linux/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 "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 = 0;
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 = 0;
if (class_attr->store)
ret = class_attr->store(dc, buf, count);
return ret;
}
static void class_release(struct kobject * kobj)
{
struct class *class = to_class(kobj);
pr_debug("class '%s': release.\n", class->name);
if (class->class_release)
class->class_release(class);
else
pr_debug("class '%s' does not have a release() function, "
"be careful\n", class->name);
}
static struct sysfs_ops class_sysfs_ops = {
.show = class_attr_show,
.store = class_attr_store,
};
static struct kobj_type ktype_class = {
.sysfs_ops = &class_sysfs_ops,
.release = class_release,
};
/* Hotplug events for classes go to the class_obj subsys */
static decl_subsys(class, &ktype_class, NULL);
int class_create_file(struct class * cls, const struct class_attribute * attr)
{
int error;
if (cls) {
error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
} else
error = -EINVAL;
return error;
}
void class_remove_file(struct class * cls, const struct class_attribute * attr)
{
if (cls)
sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
}
struct class * class_get(struct class * cls)
{
if (cls)
return container_of(subsys_get(&cls->subsys), struct class, subsys);
return NULL;
}
void class_put(struct class * cls)
{
subsys_put(&cls->subsys);
}
static int add_class_attrs(struct class * cls)
{
int i;
int error = 0;
if (cls->class_attrs) {
for (i = 0; attr_name(cls->class_attrs[i]); i++) {
error = class_create_file(cls,&cls->class_attrs[i]);
if (error)
goto Err;
}
}
Done:
return error;
Err:
while (--i >= 0)
class_remove_file(cls,&cls->class_attrs[i]);
goto Done;
}
static void remove_class_attrs(struct class * cls)
{
int i;
if (cls->class_attrs) {
for (i = 0; attr_name(cls->class_attrs[i]); i++)
class_remove_file(cls,&cls->class_attrs[i]);
}
}
int class_register(struct class * cls)
{
int error;
pr_debug("device class '%s': registering\n", cls->name);
INIT_LIST_HEAD(&cls->children);
INIT_LIST_HEAD(&cls->interfaces);
init_MUTEX(&cls->sem);
error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
if (error)
return error;
subsys_set_kset(cls, class_subsys);
error = subsystem_register(&cls->subsys);
if (!error) {
error = add_class_attrs(class_get(cls));
class_put(cls);
}
return error;
}
void class_unregister(struct class * cls)
{
pr_debug("device class '%s': unregistering\n", cls->name);
remove_class_attrs(cls);
subsystem_unregister(&cls->subsys);
}
/* 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);
if (cls->release)
cls->release(cd);
else {
printk(KERN_ERR "Device class '%s' does not have a release() function, "
"it is broken and must be fixed.\n",
cd->class_id);
WARN_ON(1);
}
}
static struct kobj_type ktype_class_device = {
.sysfs_ops = &class_dev_sysfs_ops,
.release = class_dev_release,
};
static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
{
struct kobj_type *ktype = get_ktype(kobj);
if (ktype == &ktype_class_device) {
struct class_device *class_dev = to_class_dev(kobj);
if (class_dev->class)
return 1;
}
return 0;
}
static char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
{
struct class_device *class_dev = to_class_dev(kobj);
return class_dev->class->name;
}
static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
int num_envp, char *buffer, int buffer_size)
{
struct class_device *class_dev = to_class_dev(kobj);
int i = 0;
int length = 0;
int retval = 0;
pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
if (class_dev->dev) {
/* add physical device, backing this device */
struct device *dev = class_dev->dev;
char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
&length, "PHYSDEVPATH=%s", path);
kfree(path);
if (dev->bus)
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVBUS=%s", dev->bus->name);
if (dev->driver)
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVDRIVER=%s", dev->driver->name);
}
if (MAJOR(class_dev->devt)) {
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MAJOR=%u", MAJOR(class_dev->devt));
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MINOR=%u", MINOR(class_dev->devt));
}
/* terminate, set to next free slot, shrink available space */
envp[i] = NULL;
envp = &envp[i];
num_envp -= i;
buffer = &buffer[length];
buffer_size -= length;
if (class_dev->class->hotplug) {
/* have the bus specific function add its stuff */
retval = class_dev->class->hotplug (class_dev, envp, num_envp,
buffer, buffer_size);
if (retval) {
pr_debug ("%s - hotplug() returned %d\n",
__FUNCTION__, retval);
}
}
return retval;
}
static struct kset_hotplug_ops class_hotplug_ops = {
.filter = class_hotplug_filter,
.name = class_hotplug_name,
.hotplug = class_hotplug,
};
static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
static int class_device_add_attrs(struct class_device * cd)
{
int i;
int error = 0;
struct class * cls = cd->class;
if (cls->class_dev_attrs) {
for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
error = class_device_create_file(cd,
&cls->class_dev_attrs[i]);
if (error)
goto Err;
}
}
Done:
return error;
Err:
while (--i >= 0)
class_device_remove_file(cd,&cls->class_dev_attrs[i]);
goto Done;
}
static void class_device_remove_attrs(struct class_device * cd)
{
int i;
struct class * cls = cd->class;
if (cls->class_dev_attrs) {
for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
class_device_remove_file(cd,&cls->class_dev_attrs[i]);
}
}
static ssize_t show_dev(struct class_device *class_dev, char *buf)
{
return print_dev_t(buf, class_dev->devt);
}
static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
void class_device_initialize(struct class_device *class_dev)
{
kobj_set_kset_s(class_dev, class_obj_subsys);
kobject_init(&class_dev->kobj);
INIT_LIST_HEAD(&class_dev->node);
}
int class_device_add(struct class_device *class_dev)
{
struct class * parent = NULL;
struct class_interface * class_intf;
int error;
class_dev = class_device_get(class_dev);
if (!class_dev)
return -EINVAL;
if (!strlen(class_dev->class_id)) {
error = -EINVAL;
goto register_done;
}
parent = class_get(class_dev->class);
pr_debug("CLASS: registering class device: ID = '%s'\n",
class_dev->class_id);
/* first, register with generic layer. */
kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
if (parent)
class_dev->kobj.parent = &parent->subsys.kset.kobj;
if ((error = kobject_add(&class_dev->kobj)))
goto register_done;
/* now take care of our own registration */
if (parent) {
down(&parent->sem);
list_add_tail(&class_dev->node, &parent->children);
list_for_each_entry(class_intf, &parent->interfaces, node)
if (class_intf->add)
class_intf->add(class_dev);
up(&parent->sem);
}
if (MAJOR(class_dev->devt))
class_device_create_file(class_dev, &class_device_attr_dev);
class_device_add_attrs(class_dev);
if (class_dev->dev)
sysfs_create_link(&class_dev->kobj,
&class_dev->dev->kobj, "device");
register_done:
if (error && parent)
class_put(parent);
class_device_put(class_dev);
return error;
}
int class_device_register(struct class_device *class_dev)
{
class_device_initialize(class_dev);
return class_device_add(class_dev);
}
void class_device_del(struct class_device *class_dev)
{
struct class * parent = class_dev->class;
struct class_interface * class_intf;
if (parent) {
down(&parent->sem);
list_del_init(&class_dev->node);
list_for_each_entry(class_intf, &parent->interfaces, node)
if (class_intf->remove)
class_intf->remove(class_dev);
up(&parent->sem);
}
if (class_dev->dev)
sysfs_remove_link(&class_dev->kobj, "device");
class_device_remove_attrs(class_dev);
kobject_del(&class_dev->kobj);
if (parent)
class_put(parent);
}
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);
}
int class_device_rename(struct class_device *class_dev, char *new_name)
{
int error = 0;
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);
strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
error = kobject_rename(&class_dev->kobj, new_name);
class_device_put(class_dev);
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)
{
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);
}
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);
}
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_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_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);