projects/linux·blob v2.6.13 · 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/config.h>
16#include <linux/sysdev.h>
17#include <linux/err.h>
18#include <linux/module.h>
19#include <linux/kernel.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <linux/string.h>
23#include <linux/pm.h>
24
25extern struct subsystem devices_subsys;
26
27#define to_sysdev(k) container_of(k, struct sys_device, kobj)
28#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
29
30
31static ssize_t
32sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
33{
34 struct sys_device * sysdev = to_sysdev(kobj);
35 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
36
37 if (sysdev_attr->show)
38 return sysdev_attr->show(sysdev, buffer);
39 return -EIO;
40}
41
42
43static ssize_t
44sysdev_store(struct kobject * kobj, struct attribute * attr,
45 const char * buffer, size_t count)
46{
47 struct sys_device * sysdev = to_sysdev(kobj);
48 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
49
50 if (sysdev_attr->store)
51 return sysdev_attr->store(sysdev, buffer, count);
52 return -EIO;
53}
54
55static struct sysfs_ops sysfs_ops = {
56 .show = sysdev_show,
57 .store = sysdev_store,
58};
59
60static struct kobj_type ktype_sysdev = {
61 .sysfs_ops = &sysfs_ops,
62};
63
64
65int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
66{
67 return sysfs_create_file(&s->kobj, &a->attr);
68}
69
70
71void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
72{
73 sysfs_remove_file(&s->kobj, &a->attr);
74}
75
76EXPORT_SYMBOL_GPL(sysdev_create_file);
77EXPORT_SYMBOL_GPL(sysdev_remove_file);
78
79/*
80 * declare system_subsys
81 */
82static decl_subsys(system, &ktype_sysdev, NULL);
83
84int sysdev_class_register(struct sysdev_class * cls)
85{
86 pr_debug("Registering sysdev class '%s'\n",
87 kobject_name(&cls->kset.kobj));
88 INIT_LIST_HEAD(&cls->drivers);
89 cls->kset.subsys = &system_subsys;
90 kset_set_kset_s(cls, system_subsys);
91 return kset_register(&cls->kset);
92}
93
94void sysdev_class_unregister(struct sysdev_class * cls)
95{
96 pr_debug("Unregistering sysdev class '%s'\n",
97 kobject_name(&cls->kset.kobj));
98 kset_unregister(&cls->kset);
99}
100
101EXPORT_SYMBOL_GPL(sysdev_class_register);
102EXPORT_SYMBOL_GPL(sysdev_class_unregister);
103
104
105static LIST_HEAD(sysdev_drivers);
106static DECLARE_MUTEX(sysdev_drivers_lock);
107
108/**
109 * sysdev_driver_register - Register auxillary driver
110 * @cls: Device class driver belongs to.
111 * @drv: Driver.
112 *
113 * If @cls is valid, then @drv is inserted into @cls->drivers to be
114 * called on each operation on devices of that class. The refcount
115 * of @cls is incremented.
116 * Otherwise, @drv is inserted into sysdev_drivers, and called for
117 * each device.
118 */
119
120int sysdev_driver_register(struct sysdev_class * cls,
121 struct sysdev_driver * drv)
122{
123 down(&sysdev_drivers_lock);
124 if (cls && kset_get(&cls->kset)) {
125 list_add_tail(&drv->entry, &cls->drivers);
126
127 /* If devices of this class already exist, tell the driver */
128 if (drv->add) {
129 struct sys_device *dev;
130 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
131 drv->add(dev);
132 }
133 } else
134 list_add_tail(&drv->entry, &sysdev_drivers);
135 up(&sysdev_drivers_lock);
136 return 0;
137}
138
139
140/**
141 * sysdev_driver_unregister - Remove an auxillary driver.
142 * @cls: Class driver belongs to.
143 * @drv: Driver.
144 */
145void sysdev_driver_unregister(struct sysdev_class * cls,
146 struct sysdev_driver * drv)
147{
148 down(&sysdev_drivers_lock);
149 list_del_init(&drv->entry);
150 if (cls) {
151 if (drv->remove) {
152 struct sys_device *dev;
153 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
154 drv->remove(dev);
155 }
156 kset_put(&cls->kset);
157 }
158 up(&sysdev_drivers_lock);
159}
160
161EXPORT_SYMBOL_GPL(sysdev_driver_register);
162EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
163
164
165
166/**
167 * sysdev_register - add a system device to the tree
168 * @sysdev: device in question
169 *
170 */
171int sysdev_register(struct sys_device * sysdev)
172{
173 int error;
174 struct sysdev_class * cls = sysdev->cls;
175
176 if (!cls)
177 return -EINVAL;
178
179 /* Make sure the kset is set */
180 sysdev->kobj.kset = &cls->kset;
181
182 /* But make sure we point to the right type for sysfs translation */
183 sysdev->kobj.ktype = &ktype_sysdev;
184 error = kobject_set_name(&sysdev->kobj, "%s%d",
185 kobject_name(&cls->kset.kobj), sysdev->id);
186 if (error)
187 return error;
188
189 pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
190
191 /* Register the object */
192 error = kobject_register(&sysdev->kobj);
193
194 if (!error) {
195 struct sysdev_driver * drv;
196
197 down(&sysdev_drivers_lock);
198 /* Generic notification is implicit, because it's that
199 * code that should have called us.
200 */
201
202 /* Notify global drivers */
203 list_for_each_entry(drv, &sysdev_drivers, entry) {
204 if (drv->add)
205 drv->add(sysdev);
206 }
207
208 /* Notify class auxillary drivers */
209 list_for_each_entry(drv, &cls->drivers, entry) {
210 if (drv->add)
211 drv->add(sysdev);
212 }
213 up(&sysdev_drivers_lock);
214 }
215 return error;
216}
217
218void sysdev_unregister(struct sys_device * sysdev)
219{
220 struct sysdev_driver * drv;
221
222 down(&sysdev_drivers_lock);
223 list_for_each_entry(drv, &sysdev_drivers, entry) {
224 if (drv->remove)
225 drv->remove(sysdev);
226 }
227
228 list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
229 if (drv->remove)
230 drv->remove(sysdev);
231 }
232 up(&sysdev_drivers_lock);
233
234 kobject_unregister(&sysdev->kobj);
235}
236
237
238
239/**
240 * sysdev_shutdown - Shut down all system devices.
241 *
242 * Loop over each class of system devices, and the devices in each
243 * of those classes. For each device, we call the shutdown method for
244 * each driver registered for the device - the globals, the auxillaries,
245 * and the class driver.
246 *
247 * Note: The list is iterated in reverse order, so that we shut down
248 * child devices before we shut down thier parents. The list ordering
249 * is guaranteed by virtue of the fact that child devices are registered
250 * after their parents.
251 */
252
253void sysdev_shutdown(void)
254{
255 struct sysdev_class * cls;
256
257 pr_debug("Shutting Down System Devices\n");
258
259 down(&sysdev_drivers_lock);
260 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
261 kset.kobj.entry) {
262 struct sys_device * sysdev;
263
264 pr_debug("Shutting down type '%s':\n",
265 kobject_name(&cls->kset.kobj));
266
267 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
268 struct sysdev_driver * drv;
269 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
270
271 /* Call global drivers first. */
272 list_for_each_entry(drv, &sysdev_drivers, entry) {
273 if (drv->shutdown)
274 drv->shutdown(sysdev);
275 }
276
277 /* Call auxillary drivers next. */
278 list_for_each_entry(drv, &cls->drivers, entry) {
279 if (drv->shutdown)
280 drv->shutdown(sysdev);
281 }
282
283 /* Now call the generic one */
284 if (cls->shutdown)
285 cls->shutdown(sysdev);
286 }
287 }
288 up(&sysdev_drivers_lock);
289}
290
291
292/**
293 * sysdev_suspend - Suspend all system devices.
294 * @state: Power state to enter.
295 *
296 * We perform an almost identical operation as sys_device_shutdown()
297 * above, though calling ->suspend() instead. Interrupts are disabled
298 * when this called. Devices are responsible for both saving state and
299 * quiescing or powering down the device.
300 *
301 * This is only called by the device PM core, so we let them handle
302 * all synchronization.
303 */
304
305int sysdev_suspend(pm_message_t state)
306{
307 struct sysdev_class * cls;
308
309 pr_debug("Suspending System Devices\n");
310
311 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
312 kset.kobj.entry) {
313 struct sys_device * sysdev;
314
315 pr_debug("Suspending type '%s':\n",
316 kobject_name(&cls->kset.kobj));
317
318 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
319 struct sysdev_driver * drv;
320 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
321
322 /* Call global drivers first. */
323 list_for_each_entry(drv, &sysdev_drivers, entry) {
324 if (drv->suspend)
325 drv->suspend(sysdev, state);
326 }
327
328 /* Call auxillary drivers next. */
329 list_for_each_entry(drv, &cls->drivers, entry) {
330 if (drv->suspend)
331 drv->suspend(sysdev, state);
332 }
333
334 /* Now call the generic one */
335 if (cls->suspend)
336 cls->suspend(sysdev, state);
337 }
338 }
339 return 0;
340}
341
342
343/**
344 * sysdev_resume - Bring system devices back to life.
345 *
346 * Similar to sys_device_suspend(), but we iterate the list forwards
347 * to guarantee that parent devices are resumed before their children.
348 *
349 * Note: Interrupts are disabled when called.
350 */
351
352int sysdev_resume(void)
353{
354 struct sysdev_class * cls;
355
356 pr_debug("Resuming System Devices\n");
357
358 list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) {
359 struct sys_device * sysdev;
360
361 pr_debug("Resuming type '%s':\n",
362 kobject_name(&cls->kset.kobj));
363
364 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
365 struct sysdev_driver * drv;
366 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
367
368 /* First, call the class-specific one */
369 if (cls->resume)
370 cls->resume(sysdev);
371
372 /* Call auxillary drivers next. */
373 list_for_each_entry(drv, &cls->drivers, entry) {
374 if (drv->resume)
375 drv->resume(sysdev);
376 }
377
378 /* Call global drivers. */
379 list_for_each_entry(drv, &sysdev_drivers, entry) {
380 if (drv->resume)
381 drv->resume(sysdev);
382 }
383
384 }
385 }
386 return 0;
387}
388
389
390int __init system_bus_init(void)
391{
392 system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
393 return subsystem_register(&system_subsys);
394}
395
396EXPORT_SYMBOL_GPL(sysdev_register);
397EXPORT_SYMBOL_GPL(sysdev_unregister);