linux/drivers/base/core.c

1407 lines
35 KiB
C

/*
* 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/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/genhd.h>
#include <asm/semaphore.h>
#include "base.h"
#include "power/power.h"
int (*platform_notify)(struct device * dev) = NULL;
int (*platform_notify_remove)(struct device * dev) = NULL;
/*
* sysfs bindings for devices.
*/
/**
* 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 device, 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(struct device *dev)
{
return dev->driver ? dev->driver->name :
(dev->bus ? dev->bus->name :
(dev->class ? dev->class->name : ""));
}
EXPORT_SYMBOL(dev_driver_string);
#define to_dev(obj) container_of(obj, struct device, kobj)
#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 = to_dev(kobj);
ssize_t ret = -EIO;
if (dev_attr->show)
ret = dev_attr->show(dev, dev_attr, buf);
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 = to_dev(kobj);
ssize_t ret = -EIO;
if (dev_attr->store)
ret = dev_attr->store(dev, dev_attr, buf, count);
return ret;
}
static struct sysfs_ops dev_sysfs_ops = {
.show = dev_attr_show,
.store = dev_attr_store,
};
/**
* device_release - free device structure.
* @kobj: device's kobject.
*
* This is called once the reference count for the object
* reaches 0. We forward the call to the device's release
* method, which should handle actually freeing the structure.
*/
static void device_release(struct kobject * kobj)
{
struct device * dev = to_dev(kobj);
if (dev->release)
dev->release(dev);
else if (dev->type && dev->type->release)
dev->type->release(dev);
else if (dev->class && dev->class->dev_release)
dev->class->dev_release(dev);
else {
printk(KERN_ERR "Device '%s' does not have a release() function, "
"it is broken and must be fixed.\n",
dev->bus_id);
WARN_ON(1);
}
}
static struct kobj_type device_ktype = {
.release = device_release,
.sysfs_ops = &dev_sysfs_ops,
};
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 = to_dev(kobj);
if (dev->uevent_suppress)
return 0;
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 = 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 = to_dev(kobj);
int retval = 0;
/* add the major/minor if present */
if (MAJOR(dev->devt)) {
add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
}
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);
#ifdef CONFIG_SYSFS_DEPRECATED
if (dev->class) {
struct device *parent = dev->parent;
/* find first bus device in parent chain */
while (parent && !parent->bus)
parent = parent->parent;
if (parent && parent->bus) {
const char *path;
path = kobject_get_path(&parent->kobj, GFP_KERNEL);
if (path) {
add_uevent_var(env, "PHYSDEVPATH=%s", path);
kfree(path);
}
add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
if (parent->driver)
add_uevent_var(env, "PHYSDEVDRIVER=%s",
parent->driver->name);
}
} else if (dev->bus) {
add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
if (dev->driver)
add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
}
#endif
/* 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->bus_id, __FUNCTION__, 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->bus_id,
__FUNCTION__, retval);
}
/* have the device type specific fuction 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->bus_id,
__FUNCTION__, retval);
}
return retval;
}
static struct kset_uevent_ops device_uevent_ops = {
.filter = dev_uevent_filter,
.name = dev_uevent_name,
.uevent = dev_uevent,
};
static ssize_t show_uevent(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 store_uevent(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);
goto out;
}
dev_err(dev, "uevent: unsupported action-string; this will "
"be ignored in a future kernel version\n");
kobject_uevent(&dev->kobj, KOBJ_ADD);
out:
return count;
}
static struct device_attribute uevent_attr =
__ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
static int device_add_attributes(struct device *dev,
struct device_attribute *attrs)
{
int error = 0;
int i;
if (attrs) {
for (i = 0; attr_name(attrs[i]); i++) {
error = device_create_file(dev, &attrs[i]);
if (error)
break;
}
if (error)
while (--i >= 0)
device_remove_file(dev, &attrs[i]);
}
return error;
}
static void device_remove_attributes(struct device *dev,
struct device_attribute *attrs)
{
int i;
if (attrs)
for (i = 0; attr_name(attrs[i]); i++)
device_remove_file(dev, &attrs[i]);
}
static int device_add_groups(struct device *dev,
struct attribute_group **groups)
{
int error = 0;
int i;
if (groups) {
for (i = 0; groups[i]; i++) {
error = sysfs_create_group(&dev->kobj, groups[i]);
if (error) {
while (--i >= 0)
sysfs_remove_group(&dev->kobj, groups[i]);
break;
}
}
}
return error;
}
static void device_remove_groups(struct device *dev,
struct attribute_group **groups)
{
int i;
if (groups)
for (i = 0; groups[i]; i++)
sysfs_remove_group(&dev->kobj, groups[i]);
}
static int device_add_attrs(struct device *dev)
{
struct class *class = dev->class;
struct device_type *type = dev->type;
int error;
if (class) {
error = device_add_attributes(dev, class->dev_attrs);
if (error)
return error;
}
if (type) {
error = device_add_groups(dev, type->groups);
if (error)
goto err_remove_class_attrs;
}
error = device_add_groups(dev, dev->groups);
if (error)
goto err_remove_type_groups;
return 0;
err_remove_type_groups:
if (type)
device_remove_groups(dev, type->groups);
err_remove_class_attrs:
if (class)
device_remove_attributes(dev, class->dev_attrs);
return error;
}
static void device_remove_attrs(struct device *dev)
{
struct class *class = dev->class;
struct device_type *type = dev->type;
device_remove_groups(dev, dev->groups);
if (type)
device_remove_groups(dev, type->groups);
if (class)
device_remove_attributes(dev, class->dev_attrs);
}
static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
char *buf)
{
return print_dev_t(buf, dev->devt);
}
static struct device_attribute devt_attr =
__ATTR(dev, S_IRUGO, show_dev, NULL);
/* kset to create /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, struct device_attribute * attr)
{
int error = 0;
if (get_device(dev)) {
error = sysfs_create_file(&dev->kobj, &attr->attr);
put_device(dev);
}
return error;
}
/**
* device_remove_file - remove sysfs attribute file.
* @dev: device.
* @attr: device attribute descriptor.
*/
void device_remove_file(struct device * dev, struct device_attribute * attr)
{
if (get_device(dev)) {
sysfs_remove_file(&dev->kobj, &attr->attr);
put_device(dev);
}
}
/**
* device_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, 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, struct bin_attribute *attr)
{
if (dev)
sysfs_remove_bin_file(&dev->kobj, attr);
}
EXPORT_SYMBOL_GPL(device_remove_bin_file);
/**
* device_schedule_callback_owner - helper to schedule a callback for a device
* @dev: device.
* @func: callback function to invoke later.
* @owner: module owning the callback routine
*
* Attribute methods must not unregister themselves or their parent device
* (which would amount to the same thing). Attempts to do so will deadlock,
* since unregistration is mutually exclusive with driver callbacks.
*
* Instead methods can call this routine, which will attempt to allocate
* and schedule a workqueue request to call back @func with @dev as its
* argument in the workqueue's process context. @dev will be pinned until
* @func returns.
*
* This routine is usually called via the inline device_schedule_callback(),
* which automatically sets @owner to THIS_MODULE.
*
* Returns 0 if the request was submitted, -ENOMEM if storage could not
* be allocated, -ENODEV if a reference to @owner isn't available.
*
* NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
* underlying sysfs routine (since it is intended for use by attribute
* methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
*/
int device_schedule_callback_owner(struct device *dev,
void (*func)(struct device *), struct module *owner)
{
return sysfs_schedule_callback(&dev->kobj,
(void (*)(void *)) func, dev, owner);
}
EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
static void klist_children_get(struct klist_node *n)
{
struct device *dev = container_of(n, struct device, knode_parent);
get_device(dev);
}
static void klist_children_put(struct klist_node *n)
{
struct device *dev = container_of(n, struct device, knode_parent);
put_device(dev);
}
/**
* device_initialize - init device structure.
* @dev: device.
*
* This prepares the device for use by other layers,
* including adding it to the device hierarchy.
* It is the first half of device_register(), if called by
* that, though it can also be called separately, so one
* may use @dev's fields (e.g. the refcount).
*/
void device_initialize(struct device *dev)
{
dev->kobj.kset = devices_kset;
kobject_init(&dev->kobj, &device_ktype);
klist_init(&dev->klist_children, klist_children_get,
klist_children_put);
INIT_LIST_HEAD(&dev->dma_pools);
INIT_LIST_HEAD(&dev->node);
init_MUTEX(&dev->sem);
spin_lock_init(&dev->devres_lock);
INIT_LIST_HEAD(&dev->devres_head);
device_init_wakeup(dev, 0);
set_dev_node(dev, -1);
}
#ifdef CONFIG_SYSFS_DEPRECATED
static struct kobject *get_device_parent(struct device *dev,
struct device *parent)
{
/* class devices without a parent live in /sys/class/<classname>/ */
if (dev->class && (!parent || parent->class != dev->class))
return &dev->class->subsys.kobj;
/* all other devices keep their parent */
else if (parent)
return &parent->kobj;
return NULL;
}
static inline void cleanup_device_parent(struct device *dev) {}
#else
static 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;
}
static struct kobject *get_device_parent(struct device *dev,
struct device *parent)
{
int retval;
if (dev->class) {
struct kobject *kobj = NULL;
struct kobject *parent_kobj;
struct kobject *k;
/*
* 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)
return &parent->kobj;
else
parent_kobj = &parent->kobj;
/* find our class-directory at the parent and reference it */
spin_lock(&dev->class->class_dirs.list_lock);
list_for_each_entry(k, &dev->class->class_dirs.list, entry)
if (k->parent == parent_kobj) {
kobj = kobject_get(k);
break;
}
spin_unlock(&dev->class->class_dirs.list_lock);
if (kobj)
return kobj;
/* or create a new class-directory at the parent device */
k = kobject_create();
if (!k)
return NULL;
k->kset = &dev->class->class_dirs;
retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
if (retval < 0) {
kobject_put(k);
return NULL;
}
/* do not emit an uevent for this simple "glue" directory */
return k;
}
if (parent)
return &parent->kobj;
return NULL;
}
static void cleanup_device_parent(struct device *dev)
{
struct kobject *glue_dir = dev->kobj.parent;
/* see if we live in a "glue" directory */
if (!dev->class || glue_dir->kset != &dev->class->class_dirs)
return;
kobject_put(glue_dir);
}
#endif
static int setup_parent(struct device *dev, struct device *parent)
{
struct kobject *kobj;
kobj = get_device_parent(dev, parent);
if (IS_ERR(kobj))
return PTR_ERR(kobj);
if (kobj)
dev->kobj.parent = kobj;
return 0;
}
static int device_add_class_symlinks(struct device *dev)
{
int error;
if (!dev->class)
return 0;
error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
"subsystem");
if (error)
goto out;
#ifdef CONFIG_SYSFS_DEPRECATED
/* stacked class devices need a symlink in the class directory */
if (dev->kobj.parent != &dev->class->subsys.kobj &&
dev->type != &part_type) {
error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
dev->bus_id);
if (error)
goto out_subsys;
}
if (dev->parent && dev->type != &part_type) {
struct device *parent = dev->parent;
char *class_name;
/*
* stacked class devices have the 'device' link
* pointing to the bus device instead of the parent
*/
while (parent->class && !parent->bus && parent->parent)
parent = parent->parent;
error = sysfs_create_link(&dev->kobj,
&parent->kobj,
"device");
if (error)
goto out_busid;
class_name = make_class_name(dev->class->name,
&dev->kobj);
if (class_name)
error = sysfs_create_link(&dev->parent->kobj,
&dev->kobj, class_name);
kfree(class_name);
if (error)
goto out_device;
}
return 0;
out_device:
if (dev->parent && dev->type != &part_type)
sysfs_remove_link(&dev->kobj, "device");
out_busid:
if (dev->kobj.parent != &dev->class->subsys.kobj &&
dev->type != &part_type)
sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#else
/* link in the class directory pointing to the device */
error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
dev->bus_id);
if (error)
goto out_subsys;
if (dev->parent && dev->type != &part_type) {
error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
"device");
if (error)
goto out_busid;
}
return 0;
out_busid:
sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif
out_subsys:
sysfs_remove_link(&dev->kobj, "subsystem");
out:
return error;
}
static void device_remove_class_symlinks(struct device *dev)
{
if (!dev->class)
return;
#ifdef CONFIG_SYSFS_DEPRECATED
if (dev->parent && dev->type != &part_type) {
char *class_name;
class_name = make_class_name(dev->class->name, &dev->kobj);
if (class_name) {
sysfs_remove_link(&dev->parent->kobj, class_name);
kfree(class_name);
}
sysfs_remove_link(&dev->kobj, "device");
}
if (dev->kobj.parent != &dev->class->subsys.kobj &&
dev->type != &part_type)
sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#else
if (dev->parent && dev->type != &part_type)
sysfs_remove_link(&dev->kobj, "device");
sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif
sysfs_remove_link(&dev->kobj, "subsystem");
}
/**
* device_add - add device to device hierarchy.
* @dev: device.
*
* This is part 2 of device_register(), though may be called
* separately _iff_ device_initialize() has been called separately.
*
* This adds it to the kobject hierarchy via kobject_add(), adds it
* to the global and sibling lists for the device, then
* adds it to the other relevant subsystems of the driver model.
*/
int device_add(struct device *dev)
{
struct device *parent = NULL;
struct class_interface *class_intf;
int error;
error = pm_sleep_lock();
if (error) {
dev_warn(dev, "Suspicious %s during suspend\n", __FUNCTION__);
dump_stack();
return error;
}
dev = get_device(dev);
if (!dev || !strlen(dev->bus_id)) {
error = -EINVAL;
goto Error;
}
pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
parent = get_device(dev->parent);
error = setup_parent(dev, parent);
if (error)
goto Error;
/* first, register with generic layer. */
error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
if (error)
goto Error;
/* notify platform of device entry */
if (platform_notify)
platform_notify(dev);
/* notify clients of device entry (new way) */
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_ADD_DEVICE, dev);
error = device_create_file(dev, &uevent_attr);
if (error)
goto attrError;
if (MAJOR(dev->devt)) {
error = device_create_file(dev, &devt_attr);
if (error)
goto ueventattrError;
}
error = device_add_class_symlinks(dev);
if (error)
goto SymlinkError;
error = device_add_attrs(dev);
if (error)
goto AttrsError;
error = dpm_sysfs_add(dev);
if (error)
goto PMError;
device_pm_add(dev);
error = bus_add_device(dev);
if (error)
goto BusError;
kobject_uevent(&dev->kobj, KOBJ_ADD);
bus_attach_device(dev);
if (parent)
klist_add_tail(&dev->knode_parent, &parent->klist_children);
if (dev->class) {
down(&dev->class->sem);
/* tie the class to the device */
list_add_tail(&dev->node, &dev->class->devices);
/* notify any interfaces that the device is here */
list_for_each_entry(class_intf, &dev->class->interfaces, node)
if (class_intf->add_dev)
class_intf->add_dev(dev, class_intf);
up(&dev->class->sem);
}
Done:
put_device(dev);
pm_sleep_unlock();
return error;
BusError:
device_pm_remove(dev);
dpm_sysfs_remove(dev);
PMError:
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
device_remove_attrs(dev);
AttrsError:
device_remove_class_symlinks(dev);
SymlinkError:
if (MAJOR(dev->devt))
device_remove_file(dev, &devt_attr);
ueventattrError:
device_remove_file(dev, &uevent_attr);
attrError:
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
kobject_del(&dev->kobj);
Error:
if (parent)
put_device(parent);
goto Done;
}
/**
* device_register - register a device with the system.
* @dev: pointer to the device structure
*
* This happens in two clean steps - initialize the device
* and add it to the system. The two steps can be called
* separately, but this is the easiest and most common.
* I.e. you should only call the two helpers separately if
* have a clearly defined need to use and refcount the device
* before it is added to the hierarchy.
*/
int device_register(struct device *dev)
{
device_initialize(dev);
return device_add(dev);
}
/**
* get_device - increment reference count for device.
* @dev: device.
*
* This simply forwards the call to kobject_get(), though
* we do take care to provide for the case that we get a NULL
* pointer passed in.
*/
struct device * get_device(struct device * dev)
{
return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}
/**
* put_device - decrement reference count.
* @dev: device in question.
*/
void put_device(struct device * dev)
{
/* might_sleep(); */
if (dev)
kobject_put(&dev->kobj);
}
/**
* device_del - delete device from system.
* @dev: device.
*
* This is the first part of the device unregistration
* sequence. This removes the device from the lists we control
* from here, has it removed from the other driver model
* subsystems it was added to in device_add(), and removes it
* from the kobject hierarchy.
*
* NOTE: this should be called manually _iff_ device_add() was
* also called manually.
*/
void device_del(struct device * dev)
{
struct device * parent = dev->parent;
struct class_interface *class_intf;
device_pm_remove(dev);
if (parent)
klist_del(&dev->knode_parent);
if (MAJOR(dev->devt))
device_remove_file(dev, &devt_attr);
if (dev->class) {
device_remove_class_symlinks(dev);
down(&dev->class->sem);
/* notify any interfaces that the device is now gone */
list_for_each_entry(class_intf, &dev->class->interfaces, node)
if (class_intf->remove_dev)
class_intf->remove_dev(dev, class_intf);
/* remove the device from the class list */
list_del_init(&dev->node);
up(&dev->class->sem);
}
device_remove_file(dev, &uevent_attr);
device_remove_attrs(dev);
bus_remove_device(dev);
/*
* Some platform devices are driven without driver attached
* and managed resources may have been acquired. Make sure
* all resources are released.
*/
devres_release_all(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_DEL_DEVICE, dev);
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
cleanup_device_parent(dev);
kobject_del(&dev->kobj);
put_device(parent);
}
/**
* device_unregister - unregister device from system.
* @dev: device going away.
*
* We do this in two parts, like we do device_register(). First,
* we remove it from all the subsystems with device_del(), then
* we decrement the reference count via put_device(). If that
* is the final reference count, the device will be cleaned up
* via device_release() above. Otherwise, the structure will
* stick around until the final reference to the device is dropped.
*/
void device_unregister(struct device * dev)
{
pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
device_del(dev);
put_device(dev);
}
static struct device * next_device(struct klist_iter * i)
{
struct klist_node * n = klist_next(i);
return n ? container_of(n, struct device, knode_parent) : NULL;
}
/**
* device_for_each_child - device child iterator.
* @parent: parent struct device.
* @data: data for the callback.
* @fn: function to be called for each device.
*
* 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 *, void *))
{
struct klist_iter i;
struct device * child;
int error = 0;
klist_iter_init(&parent->klist_children, &i);
while ((child = next_device(&i)) && !error)
error = fn(child, data);
klist_iter_exit(&i);
return error;
}
/**
* device_find_child - device iterator for locating a particular device.
* @parent: parent struct device
* @data: Data to pass to match function
* @match: Callback function to check device
*
* 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.
*/
struct device * device_find_child(struct device *parent, void *data,
int (*match)(struct device *, void *))
{
struct klist_iter i;
struct device *child;
if (!parent)
return NULL;
klist_iter_init(&parent->klist_children, &i);
while ((child = next_device(&i)))
if (match(child, data) && get_device(child))
break;
klist_iter_exit(&i);
return child;
}
int __init devices_init(void)
{
devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
if (!devices_kset)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL_GPL(device_for_each_child);
EXPORT_SYMBOL_GPL(device_find_child);
EXPORT_SYMBOL_GPL(device_initialize);
EXPORT_SYMBOL_GPL(device_add);
EXPORT_SYMBOL_GPL(device_register);
EXPORT_SYMBOL_GPL(device_del);
EXPORT_SYMBOL_GPL(device_unregister);
EXPORT_SYMBOL_GPL(get_device);
EXPORT_SYMBOL_GPL(put_device);
EXPORT_SYMBOL_GPL(device_create_file);
EXPORT_SYMBOL_GPL(device_remove_file);
static void device_create_release(struct device *dev)
{
pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
kfree(dev);
}
/**
* 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
* @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.
*
* 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, 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;
}
dev->devt = devt;
dev->class = class;
dev->parent = parent;
dev->release = device_create_release;
va_start(args, fmt);
vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
va_end(args);
retval = device_register(dev);
if (retval)
goto error;
return dev;
error:
kfree(dev);
return ERR_PTR(retval);
}
EXPORT_SYMBOL_GPL(device_create);
/**
* find_device - finds 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
*/
static struct device *find_device(struct class *class, dev_t devt)
{
struct device *dev = NULL;
struct device *dev_tmp;
down(&class->sem);
list_for_each_entry(dev_tmp, &class->devices, node) {
if (dev_tmp->devt == devt) {
dev = dev_tmp;
break;
}
}
up(&class->sem);
return dev;
}
/**
* 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 = find_device(class, devt);
if (dev)
device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
#ifdef CONFIG_PM_SLEEP
/**
* destroy_suspended_device - asks the PM core to remove a suspended device
* @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 notifies the PM core of the necessity to unregister a suspended
* device created with a call to device_create() (devices cannot be
* unregistered directly while suspended, since the PM core holds their
* semaphores at that time).
*
* It can only be called within the scope of a system sleep transition. In
* practice this means it has to be directly or indirectly invoked either by
* a suspend or resume method, or by the PM core (e.g. via
* disable_nonboot_cpus() or enable_nonboot_cpus()).
*/
void destroy_suspended_device(struct class *class, dev_t devt)
{
struct device *dev;
dev = find_device(class, devt);
if (dev)
device_pm_schedule_removal(dev);
}
EXPORT_SYMBOL_GPL(destroy_suspended_device);
#endif /* CONFIG_PM_SLEEP */
/**
* device_rename - renames a device
* @dev: the pointer to the struct device to be renamed
* @new_name: the new name of the device
*/
int device_rename(struct device *dev, char *new_name)
{
char *old_class_name = NULL;
char *new_class_name = NULL;
char *old_device_name = NULL;
int error;
dev = get_device(dev);
if (!dev)
return -EINVAL;
pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
__FUNCTION__, new_name);
#ifdef CONFIG_SYSFS_DEPRECATED
if ((dev->class) && (dev->parent))
old_class_name = make_class_name(dev->class->name, &dev->kobj);
#endif
old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
if (!old_device_name) {
error = -ENOMEM;
goto out;
}
strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
error = kobject_rename(&dev->kobj, new_name);
if (error) {
strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
goto out;
}
#ifdef CONFIG_SYSFS_DEPRECATED
if (old_class_name) {
new_class_name = make_class_name(dev->class->name, &dev->kobj);
if (new_class_name) {
error = sysfs_create_link(&dev->parent->kobj,
&dev->kobj, new_class_name);
if (error)
goto out;
sysfs_remove_link(&dev->parent->kobj, old_class_name);
}
}
#else
if (dev->class) {
sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
dev->bus_id);
if (error) {
dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
__FUNCTION__, error);
}
}
#endif
out:
put_device(dev);
kfree(new_class_name);
kfree(old_class_name);
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;
#ifdef CONFIG_SYSFS_DEPRECATED
char *class_name;
class_name = make_class_name(dev->class->name, &dev->kobj);
if (!class_name) {
error = -ENOMEM;
goto out;
}
if (old_parent) {
sysfs_remove_link(&dev->kobj, "device");
sysfs_remove_link(&old_parent->kobj, class_name);
}
if (new_parent) {
error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
"device");
if (error)
goto out;
error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
class_name);
if (error)
sysfs_remove_link(&dev->kobj, "device");
}
else
error = 0;
out:
kfree(class_name);
return error;
#else
if (old_parent)
sysfs_remove_link(&dev->kobj, "device");
if (new_parent)
error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
"device");
return error;
#endif
}
/**
* 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)
*/
int device_move(struct device *dev, struct device *new_parent)
{
int error;
struct device *old_parent;
struct kobject *new_parent_kobj;
dev = get_device(dev);
if (!dev)
return -EINVAL;
new_parent = get_device(new_parent);
new_parent_kobj = get_device_parent (dev, new_parent);
if (IS_ERR(new_parent_kobj)) {
error = PTR_ERR(new_parent_kobj);
put_device(new_parent);
goto out;
}
pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
__FUNCTION__, new_parent ? new_parent->bus_id : "<NULL>");
error = kobject_move(&dev->kobj, new_parent_kobj);
if (error) {
put_device(new_parent);
goto out;
}
old_parent = dev->parent;
dev->parent = new_parent;
if (old_parent)
klist_remove(&dev->knode_parent);
if (new_parent)
klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
if (!dev->class)
goto out_put;
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->knode_parent);
if (old_parent)
klist_add_tail(&dev->knode_parent,
&old_parent->klist_children);
}
put_device(new_parent);
goto out;
}
out_put:
put_device(old_parent);
out:
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, *devn;
list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
kobj.entry) {
if (dev->bus && dev->bus->shutdown) {
dev_dbg(dev, "shutdown\n");
dev->bus->shutdown(dev);
} else if (dev->driver && dev->driver->shutdown) {
dev_dbg(dev, "shutdown\n");
dev->driver->shutdown(dev);
}
}
}