458 lines
11 KiB
C
458 lines
11 KiB
C
/*
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* sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* 2002-3 Open Source Development Lab
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*
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* This file is released under the GPLv2
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*
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* This exports a 'system' bus type.
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* By default, a 'sys' bus gets added to the root of the system. There will
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* always be core system devices. Devices can use sysdev_register() to
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* add themselves as children of the system bus.
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*/
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#include <linux/config.h>
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#include <linux/sysdev.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/pm.h>
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extern struct subsystem devices_subsys;
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#define to_sysdev(k) container_of(k, struct sys_device, kobj)
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#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
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static ssize_t
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sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
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{
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struct sys_device * sysdev = to_sysdev(kobj);
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struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
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if (sysdev_attr->show)
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return sysdev_attr->show(sysdev, buffer);
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return -EIO;
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}
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static ssize_t
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sysdev_store(struct kobject * kobj, struct attribute * attr,
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const char * buffer, size_t count)
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{
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struct sys_device * sysdev = to_sysdev(kobj);
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struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
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if (sysdev_attr->store)
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return sysdev_attr->store(sysdev, buffer, count);
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return -EIO;
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}
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static struct sysfs_ops sysfs_ops = {
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.show = sysdev_show,
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.store = sysdev_store,
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};
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static struct kobj_type ktype_sysdev = {
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.sysfs_ops = &sysfs_ops,
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};
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int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
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{
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return sysfs_create_file(&s->kobj, &a->attr);
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}
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void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
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{
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sysfs_remove_file(&s->kobj, &a->attr);
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}
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EXPORT_SYMBOL_GPL(sysdev_create_file);
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EXPORT_SYMBOL_GPL(sysdev_remove_file);
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/*
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* declare system_subsys
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*/
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static decl_subsys(system, &ktype_sysdev, NULL);
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int sysdev_class_register(struct sysdev_class * cls)
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{
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pr_debug("Registering sysdev class '%s'\n",
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kobject_name(&cls->kset.kobj));
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INIT_LIST_HEAD(&cls->drivers);
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cls->kset.subsys = &system_subsys;
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kset_set_kset_s(cls, system_subsys);
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return kset_register(&cls->kset);
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}
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void sysdev_class_unregister(struct sysdev_class * cls)
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{
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pr_debug("Unregistering sysdev class '%s'\n",
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kobject_name(&cls->kset.kobj));
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kset_unregister(&cls->kset);
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}
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EXPORT_SYMBOL_GPL(sysdev_class_register);
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EXPORT_SYMBOL_GPL(sysdev_class_unregister);
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static LIST_HEAD(sysdev_drivers);
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static DECLARE_MUTEX(sysdev_drivers_lock);
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/**
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* sysdev_driver_register - Register auxillary driver
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* @cls: Device class driver belongs to.
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* @drv: Driver.
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*
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* If @cls is valid, then @drv is inserted into @cls->drivers to be
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* called on each operation on devices of that class. The refcount
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* of @cls is incremented.
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* Otherwise, @drv is inserted into sysdev_drivers, and called for
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* each device.
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*/
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int sysdev_driver_register(struct sysdev_class * cls,
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struct sysdev_driver * drv)
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{
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down(&sysdev_drivers_lock);
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if (cls && kset_get(&cls->kset)) {
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list_add_tail(&drv->entry, &cls->drivers);
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/* If devices of this class already exist, tell the driver */
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if (drv->add) {
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struct sys_device *dev;
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list_for_each_entry(dev, &cls->kset.list, kobj.entry)
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drv->add(dev);
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}
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} else
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list_add_tail(&drv->entry, &sysdev_drivers);
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up(&sysdev_drivers_lock);
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return 0;
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}
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/**
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* sysdev_driver_unregister - Remove an auxillary driver.
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* @cls: Class driver belongs to.
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* @drv: Driver.
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*/
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void sysdev_driver_unregister(struct sysdev_class * cls,
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struct sysdev_driver * drv)
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{
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down(&sysdev_drivers_lock);
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list_del_init(&drv->entry);
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if (cls) {
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if (drv->remove) {
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struct sys_device *dev;
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list_for_each_entry(dev, &cls->kset.list, kobj.entry)
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drv->remove(dev);
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}
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kset_put(&cls->kset);
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}
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up(&sysdev_drivers_lock);
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}
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EXPORT_SYMBOL_GPL(sysdev_driver_register);
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EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
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/**
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* sysdev_register - add a system device to the tree
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* @sysdev: device in question
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*
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*/
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int sysdev_register(struct sys_device * sysdev)
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{
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int error;
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struct sysdev_class * cls = sysdev->cls;
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if (!cls)
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return -EINVAL;
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/* Make sure the kset is set */
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sysdev->kobj.kset = &cls->kset;
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/* But make sure we point to the right type for sysfs translation */
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sysdev->kobj.ktype = &ktype_sysdev;
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error = kobject_set_name(&sysdev->kobj, "%s%d",
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kobject_name(&cls->kset.kobj), sysdev->id);
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if (error)
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return error;
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pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
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/* Register the object */
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error = kobject_register(&sysdev->kobj);
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if (!error) {
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struct sysdev_driver * drv;
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down(&sysdev_drivers_lock);
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/* Generic notification is implicit, because it's that
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* code that should have called us.
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*/
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/* Notify global drivers */
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list_for_each_entry(drv, &sysdev_drivers, entry) {
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if (drv->add)
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drv->add(sysdev);
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}
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/* Notify class auxillary drivers */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->add)
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drv->add(sysdev);
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}
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up(&sysdev_drivers_lock);
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}
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return error;
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}
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void sysdev_unregister(struct sys_device * sysdev)
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{
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struct sysdev_driver * drv;
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down(&sysdev_drivers_lock);
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list_for_each_entry(drv, &sysdev_drivers, entry) {
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if (drv->remove)
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drv->remove(sysdev);
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}
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list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
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if (drv->remove)
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drv->remove(sysdev);
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}
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up(&sysdev_drivers_lock);
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kobject_unregister(&sysdev->kobj);
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}
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/**
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* sysdev_shutdown - Shut down all system devices.
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*
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* Loop over each class of system devices, and the devices in each
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* of those classes. For each device, we call the shutdown method for
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* each driver registered for the device - the globals, the auxillaries,
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* and the class driver.
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*
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* Note: The list is iterated in reverse order, so that we shut down
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* child devices before we shut down thier parents. The list ordering
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* is guaranteed by virtue of the fact that child devices are registered
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* after their parents.
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*/
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void sysdev_shutdown(void)
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{
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struct sysdev_class * cls;
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pr_debug("Shutting Down System Devices\n");
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down(&sysdev_drivers_lock);
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list_for_each_entry_reverse(cls, &system_subsys.kset.list,
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kset.kobj.entry) {
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struct sys_device * sysdev;
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pr_debug("Shutting down type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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struct sysdev_driver * drv;
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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/* Call global drivers first. */
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list_for_each_entry(drv, &sysdev_drivers, entry) {
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if (drv->shutdown)
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drv->shutdown(sysdev);
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}
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/* Call auxillary drivers next. */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->shutdown)
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drv->shutdown(sysdev);
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}
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/* Now call the generic one */
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if (cls->shutdown)
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cls->shutdown(sysdev);
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}
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}
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up(&sysdev_drivers_lock);
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}
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static void __sysdev_resume(struct sys_device *dev)
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{
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struct sysdev_class *cls = dev->cls;
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struct sysdev_driver *drv;
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/* First, call the class-specific one */
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if (cls->resume)
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cls->resume(dev);
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/* Call auxillary drivers next. */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->resume)
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drv->resume(dev);
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}
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/* Call global drivers. */
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list_for_each_entry(drv, &sysdev_drivers, entry) {
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if (drv->resume)
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drv->resume(dev);
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}
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}
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/**
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* sysdev_suspend - Suspend all system devices.
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* @state: Power state to enter.
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*
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* We perform an almost identical operation as sys_device_shutdown()
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* above, though calling ->suspend() instead. Interrupts are disabled
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* when this called. Devices are responsible for both saving state and
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* quiescing or powering down the device.
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*
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* This is only called by the device PM core, so we let them handle
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* all synchronization.
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*/
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int sysdev_suspend(pm_message_t state)
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{
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struct sysdev_class * cls;
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struct sys_device *sysdev, *err_dev;
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struct sysdev_driver *drv, *err_drv;
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int ret;
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pr_debug("Suspending System Devices\n");
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list_for_each_entry_reverse(cls, &system_subsys.kset.list,
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kset.kobj.entry) {
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pr_debug("Suspending type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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/* Call global drivers first. */
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list_for_each_entry(drv, &sysdev_drivers, entry) {
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if (drv->suspend) {
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ret = drv->suspend(sysdev, state);
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if (ret)
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goto gbl_driver;
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}
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}
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/* Call auxillary drivers next. */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->suspend) {
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ret = drv->suspend(sysdev, state);
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if (ret)
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goto aux_driver;
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}
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}
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/* Now call the generic one */
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if (cls->suspend) {
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ret = cls->suspend(sysdev, state);
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if (ret)
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goto cls_driver;
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}
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}
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}
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return 0;
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/* resume current sysdev */
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cls_driver:
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drv = NULL;
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printk(KERN_ERR "Class suspend failed for %s\n",
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kobject_name(&sysdev->kobj));
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aux_driver:
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if (drv)
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printk(KERN_ERR "Class driver suspend failed for %s\n",
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kobject_name(&sysdev->kobj));
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list_for_each_entry(err_drv, &cls->drivers, entry) {
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if (err_drv == drv)
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break;
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if (err_drv->resume)
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err_drv->resume(sysdev);
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}
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drv = NULL;
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gbl_driver:
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if (drv)
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printk(KERN_ERR "sysdev driver suspend failed for %s\n",
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kobject_name(&sysdev->kobj));
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list_for_each_entry(err_drv, &sysdev_drivers, entry) {
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if (err_drv == drv)
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break;
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if (err_drv->resume)
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err_drv->resume(sysdev);
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}
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/* resume other sysdevs in current class */
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list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
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if (err_dev == sysdev)
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break;
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pr_debug(" %s\n", kobject_name(&err_dev->kobj));
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__sysdev_resume(err_dev);
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}
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/* resume other classes */
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list_for_each_entry_continue(cls, &system_subsys.kset.list,
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kset.kobj.entry) {
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list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&err_dev->kobj));
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__sysdev_resume(err_dev);
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}
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}
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return ret;
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}
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/**
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* sysdev_resume - Bring system devices back to life.
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*
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* Similar to sys_device_suspend(), but we iterate the list forwards
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* to guarantee that parent devices are resumed before their children.
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*
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* Note: Interrupts are disabled when called.
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*/
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int sysdev_resume(void)
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{
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struct sysdev_class * cls;
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pr_debug("Resuming System Devices\n");
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list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) {
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struct sys_device * sysdev;
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pr_debug("Resuming type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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__sysdev_resume(sysdev);
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}
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}
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return 0;
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}
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int __init system_bus_init(void)
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{
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system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
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return subsystem_register(&system_subsys);
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}
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EXPORT_SYMBOL_GPL(sysdev_register);
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EXPORT_SYMBOL_GPL(sysdev_unregister);
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