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 enum vb2_memory { 24 VB2_MEMORY_UNKNOWN = 0, 25 VB2_MEMORY_MMAP = 1, 26 VB2_MEMORY_USERPTR = 2, 27 VB2_MEMORY_DMABUF = 4, 28 }; 29 30 struct vb2_alloc_ctx; 31 struct vb2_fileio_data; 32 struct 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 */ 95 struct 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 * @offset: when memory in the associated struct vb2_buffer is 133 * VB2_MEMORY_MMAP, equals the offset from the start of 134 * the device memory for this plane (or is a "cookie" that 135 * should be passed to mmap() called on the video node) 136 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer 137 * pointing to this plane 138 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file 139 * descriptor associated with this plane 140 * @m: Union with memtype-specific data (@offset, @userptr or 141 * @fd). 142 * @data_offset: offset in the plane to the start of data; usually 0, 143 * unless there is a header in front of the data 144 * Should contain enough information to be able to cover all the fields 145 * of struct v4l2_plane at videodev2.h 146 */ 147 struct vb2_plane { 148 void *mem_priv; 149 struct dma_buf *dbuf; 150 unsigned int dbuf_mapped; 151 unsigned int bytesused; 152 unsigned int length; 153 union { 154 unsigned int offset; 155 unsigned long userptr; 156 int fd; 157 } m; 158 unsigned int data_offset; 159 }; 160 161 /** 162 * enum vb2_io_modes - queue access methods 163 * @VB2_MMAP: driver supports MMAP with streaming API 164 * @VB2_USERPTR: driver supports USERPTR with streaming API 165 * @VB2_READ: driver supports read() style access 166 * @VB2_WRITE: driver supports write() style access 167 * @VB2_DMABUF: driver supports DMABUF with streaming API 168 */ 169 enum vb2_io_modes { 170 VB2_MMAP = (1 << 0), 171 VB2_USERPTR = (1 << 1), 172 VB2_READ = (1 << 2), 173 VB2_WRITE = (1 << 3), 174 VB2_DMABUF = (1 << 4), 175 }; 176 177 /** 178 * enum vb2_buffer_state - current video buffer state 179 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control 180 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf 181 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver 182 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver 183 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver 184 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used 185 * in a hardware operation 186 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but 187 * not yet dequeued to userspace 188 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer 189 * has ended with an error, which will be reported 190 * to the userspace when it is dequeued 191 */ 192 enum vb2_buffer_state { 193 VB2_BUF_STATE_DEQUEUED, 194 VB2_BUF_STATE_PREPARING, 195 VB2_BUF_STATE_PREPARED, 196 VB2_BUF_STATE_QUEUED, 197 VB2_BUF_STATE_REQUEUEING, 198 VB2_BUF_STATE_ACTIVE, 199 VB2_BUF_STATE_DONE, 200 VB2_BUF_STATE_ERROR, 201 }; 202 203 struct vb2_queue; 204 205 /** 206 * struct vb2_buffer - represents a video buffer 207 * @vb2_queue: the queue to which this driver belongs 208 * @index: id number of the buffer 209 * @type: buffer type 210 * @memory: the method, in which the actual data is passed 211 * @num_planes: number of planes in the buffer 212 * on an internal driver queue 213 * @planes: private per-plane information; do not change 214 * @timestamp: frame timestamp in ns 215 */ 216 struct vb2_buffer { 217 struct vb2_queue *vb2_queue; 218 unsigned int index; 219 unsigned int type; 220 unsigned int memory; 221 unsigned int num_planes; 222 struct vb2_plane planes[VB2_MAX_PLANES]; 223 u64 timestamp; 224 225 /* private: internal use only 226 * 227 * state: current buffer state; do not change 228 * queued_entry: entry on the queued buffers list, which holds 229 * all buffers queued from userspace 230 * done_entry: entry on the list that stores all buffers ready 231 * to be dequeued to userspace 232 */ 233 enum vb2_buffer_state state; 234 235 struct list_head queued_entry; 236 struct list_head done_entry; 237 #ifdef CONFIG_VIDEO_ADV_DEBUG 238 /* 239 * Counters for how often these buffer-related ops are 240 * called. Used to check for unbalanced ops. 241 */ 242 u32 cnt_mem_alloc; 243 u32 cnt_mem_put; 244 u32 cnt_mem_get_dmabuf; 245 u32 cnt_mem_get_userptr; 246 u32 cnt_mem_put_userptr; 247 u32 cnt_mem_prepare; 248 u32 cnt_mem_finish; 249 u32 cnt_mem_attach_dmabuf; 250 u32 cnt_mem_detach_dmabuf; 251 u32 cnt_mem_map_dmabuf; 252 u32 cnt_mem_unmap_dmabuf; 253 u32 cnt_mem_vaddr; 254 u32 cnt_mem_cookie; 255 u32 cnt_mem_num_users; 256 u32 cnt_mem_mmap; 257 258 u32 cnt_buf_init; 259 u32 cnt_buf_prepare; 260 u32 cnt_buf_finish; 261 u32 cnt_buf_cleanup; 262 u32 cnt_buf_queue; 263 264 /* This counts the number of calls to vb2_buffer_done() */ 265 u32 cnt_buf_done; 266 #endif 267 }; 268 269 /** 270 * struct vb2_ops - driver-specific callbacks 271 * 272 * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS 273 * handlers before memory allocation. It can be called 274 * twice: if the original number of requested buffers 275 * could not be allocated, then it will be called a 276 * second time with the actually allocated number of 277 * buffers to verify if that is OK. 278 * The driver should return the required number of buffers 279 * in *num_buffers, the required number of planes per 280 * buffer in *num_planes, the size of each plane should be 281 * set in the sizes[] array and optional per-plane 282 * allocator specific context in the alloc_ctxs[] array. 283 * When called from VIDIOC_REQBUFS, *num_planes == 0, the 284 * driver has to use the currently configured format to 285 * determine the plane sizes and *num_buffers is the total 286 * number of buffers that are being allocated. When called 287 * from VIDIOC_CREATE_BUFS, *num_planes != 0 and it 288 * describes the requested number of planes and sizes[] 289 * contains the requested plane sizes. If either 290 * *num_planes or the requested sizes are invalid callback 291 * must return -EINVAL. In this case *num_buffers are 292 * being allocated additionally to q->num_buffers. 293 * @wait_prepare: release any locks taken while calling vb2 functions; 294 * it is called before an ioctl needs to wait for a new 295 * buffer to arrive; required to avoid a deadlock in 296 * blocking access type. 297 * @wait_finish: reacquire all locks released in the previous callback; 298 * required to continue operation after sleeping while 299 * waiting for a new buffer to arrive. 300 * @buf_init: called once after allocating a buffer (in MMAP case) 301 * or after acquiring a new USERPTR buffer; drivers may 302 * perform additional buffer-related initialization; 303 * initialization failure (return != 0) will prevent 304 * queue setup from completing successfully; optional. 305 * @buf_prepare: called every time the buffer is queued from userspace 306 * and from the VIDIOC_PREPARE_BUF ioctl; drivers may 307 * perform any initialization required before each 308 * hardware operation in this callback; drivers can 309 * access/modify the buffer here as it is still synced for 310 * the CPU; drivers that support VIDIOC_CREATE_BUFS must 311 * also validate the buffer size; if an error is returned, 312 * the buffer will not be queued in driver; optional. 313 * @buf_finish: called before every dequeue of the buffer back to 314 * userspace; the buffer is synced for the CPU, so drivers 315 * can access/modify the buffer contents; drivers may 316 * perform any operations required before userspace 317 * accesses the buffer; optional. The buffer state can be 318 * one of the following: DONE and ERROR occur while 319 * streaming is in progress, and the PREPARED state occurs 320 * when the queue has been canceled and all pending 321 * buffers are being returned to their default DEQUEUED 322 * state. Typically you only have to do something if the 323 * state is VB2_BUF_STATE_DONE, since in all other cases 324 * the buffer contents will be ignored anyway. 325 * @buf_cleanup: called once before the buffer is freed; drivers may 326 * perform any additional cleanup; optional. 327 * @start_streaming: called once to enter 'streaming' state; the driver may 328 * receive buffers with @buf_queue callback before 329 * @start_streaming is called; the driver gets the number 330 * of already queued buffers in count parameter; driver 331 * can return an error if hardware fails, in that case all 332 * buffers that have been already given by the @buf_queue 333 * callback are to be returned by the driver by calling 334 * @vb2_buffer_done(VB2_BUF_STATE_QUEUED). 335 * If you need a minimum number of buffers before you can 336 * start streaming, then set @min_buffers_needed in the 337 * vb2_queue structure. If that is non-zero then 338 * start_streaming won't be called until at least that 339 * many buffers have been queued up by userspace. 340 * @stop_streaming: called when 'streaming' state must be disabled; driver 341 * should stop any DMA transactions or wait until they 342 * finish and give back all buffers it got from buf_queue() 343 * callback by calling @vb2_buffer_done() with either 344 * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use 345 * vb2_wait_for_all_buffers() function 346 * @buf_queue: passes buffer vb to the driver; driver may start 347 * hardware operation on this buffer; driver should give 348 * the buffer back by calling vb2_buffer_done() function; 349 * it is allways called after calling STREAMON ioctl; 350 * might be called before start_streaming callback if user 351 * pre-queued buffers before calling STREAMON. 352 */ 353 struct vb2_ops { 354 int (*queue_setup)(struct vb2_queue *q, 355 unsigned int *num_buffers, unsigned int *num_planes, 356 unsigned int sizes[], void *alloc_ctxs[]); 357 358 void (*wait_prepare)(struct vb2_queue *q); 359 void (*wait_finish)(struct vb2_queue *q); 360 361 int (*buf_init)(struct vb2_buffer *vb); 362 int (*buf_prepare)(struct vb2_buffer *vb); 363 void (*buf_finish)(struct vb2_buffer *vb); 364 void (*buf_cleanup)(struct vb2_buffer *vb); 365 366 int (*start_streaming)(struct vb2_queue *q, unsigned int count); 367 void (*stop_streaming)(struct vb2_queue *q); 368 369 void (*buf_queue)(struct vb2_buffer *vb); 370 }; 371 372 struct vb2_buf_ops { 373 int (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); 374 int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb, 375 struct vb2_plane *planes); 376 int (*set_timestamp)(struct vb2_buffer *vb, const void *pb); 377 }; 378 379 /** 380 * struct vb2_queue - a videobuf queue 381 * 382 * @type: private buffer type whose content is defined by the vb2-core 383 * caller. For example, for V4L2, it should match 384 * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h 385 * @io_modes: supported io methods (see vb2_io_modes enum) 386 * @fileio_read_once: report EOF after reading the first buffer 387 * @fileio_write_immediately: queue buffer after each write() call 388 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver 389 * @lock: pointer to a mutex that protects the vb2_queue struct. The 390 * driver can set this to a mutex to let the v4l2 core serialize 391 * the queuing ioctls. If the driver wants to handle locking 392 * itself, then this should be set to NULL. This lock is not used 393 * by the videobuf2 core API. 394 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle 395 * that called reqbufs, create_buffers or started fileio. 396 * This field is not used by the videobuf2 core API, but it allows 397 * drivers to easily associate an owner filehandle with the queue. 398 * @ops: driver-specific callbacks 399 * @mem_ops: memory allocator specific callbacks 400 * @buf_ops: callbacks to deliver buffer information 401 * between user-space and kernel-space 402 * @drv_priv: driver private data 403 * @buf_struct_size: size of the driver-specific buffer structure; 404 * "0" indicates the driver doesn't want to use a custom buffer 405 * structure type. for example, sizeof(struct vb2_v4l2_buffer) 406 * will be used for v4l2. 407 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and 408 * V4L2_BUF_FLAG_TSTAMP_SRC_* 409 * @gfp_flags: additional gfp flags used when allocating the buffers. 410 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 411 * to force the buffer allocation to a specific memory zone. 412 * @min_buffers_needed: the minimum number of buffers needed before 413 * start_streaming() can be called. Used when a DMA engine 414 * cannot be started unless at least this number of buffers 415 * have been queued into the driver. 416 */ 417 /* 418 * Private elements (won't appear at the DocBook): 419 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped 420 * @memory: current memory type used 421 * @bufs: videobuf buffer structures 422 * @num_buffers: number of allocated/used buffers 423 * @queued_list: list of buffers currently queued from userspace 424 * @queued_count: number of buffers queued and ready for streaming. 425 * @owned_by_drv_count: number of buffers owned by the driver 426 * @done_list: list of buffers ready to be dequeued to userspace 427 * @done_lock: lock to protect done_list list 428 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued 429 * @alloc_ctx: memory type/allocator-specific contexts for each plane 430 * @streaming: current streaming state 431 * @start_streaming_called: start_streaming() was called successfully and we 432 * started streaming. 433 * @error: a fatal error occurred on the queue 434 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for 435 * buffers. Only set for capture queues if qbuf has not yet been 436 * called since poll() needs to return POLLERR in that situation. 437 * @is_multiplanar: set if buffer type is multiplanar 438 * @is_output: set if buffer type is output 439 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the 440 * last decoded buffer was already dequeued. Set for capture queues 441 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued. 442 * @fileio: file io emulator internal data, used only if emulator is active 443 * @threadio: thread io internal data, used only if thread is active 444 */ 445 struct vb2_queue { 446 unsigned int type; 447 unsigned int io_modes; 448 unsigned fileio_read_once:1; 449 unsigned fileio_write_immediately:1; 450 unsigned allow_zero_bytesused:1; 451 452 struct mutex *lock; 453 void *owner; 454 455 const struct vb2_ops *ops; 456 const struct vb2_mem_ops *mem_ops; 457 const struct vb2_buf_ops *buf_ops; 458 459 void *drv_priv; 460 unsigned int buf_struct_size; 461 u32 timestamp_flags; 462 gfp_t gfp_flags; 463 u32 min_buffers_needed; 464 465 /* private: internal use only */ 466 struct mutex mmap_lock; 467 unsigned int memory; 468 struct vb2_buffer *bufs[VB2_MAX_FRAME]; 469 unsigned int num_buffers; 470 471 struct list_head queued_list; 472 unsigned int queued_count; 473 474 atomic_t owned_by_drv_count; 475 struct list_head done_list; 476 spinlock_t done_lock; 477 wait_queue_head_t done_wq; 478 479 void *alloc_ctx[VB2_MAX_PLANES]; 480 unsigned int plane_sizes[VB2_MAX_PLANES]; 481 482 unsigned int streaming:1; 483 unsigned int start_streaming_called:1; 484 unsigned int error:1; 485 unsigned int waiting_for_buffers:1; 486 unsigned int is_multiplanar:1; 487 unsigned int is_output:1; 488 unsigned int last_buffer_dequeued:1; 489 490 struct vb2_fileio_data *fileio; 491 struct vb2_threadio_data *threadio; 492 493 #ifdef CONFIG_VIDEO_ADV_DEBUG 494 /* 495 * Counters for how often these queue-related ops are 496 * called. Used to check for unbalanced ops. 497 */ 498 u32 cnt_queue_setup; 499 u32 cnt_wait_prepare; 500 u32 cnt_wait_finish; 501 u32 cnt_start_streaming; 502 u32 cnt_stop_streaming; 503 #endif 504 }; 505 506 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); 507 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); 508 509 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); 510 void vb2_discard_done(struct vb2_queue *q); 511 int vb2_wait_for_all_buffers(struct vb2_queue *q); 512 513 int vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); 514 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 515 unsigned int *count); 516 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 517 unsigned int *count, unsigned requested_planes, 518 const unsigned int requested_sizes[]); 519 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); 520 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); 521 int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking); 522 523 int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 524 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); 525 526 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 527 unsigned int index, unsigned int plane, unsigned int flags); 528 529 int vb2_core_queue_init(struct vb2_queue *q); 530 void vb2_core_queue_release(struct vb2_queue *q); 531 532 void vb2_queue_error(struct vb2_queue *q); 533 534 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); 535 #ifndef CONFIG_MMU 536 unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 537 unsigned long addr, 538 unsigned long len, 539 unsigned long pgoff, 540 unsigned long flags); 541 #endif 542 543 /** 544 * vb2_is_streaming() - return streaming status of the queue 545 * @q: videobuf queue 546 */ 547 static inline bool vb2_is_streaming(struct vb2_queue *q) 548 { 549 return q->streaming; 550 } 551 552 /** 553 * vb2_fileio_is_active() - return true if fileio is active. 554 * @q: videobuf queue 555 * 556 * This returns true if read() or write() is used to stream the data 557 * as opposed to stream I/O. This is almost never an important distinction, 558 * except in rare cases. One such case is that using read() or write() to 559 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there 560 * is no way you can pass the field information of each buffer to/from 561 * userspace. A driver that supports this field format should check for 562 * this in the queue_setup op and reject it if this function returns true. 563 */ 564 static inline bool vb2_fileio_is_active(struct vb2_queue *q) 565 { 566 return q->fileio; 567 } 568 569 /** 570 * vb2_is_busy() - return busy status of the queue 571 * @q: videobuf queue 572 * 573 * This function checks if queue has any buffers allocated. 574 */ 575 static inline bool vb2_is_busy(struct vb2_queue *q) 576 { 577 return (q->num_buffers > 0); 578 } 579 580 /** 581 * vb2_get_drv_priv() - return driver private data associated with the queue 582 * @q: videobuf queue 583 */ 584 static inline void *vb2_get_drv_priv(struct vb2_queue *q) 585 { 586 return q->drv_priv; 587 } 588 589 /** 590 * vb2_set_plane_payload() - set bytesused for the plane plane_no 591 * @vb: buffer for which plane payload should be set 592 * @plane_no: plane number for which payload should be set 593 * @size: payload in bytes 594 */ 595 static inline void vb2_set_plane_payload(struct vb2_buffer *vb, 596 unsigned int plane_no, unsigned long size) 597 { 598 if (plane_no < vb->num_planes) 599 vb->planes[plane_no].bytesused = size; 600 } 601 602 /** 603 * vb2_get_plane_payload() - get bytesused for the plane plane_no 604 * @vb: buffer for which plane payload should be set 605 * @plane_no: plane number for which payload should be set 606 */ 607 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, 608 unsigned int plane_no) 609 { 610 if (plane_no < vb->num_planes) 611 return vb->planes[plane_no].bytesused; 612 return 0; 613 } 614 615 /** 616 * vb2_plane_size() - return plane size in bytes 617 * @vb: buffer for which plane size should be returned 618 * @plane_no: plane number for which size should be returned 619 */ 620 static inline unsigned long 621 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) 622 { 623 if (plane_no < vb->num_planes) 624 return vb->planes[plane_no].length; 625 return 0; 626 } 627 628 /** 629 * vb2_start_streaming_called() - return streaming status of driver 630 * @q: videobuf queue 631 */ 632 static inline bool vb2_start_streaming_called(struct vb2_queue *q) 633 { 634 return q->start_streaming_called; 635 } 636 637 /** 638 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue 639 * @q: videobuf queue 640 */ 641 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) 642 { 643 q->last_buffer_dequeued = false; 644 } 645 646 #endif /* _MEDIA_VIDEOBUF2_CORE_H */ 647