cregit-Linux how code gets into the kernel

Release 4.16 include/media/v4l2-dev.h

Directory: include/media
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *
 *      V 4 L 2   D R I V E R   H E L P E R   A P I
 *
 * Moved from videodev2.h
 *
 *      Some commonly needed functions for drivers (v4l2-common.o module)
 */
#ifndef _V4L2_DEV_H

#define _V4L2_DEV_H

#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>

#include <media/media-entity.h>


#define VIDEO_MAJOR	81

/**
 * enum vfl_devnode_type - type of V4L2 device node
 *
 * @VFL_TYPE_GRABBER:   for video input/output devices
 * @VFL_TYPE_VBI:       for vertical blank data (i.e. closed captions, teletext)
 * @VFL_TYPE_RADIO:     for radio tuners
 * @VFL_TYPE_SUBDEV:    for V4L2 subdevices
 * @VFL_TYPE_SDR:       for Software Defined Radio tuners
 * @VFL_TYPE_TOUCH:     for touch sensors
 */

enum vfl_devnode_type {
	
VFL_TYPE_GRABBER	= 0,
	
VFL_TYPE_VBI		= 1,
	
VFL_TYPE_RADIO		= 2,
	
VFL_TYPE_SUBDEV		= 3,
	
VFL_TYPE_SDR		= 4,
	
VFL_TYPE_TOUCH		= 5,
};

#define VFL_TYPE_MAX VFL_TYPE_TOUCH

/**
 * enum  vfl_direction - Identifies if a &struct video_device corresponds
 *      to a receiver, a transmitter or a mem-to-mem device.
 *
 * @VFL_DIR_RX:         device is a receiver.
 * @VFL_DIR_TX:         device is a transmitter.
 * @VFL_DIR_M2M:        device is a memory to memory device.
 *
 * Note: Ignored if &enum vfl_devnode_type is %VFL_TYPE_SUBDEV.
 */

enum vfl_devnode_direction {
	
VFL_DIR_RX,
	
VFL_DIR_TX,
	
VFL_DIR_M2M,
};

struct v4l2_ioctl_callbacks;
struct video_device;
struct v4l2_device;
struct v4l2_ctrl_handler;

/**
 * enum v4l2_video_device_flags - Flags used by &struct video_device
 *
 * @V4L2_FL_REGISTERED:
 *      indicates that a &struct video_device is registered.
 *      Drivers can clear this flag if they want to block all future
 *      device access. It is cleared by video_unregister_device.
 * @V4L2_FL_USES_V4L2_FH:
 *      indicates that file->private_data points to &struct v4l2_fh.
 *      This flag is set by the core when v4l2_fh_init() is called.
 *      All new drivers should use it.
 */

enum v4l2_video_device_flags {
	
V4L2_FL_REGISTERED	= 0,
	
V4L2_FL_USES_V4L2_FH	= 1,
};

/* Priority helper functions */

/**
 * struct v4l2_prio_state - stores the priority states
 *
 * @prios: array with elements to store the array priorities
 *
 *
 * .. note::
 *    The size of @prios array matches the number of priority types defined
 *    by enum &v4l2_priority.
 */

struct v4l2_prio_state {
	
atomic_t prios[4];
};

/**
 * v4l2_prio_init - initializes a struct v4l2_prio_state
 *
 * @global: pointer to &struct v4l2_prio_state
 */
void v4l2_prio_init(struct v4l2_prio_state *global);

/**
 * v4l2_prio_change - changes the v4l2 file handler priority
 *
 * @global: pointer to the &struct v4l2_prio_state of the device node.
 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
 * @new: Priority type requested, as defined by enum &v4l2_priority.
 *
 * .. note::
 *      This function should be used only by the V4L2 core.
 */
int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
		     enum v4l2_priority new);

/**
 * v4l2_prio_open - Implements the priority logic for a file handler open
 *
 * @global: pointer to the &struct v4l2_prio_state of the device node.
 * @local: pointer to the desired priority, as defined by enum &v4l2_priority
 *
 * .. note::
 *      This function should be used only by the V4L2 core.
 */
void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);

/**
 * v4l2_prio_close - Implements the priority logic for a file handler close
 *
 * @global: pointer to the &struct v4l2_prio_state of the device node.
 * @local: priority to be released, as defined by enum &v4l2_priority
 *
 * .. note::
 *      This function should be used only by the V4L2 core.
 */
void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);

/**
 * v4l2_prio_max - Return the maximum priority, as stored at the @global array.
 *
 * @global: pointer to the &struct v4l2_prio_state of the device node.
 *
 * .. note::
 *      This function should be used only by the V4L2 core.
 */
enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);

/**
 * v4l2_prio_check - Implements the priority logic for a file handler close
 *
 * @global: pointer to the &struct v4l2_prio_state of the device node.
 * @local: desired priority, as defined by enum &v4l2_priority local
 *
 * .. note::
 *      This function should be used only by the V4L2 core.
 */
int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);

/**
 * struct v4l2_file_operations - fs operations used by a V4L2 device
 *
 * @owner: pointer to struct module
 * @read: operations needed to implement the read() syscall
 * @write: operations needed to implement the write() syscall
 * @poll: operations needed to implement the poll() syscall
 * @unlocked_ioctl: operations needed to implement the ioctl() syscall
 * @compat_ioctl32: operations needed to implement the ioctl() syscall for
 *      the special case where the Kernel uses 64 bits instructions, but
 *      the userspace uses 32 bits.
 * @get_unmapped_area: called by the mmap() syscall, used when %!CONFIG_MMU
 * @mmap: operations needed to implement the mmap() syscall
 * @open: operations needed to implement the open() syscall
 * @release: operations needed to implement the release() syscall
 *
 * .. note::
 *
 *      Those operations are used to implemente the fs struct file_operations
 *      at the V4L2 drivers. The V4L2 core overrides the fs ops with some
 *      extra logic needed by the subsystem.
 */

struct v4l2_file_operations {
	
struct module *owner;
	
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
	
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
	
__poll_t (*poll) (struct file *, struct poll_table_struct *);
	
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
#ifdef CONFIG_COMPAT
	
long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
#endif
	
unsigned long (*get_unmapped_area) (struct file *, unsigned long,
				unsigned long, unsigned long, unsigned long);
	
int (*mmap) (struct file *, struct vm_area_struct *);
	
int (*open) (struct file *);
	
int (*release) (struct file *);
};

/*
 * Newer version of video_device, handled by videodev2.c
 *      This version moves redundant code from video device code to
 *      the common handler
 */

/**
 * struct video_device - Structure used to create and manage the V4L2 device
 *      nodes.
 *
 * @entity: &struct media_entity
 * @intf_devnode: pointer to &struct media_intf_devnode
 * @pipe: &struct media_pipeline
 * @fops: pointer to &struct v4l2_file_operations for the video device
 * @device_caps: device capabilities as used in v4l2_capabilities
 * @dev: &struct device for the video device
 * @cdev: character device
 * @v4l2_dev: pointer to &struct v4l2_device parent
 * @dev_parent: pointer to &struct device parent
 * @ctrl_handler: Control handler associated with this device node.
 *       May be NULL.
 * @queue: &struct vb2_queue associated with this device node. May be NULL.
 * @prio: pointer to &struct v4l2_prio_state with device's Priority state.
 *       If NULL, then v4l2_dev->prio will be used.
 * @name: video device name
 * @vfl_type: V4L device type, as defined by &enum vfl_devnode_type
 * @vfl_dir: V4L receiver, transmitter or m2m
 * @minor: device node 'minor'. It is set to -1 if the registration failed
 * @num: number of the video device node
 * @flags: video device flags. Use bitops to set/clear/test flags.
 *         Contains a set of &enum v4l2_video_device_flags.
 * @index: attribute to differentiate multiple indices on one physical device
 * @fh_lock: Lock for all v4l2_fhs
 * @fh_list: List of &struct v4l2_fh
 * @dev_debug: Internal device debug flags, not for use by drivers
 * @tvnorms: Supported tv norms
 *
 * @release: video device release() callback
 * @ioctl_ops: pointer to &struct v4l2_ioctl_ops with ioctl callbacks
 *
 * @valid_ioctls: bitmap with the valid ioctls for this device
 * @disable_locking: bitmap with the ioctls that don't require locking
 * @lock: pointer to &struct mutex serialization lock
 *
 * .. note::
 *      Only set @dev_parent if that can't be deduced from @v4l2_dev.
 */


struct video_device
{
#if defined(CONFIG_MEDIA_CONTROLLER)
	
struct media_entity entity;
	
struct media_intf_devnode *intf_devnode;
	
struct media_pipeline pipe;
#endif
	
const struct v4l2_file_operations *fops;

	
u32 device_caps;

	/* sysfs */
	
struct device dev;
	
struct cdev *cdev;

	
struct v4l2_device *v4l2_dev;
	
struct device *dev_parent;

	
struct v4l2_ctrl_handler *ctrl_handler;

	
struct vb2_queue *queue;

	
struct v4l2_prio_state *prio;

	/* device info */
	
char name[32];
	
enum vfl_devnode_type vfl_type;
	
enum vfl_devnode_direction vfl_dir;
	
int minor;
	
u16 num;
	
unsigned long flags;
	
int index;

	/* V4L2 file handles */
	
spinlock_t		fh_lock;
	
struct list_head	fh_list;

	
int dev_debug;

	
v4l2_std_id tvnorms;

	/* callbacks */
	
void (*release)(struct video_device *vdev);
	
const struct v4l2_ioctl_ops *ioctl_ops;
	DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE);

	DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE);
	
struct mutex *lock;
};

/**
 * media_entity_to_video_device - Returns a &struct video_device from
 *      the &struct media_entity embedded on it.
 *
 * @entity: pointer to &struct media_entity
 */

#define media_entity_to_video_device(entity) \
	container_of(entity, struct video_device, entity)

/**
 * to_video_device - Returns a &struct video_device from the
 *      &struct device embedded on it.
 *
 * @cd: pointer to &struct device
 */

#define to_video_device(cd) container_of(cd, struct video_device, dev)

/**
 * __video_register_device - register video4linux devices
 *
 * @vdev: struct video_device to register
 * @type: type of device to register, as defined by &enum vfl_devnode_type
 * @nr:   which device node number is desired:
 *      (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
 * @warn_if_nr_in_use: warn if the desired device node number
 *        was already in use and another number was chosen instead.
 * @owner: module that owns the video device node
 *
 * The registration code assigns minor numbers and device node numbers
 * based on the requested type and registers the new device node with
 * the kernel.
 *
 * This function assumes that struct video_device was zeroed when it
 * was allocated and does not contain any stale date.
 *
 * An error is returned if no free minor or device node number could be
 * found, or if the registration of the device node failed.
 *
 * Returns 0 on success.
 *
 * .. note::
 *
 *      This function is meant to be used only inside the V4L2 core.
 *      Drivers should use video_register_device() or
 *      video_register_device_no_warn().
 */
int __must_check __video_register_device(struct video_device *vdev,
					 enum vfl_devnode_type type,
					 int nr, int warn_if_nr_in_use,
					 struct module *owner);

/**
 *  video_register_device - register video4linux devices
 *
 * @vdev: struct video_device to register
 * @type: type of device to register, as defined by &enum vfl_devnode_type
 * @nr:   which device node number is desired:
 *      (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free)
 *
 * Internally, it calls __video_register_device(). Please see its
 * documentation for more details.
 *
 * .. note::
 *      if video_register_device fails, the release() callback of
 *      &struct video_device structure is *not* called, so the caller
 *      is responsible for freeing any data. Usually that means that
 *      you video_device_release() should be called on failure.
 */

static inline int __must_check video_register_device(struct video_device *vdev, enum vfl_devnode_type type, int nr) { return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); }

Contributors

PersonTokensPropCommitsCommitProp
Laurent Pinchart2257.89%120.00%
Mauro Carvalho Chehab1436.84%240.00%
Hans Verkuil25.26%240.00%
Total38100.00%5100.00%

/** * video_register_device_no_warn - register video4linux devices * * @vdev: struct video_device to register * @type: type of device to register, as defined by &enum vfl_devnode_type * @nr: which device node number is desired: * (0 == /dev/video0, 1 == /dev/video1, ..., -1 == first free) * * This function is identical to video_register_device() except that no * warning is issued if the desired device node number was already in use. * * Internally, it calls __video_register_device(). Please see its * documentation for more details. * * .. note:: * if video_register_device fails, the release() callback of * &struct video_device structure is *not* called, so the caller * is responsible for freeing any data. Usually that means that * you video_device_release() should be called on failure. */
static inline int __must_check video_register_device_no_warn(struct video_device *vdev, enum vfl_devnode_type type, int nr) { return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); }

Contributors

PersonTokensPropCommitsCommitProp
Laurent Pinchart2257.89%133.33%
Hans Verkuil1436.84%133.33%
Mauro Carvalho Chehab25.26%133.33%
Total38100.00%3100.00%

/** * video_unregister_device - Unregister video devices. * * @vdev: &struct video_device to register * * Does nothing if vdev == NULL or if video_is_registered() returns false. */ void video_unregister_device(struct video_device *vdev); /** * video_device_alloc - helper function to alloc &struct video_device * * Returns NULL if %-ENOMEM or a &struct video_device on success. */ struct video_device * __must_check video_device_alloc(void); /** * video_device_release - helper function to release &struct video_device * * @vdev: pointer to &struct video_device * * Can also be used for video_device->release\(\). */ void video_device_release(struct video_device *vdev); /** * video_device_release_empty - helper function to implement the * video_device->release\(\) callback. * * @vdev: pointer to &struct video_device * * This release function does nothing. * * It should be used when the video_device is a static global struct. * * .. note:: * Having a static video_device is a dubious construction at best. */ void video_device_release_empty(struct video_device *vdev); /** * v4l2_is_known_ioctl - Checks if a given cmd is a known V4L ioctl * * @cmd: ioctl command * * returns true if cmd is a known V4L2 ioctl */ bool v4l2_is_known_ioctl(unsigned int cmd); /** v4l2_disable_ioctl_locking - mark that a given command * shouldn't use core locking * * @vdev: pointer to &struct video_device * @cmd: ioctl command */
static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd) { if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) set_bit(_IOC_NR(cmd), vdev->disable_locking); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Verkuil37100.00%2100.00%
Total37100.00%2100.00%

/** * v4l2_disable_ioctl- mark that a given command isn't implemented. * shouldn't use core locking * * @vdev: pointer to &struct video_device * @cmd: ioctl command * * This function allows drivers to provide just one v4l2_ioctl_ops struct, but * disable ioctls based on the specific card that is actually found. * * .. note:: * * This must be called before video_register_device. * See also the comments for determine_valid_ioctls(). */
static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) { if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) set_bit(_IOC_NR(cmd), vdev->valid_ioctls); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Verkuil37100.00%2100.00%
Total37100.00%2100.00%

/** * video_get_drvdata - gets private data from &struct video_device. * * @vdev: pointer to &struct video_device * * returns a pointer to the private data */
static inline void *video_get_drvdata(struct video_device *vdev) { return dev_get_drvdata(&vdev->dev); }

Contributors

PersonTokensPropCommitsCommitProp
Mauro Carvalho Chehab1568.18%133.33%
Hans Verkuil731.82%266.67%
Total22100.00%3100.00%

/** * video_set_drvdata - sets private data from &struct video_device. * * @vdev: pointer to &struct video_device * @data: private data pointer */
static inline void video_set_drvdata(struct video_device *vdev, void *data) { dev_set_drvdata(&vdev->dev, data); }

Contributors

PersonTokensPropCommitsCommitProp
Mauro Carvalho Chehab1869.23%133.33%
Hans Verkuil830.77%266.67%
Total26100.00%3100.00%

/** * video_devdata - gets &struct video_device from struct file. * * @file: pointer to struct file */ struct video_device *video_devdata(struct file *file); /** * video_drvdata - gets private data from &struct video_device using the * struct file. * * @file: pointer to struct file * * This is function combines both video_get_drvdata() and video_devdata() * as this is used very often. */
static inline void *video_drvdata(struct file *file) { return video_get_drvdata(video_devdata(file)); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Verkuil22100.00%1100.00%
Total22100.00%1100.00%

/** * video_device_node_name - returns the video device name * * @vdev: pointer to &struct video_device * * Returns the device name string */
static inline const char *video_device_node_name(struct video_device *vdev) { return dev_name(&vdev->dev); }

Contributors

PersonTokensPropCommitsCommitProp
Laurent Pinchart23100.00%1100.00%
Total23100.00%1100.00%

/** * video_is_registered - returns true if the &struct video_device is registered. * * * @vdev: pointer to &struct video_device */
static inline int video_is_registered(struct video_device *vdev) { return test_bit(V4L2_FL_REGISTERED, &vdev->flags); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Verkuil2191.30%150.00%
Laurent Pinchart28.70%150.00%
Total23100.00%2100.00%

#endif /* _V4L2_DEV_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Hans Verkuil46952.17%2546.30%
Mauro Carvalho Chehab23826.47%1425.93%
Laurent Pinchart13715.24%59.26%
Bob Liu242.67%11.85%
Sakari Ailus91.00%11.85%
Linus Torvalds60.67%11.85%
Kay Sievers50.56%11.85%
Shuah Khan40.44%11.85%
Brandon Philips30.33%11.85%
Al Viro10.11%11.85%
Antti Palosaari10.11%11.85%
Nick Dyer10.11%11.85%
Greg Kroah-Hartman10.11%11.85%
Total899100.00%54100.00%
Directory: include/media
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.