WRT3200ACM (Marvell 88E6352 switch) PTP, AVB support

Marvell 88E6352 chip in wrt3200acm has hardware support for precision time protocol and avb. What needs to be done to be able to use those features in openwrt? Linux kernel code for DSA mv88e6xxx has code for PTP (not sure about AVB) so is it something that has not yet landed in openwrt or is it specifically disabled?