AGE_MASTER_CFG
CSR_WRITE_4(sc, AGE_MASTER_CFG, MASTER_RESET);
CSR_READ_4(sc, AGE_MASTER_CFG);
reg = CSR_READ_4(sc, AGE_MASTER_CFG);
CSR_WRITE_4(sc, AGE_MASTER_CFG, reg);
sc->age_chip_rev = CSR_READ_4(sc, AGE_MASTER_CFG) >>