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