if (hz >=24000000) return _AO_SPI_SPEED_24MHz;
if (hz >=12000000) return _AO_SPI_SPEED_12MHz;
if (hz >= 6000000) return _AO_SPI_SPEED_6MHz;
if (hz >=24000000) return _AO_SPI_SPEED_24MHz;
if (hz >=12000000) return _AO_SPI_SPEED_12MHz;
if (hz >= 6000000) return _AO_SPI_SPEED_6MHz;