/* * drivers/base/core.c - core driver model code (device registration, etc) * * Copyright (c) 2002-3 Patrick Mochel * Copyright (c) 2002-3 Open Source Development Labs * * This file is released under the GPLv2 * */ #include <linux/config.h>#include <linux/device.h>#include <linux/err.h>#include <linux/init.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/string.h> #include <asm/semaphore.h> #include "base.h"#include "power/power.h" int (*platform_notify)(struct device * dev) = NULL;int (*platform_notify_remove)(struct device * dev) = NULL; /* * sysfs bindings for devices. */ #define to_dev(obj) container_of(obj, struct device, kobj)#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) static ssize_tdev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf){	struct device_attribute * dev_attr = to_dev_attr(attr);	struct device * dev = to_dev(kobj);	ssize_t ret = -EIO; 	if (dev_attr->show)		ret = dev_attr->show(dev, dev_attr, buf);	return ret;} static ssize_tdev_attr_store(struct kobject * kobj, struct attribute * attr,	       const char * buf, size_t count){	struct device_attribute * dev_attr = to_dev_attr(attr);	struct device * dev = to_dev(kobj);	ssize_t ret = -EIO; 	if (dev_attr->store)		ret = dev_attr->store(dev, dev_attr, buf, count);	return ret;} static struct sysfs_ops dev_sysfs_ops = {	.show	= dev_attr_show,	.store	= dev_attr_store,};  /** *	device_release - free device structure. *	@kobj:	device's kobject. * *	This is called once the reference count for the object *	reaches 0. We forward the call to the device's release *	method, which should handle actually freeing the structure. */static void device_release(struct kobject * kobj){	struct device * dev = to_dev(kobj); 	if (dev->release)		dev->release(dev);	else {		printk(KERN_ERR "Device '%s' does not have a release() function, "			"it is broken and must be fixed.\n",			dev->bus_id);		WARN_ON(1);	}} static struct kobj_type ktype_device = {	.release	= device_release,	.sysfs_ops	= &dev_sysfs_ops,};  static int dev_hotplug_filter(struct kset *kset, struct kobject *kobj){	struct kobj_type *ktype = get_ktype(kobj); 	if (ktype == &ktype_device) {		struct device *dev = to_dev(kobj);		if (dev->bus)			return 1;	}	return 0;} static const char *dev_hotplug_name(struct kset *kset, struct kobject *kobj){	struct device *dev = to_dev(kobj); 	return dev->bus->name;} static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,			int num_envp, char *buffer, int buffer_size){	struct device *dev = to_dev(kobj);	int i = 0;	int length = 0;	int retval = 0; 	/* add bus name of physical device */	if (dev->bus)		add_hotplug_env_var(envp, num_envp, &i,				    buffer, buffer_size, &length,				    "PHYSDEVBUS=%s", dev->bus->name); 	/* add driver name of physical device */	if (dev->driver)		add_hotplug_env_var(envp, num_envp, &i,				    buffer, buffer_size, &length,				    "PHYSDEVDRIVER=%s", dev->driver->name); 	/* terminate, set to next free slot, shrink available space */	envp[i] = NULL;	envp = &envp[i];	num_envp -= i;	buffer = &buffer[length];	buffer_size -= length; 	if (dev->bus && dev->bus->hotplug) {		/* have the bus specific function add its stuff */		retval = dev->bus->hotplug (dev, envp, num_envp, buffer, buffer_size);			if (retval) {			pr_debug ("%s - hotplug() returned %d\n",				  __FUNCTION__, retval);		}	} 	return retval;} static struct kset_hotplug_ops device_hotplug_ops = {	.filter =	dev_hotplug_filter,	.name =		dev_hotplug_name,	.hotplug =	dev_hotplug,}; /** *	device_subsys - structure to be registered with kobject core. */ decl_subsys(devices, &ktype_device, &device_hotplug_ops);  /** *	device_create_file - create sysfs attribute file for device. *	@dev:	device. *	@attr:	device attribute descriptor. */ int device_create_file(struct device * dev, struct device_attribute * attr){	int error = 0;	if (get_device(dev)) {		error = sysfs_create_file(&dev->kobj, &attr->attr);		put_device(dev);	}	return error;} /** *	device_remove_file - remove sysfs attribute file. *	@dev:	device. *	@attr:	device attribute descriptor. */ void device_remove_file(struct device * dev, struct device_attribute * attr){	if (get_device(dev)) {		sysfs_remove_file(&dev->kobj, &attr->attr);		put_device(dev);	}}  /** *	device_initialize - init device structure. *	@dev:	device. * *	This prepares the device for use by other layers, *	including adding it to the device hierarchy. *	It is the first half of device_register(), if called by *	that, though it can also be called separately, so one *	may use @dev's fields (e.g. the refcount). */ void device_initialize(struct device *dev){	kobj_set_kset_s(dev, devices_subsys);	kobject_init(&dev->kobj);	klist_init(&dev->klist_children);	INIT_LIST_HEAD(&dev->dma_pools);	init_MUTEX(&dev->sem);} /** *	device_add - add device to device hierarchy. *	@dev:	device. * *	This is part 2 of device_register(), though may be called *	separately _iff_ device_initialize() has been called separately. * *	This adds it to the kobject hierarchy via kobject_add(), adds it *	to the global and sibling lists for the device, then *	adds it to the other relevant subsystems of the driver model. */int device_add(struct device *dev){	struct device *parent = NULL;	int error = -EINVAL; 	dev = get_device(dev);	if (!dev || !strlen(dev->bus_id))		goto Error; 	parent = get_device(dev->parent); 	pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id); 	/* first, register with generic layer. */	kobject_set_name(&dev->kobj, "%s", dev->bus_id);	if (parent)		dev->kobj.parent = &parent->kobj; 	if ((error = kobject_add(&dev->kobj)))		goto Error;	kobject_hotplug(&dev->kobj, KOBJ_ADD);	if ((error = device_pm_add(dev)))		goto PMError;	if ((error = bus_add_device(dev)))		goto BusError;	if (parent)		klist_add_tail(&parent->klist_children, &dev->knode_parent); 	/* notify platform of device entry */	if (platform_notify)		platform_notify(dev); Done:	put_device(dev);	return error; BusError:	device_pm_remove(dev); PMError:	kobject_hotplug(&dev->kobj, KOBJ_REMOVE);	kobject_del(&dev->kobj); Error:	if (parent)		put_device(parent);	goto Done;}  /** *	device_register - register a device with the system. *	@dev:	pointer to the device structure * *	This happens in two clean steps - initialize the device *	and add it to the system. The two steps can be called *	separately, but this is the easiest and most common. *	I.e. you should only call the two helpers separately if *	have a clearly defined need to use and refcount the device *	before it is added to the hierarchy. */ int device_register(struct device *dev){	device_initialize(dev);	return device_add(dev);}  /** *	get_device - increment reference count for device. *	@dev:	device. * *	This simply forwards the call to kobject_get(), though *	we do take care to provide for the case that we get a NULL *	pointer passed in. */ struct device * get_device(struct device * dev){	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;}  /** *	put_device - decrement reference count. *	@dev:	device in question. */void put_device(struct device * dev){	if (dev)		kobject_put(&dev->kobj);}  /** *	device_del - delete device from system. *	@dev:	device. * *	This is the first part of the device unregistration *	sequence. This removes the device from the lists we control *	from here, has it removed from the other driver model *	subsystems it was added to in device_add(), and removes it *	from the kobject hierarchy. * *	NOTE: this should be called manually _iff_ device_add() was *	also called manually. */ void device_del(struct device * dev){	struct device * parent = dev->parent; 	if (parent)		klist_del(&dev->knode_parent); 	/* Notify the platform of the removal, in case they	 * need to do anything...	 */	if (platform_notify_remove)		platform_notify_remove(dev);	bus_remove_device(dev);	device_pm_remove(dev);	kobject_hotplug(&dev->kobj, KOBJ_REMOVE);	kobject_del(&dev->kobj);	if (parent)		put_device(parent);} /** *	device_unregister - unregister device from system. *	@dev:	device going away. * *	We do this in two parts, like we do device_register(). First, *	we remove it from all the subsystems with device_del(), then *	we decrement the reference count via put_device(). If that *	is the final reference count, the device will be cleaned up *	via device_release() above. Otherwise, the structure will *	stick around until the final reference to the device is dropped. */void device_unregister(struct device * dev){	pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);	device_del(dev);	put_device(dev);}  static struct device * next_device(struct klist_iter * i){	struct klist_node * n = klist_next(i);	return n ? container_of(n, struct device, knode_parent) : NULL;} /** *	device_for_each_child - device child iterator. *	@dev:	parent struct device. *	@data:	data for the callback. *	@fn:	function to be called for each device. * *	Iterate over @dev's child devices, and call @fn for each, *	passing it @data. * *	We check the return of @fn each time. If it returns anything *	other than 0, we break out and return that value. */int device_for_each_child(struct device * parent, void * data,		     int (*fn)(struct device *, void *)){	struct klist_iter i;	struct device * child;	int error = 0; 	klist_iter_init(&parent->klist_children, &i);	while ((child = next_device(&i)) && !error)		error = fn(child, data);	klist_iter_exit(&i);	return error;} int __init devices_init(void){	return subsystem_register(&devices_subsys);} EXPORT_SYMBOL_GPL(device_for_each_child); EXPORT_SYMBOL_GPL(device_initialize);EXPORT_SYMBOL_GPL(device_add);EXPORT_SYMBOL_GPL(device_register); EXPORT_SYMBOL_GPL(device_del);EXPORT_SYMBOL_GPL(device_unregister);EXPORT_SYMBOL_GPL(get_device);EXPORT_SYMBOL_GPL(put_device); EXPORT_SYMBOL_GPL(device_create_file);EXPORT_SYMBOL_GPL(device_remove_file);