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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/attribute_container.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/base/attribute_container.c')
-rw-r--r--drivers/base/attribute_container.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/base/attribute_container.c b/drivers/base/attribute_container.c
new file mode 100644
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1/*
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>
21
22/* This is a private structure used to tie the classdev and the
23 * container .. it should never be visible outside this file */
24struct internal_container {
25 struct list_head node;
26 struct attribute_container *cont;
27 struct class_device classdev;
28};
29
30/**
31 * attribute_container_classdev_to_container - given a classdev, return the container
32 *
33 * @classdev: the class device created by attribute_container_add_device.
34 *
35 * Returns the container associated with this classdev.
36 */
37struct attribute_container *
38attribute_container_classdev_to_container(struct class_device *classdev)
39{
40 struct internal_container *ic =
41 container_of(classdev, struct internal_container, classdev);
42 return ic->cont;
43}
44EXPORT_SYMBOL_GPL(attribute_container_classdev_to_container);
45
46static struct list_head attribute_container_list;
47
48static DECLARE_MUTEX(attribute_container_mutex);
49
50/**
51 * attribute_container_register - register an attribute container
52 *
53 * @cont: The container to register. This must be allocated by the
54 * callee and should also be zeroed by it.
55 */
56int
57attribute_container_register(struct attribute_container *cont)
58{
59 INIT_LIST_HEAD(&cont->node);
60 INIT_LIST_HEAD(&cont->containers);
61
62 down(&attribute_container_mutex);
63 list_add_tail(&cont->node, &attribute_container_list);
64 up(&attribute_container_mutex);
65
66 return 0;
67}
68EXPORT_SYMBOL_GPL(attribute_container_register);
69
70/**
71 * attribute_container_unregister - remove a container registration
72 *
73 * @cont: previously registered container to remove
74 */
75int
76attribute_container_unregister(struct attribute_container *cont)
77{
78 int retval = -EBUSY;
79 down(&attribute_container_mutex);
80 if (!list_empty(&cont->containers))
81 goto out;
82 retval = 0;
83 list_del(&cont->node);
84 out:
85 up(&attribute_container_mutex);
86 return retval;
87
88}
89EXPORT_SYMBOL_GPL(attribute_container_unregister);
90
91/* private function used as class release */
92static void attribute_container_release(struct class_device *classdev)
93{
94 struct internal_container *ic
95 = container_of(classdev, struct internal_container, classdev);
96 struct device *dev = classdev->dev;
97
98 kfree(ic);
99 put_device(dev);
100}
101
102/**
103 * attribute_container_add_device - see if any container is interested in dev
104 *
105 * @dev: device to add attributes to
106 * @fn: function to trigger addition of class device.
107 *
108 * This function allocates storage for the class device(s) to be
109 * attached to dev (one for each matching attribute_container). If no
110 * fn is provided, the code will simply register the class device via
111 * class_device_add. If a function is provided, it is expected to add
112 * the class device at the appropriate time. One of the things that
113 * might be necessary is to allocate and initialise the classdev and
114 * then add it a later time. To do this, call this routine for
115 * allocation and initialisation and then use
116 * attribute_container_device_trigger() to call class_device_add() on
117 * it. Note: after this, the class device contains a reference to dev
118 * which is not relinquished until the release of the classdev.
119 */
120void
121attribute_container_add_device(struct device *dev,
122 int (*fn)(struct attribute_container *,
123 struct device *,
124 struct class_device *))
125{
126 struct attribute_container *cont;
127
128 down(&attribute_container_mutex);
129 list_for_each_entry(cont, &attribute_container_list, node) {
130 struct internal_container *ic;
131
132 if (attribute_container_no_classdevs(cont))
133 continue;
134
135 if (!cont->match(cont, dev))
136 continue;
137 ic = kmalloc(sizeof(struct internal_container), GFP_KERNEL);
138 if (!ic) {
139 dev_printk(KERN_ERR, dev, "failed to allocate class container\n");
140 continue;
141 }
142 memset(ic, 0, sizeof(struct internal_container));
143 INIT_LIST_HEAD(&ic->node);
144 ic->cont = cont;
145 class_device_initialize(&ic->classdev);
146 ic->classdev.dev = get_device(dev);
147 ic->classdev.class = cont->class;
148 cont->class->release = attribute_container_release;
149 strcpy(ic->classdev.class_id, dev->bus_id);
150 if (fn)
151 fn(cont, dev, &ic->classdev);
152 else
153 attribute_container_add_class_device(&ic->classdev);
154 list_add_tail(&ic->node, &cont->containers);
155 }
156 up(&attribute_container_mutex);
157}
158
159/**
160 * attribute_container_remove_device - make device eligible for removal.
161 *
162 * @dev: The generic device
163 * @fn: A function to call to remove the device
164 *
165 * This routine triggers device removal. If fn is NULL, then it is
166 * simply done via class_device_unregister (note that if something
167 * still has a reference to the classdev, then the memory occupied
168 * will not be freed until the classdev is released). If you want a
169 * two phase release: remove from visibility and then delete the
170 * device, then you should use this routine with a fn that calls
171 * class_device_del() and then use
172 * attribute_container_device_trigger() to do the final put on the
173 * classdev.
174 */
175void
176attribute_container_remove_device(struct device *dev,
177 void (*fn)(struct attribute_container *,
178 struct device *,
179 struct class_device *))
180{
181 struct attribute_container *cont;
182
183 down(&attribute_container_mutex);
184 list_for_each_entry(cont, &attribute_container_list, node) {
185 struct internal_container *ic, *tmp;
186
187 if (attribute_container_no_classdevs(cont))
188 continue;
189
190 if (!cont->match(cont, dev))
191 continue;
192 list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
193 if (dev != ic->classdev.dev)
194 continue;
195 list_del(&ic->node);
196 if (fn)
197 fn(cont, dev, &ic->classdev);
198 else {
199 attribute_container_remove_attrs(&ic->classdev);
200 class_device_unregister(&ic->classdev);
201 }
202 }
203 }
204 up(&attribute_container_mutex);
205}
206EXPORT_SYMBOL_GPL(attribute_container_remove_device);
207
208/**
209 * attribute_container_device_trigger - execute a trigger for each matching classdev
210 *
211 * @dev: The generic device to run the trigger for
212 * @fn the function to execute for each classdev.
213 *
214 * This funcion is for executing a trigger when you need to know both
215 * the container and the classdev. If you only care about the
216 * container, then use attribute_container_trigger() instead.
217 */
218void
219attribute_container_device_trigger(struct device *dev,
220 int (*fn)(struct attribute_container *,
221 struct device *,
222 struct class_device *))
223{
224 struct attribute_container *cont;
225
226 down(&attribute_container_mutex);
227 list_for_each_entry(cont, &attribute_container_list, node) {
228 struct internal_container *ic, *tmp;
229
230 if (!cont->match(cont, dev))
231 continue;
232
233 list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
234 if (dev == ic->classdev.dev)
235 fn(cont, dev, &ic->classdev);
236 }
237 }
238 up(&attribute_container_mutex);
239}
240EXPORT_SYMBOL_GPL(attribute_container_device_trigger);
241
242/**
243 * attribute_container_trigger - trigger a function for each matching container
244 *
245 * @dev: The generic device to activate the trigger for
246 * @fn: the function to trigger
247 *
248 * This routine triggers a function that only needs to know the
249 * matching containers (not the classdev) associated with a device.
250 * It is more lightweight than attribute_container_device_trigger, so
251 * should be used in preference unless the triggering function
252 * actually needs to know the classdev.
253 */
254void
255attribute_container_trigger(struct device *dev,
256 int (*fn)(struct attribute_container *,
257 struct device *))
258{
259 struct attribute_container *cont;
260
261 down(&attribute_container_mutex);
262 list_for_each_entry(cont, &attribute_container_list, node) {
263 if (cont->match(cont, dev))
264 fn(cont, dev);
265 }
266 up(&attribute_container_mutex);
267}
268EXPORT_SYMBOL_GPL(attribute_container_trigger);
269
270/**
271 * attribute_container_add_attrs - add attributes
272 *
273 * @classdev: The class device
274 *
275 * This simply creates all the class device sysfs files from the
276 * attributes listed in the container
277 */
278int
279attribute_container_add_attrs(struct class_device *classdev)
280{
281 struct attribute_container *cont =
282 attribute_container_classdev_to_container(classdev);
283 struct class_device_attribute **attrs = cont->attrs;
284 int i, error;
285
286 if (!attrs)
287 return 0;
288
289 for (i = 0; attrs[i]; i++) {
290 error = class_device_create_file(classdev, attrs[i]);
291 if (error)
292 return error;
293 }
294
295 return 0;
296}
297EXPORT_SYMBOL_GPL(attribute_container_add_attrs);
298
299/**
300 * attribute_container_add_class_device - same function as class_device_add
301 *
302 * @classdev: the class device to add
303 *
304 * This performs essentially the same function as class_device_add except for
305 * attribute containers, namely add the classdev to the system and then
306 * create the attribute files
307 */
308int
309attribute_container_add_class_device(struct class_device *classdev)
310{
311 int error = class_device_add(classdev);
312 if (error)
313 return error;
314 return attribute_container_add_attrs(classdev);
315}
316EXPORT_SYMBOL_GPL(attribute_container_add_class_device);
317
318/**
319 * attribute_container_add_class_device_adapter - simple adapter for triggers
320 *
321 * This function is identical to attribute_container_add_class_device except
322 * that it is designed to be called from the triggers
323 */
324int
325attribute_container_add_class_device_adapter(struct attribute_container *cont,
326 struct device *dev,
327 struct class_device *classdev)
328{
329 return attribute_container_add_class_device(classdev);
330}
331EXPORT_SYMBOL_GPL(attribute_container_add_class_device_adapter);
332
333/**
334 * attribute_container_remove_attrs - remove any attribute files
335 *
336 * @classdev: The class device to remove the files from
337 *
338 */
339void
340attribute_container_remove_attrs(struct class_device *classdev)
341{
342 struct attribute_container *cont =
343 attribute_container_classdev_to_container(classdev);
344 struct class_device_attribute **attrs = cont->attrs;
345 int i;
346
347 if (!attrs)
348 return;
349
350 for (i = 0; attrs[i]; i++)
351 class_device_remove_file(classdev, attrs[i]);
352}
353EXPORT_SYMBOL_GPL(attribute_container_remove_attrs);
354
355/**
356 * attribute_container_class_device_del - equivalent of class_device_del
357 *
358 * @classdev: the class device
359 *
360 * This function simply removes all the attribute files and then calls
361 * class_device_del.
362 */
363void
364attribute_container_class_device_del(struct class_device *classdev)
365{
366 attribute_container_remove_attrs(classdev);
367 class_device_del(classdev);
368}
369EXPORT_SYMBOL_GPL(attribute_container_class_device_del);
370
371int __init
372attribute_container_init(void)
373{
374 INIT_LIST_HEAD(&attribute_container_list);
375 return 0;
376}