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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 #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