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_direction - Identifies if a &struct video_device corresponds 47 * 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 { 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[32]; 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 317 */ 318 #define media_entity_to_video_device(__entity) \ 319 container_of(__entity, struct video_device, entity) 320 321 /** 322 * to_video_device - Returns a &struct video_device from the 323 * &struct device embedded on it. 324 * 325 * @cd: pointer to &struct device 326 */ 327 #define to_video_device(cd) container_of(cd, struct video_device, dev) 328 329 /** 330 * __video_register_device - register video4linux devices 331 * 332 * @vdev: struct video_device to register 333 * @type: type of device to register, as defined by &enum vfl_devnode_type 334 * @nr: which device node number is desired: 335 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 336 * @warn_if_nr_in_use: warn if the desired device node number 337 * was already in use and another number was chosen instead. 338 * @owner: module that owns the video device node 339 * 340 * The registration code assigns minor numbers and device node numbers 341 * based on the requested type and registers the new device node with 342 * the kernel. 343 * 344 * This function assumes that struct video_device was zeroed when it 345 * was allocated and does not contain any stale date. 346 * 347 * An error is returned if no free minor or device node number could be 348 * found, or if the registration of the device node failed. 349 * 350 * Returns 0 on success. 351 * 352 * .. note:: 353 * 354 * This function is meant to be used only inside the V4L2 core. 355 * Drivers should use video_register_device() or 356 * video_register_device_no_warn(). 357 */ 358 int __must_check __video_register_device(struct video_device *vdev, 359 enum vfl_devnode_type type, 360 int nr, int warn_if_nr_in_use, 361 struct module *owner); 362 363 /** 364 * video_register_device - register video4linux devices 365 * 366 * @vdev: struct video_device to register 367 * @type: type of device to register, as defined by &enum vfl_devnode_type 368 * @nr: which device node number is desired: 369 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 370 * 371 * Internally, it calls __video_register_device(). Please see its 372 * documentation for more details. 373 * 374 * .. note:: 375 * if video_register_device fails, the release() callback of 376 * &struct video_device structure is *not* called, so the caller 377 * is responsible for freeing any data. Usually that means that 378 * you video_device_release() should be called on failure. 379 */ 380 static inline int __must_check video_register_device(struct video_device *vdev, 381 enum vfl_devnode_type type, 382 int nr) 383 { 384 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 385 } 386 387 /** 388 * video_register_device_no_warn - register video4linux devices 389 * 390 * @vdev: struct video_device to register 391 * @type: type of device to register, as defined by &enum vfl_devnode_type 392 * @nr: which device node number is desired: 393 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 394 * 395 * This function is identical to video_register_device() except that no 396 * warning is issued if the desired device node number was already in use. 397 * 398 * Internally, it calls __video_register_device(). Please see its 399 * documentation for more details. 400 * 401 * .. note:: 402 * if video_register_device fails, the release() callback of 403 * &struct video_device structure is *not* called, so the caller 404 * is responsible for freeing any data. Usually that means that 405 * you video_device_release() should be called on failure. 406 */ 407 static inline int __must_check 408 video_register_device_no_warn(struct video_device *vdev, 409 enum vfl_devnode_type type, int nr) 410 { 411 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 412 } 413 414 /** 415 * video_unregister_device - Unregister video devices. 416 * 417 * @vdev: &struct video_device to register 418 * 419 * Does nothing if vdev == NULL or if video_is_registered() returns false. 420 */ 421 void video_unregister_device(struct video_device *vdev); 422 423 /** 424 * video_device_alloc - helper function to alloc &struct video_device 425 * 426 * Returns NULL if %-ENOMEM or a &struct video_device on success. 427 */ 428 struct video_device * __must_check video_device_alloc(void); 429 430 /** 431 * video_device_release - helper function to release &struct video_device 432 * 433 * @vdev: pointer to &struct video_device 434 * 435 * Can also be used for video_device->release\(\). 436 */ 437 void video_device_release(struct video_device *vdev); 438 439 /** 440 * video_device_release_empty - helper function to implement the 441 * video_device->release\(\) callback. 442 * 443 * @vdev: pointer to &struct video_device 444 * 445 * This release function does nothing. 446 * 447 * It should be used when the video_device is a static global struct. 448 * 449 * .. note:: 450 * Having a static video_device is a dubious construction at best. 451 */ 452 void video_device_release_empty(struct video_device *vdev); 453 454 /** 455 * v4l2_disable_ioctl- mark that a given command isn't implemented. 456 * shouldn't use core locking 457 * 458 * @vdev: pointer to &struct video_device 459 * @cmd: ioctl command 460 * 461 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 462 * disable ioctls based on the specific card that is actually found. 463 * 464 * .. note:: 465 * 466 * This must be called before video_register_device. 467 * See also the comments for determine_valid_ioctls(). 468 */ 469 static inline void v4l2_disable_ioctl(struct video_device *vdev, 470 unsigned int cmd) 471 { 472 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 473 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 474 } 475 476 /** 477 * video_get_drvdata - gets private data from &struct video_device. 478 * 479 * @vdev: pointer to &struct video_device 480 * 481 * returns a pointer to the private data 482 */ 483 static inline void *video_get_drvdata(struct video_device *vdev) 484 { 485 return dev_get_drvdata(&vdev->dev); 486 } 487 488 /** 489 * video_set_drvdata - sets private data from &struct video_device. 490 * 491 * @vdev: pointer to &struct video_device 492 * @data: private data pointer 493 */ 494 static inline void video_set_drvdata(struct video_device *vdev, void *data) 495 { 496 dev_set_drvdata(&vdev->dev, data); 497 } 498 499 /** 500 * video_devdata - gets &struct video_device from struct file. 501 * 502 * @file: pointer to struct file 503 */ 504 struct video_device *video_devdata(struct file *file); 505 506 /** 507 * video_drvdata - gets private data from &struct video_device using the 508 * struct file. 509 * 510 * @file: pointer to struct file 511 * 512 * This is function combines both video_get_drvdata() and video_devdata() 513 * as this is used very often. 514 */ 515 static inline void *video_drvdata(struct file *file) 516 { 517 return video_get_drvdata(video_devdata(file)); 518 } 519 520 /** 521 * video_device_node_name - returns the video device name 522 * 523 * @vdev: pointer to &struct video_device 524 * 525 * Returns the device name string 526 */ 527 static inline const char *video_device_node_name(struct video_device *vdev) 528 { 529 return dev_name(&vdev->dev); 530 } 531 532 /** 533 * video_is_registered - returns true if the &struct video_device is registered. 534 * 535 * 536 * @vdev: pointer to &struct video_device 537 */ 538 static inline int video_is_registered(struct video_device *vdev) 539 { 540 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 541 } 542 543 #endif /* _V4L2_DEV_H */ 544