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