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
, sysdev_attr
, 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
, sysdev_attr
, 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
);
129 static struct kset
*system_kset
;
131 int sysdev_class_register(struct sysdev_class
* cls
)
133 pr_debug("Registering sysdev class '%s'\n", cls
->name
);
135 INIT_LIST_HEAD(&cls
->drivers
);
136 memset(&cls
->kset
.kobj
, 0x00, sizeof(struct kobject
));
137 cls
->kset
.kobj
.parent
= &system_kset
->kobj
;
138 cls
->kset
.kobj
.ktype
= &ktype_sysdev_class
;
139 cls
->kset
.kobj
.kset
= system_kset
;
140 kobject_set_name(&cls
->kset
.kobj
, cls
->name
);
141 return kset_register(&cls
->kset
);
144 void sysdev_class_unregister(struct sysdev_class
* cls
)
146 pr_debug("Unregistering sysdev class '%s'\n",
147 kobject_name(&cls
->kset
.kobj
));
148 kset_unregister(&cls
->kset
);
151 EXPORT_SYMBOL_GPL(sysdev_class_register
);
152 EXPORT_SYMBOL_GPL(sysdev_class_unregister
);
154 static DEFINE_MUTEX(sysdev_drivers_lock
);
157 * sysdev_driver_register - Register auxillary driver
158 * @cls: Device class driver belongs to.
161 * @drv is inserted into @cls->drivers to be
162 * called on each operation on devices of that class. The refcount
163 * of @cls is incremented.
166 int sysdev_driver_register(struct sysdev_class
*cls
, struct sysdev_driver
*drv
)
171 printk(KERN_WARNING
"sysdev: invalid class passed to "
172 "sysdev_driver_register!\n");
177 /* Check whether this driver has already been added to a class. */
178 if (drv
->entry
.next
&& !list_empty(&drv
->entry
)) {
179 printk(KERN_WARNING
"sysdev: class %s: driver (%p) has already"
180 " been registered to a class, something is wrong, but "
181 "will forge on!\n", cls
->name
, drv
);
185 mutex_lock(&sysdev_drivers_lock
);
186 if (cls
&& kset_get(&cls
->kset
)) {
187 list_add_tail(&drv
->entry
, &cls
->drivers
);
189 /* If devices of this class already exist, tell the driver */
191 struct sys_device
*dev
;
192 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
)
197 printk(KERN_ERR
"%s: invalid device class\n", __func__
);
200 mutex_unlock(&sysdev_drivers_lock
);
206 * sysdev_driver_unregister - Remove an auxillary driver.
207 * @cls: Class driver belongs to.
210 void sysdev_driver_unregister(struct sysdev_class
* cls
,
211 struct sysdev_driver
* drv
)
213 mutex_lock(&sysdev_drivers_lock
);
214 list_del_init(&drv
->entry
);
217 struct sys_device
*dev
;
218 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
)
221 kset_put(&cls
->kset
);
223 mutex_unlock(&sysdev_drivers_lock
);
226 EXPORT_SYMBOL_GPL(sysdev_driver_register
);
227 EXPORT_SYMBOL_GPL(sysdev_driver_unregister
);
232 * sysdev_register - add a system device to the tree
233 * @sysdev: device in question
236 int sysdev_register(struct sys_device
* sysdev
)
239 struct sysdev_class
* cls
= sysdev
->cls
;
244 pr_debug("Registering sys device of class '%s'\n",
245 kobject_name(&cls
->kset
.kobj
));
247 /* initialize the kobject to 0, in case it had previously been used */
248 memset(&sysdev
->kobj
, 0x00, sizeof(struct kobject
));
250 /* Make sure the kset is set */
251 sysdev
->kobj
.kset
= &cls
->kset
;
253 /* Register the object */
254 error
= kobject_init_and_add(&sysdev
->kobj
, &ktype_sysdev
, NULL
,
255 "%s%d", kobject_name(&cls
->kset
.kobj
),
259 struct sysdev_driver
* drv
;
261 pr_debug("Registering sys device '%s'\n",
262 kobject_name(&sysdev
->kobj
));
264 mutex_lock(&sysdev_drivers_lock
);
265 /* Generic notification is implicit, because it's that
266 * code that should have called us.
269 /* Notify class auxillary drivers */
270 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
274 mutex_unlock(&sysdev_drivers_lock
);
277 kobject_uevent(&sysdev
->kobj
, KOBJ_ADD
);
281 void sysdev_unregister(struct sys_device
* sysdev
)
283 struct sysdev_driver
* drv
;
285 mutex_lock(&sysdev_drivers_lock
);
286 list_for_each_entry(drv
, &sysdev
->cls
->drivers
, entry
) {
290 mutex_unlock(&sysdev_drivers_lock
);
292 kobject_put(&sysdev
->kobj
);
298 * sysdev_shutdown - Shut down all system devices.
300 * Loop over each class of system devices, and the devices in each
301 * of those classes. For each device, we call the shutdown method for
302 * each driver registered for the device - the auxillaries,
303 * and the class driver.
305 * Note: The list is iterated in reverse order, so that we shut down
306 * child devices before we shut down thier parents. The list ordering
307 * is guaranteed by virtue of the fact that child devices are registered
308 * after their parents.
311 void sysdev_shutdown(void)
313 struct sysdev_class
* cls
;
315 pr_debug("Shutting Down System Devices\n");
317 mutex_lock(&sysdev_drivers_lock
);
318 list_for_each_entry_reverse(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
319 struct sys_device
* sysdev
;
321 pr_debug("Shutting down type '%s':\n",
322 kobject_name(&cls
->kset
.kobj
));
324 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
325 struct sysdev_driver
* drv
;
326 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
328 /* Call auxillary drivers first */
329 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
331 drv
->shutdown(sysdev
);
334 /* Now call the generic one */
336 cls
->shutdown(sysdev
);
339 mutex_unlock(&sysdev_drivers_lock
);
342 static void __sysdev_resume(struct sys_device
*dev
)
344 struct sysdev_class
*cls
= dev
->cls
;
345 struct sysdev_driver
*drv
;
347 /* First, call the class-specific one */
351 /* Call auxillary drivers next. */
352 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
359 * sysdev_suspend - Suspend all system devices.
360 * @state: Power state to enter.
362 * We perform an almost identical operation as sys_device_shutdown()
363 * above, though calling ->suspend() instead. Interrupts are disabled
364 * when this called. Devices are responsible for both saving state and
365 * quiescing or powering down the device.
367 * This is only called by the device PM core, so we let them handle
368 * all synchronization.
371 int sysdev_suspend(pm_message_t state
)
373 struct sysdev_class
* cls
;
374 struct sys_device
*sysdev
, *err_dev
;
375 struct sysdev_driver
*drv
, *err_drv
;
378 pr_debug("Suspending System Devices\n");
380 list_for_each_entry_reverse(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
381 pr_debug("Suspending type '%s':\n",
382 kobject_name(&cls
->kset
.kobj
));
384 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
385 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
387 /* Call auxillary drivers first */
388 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
390 ret
= drv
->suspend(sysdev
, state
);
396 /* Now call the generic one */
398 ret
= cls
->suspend(sysdev
, state
);
405 /* resume current sysdev */
408 printk(KERN_ERR
"Class suspend failed for %s\n",
409 kobject_name(&sysdev
->kobj
));
413 printk(KERN_ERR
"Class driver suspend failed for %s\n",
414 kobject_name(&sysdev
->kobj
));
415 list_for_each_entry(err_drv
, &cls
->drivers
, entry
) {
419 err_drv
->resume(sysdev
);
422 /* resume other sysdevs in current class */
423 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
424 if (err_dev
== sysdev
)
426 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
427 __sysdev_resume(err_dev
);
430 /* resume other classes */
431 list_for_each_entry_continue(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
432 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
433 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
434 __sysdev_resume(err_dev
);
442 * sysdev_resume - Bring system devices back to life.
444 * Similar to sys_device_suspend(), but we iterate the list forwards
445 * to guarantee that parent devices are resumed before their children.
447 * Note: Interrupts are disabled when called.
450 int sysdev_resume(void)
452 struct sysdev_class
* cls
;
454 pr_debug("Resuming System Devices\n");
456 list_for_each_entry(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
457 struct sys_device
* sysdev
;
459 pr_debug("Resuming type '%s':\n",
460 kobject_name(&cls
->kset
.kobj
));
462 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
463 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
465 __sysdev_resume(sysdev
);
472 int __init
system_bus_init(void)
474 system_kset
= kset_create_and_add("system", NULL
, &devices_kset
->kobj
);
480 EXPORT_SYMBOL_GPL(sysdev_register
);
481 EXPORT_SYMBOL_GPL(sysdev_unregister
);