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Diffstat (limited to 'include/linux/device/class.h')
| -rw-r--r-- | include/linux/device/class.h | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/include/linux/device/class.h b/include/linux/device/class.h new file mode 100644 index 000000000000..e8d470c457d1 --- /dev/null +++ b/include/linux/device/class.h @@ -0,0 +1,266 @@ +// 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 */ +#define class_create(owner, name) \ +({ \ + static struct lock_class_key __key; \ + __class_create(owner, name, &__key); \ +}) + + +#endif /* _DEVICE_CLASS_H_ */ |