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/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>
25 extern struct subsystem devices_subsys;
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)
32 sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
34 struct sys_device * sysdev = to_sysdev(kobj);
35 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
37 if (sysdev_attr->show)
38 return sysdev_attr->show(sysdev,buffer);
44 sysdev_store(struct kobject * kobj, struct attribute * attr,
45 const char * buffer, size_t count)
47 struct sys_device * sysdev = to_sysdev(kobj);
48 struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
50 if (sysdev_attr->store)
51 return sysdev_attr->store(sysdev,buffer,count);
55 static struct sysfs_ops sysfs_ops = {
57 .store = sysdev_store,
60 static struct kobj_type ktype_sysdev = {
61 .sysfs_ops = &sysfs_ops,
65 int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
67 return sysfs_create_file(&s->kobj,&a->attr);
71 void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
73 sysfs_remove_file(&s->kobj,&a->attr);
76 EXPORT_SYMBOL(sysdev_create_file);
77 EXPORT_SYMBOL(sysdev_remove_file);
80 * declare system_subsys
82 decl_subsys(system,&ktype_sysdev,NULL);
84 int sysdev_class_register(struct sysdev_class * cls)
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);
94 void sysdev_class_unregister(struct sysdev_class * cls)
96 pr_debug("Unregistering sysdev class '%s'\n",
97 kobject_name(&cls->kset.kobj));
98 kset_unregister(&cls->kset);
101 EXPORT_SYMBOL(sysdev_class_register);
102 EXPORT_SYMBOL(sysdev_class_unregister);
105 static LIST_HEAD(global_drivers);
108 * sysdev_driver_register - Register auxillary driver
109 * @cls: Device class driver belongs to.
112 * If @cls is valid, then @drv is inserted into @cls->drivers to be
113 * called on each operation on devices of that class. The refcount
114 * of @cls is incremented.
115 * Otherwise, @drv is inserted into global_drivers, and called for
119 int sysdev_driver_register(struct sysdev_class * cls,
120 struct sysdev_driver * drv)
122 down_write(&system_subsys.rwsem);
123 if (cls && kset_get(&cls->kset)) {
124 list_add_tail(&drv->entry,&cls->drivers);
126 /* If devices of this class already exist, tell the driver */
128 struct sys_device *dev;
129 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
133 list_add_tail(&drv->entry,&global_drivers);
134 up_write(&system_subsys.rwsem);
140 * sysdev_driver_unregister - Remove an auxillary driver.
141 * @cls: Class driver belongs to.
144 void sysdev_driver_unregister(struct sysdev_class * cls,
145 struct sysdev_driver * drv)
147 down_write(&system_subsys.rwsem);
148 list_del_init(&drv->entry);
151 struct sys_device *dev;
152 list_for_each_entry(dev, &cls->kset.list, kobj.entry)
155 kset_put(&cls->kset);
157 up_write(&system_subsys.rwsem);
160 EXPORT_SYMBOL(sysdev_driver_register);
161 EXPORT_SYMBOL(sysdev_driver_unregister);
166 * sysdev_register - add a system device to the tree
167 * @sysdev: device in question
170 int sysdev_register(struct sys_device * sysdev)
173 struct sysdev_class * cls = sysdev->cls;
178 /* Make sure the kset is set */
179 sysdev->kobj.kset = &cls->kset;
181 /* But make sure we point to the right type for sysfs translation */
182 sysdev->kobj.ktype = &ktype_sysdev;
183 kobject_set_name(&sysdev->kobj,"%s%d",
184 kobject_name(&cls->kset.kobj),sysdev->id);
185 pr_debug("Registering sys device '%s'\n",kobject_name(&sysdev->kobj));
187 /* Register the object */
188 error = kobject_register(&sysdev->kobj);
191 struct sysdev_driver * drv;
193 down_write(&system_subsys.rwsem);
194 /* Generic notification is implicit, because it's that
195 * code that should have called us.
198 /* Notify global drivers */
199 list_for_each_entry(drv,&global_drivers,entry) {
204 /* Notify class auxillary drivers */
205 list_for_each_entry(drv,&cls->drivers,entry) {
209 up_write(&system_subsys.rwsem);
214 void sysdev_unregister(struct sys_device * sysdev)
216 struct sysdev_driver * drv;
218 down_write(&system_subsys.rwsem);
219 list_for_each_entry(drv,&global_drivers,entry) {
224 list_for_each_entry(drv,&sysdev->cls->drivers,entry) {
228 up_write(&system_subsys.rwsem);
230 kobject_unregister(&sysdev->kobj);
236 * sysdev_shutdown - Shut down all system devices.
238 * Loop over each class of system devices, and the devices in each
239 * of those classes. For each device, we call the shutdown method for
240 * each driver registered for the device - the globals, the auxillaries,
241 * and the class driver.
243 * Note: The list is iterated in reverse order, so that we shut down
244 * child devices before we shut down thier parents. The list ordering
245 * is guaranteed by virtue of the fact that child devices are registered
246 * after their parents.
249 void sysdev_shutdown(void)
251 struct sysdev_class * cls;
253 pr_debug("Shutting Down System Devices\n");
255 down_write(&system_subsys.rwsem);
256 list_for_each_entry_reverse(cls,&system_subsys.kset.list,
258 struct sys_device * sysdev;
260 pr_debug("Shutting down type '%s':\n",
261 kobject_name(&cls->kset.kobj));
263 list_for_each_entry(sysdev,&cls->kset.list,kobj.entry) {
264 struct sysdev_driver * drv;
265 pr_debug(" %s\n",kobject_name(&sysdev->kobj));
267 /* Call global drivers first. */
268 list_for_each_entry(drv,&global_drivers,entry) {
270 drv->shutdown(sysdev);
273 /* Call auxillary drivers next. */
274 list_for_each_entry(drv,&cls->drivers,entry) {
276 drv->shutdown(sysdev);
279 /* Now call the generic one */
281 cls->shutdown(sysdev);
284 up_write(&system_subsys.rwsem);
289 * sysdev_suspend - Suspend all system devices.
290 * @state: Power state to enter.
292 * We perform an almost identical operation as sys_device_shutdown()
293 * above, though calling ->suspend() instead. Interrupts are disabled
294 * when this called. Devices are responsible for both saving state and
295 * quiescing or powering down the device.
297 * This is only called by the device PM core, so we let them handle
298 * all synchronization.
301 int sysdev_suspend(u32 state)
303 struct sysdev_class * cls;
305 pr_debug("Suspending System Devices\n");
307 list_for_each_entry_reverse(cls,&system_subsys.kset.list,
309 struct sys_device * sysdev;
311 pr_debug("Suspending type '%s':\n",
312 kobject_name(&cls->kset.kobj));
314 list_for_each_entry(sysdev,&cls->kset.list,kobj.entry) {
315 struct sysdev_driver * drv;
316 pr_debug(" %s\n",kobject_name(&sysdev->kobj));
318 /* Call global drivers first. */
319 list_for_each_entry(drv,&global_drivers,entry) {
321 drv->suspend(sysdev,state);
324 /* Call auxillary drivers next. */
325 list_for_each_entry(drv,&cls->drivers,entry) {
327 drv->suspend(sysdev,state);
330 /* Now call the generic one */
332 cls->suspend(sysdev,state);
340 * sysdev_resume - Bring system devices back to life.
342 * Similar to sys_device_suspend(), but we iterate the list forwards
343 * to guarantee that parent devices are resumed before their children.
345 * Note: Interrupts are disabled when called.
348 int sysdev_resume(void)
350 struct sysdev_class * cls;
352 pr_debug("Resuming System Devices\n");
354 list_for_each_entry(cls,&system_subsys.kset.list,kset.kobj.entry) {
355 struct sys_device * sysdev;
357 pr_debug("Resuming type '%s':\n",
358 kobject_name(&cls->kset.kobj));
360 list_for_each_entry(sysdev,&cls->kset.list,kobj.entry) {
361 struct sysdev_driver * drv;
362 pr_debug(" %s\n",kobject_name(&sysdev->kobj));
364 /* First, call the class-specific one */
368 /* Call auxillary drivers next. */
369 list_for_each_entry(drv,&cls->drivers,entry) {
374 /* Call global drivers. */
375 list_for_each_entry(drv,&global_drivers,entry) {
386 int __init system_bus_init(void)
388 system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
389 return subsystem_register(&system_subsys);
392 EXPORT_SYMBOL(sysdev_register);
393 EXPORT_SYMBOL(sysdev_unregister);