[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / base / sys.c

/*
 * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 *               2002-3 Open Source Development Lab
 *
 * This file is released under the GPLv2
 *
 * This exports a 'system' bus type.
 * By default, a 'sys' bus gets added to the root of the system. There will
 * always be core system devices. Devices can use sysdev_register() to
 * add themselves as children of the system bus.
 */

#include <linux/sysdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/mutex.h>

#include "base.h"

#define to_sysdev(k) container_of(k, struct sys_device, kobj)
#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)


static ssize_t
sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
{
	struct sys_device * sysdev = to_sysdev(kobj);
	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);

	if (sysdev_attr->show)
		return sysdev_attr->show(sysdev, buffer);
	return -EIO;
}


static ssize_t
sysdev_store(struct kobject * kobj, struct attribute * attr,
	     const char * buffer, size_t count)
{
	struct sys_device * sysdev = to_sysdev(kobj);
	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);

	if (sysdev_attr->store)
		return sysdev_attr->store(sysdev, buffer, count);
	return -EIO;
}

static struct sysfs_ops sysfs_ops = {
	.show	= sysdev_show,
	.store	= sysdev_store,
};

static struct kobj_type ktype_sysdev = {
	.sysfs_ops	= &sysfs_ops,
};


int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
{
	return sysfs_create_file(&s->kobj, &a->attr);
}


void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
{
	sysfs_remove_file(&s->kobj, &a->attr);
}

EXPORT_SYMBOL_GPL(sysdev_create_file);
EXPORT_SYMBOL_GPL(sysdev_remove_file);

#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
#define to_sysdev_class_attr(a) container_of(a, \
	struct sysdev_class_attribute, attr)

static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
				 char *buffer)
{
	struct sysdev_class * class = to_sysdev_class(kobj);
	struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);

	if (class_attr->show)
		return class_attr->show(class, buffer);
	return -EIO;
}

static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
				  const char *buffer, size_t count)
{
	struct sysdev_class * class = to_sysdev_class(kobj);
	struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);

	if (class_attr->store)
		return class_attr->store(class, buffer, count);
	return -EIO;
}

static struct sysfs_ops sysfs_class_ops = {
	.show	= sysdev_class_show,
	.store	= sysdev_class_store,
};

static struct kobj_type ktype_sysdev_class = {
	.sysfs_ops	= &sysfs_class_ops,
};

int sysdev_class_create_file(struct sysdev_class *c,
			     struct sysdev_class_attribute *a)
{
	return sysfs_create_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_create_file);

void sysdev_class_remove_file(struct sysdev_class *c,
			      struct sysdev_class_attribute *a)
{
	sysfs_remove_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_remove_file);

static struct kset *system_kset;

int sysdev_class_register(struct sysdev_class * cls)
{
	pr_debug("Registering sysdev class '%s'\n",
		 kobject_name(&cls->kset.kobj));
	INIT_LIST_HEAD(&cls->drivers);
	cls->kset.kobj.parent = &system_kset->kobj;
	cls->kset.kobj.ktype = &ktype_sysdev_class;
	cls->kset.kobj.kset = system_kset;
	return kset_register(&cls->kset);
}

void sysdev_class_unregister(struct sysdev_class * cls)
{
	pr_debug("Unregistering sysdev class '%s'\n",
		 kobject_name(&cls->kset.kobj));
	kset_unregister(&cls->kset);
}

EXPORT_SYMBOL_GPL(sysdev_class_register);
EXPORT_SYMBOL_GPL(sysdev_class_unregister);

static DEFINE_MUTEX(sysdev_drivers_lock);

/**
 *	sysdev_driver_register - Register auxillary driver
 *	@cls:	Device class driver belongs to.
 *	@drv:	Driver.
 *
 *	@drv is inserted into @cls->drivers to be
 *	called on each operation on devices of that class. The refcount
 *	of @cls is incremented.
 */

int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
{
	int err = 0;

	mutex_lock(&sysdev_drivers_lock);
	if (cls && kset_get(&cls->kset)) {
		list_add_tail(&drv->entry, &cls->drivers);

		/* If devices of this class already exist, tell the driver */
		if (drv->add) {
			struct sys_device *dev;
			list_for_each_entry(dev, &cls->kset.list, kobj.entry)
				drv->add(dev);
		}
	} else {
		err = -EINVAL;
		printk(KERN_ERR "%s: invalid device class\n", __FUNCTION__);
		WARN_ON(1);
	}
	mutex_unlock(&sysdev_drivers_lock);
	return err;
}


/**
 *	sysdev_driver_unregister - Remove an auxillary driver.
 *	@cls:	Class driver belongs to.
 *	@drv:	Driver.
 */
void sysdev_driver_unregister(struct sysdev_class * cls,
			      struct sysdev_driver * drv)
{
	mutex_lock(&sysdev_drivers_lock);
	list_del_init(&drv->entry);
	if (cls) {
		if (drv->remove) {
			struct sys_device *dev;
			list_for_each_entry(dev, &cls->kset.list, kobj.entry)
				drv->remove(dev);
		}
		kset_put(&cls->kset);
	}
	mutex_unlock(&sysdev_drivers_lock);
}

EXPORT_SYMBOL_GPL(sysdev_driver_register);
EXPORT_SYMBOL_GPL(sysdev_driver_unregister);


/**
 *	sysdev_register - add a system device to the tree
 *	@sysdev:	device in question
 *
 */
int sysdev_register(struct sys_device * sysdev)
{
	int error;
	struct sysdev_class * cls = sysdev->cls;

	if (!cls)
		return -EINVAL;

	/* Make sure the kset is set */
	sysdev->kobj.kset = &cls->kset;

	/* But make sure we point to the right type for sysfs translation */
	sysdev->kobj.ktype = &ktype_sysdev;
	error = kobject_set_name(&sysdev->kobj, "%s%d",
			 kobject_name(&cls->kset.kobj), sysdev->id);
	if (error)
		return error;

	pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));

	/* Register the object */
	error = kobject_register(&sysdev->kobj);

	if (!error) {
		struct sysdev_driver * drv;

		mutex_lock(&sysdev_drivers_lock);
		/* Generic notification is implicit, because it's that
		 * code that should have called us.
		 */

		/* Notify class auxillary drivers */
		list_for_each_entry(drv, &cls->drivers, entry) {
			if (drv->add)
				drv->add(sysdev);
		}
		mutex_unlock(&sysdev_drivers_lock);
	}
	return error;
}

void sysdev_unregister(struct sys_device * sysdev)
{
	struct sysdev_driver * drv;

	mutex_lock(&sysdev_drivers_lock);
	list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
		if (drv->remove)
			drv->remove(sysdev);
	}
	mutex_unlock(&sysdev_drivers_lock);

	kobject_unregister(&sysdev->kobj);
}


/**
 *	sysdev_shutdown - Shut down all system devices.
 *
 *	Loop over each class of system devices, and the devices in each
 *	of those classes. For each device, we call the shutdown method for
 *	each driver registered for the device - the auxillaries,
 *	and the class driver.
 *
 *	Note: The list is iterated in reverse order, so that we shut down
 *	child devices before we shut down thier parents. The list ordering
 *	is guaranteed by virtue of the fact that child devices are registered
 *	after their parents.
 */

void sysdev_shutdown(void)
{
	struct sysdev_class * cls;

	pr_debug("Shutting Down System Devices\n");

	mutex_lock(&sysdev_drivers_lock);
	list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
		struct sys_device * sysdev;

		pr_debug("Shutting down type '%s':\n",
			 kobject_name(&cls->kset.kobj));

		list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
			struct sysdev_driver * drv;
			pr_debug(" %s\n", kobject_name(&sysdev->kobj));

			/* Call auxillary drivers first */
			list_for_each_entry(drv, &cls->drivers, entry) {
				if (drv->shutdown)
					drv->shutdown(sysdev);
			}

			/* Now call the generic one */
			if (cls->shutdown)
				cls->shutdown(sysdev);
		}
	}
	mutex_unlock(&sysdev_drivers_lock);
}

static void __sysdev_resume(struct sys_device *dev)
{
	struct sysdev_class *cls = dev->cls;
	struct sysdev_driver *drv;

	/* First, call the class-specific one */
	if (cls->resume)
		cls->resume(dev);

	/* Call auxillary drivers next. */
	list_for_each_entry(drv, &cls->drivers, entry) {
		if (drv->resume)
			drv->resume(dev);
	}
}

/**
 *	sysdev_suspend - Suspend all system devices.
 *	@state:		Power state to enter.
 *
 *	We perform an almost identical operation as sys_device_shutdown()
 *	above, though calling ->suspend() instead. Interrupts are disabled
 *	when this called. Devices are responsible for both saving state and
 *	quiescing or powering down the device.
 *
 *	This is only called by the device PM core, so we let them handle
 *	all synchronization.
 */

int sysdev_suspend(pm_message_t state)
{
	struct sysdev_class * cls;
	struct sys_device *sysdev, *err_dev;
	struct sysdev_driver *drv, *err_drv;
	int ret;

	pr_debug("Suspending System Devices\n");

	list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
		pr_debug("Suspending type '%s':\n",
			 kobject_name(&cls->kset.kobj));

		list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
			pr_debug(" %s\n", kobject_name(&sysdev->kobj));

			/* Call auxillary drivers first */
			list_for_each_entry(drv, &cls->drivers, entry) {
				if (drv->suspend) {
					ret = drv->suspend(sysdev, state);
					if (ret)
						goto aux_driver;
				}
			}

			/* Now call the generic one */
			if (cls->suspend) {
				ret = cls->suspend(sysdev, state);
				if (ret)
					goto cls_driver;
			}
		}
	}
	return 0;
	/* resume current sysdev */
cls_driver:
	drv = NULL;
	printk(KERN_ERR "Class suspend failed for %s\n",
		kobject_name(&sysdev->kobj));

aux_driver:
	if (drv)
		printk(KERN_ERR "Class driver suspend failed for %s\n",
				kobject_name(&sysdev->kobj));
	list_for_each_entry(err_drv, &cls->drivers, entry) {
		if (err_drv == drv)
			break;
		if (err_drv->resume)
			err_drv->resume(sysdev);
	}

	/* resume other sysdevs in current class */
	list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
		if (err_dev == sysdev)
			break;
		pr_debug(" %s\n", kobject_name(&err_dev->kobj));
		__sysdev_resume(err_dev);
	}

	/* resume other classes */
	list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) {
		list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
			pr_debug(" %s\n", kobject_name(&err_dev->kobj));
			__sysdev_resume(err_dev);
		}
	}
	return ret;
}


/**
 *	sysdev_resume - Bring system devices back to life.
 *
 *	Similar to sys_device_suspend(), but we iterate the list forwards
 *	to guarantee that parent devices are resumed before their children.
 *
 *	Note: Interrupts are disabled when called.
 */

int sysdev_resume(void)
{
	struct sysdev_class * cls;

	pr_debug("Resuming System Devices\n");

	list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {
		struct sys_device * sysdev;

		pr_debug("Resuming type '%s':\n",
			 kobject_name(&cls->kset.kobj));

		list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
			pr_debug(" %s\n", kobject_name(&sysdev->kobj));

			__sysdev_resume(sysdev);
		}
	}
	return 0;
}


int __init system_bus_init(void)
{
	system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
	if (!system_kset)
		return -ENOMEM;
	return 0;
}

EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
	3	*
	4	* Copyright (c) 2002-3 Patrick Mochel
	5	* 2002-3 Open Source Development Lab
	6	*
	7	* This file is released under the GPLv2
	8	*
	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.
	13	*/
	14
1da177e4 LT	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>
438510f6	22	#include <linux/pm.h>
f67d115f	23	#include <linux/device.h>
9f3f776b	24	#include <linux/mutex.h>
1da177e4	25
f67d115f AB	26	#include "base.h"
f67d115f AB	27
1da177e4 LT	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)
	30
	31
	32	static ssize_t
	33	sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
	34	{
	35	struct sys_device * sysdev = to_sysdev(kobj);
	36	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
	37
	38	if (sysdev_attr->show)
	39	return sysdev_attr->show(sysdev, buffer);
4a0c20bf	40	return -EIO;
1da177e4 LT	41	}
	42
	43
	44	static ssize_t
	45	sysdev_store(struct kobject * kobj, struct attribute * attr,
	46	const char * buffer, size_t count)
	47	{
	48	struct sys_device * sysdev = to_sysdev(kobj);
	49	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
	50
	51	if (sysdev_attr->store)
	52	return sysdev_attr->store(sysdev, buffer, count);
4a0c20bf	53	return -EIO;
1da177e4 LT	54	}
	55
	56	static struct sysfs_ops sysfs_ops = {
	57	.show = sysdev_show,
	58	.store = sysdev_store,
	59	};
	60
	61	static struct kobj_type ktype_sysdev = {
	62	.sysfs_ops = &sysfs_ops,
	63	};
	64
	65
	66	int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
	67	{
	68	return sysfs_create_file(&s->kobj, &a->attr);
	69	}
	70
	71
	72	void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
	73	{
	74	sysfs_remove_file(&s->kobj, &a->attr);
	75	}
	76
	77	EXPORT_SYMBOL_GPL(sysdev_create_file);
	78	EXPORT_SYMBOL_GPL(sysdev_remove_file);
	79
670dd90d SL	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)
	83
	84	static ssize_t sysdev_class_show(struct kobject kobj, struct attribute attr,
	85	char *buffer)
	86	{
	87	struct sysdev_class * class = to_sysdev_class(kobj);
	88	struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
	89
	90	if (class_attr->show)
	91	return class_attr->show(class, buffer);
	92	return -EIO;
	93	}
	94
	95	static ssize_t sysdev_class_store(struct kobject kobj, struct attribute attr,
	96	const char *buffer, size_t count)
	97	{
	98	struct sysdev_class * class = to_sysdev_class(kobj);
	99	struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
	100
	101	if (class_attr->store)
	102	return class_attr->store(class, buffer, count);
	103	return -EIO;
	104	}
	105
	106	static struct sysfs_ops sysfs_class_ops = {
	107	.show = sysdev_class_show,
	108	.store = sysdev_class_store,
	109	};
	110
	111	static struct kobj_type ktype_sysdev_class = {
	112	.sysfs_ops = &sysfs_class_ops,
	113	};
	114
	115	int sysdev_class_create_file(struct sysdev_class *c,
	116	struct sysdev_class_attribute *a)
	117	{
	118	return sysfs_create_file(&c->kset.kobj, &a->attr);
	119	}
	120	EXPORT_SYMBOL_GPL(sysdev_class_create_file);
	121
	122	void sysdev_class_remove_file(struct sysdev_class *c,
	123	struct sysdev_class_attribute *a)
	124	{
	125	sysfs_remove_file(&c->kset.kobj, &a->attr);
	126	}
	127	EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
	128
aade4041	129	static struct kset *system_kset;
1da177e4 LT	130
	131	int sysdev_class_register(struct sysdev_class * cls)
	132	{
	133	pr_debug("Registering sysdev class '%s'\n",
	134	kobject_name(&cls->kset.kobj));
	135	INIT_LIST_HEAD(&cls->drivers);
aade4041	136	cls->kset.kobj.parent = &system_kset->kobj;
3514faca	137	cls->kset.kobj.ktype = &ktype_sysdev_class;
aade4041	138	cls->kset.kobj.kset = system_kset;
1da177e4 LT	139	return kset_register(&cls->kset);
	140	}
	141
	142	void sysdev_class_unregister(struct sysdev_class * cls)
	143	{
	144	pr_debug("Unregistering sysdev class '%s'\n",
	145	kobject_name(&cls->kset.kobj));
	146	kset_unregister(&cls->kset);
	147	}
	148
	149	EXPORT_SYMBOL_GPL(sysdev_class_register);
	150	EXPORT_SYMBOL_GPL(sysdev_class_unregister);
	151
9f3f776b	152	static DEFINE_MUTEX(sysdev_drivers_lock);
1da177e4 LT	153
	154	/**
	155	* sysdev_driver_register - Register auxillary driver
44b760a8	156	* @cls: Device class driver belongs to.
1da177e4 LT	157	* @drv: Driver.
1da177e4 LT	158	*
44b760a8	159	* @drv is inserted into @cls->drivers to be
1da177e4 LT	160	* called on each operation on devices of that class. The refcount
1da177e4 LT	161	* of @cls is incremented.
1da177e4 LT	162	*/
1da177e4 LT	163
44b760a8	164	int sysdev_driver_register(struct sysdev_class cls, struct sysdev_driver drv)
1da177e4	165	{
44b760a8 AM	166	int err = 0;
44b760a8 AM	167
9f3f776b	168	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	169	if (cls && kset_get(&cls->kset)) {
	170	list_add_tail(&drv->entry, &cls->drivers);
	171
	172	/* If devices of this class already exist, tell the driver */
	173	if (drv->add) {
	174	struct sys_device *dev;
	175	list_for_each_entry(dev, &cls->kset.list, kobj.entry)
	176	drv->add(dev);
	177	}
44b760a8 AM	178	} else {
	179	err = -EINVAL;
	180	printk(KERN_ERR "%s: invalid device class\n", __FUNCTION__);
	181	WARN_ON(1);
	182	}
9f3f776b	183	mutex_unlock(&sysdev_drivers_lock);
44b760a8	184	return err;
1da177e4 LT	185	}
	186
	187
	188	/**
	189	* sysdev_driver_unregister - Remove an auxillary driver.
	190	* @cls: Class driver belongs to.
	191	* @drv: Driver.
	192	*/
	193	void sysdev_driver_unregister(struct sysdev_class * cls,
	194	struct sysdev_driver * drv)
	195	{
9f3f776b	196	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	197	list_del_init(&drv->entry);
	198	if (cls) {
	199	if (drv->remove) {
	200	struct sys_device *dev;
	201	list_for_each_entry(dev, &cls->kset.list, kobj.entry)
	202	drv->remove(dev);
	203	}
	204	kset_put(&cls->kset);
	205	}
9f3f776b	206	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	207	}
	208
	209	EXPORT_SYMBOL_GPL(sysdev_driver_register);
	210	EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
	211
	212
	213
	214	/**
	215	* sysdev_register - add a system device to the tree
	216	* @sysdev: device in question
	217	*
	218	*/
	219	int sysdev_register(struct sys_device * sysdev)
	220	{
	221	int error;
	222	struct sysdev_class * cls = sysdev->cls;
	223
	224	if (!cls)
	225	return -EINVAL;
	226
	227	/* Make sure the kset is set */
	228	sysdev->kobj.kset = &cls->kset;
	229
	230	/* But make sure we point to the right type for sysfs translation */
	231	sysdev->kobj.ktype = &ktype_sysdev;
	232	error = kobject_set_name(&sysdev->kobj, "%s%d",
	233	kobject_name(&cls->kset.kobj), sysdev->id);
	234	if (error)
	235	return error;
	236
	237	pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
	238
	239	/* Register the object */
	240	error = kobject_register(&sysdev->kobj);
	241
	242	if (!error) {
	243	struct sysdev_driver * drv;
	244
9f3f776b	245	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	246	/* Generic notification is implicit, because it's that
	247	* code that should have called us.
	248	*/
	249
1da177e4 LT	250	/* Notify class auxillary drivers */
	251	list_for_each_entry(drv, &cls->drivers, entry) {
	252	if (drv->add)
	253	drv->add(sysdev);
	254	}
9f3f776b	255	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	256	}
	257	return error;
	258	}
	259
	260	void sysdev_unregister(struct sys_device * sysdev)
	261	{
	262	struct sysdev_driver * drv;
	263
9f3f776b	264	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	265	list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
	266	if (drv->remove)
	267	drv->remove(sysdev);
	268	}
9f3f776b	269	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	270
	271	kobject_unregister(&sysdev->kobj);
	272	}
	273
	274
	275
	276	/**
	277	* sysdev_shutdown - Shut down all system devices.
	278	*
	279	* Loop over each class of system devices, and the devices in each
	280	* of those classes. For each device, we call the shutdown method for
44b760a8	281	* each driver registered for the device - the auxillaries,
1da177e4 LT	282	* and the class driver.
	283	*
	284	* Note: The list is iterated in reverse order, so that we shut down
	285	* child devices before we shut down thier parents. The list ordering
	286	* is guaranteed by virtue of the fact that child devices are registered
	287	* after their parents.
	288	*/
	289
	290	void sysdev_shutdown(void)
	291	{
	292	struct sysdev_class * cls;
	293
	294	pr_debug("Shutting Down System Devices\n");
	295
9f3f776b	296	mutex_lock(&sysdev_drivers_lock);
aade4041	297	list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
1da177e4 LT	298	struct sys_device * sysdev;
	299
	300	pr_debug("Shutting down type '%s':\n",
	301	kobject_name(&cls->kset.kobj));
	302
	303	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
	304	struct sysdev_driver * drv;
	305	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
	306
44b760a8	307	/* Call auxillary drivers first */
1da177e4 LT	308	list_for_each_entry(drv, &cls->drivers, entry) {
	309	if (drv->shutdown)
	310	drv->shutdown(sysdev);
	311	}
	312
	313	/* Now call the generic one */
	314	if (cls->shutdown)
	315	cls->shutdown(sysdev);
	316	}
	317	}
9f3f776b	318	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	319	}
1da177e4 LT	320
ceaeade1 SL	321	static void __sysdev_resume(struct sys_device *dev)
	322	{
	323	struct sysdev_class *cls = dev->cls;
	324	struct sysdev_driver *drv;
	325
	326	/* First, call the class-specific one */
	327	if (cls->resume)
	328	cls->resume(dev);
	329
	330	/* Call auxillary drivers next. */
	331	list_for_each_entry(drv, &cls->drivers, entry) {
	332	if (drv->resume)
	333	drv->resume(dev);
	334	}
ceaeade1	335	}
1da177e4 LT	336
	337	/**
	338	* sysdev_suspend - Suspend all system devices.
	339	* @state: Power state to enter.
	340	*
	341	* We perform an almost identical operation as sys_device_shutdown()
	342	* above, though calling ->suspend() instead. Interrupts are disabled
	343	* when this called. Devices are responsible for both saving state and
	344	* quiescing or powering down the device.
	345	*
	346	* This is only called by the device PM core, so we let them handle
	347	* all synchronization.
	348	*/
	349
438510f6	350	int sysdev_suspend(pm_message_t state)
1da177e4 LT	351	{
1da177e4 LT	352	struct sysdev_class * cls;
ceaeade1 SL	353	struct sys_device sysdev, err_dev;
	354	struct sysdev_driver drv, err_drv;
	355	int ret;
1da177e4 LT	356
	357	pr_debug("Suspending System Devices\n");
	358
aade4041	359	list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
1da177e4 LT	360	pr_debug("Suspending type '%s':\n",
	361	kobject_name(&cls->kset.kobj));
	362
	363	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
1da177e4 LT	364	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
1da177e4 LT	365
44b760a8	366	/* Call auxillary drivers first */
1da177e4	367	list_for_each_entry(drv, &cls->drivers, entry) {
ceaeade1 SL	368	if (drv->suspend) {
	369	ret = drv->suspend(sysdev, state);
	370	if (ret)
	371	goto aux_driver;
	372	}
1da177e4 LT	373	}
	374
	375	/* Now call the generic one */
ceaeade1 SL	376	if (cls->suspend) {
	377	ret = cls->suspend(sysdev, state);
	378	if (ret)
	379	goto cls_driver;
	380	}
1da177e4 LT	381	}
	382	}
	383	return 0;
ceaeade1 SL	384	/* resume current sysdev */
	385	cls_driver:
	386	drv = NULL;
	387	printk(KERN_ERR "Class suspend failed for %s\n",
	388	kobject_name(&sysdev->kobj));
	389
	390	aux_driver:
	391	if (drv)
	392	printk(KERN_ERR "Class driver suspend failed for %s\n",
	393	kobject_name(&sysdev->kobj));
	394	list_for_each_entry(err_drv, &cls->drivers, entry) {
	395	if (err_drv == drv)
	396	break;
	397	if (err_drv->resume)
	398	err_drv->resume(sysdev);
	399	}
ceaeade1	400
ceaeade1 SL	401	/* resume other sysdevs in current class */
	402	list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
	403	if (err_dev == sysdev)
	404	break;
	405	pr_debug(" %s\n", kobject_name(&err_dev->kobj));
	406	__sysdev_resume(err_dev);
	407	}
	408
	409	/* resume other classes */
aade4041	410	list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) {
ceaeade1 SL	411	list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
	412	pr_debug(" %s\n", kobject_name(&err_dev->kobj));
	413	__sysdev_resume(err_dev);
	414	}
	415	}
	416	return ret;
1da177e4 LT	417	}
	418
	419
	420	/**
	421	* sysdev_resume - Bring system devices back to life.
	422	*
	423	* Similar to sys_device_suspend(), but we iterate the list forwards
	424	* to guarantee that parent devices are resumed before their children.
	425	*
	426	* Note: Interrupts are disabled when called.
	427	*/
	428
	429	int sysdev_resume(void)
	430	{
	431	struct sysdev_class * cls;
	432
	433	pr_debug("Resuming System Devices\n");
	434
aade4041	435	list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {
1da177e4 LT	436	struct sys_device * sysdev;
	437
	438	pr_debug("Resuming type '%s':\n",
	439	kobject_name(&cls->kset.kobj));
	440
	441	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
1da177e4 LT	442	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
1da177e4 LT	443
ceaeade1	444	__sysdev_resume(sysdev);
1da177e4 LT	445	}
	446	}
	447	return 0;
	448	}
	449
	450
	451	int __init system_bus_init(void)
	452	{
aade4041 GKH	453	system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
	454	if (!system_kset)
	455	return -ENOMEM;
	456	return 0;
1da177e4 LT	457	}
	458
	459	EXPORT_SYMBOL_GPL(sysdev_register);
	460	EXPORT_SYMBOL_GPL(sysdev_unregister);