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 #define VFL_TYPE_GRABBER 0 25 #define VFL_TYPE_VBI 1 26 #define VFL_TYPE_RADIO 2 27 #define VFL_TYPE_SUBDEV 3 28 #define VFL_TYPE_SDR 4 29 #define VFL_TYPE_TOUCH 5 30 #define VFL_TYPE_MAX 6 31 32 /* Is this a receiver, transmitter or mem-to-mem? */ 33 /* Ignored for VFL_TYPE_SUBDEV. */ 34 #define VFL_DIR_RX 0 35 #define VFL_DIR_TX 1 36 #define VFL_DIR_M2M 2 37 38 struct v4l2_ioctl_callbacks; 39 struct video_device; 40 struct v4l2_device; 41 struct v4l2_ctrl_handler; 42 43 /* Flag to mark the video_device struct as registered. 44 Drivers can clear this flag if they want to block all future 45 device access. It is cleared by video_unregister_device. */ 46 #define V4L2_FL_REGISTERED (0) 47 /* file->private_data points to struct v4l2_fh */ 48 #define V4L2_FL_USES_V4L2_FH (1) 49 50 /* Priority helper functions */ 51 52 /** 53 * struct v4l2_prio_state - stores the priority states 54 * 55 * @prios: array with elements to store the array priorities 56 * 57 * 58 * .. note:: 59 * The size of @prios array matches the number of priority types defined 60 * by enum &v4l2_priority. 61 */ 62 struct v4l2_prio_state { 63 atomic_t prios[4]; 64 }; 65 66 /** 67 * v4l2_prio_init - initializes a struct v4l2_prio_state 68 * 69 * @global: pointer to &struct v4l2_prio_state 70 */ 71 void v4l2_prio_init(struct v4l2_prio_state *global); 72 73 /** 74 * v4l2_prio_change - changes the v4l2 file handler priority 75 * 76 * @global: pointer to the &struct v4l2_prio_state of the device node. 77 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 78 * @new: Priority type requested, as defined by enum &v4l2_priority. 79 * 80 * .. note:: 81 * This function should be used only by the V4L2 core. 82 */ 83 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 84 enum v4l2_priority new); 85 86 /** 87 * v4l2_prio_open - Implements the priority logic for a file handler open 88 * 89 * @global: pointer to the &struct v4l2_prio_state of the device node. 90 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 91 * 92 * .. note:: 93 * This function should be used only by the V4L2 core. 94 */ 95 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 96 97 /** 98 * v4l2_prio_close - Implements the priority logic for a file handler close 99 * 100 * @global: pointer to the &struct v4l2_prio_state of the device node. 101 * @local: priority to be released, as defined by enum &v4l2_priority 102 * 103 * .. note:: 104 * This function should be used only by the V4L2 core. 105 */ 106 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 107 108 /** 109 * v4l2_prio_max - Return the maximum priority, as stored at the @global array. 110 * 111 * @global: pointer to the &struct v4l2_prio_state of the device node. 112 * 113 * .. note:: 114 * This function should be used only by the V4L2 core. 115 */ 116 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 117 118 /** 119 * v4l2_prio_check - Implements the priority logic for a file handler close 120 * 121 * @global: pointer to the &struct v4l2_prio_state of the device node. 122 * @local: desired priority, as defined by enum &v4l2_priority local 123 * 124 * .. note:: 125 * This function should be used only by the V4L2 core. 126 */ 127 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 128 129 /** 130 * struct v4l2_file_operations - fs operations used by a V4L2 device 131 * 132 * @owner: pointer to struct module 133 * @read: operations needed to implement the read() syscall 134 * @write: operations needed to implement the write() syscall 135 * @poll: operations needed to implement the poll() syscall 136 * @unlocked_ioctl: operations needed to implement the ioctl() syscall 137 * @compat_ioctl32: operations needed to implement the ioctl() syscall for 138 * the special case where the Kernel uses 64 bits instructions, but 139 * the userspace uses 32 bits. 140 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU 141 * @mmap: operations needed to implement the mmap() syscall 142 * @open: operations needed to implement the open() syscall 143 * @release: operations needed to implement the release() syscall 144 * 145 * .. note:: 146 * 147 * Those operations are used to implemente the fs struct file_operations 148 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some 149 * extra logic needed by the subsystem. 150 */ 151 struct v4l2_file_operations { 152 struct module *owner; 153 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 154 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 155 unsigned int (*poll) (struct file *, struct poll_table_struct *); 156 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 157 #ifdef CONFIG_COMPAT 158 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 159 #endif 160 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 161 unsigned long, unsigned long, unsigned long); 162 int (*mmap) (struct file *, struct vm_area_struct *); 163 int (*open) (struct file *); 164 int (*release) (struct file *); 165 }; 166 167 /* 168 * Newer version of video_device, handled by videodev2.c 169 * This version moves redundant code from video device code to 170 * the common handler 171 */ 172 173 /** 174 * struct video_device - Structure used to create and manage the V4L2 device 175 * nodes. 176 * 177 * @entity: &struct media_entity 178 * @intf_devnode: pointer to &struct media_intf_devnode 179 * @pipe: &struct media_pipeline 180 * @fops: pointer to &struct v4l2_file_operations for the video device 181 * @device_caps: device capabilities as used in v4l2_capabilities 182 * @dev: &struct device for the video device 183 * @cdev: character device 184 * @v4l2_dev: pointer to &struct v4l2_device parent 185 * @dev_parent: pointer to &struct device parent 186 * @ctrl_handler: Control handler associated with this device node. 187 * May be NULL. 188 * @queue: &struct vb2_queue associated with this device node. May be NULL. 189 * @prio: pointer to &struct v4l2_prio_state with device's Priority state. 190 * If NULL, then v4l2_dev->prio will be used. 191 * @name: video device name 192 * @vfl_type: V4L device type 193 * @vfl_dir: V4L receiver, transmitter or m2m 194 * @minor: device node 'minor'. It is set to -1 if the registration failed 195 * @num: number of the video device node 196 * @flags: video device flags. Use bitops to set/clear/test flags 197 * @index: attribute to differentiate multiple indices on one physical device 198 * @fh_lock: Lock for all v4l2_fhs 199 * @fh_list: List of &struct v4l2_fh 200 * @dev_debug: Internal device debug flags, not for use by drivers 201 * @tvnorms: Supported tv norms 202 * 203 * @release: video device release() callback 204 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks 205 * 206 * @valid_ioctls: bitmap with the valid ioctls for this device 207 * @disable_locking: bitmap with the ioctls that don't require locking 208 * @lock: pointer to &struct mutex serialization lock 209 * 210 * .. note:: 211 * Only set @dev_parent if that can't be deduced from @v4l2_dev. 212 */ 213 214 struct video_device 215 { 216 #if defined(CONFIG_MEDIA_CONTROLLER) 217 struct media_entity entity; 218 struct media_intf_devnode *intf_devnode; 219 struct media_pipeline pipe; 220 #endif 221 const struct v4l2_file_operations *fops; 222 223 u32 device_caps; 224 225 /* sysfs */ 226 struct device dev; 227 struct cdev *cdev; 228 229 struct v4l2_device *v4l2_dev; 230 struct device *dev_parent; 231 232 struct v4l2_ctrl_handler *ctrl_handler; 233 234 struct vb2_queue *queue; 235 236 struct v4l2_prio_state *prio; 237 238 /* device info */ 239 char name[32]; 240 int vfl_type; 241 int vfl_dir; 242 int minor; 243 u16 num; 244 unsigned long flags; 245 int index; 246 247 /* V4L2 file handles */ 248 spinlock_t fh_lock; 249 struct list_head fh_list; 250 251 int dev_debug; 252 253 v4l2_std_id tvnorms; 254 255 /* callbacks */ 256 void (*release)(struct video_device *vdev); 257 const struct v4l2_ioctl_ops *ioctl_ops; 258 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 259 260 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 261 struct mutex *lock; 262 }; 263 264 #define media_entity_to_video_device(__e) \ 265 container_of(__e, struct video_device, entity) 266 /* dev to video-device */ 267 #define to_video_device(cd) container_of(cd, struct video_device, dev) 268 269 /** 270 * __video_register_device - register video4linux devices 271 * 272 * @vdev: struct video_device to register 273 * @type: type of device to register 274 * @nr: which device node number is desired: 275 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 276 * @warn_if_nr_in_use: warn if the desired device node number 277 * was already in use and another number was chosen instead. 278 * @owner: module that owns the video device node 279 * 280 * The registration code assigns minor numbers and device node numbers 281 * based on the requested type and registers the new device node with 282 * the kernel. 283 * 284 * This function assumes that struct video_device was zeroed when it 285 * was allocated and does not contain any stale date. 286 * 287 * An error is returned if no free minor or device node number could be 288 * found, or if the registration of the device node failed. 289 * 290 * Returns 0 on success. 291 * 292 * Valid values for @type are: 293 * 294 * - %VFL_TYPE_GRABBER - A frame grabber 295 * - %VFL_TYPE_VBI - Vertical blank data (undecoded) 296 * - %VFL_TYPE_RADIO - A radio card 297 * - %VFL_TYPE_SUBDEV - A subdevice 298 * - %VFL_TYPE_SDR - Software Defined Radio 299 * - %VFL_TYPE_TOUCH - A touch sensor 300 * 301 * .. note:: 302 * 303 * This function is meant to be used only inside the V4L2 core. 304 * Drivers should use video_register_device() or 305 * video_register_device_no_warn(). 306 */ 307 int __must_check __video_register_device(struct video_device *vdev, int type, 308 int nr, int warn_if_nr_in_use, struct module *owner); 309 310 /** 311 * video_register_device - register video4linux devices 312 * 313 * @vdev: struct video_device to register 314 * @type: type of device to register 315 * @nr: which device node number is desired: 316 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 317 * 318 * Internally, it calls __video_register_device(). Please see its 319 * documentation for more details. 320 * 321 * .. note:: 322 * if video_register_device fails, the release() callback of 323 * &struct video_device structure is *not* called, so the caller 324 * is responsible for freeing any data. Usually that means that 325 * you video_device_release() should be called on failure. 326 */ 327 static inline int __must_check video_register_device(struct video_device *vdev, 328 int type, int nr) 329 { 330 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 331 } 332 333 /** 334 * video_register_device_no_warn - register video4linux devices 335 * 336 * @vdev: struct video_device to register 337 * @type: type of device to register 338 * @nr: which device node number is desired: 339 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 340 * 341 * This function is identical to video_register_device() except that no 342 * warning is issued if the desired device node number was already in use. 343 * 344 * Internally, it calls __video_register_device(). Please see its 345 * documentation for more details. 346 * 347 * .. note:: 348 * if video_register_device fails, the release() callback of 349 * &struct video_device structure is *not* called, so the caller 350 * is responsible for freeing any data. Usually that means that 351 * you video_device_release() should be called on failure. 352 */ 353 static inline int __must_check video_register_device_no_warn( 354 struct video_device *vdev, int type, int nr) 355 { 356 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 357 } 358 359 /** 360 * video_unregister_device - Unregister video devices. 361 * 362 * @vdev: &struct video_device to register 363 * 364 * Does nothing if vdev == NULL or if video_is_registered() returns false. 365 */ 366 void video_unregister_device(struct video_device *vdev); 367 368 /** 369 * video_device_alloc - helper function to alloc &struct video_device 370 * 371 * Returns NULL if %-ENOMEM or a &struct video_device on success. 372 */ 373 struct video_device * __must_check video_device_alloc(void); 374 375 /** 376 * video_device_release - helper function to release &struct video_device 377 * 378 * @vdev: pointer to &struct video_device 379 * 380 * Can also be used for video_device->release\(\). 381 */ 382 void video_device_release(struct video_device *vdev); 383 384 /** 385 * video_device_release_empty - helper function to implement the 386 * video_device->release\(\) callback. 387 * 388 * @vdev: pointer to &struct video_device 389 * 390 * This release function does nothing. 391 * 392 * It should be used when the video_device is a static global struct. 393 * 394 * .. note:: 395 * Having a static video_device is a dubious construction at best. 396 */ 397 void video_device_release_empty(struct video_device *vdev); 398 399 /** 400 * v4l2_is_known_ioctl - Checks if a given cmd is a known V4L ioctl 401 * 402 * @cmd: ioctl command 403 * 404 * returns true if cmd is a known V4L2 ioctl 405 */ 406 bool v4l2_is_known_ioctl(unsigned int cmd); 407 408 /** v4l2_disable_ioctl_locking - mark that a given command 409 * shouldn't use core locking 410 * 411 * @vdev: pointer to &struct video_device 412 * @cmd: ioctl command 413 */ 414 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, 415 unsigned int cmd) 416 { 417 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 418 set_bit(_IOC_NR(cmd), vdev->disable_locking); 419 } 420 421 /** 422 * v4l2_disable_ioctl- mark that a given command isn't implemented. 423 * shouldn't use core locking 424 * 425 * @vdev: pointer to &struct video_device 426 * @cmd: ioctl command 427 * 428 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 429 * disable ioctls based on the specific card that is actually found. 430 * 431 * .. note:: 432 * 433 * This must be called before video_register_device. 434 * See also the comments for determine_valid_ioctls(). 435 */ 436 static inline void v4l2_disable_ioctl(struct video_device *vdev, 437 unsigned int cmd) 438 { 439 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 440 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 441 } 442 443 /** 444 * video_get_drvdata - gets private data from &struct video_device. 445 * 446 * @vdev: pointer to &struct video_device 447 * 448 * returns a pointer to the private data 449 */ 450 static inline void *video_get_drvdata(struct video_device *vdev) 451 { 452 return dev_get_drvdata(&vdev->dev); 453 } 454 455 /** 456 * video_set_drvdata - sets private data from &struct video_device. 457 * 458 * @vdev: pointer to &struct video_device 459 * @data: private data pointer 460 */ 461 static inline void video_set_drvdata(struct video_device *vdev, void *data) 462 { 463 dev_set_drvdata(&vdev->dev, data); 464 } 465 466 /** 467 * video_devdata - gets &struct video_device from struct file. 468 * 469 * @file: pointer to struct file 470 */ 471 struct video_device *video_devdata(struct file *file); 472 473 /** 474 * video_drvdata - gets private data from &struct video_device using the 475 * struct file. 476 * 477 * @file: pointer to struct file 478 * 479 * This is function combines both video_get_drvdata() and video_devdata() 480 * as this is used very often. 481 */ 482 static inline void *video_drvdata(struct file *file) 483 { 484 return video_get_drvdata(video_devdata(file)); 485 } 486 487 /** 488 * video_device_node_name - returns the video device name 489 * 490 * @vdev: pointer to &struct video_device 491 * 492 * Returns the device name string 493 */ 494 static inline const char *video_device_node_name(struct video_device *vdev) 495 { 496 return dev_name(&vdev->dev); 497 } 498 499 /** 500 * video_is_registered - returns true if the &struct video_device is registered. 501 * 502 * 503 * @vdev: pointer to &struct video_device 504 */ 505 static inline int video_is_registered(struct video_device *vdev) 506 { 507 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 508 } 509 510 #endif /* _V4L2_DEV_H */ 511