AR_PHY_SPECTRAL_SCAN_FFT_PERIOD
ss->ss_fft_period = MS(val, AR_PHY_SPECTRAL_SCAN_FFT_PERIOD);
val &= ~AR_PHY_SPECTRAL_SCAN_FFT_PERIOD;
val |= SM(ss->ss_fft_period, AR_PHY_SPECTRAL_SCAN_FFT_PERIOD);