1 /* 2 * videobuf2-core.h - Video Buffer 2 Core Framework 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * 6 * Author: Pawel Osciak <pawel@osciak.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation. 11 */ 12 #ifndef _MEDIA_VIDEOBUF2_CORE_H 13 #define _MEDIA_VIDEOBUF2_CORE_H 14 15 #include <linux/mm_types.h> 16 #include <linux/mutex.h> 17 #include <linux/poll.h> 18 #include <linux/dma-buf.h> 19 20 #define VB2_MAX_FRAME (32) 21 #define VB2_MAX_PLANES (8) 22 23 enum vb2_memory { 24 VB2_MEMORY_UNKNOWN = 0, 25 VB2_MEMORY_MMAP = 1, 26 VB2_MEMORY_USERPTR = 2, 27 VB2_MEMORY_DMABUF = 4, 28 }; 29 30 struct vb2_alloc_ctx; 31 struct vb2_fileio_data; 32 struct vb2_threadio_data; 33 34 /** 35 * struct vb2_mem_ops - memory handling/memory allocator operations 36 * @alloc: allocate video memory and, optionally, allocator private data, 37 * return NULL on failure or a pointer to allocator private, 38 * per-buffer data on success; the returned private structure 39 * will then be passed as buf_priv argument to other ops in this 40 * structure. Additional gfp_flags to use when allocating the 41 * are also passed to this operation. These flags are from the 42 * gfp_flags field of vb2_queue. 43 * @put: inform the allocator that the buffer will no longer be used; 44 * usually will result in the allocator freeing the buffer (if 45 * no other users of this buffer are present); the buf_priv 46 * argument is the allocator private per-buffer structure 47 * previously returned from the alloc callback. 48 * @get_dmabuf: acquire userspace memory for a hardware operation; used for 49 * DMABUF memory types. 50 * @get_userptr: acquire userspace memory for a hardware operation; used for 51 * USERPTR memory types; vaddr is the address passed to the 52 * videobuf layer when queuing a video buffer of USERPTR type; 53 * should return an allocator private per-buffer structure 54 * associated with the buffer on success, NULL on failure; 55 * the returned private structure will then be passed as buf_priv 56 * argument to other ops in this structure. 57 * @put_userptr: inform the allocator that a USERPTR buffer will no longer 58 * be used. 59 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation; 60 * used for DMABUF memory types; alloc_ctx is the alloc context 61 * dbuf is the shared dma_buf; returns NULL on failure; 62 * allocator private per-buffer structure on success; 63 * this needs to be used for further accesses to the buffer. 64 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF 65 * buffer is no longer used; the buf_priv argument is the 66 * allocator private per-buffer structure previously returned 67 * from the attach_dmabuf callback. 68 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator 69 * of dmabuf is informed that this driver is going to use the 70 * dmabuf. 71 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified 72 * that this driver is done using the dmabuf for now. 73 * @prepare: called every time the buffer is passed from userspace to the 74 * driver, useful for cache synchronisation, optional. 75 * @finish: called every time the buffer is passed back from the driver 76 * to the userspace, also optional. 77 * @vaddr: return a kernel virtual address to a given memory buffer 78 * associated with the passed private structure or NULL if no 79 * such mapping exists. 80 * @cookie: return allocator specific cookie for a given memory buffer 81 * associated with the passed private structure or NULL if not 82 * available. 83 * @num_users: return the current number of users of a memory buffer; 84 * return 1 if the videobuf layer (or actually the driver using 85 * it) is the only user. 86 * @mmap: setup a userspace mapping for a given memory buffer under 87 * the provided virtual memory region. 88 * 89 * Required ops for USERPTR types: get_userptr, put_userptr. 90 * Required ops for MMAP types: alloc, put, num_users, mmap. 91 * Required ops for read/write access types: alloc, put, num_users, vaddr. 92 * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf, 93 * unmap_dmabuf. 94 */ 95 struct vb2_mem_ops { 96 void *(*alloc)(void *alloc_ctx, unsigned long size, 97 enum dma_data_direction dma_dir, 98 gfp_t gfp_flags); 99 void (*put)(void *buf_priv); 100 struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags); 101 102 void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr, 103 unsigned long size, 104 enum dma_data_direction dma_dir); 105 void (*put_userptr)(void *buf_priv); 106 107 void (*prepare)(void *buf_priv); 108 void (*finish)(void *buf_priv); 109 110 void *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf, 111 unsigned long size, 112 enum dma_data_direction dma_dir); 113 void (*detach_dmabuf)(void *buf_priv); 114 int (*map_dmabuf)(void *buf_priv); 115 void (*unmap_dmabuf)(void *buf_priv); 116 117 void *(*vaddr)(void *buf_priv); 118 void *(*cookie)(void *buf_priv); 119 120 unsigned int (*num_users)(void *buf_priv); 121 122 int (*mmap)(void *buf_priv, struct vm_area_struct *vma); 123 }; 124 125 /** 126 * struct vb2_plane - plane information 127 * @mem_priv: private data with this plane 128 * @dbuf: dma_buf - shared buffer object 129 * @dbuf_mapped: flag to show whether dbuf is mapped or not 130 * @bytesused: number of bytes occupied by data in the plane (payload) 131 * @length: size of this plane (NOT the payload) in bytes 132 * @min_length: minimum required size of this plane (NOT the payload) in bytes. 133 * @length is always greater or equal to @min_length. 134 * @offset: when memory in the associated struct vb2_buffer is 135 * VB2_MEMORY_MMAP, equals the offset from the start of 136 * the device memory for this plane (or is a "cookie" that 137 * should be passed to mmap() called on the video node) 138 * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer 139 * pointing to this plane 140 * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file 141 * descriptor associated with this plane 142 * @m: Union with memtype-specific data (@offset, @userptr or 143 * @fd). 144 * @data_offset: offset in the plane to the start of data; usually 0, 145 * unless there is a header in front of the data 146 * Should contain enough information to be able to cover all the fields 147 * of struct v4l2_plane at videodev2.h 148 */ 149 struct vb2_plane { 150 void *mem_priv; 151 struct dma_buf *dbuf; 152 unsigned int dbuf_mapped; 153 unsigned int bytesused; 154 unsigned int length; 155 unsigned int min_length; 156 union { 157 unsigned int offset; 158 unsigned long userptr; 159 int fd; 160 } m; 161 unsigned int data_offset; 162 }; 163 164 /** 165 * enum vb2_io_modes - queue access methods 166 * @VB2_MMAP: driver supports MMAP with streaming API 167 * @VB2_USERPTR: driver supports USERPTR with streaming API 168 * @VB2_READ: driver supports read() style access 169 * @VB2_WRITE: driver supports write() style access 170 * @VB2_DMABUF: driver supports DMABUF with streaming API 171 */ 172 enum vb2_io_modes { 173 VB2_MMAP = (1 << 0), 174 VB2_USERPTR = (1 << 1), 175 VB2_READ = (1 << 2), 176 VB2_WRITE = (1 << 3), 177 VB2_DMABUF = (1 << 4), 178 }; 179 180 /** 181 * enum vb2_buffer_state - current video buffer state 182 * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control 183 * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf 184 * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver 185 * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver 186 * @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver 187 * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used 188 * in a hardware operation 189 * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but 190 * not yet dequeued to userspace 191 * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer 192 * has ended with an error, which will be reported 193 * to the userspace when it is dequeued 194 */ 195 enum vb2_buffer_state { 196 VB2_BUF_STATE_DEQUEUED, 197 VB2_BUF_STATE_PREPARING, 198 VB2_BUF_STATE_PREPARED, 199 VB2_BUF_STATE_QUEUED, 200 VB2_BUF_STATE_REQUEUEING, 201 VB2_BUF_STATE_ACTIVE, 202 VB2_BUF_STATE_DONE, 203 VB2_BUF_STATE_ERROR, 204 }; 205 206 struct vb2_queue; 207 208 /** 209 * struct vb2_buffer - represents a video buffer 210 * @vb2_queue: the queue to which this driver belongs 211 * @index: id number of the buffer 212 * @type: buffer type 213 * @memory: the method, in which the actual data is passed 214 * @num_planes: number of planes in the buffer 215 * on an internal driver queue 216 * @planes: private per-plane information; do not change 217 * @timestamp: frame timestamp in ns 218 */ 219 struct vb2_buffer { 220 struct vb2_queue *vb2_queue; 221 unsigned int index; 222 unsigned int type; 223 unsigned int memory; 224 unsigned int num_planes; 225 struct vb2_plane planes[VB2_MAX_PLANES]; 226 u64 timestamp; 227 228 /* private: internal use only 229 * 230 * state: current buffer state; do not change 231 * queued_entry: entry on the queued buffers list, which holds 232 * all buffers queued from userspace 233 * done_entry: entry on the list that stores all buffers ready 234 * to be dequeued to userspace 235 */ 236 enum vb2_buffer_state state; 237 238 struct list_head queued_entry; 239 struct list_head done_entry; 240 #ifdef CONFIG_VIDEO_ADV_DEBUG 241 /* 242 * Counters for how often these buffer-related ops are 243 * called. Used to check for unbalanced ops. 244 */ 245 u32 cnt_mem_alloc; 246 u32 cnt_mem_put; 247 u32 cnt_mem_get_dmabuf; 248 u32 cnt_mem_get_userptr; 249 u32 cnt_mem_put_userptr; 250 u32 cnt_mem_prepare; 251 u32 cnt_mem_finish; 252 u32 cnt_mem_attach_dmabuf; 253 u32 cnt_mem_detach_dmabuf; 254 u32 cnt_mem_map_dmabuf; 255 u32 cnt_mem_unmap_dmabuf; 256 u32 cnt_mem_vaddr; 257 u32 cnt_mem_cookie; 258 u32 cnt_mem_num_users; 259 u32 cnt_mem_mmap; 260 261 u32 cnt_buf_init; 262 u32 cnt_buf_prepare; 263 u32 cnt_buf_finish; 264 u32 cnt_buf_cleanup; 265 u32 cnt_buf_queue; 266 267 /* This counts the number of calls to vb2_buffer_done() */ 268 u32 cnt_buf_done; 269 #endif 270 }; 271 272 /** 273 * struct vb2_ops - driver-specific callbacks 274 * 275 * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS 276 * handlers before memory allocation. It can be called 277 * twice: if the original number of requested buffers 278 * could not be allocated, then it will be called a 279 * second time with the actually allocated number of 280 * buffers to verify if that is OK. 281 * The driver should return the required number of buffers 282 * in *num_buffers, the required number of planes per 283 * buffer in *num_planes, the size of each plane should be 284 * set in the sizes[] array and optional per-plane 285 * allocator specific context in the alloc_ctxs[] array. 286 * When called from VIDIOC_REQBUFS, *num_planes == 0, the 287 * driver has to use the currently configured format to 288 * determine the plane sizes and *num_buffers is the total 289 * number of buffers that are being allocated. When called 290 * from VIDIOC_CREATE_BUFS, *num_planes != 0 and it 291 * describes the requested number of planes and sizes[] 292 * contains the requested plane sizes. If either 293 * *num_planes or the requested sizes are invalid callback 294 * must return -EINVAL. In this case *num_buffers are 295 * being allocated additionally to q->num_buffers. 296 * @wait_prepare: release any locks taken while calling vb2 functions; 297 * it is called before an ioctl needs to wait for a new 298 * buffer to arrive; required to avoid a deadlock in 299 * blocking access type. 300 * @wait_finish: reacquire all locks released in the previous callback; 301 * required to continue operation after sleeping while 302 * waiting for a new buffer to arrive. 303 * @buf_init: called once after allocating a buffer (in MMAP case) 304 * or after acquiring a new USERPTR buffer; drivers may 305 * perform additional buffer-related initialization; 306 * initialization failure (return != 0) will prevent 307 * queue setup from completing successfully; optional. 308 * @buf_prepare: called every time the buffer is queued from userspace 309 * and from the VIDIOC_PREPARE_BUF ioctl; drivers may 310 * perform any initialization required before each 311 * hardware operation in this callback; drivers can 312 * access/modify the buffer here as it is still synced for 313 * the CPU; drivers that support VIDIOC_CREATE_BUFS must 314 * also validate the buffer size; if an error is returned, 315 * the buffer will not be queued in driver; optional. 316 * @buf_finish: called before every dequeue of the buffer back to 317 * userspace; the buffer is synced for the CPU, so drivers 318 * can access/modify the buffer contents; drivers may 319 * perform any operations required before userspace 320 * accesses the buffer; optional. The buffer state can be 321 * one of the following: DONE and ERROR occur while 322 * streaming is in progress, and the PREPARED state occurs 323 * when the queue has been canceled and all pending 324 * buffers are being returned to their default DEQUEUED 325 * state. Typically you only have to do something if the 326 * state is VB2_BUF_STATE_DONE, since in all other cases 327 * the buffer contents will be ignored anyway. 328 * @buf_cleanup: called once before the buffer is freed; drivers may 329 * perform any additional cleanup; optional. 330 * @start_streaming: called once to enter 'streaming' state; the driver may 331 * receive buffers with @buf_queue callback before 332 * @start_streaming is called; the driver gets the number 333 * of already queued buffers in count parameter; driver 334 * can return an error if hardware fails, in that case all 335 * buffers that have been already given by the @buf_queue 336 * callback are to be returned by the driver by calling 337 * @vb2_buffer_done(VB2_BUF_STATE_QUEUED). 338 * If you need a minimum number of buffers before you can 339 * start streaming, then set @min_buffers_needed in the 340 * vb2_queue structure. If that is non-zero then 341 * start_streaming won't be called until at least that 342 * many buffers have been queued up by userspace. 343 * @stop_streaming: called when 'streaming' state must be disabled; driver 344 * should stop any DMA transactions or wait until they 345 * finish and give back all buffers it got from buf_queue() 346 * callback by calling @vb2_buffer_done() with either 347 * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use 348 * vb2_wait_for_all_buffers() function 349 * @buf_queue: passes buffer vb to the driver; driver may start 350 * hardware operation on this buffer; driver should give 351 * the buffer back by calling vb2_buffer_done() function; 352 * it is allways called after calling STREAMON ioctl; 353 * might be called before start_streaming callback if user 354 * pre-queued buffers before calling STREAMON. 355 */ 356 struct vb2_ops { 357 int (*queue_setup)(struct vb2_queue *q, 358 unsigned int *num_buffers, unsigned int *num_planes, 359 unsigned int sizes[], void *alloc_ctxs[]); 360 361 void (*wait_prepare)(struct vb2_queue *q); 362 void (*wait_finish)(struct vb2_queue *q); 363 364 int (*buf_init)(struct vb2_buffer *vb); 365 int (*buf_prepare)(struct vb2_buffer *vb); 366 void (*buf_finish)(struct vb2_buffer *vb); 367 void (*buf_cleanup)(struct vb2_buffer *vb); 368 369 int (*start_streaming)(struct vb2_queue *q, unsigned int count); 370 void (*stop_streaming)(struct vb2_queue *q); 371 372 void (*buf_queue)(struct vb2_buffer *vb); 373 }; 374 375 /** 376 * struct vb2_ops - driver-specific callbacks 377 * 378 * @fill_user_buffer: given a vb2_buffer fill in the userspace structure. 379 * For V4L2 this is a struct v4l2_buffer. 380 * @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer. 381 * If the userspace structure is invalid, then this op 382 * will return an error. 383 * @copy_timestamp: copy the timestamp from a userspace structure to 384 * the vb2_buffer struct. 385 */ 386 struct vb2_buf_ops { 387 void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); 388 int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb, 389 struct vb2_plane *planes); 390 void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); 391 }; 392 393 /** 394 * struct vb2_queue - a videobuf queue 395 * 396 * @type: private buffer type whose content is defined by the vb2-core 397 * caller. For example, for V4L2, it should match 398 * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h 399 * @io_modes: supported io methods (see vb2_io_modes enum) 400 * @fileio_read_once: report EOF after reading the first buffer 401 * @fileio_write_immediately: queue buffer after each write() call 402 * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver 403 * @lock: pointer to a mutex that protects the vb2_queue struct. The 404 * driver can set this to a mutex to let the v4l2 core serialize 405 * the queuing ioctls. If the driver wants to handle locking 406 * itself, then this should be set to NULL. This lock is not used 407 * by the videobuf2 core API. 408 * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle 409 * that called reqbufs, create_buffers or started fileio. 410 * This field is not used by the videobuf2 core API, but it allows 411 * drivers to easily associate an owner filehandle with the queue. 412 * @ops: driver-specific callbacks 413 * @mem_ops: memory allocator specific callbacks 414 * @buf_ops: callbacks to deliver buffer information 415 * between user-space and kernel-space 416 * @drv_priv: driver private data 417 * @buf_struct_size: size of the driver-specific buffer structure; 418 * "0" indicates the driver doesn't want to use a custom buffer 419 * structure type. for example, sizeof(struct vb2_v4l2_buffer) 420 * will be used for v4l2. 421 * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and 422 * V4L2_BUF_FLAG_TSTAMP_SRC_* 423 * @gfp_flags: additional gfp flags used when allocating the buffers. 424 * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 425 * to force the buffer allocation to a specific memory zone. 426 * @min_buffers_needed: the minimum number of buffers needed before 427 * start_streaming() can be called. Used when a DMA engine 428 * cannot be started unless at least this number of buffers 429 * have been queued into the driver. 430 */ 431 /* 432 * Private elements (won't appear at the DocBook): 433 * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped 434 * @memory: current memory type used 435 * @bufs: videobuf buffer structures 436 * @num_buffers: number of allocated/used buffers 437 * @queued_list: list of buffers currently queued from userspace 438 * @queued_count: number of buffers queued and ready for streaming. 439 * @owned_by_drv_count: number of buffers owned by the driver 440 * @done_list: list of buffers ready to be dequeued to userspace 441 * @done_lock: lock to protect done_list list 442 * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued 443 * @alloc_ctx: memory type/allocator-specific contexts for each plane 444 * @streaming: current streaming state 445 * @start_streaming_called: start_streaming() was called successfully and we 446 * started streaming. 447 * @error: a fatal error occurred on the queue 448 * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for 449 * buffers. Only set for capture queues if qbuf has not yet been 450 * called since poll() needs to return POLLERR in that situation. 451 * @is_multiplanar: set if buffer type is multiplanar 452 * @is_output: set if buffer type is output 453 * @copy_timestamp: set if vb2-core should set timestamps 454 * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the 455 * last decoded buffer was already dequeued. Set for capture queues 456 * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued. 457 * @fileio: file io emulator internal data, used only if emulator is active 458 * @threadio: thread io internal data, used only if thread is active 459 */ 460 struct vb2_queue { 461 unsigned int type; 462 unsigned int io_modes; 463 unsigned fileio_read_once:1; 464 unsigned fileio_write_immediately:1; 465 unsigned allow_zero_bytesused:1; 466 467 struct mutex *lock; 468 void *owner; 469 470 const struct vb2_ops *ops; 471 const struct vb2_mem_ops *mem_ops; 472 const struct vb2_buf_ops *buf_ops; 473 474 void *drv_priv; 475 unsigned int buf_struct_size; 476 u32 timestamp_flags; 477 gfp_t gfp_flags; 478 u32 min_buffers_needed; 479 480 /* private: internal use only */ 481 struct mutex mmap_lock; 482 unsigned int memory; 483 struct vb2_buffer *bufs[VB2_MAX_FRAME]; 484 unsigned int num_buffers; 485 486 struct list_head queued_list; 487 unsigned int queued_count; 488 489 atomic_t owned_by_drv_count; 490 struct list_head done_list; 491 spinlock_t done_lock; 492 wait_queue_head_t done_wq; 493 494 void *alloc_ctx[VB2_MAX_PLANES]; 495 496 unsigned int streaming:1; 497 unsigned int start_streaming_called:1; 498 unsigned int error:1; 499 unsigned int waiting_for_buffers:1; 500 unsigned int is_multiplanar:1; 501 unsigned int is_output:1; 502 unsigned int copy_timestamp:1; 503 unsigned int last_buffer_dequeued:1; 504 505 struct vb2_fileio_data *fileio; 506 struct vb2_threadio_data *threadio; 507 508 #ifdef CONFIG_VIDEO_ADV_DEBUG 509 /* 510 * Counters for how often these queue-related ops are 511 * called. Used to check for unbalanced ops. 512 */ 513 u32 cnt_queue_setup; 514 u32 cnt_wait_prepare; 515 u32 cnt_wait_finish; 516 u32 cnt_start_streaming; 517 u32 cnt_stop_streaming; 518 #endif 519 }; 520 521 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); 522 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); 523 524 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); 525 void vb2_discard_done(struct vb2_queue *q); 526 int vb2_wait_for_all_buffers(struct vb2_queue *q); 527 528 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); 529 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 530 unsigned int *count); 531 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 532 unsigned int *count, unsigned requested_planes, 533 const unsigned int requested_sizes[]); 534 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); 535 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); 536 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, 537 bool nonblocking); 538 539 int vb2_core_streamon(struct vb2_queue *q, unsigned int type); 540 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); 541 542 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, 543 unsigned int index, unsigned int plane, unsigned int flags); 544 545 int vb2_core_queue_init(struct vb2_queue *q); 546 void vb2_core_queue_release(struct vb2_queue *q); 547 548 void vb2_queue_error(struct vb2_queue *q); 549 550 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); 551 #ifndef CONFIG_MMU 552 unsigned long vb2_get_unmapped_area(struct vb2_queue *q, 553 unsigned long addr, 554 unsigned long len, 555 unsigned long pgoff, 556 unsigned long flags); 557 #endif 558 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file, 559 poll_table *wait); 560 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, 561 loff_t *ppos, int nonblock); 562 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, 563 loff_t *ppos, int nonblock); 564 565 /* 566 * vb2_thread_fnc - callback function for use with vb2_thread 567 * 568 * This is called whenever a buffer is dequeued in the thread. 569 */ 570 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); 571 572 /** 573 * vb2_thread_start() - start a thread for the given queue. 574 * @q: videobuf queue 575 * @fnc: callback function 576 * @priv: priv pointer passed to the callback function 577 * @thread_name:the name of the thread. This will be prefixed with "vb2-". 578 * 579 * This starts a thread that will queue and dequeue until an error occurs 580 * or @vb2_thread_stop is called. 581 * 582 * This function should not be used for anything else but the videobuf2-dvb 583 * support. If you think you have another good use-case for this, then please 584 * contact the linux-media mailinglist first. 585 */ 586 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, 587 const char *thread_name); 588 589 /** 590 * vb2_thread_stop() - stop the thread for the given queue. 591 * @q: videobuf queue 592 */ 593 int vb2_thread_stop(struct vb2_queue *q); 594 595 /** 596 * vb2_is_streaming() - return streaming status of the queue 597 * @q: videobuf queue 598 */ 599 static inline bool vb2_is_streaming(struct vb2_queue *q) 600 { 601 return q->streaming; 602 } 603 604 /** 605 * vb2_fileio_is_active() - return true if fileio is active. 606 * @q: videobuf queue 607 * 608 * This returns true if read() or write() is used to stream the data 609 * as opposed to stream I/O. This is almost never an important distinction, 610 * except in rare cases. One such case is that using read() or write() to 611 * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there 612 * is no way you can pass the field information of each buffer to/from 613 * userspace. A driver that supports this field format should check for 614 * this in the queue_setup op and reject it if this function returns true. 615 */ 616 static inline bool vb2_fileio_is_active(struct vb2_queue *q) 617 { 618 return q->fileio; 619 } 620 621 /** 622 * vb2_is_busy() - return busy status of the queue 623 * @q: videobuf queue 624 * 625 * This function checks if queue has any buffers allocated. 626 */ 627 static inline bool vb2_is_busy(struct vb2_queue *q) 628 { 629 return (q->num_buffers > 0); 630 } 631 632 /** 633 * vb2_get_drv_priv() - return driver private data associated with the queue 634 * @q: videobuf queue 635 */ 636 static inline void *vb2_get_drv_priv(struct vb2_queue *q) 637 { 638 return q->drv_priv; 639 } 640 641 /** 642 * vb2_set_plane_payload() - set bytesused for the plane plane_no 643 * @vb: buffer for which plane payload should be set 644 * @plane_no: plane number for which payload should be set 645 * @size: payload in bytes 646 */ 647 static inline void vb2_set_plane_payload(struct vb2_buffer *vb, 648 unsigned int plane_no, unsigned long size) 649 { 650 if (plane_no < vb->num_planes) 651 vb->planes[plane_no].bytesused = size; 652 } 653 654 /** 655 * vb2_get_plane_payload() - get bytesused for the plane plane_no 656 * @vb: buffer for which plane payload should be set 657 * @plane_no: plane number for which payload should be set 658 */ 659 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, 660 unsigned int plane_no) 661 { 662 if (plane_no < vb->num_planes) 663 return vb->planes[plane_no].bytesused; 664 return 0; 665 } 666 667 /** 668 * vb2_plane_size() - return plane size in bytes 669 * @vb: buffer for which plane size should be returned 670 * @plane_no: plane number for which size should be returned 671 */ 672 static inline unsigned long 673 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) 674 { 675 if (plane_no < vb->num_planes) 676 return vb->planes[plane_no].length; 677 return 0; 678 } 679 680 /** 681 * vb2_start_streaming_called() - return streaming status of driver 682 * @q: videobuf queue 683 */ 684 static inline bool vb2_start_streaming_called(struct vb2_queue *q) 685 { 686 return q->start_streaming_called; 687 } 688 689 /** 690 * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue 691 * @q: videobuf queue 692 */ 693 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) 694 { 695 q->last_buffer_dequeued = false; 696 } 697 698 /* 699 * The following functions are not part of the vb2 core API, but are useful 700 * functions for videobuf2-*. 701 */ 702 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); 703 int vb2_verify_memory_type(struct vb2_queue *q, 704 enum vb2_memory memory, unsigned int type); 705 #endif /* _MEDIA_VIDEOBUF2_CORE_H */ 706