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 struct vb2_buffer; 50 51 /** 52 * struct vb2_mem_ops - memory handling/memory allocator operations. 53 * @alloc: allocate video memory and, optionally, allocator private data, 54 * return ERR_PTR() on failure or a pointer to allocator private, 55 * per-buffer data on success; the returned private structure 56 * will then be passed as @buf_priv argument to other ops in this 57 * structure. The size argument to this function shall be 58 * *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 */ 118 struct vb2_mem_ops { 119 void *(*alloc)(struct vb2_buffer *vb, 120 struct device *dev, 121 unsigned long size); 122 void (*put)(void *buf_priv); 123 struct dma_buf *(*get_dmabuf)(struct vb2_buffer *vb, 124 void *buf_priv, 125 unsigned long flags); 126 127 void *(*get_userptr)(struct vb2_buffer *vb, 128 struct device *dev, 129 unsigned long vaddr, 130 unsigned long size); 131 void (*put_userptr)(void *buf_priv); 132 133 void (*prepare)(void *buf_priv); 134 void (*finish)(void *buf_priv); 135 136 void *(*attach_dmabuf)(struct vb2_buffer *vb, 137 struct device *dev, 138 struct dma_buf *dbuf, 139 unsigned long size); 140 void (*detach_dmabuf)(void *buf_priv); 141 int (*map_dmabuf)(void *buf_priv); 142 void (*unmap_dmabuf)(void *buf_priv); 143 144 void *(*vaddr)(struct vb2_buffer *vb, void *buf_priv); 145 void *(*cookie)(struct vb2_buffer *vb, void *buf_priv); 146 147 unsigned int (*num_users)(void *buf_priv); 148 149 int (*mmap)(void *buf_priv, struct vm_area_struct *vma); 150 }; 151 152 /** 153 * struct vb2_plane - plane information. 154 * @mem_priv: private data with this plane. 155 * @dbuf: dma_buf - shared buffer object. 156 * @dbuf_mapped: flag to show whether dbuf is mapped or not 157 * @bytesused: number of bytes occupied by data in the plane (payload). 158 * @length: size of this plane (NOT the payload) in bytes. The maximum 159 * valid size is MAX_UINT - PAGE_SIZE. 160 * @min_length: minimum required size of this plane (NOT the payload) in bytes. 161 * @length is always greater or equal to @min_length, and like 162 * @length, it is limited to MAX_UINT - PAGE_SIZE. 163 * @m: Union with memtype-specific data. 164 * @m.offset: when memory in the associated struct vb2_buffer is 165 * %VB2_MEMORY_MMAP, equals the offset from the start of 166 * the device memory for this plane (or is a "cookie" that 167 * should be passed to mmap() called on the video node). 168 * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer 169 * pointing to this plane. 170 * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file 171 * descriptor associated with this plane. 172 * @data_offset: offset in the plane to the start of data; usually 0, 173 * unless there is a header in front of the data. 174 * 175 * Should contain enough information to be able to cover all the fields 176 * of &struct v4l2_plane at videodev2.h. 177 */ 178 struct vb2_plane { 179 void *mem_priv; 180 struct dma_buf *dbuf; 181 unsigned int dbuf_mapped; 182 unsigned int bytesused; 183 unsigned int length; 184 unsigned int min_length; 185 union { 186 unsigned int offset; 187 unsigned long userptr; 188 int fd; 189 } m; 190 unsigned int data_offset; 191 }; 192 193 /** 194 * enum vb2_io_modes - queue access methods. 195 * @VB2_MMAP: driver supports MMAP with streaming API. 196 * @VB2_USERPTR: driver supports USERPTR with streaming API. 197 * @VB2_READ: driver supports read() style access. 198 * @VB2_WRITE: driver supports write() style access. 199 * @VB2_DMABUF: driver supports DMABUF with streaming API. 200 */ 201 enum vb2_io_modes { 202 VB2_MMAP = BIT(0), 203 VB2_USERPTR = BIT(1), 204 VB2_READ = BIT(2), 205 VB2_WRITE = BIT(3), 206 VB2_DMABUF = BIT(4), 207 }; 208 209 /** 210 * enum vb2_buffer_state - current video buffer state. 211 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control. 212 * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request. 213 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf. 214 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver. 215 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used 216 * in a hardware operation. 217 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but 218 * not yet dequeued to userspace. 219 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer 220 * has ended with an error, which will be reported 221 * to the userspace when it is dequeued. 222 */ 223 enum vb2_buffer_state { 224 VB2_BUF_STATE_DEQUEUED, 225 VB2_BUF_STATE_IN_REQUEST, 226 VB2_BUF_STATE_PREPARING, 227 VB2_BUF_STATE_QUEUED, 228 VB2_BUF_STATE_ACTIVE, 229 VB2_BUF_STATE_DONE, 230 VB2_BUF_STATE_ERROR, 231 }; 232 233 struct vb2_queue; 234 235 /** 236 * struct vb2_buffer - represents a video buffer. 237 * @vb2_queue: pointer to &struct vb2_queue with the queue to 238 * which this driver belongs. 239 * @index: id number of the buffer. 240 * @type: buffer type. 241 * @memory: the method, in which the actual data is passed. 242 * @num_planes: number of planes in the buffer 243 * on an internal driver queue. 244 * @timestamp: frame timestamp in ns. 245 * @request: the request this buffer is associated with. 246 * @req_obj: used to bind this buffer to a request. This 247 * request object has a refcount. 248 */ 249 struct vb2_buffer { 250 struct vb2_queue *vb2_queue; 251 unsigned int index; 252 unsigned int type; 253 unsigned int memory; 254 unsigned int num_planes; 255 u64 timestamp; 256 struct media_request *request; 257 struct media_request_object req_obj; 258 259 /* private: internal use only 260 * 261 * state: current buffer state; do not change 262 * synced: this buffer has been synced for DMA, i.e. the 263 * 'prepare' memop was called. It is cleared again 264 * after the 'finish' memop is called. 265 * prepared: this buffer has been prepared, i.e. the 266 * buf_prepare op was called. It is cleared again 267 * after the 'buf_finish' op is called. 268 * copied_timestamp: the timestamp of this capture buffer was copied 269 * from an output buffer. 270 * skip_cache_sync_on_prepare: when set buffer's ->prepare() function 271 * skips cache sync/invalidation. 272 * skip_cache_sync_on_finish: when set buffer's ->finish() function 273 * skips cache sync/invalidation. 274 * queued_entry: entry on the queued buffers list, which holds 275 * all buffers queued from userspace 276 * done_entry: entry on the list that stores all buffers ready 277 * to be dequeued to userspace 278 * vb2_plane: per-plane information; do not change 279 */ 280 enum vb2_buffer_state state; 281 unsigned int synced:1; 282 unsigned int prepared:1; 283 unsigned int copied_timestamp:1; 284 unsigned int skip_cache_sync_on_prepare:1; 285 unsigned int skip_cache_sync_on_finish:1; 286 287 struct vb2_plane planes[VB2_MAX_PLANES]; 288 struct list_head queued_entry; 289 struct list_head done_entry; 290 #ifdef CONFIG_VIDEO_ADV_DEBUG 291 /* 292 * Counters for how often these buffer-related ops are 293 * called. Used to check for unbalanced ops. 294 */ 295 u32 cnt_mem_alloc; 296 u32 cnt_mem_put; 297 u32 cnt_mem_get_dmabuf; 298 u32 cnt_mem_get_userptr; 299 u32 cnt_mem_put_userptr; 300 u32 cnt_mem_prepare; 301 u32 cnt_mem_finish; 302 u32 cnt_mem_attach_dmabuf; 303 u32 cnt_mem_detach_dmabuf; 304 u32 cnt_mem_map_dmabuf; 305 u32 cnt_mem_unmap_dmabuf; 306 u32 cnt_mem_vaddr; 307 u32 cnt_mem_cookie; 308 u32 cnt_mem_num_users; 309 u32 cnt_mem_mmap; 310 311 u32 cnt_buf_out_validate; 312 u32 cnt_buf_init; 313 u32 cnt_buf_prepare; 314 u32 cnt_buf_finish; 315 u32 cnt_buf_cleanup; 316 u32 cnt_buf_queue; 317 u32 cnt_buf_request_complete; 318 319 /* This counts the number of calls to vb2_buffer_done() */ 320 u32 cnt_buf_done; 321 #endif 322 }; 323 324 /** 325 * struct vb2_ops - driver-specific callbacks. 326 * 327 * These operations are not called from interrupt context except where 328 * mentioned specifically. 329 * 330 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS() 331 * handlers before memory allocation. It can be called 332 * twice: if the original number of requested buffers 333 * could not be allocated, then it will be called a 334 * second time with the actually allocated number of 335 * buffers to verify if that is OK. 336 * The driver should return the required number of buffers 337 * in \*num_buffers, the required number of planes per 338 * buffer in \*num_planes, the size of each plane should be 339 * set in the sizes\[\] array and optional per-plane 340 * allocator specific device in the alloc_devs\[\] array. 341 * When called from VIDIOC_REQBUFS(), \*num_planes == 0, 342 * the driver has to use the currently configured format to 343 * determine the plane sizes and \*num_buffers is the total 344 * number of buffers that are being allocated. When called 345 * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it 346 * describes the requested number of planes and sizes\[\] 347 * contains the requested plane sizes. In this case 348 * \*num_buffers are being allocated additionally to 349 * q->num_buffers. If either \*num_planes or the requested 350 * sizes are invalid callback must return %-EINVAL. 351 * @wait_prepare: release any locks taken while calling vb2 functions; 352 * it is called before an ioctl needs to wait for a new 353 * buffer to arrive; required to avoid a deadlock in 354 * blocking access type. 355 * @wait_finish: reacquire all locks released in the previous callback; 356 * required to continue operation after sleeping while 357 * waiting for a new buffer to arrive. 358 * @buf_out_validate: called when the output buffer is prepared or queued 359 * to a request; drivers can use this to validate 360 * userspace-provided information; this is required only 361 * for OUTPUT queues. 362 * @buf_init: called once after allocating a buffer (in MMAP case) 363 * or after acquiring a new USERPTR buffer; drivers may 364 * perform additional buffer-related initialization; 365 * initialization failure (return != 0) will prevent 366 * queue setup from completing successfully; optional. 367 * @buf_prepare: called every time the buffer is queued from userspace 368 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may 369 * perform any initialization required before each 370 * hardware operation in this callback; drivers can 371 * access/modify the buffer here as it is still synced for 372 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must 373 * also validate the buffer size; if an error is returned, 374 * the buffer will not be queued in driver; optional. 375 * @buf_finish: called before every dequeue of the buffer back to 376 * userspace; the buffer is synced for the CPU, so drivers 377 * can access/modify the buffer contents; drivers may 378 * perform any operations required before userspace 379 * accesses the buffer; optional. The buffer state can be 380 * one of the following: %DONE and %ERROR occur while 381 * streaming is in progress, and the %PREPARED state occurs 382 * when the queue has been canceled and all pending 383 * buffers are being returned to their default %DEQUEUED 384 * state. Typically you only have to do something if the 385 * state is %VB2_BUF_STATE_DONE, since in all other cases 386 * the buffer contents will be ignored anyway. 387 * @buf_cleanup: called once before the buffer is freed; drivers may 388 * perform any additional cleanup; optional. 389 * @start_streaming: called once to enter 'streaming' state; the driver may 390 * receive buffers with @buf_queue callback 391 * before @start_streaming is called; the driver gets the 392 * number of already queued buffers in count parameter; 393 * driver can return an error if hardware fails, in that 394 * case all buffers that have been already given by 395 * the @buf_queue callback are to be returned by the driver 396 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED. 397 * If you need a minimum number of buffers before you can 398 * start streaming, then set 399 * &vb2_queue->min_buffers_needed. If that is non-zero 400 * then @start_streaming won't be called until at least 401 * that many buffers have been queued up by userspace. 402 * @stop_streaming: called when 'streaming' state must be disabled; driver 403 * should stop any DMA transactions or wait until they 404 * finish and give back all buffers it got from &buf_queue 405 * callback by calling vb2_buffer_done() with either 406 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use 407 * vb2_wait_for_all_buffers() function 408 * @buf_queue: passes buffer vb to the driver; driver may start 409 * hardware operation on this buffer; driver should give 410 * the buffer back by calling vb2_buffer_done() function; 411 * it is always called after calling VIDIOC_STREAMON() 412 * ioctl; might be called before @start_streaming callback 413 * if user pre-queued buffers before calling 414 * VIDIOC_STREAMON(). 415 * @buf_request_complete: a buffer that was never queued to the driver but is 416 * associated with a queued request was canceled. 417 * The driver will have to mark associated objects in the 418 * request as completed; required if requests are 419 * supported. 420 */ 421 struct vb2_ops { 422 int (*queue_setup)(struct vb2_queue *q, 423 unsigned int *num_buffers, unsigned int *num_planes, 424 unsigned int sizes[], struct device *alloc_devs[]); 425 426 void (*wait_prepare)(struct vb2_queue *q); 427 void (*wait_finish)(struct vb2_queue *q); 428 429 int (*buf_out_validate)(struct vb2_buffer *vb); 430 int (*buf_init)(struct vb2_buffer *vb); 431 int (*buf_prepare)(struct vb2_buffer *vb); 432 void (*buf_finish)(struct vb2_buffer *vb); 433 void (*buf_cleanup)(struct vb2_buffer *vb); 434 435 int (*start_streaming)(struct vb2_queue *q, unsigned int count); 436 void (*stop_streaming)(struct vb2_queue *q); 437 438 void (*buf_queue)(struct vb2_buffer *vb); 439 440 void (*buf_request_complete)(struct vb2_buffer *vb); 441 }; 442 443 /** 444 * struct vb2_buf_ops - driver-specific callbacks. 445 * 446 * @verify_planes_array: Verify that a given user space structure contains 447 * enough planes for the buffer. This is called 448 * for each dequeued buffer. 449 * @init_buffer: given a &vb2_buffer initialize the extra data after 450 * struct vb2_buffer. 451 * For V4L2 this is a &struct vb2_v4l2_buffer. 452 * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure. 453 * For V4L2 this is a &struct v4l2_buffer. 454 * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer. 455 * If the userspace structure is invalid, then this op 456 * will return an error. 457 * @copy_timestamp: copy the timestamp from a userspace structure to 458 * the &struct vb2_buffer. 459 */ 460 struct vb2_buf_ops { 461 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb); 462 void (*init_buffer)(struct vb2_buffer *vb); 463 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); 464 int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes); 465 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); 466 }; 467 468 /** 469 * struct vb2_queue - a videobuf queue. 470 * 471 * @type: private buffer type whose content is defined by the vb2-core 472 * caller. For example, for V4L2, it should match 473 * the types defined on &enum v4l2_buf_type. 474 * @io_modes: supported io methods (see &enum vb2_io_modes). 475 * @alloc_devs: &struct device memory type/allocator-specific per-plane device 476 * @dev: device to use for the default allocation context if the driver 477 * doesn't fill in the @alloc_devs array. 478 * @dma_attrs: DMA attributes to use for the DMA. 479 * @bidirectional: when this flag is set the DMA direction for the buffers of 480 * this queue will be overridden with %DMA_BIDIRECTIONAL direction. 481 * This is useful in cases where the hardware (firmware) writes to 482 * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from 483 * buffer which is mapped for write (%DMA_FROM_DEVICE) in order 484 * to satisfy some internal hardware restrictions or adds a padding 485 * needed by the processing algorithm. In case the DMA mapping is 486 * not bidirectional but the hardware (firmware) trying to access 487 * the buffer (in the opposite direction) this could lead to an 488 * IOMMU protection faults. 489 * @fileio_read_once: report EOF after reading the first buffer 490 * @fileio_write_immediately: queue buffer after each write() call 491 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver 492 * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF 493 * has not been called. This is a vb1 idiom that has been adopted 494 * also by vb2. 495 * @supports_requests: this queue supports the Request API. 496 * @requires_requests: this queue requires the Request API. If this is set to 1, 497 * then supports_requests must be set to 1 as well. 498 * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first 499 * time this is called. Set to 0 when the queue is canceled. 500 * If this is 1, then you cannot queue buffers from a request. 501 * @uses_requests: requests are used for this queue. Set to 1 the first time 502 * a request is queued. Set to 0 when the queue is canceled. 503 * If this is 1, then you cannot queue buffers directly. 504 * @allow_cache_hints: when set user-space can pass cache management hints in 505 * order to skip cache flush/invalidation on ->prepare() or/and 506 * ->finish(). 507 * @non_coherent_mem: when set queue will attempt to allocate buffers using 508 * non-coherent memory. 509 * @lock: pointer to a mutex that protects the &struct vb2_queue. The 510 * driver can set this to a mutex to let the v4l2 core serialize 511 * the queuing ioctls. If the driver wants to handle locking 512 * itself, then this should be set to NULL. This lock is not used 513 * by the videobuf2 core API. 514 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle 515 * that called reqbufs, create_buffers or started fileio. 516 * This field is not used by the videobuf2 core API, but it allows 517 * drivers to easily associate an owner filehandle with the queue. 518 * @ops: driver-specific callbacks 519 * @mem_ops: memory allocator specific callbacks 520 * @buf_ops: callbacks to deliver buffer information. 521 * between user-space and kernel-space. 522 * @drv_priv: driver private data. 523 * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used 524 * by the vb2 core. 525 * @buf_struct_size: size of the driver-specific buffer structure; 526 * "0" indicates the driver doesn't want to use a custom buffer 527 * structure type. In that case a subsystem-specific struct 528 * will be used (in the case of V4L2 that is 529 * ``sizeof(struct vb2_v4l2_buffer)``). The first field of the 530 * driver-specific buffer structure must be the subsystem-specific 531 * struct (vb2_v4l2_buffer in the case of V4L2). 532 * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and 533 * ``V4L2_BUF_FLAG_TSTAMP_SRC_*`` 534 * @gfp_flags: additional gfp flags used when allocating the buffers. 535 * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32 536 * to force the buffer allocation to a specific memory zone. 537 * @min_buffers_needed: the minimum number of buffers needed before 538 * @start_streaming can be called. Used when a DMA engine 539 * cannot be started unless at least this number of buffers 540 * have been queued into the driver. 541 */ 542 /* 543 * Private elements (won't appear at the uAPI book): 544 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped 545 * @memory: current memory type used 546 * @dma_dir: DMA mapping direction. 547 * @bufs: videobuf buffer structures 548 * @num_buffers: number of allocated/used buffers 549 * @queued_list: list of buffers currently queued from userspace 550 * @queued_count: number of buffers queued and ready for streaming. 551 * @owned_by_drv_count: number of buffers owned by the driver 552 * @done_list: list of buffers ready to be dequeued to userspace 553 * @done_lock: lock to protect done_list list 554 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued 555 * @streaming: current streaming state 556 * @start_streaming_called: @start_streaming was called successfully and we 557 * started streaming. 558 * @error: a fatal error occurred on the queue 559 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for 560 * buffers. Only set for capture queues if qbuf has not yet been 561 * called since poll() needs to return %EPOLLERR in that situation. 562 * @is_multiplanar: set if buffer type is multiplanar 563 * @is_output: set if buffer type is output 564 * @copy_timestamp: set if vb2-core should set timestamps 565 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the 566 * last decoded buffer was already dequeued. Set for capture queues 567 * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued. 568 * @fileio: file io emulator internal data, used only if emulator is active 569 * @threadio: thread io internal data, used only if thread is active 570 * @name: queue name, used for logging purpose. Initialized automatically 571 * if left empty by drivers. 572 */ 573 struct vb2_queue { 574 unsigned int type; 575 unsigned int io_modes; 576 struct device *dev; 577 unsigned long dma_attrs; 578 unsigned int bidirectional:1; 579 unsigned int fileio_read_once:1; 580 unsigned int fileio_write_immediately:1; 581 unsigned int allow_zero_bytesused:1; 582 unsigned int quirk_poll_must_check_waiting_for_buffers:1; 583 unsigned int supports_requests:1; 584 unsigned int requires_requests:1; 585 unsigned int uses_qbuf:1; 586 unsigned int uses_requests:1; 587 unsigned int allow_cache_hints:1; 588 unsigned int non_coherent_mem:1; 589 590 struct mutex *lock; 591 void *owner; 592 593 const struct vb2_ops *ops; 594 const struct vb2_mem_ops *mem_ops; 595 const struct vb2_buf_ops *buf_ops; 596 597 void *drv_priv; 598 u32 subsystem_flags; 599 unsigned int buf_struct_size; 600 u32 timestamp_flags; 601 gfp_t gfp_flags; 602 u32 min_buffers_needed; 603 604 struct device *alloc_devs[VB2_MAX_PLANES]; 605 606 /* private: internal use only */ 607 struct mutex mmap_lock; 608 unsigned int memory; 609 enum dma_data_direction dma_dir; 610 struct vb2_buffer *bufs[VB2_MAX_FRAME]; 611 unsigned int num_buffers; 612 613 struct list_head queued_list; 614 unsigned int queued_count; 615 616 atomic_t owned_by_drv_count; 617 struct list_head done_list; 618 spinlock_t done_lock; 619 wait_queue_head_t done_wq; 620 621 unsigned int streaming:1; 622 unsigned int start_streaming_called:1; 623 unsigned int error:1; 624 unsigned int waiting_for_buffers:1; 625 unsigned int waiting_in_dqbuf:1; 626 unsigned int is_multiplanar:1; 627 unsigned int is_output:1; 628 unsigned int copy_timestamp:1; 629 unsigned int last_buffer_dequeued:1; 630 631 struct vb2_fileio_data *fileio; 632 struct vb2_threadio_data *threadio; 633 634 char name[32]; 635 636 #ifdef CONFIG_VIDEO_ADV_DEBUG 637 /* 638 * Counters for how often these queue-related ops are 639 * called. Used to check for unbalanced ops. 640 */ 641 u32 cnt_queue_setup; 642 u32 cnt_wait_prepare; 643 u32 cnt_wait_finish; 644 u32 cnt_start_streaming; 645 u32 cnt_stop_streaming; 646 #endif 647 }; 648 649 /** 650 * vb2_queue_allows_cache_hints() - Return true if the queue allows cache 651 * and memory consistency hints. 652 * 653 * @q: pointer to &struct vb2_queue with videobuf2 queue 654 */ 655 static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q) 656 { 657 return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP; 658 } 659 660 /** 661 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane. 662 * @vb: pointer to &struct vb2_buffer to which the plane in 663 * question belongs to. 664 * @plane_no: plane number for which the address is to be returned. 665 * 666 * This function returns a kernel virtual address of a given plane if 667 * such a mapping exist, NULL otherwise. 668 */ 669 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); 670 671 /** 672 * vb2_plane_cookie() - Return allocator specific cookie for the given plane. 673 * @vb: pointer to &struct vb2_buffer to which the plane in 674 * question belongs to. 675 * @plane_no: plane number for which the cookie is to be returned. 676 * 677 * This function returns an allocator specific cookie for a given plane if 678 * available, NULL otherwise. The allocator should provide some simple static 679 * inline function, which would convert this cookie to the allocator specific 680 * type that can be used directly by the driver to access the buffer. This can 681 * be for example physical address, pointer to scatter list or IOMMU mapping. 682 */ 683 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); 684 685 /** 686 * vb2_buffer_done() - inform videobuf that an operation on a buffer 687 * is finished. 688 * @vb: pointer to &struct vb2_buffer to be used. 689 * @state: state of the buffer, as defined by &enum vb2_buffer_state. 690 * Either %VB2_BUF_STATE_DONE if the operation finished 691 * successfully, %VB2_BUF_STATE_ERROR if the operation finished 692 * with an error or %VB2_BUF_STATE_QUEUED. 693 * 694 * This function should be called by the driver after a hardware operation on 695 * a buffer is finished and the buffer may be returned to userspace. The driver 696 * cannot use this buffer anymore until it is queued back to it by videobuf 697 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued 698 * to the driver by &vb2_ops->buf_queue can be passed to this function. 699 * 700 * While streaming a buffer can only be returned in state DONE or ERROR. 701 * The &vb2_ops->start_streaming op can also return them in case the DMA engine 702 * cannot be started for some reason. In that case the buffers should be 703 * returned with state QUEUED to put them back into the queue. 704 */ 705 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); 706 707 /** 708 * vb2_discard_done() - discard all buffers marked as DONE. 709 * @q: pointer to &struct vb2_queue with videobuf2 queue. 710 * 711 * This function is intended to be used with suspend/resume operations. It 712 * discards all 'done' buffers as they would be too old to be requested after 713 * resume. 714 * 715 * Drivers must stop the hardware and synchronize with interrupt handlers and/or 716 * delayed works before calling this function to make sure no buffer will be 717 * touched by the driver and/or hardware. 718 */ 719 void vb2_discard_done(struct vb2_queue *q); 720 721 /** 722 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2. 723 * @q: pointer to &struct vb2_queue with videobuf2 queue. 724 * 725 * This function will wait until all buffers that have been given to the driver 726 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It 727 * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair. 728 * It is intended to be called with all locks taken, for example from 729 * &vb2_ops->stop_streaming callback. 730 */ 731 int vb2_wait_for_all_buffers(struct vb2_queue *q); 732 733 /** 734 * vb2_core_querybuf() - query video buffer information. 735 * @q: pointer to &struct vb2_queue with videobuf2 queue. 736 * @index: id number of the buffer. 737 * @pb: buffer struct passed from userspace. 738 * 739 * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called 740 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 741 * 742 * The passed buffer should have been verified. 743 * 744 * This function fills the relevant information for the userspace. 745 * 746 * Return: returns zero on success; an error code otherwise. 747 */ 748 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); 749 750 /** 751 * vb2_core_reqbufs() - Initiate streaming. 752 * @q: pointer to &struct vb2_queue with videobuf2 queue. 753 * @memory: memory type, as defined by &enum vb2_memory. 754 * @flags: auxiliary queue/buffer management flags. Currently, the only 755 * used flag is %V4L2_MEMORY_FLAG_NON_COHERENT. 756 * @count: requested buffer count. 757 * 758 * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called 759 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 760 * 761 * This function: 762 * 763 * #) verifies streaming parameters passed from the userspace; 764 * #) sets up the queue; 765 * #) negotiates number of buffers and planes per buffer with the driver 766 * to be used during streaming; 767 * #) allocates internal buffer structures (&struct vb2_buffer), according to 768 * the agreed parameters; 769 * #) for MMAP memory type, allocates actual video memory, using the 770 * memory handling/allocation routines provided during queue initialization. 771 * 772 * If req->count is 0, all the memory will be freed instead. 773 * 774 * If the queue has been allocated previously by a previous vb2_core_reqbufs() 775 * call and the queue is not busy, memory will be reallocated. 776 * 777 * Return: returns zero on success; an error code otherwise. 778 */ 779 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 780 unsigned int flags, unsigned int *count); 781 782 /** 783 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs 784 * @q: pointer to &struct vb2_queue with videobuf2 queue. 785 * @memory: memory type, as defined by &enum vb2_memory. 786 * @flags: auxiliary queue/buffer management flags. 787 * @count: requested buffer count. 788 * @requested_planes: number of planes requested. 789 * @requested_sizes: array with the size of the planes. 790 * 791 * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is 792 * called internally by VB2 by an API-specific handler, like 793 * ``videobuf2-v4l2.h``. 794 * 795 * This function: 796 * 797 * #) verifies parameter sanity; 798 * #) calls the &vb2_ops->queue_setup queue operation; 799 * #) performs any necessary memory allocations. 800 * 801 * Return: returns zero on success; an error code otherwise. 802 */ 803 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 804 unsigned int flags, unsigned int *count, 805 unsigned int requested_planes, 806 const unsigned int requested_sizes[]); 807 808 /** 809 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace 810 * to the kernel. 811 * @q: pointer to &struct vb2_queue with videobuf2 queue. 812 * @index: id number of the buffer. 813 * @pb: buffer structure passed from userspace to 814 * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver. 815 * 816 * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is 817 * called internally by VB2 by an API-specific handler, like 818 * ``videobuf2-v4l2.h``. 819 * 820 * The passed buffer should have been verified. 821 * 822 * This function calls vb2_ops->buf_prepare callback in the driver 823 * (if provided), in which driver-specific buffer initialization can 824 * be performed. 825 * 826 * Return: returns zero on success; an error code otherwise. 827 */ 828 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); 829 830 /** 831 * vb2_core_qbuf() - Queue a buffer from userspace 832 * 833 * @q: pointer to &struct vb2_queue with videobuf2 queue. 834 * @index: id number of the buffer 835 * @pb: buffer structure passed from userspace to 836 * v4l2_ioctl_ops->vidioc_qbuf handler in driver 837 * @req: pointer to &struct media_request, may be NULL. 838 * 839 * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called 840 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 841 * 842 * This function: 843 * 844 * #) If @req is non-NULL, then the buffer will be bound to this 845 * media request and it returns. The buffer will be prepared and 846 * queued to the driver (i.e. the next two steps) when the request 847 * itself is queued. 848 * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver 849 * (if provided), in which driver-specific buffer initialization can 850 * be performed; 851 * #) if streaming is on, queues the buffer in driver by the means of 852 * &vb2_ops->buf_queue callback for processing. 853 * 854 * Return: returns zero on success; an error code otherwise. 855 */ 856 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, 857 struct media_request *req); 858 859 /** 860 * vb2_core_dqbuf() - Dequeue a buffer to the userspace 861 * @q: pointer to &struct vb2_queue with videobuf2 queue 862 * @pindex: pointer to the buffer index. May be NULL 863 * @pb: buffer structure passed from userspace to 864 * v4l2_ioctl_ops->vidioc_dqbuf handler in driver. 865 * @nonblocking: if true, this call will not sleep waiting for a buffer if no 866 * buffers ready for dequeuing are present. Normally the driver 867 * would be passing (file->f_flags & O_NONBLOCK) here. 868 * 869 * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called 870 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 871 * 872 * This function: 873 * 874 * #) calls buf_finish callback in the driver (if provided), in which 875 * driver can perform any additional operations that may be required before 876 * returning the buffer to userspace, such as cache sync, 877 * #) the buffer struct members are filled with relevant information for 878 * the userspace. 879 * 880 * Return: returns zero on success; an error code otherwise. 881 */ 882 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, 883 bool nonblocking); 884 885 /** 886 * vb2_core_streamon() - Implements VB2 stream ON logic 887 * 888 * @q: pointer to &struct vb2_queue with videobuf2 queue 889 * @type: type of the queue to be started. 890 * For V4L2, this is defined by &enum v4l2_buf_type type. 891 * 892 * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called 893 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 894 * 895 * Return: returns zero on success; an error code otherwise. 896 */ 897 int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 898 899 /** 900 * vb2_core_streamoff() - Implements VB2 stream OFF logic 901 * 902 * @q: pointer to &struct vb2_queue with videobuf2 queue 903 * @type: type of the queue to be started. 904 * For V4L2, this is defined by &enum v4l2_buf_type type. 905 * 906 * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is 907 * called internally by VB2 by an API-specific handler, like 908 * ``videobuf2-v4l2.h``. 909 * 910 * Return: returns zero on success; an error code otherwise. 911 */ 912 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); 913 914 /** 915 * vb2_core_expbuf() - Export a buffer as a file descriptor. 916 * @q: pointer to &struct vb2_queue with videobuf2 queue. 917 * @fd: pointer to the file descriptor associated with DMABUF 918 * (set by driver). 919 * @type: buffer type. 920 * @index: id number of the buffer. 921 * @plane: index of the plane to be exported, 0 for single plane queues 922 * @flags: file flags for newly created file, as defined at 923 * include/uapi/asm-generic/fcntl.h. 924 * Currently, the only used flag is %O_CLOEXEC. 925 * is supported, refer to manual of open syscall for more details. 926 * 927 * 928 * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called 929 * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. 930 * 931 * Return: returns zero on success; an error code otherwise. 932 */ 933 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 934 unsigned int index, unsigned int plane, unsigned int flags); 935 936 /** 937 * vb2_core_queue_init() - initialize a videobuf2 queue 938 * @q: pointer to &struct vb2_queue with videobuf2 queue. 939 * This structure should be allocated in driver 940 * 941 * The &vb2_queue structure should be allocated by the driver. The driver is 942 * responsible of clearing it's content and setting initial values for some 943 * required entries before calling this function. 944 * 945 * .. note:: 946 * 947 * The following fields at @q should be set before calling this function: 948 * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type. 949 */ 950 int vb2_core_queue_init(struct vb2_queue *q); 951 952 /** 953 * vb2_core_queue_release() - stop streaming, release the queue and free memory 954 * @q: pointer to &struct vb2_queue with videobuf2 queue. 955 * 956 * This function stops streaming and performs necessary clean ups, including 957 * freeing video buffer memory. The driver is responsible for freeing 958 * the &struct vb2_queue itself. 959 */ 960 void vb2_core_queue_release(struct vb2_queue *q); 961 962 /** 963 * vb2_queue_error() - signal a fatal error on the queue 964 * @q: pointer to &struct vb2_queue with videobuf2 queue. 965 * 966 * Flag that a fatal unrecoverable error has occurred and wake up all processes 967 * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing 968 * buffers will return %-EIO. 969 * 970 * The error flag will be cleared when canceling the queue, either from 971 * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this 972 * function before starting the stream, otherwise the error flag will remain set 973 * until the queue is released when closing the device node. 974 */ 975 void vb2_queue_error(struct vb2_queue *q); 976 977 /** 978 * vb2_mmap() - map video buffers into application address space. 979 * @q: pointer to &struct vb2_queue with videobuf2 queue. 980 * @vma: pointer to &struct vm_area_struct with the vma passed 981 * to the mmap file operation handler in the driver. 982 * 983 * Should be called from mmap file operation handler of a driver. 984 * This function maps one plane of one of the available video buffers to 985 * userspace. To map whole video memory allocated on reqbufs, this function 986 * has to be called once per each plane per each buffer previously allocated. 987 * 988 * When the userspace application calls mmap, it passes to it an offset returned 989 * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler. 990 * That offset acts as a "cookie", which is then used to identify the plane 991 * to be mapped. 992 * 993 * This function finds a plane with a matching offset and a mapping is performed 994 * by the means of a provided memory operation. 995 * 996 * The return values from this function are intended to be directly returned 997 * from the mmap handler in driver. 998 */ 999 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); 1000 1001 #ifndef CONFIG_MMU 1002 /** 1003 * vb2_get_unmapped_area - map video buffers into application address space. 1004 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1005 * @addr: memory address. 1006 * @len: buffer size. 1007 * @pgoff: page offset. 1008 * @flags: memory flags. 1009 * 1010 * This function is used in noMMU platforms to propose address mapping 1011 * for a given buffer. It's intended to be used as a handler for the 1012 * &file_operations->get_unmapped_area operation. 1013 * 1014 * This is called by the mmap() syscall routines will call this 1015 * to get a proposed address for the mapping, when ``!CONFIG_MMU``. 1016 */ 1017 unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 1018 unsigned long addr, 1019 unsigned long len, 1020 unsigned long pgoff, 1021 unsigned long flags); 1022 #endif 1023 1024 /** 1025 * vb2_core_poll() - implements poll syscall() logic. 1026 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1027 * @file: &struct file argument passed to the poll 1028 * file operation handler. 1029 * @wait: &poll_table wait argument passed to the poll 1030 * file operation handler. 1031 * 1032 * This function implements poll file operation handler for a driver. 1033 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will 1034 * be informed that the file descriptor of a video device is available for 1035 * reading. 1036 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor 1037 * will be reported as available for writing. 1038 * 1039 * The return values from this function are intended to be directly returned 1040 * from poll handler in driver. 1041 */ 1042 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file, 1043 poll_table *wait); 1044 1045 /** 1046 * vb2_read() - implements read() 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 read 1050 * @ppos: file handle position tracking pointer 1051 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) 1052 */ 1053 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, 1054 loff_t *ppos, int nonblock); 1055 /** 1056 * vb2_write() - implements write() syscall logic. 1057 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1058 * @data: pointed to target userspace buffer 1059 * @count: number of bytes to write 1060 * @ppos: file handle position tracking pointer 1061 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) 1062 */ 1063 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, 1064 loff_t *ppos, int nonblock); 1065 1066 /** 1067 * typedef vb2_thread_fnc - callback function for use with vb2_thread. 1068 * 1069 * @vb: pointer to struct &vb2_buffer. 1070 * @priv: pointer to a private data. 1071 * 1072 * This is called whenever a buffer is dequeued in the thread. 1073 */ 1074 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); 1075 1076 /** 1077 * vb2_thread_start() - start a thread for the given queue. 1078 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1079 * @fnc: &vb2_thread_fnc callback function. 1080 * @priv: priv pointer passed to the callback function. 1081 * @thread_name:the name of the thread. This will be prefixed with "vb2-". 1082 * 1083 * This starts a thread that will queue and dequeue until an error occurs 1084 * or vb2_thread_stop() is called. 1085 * 1086 * .. attention:: 1087 * 1088 * This function should not be used for anything else but the videobuf2-dvb 1089 * support. If you think you have another good use-case for this, then please 1090 * contact the linux-media mailing list first. 1091 */ 1092 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, 1093 const char *thread_name); 1094 1095 /** 1096 * vb2_thread_stop() - stop the thread for the given queue. 1097 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1098 */ 1099 int vb2_thread_stop(struct vb2_queue *q); 1100 1101 /** 1102 * vb2_is_streaming() - return streaming status of the queue. 1103 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1104 */ 1105 static inline bool vb2_is_streaming(struct vb2_queue *q) 1106 { 1107 return q->streaming; 1108 } 1109 1110 /** 1111 * vb2_fileio_is_active() - return true if fileio is active. 1112 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1113 * 1114 * This returns true if read() or write() is used to stream the data 1115 * as opposed to stream I/O. This is almost never an important distinction, 1116 * except in rare cases. One such case is that using read() or write() to 1117 * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there 1118 * is no way you can pass the field information of each buffer to/from 1119 * userspace. A driver that supports this field format should check for 1120 * this in the &vb2_ops->queue_setup op and reject it if this function returns 1121 * true. 1122 */ 1123 static inline bool vb2_fileio_is_active(struct vb2_queue *q) 1124 { 1125 return q->fileio; 1126 } 1127 1128 /** 1129 * vb2_is_busy() - return busy status of the queue. 1130 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1131 * 1132 * This function checks if queue has any buffers allocated. 1133 */ 1134 static inline bool vb2_is_busy(struct vb2_queue *q) 1135 { 1136 return (q->num_buffers > 0); 1137 } 1138 1139 /** 1140 * vb2_get_drv_priv() - return driver private data associated with the queue. 1141 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1142 */ 1143 static inline void *vb2_get_drv_priv(struct vb2_queue *q) 1144 { 1145 return q->drv_priv; 1146 } 1147 1148 /** 1149 * vb2_set_plane_payload() - set bytesused for the plane @plane_no. 1150 * @vb: pointer to &struct vb2_buffer to which the plane in 1151 * question belongs to. 1152 * @plane_no: plane number for which payload should be set. 1153 * @size: payload in bytes. 1154 */ 1155 static inline void vb2_set_plane_payload(struct vb2_buffer *vb, 1156 unsigned int plane_no, unsigned long size) 1157 { 1158 /* 1159 * size must never be larger than the buffer length, so 1160 * warn and clamp to the buffer length if that's the case. 1161 */ 1162 if (plane_no < vb->num_planes) { 1163 if (WARN_ON_ONCE(size > vb->planes[plane_no].length)) 1164 size = vb->planes[plane_no].length; 1165 vb->planes[plane_no].bytesused = size; 1166 } 1167 } 1168 1169 /** 1170 * vb2_get_plane_payload() - get bytesused for the plane plane_no 1171 * @vb: pointer to &struct vb2_buffer to which the plane in 1172 * question belongs to. 1173 * @plane_no: plane number for which payload should be set. 1174 */ 1175 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, 1176 unsigned int plane_no) 1177 { 1178 if (plane_no < vb->num_planes) 1179 return vb->planes[plane_no].bytesused; 1180 return 0; 1181 } 1182 1183 /** 1184 * vb2_plane_size() - return plane size in bytes. 1185 * @vb: pointer to &struct vb2_buffer to which the plane in 1186 * question belongs to. 1187 * @plane_no: plane number for which size should be returned. 1188 */ 1189 static inline unsigned long 1190 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) 1191 { 1192 if (plane_no < vb->num_planes) 1193 return vb->planes[plane_no].length; 1194 return 0; 1195 } 1196 1197 /** 1198 * vb2_start_streaming_called() - return streaming status of driver. 1199 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1200 */ 1201 static inline bool vb2_start_streaming_called(struct vb2_queue *q) 1202 { 1203 return q->start_streaming_called; 1204 } 1205 1206 /** 1207 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue. 1208 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1209 */ 1210 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) 1211 { 1212 q->last_buffer_dequeued = false; 1213 } 1214 1215 /** 1216 * vb2_get_buffer() - get a buffer from a queue 1217 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1218 * @index: buffer index 1219 * 1220 * This function obtains a buffer from a queue, by its index. 1221 * Keep in mind that there is no refcounting involved in this 1222 * operation, so the buffer lifetime should be taken into 1223 * consideration. 1224 */ 1225 static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q, 1226 unsigned int index) 1227 { 1228 if (index < q->num_buffers) 1229 return q->bufs[index]; 1230 return NULL; 1231 } 1232 1233 /* 1234 * The following functions are not part of the vb2 core API, but are useful 1235 * functions for videobuf2-*. 1236 */ 1237 1238 /** 1239 * vb2_buffer_in_use() - return true if the buffer is in use and 1240 * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call. 1241 * 1242 * @vb: buffer for which plane size should be returned. 1243 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1244 */ 1245 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); 1246 1247 /** 1248 * vb2_verify_memory_type() - Check whether the memory type and buffer type 1249 * passed to a buffer operation are compatible with the queue. 1250 * 1251 * @q: pointer to &struct vb2_queue with videobuf2 queue. 1252 * @memory: memory model, as defined by enum &vb2_memory. 1253 * @type: private buffer type whose content is defined by the vb2-core 1254 * caller. For example, for V4L2, it should match 1255 * the types defined on enum &v4l2_buf_type. 1256 */ 1257 int vb2_verify_memory_type(struct vb2_queue *q, 1258 enum vb2_memory memory, unsigned int type); 1259 1260 /** 1261 * vb2_request_object_is_buffer() - return true if the object is a buffer 1262 * 1263 * @obj: the request object. 1264 */ 1265 bool vb2_request_object_is_buffer(struct media_request_object *obj); 1266 1267 /** 1268 * vb2_request_buffer_cnt() - return the number of buffers in the request 1269 * 1270 * @req: the request. 1271 */ 1272 unsigned int vb2_request_buffer_cnt(struct media_request *req); 1273 1274 #endif /* _MEDIA_VIDEOBUF2_CORE_H */ 1275