1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * 4 * V 4 L 2 D R I V E R H E L P E R A P I 5 * 6 * Moved from videodev2.h 7 * 8 * Some commonly needed functions for drivers (v4l2-common.o module) 9 */ 10 #ifndef _V4L2_DEV_H 11 #define _V4L2_DEV_H 12 13 #include <linux/poll.h> 14 #include <linux/fs.h> 15 #include <linux/device.h> 16 #include <linux/cdev.h> 17 #include <linux/mutex.h> 18 #include <linux/videodev2.h> 19 20 #include <media/media-entity.h> 21 22 #define VIDEO_MAJOR 81 23 24 /** 25 * enum vfl_devnode_type - type of V4L2 device node 26 * 27 * @VFL_TYPE_VIDEO: for video input/output devices 28 * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext) 29 * @VFL_TYPE_RADIO: for radio tuners 30 * @VFL_TYPE_SUBDEV: for V4L2 subdevices 31 * @VFL_TYPE_SDR: for Software Defined Radio tuners 32 * @VFL_TYPE_TOUCH: for touch sensors 33 * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum 34 */ 35 enum vfl_devnode_type { 36 VFL_TYPE_VIDEO, 37 VFL_TYPE_VBI, 38 VFL_TYPE_RADIO, 39 VFL_TYPE_SUBDEV, 40 VFL_TYPE_SDR, 41 VFL_TYPE_TOUCH, 42 VFL_TYPE_MAX /* Shall be the last one */ 43 }; 44 45 /** 46 * enum vfl_devnode_direction - Identifies if a &struct video_device 47 * corresponds to a receiver, a transmitter or a mem-to-mem device. 48 * 49 * @VFL_DIR_RX: device is a receiver. 50 * @VFL_DIR_TX: device is a transmitter. 51 * @VFL_DIR_M2M: device is a memory to memory device. 52 * 53 * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV. 54 */ 55 enum vfl_devnode_direction { 56 VFL_DIR_RX, 57 VFL_DIR_TX, 58 VFL_DIR_M2M, 59 }; 60 61 struct v4l2_ioctl_callbacks; 62 struct video_device; 63 struct v4l2_device; 64 struct v4l2_ctrl_handler; 65 struct dentry; 66 67 /** 68 * enum v4l2_video_device_flags - Flags used by &struct video_device 69 * 70 * @V4L2_FL_REGISTERED: 71 * indicates that a &struct video_device is registered. 72 * Drivers can clear this flag if they want to block all future 73 * device access. It is cleared by video_unregister_device. 74 * @V4L2_FL_USES_V4L2_FH: 75 * indicates that file->private_data points to &struct v4l2_fh. 76 * This flag is set by the core when v4l2_fh_init() is called. 77 * All new drivers should use it. 78 * @V4L2_FL_QUIRK_INVERTED_CROP: 79 * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and 80 * compose are swapped. If this flag is set, then the selection 81 * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c. 82 * This allows those drivers to correctly implement the selection API, 83 * but the old crop API will still work as expected in order to preserve 84 * backwards compatibility. 85 * Never set this flag for new drivers. 86 * @V4L2_FL_SUBDEV_RO_DEVNODE: 87 * indicates that the video device node is registered in read-only mode. 88 * The flag only applies to device nodes registered for sub-devices, it is 89 * set by the core when the sub-devices device nodes are registered with 90 * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl 91 * handler to restrict access to some ioctl calls. 92 */ 93 enum v4l2_video_device_flags { 94 V4L2_FL_REGISTERED = 0, 95 V4L2_FL_USES_V4L2_FH = 1, 96 V4L2_FL_QUIRK_INVERTED_CROP = 2, 97 V4L2_FL_SUBDEV_RO_DEVNODE = 3, 98 }; 99 100 /* Priority helper functions */ 101 102 /** 103 * struct v4l2_prio_state - stores the priority states 104 * 105 * @prios: array with elements to store the array priorities 106 * 107 * 108 * .. note:: 109 * The size of @prios array matches the number of priority types defined 110 * by enum &v4l2_priority. 111 */ 112 struct v4l2_prio_state { 113 atomic_t prios[4]; 114 }; 115 116 /** 117 * v4l2_prio_init - initializes a struct v4l2_prio_state 118 * 119 * @global: pointer to &struct v4l2_prio_state 120 */ 121 void v4l2_prio_init(struct v4l2_prio_state *global); 122 123 /** 124 * v4l2_prio_change - changes the v4l2 file handler priority 125 * 126 * @global: pointer to the &struct v4l2_prio_state of the device node. 127 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 128 * @new: Priority type requested, as defined by enum &v4l2_priority. 129 * 130 * .. note:: 131 * This function should be used only by the V4L2 core. 132 */ 133 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 134 enum v4l2_priority new); 135 136 /** 137 * v4l2_prio_open - Implements the priority logic for a file handler open 138 * 139 * @global: pointer to the &struct v4l2_prio_state of the device node. 140 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 141 * 142 * .. note:: 143 * This function should be used only by the V4L2 core. 144 */ 145 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 146 147 /** 148 * v4l2_prio_close - Implements the priority logic for a file handler close 149 * 150 * @global: pointer to the &struct v4l2_prio_state of the device node. 151 * @local: priority to be released, as defined by enum &v4l2_priority 152 * 153 * .. note:: 154 * This function should be used only by the V4L2 core. 155 */ 156 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 157 158 /** 159 * v4l2_prio_max - Return the maximum priority, as stored at the @global array. 160 * 161 * @global: pointer to the &struct v4l2_prio_state of the device node. 162 * 163 * .. note:: 164 * This function should be used only by the V4L2 core. 165 */ 166 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 167 168 /** 169 * v4l2_prio_check - Implements the priority logic for a file handler close 170 * 171 * @global: pointer to the &struct v4l2_prio_state of the device node. 172 * @local: desired priority, as defined by enum &v4l2_priority local 173 * 174 * .. note:: 175 * This function should be used only by the V4L2 core. 176 */ 177 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 178 179 /** 180 * struct v4l2_file_operations - fs operations used by a V4L2 device 181 * 182 * @owner: pointer to struct module 183 * @read: operations needed to implement the read() syscall 184 * @write: operations needed to implement the write() syscall 185 * @poll: operations needed to implement the poll() syscall 186 * @unlocked_ioctl: operations needed to implement the ioctl() syscall 187 * @compat_ioctl32: operations needed to implement the ioctl() syscall for 188 * the special case where the Kernel uses 64 bits instructions, but 189 * the userspace uses 32 bits. 190 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU 191 * @mmap: operations needed to implement the mmap() syscall 192 * @open: operations needed to implement the open() syscall 193 * @release: operations needed to implement the release() syscall 194 * 195 * .. note:: 196 * 197 * Those operations are used to implemente the fs struct file_operations 198 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some 199 * extra logic needed by the subsystem. 200 */ 201 struct v4l2_file_operations { 202 struct module *owner; 203 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 204 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 205 __poll_t (*poll) (struct file *, struct poll_table_struct *); 206 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 207 #ifdef CONFIG_COMPAT 208 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 209 #endif 210 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 211 unsigned long, unsigned long, unsigned long); 212 int (*mmap) (struct file *, struct vm_area_struct *); 213 int (*open) (struct file *); 214 int (*release) (struct file *); 215 }; 216 217 /* 218 * Newer version of video_device, handled by videodev2.c 219 * This version moves redundant code from video device code to 220 * the common handler 221 */ 222 223 /** 224 * struct video_device - Structure used to create and manage the V4L2 device 225 * nodes. 226 * 227 * @entity: &struct media_entity 228 * @intf_devnode: pointer to &struct media_intf_devnode 229 * @pipe: &struct media_pipeline 230 * @fops: pointer to &struct v4l2_file_operations for the video device 231 * @device_caps: device capabilities as used in v4l2_capabilities 232 * @dev: &struct device for the video device 233 * @cdev: character device 234 * @v4l2_dev: pointer to &struct v4l2_device parent 235 * @dev_parent: pointer to &struct device parent 236 * @ctrl_handler: Control handler associated with this device node. 237 * May be NULL. 238 * @queue: &struct vb2_queue associated with this device node. May be NULL. 239 * @prio: pointer to &struct v4l2_prio_state with device's Priority state. 240 * If NULL, then v4l2_dev->prio will be used. 241 * @name: video device name 242 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type 243 * @vfl_dir: V4L receiver, transmitter or m2m 244 * @minor: device node 'minor'. It is set to -1 if the registration failed 245 * @num: number of the video device node 246 * @flags: video device flags. Use bitops to set/clear/test flags. 247 * Contains a set of &enum v4l2_video_device_flags. 248 * @index: attribute to differentiate multiple indices on one physical device 249 * @fh_lock: Lock for all v4l2_fhs 250 * @fh_list: List of &struct v4l2_fh 251 * @dev_debug: Internal device debug flags, not for use by drivers 252 * @tvnorms: Supported tv norms 253 * 254 * @release: video device release() callback 255 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks 256 * 257 * @valid_ioctls: bitmap with the valid ioctls for this device 258 * @lock: pointer to &struct mutex serialization lock 259 * 260 * .. note:: 261 * Only set @dev_parent if that can't be deduced from @v4l2_dev. 262 */ 263 264 struct video_device { 265 #if defined(CONFIG_MEDIA_CONTROLLER) 266 struct media_entity entity; 267 struct media_intf_devnode *intf_devnode; 268 struct media_pipeline pipe; 269 #endif 270 const struct v4l2_file_operations *fops; 271 272 u32 device_caps; 273 274 /* sysfs */ 275 struct device dev; 276 struct cdev *cdev; 277 278 struct v4l2_device *v4l2_dev; 279 struct device *dev_parent; 280 281 struct v4l2_ctrl_handler *ctrl_handler; 282 283 struct vb2_queue *queue; 284 285 struct v4l2_prio_state *prio; 286 287 /* device info */ 288 char name[64]; 289 enum vfl_devnode_type vfl_type; 290 enum vfl_devnode_direction vfl_dir; 291 int minor; 292 u16 num; 293 unsigned long flags; 294 int index; 295 296 /* V4L2 file handles */ 297 spinlock_t fh_lock; 298 struct list_head fh_list; 299 300 int dev_debug; 301 302 v4l2_std_id tvnorms; 303 304 /* callbacks */ 305 void (*release)(struct video_device *vdev); 306 const struct v4l2_ioctl_ops *ioctl_ops; 307 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 308 309 struct mutex *lock; 310 }; 311 312 /** 313 * media_entity_to_video_device - Returns a &struct video_device from 314 * the &struct media_entity embedded on it. 315 * 316 * @__entity: pointer to &struct media_entity, may be NULL 317 */ 318 #define media_entity_to_video_device(__entity) \ 319 ({ \ 320 typeof(__entity) __me_vdev_ent = __entity; \ 321 \ 322 __me_vdev_ent ? \ 323 container_of(__me_vdev_ent, struct video_device, entity) : \ 324 NULL; \ 325 }) 326 327 /** 328 * to_video_device - Returns a &struct video_device from the 329 * &struct device embedded on it. 330 * 331 * @cd: pointer to &struct device 332 */ 333 #define to_video_device(cd) container_of(cd, struct video_device, dev) 334 335 /** 336 * __video_register_device - register video4linux devices 337 * 338 * @vdev: struct video_device to register 339 * @type: type of device to register, as defined by &enum vfl_devnode_type 340 * @nr: which device node number is desired: 341 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 342 * @warn_if_nr_in_use: warn if the desired device node number 343 * was already in use and another number was chosen instead. 344 * @owner: module that owns the video device node 345 * 346 * The registration code assigns minor numbers and device node numbers 347 * based on the requested type and registers the new device node with 348 * the kernel. 349 * 350 * This function assumes that struct video_device was zeroed when it 351 * was allocated and does not contain any stale date. 352 * 353 * An error is returned if no free minor or device node number could be 354 * found, or if the registration of the device node failed. 355 * 356 * Returns 0 on success. 357 * 358 * .. note:: 359 * 360 * This function is meant to be used only inside the V4L2 core. 361 * Drivers should use video_register_device() or 362 * video_register_device_no_warn(). 363 */ 364 int __must_check __video_register_device(struct video_device *vdev, 365 enum vfl_devnode_type type, 366 int nr, int warn_if_nr_in_use, 367 struct module *owner); 368 369 /** 370 * video_register_device - register video4linux devices 371 * 372 * @vdev: struct video_device to register 373 * @type: type of device to register, as defined by &enum vfl_devnode_type 374 * @nr: which device node number is desired: 375 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 376 * 377 * Internally, it calls __video_register_device(). Please see its 378 * documentation for more details. 379 * 380 * .. note:: 381 * if video_register_device fails, the release() callback of 382 * &struct video_device structure is *not* called, so the caller 383 * is responsible for freeing any data. Usually that means that 384 * you video_device_release() should be called on failure. 385 */ 386 static inline int __must_check video_register_device(struct video_device *vdev, 387 enum vfl_devnode_type type, 388 int nr) 389 { 390 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 391 } 392 393 /** 394 * video_register_device_no_warn - register video4linux devices 395 * 396 * @vdev: struct video_device to register 397 * @type: type of device to register, as defined by &enum vfl_devnode_type 398 * @nr: which device node number is desired: 399 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 400 * 401 * This function is identical to video_register_device() except that no 402 * warning is issued if the desired device node number was already in use. 403 * 404 * Internally, it calls __video_register_device(). Please see its 405 * documentation for more details. 406 * 407 * .. note:: 408 * if video_register_device fails, the release() callback of 409 * &struct video_device structure is *not* called, so the caller 410 * is responsible for freeing any data. Usually that means that 411 * you video_device_release() should be called on failure. 412 */ 413 static inline int __must_check 414 video_register_device_no_warn(struct video_device *vdev, 415 enum vfl_devnode_type type, int nr) 416 { 417 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 418 } 419 420 /** 421 * video_unregister_device - Unregister video devices. 422 * 423 * @vdev: &struct video_device to register 424 * 425 * Does nothing if vdev == NULL or if video_is_registered() returns false. 426 */ 427 void video_unregister_device(struct video_device *vdev); 428 429 /** 430 * video_device_alloc - helper function to alloc &struct video_device 431 * 432 * Returns NULL if %-ENOMEM or a &struct video_device on success. 433 */ 434 struct video_device * __must_check video_device_alloc(void); 435 436 /** 437 * video_device_release - helper function to release &struct video_device 438 * 439 * @vdev: pointer to &struct video_device 440 * 441 * Can also be used for video_device->release\(\). 442 */ 443 void video_device_release(struct video_device *vdev); 444 445 /** 446 * video_device_release_empty - helper function to implement the 447 * video_device->release\(\) callback. 448 * 449 * @vdev: pointer to &struct video_device 450 * 451 * This release function does nothing. 452 * 453 * It should be used when the video_device is a static global struct. 454 * 455 * .. note:: 456 * Having a static video_device is a dubious construction at best. 457 */ 458 void video_device_release_empty(struct video_device *vdev); 459 460 /** 461 * v4l2_disable_ioctl- mark that a given command isn't implemented. 462 * shouldn't use core locking 463 * 464 * @vdev: pointer to &struct video_device 465 * @cmd: ioctl command 466 * 467 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 468 * disable ioctls based on the specific card that is actually found. 469 * 470 * .. note:: 471 * 472 * This must be called before video_register_device. 473 * See also the comments for determine_valid_ioctls(). 474 */ 475 static inline void v4l2_disable_ioctl(struct video_device *vdev, 476 unsigned int cmd) 477 { 478 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 479 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 480 } 481 482 /** 483 * video_get_drvdata - gets private data from &struct video_device. 484 * 485 * @vdev: pointer to &struct video_device 486 * 487 * returns a pointer to the private data 488 */ 489 static inline void *video_get_drvdata(struct video_device *vdev) 490 { 491 return dev_get_drvdata(&vdev->dev); 492 } 493 494 /** 495 * video_set_drvdata - sets private data from &struct video_device. 496 * 497 * @vdev: pointer to &struct video_device 498 * @data: private data pointer 499 */ 500 static inline void video_set_drvdata(struct video_device *vdev, void *data) 501 { 502 dev_set_drvdata(&vdev->dev, data); 503 } 504 505 /** 506 * video_devdata - gets &struct video_device from struct file. 507 * 508 * @file: pointer to struct file 509 */ 510 struct video_device *video_devdata(struct file *file); 511 512 /** 513 * video_drvdata - gets private data from &struct video_device using the 514 * struct file. 515 * 516 * @file: pointer to struct file 517 * 518 * This is function combines both video_get_drvdata() and video_devdata() 519 * as this is used very often. 520 */ 521 static inline void *video_drvdata(struct file *file) 522 { 523 return video_get_drvdata(video_devdata(file)); 524 } 525 526 /** 527 * video_device_node_name - returns the video device name 528 * 529 * @vdev: pointer to &struct video_device 530 * 531 * Returns the device name string 532 */ 533 static inline const char *video_device_node_name(struct video_device *vdev) 534 { 535 return dev_name(&vdev->dev); 536 } 537 538 /** 539 * video_is_registered - returns true if the &struct video_device is registered. 540 * 541 * 542 * @vdev: pointer to &struct video_device 543 */ 544 static inline int video_is_registered(struct video_device *vdev) 545 { 546 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 547 } 548 549 /** 550 * v4l2_debugfs_root - returns the dentry of the top-level "v4l2" debugfs dir 551 * 552 * If this directory does not yet exist, then it will be created. 553 */ 554 #ifdef CONFIG_DEBUG_FS 555 struct dentry *v4l2_debugfs_root(void); 556 #else 557 static inline struct dentry *v4l2_debugfs_root(void) 558 { 559 return NULL; 560 } 561 #endif 562 563 #if defined(CONFIG_MEDIA_CONTROLLER) 564 565 /** 566 * video_device_pipeline_start - Mark a pipeline as streaming 567 * @vdev: Starting video device 568 * @pipe: Media pipeline to be assigned to all entities in the pipeline. 569 * 570 * Mark all entities connected to a given video device through enabled links, 571 * either directly or indirectly, as streaming. The given pipeline object is 572 * assigned to every pad in the pipeline and stored in the media_pad pipe 573 * field. 574 * 575 * Calls to this function can be nested, in which case the same number of 576 * video_device_pipeline_stop() calls will be required to stop streaming. The 577 * pipeline pointer must be identical for all nested calls to 578 * video_device_pipeline_start(). 579 * 580 * The video device must contain a single pad. 581 * 582 * This is a convenience wrapper around media_pipeline_start(). 583 */ 584 __must_check int video_device_pipeline_start(struct video_device *vdev, 585 struct media_pipeline *pipe); 586 587 /** 588 * __video_device_pipeline_start - Mark a pipeline as streaming 589 * @vdev: Starting video device 590 * @pipe: Media pipeline to be assigned to all entities in the pipeline. 591 * 592 * ..note:: This is the non-locking version of video_device_pipeline_start() 593 * 594 * The video device must contain a single pad. 595 * 596 * This is a convenience wrapper around __media_pipeline_start(). 597 */ 598 __must_check int __video_device_pipeline_start(struct video_device *vdev, 599 struct media_pipeline *pipe); 600 601 /** 602 * video_device_pipeline_stop - Mark a pipeline as not streaming 603 * @vdev: Starting video device 604 * 605 * Mark all entities connected to a given video device through enabled links, 606 * either directly or indirectly, as not streaming. The media_pad pipe field 607 * is reset to %NULL. 608 * 609 * If multiple calls to media_pipeline_start() have been made, the same 610 * number of calls to this function are required to mark the pipeline as not 611 * streaming. 612 * 613 * The video device must contain a single pad. 614 * 615 * This is a convenience wrapper around media_pipeline_stop(). 616 */ 617 void video_device_pipeline_stop(struct video_device *vdev); 618 619 /** 620 * __video_device_pipeline_stop - Mark a pipeline as not streaming 621 * @vdev: Starting video device 622 * 623 * .. note:: This is the non-locking version of media_pipeline_stop() 624 * 625 * The video device must contain a single pad. 626 * 627 * This is a convenience wrapper around __media_pipeline_stop(). 628 */ 629 void __video_device_pipeline_stop(struct video_device *vdev); 630 631 /** 632 * video_device_pipeline_alloc_start - Mark a pipeline as streaming 633 * @vdev: Starting video device 634 * 635 * video_device_pipeline_alloc_start() is similar to video_device_pipeline_start() 636 * but instead of working on a given pipeline the function will use an 637 * existing pipeline if the video device is already part of a pipeline, or 638 * allocate a new pipeline. 639 * 640 * Calls to video_device_pipeline_alloc_start() must be matched with 641 * video_device_pipeline_stop(). 642 */ 643 __must_check int video_device_pipeline_alloc_start(struct video_device *vdev); 644 645 /** 646 * video_device_pipeline - Get the media pipeline a video device is part of 647 * @vdev: The video device 648 * 649 * This function returns the media pipeline that a video device has been 650 * associated with when constructing the pipeline with 651 * video_device_pipeline_start(). The pointer remains valid until 652 * video_device_pipeline_stop() is called. 653 * 654 * Return: The media_pipeline the video device is part of, or NULL if the video 655 * device is not part of any pipeline. 656 * 657 * The video device must contain a single pad. 658 * 659 * This is a convenience wrapper around media_entity_pipeline(). 660 */ 661 struct media_pipeline *video_device_pipeline(struct video_device *vdev); 662 663 #endif /* CONFIG_MEDIA_CONTROLLER */ 664 665 #endif /* _V4L2_DEV_H */ 666