EMS/drv/drv_uart.c

#include "drv_uart.h"

int drv_uart_open(char *dev, int32_t baudrate, int32_t databit, char parity, char stopbit)
{
    int devFd = open(dev, O_RDWR | O_NONBLOCK| O_NOCTTY | O_NDELAY);
    if(devFd == -1) {
        printf("open uart failed\n");
    }
    else {
        struct termios oldtio, newtio;
        memset(&newtio, 0, sizeof(newtio));
        speed_t speed;
        switch (baudrate)
        {
        case 9600: 
            speed = B9600;
            break;
        case 38400:
            speed = B38400;
            break;
        case 115200:
            speed = B115200;
            break;
        default:
            speed = B115200;
            break;
        }

        switch (databit)
        {
		case 8:
			newtio.c_cflag |= CS8;
			break;
		case 7:
			newtio.c_cflag |= CS7;
			break;
		case 6:
			newtio.c_cflag |= CS6;
			break;
		case 5:
			newtio.c_cflag |= CS5;
			break;
		default:
			newtio.c_cflag |= CS8;
			break;
        }

        switch (parity)
        {
		case 'N': 
			newtio.c_cflag &= ~PARENB;
			break;
		case 'E':
			newtio.c_cflag |= PARENB;
			newtio.c_cflag &= ~PARODD;
			break;
		case 'O':
            newtio.c_cflag |= (PARENB | PARODD);
			break;
		default:
			newtio.c_cflag &= ~PARENB;
			break;
        }

        switch (stopbit)
        {
        case '1':
            newtio.c_cflag &= ~CSTOPB;
            break;
        case '2':
            newtio.c_cflag |= CSTOPB; 
        default:
            newtio.c_cflag &= ~CSTOPB;
            break;
        }
        
        newtio.c_cflag |= (CLOCAL | CREAD);      /* | CRTSCTS */
        newtio.c_oflag &= ~OPOST;
        newtio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
        newtio.c_cc[VTIME] 	= 1;        /* unit: 1/10 second. */
        newtio.c_cc[VMIN]   = 255; /* minimal characters for reading */
        tcflush(devFd, TCIFLUSH);  
        tcsetattr(devFd, TCSANOW, &newtio); 
    }
    return devFd;
}