MTKSWITCH_PVID
val = MTKSWITCH_READ(sc, MTKSWITCH_PVID(i));
MTKSWITCH_WRITE(sc, MTKSWITCH_PVID(i), val);
*pvid = (MTKSWITCH_READ(sc, MTKSWITCH_PVID(port)) >> PVID_OFF(port)) &
val = MTKSWITCH_READ(sc, MTKSWITCH_PVID(port));
MTKSWITCH_WRITE(sc, MTKSWITCH_PVID(port), val);