static ssize_t ecard_show_device(struct device *dev, char *buf)
static ssize_t ecard_show_device(struct device *dev, struct device_attribute *attr, char *buf)
static ssize_t ecard_show_device(struct device *dev, char *buf){	struct expansion_card *ec = ECARD_DEV(dev);	return sprintf(buf, "%u\n", ec->cid.product);}