/* * class.c - basic device class management * * Copyright (c) 2002-3 Patrick Mochel * Copyright (c) 2002-3 Open Source Development Labs * Copyright (c) 2003-2004 Greg Kroah-Hartman * Copyright (c) 2003-2004 IBM Corp. * * This file is released under the GPLv2 * */ #include <linux/config.h>#include <linux/device.h>#include <linux/module.h>#include <linux/init.h>#include <linux/string.h>#include <linux/kdev_t.h>#include <linux/err.h>#include "base.h" #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj) static ssize_tclass_attr_show(struct kobject * kobj, struct attribute * attr, char * buf){	struct class_attribute * class_attr = to_class_attr(attr);	struct class * dc = to_class(kobj);	ssize_t ret = -EIO; 	if (class_attr->show)		ret = class_attr->show(dc, buf);	return ret;} static ssize_tclass_attr_store(struct kobject * kobj, struct attribute * attr,		 const char * buf, size_t count){	struct class_attribute * class_attr = to_class_attr(attr);	struct class * dc = to_class(kobj);	ssize_t ret = -EIO; 	if (class_attr->store)		ret = class_attr->store(dc, buf, count);	return ret;} static void class_release(struct kobject * kobj){	struct class *class = to_class(kobj); 	pr_debug("class '%s': release.\n", class->name); 	if (class->class_release)		class->class_release(class);	else		pr_debug("class '%s' does not have a release() function, "			 "be careful\n", class->name);} static struct sysfs_ops class_sysfs_ops = {	.show	= class_attr_show,	.store	= class_attr_store,}; static struct kobj_type ktype_class = {	.sysfs_ops	= &class_sysfs_ops,	.release	= class_release,}; /* Hotplug events for classes go to the class_obj subsys */static decl_subsys(class, &ktype_class, NULL);  int class_create_file(struct class * cls, const struct class_attribute * attr){	int error;	if (cls) {		error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);	} else		error = -EINVAL;	return error;} void class_remove_file(struct class * cls, const struct class_attribute * attr){	if (cls)		sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);} struct class * class_get(struct class * cls){	if (cls)		return container_of(subsys_get(&cls->subsys), struct class, subsys);	return NULL;} void class_put(struct class * cls){	subsys_put(&cls->subsys);}  static int add_class_attrs(struct class * cls){	int i;	int error = 0; 	if (cls->class_attrs) {		for (i = 0; attr_name(cls->class_attrs[i]); i++) {			error = class_create_file(cls,&cls->class_attrs[i]);			if (error)				goto Err;		}	} Done:	return error; Err:	while (--i >= 0)		class_remove_file(cls,&cls->class_attrs[i]);	goto Done;} static void remove_class_attrs(struct class * cls){	int i; 	if (cls->class_attrs) {		for (i = 0; attr_name(cls->class_attrs[i]); i++)			class_remove_file(cls,&cls->class_attrs[i]);	}} int class_register(struct class * cls){	int error; 	pr_debug("device class '%s': registering\n", cls->name); 	INIT_LIST_HEAD(&cls->children);	INIT_LIST_HEAD(&cls->interfaces);	init_MUTEX(&cls->sem);	error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);	if (error)		return error; 	subsys_set_kset(cls, class_subsys); 	error = subsystem_register(&cls->subsys);	if (!error) {		error = add_class_attrs(class_get(cls));		class_put(cls);	}	return error;} void class_unregister(struct class * cls){	pr_debug("device class '%s': unregistering\n", cls->name);	remove_class_attrs(cls);	subsystem_unregister(&cls->subsys);} static void class_create_release(struct class *cls){	kfree(cls);} static void class_device_create_release(struct class_device *class_dev){	kfree(class_dev);} /** * class_create - create a struct class structure * @owner: pointer to the module that is to "own" this struct class * @name: pointer to a string for the name of this class. * * This is used to create a struct class pointer that can then be used * in calls to class_device_create(). * * Note, the pointer created here is to be destroyed when finished by * making a call to class_destroy(). */struct class *class_create(struct module *owner, char *name){	struct class *cls;	int retval; 	cls = kmalloc(sizeof(struct class), GFP_KERNEL);	if (!cls) {		retval = -ENOMEM;		goto error;	}	memset(cls, 0x00, sizeof(struct class)); 	cls->name = name;	cls->owner = owner;	cls->class_release = class_create_release;	cls->release = class_device_create_release; 	retval = class_register(cls);	if (retval)		goto error; 	return cls; error:	kfree(cls);	return ERR_PTR(retval);} /** * class_destroy - destroys a struct class structure * @cs: pointer to the struct class that is to be destroyed * * Note, the pointer to be destroyed must have been created with a call * to class_create(). */void class_destroy(struct class *cls){	if ((cls == NULL) || (IS_ERR(cls)))		return; 	class_unregister(cls);} /* Class Device Stuff */ int class_device_create_file(struct class_device * class_dev,			     const struct class_device_attribute * attr){	int error = -EINVAL;	if (class_dev)		error = sysfs_create_file(&class_dev->kobj, &attr->attr);	return error;} void class_device_remove_file(struct class_device * class_dev,			      const struct class_device_attribute * attr){	if (class_dev)		sysfs_remove_file(&class_dev->kobj, &attr->attr);} int class_device_create_bin_file(struct class_device *class_dev,				 struct bin_attribute *attr){	int error = -EINVAL;	if (class_dev)		error = sysfs_create_bin_file(&class_dev->kobj, attr);	return error;} void class_device_remove_bin_file(struct class_device *class_dev,				  struct bin_attribute *attr){	if (class_dev)		sysfs_remove_bin_file(&class_dev->kobj, attr);} static ssize_tclass_device_attr_show(struct kobject * kobj, struct attribute * attr,		       char * buf){	struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);	struct class_device * cd = to_class_dev(kobj);	ssize_t ret = 0; 	if (class_dev_attr->show)		ret = class_dev_attr->show(cd, buf);	return ret;} static ssize_tclass_device_attr_store(struct kobject * kobj, struct attribute * attr,			const char * buf, size_t count){	struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);	struct class_device * cd = to_class_dev(kobj);	ssize_t ret = 0; 	if (class_dev_attr->store)		ret = class_dev_attr->store(cd, buf, count);	return ret;} static struct sysfs_ops class_dev_sysfs_ops = {	.show	= class_device_attr_show,	.store	= class_device_attr_store,}; static void class_dev_release(struct kobject * kobj){	struct class_device *cd = to_class_dev(kobj);	struct class * cls = cd->class; 	pr_debug("device class '%s': release.\n", cd->class_id); 	if (cd->devt_attr) {		kfree(cd->devt_attr);		cd->devt_attr = NULL;	} 	if (cls->release)		cls->release(cd);	else {		printk(KERN_ERR "Device class '%s' does not have a release() function, "			"it is broken and must be fixed.\n",			cd->class_id);		WARN_ON(1);	}} static struct kobj_type ktype_class_device = {	.sysfs_ops	= &class_dev_sysfs_ops,	.release	= class_dev_release,}; static int class_hotplug_filter(struct kset *kset, struct kobject *kobj){	struct kobj_type *ktype = get_ktype(kobj); 	if (ktype == &ktype_class_device) {		struct class_device *class_dev = to_class_dev(kobj);		if (class_dev->class)			return 1;	}	return 0;} static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj){	struct class_device *class_dev = to_class_dev(kobj); 	return class_dev->class->name;} static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,			 int num_envp, char *buffer, int buffer_size){	struct class_device *class_dev = to_class_dev(kobj);	int i = 0;	int length = 0;	int retval = 0; 	pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id); 	if (class_dev->dev) {		/* add physical device, backing this device  */		struct device *dev = class_dev->dev;		char *path = kobject_get_path(&dev->kobj, GFP_KERNEL); 		add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,				    &length, "PHYSDEVPATH=%s", path);		kfree(path); 		if (dev->bus)			add_hotplug_env_var(envp, num_envp, &i,					    buffer, buffer_size, &length,					    "PHYSDEVBUS=%s", dev->bus->name); 		if (dev->driver)			add_hotplug_env_var(envp, num_envp, &i,					    buffer, buffer_size, &length,					    "PHYSDEVDRIVER=%s", dev->driver->name);	} 	if (MAJOR(class_dev->devt)) {		add_hotplug_env_var(envp, num_envp, &i,				    buffer, buffer_size, &length,				    "MAJOR=%u", MAJOR(class_dev->devt)); 		add_hotplug_env_var(envp, num_envp, &i,				    buffer, buffer_size, &length,				    "MINOR=%u", MINOR(class_dev->devt));	} 	/* 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 (class_dev->class->hotplug) {		/* have the bus specific function add its stuff */		retval = class_dev->class->hotplug (class_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 class_hotplug_ops = {	.filter =	class_hotplug_filter,	.name =		class_hotplug_name,	.hotplug =	class_hotplug,}; static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);  static int class_device_add_attrs(struct class_device * cd){	int i;	int error = 0;	struct class * cls = cd->class; 	if (cls->class_dev_attrs) {		for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {			error = class_device_create_file(cd,							 &cls->class_dev_attrs[i]);			if (error)				goto Err;		}	} Done:	return error; Err:	while (--i >= 0)		class_device_remove_file(cd,&cls->class_dev_attrs[i]);	goto Done;} static void class_device_remove_attrs(struct class_device * cd){	int i;	struct class * cls = cd->class; 	if (cls->class_dev_attrs) {		for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)			class_device_remove_file(cd,&cls->class_dev_attrs[i]);	}} static ssize_t show_dev(struct class_device *class_dev, char *buf){	return print_dev_t(buf, class_dev->devt);} void class_device_initialize(struct class_device *class_dev){	kobj_set_kset_s(class_dev, class_obj_subsys);	kobject_init(&class_dev->kobj);	INIT_LIST_HEAD(&class_dev->node);} int class_device_add(struct class_device *class_dev){	struct class * parent = NULL;	struct class_interface * class_intf;	int error; 	class_dev = class_device_get(class_dev);	if (!class_dev)		return -EINVAL; 	if (!strlen(class_dev->class_id)) {		error = -EINVAL;		goto register_done;	} 	parent = class_get(class_dev->class); 	pr_debug("CLASS: registering class device: ID = '%s'\n",		 class_dev->class_id); 	/* first, register with generic layer. */	kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);	if (parent)		class_dev->kobj.parent = &parent->subsys.kset.kobj; 	if ((error = kobject_add(&class_dev->kobj)))		goto register_done; 	/* add the needed attributes to this device */	if (MAJOR(class_dev->devt)) {		struct class_device_attribute *attr;		attr = kmalloc(sizeof(*attr), GFP_KERNEL);		if (!attr) {			error = -ENOMEM;			kobject_del(&class_dev->kobj);			goto register_done;		}		memset(attr, sizeof(*attr), 0x00);		attr->attr.name = "dev";		attr->attr.mode = S_IRUGO;		attr->attr.owner = parent->owner;		attr->show = show_dev;		attr->store = NULL;		class_device_create_file(class_dev, attr);		class_dev->devt_attr = attr;	}

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