DM368 Uart0 Linux App

I guess you can use read() and write() system calls to access /dev/ttyS0

hi,

In the camera, root/dev/ don't have a note for ttyS0. I have already checked the ti_davinci/documentation/devices.txt and saw these:

4 char    TTY devices
          0 = /dev/tty0        Current virtual console

          1 = /dev/tty1        First virtual console
            ...
         63 = /dev/tty63    63rd virtual console
         64 = /dev/ttyS0    First UART serial port
            ...
        255 = /dev/ttyS191    192nd UART serial port

        UART serial ports refer to 8250/16450/16550 series devices.

I used command: mknod /dev/ttyS0 c 4 64 to create a node of Serial port. and then used

fd = open(device_name, O_RDWR | O_NDELAY | O_NOCTTY);  // open device

err = write(iface->port_fd, packet->bytes, packet->length); // write data to device

// read data from device

ioctl(iface->port_fd, FIONREAD, &(iface->bytes));

bytes_read=read(iface->port_fd, &iface->ibuf[pos], 1);

Actually, in camera, we have /dev/tts/0 and /dev/tts/1, I guess they are also present to UART0 and UART1 and I tried to do same process with them but no data responses.

I also checked the board-dm368-ipnc.c and saw that UART has already initialized by serial ports 8250.

If you have more idea please give me a hand, thanks.