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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_GRABBER: 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_GRABBER = 0,
37 : : VFL_TYPE_VIDEO = VFL_TYPE_GRABBER,
38 : : VFL_TYPE_VBI,
39 : : VFL_TYPE_RADIO,
40 : : VFL_TYPE_SUBDEV,
41 : : VFL_TYPE_SDR,
42 : : VFL_TYPE_TOUCH,
43 : : VFL_TYPE_MAX /* Shall be the last one */
44 : : };
45 : :
46 : : /**
47 : : * enum vfl_direction - Identifies if a &struct video_device corresponds
48 : : * to a receiver, a transmitter or a mem-to-mem device.
49 : : *
50 : : * @VFL_DIR_RX: device is a receiver.
51 : : * @VFL_DIR_TX: device is a transmitter.
52 : : * @VFL_DIR_M2M: device is a memory to memory device.
53 : : *
54 : : * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV.
55 : : */
56 : : enum vfl_devnode_direction {
57 : : VFL_DIR_RX,
58 : : VFL_DIR_TX,
59 : : VFL_DIR_M2M,
60 : : };
61 : :
62 : : struct v4l2_ioctl_callbacks;
63 : : struct video_device;
64 : : struct v4l2_device;
65 : : struct v4l2_ctrl_handler;
66 : :
67 : : /**
68 : : * enum v4l2_video_device_flags - Flags used by &struct video_device
69 : : *
70 : : * @V4L2_FL_REGISTERED:
71 : : * indicates that a &struct video_device is registered.
72 : : * Drivers can clear this flag if they want to block all future
73 : : * device access. It is cleared by video_unregister_device.
74 : : * @V4L2_FL_USES_V4L2_FH:
75 : : * indicates that file->private_data points to &struct v4l2_fh.
76 : : * This flag is set by the core when v4l2_fh_init() is called.
77 : : * All new drivers should use it.
78 : : * @V4L2_FL_QUIRK_INVERTED_CROP:
79 : : * some old M2M drivers use g/s_crop/cropcap incorrectly: crop and
80 : : * compose are swapped. If this flag is set, then the selection
81 : : * targets are swapped in the g/s_crop/cropcap functions in v4l2-ioctl.c.
82 : : * This allows those drivers to correctly implement the selection API,
83 : : * but the old crop API will still work as expected in order to preserve
84 : : * backwards compatibility.
85 : : * Never set this flag for new drivers.
86 : : * @V4L2_FL_SUBDEV_RO_DEVNODE:
87 : : * indicates that the video device node is registered in read-only mode.
88 : : * The flag only applies to device nodes registered for sub-devices, it is
89 : : * set by the core when the sub-devices device nodes are registered with
90 : : * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl
91 : : * handler to restrict access to some ioctl calls.
92 : : */
93 : : enum v4l2_video_device_flags {
94 : : V4L2_FL_REGISTERED = 0,
95 : : V4L2_FL_USES_V4L2_FH = 1,
96 : : V4L2_FL_QUIRK_INVERTED_CROP = 2,
97 : : V4L2_FL_SUBDEV_RO_DEVNODE = 3,
98 : : };
99 : :
100 : : /* Priority helper functions */
101 : :
102 : : /**
103 : : * struct v4l2_prio_state - stores the priority states
104 : : *
105 : : * @prios: array with elements to store the array priorities
106 : : *
107 : : *
108 : : * .. note::
109 : : * The size of @prios array matches the number of priority types defined
110 : : * by enum &v4l2_priority.
111 : : */
112 : : struct v4l2_prio_state {
113 : : atomic_t prios[4];
114 : : };
115 : :
116 : : /**
117 : : * v4l2_prio_init - initializes a struct v4l2_prio_state
118 : : *
119 : : * @global: pointer to &struct v4l2_prio_state
120 : : */
121 : : void v4l2_prio_init(struct v4l2_prio_state *global);
122 : :
123 : : /**
124 : : * v4l2_prio_change - changes the v4l2 file handler priority
125 : : *
126 : : * @global: pointer to the &struct v4l2_prio_state of the device node.
127 : : * @local: pointer to the desired priority, as defined by enum &v4l2_priority
128 : : * @new: Priority type requested, as defined by enum &v4l2_priority.
129 : : *
130 : : * .. note::
131 : : * This function should be used only by the V4L2 core.
132 : : */
133 : : int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
134 : : enum v4l2_priority new);
135 : :
136 : : /**
137 : : * v4l2_prio_open - Implements the priority logic for a file handler open
138 : : *
139 : : * @global: pointer to the &struct v4l2_prio_state of the device node.
140 : : * @local: pointer to the desired priority, as defined by enum &v4l2_priority
141 : : *
142 : : * .. note::
143 : : * This function should be used only by the V4L2 core.
144 : : */
145 : : void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
146 : :
147 : : /**
148 : : * v4l2_prio_close - Implements the priority logic for a file handler close
149 : : *
150 : : * @global: pointer to the &struct v4l2_prio_state of the device node.
151 : : * @local: priority to be released, as defined by enum &v4l2_priority
152 : : *
153 : : * .. note::
154 : : * This function should be used only by the V4L2 core.
155 : : */
156 : : void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
157 : :
158 : : /**
159 : : * v4l2_prio_max - Return the maximum priority, as stored at the @global array.
160 : : *
161 : : * @global: pointer to the &struct v4l2_prio_state of the device node.
162 : : *
163 : : * .. note::
164 : : * This function should be used only by the V4L2 core.
165 : : */
166 : : enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
167 : :
168 : : /**
169 : : * v4l2_prio_check - Implements the priority logic for a file handler close
170 : : *
171 : : * @global: pointer to the &struct v4l2_prio_state of the device node.
172 : : * @local: desired priority, as defined by enum &v4l2_priority local
173 : : *
174 : : * .. note::
175 : : * This function should be used only by the V4L2 core.
176 : : */
177 : : int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
178 : :
179 : : /**
180 : : * struct v4l2_file_operations - fs operations used by a V4L2 device
181 : : *
182 : : * @owner: pointer to struct module
183 : : * @read: operations needed to implement the read() syscall
184 : : * @write: operations needed to implement the write() syscall
185 : : * @poll: operations needed to implement the poll() syscall
186 : : * @unlocked_ioctl: operations needed to implement the ioctl() syscall
187 : : * @compat_ioctl32: operations needed to implement the ioctl() syscall for
188 : : * the special case where the Kernel uses 64 bits instructions, but
189 : : * the userspace uses 32 bits.
190 : : * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU
191 : : * @mmap: operations needed to implement the mmap() syscall
192 : : * @open: operations needed to implement the open() syscall
193 : : * @release: operations needed to implement the release() syscall
194 : : *
195 : : * .. note::
196 : : *
197 : : * Those operations are used to implemente the fs struct file_operations
198 : : * at the V4L2 drivers. The V4L2 core overrides the fs ops with some
199 : : * extra logic needed by the subsystem.
200 : : */
201 : : struct v4l2_file_operations {
202 : : struct module *owner;
203 : : ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
204 : : ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
205 : : __poll_t (*poll) (struct file *, struct poll_table_struct *);
206 : : long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
207 : : #ifdef CONFIG_COMPAT
208 : : long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
209 : : #endif
210 : : unsigned long (*get_unmapped_area) (struct file *, unsigned long,
211 : : unsigned long, unsigned long, unsigned long);
212 : : int (*mmap) (struct file *, struct vm_area_struct *);
213 : : int (*open) (struct file *);
214 : : int (*release) (struct file *);
215 : : };
216 : :
217 : : /*
218 : : * Newer version of video_device, handled by videodev2.c
219 : : * This version moves redundant code from video device code to
220 : : * the common handler
221 : : */
222 : :
223 : : /**
224 : : * struct video_device - Structure used to create and manage the V4L2 device
225 : : * nodes.
226 : : *
227 : : * @entity: &struct media_entity
228 : : * @intf_devnode: pointer to &struct media_intf_devnode
229 : : * @pipe: &struct media_pipeline
230 : : * @fops: pointer to &struct v4l2_file_operations for the video device
231 : : * @device_caps: device capabilities as used in v4l2_capabilities
232 : : * @dev: &struct device for the video device
233 : : * @cdev: character device
234 : : * @v4l2_dev: pointer to &struct v4l2_device parent
235 : : * @dev_parent: pointer to &struct device parent
236 : : * @ctrl_handler: Control handler associated with this device node.
237 : : * May be NULL.
238 : : * @queue: &struct vb2_queue associated with this device node. May be NULL.
239 : : * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
240 : : * If NULL, then v4l2_dev->prio will be used.
241 : : * @name: video device name
242 : : * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
243 : : * @vfl_dir: V4L receiver, transmitter or m2m
244 : : * @minor: device node 'minor'. It is set to -1 if the registration failed
245 : : * @num: number of the video device node
246 : : * @flags: video device flags. Use bitops to set/clear/test flags.
247 : : * Contains a set of &enum v4l2_video_device_flags.
248 : : * @index: attribute to differentiate multiple indices on one physical device
249 : : * @fh_lock: Lock for all v4l2_fhs
250 : : * @fh_list: List of &struct v4l2_fh
251 : : * @dev_debug: Internal device debug flags, not for use by drivers
252 : : * @tvnorms: Supported tv norms
253 : : *
254 : : * @release: video device release() callback
255 : : * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
256 : : *
257 : : * @valid_ioctls: bitmap with the valid ioctls for this device
258 : : * @lock: pointer to &struct mutex serialization lock
259 : : *
260 : : * .. note::
261 : : * Only set @dev_parent if that can't be deduced from @v4l2_dev.
262 : : */
263 : :
264 : : struct video_device
265 : : {
266 : : #if defined(CONFIG_MEDIA_CONTROLLER)
267 : : struct media_entity entity;
268 : : struct media_intf_devnode *intf_devnode;
269 : : struct media_pipeline pipe;
270 : : #endif
271 : : const struct v4l2_file_operations *fops;
272 : :
273 : : u32 device_caps;
274 : :
275 : : /* sysfs */
276 : : struct device dev;
277 : : struct cdev *cdev;
278 : :
279 : : struct v4l2_device *v4l2_dev;
280 : : struct device *dev_parent;
281 : :
282 : : struct v4l2_ctrl_handler *ctrl_handler;
283 : :
284 : : struct vb2_queue *queue;
285 : :
286 : : struct v4l2_prio_state *prio;
287 : :
288 : : /* device info */
289 : : char name[32];
290 : : enum vfl_devnode_type vfl_type;
291 : : enum vfl_devnode_direction vfl_dir;
292 : : int minor;
293 : : u16 num;
294 : : unsigned long flags;
295 : : int index;
296 : :
297 : : /* V4L2 file handles */
298 : : spinlock_t fh_lock;
299 : : struct list_head fh_list;
300 : :
301 : : int dev_debug;
302 : :
303 : : v4l2_std_id tvnorms;
304 : :
305 : : /* callbacks */
306 : : void (*release)(struct video_device *vdev);
307 : : const struct v4l2_ioctl_ops *ioctl_ops;
308 : : DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
309 : :
310 : : struct mutex *lock;
311 : : };
312 : :
313 : : /**
314 : : * media_entity_to_video_device - Returns a &struct video_device from
315 : : * the &struct media_entity embedded on it.
316 : : *
317 : : * @__entity: pointer to &struct media_entity
318 : : */
319 : : #define media_entity_to_video_device(__entity) \
320 : : container_of(__entity, struct video_device, entity)
321 : :
322 : : /**
323 : : * to_video_device - Returns a &struct video_device from the
324 : : * &struct device embedded on it.
325 : : *
326 : : * @cd: pointer to &struct device
327 : : */
328 : : #define to_video_device(cd) container_of(cd, struct video_device, dev)
329 : :
330 : : /**
331 : : * __video_register_device - register video4linux devices
332 : : *
333 : : * @vdev: struct video_device to register
334 : : * @type: type of device to register, as defined by &enum vfl_devnode_type
335 : : * @nr: which device node number is desired:
336 : : * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
337 : : * @warn_if_nr_in_use: warn if the desired device node number
338 : : * was already in use and another number was chosen instead.
339 : : * @owner: module that owns the video device node
340 : : *
341 : : * The registration code assigns minor numbers and device node numbers
342 : : * based on the requested type and registers the new device node with
343 : : * the kernel.
344 : : *
345 : : * This function assumes that struct video_device was zeroed when it
346 : : * was allocated and does not contain any stale date.
347 : : *
348 : : * An error is returned if no free minor or device node number could be
349 : : * found, or if the registration of the device node failed.
350 : : *
351 : : * Returns 0 on success.
352 : : *
353 : : * .. note::
354 : : *
355 : : * This function is meant to be used only inside the V4L2 core.
356 : : * Drivers should use video_register_device() or
357 : : * video_register_device_no_warn().
358 : : */
359 : : int __must_check __video_register_device(struct video_device *vdev,
360 : : enum vfl_devnode_type type,
361 : : int nr, int warn_if_nr_in_use,
362 : : struct module *owner);
363 : :
364 : : /**
365 : : * video_register_device - register video4linux devices
366 : : *
367 : : * @vdev: struct video_device to register
368 : : * @type: type of device to register, as defined by &enum vfl_devnode_type
369 : : * @nr: which device node number is desired:
370 : : * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
371 : : *
372 : : * Internally, it calls __video_register_device(). Please see its
373 : : * documentation for more details.
374 : : *
375 : : * .. note::
376 : : * if video_register_device fails, the release() callback of
377 : : * &struct video_device structure is *not* called, so the caller
378 : : * is responsible for freeing any data. Usually that means that
379 : : * you video_device_release() should be called on failure.
380 : : */
381 : : static inline int __must_check video_register_device(struct video_device *vdev,
382 : : enum vfl_devnode_type type,
383 : : int nr)
384 : : {
385 : 1449 : return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
386 : : }
387 : :
388 : : /**
389 : : * video_register_device_no_warn - register video4linux devices
390 : : *
391 : : * @vdev: struct video_device to register
392 : : * @type: type of device to register, as defined by &enum vfl_devnode_type
393 : : * @nr: which device node number is desired:
394 : : * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
395 : : *
396 : : * This function is identical to video_register_device() except that no
397 : : * warning is issued if the desired device node number was already in use.
398 : : *
399 : : * Internally, it calls __video_register_device(). Please see its
400 : : * documentation for more details.
401 : : *
402 : : * .. note::
403 : : * if video_register_device fails, the release() callback of
404 : : * &struct video_device structure is *not* called, so the caller
405 : : * is responsible for freeing any data. Usually that means that
406 : : * you video_device_release() should be called on failure.
407 : : */
408 : : static inline int __must_check
409 : : video_register_device_no_warn(struct video_device *vdev,
410 : : enum vfl_devnode_type type, int nr)
411 : : {
412 : : return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
413 : : }
414 : :
415 : : /**
416 : : * video_unregister_device - Unregister video devices.
417 : : *
418 : : * @vdev: &struct video_device to register
419 : : *
420 : : * Does nothing if vdev == NULL or if video_is_registered() returns false.
421 : : */
422 : : void video_unregister_device(struct video_device *vdev);
423 : :
424 : : /**
425 : : * video_device_alloc - helper function to alloc &struct video_device
426 : : *
427 : : * Returns NULL if %-ENOMEM or a &struct video_device on success.
428 : : */
429 : : struct video_device * __must_check video_device_alloc(void);
430 : :
431 : : /**
432 : : * video_device_release - helper function to release &struct video_device
433 : : *
434 : : * @vdev: pointer to &struct video_device
435 : : *
436 : : * Can also be used for video_device->release\(\).
437 : : */
438 : : void video_device_release(struct video_device *vdev);
439 : :
440 : : /**
441 : : * video_device_release_empty - helper function to implement the
442 : : * video_device->release\(\) callback.
443 : : *
444 : : * @vdev: pointer to &struct video_device
445 : : *
446 : : * This release function does nothing.
447 : : *
448 : : * It should be used when the video_device is a static global struct.
449 : : *
450 : : * .. note::
451 : : * Having a static video_device is a dubious construction at best.
452 : : */
453 : : void video_device_release_empty(struct video_device *vdev);
454 : :
455 : : /**
456 : : * v4l2_disable_ioctl- mark that a given command isn't implemented.
457 : : * shouldn't use core locking
458 : : *
459 : : * @vdev: pointer to &struct video_device
460 : : * @cmd: ioctl command
461 : : *
462 : : * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
463 : : * disable ioctls based on the specific card that is actually found.
464 : : *
465 : : * .. note::
466 : : *
467 : : * This must be called before video_register_device.
468 : : * See also the comments for determine_valid_ioctls().
469 : : */
470 : : static inline void v4l2_disable_ioctl(struct video_device *vdev,
471 : : unsigned int cmd)
472 : : {
473 : : if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
474 : 1242 : set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
475 : : }
476 : :
477 : : /**
478 : : * video_get_drvdata - gets private data from &struct video_device.
479 : : *
480 : : * @vdev: pointer to &struct video_device
481 : : *
482 : : * returns a pointer to the private data
483 : : */
484 : : static inline void *video_get_drvdata(struct video_device *vdev)
485 : : {
486 : : return dev_get_drvdata(&vdev->dev);
487 : : }
488 : :
489 : : /**
490 : : * video_set_drvdata - sets private data from &struct video_device.
491 : : *
492 : : * @vdev: pointer to &struct video_device
493 : : * @data: private data pointer
494 : : */
495 : : static inline void video_set_drvdata(struct video_device *vdev, void *data)
496 : : {
497 : : dev_set_drvdata(&vdev->dev, data);
498 : : }
499 : :
500 : : /**
501 : : * video_devdata - gets &struct video_device from struct file.
502 : : *
503 : : * @file: pointer to struct file
504 : : */
505 : : struct video_device *video_devdata(struct file *file);
506 : :
507 : : /**
508 : : * video_drvdata - gets private data from &struct video_device using the
509 : : * struct file.
510 : : *
511 : : * @file: pointer to struct file
512 : : *
513 : : * This is function combines both video_get_drvdata() and video_devdata()
514 : : * as this is used very often.
515 : : */
516 : : static inline void *video_drvdata(struct file *file)
517 : : {
518 : 1863 : return video_get_drvdata(video_devdata(file));
519 : : }
520 : :
521 : : /**
522 : : * video_device_node_name - returns the video device name
523 : : *
524 : : * @vdev: pointer to &struct video_device
525 : : *
526 : : * Returns the device name string
527 : : */
528 : : static inline const char *video_device_node_name(struct video_device *vdev)
529 : : {
530 : : return dev_name(&vdev->dev);
531 : : }
532 : :
533 : : /**
534 : : * video_is_registered - returns true if the &struct video_device is registered.
535 : : *
536 : : *
537 : : * @vdev: pointer to &struct video_device
538 : : */
539 : : static inline int video_is_registered(struct video_device *vdev)
540 : : {
541 : : return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
542 : : }
543 : :
544 : : #endif /* _V4L2_DEV_H */
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