blob: 9c63a5687d694345bc80676238ffda81d7087256 [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);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -050030 struct class_private *cp = to_class(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);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -050042 struct class_private *cp = to_class(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{
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -050052 struct class_private *cp = to_class(kobj);
53 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{
68 struct class_private *cp = to_class(kobj);
69 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 = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 .show = class_attr_show,
76 .store = class_attr_store,
77};
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
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -070085/* Hotplug events for classes go to the class class_subsys */
Greg Kroah-Hartman443dbf92007-10-29 23:22:26 -050086static struct kset *class_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080089int class_create_file(struct class *cls, const struct class_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
91 int error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080092 if (cls)
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -070093 error = sysfs_create_file(&cls->p->class_subsys.kobj,
94 &attr->attr);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -080095 else
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 error = -EINVAL;
97 return error;
98}
99
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800100void class_remove_file(struct class *cls, const struct class_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101{
102 if (cls)
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700103 sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104}
105
Greg Kroah-Hartman17407572006-05-02 16:59:59 +0200106static struct class *class_get(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
108 if (cls)
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700109 kset_get(&cls->p->class_subsys);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500110 return cls;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800113static void class_put(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
Greg Kroah-Hartman51d172d2005-10-27 22:25:43 -0700115 if (cls)
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700116 kset_put(&cls->p->class_subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117}
118
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800119static int add_class_attrs(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
121 int i;
122 int error = 0;
123
124 if (cls->class_attrs) {
125 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800126 error = class_create_file(cls, &cls->class_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 if (error)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800128 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 }
130 }
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800131done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 return error;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800133error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 while (--i >= 0)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800135 class_remove_file(cls, &cls->class_attrs[i]);
136 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137}
138
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800139static void remove_class_attrs(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140{
141 int i;
142
143 if (cls->class_attrs) {
144 for (i = 0; attr_name(cls->class_attrs[i]); i++)
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800145 class_remove_file(cls, &cls->class_attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147}
148
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200149static void klist_class_dev_get(struct klist_node *n)
150{
151 struct device *dev = container_of(n, struct device, knode_class);
152
153 get_device(dev);
154}
155
156static void klist_class_dev_put(struct klist_node *n)
157{
158 struct device *dev = container_of(n, struct device, knode_class);
159
160 put_device(dev);
161}
162
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700163int __class_register(struct class *cls, struct lock_class_key *key)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500165 struct class_private *cp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 int error;
167
168 pr_debug("device class '%s': registering\n", cls->name);
169
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500170 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
171 if (!cp)
172 return -ENOMEM;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200173 klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put);
Greg Kroah-Hartman184f1f72008-05-28 09:28:39 -0700174 INIT_LIST_HEAD(&cp->class_interfaces);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500175 kset_init(&cp->class_dirs);
Dave Youngf75b1c62008-05-28 09:28:39 -0700176 __mutex_init(&cp->class_mutex, "struct class mutex", key);
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700177 error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500178 if (error) {
179 kfree(cp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 return error;
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500181 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Dan Williamse105b8b2008-04-21 10:51:07 -0700183 /* set the default /sys/dev directory for devices of this class */
184 if (!cls->dev_kobj)
185 cls->dev_kobj = sysfs_dev_char_kobj;
186
Andi Kleene52eec12010-09-08 16:54:17 +0200187#if defined(CONFIG_BLOCK)
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200188 /* let the block class directory show up in the root of sysfs */
Andi Kleene52eec12010-09-08 16:54:17 +0200189 if (!sysfs_deprecated || cls != &block_class)
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700190 cp->class_subsys.kobj.kset = class_kset;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200191#else
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700192 cp->class_subsys.kobj.kset = class_kset;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200193#endif
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700194 cp->class_subsys.kobj.ktype = &class_ktype;
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500195 cp->class = cls;
196 cls->p = cp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700198 error = kset_register(&cp->class_subsys);
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500199 if (error) {
200 kfree(cp);
201 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
Greg Kroah-Hartman7c714482008-01-22 18:17:41 -0500203 error = add_class_attrs(class_get(cls));
204 class_put(cls);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 return error;
206}
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700207EXPORT_SYMBOL_GPL(__class_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800209void class_unregister(struct class *cls)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210{
211 pr_debug("device class '%s': unregistering\n", cls->name);
212 remove_class_attrs(cls);
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -0700213 kset_unregister(&cls->p->class_subsys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214}
215
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800216static void class_create_release(struct class *cls)
217{
Harvey Harrison2b3a3022008-03-04 16:41:05 -0800218 pr_debug("%s called for %s\n", __func__, cls->name);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800219 kfree(cls);
220}
221
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800222/**
223 * class_create - create a struct class structure
224 * @owner: pointer to the module that is to "own" this struct class
225 * @name: pointer to a string for the name of this class.
Randy Dunlap0e241ff2008-07-24 16:58:42 -0700226 * @key: the lock_class_key for this class; used by mutex lock debugging
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800227 *
228 * This is used to create a struct class pointer that can then be used
Kay Sieversc3b19ff2008-03-12 20:47:35 +0100229 * in calls to device_create().
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800230 *
Jani Nikulaf0eae0e2010-03-11 18:11:45 +0200231 * Returns &struct class pointer on success, or ERR_PTR() on error.
232 *
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800233 * Note, the pointer created here is to be destroyed when finished by
234 * making a call to class_destroy().
235 */
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700236struct class *__class_create(struct module *owner, const char *name,
237 struct lock_class_key *key)
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800238{
239 struct class *cls;
240 int retval;
241
Jiri Slaby4aed0642005-09-13 01:25:01 -0700242 cls = kzalloc(sizeof(*cls), GFP_KERNEL);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800243 if (!cls) {
244 retval = -ENOMEM;
245 goto error;
246 }
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800247
248 cls->name = name;
249 cls->owner = owner;
250 cls->class_release = class_create_release;
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800251
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700252 retval = __class_register(cls, key);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800253 if (retval)
254 goto error;
255
256 return cls;
257
258error:
259 kfree(cls);
260 return ERR_PTR(retval);
261}
Matthew Wilcoxd2a3b912008-05-28 09:28:39 -0700262EXPORT_SYMBOL_GPL(__class_create);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800263
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800264/**
265 * class_destroy - destroys a struct class structure
Rolf Eike Beer92a0f862006-09-29 01:59:13 -0700266 * @cls: pointer to the struct class that is to be destroyed
gregkh@suse.de2fc68442005-03-23 10:02:56 -0800267 *
268 * Note, the pointer to be destroyed must have been created with a call
269 * to class_create().
270 */
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800271void class_destroy(struct class *cls)
272{
273 if ((cls == NULL) || (IS_ERR(cls)))
274 return;
275
276 class_unregister(cls);
277}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Dave Youngfd048972008-01-22 15:27:08 +0800279/**
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200280 * class_dev_iter_init - initialize class device iterator
281 * @iter: class iterator to initialize
282 * @class: the class we wanna iterate over
283 * @start: the device to start iterating from, if any
284 * @type: device_type of the devices to iterate over, NULL for all
285 *
286 * Initialize class iterator @iter such that it iterates over devices
287 * of @class. If @start is set, the list iteration will start there,
288 * otherwise if it is NULL, the iteration starts at the beginning of
289 * the list.
290 */
291void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
292 struct device *start, const struct device_type *type)
293{
294 struct klist_node *start_knode = NULL;
295
296 if (start)
297 start_knode = &start->knode_class;
298 klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode);
299 iter->type = type;
300}
301EXPORT_SYMBOL_GPL(class_dev_iter_init);
302
303/**
304 * class_dev_iter_next - iterate to the next device
305 * @iter: class iterator to proceed
306 *
307 * Proceed @iter to the next device and return it. Returns NULL if
308 * iteration is complete.
309 *
310 * The returned device is referenced and won't be released till
311 * iterator is proceed to the next device or exited. The caller is
312 * free to do whatever it wants to do with the device including
313 * calling back into class code.
314 */
315struct device *class_dev_iter_next(struct class_dev_iter *iter)
316{
317 struct klist_node *knode;
318 struct device *dev;
319
320 while (1) {
321 knode = klist_next(&iter->ki);
322 if (!knode)
323 return NULL;
324 dev = container_of(knode, struct device, knode_class);
325 if (!iter->type || iter->type == dev->type)
326 return dev;
327 }
328}
329EXPORT_SYMBOL_GPL(class_dev_iter_next);
330
331/**
332 * class_dev_iter_exit - finish iteration
333 * @iter: class iterator to finish
334 *
335 * Finish an iteration. Always call this function after iteration is
336 * complete whether the iteration ran till the end or not.
337 */
338void class_dev_iter_exit(struct class_dev_iter *iter)
339{
340 klist_iter_exit(&iter->ki);
341}
342EXPORT_SYMBOL_GPL(class_dev_iter_exit);
343
344/**
Dave Youngfd048972008-01-22 15:27:08 +0800345 * class_for_each_device - device iterator
346 * @class: the class we're iterating
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400347 * @start: the device to start with in the list, if any.
Dave Youngfd048972008-01-22 15:27:08 +0800348 * @data: data for the callback
349 * @fn: function to be called for each device
350 *
351 * Iterate over @class's list of devices, and call @fn for each,
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400352 * passing it @data. If @start is set, the list iteration will start
353 * there, otherwise if it is NULL, the iteration starts at the
354 * beginning of the list.
Dave Youngfd048972008-01-22 15:27:08 +0800355 *
356 * We check the return of @fn each time. If it returns anything
357 * other than 0, we break out and return that value.
358 *
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200359 * @fn is allowed to do anything including calling back into class
360 * code. There's no locking restriction.
Dave Youngfd048972008-01-22 15:27:08 +0800361 */
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400362int class_for_each_device(struct class *class, struct device *start,
363 void *data, int (*fn)(struct device *, void *))
Dave Youngfd048972008-01-22 15:27:08 +0800364{
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200365 struct class_dev_iter iter;
Dave Youngfd048972008-01-22 15:27:08 +0800366 struct device *dev;
367 int error = 0;
368
369 if (!class)
370 return -EINVAL;
David Brownell7c225032008-08-06 18:52:44 -0700371 if (!class->p) {
372 WARN(1, "%s called for class '%s' before it was initialized",
373 __func__, class->name);
374 return -EINVAL;
375 }
376
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200377 class_dev_iter_init(&iter, class, start, NULL);
378 while ((dev = class_dev_iter_next(&iter))) {
Greg Kroah-Hartman93562b52008-05-22 17:21:08 -0400379 error = fn(dev, data);
Dave Youngfd048972008-01-22 15:27:08 +0800380 if (error)
381 break;
382 }
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200383 class_dev_iter_exit(&iter);
Dave Youngfd048972008-01-22 15:27:08 +0800384
385 return error;
386}
387EXPORT_SYMBOL_GPL(class_for_each_device);
388
389/**
390 * class_find_device - device iterator for locating a particular device
391 * @class: the class we're iterating
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400392 * @start: Device to begin with
Dave Youngfd048972008-01-22 15:27:08 +0800393 * @data: data for the match function
394 * @match: function to check device
395 *
396 * This is similar to the class_for_each_dev() function above, but it
397 * returns a reference to a device that is 'found' for later use, as
398 * determined by the @match callback.
399 *
400 * The callback should return 0 if the device doesn't match and non-zero
401 * if it does. If the callback returns non-zero, this function will
402 * return to the caller and not iterate over any more devices.
Randy Dunlapa63ca8f2008-01-30 11:51:08 -0800403 *
Dave Youngfd048972008-01-22 15:27:08 +0800404 * Note, you will need to drop the reference with put_device() after use.
405 *
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200406 * @fn is allowed to do anything including calling back into class
407 * code. There's no locking restriction.
Dave Youngfd048972008-01-22 15:27:08 +0800408 */
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400409struct device *class_find_device(struct class *class, struct device *start,
410 void *data,
411 int (*match)(struct device *, void *))
Dave Youngfd048972008-01-22 15:27:08 +0800412{
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200413 struct class_dev_iter iter;
Dave Youngfd048972008-01-22 15:27:08 +0800414 struct device *dev;
Dave Youngfd048972008-01-22 15:27:08 +0800415
416 if (!class)
417 return NULL;
David Brownell7c225032008-08-06 18:52:44 -0700418 if (!class->p) {
419 WARN(1, "%s called for class '%s' before it was initialized",
420 __func__, class->name);
421 return NULL;
422 }
Dave Youngfd048972008-01-22 15:27:08 +0800423
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200424 class_dev_iter_init(&iter, class, start, NULL);
425 while ((dev = class_dev_iter_next(&iter))) {
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400426 if (match(dev, data)) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200427 get_device(dev);
Dave Youngfd048972008-01-22 15:27:08 +0800428 break;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200429 }
Dave Youngfd048972008-01-22 15:27:08 +0800430 }
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200431 class_dev_iter_exit(&iter);
Dave Youngfd048972008-01-22 15:27:08 +0800432
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200433 return dev;
Dave Youngfd048972008-01-22 15:27:08 +0800434}
435EXPORT_SYMBOL_GPL(class_find_device);
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437int class_interface_register(struct class_interface *class_intf)
438{
439 struct class *parent;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200440 struct class_dev_iter iter;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200441 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
443 if (!class_intf || !class_intf->class)
444 return -ENODEV;
445
446 parent = class_get(class_intf->class);
447 if (!parent)
448 return -EINVAL;
449
Dave Youngf75b1c62008-05-28 09:28:39 -0700450 mutex_lock(&parent->p->class_mutex);
Greg Kroah-Hartman184f1f72008-05-28 09:28:39 -0700451 list_add_tail(&class_intf->node, &parent->p->class_interfaces);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200452 if (class_intf->add_dev) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200453 class_dev_iter_init(&iter, parent, NULL, NULL);
454 while ((dev = class_dev_iter_next(&iter)))
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200455 class_intf->add_dev(dev, class_intf);
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200456 class_dev_iter_exit(&iter);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200457 }
Dave Youngf75b1c62008-05-28 09:28:39 -0700458 mutex_unlock(&parent->p->class_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
460 return 0;
461}
462
463void class_interface_unregister(struct class_interface *class_intf)
464{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -0800465 struct class *parent = class_intf->class;
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200466 struct class_dev_iter iter;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200467 struct device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468
469 if (!parent)
470 return;
471
Dave Youngf75b1c62008-05-28 09:28:39 -0700472 mutex_lock(&parent->p->class_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 list_del_init(&class_intf->node);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200474 if (class_intf->remove_dev) {
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200475 class_dev_iter_init(&iter, parent, NULL, NULL);
476 while ((dev = class_dev_iter_next(&iter)))
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200477 class_intf->remove_dev(dev, class_intf);
Tejun Heo5a3ceb82008-08-25 19:50:19 +0200478 class_dev_iter_exit(&iter);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +0200479 }
Dave Youngf75b1c62008-05-28 09:28:39 -0700480 mutex_unlock(&parent->p->class_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
482 class_put(parent);
483}
484
Andi Kleen869dfc82010-01-05 12:48:08 +0100485ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr,
486 char *buf)
487{
488 struct class_attribute_string *cs;
489 cs = container_of(attr, struct class_attribute_string, attr);
490 return snprintf(buf, PAGE_SIZE, "%s\n", cs->str);
491}
492
493EXPORT_SYMBOL_GPL(show_class_attr_string);
494
Jean Delvare46227092009-08-04 12:55:34 +0200495struct class_compat {
496 struct kobject *kobj;
497};
498
499/**
500 * class_compat_register - register a compatibility class
501 * @name: the name of the class
502 *
503 * Compatibility class are meant as a temporary user-space compatibility
504 * workaround when converting a family of class devices to a bus devices.
505 */
506struct class_compat *class_compat_register(const char *name)
507{
508 struct class_compat *cls;
509
510 cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL);
511 if (!cls)
512 return NULL;
513 cls->kobj = kobject_create_and_add(name, &class_kset->kobj);
514 if (!cls->kobj) {
515 kfree(cls);
516 return NULL;
517 }
518 return cls;
519}
520EXPORT_SYMBOL_GPL(class_compat_register);
521
522/**
523 * class_compat_unregister - unregister a compatibility class
524 * @cls: the class to unregister
525 */
526void class_compat_unregister(struct class_compat *cls)
527{
528 kobject_put(cls->kobj);
529 kfree(cls);
530}
531EXPORT_SYMBOL_GPL(class_compat_unregister);
532
533/**
534 * class_compat_create_link - create a compatibility class device link to
535 * a bus device
536 * @cls: the compatibility class
537 * @dev: the target bus device
538 * @device_link: an optional device to which a "device" link should be created
539 */
540int class_compat_create_link(struct class_compat *cls, struct device *dev,
541 struct device *device_link)
542{
543 int error;
544
545 error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev));
546 if (error)
547 return error;
548
549 /*
550 * Optionally add a "device" link (typically to the parent), as a
551 * class device would have one and we want to provide as much
552 * backwards compatibility as possible.
553 */
554 if (device_link) {
555 error = sysfs_create_link(&dev->kobj, &device_link->kobj,
556 "device");
557 if (error)
558 sysfs_remove_link(cls->kobj, dev_name(dev));
559 }
560
561 return error;
562}
563EXPORT_SYMBOL_GPL(class_compat_create_link);
564
565/**
566 * class_compat_remove_link - remove a compatibility class device link to
567 * a bus device
568 * @cls: the compatibility class
569 * @dev: the target bus device
570 * @device_link: an optional device to which a "device" link was previously
571 * created
572 */
573void class_compat_remove_link(struct class_compat *cls, struct device *dev,
574 struct device *device_link)
575{
576 if (device_link)
577 sysfs_remove_link(&dev->kobj, "device");
578 sysfs_remove_link(cls->kobj, dev_name(dev));
579}
580EXPORT_SYMBOL_GPL(class_compat_remove_link);
581
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582int __init classes_init(void)
583{
Greg Kroah-Hartman443dbf92007-10-29 23:22:26 -0500584 class_kset = kset_create_and_add("class", NULL, NULL);
585 if (!class_kset)
586 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 return 0;
588}
589
590EXPORT_SYMBOL_GPL(class_create_file);
591EXPORT_SYMBOL_GPL(class_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592EXPORT_SYMBOL_GPL(class_unregister);
gregkh@suse.dee9ba6362005-03-15 11:54:21 -0800593EXPORT_SYMBOL_GPL(class_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595EXPORT_SYMBOL_GPL(class_interface_register);
596EXPORT_SYMBOL_GPL(class_interface_unregister);