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v3.15
 
  1/*
  2 *
  3 *	V 4 L 2   D R I V E R   H E L P E R   A P I
  4 *
  5 * Moved from videodev2.h
  6 *
  7 *	Some commonly needed functions for drivers (v4l2-common.o module)
  8 */
  9#ifndef _V4L2_DEV_H
 10#define _V4L2_DEV_H
 11
 12#include <linux/poll.h>
 13#include <linux/fs.h>
 14#include <linux/device.h>
 15#include <linux/cdev.h>
 16#include <linux/mutex.h>
 17#include <linux/videodev2.h>
 18
 19#include <media/media-entity.h>
 20
 21#define VIDEO_MAJOR	81
 22
 23#define VFL_TYPE_GRABBER	0
 24#define VFL_TYPE_VBI		1
 25#define VFL_TYPE_RADIO		2
 26#define VFL_TYPE_SUBDEV		3
 27#define VFL_TYPE_SDR		4
 28#define VFL_TYPE_MAX		5
 29
 30/* Is this a receiver, transmitter or mem-to-mem? */
 31/* Ignored for VFL_TYPE_SUBDEV. */
 32#define VFL_DIR_RX		0
 33#define VFL_DIR_TX		1
 34#define VFL_DIR_M2M		2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 35
 36struct v4l2_ioctl_callbacks;
 37struct video_device;
 38struct v4l2_device;
 39struct v4l2_ctrl_handler;
 40
 41/* Flag to mark the video_device struct as registered.
 42   Drivers can clear this flag if they want to block all future
 43   device access. It is cleared by video_unregister_device. */
 44#define V4L2_FL_REGISTERED	(0)
 45/* file->private_data points to struct v4l2_fh */
 46#define V4L2_FL_USES_V4L2_FH	(1)
 47/* Use the prio field of v4l2_fh for core priority checking */
 48#define V4L2_FL_USE_FH_PRIO	(2)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 49
 50/* Priority helper functions */
 51
 
 
 
 
 
 
 
 
 
 
 52struct v4l2_prio_state {
 53	atomic_t prios[4];
 54};
 55
 
 
 
 
 
 56void v4l2_prio_init(struct v4l2_prio_state *global);
 
 
 
 
 
 
 
 
 
 
 
 57int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
 58		     enum v4l2_priority new);
 
 
 
 
 
 
 
 
 
 
 59void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
 
 
 
 
 
 
 
 
 
 
 60void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
 
 
 
 
 
 
 
 
 
 61enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
 62int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
 63
 
 
 
 
 
 
 
 
 
 
 64
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 65struct v4l2_file_operations {
 66	struct module *owner;
 67	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 68	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 69	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 70	long (*ioctl) (struct file *, unsigned int, unsigned long);
 71	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 72#ifdef CONFIG_COMPAT
 73	long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
 74#endif
 75	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
 76				unsigned long, unsigned long, unsigned long);
 77	int (*mmap) (struct file *, struct vm_area_struct *);
 78	int (*open) (struct file *);
 79	int (*release) (struct file *);
 80};
 81
 82/*
 83 * Newer version of video_device, handled by videodev2.c
 84 * 	This version moves redundant code from video device code to
 85 *	the common handler
 86 */
 87
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 88struct video_device
 89{
 90#if defined(CONFIG_MEDIA_CONTROLLER)
 91	struct media_entity entity;
 
 
 92#endif
 93	/* device ops */
 94	const struct v4l2_file_operations *fops;
 95
 
 
 96	/* sysfs */
 97	struct device dev;		/* v4l device */
 98	struct cdev *cdev;		/* character device */
 99
100	struct v4l2_device *v4l2_dev;	/* v4l2_device parent */
101	/* Only set parent if that can't be deduced from v4l2_dev */
102	struct device *dev_parent;	/* device parent */
103
104	/* Control handler associated with this device node. May be NULL. */
105	struct v4l2_ctrl_handler *ctrl_handler;
106
107	/* vb2_queue associated with this device node. May be NULL. */
108	struct vb2_queue *queue;
109
110	/* Priority state. If NULL, then v4l2_dev->prio will be used. */
111	struct v4l2_prio_state *prio;
112
113	/* device info */
114	char name[32];
115	int vfl_type;	/* device type */
116	int vfl_dir;	/* receiver, transmitter or m2m */
117	/* 'minor' is set to -1 if the registration failed */
118	int minor;
119	u16 num;
120	/* use bitops to set/clear/test flags */
121	unsigned long flags;
122	/* attribute to differentiate multiple indices on one physical device */
123	int index;
124
125	/* V4L2 file handles */
126	spinlock_t		fh_lock; /* Lock for all v4l2_fhs */
127	struct list_head	fh_list; /* List of struct v4l2_fh */
128
129	int debug;			/* Activates debug level*/
130
131	/* Video standard vars */
132	v4l2_std_id tvnorms;		/* Supported tv norms */
133
134	/* callbacks */
135	void (*release)(struct video_device *vdev);
136
137	/* ioctl callbacks */
138	const struct v4l2_ioctl_ops *ioctl_ops;
139	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
140
141	/* serialization lock */
142	DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
143	struct mutex *lock;
144};
145
146#define media_entity_to_video_device(__e) \
147	container_of(__e, struct video_device, entity)
148/* dev to video-device */
 
 
 
 
 
 
 
 
 
 
 
 
149#define to_video_device(cd) container_of(cd, struct video_device, dev)
150
151int __must_check __video_register_device(struct video_device *vdev, int type,
152		int nr, int warn_if_nr_in_use, struct module *owner);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
153
154/* Register video devices. Note that if video_register_device fails,
155   the release() callback of the video_device structure is *not* called, so
156   the caller is responsible for freeing any data. Usually that means that
157   you call video_device_release() on failure. */
 
 
 
 
 
 
 
 
 
 
 
 
 
158static inline int __must_check video_register_device(struct video_device *vdev,
159		int type, int nr)
 
160{
161	return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
162}
163
164/* Same as video_register_device, but no warning is issued if the desired
165   device node number was already in use. */
166static inline int __must_check video_register_device_no_warn(
167		struct video_device *vdev, int type, int nr)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
168{
169	return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
170}
171
172/* Unregister video devices. Will do nothing if vdev == NULL or
173   video_is_registered() returns false. */
 
 
 
 
 
174void video_unregister_device(struct video_device *vdev);
175
176/* helper functions to alloc/release struct video_device, the
177   latter can also be used for video_device->release(). */
 
 
 
178struct video_device * __must_check video_device_alloc(void);
179
180/* this release function frees the vdev pointer */
 
 
 
 
 
 
181void video_device_release(struct video_device *vdev);
182
183/* this release function does nothing, use when the video_device is a
184   static global struct. Note that having a static video_device is
185   a dubious construction at best. */
 
 
 
 
 
 
 
 
 
 
186void video_device_release_empty(struct video_device *vdev);
187
188/* returns true if cmd is a known V4L2 ioctl */
189bool v4l2_is_known_ioctl(unsigned int cmd);
190
191/* mark that this command shouldn't use core locking */
192static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd)
193{
194	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
195		set_bit(_IOC_NR(cmd), vdev->disable_locking);
196}
197
198/* Mark that this command isn't implemented. This must be called before
199   video_device_register. See also the comments in determine_valid_ioctls().
200   This function allows drivers to provide just one v4l2_ioctl_ops struct, but
201   disable ioctls based on the specific card that is actually found. */
202static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd)
 
 
203{
204	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
205		set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
206}
207
208/* helper functions to access driver private data. */
 
 
 
 
 
 
209static inline void *video_get_drvdata(struct video_device *vdev)
210{
211	return dev_get_drvdata(&vdev->dev);
212}
213
 
 
 
 
 
 
214static inline void video_set_drvdata(struct video_device *vdev, void *data)
215{
216	dev_set_drvdata(&vdev->dev, data);
217}
218
 
 
 
 
 
219struct video_device *video_devdata(struct file *file);
220
221/* Combine video_get_drvdata and video_devdata as this is
222   used very often. */
 
 
 
 
 
 
 
223static inline void *video_drvdata(struct file *file)
224{
225	return video_get_drvdata(video_devdata(file));
226}
227
 
 
 
 
 
 
 
228static inline const char *video_device_node_name(struct video_device *vdev)
229{
230	return dev_name(&vdev->dev);
231}
232
 
 
 
 
 
 
233static inline int video_is_registered(struct video_device *vdev)
234{
235	return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
236}
237
238#endif /* _V4L2_DEV_H */
v5.4
  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 */
 35enum vfl_devnode_type {
 36	VFL_TYPE_GRABBER	= 0,
 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_direction - Identifies if a &struct video_device corresponds
 47 *	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 */
 55enum vfl_devnode_direction {
 56	VFL_DIR_RX,
 57	VFL_DIR_TX,
 58	VFL_DIR_M2M,
 59};
 60
 61struct v4l2_ioctl_callbacks;
 62struct video_device;
 63struct v4l2_device;
 64struct 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 */
 86enum v4l2_video_device_flags {
 87	V4L2_FL_REGISTERED		= 0,
 88	V4L2_FL_USES_V4L2_FH		= 1,
 89	V4L2_FL_QUIRK_INVERTED_CROP	= 2,
 90};
 91
 92/* Priority helper functions */
 93
 94/**
 95 * struct v4l2_prio_state - stores the priority states
 96 *
 97 * @prios: array with elements to store the array priorities
 98 *
 99 *
100 * .. note::
101 *    The size of @prios array matches the number of priority types defined
102 *    by enum &v4l2_priority.
103 */
104struct v4l2_prio_state {
105	atomic_t prios[4];
106};
107
108/**
109 * v4l2_prio_init - initializes a struct v4l2_prio_state
110 *
111 * @global: pointer to &struct v4l2_prio_state
112 */
113void v4l2_prio_init(struct v4l2_prio_state *global);
114
115/**
116 * v4l2_prio_change - changes the v4l2 file handler priority
117 *
118 * @global: pointer to the &struct v4l2_prio_state of the device node.
119 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
120 * @new: Priority type requested, as defined by enum &v4l2_priority.
121 *
122 * .. note::
123 *	This function should be used only by the V4L2 core.
124 */
125int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
126		     enum v4l2_priority new);
127
128/**
129 * v4l2_prio_open - Implements the priority logic for a file handler open
130 *
131 * @global: pointer to the &struct v4l2_prio_state of the device node.
132 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
133 *
134 * .. note::
135 *	This function should be used only by the V4L2 core.
136 */
137void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
138
139/**
140 * v4l2_prio_close - Implements the priority logic for a file handler close
141 *
142 * @global: pointer to the &struct v4l2_prio_state of the device node.
143 * @local: priority to be released, as defined by enum &v4l2_priority
144 *
145 * .. note::
146 *	This function should be used only by the V4L2 core.
147 */
148void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
149
150/**
151 * v4l2_prio_max - Return the maximum priority, as stored at the @global array.
152 *
153 * @global: pointer to the &struct v4l2_prio_state of the device node.
154 *
155 * .. note::
156 *	This function should be used only by the V4L2 core.
157 */
158enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
 
159
160/**
161 * v4l2_prio_check - Implements the priority logic for a file handler close
162 *
163 * @global: pointer to the &struct v4l2_prio_state of the device node.
164 * @local: desired priority, as defined by enum &v4l2_priority local
165 *
166 * .. note::
167 *	This function should be used only by the V4L2 core.
168 */
169int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
170
171/**
172 * struct v4l2_file_operations - fs operations used by a V4L2 device
173 *
174 * @owner: pointer to struct module
175 * @read: operations needed to implement the read() syscall
176 * @write: operations needed to implement the write() syscall
177 * @poll: operations needed to implement the poll() syscall
178 * @unlocked_ioctl: operations needed to implement the ioctl() syscall
179 * @compat_ioctl32: operations needed to implement the ioctl() syscall for
180 *	the special case where the Kernel uses 64 bits instructions, but
181 *	the userspace uses 32 bits.
182 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU
183 * @mmap: operations needed to implement the mmap() syscall
184 * @open: operations needed to implement the open() syscall
185 * @release: operations needed to implement the release() syscall
186 *
187 * .. note::
188 *
189 *	Those operations are used to implemente the fs struct file_operations
190 *	at the V4L2 drivers. The V4L2 core overrides the fs ops with some
191 *	extra logic needed by the subsystem.
192 */
193struct v4l2_file_operations {
194	struct module *owner;
195	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
196	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
197	__poll_t (*poll) (struct file *, struct poll_table_struct *);
 
198	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
199#ifdef CONFIG_COMPAT
200	long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
201#endif
202	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
203				unsigned long, unsigned long, unsigned long);
204	int (*mmap) (struct file *, struct vm_area_struct *);
205	int (*open) (struct file *);
206	int (*release) (struct file *);
207};
208
209/*
210 * Newer version of video_device, handled by videodev2.c
211 *	This version moves redundant code from video device code to
212 *	the common handler
213 */
214
215/**
216 * struct video_device - Structure used to create and manage the V4L2 device
217 *	nodes.
218 *
219 * @entity: &struct media_entity
220 * @intf_devnode: pointer to &struct media_intf_devnode
221 * @pipe: &struct media_pipeline
222 * @fops: pointer to &struct v4l2_file_operations for the video device
223 * @device_caps: device capabilities as used in v4l2_capabilities
224 * @dev: &struct device for the video device
225 * @cdev: character device
226 * @v4l2_dev: pointer to &struct v4l2_device parent
227 * @dev_parent: pointer to &struct device parent
228 * @ctrl_handler: Control handler associated with this device node.
229 *	 May be NULL.
230 * @queue: &struct vb2_queue associated with this device node. May be NULL.
231 * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
232 *	 If NULL, then v4l2_dev->prio will be used.
233 * @name: video device name
234 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
235 * @vfl_dir: V4L receiver, transmitter or m2m
236 * @minor: device node 'minor'. It is set to -1 if the registration failed
237 * @num: number of the video device node
238 * @flags: video device flags. Use bitops to set/clear/test flags.
239 *	   Contains a set of &enum v4l2_video_device_flags.
240 * @index: attribute to differentiate multiple indices on one physical device
241 * @fh_lock: Lock for all v4l2_fhs
242 * @fh_list: List of &struct v4l2_fh
243 * @dev_debug: Internal device debug flags, not for use by drivers
244 * @tvnorms: Supported tv norms
245 *
246 * @release: video device release() callback
247 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
248 *
249 * @valid_ioctls: bitmap with the valid ioctls for this device
250 * @lock: pointer to &struct mutex serialization lock
251 *
252 * .. note::
253 *	Only set @dev_parent if that can't be deduced from @v4l2_dev.
254 */
255
256struct video_device
257{
258#if defined(CONFIG_MEDIA_CONTROLLER)
259	struct media_entity entity;
260	struct media_intf_devnode *intf_devnode;
261	struct media_pipeline pipe;
262#endif
 
263	const struct v4l2_file_operations *fops;
264
265	u32 device_caps;
266
267	/* sysfs */
268	struct device dev;
269	struct cdev *cdev;
270
271	struct v4l2_device *v4l2_dev;
272	struct device *dev_parent;
 
273
 
274	struct v4l2_ctrl_handler *ctrl_handler;
275
 
276	struct vb2_queue *queue;
277
 
278	struct v4l2_prio_state *prio;
279
280	/* device info */
281	char name[32];
282	enum vfl_devnode_type vfl_type;
283	enum vfl_devnode_direction vfl_dir;
 
284	int minor;
285	u16 num;
 
286	unsigned long flags;
 
287	int index;
288
289	/* V4L2 file handles */
290	spinlock_t		fh_lock;
291	struct list_head	fh_list;
292
293	int dev_debug;
294
295	v4l2_std_id tvnorms;
 
296
297	/* callbacks */
298	void (*release)(struct video_device *vdev);
 
 
299	const struct v4l2_ioctl_ops *ioctl_ops;
300	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);
301
 
 
302	struct mutex *lock;
303};
304
305/**
306 * media_entity_to_video_device - Returns a &struct video_device from
307 *	the &struct media_entity embedded on it.
308 *
309 * @__entity: pointer to &struct media_entity
310 */
311#define media_entity_to_video_device(__entity) \
312	container_of(__entity, struct video_device, entity)
313
314/**
315 * to_video_device - Returns a &struct video_device from the
316 *	&struct device embedded on it.
317 *
318 * @cd: pointer to &struct device
319 */
320#define to_video_device(cd) container_of(cd, struct video_device, dev)
321
322/**
323 * __video_register_device - register video4linux devices
324 *
325 * @vdev: struct video_device to register
326 * @type: type of device to register, as defined by &enum vfl_devnode_type
327 * @nr:   which device node number is desired:
328 *	(0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
329 * @warn_if_nr_in_use: warn if the desired device node number
330 *        was already in use and another number was chosen instead.
331 * @owner: module that owns the video device node
332 *
333 * The registration code assigns minor numbers and device node numbers
334 * based on the requested type and registers the new device node with
335 * the kernel.
336 *
337 * This function assumes that struct video_device was zeroed when it
338 * was allocated and does not contain any stale date.
339 *
340 * An error is returned if no free minor or device node number could be
341 * found, or if the registration of the device node failed.
342 *
343 * Returns 0 on success.
344 *
345 * .. note::
346 *
347 *	This function is meant to be used only inside the V4L2 core.
348 *	Drivers should use video_register_device() or
349 *	video_register_device_no_warn().
350 */
351int __must_check __video_register_device(struct video_device *vdev,
352					 enum vfl_devnode_type type,
353					 int nr, int warn_if_nr_in_use,
354					 struct module *owner);
355
356/**
357 *  video_register_device - register video4linux devices
358 *
359 * @vdev: struct video_device to register
360 * @type: type of device to register, as defined by &enum vfl_devnode_type
361 * @nr:   which device node number is desired:
362 *	(0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
363 *
364 * Internally, it calls __video_register_device(). Please see its
365 * documentation for more details.
366 *
367 * .. note::
368 *	if video_register_device fails, the release() callback of
369 *	&struct video_device structure is *not* called, so the caller
370 *	is responsible for freeing any data. Usually that means that
371 *	you video_device_release() should be called on failure.
372 */
373static inline int __must_check video_register_device(struct video_device *vdev,
374						     enum vfl_devnode_type type,
375						     int nr)
376{
377	return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
378}
379
380/**
381 *  video_register_device_no_warn - register video4linux devices
382 *
383 * @vdev: struct video_device to register
384 * @type: type of device to register, as defined by &enum vfl_devnode_type
385 * @nr:   which device node number is desired:
386 *	(0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
387 *
388 * This function is identical to video_register_device() except that no
389 * warning is issued if the desired device node number was already in use.
390 *
391 * Internally, it calls __video_register_device(). Please see its
392 * documentation for more details.
393 *
394 * .. note::
395 *	if video_register_device fails, the release() callback of
396 *	&struct video_device structure is *not* called, so the caller
397 *	is responsible for freeing any data. Usually that means that
398 *	you video_device_release() should be called on failure.
399 */
400static inline int __must_check
401video_register_device_no_warn(struct video_device *vdev,
402			      enum vfl_devnode_type type, int nr)
403{
404	return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
405}
406
407/**
408 * video_unregister_device - Unregister video devices.
409 *
410 * @vdev: &struct video_device to register
411 *
412 * Does nothing if vdev == NULL or if video_is_registered() returns false.
413 */
414void video_unregister_device(struct video_device *vdev);
415
416/**
417 * video_device_alloc - helper function to alloc &struct video_device
418 *
419 * Returns NULL if %-ENOMEM or a &struct video_device on success.
420 */
421struct video_device * __must_check video_device_alloc(void);
422
423/**
424 * video_device_release - helper function to release &struct video_device
425 *
426 * @vdev: pointer to &struct video_device
427 *
428 * Can also be used for video_device->release\(\).
429 */
430void video_device_release(struct video_device *vdev);
431
432/**
433 * video_device_release_empty - helper function to implement the
434 *	video_device->release\(\) callback.
435 *
436 * @vdev: pointer to &struct video_device
437 *
438 * This release function does nothing.
439 *
440 * It should be used when the video_device is a static global struct.
441 *
442 * .. note::
443 *	Having a static video_device is a dubious construction at best.
444 */
445void video_device_release_empty(struct video_device *vdev);
446
447/**
448 * v4l2_disable_ioctl- mark that a given command isn't implemented.
449 *	shouldn't use core locking
450 *
451 * @vdev: pointer to &struct video_device
452 * @cmd: ioctl command
453 *
454 * This function allows drivers to provide just one v4l2_ioctl_ops struct, but
455 * disable ioctls based on the specific card that is actually found.
456 *
457 * .. note::
458 *
459 *    This must be called before video_register_device.
460 *    See also the comments for determine_valid_ioctls().
461 */
462static inline void v4l2_disable_ioctl(struct video_device *vdev,
463				      unsigned int cmd)
464{
465	if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE)
466		set_bit(_IOC_NR(cmd), vdev->valid_ioctls);
467}
468
469/**
470 * video_get_drvdata - gets private data from &struct video_device.
471 *
472 * @vdev: pointer to &struct video_device
473 *
474 * returns a pointer to the private data
475 */
476static inline void *video_get_drvdata(struct video_device *vdev)
477{
478	return dev_get_drvdata(&vdev->dev);
479}
480
481/**
482 * video_set_drvdata - sets private data from &struct video_device.
483 *
484 * @vdev: pointer to &struct video_device
485 * @data: private data pointer
486 */
487static inline void video_set_drvdata(struct video_device *vdev, void *data)
488{
489	dev_set_drvdata(&vdev->dev, data);
490}
491
492/**
493 * video_devdata - gets &struct video_device from struct file.
494 *
495 * @file: pointer to struct file
496 */
497struct video_device *video_devdata(struct file *file);
498
499/**
500 * video_drvdata - gets private data from &struct video_device using the
501 *	struct file.
502 *
503 * @file: pointer to struct file
504 *
505 * This is function combines both video_get_drvdata() and video_devdata()
506 * as this is used very often.
507 */
508static inline void *video_drvdata(struct file *file)
509{
510	return video_get_drvdata(video_devdata(file));
511}
512
513/**
514 * video_device_node_name - returns the video device name
515 *
516 * @vdev: pointer to &struct video_device
517 *
518 * Returns the device name string
519 */
520static inline const char *video_device_node_name(struct video_device *vdev)
521{
522	return dev_name(&vdev->dev);
523}
524
525/**
526 * video_is_registered - returns true if the &struct video_device is registered.
527 *
528 *
529 * @vdev: pointer to &struct video_device
530 */
531static inline int video_is_registered(struct video_device *vdev)
532{
533	return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
534}
535
536#endif /* _V4L2_DEV_H */