Current File : //usr/src/linux-headers-5.15.0-125-generic/include/linux/device/class.h
// SPDX-License-Identifier: GPL-2.0
/*
* The class-specific portions of the driver model
*
* Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
* Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (c) 2008-2009 Novell Inc.
* Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Copyright (c) 2012-2019 Linux Foundation
*
* See Documentation/driver-api/driver-model/ for more information.
*/
#ifndef _DEVICE_CLASS_H_
#define _DEVICE_CLASS_H_
#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/pm.h>
#include <linux/device/bus.h>
struct device;
struct fwnode_handle;
/**
* struct class - device classes
* @name: Name of the class.
* @owner: The module owner.
* @class_groups: Default attributes of this class.
* @dev_groups: Default attributes of the devices that belong to the class.
* @dev_kobj: The kobject that represents this class and links it into the hierarchy.
* @dev_uevent: Called when a device is added, removed from this class, or a
* few other things that generate uevents to add the environment
* variables.
* @devnode: Callback to provide the devtmpfs.
* @class_release: Called to release this class.
* @dev_release: Called to release the device.
* @shutdown_pre: Called at shut-down time before driver shutdown.
* @ns_type: Callbacks so sysfs can detemine namespaces.
* @namespace: Namespace of the device belongs to this class.
* @get_ownership: Allows class to specify uid/gid of the sysfs directories
* for the devices belonging to the class. Usually tied to
* device's namespace.
* @pm: The default device power management operations of this class.
* @p: The private data of the driver core, no one other than the
* driver core can touch this.
*
* A class is a higher-level view of a device that abstracts out low-level
* implementation details. Drivers may see a SCSI disk or an ATA disk, but,
* at the class level, they are all simply disks. Classes allow user space
* to work with devices based on what they do, rather than how they are
* connected or how they work.
*/
struct class {
const char *name;
struct module *owner;
const struct attribute_group **class_groups;
const struct attribute_group **dev_groups;
struct kobject *dev_kobj;
int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
char *(*devnode)(struct device *dev, umode_t *mode);
void (*class_release)(struct class *class);
void (*dev_release)(struct device *dev);
int (*shutdown_pre)(struct device *dev);
const struct kobj_ns_type_operations *ns_type;
const void *(*namespace)(struct device *dev);
void (*get_ownership)(struct device *dev, kuid_t *uid, kgid_t *gid);
const struct dev_pm_ops *pm;
struct subsys_private *p;
};
struct class_dev_iter {
struct klist_iter ki;
const struct device_type *type;
};
extern struct kobject *sysfs_dev_block_kobj;
extern struct kobject *sysfs_dev_char_kobj;
extern int __must_check __class_register(struct class *class,
struct lock_class_key *key);
extern void class_unregister(struct class *class);
/* This is a #define to keep the compiler from merging different
* instances of the __key variable */
#define class_register(class) \
({ \
static struct lock_class_key __key; \
__class_register(class, &__key); \
})
struct class_compat;
struct class_compat *class_compat_register(const char *name);
void class_compat_unregister(struct class_compat *cls);
int class_compat_create_link(struct class_compat *cls, struct device *dev,
struct device *device_link);
void class_compat_remove_link(struct class_compat *cls, struct device *dev,
struct device *device_link);
extern void class_dev_iter_init(struct class_dev_iter *iter,
struct class *class,
struct device *start,
const struct device_type *type);
extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
extern void class_dev_iter_exit(struct class_dev_iter *iter);
extern int class_for_each_device(struct class *class, struct device *start,
void *data,
int (*fn)(struct device *dev, void *data));
extern struct device *class_find_device(struct class *class,
struct device *start, const void *data,
int (*match)(struct device *, const void *));
/**
* class_find_device_by_name - device iterator for locating a particular device
* of a specific name.
* @class: class type
* @name: name of the device to match
*/
static inline struct device *class_find_device_by_name(struct class *class,
const char *name)
{
return class_find_device(class, NULL, name, device_match_name);
}
/**
* class_find_device_by_of_node : device iterator for locating a particular device
* matching the of_node.
* @class: class type
* @np: of_node of the device to match.
*/
static inline struct device *
class_find_device_by_of_node(struct class *class, const struct device_node *np)
{
return class_find_device(class, NULL, np, device_match_of_node);
}
/**
* class_find_device_by_fwnode : device iterator for locating a particular device
* matching the fwnode.
* @class: class type
* @fwnode: fwnode of the device to match.
*/
static inline struct device *
class_find_device_by_fwnode(struct class *class,
const struct fwnode_handle *fwnode)
{
return class_find_device(class, NULL, fwnode, device_match_fwnode);
}
/**
* class_find_device_by_devt : device iterator for locating a particular device
* matching the device type.
* @class: class type
* @devt: device type of the device to match.
*/
static inline struct device *class_find_device_by_devt(struct class *class,
dev_t devt)
{
return class_find_device(class, NULL, &devt, device_match_devt);
}
#ifdef CONFIG_ACPI
struct acpi_device;
/**
* class_find_device_by_acpi_dev : device iterator for locating a particular
* device matching the ACPI_COMPANION device.
* @class: class type
* @adev: ACPI_COMPANION device to match.
*/
static inline struct device *
class_find_device_by_acpi_dev(struct class *class, const struct acpi_device *adev)
{
return class_find_device(class, NULL, adev, device_match_acpi_dev);
}
#else
static inline struct device *
class_find_device_by_acpi_dev(struct class *class, const void *adev)
{
return NULL;
}
#endif
struct class_attribute {
struct attribute attr;
ssize_t (*show)(struct class *class, struct class_attribute *attr,
char *buf);
ssize_t (*store)(struct class *class, struct class_attribute *attr,
const char *buf, size_t count);
};
#define CLASS_ATTR_RW(_name) \
struct class_attribute class_attr_##_name = __ATTR_RW(_name)
#define CLASS_ATTR_RO(_name) \
struct class_attribute class_attr_##_name = __ATTR_RO(_name)
#define CLASS_ATTR_WO(_name) \
struct class_attribute class_attr_##_name = __ATTR_WO(_name)
extern int __must_check class_create_file_ns(struct class *class,
const struct class_attribute *attr,
const void *ns);
extern void class_remove_file_ns(struct class *class,
const struct class_attribute *attr,
const void *ns);
static inline int __must_check class_create_file(struct class *class,
const struct class_attribute *attr)
{
return class_create_file_ns(class, attr, NULL);
}
static inline void class_remove_file(struct class *class,
const struct class_attribute *attr)
{
return class_remove_file_ns(class, attr, NULL);
}
/* Simple class attribute that is just a static string */
struct class_attribute_string {
struct class_attribute attr;
char *str;
};
/* Currently read-only only */
#define _CLASS_ATTR_STRING(_name, _mode, _str) \
{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
#define CLASS_ATTR_STRING(_name, _mode, _str) \
struct class_attribute_string class_attr_##_name = \
_CLASS_ATTR_STRING(_name, _mode, _str)
extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
char *buf);
struct class_interface {
struct list_head node;
struct class *class;
int (*add_dev) (struct device *, struct class_interface *);
void (*remove_dev) (struct device *, struct class_interface *);
};
extern int __must_check class_interface_register(struct class_interface *);
extern void class_interface_unregister(struct class_interface *);
extern struct class * __must_check __class_create(struct module *owner,
const char *name,
struct lock_class_key *key);
extern void class_destroy(struct class *cls);
/* This is a #define to keep the compiler from merging different
* instances of the __key variable */
/**
* class_create - create a struct class structure
* @owner: pointer to the module that is to "own" this struct class
* @name: pointer to a string for the name of this class.
*
* This is used to create a struct class pointer that can then be used
* in calls to device_create().
*
* Returns &struct class pointer on success, or ERR_PTR() on error.
*
* Note, the pointer created here is to be destroyed when finished by
* making a call to class_destroy().
*/
#define class_create(owner, name) \
({ \
static struct lock_class_key __key; \
__class_create(owner, name, &__key); \
})
#endif /* _DEVICE_CLASS_H_ */
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