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-rw-r--r--kernel/drivers/base/core.c2197
1 files changed, 2197 insertions, 0 deletions
diff --git a/kernel/drivers/base/core.c b/kernel/drivers/base/core.c
new file mode 100644
index 000000000..21d130385
--- /dev/null
+++ b/kernel/drivers/base/core.c
@@ -0,0 +1,2197 @@
+/*
+ * 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);
+ err_remove_type_groups:
+ if (type)
+ device_remove_groups(dev, type->groups);
+ err_remove_class_groups:
+ if (class)
+ device_remove_groups(dev, class->dev_groups);
+
+ return error;
+}
+
+static void device_remove_attrs(struct device *dev)
+{
+ struct class *class = dev->class;
+ const struct device_type *type = dev->type;
+
+ device_remove_file(dev, &dev_attr_online);
+ device_remove_groups(dev, dev->groups);
+
+ if (type)
+ device_remove_groups(dev, type->groups);
+
+ if (class)
+ device_remove_groups(dev, class->dev_groups);
+}
+
+static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return print_dev_t(buf, dev->devt);
+}
+static DEVICE_ATTR_RO(dev);
+
+/* /sys/devices/ */
+struct kset *devices_kset;
+
+/**
+ * device_create_file - create sysfs attribute file for device.
+ * @dev: device.
+ * @attr: device attribute descriptor.
+ */
+int device_create_file(struct device *dev,
+ const struct device_attribute *attr)
+{
+ int error = 0;
+
+ if (dev) {
+ WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
+ "Attribute %s: write permission without 'store'\n",
+ attr->attr.name);
+ WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
+ "Attribute %s: read permission without 'show'\n",
+ attr->attr.name);
+ error = sysfs_create_file(&dev->kobj, &attr->attr);
+ }
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_create_file);
+
+/**
+ * device_remove_file - remove sysfs attribute file.
+ * @dev: device.
+ * @attr: device attribute descriptor.
+ */
+void device_remove_file(struct device *dev,
+ const struct device_attribute *attr)
+{
+ if (dev)
+ sysfs_remove_file(&dev->kobj, &attr->attr);
+}
+EXPORT_SYMBOL_GPL(device_remove_file);
+
+/**
+ * device_remove_file_self - remove sysfs attribute file from its own method.
+ * @dev: device.
+ * @attr: device attribute descriptor.
+ *
+ * See kernfs_remove_self() for details.
+ */
+bool device_remove_file_self(struct device *dev,
+ const struct device_attribute *attr)
+{
+ if (dev)
+ return sysfs_remove_file_self(&dev->kobj, &attr->attr);
+ else
+ return false;
+}
+EXPORT_SYMBOL_GPL(device_remove_file_self);
+
+/**
+ * device_create_bin_file - create sysfs binary attribute file for device.
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+int device_create_bin_file(struct device *dev,
+ const struct bin_attribute *attr)
+{
+ int error = -EINVAL;
+ if (dev)
+ error = sysfs_create_bin_file(&dev->kobj, attr);
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_create_bin_file);
+
+/**
+ * device_remove_bin_file - remove sysfs binary attribute file
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+void device_remove_bin_file(struct device *dev,
+ const struct bin_attribute *attr)
+{
+ if (dev)
+ sysfs_remove_bin_file(&dev->kobj, attr);
+}
+EXPORT_SYMBOL_GPL(device_remove_bin_file);
+
+static void klist_children_get(struct klist_node *n)
+{
+ struct device_private *p = to_device_private_parent(n);
+ struct device *dev = p->device;
+
+ get_device(dev);
+}
+
+static void klist_children_put(struct klist_node *n)
+{
+ struct device_private *p = to_device_private_parent(n);
+ struct device *dev = p->device;
+
+ put_device(dev);
+}
+
+/**
+ * device_initialize - init device structure.
+ * @dev: device.
+ *
+ * This prepares the device for use by other layers by initializing
+ * its fields.
+ * It is the first half of device_register(), if called by
+ * that function, though it can also be called separately, so one
+ * may use @dev's fields. In particular, get_device()/put_device()
+ * may be used for reference counting of @dev after calling this
+ * function.
+ *
+ * All fields in @dev must be initialized by the caller to 0, except
+ * for those explicitly set to some other value. The simplest
+ * approach is to use kzalloc() to allocate the structure containing
+ * @dev.
+ *
+ * NOTE: Use put_device() to give up your reference instead of freeing
+ * @dev directly once you have called this function.
+ */
+void device_initialize(struct device *dev)
+{
+ dev->kobj.kset = devices_kset;
+ kobject_init(&dev->kobj, &device_ktype);
+ INIT_LIST_HEAD(&dev->dma_pools);
+ mutex_init(&dev->mutex);
+ lockdep_set_novalidate_class(&dev->mutex);
+ spin_lock_init(&dev->devres_lock);
+ INIT_LIST_HEAD(&dev->devres_head);
+ device_pm_init(dev);
+ set_dev_node(dev, -1);
+}
+EXPORT_SYMBOL_GPL(device_initialize);
+
+struct kobject *virtual_device_parent(struct device *dev)
+{
+ static struct kobject *virtual_dir = NULL;
+
+ if (!virtual_dir)
+ virtual_dir = kobject_create_and_add("virtual",
+ &devices_kset->kobj);
+
+ return virtual_dir;
+}
+
+struct class_dir {
+ struct kobject kobj;
+ struct class *class;
+};
+
+#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
+
+static void class_dir_release(struct kobject *kobj)
+{
+ struct class_dir *dir = to_class_dir(kobj);
+ kfree(dir);
+}
+
+static const
+struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
+{
+ struct class_dir *dir = to_class_dir(kobj);
+ return dir->class->ns_type;
+}
+
+static struct kobj_type class_dir_ktype = {
+ .release = class_dir_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .child_ns_type = class_dir_child_ns_type
+};
+
+static struct kobject *
+class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
+{
+ struct class_dir *dir;
+ int retval;
+
+ dir = kzalloc(sizeof(*dir), GFP_KERNEL);
+ if (!dir)
+ return NULL;
+
+ dir->class = class;
+ kobject_init(&dir->kobj, &class_dir_ktype);
+
+ dir->kobj.kset = &class->p->glue_dirs;
+
+ retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
+ if (retval < 0) {
+ kobject_put(&dir->kobj);
+ return NULL;
+ }
+ return &dir->kobj;
+}
+
+static DEFINE_MUTEX(gdp_mutex);
+
+static struct kobject *get_device_parent(struct device *dev,
+ struct device *parent)
+{
+ if (dev->class) {
+ struct kobject *kobj = NULL;
+ struct kobject *parent_kobj;
+ struct kobject *k;
+
+#ifdef CONFIG_BLOCK
+ /* block disks show up in /sys/block */
+ if (sysfs_deprecated && dev->class == &block_class) {
+ if (parent && parent->class == &block_class)
+ return &parent->kobj;
+ return &block_class.p->subsys.kobj;
+ }
+#endif
+
+ /*
+ * If we have no parent, we live in "virtual".
+ * Class-devices with a non class-device as parent, live
+ * in a "glue" directory to prevent namespace collisions.
+ */
+ if (parent == NULL)
+ parent_kobj = virtual_device_parent(dev);
+ else if (parent->class && !dev->class->ns_type)
+ return &parent->kobj;
+ else
+ parent_kobj = &parent->kobj;
+
+ mutex_lock(&gdp_mutex);
+
+ /* find our class-directory at the parent and reference it */
+ spin_lock(&dev->class->p->glue_dirs.list_lock);
+ list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
+ if (k->parent == parent_kobj) {
+ kobj = kobject_get(k);
+ break;
+ }
+ spin_unlock(&dev->class->p->glue_dirs.list_lock);
+ if (kobj) {
+ mutex_unlock(&gdp_mutex);
+ return kobj;
+ }
+
+ /* or create a new class-directory at the parent device */
+ k = class_dir_create_and_add(dev->class, parent_kobj);
+ /* do not emit an uevent for this simple "glue" directory */
+ mutex_unlock(&gdp_mutex);
+ return k;
+ }
+
+ /* subsystems can specify a default root directory for their devices */
+ if (!parent && dev->bus && dev->bus->dev_root)
+ return &dev->bus->dev_root->kobj;
+
+ if (parent)
+ return &parent->kobj;
+ return NULL;
+}
+
+static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
+{
+ /* see if we live in a "glue" directory */
+ if (!glue_dir || !dev->class ||
+ glue_dir->kset != &dev->class->p->glue_dirs)
+ return;
+
+ mutex_lock(&gdp_mutex);
+ kobject_put(glue_dir);
+ mutex_unlock(&gdp_mutex);
+}
+
+static void cleanup_device_parent(struct device *dev)
+{
+ cleanup_glue_dir(dev, dev->kobj.parent);
+}
+
+static int device_add_class_symlinks(struct device *dev)
+{
+ struct device_node *of_node = dev_of_node(dev);
+ int error;
+
+ if (of_node) {
+ error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
+ if (error)
+ dev_warn(dev, "Error %d creating of_node link\n",error);
+ /* An error here doesn't warrant bringing down the device */
+ }
+
+ if (!dev->class)
+ return 0;
+
+ error = sysfs_create_link(&dev->kobj,
+ &dev->class->p->subsys.kobj,
+ "subsystem");
+ if (error)
+ goto out_devnode;
+
+ if (dev->parent && device_is_not_partition(dev)) {
+ error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+ "device");
+ if (error)
+ goto out_subsys;
+ }
+
+#ifdef CONFIG_BLOCK
+ /* /sys/block has directories and does not need symlinks */
+ if (sysfs_deprecated && dev->class == &block_class)
+ return 0;
+#endif
+
+ /* link in the class directory pointing to the device */
+ error = sysfs_create_link(&dev->class->p->subsys.kobj,
+ &dev->kobj, dev_name(dev));
+ if (error)
+ goto out_device;
+
+ return 0;
+
+out_device:
+ sysfs_remove_link(&dev->kobj, "device");
+
+out_subsys:
+ sysfs_remove_link(&dev->kobj, "subsystem");
+out_devnode:
+ sysfs_remove_link(&dev->kobj, "of_node");
+ return error;
+}
+
+static void device_remove_class_symlinks(struct device *dev)
+{
+ if (dev_of_node(dev))
+ sysfs_remove_link(&dev->kobj, "of_node");
+
+ if (!dev->class)
+ return;
+
+ if (dev->parent && device_is_not_partition(dev))
+ sysfs_remove_link(&dev->kobj, "device");
+ sysfs_remove_link(&dev->kobj, "subsystem");
+#ifdef CONFIG_BLOCK
+ if (sysfs_deprecated && dev->class == &block_class)
+ return;
+#endif
+ sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
+}
+
+/**
+ * dev_set_name - set a device name
+ * @dev: device
+ * @fmt: format string for the device's name
+ */
+int dev_set_name(struct device *dev, const char *fmt, ...)
+{
+ va_list vargs;
+ int err;
+
+ va_start(vargs, fmt);
+ err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
+ va_end(vargs);
+ return err;
+}
+EXPORT_SYMBOL_GPL(dev_set_name);
+
+/**
+ * device_to_dev_kobj - select a /sys/dev/ directory for the device
+ * @dev: device
+ *
+ * By default we select char/ for new entries. Setting class->dev_obj
+ * to NULL prevents an entry from being created. class->dev_kobj must
+ * be set (or cleared) before any devices are registered to the class
+ * otherwise device_create_sys_dev_entry() and
+ * device_remove_sys_dev_entry() will disagree about the presence of
+ * the link.
+ */
+static struct kobject *device_to_dev_kobj(struct device *dev)
+{
+ struct kobject *kobj;
+
+ if (dev->class)
+ kobj = dev->class->dev_kobj;
+ else
+ kobj = sysfs_dev_char_kobj;
+
+ return kobj;
+}
+
+static int device_create_sys_dev_entry(struct device *dev)
+{
+ struct kobject *kobj = device_to_dev_kobj(dev);
+ int error = 0;
+ char devt_str[15];
+
+ if (kobj) {
+ format_dev_t(devt_str, dev->devt);
+ error = sysfs_create_link(kobj, &dev->kobj, devt_str);
+ }
+
+ return error;
+}
+
+static void device_remove_sys_dev_entry(struct device *dev)
+{
+ struct kobject *kobj = device_to_dev_kobj(dev);
+ char devt_str[15];
+
+ if (kobj) {
+ format_dev_t(devt_str, dev->devt);
+ sysfs_remove_link(kobj, devt_str);
+ }
+}
+
+int device_private_init(struct device *dev)
+{
+ dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
+ if (!dev->p)
+ return -ENOMEM;
+ dev->p->device = dev;
+ klist_init(&dev->p->klist_children, klist_children_get,
+ klist_children_put);
+ INIT_LIST_HEAD(&dev->p->deferred_probe);
+ return 0;
+}
+
+/**
+ * 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 @dev 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.
+ *
+ * Do not call this routine or device_register() more than once for
+ * any device structure. The driver model core is not designed to work
+ * with devices that get unregistered and then spring back to life.
+ * (Among other things, it's very hard to guarantee that all references
+ * to the previous incarnation of @dev have been dropped.) Allocate
+ * and register a fresh new struct device instead.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up your
+ * reference instead.
+ */
+int device_add(struct device *dev)
+{
+ struct device *parent = NULL;
+ struct kobject *kobj;
+ struct class_interface *class_intf;
+ int error = -EINVAL;
+
+ dev = get_device(dev);
+ if (!dev)
+ goto done;
+
+ if (!dev->p) {
+ error = device_private_init(dev);
+ if (error)
+ goto done;
+ }
+
+ /*
+ * for statically allocated devices, which should all be converted
+ * some day, we need to initialize the name. We prevent reading back
+ * the name, and force the use of dev_name()
+ */
+ if (dev->init_name) {
+ dev_set_name(dev, "%s", dev->init_name);
+ dev->init_name = NULL;
+ }
+
+ /* subsystems can specify simple device enumeration */
+ if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
+ dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
+
+ if (!dev_name(dev)) {
+ error = -EINVAL;
+ goto name_error;
+ }
+
+ pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
+
+ parent = get_device(dev->parent);
+ kobj = get_device_parent(dev, parent);
+ if (kobj)
+ dev->kobj.parent = kobj;
+
+ /* use parent numa_node */
+ if (parent)
+ set_dev_node(dev, dev_to_node(parent));
+
+ /* first, register with generic layer. */
+ /* we require the name to be set before, and pass NULL */
+ error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
+ if (error)
+ goto Error;
+
+ /* notify platform of device entry */
+ if (platform_notify)
+ platform_notify(dev);
+
+ error = device_create_file(dev, &dev_attr_uevent);
+ if (error)
+ goto attrError;
+
+ error = device_add_class_symlinks(dev);
+ if (error)
+ goto SymlinkError;
+ error = device_add_attrs(dev);
+ if (error)
+ goto AttrsError;
+ error = bus_add_device(dev);
+ if (error)
+ goto BusError;
+ error = dpm_sysfs_add(dev);
+ if (error)
+ goto DPMError;
+ device_pm_add(dev);
+
+ if (MAJOR(dev->devt)) {
+ error = device_create_file(dev, &dev_attr_dev);
+ if (error)
+ goto DevAttrError;
+
+ error = device_create_sys_dev_entry(dev);
+ if (error)
+ goto SysEntryError;
+
+ devtmpfs_create_node(dev);
+ }
+
+ /* Notify clients of device addition. This call must come
+ * after dpm_sysfs_add() and before kobject_uevent().
+ */
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_ADD_DEVICE, dev);
+
+ kobject_uevent(&dev->kobj, KOBJ_ADD);
+ bus_probe_device(dev);
+ if (parent)
+ klist_add_tail(&dev->p->knode_parent,
+ &parent->p->klist_children);
+
+ if (dev->class) {
+ mutex_lock(&dev->class->p->mutex);
+ /* tie the class to the device */
+ klist_add_tail(&dev->knode_class,
+ &dev->class->p->klist_devices);
+
+ /* notify any interfaces that the device is here */
+ list_for_each_entry(class_intf,
+ &dev->class->p->interfaces, node)
+ if (class_intf->add_dev)
+ class_intf->add_dev(dev, class_intf);
+ mutex_unlock(&dev->class->p->mutex);
+ }
+done:
+ put_device(dev);
+ return error;
+ SysEntryError:
+ if (MAJOR(dev->devt))
+ device_remove_file(dev, &dev_attr_dev);
+ DevAttrError:
+ device_pm_remove(dev);
+ dpm_sysfs_remove(dev);
+ DPMError:
+ bus_remove_device(dev);
+ BusError:
+ device_remove_attrs(dev);
+ AttrsError:
+ device_remove_class_symlinks(dev);
+ SymlinkError:
+ device_remove_file(dev, &dev_attr_uevent);
+ attrError:
+ kobject_uevent(&dev->kobj, KOBJ_REMOVE);
+ kobject_del(&dev->kobj);
+ Error:
+ cleanup_device_parent(dev);
+ put_device(parent);
+name_error:
+ kfree(dev->p);
+ dev->p = NULL;
+ goto done;
+}
+EXPORT_SYMBOL_GPL(device_add);
+
+/**
+ * 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.
+ *
+ * For more information, see the kerneldoc for device_initialize()
+ * and device_add().
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up the
+ * reference initialized in this function instead.
+ */
+int device_register(struct device *dev)
+{
+ device_initialize(dev);
+ return device_add(dev);
+}
+EXPORT_SYMBOL_GPL(device_register);
+
+/**
+ * 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 ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
+}
+EXPORT_SYMBOL_GPL(get_device);
+
+/**
+ * put_device - decrement reference count.
+ * @dev: device in question.
+ */
+void put_device(struct device *dev)
+{
+ /* might_sleep(); */
+ if (dev)
+ kobject_put(&dev->kobj);
+}
+EXPORT_SYMBOL_GPL(put_device);
+
+/**
+ * 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;
+ struct class_interface *class_intf;
+
+ /* Notify clients of device removal. This call must come
+ * before dpm_sysfs_remove().
+ */
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_DEL_DEVICE, dev);
+ dpm_sysfs_remove(dev);
+ if (parent)
+ klist_del(&dev->p->knode_parent);
+ if (MAJOR(dev->devt)) {
+ devtmpfs_delete_node(dev);
+ device_remove_sys_dev_entry(dev);
+ device_remove_file(dev, &dev_attr_dev);
+ }
+ if (dev->class) {
+ device_remove_class_symlinks(dev);
+
+ mutex_lock(&dev->class->p->mutex);
+ /* notify any interfaces that the device is now gone */
+ list_for_each_entry(class_intf,
+ &dev->class->p->interfaces, node)
+ if (class_intf->remove_dev)
+ class_intf->remove_dev(dev, class_intf);
+ /* remove the device from the class list */
+ klist_del(&dev->knode_class);
+ mutex_unlock(&dev->class->p->mutex);
+ }
+ device_remove_file(dev, &dev_attr_uevent);
+ device_remove_attrs(dev);
+ bus_remove_device(dev);
+ device_pm_remove(dev);
+ driver_deferred_probe_del(dev);
+
+ /* Notify the platform of the removal, in case they
+ * need to do anything...
+ */
+ if (platform_notify_remove)
+ platform_notify_remove(dev);
+ if (dev->bus)
+ blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+ BUS_NOTIFY_REMOVED_DEVICE, dev);
+ kobject_uevent(&dev->kobj, KOBJ_REMOVE);
+ cleanup_device_parent(dev);
+ kobject_del(&dev->kobj);
+ put_device(parent);
+}
+EXPORT_SYMBOL_GPL(device_del);
+
+/**
+ * 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("device: '%s': %s\n", dev_name(dev), __func__);
+ device_del(dev);
+ put_device(dev);
+}
+EXPORT_SYMBOL_GPL(device_unregister);
+
+static struct device *next_device(struct klist_iter *i)
+{
+ struct klist_node *n = klist_next(i);
+ struct device *dev = NULL;
+ struct device_private *p;
+
+ if (n) {
+ p = to_device_private_parent(n);
+ dev = p->device;
+ }
+ return dev;
+}
+
+/**
+ * device_get_devnode - path of device node file
+ * @dev: device
+ * @mode: returned file access mode
+ * @uid: returned file owner
+ * @gid: returned file group
+ * @tmp: possibly allocated string
+ *
+ * Return the relative path of a possible device node.
+ * Non-default names may need to allocate a memory to compose
+ * a name. This memory is returned in tmp and needs to be
+ * freed by the caller.
+ */
+const char *device_get_devnode(struct device *dev,
+ umode_t *mode, kuid_t *uid, kgid_t *gid,
+ const char **tmp)
+{
+ char *s;
+
+ *tmp = NULL;
+
+ /* the device type may provide a specific name */
+ if (dev->type && dev->type->devnode)
+ *tmp = dev->type->devnode(dev, mode, uid, gid);
+ if (*tmp)
+ return *tmp;
+
+ /* the class may provide a specific name */
+ if (dev->class && dev->class->devnode)
+ *tmp = dev->class->devnode(dev, mode);
+ if (*tmp)
+ return *tmp;
+
+ /* return name without allocation, tmp == NULL */
+ if (strchr(dev_name(dev), '!') == NULL)
+ return dev_name(dev);
+
+ /* replace '!' in the name with '/' */
+ *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
+ if (!*tmp)
+ return NULL;
+ while ((s = strchr(*tmp, '!')))
+ s[0] = '/';
+ return *tmp;
+}
+
+/**
+ * device_for_each_child - device child iterator.
+ * @parent: parent struct device.
+ * @fn: function to be called for each device.
+ * @data: data for the callback.
+ *
+ * Iterate over @parent'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 *dev, void *data))
+{
+ struct klist_iter i;
+ struct device *child;
+ int error = 0;
+
+ if (!parent->p)
+ return 0;
+
+ klist_iter_init(&parent->p->klist_children, &i);
+ while ((child = next_device(&i)) && !error)
+ error = fn(child, data);
+ klist_iter_exit(&i);
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_for_each_child);
+
+/**
+ * device_find_child - device iterator for locating a particular device.
+ * @parent: parent struct device
+ * @match: Callback function to check device
+ * @data: Data to pass to match function
+ *
+ * This is similar to the device_for_each_child() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero and a reference to the
+ * current device can be obtained, this function will return to the caller
+ * and not iterate over any more devices.
+ *
+ * NOTE: you will need to drop the reference with put_device() after use.
+ */
+struct device *device_find_child(struct device *parent, void *data,
+ int (*match)(struct device *dev, void *data))
+{
+ struct klist_iter i;
+ struct device *child;
+
+ if (!parent)
+ return NULL;
+
+ klist_iter_init(&parent->p->klist_children, &i);
+ while ((child = next_device(&i)))
+ if (match(child, data) && get_device(child))
+ break;
+ klist_iter_exit(&i);
+ return child;
+}
+EXPORT_SYMBOL_GPL(device_find_child);
+
+int __init devices_init(void)
+{
+ devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
+ if (!devices_kset)
+ return -ENOMEM;
+ dev_kobj = kobject_create_and_add("dev", NULL);
+ if (!dev_kobj)
+ goto dev_kobj_err;
+ sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
+ if (!sysfs_dev_block_kobj)
+ goto block_kobj_err;
+ sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
+ if (!sysfs_dev_char_kobj)
+ goto char_kobj_err;
+
+ return 0;
+
+ char_kobj_err:
+ kobject_put(sysfs_dev_block_kobj);
+ block_kobj_err:
+ kobject_put(dev_kobj);
+ dev_kobj_err:
+ kset_unregister(devices_kset);
+ return -ENOMEM;
+}
+
+static int device_check_offline(struct device *dev, void *not_used)
+{
+ int ret;
+
+ ret = device_for_each_child(dev, NULL, device_check_offline);
+ if (ret)
+ return ret;
+
+ return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
+}
+
+/**
+ * device_offline - Prepare the device for hot-removal.
+ * @dev: Device to be put offline.
+ *
+ * Execute the device bus type's .offline() callback, if present, to prepare
+ * the device for a subsequent hot-removal. If that succeeds, the device must
+ * not be used until either it is removed or its bus type's .online() callback
+ * is executed.
+ *
+ * Call under device_hotplug_lock.
+ */
+int device_offline(struct device *dev)
+{
+ int ret;
+
+ if (dev->offline_disabled)
+ return -EPERM;
+
+ ret = device_for_each_child(dev, NULL, device_check_offline);
+ if (ret)
+ return ret;
+
+ device_lock(dev);
+ if (device_supports_offline(dev)) {
+ if (dev->offline) {
+ ret = 1;
+ } else {
+ ret = dev->bus->offline(dev);
+ if (!ret) {
+ kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
+ dev->offline = true;
+ }
+ }
+ }
+ device_unlock(dev);
+
+ return ret;
+}
+
+/**
+ * device_online - Put the device back online after successful device_offline().
+ * @dev: Device to be put back online.
+ *
+ * If device_offline() has been successfully executed for @dev, but the device
+ * has not been removed subsequently, execute its bus type's .online() callback
+ * to indicate that the device can be used again.
+ *
+ * Call under device_hotplug_lock.
+ */
+int device_online(struct device *dev)
+{
+ int ret = 0;
+
+ device_lock(dev);
+ if (device_supports_offline(dev)) {
+ if (dev->offline) {
+ ret = dev->bus->online(dev);
+ if (!ret) {
+ kobject_uevent(&dev->kobj, KOBJ_ONLINE);
+ dev->offline = false;
+ }
+ } else {
+ ret = 1;
+ }
+ }
+ device_unlock(dev);
+
+ return ret;
+}
+
+struct root_device {
+ struct device dev;
+ struct module *owner;
+};
+
+static inline struct root_device *to_root_device(struct device *d)
+{
+ return container_of(d, struct root_device, dev);
+}
+
+static void root_device_release(struct device *dev)
+{
+ kfree(to_root_device(dev));
+}
+
+/**
+ * __root_device_register - allocate and register a root device
+ * @name: root device name
+ * @owner: owner module of the root device, usually THIS_MODULE
+ *
+ * This function allocates a root device and registers it
+ * using device_register(). In order to free the returned
+ * device, use root_device_unregister().
+ *
+ * Root devices are dummy devices which allow other devices
+ * to be grouped under /sys/devices. Use this function to
+ * allocate a root device and then use it as the parent of
+ * any device which should appear under /sys/devices/{name}
+ *
+ * The /sys/devices/{name} directory will also contain a
+ * 'module' symlink which points to the @owner directory
+ * in sysfs.
+ *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
+ * Note: You probably want to use root_device_register().
+ */
+struct device *__root_device_register(const char *name, struct module *owner)
+{
+ struct root_device *root;
+ int err = -ENOMEM;
+
+ root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
+ if (!root)
+ return ERR_PTR(err);
+
+ err = dev_set_name(&root->dev, "%s", name);
+ if (err) {
+ kfree(root);
+ return ERR_PTR(err);
+ }
+
+ root->dev.release = root_device_release;
+
+ err = device_register(&root->dev);
+ if (err) {
+ put_device(&root->dev);
+ return ERR_PTR(err);
+ }
+
+#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
+ if (owner) {
+ struct module_kobject *mk = &owner->mkobj;
+
+ err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
+ if (err) {
+ device_unregister(&root->dev);
+ return ERR_PTR(err);
+ }
+ root->owner = owner;
+ }
+#endif
+
+ return &root->dev;
+}
+EXPORT_SYMBOL_GPL(__root_device_register);
+
+/**
+ * root_device_unregister - unregister and free a root device
+ * @dev: device going away
+ *
+ * This function unregisters and cleans up a device that was created by
+ * root_device_register().
+ */
+void root_device_unregister(struct device *dev)
+{
+ struct root_device *root = to_root_device(dev);
+
+ if (root->owner)
+ sysfs_remove_link(&root->dev.kobj, "module");
+
+ device_unregister(dev);
+}
+EXPORT_SYMBOL_GPL(root_device_unregister);
+
+
+static void device_create_release(struct device *dev)
+{
+ pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
+ kfree(dev);
+}
+
+static struct device *
+device_create_groups_vargs(struct class *class, struct device *parent,
+ dev_t devt, void *drvdata,
+ const struct attribute_group **groups,
+ const char *fmt, va_list args)
+{
+ struct device *dev = NULL;
+ int retval = -ENODEV;
+
+ if (class == NULL || IS_ERR(class))
+ goto error;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ device_initialize(dev);
+ dev->devt = devt;
+ dev->class = class;
+ dev->parent = parent;
+ dev->groups = groups;
+ dev->release = device_create_release;
+ dev_set_drvdata(dev, drvdata);
+
+ retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
+ if (retval)
+ goto error;
+
+ retval = device_add(dev);
+ if (retval)
+ goto error;
+
+ return dev;
+
+error:
+ put_device(dev);
+ return ERR_PTR(retval);
+}
+
+/**
+ * device_create_vargs - creates a device and registers it with sysfs
+ * @class: pointer to the struct class that this device should be registered to
+ * @parent: pointer to the parent struct device of this new device, if any
+ * @devt: the dev_t for the char device to be added
+ * @drvdata: the data to be added to the device for callbacks
+ * @fmt: string for the device's name
+ * @args: va_list for the device's name
+ *
+ * This function can be used by char device classes. A struct device
+ * will be created in sysfs, registered to the specified class.
+ *
+ * A "dev" file will be created, showing the dev_t for the device, if
+ * the dev_t is not 0,0.
+ * If a pointer to a parent struct device is passed in, the newly created
+ * struct device will be a child of that device in sysfs.
+ * The pointer to the struct device will be returned from the call.
+ * Any further sysfs files that might be required can be created using this
+ * pointer.
+ *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct device *device_create_vargs(struct class *class, struct device *parent,
+ dev_t devt, void *drvdata, const char *fmt,
+ va_list args)
+{
+ return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
+ fmt, args);
+}
+EXPORT_SYMBOL_GPL(device_create_vargs);
+
+/**
+ * device_create - creates a device and registers it with sysfs
+ * @class: pointer to the struct class that this device should be registered to
+ * @parent: pointer to the parent struct device of this new device, if any
+ * @devt: the dev_t for the char device to be added
+ * @drvdata: the data to be added to the device for callbacks
+ * @fmt: string for the device's name
+ *
+ * This function can be used by char device classes. A struct device
+ * will be created in sysfs, registered to the specified class.
+ *
+ * A "dev" file will be created, showing the dev_t for the device, if
+ * the dev_t is not 0,0.
+ * If a pointer to a parent struct device is passed in, the newly created
+ * struct device will be a child of that device in sysfs.
+ * The pointer to the struct device will be returned from the call.
+ * Any further sysfs files that might be required can be created using this
+ * pointer.
+ *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct device *device_create(struct class *class, struct device *parent,
+ dev_t devt, void *drvdata, const char *fmt, ...)
+{
+ va_list vargs;
+ struct device *dev;
+
+ va_start(vargs, fmt);
+ dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
+ va_end(vargs);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(device_create);
+
+/**
+ * device_create_with_groups - creates a device and registers it with sysfs
+ * @class: pointer to the struct class that this device should be registered to
+ * @parent: pointer to the parent struct device of this new device, if any
+ * @devt: the dev_t for the char device to be added
+ * @drvdata: the data to be added to the device for callbacks
+ * @groups: NULL-terminated list of attribute groups to be created
+ * @fmt: string for the device's name
+ *
+ * This function can be used by char device classes. A struct device
+ * will be created in sysfs, registered to the specified class.
+ * Additional attributes specified in the groups parameter will also
+ * be created automatically.
+ *
+ * A "dev" file will be created, showing the dev_t for the device, if
+ * the dev_t is not 0,0.
+ * If a pointer to a parent struct device is passed in, the newly created
+ * struct device will be a child of that device in sysfs.
+ * The pointer to the struct device will be returned from the call.
+ * Any further sysfs files that might be required can be created using this
+ * pointer.
+ *
+ * Returns &struct device pointer on success, or ERR_PTR() on error.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct device *device_create_with_groups(struct class *class,
+ struct device *parent, dev_t devt,
+ void *drvdata,
+ const struct attribute_group **groups,
+ const char *fmt, ...)
+{
+ va_list vargs;
+ struct device *dev;
+
+ va_start(vargs, fmt);
+ dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
+ fmt, vargs);
+ va_end(vargs);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(device_create_with_groups);
+
+static int __match_devt(struct device *dev, const void *data)
+{
+ const dev_t *devt = data;
+
+ return dev->devt == *devt;
+}
+
+/**
+ * device_destroy - removes a device that was created with device_create()
+ * @class: pointer to the struct class that this device was registered with
+ * @devt: the dev_t of the device that was previously registered
+ *
+ * This call unregisters and cleans up a device that was created with a
+ * call to device_create().
+ */
+void device_destroy(struct class *class, dev_t devt)
+{
+ struct device *dev;
+
+ dev = class_find_device(class, NULL, &devt, __match_devt);
+ if (dev) {
+ put_device(dev);
+ device_unregister(dev);
+ }
+}
+EXPORT_SYMBOL_GPL(device_destroy);
+
+/**
+ * device_rename - renames a device
+ * @dev: the pointer to the struct device to be renamed
+ * @new_name: the new name of the device
+ *
+ * It is the responsibility of the caller to provide mutual
+ * exclusion between two different calls of device_rename
+ * on the same device to ensure that new_name is valid and
+ * won't conflict with other devices.
+ *
+ * Note: Don't call this function. Currently, the networking layer calls this
+ * function, but that will change. The following text from Kay Sievers offers
+ * some insight:
+ *
+ * Renaming devices is racy at many levels, symlinks and other stuff are not
+ * replaced atomically, and you get a "move" uevent, but it's not easy to
+ * connect the event to the old and new device. Device nodes are not renamed at
+ * all, there isn't even support for that in the kernel now.
+ *
+ * In the meantime, during renaming, your target name might be taken by another
+ * driver, creating conflicts. Or the old name is taken directly after you
+ * renamed it -- then you get events for the same DEVPATH, before you even see
+ * the "move" event. It's just a mess, and nothing new should ever rely on
+ * kernel device renaming. Besides that, it's not even implemented now for
+ * other things than (driver-core wise very simple) network devices.
+ *
+ * We are currently about to change network renaming in udev to completely
+ * disallow renaming of devices in the same namespace as the kernel uses,
+ * because we can't solve the problems properly, that arise with swapping names
+ * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
+ * be allowed to some other name than eth[0-9]*, for the aforementioned
+ * reasons.
+ *
+ * Make up a "real" name in the driver before you register anything, or add
+ * some other attributes for userspace to find the device, or use udev to add
+ * symlinks -- but never rename kernel devices later, it's a complete mess. We
+ * don't even want to get into that and try to implement the missing pieces in
+ * the core. We really have other pieces to fix in the driver core mess. :)
+ */
+int device_rename(struct device *dev, const char *new_name)
+{
+ struct kobject *kobj = &dev->kobj;
+ char *old_device_name = NULL;
+ int error;
+
+ dev = get_device(dev);
+ if (!dev)
+ return -EINVAL;
+
+ dev_dbg(dev, "renaming to %s\n", new_name);
+
+ old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
+ if (!old_device_name) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ if (dev->class) {
+ error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
+ kobj, old_device_name,
+ new_name, kobject_namespace(kobj));
+ if (error)
+ goto out;
+ }
+
+ error = kobject_rename(kobj, new_name);
+ if (error)
+ goto out;
+
+out:
+ put_device(dev);
+
+ kfree(old_device_name);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_rename);
+
+static int device_move_class_links(struct device *dev,
+ struct device *old_parent,
+ struct device *new_parent)
+{
+ int error = 0;
+
+ if (old_parent)
+ sysfs_remove_link(&dev->kobj, "device");
+ if (new_parent)
+ error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
+ "device");
+ return error;
+}
+
+/**
+ * device_move - moves a device to a new parent
+ * @dev: the pointer to the struct device to be moved
+ * @new_parent: the new parent of the device (can by NULL)
+ * @dpm_order: how to reorder the dpm_list
+ */
+int device_move(struct device *dev, struct device *new_parent,
+ enum dpm_order dpm_order)
+{
+ int error;
+ struct device *old_parent;
+ struct kobject *new_parent_kobj;
+
+ dev = get_device(dev);
+ if (!dev)
+ return -EINVAL;
+
+ device_pm_lock();
+ new_parent = get_device(new_parent);
+ new_parent_kobj = get_device_parent(dev, new_parent);
+
+ pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
+ __func__, new_parent ? dev_name(new_parent) : "<NULL>");
+ error = kobject_move(&dev->kobj, new_parent_kobj);
+ if (error) {
+ cleanup_glue_dir(dev, new_parent_kobj);
+ put_device(new_parent);
+ goto out;
+ }
+ old_parent = dev->parent;
+ dev->parent = new_parent;
+ if (old_parent)
+ klist_remove(&dev->p->knode_parent);
+ if (new_parent) {
+ klist_add_tail(&dev->p->knode_parent,
+ &new_parent->p->klist_children);
+ set_dev_node(dev, dev_to_node(new_parent));
+ }
+
+ if (dev->class) {
+ error = device_move_class_links(dev, old_parent, new_parent);
+ if (error) {
+ /* We ignore errors on cleanup since we're hosed anyway... */
+ device_move_class_links(dev, new_parent, old_parent);
+ if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
+ if (new_parent)
+ klist_remove(&dev->p->knode_parent);
+ dev->parent = old_parent;
+ if (old_parent) {
+ klist_add_tail(&dev->p->knode_parent,
+ &old_parent->p->klist_children);
+ set_dev_node(dev, dev_to_node(old_parent));
+ }
+ }
+ cleanup_glue_dir(dev, new_parent_kobj);
+ put_device(new_parent);
+ goto out;
+ }
+ }
+ switch (dpm_order) {
+ case DPM_ORDER_NONE:
+ break;
+ case DPM_ORDER_DEV_AFTER_PARENT:
+ device_pm_move_after(dev, new_parent);
+ break;
+ case DPM_ORDER_PARENT_BEFORE_DEV:
+ device_pm_move_before(new_parent, dev);
+ break;
+ case DPM_ORDER_DEV_LAST:
+ device_pm_move_last(dev);
+ break;
+ }
+
+ put_device(old_parent);
+out:
+ device_pm_unlock();
+ put_device(dev);
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_move);
+
+/**
+ * device_shutdown - call ->shutdown() on each device to shutdown.
+ */
+void device_shutdown(void)
+{
+ struct device *dev, *parent;
+
+ spin_lock(&devices_kset->list_lock);
+ /*
+ * Walk the devices list backward, shutting down each in turn.
+ * Beware that device unplug events may also start pulling
+ * devices offline, even as the system is shutting down.
+ */
+ while (!list_empty(&devices_kset->list)) {
+ dev = list_entry(devices_kset->list.prev, struct device,
+ kobj.entry);
+
+ /*
+ * hold reference count of device's parent to
+ * prevent it from being freed because parent's
+ * lock is to be held
+ */
+ parent = get_device(dev->parent);
+ get_device(dev);
+ /*
+ * Make sure the device is off the kset list, in the
+ * event that dev->*->shutdown() doesn't remove it.
+ */
+ list_del_init(&dev->kobj.entry);
+ spin_unlock(&devices_kset->list_lock);
+
+ /* hold lock to avoid race with probe/release */
+ if (parent)
+ device_lock(parent);
+ device_lock(dev);
+
+ /* Don't allow any more runtime suspends */
+ pm_runtime_get_noresume(dev);
+ pm_runtime_barrier(dev);
+
+ if (dev->bus && dev->bus->shutdown) {
+ if (initcall_debug)
+ dev_info(dev, "shutdown\n");
+ dev->bus->shutdown(dev);
+ } else if (dev->driver && dev->driver->shutdown) {
+ if (initcall_debug)
+ dev_info(dev, "shutdown\n");
+ dev->driver->shutdown(dev);
+ }
+
+ device_unlock(dev);
+ if (parent)
+ device_unlock(parent);
+
+ put_device(dev);
+ put_device(parent);
+
+ spin_lock(&devices_kset->list_lock);
+ }
+ spin_unlock(&devices_kset->list_lock);
+}
+
+/*
+ * Device logging functions
+ */
+
+#ifdef CONFIG_PRINTK
+static int
+create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
+{
+ const char *subsys;
+ size_t pos = 0;
+
+ if (dev->class)
+ subsys = dev->class->name;
+ else if (dev->bus)
+ subsys = dev->bus->name;
+ else
+ return 0;
+
+ pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
+ if (pos >= hdrlen)
+ goto overflow;
+
+ /*
+ * Add device identifier DEVICE=:
+ * b12:8 block dev_t
+ * c127:3 char dev_t
+ * n8 netdev ifindex
+ * +sound:card0 subsystem:devname
+ */
+ if (MAJOR(dev->devt)) {
+ char c;
+
+ if (strcmp(subsys, "block") == 0)
+ c = 'b';
+ else
+ c = 'c';
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=%c%u:%u",
+ c, MAJOR(dev->devt), MINOR(dev->devt));
+ } else if (strcmp(subsys, "net") == 0) {
+ struct net_device *net = to_net_dev(dev);
+
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=n%u", net->ifindex);
+ } else {
+ pos++;
+ pos += snprintf(hdr + pos, hdrlen - pos,
+ "DEVICE=+%s:%s", subsys, dev_name(dev));
+ }
+
+ if (pos >= hdrlen)
+ goto overflow;
+
+ return pos;
+
+overflow:
+ dev_WARN(dev, "device/subsystem name too long");
+ return 0;
+}
+
+int dev_vprintk_emit(int level, const struct device *dev,
+ const char *fmt, va_list args)
+{
+ char hdr[128];
+ size_t hdrlen;
+
+ hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
+
+ return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
+}
+EXPORT_SYMBOL(dev_vprintk_emit);
+
+int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
+{
+ va_list args;
+ int r;
+
+ va_start(args, fmt);
+
+ r = dev_vprintk_emit(level, dev, fmt, args);
+
+ va_end(args);
+
+ return r;
+}
+EXPORT_SYMBOL(dev_printk_emit);
+
+static void __dev_printk(const char *level, const struct device *dev,
+ struct va_format *vaf)
+{
+ if (dev)
+ dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
+ dev_driver_string(dev), dev_name(dev), vaf);
+ else
+ printk("%s(NULL device *): %pV", level, vaf);
+}
+
+void dev_printk(const char *level, const struct device *dev,
+ const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ __dev_printk(level, dev, &vaf);
+
+ va_end(args);
+}
+EXPORT_SYMBOL(dev_printk);
+
+#define define_dev_printk_level(func, kern_level) \
+void func(const struct device *dev, const char *fmt, ...) \
+{ \
+ struct va_format vaf; \
+ va_list args; \
+ \
+ va_start(args, fmt); \
+ \
+ vaf.fmt = fmt; \
+ vaf.va = &args; \
+ \
+ __dev_printk(kern_level, dev, &vaf); \
+ \
+ va_end(args); \
+} \
+EXPORT_SYMBOL(func);
+
+define_dev_printk_level(dev_emerg, KERN_EMERG);
+define_dev_printk_level(dev_alert, KERN_ALERT);
+define_dev_printk_level(dev_crit, KERN_CRIT);
+define_dev_printk_level(dev_err, KERN_ERR);
+define_dev_printk_level(dev_warn, KERN_WARNING);
+define_dev_printk_level(dev_notice, KERN_NOTICE);
+define_dev_printk_level(_dev_info, KERN_INFO);
+
+#endif
+
+static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
+{
+ return fwnode && !IS_ERR(fwnode->secondary);
+}
+
+/**
+ * set_primary_fwnode - Change the primary firmware node of a given device.
+ * @dev: Device to handle.
+ * @fwnode: New primary firmware node of the device.
+ *
+ * Set the device's firmware node pointer to @fwnode, but if a secondary
+ * firmware node of the device is present, preserve it.
+ */
+void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
+{
+ if (fwnode) {
+ struct fwnode_handle *fn = dev->fwnode;
+
+ if (fwnode_is_primary(fn))
+ fn = fn->secondary;
+
+ fwnode->secondary = fn;
+ dev->fwnode = fwnode;
+ } else {
+ dev->fwnode = fwnode_is_primary(dev->fwnode) ?
+ dev->fwnode->secondary : NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(set_primary_fwnode);
+
+/**
+ * set_secondary_fwnode - Change the secondary firmware node of a given device.
+ * @dev: Device to handle.
+ * @fwnode: New secondary firmware node of the device.
+ *
+ * If a primary firmware node of the device is present, set its secondary
+ * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
+ * @fwnode.
+ */
+void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
+{
+ if (fwnode)
+ fwnode->secondary = ERR_PTR(-ENODEV);
+
+ if (fwnode_is_primary(dev->fwnode))
+ dev->fwnode->secondary = fwnode;
+ else
+ dev->fwnode = fwnode;
+}