1 /* 2 * 3 * V 4 L 2 D R I V E R H E L P E R A P I 4 * 5 * Moved from videodev2.h 6 * 7 * Some commonly needed functions for drivers (v4l2-common.o module) 8 */ 9 #ifndef _V4L2_DEV_H 10 #define _V4L2_DEV_H 11 12 #include <linux/poll.h> 13 #include <linux/fs.h> 14 #include <linux/device.h> 15 #include <linux/cdev.h> 16 #include <linux/mutex.h> 17 #include <linux/videodev2.h> 18 19 #include <media/media-entity.h> 20 21 #define VIDEO_MAJOR 81 22 23 #define VFL_TYPE_GRABBER 0 24 #define VFL_TYPE_VBI 1 25 #define VFL_TYPE_RADIO 2 26 #define VFL_TYPE_SUBDEV 3 27 #define VFL_TYPE_SDR 4 28 #define VFL_TYPE_MAX 5 29 30 /* Is this a receiver, transmitter or mem-to-mem? */ 31 /* Ignored for VFL_TYPE_SUBDEV. */ 32 #define VFL_DIR_RX 0 33 #define VFL_DIR_TX 1 34 #define VFL_DIR_M2M 2 35 36 struct v4l2_ioctl_callbacks; 37 struct video_device; 38 struct v4l2_device; 39 struct v4l2_ctrl_handler; 40 41 /* Flag to mark the video_device struct as registered. 42 Drivers can clear this flag if they want to block all future 43 device access. It is cleared by video_unregister_device. */ 44 #define V4L2_FL_REGISTERED (0) 45 /* file->private_data points to struct v4l2_fh */ 46 #define V4L2_FL_USES_V4L2_FH (1) 47 48 /* Priority helper functions */ 49 50 /** 51 * struct v4l2_prio_state - stores the priority states 52 * 53 * @prios: array with elements to store the array priorities 54 * 55 * 56 * .. note:: 57 * The size of @prios array matches the number of priority types defined 58 * by :ref:`enum v4l2_priority <v4l2-priority>`. 59 */ 60 struct v4l2_prio_state { 61 atomic_t prios[4]; 62 }; 63 64 /** 65 * v4l2_prio_init - initializes a struct v4l2_prio_state 66 * 67 * @global: pointer to &struct v4l2_prio_state 68 */ 69 void v4l2_prio_init(struct v4l2_prio_state *global); 70 71 /** 72 * v4l2_prio_change - changes the v4l2 file handler priority 73 * 74 * @global: pointer to the &struct v4l2_prio_state of the device node. 75 * @local: pointer to the desired priority, as defined by :ref:`enum v4l2_priority <v4l2-priority>` 76 * @new: Priority type requested, as defined by :ref:`enum v4l2_priority <v4l2-priority>`. 77 * 78 * .. note:: 79 * This function should be used only by the V4L2 core. 80 */ 81 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 82 enum v4l2_priority new); 83 84 /** 85 * v4l2_prio_open - Implements the priority logic for a file handler open 86 * 87 * @global: pointer to the &struct v4l2_prio_state of the device node. 88 * @local: pointer to the desired priority, as defined by :ref:`enum v4l2_priority <v4l2-priority>` 89 * 90 * .. note:: 91 * This function should be used only by the V4L2 core. 92 */ 93 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 94 95 /** 96 * v4l2_prio_close - Implements the priority logic for a file handler close 97 * 98 * @global: pointer to the &struct v4l2_prio_state of the device node. 99 * @local: priority to be released, as defined by :ref:`enum v4l2_priority <v4l2-priority>` 100 * 101 * .. note:: 102 * This function should be used only by the V4L2 core. 103 */ 104 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 105 106 /** 107 * v4l2_prio_max - Return the maximum priority, as stored at the @global array. 108 * 109 * @global: pointer to the &struct v4l2_prio_state of the device node. 110 * 111 * .. note:: 112 * This function should be used only by the V4L2 core. 113 */ 114 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 115 116 /** 117 * v4l2_prio_close - Implements the priority logic for a file handler close 118 * 119 * @global: pointer to the &struct v4l2_prio_state of the device node. 120 * @local: desired priority, as defined by :ref:`enum v4l2_priority <v4l2-priority>` local 121 * 122 * .. note:: 123 * This function should be used only by the V4L2 core. 124 */ 125 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 126 127 /** 128 * struct v4l2_file_operations - fs operations used by a V4L2 device 129 * 130 * @owner: pointer to struct module 131 * @read: operations needed to implement the read() syscall 132 * @write: operations needed to implement the write() syscall 133 * @poll: operations needed to implement the poll() syscall 134 * @unlocked_ioctl: operations needed to implement the ioctl() syscall 135 * @compat_ioctl32: operations needed to implement the ioctl() syscall for 136 * the special case where the Kernel uses 64 bits instructions, but 137 * the userspace uses 32 bits. 138 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU 139 * @mmap: operations needed to implement the mmap() syscall 140 * @open: operations needed to implement the open() syscall 141 * @release: operations needed to implement the release() syscall 142 * 143 * .. note:: 144 * 145 * Those operations are used to implemente the fs struct file_operations 146 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some 147 * extra logic needed by the subsystem. 148 */ 149 struct v4l2_file_operations { 150 struct module *owner; 151 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 152 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 153 unsigned int (*poll) (struct file *, struct poll_table_struct *); 154 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 155 #ifdef CONFIG_COMPAT 156 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 157 #endif 158 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 159 unsigned long, unsigned long, unsigned long); 160 int (*mmap) (struct file *, struct vm_area_struct *); 161 int (*open) (struct file *); 162 int (*release) (struct file *); 163 }; 164 165 /* 166 * Newer version of video_device, handled by videodev2.c 167 * This version moves redundant code from video device code to 168 * the common handler 169 */ 170 171 /** 172 * struct video_device - Structure used to create and manage the V4L2 device 173 * nodes. 174 * 175 * @entity: &struct media_entity 176 * @intf_devnode: pointer to &struct media_intf_devnode 177 * @pipe: &struct media_pipeline 178 * @fops: pointer to &struct v4l2_file_operations for the video device 179 * @device_caps: device capabilities as used in v4l2_capabilities 180 * @dev: &struct device for the video device 181 * @cdev: character device 182 * @v4l2_dev: pointer to &struct v4l2_device parent 183 * @dev_parent: pointer to &struct device parent 184 * @ctrl_handler: Control handler associated with this device node. 185 * May be NULL. 186 * @queue: &struct vb2_queue associated with this device node. May be NULL. 187 * @prio: pointer to &struct v4l2_prio_state with device's Priority state. 188 * If NULL, then v4l2_dev->prio will be used. 189 * @name: video device name 190 * @vfl_type: V4L device type 191 * @vfl_dir: V4L receiver, transmitter or m2m 192 * @minor: device node 'minor'. It is set to -1 if the registration failed 193 * @num: number of the video device node 194 * @flags: video device flags. Use bitops to set/clear/test flags 195 * @index: attribute to differentiate multiple indices on one physical device 196 * @fh_lock: Lock for all v4l2_fhs 197 * @fh_list: List of &struct v4l2_fh 198 * @dev_debug: Internal device debug flags, not for use by drivers 199 * @tvnorms: Supported tv norms 200 * 201 * @release: video device release() callback 202 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks 203 * 204 * @valid_ioctls: bitmap with the valid ioctls for this device 205 * @disable_locking: bitmap with the ioctls that don't require locking 206 * @lock: pointer to &struct mutex serialization lock 207 * 208 * .. note:: 209 * Only set @dev_parent if that can't be deduced from @v4l2_dev. 210 */ 211 212 struct video_device 213 { 214 #if defined(CONFIG_MEDIA_CONTROLLER) 215 struct media_entity entity; 216 struct media_intf_devnode *intf_devnode; 217 struct media_pipeline pipe; 218 #endif 219 const struct v4l2_file_operations *fops; 220 221 u32 device_caps; 222 223 /* sysfs */ 224 struct device dev; 225 struct cdev *cdev; 226 227 struct v4l2_device *v4l2_dev; 228 struct device *dev_parent; 229 230 struct v4l2_ctrl_handler *ctrl_handler; 231 232 struct vb2_queue *queue; 233 234 struct v4l2_prio_state *prio; 235 236 /* device info */ 237 char name[32]; 238 int vfl_type; 239 int vfl_dir; 240 int minor; 241 u16 num; 242 unsigned long flags; 243 int index; 244 245 /* V4L2 file handles */ 246 spinlock_t fh_lock; 247 struct list_head fh_list; 248 249 int dev_debug; 250 251 v4l2_std_id tvnorms; 252 253 /* callbacks */ 254 void (*release)(struct video_device *vdev); 255 const struct v4l2_ioctl_ops *ioctl_ops; 256 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 257 258 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 259 struct mutex *lock; 260 }; 261 262 #define media_entity_to_video_device(__e) \ 263 container_of(__e, struct video_device, entity) 264 /* dev to video-device */ 265 #define to_video_device(cd) container_of(cd, struct video_device, dev) 266 267 /** 268 * __video_register_device - register video4linux devices 269 * 270 * @vdev: struct video_device to register 271 * @type: type of device to register 272 * @nr: which device node number is desired: 273 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 274 * @warn_if_nr_in_use: warn if the desired device node number 275 * was already in use and another number was chosen instead. 276 * @owner: module that owns the video device node 277 * 278 * The registration code assigns minor numbers and device node numbers 279 * based on the requested type and registers the new device node with 280 * the kernel. 281 * 282 * This function assumes that struct video_device was zeroed when it 283 * was allocated and does not contain any stale date. 284 * 285 * An error is returned if no free minor or device node number could be 286 * found, or if the registration of the device node failed. 287 * 288 * Returns 0 on success. 289 * 290 * Valid values for @type are: 291 * 292 * - %VFL_TYPE_GRABBER - A frame grabber 293 * - %VFL_TYPE_VBI - Vertical blank data (undecoded) 294 * - %VFL_TYPE_RADIO - A radio card 295 * - %VFL_TYPE_SUBDEV - A subdevice 296 * - %VFL_TYPE_SDR - Software Defined Radio 297 * 298 * .. note:: 299 * 300 * This function is meant to be used only inside the V4L2 core. 301 * Drivers should use video_register_device() or 302 * video_register_device_no_warn(). 303 */ 304 int __must_check __video_register_device(struct video_device *vdev, int type, 305 int nr, int warn_if_nr_in_use, struct module *owner); 306 307 /** 308 * video_register_device - register video4linux devices 309 * 310 * @vdev: struct video_device to register 311 * @type: type of device to register 312 * @nr: which device node number is desired: 313 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 314 * 315 * Internally, it calls __video_register_device(). Please see its 316 * documentation for more details. 317 * 318 * .. note:: 319 * if video_register_device fails, the release() callback of 320 * &struct video_device structure is *not* called, so the caller 321 * is responsible for freeing any data. Usually that means that 322 * you video_device_release() should be called on failure. 323 */ 324 static inline int __must_check video_register_device(struct video_device *vdev, 325 int type, int nr) 326 { 327 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 328 } 329 330 /** 331 * video_register_device_no_warn - register video4linux devices 332 * 333 * @vdev: struct video_device to register 334 * @type: type of device to register 335 * @nr: which device node number is desired: 336 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 337 * 338 * This function is identical to video_register_device() except that no 339 * warning is issued if the desired device node number was already in use. 340 * 341 * Internally, it calls __video_register_device(). Please see its 342 * documentation for more details. 343 * 344 * .. note:: 345 * if video_register_device fails, the release() callback of 346 * &struct video_device structure is *not* called, so the caller 347 * is responsible for freeing any data. Usually that means that 348 * you video_device_release() should be called on failure. 349 */ 350 static inline int __must_check video_register_device_no_warn( 351 struct video_device *vdev, int type, int nr) 352 { 353 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 354 } 355 356 /** 357 * video_unregister_device - Unregister video devices. 358 * 359 * @vdev: &struct video_device to register 360 * 361 * Does nothing if vdev == NULL or if video_is_registered() returns false. 362 */ 363 void video_unregister_device(struct video_device *vdev); 364 365 /** 366 * video_device_alloc - helper function to alloc &struct video_device 367 * 368 * Returns NULL if %-ENOMEM or a &struct video_device on success. 369 */ 370 struct video_device * __must_check video_device_alloc(void); 371 372 /** 373 * video_device_release - helper function to release &struct video_device 374 * 375 * @vdev: pointer to &struct video_device 376 * 377 * Can also be used for video_device->release\(\). 378 */ 379 void video_device_release(struct video_device *vdev); 380 381 /** 382 * video_device_release_empty - helper function to implement the 383 * video_device->release\(\) callback. 384 * 385 * @vdev: pointer to &struct video_device 386 * 387 * This release function does nothing. 388 * 389 * It should be used when the video_device is a static global struct. 390 * 391 * .. note:: 392 * Having a static video_device is a dubious construction at best. 393 */ 394 void video_device_release_empty(struct video_device *vdev); 395 396 /** 397 * v4l2_is_known_ioctl - Checks if a given cmd is a known V4L ioctl 398 * 399 * @cmd: ioctl command 400 * 401 * returns true if cmd is a known V4L2 ioctl 402 */ 403 bool v4l2_is_known_ioctl(unsigned int cmd); 404 405 /** v4l2_disable_ioctl_locking - mark that a given command 406 * shouldn't use core locking 407 * 408 * @vdev: pointer to &struct video_device 409 * @cmd: ioctl command 410 */ 411 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, 412 unsigned int cmd) 413 { 414 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 415 set_bit(_IOC_NR(cmd), vdev->disable_locking); 416 } 417 418 /** 419 * v4l2_disable_ioctl- mark that a given command isn't implemented. 420 * shouldn't use core locking 421 * 422 * @vdev: pointer to &struct video_device 423 * @cmd: ioctl command 424 * 425 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 426 * disable ioctls based on the specific card that is actually found. 427 * 428 * .. note:: 429 * 430 * This must be called before video_register_device. 431 * See also the comments for determine_valid_ioctls(). 432 */ 433 static inline void v4l2_disable_ioctl(struct video_device *vdev, 434 unsigned int cmd) 435 { 436 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 437 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 438 } 439 440 /** 441 * video_get_drvdata - gets private data from &struct video_device. 442 * 443 * @vdev: pointer to &struct video_device 444 * 445 * returns a pointer to the private data 446 */ 447 static inline void *video_get_drvdata(struct video_device *vdev) 448 { 449 return dev_get_drvdata(&vdev->dev); 450 } 451 452 /** 453 * video_set_drvdata - sets private data from &struct video_device. 454 * 455 * @vdev: pointer to &struct video_device 456 * @data: private data pointer 457 */ 458 static inline void video_set_drvdata(struct video_device *vdev, void *data) 459 { 460 dev_set_drvdata(&vdev->dev, data); 461 } 462 463 /** 464 * video_devdata - gets &struct video_device from struct file. 465 * 466 * @file: pointer to struct file 467 */ 468 struct video_device *video_devdata(struct file *file); 469 470 /** 471 * video_drvdata - gets private data from &struct video_device using the 472 * struct file. 473 * 474 * @file: pointer to struct file 475 * 476 * This is function combines both video_get_drvdata() and video_devdata() 477 * as this is used very often. 478 */ 479 static inline void *video_drvdata(struct file *file) 480 { 481 return video_get_drvdata(video_devdata(file)); 482 } 483 484 /** 485 * video_device_node_name - returns the video device name 486 * 487 * @vdev: pointer to &struct video_device 488 * 489 * Returns the device name string 490 */ 491 static inline const char *video_device_node_name(struct video_device *vdev) 492 { 493 return dev_name(&vdev->dev); 494 } 495 496 /** 497 * video_is_registered - returns true if the &struct video_device is registered. 498 * 499 * 500 * @vdev: pointer to &struct video_device 501 */ 502 static inline int video_is_registered(struct video_device *vdev) 503 { 504 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 505 } 506 507 #endif /* _V4L2_DEV_H */ 508