2 * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * 2002-3 Open Source Development Lab
7 * This file is released under the GPLv2
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.
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>
23 #include <linux/device.h>
24 #include <linux/mutex.h>
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)
33 sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
35 struct sys_device * sysdev = to_sysdev(kobj);
36 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
38 if (sysdev_attr->show)
39 return sysdev_attr->show(sysdev, buffer);
45 sysdev_store(struct kobject * kobj, struct attribute * attr,
46 const char * buffer, size_t count)
48 struct sys_device * sysdev = to_sysdev(kobj);
49 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
51 if (sysdev_attr->store)
52 return sysdev_attr->store(sysdev, buffer, count);
56 static struct sysfs_ops sysfs_ops = {
58 .store = sysdev_store,
61 static struct kobj_type ktype_sysdev = {
62 .sysfs_ops = &sysfs_ops,
66 int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
68 return sysfs_create_file(&s->kobj, &a->attr);
72 void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
74 sysfs_remove_file(&s->kobj, &a->attr);
77 EXPORT_SYMBOL_GPL(sysdev_create_file);
78 EXPORT_SYMBOL_GPL(sysdev_remove_file);
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)
84 static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
87 struct sysdev_class * class = to_sysdev_class(kobj);
88 struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
91 return class_attr->show(class, buffer);
95 static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
96 const char *buffer, size_t count)
98 struct sysdev_class * class = to_sysdev_class(kobj);
99 struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
101 if (class_attr->store)
102 return class_attr->store(class, buffer, count);
106 static struct sysfs_ops sysfs_class_ops = {
107 .show = sysdev_class_show,
108 .store = sysdev_class_store,
111 static struct kobj_type ktype_sysdev_class = {
112 .sysfs_ops = &sysfs_class_ops,
115 int sysdev_class_create_file(struct sysdev_class *c,
116 struct sysdev_class_attribute *a)
118 return sysfs_create_file(&c->kset.kobj, &a->attr);
120 EXPORT_SYMBOL_GPL(sysdev_class_create_file);
122 void sysdev_class_remove_file(struct sysdev_class *c,
123 struct sysdev_class_attribute *a)
125 sysfs_remove_file(&c->kset.kobj, &a->attr);
127 EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
130 * declare system_subsys
132 static decl_subsys(system, NULL);
134 int sysdev_class_register(struct sysdev_class * cls)
136 pr_debug("Registering sysdev class '%s'\n",
137 kobject_name(&cls->kset.kobj));
138 INIT_LIST_HEAD(&cls->drivers);
139 cls->kset.kobj.parent = &system_subsys.kobj;
140 cls->kset.kobj.ktype = &ktype_sysdev_class;
141 cls->kset.kobj.kset = &system_subsys;
142 return kset_register(&cls->kset);
145 void sysdev_class_unregister(struct sysdev_class * cls)
147 pr_debug("Unregistering sysdev class '%s'\n",
148 kobject_name(&cls->kset.kobj));
149 kset_unregister(&cls->kset);
152 EXPORT_SYMBOL_GPL(sysdev_class_register);
153 EXPORT_SYMBOL_GPL(sysdev_class_unregister);
155 static DEFINE_MUTEX(sysdev_drivers_lock);
158 * sysdev_driver_register - Register auxillary driver
159 * @cls: Device class driver belongs to.
162 * @drv is inserted into @cls->drivers to be
163 * called on each operation on devices of that class. The refcount
164 * of @cls is incremented.
167 int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
171 mutex_lock(&sysdev_drivers_lock);
172 if (cls && kset_get(&cls->kset)) {
173 list_add_tail(&drv->entry, &cls->drivers);
175 /* If devices of this class already exist, tell the driver */
177 struct sys_device *dev;
178 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
183 printk(KERN_ERR "%s: invalid device class\n", __FUNCTION__);
186 mutex_unlock(&sysdev_drivers_lock);
192 * sysdev_driver_unregister - Remove an auxillary driver.
193 * @cls: Class driver belongs to.
196 void sysdev_driver_unregister(struct sysdev_class * cls,
197 struct sysdev_driver * drv)
199 mutex_lock(&sysdev_drivers_lock);
200 list_del_init(&drv->entry);
203 struct sys_device *dev;
204 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
207 kset_put(&cls->kset);
209 mutex_unlock(&sysdev_drivers_lock);
212 EXPORT_SYMBOL_GPL(sysdev_driver_register);
213 EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
218 * sysdev_register - add a system device to the tree
219 * @sysdev: device in question
222 int sysdev_register(struct sys_device * sysdev)
225 struct sysdev_class * cls = sysdev->cls;
230 /* Make sure the kset is set */
231 sysdev->kobj.kset = &cls->kset;
233 /* But make sure we point to the right type for sysfs translation */
234 sysdev->kobj.ktype = &ktype_sysdev;
235 error = kobject_set_name(&sysdev->kobj, "%s%d",
236 kobject_name(&cls->kset.kobj), sysdev->id);
240 pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
242 /* Register the object */
243 error = kobject_register(&sysdev->kobj);
246 struct sysdev_driver * drv;
248 mutex_lock(&sysdev_drivers_lock);
249 /* Generic notification is implicit, because it's that
250 * code that should have called us.
253 /* Notify class auxillary drivers */
254 list_for_each_entry(drv, &cls->drivers, entry) {
258 mutex_unlock(&sysdev_drivers_lock);
263 void sysdev_unregister(struct sys_device * sysdev)
265 struct sysdev_driver * drv;
267 mutex_lock(&sysdev_drivers_lock);
268 list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
272 mutex_unlock(&sysdev_drivers_lock);
274 kobject_unregister(&sysdev->kobj);
280 * sysdev_shutdown - Shut down all system devices.
282 * Loop over each class of system devices, and the devices in each
283 * of those classes. For each device, we call the shutdown method for
284 * each driver registered for the device - the auxillaries,
285 * and the class driver.
287 * Note: The list is iterated in reverse order, so that we shut down
288 * child devices before we shut down thier parents. The list ordering
289 * is guaranteed by virtue of the fact that child devices are registered
290 * after their parents.
293 void sysdev_shutdown(void)
295 struct sysdev_class * cls;
297 pr_debug("Shutting Down System Devices\n");
299 mutex_lock(&sysdev_drivers_lock);
300 list_for_each_entry_reverse(cls, &system_subsys.list,
302 struct sys_device * sysdev;
304 pr_debug("Shutting down type '%s':\n",
305 kobject_name(&cls->kset.kobj));
307 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
308 struct sysdev_driver * drv;
309 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
311 /* Call auxillary drivers first */
312 list_for_each_entry(drv, &cls->drivers, entry) {
314 drv->shutdown(sysdev);
317 /* Now call the generic one */
319 cls->shutdown(sysdev);
322 mutex_unlock(&sysdev_drivers_lock);
325 static void __sysdev_resume(struct sys_device *dev)
327 struct sysdev_class *cls = dev->cls;
328 struct sysdev_driver *drv;
330 /* First, call the class-specific one */
334 /* Call auxillary drivers next. */
335 list_for_each_entry(drv, &cls->drivers, entry) {
342 * sysdev_suspend - Suspend all system devices.
343 * @state: Power state to enter.
345 * We perform an almost identical operation as sys_device_shutdown()
346 * above, though calling ->suspend() instead. Interrupts are disabled
347 * when this called. Devices are responsible for both saving state and
348 * quiescing or powering down the device.
350 * This is only called by the device PM core, so we let them handle
351 * all synchronization.
354 int sysdev_suspend(pm_message_t state)
356 struct sysdev_class * cls;
357 struct sys_device *sysdev, *err_dev;
358 struct sysdev_driver *drv, *err_drv;
361 pr_debug("Suspending System Devices\n");
363 list_for_each_entry_reverse(cls, &system_subsys.list,
366 pr_debug("Suspending type '%s':\n",
367 kobject_name(&cls->kset.kobj));
369 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
370 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
372 /* Call auxillary drivers first */
373 list_for_each_entry(drv, &cls->drivers, entry) {
375 ret = drv->suspend(sysdev, state);
381 /* Now call the generic one */
383 ret = cls->suspend(sysdev, state);
390 /* resume current sysdev */
393 printk(KERN_ERR "Class suspend failed for %s\n",
394 kobject_name(&sysdev->kobj));
398 printk(KERN_ERR "Class driver suspend failed for %s\n",
399 kobject_name(&sysdev->kobj));
400 list_for_each_entry(err_drv, &cls->drivers, entry) {
404 err_drv->resume(sysdev);
407 /* resume other sysdevs in current class */
408 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
409 if (err_dev == sysdev)
411 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
412 __sysdev_resume(err_dev);
415 /* resume other classes */
416 list_for_each_entry_continue(cls, &system_subsys.list,
418 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
419 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
420 __sysdev_resume(err_dev);
428 * sysdev_resume - Bring system devices back to life.
430 * Similar to sys_device_suspend(), but we iterate the list forwards
431 * to guarantee that parent devices are resumed before their children.
433 * Note: Interrupts are disabled when called.
436 int sysdev_resume(void)
438 struct sysdev_class * cls;
440 pr_debug("Resuming System Devices\n");
442 list_for_each_entry(cls, &system_subsys.list, kset.kobj.entry) {
443 struct sys_device * sysdev;
445 pr_debug("Resuming type '%s':\n",
446 kobject_name(&cls->kset.kobj));
448 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
449 pr_debug(" %s\n", kobject_name(&sysdev->kobj));
451 __sysdev_resume(sysdev);
458 int __init system_bus_init(void)
460 system_subsys.kobj.parent = &devices_kset->kobj;
461 return subsystem_register(&system_subsys);
464 EXPORT_SYMBOL_GPL(sysdev_register);
465 EXPORT_SYMBOL_GPL(sysdev_unregister);