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_devnode_direction - Identifies if a &struct video_device
47 * corresponds 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 struct dentry;
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 #if defined(CONFIG_MEDIA_CONTROLLER)
266 struct media_entity entity;
267 struct media_intf_devnode *intf_devnode;
268 struct media_pipeline pipe;
269 #endif
270 const struct v4l2_file_operations *fops;
271
272 u32 device_caps;
273
274 /* sysfs */
275 struct device dev;
276 struct cdev *cdev;
277
278 struct v4l2_device *v4l2_dev;
279 struct device *dev_parent;
280
281 struct v4l2_ctrl_handler *ctrl_handler;
282
283 struct vb2_queue *queue;
284
285 struct v4l2_prio_state *prio;
286
287 /* device info */
288 char name[64];
289 enum vfl_devnode_type vfl_type;
290 enum vfl_devnode_direction vfl_dir;
291 int minor;
292 u16 num;
293 unsigned long flags;
294 int index;
295
296 /* V4L2 file handles */
297 spinlock_t fh_lock;
298 struct list_head fh_list;
299
300 int dev_debug;
301
302 v4l2_std_id tvnorms;
303
304 /* callbacks */
305 void (*release)(struct video_device *vdev);
306 const struct v4l2_ioctl_ops *ioctl_ops;
307 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
308
309 struct mutex *lock;
310 };
311
312 /**
313 * media_entity_to_video_device - Returns a &struct video_device from
314 * the &struct media_entity embedded on it.
315 *
316 * @__entity: pointer to &struct media_entity, may be NULL
317 */
318 #define media_entity_to_video_device(__entity) \
319 ({ \
320 typeof(__entity) __me_vdev_ent = __entity; \
321 \
322 __me_vdev_ent ? \
323 container_of(__me_vdev_ent, struct video_device, entity) : \
324 NULL; \
325 })
326
327 /**
328 * to_video_device - Returns a &struct video_device from the
329 * &struct device embedded on it.
330 *
331 * @cd: pointer to &struct device
332 */
333 #define to_video_device(cd) container_of(cd, struct video_device, dev)
334
335 /**
336 * __video_register_device - register video4linux devices
337 *
338 * @vdev: struct video_device to register
339 * @type: type of device to register, as defined by &enum vfl_devnode_type
340 * @nr: which device node number is desired:
341 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
342 * @warn_if_nr_in_use: warn if the desired device node number
343 * was already in use and another number was chosen instead.
344 * @owner: module that owns the video device node
345 *
346 * The registration code assigns minor numbers and device node numbers
347 * based on the requested type and registers the new device node with
348 * the kernel.
349 *
350 * This function assumes that struct video_device was zeroed when it
351 * was allocated and does not contain any stale date.
352 *
353 * An error is returned if no free minor or device node number could be
354 * found, or if the registration of the device node failed.
355 *
356 * Returns 0 on success.
357 *
358 * .. note::
359 *
360 * This function is meant to be used only inside the V4L2 core.
361 * Drivers should use video_register_device() or
362 * video_register_device_no_warn().
363 */
364 int __must_check __video_register_device(struct video_device *vdev,
365 enum vfl_devnode_type type,
366 int nr, int warn_if_nr_in_use,
367 struct module *owner);
368
369 /**
370 * video_register_device - register video4linux devices
371 *
372 * @vdev: struct video_device to register
373 * @type: type of device to register, as defined by &enum vfl_devnode_type
374 * @nr: which device node number is desired:
375 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
376 *
377 * Internally, it calls __video_register_device(). Please see its
378 * documentation for more details.
379 *
380 * .. note::
381 * if video_register_device fails, the release() callback of
382 * &struct video_device structure is *not* called, so the caller
383 * is responsible for freeing any data. Usually that means that
384 * you video_device_release() should be called on failure.
385 */
video_register_device(struct video_device * vdev,enum vfl_devnode_type type,int nr)386 static inline int __must_check video_register_device(struct video_device *vdev,
387 enum vfl_devnode_type type,
388 int nr)
389 {
390 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
391 }
392
393 /**
394 * video_register_device_no_warn - register video4linux devices
395 *
396 * @vdev: struct video_device to register
397 * @type: type of device to register, as defined by &enum vfl_devnode_type
398 * @nr: which device node number is desired:
399 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
400 *
401 * This function is identical to video_register_device() except that no
402 * warning is issued if the desired device node number was already in use.
403 *
404 * Internally, it calls __video_register_device(). Please see its
405 * documentation for more details.
406 *
407 * .. note::
408 * if video_register_device fails, the release() callback of
409 * &struct video_device structure is *not* called, so the caller
410 * is responsible for freeing any data. Usually that means that
411 * you video_device_release() should be called on failure.
412 */
413 static inline int __must_check
video_register_device_no_warn(struct video_device * vdev,enum vfl_devnode_type type,int nr)414 video_register_device_no_warn(struct video_device *vdev,
415 enum vfl_devnode_type type, int nr)
416 {
417 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
418 }
419
420 /**
421 * video_unregister_device - Unregister video devices.
422 *
423 * @vdev: &struct video_device to register
424 *
425 * Does nothing if vdev == NULL or if video_is_registered() returns false.
426 */
427 void video_unregister_device(struct video_device *vdev);
428
429 /**
430 * video_device_alloc - helper function to alloc &struct video_device
431 *
432 * Returns NULL if %-ENOMEM or a &struct video_device on success.
433 */
434 struct video_device * __must_check video_device_alloc(void);
435
436 /**
437 * video_device_release - helper function to release &struct video_device
438 *
439 * @vdev: pointer to &struct video_device
440 *
441 * Can also be used for video_device->release\(\).
442 */
443 void video_device_release(struct video_device *vdev);
444
445 /**
446 * video_device_release_empty - helper function to implement the
447 * video_device->release\(\) callback.
448 *
449 * @vdev: pointer to &struct video_device
450 *
451 * This release function does nothing.
452 *
453 * It should be used when the video_device is a static global struct.
454 *
455 * .. note::
456 * Having a static video_device is a dubious construction at best.
457 */
458 void video_device_release_empty(struct video_device *vdev);
459
460 /**
461 * v4l2_disable_ioctl- mark that a given command isn't implemented.
462 * shouldn't use core locking
463 *
464 * @vdev: pointer to &struct video_device
465 * @cmd: ioctl command
466 *
467 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
468 * disable ioctls based on the specific card that is actually found.
469 *
470 * .. note::
471 *
472 * This must be called before video_register_device.
473 * See also the comments for determine_valid_ioctls().
474 */
v4l2_disable_ioctl(struct video_device * vdev,unsigned int cmd)475 static inline void v4l2_disable_ioctl(struct video_device *vdev,
476 unsigned int cmd)
477 {
478 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
479 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
480 }
481
482 /**
483 * video_get_drvdata - gets private data from &struct video_device.
484 *
485 * @vdev: pointer to &struct video_device
486 *
487 * returns a pointer to the private data
488 */
video_get_drvdata(struct video_device * vdev)489 static inline void *video_get_drvdata(struct video_device *vdev)
490 {
491 return dev_get_drvdata(&vdev->dev);
492 }
493
494 /**
495 * video_set_drvdata - sets private data from &struct video_device.
496 *
497 * @vdev: pointer to &struct video_device
498 * @data: private data pointer
499 */
video_set_drvdata(struct video_device * vdev,void * data)500 static inline void video_set_drvdata(struct video_device *vdev, void *data)
501 {
502 dev_set_drvdata(&vdev->dev, data);
503 }
504
505 /**
506 * video_devdata - gets &struct video_device from struct file.
507 *
508 * @file: pointer to struct file
509 */
510 struct video_device *video_devdata(struct file *file);
511
512 /**
513 * video_drvdata - gets private data from &struct video_device using the
514 * struct file.
515 *
516 * @file: pointer to struct file
517 *
518 * This is function combines both video_get_drvdata() and video_devdata()
519 * as this is used very often.
520 */
video_drvdata(struct file * file)521 static inline void *video_drvdata(struct file *file)
522 {
523 return video_get_drvdata(video_devdata(file));
524 }
525
526 /**
527 * video_device_node_name - returns the video device name
528 *
529 * @vdev: pointer to &struct video_device
530 *
531 * Returns the device name string
532 */
video_device_node_name(struct video_device * vdev)533 static inline const char *video_device_node_name(struct video_device *vdev)
534 {
535 return dev_name(&vdev->dev);
536 }
537
538 /**
539 * video_is_registered - returns true if the &struct video_device is registered.
540 *
541 *
542 * @vdev: pointer to &struct video_device
543 */
video_is_registered(struct video_device * vdev)544 static inline int video_is_registered(struct video_device *vdev)
545 {
546 return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
547 }
548
549 /**
550 * v4l2_debugfs_root - returns the dentry of the top-level "v4l2" debugfs dir
551 *
552 * If this directory does not yet exist, then it will be created.
553 */
554 #ifdef CONFIG_DEBUG_FS
555 struct dentry *v4l2_debugfs_root(void);
556 #else
v4l2_debugfs_root(void)557 static inline struct dentry *v4l2_debugfs_root(void)
558 {
559 return NULL;
560 }
561 #endif
562
563 #if defined(CONFIG_MEDIA_CONTROLLER)
564
565 /**
566 * video_device_pipeline_start - Mark a pipeline as streaming
567 * @vdev: Starting video device
568 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
569 *
570 * Mark all entities connected to a given video device through enabled links,
571 * either directly or indirectly, as streaming. The given pipeline object is
572 * assigned to every pad in the pipeline and stored in the media_pad pipe
573 * field.
574 *
575 * Calls to this function can be nested, in which case the same number of
576 * video_device_pipeline_stop() calls will be required to stop streaming. The
577 * pipeline pointer must be identical for all nested calls to
578 * video_device_pipeline_start().
579 *
580 * The video device must contain a single pad.
581 *
582 * This is a convenience wrapper around media_pipeline_start().
583 */
584 __must_check int video_device_pipeline_start(struct video_device *vdev,
585 struct media_pipeline *pipe);
586
587 /**
588 * __video_device_pipeline_start - Mark a pipeline as streaming
589 * @vdev: Starting video device
590 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
591 *
592 * ..note:: This is the non-locking version of video_device_pipeline_start()
593 *
594 * The video device must contain a single pad.
595 *
596 * This is a convenience wrapper around __media_pipeline_start().
597 */
598 __must_check int __video_device_pipeline_start(struct video_device *vdev,
599 struct media_pipeline *pipe);
600
601 /**
602 * video_device_pipeline_stop - Mark a pipeline as not streaming
603 * @vdev: Starting video device
604 *
605 * Mark all entities connected to a given video device through enabled links,
606 * either directly or indirectly, as not streaming. The media_pad pipe field
607 * is reset to %NULL.
608 *
609 * If multiple calls to media_pipeline_start() have been made, the same
610 * number of calls to this function are required to mark the pipeline as not
611 * streaming.
612 *
613 * The video device must contain a single pad.
614 *
615 * This is a convenience wrapper around media_pipeline_stop().
616 */
617 void video_device_pipeline_stop(struct video_device *vdev);
618
619 /**
620 * __video_device_pipeline_stop - Mark a pipeline as not streaming
621 * @vdev: Starting video device
622 *
623 * .. note:: This is the non-locking version of media_pipeline_stop()
624 *
625 * The video device must contain a single pad.
626 *
627 * This is a convenience wrapper around __media_pipeline_stop().
628 */
629 void __video_device_pipeline_stop(struct video_device *vdev);
630
631 /**
632 * video_device_pipeline_alloc_start - Mark a pipeline as streaming
633 * @vdev: Starting video device
634 *
635 * video_device_pipeline_alloc_start() is similar to video_device_pipeline_start()
636 * but instead of working on a given pipeline the function will use an
637 * existing pipeline if the video device is already part of a pipeline, or
638 * allocate a new pipeline.
639 *
640 * Calls to video_device_pipeline_alloc_start() must be matched with
641 * video_device_pipeline_stop().
642 */
643 __must_check int video_device_pipeline_alloc_start(struct video_device *vdev);
644
645 /**
646 * video_device_pipeline - Get the media pipeline a video device is part of
647 * @vdev: The video device
648 *
649 * This function returns the media pipeline that a video device has been
650 * associated with when constructing the pipeline with
651 * video_device_pipeline_start(). The pointer remains valid until
652 * video_device_pipeline_stop() is called.
653 *
654 * Return: The media_pipeline the video device is part of, or NULL if the video
655 * device is not part of any pipeline.
656 *
657 * The video device must contain a single pad.
658 *
659 * This is a convenience wrapper around media_entity_pipeline().
660 */
661 struct media_pipeline *video_device_pipeline(struct video_device *vdev);
662
663 #endif /* CONFIG_MEDIA_CONTROLLER */
664
665 #endif /* _V4L2_DEV_H */
666