RTK_TXCFG
CSR_WRITE_4(sc, RTK_TXCFG,
CSR_WRITE_4(sc, RTK_TXCFG, RE_TXCFG_CONFIG);
sc->sc_hwrev = CSR_READ_4(sc, RTK_TXCFG) & RTK_TXCFG_HWREV;
CSR_WRITE_4(sc, RTK_TXCFG, RTK_TXCFG_CONFIG);
CSR_WRITE_4(sc, RTK_TXCFG, RTK_TXCFG_CONFIG);
hwrev = CSR_READ_4(sc, RTK_TXCFG) & RTK_TXCFG_HWREV;