ret = dev_attr->store(dev, buf, count);
ret = dev_attr->store(dev, dev_attr, buf, count);
dev_attr_store(struct kobject * kobj, struct attribute * attr,	       const char * buf, size_t count){	struct device_attribute * dev_attr = to_dev_attr(attr);	struct device * dev = to_dev(kobj);	ssize_t ret = -EIO;	if (dev_attr->store)		ret = dev_attr->store(dev, buf, count);	return ret;}