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