projects/linux·blob v3.0 · refs

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1/*
2 * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * 2002-3 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 * This exports a 'system' bus type.
10 * By default, a 'sys' bus gets added to the root of the system. There will
11 * always be core system devices. Devices can use sysdev_register() to
12 * add themselves as children of the system bus.
13 */
14
15#include <linux/sysdev.h>
16#include <linux/err.h>
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/init.h>
20#include <linux/string.h>
21#include <linux/pm.h>
22#include <linux/device.h>
23#include <linux/mutex.h>
24#include <linux/interrupt.h>
25
26#include "base.h"
27
28#define to_sysdev(k) container_of(k, struct sys_device, kobj)
29#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
30
31
32static ssize_t
33sysdev_show(struct kobject *kobj, struct attribute *attr, char *buffer)
34{
35 struct sys_device *sysdev = to_sysdev(kobj);
36 struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
37
38 if (sysdev_attr->show)
39 return sysdev_attr->show(sysdev, sysdev_attr, buffer);
40 return -EIO;
41}
42
43
44static ssize_t
45sysdev_store(struct kobject *kobj, struct attribute *attr,
46 const char *buffer, size_t count)
47{
48 struct sys_device *sysdev = to_sysdev(kobj);
49 struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
50
51 if (sysdev_attr->store)
52 return sysdev_attr->store(sysdev, sysdev_attr, buffer, count);
53 return -EIO;
54}
55
56static const struct sysfs_ops sysfs_ops = {
57 .show = sysdev_show,
58 .store = sysdev_store,
59};
60
61static struct kobj_type ktype_sysdev = {
62 .sysfs_ops = &sysfs_ops,
63};
64
65
66int sysdev_create_file(struct sys_device *s, struct sysdev_attribute *a)
67{
68 return sysfs_create_file(&s->kobj, &a->attr);
69}
70
71
72void sysdev_remove_file(struct sys_device *s, struct sysdev_attribute *a)
73{
74 sysfs_remove_file(&s->kobj, &a->attr);
75}
76
77EXPORT_SYMBOL_GPL(sysdev_create_file);
78EXPORT_SYMBOL_GPL(sysdev_remove_file);
79
80#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
81#define to_sysdev_class_attr(a) container_of(a, \
82 struct sysdev_class_attribute, attr)
83
84static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
85 char *buffer)
86{
87 struct sysdev_class *class = to_sysdev_class(kobj);
88 struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
89
90 if (class_attr->show)
91 return class_attr->show(class, class_attr, buffer);
92 return -EIO;
93}
94
95static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
96 const char *buffer, size_t count)
97{
98 struct sysdev_class *class = to_sysdev_class(kobj);
99 struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
100
101 if (class_attr->store)
102 return class_attr->store(class, class_attr, buffer, count);
103 return -EIO;
104}
105
106static const struct sysfs_ops sysfs_class_ops = {
107 .show = sysdev_class_show,
108 .store = sysdev_class_store,
109};
110
111static struct kobj_type ktype_sysdev_class = {
112 .sysfs_ops = &sysfs_class_ops,
113};
114
115int sysdev_class_create_file(struct sysdev_class *c,
116 struct sysdev_class_attribute *a)
117{
118 return sysfs_create_file(&c->kset.kobj, &a->attr);
119}
120EXPORT_SYMBOL_GPL(sysdev_class_create_file);
121
122void sysdev_class_remove_file(struct sysdev_class *c,
123 struct sysdev_class_attribute *a)
124{
125 sysfs_remove_file(&c->kset.kobj, &a->attr);
126}
127EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
128
129static struct kset *system_kset;
130
131int sysdev_class_register(struct sysdev_class *cls)
132{
133 int retval;
134
135 pr_debug("Registering sysdev class '%s'\n", cls->name);
136
137 INIT_LIST_HEAD(&cls->drivers);
138 memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
139 cls->kset.kobj.parent = &system_kset->kobj;
140 cls->kset.kobj.ktype = &ktype_sysdev_class;
141 cls->kset.kobj.kset = system_kset;
142
143 retval = kobject_set_name(&cls->kset.kobj, "%s", cls->name);
144 if (retval)
145 return retval;
146
147 retval = kset_register(&cls->kset);
148 if (!retval && cls->attrs)
149 retval = sysfs_create_files(&cls->kset.kobj,
150 (const struct attribute **)cls->attrs);
151 return retval;
152}
153
154void sysdev_class_unregister(struct sysdev_class *cls)
155{
156 pr_debug("Unregistering sysdev class '%s'\n",
157 kobject_name(&cls->kset.kobj));
158 if (cls->attrs)
159 sysfs_remove_files(&cls->kset.kobj,
160 (const struct attribute **)cls->attrs);
161 kset_unregister(&cls->kset);
162}
163
164EXPORT_SYMBOL_GPL(sysdev_class_register);
165EXPORT_SYMBOL_GPL(sysdev_class_unregister);
166
167static DEFINE_MUTEX(sysdev_drivers_lock);
168
169/*
170 * @dev != NULL means that we're unwinding because some drv->add()
171 * failed for some reason. You need to grab sysdev_drivers_lock before
172 * calling this.
173 */
174static void __sysdev_driver_remove(struct sysdev_class *cls,
175 struct sysdev_driver *drv,
176 struct sys_device *from_dev)
177{
178 struct sys_device *dev = from_dev;
179
180 list_del_init(&drv->entry);
181 if (!cls)
182 return;
183
184 if (!drv->remove)
185 goto kset_put;
186
187 if (dev)
188 list_for_each_entry_continue_reverse(dev, &cls->kset.list,
189 kobj.entry)
190 drv->remove(dev);
191 else
192 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
193 drv->remove(dev);
194
195kset_put:
196 kset_put(&cls->kset);
197}
198
199/**
200 * sysdev_driver_register - Register auxiliary driver
201 * @cls: Device class driver belongs to.
202 * @drv: Driver.
203 *
204 * @drv is inserted into @cls->drivers to be
205 * called on each operation on devices of that class. The refcount
206 * of @cls is incremented.
207 */
208int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
209{
210 struct sys_device *dev = NULL;
211 int err = 0;
212
213 if (!cls) {
214 WARN(1, KERN_WARNING "sysdev: invalid class passed to %s!\n",
215 __func__);
216 return -EINVAL;
217 }
218
219 /* Check whether this driver has already been added to a class. */
220 if (drv->entry.next && !list_empty(&drv->entry))
221 WARN(1, KERN_WARNING "sysdev: class %s: driver (%p) has already"
222 " been registered to a class, something is wrong, but "
223 "will forge on!\n", cls->name, drv);
224
225 mutex_lock(&sysdev_drivers_lock);
226 if (cls && kset_get(&cls->kset)) {
227 list_add_tail(&drv->entry, &cls->drivers);
228
229 /* If devices of this class already exist, tell the driver */
230 if (drv->add) {
231 list_for_each_entry(dev, &cls->kset.list, kobj.entry) {
232 err = drv->add(dev);
233 if (err)
234 goto unwind;
235 }
236 }
237 } else {
238 err = -EINVAL;
239 WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
240 }
241
242 goto unlock;
243
244unwind:
245 __sysdev_driver_remove(cls, drv, dev);
246
247unlock:
248 mutex_unlock(&sysdev_drivers_lock);
249 return err;
250}
251
252/**
253 * sysdev_driver_unregister - Remove an auxiliary driver.
254 * @cls: Class driver belongs to.
255 * @drv: Driver.
256 */
257void sysdev_driver_unregister(struct sysdev_class *cls,
258 struct sysdev_driver *drv)
259{
260 mutex_lock(&sysdev_drivers_lock);
261 __sysdev_driver_remove(cls, drv, NULL);
262 mutex_unlock(&sysdev_drivers_lock);
263}
264EXPORT_SYMBOL_GPL(sysdev_driver_register);
265EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
266
267/**
268 * sysdev_register - add a system device to the tree
269 * @sysdev: device in question
270 *
271 */
272int sysdev_register(struct sys_device *sysdev)
273{
274 int error;
275 struct sysdev_class *cls = sysdev->cls;
276
277 if (!cls)
278 return -EINVAL;
279
280 pr_debug("Registering sys device of class '%s'\n",
281 kobject_name(&cls->kset.kobj));
282
283 /* initialize the kobject to 0, in case it had previously been used */
284 memset(&sysdev->kobj, 0x00, sizeof(struct kobject));
285
286 /* Make sure the kset is set */
287 sysdev->kobj.kset = &cls->kset;
288
289 /* Register the object */
290 error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
291 "%s%d", kobject_name(&cls->kset.kobj),
292 sysdev->id);
293
294 if (!error) {
295 struct sysdev_driver *drv;
296
297 pr_debug("Registering sys device '%s'\n",
298 kobject_name(&sysdev->kobj));
299
300 mutex_lock(&sysdev_drivers_lock);
301 /* Generic notification is implicit, because it's that
302 * code that should have called us.
303 */
304
305 /* Notify class auxiliary drivers */
306 list_for_each_entry(drv, &cls->drivers, entry) {
307 if (drv->add)
308 drv->add(sysdev);
309 }
310 mutex_unlock(&sysdev_drivers_lock);
311 kobject_uevent(&sysdev->kobj, KOBJ_ADD);
312 }
313
314 return error;
315}
316
317void sysdev_unregister(struct sys_device *sysdev)
318{
319 struct sysdev_driver *drv;
320
321 mutex_lock(&sysdev_drivers_lock);
322 list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
323 if (drv->remove)
324 drv->remove(sysdev);
325 }
326 mutex_unlock(&sysdev_drivers_lock);
327
328 kobject_put(&sysdev->kobj);
329}
330
331EXPORT_SYMBOL_GPL(sysdev_register);
332EXPORT_SYMBOL_GPL(sysdev_unregister);
333
334int __init system_bus_init(void)
335{
336 system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
337 if (!system_kset)
338 return -ENOMEM;
339 return 0;
340}
341
342#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
343
344ssize_t sysdev_store_ulong(struct sys_device *sysdev,
345 struct sysdev_attribute *attr,
346 const char *buf, size_t size)
347{
348 struct sysdev_ext_attribute *ea = to_ext_attr(attr);
349 char *end;
350 unsigned long new = simple_strtoul(buf, &end, 0);
351 if (end == buf)
352 return -EINVAL;
353 *(unsigned long *)(ea->var) = new;
354 /* Always return full write size even if we didn't consume all */
355 return size;
356}
357EXPORT_SYMBOL_GPL(sysdev_store_ulong);
358
359ssize_t sysdev_show_ulong(struct sys_device *sysdev,
360 struct sysdev_attribute *attr,
361 char *buf)
362{
363 struct sysdev_ext_attribute *ea = to_ext_attr(attr);
364 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
365}
366EXPORT_SYMBOL_GPL(sysdev_show_ulong);
367
368ssize_t sysdev_store_int(struct sys_device *sysdev,
369 struct sysdev_attribute *attr,
370 const char *buf, size_t size)
371{
372 struct sysdev_ext_attribute *ea = to_ext_attr(attr);
373 char *end;
374 long new = simple_strtol(buf, &end, 0);
375 if (end == buf || new > INT_MAX || new < INT_MIN)
376 return -EINVAL;
377 *(int *)(ea->var) = new;
378 /* Always return full write size even if we didn't consume all */
379 return size;
380}
381EXPORT_SYMBOL_GPL(sysdev_store_int);
382
383ssize_t sysdev_show_int(struct sys_device *sysdev,
384 struct sysdev_attribute *attr,
385 char *buf)
386{
387 struct sysdev_ext_attribute *ea = to_ext_attr(attr);
388 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
389}
390EXPORT_SYMBOL_GPL(sysdev_show_int);
391