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 #include <linux/android_kabi.h>
20
21 #include <media/media-entity.h>
22
23 #define VIDEO_MAJOR 81
24
25 /**
26 * enum vfl_devnode_type - type of V4L2 device node
27 *
28 * @VFL_TYPE_VIDEO: for video input/output devices
29 * @VFL_TYPE_VBI: for vertical blank data (i.e. closed captions, teletext)
30 * @VFL_TYPE_RADIO: for radio tuners
31 * @VFL_TYPE_SUBDEV: for V4L2 subdevices
32 * @VFL_TYPE_SDR: for Software Defined Radio tuners
33 * @VFL_TYPE_TOUCH: for touch sensors
34 * @VFL_TYPE_MAX: number of VFL types, must always be last in the enum
35 */
36 enum vfl_devnode_type {
37 VFL_TYPE_VIDEO,
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_devnode_direction - Identifies if a &struct video_device
48 * corresponds 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 ANDROID_KABI_RESERVE(1);
217 };
218
219 /*
220 * Newer version of video_device, handled by videodev2.c
221 * This version moves redundant code from video device code to
222 * the common handler
223 */
224
225 /**
226 * struct video_device - Structure used to create and manage the V4L2 device
227 * nodes.
228 *
229 * @entity: &struct media_entity
230 * @intf_devnode: pointer to &struct media_intf_devnode
231 * @pipe: &struct media_pipeline
232 * @fops: pointer to &struct v4l2_file_operations for the video device
233 * @device_caps: device capabilities as used in v4l2_capabilities
234 * @dev: &struct device for the video device
235 * @cdev: character device
236 * @v4l2_dev: pointer to &struct v4l2_device parent
237 * @dev_parent: pointer to &struct device parent
238 * @ctrl_handler: Control handler associated with this device node.
239 * May be NULL.
240 * @queue: &struct vb2_queue associated with this device node. May be NULL.
241 * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
242 * If NULL, then v4l2_dev->prio will be used.
243 * @name: video device name
244 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
245 * @vfl_dir: V4L receiver, transmitter or m2m
246 * @minor: device node 'minor'. It is set to -1 if the registration failed
247 * @num: number of the video device node
248 * @flags: video device flags. Use bitops to set/clear/test flags.
249 * Contains a set of &enum v4l2_video_device_flags.
250 * @index: attribute to differentiate multiple indices on one physical device
251 * @fh_lock: Lock for all v4l2_fhs
252 * @fh_list: List of &struct v4l2_fh
253 * @dev_debug: Internal device debug flags, not for use by drivers
254 * @tvnorms: Supported tv norms
255 *
256 * @release: video device release() callback
257 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
258 *
259 * @valid_ioctls: bitmap with the valid ioctls for this device
260 * @lock: pointer to &struct mutex serialization lock
261 *
262 * .. note::
263 * Only set @dev_parent if that can't be deduced from @v4l2_dev.
264 */
265
266 struct video_device {
267 #if defined(CONFIG_MEDIA_CONTROLLER)
268 struct media_entity entity;
269 struct media_intf_devnode *intf_devnode;
270 struct media_pipeline pipe;
271 #endif
272 const struct v4l2_file_operations *fops;
273
274 u32 device_caps;
275
276 /* sysfs */
277 struct device dev;
278 struct cdev *cdev;
279
280 struct v4l2_device *v4l2_dev;
281 struct device *dev_parent;
282
283 struct v4l2_ctrl_handler *ctrl_handler;
284
285 struct vb2_queue *queue;
286
287 struct v4l2_prio_state *prio;
288
289 /* device info */
290 char name[32];
291 enum vfl_devnode_type vfl_type;
292 enum vfl_devnode_direction vfl_dir;
293 int minor;
294 u16 num;
295 unsigned long flags;
296 int index;
297
298 /* V4L2 file handles */
299 spinlock_t fh_lock;
300 struct list_head fh_list;
301
302 int dev_debug;
303
304 v4l2_std_id tvnorms;
305
306 /* callbacks */
307 void (*release)(struct video_device *vdev);
308 const struct v4l2_ioctl_ops *ioctl_ops;
309 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
310
311 struct mutex *lock;
312
313 ANDROID_KABI_RESERVE(1);
314 ANDROID_KABI_RESERVE(2);
315 };
316
317 /**
318 * media_entity_to_video_device - Returns a &struct video_device from
319 * the &struct media_entity embedded on it.
320 *
321 * @__entity: pointer to &struct media_entity
322 */
323 #define media_entity_to_video_device(__entity) \
324 container_of(__entity, struct video_device, entity)
325
326 /**
327 * to_video_device - Returns a &struct video_device from the
328 * &struct device embedded on it.
329 *
330 * @cd: pointer to &struct device
331 */
332 #define to_video_device(cd) container_of(cd, struct video_device, dev)
333
334 /**
335 * __video_register_device - register video4linux devices
336 *
337 * @vdev: struct video_device to register
338 * @type: type of device to register, as defined by &enum vfl_devnode_type
339 * @nr: which device node number is desired:
340 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
341 * @warn_if_nr_in_use: warn if the desired device node number
342 * was already in use and another number was chosen instead.
343 * @owner: module that owns the video device node
344 *
345 * The registration code assigns minor numbers and device node numbers
346 * based on the requested type and registers the new device node with
347 * the kernel.
348 *
349 * This function assumes that struct video_device was zeroed when it
350 * was allocated and does not contain any stale date.
351 *
352 * An error is returned if no free minor or device node number could be
353 * found, or if the registration of the device node failed.
354 *
355 * Returns 0 on success.
356 *
357 * .. note::
358 *
359 * This function is meant to be used only inside the V4L2 core.
360 * Drivers should use video_register_device() or
361 * video_register_device_no_warn().
362 */
363 int __must_check __video_register_device(struct video_device *vdev,
364 enum vfl_devnode_type type,
365 int nr, int warn_if_nr_in_use,
366 struct module *owner);
367
368 /**
369 * video_register_device - register video4linux devices
370 *
371 * @vdev: struct video_device to register
372 * @type: type of device to register, as defined by &enum vfl_devnode_type
373 * @nr: which device node number is desired:
374 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
375 *
376 * Internally, it calls __video_register_device(). Please see its
377 * documentation for more details.
378 *
379 * .. note::
380 * if video_register_device fails, the release() callback of
381 * &struct video_device structure is *not* called, so the caller
382 * is responsible for freeing any data. Usually that means that
383 * you video_device_release() should be called on failure.
384 */
video_register_device(struct video_device * vdev,enum vfl_devnode_type type,int nr)385 static inline int __must_check video_register_device(struct video_device *vdev,
386 enum vfl_devnode_type type,
387 int nr)
388 {
389 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
390 }
391
392 /**
393 * video_register_device_no_warn - register video4linux devices
394 *
395 * @vdev: struct video_device to register
396 * @type: type of device to register, as defined by &enum vfl_devnode_type
397 * @nr: which device node number is desired:
398 * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
399 *
400 * This function is identical to video_register_device() except that no
401 * warning is issued if the desired device node number was already in use.
402 *
403 * Internally, it calls __video_register_device(). Please see its
404 * documentation for more details.
405 *
406 * .. note::
407 * if video_register_device fails, the release() callback of
408 * &struct video_device structure is *not* called, so the caller
409 * is responsible for freeing any data. Usually that means that
410 * you video_device_release() should be called on failure.
411 */
412 static inline int __must_check
video_register_device_no_warn(struct video_device * vdev,enum vfl_devnode_type type,int nr)413 video_register_device_no_warn(struct video_device *vdev,
414 enum vfl_devnode_type type, int nr)
415 {
416 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
417 }
418
419 /**
420 * video_unregister_device - Unregister video devices.
421 *
422 * @vdev: &struct video_device to register
423 *
424 * Does nothing if vdev == NULL or if video_is_registered() returns false.
425 */
426 void video_unregister_device(struct video_device *vdev);
427
428 /**
429 * video_device_alloc - helper function to alloc &struct video_device
430 *
431 * Returns NULL if %-ENOMEM or a &struct video_device on success.
432 */
433 struct video_device * __must_check video_device_alloc(void);
434
435 /**
436 * video_device_release - helper function to release &struct video_device
437 *
438 * @vdev: pointer to &struct video_device
439 *
440 * Can also be used for video_device->release\(\).
441 */
442 void video_device_release(struct video_device *vdev);
443
444 /**
445 * video_device_release_empty - helper function to implement the
446 * video_device->release\(\) callback.
447 *
448 * @vdev: pointer to &struct video_device
449 *
450 * This release function does nothing.
451 *
452 * It should be used when the video_device is a static global struct.
453 *
454 * .. note::
455 * Having a static video_device is a dubious construction at best.
456 */
457 void video_device_release_empty(struct video_device *vdev);
458
459 /**
460 * v4l2_disable_ioctl- mark that a given command isn't implemented.
461 * shouldn't use core locking
462 *
463 * @vdev: pointer to &struct video_device
464 * @cmd: ioctl command
465 *
466 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
467 * disable ioctls based on the specific card that is actually found.
468 *
469 * .. note::
470 *
471 * This must be called before video_register_device.
472 * See also the comments for determine_valid_ioctls().
473 */
v4l2_disable_ioctl(struct video_device * vdev,unsigned int cmd)474 static inline void v4l2_disable_ioctl(struct video_device *vdev,
475 unsigned int cmd)
476 {
477 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
478 set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
479 }
480
481 /**
482 * video_get_drvdata - gets private data from &struct video_device.
483 *
484 * @vdev: pointer to &struct video_device
485 *
486 * returns a pointer to the private data
487 */
video_get_drvdata(struct video_device * vdev)488 static inline void *video_get_drvdata(struct video_device *vdev)
489 {
490 return dev_get_drvdata(&vdev->dev);
491 }
492
493 /**
494 * video_set_drvdata - sets private data from &struct video_device.
495 *
496 * @vdev: pointer to &struct video_device
497 * @data: private data pointer
498 */
video_set_drvdata(struct video_device * vdev,void * data)499 static inline void video_set_drvdata(struct video_device *vdev, void *data)
500 {
501 dev_set_drvdata(&vdev->dev, data);
502 }
503
504 /**
505 * video_devdata - gets &struct video_device from struct file.
506 *
507 * @file: pointer to struct file
508 */
509 struct video_device *video_devdata(struct file *file);
510
511 /**
512 * video_drvdata - gets private data from &struct video_device using the
513 * struct file.
514 *
515 * @file: pointer to struct file
516 *
517 * This is function combines both video_get_drvdata() and video_devdata()
518 * as this is used very often.
519 */
video_drvdata(struct file * file)520 static inline void *video_drvdata(struct file *file)
521 {
522 return video_get_drvdata(video_devdata(file));
523 }
524
525 /**
526 * video_device_node_name - returns the video device name
527 *
528 * @vdev: pointer to &struct video_device
529 *
530 * Returns the device name string
531 */
video_device_node_name(struct video_device * vdev)532 static inline const char *video_device_node_name(struct video_device *vdev)
533 {
534 return dev_name(&vdev->dev);
535 }
536
537 /**
538 * video_is_registered - returns true if the &struct video_device is registered.
539 *
540 *
541 * @vdev: pointer to &struct video_device
542 */
video_is_registered(struct video_device * vdev)543 static inline int video_is_registered(struct video_device *vdev)
544 {
545 return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
546 }
547
548 #if defined(CONFIG_MEDIA_CONTROLLER)
549
550 /**
551 * video_device_pipeline_start - Mark a pipeline as streaming
552 * @vdev: Starting video device
553 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
554 *
555 * Mark all entities connected to a given video device through enabled links,
556 * either directly or indirectly, as streaming. The given pipeline object is
557 * assigned to every pad in the pipeline and stored in the media_pad pipe
558 * field.
559 *
560 * Calls to this function can be nested, in which case the same number of
561 * video_device_pipeline_stop() calls will be required to stop streaming. The
562 * pipeline pointer must be identical for all nested calls to
563 * video_device_pipeline_start().
564 *
565 * The video device must contain a single pad.
566 *
567 * This is a convenience wrapper around media_pipeline_start().
568 */
569 __must_check int video_device_pipeline_start(struct video_device *vdev,
570 struct media_pipeline *pipe);
571
572 /**
573 * __video_device_pipeline_start - Mark a pipeline as streaming
574 * @vdev: Starting video device
575 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
576 *
577 * ..note:: This is the non-locking version of video_device_pipeline_start()
578 *
579 * The video device must contain a single pad.
580 *
581 * This is a convenience wrapper around __media_pipeline_start().
582 */
583 __must_check int __video_device_pipeline_start(struct video_device *vdev,
584 struct media_pipeline *pipe);
585
586 /**
587 * video_device_pipeline_stop - Mark a pipeline as not streaming
588 * @vdev: Starting video device
589 *
590 * Mark all entities connected to a given video device through enabled links,
591 * either directly or indirectly, as not streaming. The media_pad pipe field
592 * is reset to %NULL.
593 *
594 * If multiple calls to media_pipeline_start() have been made, the same
595 * number of calls to this function are required to mark the pipeline as not
596 * streaming.
597 *
598 * The video device must contain a single pad.
599 *
600 * This is a convenience wrapper around media_pipeline_stop().
601 */
602 void video_device_pipeline_stop(struct video_device *vdev);
603
604 /**
605 * __video_device_pipeline_stop - Mark a pipeline as not streaming
606 * @vdev: Starting video device
607 *
608 * .. note:: This is the non-locking version of media_pipeline_stop()
609 *
610 * The video device must contain a single pad.
611 *
612 * This is a convenience wrapper around __media_pipeline_stop().
613 */
614 void __video_device_pipeline_stop(struct video_device *vdev);
615
616 /**
617 * video_device_pipeline_alloc_start - Mark a pipeline as streaming
618 * @vdev: Starting video device
619 *
620 * video_device_pipeline_alloc_start() is similar to video_device_pipeline_start()
621 * but instead of working on a given pipeline the function will use an
622 * existing pipeline if the video device is already part of a pipeline, or
623 * allocate a new pipeline.
624 *
625 * Calls to video_device_pipeline_alloc_start() must be matched with
626 * video_device_pipeline_stop().
627 */
628 __must_check int video_device_pipeline_alloc_start(struct video_device *vdev);
629
630 /**
631 * video_device_pipeline - Get the media pipeline a video device is part of
632 * @vdev: The video device
633 *
634 * This function returns the media pipeline that a video device has been
635 * associated with when constructing the pipeline with
636 * video_device_pipeline_start(). The pointer remains valid until
637 * video_device_pipeline_stop() is called.
638 *
639 * Return: The media_pipeline the video device is part of, or NULL if the video
640 * device is not part of any pipeline.
641 *
642 * The video device must contain a single pad.
643 *
644 * This is a convenience wrapper around media_entity_pipeline().
645 */
646 struct media_pipeline *video_device_pipeline(struct video_device *vdev);
647
648 #endif /* CONFIG_MEDIA_CONTROLLER */
649
650 #endif /* _V4L2_DEV_H */
651