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/string.h>
22 #include <linux/device.h>
23 #include <linux/mutex.h>
24 #include <linux/interrupt.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 const 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, class_attr
, 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, class_attr
, buffer
, count
);
106 static const 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
)
135 pr_debug("Registering sysdev class '%s'\n", cls
->name
);
137 INIT_LIST_HEAD(&cls
->drivers
);
138 memset(&cls
->kset
.kobj
, 0x00, sizeof(struct kobject
));
139 cls
->kset
.kobj
.parent
= &system_kset
->kobj
;
140 cls
->kset
.kobj
.ktype
= &ktype_sysdev_class
;
141 cls
->kset
.kobj
.kset
= system_kset
;
143 retval
= kobject_set_name(&cls
->kset
.kobj
, "%s", cls
->name
);
147 retval
= kset_register(&cls
->kset
);
148 if (!retval
&& cls
->attrs
)
149 retval
= sysfs_create_files(&cls
->kset
.kobj
,
150 (const struct attribute
**)cls
->attrs
);
154 void sysdev_class_unregister(struct sysdev_class
*cls
)
156 pr_debug("Unregistering sysdev class '%s'\n",
157 kobject_name(&cls
->kset
.kobj
));
159 sysfs_remove_files(&cls
->kset
.kobj
,
160 (const struct attribute
**)cls
->attrs
);
161 kset_unregister(&cls
->kset
);
164 EXPORT_SYMBOL_GPL(sysdev_class_register
);
165 EXPORT_SYMBOL_GPL(sysdev_class_unregister
);
167 static DEFINE_MUTEX(sysdev_drivers_lock
);
170 * @dev != NULL means that we're unwinding because some drv->add()
171 * failed for some reason. You need to grab sysdev_drivers_lock before
174 static void __sysdev_driver_remove(struct sysdev_class
*cls
,
175 struct sysdev_driver
*drv
,
176 struct sys_device
*from_dev
)
178 struct sys_device
*dev
= from_dev
;
180 list_del_init(&drv
->entry
);
188 list_for_each_entry_continue_reverse(dev
, &cls
->kset
.list
,
192 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
)
196 kset_put(&cls
->kset
);
200 * sysdev_driver_register - Register auxillary driver
201 * @cls: Device class driver belongs to.
204 * @drv is inserted into @cls->drivers to be
205 * called on each operation on devices of that class. The refcount
206 * of @cls is incremented.
208 int sysdev_driver_register(struct sysdev_class
*cls
, struct sysdev_driver
*drv
)
210 struct sys_device
*dev
= NULL
;
214 WARN(1, KERN_WARNING
"sysdev: invalid class passed to %s!\n",
219 /* Check whether this driver has already been added to a class. */
220 if (drv
->entry
.next
&& !list_empty(&drv
->entry
))
221 WARN(1, KERN_WARNING
"sysdev: class %s: driver (%p) has already"
222 " been registered to a class, something is wrong, but "
223 "will forge on!\n", cls
->name
, drv
);
225 mutex_lock(&sysdev_drivers_lock
);
226 if (cls
&& kset_get(&cls
->kset
)) {
227 list_add_tail(&drv
->entry
, &cls
->drivers
);
229 /* If devices of this class already exist, tell the driver */
231 list_for_each_entry(dev
, &cls
->kset
.list
, kobj
.entry
) {
239 WARN(1, KERN_ERR
"%s: invalid device class\n", __func__
);
245 __sysdev_driver_remove(cls
, drv
, dev
);
248 mutex_unlock(&sysdev_drivers_lock
);
253 * sysdev_driver_unregister - Remove an auxillary driver.
254 * @cls: Class driver belongs to.
257 void sysdev_driver_unregister(struct sysdev_class
*cls
,
258 struct sysdev_driver
*drv
)
260 mutex_lock(&sysdev_drivers_lock
);
261 __sysdev_driver_remove(cls
, drv
, NULL
);
262 mutex_unlock(&sysdev_drivers_lock
);
264 EXPORT_SYMBOL_GPL(sysdev_driver_register
);
265 EXPORT_SYMBOL_GPL(sysdev_driver_unregister
);
268 * sysdev_register - add a system device to the tree
269 * @sysdev: device in question
272 int sysdev_register(struct sys_device
*sysdev
)
275 struct sysdev_class
*cls
= sysdev
->cls
;
280 pr_debug("Registering sys device of class '%s'\n",
281 kobject_name(&cls
->kset
.kobj
));
283 /* initialize the kobject to 0, in case it had previously been used */
284 memset(&sysdev
->kobj
, 0x00, sizeof(struct kobject
));
286 /* Make sure the kset is set */
287 sysdev
->kobj
.kset
= &cls
->kset
;
289 /* Register the object */
290 error
= kobject_init_and_add(&sysdev
->kobj
, &ktype_sysdev
, NULL
,
291 "%s%d", kobject_name(&cls
->kset
.kobj
),
295 struct sysdev_driver
*drv
;
297 pr_debug("Registering sys device '%s'\n",
298 kobject_name(&sysdev
->kobj
));
300 mutex_lock(&sysdev_drivers_lock
);
301 /* Generic notification is implicit, because it's that
302 * code that should have called us.
305 /* Notify class auxillary drivers */
306 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
310 mutex_unlock(&sysdev_drivers_lock
);
311 kobject_uevent(&sysdev
->kobj
, KOBJ_ADD
);
317 void sysdev_unregister(struct sys_device
*sysdev
)
319 struct sysdev_driver
*drv
;
321 mutex_lock(&sysdev_drivers_lock
);
322 list_for_each_entry(drv
, &sysdev
->cls
->drivers
, entry
) {
326 mutex_unlock(&sysdev_drivers_lock
);
328 kobject_put(&sysdev
->kobj
);
332 #ifndef CONFIG_ARCH_NO_SYSDEV_OPS
334 * sysdev_shutdown - Shut down all system devices.
336 * Loop over each class of system devices, and the devices in each
337 * of those classes. For each device, we call the shutdown method for
338 * each driver registered for the device - the auxillaries,
339 * and the class driver.
341 * Note: The list is iterated in reverse order, so that we shut down
342 * child devices before we shut down their parents. The list ordering
343 * is guaranteed by virtue of the fact that child devices are registered
344 * after their parents.
346 void sysdev_shutdown(void)
348 struct sysdev_class
*cls
;
350 pr_debug("Shutting Down System Devices\n");
352 mutex_lock(&sysdev_drivers_lock
);
353 list_for_each_entry_reverse(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
354 struct sys_device
*sysdev
;
356 pr_debug("Shutting down type '%s':\n",
357 kobject_name(&cls
->kset
.kobj
));
359 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
360 struct sysdev_driver
*drv
;
361 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
363 /* Call auxillary drivers first */
364 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
366 drv
->shutdown(sysdev
);
369 /* Now call the generic one */
371 cls
->shutdown(sysdev
);
374 mutex_unlock(&sysdev_drivers_lock
);
377 static void __sysdev_resume(struct sys_device
*dev
)
379 struct sysdev_class
*cls
= dev
->cls
;
380 struct sysdev_driver
*drv
;
382 /* First, call the class-specific one */
385 WARN_ONCE(!irqs_disabled(),
386 "Interrupts enabled after %pF\n", cls
->resume
);
388 /* Call auxillary drivers next. */
389 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
392 WARN_ONCE(!irqs_disabled(),
393 "Interrupts enabled after %pF\n", drv
->resume
);
398 * sysdev_suspend - Suspend all system devices.
399 * @state: Power state to enter.
401 * We perform an almost identical operation as sysdev_shutdown()
402 * above, though calling ->suspend() instead. Interrupts are disabled
403 * when this called. Devices are responsible for both saving state and
404 * quiescing or powering down the device.
406 * This is only called by the device PM core, so we let them handle
407 * all synchronization.
409 int sysdev_suspend(pm_message_t state
)
411 struct sysdev_class
*cls
;
412 struct sys_device
*sysdev
, *err_dev
;
413 struct sysdev_driver
*drv
, *err_drv
;
416 pr_debug("Checking wake-up interrupts\n");
418 /* Return error code if there are any wake-up interrupts pending */
419 ret
= check_wakeup_irqs();
423 WARN_ONCE(!irqs_disabled(),
424 "Interrupts enabled while suspending system devices\n");
426 pr_debug("Suspending System Devices\n");
428 list_for_each_entry_reverse(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
429 pr_debug("Suspending type '%s':\n",
430 kobject_name(&cls
->kset
.kobj
));
432 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
433 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
435 /* Call auxillary drivers first */
436 list_for_each_entry(drv
, &cls
->drivers
, entry
) {
438 ret
= drv
->suspend(sysdev
, state
);
442 WARN_ONCE(!irqs_disabled(),
443 "Interrupts enabled after %pF\n",
447 /* Now call the generic one */
449 ret
= cls
->suspend(sysdev
, state
);
452 WARN_ONCE(!irqs_disabled(),
453 "Interrupts enabled after %pF\n",
459 /* resume current sysdev */
462 printk(KERN_ERR
"Class suspend failed for %s: %d\n",
463 kobject_name(&sysdev
->kobj
), ret
);
467 printk(KERN_ERR
"Class driver suspend failed for %s: %d\n",
468 kobject_name(&sysdev
->kobj
), ret
);
469 list_for_each_entry(err_drv
, &cls
->drivers
, entry
) {
473 err_drv
->resume(sysdev
);
476 /* resume other sysdevs in current class */
477 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
478 if (err_dev
== sysdev
)
480 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
481 __sysdev_resume(err_dev
);
484 /* resume other classes */
485 list_for_each_entry_continue(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
486 list_for_each_entry(err_dev
, &cls
->kset
.list
, kobj
.entry
) {
487 pr_debug(" %s\n", kobject_name(&err_dev
->kobj
));
488 __sysdev_resume(err_dev
);
493 EXPORT_SYMBOL_GPL(sysdev_suspend
);
496 * sysdev_resume - Bring system devices back to life.
498 * Similar to sysdev_suspend(), but we iterate the list forwards
499 * to guarantee that parent devices are resumed before their children.
501 * Note: Interrupts are disabled when called.
503 int sysdev_resume(void)
505 struct sysdev_class
*cls
;
507 WARN_ONCE(!irqs_disabled(),
508 "Interrupts enabled while resuming system devices\n");
510 pr_debug("Resuming System Devices\n");
512 list_for_each_entry(cls
, &system_kset
->list
, kset
.kobj
.entry
) {
513 struct sys_device
*sysdev
;
515 pr_debug("Resuming type '%s':\n",
516 kobject_name(&cls
->kset
.kobj
));
518 list_for_each_entry(sysdev
, &cls
->kset
.list
, kobj
.entry
) {
519 pr_debug(" %s\n", kobject_name(&sysdev
->kobj
));
521 __sysdev_resume(sysdev
);
526 EXPORT_SYMBOL_GPL(sysdev_resume
);
527 #endif /* CONFIG_ARCH_NO_SYSDEV_OPS */
529 int __init
system_bus_init(void)
531 system_kset
= kset_create_and_add("system", NULL
, &devices_kset
->kobj
);
537 EXPORT_SYMBOL_GPL(sysdev_register
);
538 EXPORT_SYMBOL_GPL(sysdev_unregister
);
540 #define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
542 ssize_t
sysdev_store_ulong(struct sys_device
*sysdev
,
543 struct sysdev_attribute
*attr
,
544 const char *buf
, size_t size
)
546 struct sysdev_ext_attribute
*ea
= to_ext_attr(attr
);
548 unsigned long new = simple_strtoul(buf
, &end
, 0);
551 *(unsigned long *)(ea
->var
) = new;
552 /* Always return full write size even if we didn't consume all */
555 EXPORT_SYMBOL_GPL(sysdev_store_ulong
);
557 ssize_t
sysdev_show_ulong(struct sys_device
*sysdev
,
558 struct sysdev_attribute
*attr
,
561 struct sysdev_ext_attribute
*ea
= to_ext_attr(attr
);
562 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
564 EXPORT_SYMBOL_GPL(sysdev_show_ulong
);
566 ssize_t
sysdev_store_int(struct sys_device
*sysdev
,
567 struct sysdev_attribute
*attr
,
568 const char *buf
, size_t size
)
570 struct sysdev_ext_attribute
*ea
= to_ext_attr(attr
);
572 long new = simple_strtol(buf
, &end
, 0);
573 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
575 *(int *)(ea
->var
) = new;
576 /* Always return full write size even if we didn't consume all */
579 EXPORT_SYMBOL_GPL(sysdev_store_int
);
581 ssize_t
sysdev_show_int(struct sys_device
*sysdev
,
582 struct sysdev_attribute
*attr
,
585 struct sysdev_ext_attribute
*ea
= to_ext_attr(attr
);
586 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
588 EXPORT_SYMBOL_GPL(sysdev_show_int
);