static ssize_t show_port1(struct device *dev, char *buf)
static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf)
static ssize_t show_port1(struct device *dev, char *buf){	struct usb_interface *intf = to_usb_interface(dev);	struct usb_cytherm *cytherm = usb_get_intfdata(intf);	int retval;	unsigned char *buffer;	buffer = kmalloc(8, GFP_KERNEL);	if (!buffer) {		dev_err(&cytherm->udev->dev, "out of memory\n");		return 0;	}	retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);	if (retval)		dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);   	retval = buffer[1];	kfree(buffer);	return sprintf(buf, "%d", retval);}