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OpenCloudOS-Kernel/drivers/base/class.c

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/*
* class.c - basic device class management
*
* Copyright (c) 2002-3 Patrick Mochel
* Copyright (c) 2002-3 Open Source Development Labs
* Copyright (c) 2003-2004 Greg Kroah-Hartman
* Copyright (c) 2003-2004 IBM Corp.
*
* This file is released under the GPLv2
*
*/
#include <linux/config.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
#include <linux/slab.h>
#include "base.h"
#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
static ssize_t
class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct class_attribute * class_attr = to_class_attr(attr);
struct class * dc = to_class(kobj);
ssize_t ret = -EIO;
if (class_attr->show)
ret = class_attr->show(dc, buf);
return ret;
}
static ssize_t
class_attr_store(struct kobject * kobj, struct attribute * attr,
const char * buf, size_t count)
{
struct class_attribute * class_attr = to_class_attr(attr);
struct class * dc = to_class(kobj);
ssize_t ret = -EIO;
if (class_attr->store)
ret = class_attr->store(dc, buf, count);
return ret;
}
static void class_release(struct kobject * kobj)
{
struct class *class = to_class(kobj);
pr_debug("class '%s': release.\n", class->name);
if (class->class_release)
class->class_release(class);
else
pr_debug("class '%s' does not have a release() function, "
"be careful\n", class->name);
}
static struct sysfs_ops class_sysfs_ops = {
.show = class_attr_show,
.store = class_attr_store,
};
static struct kobj_type ktype_class = {
.sysfs_ops = &class_sysfs_ops,
.release = class_release,
};
/* Hotplug events for classes go to the class_obj subsys */
static decl_subsys(class, &ktype_class, NULL);
int class_create_file(struct class * cls, const struct class_attribute * attr)
{
int error;
if (cls) {
error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
} else
error = -EINVAL;
return error;
}
void class_remove_file(struct class * cls, const struct class_attribute * attr)
{
if (cls)
sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
}
struct class * class_get(struct class * cls)
{
if (cls)
return container_of(subsys_get(&cls->subsys), struct class, subsys);
return NULL;
}
void class_put(struct class * cls)
{
if (cls)
subsys_put(&cls->subsys);
}
static int add_class_attrs(struct class * cls)
{
int i;
int error = 0;
if (cls->class_attrs) {
for (i = 0; attr_name(cls->class_attrs[i]); i++) {
error = class_create_file(cls,&cls->class_attrs[i]);
if (error)
goto Err;
}
}
Done:
return error;
Err:
while (--i >= 0)
class_remove_file(cls,&cls->class_attrs[i]);
goto Done;
}
static void remove_class_attrs(struct class * cls)
{
int i;
if (cls->class_attrs) {
for (i = 0; attr_name(cls->class_attrs[i]); i++)
class_remove_file(cls,&cls->class_attrs[i]);
}
}
int class_register(struct class * cls)
{
int error;
pr_debug("device class '%s': registering\n", cls->name);
INIT_LIST_HEAD(&cls->children);
INIT_LIST_HEAD(&cls->interfaces);
init_MUTEX(&cls->sem);
error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
if (error)
return error;
subsys_set_kset(cls, class_subsys);
error = subsystem_register(&cls->subsys);
if (!error) {
error = add_class_attrs(class_get(cls));
class_put(cls);
}
return error;
}
void class_unregister(struct class * cls)
{
pr_debug("device class '%s': unregistering\n", cls->name);
remove_class_attrs(cls);
subsystem_unregister(&cls->subsys);
}
static void class_create_release(struct class *cls)
{
pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
kfree(cls);
}
static void class_device_create_release(struct class_device *class_dev)
{
pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
kfree(class_dev);
}
/* needed to allow these devices to have parent class devices */
static int class_device_create_uevent(struct class_device *class_dev,
char **envp, int num_envp,
char *buffer, int buffer_size)
{
pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
return 0;
}
/**
* class_create - create a struct class structure
* @owner: pointer to the module that is to "own" this struct class
* @name: pointer to a string for the name of this class.
*
* This is used to create a struct class pointer that can then be used
* in calls to class_device_create().
*
* Note, the pointer created here is to be destroyed when finished by
* making a call to class_destroy().
*/
struct class *class_create(struct module *owner, char *name)
{
struct class *cls;
int retval;
cls = kzalloc(sizeof(*cls), GFP_KERNEL);
if (!cls) {
retval = -ENOMEM;
goto error;
}
cls->name = name;
cls->owner = owner;
cls->class_release = class_create_release;
cls->release = class_device_create_release;
retval = class_register(cls);
if (retval)
goto error;
return cls;
error:
kfree(cls);
return ERR_PTR(retval);
}
/**
* class_destroy - destroys a struct class structure
* @cs: pointer to the struct class that is to be destroyed
*
* Note, the pointer to be destroyed must have been created with a call
* to class_create().
*/
void class_destroy(struct class *cls)
{
if ((cls == NULL) || (IS_ERR(cls)))
return;
class_unregister(cls);
}
/* Class Device Stuff */
int class_device_create_file(struct class_device * class_dev,
const struct class_device_attribute * attr)
{
int error = -EINVAL;
if (class_dev)
error = sysfs_create_file(&class_dev->kobj, &attr->attr);
return error;
}
void class_device_remove_file(struct class_device * class_dev,
const struct class_device_attribute * attr)
{
if (class_dev)
sysfs_remove_file(&class_dev->kobj, &attr->attr);
}
int class_device_create_bin_file(struct class_device *class_dev,
struct bin_attribute *attr)
{
int error = -EINVAL;
if (class_dev)
error = sysfs_create_bin_file(&class_dev->kobj, attr);
return error;
}
void class_device_remove_bin_file(struct class_device *class_dev,
struct bin_attribute *attr)
{
if (class_dev)
sysfs_remove_bin_file(&class_dev->kobj, attr);
}
static ssize_t
class_device_attr_show(struct kobject * kobj, struct attribute * attr,
char * buf)
{
struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
struct class_device * cd = to_class_dev(kobj);
ssize_t ret = 0;
if (class_dev_attr->show)
ret = class_dev_attr->show(cd, buf);
return ret;
}
static ssize_t
class_device_attr_store(struct kobject * kobj, struct attribute * attr,
const char * buf, size_t count)
{
struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
struct class_device * cd = to_class_dev(kobj);
ssize_t ret = 0;
if (class_dev_attr->store)
ret = class_dev_attr->store(cd, buf, count);
return ret;
}
static struct sysfs_ops class_dev_sysfs_ops = {
.show = class_device_attr_show,
.store = class_device_attr_store,
};
static void class_dev_release(struct kobject * kobj)
{
struct class_device *cd = to_class_dev(kobj);
struct class * cls = cd->class;
pr_debug("device class '%s': release.\n", cd->class_id);
kfree(cd->devt_attr);
cd->devt_attr = NULL;
if (cd->release)
cd->release(cd);
else if (cls->release)
cls->release(cd);
else {
printk(KERN_ERR "Class Device '%s' does not have a release() function, "
"it is broken and must be fixed.\n",
cd->class_id);
WARN_ON(1);
}
}
static struct kobj_type ktype_class_device = {
.sysfs_ops = &class_dev_sysfs_ops,
.release = class_dev_release,
};
static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
{
struct kobj_type *ktype = get_ktype(kobj);
if (ktype == &ktype_class_device) {
struct class_device *class_dev = to_class_dev(kobj);
if (class_dev->class)
return 1;
}
return 0;
}
static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
{
struct class_device *class_dev = to_class_dev(kobj);
return class_dev->class->name;
}
static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
int num_envp, char *buffer, int buffer_size)
{
struct class_device *class_dev = to_class_dev(kobj);
int i = 0;
int length = 0;
int retval = 0;
pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
if (class_dev->dev) {
/* add physical device, backing this device */
struct device *dev = class_dev->dev;
char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
&length, "PHYSDEVPATH=%s", path);
kfree(path);
if (dev->bus)
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVBUS=%s", dev->bus->name);
if (dev->driver)
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVDRIVER=%s", dev->driver->name);
}
if (MAJOR(class_dev->devt)) {
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MAJOR=%u", MAJOR(class_dev->devt));
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MINOR=%u", MINOR(class_dev->devt));
}
/* terminate, set to next free slot, shrink available space */
envp[i] = NULL;
envp = &envp[i];
num_envp -= i;
buffer = &buffer[length];
buffer_size -= length;
if (class_dev->uevent) {
/* have the class device specific function add its stuff */
retval = class_dev->uevent(class_dev, envp, num_envp,
buffer, buffer_size);
if (retval)
pr_debug("class_dev->uevent() returned %d\n", retval);
} else if (class_dev->class->uevent) {
/* have the class specific function add its stuff */
retval = class_dev->class->uevent(class_dev, envp, num_envp,
buffer, buffer_size);
if (retval)
pr_debug("class->uevent() returned %d\n", retval);
}
return retval;
}
static struct kset_uevent_ops class_uevent_ops = {
.filter = class_uevent_filter,
.name = class_uevent_name,
.uevent = class_uevent,
};
static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
static int class_device_add_attrs(struct class_device * cd)
{
int i;
int error = 0;
struct class * cls = cd->class;
if (cls->class_dev_attrs) {
for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
error = class_device_create_file(cd,
&cls->class_dev_attrs[i]);
if (error)
goto Err;
}
}
Done:
return error;
Err:
while (--i >= 0)
class_device_remove_file(cd,&cls->class_dev_attrs[i]);
goto Done;
}
static void class_device_remove_attrs(struct class_device * cd)
{
int i;
struct class * cls = cd->class;
if (cls->class_dev_attrs) {
for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
class_device_remove_file(cd,&cls->class_dev_attrs[i]);
}
}
static ssize_t show_dev(struct class_device *class_dev, char *buf)
{
return print_dev_t(buf, class_dev->devt);
}
static ssize_t store_uevent(struct class_device *class_dev,
const char *buf, size_t count)
{
kobject_uevent(&class_dev->kobj, KOBJ_ADD);
return count;
}
void class_device_initialize(struct class_device *class_dev)
{
kobj_set_kset_s(class_dev, class_obj_subsys);
kobject_init(&class_dev->kobj);
INIT_LIST_HEAD(&class_dev->node);
}
static char *make_class_name(struct class_device *class_dev)
{
char *name;
int size;
size = strlen(class_dev->class->name) +
strlen(kobject_name(&class_dev->kobj)) + 2;
name = kmalloc(size, GFP_KERNEL);
if (!name)
return ERR_PTR(-ENOMEM);
strcpy(name, class_dev->class->name);
strcat(name, ":");
strcat(name, kobject_name(&class_dev->kobj));
return name;
}
int class_device_add(struct class_device *class_dev)
{
struct class *parent_class = NULL;
struct class_device *parent_class_dev = NULL;
struct class_interface *class_intf;
char *class_name = NULL;
int error = -EINVAL;
class_dev = class_device_get(class_dev);
if (!class_dev)
return -EINVAL;
if (!strlen(class_dev->class_id))
goto register_done;
parent_class = class_get(class_dev->class);
if (!parent_class)
goto register_done;
parent_class_dev = class_device_get(class_dev->parent);
pr_debug("CLASS: registering class device: ID = '%s'\n",
class_dev->class_id);
/* first, register with generic layer. */
kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
if (parent_class_dev)
class_dev->kobj.parent = &parent_class_dev->kobj;
else
class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
error = kobject_add(&class_dev->kobj);
if (error)
goto register_done;
/* add the needed attributes to this device */
class_dev->uevent_attr.attr.name = "uevent";
class_dev->uevent_attr.attr.mode = S_IWUSR;
class_dev->uevent_attr.attr.owner = parent_class->owner;
class_dev->uevent_attr.store = store_uevent;
class_device_create_file(class_dev, &class_dev->uevent_attr);
if (MAJOR(class_dev->devt)) {
struct class_device_attribute *attr;
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
if (!attr) {
error = -ENOMEM;
kobject_del(&class_dev->kobj);
goto register_done;
}
attr->attr.name = "dev";
attr->attr.mode = S_IRUGO;
attr->attr.owner = parent_class->owner;
attr->show = show_dev;
class_device_create_file(class_dev, attr);
class_dev->devt_attr = attr;
}
class_device_add_attrs(class_dev);
if (class_dev->dev) {
class_name = make_class_name(class_dev);
sysfs_create_link(&class_dev->kobj,
&class_dev->dev->kobj, "device");
sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
class_name);
}
kobject_uevent(&class_dev->kobj, KOBJ_ADD);
/* notify any interfaces this device is now here */
if (parent_class) {
down(&parent_class->sem);
list_add_tail(&class_dev->node, &parent_class->children);
list_for_each_entry(class_intf, &parent_class->interfaces, node)
if (class_intf->add)
class_intf->add(class_dev, class_intf);
up(&parent_class->sem);
}
register_done:
if (error) {
class_put(parent_class);
class_device_put(parent_class_dev);
}
class_device_put(class_dev);
kfree(class_name);
return error;
}
int class_device_register(struct class_device *class_dev)
{
class_device_initialize(class_dev);
return class_device_add(class_dev);
}
/**
* class_device_create - creates a class device and registers it with sysfs
* @cs: pointer to the struct class that this device should be registered to.
* @parent: pointer to the parent struct class_device of this new device, if any.
* @dev: the dev_t for the char device to be added.
* @device: a pointer to a struct device that is assiociated with this class device.
* @fmt: string for the class device's name
*
* This function can be used by char device classes. A struct
* class_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 class_device is passed in, the newly
* created struct class_device will be a child of that device in sysfs.
* The pointer to the struct class_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 class_device *class_device_create(struct class *cls,
struct class_device *parent,
dev_t devt,
struct device *device, char *fmt, ...)
{
va_list args;
struct class_device *class_dev = NULL;
int retval = -ENODEV;
if (cls == NULL || IS_ERR(cls))
goto error;
class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
if (!class_dev) {
retval = -ENOMEM;
goto error;
}
class_dev->devt = devt;
class_dev->dev = device;
class_dev->class = cls;
class_dev->parent = parent;
class_dev->release = class_device_create_release;
class_dev->uevent = class_device_create_uevent;
va_start(args, fmt);
vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
va_end(args);
retval = class_device_register(class_dev);
if (retval)
goto error;
return class_dev;
error:
kfree(class_dev);
return ERR_PTR(retval);
}
void class_device_del(struct class_device *class_dev)
{
struct class *parent_class = class_dev->class;
struct class_device *parent_device = class_dev->parent;
struct class_interface *class_intf;
char *class_name = NULL;
if (parent_class) {
down(&parent_class->sem);
list_del_init(&class_dev->node);
list_for_each_entry(class_intf, &parent_class->interfaces, node)
if (class_intf->remove)
class_intf->remove(class_dev, class_intf);
up(&parent_class->sem);
}
if (class_dev->dev) {
class_name = make_class_name(class_dev);
sysfs_remove_link(&class_dev->kobj, "device");
sysfs_remove_link(&class_dev->dev->kobj, class_name);
}
class_device_remove_file(class_dev, &class_dev->uevent_attr);
if (class_dev->devt_attr)
class_device_remove_file(class_dev, class_dev->devt_attr);
class_device_remove_attrs(class_dev);
kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
kobject_del(&class_dev->kobj);
class_device_put(parent_device);
class_put(parent_class);
kfree(class_name);
}
void class_device_unregister(struct class_device *class_dev)
{
pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
class_dev->class_id);
class_device_del(class_dev);
class_device_put(class_dev);
}
/**
* class_device_destroy - removes a class device that was created with class_device_create()
* @cls: the pointer to the struct class that this device was registered * with.
* @dev: the dev_t of the device that was previously registered.
*
* This call unregisters and cleans up a class device that was created with a
* call to class_device_create()
*/
void class_device_destroy(struct class *cls, dev_t devt)
{
struct class_device *class_dev = NULL;
struct class_device *class_dev_tmp;
down(&cls->sem);
list_for_each_entry(class_dev_tmp, &cls->children, node) {
if (class_dev_tmp->devt == devt) {
class_dev = class_dev_tmp;
break;
}
}
up(&cls->sem);
if (class_dev)
class_device_unregister(class_dev);
}
int class_device_rename(struct class_device *class_dev, char *new_name)
{
int error = 0;
char *old_class_name = NULL, *new_class_name = NULL;
class_dev = class_device_get(class_dev);
if (!class_dev)
return -EINVAL;
pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
new_name);
if (class_dev->dev)
old_class_name = make_class_name(class_dev);
strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
error = kobject_rename(&class_dev->kobj, new_name);
if (class_dev->dev) {
new_class_name = make_class_name(class_dev);
sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
new_class_name);
sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
}
class_device_put(class_dev);
kfree(old_class_name);
kfree(new_class_name);
return error;
}
struct class_device * class_device_get(struct class_device *class_dev)
{
if (class_dev)
return to_class_dev(kobject_get(&class_dev->kobj));
return NULL;
}
void class_device_put(struct class_device *class_dev)
{
if (class_dev)
kobject_put(&class_dev->kobj);
}
int class_interface_register(struct class_interface *class_intf)
{
struct class *parent;
struct class_device *class_dev;
if (!class_intf || !class_intf->class)
return -ENODEV;
parent = class_get(class_intf->class);
if (!parent)
return -EINVAL;
down(&parent->sem);
list_add_tail(&class_intf->node, &parent->interfaces);
if (class_intf->add) {
list_for_each_entry(class_dev, &parent->children, node)
class_intf->add(class_dev, class_intf);
}
up(&parent->sem);
return 0;
}
void class_interface_unregister(struct class_interface *class_intf)
{
struct class * parent = class_intf->class;
struct class_device *class_dev;
if (!parent)
return;
down(&parent->sem);
list_del_init(&class_intf->node);
if (class_intf->remove) {
list_for_each_entry(class_dev, &parent->children, node)
class_intf->remove(class_dev, class_intf);
}
up(&parent->sem);
class_put(parent);
}
int __init classes_init(void)
{
int retval;
retval = subsystem_register(&class_subsys);
if (retval)
return retval;
/* ick, this is ugly, the things we go through to keep from showing up
* in sysfs... */
subsystem_init(&class_obj_subsys);
if (!class_obj_subsys.kset.subsys)
class_obj_subsys.kset.subsys = &class_obj_subsys;
return 0;
}
EXPORT_SYMBOL_GPL(class_create_file);
EXPORT_SYMBOL_GPL(class_remove_file);
EXPORT_SYMBOL_GPL(class_register);
EXPORT_SYMBOL_GPL(class_unregister);
EXPORT_SYMBOL_GPL(class_get);
EXPORT_SYMBOL_GPL(class_put);
EXPORT_SYMBOL_GPL(class_create);
EXPORT_SYMBOL_GPL(class_destroy);
EXPORT_SYMBOL_GPL(class_device_register);
EXPORT_SYMBOL_GPL(class_device_unregister);
EXPORT_SYMBOL_GPL(class_device_initialize);
EXPORT_SYMBOL_GPL(class_device_add);
EXPORT_SYMBOL_GPL(class_device_del);
EXPORT_SYMBOL_GPL(class_device_get);
EXPORT_SYMBOL_GPL(class_device_put);
EXPORT_SYMBOL_GPL(class_device_create);
EXPORT_SYMBOL_GPL(class_device_destroy);
EXPORT_SYMBOL_GPL(class_device_create_file);
EXPORT_SYMBOL_GPL(class_device_remove_file);
EXPORT_SYMBOL_GPL(class_device_create_bin_file);
EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
EXPORT_SYMBOL_GPL(class_interface_register);
EXPORT_SYMBOL_GPL(class_interface_unregister);
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