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 */ 1258