SPI驱动开发¶
添加设备
设备树
&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>;
};
};
status:如果要启用SPI,则设为okay,如不启用,设为disable;
max-freq:rk3399pro SPI最大支持的速率为48000000,不要修改;
spi_test@00:如果使用CS0,设为00,如果使用CS1,则设为01,并且呀和reg字段一样;
compatible:用于和of_device_id匹配;
id:如果一个SPI驱动操作多个设备时,用于区分;
spi-max-frequency:SPI和当前设备通信速率;
驱动文件
“drivers/spi/spi-rockchip-test.c”