LCOV - code coverage report
Current view: top level - include/linux/device - class.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 1 3 33.3 %
Date: 2023-03-27 20:00:47 Functions: 0 0 -

          Line data    Source code
       1             : // SPDX-License-Identifier: GPL-2.0
       2             : /*
       3             :  * The class-specific portions of the driver model
       4             :  *
       5             :  * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
       6             :  * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
       7             :  * Copyright (c) 2008-2009 Novell Inc.
       8             :  * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
       9             :  * Copyright (c) 2012-2019 Linux Foundation
      10             :  *
      11             :  * See Documentation/driver-api/driver-model/ for more information.
      12             :  */
      13             : 
      14             : #ifndef _DEVICE_CLASS_H_
      15             : #define _DEVICE_CLASS_H_
      16             : 
      17             : #include <linux/kobject.h>
      18             : #include <linux/klist.h>
      19             : #include <linux/pm.h>
      20             : #include <linux/device/bus.h>
      21             : 
      22             : struct device;
      23             : struct fwnode_handle;
      24             : 
      25             : /**
      26             :  * struct class - device classes
      27             :  * @name:       Name of the class.
      28             :  * @owner:      The module owner.
      29             :  * @class_groups: Default attributes of this class.
      30             :  * @dev_groups: Default attributes of the devices that belong to the class.
      31             :  * @dev_kobj:   The kobject that represents this class and links it into the hierarchy.
      32             :  * @dev_uevent: Called when a device is added, removed from this class, or a
      33             :  *              few other things that generate uevents to add the environment
      34             :  *              variables.
      35             :  * @devnode:    Callback to provide the devtmpfs.
      36             :  * @class_release: Called to release this class.
      37             :  * @dev_release: Called to release the device.
      38             :  * @shutdown_pre: Called at shut-down time before driver shutdown.
      39             :  * @ns_type:    Callbacks so sysfs can detemine namespaces.
      40             :  * @namespace:  Namespace of the device belongs to this class.
      41             :  * @get_ownership: Allows class to specify uid/gid of the sysfs directories
      42             :  *              for the devices belonging to the class. Usually tied to
      43             :  *              device's namespace.
      44             :  * @pm:         The default device power management operations of this class.
      45             :  * @p:          The private data of the driver core, no one other than the
      46             :  *              driver core can touch this.
      47             :  *
      48             :  * A class is a higher-level view of a device that abstracts out low-level
      49             :  * implementation details. Drivers may see a SCSI disk or an ATA disk, but,
      50             :  * at the class level, they are all simply disks. Classes allow user space
      51             :  * to work with devices based on what they do, rather than how they are
      52             :  * connected or how they work.
      53             :  */
      54             : struct class {
      55             :         const char              *name;
      56             :         struct module           *owner;
      57             : 
      58             :         const struct attribute_group    **class_groups;
      59             :         const struct attribute_group    **dev_groups;
      60             :         struct kobject                  *dev_kobj;
      61             : 
      62             :         int (*dev_uevent)(const struct device *dev, struct kobj_uevent_env *env);
      63             :         char *(*devnode)(const struct device *dev, umode_t *mode);
      64             : 
      65             :         void (*class_release)(struct class *class);
      66             :         void (*dev_release)(struct device *dev);
      67             : 
      68             :         int (*shutdown_pre)(struct device *dev);
      69             : 
      70             :         const struct kobj_ns_type_operations *ns_type;
      71             :         const void *(*namespace)(const struct device *dev);
      72             : 
      73             :         void (*get_ownership)(const struct device *dev, kuid_t *uid, kgid_t *gid);
      74             : 
      75             :         const struct dev_pm_ops *pm;
      76             : 
      77             :         struct subsys_private *p;
      78             : };
      79             : 
      80             : struct class_dev_iter {
      81             :         struct klist_iter               ki;
      82             :         const struct device_type        *type;
      83             : };
      84             : 
      85             : extern struct kobject *sysfs_dev_block_kobj;
      86             : extern struct kobject *sysfs_dev_char_kobj;
      87             : extern int __must_check __class_register(struct class *class,
      88             :                                          struct lock_class_key *key);
      89             : extern void class_unregister(struct class *class);
      90             : 
      91             : /* This is a #define to keep the compiler from merging different
      92             :  * instances of the __key variable */
      93             : #define class_register(class)                   \
      94             : ({                                              \
      95             :         static struct lock_class_key __key;     \
      96             :         __class_register(class, &__key);    \
      97             : })
      98             : 
      99             : struct class_compat;
     100             : struct class_compat *class_compat_register(const char *name);
     101             : void class_compat_unregister(struct class_compat *cls);
     102             : int class_compat_create_link(struct class_compat *cls, struct device *dev,
     103             :                              struct device *device_link);
     104             : void class_compat_remove_link(struct class_compat *cls, struct device *dev,
     105             :                               struct device *device_link);
     106             : 
     107             : extern void class_dev_iter_init(struct class_dev_iter *iter,
     108             :                                 struct class *class,
     109             :                                 struct device *start,
     110             :                                 const struct device_type *type);
     111             : extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
     112             : extern void class_dev_iter_exit(struct class_dev_iter *iter);
     113             : 
     114             : extern int class_for_each_device(struct class *class, struct device *start,
     115             :                                  void *data,
     116             :                                  int (*fn)(struct device *dev, void *data));
     117             : extern struct device *class_find_device(struct class *class,
     118             :                                         struct device *start, const void *data,
     119             :                                         int (*match)(struct device *, const void *));
     120             : 
     121             : /**
     122             :  * class_find_device_by_name - device iterator for locating a particular device
     123             :  * of a specific name.
     124             :  * @class: class type
     125             :  * @name: name of the device to match
     126             :  */
     127             : static inline struct device *class_find_device_by_name(struct class *class,
     128             :                                                        const char *name)
     129             : {
     130             :         return class_find_device(class, NULL, name, device_match_name);
     131             : }
     132             : 
     133             : /**
     134             :  * class_find_device_by_of_node : device iterator for locating a particular device
     135             :  * matching the of_node.
     136             :  * @class: class type
     137             :  * @np: of_node of the device to match.
     138             :  */
     139             : static inline struct device *
     140             : class_find_device_by_of_node(struct class *class, const struct device_node *np)
     141             : {
     142             :         return class_find_device(class, NULL, np, device_match_of_node);
     143             : }
     144             : 
     145             : /**
     146             :  * class_find_device_by_fwnode : device iterator for locating a particular device
     147             :  * matching the fwnode.
     148             :  * @class: class type
     149             :  * @fwnode: fwnode of the device to match.
     150             :  */
     151             : static inline struct device *
     152             : class_find_device_by_fwnode(struct class *class,
     153             :                             const struct fwnode_handle *fwnode)
     154             : {
     155             :         return class_find_device(class, NULL, fwnode, device_match_fwnode);
     156             : }
     157             : 
     158             : /**
     159             :  * class_find_device_by_devt : device iterator for locating a particular device
     160             :  * matching the device type.
     161             :  * @class: class type
     162             :  * @devt: device type of the device to match.
     163             :  */
     164             : static inline struct device *class_find_device_by_devt(struct class *class,
     165             :                                                        dev_t devt)
     166             : {
     167           0 :         return class_find_device(class, NULL, &devt, device_match_devt);
     168             : }
     169             : 
     170             : #ifdef CONFIG_ACPI
     171             : struct acpi_device;
     172             : /**
     173             :  * class_find_device_by_acpi_dev : device iterator for locating a particular
     174             :  * device matching the ACPI_COMPANION device.
     175             :  * @class: class type
     176             :  * @adev: ACPI_COMPANION device to match.
     177             :  */
     178             : static inline struct device *
     179             : class_find_device_by_acpi_dev(struct class *class, const struct acpi_device *adev)
     180             : {
     181             :         return class_find_device(class, NULL, adev, device_match_acpi_dev);
     182             : }
     183             : #else
     184             : static inline struct device *
     185             : class_find_device_by_acpi_dev(struct class *class, const void *adev)
     186             : {
     187             :         return NULL;
     188             : }
     189             : #endif
     190             : 
     191             : struct class_attribute {
     192             :         struct attribute attr;
     193             :         ssize_t (*show)(struct class *class, struct class_attribute *attr,
     194             :                         char *buf);
     195             :         ssize_t (*store)(struct class *class, struct class_attribute *attr,
     196             :                         const char *buf, size_t count);
     197             : };
     198             : 
     199             : #define CLASS_ATTR_RW(_name) \
     200             :         struct class_attribute class_attr_##_name = __ATTR_RW(_name)
     201             : #define CLASS_ATTR_RO(_name) \
     202             :         struct class_attribute class_attr_##_name = __ATTR_RO(_name)
     203             : #define CLASS_ATTR_WO(_name) \
     204             :         struct class_attribute class_attr_##_name = __ATTR_WO(_name)
     205             : 
     206             : extern int __must_check class_create_file_ns(struct class *class,
     207             :                                              const struct class_attribute *attr,
     208             :                                              const void *ns);
     209             : extern void class_remove_file_ns(struct class *class,
     210             :                                  const struct class_attribute *attr,
     211             :                                  const void *ns);
     212             : 
     213             : static inline int __must_check class_create_file(struct class *class,
     214             :                                         const struct class_attribute *attr)
     215             : {
     216           1 :         return class_create_file_ns(class, attr, NULL);
     217             : }
     218             : 
     219             : static inline void class_remove_file(struct class *class,
     220             :                                      const struct class_attribute *attr)
     221             : {
     222           0 :         return class_remove_file_ns(class, attr, NULL);
     223             : }
     224             : 
     225             : /* Simple class attribute that is just a static string */
     226             : struct class_attribute_string {
     227             :         struct class_attribute attr;
     228             :         char *str;
     229             : };
     230             : 
     231             : /* Currently read-only only */
     232             : #define _CLASS_ATTR_STRING(_name, _mode, _str) \
     233             :         { __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
     234             : #define CLASS_ATTR_STRING(_name, _mode, _str) \
     235             :         struct class_attribute_string class_attr_##_name = \
     236             :                 _CLASS_ATTR_STRING(_name, _mode, _str)
     237             : 
     238             : extern ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
     239             :                         char *buf);
     240             : 
     241             : struct class_interface {
     242             :         struct list_head        node;
     243             :         struct class            *class;
     244             : 
     245             :         int (*add_dev)          (struct device *, struct class_interface *);
     246             :         void (*remove_dev)      (struct device *, struct class_interface *);
     247             : };
     248             : 
     249             : extern int __must_check class_interface_register(struct class_interface *);
     250             : extern void class_interface_unregister(struct class_interface *);
     251             : 
     252             : extern struct class * __must_check __class_create(struct module *owner,
     253             :                                                   const char *name,
     254             :                                                   struct lock_class_key *key);
     255             : extern void class_destroy(struct class *cls);
     256             : 
     257             : /* This is a #define to keep the compiler from merging different
     258             :  * instances of the __key variable */
     259             : 
     260             : /**
     261             :  * class_create - create a struct class structure
     262             :  * @owner: pointer to the module that is to "own" this struct class
     263             :  * @name: pointer to a string for the name of this class.
     264             :  *
     265             :  * This is used to create a struct class pointer that can then be used
     266             :  * in calls to device_create().
     267             :  *
     268             :  * Returns &struct class pointer on success, or ERR_PTR() on error.
     269             :  *
     270             :  * Note, the pointer created here is to be destroyed when finished by
     271             :  * making a call to class_destroy().
     272             :  */
     273             : #define class_create(owner, name)               \
     274             : ({                                              \
     275             :         static struct lock_class_key __key;     \
     276             :         __class_create(owner, name, &__key);        \
     277             : })
     278             : 
     279             : 
     280             : #endif  /* _DEVICE_CLASS_H_ */

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