Good news!
I've managed to get the touchpad working using the VoodooI2C and VoodooI2CHID kexts and by changing a few things in the DSDT:
First, make sure _STA in GPI0 device only returns 0x0F
Then, make sure _CRS in every TPD0 instance only returns
Code:
ConcatenateResTemplate (SBFB, SBFI)
For convenience I've created this DSDT patch (paste in MaciASL patch window):
Code:
into method label _STA parent_label GPI0 replace_content begin
Return (0x0F)
end;
into_all method label _CRS parent_label TPD0 replace_content begin
ConcatenateResTemplate (SBFB, SBFI)
end;
Also, the info.plist of the VoodooI2C needs to be edited so that it will load with the I2C controller. Under IOKitPersonalities > VoodooI2CPCIController > IONameMatch add a field with a string value of pci8086,a368 (Could probably be done with a clover kext patch / will probably be fixed in a later version of VoodooI2C)
P.S. scroll and some gestures seem to work as well, which is a nice bonus!