UART 使用

硬件

AIO-3588L 硬件版本的串口接口图如下：


DTS配置

文件路径"kernel-5.10/arch/arm64/boot/dts/rockchip/aio-3588l.dtsi" 其中
UART3可配置为CAN1,默认公版sdk都是配置为UART3,如果需要配置为CAN1,只需要
配置CAN1_OR_UART3为1

   #define CAN1_OR_UART3 0 /*1 = CAN1 , 0 = UART3 */
   ...
   ...
   ...
   //ext gpio
   &uart6 {
       pinctrl-names = "default";
       pinctrl-0 = <&uart6m1_xfer &uart6m1_ctsn &uart6m1_rtsn>;
       status = "okay";
   };

   &uart7 {
       pinctrl-names = "default";
       pinctrl-0 = <&uart7m1_xfer>;
       status = "okay";
   };

   &uart8 {
       pinctrl-names = "default";
       pinctrl-0 = <&uart8m1_xfer>;
       status = "okay";
   };

   #if CAN1_OR_UART3
   &can1 {
       status = "okay";
       assigned-clocks = <&cru CLK_CAN1>;
       assigned-clock-rates = <200000000>;
       pinctrl-names = "default";
       pinctrl-0 = <&can1m0_pins>;
   };
   #else
   &uart3 {
       pinctrl-names = "default";
       pinctrl-0 = <&uart3m1_xfer>;
       status = "okay";
   };
   #endif

配置好串口后，硬件接口对应软件上的节点为：

   UART3:   /dev/ttyS3
   UART6:   /dev/ttyS6
   UART7:   /dev/ttyS7
   UART8:   /dev/ttyS8

UART 收发验证

最简单的方式短接UART7 TX RX 引脚, 然后使用命令在调试串口或ADB执行命令

   busybox  stty -echo -F /dev/ttyS7          # 关闭回显
   cat /dev/ttyS7 &                           # 后台获取/dev/ttyS7输入字符串
   echo "firefly uart test..." > /dev/ttyS7   # 输入字符串

最终调试串口终端即可接收到字符串 "firefly uart test..."