1 /* 2 * videobuf2-core.h - Video Buffer 2 Core Framework 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * 6 * Author: Pawel Osciak <pawel@osciak.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation. 11 */ 12 #ifndef _MEDIA_VIDEOBUF2_CORE_H 13 #define _MEDIA_VIDEOBUF2_CORE_H 14 15 #include <linux/mm_types.h> 16 #include <linux/mutex.h> 17 #include <linux/poll.h> 18 #include <linux/dma-buf.h> 19 20 #define VB2_MAX_FRAME (32) 21 #define VB2_MAX_PLANES (8) 22 23 /** 24 * enum vb2_memory - type of memory model used to make the buffers visible 25 * on userspace. 26 * 27 * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on 28 * userspace. 29 * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is 30 * memory mapped via mmap() ioctl. This model is 31 * also used when the user is using the buffers via 32 * read() or write() system calls. 33 * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is 34 * memory mapped via mmap() ioctl. 35 * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer. 36 */ 37 enum vb2_memory { 38 VB2_MEMORY_UNKNOWN = 0, 39 VB2_MEMORY_MMAP = 1, 40 VB2_MEMORY_USERPTR = 2, 41 VB2_MEMORY_DMABUF = 4, 42 }; 43 44 struct vb2_fileio_data; 45 struct vb2_threadio_data; 46 47 /** 48 * struct vb2_mem_ops - memory handling/memory allocator operations 49 * @alloc: allocate video memory and, optionally, allocator private data, 50 * return ERR_PTR() on failure or a pointer to allocator private, 51 * per-buffer data on success; the returned private structure 52 * will then be passed as @buf_priv argument to other ops in this 53 * structure. Additional gfp_flags to use when allocating the 54 * are also passed to this operation. These flags are from the 55 * gfp_flags field of vb2_queue. 56 * @put: inform the allocator that the buffer will no longer be used; 57 * usually will result in the allocator freeing the buffer (if 58 * no other users of this buffer are present); the @buf_priv 59 * argument is the allocator private per-buffer structure 60 * previously returned from the alloc callback. 61 * @get_dmabuf: acquire userspace memory for a hardware operation; used for 62 * DMABUF memory types. 63 * @get_userptr: acquire userspace memory for a hardware operation; used for 64 * USERPTR memory types; vaddr is the address passed to the 65 * videobuf layer when queuing a video buffer of USERPTR type; 66 * should return an allocator private per-buffer structure 67 * associated with the buffer on success, ERR_PTR() on failure; 68 * the returned private structure will then be passed as @buf_priv 69 * argument to other ops in this structure. 70 * @put_userptr: inform the allocator that a USERPTR buffer will no longer 71 * be used. 72 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation; 73 * used for DMABUF memory types; dev is the alloc device 74 * dbuf is the shared dma_buf; returns ERR_PTR() on failure; 75 * allocator private per-buffer structure on success; 76 * this needs to be used for further accesses to the buffer. 77 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF 78 * buffer is no longer used; the @buf_priv argument is the 79 * allocator private per-buffer structure previously returned 80 * from the attach_dmabuf callback. 81 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator 82 * of dmabuf is informed that this driver is going to use the 83 * dmabuf. 84 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified 85 * that this driver is done using the dmabuf for now. 86 * @prepare: called every time the buffer is passed from userspace to the 87 * driver, useful for cache synchronisation, optional. 88 * @finish: called every time the buffer is passed back from the driver 89 * to the userspace, also optional. 90 * @vaddr: return a kernel virtual address to a given memory buffer 91 * associated with the passed private structure or NULL if no 92 * such mapping exists. 93 * @cookie: return allocator specific cookie for a given memory buffer 94 * associated with the passed private structure or NULL if not 95 * available. 96 * @num_users: return the current number of users of a memory buffer; 97 * return 1 if the videobuf layer (or actually the driver using 98 * it) is the only user. 99 * @mmap: setup a userspace mapping for a given memory buffer under 100 * the provided virtual memory region. 101 * 102 * Those operations are used by the videobuf2 core to implement the memory 103 * handling/memory allocators for each type of supported streaming I/O method. 104 * 105 * .. note:: 106 * #) Required ops for USERPTR types: get_userptr, put_userptr. 107 * 108 * #) Required ops for MMAP types: alloc, put, num_users, mmap. 109 * 110 * #) Required ops for read/write access types: alloc, put, num_users, vaddr. 111 * 112 * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, 113 * map_dmabuf, unmap_dmabuf. 114 */ 115 struct vb2_mem_ops { 116 void *(*alloc)(struct device *dev, unsigned long attrs, 117 unsigned long size, 118 enum dma_data_direction dma_dir, 119 gfp_t gfp_flags); 120 void (*put)(void *buf_priv); 121 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags); 122 123 void *(*get_userptr)(struct device *dev, unsigned long vaddr, 124 unsigned long size, 125 enum dma_data_direction dma_dir); 126 void (*put_userptr)(void *buf_priv); 127 128 void (*prepare)(void *buf_priv); 129 void (*finish)(void *buf_priv); 130 131 void *(*attach_dmabuf)(struct device *dev, 132 struct dma_buf *dbuf, 133 unsigned long size, 134 enum dma_data_direction dma_dir); 135 void (*detach_dmabuf)(void *buf_priv); 136 int (*map_dmabuf)(void *buf_priv); 137 void (*unmap_dmabuf)(void *buf_priv); 138 139 void *(*vaddr)(void *buf_priv); 140 void *(*cookie)(void *buf_priv); 141 142 unsigned int (*num_users)(void *buf_priv); 143 144 int (*mmap)(void *buf_priv, struct vm_area_struct *vma); 145 }; 146 147 /** 148 * struct vb2_plane - plane information 149 * @mem_priv: private data with this plane 150 * @dbuf: dma_buf - shared buffer object 151 * @dbuf_mapped: flag to show whether dbuf is mapped or not 152 * @bytesused: number of bytes occupied by data in the plane (payload) 153 * @length: size of this plane (NOT the payload) in bytes 154 * @min_length: minimum required size of this plane (NOT the payload) in bytes. 155 * @length is always greater or equal to @min_length. 156 * @offset: when memory in the associated struct vb2_buffer is 157 * VB2_MEMORY_MMAP, equals the offset from the start of 158 * the device memory for this plane (or is a "cookie" that 159 * should be passed to mmap() called on the video node) 160 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer 161 * pointing to this plane 162 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file 163 * descriptor associated with this plane 164 * @m: Union with memtype-specific data (@offset, @userptr or 165 * @fd). 166 * @data_offset: offset in the plane to the start of data; usually 0, 167 * unless there is a header in front of the data 168 * Should contain enough information to be able to cover all the fields 169 * of struct v4l2_plane at videodev2.h 170 */ 171 struct vb2_plane { 172 void *mem_priv; 173 struct dma_buf *dbuf; 174 unsigned int dbuf_mapped; 175 unsigned int bytesused; 176 unsigned int length; 177 unsigned int min_length; 178 union { 179 unsigned int offset; 180 unsigned long userptr; 181 int fd; 182 } m; 183 unsigned int data_offset; 184 }; 185 186 /** 187 * enum vb2_io_modes - queue access methods 188 * @VB2_MMAP: driver supports MMAP with streaming API 189 * @VB2_USERPTR: driver supports USERPTR with streaming API 190 * @VB2_READ: driver supports read() style access 191 * @VB2_WRITE: driver supports write() style access 192 * @VB2_DMABUF: driver supports DMABUF with streaming API 193 */ 194 enum vb2_io_modes { 195 VB2_MMAP = (1 << 0), 196 VB2_USERPTR = (1 << 1), 197 VB2_READ = (1 << 2), 198 VB2_WRITE = (1 << 3), 199 VB2_DMABUF = (1 << 4), 200 }; 201 202 /** 203 * enum vb2_buffer_state - current video buffer state 204 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control 205 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf 206 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver 207 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver 208 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver 209 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used 210 * in a hardware operation 211 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but 212 * not yet dequeued to userspace 213 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer 214 * has ended with an error, which will be reported 215 * to the userspace when it is dequeued 216 */ 217 enum vb2_buffer_state { 218 VB2_BUF_STATE_DEQUEUED, 219 VB2_BUF_STATE_PREPARING, 220 VB2_BUF_STATE_PREPARED, 221 VB2_BUF_STATE_QUEUED, 222 VB2_BUF_STATE_REQUEUEING, 223 VB2_BUF_STATE_ACTIVE, 224 VB2_BUF_STATE_DONE, 225 VB2_BUF_STATE_ERROR, 226 }; 227 228 struct vb2_queue; 229 230 /** 231 * struct vb2_buffer - represents a video buffer 232 * @vb2_queue: the queue to which this driver belongs 233 * @index: id number of the buffer 234 * @type: buffer type 235 * @memory: the method, in which the actual data is passed 236 * @num_planes: number of planes in the buffer 237 * on an internal driver queue 238 * @planes: private per-plane information; do not change 239 * @timestamp: frame timestamp in ns 240 */ 241 struct vb2_buffer { 242 struct vb2_queue *vb2_queue; 243 unsigned int index; 244 unsigned int type; 245 unsigned int memory; 246 unsigned int num_planes; 247 struct vb2_plane planes[VB2_MAX_PLANES]; 248 u64 timestamp; 249 250 /* private: internal use only 251 * 252 * state: current buffer state; do not change 253 * queued_entry: entry on the queued buffers list, which holds 254 * all buffers queued from userspace 255 * done_entry: entry on the list that stores all buffers ready 256 * to be dequeued to userspace 257 */ 258 enum vb2_buffer_state state; 259 260 struct list_head queued_entry; 261 struct list_head done_entry; 262 #ifdef CONFIG_VIDEO_ADV_DEBUG 263 /* 264 * Counters for how often these buffer-related ops are 265 * called. Used to check for unbalanced ops. 266 */ 267 u32 cnt_mem_alloc; 268 u32 cnt_mem_put; 269 u32 cnt_mem_get_dmabuf; 270 u32 cnt_mem_get_userptr; 271 u32 cnt_mem_put_userptr; 272 u32 cnt_mem_prepare; 273 u32 cnt_mem_finish; 274 u32 cnt_mem_attach_dmabuf; 275 u32 cnt_mem_detach_dmabuf; 276 u32 cnt_mem_map_dmabuf; 277 u32 cnt_mem_unmap_dmabuf; 278 u32 cnt_mem_vaddr; 279 u32 cnt_mem_cookie; 280 u32 cnt_mem_num_users; 281 u32 cnt_mem_mmap; 282 283 u32 cnt_buf_init; 284 u32 cnt_buf_prepare; 285 u32 cnt_buf_finish; 286 u32 cnt_buf_cleanup; 287 u32 cnt_buf_queue; 288 289 /* This counts the number of calls to vb2_buffer_done() */ 290 u32 cnt_buf_done; 291 #endif 292 }; 293 294 /** 295 * struct vb2_ops - driver-specific callbacks 296 * 297 * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS() 298 * handlers before memory allocation. It can be called 299 * twice: if the original number of requested buffers 300 * could not be allocated, then it will be called a 301 * second time with the actually allocated number of 302 * buffers to verify if that is OK. 303 * The driver should return the required number of buffers 304 * in \*num_buffers, the required number of planes per 305 * buffer in \*num_planes, the size of each plane should be 306 * set in the sizes\[\] array and optional per-plane 307 * allocator specific device in the alloc_devs\[\] array. 308 * When called from VIDIOC_REQBUFS,() \*num_planes == 0, 309 * the driver has to use the currently configured format to 310 * determine the plane sizes and \*num_buffers is the total 311 * number of buffers that are being allocated. When called 312 * from VIDIOC_CREATE_BUFS,() \*num_planes != 0 and it 313 * describes the requested number of planes and sizes\[\] 314 * contains the requested plane sizes. If either 315 * \*num_planes or the requested sizes are invalid callback 316 * must return %-EINVAL. In this case \*num_buffers are 317 * being allocated additionally to q->num_buffers. 318 * @wait_prepare: release any locks taken while calling vb2 functions; 319 * it is called before an ioctl needs to wait for a new 320 * buffer to arrive; required to avoid a deadlock in 321 * blocking access type. 322 * @wait_finish: reacquire all locks released in the previous callback; 323 * required to continue operation after sleeping while 324 * waiting for a new buffer to arrive. 325 * @buf_init: called once after allocating a buffer (in MMAP case) 326 * or after acquiring a new USERPTR buffer; drivers may 327 * perform additional buffer-related initialization; 328 * initialization failure (return != 0) will prevent 329 * queue setup from completing successfully; optional. 330 * @buf_prepare: called every time the buffer is queued from userspace 331 * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may 332 * perform any initialization required before each 333 * hardware operation in this callback; drivers can 334 * access/modify the buffer here as it is still synced for 335 * the CPU; drivers that support VIDIOC_CREATE_BUFS() must 336 * also validate the buffer size; if an error is returned, 337 * the buffer will not be queued in driver; optional. 338 * @buf_finish: called before every dequeue of the buffer back to 339 * userspace; the buffer is synced for the CPU, so drivers 340 * can access/modify the buffer contents; drivers may 341 * perform any operations required before userspace 342 * accesses the buffer; optional. The buffer state can be 343 * one of the following: %DONE and %ERROR occur while 344 * streaming is in progress, and the %PREPARED state occurs 345 * when the queue has been canceled and all pending 346 * buffers are being returned to their default %DEQUEUED 347 * state. Typically you only have to do something if the 348 * state is %VB2_BUF_STATE_DONE, since in all other cases 349 * the buffer contents will be ignored anyway. 350 * @buf_cleanup: called once before the buffer is freed; drivers may 351 * perform any additional cleanup; optional. 352 * @start_streaming: called once to enter 'streaming' state; the driver may 353 * receive buffers with @buf_queue callback 354 * before @start_streaming is called; the driver gets the 355 * number of already queued buffers in count parameter; 356 * driver can return an error if hardware fails, in that 357 * case all buffers that have been already given by 358 * the @buf_queue callback are to be returned by the driver 359 * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED. 360 * If you need a minimum number of buffers before you can 361 * start streaming, then set @min_buffers_needed in the 362 * vb2_queue structure. If that is non-zero then 363 * @start_streaming won't be called until at least that 364 * many buffers have been queued up by userspace. 365 * @stop_streaming: called when 'streaming' state must be disabled; driver 366 * should stop any DMA transactions or wait until they 367 * finish and give back all buffers it got from &buf_queue 368 * callback by calling vb2_buffer_done() with either 369 * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use 370 * vb2_wait_for_all_buffers() function 371 * @buf_queue: passes buffer vb to the driver; driver may start 372 * hardware operation on this buffer; driver should give 373 * the buffer back by calling vb2_buffer_done() function; 374 * it is allways called after calling VIDIOC_STREAMON() 375 * ioctl; might be called before @start_streaming callback 376 * if user pre-queued buffers before calling 377 * VIDIOC_STREAMON(). 378 */ 379 struct vb2_ops { 380 int (*queue_setup)(struct vb2_queue *q, 381 unsigned int *num_buffers, unsigned int *num_planes, 382 unsigned int sizes[], struct device *alloc_devs[]); 383 384 void (*wait_prepare)(struct vb2_queue *q); 385 void (*wait_finish)(struct vb2_queue *q); 386 387 int (*buf_init)(struct vb2_buffer *vb); 388 int (*buf_prepare)(struct vb2_buffer *vb); 389 void (*buf_finish)(struct vb2_buffer *vb); 390 void (*buf_cleanup)(struct vb2_buffer *vb); 391 392 int (*start_streaming)(struct vb2_queue *q, unsigned int count); 393 void (*stop_streaming)(struct vb2_queue *q); 394 395 void (*buf_queue)(struct vb2_buffer *vb); 396 }; 397 398 /** 399 * struct vb2_buf_ops - driver-specific callbacks 400 * 401 * @verify_planes_array: Verify that a given user space structure contains 402 * enough planes for the buffer. This is called 403 * for each dequeued buffer. 404 * @fill_user_buffer: given a vb2_buffer fill in the userspace structure. 405 * For V4L2 this is a struct v4l2_buffer. 406 * @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer. 407 * If the userspace structure is invalid, then this op 408 * will return an error. 409 * @copy_timestamp: copy the timestamp from a userspace structure to 410 * the vb2_buffer struct. 411 */ 412 struct vb2_buf_ops { 413 int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb); 414 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); 415 int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb, 416 struct vb2_plane *planes); 417 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); 418 }; 419 420 /** 421 * struct vb2_queue - a videobuf queue 422 * 423 * @type: private buffer type whose content is defined by the vb2-core 424 * caller. For example, for V4L2, it should match 425 * the types defined on enum &v4l2_buf_type 426 * @io_modes: supported io methods (see vb2_io_modes enum) 427 * @dev: device to use for the default allocation context if the driver 428 * doesn't fill in the @alloc_devs array. 429 * @dma_attrs: DMA attributes to use for the DMA. 430 * @fileio_read_once: report EOF after reading the first buffer 431 * @fileio_write_immediately: queue buffer after each write() call 432 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver 433 * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF 434 * has not been called. This is a vb1 idiom that has been adopted 435 * also by vb2. 436 * @lock: pointer to a mutex that protects the vb2_queue struct. The 437 * driver can set this to a mutex to let the v4l2 core serialize 438 * the queuing ioctls. If the driver wants to handle locking 439 * itself, then this should be set to NULL. This lock is not used 440 * by the videobuf2 core API. 441 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle 442 * that called reqbufs, create_buffers or started fileio. 443 * This field is not used by the videobuf2 core API, but it allows 444 * drivers to easily associate an owner filehandle with the queue. 445 * @ops: driver-specific callbacks 446 * @mem_ops: memory allocator specific callbacks 447 * @buf_ops: callbacks to deliver buffer information 448 * between user-space and kernel-space 449 * @drv_priv: driver private data 450 * @buf_struct_size: size of the driver-specific buffer structure; 451 * "0" indicates the driver doesn't want to use a custom buffer 452 * structure type. for example, sizeof(struct vb2_v4l2_buffer) 453 * will be used for v4l2. 454 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and 455 * V4L2_BUF_FLAG_TSTAMP_SRC_* 456 * @gfp_flags: additional gfp flags used when allocating the buffers. 457 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 458 * to force the buffer allocation to a specific memory zone. 459 * @min_buffers_needed: the minimum number of buffers needed before 460 * @start_streaming can be called. Used when a DMA engine 461 * cannot be started unless at least this number of buffers 462 * have been queued into the driver. 463 */ 464 /* 465 * Private elements (won't appear at the uAPI book): 466 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped 467 * @memory: current memory type used 468 * @bufs: videobuf buffer structures 469 * @num_buffers: number of allocated/used buffers 470 * @queued_list: list of buffers currently queued from userspace 471 * @queued_count: number of buffers queued and ready for streaming. 472 * @owned_by_drv_count: number of buffers owned by the driver 473 * @done_list: list of buffers ready to be dequeued to userspace 474 * @done_lock: lock to protect done_list list 475 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued 476 * @alloc_devs: memory type/allocator-specific per-plane device 477 * @streaming: current streaming state 478 * @start_streaming_called: @start_streaming was called successfully and we 479 * started streaming. 480 * @error: a fatal error occurred on the queue 481 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for 482 * buffers. Only set for capture queues if qbuf has not yet been 483 * called since poll() needs to return POLLERR in that situation. 484 * @is_multiplanar: set if buffer type is multiplanar 485 * @is_output: set if buffer type is output 486 * @copy_timestamp: set if vb2-core should set timestamps 487 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the 488 * last decoded buffer was already dequeued. Set for capture queues 489 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued. 490 * @fileio: file io emulator internal data, used only if emulator is active 491 * @threadio: thread io internal data, used only if thread is active 492 */ 493 struct vb2_queue { 494 unsigned int type; 495 unsigned int io_modes; 496 struct device *dev; 497 unsigned long dma_attrs; 498 unsigned fileio_read_once:1; 499 unsigned fileio_write_immediately:1; 500 unsigned allow_zero_bytesused:1; 501 unsigned quirk_poll_must_check_waiting_for_buffers:1; 502 503 struct mutex *lock; 504 void *owner; 505 506 const struct vb2_ops *ops; 507 const struct vb2_mem_ops *mem_ops; 508 const struct vb2_buf_ops *buf_ops; 509 510 void *drv_priv; 511 unsigned int buf_struct_size; 512 u32 timestamp_flags; 513 gfp_t gfp_flags; 514 u32 min_buffers_needed; 515 516 /* private: internal use only */ 517 struct mutex mmap_lock; 518 unsigned int memory; 519 struct vb2_buffer *bufs[VB2_MAX_FRAME]; 520 unsigned int num_buffers; 521 522 struct list_head queued_list; 523 unsigned int queued_count; 524 525 atomic_t owned_by_drv_count; 526 struct list_head done_list; 527 spinlock_t done_lock; 528 wait_queue_head_t done_wq; 529 530 struct device *alloc_devs[VB2_MAX_PLANES]; 531 532 unsigned int streaming:1; 533 unsigned int start_streaming_called:1; 534 unsigned int error:1; 535 unsigned int waiting_for_buffers:1; 536 unsigned int is_multiplanar:1; 537 unsigned int is_output:1; 538 unsigned int copy_timestamp:1; 539 unsigned int last_buffer_dequeued:1; 540 541 struct vb2_fileio_data *fileio; 542 struct vb2_threadio_data *threadio; 543 544 #ifdef CONFIG_VIDEO_ADV_DEBUG 545 /* 546 * Counters for how often these queue-related ops are 547 * called. Used to check for unbalanced ops. 548 */ 549 u32 cnt_queue_setup; 550 u32 cnt_wait_prepare; 551 u32 cnt_wait_finish; 552 u32 cnt_start_streaming; 553 u32 cnt_stop_streaming; 554 #endif 555 }; 556 557 /** 558 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane 559 * @vb: vb2_buffer to which the plane in question belongs to 560 * @plane_no: plane number for which the address is to be returned 561 * 562 * This function returns a kernel virtual address of a given plane if 563 * such a mapping exist, NULL otherwise. 564 */ 565 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); 566 567 /** 568 * vb2_plane_cookie() - Return allocator specific cookie for the given plane 569 * @vb: vb2_buffer to which the plane in question belongs to 570 * @plane_no: plane number for which the cookie is to be returned 571 * 572 * This function returns an allocator specific cookie for a given plane if 573 * available, NULL otherwise. The allocator should provide some simple static 574 * inline function, which would convert this cookie to the allocator specific 575 * type that can be used directly by the driver to access the buffer. This can 576 * be for example physical address, pointer to scatter list or IOMMU mapping. 577 */ 578 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); 579 580 /** 581 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished 582 * @vb: vb2_buffer returned from the driver 583 * @state: either %VB2_BUF_STATE_DONE if the operation finished 584 * successfully, %VB2_BUF_STATE_ERROR if the operation finished 585 * with an error or %VB2_BUF_STATE_QUEUED if the driver wants to 586 * requeue buffers. If start_streaming fails then it should return 587 * buffers with state %VB2_BUF_STATE_QUEUED to put them back into 588 * the queue. 589 * 590 * This function should be called by the driver after a hardware operation on 591 * a buffer is finished and the buffer may be returned to userspace. The driver 592 * cannot use this buffer anymore until it is queued back to it by videobuf 593 * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued 594 * to the driver by &vb2_ops->buf_queue can be passed to this function. 595 * 596 * While streaming a buffer can only be returned in state DONE or ERROR. 597 * The start_streaming op can also return them in case the DMA engine cannot 598 * be started for some reason. In that case the buffers should be returned with 599 * state QUEUED. 600 */ 601 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); 602 603 /** 604 * vb2_discard_done() - discard all buffers marked as DONE 605 * @q: videobuf2 queue 606 * 607 * This function is intended to be used with suspend/resume operations. It 608 * discards all 'done' buffers as they would be too old to be requested after 609 * resume. 610 * 611 * Drivers must stop the hardware and synchronize with interrupt handlers and/or 612 * delayed works before calling this function to make sure no buffer will be 613 * touched by the driver and/or hardware. 614 */ 615 void vb2_discard_done(struct vb2_queue *q); 616 617 /** 618 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2 619 * @q: videobuf2 queue 620 * 621 * This function will wait until all buffers that have been given to the driver 622 * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It 623 * doesn't call wait_prepare()/wait_finish() pair. It is intended to be called 624 * with all locks taken, for example from &vb2_ops->stop_streaming callback. 625 */ 626 int vb2_wait_for_all_buffers(struct vb2_queue *q); 627 628 /** 629 * vb2_core_querybuf() - query video buffer information 630 * @q: videobuf queue 631 * @index: id number of the buffer 632 * @pb: buffer struct passed from userspace 633 * 634 * Should be called from vidioc_querybuf ioctl handler in driver. 635 * The passed buffer should have been verified. 636 * This function fills the relevant information for the userspace. 637 */ 638 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); 639 640 /** 641 * vb2_core_reqbufs() - Initiate streaming 642 * @q: videobuf2 queue 643 * @memory: memory type 644 * @count: requested buffer count 645 * 646 * Should be called from vidioc_reqbufs ioctl handler of a driver. 647 * 648 * This function: 649 * 650 * #) verifies streaming parameters passed from the userspace, 651 * #) sets up the queue, 652 * #) negotiates number of buffers and planes per buffer with the driver 653 * to be used during streaming, 654 * #) allocates internal buffer structures (struct vb2_buffer), according to 655 * the agreed parameters, 656 * #) for MMAP memory type, allocates actual video memory, using the 657 * memory handling/allocation routines provided during queue initialization 658 * 659 * If req->count is 0, all the memory will be freed instead. 660 * If the queue has been allocated previously (by a previous vb2_reqbufs) call 661 * and the queue is not busy, memory will be reallocated. 662 * 663 * The return values from this function are intended to be directly returned 664 * from vidioc_reqbufs handler in driver. 665 */ 666 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 667 unsigned int *count); 668 669 /** 670 * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs 671 * @q: videobuf2 queue 672 * @memory: memory type 673 * @count: requested buffer count 674 * @requested_planes: number of planes requested 675 * @requested_sizes: array with the size of the planes 676 * 677 * Should be called from VIDIOC_CREATE_BUFS() ioctl handler of a driver. 678 * This function: 679 * 680 * #) verifies parameter sanity 681 * #) calls the .queue_setup() queue operation 682 * #) performs any necessary memory allocations 683 * 684 * Return: the return values from this function are intended to be directly 685 * returned from VIDIOC_CREATE_BUFS() handler in driver. 686 */ 687 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 688 unsigned int *count, unsigned int requested_planes, 689 const unsigned int requested_sizes[]); 690 691 /** 692 * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace 693 * to the kernel 694 * @q: videobuf2 queue 695 * @index: id number of the buffer 696 * @pb: buffer structure passed from userspace to vidioc_prepare_buf 697 * handler in driver 698 * 699 * Should be called from vidioc_prepare_buf ioctl handler of a driver. 700 * The passed buffer should have been verified. 701 * This function calls buf_prepare callback in the driver (if provided), 702 * in which driver-specific buffer initialization can be performed, 703 * 704 * The return values from this function are intended to be directly returned 705 * from vidioc_prepare_buf handler in driver. 706 */ 707 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); 708 709 /** 710 * vb2_core_qbuf() - Queue a buffer from userspace 711 * 712 * @q: videobuf2 queue 713 * @index: id number of the buffer 714 * @pb: buffer structure passed from userspace to vidioc_qbuf handler 715 * in driver 716 * 717 * Should be called from vidioc_qbuf ioctl handler of a driver. 718 * The passed buffer should have been verified. 719 * 720 * This function: 721 * 722 * #) if necessary, calls buf_prepare callback in the driver (if provided), in 723 * which driver-specific buffer initialization can be performed, 724 * #) if streaming is on, queues the buffer in driver by the means of 725 * &vb2_ops->buf_queue callback for processing. 726 * 727 * The return values from this function are intended to be directly returned 728 * from vidioc_qbuf handler in driver. 729 */ 730 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); 731 732 /** 733 * vb2_core_dqbuf() - Dequeue a buffer to the userspace 734 * @q: videobuf2 queue 735 * @pindex: pointer to the buffer index. May be NULL 736 * @pb: buffer structure passed from userspace to vidioc_dqbuf handler 737 * in driver 738 * @nonblocking: if true, this call will not sleep waiting for a buffer if no 739 * buffers ready for dequeuing are present. Normally the driver 740 * would be passing (file->f_flags & O_NONBLOCK) here 741 * 742 * Should be called from vidioc_dqbuf ioctl handler of a driver. 743 * The passed buffer should have been verified. 744 * 745 * This function: 746 * 747 * #) calls buf_finish callback in the driver (if provided), in which 748 * driver can perform any additional operations that may be required before 749 * returning the buffer to userspace, such as cache sync, 750 * #) the buffer struct members are filled with relevant information for 751 * the userspace. 752 * 753 * The return values from this function are intended to be directly returned 754 * from vidioc_dqbuf handler in driver. 755 */ 756 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, 757 bool nonblocking); 758 759 int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 760 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); 761 762 /** 763 * vb2_core_expbuf() - Export a buffer as a file descriptor 764 * @q: videobuf2 queue 765 * @fd: file descriptor associated with DMABUF (set by driver) * 766 * @type: buffer type 767 * @index: id number of the buffer 768 * @plane: index of the plane to be exported, 0 for single plane queues 769 * @flags: flags for newly created file, currently only O_CLOEXEC is 770 * supported, refer to manual of open syscall for more details 771 * 772 * The return values from this function are intended to be directly returned 773 * from vidioc_expbuf handler in driver. 774 */ 775 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 776 unsigned int index, unsigned int plane, unsigned int flags); 777 778 /** 779 * vb2_core_queue_init() - initialize a videobuf2 queue 780 * @q: videobuf2 queue; this structure should be allocated in driver 781 * 782 * The vb2_queue structure should be allocated by the driver. The driver is 783 * responsible of clearing it's content and setting initial values for some 784 * required entries before calling this function. 785 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer 786 * to the struct vb2_queue description in include/media/videobuf2-core.h 787 * for more information. 788 */ 789 int vb2_core_queue_init(struct vb2_queue *q); 790 791 /** 792 * vb2_core_queue_release() - stop streaming, release the queue and free memory 793 * @q: videobuf2 queue 794 * 795 * This function stops streaming and performs necessary clean ups, including 796 * freeing video buffer memory. The driver is responsible for freeing 797 * the vb2_queue structure itself. 798 */ 799 void vb2_core_queue_release(struct vb2_queue *q); 800 801 /** 802 * vb2_queue_error() - signal a fatal error on the queue 803 * @q: videobuf2 queue 804 * 805 * Flag that a fatal unrecoverable error has occurred and wake up all processes 806 * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing 807 * buffers will return -EIO. 808 * 809 * The error flag will be cleared when cancelling the queue, either from 810 * vb2_streamoff or vb2_queue_release. Drivers should thus not call this 811 * function before starting the stream, otherwise the error flag will remain set 812 * until the queue is released when closing the device node. 813 */ 814 void vb2_queue_error(struct vb2_queue *q); 815 816 /** 817 * vb2_mmap() - map video buffers into application address space 818 * @q: videobuf2 queue 819 * @vma: vma passed to the mmap file operation handler in the driver 820 * 821 * Should be called from mmap file operation handler of a driver. 822 * This function maps one plane of one of the available video buffers to 823 * userspace. To map whole video memory allocated on reqbufs, this function 824 * has to be called once per each plane per each buffer previously allocated. 825 * 826 * When the userspace application calls mmap, it passes to it an offset returned 827 * to it earlier by the means of vidioc_querybuf handler. That offset acts as 828 * a "cookie", which is then used to identify the plane to be mapped. 829 * This function finds a plane with a matching offset and a mapping is performed 830 * by the means of a provided memory operation. 831 * 832 * The return values from this function are intended to be directly returned 833 * from the mmap handler in driver. 834 */ 835 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); 836 837 #ifndef CONFIG_MMU 838 unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 839 unsigned long addr, 840 unsigned long len, 841 unsigned long pgoff, 842 unsigned long flags); 843 #endif 844 845 /** 846 * vb2_core_poll() - implements poll userspace operation 847 * @q: videobuf2 queue 848 * @file: file argument passed to the poll file operation handler 849 * @wait: wait argument passed to the poll file operation handler 850 * 851 * This function implements poll file operation handler for a driver. 852 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will 853 * be informed that the file descriptor of a video device is available for 854 * reading. 855 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor 856 * will be reported as available for writing. 857 * 858 * The return values from this function are intended to be directly returned 859 * from poll handler in driver. 860 */ 861 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file, 862 poll_table *wait); 863 864 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, 865 loff_t *ppos, int nonblock); 866 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, 867 loff_t *ppos, int nonblock); 868 869 /** 870 * typedef vb2_thread_fnc - callback function for use with vb2_thread 871 * 872 * @vb: pointer to struct &vb2_buffer 873 * @priv: pointer to a private pointer 874 * 875 * This is called whenever a buffer is dequeued in the thread. 876 */ 877 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); 878 879 /** 880 * vb2_thread_start() - start a thread for the given queue. 881 * @q: videobuf queue 882 * @fnc: callback function 883 * @priv: priv pointer passed to the callback function 884 * @thread_name:the name of the thread. This will be prefixed with "vb2-". 885 * 886 * This starts a thread that will queue and dequeue until an error occurs 887 * or @vb2_thread_stop is called. 888 * 889 * .. attention:: 890 * 891 * This function should not be used for anything else but the videobuf2-dvb 892 * support. If you think you have another good use-case for this, then please 893 * contact the linux-media mailing list first. 894 */ 895 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, 896 const char *thread_name); 897 898 /** 899 * vb2_thread_stop() - stop the thread for the given queue. 900 * @q: videobuf queue 901 */ 902 int vb2_thread_stop(struct vb2_queue *q); 903 904 /** 905 * vb2_is_streaming() - return streaming status of the queue 906 * @q: videobuf queue 907 */ 908 static inline bool vb2_is_streaming(struct vb2_queue *q) 909 { 910 return q->streaming; 911 } 912 913 /** 914 * vb2_fileio_is_active() - return true if fileio is active. 915 * @q: videobuf queue 916 * 917 * This returns true if read() or write() is used to stream the data 918 * as opposed to stream I/O. This is almost never an important distinction, 919 * except in rare cases. One such case is that using read() or write() to 920 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there 921 * is no way you can pass the field information of each buffer to/from 922 * userspace. A driver that supports this field format should check for 923 * this in the queue_setup op and reject it if this function returns true. 924 */ 925 static inline bool vb2_fileio_is_active(struct vb2_queue *q) 926 { 927 return q->fileio; 928 } 929 930 /** 931 * vb2_is_busy() - return busy status of the queue 932 * @q: videobuf queue 933 * 934 * This function checks if queue has any buffers allocated. 935 */ 936 static inline bool vb2_is_busy(struct vb2_queue *q) 937 { 938 return (q->num_buffers > 0); 939 } 940 941 /** 942 * vb2_get_drv_priv() - return driver private data associated with the queue 943 * @q: videobuf queue 944 */ 945 static inline void *vb2_get_drv_priv(struct vb2_queue *q) 946 { 947 return q->drv_priv; 948 } 949 950 /** 951 * vb2_set_plane_payload() - set bytesused for the plane plane_no 952 * @vb: buffer for which plane payload should be set 953 * @plane_no: plane number for which payload should be set 954 * @size: payload in bytes 955 */ 956 static inline void vb2_set_plane_payload(struct vb2_buffer *vb, 957 unsigned int plane_no, unsigned long size) 958 { 959 if (plane_no < vb->num_planes) 960 vb->planes[plane_no].bytesused = size; 961 } 962 963 /** 964 * vb2_get_plane_payload() - get bytesused for the plane plane_no 965 * @vb: buffer for which plane payload should be set 966 * @plane_no: plane number for which payload should be set 967 */ 968 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, 969 unsigned int plane_no) 970 { 971 if (plane_no < vb->num_planes) 972 return vb->planes[plane_no].bytesused; 973 return 0; 974 } 975 976 /** 977 * vb2_plane_size() - return plane size in bytes 978 * @vb: buffer for which plane size should be returned 979 * @plane_no: plane number for which size should be returned 980 */ 981 static inline unsigned long 982 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) 983 { 984 if (plane_no < vb->num_planes) 985 return vb->planes[plane_no].length; 986 return 0; 987 } 988 989 /** 990 * vb2_start_streaming_called() - return streaming status of driver 991 * @q: videobuf queue 992 */ 993 static inline bool vb2_start_streaming_called(struct vb2_queue *q) 994 { 995 return q->start_streaming_called; 996 } 997 998 /** 999 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue 1000 * @q: videobuf queue 1001 */ 1002 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) 1003 { 1004 q->last_buffer_dequeued = false; 1005 } 1006 1007 /* 1008 * The following functions are not part of the vb2 core API, but are useful 1009 * functions for videobuf2-*. 1010 */ 1011 1012 /** 1013 * vb2_buffer_in_use() - return true if the buffer is in use and 1014 * the queue cannot be freed (by the means of REQBUFS(0)) call 1015 * 1016 * @vb: buffer for which plane size should be returned 1017 * @q: videobuf queue 1018 */ 1019 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); 1020 1021 /** 1022 * vb2_verify_memory_type() - Check whether the memory type and buffer type 1023 * passed to a buffer operation are compatible with the queue. 1024 * 1025 * @q: videobuf queue 1026 * @memory: memory model, as defined by enum &vb2_memory. 1027 * @type: private buffer type whose content is defined by the vb2-core 1028 * caller. For example, for V4L2, it should match 1029 * the types defined on enum &v4l2_buf_type 1030 */ 1031 int vb2_verify_memory_type(struct vb2_queue *q, 1032 enum vb2_memory memory, unsigned int type); 1033 #endif /* _MEDIA_VIDEOBUF2_CORE_H */ 1034