REG_FPGA0_PSD_FUNC
rtl8xxxu_write32(priv, REG_FPGA0_PSD_FUNC, frequencies[channel]);
rtl8xxxu_write32(priv, REG_FPGA0_PSD_FUNC, 0x400000 | frequencies[channel]);
rtl8xxxu_write32(priv, REG_FPGA0_PSD_FUNC, frequencies[channel]);