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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * class.c - basic device class management | |
3 | * | |
4 | * Copyright (c) 2002-3 Patrick Mochel | |
5 | * Copyright (c) 2002-3 Open Source Development Labs | |
6 | * Copyright (c) 2003-2004 Greg Kroah-Hartman | |
7 | * Copyright (c) 2003-2004 IBM Corp. | |
8 | * | |
9 | * This file is released under the GPLv2 | |
10 | * | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/device.h> |
14 | #include <linux/module.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/kdev_t.h> | |
e9ba6365 | 18 | #include <linux/err.h> |
4e57b681 | 19 | #include <linux/slab.h> |
edfaa7c3 | 20 | #include <linux/genhd.h> |
1da177e4 LT |
21 | #include "base.h" |
22 | ||
23 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
823bccfc | 24 | #define to_class(obj) container_of(obj, struct class, subsys.kobj) |
1da177e4 | 25 | |
4a3ad20c GKH |
26 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
27 | char *buf) | |
1da177e4 | 28 | { |
4a3ad20c GKH |
29 | struct class_attribute *class_attr = to_class_attr(attr); |
30 | struct class *dc = to_class(kobj); | |
4a0c20bf | 31 | ssize_t ret = -EIO; |
1da177e4 LT |
32 | |
33 | if (class_attr->show) | |
34 | ret = class_attr->show(dc, buf); | |
35 | return ret; | |
36 | } | |
37 | ||
4a3ad20c GKH |
38 | static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, |
39 | const char *buf, size_t count) | |
1da177e4 | 40 | { |
4a3ad20c GKH |
41 | struct class_attribute *class_attr = to_class_attr(attr); |
42 | struct class *dc = to_class(kobj); | |
4a0c20bf | 43 | ssize_t ret = -EIO; |
1da177e4 LT |
44 | |
45 | if (class_attr->store) | |
46 | ret = class_attr->store(dc, buf, count); | |
47 | return ret; | |
48 | } | |
49 | ||
4a3ad20c | 50 | static void class_release(struct kobject *kobj) |
1da177e4 LT |
51 | { |
52 | struct class *class = to_class(kobj); | |
53 | ||
54 | pr_debug("class '%s': release.\n", class->name); | |
55 | ||
56 | if (class->class_release) | |
57 | class->class_release(class); | |
58 | else | |
59 | pr_debug("class '%s' does not have a release() function, " | |
60 | "be careful\n", class->name); | |
61 | } | |
62 | ||
63 | static struct sysfs_ops class_sysfs_ops = { | |
64 | .show = class_attr_show, | |
65 | .store = class_attr_store, | |
66 | }; | |
67 | ||
adc56808 | 68 | static struct kobj_type class_ktype = { |
1da177e4 LT |
69 | .sysfs_ops = &class_sysfs_ops, |
70 | .release = class_release, | |
71 | }; | |
72 | ||
73 | /* Hotplug events for classes go to the class_obj subsys */ | |
443dbf90 | 74 | static struct kset *class_kset; |
1da177e4 LT |
75 | |
76 | ||
4a3ad20c | 77 | int class_create_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
78 | { |
79 | int error; | |
4a3ad20c | 80 | if (cls) |
823bccfc | 81 | error = sysfs_create_file(&cls->subsys.kobj, &attr->attr); |
4a3ad20c | 82 | else |
1da177e4 LT |
83 | error = -EINVAL; |
84 | return error; | |
85 | } | |
86 | ||
4a3ad20c | 87 | void class_remove_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
88 | { |
89 | if (cls) | |
823bccfc | 90 | sysfs_remove_file(&cls->subsys.kobj, &attr->attr); |
1da177e4 LT |
91 | } |
92 | ||
1740757e | 93 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
94 | { |
95 | if (cls) | |
4a3ad20c GKH |
96 | return container_of(kset_get(&cls->subsys), |
97 | struct class, subsys); | |
1da177e4 LT |
98 | return NULL; |
99 | } | |
100 | ||
4a3ad20c | 101 | static void class_put(struct class *cls) |
1da177e4 | 102 | { |
51d172d5 | 103 | if (cls) |
6e9d930d | 104 | kset_put(&cls->subsys); |
1da177e4 LT |
105 | } |
106 | ||
4a3ad20c | 107 | static int add_class_attrs(struct class *cls) |
1da177e4 LT |
108 | { |
109 | int i; | |
110 | int error = 0; | |
111 | ||
112 | if (cls->class_attrs) { | |
113 | for (i = 0; attr_name(cls->class_attrs[i]); i++) { | |
4a3ad20c | 114 | error = class_create_file(cls, &cls->class_attrs[i]); |
1da177e4 | 115 | if (error) |
4a3ad20c | 116 | goto error; |
1da177e4 LT |
117 | } |
118 | } | |
4a3ad20c | 119 | done: |
1da177e4 | 120 | return error; |
4a3ad20c | 121 | error: |
1da177e4 | 122 | while (--i >= 0) |
4a3ad20c GKH |
123 | class_remove_file(cls, &cls->class_attrs[i]); |
124 | goto done; | |
1da177e4 LT |
125 | } |
126 | ||
4a3ad20c | 127 | static void remove_class_attrs(struct class *cls) |
1da177e4 LT |
128 | { |
129 | int i; | |
130 | ||
131 | if (cls->class_attrs) { | |
132 | for (i = 0; attr_name(cls->class_attrs[i]); i++) | |
4a3ad20c | 133 | class_remove_file(cls, &cls->class_attrs[i]); |
1da177e4 LT |
134 | } |
135 | } | |
136 | ||
4a3ad20c | 137 | int class_register(struct class *cls) |
1da177e4 LT |
138 | { |
139 | int error; | |
140 | ||
141 | pr_debug("device class '%s': registering\n", cls->name); | |
142 | ||
23681e47 | 143 | INIT_LIST_HEAD(&cls->devices); |
1da177e4 | 144 | INIT_LIST_HEAD(&cls->interfaces); |
86406245 | 145 | kset_init(&cls->class_dirs); |
1da177e4 | 146 | init_MUTEX(&cls->sem); |
823bccfc | 147 | error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name); |
1da177e4 LT |
148 | if (error) |
149 | return error; | |
150 | ||
e105b8bf DW |
151 | /* set the default /sys/dev directory for devices of this class */ |
152 | if (!cls->dev_kobj) | |
153 | cls->dev_kobj = sysfs_dev_char_kobj; | |
154 | ||
4e886c29 | 155 | #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) |
edfaa7c3 KS |
156 | /* let the block class directory show up in the root of sysfs */ |
157 | if (cls != &block_class) | |
158 | cls->subsys.kobj.kset = class_kset; | |
159 | #else | |
443dbf90 | 160 | cls->subsys.kobj.kset = class_kset; |
edfaa7c3 | 161 | #endif |
3514faca | 162 | cls->subsys.kobj.ktype = &class_ktype; |
1da177e4 | 163 | |
2fb9113b | 164 | error = kset_register(&cls->subsys); |
1da177e4 LT |
165 | if (!error) { |
166 | error = add_class_attrs(class_get(cls)); | |
167 | class_put(cls); | |
168 | } | |
169 | return error; | |
170 | } | |
171 | ||
4a3ad20c | 172 | void class_unregister(struct class *cls) |
1da177e4 LT |
173 | { |
174 | pr_debug("device class '%s': unregistering\n", cls->name); | |
175 | remove_class_attrs(cls); | |
2fb9113b | 176 | kset_unregister(&cls->subsys); |
1da177e4 LT |
177 | } |
178 | ||
e9ba6365 GKH |
179 | static void class_create_release(struct class *cls) |
180 | { | |
2b3a302a | 181 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 GKH |
182 | kfree(cls); |
183 | } | |
184 | ||
2fc68447 GKH |
185 | /** |
186 | * class_create - create a struct class structure | |
187 | * @owner: pointer to the module that is to "own" this struct class | |
188 | * @name: pointer to a string for the name of this class. | |
189 | * | |
190 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 191 | * in calls to device_create(). |
2fc68447 GKH |
192 | * |
193 | * Note, the pointer created here is to be destroyed when finished by | |
194 | * making a call to class_destroy(). | |
195 | */ | |
ab7d7371 | 196 | struct class *class_create(struct module *owner, const char *name) |
e9ba6365 GKH |
197 | { |
198 | struct class *cls; | |
199 | int retval; | |
200 | ||
4aed0644 | 201 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 GKH |
202 | if (!cls) { |
203 | retval = -ENOMEM; | |
204 | goto error; | |
205 | } | |
e9ba6365 GKH |
206 | |
207 | cls->name = name; | |
208 | cls->owner = owner; | |
209 | cls->class_release = class_create_release; | |
e9ba6365 GKH |
210 | |
211 | retval = class_register(cls); | |
212 | if (retval) | |
213 | goto error; | |
214 | ||
215 | return cls; | |
216 | ||
217 | error: | |
218 | kfree(cls); | |
219 | return ERR_PTR(retval); | |
220 | } | |
221 | ||
2fc68447 GKH |
222 | /** |
223 | * class_destroy - destroys a struct class structure | |
92a0f861 | 224 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 GKH |
225 | * |
226 | * Note, the pointer to be destroyed must have been created with a call | |
227 | * to class_create(). | |
228 | */ | |
e9ba6365 GKH |
229 | void class_destroy(struct class *cls) |
230 | { | |
231 | if ((cls == NULL) || (IS_ERR(cls))) | |
232 | return; | |
233 | ||
234 | class_unregister(cls); | |
235 | } | |
1da177e4 | 236 | |
805fab47 KS |
237 | #ifdef CONFIG_SYSFS_DEPRECATED |
238 | char *make_class_name(const char *name, struct kobject *kobj) | |
239 | { | |
240 | char *class_name; | |
241 | int size; | |
242 | ||
243 | size = strlen(name) + strlen(kobject_name(kobj)) + 2; | |
244 | ||
245 | class_name = kmalloc(size, GFP_KERNEL); | |
246 | if (!class_name) | |
cb360bbf | 247 | return NULL; |
805fab47 KS |
248 | |
249 | strcpy(class_name, name); | |
250 | strcat(class_name, ":"); | |
251 | strcat(class_name, kobject_name(kobj)); | |
252 | return class_name; | |
253 | } | |
805fab47 KS |
254 | #endif |
255 | ||
fd04897b DY |
256 | /** |
257 | * class_for_each_device - device iterator | |
258 | * @class: the class we're iterating | |
259 | * @data: data for the callback | |
260 | * @fn: function to be called for each device | |
261 | * | |
262 | * Iterate over @class's list of devices, and call @fn for each, | |
263 | * passing it @data. | |
264 | * | |
265 | * We check the return of @fn each time. If it returns anything | |
266 | * other than 0, we break out and return that value. | |
267 | * | |
268 | * Note, we hold class->sem in this function, so it can not be | |
269 | * re-acquired in @fn, otherwise it will self-deadlocking. For | |
270 | * example, calls to add or remove class members would be verboten. | |
271 | */ | |
272 | int class_for_each_device(struct class *class, void *data, | |
273 | int (*fn)(struct device *, void *)) | |
274 | { | |
275 | struct device *dev; | |
276 | int error = 0; | |
277 | ||
278 | if (!class) | |
279 | return -EINVAL; | |
280 | down(&class->sem); | |
281 | list_for_each_entry(dev, &class->devices, node) { | |
282 | dev = get_device(dev); | |
283 | if (dev) { | |
284 | error = fn(dev, data); | |
285 | put_device(dev); | |
286 | } else | |
287 | error = -ENODEV; | |
288 | if (error) | |
289 | break; | |
290 | } | |
291 | up(&class->sem); | |
292 | ||
293 | return error; | |
294 | } | |
295 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
296 | ||
297 | /** | |
298 | * class_find_device - device iterator for locating a particular device | |
299 | * @class: the class we're iterating | |
300 | * @data: data for the match function | |
301 | * @match: function to check device | |
302 | * | |
303 | * This is similar to the class_for_each_dev() function above, but it | |
304 | * returns a reference to a device that is 'found' for later use, as | |
305 | * determined by the @match callback. | |
306 | * | |
307 | * The callback should return 0 if the device doesn't match and non-zero | |
308 | * if it does. If the callback returns non-zero, this function will | |
309 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 310 | * |
fd04897b DY |
311 | * Note, you will need to drop the reference with put_device() after use. |
312 | * | |
313 | * We hold class->sem in this function, so it can not be | |
314 | * re-acquired in @match, otherwise it will self-deadlocking. For | |
315 | * example, calls to add or remove class members would be verboten. | |
316 | */ | |
317 | struct device *class_find_device(struct class *class, void *data, | |
318 | int (*match)(struct device *, void *)) | |
319 | { | |
320 | struct device *dev; | |
321 | int found = 0; | |
322 | ||
323 | if (!class) | |
324 | return NULL; | |
325 | ||
326 | down(&class->sem); | |
327 | list_for_each_entry(dev, &class->devices, node) { | |
328 | dev = get_device(dev); | |
329 | if (dev) { | |
330 | if (match(dev, data)) { | |
331 | found = 1; | |
332 | break; | |
333 | } else | |
334 | put_device(dev); | |
335 | } else | |
336 | break; | |
337 | } | |
338 | up(&class->sem); | |
339 | ||
340 | return found ? dev : NULL; | |
341 | } | |
342 | EXPORT_SYMBOL_GPL(class_find_device); | |
343 | ||
1da177e4 LT |
344 | int class_interface_register(struct class_interface *class_intf) |
345 | { | |
346 | struct class *parent; | |
c47ed219 | 347 | struct device *dev; |
1da177e4 LT |
348 | |
349 | if (!class_intf || !class_intf->class) | |
350 | return -ENODEV; | |
351 | ||
352 | parent = class_get(class_intf->class); | |
353 | if (!parent) | |
354 | return -EINVAL; | |
355 | ||
356 | down(&parent->sem); | |
357 | list_add_tail(&class_intf->node, &parent->interfaces); | |
c47ed219 GKH |
358 | if (class_intf->add_dev) { |
359 | list_for_each_entry(dev, &parent->devices, node) | |
360 | class_intf->add_dev(dev, class_intf); | |
361 | } | |
1da177e4 LT |
362 | up(&parent->sem); |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
367 | void class_interface_unregister(struct class_interface *class_intf) | |
368 | { | |
4a3ad20c | 369 | struct class *parent = class_intf->class; |
c47ed219 | 370 | struct device *dev; |
1da177e4 LT |
371 | |
372 | if (!parent) | |
373 | return; | |
374 | ||
375 | down(&parent->sem); | |
376 | list_del_init(&class_intf->node); | |
c47ed219 GKH |
377 | if (class_intf->remove_dev) { |
378 | list_for_each_entry(dev, &parent->devices, node) | |
379 | class_intf->remove_dev(dev, class_intf); | |
380 | } | |
1da177e4 LT |
381 | up(&parent->sem); |
382 | ||
383 | class_put(parent); | |
384 | } | |
385 | ||
1da177e4 LT |
386 | int __init classes_init(void) |
387 | { | |
443dbf90 GKH |
388 | class_kset = kset_create_and_add("class", NULL, NULL); |
389 | if (!class_kset) | |
390 | return -ENOMEM; | |
1da177e4 LT |
391 | return 0; |
392 | } | |
393 | ||
394 | EXPORT_SYMBOL_GPL(class_create_file); | |
395 | EXPORT_SYMBOL_GPL(class_remove_file); | |
396 | EXPORT_SYMBOL_GPL(class_register); | |
397 | EXPORT_SYMBOL_GPL(class_unregister); | |
e9ba6365 GKH |
398 | EXPORT_SYMBOL_GPL(class_create); |
399 | EXPORT_SYMBOL_GPL(class_destroy); | |
1da177e4 | 400 | |
1da177e4 LT |
401 | EXPORT_SYMBOL_GPL(class_interface_register); |
402 | EXPORT_SYMBOL_GPL(class_interface_unregister); |