rtwn_rf_read
static uint32_t rtwn_rf_read(struct rtwn_softc *, int, uint8_t);
sc->rf_chnlbw[i] = rtwn_rf_read(sc, i, R92C_RF_CHNLBW);
rf_ac[i] = rtwn_rf_read(sc, i, R92C_RF_AC);
rtwn_rf_read(sc, 0, R92C_RF_CHNLBW) | R92C_RF_CHNLBW_LCSTART);
temp = rtwn_rf_read(sc, 0, R92C_RF_T_METER) & 0x1f;