13. UART

13.1. Hardware interface

Core-3588L The following figure shows the serial port of the hardware version：

13.2. DTS config

File path kernel-5.10/arch/arm64/boot/dts/rockchip/aio-3588l.dtsi There is one M.2 SATA interface on the development board AIO-3588L

#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

After the serial port is configured, the node corresponding to the hardware interface

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

13.3. UART send and receive

The easiest way to do this is to stub the UART7 TX RX pin and then use the command to execute the command in the debug serial port or ADB

busybox  stty -echo -F /dev/ttyS7          # Close the echo
cat /dev/ttyS7 &                           # Get /dev/ttyS7 
echo "firefly uart test..." > /dev/ttyS7   # Input string

The final debugging serial port terminal can receive the string “firefly uart test…”