Commit | Line | Data |
---|---|---|
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> |
f75b1c60 | 21 | #include <linux/mutex.h> |
1da177e4 LT |
22 | #include "base.h" |
23 | ||
24 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
1da177e4 | 25 | |
4a3ad20c GKH |
26 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
27 | char *buf) | |
1da177e4 | 28 | { |
4a3ad20c | 29 | struct class_attribute *class_attr = to_class_attr(attr); |
7c71448b | 30 | struct class_private *cp = to_class(kobj); |
4a0c20bf | 31 | ssize_t ret = -EIO; |
1da177e4 LT |
32 | |
33 | if (class_attr->show) | |
7c71448b | 34 | ret = class_attr->show(cp->class, buf); |
1da177e4 LT |
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 | 41 | struct class_attribute *class_attr = to_class_attr(attr); |
7c71448b | 42 | struct class_private *cp = to_class(kobj); |
4a0c20bf | 43 | ssize_t ret = -EIO; |
1da177e4 LT |
44 | |
45 | if (class_attr->store) | |
7c71448b | 46 | ret = class_attr->store(cp->class, buf, count); |
1da177e4 LT |
47 | return ret; |
48 | } | |
49 | ||
4a3ad20c | 50 | static void class_release(struct kobject *kobj) |
1da177e4 | 51 | { |
7c71448b GKH |
52 | struct class_private *cp = to_class(kobj); |
53 | struct class *class = cp->class; | |
1da177e4 LT |
54 | |
55 | pr_debug("class '%s': release.\n", class->name); | |
56 | ||
57 | if (class->class_release) | |
58 | class->class_release(class); | |
59 | else | |
60 | pr_debug("class '%s' does not have a release() function, " | |
61 | "be careful\n", class->name); | |
62 | } | |
63 | ||
64 | static struct sysfs_ops class_sysfs_ops = { | |
65 | .show = class_attr_show, | |
66 | .store = class_attr_store, | |
67 | }; | |
68 | ||
adc56808 | 69 | static struct kobj_type class_ktype = { |
1da177e4 LT |
70 | .sysfs_ops = &class_sysfs_ops, |
71 | .release = class_release, | |
72 | }; | |
73 | ||
1fbfee6c | 74 | /* Hotplug events for classes go to the class class_subsys */ |
443dbf90 | 75 | static struct kset *class_kset; |
1da177e4 LT |
76 | |
77 | ||
4a3ad20c | 78 | int class_create_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
79 | { |
80 | int error; | |
4a3ad20c | 81 | if (cls) |
1fbfee6c GKH |
82 | error = sysfs_create_file(&cls->p->class_subsys.kobj, |
83 | &attr->attr); | |
4a3ad20c | 84 | else |
1da177e4 LT |
85 | error = -EINVAL; |
86 | return error; | |
87 | } | |
88 | ||
4a3ad20c | 89 | void class_remove_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
90 | { |
91 | if (cls) | |
1fbfee6c | 92 | sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr); |
1da177e4 LT |
93 | } |
94 | ||
1740757e | 95 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
96 | { |
97 | if (cls) | |
1fbfee6c | 98 | kset_get(&cls->p->class_subsys); |
7c71448b | 99 | return cls; |
1da177e4 LT |
100 | } |
101 | ||
4a3ad20c | 102 | static void class_put(struct class *cls) |
1da177e4 | 103 | { |
51d172d5 | 104 | if (cls) |
1fbfee6c | 105 | kset_put(&cls->p->class_subsys); |
1da177e4 LT |
106 | } |
107 | ||
4a3ad20c | 108 | static int add_class_attrs(struct class *cls) |
1da177e4 LT |
109 | { |
110 | int i; | |
111 | int error = 0; | |
112 | ||
113 | if (cls->class_attrs) { | |
114 | for (i = 0; attr_name(cls->class_attrs[i]); i++) { | |
4a3ad20c | 115 | error = class_create_file(cls, &cls->class_attrs[i]); |
1da177e4 | 116 | if (error) |
4a3ad20c | 117 | goto error; |
1da177e4 LT |
118 | } |
119 | } | |
4a3ad20c | 120 | done: |
1da177e4 | 121 | return error; |
4a3ad20c | 122 | error: |
1da177e4 | 123 | while (--i >= 0) |
4a3ad20c GKH |
124 | class_remove_file(cls, &cls->class_attrs[i]); |
125 | goto done; | |
1da177e4 LT |
126 | } |
127 | ||
4a3ad20c | 128 | static void remove_class_attrs(struct class *cls) |
1da177e4 LT |
129 | { |
130 | int i; | |
131 | ||
132 | if (cls->class_attrs) { | |
133 | for (i = 0; attr_name(cls->class_attrs[i]); i++) | |
4a3ad20c | 134 | class_remove_file(cls, &cls->class_attrs[i]); |
1da177e4 LT |
135 | } |
136 | } | |
137 | ||
d2a3b914 | 138 | int __class_register(struct class *cls, struct lock_class_key *key) |
1da177e4 | 139 | { |
7c71448b | 140 | struct class_private *cp; |
1da177e4 LT |
141 | int error; |
142 | ||
143 | pr_debug("device class '%s': registering\n", cls->name); | |
144 | ||
7c71448b GKH |
145 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
146 | if (!cp) | |
147 | return -ENOMEM; | |
97ae69fd | 148 | INIT_LIST_HEAD(&cp->class_devices); |
184f1f77 | 149 | INIT_LIST_HEAD(&cp->class_interfaces); |
7c71448b | 150 | kset_init(&cp->class_dirs); |
f75b1c60 | 151 | __mutex_init(&cp->class_mutex, "struct class mutex", key); |
1fbfee6c | 152 | error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name); |
7c71448b GKH |
153 | if (error) { |
154 | kfree(cp); | |
1da177e4 | 155 | return error; |
7c71448b | 156 | } |
1da177e4 | 157 | |
e105b8bf DW |
158 | /* set the default /sys/dev directory for devices of this class */ |
159 | if (!cls->dev_kobj) | |
160 | cls->dev_kobj = sysfs_dev_char_kobj; | |
161 | ||
4e886c29 | 162 | #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) |
edfaa7c3 KS |
163 | /* let the block class directory show up in the root of sysfs */ |
164 | if (cls != &block_class) | |
1fbfee6c | 165 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 166 | #else |
1fbfee6c | 167 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 168 | #endif |
1fbfee6c | 169 | cp->class_subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
170 | cp->class = cls; |
171 | cls->p = cp; | |
1da177e4 | 172 | |
1fbfee6c | 173 | error = kset_register(&cp->class_subsys); |
7c71448b GKH |
174 | if (error) { |
175 | kfree(cp); | |
176 | return error; | |
1da177e4 | 177 | } |
7c71448b GKH |
178 | error = add_class_attrs(class_get(cls)); |
179 | class_put(cls); | |
1da177e4 LT |
180 | return error; |
181 | } | |
d2a3b914 | 182 | EXPORT_SYMBOL_GPL(__class_register); |
1da177e4 | 183 | |
4a3ad20c | 184 | void class_unregister(struct class *cls) |
1da177e4 LT |
185 | { |
186 | pr_debug("device class '%s': unregistering\n", cls->name); | |
187 | remove_class_attrs(cls); | |
1fbfee6c | 188 | kset_unregister(&cls->p->class_subsys); |
1da177e4 LT |
189 | } |
190 | ||
e9ba6365 | 191 | static void class_create_release(struct class *cls) |
192 | { | |
2b3a302a | 193 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 | 194 | kfree(cls); |
195 | } | |
196 | ||
2fc68447 | 197 | /** |
198 | * class_create - create a struct class structure | |
199 | * @owner: pointer to the module that is to "own" this struct class | |
200 | * @name: pointer to a string for the name of this class. | |
0e241ffd | 201 | * @key: the lock_class_key for this class; used by mutex lock debugging |
2fc68447 | 202 | * |
203 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 204 | * in calls to device_create(). |
2fc68447 | 205 | * |
206 | * Note, the pointer created here is to be destroyed when finished by | |
207 | * making a call to class_destroy(). | |
208 | */ | |
d2a3b914 MW |
209 | struct class *__class_create(struct module *owner, const char *name, |
210 | struct lock_class_key *key) | |
e9ba6365 | 211 | { |
212 | struct class *cls; | |
213 | int retval; | |
214 | ||
4aed0644 | 215 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 | 216 | if (!cls) { |
217 | retval = -ENOMEM; | |
218 | goto error; | |
219 | } | |
e9ba6365 | 220 | |
221 | cls->name = name; | |
222 | cls->owner = owner; | |
223 | cls->class_release = class_create_release; | |
e9ba6365 | 224 | |
d2a3b914 | 225 | retval = __class_register(cls, key); |
e9ba6365 | 226 | if (retval) |
227 | goto error; | |
228 | ||
229 | return cls; | |
230 | ||
231 | error: | |
232 | kfree(cls); | |
233 | return ERR_PTR(retval); | |
234 | } | |
d2a3b914 | 235 | EXPORT_SYMBOL_GPL(__class_create); |
e9ba6365 | 236 | |
2fc68447 | 237 | /** |
238 | * class_destroy - destroys a struct class structure | |
92a0f861 | 239 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 | 240 | * |
241 | * Note, the pointer to be destroyed must have been created with a call | |
242 | * to class_create(). | |
243 | */ | |
e9ba6365 | 244 | void class_destroy(struct class *cls) |
245 | { | |
246 | if ((cls == NULL) || (IS_ERR(cls))) | |
247 | return; | |
248 | ||
249 | class_unregister(cls); | |
250 | } | |
1da177e4 | 251 | |
805fab47 KS |
252 | #ifdef CONFIG_SYSFS_DEPRECATED |
253 | char *make_class_name(const char *name, struct kobject *kobj) | |
254 | { | |
255 | char *class_name; | |
256 | int size; | |
257 | ||
258 | size = strlen(name) + strlen(kobject_name(kobj)) + 2; | |
259 | ||
260 | class_name = kmalloc(size, GFP_KERNEL); | |
261 | if (!class_name) | |
cb360bbf | 262 | return NULL; |
805fab47 KS |
263 | |
264 | strcpy(class_name, name); | |
265 | strcat(class_name, ":"); | |
266 | strcat(class_name, kobject_name(kobj)); | |
267 | return class_name; | |
268 | } | |
805fab47 KS |
269 | #endif |
270 | ||
fd04897b DY |
271 | /** |
272 | * class_for_each_device - device iterator | |
273 | * @class: the class we're iterating | |
93562b53 | 274 | * @start: the device to start with in the list, if any. |
fd04897b DY |
275 | * @data: data for the callback |
276 | * @fn: function to be called for each device | |
277 | * | |
278 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
279 | * passing it @data. If @start is set, the list iteration will start |
280 | * there, otherwise if it is NULL, the iteration starts at the | |
281 | * beginning of the list. | |
fd04897b DY |
282 | * |
283 | * We check the return of @fn each time. If it returns anything | |
284 | * other than 0, we break out and return that value. | |
285 | * | |
f75b1c60 | 286 | * Note, we hold class->class_mutex in this function, so it can not be |
fd04897b DY |
287 | * re-acquired in @fn, otherwise it will self-deadlocking. For |
288 | * example, calls to add or remove class members would be verboten. | |
289 | */ | |
93562b53 GKH |
290 | int class_for_each_device(struct class *class, struct device *start, |
291 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b DY |
292 | { |
293 | struct device *dev; | |
294 | int error = 0; | |
295 | ||
296 | if (!class) | |
297 | return -EINVAL; | |
7c225035 DB |
298 | if (!class->p) { |
299 | WARN(1, "%s called for class '%s' before it was initialized", | |
300 | __func__, class->name); | |
301 | return -EINVAL; | |
302 | } | |
303 | ||
f75b1c60 | 304 | mutex_lock(&class->p->class_mutex); |
97ae69fd | 305 | list_for_each_entry(dev, &class->p->class_devices, node) { |
93562b53 GKH |
306 | if (start) { |
307 | if (start == dev) | |
308 | start = NULL; | |
309 | continue; | |
310 | } | |
fd04897b | 311 | dev = get_device(dev); |
93562b53 GKH |
312 | error = fn(dev, data); |
313 | put_device(dev); | |
fd04897b DY |
314 | if (error) |
315 | break; | |
316 | } | |
f75b1c60 | 317 | mutex_unlock(&class->p->class_mutex); |
fd04897b DY |
318 | |
319 | return error; | |
320 | } | |
321 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
322 | ||
323 | /** | |
324 | * class_find_device - device iterator for locating a particular device | |
325 | * @class: the class we're iterating | |
695794ae | 326 | * @start: Device to begin with |
fd04897b DY |
327 | * @data: data for the match function |
328 | * @match: function to check device | |
329 | * | |
330 | * This is similar to the class_for_each_dev() function above, but it | |
331 | * returns a reference to a device that is 'found' for later use, as | |
332 | * determined by the @match callback. | |
333 | * | |
334 | * The callback should return 0 if the device doesn't match and non-zero | |
335 | * if it does. If the callback returns non-zero, this function will | |
336 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 337 | * |
fd04897b DY |
338 | * Note, you will need to drop the reference with put_device() after use. |
339 | * | |
f75b1c60 | 340 | * We hold class->class_mutex in this function, so it can not be |
fd04897b DY |
341 | * re-acquired in @match, otherwise it will self-deadlocking. For |
342 | * example, calls to add or remove class members would be verboten. | |
343 | */ | |
695794ae GKH |
344 | struct device *class_find_device(struct class *class, struct device *start, |
345 | void *data, | |
346 | int (*match)(struct device *, void *)) | |
fd04897b DY |
347 | { |
348 | struct device *dev; | |
349 | int found = 0; | |
350 | ||
351 | if (!class) | |
352 | return NULL; | |
7c225035 DB |
353 | if (!class->p) { |
354 | WARN(1, "%s called for class '%s' before it was initialized", | |
355 | __func__, class->name); | |
356 | return NULL; | |
357 | } | |
fd04897b | 358 | |
f75b1c60 | 359 | mutex_lock(&class->p->class_mutex); |
97ae69fd | 360 | list_for_each_entry(dev, &class->p->class_devices, node) { |
695794ae GKH |
361 | if (start) { |
362 | if (start == dev) | |
363 | start = NULL; | |
364 | continue; | |
365 | } | |
fd04897b | 366 | dev = get_device(dev); |
695794ae GKH |
367 | if (match(dev, data)) { |
368 | found = 1; | |
fd04897b | 369 | break; |
695794ae GKH |
370 | } else |
371 | put_device(dev); | |
fd04897b | 372 | } |
f75b1c60 | 373 | mutex_unlock(&class->p->class_mutex); |
fd04897b DY |
374 | |
375 | return found ? dev : NULL; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(class_find_device); | |
378 | ||
1da177e4 LT |
379 | int class_interface_register(struct class_interface *class_intf) |
380 | { | |
381 | struct class *parent; | |
c47ed219 | 382 | struct device *dev; |
1da177e4 LT |
383 | |
384 | if (!class_intf || !class_intf->class) | |
385 | return -ENODEV; | |
386 | ||
387 | parent = class_get(class_intf->class); | |
388 | if (!parent) | |
389 | return -EINVAL; | |
390 | ||
f75b1c60 | 391 | mutex_lock(&parent->p->class_mutex); |
184f1f77 | 392 | list_add_tail(&class_intf->node, &parent->p->class_interfaces); |
c47ed219 | 393 | if (class_intf->add_dev) { |
97ae69fd | 394 | list_for_each_entry(dev, &parent->p->class_devices, node) |
c47ed219 GKH |
395 | class_intf->add_dev(dev, class_intf); |
396 | } | |
f75b1c60 | 397 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
398 | |
399 | return 0; | |
400 | } | |
401 | ||
402 | void class_interface_unregister(struct class_interface *class_intf) | |
403 | { | |
4a3ad20c | 404 | struct class *parent = class_intf->class; |
c47ed219 | 405 | struct device *dev; |
1da177e4 LT |
406 | |
407 | if (!parent) | |
408 | return; | |
409 | ||
f75b1c60 | 410 | mutex_lock(&parent->p->class_mutex); |
1da177e4 | 411 | list_del_init(&class_intf->node); |
c47ed219 | 412 | if (class_intf->remove_dev) { |
97ae69fd | 413 | list_for_each_entry(dev, &parent->p->class_devices, node) |
c47ed219 GKH |
414 | class_intf->remove_dev(dev, class_intf); |
415 | } | |
f75b1c60 | 416 | mutex_unlock(&parent->p->class_mutex); |
1da177e4 LT |
417 | |
418 | class_put(parent); | |
419 | } | |
420 | ||
1da177e4 LT |
421 | int __init classes_init(void) |
422 | { | |
443dbf90 GKH |
423 | class_kset = kset_create_and_add("class", NULL, NULL); |
424 | if (!class_kset) | |
425 | return -ENOMEM; | |
1da177e4 LT |
426 | return 0; |
427 | } | |
428 | ||
429 | EXPORT_SYMBOL_GPL(class_create_file); | |
430 | EXPORT_SYMBOL_GPL(class_remove_file); | |
1da177e4 | 431 | EXPORT_SYMBOL_GPL(class_unregister); |
e9ba6365 | 432 | EXPORT_SYMBOL_GPL(class_destroy); |
1da177e4 | 433 | |
1da177e4 LT |
434 | EXPORT_SYMBOL_GPL(class_interface_register); |
435 | EXPORT_SYMBOL_GPL(class_interface_unregister); |