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> |
1da177e4 LT |
21 | #include "base.h" |
22 | ||
23 | #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) | |
1da177e4 | 24 | |
4a3ad20c GKH |
25 | static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr, |
26 | char *buf) | |
1da177e4 | 27 | { |
4a3ad20c | 28 | struct class_attribute *class_attr = to_class_attr(attr); |
7c71448b | 29 | struct class_private *cp = to_class(kobj); |
4a0c20bf | 30 | ssize_t ret = -EIO; |
1da177e4 LT |
31 | |
32 | if (class_attr->show) | |
7c71448b | 33 | ret = class_attr->show(cp->class, buf); |
1da177e4 LT |
34 | return ret; |
35 | } | |
36 | ||
4a3ad20c GKH |
37 | static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr, |
38 | const char *buf, size_t count) | |
1da177e4 | 39 | { |
4a3ad20c | 40 | struct class_attribute *class_attr = to_class_attr(attr); |
7c71448b | 41 | struct class_private *cp = to_class(kobj); |
4a0c20bf | 42 | ssize_t ret = -EIO; |
1da177e4 LT |
43 | |
44 | if (class_attr->store) | |
7c71448b | 45 | ret = class_attr->store(cp->class, buf, count); |
1da177e4 LT |
46 | return ret; |
47 | } | |
48 | ||
4a3ad20c | 49 | static void class_release(struct kobject *kobj) |
1da177e4 | 50 | { |
7c71448b GKH |
51 | struct class_private *cp = to_class(kobj); |
52 | struct class *class = cp->class; | |
1da177e4 LT |
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 | ||
1fbfee6c | 73 | /* Hotplug events for classes go to the class class_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) |
1fbfee6c GKH |
81 | error = sysfs_create_file(&cls->p->class_subsys.kobj, |
82 | &attr->attr); | |
4a3ad20c | 83 | else |
1da177e4 LT |
84 | error = -EINVAL; |
85 | return error; | |
86 | } | |
87 | ||
4a3ad20c | 88 | void class_remove_file(struct class *cls, const struct class_attribute *attr) |
1da177e4 LT |
89 | { |
90 | if (cls) | |
1fbfee6c | 91 | sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr); |
1da177e4 LT |
92 | } |
93 | ||
1740757e | 94 | static struct class *class_get(struct class *cls) |
1da177e4 LT |
95 | { |
96 | if (cls) | |
1fbfee6c | 97 | kset_get(&cls->p->class_subsys); |
7c71448b | 98 | return cls; |
1da177e4 LT |
99 | } |
100 | ||
4a3ad20c | 101 | static void class_put(struct class *cls) |
1da177e4 | 102 | { |
51d172d5 | 103 | if (cls) |
1fbfee6c | 104 | kset_put(&cls->p->class_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 | 138 | { |
7c71448b | 139 | struct class_private *cp; |
1da177e4 LT |
140 | int error; |
141 | ||
142 | pr_debug("device class '%s': registering\n", cls->name); | |
143 | ||
7c71448b GKH |
144 | cp = kzalloc(sizeof(*cp), GFP_KERNEL); |
145 | if (!cp) | |
146 | return -ENOMEM; | |
97ae69fd | 147 | INIT_LIST_HEAD(&cp->class_devices); |
184f1f77 | 148 | INIT_LIST_HEAD(&cp->class_interfaces); |
7c71448b | 149 | kset_init(&cp->class_dirs); |
d9a01573 | 150 | init_MUTEX(&cp->class_sem); |
1fbfee6c | 151 | error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name); |
7c71448b GKH |
152 | if (error) { |
153 | kfree(cp); | |
1da177e4 | 154 | return error; |
7c71448b | 155 | } |
1da177e4 | 156 | |
e105b8bf DW |
157 | /* set the default /sys/dev directory for devices of this class */ |
158 | if (!cls->dev_kobj) | |
159 | cls->dev_kobj = sysfs_dev_char_kobj; | |
160 | ||
4e886c29 | 161 | #if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) |
edfaa7c3 KS |
162 | /* let the block class directory show up in the root of sysfs */ |
163 | if (cls != &block_class) | |
1fbfee6c | 164 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 165 | #else |
1fbfee6c | 166 | cp->class_subsys.kobj.kset = class_kset; |
edfaa7c3 | 167 | #endif |
1fbfee6c | 168 | cp->class_subsys.kobj.ktype = &class_ktype; |
7c71448b GKH |
169 | cp->class = cls; |
170 | cls->p = cp; | |
1da177e4 | 171 | |
1fbfee6c | 172 | error = kset_register(&cp->class_subsys); |
7c71448b GKH |
173 | if (error) { |
174 | kfree(cp); | |
175 | return error; | |
1da177e4 | 176 | } |
7c71448b GKH |
177 | error = add_class_attrs(class_get(cls)); |
178 | class_put(cls); | |
1da177e4 LT |
179 | return error; |
180 | } | |
181 | ||
4a3ad20c | 182 | void class_unregister(struct class *cls) |
1da177e4 LT |
183 | { |
184 | pr_debug("device class '%s': unregistering\n", cls->name); | |
185 | remove_class_attrs(cls); | |
1fbfee6c | 186 | kset_unregister(&cls->p->class_subsys); |
1da177e4 LT |
187 | } |
188 | ||
e9ba6365 | 189 | static void class_create_release(struct class *cls) |
190 | { | |
2b3a302a | 191 | pr_debug("%s called for %s\n", __func__, cls->name); |
e9ba6365 | 192 | kfree(cls); |
193 | } | |
194 | ||
2fc68447 | 195 | /** |
196 | * class_create - create a struct class structure | |
197 | * @owner: pointer to the module that is to "own" this struct class | |
198 | * @name: pointer to a string for the name of this class. | |
199 | * | |
200 | * This is used to create a struct class pointer that can then be used | |
c3b19ff0 | 201 | * in calls to device_create(). |
2fc68447 | 202 | * |
203 | * Note, the pointer created here is to be destroyed when finished by | |
204 | * making a call to class_destroy(). | |
205 | */ | |
ab7d7371 | 206 | struct class *class_create(struct module *owner, const char *name) |
e9ba6365 | 207 | { |
208 | struct class *cls; | |
209 | int retval; | |
210 | ||
4aed0644 | 211 | cls = kzalloc(sizeof(*cls), GFP_KERNEL); |
e9ba6365 | 212 | if (!cls) { |
213 | retval = -ENOMEM; | |
214 | goto error; | |
215 | } | |
e9ba6365 | 216 | |
217 | cls->name = name; | |
218 | cls->owner = owner; | |
219 | cls->class_release = class_create_release; | |
e9ba6365 | 220 | |
221 | retval = class_register(cls); | |
222 | if (retval) | |
223 | goto error; | |
224 | ||
225 | return cls; | |
226 | ||
227 | error: | |
228 | kfree(cls); | |
229 | return ERR_PTR(retval); | |
230 | } | |
231 | ||
2fc68447 | 232 | /** |
233 | * class_destroy - destroys a struct class structure | |
92a0f861 | 234 | * @cls: pointer to the struct class that is to be destroyed |
2fc68447 | 235 | * |
236 | * Note, the pointer to be destroyed must have been created with a call | |
237 | * to class_create(). | |
238 | */ | |
e9ba6365 | 239 | void class_destroy(struct class *cls) |
240 | { | |
241 | if ((cls == NULL) || (IS_ERR(cls))) | |
242 | return; | |
243 | ||
244 | class_unregister(cls); | |
245 | } | |
1da177e4 | 246 | |
805fab47 KS |
247 | #ifdef CONFIG_SYSFS_DEPRECATED |
248 | char *make_class_name(const char *name, struct kobject *kobj) | |
249 | { | |
250 | char *class_name; | |
251 | int size; | |
252 | ||
253 | size = strlen(name) + strlen(kobject_name(kobj)) + 2; | |
254 | ||
255 | class_name = kmalloc(size, GFP_KERNEL); | |
256 | if (!class_name) | |
cb360bbf | 257 | return NULL; |
805fab47 KS |
258 | |
259 | strcpy(class_name, name); | |
260 | strcat(class_name, ":"); | |
261 | strcat(class_name, kobject_name(kobj)); | |
262 | return class_name; | |
263 | } | |
805fab47 KS |
264 | #endif |
265 | ||
fd04897b DY |
266 | /** |
267 | * class_for_each_device - device iterator | |
268 | * @class: the class we're iterating | |
93562b53 | 269 | * @start: the device to start with in the list, if any. |
fd04897b DY |
270 | * @data: data for the callback |
271 | * @fn: function to be called for each device | |
272 | * | |
273 | * Iterate over @class's list of devices, and call @fn for each, | |
93562b53 GKH |
274 | * passing it @data. If @start is set, the list iteration will start |
275 | * there, otherwise if it is NULL, the iteration starts at the | |
276 | * beginning of the list. | |
fd04897b DY |
277 | * |
278 | * We check the return of @fn each time. If it returns anything | |
279 | * other than 0, we break out and return that value. | |
280 | * | |
d9a01573 | 281 | * Note, we hold class->class_sem in this function, so it can not be |
fd04897b DY |
282 | * re-acquired in @fn, otherwise it will self-deadlocking. For |
283 | * example, calls to add or remove class members would be verboten. | |
284 | */ | |
93562b53 GKH |
285 | int class_for_each_device(struct class *class, struct device *start, |
286 | void *data, int (*fn)(struct device *, void *)) | |
fd04897b DY |
287 | { |
288 | struct device *dev; | |
289 | int error = 0; | |
290 | ||
291 | if (!class) | |
292 | return -EINVAL; | |
d9a01573 | 293 | down(&class->p->class_sem); |
97ae69fd | 294 | list_for_each_entry(dev, &class->p->class_devices, node) { |
93562b53 GKH |
295 | if (start) { |
296 | if (start == dev) | |
297 | start = NULL; | |
298 | continue; | |
299 | } | |
fd04897b | 300 | dev = get_device(dev); |
93562b53 GKH |
301 | error = fn(dev, data); |
302 | put_device(dev); | |
fd04897b DY |
303 | if (error) |
304 | break; | |
305 | } | |
d9a01573 | 306 | up(&class->p->class_sem); |
fd04897b DY |
307 | |
308 | return error; | |
309 | } | |
310 | EXPORT_SYMBOL_GPL(class_for_each_device); | |
311 | ||
312 | /** | |
313 | * class_find_device - device iterator for locating a particular device | |
314 | * @class: the class we're iterating | |
695794ae | 315 | * @start: Device to begin with |
fd04897b DY |
316 | * @data: data for the match function |
317 | * @match: function to check device | |
318 | * | |
319 | * This is similar to the class_for_each_dev() function above, but it | |
320 | * returns a reference to a device that is 'found' for later use, as | |
321 | * determined by the @match callback. | |
322 | * | |
323 | * The callback should return 0 if the device doesn't match and non-zero | |
324 | * if it does. If the callback returns non-zero, this function will | |
325 | * return to the caller and not iterate over any more devices. | |
a63ca8f6 | 326 | * |
fd04897b DY |
327 | * Note, you will need to drop the reference with put_device() after use. |
328 | * | |
d9a01573 | 329 | * We hold class->class_sem in this function, so it can not be |
fd04897b DY |
330 | * re-acquired in @match, otherwise it will self-deadlocking. For |
331 | * example, calls to add or remove class members would be verboten. | |
332 | */ | |
695794ae GKH |
333 | struct device *class_find_device(struct class *class, struct device *start, |
334 | void *data, | |
335 | int (*match)(struct device *, void *)) | |
fd04897b DY |
336 | { |
337 | struct device *dev; | |
338 | int found = 0; | |
339 | ||
340 | if (!class) | |
341 | return NULL; | |
342 | ||
d9a01573 | 343 | down(&class->p->class_sem); |
97ae69fd | 344 | list_for_each_entry(dev, &class->p->class_devices, node) { |
695794ae GKH |
345 | if (start) { |
346 | if (start == dev) | |
347 | start = NULL; | |
348 | continue; | |
349 | } | |
fd04897b | 350 | dev = get_device(dev); |
695794ae GKH |
351 | if (match(dev, data)) { |
352 | found = 1; | |
fd04897b | 353 | break; |
695794ae GKH |
354 | } else |
355 | put_device(dev); | |
fd04897b | 356 | } |
d9a01573 | 357 | up(&class->p->class_sem); |
fd04897b DY |
358 | |
359 | return found ? dev : NULL; | |
360 | } | |
361 | EXPORT_SYMBOL_GPL(class_find_device); | |
362 | ||
1da177e4 LT |
363 | int class_interface_register(struct class_interface *class_intf) |
364 | { | |
365 | struct class *parent; | |
c47ed219 | 366 | struct device *dev; |
1da177e4 LT |
367 | |
368 | if (!class_intf || !class_intf->class) | |
369 | return -ENODEV; | |
370 | ||
371 | parent = class_get(class_intf->class); | |
372 | if (!parent) | |
373 | return -EINVAL; | |
374 | ||
d9a01573 | 375 | down(&parent->p->class_sem); |
184f1f77 | 376 | list_add_tail(&class_intf->node, &parent->p->class_interfaces); |
c47ed219 | 377 | if (class_intf->add_dev) { |
97ae69fd | 378 | list_for_each_entry(dev, &parent->p->class_devices, node) |
c47ed219 GKH |
379 | class_intf->add_dev(dev, class_intf); |
380 | } | |
d9a01573 | 381 | up(&parent->p->class_sem); |
1da177e4 LT |
382 | |
383 | return 0; | |
384 | } | |
385 | ||
386 | void class_interface_unregister(struct class_interface *class_intf) | |
387 | { | |
4a3ad20c | 388 | struct class *parent = class_intf->class; |
c47ed219 | 389 | struct device *dev; |
1da177e4 LT |
390 | |
391 | if (!parent) | |
392 | return; | |
393 | ||
d9a01573 | 394 | down(&parent->p->class_sem); |
1da177e4 | 395 | list_del_init(&class_intf->node); |
c47ed219 | 396 | if (class_intf->remove_dev) { |
97ae69fd | 397 | list_for_each_entry(dev, &parent->p->class_devices, node) |
c47ed219 GKH |
398 | class_intf->remove_dev(dev, class_intf); |
399 | } | |
d9a01573 | 400 | up(&parent->p->class_sem); |
1da177e4 LT |
401 | |
402 | class_put(parent); | |
403 | } | |
404 | ||
1da177e4 LT |
405 | int __init classes_init(void) |
406 | { | |
443dbf90 GKH |
407 | class_kset = kset_create_and_add("class", NULL, NULL); |
408 | if (!class_kset) | |
409 | return -ENOMEM; | |
1da177e4 LT |
410 | return 0; |
411 | } | |
412 | ||
413 | EXPORT_SYMBOL_GPL(class_create_file); | |
414 | EXPORT_SYMBOL_GPL(class_remove_file); | |
415 | EXPORT_SYMBOL_GPL(class_register); | |
416 | EXPORT_SYMBOL_GPL(class_unregister); | |
e9ba6365 | 417 | EXPORT_SYMBOL_GPL(class_create); |
418 | EXPORT_SYMBOL_GPL(class_destroy); | |
1da177e4 | 419 | |
1da177e4 LT |
420 | EXPORT_SYMBOL_GPL(class_interface_register); |
421 | EXPORT_SYMBOL_GPL(class_interface_unregister); |