projects/linux·blob v2.6.21 · 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/slab.h>
21#include <linux/string.h>
22#include <linux/pm.h>
23#include <linux/device.h>
24#include <asm/semaphore.h>
25
26#include "base.h"
27
28extern struct subsystem devices_subsys;
29
30#define to_sysdev(k) container_of(k, struct sys_device, kobj)
31#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
32
33
34static ssize_t
35sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
36{
37 struct sys_device * sysdev = to_sysdev(kobj);
38 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
39
40 if (sysdev_attr->show)
41 return sysdev_attr->show(sysdev, buffer);
42 return -EIO;
43}
44
45
46static ssize_t
47sysdev_store(struct kobject * kobj, struct attribute * attr,
48 const char * buffer, size_t count)
49{
50 struct sys_device * sysdev = to_sysdev(kobj);
51 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
52
53 if (sysdev_attr->store)
54 return sysdev_attr->store(sysdev, buffer, count);
55 return -EIO;
56}
57
58static struct sysfs_ops sysfs_ops = {
59 .show = sysdev_show,
60 .store = sysdev_store,
61};
62
63static struct kobj_type ktype_sysdev = {
64 .sysfs_ops = &sysfs_ops,
65};
66
67
68int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
69{
70 return sysfs_create_file(&s->kobj, &a->attr);
71}
72
73
74void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
75{
76 sysfs_remove_file(&s->kobj, &a->attr);
77}
78
79EXPORT_SYMBOL_GPL(sysdev_create_file);
80EXPORT_SYMBOL_GPL(sysdev_remove_file);
81
82#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
83#define to_sysdev_class_attr(a) container_of(a, \
84 struct sysdev_class_attribute, attr)
85
86static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
87 char *buffer)
88{
89 struct sysdev_class * class = to_sysdev_class(kobj);
90 struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
91
92 if (class_attr->show)
93 return class_attr->show(class, buffer);
94 return -EIO;
95}
96
97static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
98 const char *buffer, size_t count)
99{
100 struct sysdev_class * class = to_sysdev_class(kobj);
101 struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
102
103 if (class_attr->store)
104 return class_attr->store(class, buffer, count);
105 return -EIO;
106}
107
108static struct sysfs_ops sysfs_class_ops = {
109 .show = sysdev_class_show,
110 .store = sysdev_class_store,
111};
112
113static struct kobj_type ktype_sysdev_class = {
114 .sysfs_ops = &sysfs_class_ops,
115};
116
117int sysdev_class_create_file(struct sysdev_class *c,
118 struct sysdev_class_attribute *a)
119{
120 return sysfs_create_file(&c->kset.kobj, &a->attr);
121}
122EXPORT_SYMBOL_GPL(sysdev_class_create_file);
123
124void sysdev_class_remove_file(struct sysdev_class *c,
125 struct sysdev_class_attribute *a)
126{
127 sysfs_remove_file(&c->kset.kobj, &a->attr);
128}
129EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
130
131/*
132 * declare system_subsys
133 */
134static decl_subsys(system, &ktype_sysdev_class, NULL);
135
136int sysdev_class_register(struct sysdev_class * cls)
137{
138 pr_debug("Registering sysdev class '%s'\n",
139 kobject_name(&cls->kset.kobj));
140 INIT_LIST_HEAD(&cls->drivers);
141 cls->kset.subsys = &system_subsys;
142 kset_set_kset_s(cls, system_subsys);
143 return kset_register(&cls->kset);
144}
145
146void sysdev_class_unregister(struct sysdev_class * cls)
147{
148 pr_debug("Unregistering sysdev class '%s'\n",
149 kobject_name(&cls->kset.kobj));
150 kset_unregister(&cls->kset);
151}
152
153EXPORT_SYMBOL_GPL(sysdev_class_register);
154EXPORT_SYMBOL_GPL(sysdev_class_unregister);
155
156
157static LIST_HEAD(sysdev_drivers);
158static DECLARE_MUTEX(sysdev_drivers_lock);
159
160/**
161 * sysdev_driver_register - Register auxillary driver
162 * @cls: Device class driver belongs to.
163 * @drv: Driver.
164 *
165 * If @cls is valid, then @drv is inserted into @cls->drivers to be
166 * called on each operation on devices of that class. The refcount
167 * of @cls is incremented.
168 * Otherwise, @drv is inserted into sysdev_drivers, and called for
169 * each device.
170 */
171
172int sysdev_driver_register(struct sysdev_class * cls,
173 struct sysdev_driver * drv)
174{
175 down(&sysdev_drivers_lock);
176 if (cls && kset_get(&cls->kset)) {
177 list_add_tail(&drv->entry, &cls->drivers);
178
179 /* If devices of this class already exist, tell the driver */
180 if (drv->add) {
181 struct sys_device *dev;
182 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
183 drv->add(dev);
184 }
185 } else
186 list_add_tail(&drv->entry, &sysdev_drivers);
187 up(&sysdev_drivers_lock);
188 return 0;
189}
190
191
192/**
193 * sysdev_driver_unregister - Remove an auxillary driver.
194 * @cls: Class driver belongs to.
195 * @drv: Driver.
196 */
197void sysdev_driver_unregister(struct sysdev_class * cls,
198 struct sysdev_driver * drv)
199{
200 down(&sysdev_drivers_lock);
201 list_del_init(&drv->entry);
202 if (cls) {
203 if (drv->remove) {
204 struct sys_device *dev;
205 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
206 drv->remove(dev);
207 }
208 kset_put(&cls->kset);
209 }
210 up(&sysdev_drivers_lock);
211}
212
213EXPORT_SYMBOL_GPL(sysdev_driver_register);
214EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
215
216
217
218/**
219 * sysdev_register - add a system device to the tree
220 * @sysdev: device in question
221 *
222 */
223int sysdev_register(struct sys_device * sysdev)
224{
225 int error;
226 struct sysdev_class * cls = sysdev->cls;
227
228 if (!cls)
229 return -EINVAL;
230
231 /* Make sure the kset is set */
232 sysdev->kobj.kset = &cls->kset;
233
234 /* But make sure we point to the right type for sysfs translation */
235 sysdev->kobj.ktype = &ktype_sysdev;
236 error = kobject_set_name(&sysdev->kobj, "%s%d",
237 kobject_name(&cls->kset.kobj), sysdev->id);
238 if (error)
239 return error;
240
241 pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
242
243 /* Register the object */
244 error = kobject_register(&sysdev->kobj);
245
246 if (!error) {
247 struct sysdev_driver * drv;
248
249 down(&sysdev_drivers_lock);
250 /* Generic notification is implicit, because it's that
251 * code that should have called us.
252 */
253
254 /* Notify global drivers */
255 list_for_each_entry(drv, &sysdev_drivers, entry) {
256 if (drv->add)
257 drv->add(sysdev);
258 }
259
260 /* Notify class auxillary drivers */
261 list_for_each_entry(drv, &cls->drivers, entry) {
262 if (drv->add)
263 drv->add(sysdev);
264 }
265 up(&sysdev_drivers_lock);
266 }
267 return error;
268}
269
270void sysdev_unregister(struct sys_device * sysdev)
271{
272 struct sysdev_driver * drv;
273
274 down(&sysdev_drivers_lock);
275 list_for_each_entry(drv, &sysdev_drivers, entry) {
276 if (drv->remove)
277 drv->remove(sysdev);
278 }
279
280 list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
281 if (drv->remove)
282 drv->remove(sysdev);
283 }
284 up(&sysdev_drivers_lock);
285
286 kobject_unregister(&sysdev->kobj);
287}
288
289
290
291/**
292 * sysdev_shutdown - Shut down all system devices.
293 *
294 * Loop over each class of system devices, and the devices in each
295 * of those classes. For each device, we call the shutdown method for
296 * each driver registered for the device - the globals, the auxillaries,
297 * and the class driver.
298 *
299 * Note: The list is iterated in reverse order, so that we shut down
300 * child devices before we shut down thier parents. The list ordering
301 * is guaranteed by virtue of the fact that child devices are registered
302 * after their parents.
303 */
304
305void sysdev_shutdown(void)
306{
307 struct sysdev_class * cls;
308
309 pr_debug("Shutting Down System Devices\n");
310
311 down(&sysdev_drivers_lock);
312 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
313 kset.kobj.entry) {
314 struct sys_device * sysdev;
315
316 pr_debug("Shutting down type '%s':\n",
317 kobject_name(&cls->kset.kobj));
318
319 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
320 struct sysdev_driver * drv;
321 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
322
323 /* Call global drivers first. */
324 list_for_each_entry(drv, &sysdev_drivers, entry) {
325 if (drv->shutdown)
326 drv->shutdown(sysdev);
327 }
328
329 /* Call auxillary drivers next. */
330 list_for_each_entry(drv, &cls->drivers, entry) {
331 if (drv->shutdown)
332 drv->shutdown(sysdev);
333 }
334
335 /* Now call the generic one */
336 if (cls->shutdown)
337 cls->shutdown(sysdev);
338 }
339 }
340 up(&sysdev_drivers_lock);
341}
342
343static void __sysdev_resume(struct sys_device *dev)
344{
345 struct sysdev_class *cls = dev->cls;
346 struct sysdev_driver *drv;
347
348 /* First, call the class-specific one */
349 if (cls->resume)
350 cls->resume(dev);
351
352 /* Call auxillary drivers next. */
353 list_for_each_entry(drv, &cls->drivers, entry) {
354 if (drv->resume)
355 drv->resume(dev);
356 }
357
358 /* Call global drivers. */
359 list_for_each_entry(drv, &sysdev_drivers, entry) {
360 if (drv->resume)
361 drv->resume(dev);
362 }
363}
364
365/**
366 * sysdev_suspend - Suspend all system devices.
367 * @state: Power state to enter.
368 *
369 * We perform an almost identical operation as sys_device_shutdown()
370 * above, though calling ->suspend() instead. Interrupts are disabled
371 * when this called. Devices are responsible for both saving state and
372 * quiescing or powering down the device.
373 *
374 * This is only called by the device PM core, so we let them handle
375 * all synchronization.
376 */
377
378int sysdev_suspend(pm_message_t state)
379{
380 struct sysdev_class * cls;
381 struct sys_device *sysdev, *err_dev;
382 struct sysdev_driver *drv, *err_drv;
383 int ret;
384
385 pr_debug("Suspending System Devices\n");
386
387 list_for_each_entry_reverse(cls, &system_subsys.kset.list,
388 kset.kobj.entry) {
389
390 pr_debug("Suspending type '%s':\n",
391 kobject_name(&cls->kset.kobj));
392
393 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
394 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
395
396 /* Call global drivers first. */
397 list_for_each_entry(drv, &sysdev_drivers, entry) {
398 if (drv->suspend) {
399 ret = drv->suspend(sysdev, state);
400 if (ret)
401 goto gbl_driver;
402 }
403 }
404
405 /* Call auxillary drivers next. */
406 list_for_each_entry(drv, &cls->drivers, entry) {
407 if (drv->suspend) {
408 ret = drv->suspend(sysdev, state);
409 if (ret)
410 goto aux_driver;
411 }
412 }
413
414 /* Now call the generic one */
415 if (cls->suspend) {
416 ret = cls->suspend(sysdev, state);
417 if (ret)
418 goto cls_driver;
419 }
420 }
421 }
422 return 0;
423 /* resume current sysdev */
424cls_driver:
425 drv = NULL;
426 printk(KERN_ERR "Class suspend failed for %s\n",
427 kobject_name(&sysdev->kobj));
428
429aux_driver:
430 if (drv)
431 printk(KERN_ERR "Class driver suspend failed for %s\n",
432 kobject_name(&sysdev->kobj));
433 list_for_each_entry(err_drv, &cls->drivers, entry) {
434 if (err_drv == drv)
435 break;
436 if (err_drv->resume)
437 err_drv->resume(sysdev);
438 }
439 drv = NULL;
440
441gbl_driver:
442 if (drv)
443 printk(KERN_ERR "sysdev driver suspend failed for %s\n",
444 kobject_name(&sysdev->kobj));
445 list_for_each_entry(err_drv, &sysdev_drivers, entry) {
446 if (err_drv == drv)
447 break;
448 if (err_drv->resume)
449 err_drv->resume(sysdev);
450 }
451 /* resume other sysdevs in current class */
452 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
453 if (err_dev == sysdev)
454 break;
455 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
456 __sysdev_resume(err_dev);
457 }
458
459 /* resume other classes */
460 list_for_each_entry_continue(cls, &system_subsys.kset.list,
461 kset.kobj.entry) {
462 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
463 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
464 __sysdev_resume(err_dev);
465 }
466 }
467 return ret;
468}
469
470
471/**
472 * sysdev_resume - Bring system devices back to life.
473 *
474 * Similar to sys_device_suspend(), but we iterate the list forwards
475 * to guarantee that parent devices are resumed before their children.
476 *
477 * Note: Interrupts are disabled when called.
478 */
479
480int sysdev_resume(void)
481{
482 struct sysdev_class * cls;
483
484 pr_debug("Resuming System Devices\n");
485
486 list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) {
487 struct sys_device * sysdev;
488
489 pr_debug("Resuming type '%s':\n",
490 kobject_name(&cls->kset.kobj));
491
492 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
493 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
494
495 __sysdev_resume(sysdev);
496 }
497 }
498 return 0;
499}
500
501
502int __init system_bus_init(void)
503{
504 system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
505 return subsystem_register(&system_subsys);
506}
507
508EXPORT_SYMBOL_GPL(sysdev_register);
509EXPORT_SYMBOL_GPL(sysdev_unregister);