switch (cmd) {
        case TIOCSRS485:
-               if (copy_from_user(&rs485, (struct serial_rs485 *)arg,
-                                  sizeof(rs485)))
+               if (copy_from_user(&rs485, (void __user *)arg, sizeof(rs485)))
                        return -EFAULT;
                if (rs485.delay_rts_before_send > 0x0f ||
                    rs485.delay_rts_after_send > 0x0f)
                val = max310x_port_read(port, MAX310X_HDPIXDELAY_REG);
                rs485.delay_rts_before_send = val >> 4;
                rs485.delay_rts_after_send = val & 0x0f;
-               if (copy_to_user((struct serial_rs485 *)arg, &rs485,
-                                sizeof(rs485)))
+               if (copy_to_user((void __user *)arg, &rs485, sizeof(rs485)))
                        return -EFAULT;
                return 0;
        default: