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 | * @class_groups: Default attributes of this class. |
29 | * @dev_groups: Default attributes of the devices that belong to the class. |
30 | * @dev_uevent: Called when a device is added, removed from this class, or a |
31 | * few other things that generate uevents to add the environment |
32 | * variables. |
33 | * @devnode: Callback to provide the devtmpfs. |
34 | * @class_release: Called to release this class. |
35 | * @dev_release: Called to release the device. |
36 | * @shutdown_pre: Called at shut-down time before driver shutdown. |
37 | * @ns_type: Callbacks so sysfs can detemine namespaces. |
38 | * @namespace: Namespace of the device belongs to this class. |
39 | * @get_ownership: Allows class to specify uid/gid of the sysfs directories |
40 | * for the devices belonging to the class. Usually tied to |
41 | * device's namespace. |
42 | * @pm: The default device power management operations of this class. |
43 | * |
44 | * A class is a higher-level view of a device that abstracts out low-level |
45 | * implementation details. Drivers may see a SCSI disk or an ATA disk, but, |
46 | * at the class level, they are all simply disks. Classes allow user space |
47 | * to work with devices based on what they do, rather than how they are |
48 | * connected or how they work. |
49 | */ |
50 | struct class { |
51 | const char *name; |
52 | |
53 | const struct attribute_group **class_groups; |
54 | const struct attribute_group **dev_groups; |
55 | |
56 | int (*dev_uevent)(const struct device *dev, struct kobj_uevent_env *env); |
57 | char *(*devnode)(const struct device *dev, umode_t *mode); |
58 | |
59 | void (*class_release)(const struct class *class); |
60 | void (*dev_release)(struct device *dev); |
61 | |
62 | int (*shutdown_pre)(struct device *dev); |
63 | |
64 | const struct kobj_ns_type_operations *ns_type; |
65 | const void *(*namespace)(const struct device *dev); |
66 | |
67 | void (*get_ownership)(const struct device *dev, kuid_t *uid, kgid_t *gid); |
68 | |
69 | const struct dev_pm_ops *pm; |
70 | }; |
71 | |
72 | struct class_dev_iter { |
73 | struct klist_iter ki; |
74 | const struct device_type *type; |
75 | struct subsys_private *sp; |
76 | }; |
77 | |
78 | int __must_check class_register(const struct class *class); |
79 | void class_unregister(const struct class *class); |
80 | bool class_is_registered(const struct class *class); |
81 | |
82 | struct class_compat; |
83 | struct class_compat *class_compat_register(const char *name); |
84 | void class_compat_unregister(struct class_compat *cls); |
85 | int class_compat_create_link(struct class_compat *cls, struct device *dev, |
86 | struct device *device_link); |
87 | void class_compat_remove_link(struct class_compat *cls, struct device *dev, |
88 | struct device *device_link); |
89 | |
90 | void class_dev_iter_init(struct class_dev_iter *iter, const struct class *class, |
91 | const struct device *start, const struct device_type *type); |
92 | struct device *class_dev_iter_next(struct class_dev_iter *iter); |
93 | void class_dev_iter_exit(struct class_dev_iter *iter); |
94 | |
95 | int class_for_each_device(const struct class *class, const struct device *start, void *data, |
96 | int (*fn)(struct device *dev, void *data)); |
97 | struct device *class_find_device(const struct class *class, const struct device *start, |
98 | const void *data, int (*match)(struct device *, const void *)); |
99 | |
100 | /** |
101 | * class_find_device_by_name - device iterator for locating a particular device |
102 | * of a specific name. |
103 | * @class: class type |
104 | * @name: name of the device to match |
105 | */ |
106 | static inline struct device *class_find_device_by_name(const struct class *class, |
107 | const char *name) |
108 | { |
109 | return class_find_device(class, NULL, data: name, match: device_match_name); |
110 | } |
111 | |
112 | /** |
113 | * class_find_device_by_of_node : device iterator for locating a particular device |
114 | * matching the of_node. |
115 | * @class: class type |
116 | * @np: of_node of the device to match. |
117 | */ |
118 | static inline struct device *class_find_device_by_of_node(const struct class *class, |
119 | const struct device_node *np) |
120 | { |
121 | return class_find_device(class, NULL, data: np, match: device_match_of_node); |
122 | } |
123 | |
124 | /** |
125 | * class_find_device_by_fwnode : device iterator for locating a particular device |
126 | * matching the fwnode. |
127 | * @class: class type |
128 | * @fwnode: fwnode of the device to match. |
129 | */ |
130 | static inline struct device *class_find_device_by_fwnode(const struct class *class, |
131 | const struct fwnode_handle *fwnode) |
132 | { |
133 | return class_find_device(class, NULL, data: fwnode, match: device_match_fwnode); |
134 | } |
135 | |
136 | /** |
137 | * class_find_device_by_devt : device iterator for locating a particular device |
138 | * matching the device type. |
139 | * @class: class type |
140 | * @devt: device type of the device to match. |
141 | */ |
142 | static inline struct device *class_find_device_by_devt(const struct class *class, |
143 | dev_t devt) |
144 | { |
145 | return class_find_device(class, NULL, data: &devt, match: device_match_devt); |
146 | } |
147 | |
148 | #ifdef CONFIG_ACPI |
149 | struct acpi_device; |
150 | /** |
151 | * class_find_device_by_acpi_dev : device iterator for locating a particular |
152 | * device matching the ACPI_COMPANION device. |
153 | * @class: class type |
154 | * @adev: ACPI_COMPANION device to match. |
155 | */ |
156 | static inline struct device *class_find_device_by_acpi_dev(const struct class *class, |
157 | const struct acpi_device *adev) |
158 | { |
159 | return class_find_device(class, NULL, data: adev, match: device_match_acpi_dev); |
160 | } |
161 | #else |
162 | static inline struct device *class_find_device_by_acpi_dev(const struct class *class, |
163 | const void *adev) |
164 | { |
165 | return NULL; |
166 | } |
167 | #endif |
168 | |
169 | struct class_attribute { |
170 | struct attribute attr; |
171 | ssize_t (*show)(const struct class *class, const struct class_attribute *attr, |
172 | char *buf); |
173 | ssize_t (*store)(const struct class *class, const struct class_attribute *attr, |
174 | const char *buf, size_t count); |
175 | }; |
176 | |
177 | #define CLASS_ATTR_RW(_name) \ |
178 | struct class_attribute class_attr_##_name = __ATTR_RW(_name) |
179 | #define CLASS_ATTR_RO(_name) \ |
180 | struct class_attribute class_attr_##_name = __ATTR_RO(_name) |
181 | #define CLASS_ATTR_WO(_name) \ |
182 | struct class_attribute class_attr_##_name = __ATTR_WO(_name) |
183 | |
184 | int __must_check class_create_file_ns(const struct class *class, const struct class_attribute *attr, |
185 | const void *ns); |
186 | void class_remove_file_ns(const struct class *class, const struct class_attribute *attr, |
187 | const void *ns); |
188 | |
189 | static inline int __must_check class_create_file(const struct class *class, |
190 | const struct class_attribute *attr) |
191 | { |
192 | return class_create_file_ns(class, attr, NULL); |
193 | } |
194 | |
195 | static inline void class_remove_file(const struct class *class, |
196 | const struct class_attribute *attr) |
197 | { |
198 | return class_remove_file_ns(class, attr, NULL); |
199 | } |
200 | |
201 | /* Simple class attribute that is just a static string */ |
202 | struct class_attribute_string { |
203 | struct class_attribute attr; |
204 | char *str; |
205 | }; |
206 | |
207 | /* Currently read-only only */ |
208 | #define _CLASS_ATTR_STRING(_name, _mode, _str) \ |
209 | { __ATTR(_name, _mode, show_class_attr_string, NULL), _str } |
210 | #define CLASS_ATTR_STRING(_name, _mode, _str) \ |
211 | struct class_attribute_string class_attr_##_name = \ |
212 | _CLASS_ATTR_STRING(_name, _mode, _str) |
213 | |
214 | ssize_t show_class_attr_string(const struct class *class, const struct class_attribute *attr, |
215 | char *buf); |
216 | |
217 | struct class_interface { |
218 | struct list_head node; |
219 | const struct class *class; |
220 | |
221 | int (*add_dev) (struct device *dev); |
222 | void (*remove_dev) (struct device *dev); |
223 | }; |
224 | |
225 | int __must_check class_interface_register(struct class_interface *); |
226 | void class_interface_unregister(struct class_interface *); |
227 | |
228 | struct class * __must_check class_create(const char *name); |
229 | void class_destroy(const struct class *cls); |
230 | |
231 | #endif /* _DEVICE_CLASS_H_ */ |
232 | |