path: root/drivers/base/bus.c

/*
 * bus.c - bus driver management
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2007 Novell Inc.
 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/string.h>
#include "base.h"
#include "power/power.h"

#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)

/*
 * sysfs bindings for drivers
 */

#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)


static int __must_check bus_rescan_devices_helper(struct device *dev,
						void *data);

static struct bus_type *bus_get(struct bus_type *bus)
{
	if (bus) {
		kset_get(&bus->p->subsys);
		return bus;
	}
	return NULL;
}

static void bus_put(struct bus_type *bus)
{
	if (bus)
		kset_put(&bus->p->subsys);
}

static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
			     char *buf)
{
	struct driver_attribute *drv_attr = to_drv_attr(attr);
	struct driver_private *drv_priv = to_driver(kobj);
	ssize_t ret = -EIO;

	if (drv_attr->show)
		ret = drv_attr->show(drv_priv->driver, buf);
	return ret;
}

static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
			      const char *buf, size_t count)
{
	struct driver_attribute *drv_attr = to_drv_attr(attr);
	struct driver_private *drv_priv = to_driver(kobj);
	ssize_t ret = -EIO;

	if (drv_attr->store)
		ret = drv_attr->store(drv_priv->driver, buf, count);
	return ret;
}

static struct sysfs_ops driver_sysfs_ops = {
	.show	= drv_attr_show,
	.store	= drv_attr_store,
};

static void driver_release(struct kobject *kobj)
{
	struct driver_private *drv_priv = to_driver(kobj);

	pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
	kfree(drv_priv);
}

static struct kobj_type driver_ktype = {
	.sysfs_ops	= &driver_sysfs_ops,
	.release	= driver_release,
};

/*
 * sysfs bindings for buses
 */
static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
			     char *buf)
{
	struct bus_attribute *bus_attr = to_bus_attr(attr);
	struct bus_type_private *bus_priv = to_bus(kobj);
	ssize_t ret = 0;

	if (bus_attr->show)
		ret = bus_attr->show(bus_priv->bus, buf);
	return ret;
}

static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
			      const char *buf, size_t count)
{
	struct bus_attribute *bus_attr = to_bus_attr(attr);
	struct bus_type_private *bus_priv = to_bus(kobj);
	ssize_t ret = 0;

	if (bus_attr->store)
		ret = bus_attr->store(bus_priv->bus, buf, count);
	return ret;
}

static struct sysfs_ops bus_sysfs_ops = {
	.show	= bus_attr_show,
	.store	= bus_attr_store,
};

int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
{
	int error;
	if (bus_get(bus)) {
		error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
		bus_put(bus);
	} else
		error = -EINVAL;
	return error;
}
EXPORT_SYMBOL_GPL(bus_create_file);

void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
{
	if (bus_get(bus)) {
		sysfs_remove_file(&bus->p