class.c

/*
 * 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/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 <linux/genhd.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.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 class_ktype = {
	.sysfs_ops	= &class_sysfs_ops,