Enable the SPI device in device tree

&spi5 {
    status = "okay";
    max-freq = <48000000>;   //spi internal clk, don't modify
    spi_test@00 {
           compatible = "rockchip,spi_test_bus0_cs0";
           reg = <0>;   //chip select  0:cs0  1:cs1
           id = <0>;
           spi-max-frequency = <24000000>;   //spi output clock
             };
 
    spi_test@01 {
           compatible = "rockchip,spi_test_bus0_cs1";
           reg = <1>;
           id = <1>;
           spi-max-frequency = <24000000>;
            };
       };

max-freq: We only support the max 48000000HZ, a large value would result in error.

spi_test@00: Which CS pin is used for this device, it would be the same value for the index of CS pin and reg value.

compatible: The device driver of the SPI device, the string here should match its driver；

id: When you have multiple same devices here, you should assign an unique id for each of them.

spi-max-frequency: The max frequency for this device；

You can find a sample code for the SPI device here:

"drivers/spi/spi-rockchip-test.c"