[linux-2.6-block.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"

extern struct kset devices_subsys;

#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);

/*
 * declare system_subsys
 */
static decl_subsys(system, &ktype_sysdev_class, NULL);

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_subsys.kobj;
	cls->kset.kobj.kset = &system_subsys;
	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_subsys.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_subsys.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_subsys.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_subsys.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_subsys.kobj.parent = &devices_subsys.kobj;
	return subsystem_register(&system_subsys);
}

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
823bccfc	28	extern struct kset devices_subsys;
1da177e4 LT	29
	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)
	32
	33
	34	static ssize_t
	35	sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
	36	{
	37	struct sys_device * sysdev = to_sysdev(kobj);
	38	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
	39
	40	if (sysdev_attr->show)
	41	return sysdev_attr->show(sysdev, buffer);
4a0c20bf	42	return -EIO;
1da177e4 LT	43	}
	44
	45
	46	static ssize_t
	47	sysdev_store(struct kobject * kobj, struct attribute * attr,
	48	const char * buffer, size_t count)
	49	{
	50	struct sys_device * sysdev = to_sysdev(kobj);
	51	struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
	52
	53	if (sysdev_attr->store)
	54	return sysdev_attr->store(sysdev, buffer, count);
4a0c20bf	55	return -EIO;
1da177e4 LT	56	}
	57
	58	static struct sysfs_ops sysfs_ops = {
	59	.show = sysdev_show,
	60	.store = sysdev_store,
	61	};
	62
	63	static struct kobj_type ktype_sysdev = {
	64	.sysfs_ops = &sysfs_ops,
	65	};
	66
	67
	68	int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
	69	{
	70	return sysfs_create_file(&s->kobj, &a->attr);
	71	}
	72
	73
	74	void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
	75	{
	76	sysfs_remove_file(&s->kobj, &a->attr);
	77	}
	78
	79	EXPORT_SYMBOL_GPL(sysdev_create_file);
	80	EXPORT_SYMBOL_GPL(sysdev_remove_file);
	81
670dd90d SL	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)
	85
	86	static ssize_t sysdev_class_show(struct kobject kobj, struct attribute attr,
	87	char *buffer)
	88	{
	89	struct sysdev_class * class = to_sysdev_class(kobj);
	90	struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
	91
	92	if (class_attr->show)
	93	return class_attr->show(class, buffer);
	94	return -EIO;
	95	}
	96
	97	static ssize_t sysdev_class_store(struct kobject kobj, struct attribute attr,
	98	const char *buffer, size_t count)
	99	{
	100	struct sysdev_class * class = to_sysdev_class(kobj);
	101	struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
	102
	103	if (class_attr->store)
	104	return class_attr->store(class, buffer, count);
	105	return -EIO;
	106	}
	107
	108	static struct sysfs_ops sysfs_class_ops = {
	109	.show = sysdev_class_show,
	110	.store = sysdev_class_store,
	111	};
	112
	113	static struct kobj_type ktype_sysdev_class = {
	114	.sysfs_ops = &sysfs_class_ops,
	115	};
	116
	117	int sysdev_class_create_file(struct sysdev_class *c,
	118	struct sysdev_class_attribute *a)
	119	{
	120	return sysfs_create_file(&c->kset.kobj, &a->attr);
	121	}
	122	EXPORT_SYMBOL_GPL(sysdev_class_create_file);
	123
	124	void sysdev_class_remove_file(struct sysdev_class *c,
	125	struct sysdev_class_attribute *a)
	126	{
	127	sysfs_remove_file(&c->kset.kobj, &a->attr);
	128	}
	129	EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
	130
1da177e4 LT	131	/*
	132	* declare system_subsys
	133	*/
670dd90d	134	static decl_subsys(system, &ktype_sysdev_class, NULL);
1da177e4 LT	135
	136	int sysdev_class_register(struct sysdev_class * cls)
	137	{
	138	pr_debug("Registering sysdev class '%s'\n",
	139	kobject_name(&cls->kset.kobj));
	140	INIT_LIST_HEAD(&cls->drivers);
823bccfc	141	cls->kset.kobj.parent = &system_subsys.kobj;
27f20e5e	142	cls->kset.kobj.kset = &system_subsys;
1da177e4 LT	143	return kset_register(&cls->kset);
	144	}
	145
	146	void sysdev_class_unregister(struct sysdev_class * cls)
	147	{
	148	pr_debug("Unregistering sysdev class '%s'\n",
	149	kobject_name(&cls->kset.kobj));
	150	kset_unregister(&cls->kset);
	151	}
	152
	153	EXPORT_SYMBOL_GPL(sysdev_class_register);
	154	EXPORT_SYMBOL_GPL(sysdev_class_unregister);
	155
9f3f776b	156	static DEFINE_MUTEX(sysdev_drivers_lock);
1da177e4 LT	157
	158	/**
	159	* sysdev_driver_register - Register auxillary driver
44b760a8	160	* @cls: Device class driver belongs to.
1da177e4 LT	161	* @drv: Driver.
1da177e4 LT	162	*
44b760a8	163	* @drv is inserted into @cls->drivers to be
1da177e4 LT	164	* called on each operation on devices of that class. The refcount
1da177e4 LT	165	* of @cls is incremented.
1da177e4 LT	166	*/
1da177e4 LT	167
44b760a8	168	int sysdev_driver_register(struct sysdev_class cls, struct sysdev_driver drv)
1da177e4	169	{
44b760a8 AM	170	int err = 0;
44b760a8 AM	171
9f3f776b	172	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	173	if (cls && kset_get(&cls->kset)) {
	174	list_add_tail(&drv->entry, &cls->drivers);
	175
	176	/* If devices of this class already exist, tell the driver */
	177	if (drv->add) {
	178	struct sys_device *dev;
	179	list_for_each_entry(dev, &cls->kset.list, kobj.entry)
	180	drv->add(dev);
	181	}
44b760a8 AM	182	} else {
	183	err = -EINVAL;
	184	printk(KERN_ERR "%s: invalid device class\n", __FUNCTION__);
	185	WARN_ON(1);
	186	}
9f3f776b	187	mutex_unlock(&sysdev_drivers_lock);
44b760a8	188	return err;
1da177e4 LT	189	}
	190
	191
	192	/**
	193	* sysdev_driver_unregister - Remove an auxillary driver.
	194	* @cls: Class driver belongs to.
	195	* @drv: Driver.
	196	*/
	197	void sysdev_driver_unregister(struct sysdev_class * cls,
	198	struct sysdev_driver * drv)
	199	{
9f3f776b	200	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	201	list_del_init(&drv->entry);
	202	if (cls) {
	203	if (drv->remove) {
	204	struct sys_device *dev;
	205	list_for_each_entry(dev, &cls->kset.list, kobj.entry)
	206	drv->remove(dev);
	207	}
	208	kset_put(&cls->kset);
	209	}
9f3f776b	210	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	211	}
	212
	213	EXPORT_SYMBOL_GPL(sysdev_driver_register);
	214	EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
	215
	216
	217
	218	/**
	219	* sysdev_register - add a system device to the tree
	220	* @sysdev: device in question
	221	*
	222	*/
	223	int sysdev_register(struct sys_device * sysdev)
	224	{
	225	int error;
	226	struct sysdev_class * cls = sysdev->cls;
	227
	228	if (!cls)
	229	return -EINVAL;
	230
	231	/* Make sure the kset is set */
	232	sysdev->kobj.kset = &cls->kset;
	233
	234	/* But make sure we point to the right type for sysfs translation */
	235	sysdev->kobj.ktype = &ktype_sysdev;
	236	error = kobject_set_name(&sysdev->kobj, "%s%d",
	237	kobject_name(&cls->kset.kobj), sysdev->id);
	238	if (error)
	239	return error;
	240
	241	pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
	242
	243	/* Register the object */
	244	error = kobject_register(&sysdev->kobj);
	245
	246	if (!error) {
	247	struct sysdev_driver * drv;
	248
9f3f776b	249	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	250	/* Generic notification is implicit, because it's that
	251	* code that should have called us.
	252	*/
	253
1da177e4 LT	254	/* Notify class auxillary drivers */
	255	list_for_each_entry(drv, &cls->drivers, entry) {
	256	if (drv->add)
	257	drv->add(sysdev);
	258	}
9f3f776b	259	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	260	}
	261	return error;
	262	}
	263
	264	void sysdev_unregister(struct sys_device * sysdev)
	265	{
	266	struct sysdev_driver * drv;
	267
9f3f776b	268	mutex_lock(&sysdev_drivers_lock);
1da177e4 LT	269	list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
	270	if (drv->remove)
	271	drv->remove(sysdev);
	272	}
9f3f776b	273	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	274
	275	kobject_unregister(&sysdev->kobj);
	276	}
	277
	278
	279
	280	/**
	281	* sysdev_shutdown - Shut down all system devices.
	282	*
	283	* Loop over each class of system devices, and the devices in each
	284	* of those classes. For each device, we call the shutdown method for
44b760a8	285	* each driver registered for the device - the auxillaries,
1da177e4 LT	286	* and the class driver.
	287	*
	288	* Note: The list is iterated in reverse order, so that we shut down
	289	* child devices before we shut down thier parents. The list ordering
	290	* is guaranteed by virtue of the fact that child devices are registered
	291	* after their parents.
	292	*/
	293
	294	void sysdev_shutdown(void)
	295	{
	296	struct sysdev_class * cls;
	297
	298	pr_debug("Shutting Down System Devices\n");
	299
9f3f776b	300	mutex_lock(&sysdev_drivers_lock);
823bccfc	301	list_for_each_entry_reverse(cls, &system_subsys.list,
1da177e4 LT	302	kset.kobj.entry) {
	303	struct sys_device * sysdev;
	304
	305	pr_debug("Shutting down type '%s':\n",
	306	kobject_name(&cls->kset.kobj));
	307
	308	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
	309	struct sysdev_driver * drv;
	310	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
	311
44b760a8	312	/* Call auxillary drivers first */
1da177e4 LT	313	list_for_each_entry(drv, &cls->drivers, entry) {
	314	if (drv->shutdown)
	315	drv->shutdown(sysdev);
	316	}
	317
	318	/* Now call the generic one */
	319	if (cls->shutdown)
	320	cls->shutdown(sysdev);
	321	}
	322	}
9f3f776b	323	mutex_unlock(&sysdev_drivers_lock);
1da177e4 LT	324	}
1da177e4 LT	325
ceaeade1 SL	326	static void __sysdev_resume(struct sys_device *dev)
	327	{
	328	struct sysdev_class *cls = dev->cls;
	329	struct sysdev_driver *drv;
	330
	331	/* First, call the class-specific one */
	332	if (cls->resume)
	333	cls->resume(dev);
	334
	335	/* Call auxillary drivers next. */
	336	list_for_each_entry(drv, &cls->drivers, entry) {
	337	if (drv->resume)
	338	drv->resume(dev);
	339	}
ceaeade1	340	}
1da177e4 LT	341
	342	/**
	343	* sysdev_suspend - Suspend all system devices.
	344	* @state: Power state to enter.
	345	*
	346	* We perform an almost identical operation as sys_device_shutdown()
	347	* above, though calling ->suspend() instead. Interrupts are disabled
	348	* when this called. Devices are responsible for both saving state and
	349	* quiescing or powering down the device.
	350	*
	351	* This is only called by the device PM core, so we let them handle
	352	* all synchronization.
	353	*/
	354
438510f6	355	int sysdev_suspend(pm_message_t state)
1da177e4 LT	356	{
1da177e4 LT	357	struct sysdev_class * cls;
ceaeade1 SL	358	struct sys_device sysdev, err_dev;
	359	struct sysdev_driver drv, err_drv;
	360	int ret;
1da177e4 LT	361
	362	pr_debug("Suspending System Devices\n");
	363
823bccfc	364	list_for_each_entry_reverse(cls, &system_subsys.list,
1da177e4	365	kset.kobj.entry) {
1da177e4 LT	366
	367	pr_debug("Suspending type '%s':\n",
	368	kobject_name(&cls->kset.kobj));
	369
	370	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
1da177e4 LT	371	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
1da177e4 LT	372
44b760a8	373	/* Call auxillary drivers first */
1da177e4	374	list_for_each_entry(drv, &cls->drivers, entry) {
ceaeade1 SL	375	if (drv->suspend) {
	376	ret = drv->suspend(sysdev, state);
	377	if (ret)
	378	goto aux_driver;
	379	}
1da177e4 LT	380	}
	381
	382	/* Now call the generic one */
ceaeade1 SL	383	if (cls->suspend) {
	384	ret = cls->suspend(sysdev, state);
	385	if (ret)
	386	goto cls_driver;
	387	}
1da177e4 LT	388	}
	389	}
	390	return 0;
ceaeade1 SL	391	/* resume current sysdev */
	392	cls_driver:
	393	drv = NULL;
	394	printk(KERN_ERR "Class suspend failed for %s\n",
	395	kobject_name(&sysdev->kobj));
	396
	397	aux_driver:
	398	if (drv)
	399	printk(KERN_ERR "Class driver suspend failed for %s\n",
	400	kobject_name(&sysdev->kobj));
	401	list_for_each_entry(err_drv, &cls->drivers, entry) {
	402	if (err_drv == drv)
	403	break;
	404	if (err_drv->resume)
	405	err_drv->resume(sysdev);
	406	}
ceaeade1	407
ceaeade1 SL	408	/* resume other sysdevs in current class */
	409	list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
	410	if (err_dev == sysdev)
	411	break;
	412	pr_debug(" %s\n", kobject_name(&err_dev->kobj));
	413	__sysdev_resume(err_dev);
	414	}
	415
	416	/* resume other classes */
823bccfc	417	list_for_each_entry_continue(cls, &system_subsys.list,
ceaeade1 SL	418	kset.kobj.entry) {
	419	list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
	420	pr_debug(" %s\n", kobject_name(&err_dev->kobj));
	421	__sysdev_resume(err_dev);
	422	}
	423	}
	424	return ret;
1da177e4 LT	425	}
	426
	427
	428	/**
	429	* sysdev_resume - Bring system devices back to life.
	430	*
	431	* Similar to sys_device_suspend(), but we iterate the list forwards
	432	* to guarantee that parent devices are resumed before their children.
	433	*
	434	* Note: Interrupts are disabled when called.
	435	*/
	436
	437	int sysdev_resume(void)
	438	{
	439	struct sysdev_class * cls;
	440
	441	pr_debug("Resuming System Devices\n");
	442
823bccfc	443	list_for_each_entry(cls, &system_subsys.list, kset.kobj.entry) {
1da177e4 LT	444	struct sys_device * sysdev;
	445
	446	pr_debug("Resuming type '%s':\n",
	447	kobject_name(&cls->kset.kobj));
	448
	449	list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
1da177e4 LT	450	pr_debug(" %s\n", kobject_name(&sysdev->kobj));
1da177e4 LT	451
ceaeade1	452	__sysdev_resume(sysdev);
1da177e4 LT	453	}
	454	}
	455	return 0;
	456	}
	457
	458
	459	int __init system_bus_init(void)
	460	{
823bccfc	461	system_subsys.kobj.parent = &devices_subsys.kobj;
1da177e4 LT	462	return subsystem_register(&system_subsys);
	463	}
	464
	465	EXPORT_SYMBOL_GPL(sysdev_register);
	466	EXPORT_SYMBOL_GPL(sysdev_unregister);