Hi,
I'm not sure, but if you look the ioreg dump of MacBooks, some do have the address property under SMBUS, and some don't. That property is in fact injected by the _DSM method in DSDT.
Method (_DSM, 4, NotSerialized)
{
Store (Package (0x08)
{
"refnum",
0x00,
"address",
0x39,
"device-id",
0x0CD2,
"hdet",
0x01
}, Local0)
DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0))
Return (Local0)
}
http://tdev.me/2010/12/apple-hardware-dumps/