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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * attribute_container.c - implementation of a simple container for classes
3 *
4 * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
5 *
6 * This file is licensed under GPLv2
7 *
8 * The basic idea here is to enable a device to be attached to an
9 * aritrary numer of classes without having to allocate storage for them.
10 * Instead, the contained classes select the devices they need to attach
11 * to via a matching function.
12 */
13
14#include <linux/attribute_container.h>
15#include <linux/init.h>
16#include <linux/device.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19#include <linux/list.h>
20#include <linux/module.h>
Michael S. Tsirkinf8916c12007-06-10 22:39:12 +030021#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Ben Dooksa1bdc7a2005-10-13 17:54:41 +010023#include "base.h"
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025/* This is a private structure used to tie the classdev and the
26 * container .. it should never be visible outside this file */
27struct internal_container {
James Bottomley53c165e2005-08-22 10:06:19 -050028 struct klist_node node;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 struct attribute_container *cont;
Tony Jonesee959b02008-02-22 00:13:36 +010030 struct device classdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070031};
32
Linus Torvaldscaf39e82005-09-07 18:44:33 -070033static void internal_container_klist_get(struct klist_node *n)
34{
35 struct internal_container *ic =
36 container_of(n, struct internal_container, node);
Tony Jonesee959b02008-02-22 00:13:36 +010037 get_device(&ic->classdev);
Linus Torvaldscaf39e82005-09-07 18:44:33 -070038}
39
40static void internal_container_klist_put(struct klist_node *n)
41{
42 struct internal_container *ic =
43 container_of(n, struct internal_container, node);
Tony Jonesee959b02008-02-22 00:13:36 +010044 put_device(&ic->classdev);
Linus Torvaldscaf39e82005-09-07 18:44:33 -070045}
46
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048/**
49 * attribute_container_classdev_to_container - given a classdev, return the container
50 *
51 * @classdev: the class device created by attribute_container_add_device.
52 *
53 * Returns the container associated with this classdev.
54 */
55struct attribute_container *
Tony Jonesee959b02008-02-22 00:13:36 +010056attribute_container_classdev_to_container(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
58 struct internal_container *ic =
59 container_of(classdev, struct internal_container, classdev);
60 return ic->cont;
61}
62EXPORT_SYMBOL_GPL(attribute_container_classdev_to_container);
63
Denis Chengdb1118a2007-12-06 02:24:40 +080064static LIST_HEAD(attribute_container_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -070066static DEFINE_MUTEX(attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68/**
69 * attribute_container_register - register an attribute container
70 *
71 * @cont: The container to register. This must be allocated by the
72 * callee and should also be zeroed by it.
73 */
74int
75attribute_container_register(struct attribute_container *cont)
76{
77 INIT_LIST_HEAD(&cont->node);
Linus Torvaldscaf39e82005-09-07 18:44:33 -070078 klist_init(&cont->containers,internal_container_klist_get,
79 internal_container_klist_put);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -070081 mutex_lock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 list_add_tail(&cont->node, &attribute_container_list);
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -070083 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85 return 0;
86}
87EXPORT_SYMBOL_GPL(attribute_container_register);
88
89/**
90 * attribute_container_unregister - remove a container registration
91 *
92 * @cont: previously registered container to remove
93 */
94int
95attribute_container_unregister(struct attribute_container *cont)
96{
97 int retval = -EBUSY;
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -070098 mutex_lock(&attribute_container_mutex);
James Bottomley53c165e2005-08-22 10:06:19 -050099 spin_lock(&cont->containers.k_lock);
100 if (!list_empty(&cont->containers.k_list))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 goto out;
102 retval = 0;
103 list_del(&cont->node);
104 out:
James Bottomley53c165e2005-08-22 10:06:19 -0500105 spin_unlock(&cont->containers.k_lock);
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700106 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return retval;
108
109}
110EXPORT_SYMBOL_GPL(attribute_container_unregister);
111
112/* private function used as class release */
Tony Jonesee959b02008-02-22 00:13:36 +0100113static void attribute_container_release(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
115 struct internal_container *ic
116 = container_of(classdev, struct internal_container, classdev);
Tony Jonesee959b02008-02-22 00:13:36 +0100117 struct device *dev = classdev->parent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119 kfree(ic);
120 put_device(dev);
121}
122
123/**
124 * attribute_container_add_device - see if any container is interested in dev
125 *
126 * @dev: device to add attributes to
127 * @fn: function to trigger addition of class device.
128 *
129 * This function allocates storage for the class device(s) to be
130 * attached to dev (one for each matching attribute_container). If no
131 * fn is provided, the code will simply register the class device via
Tony Jonesee959b02008-02-22 00:13:36 +0100132 * device_add. If a function is provided, it is expected to add
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * the class device at the appropriate time. One of the things that
134 * might be necessary is to allocate and initialise the classdev and
135 * then add it a later time. To do this, call this routine for
136 * allocation and initialisation and then use
Tony Jonesee959b02008-02-22 00:13:36 +0100137 * attribute_container_device_trigger() to call device_add() on
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 * it. Note: after this, the class device contains a reference to dev
139 * which is not relinquished until the release of the classdev.
140 */
141void
142attribute_container_add_device(struct device *dev,
143 int (*fn)(struct attribute_container *,
144 struct device *,
Tony Jonesee959b02008-02-22 00:13:36 +0100145 struct device *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
147 struct attribute_container *cont;
148
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700149 mutex_lock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 list_for_each_entry(cont, &attribute_container_list, node) {
151 struct internal_container *ic;
152
153 if (attribute_container_no_classdevs(cont))
154 continue;
155
156 if (!cont->match(cont, dev))
157 continue;
Jiri Slaby4aed0642005-09-13 01:25:01 -0700158
159 ic = kzalloc(sizeof(*ic), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 if (!ic) {
161 dev_printk(KERN_ERR, dev, "failed to allocate class container\n");
162 continue;
163 }
Jiri Slaby4aed0642005-09-13 01:25:01 -0700164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 ic->cont = cont;
Tony Jonesee959b02008-02-22 00:13:36 +0100166 device_initialize(&ic->classdev);
167 ic->classdev.parent = get_device(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 ic->classdev.class = cont->class;
Tony Jonesee959b02008-02-22 00:13:36 +0100169 cont->class->dev_release = attribute_container_release;
170 strcpy(ic->classdev.bus_id, dev->bus_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 if (fn)
172 fn(cont, dev, &ic->classdev);
173 else
174 attribute_container_add_class_device(&ic->classdev);
James Bottomley53c165e2005-08-22 10:06:19 -0500175 klist_add_tail(&ic->node, &cont->containers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 }
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700177 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178}
179
James Bottomley53c165e2005-08-22 10:06:19 -0500180/* FIXME: can't break out of this unless klist_iter_exit is also
181 * called before doing the break
182 */
183#define klist_for_each_entry(pos, head, member, iter) \
184 for (klist_iter_init(head, iter); (pos = ({ \
185 struct klist_node *n = klist_next(iter); \
Linus Torvaldscaf39e82005-09-07 18:44:33 -0700186 n ? container_of(n, typeof(*pos), member) : \
187 ({ klist_iter_exit(iter) ; NULL; }); \
James Bottomley53c165e2005-08-22 10:06:19 -0500188 }) ) != NULL; )
189
190
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191/**
192 * attribute_container_remove_device - make device eligible for removal.
193 *
194 * @dev: The generic device
195 * @fn: A function to call to remove the device
196 *
197 * This routine triggers device removal. If fn is NULL, then it is
Tony Jonesee959b02008-02-22 00:13:36 +0100198 * simply done via device_unregister (note that if something
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 * still has a reference to the classdev, then the memory occupied
200 * will not be freed until the classdev is released). If you want a
201 * two phase release: remove from visibility and then delete the
202 * device, then you should use this routine with a fn that calls
Tony Jonesee959b02008-02-22 00:13:36 +0100203 * device_del() and then use attribute_container_device_trigger()
204 * to do the final put on the classdev.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 */
206void
207attribute_container_remove_device(struct device *dev,
208 void (*fn)(struct attribute_container *,
209 struct device *,
Tony Jonesee959b02008-02-22 00:13:36 +0100210 struct device *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
212 struct attribute_container *cont;
213
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700214 mutex_lock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 list_for_each_entry(cont, &attribute_container_list, node) {
James Bottomley53c165e2005-08-22 10:06:19 -0500216 struct internal_container *ic;
217 struct klist_iter iter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
219 if (attribute_container_no_classdevs(cont))
220 continue;
221
222 if (!cont->match(cont, dev))
223 continue;
James Bottomley53c165e2005-08-22 10:06:19 -0500224
225 klist_for_each_entry(ic, &cont->containers, node, &iter) {
Tony Jonesee959b02008-02-22 00:13:36 +0100226 if (dev != ic->classdev.parent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 continue;
Linus Torvaldscaf39e82005-09-07 18:44:33 -0700228 klist_del(&ic->node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (fn)
230 fn(cont, dev, &ic->classdev);
231 else {
232 attribute_container_remove_attrs(&ic->classdev);
Tony Jonesee959b02008-02-22 00:13:36 +0100233 device_unregister(&ic->classdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 }
235 }
236 }
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700237 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240/**
241 * attribute_container_device_trigger - execute a trigger for each matching classdev
242 *
243 * @dev: The generic device to run the trigger for
244 * @fn the function to execute for each classdev.
245 *
246 * This funcion is for executing a trigger when you need to know both
247 * the container and the classdev. If you only care about the
248 * container, then use attribute_container_trigger() instead.
249 */
250void
251attribute_container_device_trigger(struct device *dev,
252 int (*fn)(struct attribute_container *,
253 struct device *,
Tony Jonesee959b02008-02-22 00:13:36 +0100254 struct device *))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
256 struct attribute_container *cont;
257
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700258 mutex_lock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 list_for_each_entry(cont, &attribute_container_list, node) {
James Bottomley53c165e2005-08-22 10:06:19 -0500260 struct internal_container *ic;
261 struct klist_iter iter;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 if (!cont->match(cont, dev))
264 continue;
265
James Bottomleyebd8bb72005-08-15 16:13:19 -0500266 if (attribute_container_no_classdevs(cont)) {
267 fn(cont, dev, NULL);
268 continue;
269 }
270
James Bottomley53c165e2005-08-22 10:06:19 -0500271 klist_for_each_entry(ic, &cont->containers, node, &iter) {
Tony Jonesee959b02008-02-22 00:13:36 +0100272 if (dev == ic->classdev.parent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 fn(cont, dev, &ic->classdev);
274 }
275 }
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700276 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
279/**
280 * attribute_container_trigger - trigger a function for each matching container
281 *
282 * @dev: The generic device to activate the trigger for
283 * @fn: the function to trigger
284 *
285 * This routine triggers a function that only needs to know the
286 * matching containers (not the classdev) associated with a device.
287 * It is more lightweight than attribute_container_device_trigger, so
288 * should be used in preference unless the triggering function
289 * actually needs to know the classdev.
290 */
291void
292attribute_container_trigger(struct device *dev,
293 int (*fn)(struct attribute_container *,
294 struct device *))
295{
296 struct attribute_container *cont;
297
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700298 mutex_lock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 list_for_each_entry(cont, &attribute_container_list, node) {
300 if (cont->match(cont, dev))
301 fn(cont, dev);
302 }
Matthias Kaehlcke61a2f592007-04-26 00:12:09 -0700303 mutex_unlock(&attribute_container_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
306/**
307 * attribute_container_add_attrs - add attributes
308 *
309 * @classdev: The class device
310 *
311 * This simply creates all the class device sysfs files from the
312 * attributes listed in the container
313 */
314int
Tony Jonesee959b02008-02-22 00:13:36 +0100315attribute_container_add_attrs(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316{
317 struct attribute_container *cont =
318 attribute_container_classdev_to_container(classdev);
Tony Jonesee959b02008-02-22 00:13:36 +0100319 struct device_attribute **attrs = cont->attrs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 int i, error;
321
James Bottomleyfd110972008-01-02 18:48:47 -0600322 BUG_ON(attrs && cont->grp);
323
324 if (!attrs && !cont->grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 return 0;
326
James Bottomleyfd110972008-01-02 18:48:47 -0600327 if (cont->grp)
328 return sysfs_create_group(&classdev->kobj, cont->grp);
329
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 for (i = 0; attrs[i]; i++) {
Tony Jonesee959b02008-02-22 00:13:36 +0100331 error = device_create_file(classdev, attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 if (error)
333 return error;
334 }
335
336 return 0;
337}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
339/**
Tony Jonesee959b02008-02-22 00:13:36 +0100340 * attribute_container_add_class_device - same function as device_add
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 *
342 * @classdev: the class device to add
343 *
Tony Jonesee959b02008-02-22 00:13:36 +0100344 * This performs essentially the same function as device_add except for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 * attribute containers, namely add the classdev to the system and then
346 * create the attribute files
347 */
348int
Tony Jonesee959b02008-02-22 00:13:36 +0100349attribute_container_add_class_device(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350{
Tony Jonesee959b02008-02-22 00:13:36 +0100351 int error = device_add(classdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 if (error)
353 return error;
354 return attribute_container_add_attrs(classdev);
355}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357/**
358 * attribute_container_add_class_device_adapter - simple adapter for triggers
359 *
360 * This function is identical to attribute_container_add_class_device except
361 * that it is designed to be called from the triggers
362 */
363int
364attribute_container_add_class_device_adapter(struct attribute_container *cont,
365 struct device *dev,
Tony Jonesee959b02008-02-22 00:13:36 +0100366 struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367{
368 return attribute_container_add_class_device(classdev);
369}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371/**
372 * attribute_container_remove_attrs - remove any attribute files
373 *
374 * @classdev: The class device to remove the files from
375 *
376 */
377void
Tony Jonesee959b02008-02-22 00:13:36 +0100378attribute_container_remove_attrs(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379{
380 struct attribute_container *cont =
381 attribute_container_classdev_to_container(classdev);
Tony Jonesee959b02008-02-22 00:13:36 +0100382 struct device_attribute **attrs = cont->attrs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 int i;
384
James Bottomleyfd110972008-01-02 18:48:47 -0600385 if (!attrs && !cont->grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 return;
387
James Bottomleyfd110972008-01-02 18:48:47 -0600388 if (cont->grp) {
389 sysfs_remove_group(&classdev->kobj, cont->grp);
390 return ;
391 }
392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 for (i = 0; attrs[i]; i++)
Tony Jonesee959b02008-02-22 00:13:36 +0100394 device_remove_file(classdev, attrs[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
397/**
398 * attribute_container_class_device_del - equivalent of class_device_del
399 *
400 * @classdev: the class device
401 *
402 * This function simply removes all the attribute files and then calls
Tony Jonesee959b02008-02-22 00:13:36 +0100403 * device_del.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 */
405void
Tony Jonesee959b02008-02-22 00:13:36 +0100406attribute_container_class_device_del(struct device *classdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407{
408 attribute_container_remove_attrs(classdev);
Tony Jonesee959b02008-02-22 00:13:36 +0100409 device_del(classdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
James Bottomleyd0a7e572005-08-14 17:09:01 -0500412/**
413 * attribute_container_find_class_device - find the corresponding class_device
414 *
415 * @cont: the container
416 * @dev: the generic device
417 *
418 * Looks up the device in the container's list of class devices and returns
419 * the corresponding class_device.
420 */
Tony Jonesee959b02008-02-22 00:13:36 +0100421struct device *
James Bottomleyd0a7e572005-08-14 17:09:01 -0500422attribute_container_find_class_device(struct attribute_container *cont,
423 struct device *dev)
424{
Tony Jonesee959b02008-02-22 00:13:36 +0100425 struct device *cdev = NULL;
James Bottomleyd0a7e572005-08-14 17:09:01 -0500426 struct internal_container *ic;
James Bottomley53c165e2005-08-22 10:06:19 -0500427 struct klist_iter iter;
James Bottomleyd0a7e572005-08-14 17:09:01 -0500428
James Bottomley53c165e2005-08-22 10:06:19 -0500429 klist_for_each_entry(ic, &cont->containers, node, &iter) {
Tony Jonesee959b02008-02-22 00:13:36 +0100430 if (ic->classdev.parent == dev) {
James Bottomleyd0a7e572005-08-14 17:09:01 -0500431 cdev = &ic->classdev;
James Bottomley53c165e2005-08-22 10:06:19 -0500432 /* FIXME: must exit iterator then break */
433 klist_iter_exit(&iter);
James Bottomleyd0a7e572005-08-14 17:09:01 -0500434 break;
435 }
436 }
James Bottomleyd0a7e572005-08-14 17:09:01 -0500437
438 return cdev;
439}
440EXPORT_SYMBOL_GPL(attribute_container_find_class_device);