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0001 /* SPDX-License-Identifier: GPL-2.0 */ 0002 /* 0003 * 0004 * V 4 L 2 D R I V E R H E L P E R A P I 0005 * 0006 * Moved from videodev2.h 0007 * 0008 * Some commonly needed functions for drivers (v4l2-common.o module) 0009 */ 0010 #ifndef _V4L2_DEV_H 0011 #define _V4L2_DEV_H 0012 0013 #include <linux/poll.h> 0014 #include <linux/fs.h> 0015 #include <linux/device.h> 0016 #include <linux/cdev.h> 0017 #include <linux/mutex.h> 0018 #include <linux/videodev2.h> 0019 0020 #include <media/media-entity.h> 0021 0022 #define VIDEO_MAJOR 81 0023 0024 /** 0025 * enum vfl_devnode_type - type of V4L2 device node 0026 * 0027 * @VFL_TYPE_VIDEO: for video input/output devices 0028 * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext) 0029 * @VFL_TYPE_RADIO: for radio tuners 0030 * @VFL_TYPE_SUBDEV: for V4L2 subdevices 0031 * @VFL_TYPE_SDR: for Software Defined Radio tuners 0032 * @VFL_TYPE_TOUCH: for touch sensors 0033 * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum 0034 */ 0035 enum vfl_devnode_type { 0036 VFL_TYPE_VIDEO, 0037 VFL_TYPE_VBI, 0038 VFL_TYPE_RADIO, 0039 VFL_TYPE_SUBDEV, 0040 VFL_TYPE_SDR, 0041 VFL_TYPE_TOUCH, 0042 VFL_TYPE_MAX /* Shall be the last one */ 0043 }; 0044 0045 /** 0046 * enum vfl_devnode_direction - Identifies if a &struct video_device 0047 * corresponds to a receiver, a transmitter or a mem-to-mem device. 0048 * 0049 * @VFL_DIR_RX: device is a receiver. 0050 * @VFL_DIR_TX: device is a transmitter. 0051 * @VFL_DIR_M2M: device is a memory to memory device. 0052 * 0053 * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV. 0054 */ 0055 enum vfl_devnode_direction { 0056 VFL_DIR_RX, 0057 VFL_DIR_TX, 0058 VFL_DIR_M2M, 0059 }; 0060 0061 struct v4l2_ioctl_callbacks; 0062 struct video_device; 0063 struct v4l2_device; 0064 struct v4l2_ctrl_handler; 0065 0066 /** 0067 * enum v4l2_video_device_flags - Flags used by &struct video_device 0068 * 0069 * @V4L2_FL_REGISTERED: 0070 * indicates that a &struct video_device is registered. 0071 * Drivers can clear this flag if they want to block all future 0072 * device access. It is cleared by video_unregister_device. 0073 * @V4L2_FL_USES_V4L2_FH: 0074 * indicates that file->private_data points to &struct v4l2_fh. 0075 * This flag is set by the core when v4l2_fh_init() is called. 0076 * All new drivers should use it. 0077 * @V4L2_FL_QUIRK_INVERTED_CROP: 0078 * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and 0079 * compose are swapped. If this flag is set, then the selection 0080 * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c. 0081 * This allows those drivers to correctly implement the selection API, 0082 * but the old crop API will still work as expected in order to preserve 0083 * backwards compatibility. 0084 * Never set this flag for new drivers. 0085 * @V4L2_FL_SUBDEV_RO_DEVNODE: 0086 * indicates that the video device node is registered in read-only mode. 0087 * The flag only applies to device nodes registered for sub-devices, it is 0088 * set by the core when the sub-devices device nodes are registered with 0089 * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl 0090 * handler to restrict access to some ioctl calls. 0091 */ 0092 enum v4l2_video_device_flags { 0093 V4L2_FL_REGISTERED = 0, 0094 V4L2_FL_USES_V4L2_FH = 1, 0095 V4L2_FL_QUIRK_INVERTED_CROP = 2, 0096 V4L2_FL_SUBDEV_RO_DEVNODE = 3, 0097 }; 0098 0099 /* Priority helper functions */ 0100 0101 /** 0102 * struct v4l2_prio_state - stores the priority states 0103 * 0104 * @prios: array with elements to store the array priorities 0105 * 0106 * 0107 * .. note:: 0108 * The size of @prios array matches the number of priority types defined 0109 * by enum &v4l2_priority. 0110 */ 0111 struct v4l2_prio_state { 0112 atomic_t prios[4]; 0113 }; 0114 0115 /** 0116 * v4l2_prio_init - initializes a struct v4l2_prio_state 0117 * 0118 * @global: pointer to &struct v4l2_prio_state 0119 */ 0120 void v4l2_prio_init(struct v4l2_prio_state *global); 0121 0122 /** 0123 * v4l2_prio_change - changes the v4l2 file handler priority 0124 * 0125 * @global: pointer to the &struct v4l2_prio_state of the device node. 0126 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 0127 * @new: Priority type requested, as defined by enum &v4l2_priority. 0128 * 0129 * .. note:: 0130 * This function should be used only by the V4L2 core. 0131 */ 0132 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 0133 enum v4l2_priority new); 0134 0135 /** 0136 * v4l2_prio_open - Implements the priority logic for a file handler open 0137 * 0138 * @global: pointer to the &struct v4l2_prio_state of the device node. 0139 * @local: pointer to the desired priority, as defined by enum &v4l2_priority 0140 * 0141 * .. note:: 0142 * This function should be used only by the V4L2 core. 0143 */ 0144 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 0145 0146 /** 0147 * v4l2_prio_close - Implements the priority logic for a file handler close 0148 * 0149 * @global: pointer to the &struct v4l2_prio_state of the device node. 0150 * @local: priority to be released, as defined by enum &v4l2_priority 0151 * 0152 * .. note:: 0153 * This function should be used only by the V4L2 core. 0154 */ 0155 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 0156 0157 /** 0158 * v4l2_prio_max - Return the maximum priority, as stored at the @global array. 0159 * 0160 * @global: pointer to the &struct v4l2_prio_state of the device node. 0161 * 0162 * .. note:: 0163 * This function should be used only by the V4L2 core. 0164 */ 0165 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 0166 0167 /** 0168 * v4l2_prio_check - Implements the priority logic for a file handler close 0169 * 0170 * @global: pointer to the &struct v4l2_prio_state of the device node. 0171 * @local: desired priority, as defined by enum &v4l2_priority local 0172 * 0173 * .. note:: 0174 * This function should be used only by the V4L2 core. 0175 */ 0176 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 0177 0178 /** 0179 * struct v4l2_file_operations - fs operations used by a V4L2 device 0180 * 0181 * @owner: pointer to struct module 0182 * @read: operations needed to implement the read() syscall 0183 * @write: operations needed to implement the write() syscall 0184 * @poll: operations needed to implement the poll() syscall 0185 * @unlocked_ioctl: operations needed to implement the ioctl() syscall 0186 * @compat_ioctl32: operations needed to implement the ioctl() syscall for 0187 * the special case where the Kernel uses 64 bits instructions, but 0188 * the userspace uses 32 bits. 0189 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU 0190 * @mmap: operations needed to implement the mmap() syscall 0191 * @open: operations needed to implement the open() syscall 0192 * @release: operations needed to implement the release() syscall 0193 * 0194 * .. note:: 0195 * 0196 * Those operations are used to implemente the fs struct file_operations 0197 * at the V4L2 drivers. The V4L2 core overrides the fs ops with some 0198 * extra logic needed by the subsystem. 0199 */ 0200 struct v4l2_file_operations { 0201 struct module *owner; 0202 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 0203 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 0204 __poll_t (*poll) (struct file *, struct poll_table_struct *); 0205 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 0206 #ifdef CONFIG_COMPAT 0207 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 0208 #endif 0209 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 0210 unsigned long, unsigned long, unsigned long); 0211 int (*mmap) (struct file *, struct vm_area_struct *); 0212 int (*open) (struct file *); 0213 int (*release) (struct file *); 0214 }; 0215 0216 /* 0217 * Newer version of video_device, handled by videodev2.c 0218 * This version moves redundant code from video device code to 0219 * the common handler 0220 */ 0221 0222 /** 0223 * struct video_device - Structure used to create and manage the V4L2 device 0224 * nodes. 0225 * 0226 * @entity: &struct media_entity 0227 * @intf_devnode: pointer to &struct media_intf_devnode 0228 * @pipe: &struct media_pipeline 0229 * @fops: pointer to &struct v4l2_file_operations for the video device 0230 * @device_caps: device capabilities as used in v4l2_capabilities 0231 * @dev: &struct device for the video device 0232 * @cdev: character device 0233 * @v4l2_dev: pointer to &struct v4l2_device parent 0234 * @dev_parent: pointer to &struct device parent 0235 * @ctrl_handler: Control handler associated with this device node. 0236 * May be NULL. 0237 * @queue: &struct vb2_queue associated with this device node. May be NULL. 0238 * @prio: pointer to &struct v4l2_prio_state with device's Priority state. 0239 * If NULL, then v4l2_dev->prio will be used. 0240 * @name: video device name 0241 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type 0242 * @vfl_dir: V4L receiver, transmitter or m2m 0243 * @minor: device node 'minor'. It is set to -1 if the registration failed 0244 * @num: number of the video device node 0245 * @flags: video device flags. Use bitops to set/clear/test flags. 0246 * Contains a set of &enum v4l2_video_device_flags. 0247 * @index: attribute to differentiate multiple indices on one physical device 0248 * @fh_lock: Lock for all v4l2_fhs 0249 * @fh_list: List of &struct v4l2_fh 0250 * @dev_debug: Internal device debug flags, not for use by drivers 0251 * @tvnorms: Supported tv norms 0252 * 0253 * @release: video device release() callback 0254 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks 0255 * 0256 * @valid_ioctls: bitmap with the valid ioctls for this device 0257 * @lock: pointer to &struct mutex serialization lock 0258 * 0259 * .. note:: 0260 * Only set @dev_parent if that can't be deduced from @v4l2_dev. 0261 */ 0262 0263 struct video_device { 0264 #if defined(CONFIG_MEDIA_CONTROLLER) 0265 struct media_entity entity; 0266 struct media_intf_devnode *intf_devnode; 0267 struct media_pipeline pipe; 0268 #endif 0269 const struct v4l2_file_operations *fops; 0270 0271 u32 device_caps; 0272 0273 /* sysfs */ 0274 struct device dev; 0275 struct cdev *cdev; 0276 0277 struct v4l2_device *v4l2_dev; 0278 struct device *dev_parent; 0279 0280 struct v4l2_ctrl_handler *ctrl_handler; 0281 0282 struct vb2_queue *queue; 0283 0284 struct v4l2_prio_state *prio; 0285 0286 /* device info */ 0287 char name[32]; 0288 enum vfl_devnode_type vfl_type; 0289 enum vfl_devnode_direction vfl_dir; 0290 int minor; 0291 u16 num; 0292 unsigned long flags; 0293 int index; 0294 0295 /* V4L2 file handles */ 0296 spinlock_t fh_lock; 0297 struct list_head fh_list; 0298 0299 int dev_debug; 0300 0301 v4l2_std_id tvnorms; 0302 0303 /* callbacks */ 0304 void (*release)(struct video_device *vdev); 0305 const struct v4l2_ioctl_ops *ioctl_ops; 0306 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 0307 0308 struct mutex *lock; 0309 }; 0310 0311 /** 0312 * media_entity_to_video_device - Returns a &struct video_device from 0313 * the &struct media_entity embedded on it. 0314 * 0315 * @__entity: pointer to &struct media_entity 0316 */ 0317 #define media_entity_to_video_device(__entity) \ 0318 container_of(__entity, struct video_device, entity) 0319 0320 /** 0321 * to_video_device - Returns a &struct video_device from the 0322 * &struct device embedded on it. 0323 * 0324 * @cd: pointer to &struct device 0325 */ 0326 #define to_video_device(cd) container_of(cd, struct video_device, dev) 0327 0328 /** 0329 * __video_register_device - register video4linux devices 0330 * 0331 * @vdev: struct video_device to register 0332 * @type: type of device to register, as defined by &enum vfl_devnode_type 0333 * @nr: which device node number is desired: 0334 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 0335 * @warn_if_nr_in_use: warn if the desired device node number 0336 * was already in use and another number was chosen instead. 0337 * @owner: module that owns the video device node 0338 * 0339 * The registration code assigns minor numbers and device node numbers 0340 * based on the requested type and registers the new device node with 0341 * the kernel. 0342 * 0343 * This function assumes that struct video_device was zeroed when it 0344 * was allocated and does not contain any stale date. 0345 * 0346 * An error is returned if no free minor or device node number could be 0347 * found, or if the registration of the device node failed. 0348 * 0349 * Returns 0 on success. 0350 * 0351 * .. note:: 0352 * 0353 * This function is meant to be used only inside the V4L2 core. 0354 * Drivers should use video_register_device() or 0355 * video_register_device_no_warn(). 0356 */ 0357 int __must_check __video_register_device(struct video_device *vdev, 0358 enum vfl_devnode_type type, 0359 int nr, int warn_if_nr_in_use, 0360 struct module *owner); 0361 0362 /** 0363 * video_register_device - register video4linux devices 0364 * 0365 * @vdev: struct video_device to register 0366 * @type: type of device to register, as defined by &enum vfl_devnode_type 0367 * @nr: which device node number is desired: 0368 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 0369 * 0370 * Internally, it calls __video_register_device(). Please see its 0371 * documentation for more details. 0372 * 0373 * .. note:: 0374 * if video_register_device fails, the release() callback of 0375 * &struct video_device structure is *not* called, so the caller 0376 * is responsible for freeing any data. Usually that means that 0377 * you video_device_release() should be called on failure. 0378 */ 0379 static inline int __must_check video_register_device(struct video_device *vdev, 0380 enum vfl_devnode_type type, 0381 int nr) 0382 { 0383 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 0384 } 0385 0386 /** 0387 * video_register_device_no_warn - register video4linux devices 0388 * 0389 * @vdev: struct video_device to register 0390 * @type: type of device to register, as defined by &enum vfl_devnode_type 0391 * @nr: which device node number is desired: 0392 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) 0393 * 0394 * This function is identical to video_register_device() except that no 0395 * warning is issued if the desired device node number was already in use. 0396 * 0397 * Internally, it calls __video_register_device(). Please see its 0398 * documentation for more details. 0399 * 0400 * .. note:: 0401 * if video_register_device fails, the release() callback of 0402 * &struct video_device structure is *not* called, so the caller 0403 * is responsible for freeing any data. Usually that means that 0404 * you video_device_release() should be called on failure. 0405 */ 0406 static inline int __must_check 0407 video_register_device_no_warn(struct video_device *vdev, 0408 enum vfl_devnode_type type, int nr) 0409 { 0410 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 0411 } 0412 0413 /** 0414 * video_unregister_device - Unregister video devices. 0415 * 0416 * @vdev: &struct video_device to register 0417 * 0418 * Does nothing if vdev == NULL or if video_is_registered() returns false. 0419 */ 0420 void video_unregister_device(struct video_device *vdev); 0421 0422 /** 0423 * video_device_alloc - helper function to alloc &struct video_device 0424 * 0425 * Returns NULL if %-ENOMEM or a &struct video_device on success. 0426 */ 0427 struct video_device * __must_check video_device_alloc(void); 0428 0429 /** 0430 * video_device_release - helper function to release &struct video_device 0431 * 0432 * @vdev: pointer to &struct video_device 0433 * 0434 * Can also be used for video_device->release\(\). 0435 */ 0436 void video_device_release(struct video_device *vdev); 0437 0438 /** 0439 * video_device_release_empty - helper function to implement the 0440 * video_device->release\(\) callback. 0441 * 0442 * @vdev: pointer to &struct video_device 0443 * 0444 * This release function does nothing. 0445 * 0446 * It should be used when the video_device is a static global struct. 0447 * 0448 * .. note:: 0449 * Having a static video_device is a dubious construction at best. 0450 */ 0451 void video_device_release_empty(struct video_device *vdev); 0452 0453 /** 0454 * v4l2_disable_ioctl- mark that a given command isn't implemented. 0455 * shouldn't use core locking 0456 * 0457 * @vdev: pointer to &struct video_device 0458 * @cmd: ioctl command 0459 * 0460 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but 0461 * disable ioctls based on the specific card that is actually found. 0462 * 0463 * .. note:: 0464 * 0465 * This must be called before video_register_device. 0466 * See also the comments for determine_valid_ioctls(). 0467 */ 0468 static inline void v4l2_disable_ioctl(struct video_device *vdev, 0469 unsigned int cmd) 0470 { 0471 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 0472 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 0473 } 0474 0475 /** 0476 * video_get_drvdata - gets private data from &struct video_device. 0477 * 0478 * @vdev: pointer to &struct video_device 0479 * 0480 * returns a pointer to the private data 0481 */ 0482 static inline void *video_get_drvdata(struct video_device *vdev) 0483 { 0484 return dev_get_drvdata(&vdev->dev); 0485 } 0486 0487 /** 0488 * video_set_drvdata - sets private data from &struct video_device. 0489 * 0490 * @vdev: pointer to &struct video_device 0491 * @data: private data pointer 0492 */ 0493 static inline void video_set_drvdata(struct video_device *vdev, void *data) 0494 { 0495 dev_set_drvdata(&vdev->dev, data); 0496 } 0497 0498 /** 0499 * video_devdata - gets &struct video_device from struct file. 0500 * 0501 * @file: pointer to struct file 0502 */ 0503 struct video_device *video_devdata(struct file *file); 0504 0505 /** 0506 * video_drvdata - gets private data from &struct video_device using the 0507 * struct file. 0508 * 0509 * @file: pointer to struct file 0510 * 0511 * This is function combines both video_get_drvdata() and video_devdata() 0512 * as this is used very often. 0513 */ 0514 static inline void *video_drvdata(struct file *file) 0515 { 0516 return video_get_drvdata(video_devdata(file)); 0517 } 0518 0519 /** 0520 * video_device_node_name - returns the video device name 0521 * 0522 * @vdev: pointer to &struct video_device 0523 * 0524 * Returns the device name string 0525 */ 0526 static inline const char *video_device_node_name(struct video_device *vdev) 0527 { 0528 return dev_name(&vdev->dev); 0529 } 0530 0531 /** 0532 * video_is_registered - returns true if the &struct video_device is registered. 0533 * 0534 * 0535 * @vdev: pointer to &struct video_device 0536 */ 0537 static inline int video_is_registered(struct video_device *vdev) 0538 { 0539 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 0540 } 0541 0542 #endif /* _V4L2_DEV_H */
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