blob: 71059e32bebc989e180bee874372f24582ba10b9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#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>
gregkh@suse.dee9ba6362005-03-15 11:54:21 -080018#include <linux/err.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080019#include <linux/slab.h>
Kay Sieversedfaa7c2007-05-21 22:08:01 +020020#include <linux/genhd.h>
Dave Youngf75b1c62008-05-28 09:28:39 -070021#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "base.h"
23
24#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080026static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr,
27 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080029 struct class_attribute *class_attr = to_class_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +010030 struct subsys_private *cp = to_subsys_private(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050031 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33 if (class_attr->show)
Andi Kleen28812fe2010-01-05 12:48:07 +010034 ret = class_attr->show(cp->class, class_attr, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 return ret;
36}
37
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080038static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr,
39 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080041 struct class_attribute *class_attr = to_class_attr(attr);
Kay Sievers6b6e39a2010-11-15 23:13:18 +010042 struct subsys_private *cp = to_subsys_private(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -050043 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45 if (class_attr->store)
Andi Kleen28812fe2010-01-05 12:48:07 +010046 ret = class_attr->store(cp->class, class_attr, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 return ret;
48}
49
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080050static void class_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Kay Sievers6b6e39a2010-11-15 23:13:18 +010052 struct subsys_private *cp = to_subsys_private(kobj);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -050053 struct class *class = cp->class;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
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);
Laurent Pinchart18d19c92010-02-10 13:32:49 +010062
63 kfree(cp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064}
65
Eric W. Biedermanbc451f22010-03-30 11:31:25 -070066static const struct kobj_ns_type_operations *class_child_ns_type(struct kobject *kobj)
67{
Kay Sievers6b6e39a2010-11-15 23:13:18 +010068 struct subsys_private *cp = to_subsys_private(kobj);
Eric W. Biedermanbc451f22010-03-30 11:31:25 -070069 struct class *class = cp->class;
70
71 return class->ns_type;
72}
73
Emese Revfy52cf25d2010-01-19 02:58:23 +010074static const struct sysfs_ops class_sysfs_ops = {
Eric W. Biederman672d82c2011-10-12 21:55:08 +000075 .show = class_attr_show,
76 .store = class_attr_store,
Linus Torvalds1da177e2005-04-16 15:20:36 -070077};
78
Greg Kroah-Hartmanadc56802007-10-11 10:47:49 -060079static struct kobj_type class_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 .sysfs_ops = &class_sysfs_ops,
81 .release = class_release,
Eric W. Biedermanbc451f22010-03-30 11:31:25 -070082 .child_ns_type = class_child_ns_type,
Linus Torvalds1da177e2005-04-16 15:20:36 -070083};
84
Kay Sievers6b6e39a2010-11-15 23:13:18 +010085/* Hotplug events for classes go to the class subsys */
Greg Kroah-Hartman443dbf92007-10-29 23:22:26 -050086static struct kset *class_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88
Tejun Heo58292cbe2013-09-11 22:29:04 -040089int class_create_file_ns(struct class *cls, const struct class_attribute *attr,
90 const void *ns)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 int error;
Cosmin Tomulescud34898d2015-03-08 12:31:54 +020093
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080094 if (cls)
Tejun Heo58292cbe2013-09-11 22:29:04 -040095 error = sysfs_create_file_ns(&cls->p->subsys.kobj,
96 &attr->attr, ns);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080097 else
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 error = -EINVAL;
99 return error;
100}
101
Tejun Heo58292cbe2013-09-11 22:29:04 -0400102void class_remove_file_ns(struct class *cls, const struct class_attribute *attr,
103 const void *ns)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
105 if (cls)
Tejun Heo58292cbe2013-09-11 22:29:04 -0400106 sysfs_remove_file_ns(&cls->p->subsys.kobj, &attr->attr, ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107}
108
Greg Kroah-Hartman17407572006-05-02 16:59:59 +0200109static struct class *class_get(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 if (cls)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100112 kset_get(&cls->p->subsys);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500113 return cls;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114}
115
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800116static void class_put(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
Greg Kroah-Hartman51d172d2005-10-27 22:25:43 -0700118 if (cls)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100119 kset_put(&cls->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120}
121
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800122static int add_class_attrs(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123{
124 int i;
125 int error = 0;
126
127 if (cls->class_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700128 for (i = 0; cls->class_attrs[i].attr.name; i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800129 error = class_create_file(cls, &cls->class_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800131 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 }
133 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800134done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800136error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800138 class_remove_file(cls, &cls->class_attrs[i]);
139 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800142static void remove_class_attrs(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 int i;
145
146 if (cls->class_attrs) {
Greg Kroah-Hartman3e1026b2013-08-22 10:25:34 -0700147 for (i = 0; cls->class_attrs[i].attr.name; i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800148 class_remove_file(cls, &cls->class_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 }
150}
151
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200152static void klist_class_dev_get(struct klist_node *n)
153{
154 struct device *dev = container_of(n, struct device, knode_class);
155
156 get_device(dev);
157}
158
159static void klist_class_dev_put(struct klist_node *n)
160{
161 struct device *dev = container_of(n, struct device, knode_class);
162
163 put_device(dev);
164}
165
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700166int __class_register(struct class *cls, struct lock_class_key *key)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100168 struct subsys_private *cp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 int error;
170
171 pr_debug("device class '%s': registering\n", cls->name);
172
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500173 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
174 if (!cp)
175 return -ENOMEM;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100176 klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put);
Kay Sieversca22e562011-12-14 14:29:38 -0800177 INIT_LIST_HEAD(&cp->interfaces);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100178 kset_init(&cp->glue_dirs);
Kay Sieversca22e562011-12-14 14:29:38 -0800179 __mutex_init(&cp->mutex, "subsys mutex", key);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100180 error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500181 if (error) {
182 kfree(cp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 return error;
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500184 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Dan Williamse105b8b2008-04-21 10:51:07 -0700186 /* set the default /sys/dev directory for devices of this class */
187 if (!cls->dev_kobj)
188 cls->dev_kobj = sysfs_dev_char_kobj;
189
Andi Kleene52eec12010-09-08 16:54:17 +0200190#if defined(CONFIG_BLOCK)
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200191 /* let the block class directory show up in the root of sysfs */
Andi Kleene52eec12010-09-08 16:54:17 +0200192 if (!sysfs_deprecated || cls != &block_class)
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100193 cp->subsys.kobj.kset = class_kset;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200194#else
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100195 cp->subsys.kobj.kset = class_kset;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200196#endif
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100197 cp->subsys.kobj.ktype = &class_ktype;
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500198 cp->class = cls;
199 cls->p = cp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100201 error = kset_register(&cp->subsys);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500202 if (error) {
203 kfree(cp);
204 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 }
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500206 error = add_class_attrs(class_get(cls));
207 class_put(cls);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 return error;
209}
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700210EXPORT_SYMBOL_GPL(__class_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800212void class_unregister(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
214 pr_debug("device class '%s': unregistering\n", cls->name);
215 remove_class_attrs(cls);
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100216 kset_unregister(&cls->p->subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800219static void class_create_release(struct class *cls)
220{
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800221 pr_debug("%s called for %s\n", __func__, cls->name);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800222 kfree(cls);
223}
224
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800225/**
226 * class_create - create a struct class structure
227 * @owner: pointer to the module that is to "own" this struct class
228 * @name: pointer to a string for the name of this class.
Randy Dunlap0e241ff2008-07-24 16:58:42 -0700229 * @key: the lock_class_key for this class; used by mutex lock debugging
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800230 *
231 * This is used to create a struct class pointer that can then be used
Kay Sieversc3b19ff2008-03-12 20:47:35 +0100232 * in calls to device_create().
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800233 *
Jani Nikulaf0eae0e2010-03-11 18:11:45 +0200234 * Returns &struct class pointer on success, or ERR_PTR() on error.
235 *
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800236 * Note, the pointer created here is to be destroyed when finished by
237 * making a call to class_destroy().
238 */
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700239struct class *__class_create(struct module *owner, const char *name,
240 struct lock_class_key *key)
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800241{
242 struct class *cls;
243 int retval;
244
Jiri Slaby4aed0642005-09-13 01:25:01 -0700245 cls = kzalloc(sizeof(*cls), GFP_KERNEL);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800246 if (!cls) {
247 retval = -ENOMEM;
248 goto error;
249 }
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800250
251 cls->name = name;
252 cls->owner = owner;
253 cls->class_release = class_create_release;
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800254
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700255 retval = __class_register(cls, key);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800256 if (retval)
257 goto error;
258
259 return cls;
260
261error:
262 kfree(cls);
263 return ERR_PTR(retval);
264}
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700265EXPORT_SYMBOL_GPL(__class_create);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800266
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800267/**
268 * class_destroy - destroys a struct class structure
Rolf Eike Beer92a0f862006-09-29 01:59:13 -0700269 * @cls: pointer to the struct class that is to be destroyed
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800270 *
271 * Note, the pointer to be destroyed must have been created with a call
272 * to class_create().
273 */
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800274void class_destroy(struct class *cls)
275{
276 if ((cls == NULL) || (IS_ERR(cls)))
277 return;
278
279 class_unregister(cls);
280}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Dave Youngfd048972008-01-22 15:27:08 +0800282/**
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200283 * class_dev_iter_init - initialize class device iterator
284 * @iter: class iterator to initialize
285 * @class: the class we wanna iterate over
286 * @start: the device to start iterating from, if any
287 * @type: device_type of the devices to iterate over, NULL for all
288 *
289 * Initialize class iterator @iter such that it iterates over devices
290 * of @class. If @start is set, the list iteration will start there,
291 * otherwise if it is NULL, the iteration starts at the beginning of
292 * the list.
293 */
294void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
295 struct device *start, const struct device_type *type)
296{
297 struct klist_node *start_knode = NULL;
298
299 if (start)
300 start_knode = &start->knode_class;
Kay Sievers6b6e39a2010-11-15 23:13:18 +0100301 klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode);
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200302 iter->type = type;
303}
304EXPORT_SYMBOL_GPL(class_dev_iter_init);
305
306/**
307 * class_dev_iter_next - iterate to the next device
308 * @iter: class iterator to proceed
309 *
310 * Proceed @iter to the next device and return it. Returns NULL if
311 * iteration is complete.
312 *
313 * The returned device is referenced and won't be released till
314 * iterator is proceed to the next device or exited. The caller is
315 * free to do whatever it wants to do with the device including
316 * calling back into class code.
317 */
318struct device *class_dev_iter_next(struct class_dev_iter *iter)
319{
320 struct klist_node *knode;
321 struct device *dev;
322
323 while (1) {
324 knode = klist_next(&iter->ki);
325 if (!knode)
326 return NULL;
327 dev = container_of(knode, struct device, knode_class);
328 if (!iter->type || iter->type == dev->type)
329 return dev;
330 }
331}
332EXPORT_SYMBOL_GPL(class_dev_iter_next);
333
334/**
335 * class_dev_iter_exit - finish iteration
336 * @iter: class iterator to finish
337 *
338 * Finish an iteration. Always call this function after iteration is
339 * complete whether the iteration ran till the end or not.
340 */
341void class_dev_iter_exit(struct class_dev_iter *iter)
342{
343 klist_iter_exit(&iter->ki);
344}
345EXPORT_SYMBOL_GPL(class_dev_iter_exit);
346
347/**
Dave Youngfd048972008-01-22 15:27:08 +0800348 * class_for_each_device - device iterator
349 * @class: the class we're iterating
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400350 * @start: the device to start with in the list, if any.
Dave Youngfd048972008-01-22 15:27:08 +0800351 * @data: data for the callback
352 * @fn: function to be called for each device
353 *
354 * Iterate over @class's list of devices, and call @fn for each,
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400355 * passing it @data. If @start is set, the list iteration will start
356 * there, otherwise if it is NULL, the iteration starts at the
357 * beginning of the list.
Dave Youngfd048972008-01-22 15:27:08 +0800358 *
359 * We check the return of @fn each time. If it returns anything
360 * other than 0, we break out and return that value.
361 *
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200362 * @fn is allowed to do anything including calling back into class
363 * code. There's no locking restriction.
Dave Youngfd048972008-01-22 15:27:08 +0800364 */
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400365int class_for_each_device(struct class *class, struct device *start,
366 void *data, int (*fn)(struct device *, void *))
Dave Youngfd048972008-01-22 15:27:08 +0800367{
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200368 struct class_dev_iter iter;
Dave Youngfd048972008-01-22 15:27:08 +0800369 struct device *dev;
370 int error = 0;
371
372 if (!class)
373 return -EINVAL;
David Brownell7c225032008-08-06 18:52:44 -0700374 if (!class->p) {
375 WARN(1, "%s called for class '%s' before it was initialized",
376 __func__, class->name);
377 return -EINVAL;
378 }
379
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200380 class_dev_iter_init(&iter, class, start, NULL);
381 while ((dev = class_dev_iter_next(&iter))) {
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400382 error = fn(dev, data);
Dave Youngfd048972008-01-22 15:27:08 +0800383 if (error)
384 break;
385 }
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200386 class_dev_iter_exit(&iter);
Dave Youngfd048972008-01-22 15:27:08 +0800387
388 return error;
389}
390EXPORT_SYMBOL_GPL(class_for_each_device);
391
392/**
393 * class_find_device - device iterator for locating a particular device
394 * @class: the class we're iterating
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400395 * @start: Device to begin with
Dave Youngfd048972008-01-22 15:27:08 +0800396 * @data: data for the match function
397 * @match: function to check device
398 *
399 * This is similar to the class_for_each_dev() function above, but it
400 * returns a reference to a device that is 'found' for later use, as
401 * determined by the @match callback.
402 *
403 * The callback should return 0 if the device doesn't match and non-zero
404 * if it does. If the callback returns non-zero, this function will
405 * return to the caller and not iterate over any more devices.
Randy Dunlapa63ca8f2008-01-30 11:51:08 -0800406 *
Dave Youngfd048972008-01-22 15:27:08 +0800407 * Note, you will need to drop the reference with put_device() after use.
408 *
Rolf Eike Beer12077752015-09-04 20:49:14 +0200409 * @match is allowed to do anything including calling back into class
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200410 * code. There's no locking restriction.
Dave Youngfd048972008-01-22 15:27:08 +0800411 */
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400412struct device *class_find_device(struct class *class, struct device *start,
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100413 const void *data,
414 int (*match)(struct device *, const void *))
Dave Youngfd048972008-01-22 15:27:08 +0800415{
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200416 struct class_dev_iter iter;
Dave Youngfd048972008-01-22 15:27:08 +0800417 struct device *dev;
Dave Youngfd048972008-01-22 15:27:08 +0800418
419 if (!class)
420 return NULL;
David Brownell7c225032008-08-06 18:52:44 -0700421 if (!class->p) {
422 WARN(1, "%s called for class '%s' before it was initialized",
423 __func__, class->name);
424 return NULL;
425 }
Dave Youngfd048972008-01-22 15:27:08 +0800426
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200427 class_dev_iter_init(&iter, class, start, NULL);
428 while ((dev = class_dev_iter_next(&iter))) {
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400429 if (match(dev, data)) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200430 get_device(dev);
Dave Youngfd048972008-01-22 15:27:08 +0800431 break;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200432 }
Dave Youngfd048972008-01-22 15:27:08 +0800433 }
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200434 class_dev_iter_exit(&iter);
Dave Youngfd048972008-01-22 15:27:08 +0800435
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200436 return dev;
Dave Youngfd048972008-01-22 15:27:08 +0800437}
438EXPORT_SYMBOL_GPL(class_find_device);
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440int class_interface_register(struct class_interface *class_intf)
441{
442 struct class *parent;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200443 struct class_dev_iter iter;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200444 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446 if (!class_intf || !class_intf->class)
447 return -ENODEV;
448
449 parent = class_get(class_intf->class);
450 if (!parent)
451 return -EINVAL;
452
Kay Sieversca22e562011-12-14 14:29:38 -0800453 mutex_lock(&parent->p->mutex);
454 list_add_tail(&class_intf->node, &parent->p->interfaces);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200455 if (class_intf->add_dev) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200456 class_dev_iter_init(&iter, parent, NULL, NULL);
457 while ((dev = class_dev_iter_next(&iter)))
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200458 class_intf->add_dev(dev, class_intf);
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200459 class_dev_iter_exit(&iter);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200460 }
Kay Sieversca22e562011-12-14 14:29:38 -0800461 mutex_unlock(&parent->p->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
463 return 0;
464}
465
466void class_interface_unregister(struct class_interface *class_intf)
467{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800468 struct class *parent = class_intf->class;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200469 struct class_dev_iter iter;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200470 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 if (!parent)
473 return;
474
Kay Sieversca22e562011-12-14 14:29:38 -0800475 mutex_lock(&parent->p->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 list_del_init(&class_intf->node);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200477 if (class_intf->remove_dev) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200478 class_dev_iter_init(&iter, parent, NULL, NULL);
479 while ((dev = class_dev_iter_next(&iter)))
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200480 class_intf->remove_dev(dev, class_intf);
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200481 class_dev_iter_exit(&iter);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200482 }
Kay Sieversca22e562011-12-14 14:29:38 -0800483 mutex_unlock(&parent->p->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485 class_put(parent);
486}
487
Brandon Philips319684b2010-11-06 21:19:22 -0400488ssize_t show_class_attr_string(struct class *class,
489 struct class_attribute *attr, char *buf)
Andi Kleen869dfc82010-01-05 12:48:08 +0100490{
491 struct class_attribute_string *cs;
Cosmin Tomulescud34898d2015-03-08 12:31:54 +0200492
Andi Kleen869dfc82010-01-05 12:48:08 +0100493 cs = container_of(attr, struct class_attribute_string, attr);
494 return snprintf(buf, PAGE_SIZE, "%s\n", cs->str);
495}
496
497EXPORT_SYMBOL_GPL(show_class_attr_string);
498
Jean Delvare46227092009-08-04 12:55:34 +0200499struct class_compat {
500 struct kobject *kobj;
501};
502
503/**
504 * class_compat_register - register a compatibility class
505 * @name: the name of the class
506 *
507 * Compatibility class are meant as a temporary user-space compatibility
508 * workaround when converting a family of class devices to a bus devices.
509 */
510struct class_compat *class_compat_register(const char *name)
511{
512 struct class_compat *cls;
513
514 cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL);
515 if (!cls)
516 return NULL;
517 cls->kobj = kobject_create_and_add(name, &class_kset->kobj);
518 if (!cls->kobj) {
519 kfree(cls);
520 return NULL;
521 }
522 return cls;
523}
524EXPORT_SYMBOL_GPL(class_compat_register);
525
526/**
527 * class_compat_unregister - unregister a compatibility class
528 * @cls: the class to unregister
529 */
530void class_compat_unregister(struct class_compat *cls)
531{
532 kobject_put(cls->kobj);
533 kfree(cls);
534}
535EXPORT_SYMBOL_GPL(class_compat_unregister);
536
537/**
538 * class_compat_create_link - create a compatibility class device link to
539 * a bus device
540 * @cls: the compatibility class
541 * @dev: the target bus device
542 * @device_link: an optional device to which a "device" link should be created
543 */
544int class_compat_create_link(struct class_compat *cls, struct device *dev,
545 struct device *device_link)
546{
547 int error;
548
549 error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev));
550 if (error)
551 return error;
552
553 /*
554 * Optionally add a "device" link (typically to the parent), as a
555 * class device would have one and we want to provide as much
556 * backwards compatibility as possible.
557 */
558 if (device_link) {
559 error = sysfs_create_link(&dev->kobj, &device_link->kobj,
560 "device");
561 if (error)
562 sysfs_remove_link(cls->kobj, dev_name(dev));
563 }
564
565 return error;
566}
567EXPORT_SYMBOL_GPL(class_compat_create_link);
568
569/**
570 * class_compat_remove_link - remove a compatibility class device link to
571 * a bus device
572 * @cls: the compatibility class
573 * @dev: the target bus device
574 * @device_link: an optional device to which a "device" link was previously
575 * created
576 */
577void class_compat_remove_link(struct class_compat *cls, struct device *dev,
578 struct device *device_link)
579{
580 if (device_link)
581 sysfs_remove_link(&dev->kobj, "device");
582 sysfs_remove_link(cls->kobj, dev_name(dev));
583}
584EXPORT_SYMBOL_GPL(class_compat_remove_link);
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586int __init classes_init(void)
587{
Greg Kroah-Hartman443dbf92007-10-29 23:22:26 -0500588 class_kset = kset_create_and_add("class", NULL, NULL);
589 if (!class_kset)
590 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 return 0;
592}
593
Tejun Heo58292cbe2013-09-11 22:29:04 -0400594EXPORT_SYMBOL_GPL(class_create_file_ns);
595EXPORT_SYMBOL_GPL(class_remove_file_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596EXPORT_SYMBOL_GPL(class_unregister);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800597EXPORT_SYMBOL_GPL(class_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599EXPORT_SYMBOL_GPL(class_interface_register);
600EXPORT_SYMBOL_GPL(class_interface_unregister);