/* * 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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de> * Copyright (c) 2006 Novell, Inc. * * This file is released under the GPLv2 * */ #include <linux/device.h>#include <linux/err.h>#include <linux/fwnode.h>#include <linux/init.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/kdev_t.h>#include <linux/notifier.h>#include <linux/of.h>#include <linux/of_device.h>#include <linux/genhd.h>#include <linux/kallsyms.h>#include <linux/mutex.h>#include <linux/pm_runtime.h>#include <linux/netdevice.h>#include <linux/sysfs.h> #include "base.h"#include "power/power.h" #ifdef CONFIG_SYSFS_DEPRECATED#ifdef CONFIG_SYSFS_DEPRECATED_V2long sysfs_deprecated = 1;#elselong sysfs_deprecated = 0;#endifstatic int __init sysfs_deprecated_setup(char *arg){ return kstrtol(arg, 10, &sysfs_deprecated);}early_param("sysfs.deprecated", sysfs_deprecated_setup);#endif int (*platform_notify)(struct device *dev) = NULL;int (*platform_notify_remove)(struct device *dev) = NULL;static struct kobject *dev_kobj;struct kobject *sysfs_dev_char_kobj;struct kobject *sysfs_dev_block_kobj; static DEFINE_MUTEX(device_hotplug_lock); void lock_device_hotplug(void){ mutex_lock(&device_hotplug_lock);} void unlock_device_hotplug(void){ mutex_unlock(&device_hotplug_lock);} int lock_device_hotplug_sysfs(void){ if (mutex_trylock(&device_hotplug_lock)) return 0; /* Avoid busy looping (5 ms of sleep should do). */ msleep(5); return restart_syscall();} #ifdef CONFIG_BLOCKstatic inline int device_is_not_partition(struct device *dev){ return !(dev->type == &part_type);}#elsestatic inline int device_is_not_partition(struct device *dev){ return 1;}#endif /** * dev_driver_string - Return a device's driver name, if at all possible * @dev: struct device to get the name of * * Will return the device's driver's name if it is bound to a device. If * the device is not bound to a driver, it will return the name of the bus * it is attached to. If it is not attached to a bus either, an empty * string will be returned. */const char *dev_driver_string(const struct device *dev){ struct device_driver *drv; /* dev->driver can change to NULL underneath us because of unbinding, * so be careful about accessing it. dev->bus and dev->class should * never change once they are set, so they don't need special care. */ drv = ACCESS_ONCE(dev->driver); return drv ? drv->name : (dev->bus ? dev->bus->name : (dev->class ? dev->class->name : ""));}EXPORT_SYMBOL(dev_driver_string); #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, char *buf){ struct device_attribute *dev_attr = to_dev_attr(attr); struct device *dev = kobj_to_dev(kobj); ssize_t ret = -EIO; if (dev_attr->show) ret = dev_attr->show(dev, dev_attr, buf); if (ret >= (ssize_t)PAGE_SIZE) { print_symbol("dev_attr_show: %s returned bad count\n", (unsigned long)dev_attr->show); } return ret;} static ssize_t dev_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 = kobj_to_dev(kobj); ssize_t ret = -EIO; if (dev_attr->store) ret = dev_attr->store(dev, dev_attr, buf, count); return ret;} static const struct sysfs_ops dev_sysfs_ops = { .show = dev_attr_show, .store = dev_attr_store,}; #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr) ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, const char *buf, size_t size){ struct dev_ext_attribute *ea = to_ext_attr(attr); char *end; unsigned long new = simple_strtoul(buf, &end, 0); if (end == buf) return -EINVAL; *(unsigned long *)(ea->var) = new; /* Always return full write size even if we didn't consume all */ return size;}EXPORT_SYMBOL_GPL(device_store_ulong); ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, char *buf){ struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));}EXPORT_SYMBOL_GPL(device_show_ulong); ssize_t device_store_int(struct device *dev, struct device_attribute *attr, const char *buf, size_t size){ struct dev_ext_attribute *ea = to_ext_attr(attr); char *end; long new = simple_strtol(buf, &end, 0); if (end == buf || new > INT_MAX || new < INT_MIN) return -EINVAL; *(int *)(ea->var) = new; /* Always return full write size even if we didn't consume all */ return size;}EXPORT_SYMBOL_GPL(device_store_int); ssize_t device_show_int(struct device *dev, struct device_attribute *attr, char *buf){ struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));}EXPORT_SYMBOL_GPL(device_show_int); ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, const char *buf, size_t size){ struct dev_ext_attribute *ea = to_ext_attr(attr); if (strtobool(buf, ea->var) < 0) return -EINVAL; return size;}EXPORT_SYMBOL_GPL(device_store_bool); ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, char *buf){ struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));}EXPORT_SYMBOL_GPL(device_show_bool); /** * 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 = kobj_to_dev(kobj); struct device_private *p = dev->p; /* * Some platform devices are driven without driver attached * and managed resources may have been acquired. Make sure * all resources are released. * * Drivers still can add resources into device after device * is deleted but alive, so release devres here to avoid * possible memory leak. */ devres_release_all(dev); if (dev->release) dev->release(dev); else if (dev->type && dev->type->release) dev->type->release(dev); else if (dev->class && dev->class->dev_release) dev->class->dev_release(dev); else WARN(1, KERN_ERR "Device '%s' does not have a release() " "function, it is broken and must be fixed.\n", dev_name(dev)); kfree(p);} static const void *device_namespace(struct kobject *kobj){ struct device *dev = kobj_to_dev(kobj); const void *ns = NULL; if (dev->class && dev->class->ns_type) ns = dev->class->namespace(dev); return ns;} static struct kobj_type device_ktype = { .release = device_release, .sysfs_ops = &dev_sysfs_ops, .namespace = device_namespace,}; static int dev_uevent_filter(struct kset *kset, struct kobject *kobj){ struct kobj_type *ktype = get_ktype(kobj); if (ktype == &device_ktype) { struct device *dev = kobj_to_dev(kobj); if (dev->bus) return 1; if (dev->class) return 1; } return 0;} static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj){ struct device *dev = kobj_to_dev(kobj); if (dev->bus) return dev->bus->name; if (dev->class) return dev->class->name; return NULL;} static int dev_uevent(struct kset *kset, struct kobject *kobj, struct kobj_uevent_env *env){ struct device *dev = kobj_to_dev(kobj); int retval = 0; /* add device node properties if present */ if (MAJOR(dev->devt)) { const char *tmp; const char *name; umode_t mode = 0; kuid_t uid = GLOBAL_ROOT_UID; kgid_t gid = GLOBAL_ROOT_GID; add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt)); add_uevent_var(env, "MINOR=%u", MINOR(dev->devt)); name = device_get_devnode(dev, &mode, &uid, &gid, &tmp); if (name) { add_uevent_var(env, "DEVNAME=%s", name); if (mode) add_uevent_var(env, "DEVMODE=%#o", mode & 0777); if (!uid_eq(uid, GLOBAL_ROOT_UID)) add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid)); if (!gid_eq(gid, GLOBAL_ROOT_GID)) add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid)); kfree(tmp); } } if (dev->type && dev->type->name) add_uevent_var(env, "DEVTYPE=%s", dev->type->name); if (dev->driver) add_uevent_var(env, "DRIVER=%s", dev->driver->name); /* Add common DT information about the device */ of_device_uevent(dev, env); /* have the bus specific function add its stuff */ if (dev->bus && dev->bus->uevent) { retval = dev->bus->uevent(dev, env); if (retval) pr_debug("device: '%s': %s: bus uevent() returned %d\n", dev_name(dev), __func__, retval); } /* have the class specific function add its stuff */ if (dev->class && dev->class->dev_uevent) { retval = dev->class->dev_uevent(dev, env); if (retval) pr_debug("device: '%s': %s: class uevent() " "returned %d\n", dev_name(dev), __func__, retval); } /* have the device type specific function add its stuff */ if (dev->type && dev->type->uevent) { retval = dev->type->uevent(dev, env); if (retval) pr_debug("device: '%s': %s: dev_type uevent() " "returned %d\n", dev_name(dev), __func__, retval); } return retval;} static const struct kset_uevent_ops device_uevent_ops = { .filter = dev_uevent_filter, .name = dev_uevent_name, .uevent = dev_uevent,}; static ssize_t uevent_show(struct device *dev, struct device_attribute *attr, char *buf){ struct kobject *top_kobj; struct kset *kset; struct kobj_uevent_env *env = NULL; int i; size_t count = 0; int retval; /* search the kset, the device belongs to */ top_kobj = &dev->kobj; while (!top_kobj->kset && top_kobj->parent) top_kobj = top_kobj->parent; if (!top_kobj->kset) goto out; kset = top_kobj->kset; if (!kset->uevent_ops || !kset->uevent_ops->uevent) goto out; /* respect filter */ if (kset->uevent_ops && kset->uevent_ops->filter) if (!kset->uevent_ops->filter(kset, &dev->kobj)) goto out; env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); if (!env) return -ENOMEM; /* let the kset specific function add its keys */ retval = kset->uevent_ops->uevent(kset, &dev->kobj, env); if (retval) goto out; /* copy keys to file */ for (i = 0; i < env->envp_idx; i++) count += sprintf(&buf[count], "%s\n", env->envp[i]);out: kfree(env); return count;} static ssize_t uevent_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ enum kobject_action action; if (kobject_action_type(buf, count, &action) == 0) kobject_uevent(&dev->kobj, action); else dev_err(dev, "uevent: unknown action-string\n"); return count;}static DEVICE_ATTR_RW(uevent); static ssize_t online_show(struct device *dev, struct device_attribute *attr, char *buf){ bool val; device_lock(dev); val = !dev->offline; device_unlock(dev); return sprintf(buf, "%u\n", val);} static ssize_t online_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ bool val; int ret; ret = strtobool(buf, &val); if (ret < 0) return ret; ret = lock_device_hotplug_sysfs(); if (ret) return ret; ret = val ? device_online(dev) : device_offline(dev); unlock_device_hotplug(); return ret < 0 ? ret : count;}static DEVICE_ATTR_RW(online); int device_add_groups(struct device *dev, const struct attribute_group **groups){ return sysfs_create_groups(&dev->kobj, groups);} void device_remove_groups(struct device *dev, const struct attribute_group **groups){ sysfs_remove_groups(&dev->kobj, groups);} static int device_add_attrs(struct device *dev){ struct class *class = dev->class; const struct device_type *type = dev->type; int error; if (class) { error = device_add_groups(dev, class->dev_groups); if (error) return error; } if (type) { error = device_add_groups(dev, type->groups); if (error) goto err_remove_class_groups; } error = device_add_groups(dev, dev->groups); if (error) goto err_remove_type_groups; if (device_supports_offline(dev) && !dev->offline_disabled) { error = device_create_file(dev, &dev_attr_online); if (error) goto err_remove_dev_groups; } return 0; err_remove_dev_groups: device_remove_groups(dev, dev->groups);Lines 1–500 of 2291. 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/* * 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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de> * Copyright (c) 2006 Novell, Inc. * * This file is released under the GPLv2 * */ #include <linux/device.h> #include <linux/err.h> #include <linux/fwnode.h> #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/kdev_t.h> #include <linux/notifier.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/genhd.h> #include <linux/kallsyms.h> #include <linux/mutex.h> #include <linux/pm_runtime.h> #include <linux/netdevice.h> #include <linux/sysfs.h> #include "base.h" #include "power/power.h" #ifdef CONFIG_SYSFS_DEPRECATED #ifdef CONFIG_SYSFS_DEPRECATED_V2 long sysfs_deprecated = 1; #else long sysfs_deprecated = 0; #endif static int __init sysfs_deprecated_setup(char *arg) { return kstrtol(arg, 10, &sysfs_deprecated); } early_param("sysfs.deprecated", sysfs_deprecated_setup); #endif int (*platform_notify)(struct device *dev) = NULL; int (*platform_notify_remove)(struct device *dev) = NULL; static struct kobject *dev_kobj; struct kobject *sysfs_dev_char_kobj; struct kobject *sysfs_dev_block_kobj; static DEFINE_MUTEX(device_hotplug_lock); void lock_device_hotplug(void) { mutex_lock(&device_hotplug_lock); } void unlock_device_hotplug(void) { mutex_unlock(&device_hotplug_lock); } int lock_device_hotplug_sysfs(void) { if (mutex_trylock(&device_hotplug_lock)) return 0; /* Avoid busy looping (5 ms of sleep should do). */ msleep(5); return restart_syscall(); } #ifdef CONFIG_BLOCK static inline int device_is_not_partition(struct device *dev) { return !(dev->type == &part_type); } #else static inline int device_is_not_partition(struct device *dev) { return 1; } #endif /** * dev_driver_string - Return a device's driver name, if at all possible * @dev: struct device to get the name of * * Will return the device's driver's name if it is bound to a device. If * the device is not bound to a driver, it will return the name of the bus * it is attached to. If it is not attached to a bus either, an empty * string will be returned. */ const char *dev_driver_string(const struct device *dev) { struct device_driver *drv; /* dev->driver can change to NULL underneath us because of unbinding, * so be careful about accessing it. dev->bus and dev->class should * never change once they are set, so they don't need special care. */ drv = ACCESS_ONCE(dev->driver); return drv ? drv->name : (dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "")); } EXPORT_SYMBOL(dev_driver_string); #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct device_attribute *dev_attr = to_dev_attr(attr); struct device *dev = kobj_to_dev(kobj); ssize_t ret = -EIO; if (dev_attr->show) ret = dev_attr->show(dev, dev_attr, buf); if (ret >= (ssize_t)PAGE_SIZE) { print_symbol("dev_attr_show: %s returned bad count\n", (unsigned long)dev_attr->show); } return ret; } static ssize_t dev_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 = kobj_to_dev(kobj); ssize_t ret = -EIO; if (dev_attr->store) ret = dev_attr->store(dev, dev_attr, buf, count); return ret; } static const struct sysfs_ops dev_sysfs_ops = { .show = dev_attr_show, .store = dev_attr_store, }; #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr) ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct dev_ext_attribute *ea = to_ext_attr(attr); char *end; unsigned long new = simple_strtoul(buf, &end, 0); if (end == buf) return -EINVAL; *(unsigned long *)(ea->var) = new; /* Always return full write size even if we didn't consume all */ return size; } EXPORT_SYMBOL_GPL(device_store_ulong); ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr, char *buf) { struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_ulong); ssize_t device_store_int(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct dev_ext_attribute *ea = to_ext_attr(attr); char *end; long new = simple_strtol(buf, &end, 0); if (end == buf || new > INT_MAX || new < INT_MIN) return -EINVAL; *(int *)(ea->var) = new; /* Always return full write size even if we didn't consume all */ return size; } EXPORT_SYMBOL_GPL(device_store_int); ssize_t device_show_int(struct device *dev, struct device_attribute *attr, char *buf) { struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_int); ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct dev_ext_attribute *ea = to_ext_attr(attr); if (strtobool(buf, ea->var) < 0) return -EINVAL; return size; } EXPORT_SYMBOL_GPL(device_store_bool); ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, char *buf) { struct dev_ext_attribute *ea = to_ext_attr(attr); return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_bool); /** * 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 = kobj_to_dev(kobj); struct device_private *p = dev->p; /* * Some platform devices are driven without driver attached * and managed resources may have been acquired. Make sure * all resources are released. * * Drivers still can add resources into device after device * is deleted but alive, so release devres here to avoid * possible memory leak. */ devres_release_all(dev); if (dev->release) dev->release(dev); else if (dev->type && dev->type->release) dev->type->release(dev); else if (dev->class && dev->class->dev_release) dev->class->dev_release(dev); else WARN(1, KERN_ERR "Device '%s' does not have a release() " "function, it is broken and must be fixed.\n", dev_name(dev)); kfree(p); } static const void *device_namespace(struct kobject *kobj) { struct device *dev = kobj_to_dev(kobj); const void *ns = NULL; if (dev->class && dev->class->ns_type) ns = dev->class->namespace(dev); return ns; } static struct kobj_type device_ktype = { .release = device_release, .sysfs_ops = &dev_sysfs_ops, .namespace = device_namespace, }; static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) { struct kobj_type *ktype = get_ktype(kobj); if (ktype == &device_ktype) { struct device *dev = kobj_to_dev(kobj); if (dev->bus) return 1; if (dev->class) return 1; } return 0; } static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) { struct device *dev = kobj_to_dev(kobj); if (dev->bus) return dev->bus->name; if (dev->class) return dev->class->name; return NULL; } static int dev_uevent(struct kset *kset, struct kobject *kobj, struct kobj_uevent_env *env) { struct device *dev = kobj_to_dev(kobj); int retval = 0; /* add device node properties if present */ if (MAJOR(dev->devt)) { const char *tmp; const char *name; umode_t mode = 0; kuid_t uid = GLOBAL_ROOT_UID; kgid_t gid = GLOBAL_ROOT_GID; add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt)); add_uevent_var(env, "MINOR=%u", MINOR(dev->devt)); name = device_get_devnode(dev, &mode, &uid, &gid, &tmp); if (name) { add_uevent_var(env, "DEVNAME=%s", name); if (mode) add_uevent_var(env, "DEVMODE=%#o", mode & 0777); if (!uid_eq(uid, GLOBAL_ROOT_UID)) add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid)); if (!gid_eq(gid, GLOBAL_ROOT_GID)) add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid)); kfree(tmp); } } if (dev->type && dev->type->name) add_uevent_var(env, "DEVTYPE=%s", dev->type->name); if (dev->driver) add_uevent_var(env, "DRIVER=%s", dev->driver->name); /* Add common DT information about the device */ of_device_uevent(dev, env); /* have the bus specific function add its stuff */ if (dev->bus && dev->bus->uevent) { retval = dev->bus->uevent(dev, env); if (retval) pr_debug("device: '%s': %s: bus uevent() returned %d\n", dev_name(dev), __func__, retval); } /* have the class specific function add its stuff */ if (dev->class && dev->class->dev_uevent) { retval = dev->class->dev_uevent(dev, env); if (retval) pr_debug("device: '%s': %s: class uevent() " "returned %d\n", dev_name(dev), __func__, retval); } /* have the device type specific function add its stuff */ if (dev->type && dev->type->uevent) { retval = dev->type->uevent(dev, env); if (retval) pr_debug("device: '%s': %s: dev_type uevent() " "returned %d\n", dev_name(dev), __func__, retval); } return retval; } static const struct kset_uevent_ops device_uevent_ops = { .filter = dev_uevent_filter, .name = dev_uevent_name, .uevent = dev_uevent, }; static ssize_t uevent_show(struct device *dev, struct device_attribute *attr, char *buf) { struct kobject *top_kobj; struct kset *kset; struct kobj_uevent_env *env = NULL; int i; size_t count = 0; int retval; /* search the kset, the device belongs to */ top_kobj = &dev->kobj; while (!top_kobj->kset && top_kobj->parent) top_kobj = top_kobj->parent; if (!top_kobj->kset) goto out; kset = top_kobj->kset; if (!kset->uevent_ops || !kset->uevent_ops->uevent) goto out; /* respect filter */ if (kset->uevent_ops && kset->uevent_ops->filter) if (!kset->uevent_ops->filter(kset, &dev->kobj)) goto out; env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); if (!env) return -ENOMEM; /* let the kset specific function add its keys */ retval = kset->uevent_ops->uevent(kset, &dev->kobj, env); if (retval) goto out; /* copy keys to file */ for (i = 0; i < env->envp_idx; i++) count += sprintf(&buf[count], "%s\n", env->envp[i]); out: kfree(env); return count; } static ssize_t uevent_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { enum kobject_action action; if (kobject_action_type(buf, count, &action) == 0) kobject_uevent(&dev->kobj, action); else dev_err(dev, "uevent: unknown action-string\n"); return count; } static DEVICE_ATTR_RW(uevent); static ssize_t online_show(struct device *dev, struct device_attribute *attr, char *buf) { bool val; device_lock(dev); val = !dev->offline; device_unlock(dev); return sprintf(buf, "%u\n", val); } static ssize_t online_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { bool val; int ret; ret = strtobool(buf, &val); if (ret < 0) return ret; ret = lock_device_hotplug_sysfs(); if (ret) return ret; ret = val ? device_online(dev) : device_offline(dev); unlock_device_hotplug(); return ret < 0 ? ret : count; } static DEVICE_ATTR_RW(online); int device_add_groups(struct device *dev, const struct attribute_group **groups) { return sysfs_create_groups(&dev->kobj, groups); } void device_remove_groups(struct device *dev, const struct attribute_group **groups) { sysfs_remove_groups(&dev->kobj, groups); } static int device_add_attrs(struct device *dev) { struct class *class = dev->class; const struct device_type *type = dev->type; int error; if (class) { error = device_add_groups(dev, class->dev_groups); if (error) return error; } if (type) { error = device_add_groups(dev, type->groups); if (error) goto err_remove_class_groups; } error = device_add_groups(dev, dev->groups); if (error) goto err_remove_type_groups; if (device_supports_offline(dev) && !dev->offline_disabled) { error = device_create_file(dev, &dev_attr_online); if (error) goto err_remove_dev_groups; } return 0; err_remove_dev_groups: device_remove_groups(dev, dev->groups);