Acer Labs M5287 SATA not configured

[Matt Jibson]

While trying to install -current on a new machine (amd64, asus
A8R-MX/DP board), the install script failed complaining about no
disks. There is an unconfigured SATA controller listed in the dmesg:
"Acer Labs M5287 SATA" rev 0x02 ay pci0 dev 31 function 1 not configured
Is it possible to get this device supported easily, or does it require
a new driver?