static ssize_t set_brightness(struct device *dev, const char *buf,
static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf,
static ssize_t set_brightness(struct device *dev, const char *buf, 			      size_t count){	struct usb_interface *intf = to_usb_interface(dev);	struct usb_cytherm *cytherm = usb_get_intfdata(intf);	unsigned char *buffer;	int retval;   	buffer = kmalloc(8, GFP_KERNEL);	if (!buffer) {		dev_err(&cytherm->udev->dev, "out of memory\n");		return 0;	}	cytherm->brightness = simple_strtoul(buf, NULL, 10);   	if (cytherm->brightness > 0xFF)		cytherm->brightness = 0xFF;	else if (cytherm->brightness < 0)		cytherm->brightness = 0;   	/* Set brightness */	retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 				cytherm->brightness, buffer, 8);	if (retval)		dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);	/* Inform C that we have changed the brightness setting */	retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,				0x01, buffer, 8);	if (retval)		dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);   	kfree(buffer);   	return count;}