/* * 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/config.h>#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> extern struct subsystem 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_tsysdev_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_tsysdev_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); /* * declare system_subsys */static decl_subsys(system, &ktype_sysdev, 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.subsys = &system_subsys;	kset_set_kset_s(cls, 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 LIST_HEAD(sysdev_drivers);static DECLARE_MUTEX(sysdev_drivers_lock); /** *	sysdev_driver_register - Register auxillary driver * 	@cls:	Device class driver belongs to. *	@drv:	Driver. * *	If @cls is valid, then @drv is inserted into @cls->drivers to be *	called on each operation on devices of that class. The refcount *	of @cls is incremented. *	Otherwise, @drv is inserted into sysdev_drivers, and called for *	each device. */ int sysdev_driver_register(struct sysdev_class * cls,			   struct sysdev_driver * drv){	down(&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		list_add_tail(&drv->entry, &sysdev_drivers);	up(&sysdev_drivers_lock);	return 0;}  /** *	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){	down(&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);	}	up(&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; 		down(&sysdev_drivers_lock);		/* Generic notification is implicit, because it's that		 * code that should have called us.		 */ 		/* Notify global drivers */		list_for_each_entry(drv, &sysdev_drivers, entry) {			if (drv->add)				drv->add(sysdev);		} 		/* Notify class auxillary drivers */		list_for_each_entry(drv, &cls->drivers, entry) {			if (drv->add)				drv->add(sysdev);		}		up(&sysdev_drivers_lock);	}	return error;} void sysdev_unregister(struct sys_device * sysdev){	struct sysdev_driver * drv; 	down(&sysdev_drivers_lock);	list_for_each_entry(drv, &sysdev_drivers, entry) {		if (drv->remove)			drv->remove(sysdev);	} 	list_for_each_entry(drv, &sysdev->cls->drivers, entry) {		if (drv->remove)			drv->remove(sysdev);	}	up(&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 globals, 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"); 	down(&sysdev_drivers_lock);	list_for_each_entry_reverse(cls, &system_subsys.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 global drivers first. */			list_for_each_entry(drv, &sysdev_drivers, entry) {				if (drv->shutdown)					drv->shutdown(sysdev);			} 			/* Call auxillary drivers next. */			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);		}	}	up(&sysdev_drivers_lock);}  /** *	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; 	pr_debug("Suspending System Devices\n"); 	list_for_each_entry_reverse(cls, &system_subsys.kset.list,				    kset.kobj.entry) {		struct sys_device * sysdev; 		pr_debug("Suspending 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 global drivers first. */			list_for_each_entry(drv, &sysdev_drivers, entry) {				if (drv->suspend)					drv->suspend(sysdev, state);			} 			/* Call auxillary drivers next. */			list_for_each_entry(drv, &cls->drivers, entry) {				if (drv->suspend)					drv->suspend(sysdev, state);			} 			/* Now call the generic one */			if (cls->suspend)				cls->suspend(sysdev, state);		}	}	return 0;}  /** *	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.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) {			struct sysdev_driver * drv;			pr_debug(" %s\n", kobject_name(&sysdev->kobj)); 			/* First, call the class-specific one */			if (cls->resume)				cls->resume(sysdev); 			/* Call auxillary drivers next. */			list_for_each_entry(drv, &cls->drivers, entry) {				if (drv->resume)					drv->resume(sysdev);			} 			/* Call global drivers. */			list_for_each_entry(drv, &sysdev_drivers, entry) {				if (drv->resume)					drv->resume(sysdev);			} 		}	}	return 0;}  int __init system_bus_init(void){	system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;	return subsystem_register(&system_subsys);} EXPORT_SYMBOL_GPL(sysdev_register);EXPORT_SYMBOL_GPL(sysdev_unregister);