 * @is_output: set if buffer type is output
486 * @copy_timestamp: set if vb2-core should set timestamps
487 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
488 * last decoded buffer was already dequeued. Set for capture queues
489 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
490 * @fileio: file io emulator internal data, used only if emulator is active
491 * @threadio: thread io internal data, used only if thread is active
492 */
493struct vb2_queue {
494 unsigned int type;
495 unsigned int io_modes;
496 struct device *dev;
497 unsigned long dma_attrs;
498 unsigned fileio_read_once:1;
499 unsigned fileio_write_immediately:1;
500 unsigned allow_zero_bytesused:1;
501 unsigned quirk_poll_must_check_waiting_for_buffers:1;
502
503 struct mutex *lock;
504 void *owner;
505
506 const struct vb2_ops *ops;
507 const struct vb2_mem_ops *mem_ops;
508 const struct vb2_buf_ops *buf_ops;
509
510 void *drv_priv;
511 unsigned int buf_struct_size;
512 u32 timestamp_flags;
513 gfp_t gfp_flags;
514 u32 min_buffers_needed;
515
516 /* private: internal use only */
517 struct mutex mmap_lock;
518 unsigned int memory;
519 struct vb2_buffer *bufs[VB2_MAX_FRAME];
520 unsigned int num_buffers;
521
522 struct list_head queued_list;
523 unsigned int queued_count;
524
525 atomic_t owned_by_drv_count;
526 struct list_head done_list;
527 spinlock_t done_lock;
528 wait_queue_head_t done_wq;
529
530 struct device *alloc_devs[VB2_MAX_PLANES];
531
532 unsigned int streaming:1;
533 unsigned int start_streaming_called:1;
534 unsigned int error:1;
535 unsigned int waiting_for_buffers:1;
536 unsigned int is_multiplanar:1;
537 unsigned int is_output:1;
538 unsigned int copy_timestamp:1;
539 unsigned int last_buffer_dequeued:1;
540
541 struct vb2_fileio_data *fileio;
542 struct vb2_threadio_data *threadio;
543
544#ifdef CONFIG_VIDEO_ADV_DEBUG
545 /*
546 * Counters for how often these queue-related ops are
547 * called. Used to check for unbalanced ops.
548 */
549 u32 cnt_queue_setup;
550 u32 cnt_wait_prepare;
551 u32 cnt_wait_finish;
552 u32 cnt_start_streaming;
553 u32 cnt_stop_streaming;
554#endif
555};
556
557/**
558 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
559 * @vb: vb2_buffer to which the plane in question belongs to
560 * @plane_no: plane number for which the address is to be returned
561 *
562 * This function returns a kernel virtual address of a given plane if
563 * such a mapping exist, NULL otherwise.
564 */
565void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
566
567/**
568 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
569 * @vb: vb2_buffer to which the plane in question belongs to
570 * @plane_no: plane number for which the cookie is to be returned
571 *
572 * This function returns an allocator specific cookie for a given plane if
573 * available, NULL otherwise. The allocator should provide some simple static
574 * inline function, which would convert this cookie to the allocator specific
575 * type that can be used directly by the driver to access the buffer. This can
576 * be for example physical address, pointer to scatter list or IOMMU mapping.
577 */
578void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
579
580/**
581 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
582 * @vb: vb2_buffer returned from the driver
583 * @state: either %VB2_BUF_STATE_DONE if the operation finished
584 * successfully, %VB2_BUF_STATE_ERROR if the operation finished
585 * with an error or %VB2_BUF_STATE_QUEUED if the driver wants to
586 * requeue buffers. If start_streaming fails then it should return
587 * buffers with state %VB2_BUF_STATE_QUEUED to put them back into
588 * the queue.
589 *
590 * This function should be called by the driver after a hardware operation on
591 * a buffer is finished and the buffer may be returned to userspace. The driver
592 * cannot use this buffer anymore until it is queued back to it by videobuf
593 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
594 * to the driver by &vb2_ops->buf_queue can be passed to this function.
595 *
596 * While streaming a buffer can only be returned in state DONE or ERROR.
597 * The start_streaming op can also return them in case the DMA engine cannot
598 * be started for some reason. In that case the buffers should be returned with
599 * state QUEUED.
600 */
601void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
602
603/**
604 * vb2_discard_done() - discard all buffers marked as DONE
605 * @q: videobuf2 queue
606 *
607 * This function is intended to be used with suspend/resume operations. It
608 * discards all 'done' buffers as they would be too old to be requested after
609 * resume.
610 *
611 * Drivers must stop the hardware and synchronize with interrupt handlers and/or
612 * delayed works before calling this function to make sure no buffer will be
613 * touched by the driver and/or hardware.
614 */
615void vb2_discard_done(struct vb2_queue *q);
616
617/**
618 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
619 * @q: videobuf2 queue
620 *
621 * This function will wait until all buffers that have been given to the driver
622 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
623 * doesn't call wait_prepare()/wait_finish() pair. It is intended to be called
624 * with all locks taken, for example from &vb2_ops->stop_streaming callback.
625 */
626int vb2_wait_for_all_buffers(struct vb2_queue *q);
627
628/**
629 * vb2_core_querybuf() - query video buffer information
630 * @q: videobuf queue
631 * @index: id number of the buffer
632 * @pb: buffer struct passed from userspace
633 *
634 * Should be called from vidioc_querybuf ioctl handler in driver.
635 * The passed buffer should have been verified.
636 * This function fills the relevant information for the userspace.
637 */
638void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
639
640/**
641 * vb2_core_reqbufs() - Initiate streaming
642 * @q: videobuf2 queue
643 * @memory: memory type
644 * @count: requested buffer count
645 *
646 * Should be called from vidioc_reqbufs ioctl handler of a driver.
647 *
648 * This function:
649 *
650 * #) verifies streaming parameters passed from the userspace,
651 * #) sets up the queue,
652 * #) negotiates number of buffers and planes per buffer with the driver
653 * to be used during streaming,
654 * #) allocates internal buffer structures (struct vb2_buffer), according to
655 * the agreed parameters,
656 * #) for MMAP memory type, allocates actual video memory, using the
657 * memory handling/allocation routines provided during queue initialization
658 *
659 * If req->count is 0, all the memory will be freed instead.
660 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
661 * and the queue is not busy, memory will be reallocated.
662 *
663 * The return values from this function are intended to be directly returned
664 * from vidioc_reqbufs handler in driver.
665 */
666int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
667 unsigned int *count);
668
669/**
670 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
671 * @q: videobuf2 queue
672 * @memory: memory type
673 * @count: requested buffer count
674 * @requested_planes: number of planes requested
675 * @requested_sizes: array with the size of the planes
676 *
677 * Should be called from VIDIOC_CREATE_BUFS() ioctl handler of a driver.
678 * This function:
679 *
680 * #) verifies parameter sanity
681 * #) calls the .queue_setup() queue operation
682 * #) performs any necessary memory allocations
683 *
684 * Return: the return values from this function are intended to be directly
685 * returned from VIDIOC_CREATE_BUFS() handler in driver.
686 */
687int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
688 unsigned int *count, unsigned int requested_planes,
689 const unsigned int requested_sizes[]);
690
691/**
692 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
693 * to the kernel
694 * @q: videobuf2 queue
695 * @index: id number of the buffer
696 * @pb: buffer structure passed from userspace to vidioc_prepare_buf
697 * handler in driver
698 *
699 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
700 * The passed buffer should have been verified.
701 * This function calls buf_prepare callback in the driver (if provided),
702 * in which driver-specific buffer initialization can be performed,
703 *
704 * The return values from this function are intended to be directly returned
705 * from vidioc_prepare_buf handler in driver.
706 */
707int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
708
709/**
710 * vb2_core_qbuf() - Queue a buffer from userspace
711 *
712 * @q: videobuf2 queue
713 * @index: id number of the buffer
714 * @pb: buffer structure passed from userspace to vidioc_qbuf handler
715 * in driver
716 *
717 * Should be called from vidioc_qbuf ioctl handler of a driver.
718 * The passed buffer should have been verified.
719 *
720 * This function:
721 *
722 * #) if necessary, calls buf_prepare callback in the driver (if provided), in
723 * which driver-specific buffer initialization can be performed,
724 * #) if streaming is on, queues the buffer in driver by the means of
725 * &vb2_ops->buf_queue callback for processing.
726 *
727 * The return values from this function are intended to be directly returned
728 * from vidioc_qbuf handler in driver.
729 */
730int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
731
732/**
733 * vb2_core_dqbuf() - Dequeue a buffer to the userspace
734 * @q: videobuf2 queue
735 * @pindex: pointer to the buffer index. May be NULL
736 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler
737 * in driver
738 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
739 * buffers ready for dequeuing are present. Normally the driver
740 * would be passing (file->f_flags & O_NONBLOCK) here
741 *
742 * Should be called from vidioc_dqbuf ioctl handler of a driver.
743 * The passed buffer should have been verified.
744 *
745 * This function:
746 *
747 * #) calls buf_finish callback in the driver (if provided), in which
748 * driver can perform any additional operations that may be required before
749 * returning the buffer to userspace, such as cache sync,
750 * #) the buffer struct members are filled with relevant information for
751 * the userspace.
752 *
753 * The return values from this function are intended to be directly returned
754 * from vidioc_dqbuf handler in driver.
755 */
756int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
757 bool nonblocking);
758
759int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
760int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
761
762/**
763 * vb2_core_expbuf() - Export a buffer as a file descriptor
764 * @q: videobuf2 queue
765 * @fd: file descriptor associated with DMABUF (set by driver) *
766 * @type: buffer type
767 * @index: id number of the buffer
768 * @plane: index of the plane to be exported, 0 for single plane queues
769 * @flags: flags for newly created file, currently only O_CLOEXEC is
770 * supported, refer to manual of open syscall for more details
771 *
772 * The return values from this function are intended to be directly returned
773 * from vidioc_expbuf handler in driver.
774 */
775int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
776 unsigned int index, unsigned int plane, unsigned int flags);
777
778/**
779 * vb2_core_queue_init() - initialize a videobuf2 queue
780 * @q: videobuf2 queue; this structure should be allocated in driver
781 *
782 * The vb2_queue structure should be allocated by the driver. The driver is
783 * responsible of clearing it's content and setting initial values for some
784 * required entries before calling this function.
785 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
786 * to the struct vb2_queue description in include/media/videobuf2-core.h
787 * for more information.
788 */
789int vb2_core_queue_init(struct vb2_queue *q);
790
791/**
792 * vb2_core_queue_release() - stop streaming, release the queue and free memory
793 * @q: videobuf2 queue
794 *
795 * This function stops streaming and performs necessary clean ups, including
796 * freeing video buffer memory. The driver is responsible for freeing
797 * the vb2_queue structure itself.
798 */
799void vb2_core_queue_release(struct vb2_queue *q);
800
801/**
802 * vb2_queue_error() - signal a fatal error on the queue
803 * @q: videobuf2 queue
804 *
805 * Flag that a fatal unrecoverable error has occurred and wake up all processes
806 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
807 * buffers will return -EIO.
808 *
809 * The error flag will be cleared when cancelling the queue, either from
810 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this
811 * function before starting the stream, otherwise the error flag will remain set
812 * until the queue is released when closing the device node.
813 */
814void vb2_queue_error(struct vb2_queue *q);
815
816/**
817 * vb2_mmap() - map video buffers into application address space
818 * @q: videobuf2 queue
819 * @vma: vma passed to the mmap file operation handler in the driver
820 *
821 * Should be called from mmap file operation handler of a driver.
822 * This function maps one plane of one of the available video buffers to
823 * userspace. To map whole video memory allocated on reqbufs, this function
824 * has to be called once per each plane per each buffer previously allocated.
825 *
826 * When the userspace application calls mmap, it passes to it an offset returned
827 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
828 * a "cookie", which is then used to identify the plane to be mapped.
829 * This function finds a plane with a matching offset and a mapping is performed
830 * by the means of a provided memory operation.
831 *
832 * The return values from this function are intended to be directly returned
833 * from the mmap handler in driver.
834 */
835int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
836
837#ifndef CONFIG_MMU
838unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
839 unsigned long addr,
840 unsigned long len,
841 unsigned long pgoff,
842 unsigned long flags);
843#endif
844
845/**
846 * vb2_core_poll() - implements poll userspace operation
847 * @q: videobuf2 queue
848 * @file: file argument passed to the poll file operation handler
849 * @wait: wait argument passed to the poll file operation handler
850 *
851 * This function implements poll file operation handler for a driver.
852 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
853 * be informed that the file descriptor of a video device is available for
854 * reading.
855 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
856 * will be reported as available for writing.
857 *
858 * The return values from this function are intended to be directly returned
859 * from poll handler in driver.
860 */
861unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
862 poll_table *wait);
863
864size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
865 loff_t *ppos, int nonblock);
866size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
867 loff_t *ppos, int nonblock);
868
869/**
870 * typedef vb2_thread_fnc - callback function for use with vb2_thread
871 *
872 * @vb: pointer to struct &vb2_buffer
873 * @priv: pointer to a private pointer
874 *
875 * This is called whenever a buffer is dequeued in the thread.
876 */
877typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
878
879/**
880 * vb2_thread_start() - start a thread for the given queue.
881 * @q: videobuf queue
882 * @fnc: callback function
883 * @priv: priv pointer passed to the callback function
884 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
885 *
886 * This starts a thread that will queue and dequeue until an error occurs
887 * or @vb2_thread_stop is called.
888 *
889 * .. attention::
890 *
891 * This function should not be used for anything else but the videobuf2-dvb
892 * support. If you think you have another good use-case for this, then please
893 * contact the linux-media mailing list first.
894 */
895int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
896 const char *thread_name);
897
898/**
899 * vb2_thread_stop() - stop the thread for the given queue.
900 * @q: videobuf queue
901 */
902int vb2_thread_stop(struct vb2_queue *q);
903
904/**
905 * vb2_is_streaming() - return streaming status of the queue
906 * @q: videobuf queue
907 */
908static inline bool vb2_is_streaming(struct vb2_queue *q)
909{
910 return q->streaming;
911}
912
913/**
914 * vb2_fileio_is_active() - return true if fileio is active.
915 * @q: videobuf queue
916 *
917 * This returns true if read() or write() is used to stream the data
918 * as opposed to stream I/O. This is almost never an important distinction,
919 * except in rare cases. One such case is that using read() or write() to
920 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
921 * is no way you can pass the field information of each buffer to/from
922 * userspace. A driver that supports this field format should check for
923 * this in the queue_setup op and reject it if this function returns true.
924 */
925static inline bool vb2_fileio_is_active(struct vb2_queue *q)
926{
927 return q->fileio;
928}
929
930/**
931 * vb2_is_busy() - return busy status of the queue
932 * @q: videobuf queue
933 *
934 * This function checks if queue has any buffers allocated.
935 */
936static inline bool vb2_is_busy(struct vb2_queue *q)
937{
938 return (q->num_buffers > 0);
939}
940
941/**
942 * vb2_get_drv_priv() - return driver private data associated with the queue
943 * @q: videobuf queue
944 */
945static inline void *vb2_get_drv_priv(struct vb2_queue *q)
946{
947 return q->drv_priv;
948}
949
950/**
951 * vb2_set_plane_payload() - set bytesused for the plane plane_no
952 * @vb: buffer for which plane payload should be set
953 * @plane_no: plane number for which payload should be set
954 * @size: payload in bytes
955 */
956static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
957 unsigned int plane_no, unsigned long size)
958{
959 if (plane_no < vb->num_planes)
960 vb->planes[plane_no].bytesused = size;
961}
962
963/**
964 * vb2_get_plane_payload() - get bytesused for the plane plane_no
965 * @vb: buffer for which plane payload should be set
966 * @plane_no: plane number for which payload should be set
967 */
968static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
969 unsigned int plane_no)
970{
971 if (plane_no < vb->num_planes)
972 return vb->planes[plane_no].bytesused;
973 return 0;
974}
975
976/**
977 * vb2_plane_size() - return plane size in bytes
978 * @vb: buffer for which plane size should be returned
979 * @plane_no: plane number for which size should be returned
980 */
981static inline unsigned long
982vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
983{
984 if (plane_no < vb->num_planes)
985 return vb->planes[plane_no].length;
986 return 0;
987}
988
989/**
990 * vb2_start_streaming_called() - return streaming status of driver
991 * @q: videobuf queue
992 */
993static inline bool vb2_start_streaming_called(struct vb2_queue *q)
994{
995 return q->start_streaming_called;
996}
997
998/**
999 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
1000 * @q: videobuf queue
1001 */
1002static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1003{
1004 q->last_buffer_dequeued = false;
1005}
1006
1007/*
1008 * The following functions are not part of the vb2 core API, but are useful
1009 * functions for videobuf2-*.
1010 */
1011
1012/**
1013 * vb2_buffer_in_use() - return true if the buffer is in use and
1014 * the queue cannot be freed (by the means of REQBUFS(0)) call
1015 *
1016 * @vb: buffer for which plane size should be returned
1017 * @q: videobuf queue
1018 */
1019bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1020
1021/**
1022 * vb2_verify_memory_type() - Check whether the memory type and buffer type
1023 * passed to a buffer operation are compatible with the queue.
1024 *
1025 * @q: videobuf queue
1026 * @memory: memory model, as defined by enum &vb2_memory.
1027 * @type: private buffer type whose content is defined by the vb2-core
1028 * caller. For example, for V4L2, it should match
1029 * the types defined on enum &v4l2_buf_type
1030 */
1031int vb2_verify_memory_type(struct vb2_queue *q,
1032 enum vb2_memory memory, unsigned int type);
1033#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
20#define VB2_MAX_FRAME (32)
21#define VB2_MAX_PLANES (8)
22
23enum vb2_memory {
24 VB2_MEMORY_UNKNOWN = 0,
25 VB2_MEMORY_MMAP = 1,
26 VB2_MEMORY_USERPTR = 2,
27 VB2_MEMORY_DMABUF = 4,
28};
29
30struct vb2_alloc_ctx;
31struct vb2_fileio_data;
32struct vb2_threadio_data;
33
34/**
35 * struct vb2_mem_ops - memory handling/memory allocator operations
36 * @alloc: allocate video memory and, optionally, allocator private data,
37 * return NULL on failure or a pointer to allocator private,
38 * per-buffer data on success; the returned private structure
39 * will then be passed as buf_priv argument to other ops in this
40 * structure. Additional gfp_flags to use when allocating the
41 * are also passed to this operation. These flags are from the
42 * gfp_flags field of vb2_queue.
43 * @put: inform the allocator that the buffer will no longer be used;
44 * usually will result in the allocator freeing the buffer (if
45 * no other users of this buffer are present); the buf_priv
46 * argument is the allocator private per-buffer structure
47 * previously returned from the alloc callback.
48 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
49 * DMABUF memory types.
50 * @get_userptr: acquire userspace memory for a hardware operation; used for
51 * USERPTR memory types; vaddr is the address passed to the
52 * videobuf layer when queuing a video buffer of USERPTR type;
53 * should return an allocator private per-buffer structure
54 * associated with the buffer on success, NULL on failure;
55 * the returned private structure will then be passed as buf_priv
56 * argument to other ops in this structure.
57 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
58 * be used.
59 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
60 * used for DMABUF memory types; alloc_ctx is the alloc context
61 * dbuf is the shared dma_buf; returns NULL on failure;
62 * allocator private per-buffer structure on success;
63 * this needs to be used for further accesses to the buffer.
64 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
65 * buffer is no longer used; the buf_priv argument is the
66 * allocator private per-buffer structure previously returned
67 * from the attach_dmabuf callback.
68 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
69 * of dmabuf is informed that this driver is going to use the
70 * dmabuf.
71 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
72 * that this driver is done using the dmabuf for now.
73 * @prepare: called every time the buffer is passed from userspace to the
74 * driver, useful for cache synchronisation, optional.
75 * @finish: called every time the buffer is passed back from the driver
76 * to the userspace, also optional.
77 * @vaddr: return a kernel virtual address to a given memory buffer
78 * associated with the passed private structure or NULL if no
79 * such mapping exists.
80 * @cookie: return allocator specific cookie for a given memory buffer
81 * associated with the passed private structure or NULL if not
82 * available.
83 * @num_users: return the current number of users of a memory buffer;
84 * return 1 if the videobuf layer (or actually the driver using
85 * it) is the only user.
86 * @mmap: setup a userspace mapping for a given memory buffer under
87 * the provided virtual memory region.
88 *
89 * Required ops for USERPTR types: get_userptr, put_userptr.
90 * Required ops for MMAP types: alloc, put, num_users, mmap.
91 * Required ops for read/write access types: alloc, put, num_users, vaddr.
92 * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
93 * unmap_dmabuf.
94 */
95struct vb2_mem_ops {
96 void *(*alloc)(void *alloc_ctx, unsigned long size,
97 enum dma_data_direction dma_dir,
98 gfp_t gfp_flags);
99 void (*put)(void *buf_priv);
100 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
101
102 void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
103 unsigned long size,
104 enum dma_data_direction dma_dir);
105 void (*put_userptr)(void *buf_priv);
106
107 void (*prepare)(void *buf_priv);
108 void (*finish)(void *buf_priv);
109
110 void *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
111 unsigned long size,
112 enum dma_data_direction dma_dir);
113 void (*detach_dmabuf)(void *buf_priv);
114 int (*map_dmabuf)(void *buf_priv);
115 void (*unmap_dmabuf)(void *buf_priv);
116
117 void *(*vaddr)(void *buf_priv);
118 void *(*cookie)(void *buf_priv);
119
120 unsigned int (*num_users)(void *buf_priv);
121
122 int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
123};
124
125/**
126 * struct vb2_plane - plane information
127 * @mem_priv: private data with this plane
128 * @dbuf: dma_buf - shared buffer object
129 * @dbuf_mapped: flag to show whether dbuf is mapped or not
130 * @bytesused: number of bytes occupied by data in the plane (payload)
131 * @length: size of this plane (NOT the payload) in bytes
132 * @min_length: minimum required size of this plane (NOT the payload) in bytes.
133 * @length is always greater or equal to @min_length.
134 * @offset: when memory in the associated struct vb2_buffer is
135 * VB2_MEMORY_MMAP, equals the offset from the start of
136 * the device memory for this plane (or is a "cookie" that
137 * should be passed to mmap() called on the video node)
138 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
139 * pointing to this plane
140 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
141 * descriptor associated with this plane
142 * @m: Union with memtype-specific data (@offset, @userptr or
143 * @fd).
144 * @data_offset: offset in the plane to the start of data; usually 0,
145 * unless there is a header in front of the data
146 * Should contain enough information to be able to cover all the fields
147 * of struct v4l2_plane at videodev2.h
148 */
149struct vb2_plane {
150 void *mem_priv;
151 struct dma_buf *dbuf;
152 unsigned int dbuf_mapped;
153 unsigned int bytesused;
154 unsigned int length;
155 unsigned int min_length;
156 union {
157 unsigned int offset;
158 unsigned long userptr;
159 int fd;
160 } m;
161 unsigned int data_offset;
162};
163
164/**
165 * enum vb2_io_modes - queue access methods
166 * @VB2_MMAP: driver supports MMAP with streaming API
167 * @VB2_USERPTR: driver supports USERPTR with streaming API
168 * @VB2_READ: driver supports read() style access
169 * @VB2_WRITE: driver supports write() style access
170 * @VB2_DMABUF: driver supports DMABUF with streaming API
171 */
172enum vb2_io_modes {
173 VB2_MMAP = (1 << 0),
174 VB2_USERPTR = (1 << 1),
175 VB2_READ = (1 << 2),
176 VB2_WRITE = (1 << 3),
177 VB2_DMABUF = (1 << 4),
178};
179
180/**
181 * enum vb2_buffer_state - current video buffer state
182 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
183 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
184 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
185 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
186 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
187 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
188 * in a hardware operation
189 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
190 * not yet dequeued to userspace
191 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
192 * has ended with an error, which will be reported
193 * to the userspace when it is dequeued
194 */
195enum vb2_buffer_state {
196 VB2_BUF_STATE_DEQUEUED,
197 VB2_BUF_STATE_PREPARING,
198 VB2_BUF_STATE_PREPARED,
199 VB2_BUF_STATE_QUEUED,
200 VB2_BUF_STATE_REQUEUEING,
201 VB2_BUF_STATE_ACTIVE,
202 VB2_BUF_STATE_DONE,
203 VB2_BUF_STATE_ERROR,
204};
205
206struct vb2_queue;
207
208/**
209 * struct vb2_buffer - represents a video buffer
210 * @vb2_queue: the queue to which this driver belongs
211 * @index: id number of the buffer
212 * @type: buffer type
213 * @memory: the method, in which the actual data is passed
214 * @num_planes: number of planes in the buffer
215 * on an internal driver queue
216 * @planes: private per-plane information; do not change
217 * @timestamp: frame timestamp in ns
218 */
219struct vb2_buffer {
220 struct vb2_queue *vb2_queue;
221 unsigned int index;
222 unsigned int type;
223 unsigned int memory;
224 unsigned int num_planes;
225 struct vb2_plane planes[VB2_MAX_PLANES];
226 u64 timestamp;
227
228 /* private: internal use only
229 *
230 * state: current buffer state; do not change
231 * queued_entry: entry on the queued buffers list, which holds
232 * all buffers queued from userspace
233 * done_entry: entry on the list that stores all buffers ready
234 * to be dequeued to userspace
235 */
236 enum vb2_buffer_state state;
237
238 struct list_head queued_entry;
239 struct list_head done_entry;
240#ifdef CONFIG_VIDEO_ADV_DEBUG
241 /*
242 * Counters for how often these buffer-related ops are
243 * called. Used to check for unbalanced ops.
244 */
245 u32 cnt_mem_alloc;
246 u32 cnt_mem_put;
247 u32 cnt_mem_get_dmabuf;
248 u32 cnt_mem_get_userptr;
249 u32 cnt_mem_put_userptr;
250 u32 cnt_mem_prepare;
251 u32 cnt_mem_finish;
252 u32 cnt_mem_attach_dmabuf;
253 u32 cnt_mem_detach_dmabuf;
254 u32 cnt_mem_map_dmabuf;
255 u32 cnt_mem_unmap_dmabuf;
256 u32 cnt_mem_vaddr;
257 u32 cnt_mem_cookie;
258 u32 cnt_mem_num_users;
259 u32 cnt_mem_mmap;
260
261 u32 cnt_buf_init;
262 u32 cnt_buf_prepare;
263 u32 cnt_buf_finish;
264 u32 cnt_buf_cleanup;
265 u32 cnt_buf_queue;
266
267 /* This counts the number of calls to vb2_buffer_done() */
268 u32 cnt_buf_done;
269#endif
270};
271
272/**
273 * struct vb2_ops - driver-specific callbacks
274 *
275 * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
276 * handlers before memory allocation. It can be called
277 * twice: if the original number of requested buffers
278 * could not be allocated, then it will be called a
279 * second time with the actually allocated number of
280 * buffers to verify if that is OK.
281 * The driver should return the required number of buffers
282 * in *num_buffers, the required number of planes per
283 * buffer in *num_planes, the size of each plane should be
284 * set in the sizes[] array and optional per-plane
285 * allocator specific context in the alloc_ctxs[] array.
286 * When called from VIDIOC_REQBUFS, *num_planes == 0, the
287 * driver has to use the currently configured format to
288 * determine the plane sizes and *num_buffers is the total
289 * number of buffers that are being allocated. When called
290 * from VIDIOC_CREATE_BUFS, *num_planes != 0 and it
291 * describes the requested number of planes and sizes[]
292 * contains the requested plane sizes. If either
293 * *num_planes or the requested sizes are invalid callback
294 * must return -EINVAL. In this case *num_buffers are
295 * being allocated additionally to q->num_buffers.
296 * @wait_prepare: release any locks taken while calling vb2 functions;
297 * it is called before an ioctl needs to wait for a new
298 * buffer to arrive; required to avoid a deadlock in
299 * blocking access type.
300 * @wait_finish: reacquire all locks released in the previous callback;
301 * required to continue operation after sleeping while
302 * waiting for a new buffer to arrive.
303 * @buf_init: called once after allocating a buffer (in MMAP case)
304 * or after acquiring a new USERPTR buffer; drivers may
305 * perform additional buffer-related initialization;
306 * initialization failure (return != 0) will prevent
307 * queue setup from completing successfully; optional.
308 * @buf_prepare: called every time the buffer is queued from userspace
309 * and from the VIDIOC_PREPARE_BUF ioctl; drivers may
310 * perform any initialization required before each
311 * hardware operation in this callback; drivers can
312 * access/modify the buffer here as it is still synced for
313 * the CPU; drivers that support VIDIOC_CREATE_BUFS must
314 * also validate the buffer size; if an error is returned,
315 * the buffer will not be queued in driver; optional.
316 * @buf_finish: called before every dequeue of the buffer back to
317 * userspace; the buffer is synced for the CPU, so drivers
318 * can access/modify the buffer contents; drivers may
319 * perform any operations required before userspace
320 * accesses the buffer; optional. The buffer state can be
321 * one of the following: DONE and ERROR occur while
322 * streaming is in progress, and the PREPARED state occurs
323 * when the queue has been canceled and all pending
324 * buffers are being returned to their default DEQUEUED
325 * state. Typically you only have to do something if the
326 * state is VB2_BUF_STATE_DONE, since in all other cases
327 * the buffer contents will be ignored anyway.
328 * @buf_cleanup: called once before the buffer is freed; drivers may
329 * perform any additional cleanup; optional.
330 * @start_streaming: called once to enter 'streaming' state; the driver may
331 * receive buffers with @buf_queue callback before
332 * @start_streaming is called; the driver gets the number
333 * of already queued buffers in count parameter; driver
334 * can return an error if hardware fails, in that case all
335 * buffers that have been already given by the @buf_queue
336 * callback are to be returned by the driver by calling
337 * @vb2_buffer_done(VB2_BUF_STATE_QUEUED).
338 * If you need a minimum number of buffers before you can
339 * start streaming, then set @min_buffers_needed in the
340 * vb2_queue structure. If that is non-zero then
341 * start_streaming won't be called until at least that
342 * many buffers have been queued up by userspace.
343 * @stop_streaming: called when 'streaming' state must be disabled; driver
344 * should stop any DMA transactions or wait until they
345 * finish and give back all buffers it got from buf_queue()
346 * callback by calling @vb2_buffer_done() with either
347 * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use
348 * vb2_wait_for_all_buffers() function
349 * @buf_queue: passes buffer vb to the driver; driver may start
350 * hardware operation on this buffer; driver should give
351 * the buffer back by calling vb2_buffer_done() function;
352 * it is allways called after calling STREAMON ioctl;
353 * might be called before start_streaming callback if user
354 * pre-queued buffers before calling STREAMON.
355 */
356struct vb2_ops {
357 int (*queue_setup)(struct vb2_queue *q,
358 unsigned int *num_buffers, unsigned int *num_planes,
359 unsigned int sizes[], void *alloc_ctxs[]);
360
361 void (*wait_prepare)(struct vb2_queue *q);
362 void (*wait_finish)(struct vb2_queue *q);
363
364 int (*buf_init)(struct vb2_buffer *vb);
365 int (*buf_prepare)(struct vb2_buffer *vb);
366 void (*buf_finish)(struct vb2_buffer *vb);
367 void (*buf_cleanup)(struct vb2_buffer *vb);
368
369 int (*start_streaming)(struct vb2_queue *q, unsigned int count);
370 void (*stop_streaming)(struct vb2_queue *q);
371
372 void (*buf_queue)(struct vb2_buffer *vb);
373};
374
375/**
376 * struct vb2_ops - driver-specific callbacks
377 *
378 * @verify_planes_array: Verify that a given user space structure contains
379 * enough planes for the buffer. This is called
380 * for each dequeued buffer.
381 * @fill_user_buffer: given a vb2_buffer fill in the userspace structure.
382 * For V4L2 this is a struct v4l2_buffer.
383 * @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer.
384 * If the userspace structure is invalid, then this op
385 * will return an error.
386 * @copy_timestamp: copy the timestamp from a userspace structure to
387 * the vb2_buffer struct.
388 */
389struct vb2_buf_ops {
390 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
391 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
392 int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
393 struct vb2_plane *planes);
394 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
395};
396
397/**
398 * struct vb2_queue - a videobuf queue
399 *
400 * @type: private buffer type whose content is defined by the vb2-core
401 * caller. For example, for V4L2, it should match
402 * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h
403 * @io_modes: supported io methods (see vb2_io_modes enum)
404 * @fileio_read_once: report EOF after reading the first buffer
405 * @fileio_write_immediately: queue buffer after each write() call
406 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver
407 * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
408 * has not been called. This is a vb1 idiom that has been adopted
409 * also by vb2.
410 * @lock: pointer to a mutex that protects the vb2_queue struct. The
411 * driver can set this to a mutex to let the v4l2 core serialize
412 * the queuing ioctls. If the driver wants to handle locking
413 * itself, then this should be set to NULL. This lock is not used
414 * by the videobuf2 core API.
415 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
416 * that called reqbufs, create_buffers or started fileio.
417 * This field is not used by the videobuf2 core API, but it allows
418 * drivers to easily associate an owner filehandle with the queue.
419 * @ops: driver-specific callbacks
420 * @mem_ops: memory allocator specific callbacks
421 * @buf_ops: callbacks to deliver buffer information
422 * between user-space and kernel-space
423 * @drv_priv: driver private data
424 * @buf_struct_size: size of the driver-specific buffer structure;
425 * "0" indicates the driver doesn't want to use a custom buffer
426 * structure type. for example, sizeof(struct vb2_v4l2_buffer)
427 * will be used for v4l2.
428 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
429 * V4L2_BUF_FLAG_TSTAMP_SRC_*
430 * @gfp_flags: additional gfp flags used when allocating the buffers.
431 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
432 * to force the buffer allocation to a specific memory zone.
433 * @min_buffers_needed: the minimum number of buffers needed before
434 * start_streaming() can be called. Used when a DMA engine
435 * cannot be started unless at least this number of buffers
436 * have been queued into the driver.
437 */
438/*
439 * Private elements (won't appear at the DocBook):
440 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped
441 * @memory: current memory type used
442 * @bufs: videobuf buffer structures
443 * @num_buffers: number of allocated/used buffers
444 * @queued_list: list of buffers currently queued from userspace
445 * @queued_count: number of buffers queued and ready for streaming.
446 * @owned_by_drv_count: number of buffers owned by the driver
447 * @done_list: list of buffers ready to be dequeued to userspace
448 * @done_lock: lock to protect done_list list
449 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
450 * @alloc_ctx: memory type/allocator-specific contexts for each plane
451 * @streaming: current streaming state
452 * @start_streaming_called: start_streaming() was called successfully and we
453 * started streaming.
454 * @error: a fatal error occurred on the queue
455 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
456 * buffers. Only set for capture queues if qbuf has not yet been
457 * called since poll() needs to return POLLERR in that situation.
458 * @is_multiplanar: set if buffer type is multiplanar
459 * @is_output: set if buffer type is output
460 * @copy_timestamp: set if vb2-core should set timestamps
461 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
462 * last decoded buffer was already dequeued. Set for capture queues
463 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
464 * @fileio: file io emulator internal data, used only if emulator is active
465 * @threadio: thread io internal data, used only if thread is active
466 */
467struct vb2_queue {
468 unsigned int type;
469 unsigned int io_modes;
470 unsigned fileio_read_once:1;
471 unsigned fileio_write_immediately:1;
472 unsigned allow_zero_bytesused:1;
473 unsigned quirk_poll_must_check_waiting_for_buffers:1;
474
475 struct mutex *lock;
476 void *owner;
477
478 const struct vb2_ops *ops;
479 const struct vb2_mem_ops *mem_ops;
480 const struct vb2_buf_ops *buf_ops;
481
482 void *drv_priv;
483 unsigned int buf_struct_size;
484 u32 timestamp_flags;
485 gfp_t gfp_flags;
486 u32 min_buffers_needed;
487
488 /* private: internal use only */
489 struct mutex mmap_lock;
490 unsigned int memory;
491 struct vb2_buffer *bufs[VB2_MAX_FRAME];
492 unsigned int num_buffers;
493
494 struct list_head queued_list;
495 unsigned int queued_count;
496
497 atomic_t owned_by_drv_count;
498 struct list_head done_list;
499 spinlock_t done_lock;
500 wait_queue_head_t done_wq;
501
502 void *alloc_ctx[VB2_MAX_PLANES];
503
504 unsigned int streaming:1;
505 unsigned int start_streaming_called:1;
506 unsigned int error:1;
507 unsigned int waiting_for_buffers:1;
508 unsigned int is_multiplanar:1;
509 unsigned int is_output:1;
510 unsigned int copy_timestamp:1;
511 unsigned int last_buffer_dequeued:1;
512
513 struct vb2_fileio_data *fileio;
514 struct vb2_threadio_data *threadio;
515
516#ifdef CONFIG_VIDEO_ADV_DEBUG
517 /*
518 * Counters for how often these queue-related ops are
519 * called. Used to check for unbalanced ops.
520 */
521 u32 cnt_queue_setup;
522 u32 cnt_wait_prepare;
523 u32 cnt_wait_finish;
524 u32 cnt_start_streaming;
525 u32 cnt_stop_streaming;
526#endif
527};
528
529void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
530void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
531
532void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
533void vb2_discard_done(struct vb2_queue *q);
534int vb2_wait_for_all_buffers(struct vb2_queue *q);
535
536void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
537int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
538 unsigned int *count);
539int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
540 unsigned int *count, unsigned requested_planes,
541 const unsigned int requested_sizes[]);
542int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
543int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
544int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
545 bool nonblocking);
546
547int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
548int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
549
550int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
551 unsigned int index, unsigned int plane, unsigned int flags);
552
553int vb2_core_queue_init(struct vb2_queue *q);
554void vb2_core_queue_release(struct vb2_queue *q);
555
556void vb2_queue_error(struct vb2_queue *q);
557
558int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
559#ifndef CONFIG_MMU
560unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
561 unsigned long addr,
562 unsigned long len,
563 unsigned long pgoff,
564 unsigned long flags);
565#endif
566unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
567 poll_table *wait);
568size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
569 loff_t *ppos, int nonblock);
570size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
571 loff_t *ppos, int nonblock);
572
573/*
574 * vb2_thread_fnc - callback function for use with vb2_thread
575 *
576 * This is called whenever a buffer is dequeued in the thread.
577 */
578typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
579
580/**
581 * vb2_thread_start() - start a thread for the given queue.
582 * @q: videobuf queue
583 * @fnc: callback function
584 * @priv: priv pointer passed to the callback function
585 * @thread_name:the name of the thread. This will be prefixed with "vb2-".
586 *
587 * This starts a thread that will queue and dequeue until an error occurs
588 * or @vb2_thread_stop is called.
589 *
590 * This function should not be used for anything else but the videobuf2-dvb
591 * support. If you think you have another good use-case for this, then please
592 * contact the linux-media mailinglist first.
593 */
594int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
595 const char *thread_name);
596
597/**
598 * vb2_thread_stop() - stop the thread for the given queue.
599 * @q: videobuf queue
600 */
601int vb2_thread_stop(struct vb2_queue *q);
602
603/**
604 * vb2_is_streaming() - return streaming status of the queue
605 * @q: videobuf queue
606 */
607static inline bool vb2_is_streaming(struct vb2_queue *q)
608{
609 return q->streaming;
610}
611
612/**
613 * vb2_fileio_is_active() - return true if fileio is active.
614 * @q: videobuf queue
615 *
616 * This returns true if read() or write() is used to stream the data
617 * as opposed to stream I/O. This is almost never an important distinction,
618 * except in rare cases. One such case is that using read() or write() to
619 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
620 * is no way you can pass the field information of each buffer to/from
621 * userspace. A driver that supports this field format should check for
622 * this in the queue_setup op and reject it if this function returns true.
623 */
624static inline bool vb2_fileio_is_active(struct vb2_queue *q)
625{
626 return q->fileio;
627}
628
629/**
630 * vb2_is_busy() - return busy status of the queue
631 * @q: videobuf queue
632 *
633 * This function checks if queue has any buffers allocated.
634 */
635static inline bool vb2_is_busy(struct vb2_queue *q)
636{
637 return (q->num_buffers > 0);
638}
639
640/**
641 * vb2_get_drv_priv() - return driver private data associated with the queue
642 * @q: videobuf queue
643 */
644static inline void *vb2_get_drv_priv(struct vb2_queue *q)
645{
646 return q->drv_priv;
647}
648
649/**
650 * vb2_set_plane_payload() - set bytesused for the plane plane_no
651 * @vb: buffer for which plane payload should be set
652 * @plane_no: plane number for which payload should be set
653 * @size: payload in bytes
654 */
655static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
656 unsigned int plane_no, unsigned long size)
657{
658 if (plane_no < vb->num_planes)
659 vb->planes[plane_no].bytesused = size;
660}
661
662/**
663 * vb2_get_plane_payload() - get bytesused for the plane plane_no
664 * @vb: buffer for which plane payload should be set
665 * @plane_no: plane number for which payload should be set
666 */
667static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
668 unsigned int plane_no)
669{
670 if (plane_no < vb->num_planes)
671 return vb->planes[plane_no].bytesused;
672 return 0;
673}
674
675/**
676 * vb2_plane_size() - return plane size in bytes
677 * @vb: buffer for which plane size should be returned
678 * @plane_no: plane number for which size should be returned
679 */
680static inline unsigned long
681vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
682{
683 if (plane_no < vb->num_planes)
684 return vb->planes[plane_no].length;
685 return 0;
686}
687
688/**
689 * vb2_start_streaming_called() - return streaming status of driver
690 * @q: videobuf queue
691 */
692static inline bool vb2_start_streaming_called(struct vb2_queue *q)
693{
694 return q->start_streaming_called;
695}
696
697/**
698 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
699 * @q: videobuf queue
700 */
701static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
702{
703 q->last_buffer_dequeued = false;
704}
705
706/*
707 * The following functions are not part of the vb2 core API, but are useful
708 * functions for videobuf2-*.
709 */
710bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
711int vb2_verify_memory_type(struct vb2_queue *q,
712 enum vb2_memory memory, unsigned int type);
713#endif /* _MEDIA_VIDEOBUF2_CORE_H */