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_GRABBER: deprecated, same as VFL_TYPE_VIDEO 29 * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext) 30 * @VFL_TYPE_RADIO: for radio tuners 31 * @VFL_TYPE_SUBDEV: for V4L2 subdevices 32 * @VFL_TYPE_SDR: for Software Defined Radio tuners 33 * @VFL_TYPE_TOUCH: for touch sensors 34 * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum 35 */ 36 enum vfl_devnode_type { 37 VFL_TYPE_VIDEO, 38 VFL_TYPE_GRABBER = VFL_TYPE_VIDEO, 39 VFL_TYPE_VBI, 40 VFL_TYPE_RADIO, 41 VFL_TYPE_SUBDEV, 42 VFL_TYPE_SDR, 43 VFL_TYPE_TOUCH, 44 VFL_TYPE_MAX /* Shall be the last one */ 45 }; 46 47 /** 48 * enum vfl_direction - Identifies if a &struct video_device corresponds 49 * to a receiver, a transmitter or a mem-to-mem device. 50 * 51 * @VFL_DIR_RX: device is a receiver. 52 * @VFL_DIR_TX: device is a transmitter. 53 * @VFL_DIR_M2M: device is a memory to memory device. 54 * 55 * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV. 56 */ 57 enum vfl_devnode_direction { 58 VFL_DIR_RX, 59 VFL_DIR_TX, 60 VFL_DIR_M2M, 61 }; 62 63 struct v4l2_ioctl_callbacks; 64 struct video_device; 65 struct v4l2_device; 66 struct v4l2_ctrl_handler; 67 68 /** 69 * enum v4l2_video_device_flags - Flags used by &struct video_device 70 * 71 * @V4L2_FL_REGISTERED: 72 * indicates that a &struct video_device is registered. 73 * Drivers can clear this flag if they want to block all future 74 * device access. It is cleared by video_unregister_device. 75 * @V4L2_FL_USES_V4L2_FH: 76 * indicates that file->private_data points to &struct v4l2_fh. 77 * This flag is set by the core when v4l2_fh_init() is called. 78 * All new drivers should use it. 79 * @V4L2_FL_QUIRK_INVERTED_CROP: 80 * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and 81 * compose are swapped. If this flag is set, then the selection 82 * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c. 83 * This allows those drivers to correctly implement the selection API, 84 * but the old crop API will still work as expected in order to preserve 85 * backwards compatibility. 86 * Never set this flag for new drivers. 87 */ 88 enum v4l2_video_device_flags { 89 V4L2_FL_REGISTERED = 0, 90 V4L2_FL_USES_V4L2_FH = 1, 91 V4L2_FL_QUIRK_INVERTED_CROP = 2, 92 }; 93 94 /* Priority helper functions */ 95 96 /** 97 * struct v4l2_prio_state - stores the priority states 98 * 99 * @prios: array with elements to store the array priorities 100 * 101 * 102 * .. note:: 103 * The size of @prios array matches the number of priority types defined 104 * by enum &v4l2_priority. 105 */ 106 struct v4l2_prio_state { 107 atomic_t prios[4]; 108 }; 109 110 /** 111 * v4l2_prio_init - initializes a struct v4l2_prio_state 112 * 113 * @global: pointer to &struct v4l2_prio_state 114 */ 115 void v4l2_prio_init(struct v4l2_prio_state *global); 116 117 /** 118 * v4l2_prio_change - changes the v4l2 file handler priority 119 * 120 * @global: pointer to the &struct v4l2_prio_state of the device node. 121 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 122 * @new: Priority type requested, as defined by enum &v4l2_priority. 123 * 124 * .. note:: 125 * This function should be used only by the V4L2 core. 126 */ 127 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 128 enum v4l2_priority new); 129 130 /** 131 * v4l2_prio_open - Implements the priority logic for a file handler open 132 * 133 * @global: pointer to the &struct v4l2_prio_state of the device node. 134 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 135 * 136 * .. note:: 137 * This function should be used only by the V4L2 core. 138 */ 139 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 140 141 /** 142 * v4l2_prio_close - Implements the priority logic for a file handler close 143 * 144 * @global: pointer to the &struct v4l2_prio_state of the device node. 145 * @local: priority to be released, as defined by enum &v4l2_priority 146 * 147 * .. note:: 148 * This function should be used only by the V4L2 core. 149 */ 150 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 151 152 /** 153 * v4l2_prio_max - Return the maximum priority, as stored at the @global array. 154 * 155 * @global: pointer to the &struct v4l2_prio_state of the device node. 156 * 157 * .. note:: 158 * This function should be used only by the V4L2 core. 159 */ 160 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 161 162 /** 163 * v4l2_prio_check - Implements the priority logic for a file handler close 164 * 165 * @global: pointer to the &struct v4l2_prio_state of the device node. 166 * @local: desired priority, as defined by enum &v4l2_priority local 167 * 168 * .. note:: 169 * This function should be used only by the V4L2 core. 170 */ 171 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 172 173 /** 174 * struct v4l2_file_operations - fs operations used by a V4L2 device 175 * 176 * @owner: pointer to struct module 177 * @read: operations needed to implement the read() syscall 178 * @write: operations needed to implement the write() syscall 179 * @poll: operations needed to implement the poll() syscall 180 * @unlocked_ioctl: operations needed to implement the ioctl() syscall 181 * @compat_ioctl32: operations needed to implement the ioctl() syscall for 182 * the special case where the Kernel uses 64 bits instructions, but 183 * the userspace uses 32 bits. 184 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU 185 * @mmap: operations needed to implement the mmap() syscall 186 * @open: operations needed to implement the open() syscall 187 * @release: operations needed to implement the release() syscall 188 * 189 * .. note:: 190 * 191 * Those operations are used to implemente the fs struct file_operations 192 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some 193 * extra logic needed by the subsystem. 194 */ 195 struct v4l2_file_operations { 196 struct module *owner; 197 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 198 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 199 __poll_t (*poll) (struct file *, struct poll_table_struct *); 200 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 201 #ifdef CONFIG_COMPAT 202 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 203 #endif 204 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 205 unsigned long, unsigned long, unsigned long); 206 int (*mmap) (struct file *, struct vm_area_struct *); 207 int (*open) (struct file *); 208 int (*release) (struct file *); 209 }; 210 211 /* 212 * Newer version of video_device, handled by videodev2.c 213 * This version moves redundant code from video device code to 214 * the common handler 215 */ 216 217 /** 218 * struct video_device - Structure used to create and manage the V4L2 device 219 * nodes. 220 * 221 * @entity: &struct media_entity 222 * @intf_devnode: pointer to &struct media_intf_devnode 223 * @pipe: &struct media_pipeline 224 * @fops: pointer to &struct v4l2_file_operations for the video device 225 * @device_caps: device capabilities as used in v4l2_capabilities 226 * @dev: &struct device for the video device 227 * @cdev: character device 228 * @v4l2_dev: pointer to &struct v4l2_device parent 229 * @dev_parent: pointer to &struct device parent 230 * @ctrl_handler: Control handler associated with this device node. 231 * May be NULL. 232 * @queue: &struct vb2_queue associated with this device node. May be NULL. 233 * @prio: pointer to &struct v4l2_prio_state with device's Priority state. 234 * If NULL, then v4l2_dev->prio will be used. 235 * @name: video device name 236 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type 237 * @vfl_dir: V4L receiver, transmitter or m2m 238 * @minor: device node 'minor'. It is set to -1 if the registration failed 239 * @num: number of the video device node 240 * @flags: video device flags. Use bitops to set/clear/test flags. 241 * Contains a set of &enum v4l2_video_device_flags. 242 * @index: attribute to differentiate multiple indices on one physical device 243 * @fh_lock: Lock for all v4l2_fhs 244 * @fh_list: List of &struct v4l2_fh 245 * @dev_debug: Internal device debug flags, not for use by drivers 246 * @tvnorms: Supported tv norms 247 * 248 * @release: video device release() callback 249 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks 250 * 251 * @valid_ioctls: bitmap with the valid ioctls for this device 252 * @lock: pointer to &struct mutex serialization lock 253 * 254 * .. note:: 255 * Only set @dev_parent if that can't be deduced from @v4l2_dev. 256 */ 257 258 struct video_device 259 { 260 #if defined(CONFIG_MEDIA_CONTROLLER) 261 struct media_entity entity; 262 struct media_intf_devnode *intf_devnode; 263 struct media_pipeline pipe; 264 #endif 265 const struct v4l2_file_operations *fops; 266 267 u32 device_caps; 268 269 /* sysfs */ 270 struct device dev; 271 struct cdev *cdev; 272 273 struct v4l2_device *v4l2_dev; 274 struct device *dev_parent; 275 276 struct v4l2_ctrl_handler *ctrl_handler; 277 278 struct vb2_queue *queue; 279 280 struct v4l2_prio_state *prio; 281 282 /* device info */ 283 char name[32]; 284 enum vfl_devnode_type vfl_type; 285 enum vfl_devnode_direction vfl_dir; 286 int minor; 287 u16 num; 288 unsigned long flags; 289 int index; 290 291 /* V4L2 file handles */ 292 spinlock_t fh_lock; 293 struct list_head fh_list; 294 295 int dev_debug; 296 297 v4l2_std_id tvnorms; 298 299 /* callbacks */ 300 void (*release)(struct video_device *vdev); 301 const struct v4l2_ioctl_ops *ioctl_ops; 302 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 303 304 struct mutex *lock; 305 }; 306 307 /** 308 * media_entity_to_video_device - Returns a &struct video_device from 309 * the &struct media_entity embedded on it. 310 * 311 * @__entity: pointer to &struct media_entity 312 */ 313 #define media_entity_to_video_device(__entity) \ 314 container_of(__entity, struct video_device, entity) 315 316 /** 317 * to_video_device - Returns a &struct video_device from the 318 * &struct device embedded on it. 319 * 320 * @cd: pointer to &struct device 321 */ 322 #define to_video_device(cd) container_of(cd, struct video_device, dev) 323 324 /** 325 * __video_register_device - register video4linux devices 326 * 327 * @vdev: struct video_device to register 328 * @type: type of device to register, as defined by &enum vfl_devnode_type 329 * @nr: which device node number is desired: 330 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 331 * @warn_if_nr_in_use: warn if the desired device node number 332 * was already in use and another number was chosen instead. 333 * @owner: module that owns the video device node 334 * 335 * The registration code assigns minor numbers and device node numbers 336 * based on the requested type and registers the new device node with 337 * the kernel. 338 * 339 * This function assumes that struct video_device was zeroed when it 340 * was allocated and does not contain any stale date. 341 * 342 * An error is returned if no free minor or device node number could be 343 * found, or if the registration of the device node failed. 344 * 345 * Returns 0 on success. 346 * 347 * .. note:: 348 * 349 * This function is meant to be used only inside the V4L2 core. 350 * Drivers should use video_register_device() or 351 * video_register_device_no_warn(). 352 */ 353 int __must_check __video_register_device(struct video_device *vdev, 354 enum vfl_devnode_type type, 355 int nr, int warn_if_nr_in_use, 356 struct module *owner); 357 358 /** 359 * video_register_device - register video4linux devices 360 * 361 * @vdev: struct video_device to register 362 * @type: type of device to register, as defined by &enum vfl_devnode_type 363 * @nr: which device node number is desired: 364 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 365 * 366 * Internally, it calls __video_register_device(). Please see its 367 * documentation for more details. 368 * 369 * .. note:: 370 * if video_register_device fails, the release() callback of 371 * &struct video_device structure is *not* called, so the caller 372 * is responsible for freeing any data. Usually that means that 373 * you video_device_release() should be called on failure. 374 */ 375 static inline int __must_check video_register_device(struct video_device *vdev, 376 enum vfl_devnode_type type, 377 int nr) 378 { 379 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 380 } 381 382 /** 383 * video_register_device_no_warn - register video4linux devices 384 * 385 * @vdev: struct video_device to register 386 * @type: type of device to register, as defined by &enum vfl_devnode_type 387 * @nr: which device node number is desired: 388 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 389 * 390 * This function is identical to video_register_device() except that no 391 * warning is issued if the desired device node number was already in use. 392 * 393 * Internally, it calls __video_register_device(). Please see its 394 * documentation for more details. 395 * 396 * .. note:: 397 * if video_register_device fails, the release() callback of 398 * &struct video_device structure is *not* called, so the caller 399 * is responsible for freeing any data. Usually that means that 400 * you video_device_release() should be called on failure. 401 */ 402 static inline int __must_check 403 video_register_device_no_warn(struct video_device *vdev, 404 enum vfl_devnode_type type, int nr) 405 { 406 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 407 } 408 409 /** 410 * video_unregister_device - Unregister video devices. 411 * 412 * @vdev: &struct video_device to register 413 * 414 * Does nothing if vdev == NULL or if video_is_registered() returns false. 415 */ 416 void video_unregister_device(struct video_device *vdev); 417 418 /** 419 * video_device_alloc - helper function to alloc &struct video_device 420 * 421 * Returns NULL if %-ENOMEM or a &struct video_device on success. 422 */ 423 struct video_device * __must_check video_device_alloc(void); 424 425 /** 426 * video_device_release - helper function to release &struct video_device 427 * 428 * @vdev: pointer to &struct video_device 429 * 430 * Can also be used for video_device->release\(\). 431 */ 432 void video_device_release(struct video_device *vdev); 433 434 /** 435 * video_device_release_empty - helper function to implement the 436 * video_device->release\(\) callback. 437 * 438 * @vdev: pointer to &struct video_device 439 * 440 * This release function does nothing. 441 * 442 * It should be used when the video_device is a static global struct. 443 * 444 * .. note:: 445 * Having a static video_device is a dubious construction at best. 446 */ 447 void video_device_release_empty(struct video_device *vdev); 448 449 /** 450 * v4l2_disable_ioctl- mark that a given command isn't implemented. 451 * shouldn't use core locking 452 * 453 * @vdev: pointer to &struct video_device 454 * @cmd: ioctl command 455 * 456 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 457 * disable ioctls based on the specific card that is actually found. 458 * 459 * .. note:: 460 * 461 * This must be called before video_register_device. 462 * See also the comments for determine_valid_ioctls(). 463 */ 464 static inline void v4l2_disable_ioctl(struct video_device *vdev, 465 unsigned int cmd) 466 { 467 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 468 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 469 } 470 471 /** 472 * video_get_drvdata - gets private data from &struct video_device. 473 * 474 * @vdev: pointer to &struct video_device 475 * 476 * returns a pointer to the private data 477 */ 478 static inline void *video_get_drvdata(struct video_device *vdev) 479 { 480 return dev_get_drvdata(&vdev->dev); 481 } 482 483 /** 484 * video_set_drvdata - sets private data from &struct video_device. 485 * 486 * @vdev: pointer to &struct video_device 487 * @data: private data pointer 488 */ 489 static inline void video_set_drvdata(struct video_device *vdev, void *data) 490 { 491 dev_set_drvdata(&vdev->dev, data); 492 } 493 494 /** 495 * video_devdata - gets &struct video_device from struct file. 496 * 497 * @file: pointer to struct file 498 */ 499 struct video_device *video_devdata(struct file *file); 500 501 /** 502 * video_drvdata - gets private data from &struct video_device using the 503 * struct file. 504 * 505 * @file: pointer to struct file 506 * 507 * This is function combines both video_get_drvdata() and video_devdata() 508 * as this is used very often. 509 */ 510 static inline void *video_drvdata(struct file *file) 511 { 512 return video_get_drvdata(video_devdata(file)); 513 } 514 515 /** 516 * video_device_node_name - returns the video device name 517 * 518 * @vdev: pointer to &struct video_device 519 * 520 * Returns the device name string 521 */ 522 static inline const char *video_device_node_name(struct video_device *vdev) 523 { 524 return dev_name(&vdev->dev); 525 } 526 527 /** 528 * video_is_registered - returns true if the &struct video_device is registered. 529 * 530 * 531 * @vdev: pointer to &struct video_device 532 */ 533 static inline int video_is_registered(struct video_device *vdev) 534 { 535 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 536 } 537 538 #endif /* _V4L2_DEV_H */ 539