Hi
no clue how TPM works, never played with it so far... :)
Well as far I know it is just a LPC device (if it is 1,1 device), make sure the region for that chip is decoded and enable decoding of 0xfed0_0000 (sorry do not remember right range out of my head) in chipset which is needed for special LPC cycles. That is all I know. This special cycles have something in common with SKINIT or maybe with TPM 1.2
http://www.informit.com/articles/article.aspx?p=1154764&seqNum=3
Thanks Rudolf