49000000
&spi0 {
    status = "okay";
    spi_test@00 {
        compatible = "rockchip,spidev";
        reg = <0>;    
        spi-cpha;  
        spi-cpol;    
        spi-lsb-first; 
        spi-max-frequency = <49000000>;  
        status = "okay";
    };
}; 
                         
                         
                     
                    