serial.c

linux下modem初始化测试

#include <stdio.h>   /* Standard input/output definitions */
#include <stdlib.h>
#include <string.h>  /* String function definitions */
#include <unistd.h>  /* UNIX standard function definitions */
#include <fcntl.h>   /* File control definitions */
#include <errno.h>   /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */
#include <sys/time.h>

#include "serial.h"


void delay(int ms)
{
	struct timeval delaytimer;

	delaytimer.tv_sec = ms / 1000;
	delaytimer.tv_usec = (ms % 1000) * 1000;
	select(0, NULL, NULL, NULL, &delaytimer);
	return;
}

int gettickcount()
{
	struct timeval tv;
	struct timezone tz;

	gettimeofday (&tv , &tz);
	return tv.tv_sec*1000 + tv.tv_usec / 1000;
}

int Comm_Wait(int fd, unsigned int secs, unsigned int usecs)
{
    fd_set rfds, testfds;
    struct timeval timer;
    int retval;
    FD_ZERO(&rfds);
    FD_SET(fd, &rfds);
 
    while (1)
    {
        testfds = rfds;
        timer.tv_sec = secs;
        timer.tv_usec = usecs;
        retval = select(fd + 1, &testfds, NULL, NULL, &timer);
        switch (retval)
                {
                    case 0:
                        return retval;
                    case -1:
                                return retval;
                    default:
                                if(FD_ISSET(fd, &testfds))
                            return 1;
                }// end switch
    }
    return 0;
}

/*
打开串口，并设置串口属性，
入口参数：
		devname-设备名称  /dev/ttyS0 /dev/ttyS1......
		termios-保留默认串口属性的指针
		baud-波特率，允许值1200,2400,4800,9600,19200,38400,57600,115200 其他值不允许
		databits－数据位7,8  其他值不允许
		stopbits－停止位 0 1 2
		parity－校验，允许值：'Oo' 'Ee' 'Nn' 'Ss'
返回值：<0 失败
		>0 文件描述符
*/
int _comm_open(const char* devname, struct termios* psaveoptions, int baud, int databits, int stopbits, char parity, char flowControl)
{
	int fd;
	struct termios options;

	fd = open(devname, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
	if (fd == -1)
		return -1;
	else
		fcntl(fd, F_SETFL, FNDELAY);

	if (tcgetattr(fd, psaveoptions) == -1)
	{
		return ERR_GETOPT;
	}

	bzero(&options, sizeof(options));
	speed_t baudRate = B9600;
	switch (baud)
	{
		case 115200:
			baudRate = B115200;
			break;
		case 57600:
			baudRate = B57600;
			break;
		case 38400:
			baudRate = B38400;
			break;
		case 19200:
			baudRate = B19200;
			break;
		case 9600:
			baudRate = B9600;
			break;
		case 4800:
			baudRate = B4800;
			break;
		case 2400:
			baudRate = B2400;
			break;
		case 1200:
			baudRate = B1200;
			break;
		default:
			return ERR_BAUDRATE;
	}//end switch baud
	if ((cfsetispeed(&options, baudRate) == -1) || (cfsetospeed(&options, baudRate) == -1))
	{
		return ERR_BAUDRATE;
	}
	options.c_cflag |= (CLOCAL | CREAD);

	switch (databits)
	{
		case 8:
			options.c_cflag &= ~CSIZE;
			options.c_cflag |= CS8;
			break;
		case 7:
			options.c_cflag &= ~CSIZE;
			options.c_cflag |= CS7;
			break;
		default:
			return ERR_DATABIT;
	}

	switch (stopbits)
	{
		case 0:
		case 1:
			options.c_cflag &= ~CSTOPB;
			break;
		case 2:
			options.c_cflag |= CSTOPB;
			break;
		default:
			return ERR_STOPBIT;
	}

	switch (parity)
	{
		case 'e':		//偶校验
		case 'E':
			options.c_cflag |= PARENB;
			options.c_cflag &= ~PARODD;
			options.c_iflag |= (INPCK | ISTRIP);
			break;
		case 'o':		//奇校验
		case 'O':
			options.c_cflag |= PARENB;
			options.c_cflag |= PARODD;
			options.c_iflag |= (INPCK | ISTRIP);
			break;
		case 'n':		//无校验
		case 'N':
			options.c_cflag &= ~PARENB;
			break;
		case 's':
		case 'S':
			options.c_cflag &= ~PARENB;	//复位奇偶校验标志位 ？？
			options.c_cflag &= ~CSTOPB;	//复位停止位？？
			break;
		default:
			return ERR_PARITY;
	}
	/*
	   if (settings->flowControl != 0)
	   {
	       if (settings->flowControl == 'n')
	       {
	           options.c_cflag &= ~CRTSCTS;
	           options.c_iflag &= ~(IXON | IXOFF | IXANY);
	       }
	       else if (settings->flowControl == 'h')
	       {
	           // DSR signal checked manually during transmission
	           options.c_cflag &= ~CRTSCTS;
	           options.c_iflag &= ~(IXON | IXOFF | IXANY);
	       }
	   }*/

	switch (flowControl)
	{
		case 'h':
		case 'H':
			options.c_cflag |= CRTSCTS;
			options.c_iflag &= ~(IXON | IXOFF | IXANY);
			break;

		case 's':
		case 'S':
			options.c_cflag &= ~CRTSCTS;
			options.c_iflag |= (IXON | IXOFF | IXANY);
			break;
		case 'N':
		case 'n':
			options.c_cflag &= ~CRTSCTS;
			options.c_iflag &= ~(IXON | IXOFF | IXANY);
			break;
		default:
			return ERR_FLOWCONTROL;
	}

	//options.c_cflag &= ~CRTSCTS;
	//options.c_iflag &= ~(IXON | IXOFF | IXANY);

	options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);		//Choosing Raw Input
	options.c_oflag &= ~OPOST; 								//Choosing Raw Output
	options.c_cc[VMIN] = 1;
	options.c_cc[VTIME] = 0;

	tcflush(fd, TCIFLUSH);
	if (tcsetattr(fd, TCSANOW, &options) == -1)
	{
		return ERR_SETOPT;
	}
	return fd;
}


int comm_close(int fd, struct termios* psaveoptions)
{
	tcsetattr(fd, TCSANOW, psaveoptions);
	close(fd);
	return 0;
}


int comm_open(const char* devname, struct termios* psaveoptions, const char* settings)
{

	char* baudToken = NULL;
	char* databitsToken = NULL;
	char* stopbitsToken = NULL;
	char* parityToken = NULL;
	char * flowControlToken = NULL;

	int baud, databits, stopbits;
	char parity, flowControl;
	char databuff[512];


	strncpy(databuff, settings, sizeof(databuff));

	do
	{
		baudToken = (char*)databuff;

		if ((databitsToken      = strstr(baudToken ,    ",")) == NULL) break;
		*databitsToken++ = '\0';

		if ((stopbitsToken      = strstr(databitsToken, ",")) == NULL) break;
		*stopbitsToken++ = '\0';

		if ((parityToken        = strstr(stopbitsToken, ",")) == NULL) break;
		*parityToken++ = '\0';

		if ((flowControlToken   = strstr(parityToken,   ",")) == NULL) break;
		*flowControlToken++ = '\0';
	}
	while (0);

	if ((baudToken == NULL) || (databitsToken == NULL) || (stopbitsToken == NULL) || (parityToken == NULL) || (flowControlToken == NULL) )
	{
		return ERR_SETTING;
	}

	//fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n", baudToken, databitsToken, stopbitsToken, parityToken, flowControlToken);

	baud = atol(baudToken);

	databits = atol(databitsToken);
	if ((databits != 8) && (databits != 7))
	{
		return ERR_SETTING;
	}

	stopbits = atol(stopbitsToken);
	if ((stopbits != 1) && (stopbits != 2))
	{
		return ERR_SETTING;
	}

	if ((strchr(parityToken, 'N') != NULL) || (strchr(parityToken, 'n') != NULL))
	{
		parity = 'N';
	}
	else if ((strchr(parityToken, 'O') != NULL) || (strchr(parityToken, 'o') != NULL))
	{
		parity = 'O';
	}
	else if ((strchr(parityToken, 'E') != NULL) || (strchr(parityToken, 'e') != NULL))
	{
		parity = 'E';
	}
	else if ((strchr(parityToken, 'S') != NULL) || (strchr(parityToken, 's') != NULL))
	{
		parity = 'S';
	}
	else
	{
		return ERR_SETTING;
	}

	if ((strchr(flowControlToken, 'H') != NULL) || (strchr(flowControlToken, 'h') != NULL))
	{
		flowControl = 'h';
	}
	else if ((strchr(flowControlToken, 'S') != NULL) || (strchr(flowControlToken, 's') != NULL))
	{
		flowControl = 's';
	}
	else if ((strchr(flowControlToken, 'N') != NULL) || (strchr(flowControlToken, 'n') != NULL))
	{
		flowControl = 'n';
	}
	else
	{
		return ERR_SETTING;
	}
	return _comm_open(devname, psaveoptions, baud, databits, stopbits, parity, flowControl);
}

int comm_write(int fd,char *buf,int len)
{
	return(write(fd,buf,len));
}

int comm_read(int fd,char *buf,int len,int time)
{
        int bTemp,i;
        memset(buf,0x00,len);
        for(bTemp=0;bTemp<len;){
                i= Comm_Wait(fd, 0, 1);
                if(i==1){
                        i=read(fd,buf+bTemp,len-bTemp);
                }
                if(i>0){
                        bTemp+=i;
                }
                if (gettickcount()>time){
                        return -1;
                }
        }
        return(bTemp);
}


/*
int main()
{
	struct termios oldtio;
	int fd;

	fd = comm_open("/dev/ttyS0", &oldtio, (const char*)"115200, 8, 1, e");

	printf("fd=%d\n", fd);
	comm_close(fd, &oldtio);
	return 0;

}*/