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