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 #include <media/frame_vector.h> 22 23 #define VB2_MAX_FRAME (32) 24 #define VB2_MAX_PLANES (8) 25 26 /** 27 * enum vb2_memory - type of memory model used to make the buffers visible 28 * on userspace. 29 * 30 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on 31 * userspace. 32 * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is 33 * memory mapped via mmap() ioctl. This model is 34 * also used when the user is using the buffers via 35 * read() or write() system calls. 36 * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is 37 * memory mapped via mmap() ioctl. 38 * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer. 39 */ 40 enum vb2_memory { 41 VB2_MEMORY_UNKNOWN = 0, 42 VB2_MEMORY_MMAP = 1, 43 VB2_MEMORY_USERPTR = 2, 44 VB2_MEMORY_DMABUF = 4, 45 }; 46 47 struct vb2_fileio_data; 48 struct vb2_threadio_data; 49 50 /** 51 * struct vb2_mem_ops - memory handling/memory allocator operations. 52 * @alloc: allocate video memory and, optionally, allocator private data, 53 * return ERR_PTR() on failure or a pointer to allocator private, 54 * per-buffer data on success; the returned private structure 55 * will then be passed as @buf_priv argument to other ops in this 56 * structure. Additional gfp_flags to use when allocating the 57 * are also passed to this operation. These flags are from the 58 * gfp_flags field of vb2_queue. The size argument to this function 59 * shall be *page aligned*. 60 * @put: inform the allocator that the buffer will no longer be used; 61 * usually will result in the allocator freeing the buffer (if 62 * no other users of this buffer are present); the @buf_priv 63 * argument is the allocator private per-buffer structure 64 * previously returned from the alloc callback. 65 * @get_dmabuf: acquire userspace memory for a hardware operation; used for 66 * DMABUF memory types. 67 * @get_userptr: acquire userspace memory for a hardware operation; used for 68 * USERPTR memory types; vaddr is the address passed to the 69 * videobuf layer when queuing a video buffer of USERPTR type; 70 * should return an allocator private per-buffer structure 71 * associated with the buffer on success, ERR_PTR() on failure; 72 * the returned private structure will then be passed as @buf_priv 73 * argument to other ops in this structure. 74 * @put_userptr: inform the allocator that a USERPTR buffer will no longer 75 * be used. 76 * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation; 77 * used for DMABUF memory types; dev is the alloc device 78 * dbuf is the shared dma_buf; returns ERR_PTR() on failure; 79 * allocator private per-buffer structure on success; 80 * this needs to be used for further accesses to the buffer. 81 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF 82 * buffer is no longer used; the @buf_priv argument is the 83 * allocator private per-buffer structure previously returned 84 * from the attach_dmabuf callback. 85 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator 86 * of dmabuf is informed that this driver is going to use the 87 * dmabuf. 88 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified 89 * that this driver is done using the dmabuf for now. 90 * @prepare: called every time the buffer is passed from userspace to the 91 * driver, useful for cache synchronisation, optional. 92 * @finish: called every time the buffer is passed back from the driver 93 * to the userspace, also optional. 94 * @vaddr: return a kernel virtual address to a given memory buffer 95 * associated with the passed private structure or NULL if no 96 * such mapping exists. 97 * @cookie: return allocator specific cookie for a given memory buffer 98 * associated with the passed private structure or NULL if not 99 * available. 100 * @num_users: return the current number of users of a memory buffer; 101 * return 1 if the videobuf layer (or actually the driver using 102 * it) is the only user. 103 * @mmap: setup a userspace mapping for a given memory buffer under 104 * the provided virtual memory region. 105 * 106 * Those operations are used by the videobuf2 core to implement the memory 107 * handling/memory allocators for each type of supported streaming I/O method. 108 * 109 * .. note:: 110 * #) Required ops for USERPTR types: get_userptr, put_userptr. 111 * 112 * #) Required ops for MMAP types: alloc, put, num_users, mmap. 113 * 114 * #) Required ops for read/write access types: alloc, put, num_users, vaddr. 115 * 116 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, 117 * map_dmabuf, unmap_dmabuf. 118 */ 119 struct vb2_mem_ops { 120 void *(*alloc)(struct device *dev, unsigned long attrs, 121 unsigned long size, 122 enum dma_data_direction dma_dir, 123 gfp_t gfp_flags); 124 void (*put)(void *buf_priv); 125 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags); 126 127 void *(*get_userptr)(struct device *dev, unsigned long vaddr, 128 unsigned long size, 129 enum dma_data_direction dma_dir); 130 void (*put_userptr)(void *buf_priv); 131 132 void (*prepare)(void *buf_priv); 133 void (*finish)(void *buf_priv); 134 135 void *(*attach_dmabuf)(struct device *dev, 136 struct dma_buf *dbuf, 137 unsigned long size, 138 enum dma_data_direction dma_dir); 139 void (*detach_dmabuf)(void *buf_priv); 140 int (*map_dmabuf)(void *buf_priv); 141 void (*unmap_dmabuf)(void *buf_priv); 142 143 void *(*vaddr)(void *buf_priv); 144 void *(*cookie)(void *buf_priv); 145 146 unsigned int (*num_users)(void *buf_priv); 147 148 int (*mmap)(void *buf_priv, struct vm_area_struct *vma); 149 }; 150 151 /** 152 * struct vb2_plane - plane information. 153 * @mem_priv: private data with this plane. 154 * @dbuf: dma_buf - shared buffer object. 155 * @dbuf_mapped: flag to show whether dbuf is mapped or not 156 * @bytesused: number of bytes occupied by data in the plane (payload). 157 * @length: size of this plane (NOT the payload) in bytes. 158 * @min_length: minimum required size of this plane (NOT the payload) in bytes. 159 * @length is always greater or equal to @min_length. 160 * @m: Union with memtype-specific data. 161 * @m.offset: when memory in the associated struct vb2_buffer is 162 * %VB2_MEMORY_MMAP, equals the offset from the start of 163 * the device memory for this plane (or is a "cookie" that 164 * should be passed to mmap() called on the video node). 165 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer 166 * pointing to this plane. 167 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file 168 * descriptor associated with this plane. 169 * @data_offset: offset in the plane to the start of data; usually 0, 170 * unless there is a header in front of the data. 171 * 172 * Should contain enough information to be able to cover all the fields 173 * of &struct v4l2_plane at videodev2.h. 174 */ 175 struct vb2_plane { 176 void *mem_priv; 177 struct dma_buf *dbuf; 178 unsigned int dbuf_mapped; 179 unsigned int bytesused; 180 unsigned int length; 181 unsigned int min_length; 182 union { 183 unsigned int offset; 184 unsigned long userptr; 185 int fd; 186 } m; 187 unsigned int data_offset; 188 }; 189 190 /** 191 * enum vb2_io_modes - queue access methods. 192 * @VB2_MMAP: driver supports MMAP with streaming API. 193 * @VB2_USERPTR: driver supports USERPTR with streaming API. 194 * @VB2_READ: driver supports read() style access. 195 * @VB2_WRITE: driver supports write() style access. 196 * @VB2_DMABUF: driver supports DMABUF with streaming API. 197 */ 198 enum vb2_io_modes { 199 VB2_MMAP = BIT(0), 200 VB2_USERPTR = BIT(1), 201 VB2_READ = BIT(2), 202 VB2_WRITE = BIT(3), 203 VB2_DMABUF = BIT(4), 204 }; 205 206 /** 207 * enum vb2_buffer_state - current video buffer state. 208 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control. 209 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request. 210 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf. 211 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver. 212 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used 213 * in a hardware operation. 214 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but 215 * not yet dequeued to userspace. 216 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer 217 * has ended with an error, which will be reported 218 * to the userspace when it is dequeued. 219 */ 220 enum vb2_buffer_state { 221 VB2_BUF_STATE_DEQUEUED, 222 VB2_BUF_STATE_IN_REQUEST, 223 VB2_BUF_STATE_PREPARING, 224 VB2_BUF_STATE_QUEUED, 225 VB2_BUF_STATE_ACTIVE, 226 VB2_BUF_STATE_DONE, 227 VB2_BUF_STATE_ERROR, 228 }; 229 230 struct vb2_queue; 231 232 /** 233 * struct vb2_buffer - represents a video buffer. 234 * @vb2_queue: pointer to &struct vb2_queue with the queue to 235 * which this driver belongs. 236 * @index: id number of the buffer. 237 * @type: buffer type. 238 * @memory: the method, in which the actual data is passed. 239 * @num_planes: number of planes in the buffer 240 * on an internal driver queue. 241 * @timestamp: frame timestamp in ns. 242 * @request: the request this buffer is associated with. 243 * @req_obj: used to bind this buffer to a request. This 244 * request object has a refcount. 245 */ 246 struct vb2_buffer { 247 struct vb2_queue *vb2_queue; 248 unsigned int index; 249 unsigned int type; 250 unsigned int memory; 251 unsigned int num_planes; 252 u64 timestamp; 253 struct media_request *request; 254 struct media_request_object req_obj; 255 256 /* private: internal use only 257 * 258 * state: current buffer state; do not change 259 * synced: this buffer has been synced for DMA, i.e. the 260 * 'prepare' memop was called. It is cleared again 261 * after the 'finish' memop is called. 262 * prepared: this buffer has been prepared, i.e. the 263 * buf_prepare op was called. It is cleared again 264 * after the 'buf_finish' op is called. 265 * copied_timestamp: the timestamp of this capture buffer was copied 266 * from an output buffer. 267 * need_cache_sync_on_prepare: when set buffer's ->prepare() function 268 * performs cache sync/invalidation. 269 * need_cache_sync_on_finish: when set buffer's ->finish() function 270 * performs cache sync/invalidation. 271 * queued_entry: entry on the queued buffers list, which holds 272 * all buffers queued from userspace 273 * done_entry: entry on the list that stores all buffers ready 274 * to be dequeued to userspace 275 * vb2_plane: per-plane information; do not change 276 */ 277 enum vb2_buffer_state state; 278 unsigned int synced:1; 279 unsigned int prepared:1; 280 unsigned int copied_timestamp:1; 281 unsigned int need_cache_sync_on_prepare:1; 282 unsigned int need_cache_sync_on_finish:1; 283 284 struct vb2_plane planes[VB2_MAX_PLANES]; 285 struct list_head queued_entry; 286 struct list_head done_entry; 287 #ifdef CONFIG_VIDEO_ADV_DEBUG 288 /* 289 * Counters for how often these buffer-related ops are 290 * called. Used to check for unbalanced ops. 291 */ 292 u32 cnt_mem_alloc; 293 u32 cnt_mem_put; 294 u32 cnt_mem_get_dmabuf; 295 u32 cnt_mem_get_userptr; 296 u32 cnt_mem_put_userptr; 297 u32 cnt_mem_prepare; 298 u32 cnt_mem_finish; 299 u32 cnt_mem_attach_dmabuf; 300 u32 cnt_mem_detach_dmabuf; 301 u32 cnt_mem_map_dmabuf; 302 u32 cnt_mem_unmap_dmabuf; 303 u32 cnt_mem_vaddr; 304 u32 cnt_mem_cookie; 305 u32 cnt_mem_num_users; 306 u32 cnt_mem_mmap; 307 308 u32 cnt_buf_out_validate; 309 u32 cnt_buf_init; 310 u32 cnt_buf_prepare; 311 u32 cnt_buf_finish; 312 u32 cnt_buf_cleanup; 313 u32 cnt_buf_queue; 314 u32 cnt_buf_request_complete; 315 316 /* This counts the number of calls to vb2_buffer_done() */ 317 u32 cnt_buf_done; 318 #endif 319 }; 320 321 /** 322 * struct vb2_ops - driver-specific callbacks. 323 * 324 * These operations are not called from interrupt context except where 325 * mentioned specifically. 326 * 327 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS() 328 * handlers before memory allocation. It can be called 329 * twice: if the original number of requested buffers 330 * could not be allocated, then it will be called a 331 * second time with the actually allocated number of 332 * buffers to verify if that is OK. 333 * The driver should return the required number of buffers 334 * in \*num_buffers, the required number of planes per 335 * buffer in \*num_planes, the size of each plane should be 336 * set in the sizes\[\] array and optional per-plane 337 * allocator specific device in the alloc_devs\[\] array. 338 * When called from VIDIOC_REQBUFS(), \*num_planes == 0, 339 * the driver has to use the currently configured format to 340 * determine the plane sizes and \*num_buffers is the total 341 * number of buffers that are being allocated. When called 342 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it 343 * describes the requested number of planes and sizes\[\] 344 * contains the requested plane sizes. In this case 345 * \*num_buffers are being allocated additionally to 346 * q->num_buffers. If either \*num_planes or the requested 347 * sizes are invalid callback must return %-EINVAL. 348 * @wait_prepare: release any locks taken while calling vb2 functions; 349 * it is called before an ioctl needs to wait for a new 350 * buffer to arrive; required to avoid a deadlock in 351 * blocking access type. 352 * @wait_finish: reacquire all locks released in the previous callback; 353 * required to continue operation after sleeping while 354 * waiting for a new buffer to arrive. 355 * @buf_out_validate: called when the output buffer is prepared or queued 356 * to a request; drivers can use this to validate 357 * userspace-provided information; this is required only 358 * for OUTPUT queues. 359 * @buf_init: called once after allocating a buffer (in MMAP case) 360 * or after acquiring a new USERPTR buffer; drivers may 361 * perform additional buffer-related initialization; 362 * initialization failure (return != 0) will prevent 363 * queue setup from completing successfully; optional. 364 * @buf_prepare: called every time the buffer is queued from userspace 365 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may 366 * perform any initialization required before each 367 * hardware operation in this callback; drivers can 368 * access/modify the buffer here as it is still synced for 369 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must 370 * also validate the buffer size; if an error is returned, 371 * the buffer will not be queued in driver; optional. 372 * @buf_finish: called before every dequeue of the buffer back to 373 * userspace; the buffer is synced for the CPU, so drivers 374 * can access/modify the buffer contents; drivers may 375 * perform any operations required before userspace 376 * accesses the buffer; optional. The buffer state can be 377 * one of the following: %DONE and %ERROR occur while 378 * streaming is in progress, and the %PREPARED state occurs 379 * when the queue has been canceled and all pending 380 * buffers are being returned to their default %DEQUEUED 381 * state. Typically you only have to do something if the 382 * state is %VB2_BUF_STATE_DONE, since in all other cases 383 * the buffer contents will be ignored anyway. 384 * @buf_cleanup: called once before the buffer is freed; drivers may 385 * perform any additional cleanup; optional. 386 * @start_streaming: called once to enter 'streaming' state; the driver may 387 * receive buffers with @buf_queue callback 388 * before @start_streaming is called; the driver gets the 389 * number of already queued buffers in count parameter; 390 * driver can return an error if hardware fails, in that 391 * case all buffers that have been already given by 392 * the @buf_queue callback are to be returned by the driver 393 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED. 394 * If you need a minimum number of buffers before you can 395 * start streaming, then set 396 * &vb2_queue->min_buffers_needed. If that is non-zero 397 * then @start_streaming won't be called until at least 398 * that many buffers have been queued up by userspace. 399 * @stop_streaming: called when 'streaming' state must be disabled; driver 400 * should stop any DMA transactions or wait until they 401 * finish and give back all buffers it got from &buf_queue 402 * callback by calling vb2_buffer_done() with either 403 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use 404 * vb2_wait_for_all_buffers() function 405 * @buf_queue: passes buffer vb to the driver; driver may start 406 * hardware operation on this buffer; driver should give 407 * the buffer back by calling vb2_buffer_done() function; 408 * it is always called after calling VIDIOC_STREAMON() 409 * ioctl; might be called before @start_streaming callback 410 * if user pre-queued buffers before calling 411 * VIDIOC_STREAMON(). 412 * @buf_request_complete: a buffer that was never queued to the driver but is 413 * associated with a queued request was canceled. 414 * The driver will have to mark associated objects in the 415 * request as completed; required if requests are 416 * supported. 417 */ 418 struct vb2_ops { 419 int (*queue_setup)(struct vb2_queue *q, 420 unsigned int *num_buffers, unsigned int *num_planes, 421 unsigned int sizes[], struct device *alloc_devs[]); 422 423 void (*wait_prepare)(struct vb2_queue *q); 424 void (*wait_finish)(struct vb2_queue *q); 425 426 int (*buf_out_validate)(struct vb2_buffer *vb); 427 int (*buf_init)(struct vb2_buffer *vb); 428 int (*buf_prepare)(struct vb2_buffer *vb); 429 void (*buf_finish)(struct vb2_buffer *vb); 430 void (*buf_cleanup)(struct vb2_buffer *vb); 431 432 int (*start_streaming)(struct vb2_queue *q, unsigned int count); 433 void (*stop_streaming)(struct vb2_queue *q); 434 435 void (*buf_queue)(struct vb2_buffer *vb); 436 437 void (*buf_request_complete)(struct vb2_buffer *vb); 438 }; 439 440 /** 441 * struct vb2_buf_ops - driver-specific callbacks. 442 * 443 * @verify_planes_array: Verify that a given user space structure contains 444 * enough planes for the buffer. This is called 445 * for each dequeued buffer. 446 * @init_buffer: given a &vb2_buffer initialize the extra data after 447 * struct vb2_buffer. 448 * For V4L2 this is a &struct vb2_v4l2_buffer. 449 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure. 450 * For V4L2 this is a &struct v4l2_buffer. 451 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer. 452 * If the userspace structure is invalid, then this op 453 * will return an error. 454 * @copy_timestamp: copy the timestamp from a userspace structure to 455 * the &struct vb2_buffer. 456 */ 457 struct vb2_buf_ops { 458 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb); 459 void (*init_buffer)(struct vb2_buffer *vb); 460 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); 461 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes); 462 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); 463 }; 464 465 /** 466 * struct vb2_queue - a videobuf queue. 467 * 468 * @type: private buffer type whose content is defined by the vb2-core 469 * caller. For example, for V4L2, it should match 470 * the types defined on &enum v4l2_buf_type. 471 * @io_modes: supported io methods (see &enum vb2_io_modes). 472 * @alloc_devs: &struct device memory type/allocator-specific per-plane device 473 * @dev: device to use for the default allocation context if the driver 474 * doesn't fill in the @alloc_devs array. 475 * @dma_attrs: DMA attributes to use for the DMA. 476 * @bidirectional: when this flag is set the DMA direction for the buffers of 477 * this queue will be overridden with %DMA_BIDIRECTIONAL direction. 478 * This is useful in cases where the hardware (firmware) writes to 479 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from 480 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order 481 * to satisfy some internal hardware restrictions or adds a padding 482 * needed by the processing algorithm. In case the DMA mapping is 483 * not bidirectional but the hardware (firmware) trying to access 484 * the buffer (in the opposite direction) this could lead to an 485 * IOMMU protection faults. 486 * @fileio_read_once: report EOF after reading the first buffer 487 * @fileio_write_immediately: queue buffer after each write() call 488 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver 489 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF 490 * has not been called. This is a vb1 idiom that has been adopted 491 * also by vb2. 492 * @supports_requests: this queue supports the Request API. 493 * @requires_requests: this queue requires the Request API. If this is set to 1, 494 * then supports_requests must be set to 1 as well. 495 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first 496 * time this is called. Set to 0 when the queue is canceled. 497 * If this is 1, then you cannot queue buffers from a request. 498 * @uses_requests: requests are used for this queue. Set to 1 the first time 499 * a request is queued. Set to 0 when the queue is canceled. 500 * If this is 1, then you cannot queue buffers directly. 501 * @allow_cache_hints: when set user-space can pass cache management hints in 502 * order to skip cache flush/invalidation on ->prepare() or/and 503 * ->finish(). 504 * @lock: pointer to a mutex that protects the &struct vb2_queue. The 505 * driver can set this to a mutex to let the v4l2 core serialize 506 * the queuing ioctls. If the driver wants to handle locking 507 * itself, then this should be set to NULL. This lock is not used 508 * by the videobuf2 core API. 509 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle 510 * that called reqbufs, create_buffers or started fileio. 511 * This field is not used by the videobuf2 core API, but it allows 512 * drivers to easily associate an owner filehandle with the queue. 513 * @ops: driver-specific callbacks 514 * @mem_ops: memory allocator specific callbacks 515 * @buf_ops: callbacks to deliver buffer information. 516 * between user-space and kernel-space. 517 * @drv_priv: driver private data. 518 * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used 519 * by the vb2 core. 520 * @buf_struct_size: size of the driver-specific buffer structure; 521 * "0" indicates the driver doesn't want to use a custom buffer 522 * structure type. In that case a subsystem-specific struct 523 * will be used (in the case of V4L2 that is 524 * ``sizeof(struct vb2_v4l2_buffer)``). The first field of the 525 * driver-specific buffer structure must be the subsystem-specific 526 * struct (vb2_v4l2_buffer in the case of V4L2). 527 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and 528 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*`` 529 * @gfp_flags: additional gfp flags used when allocating the buffers. 530 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32 531 * to force the buffer allocation to a specific memory zone. 532 * @min_buffers_needed: the minimum number of buffers needed before 533 * @start_streaming can be called. Used when a DMA engine 534 * cannot be started unless at least this number of buffers 535 * have been queued into the driver. 536 */ 537 /* 538 * Private elements (won't appear at the uAPI book): 539 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped 540 * @memory: current memory type used 541 * @dma_dir: DMA mapping direction. 542 * @bufs: videobuf buffer structures 543 * @num_buffers: number of allocated/used buffers 544 * @queued_list: list of buffers currently queued from userspace 545 * @queued_count: number of buffers queued and ready for streaming. 546 * @owned_by_drv_count: number of buffers owned by the driver 547 * @done_list: list of buffers ready to be dequeued to userspace 548 * @done_lock: lock to protect done_list list 549 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued 550 * @streaming: current streaming state 551 * @start_streaming_called: @start_streaming was called successfully and we 552 * started streaming. 553 * @error: a fatal error occurred on the queue 554 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for 555 * buffers. Only set for capture queues if qbuf has not yet been 556 * called since poll() needs to return %EPOLLERR in that situation. 557 * @is_multiplanar: set if buffer type is multiplanar 558 * @is_output: set if buffer type is output 559 * @copy_timestamp: set if vb2-core should set timestamps 560 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the 561 * last decoded buffer was already dequeued. Set for capture queues 562 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued. 563 * @fileio: file io emulator internal data, used only if emulator is active 564 * @threadio: thread io internal data, used only if thread is active 565 * @name: queue name, used for logging purpose. Initialized automatically 566 * if left empty by drivers. 567 */ 568 struct vb2_queue { 569 unsigned int type; 570 unsigned int io_modes; 571 struct device *dev; 572 unsigned long dma_attrs; 573 unsigned int bidirectional:1; 574 unsigned int fileio_read_once:1; 575 unsigned int fileio_write_immediately:1; 576 unsigned int allow_zero_bytesused:1; 577 unsigned int quirk_poll_must_check_waiting_for_buffers:1; 578 unsigned int supports_requests:1; 579 unsigned int requires_requests:1; 580 unsigned int uses_qbuf:1; 581 unsigned int uses_requests:1; 582 unsigned int allow_cache_hints:1; 583 584 struct mutex *lock; 585 void *owner; 586 587 const struct vb2_ops *ops; 588 const struct vb2_mem_ops *mem_ops; 589 const struct vb2_buf_ops *buf_ops; 590 591 void *drv_priv; 592 u32 subsystem_flags; 593 unsigned int buf_struct_size; 594 u32 timestamp_flags; 595 gfp_t gfp_flags; 596 u32 min_buffers_needed; 597 598 struct device *alloc_devs[VB2_MAX_PLANES]; 599 600 /* private: internal use only */ 601 struct mutex mmap_lock; 602 unsigned int memory; 603 enum dma_data_direction dma_dir; 604 struct vb2_buffer *bufs[VB2_MAX_FRAME]; 605 unsigned int num_buffers; 606 607 struct list_head queued_list; 608 unsigned int queued_count; 609 610 atomic_t owned_by_drv_count; 611 struct list_head done_list; 612 spinlock_t done_lock; 613 wait_queue_head_t done_wq; 614 615 unsigned int streaming:1; 616 unsigned int start_streaming_called:1; 617 unsigned int error:1; 618 unsigned int waiting_for_buffers:1; 619 unsigned int waiting_in_dqbuf:1; 620 unsigned int is_multiplanar:1; 621 unsigned int is_output:1; 622 unsigned int copy_timestamp:1; 623 unsigned int last_buffer_dequeued:1; 624 625 struct vb2_fileio_data *fileio; 626 struct vb2_threadio_data *threadio; 627 628 char name[32]; 629 630 #ifdef CONFIG_VIDEO_ADV_DEBUG 631 /* 632 * Counters for how often these queue-related ops are 633 * called. Used to check for unbalanced ops. 634 */ 635 u32 cnt_queue_setup; 636 u32 cnt_wait_prepare; 637 u32 cnt_wait_finish; 638 u32 cnt_start_streaming; 639 u32 cnt_stop_streaming; 640 #endif 641 }; 642 643 /** 644 * vb2_queue_allows_cache_hints() - Return true if the queue allows cache 645 * and memory consistency hints. 646 * 647 * @q: pointer to &struct vb2_queue with videobuf2 queue 648 */ 649 static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q) 650 { 651 return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP; 652 } 653 654 /** 655 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane. 656 * @vb: pointer to &struct vb2_buffer to which the plane in 657 * question belongs to. 658 * @plane_no: plane number for which the address is to be returned. 659 * 660 * This function returns a kernel virtual address of a given plane if 661 * such a mapping exist, NULL otherwise. 662 */ 663 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); 664 665 /** 666 * vb2_plane_cookie() - Return allocator specific cookie for the given plane. 667 * @vb: pointer to &struct vb2_buffer to which the plane in 668 * question belongs to. 669 * @plane_no: plane number for which the cookie is to be returned. 670 * 671 * This function returns an allocator specific cookie for a given plane if 672 * available, NULL otherwise. The allocator should provide some simple static 673 * inline function, which would convert this cookie to the allocator specific 674 * type that can be used directly by the driver to access the buffer. This can 675 * be for example physical address, pointer to scatter list or IOMMU mapping. 676 */ 677 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); 678 679 /** 680 * vb2_buffer_done() - inform videobuf that an operation on a buffer 681 * is finished. 682 * @vb: pointer to &struct vb2_buffer to be used. 683 * @state: state of the buffer, as defined by &enum vb2_buffer_state. 684 * Either %VB2_BUF_STATE_DONE if the operation finished 685 * successfully, %VB2_BUF_STATE_ERROR if the operation finished 686 * with an error or %VB2_BUF_STATE_QUEUED. 687 * 688 * This function should be called by the driver after a hardware operation on 689 * a buffer is finished and the buffer may be returned to userspace. The driver 690 * cannot use this buffer anymore until it is queued back to it by videobuf 691 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued 692 * to the driver by &vb2_ops->buf_queue can be passed to this function. 693 * 694 * While streaming a buffer can only be returned in state DONE or ERROR. 695 * The &vb2_ops->start_streaming op can also return them in case the DMA engine 696 * cannot be started for some reason. In that case the buffers should be 697 * returned with state QUEUED to put them back into the queue. 698 */ 699 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); 700 701 /** 702 * vb2_discard_done() - discard all buffers marked as DONE. 703 * @q: pointer to &struct vb2_queue with videobuf2 queue. 704 * 705 * This function is intended to be used with suspend/resume operations. It 706 * discards all 'done' buffers as they would be too old to be requested after 707 * resume. 708 * 709 * Drivers must stop the hardware and synchronize with interrupt handlers and/or 710 * delayed works before calling this function to make sure no buffer will be 711 * touched by the driver and/or hardware. 712 */ 713 void vb2_discard_done(struct vb2_queue *q); 714 715 /** 716 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2. 717 * @q: pointer to &struct vb2_queue with videobuf2 queue. 718 * 719 * This function will wait until all buffers that have been given to the driver 720 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It 721 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair. 722 * It is intended to be called with all locks taken, for example from 723 * &vb2_ops->stop_streaming callback. 724 */ 725 int vb2_wait_for_all_buffers(struct vb2_queue *q); 726 727 /** 728 * vb2_core_querybuf() - query video buffer information. 729 * @q: pointer to &struct vb2_queue with videobuf2 queue. 730 * @index: id number of the buffer. 731 * @pb: buffer struct passed from userspace. 732 * 733 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called 734 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 735 * 736 * The passed buffer should have been verified. 737 * 738 * This function fills the relevant information for the userspace. 739 * 740 * Return: returns zero on success; an error code otherwise. 741 */ 742 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); 743 744 /** 745 * vb2_core_reqbufs() - Initiate streaming. 746 * @q: pointer to &struct vb2_queue with videobuf2 queue. 747 * @memory: memory type, as defined by &enum vb2_memory. 748 * @count: requested buffer count. 749 * 750 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called 751 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 752 * 753 * This function: 754 * 755 * #) verifies streaming parameters passed from the userspace; 756 * #) sets up the queue; 757 * #) negotiates number of buffers and planes per buffer with the driver 758 * to be used during streaming; 759 * #) allocates internal buffer structures (&struct vb2_buffer), according to 760 * the agreed parameters; 761 * #) for MMAP memory type, allocates actual video memory, using the 762 * memory handling/allocation routines provided during queue initialization. 763 * 764 * If req->count is 0, all the memory will be freed instead. 765 * 766 * If the queue has been allocated previously by a previous vb2_core_reqbufs() 767 * call and the queue is not busy, memory will be reallocated. 768 * 769 * Return: returns zero on success; an error code otherwise. 770 */ 771 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 772 unsigned int *count); 773 774 /** 775 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs 776 * @q: pointer to &struct vb2_queue with videobuf2 queue. 777 * @memory: memory type, as defined by &enum vb2_memory. 778 * @count: requested buffer count. 779 * @requested_planes: number of planes requested. 780 * @requested_sizes: array with the size of the planes. 781 * 782 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is 783 * called internally by VB2 by an API-specific handler, like 784 * ``videobuf2-v4l2.h``. 785 * 786 * This function: 787 * 788 * #) verifies parameter sanity; 789 * #) calls the &vb2_ops->queue_setup queue operation; 790 * #) performs any necessary memory allocations. 791 * 792 * Return: returns zero on success; an error code otherwise. 793 */ 794 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 795 unsigned int *count, 796 unsigned int requested_planes, 797 const unsigned int requested_sizes[]); 798 799 /** 800 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace 801 * to the kernel. 802 * @q: pointer to &struct vb2_queue with videobuf2 queue. 803 * @index: id number of the buffer. 804 * @pb: buffer structure passed from userspace to 805 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver. 806 * 807 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is 808 * called internally by VB2 by an API-specific handler, like 809 * ``videobuf2-v4l2.h``. 810 * 811 * The passed buffer should have been verified. 812 * 813 * This function calls vb2_ops->buf_prepare callback in the driver 814 * (if provided), in which driver-specific buffer initialization can 815 * be performed. 816 * 817 * Return: returns zero on success; an error code otherwise. 818 */ 819 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); 820 821 /** 822 * vb2_core_qbuf() - Queue a buffer from userspace 823 * 824 * @q: pointer to &struct vb2_queue with videobuf2 queue. 825 * @index: id number of the buffer 826 * @pb: buffer structure passed from userspace to 827 * v4l2_ioctl_ops->vidioc_qbuf handler in driver 828 * @req: pointer to &struct media_request, may be NULL. 829 * 830 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called 831 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 832 * 833 * This function: 834 * 835 * #) If @req is non-NULL, then the buffer will be bound to this 836 * media request and it returns. The buffer will be prepared and 837 * queued to the driver (i.e. the next two steps) when the request 838 * itself is queued. 839 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver 840 * (if provided), in which driver-specific buffer initialization can 841 * be performed; 842 * #) if streaming is on, queues the buffer in driver by the means of 843 * &vb2_ops->buf_queue callback for processing. 844 * 845 * Return: returns zero on success; an error code otherwise. 846 */ 847 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, 848 struct media_request *req); 849 850 /** 851 * vb2_core_dqbuf() - Dequeue a buffer to the userspace 852 * @q: pointer to &struct vb2_queue with videobuf2 queue 853 * @pindex: pointer to the buffer index. May be NULL 854 * @pb: buffer structure passed from userspace to 855 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver. 856 * @nonblocking: if true, this call will not sleep waiting for a buffer if no 857 * buffers ready for dequeuing are present. Normally the driver 858 * would be passing (file->f_flags & O_NONBLOCK) here. 859 * 860 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called 861 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 862 * 863 * This function: 864 * 865 * #) calls buf_finish callback in the driver (if provided), in which 866 * driver can perform any additional operations that may be required before 867 * returning the buffer to userspace, such as cache sync, 868 * #) the buffer struct members are filled with relevant information for 869 * the userspace. 870 * 871 * Return: returns zero on success; an error code otherwise. 872 */ 873 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, 874 bool nonblocking); 875 876 /** 877 * vb2_core_streamon() - Implements VB2 stream ON logic 878 * 879 * @q: pointer to &struct vb2_queue with videobuf2 queue 880 * @type: type of the queue to be started. 881 * For V4L2, this is defined by &enum v4l2_buf_type type. 882 * 883 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called 884 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 885 * 886 * Return: returns zero on success; an error code otherwise. 887 */ 888 int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 889 890 /** 891 * vb2_core_streamoff() - Implements VB2 stream OFF logic 892 * 893 * @q: pointer to &struct vb2_queue with videobuf2 queue 894 * @type: type of the queue to be started. 895 * For V4L2, this is defined by &enum v4l2_buf_type type. 896 * 897 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is 898 * called internally by VB2 by an API-specific handler, like 899 * ``videobuf2-v4l2.h``. 900 * 901 * Return: returns zero on success; an error code otherwise. 902 */ 903 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); 904 905 /** 906 * vb2_core_expbuf() - Export a buffer as a file descriptor. 907 * @q: pointer to &struct vb2_queue with videobuf2 queue. 908 * @fd: pointer to the file descriptor associated with DMABUF 909 * (set by driver). 910 * @type: buffer type. 911 * @index: id number of the buffer. 912 * @plane: index of the plane to be exported, 0 for single plane queues 913 * @flags: file flags for newly created file, as defined at 914 * include/uapi/asm-generic/fcntl.h. 915 * Currently, the only used flag is %O_CLOEXEC. 916 * is supported, refer to manual of open syscall for more details. 917 * 918 * 919 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called 920 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 921 * 922 * Return: returns zero on success; an error code otherwise. 923 */ 924 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 925 unsigned int index, unsigned int plane, unsigned int flags); 926 927 /** 928 * vb2_core_queue_init() - initialize a videobuf2 queue 929 * @q: pointer to &struct vb2_queue with videobuf2 queue. 930 * This structure should be allocated in driver 931 * 932 * The &vb2_queue structure should be allocated by the driver. The driver is 933 * responsible of clearing it's content and setting initial values for some 934 * required entries before calling this function. 935 * 936 * .. note:: 937 * 938 * The following fields at @q should be set before calling this function: 939 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type. 940 */ 941 int vb2_core_queue_init(struct vb2_queue *q); 942 943 /** 944 * vb2_core_queue_release() - stop streaming, release the queue and free memory 945 * @q: pointer to &struct vb2_queue with videobuf2 queue. 946 * 947 * This function stops streaming and performs necessary clean ups, including 948 * freeing video buffer memory. The driver is responsible for freeing 949 * the &struct vb2_queue itself. 950 */ 951 void vb2_core_queue_release(struct vb2_queue *q); 952 953 /** 954 * vb2_queue_error() - signal a fatal error on the queue 955 * @q: pointer to &struct vb2_queue with videobuf2 queue. 956 * 957 * Flag that a fatal unrecoverable error has occurred and wake up all processes 958 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing 959 * buffers will return %-EIO. 960 * 961 * The error flag will be cleared when canceling the queue, either from 962 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this 963 * function before starting the stream, otherwise the error flag will remain set 964 * until the queue is released when closing the device node. 965 */ 966 void vb2_queue_error(struct vb2_queue *q); 967 968 /** 969 * vb2_mmap() - map video buffers into application address space. 970 * @q: pointer to &struct vb2_queue with videobuf2 queue. 971 * @vma: pointer to &struct vm_area_struct with the vma passed 972 * to the mmap file operation handler in the driver. 973 * 974 * Should be called from mmap file operation handler of a driver. 975 * This function maps one plane of one of the available video buffers to 976 * userspace. To map whole video memory allocated on reqbufs, this function 977 * has to be called once per each plane per each buffer previously allocated. 978 * 979 * When the userspace application calls mmap, it passes to it an offset returned 980 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler. 981 * That offset acts as a "cookie", which is then used to identify the plane 982 * to be mapped. 983 * 984 * This function finds a plane with a matching offset and a mapping is performed 985 * by the means of a provided memory operation. 986 * 987 * The return values from this function are intended to be directly returned 988 * from the mmap handler in driver. 989 */ 990 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); 991 992 #ifndef CONFIG_MMU 993 /** 994 * vb2_get_unmapped_area - map video buffers into application address space. 995 * @q: pointer to &struct vb2_queue with videobuf2 queue. 996 * @addr: memory address. 997 * @len: buffer size. 998 * @pgoff: page offset. 999 * @flags: memory flags. 1000 * 1001 * This function is used in noMMU platforms to propose address mapping 1002 * for a given buffer. It's intended to be used as a handler for the 1003 * &file_operations->get_unmapped_area operation. 1004 * 1005 * This is called by the mmap() syscall routines will call this 1006 * to get a proposed address for the mapping, when ``!CONFIG_MMU``. 1007 */ 1008 unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 1009 unsigned long addr, 1010 unsigned long len, 1011 unsigned long pgoff, 1012 unsigned long flags); 1013 #endif 1014 1015 /** 1016 * vb2_core_poll() - implements poll syscall() logic. 1017 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1018 * @file: &struct file argument passed to the poll 1019 * file operation handler. 1020 * @wait: &poll_table wait argument passed to the poll 1021 * file operation handler. 1022 * 1023 * This function implements poll file operation handler for a driver. 1024 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will 1025 * be informed that the file descriptor of a video device is available for 1026 * reading. 1027 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor 1028 * will be reported as available for writing. 1029 * 1030 * The return values from this function are intended to be directly returned 1031 * from poll handler in driver. 1032 */ 1033 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file, 1034 poll_table *wait); 1035 1036 /** 1037 * vb2_read() - implements read() syscall logic. 1038 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1039 * @data: pointed to target userspace buffer 1040 * @count: number of bytes to read 1041 * @ppos: file handle position tracking pointer 1042 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) 1043 */ 1044 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, 1045 loff_t *ppos, int nonblock); 1046 /** 1047 * vb2_write() - implements write() syscall logic. 1048 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1049 * @data: pointed to target userspace buffer 1050 * @count: number of bytes to write 1051 * @ppos: file handle position tracking pointer 1052 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) 1053 */ 1054 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, 1055 loff_t *ppos, int nonblock); 1056 1057 /** 1058 * typedef vb2_thread_fnc - callback function for use with vb2_thread. 1059 * 1060 * @vb: pointer to struct &vb2_buffer. 1061 * @priv: pointer to a private data. 1062 * 1063 * This is called whenever a buffer is dequeued in the thread. 1064 */ 1065 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); 1066 1067 /** 1068 * vb2_thread_start() - start a thread for the given queue. 1069 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1070 * @fnc: &vb2_thread_fnc callback function. 1071 * @priv: priv pointer passed to the callback function. 1072 * @thread_name:the name of the thread. This will be prefixed with "vb2-". 1073 * 1074 * This starts a thread that will queue and dequeue until an error occurs 1075 * or vb2_thread_stop() is called. 1076 * 1077 * .. attention:: 1078 * 1079 * This function should not be used for anything else but the videobuf2-dvb 1080 * support. If you think you have another good use-case for this, then please 1081 * contact the linux-media mailing list first. 1082 */ 1083 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, 1084 const char *thread_name); 1085 1086 /** 1087 * vb2_thread_stop() - stop the thread for the given queue. 1088 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1089 */ 1090 int vb2_thread_stop(struct vb2_queue *q); 1091 1092 /** 1093 * vb2_is_streaming() - return streaming status of the queue. 1094 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1095 */ 1096 static inline bool vb2_is_streaming(struct vb2_queue *q) 1097 { 1098 return q->streaming; 1099 } 1100 1101 /** 1102 * vb2_fileio_is_active() - return true if fileio is active. 1103 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1104 * 1105 * This returns true if read() or write() is used to stream the data 1106 * as opposed to stream I/O. This is almost never an important distinction, 1107 * except in rare cases. One such case is that using read() or write() to 1108 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there 1109 * is no way you can pass the field information of each buffer to/from 1110 * userspace. A driver that supports this field format should check for 1111 * this in the &vb2_ops->queue_setup op and reject it if this function returns 1112 * true. 1113 */ 1114 static inline bool vb2_fileio_is_active(struct vb2_queue *q) 1115 { 1116 return q->fileio; 1117 } 1118 1119 /** 1120 * vb2_is_busy() - return busy status of the queue. 1121 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1122 * 1123 * This function checks if queue has any buffers allocated. 1124 */ 1125 static inline bool vb2_is_busy(struct vb2_queue *q) 1126 { 1127 return (q->num_buffers > 0); 1128 } 1129 1130 /** 1131 * vb2_get_drv_priv() - return driver private data associated with the queue. 1132 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1133 */ 1134 static inline void *vb2_get_drv_priv(struct vb2_queue *q) 1135 { 1136 return q->drv_priv; 1137 } 1138 1139 /** 1140 * vb2_set_plane_payload() - set bytesused for the plane @plane_no. 1141 * @vb: pointer to &struct vb2_buffer to which the plane in 1142 * question belongs to. 1143 * @plane_no: plane number for which payload should be set. 1144 * @size: payload in bytes. 1145 */ 1146 static inline void vb2_set_plane_payload(struct vb2_buffer *vb, 1147 unsigned int plane_no, unsigned long size) 1148 { 1149 if (plane_no < vb->num_planes) 1150 vb->planes[plane_no].bytesused = size; 1151 } 1152 1153 /** 1154 * vb2_get_plane_payload() - get bytesused for the plane plane_no 1155 * @vb: pointer to &struct vb2_buffer to which the plane in 1156 * question belongs to. 1157 * @plane_no: plane number for which payload should be set. 1158 */ 1159 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, 1160 unsigned int plane_no) 1161 { 1162 if (plane_no < vb->num_planes) 1163 return vb->planes[plane_no].bytesused; 1164 return 0; 1165 } 1166 1167 /** 1168 * vb2_plane_size() - return plane size in bytes. 1169 * @vb: pointer to &struct vb2_buffer to which the plane in 1170 * question belongs to. 1171 * @plane_no: plane number for which size should be returned. 1172 */ 1173 static inline unsigned long 1174 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) 1175 { 1176 if (plane_no < vb->num_planes) 1177 return vb->planes[plane_no].length; 1178 return 0; 1179 } 1180 1181 /** 1182 * vb2_start_streaming_called() - return streaming status of driver. 1183 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1184 */ 1185 static inline bool vb2_start_streaming_called(struct vb2_queue *q) 1186 { 1187 return q->start_streaming_called; 1188 } 1189 1190 /** 1191 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue. 1192 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1193 */ 1194 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) 1195 { 1196 q->last_buffer_dequeued = false; 1197 } 1198 1199 /** 1200 * vb2_get_buffer() - get a buffer from a queue 1201 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1202 * @index: buffer index 1203 * 1204 * This function obtains a buffer from a queue, by its index. 1205 * Keep in mind that there is no refcounting involved in this 1206 * operation, so the buffer lifetime should be taken into 1207 * consideration. 1208 */ 1209 static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q, 1210 unsigned int index) 1211 { 1212 if (index < q->num_buffers) 1213 return q->bufs[index]; 1214 return NULL; 1215 } 1216 1217 /* 1218 * The following functions are not part of the vb2 core API, but are useful 1219 * functions for videobuf2-*. 1220 */ 1221 1222 /** 1223 * vb2_buffer_in_use() - return true if the buffer is in use and 1224 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call. 1225 * 1226 * @vb: buffer for which plane size should be returned. 1227 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1228 */ 1229 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); 1230 1231 /** 1232 * vb2_verify_memory_type() - Check whether the memory type and buffer type 1233 * passed to a buffer operation are compatible with the queue. 1234 * 1235 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1236 * @memory: memory model, as defined by enum &vb2_memory. 1237 * @type: private buffer type whose content is defined by the vb2-core 1238 * caller. For example, for V4L2, it should match 1239 * the types defined on enum &v4l2_buf_type. 1240 */ 1241 int vb2_verify_memory_type(struct vb2_queue *q, 1242 enum vb2_memory memory, unsigned int type); 1243 1244 /** 1245 * vb2_request_object_is_buffer() - return true if the object is a buffer 1246 * 1247 * @obj: the request object. 1248 */ 1249 bool vb2_request_object_is_buffer(struct media_request_object *obj); 1250 1251 /** 1252 * vb2_request_buffer_cnt() - return the number of buffers in the request 1253 * 1254 * @req: the request. 1255 */ 1256 unsigned int vb2_request_buffer_cnt(struct media_request *req); 1257 1258 #endif /* _MEDIA_VIDEOBUF2_CORE_H */ 1259