static ssize_t control_store(struct device * dev, struct device_attribute *attr,
			     const char * buf, size_t n)
{
	device_lock(dev);
	if (sysfs_streq(buf, ctrl_auto))
		pm_runtime_allow(dev);
	else if (sysfs_streq(buf, ctrl_on))
		pm_runtime_forbid(dev);
	else
		n = -EINVAL;
	device_unlock(dev);
	return n;
}
static ssize_t control_store(struct device * dev, struct device_attribute *attr,
			     const char * buf, size_t n)
{
	device_lock(dev);
	if (sysfs_streq(buf, ctrl_auto))
		pm_runtime_allow(dev);
	else if (sysfs_streq(buf, ctrl_on))
		pm_runtime_forbid(dev);
	else
		n = -EINVAL;
	device_unlock(dev);
	return n;
}