It can be understood from the data manual that SSD20X has a total of 4 serial ports, of which 3 are ordinary uart and one fuart with flow control function:
- Correspondence between serial port and device node
According to the following correspondence:
- Open the serial port
Let’s take opening uart1 as an example to describe the configuration in the kernel when opening a common serial port.
Change the status in DTS to ok:
Configure the corresponding pin as UART_MODE_1:
Load SStar Serial/UART driver:
#cd kernel && ARCH=arm make menuconfig
According to the corresponding relationship between the device node and the serial port, the device node corresponding to uart1 is /dev/ttyS1. Therefore, it is necessary to confirm whether /dev/ttyS1 exists first. If it exists, the node can be operated through the application program to conduct a communication test with the external serial device.