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 extern struct kset devices_subsys
;
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)
35 sysdev_show(struct kobject
* kobj
, struct attribute
* attr
, char * buffer
)
37 struct sys_device
* sysdev
= to_sysdev(kobj
);
38 struct sysdev_attribute
* sysdev_attr
= to_sysdev_attr(attr
);
40 if (sysdev_attr
->show
)
41 return sysdev_attr
->show(sysdev
, buffer
);
47 sysdev_store(struct kobject
* kobj
, struct attribute
* attr
,
48 const char * buffer
, size_t count
)
50 struct sys_device
* sysdev
= to_sysdev(kobj
);
51 struct sysdev_attribute
* sysdev_attr
= to_sysdev_attr(attr
);
53 if (sysdev_attr
->store
)
54 return sysdev_attr
->store(sysdev
, buffer
, count
);
58 static struct sysfs_ops sysfs_ops
= {
60 .store
= sysdev_store
,
63 static struct kobj_type ktype_sysdev
= {
64 .sysfs_ops
= &sysfs_ops
,
68 int sysdev_create_file(struct sys_device
* s
, struct sysdev_attribute
* a
)
70 return sysfs_create_file(&s
->kobj
, &a
->attr
);
74 void sysdev_remove_file(struct sys_device
* s
, struct sysdev_attribute
* a
)
76 sysfs_remove_file(&s
->kobj
, &a
->attr
);
79 EXPORT_SYMBOL_GPL(sysdev_create_file
);
80 EXPORT_SYMBOL_GPL(sysdev_remove_file
);
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)
86 static ssize_t
sysdev_class_show(struct kobject
*kobj
, struct attribute
*attr
,
89 struct sysdev_class
* class = to_sysdev_class(kobj
);
90 struct sysdev_class_attribute
*class_attr
= to_sysdev_class_attr(attr
);
93 return class_attr
->show(class, buffer
);
97 static ssize_t
sysdev_class_store(struct kobject
*kobj
, struct attribute
*attr
,
98 const char *buffer
, size_t count
)
100 struct sysdev_class
* class = to_sysdev_class(kobj
);
101 struct sysdev_class_attribute
* class_attr
= to_sysdev_class_attr(attr
);
103 if (class_attr
->store
)
104 return class_attr
->store(class, buffer
, count
);
108 static struct sysfs_ops sysfs_class_ops
= {
109 .show
= sysdev_class_show
,
110 .store
= sysdev_class_store
,
113 static struct kobj_type ktype_sysdev_class
= {
114 .sysfs_ops
= &sysfs_class_ops
,
117 int sysdev_class_create_file(struct sysdev_class
*c
,
118 struct sysdev_class_attribute
*a
)
120 return sysfs_create_file(&c
->kset
.kobj
, &a
->attr
);
122 EXPORT_SYMBOL_GPL(sysdev_class_create_file
);
124 void sysdev_class_remove_file(struct sysdev_class
*c
,
125 struct sysdev_class_attribute
*a
)
127 sysfs_remove_file(&c
->kset
.kobj
, &a
->attr
);
129 EXPORT_SYMBOL_GPL(sysdev_class_remove_file
);
132 * declare system_subsys
134 static decl_subsys(system
, NULL
);
136 int sysdev_class_register(struct sysdev_class
* cls
)
138 pr_debug("Registering sysdev class '%s'\n",
139 kobject_name(&cls
->kset
.kobj
));
140 INIT_LIST_HEAD(&cls
->drivers
);
141 cls
->kset
.kobj
.parent
= &system_subsys
.kobj
;
142 cls
->kset
.kobj
.ktype
= &ktype_sysdev_class
;
143 cls
->kset
.kobj
.kset
= &system_subsys
;
144 return kset_register(&cls
->kset
);
147 void sysdev_class_unregister(struct sysdev_class
* cls
)
149 pr_debug("Unregistering sysdev class '%s'\n",
150 kobject_name(&cls
->kset
.kobj
));
151 kset_unregister(&cls
->kset
);
154 EXPORT_SYMBOL_GPL(sysdev_class_register
);
155 EXPORT_SYMBOL_GPL(sysdev_class_unregister
);
157 static DEFINE_MUTEX(sysdev_drivers_lock
);
160 * sysdev_driver_register - Register auxillary driver
161 * @cls: Device class driver belongs to.
164 * @drv is inserted into @cls->drivers to be
165 * called on each operation on devices of that class. The refcount
166 * of @cls is incremented.
169 int sysdev_driver_register(struct sysdev_class
*cls
, struct sysdev_driver
*drv
)
173 mutex_lock(&sysdev_drivers_lock
);
174 if (cls
&& kset_get(&cls
->kset
)) {
175 list_add_tail(&drv
->entry
, &cls
->drivers
);
177 /* If devices of this class already exist, tell the driver */
179 struct sys_device
*dev
;
180 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
)
185 printk(KERN_ERR
"%s: invalid device class\n", __FUNCTION__
);
188 mutex_unlock(&sysdev_drivers_lock
);
194 * sysdev_driver_unregister - Remove an auxillary driver.
195 * @cls: Class driver belongs to.
198 void sysdev_driver_unregister(struct sysdev_class
* cls
,
199 struct sysdev_driver
* drv
)
201 mutex_lock(&sysdev_drivers_lock
);
202 list_del_init(&drv
->entry
);
205 struct sys_device
*dev
;
206 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
)
209 kset_put(&cls
->kset
);
211 mutex_unlock(&sysdev_drivers_lock
);
214 EXPORT_SYMBOL_GPL(sysdev_driver_register
);
215 EXPORT_SYMBOL_GPL(sysdev_driver_unregister
);
220 * sysdev_register - add a system device to the tree
221 * @sysdev: device in question
224 int sysdev_register(struct sys_device
* sysdev
)
227 struct sysdev_class
* cls
= sysdev
->cls
;
232 /* Make sure the kset is set */
233 sysdev
->kobj
.kset
= &cls
->kset
;
235 /* But make sure we point to the right type for sysfs translation */
236 sysdev
->kobj
.ktype
= &ktype_sysdev
;
237 error
= kobject_set_name(&sysdev
->kobj
, "%s%d",
238 kobject_name(&cls
->kset
.kobj
), sysdev
->id
);
242 pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev
->kobj
));
244 /* Register the object */
245 error
= kobject_register(&sysdev
->kobj
);
248 struct sysdev_driver
* drv
;
250 mutex_lock(&sysdev_drivers_lock
);
251 /* Generic notification is implicit, because it's that
252 * code that should have called us.
255 /* Notify class auxillary drivers */
256 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
260 mutex_unlock(&sysdev_drivers_lock
);
265 void sysdev_unregister(struct sys_device
* sysdev
)
267 struct sysdev_driver
* drv
;
269 mutex_lock(&sysdev_drivers_lock
);
270 list_for_each_entry(drv
, &sysdev
->cls
->drivers
, entry
) {
274 mutex_unlock(&sysdev_drivers_lock
);
276 kobject_unregister(&sysdev
->kobj
);
282 * sysdev_shutdown - Shut down all system devices.
284 * Loop over each class of system devices, and the devices in each
285 * of those classes. For each device, we call the shutdown method for
286 * each driver registered for the device - the auxillaries,
287 * and the class driver.
289 * Note: The list is iterated in reverse order, so that we shut down
290 * child devices before we shut down thier parents. The list ordering
291 * is guaranteed by virtue of the fact that child devices are registered
292 * after their parents.
295 void sysdev_shutdown(void)
297 struct sysdev_class
* cls
;
299 pr_debug("Shutting Down System Devices\n");
301 mutex_lock(&sysdev_drivers_lock
);
302 list_for_each_entry_reverse(cls
, &system_subsys
.list
,
304 struct sys_device
* sysdev
;
306 pr_debug("Shutting down type '%s':\n",
307 kobject_name(&cls
->kset
.kobj
));
309 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
310 struct sysdev_driver
* drv
;
311 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
313 /* Call auxillary drivers first */
314 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
316 drv
->shutdown(sysdev
);
319 /* Now call the generic one */
321 cls
->shutdown(sysdev
);
324 mutex_unlock(&sysdev_drivers_lock
);
327 static void __sysdev_resume(struct sys_device
*dev
)
329 struct sysdev_class
*cls
= dev
->cls
;
330 struct sysdev_driver
*drv
;
332 /* First, call the class-specific one */
336 /* Call auxillary drivers next. */
337 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
344 * sysdev_suspend - Suspend all system devices.
345 * @state: Power state to enter.
347 * We perform an almost identical operation as sys_device_shutdown()
348 * above, though calling ->suspend() instead. Interrupts are disabled
349 * when this called. Devices are responsible for both saving state and
350 * quiescing or powering down the device.
352 * This is only called by the device PM core, so we let them handle
353 * all synchronization.
356 int sysdev_suspend(pm_message_t state
)
358 struct sysdev_class
* cls
;
359 struct sys_device
*sysdev
, *err_dev
;
360 struct sysdev_driver
*drv
, *err_drv
;
363 pr_debug("Suspending System Devices\n");
365 list_for_each_entry_reverse(cls
, &system_subsys
.list
,
368 pr_debug("Suspending type '%s':\n",
369 kobject_name(&cls
->kset
.kobj
));
371 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
372 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
374 /* Call auxillary drivers first */
375 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
377 ret
= drv
->suspend(sysdev
, state
);
383 /* Now call the generic one */
385 ret
= cls
->suspend(sysdev
, state
);
392 /* resume current sysdev */
395 printk(KERN_ERR
"Class suspend failed for %s\n",
396 kobject_name(&sysdev
->kobj
));
400 printk(KERN_ERR
"Class driver suspend failed for %s\n",
401 kobject_name(&sysdev
->kobj
));
402 list_for_each_entry(err_drv
, &cls
->drivers
, entry
) {
406 err_drv
->resume(sysdev
);
409 /* resume other sysdevs in current class */
410 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
411 if (err_dev
== sysdev
)
413 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
414 __sysdev_resume(err_dev
);
417 /* resume other classes */
418 list_for_each_entry_continue(cls
, &system_subsys
.list
,
420 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
421 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
422 __sysdev_resume(err_dev
);
430 * sysdev_resume - Bring system devices back to life.
432 * Similar to sys_device_suspend(), but we iterate the list forwards
433 * to guarantee that parent devices are resumed before their children.
435 * Note: Interrupts are disabled when called.
438 int sysdev_resume(void)
440 struct sysdev_class
* cls
;
442 pr_debug("Resuming System Devices\n");
444 list_for_each_entry(cls
, &system_subsys
.list
, kset
.kobj
.entry
) {
445 struct sys_device
* sysdev
;
447 pr_debug("Resuming type '%s':\n",
448 kobject_name(&cls
->kset
.kobj
));
450 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
451 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
453 __sysdev_resume(sysdev
);
460 int __init
system_bus_init(void)
462 system_subsys
.kobj
.parent
= &devices_subsys
.kobj
;
463 return subsystem_register(&system_subsys
);
466 EXPORT_SYMBOL_GPL(sysdev_register
);
467 EXPORT_SYMBOL_GPL(sysdev_unregister
);