max6900.c

MAX6900是MAXIAM公司出品的实时时钟芯片

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
#include <linux/i2c-dev.h>
#include <asm/errno.h>

#include "max6900.h"

#define I2C_SLAVE 0x0703
#define ID_PHY 0xA0
#define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10)
#define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10)
#define BUF_TO_BIN(buf, x) ((buf[x]-0x30)*10+(buf[x+1])-0x30);

#if DBG
#define _DBGRTCTM(rtctm) printf("%s: secs=%d, mins=%d, hours=%d, mday=%d, " \
                        "mon=%d, wday=%d, year=%d, cent=%d\n", __FUNCTION__, \
                        (rtctm).secs, (rtctm).mins, (rtctm).hours, (rtctm).mday, \
                        (rtctm).mon, (rtctm).wday, (rtctm).year, (rtctm).cent);
#else
#define _DBGRTCTM(rtctm) do{ } while(0);
#endif
#define DISPLAY(rtctm) printf( "%02d%02d-%02d-%02d %02d:%02d:%02d\n",\
				(rtctm).cent,(rtctm).year, (rtctm).mon,(rtctm).mday,\
				(rtctm).hours,(rtctm).mins,(rtctm).secs	);



static int max6900_get_datetime(int file, struct rtc_tm *dt);
static int max6900_set_datetime(int file, struct rtc_tm *dt);
static int max6900_sync_to_sys(int file, struct rtc_tm *dt);

main(int argc, char **argv)
{
	int file;
  	int adapter_nr = 0;
  	char filename[20];
	int  ret;

	struct rtc_tm dt;

	if (argc < 2){
		printf("rtc help:\n\n"
			"rtc -g 	: get date form RTC device\n"
			"rtc -s string 	: set date to RTC device\n"
			"		  string: 20060304050609(2006-03-04 05:06:09)\n"
			"rtc -t 	: sync to system\n");

		exit(1);
	}
  	sprintf(filename, "/dev/i2c-%d", adapter_nr);
  	if ((file = open(filename, O_RDWR)) < 0) {
		perror("No such i2c device!\n");
  	  	exit(1);
  	}
	
	int addr = ID_PHY>>1; /* The I2C address */
	if ((ret = ioctl(file, I2C_SLAVE, addr)) < 0) {
		if(ret ==  -EBUSY)
			printf("Device busy\n");
		if(ret == -EINVAL)
			printf("invalid addr\n");
		printf("No such slave device. %d\n ", ret);
		close(file);
   		exit(1);
  	}
	

	if(argv[1][1] == 'g' )
		max6900_get_datetime(file, &dt);		

	if(argv[1][1] == 's' ){
		char *d = argv[2];
		dt.secs = BUF_TO_BIN(d, 12);
		dt.mins = BUF_TO_BIN(d, 10);
		dt.hours= BUF_TO_BIN(d, 8);
		dt.mday = BUF_TO_BIN(d, 6);
		dt.mon  = BUF_TO_BIN(d, 4);
		dt.year = BUF_TO_BIN(d, 2);
		dt.cent = BUF_TO_BIN(d, 0);

		max6900_set_datetime(file, &dt);
	}
	if(argv[1][1] == 't'){
		max6900_get_datetime(file, &dt);
		max6900_sync_to_sys(file, &dt);	
	}
	close(file);
}


static int 
max6900_get_datetime(int file, struct rtc_tm *dt)
{
        int ret = -EIO;
	int access_addr = 0xBF;
        unsigned char buf[10];
	int i;
	unsigned char reg;
        if (!dt)
                return -EINVAL;

    memset(buf, 0, sizeof(buf));
	buf[0] = RTC6900_REG_SEC1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->secs = BCD_TO_BIN(buf[0] & 0x7f);

	buf[0] = RTC6900_REG_MIN1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->mins = BCD_TO_BIN(buf[0] & 0x7f);

	buf[0] = RTC6900_REG_HR1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->hours = BCD_TO_BIN(buf[0] & 0x3f);

	buf[0] = RTC6900_REG_MDAY1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->mday = BCD_TO_BIN(buf[0] & 0x3f);

	buf[0] = RTC6900_REG_MON1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->mon = BCD_TO_BIN(buf[0] & 0x1f);

	buf[0] = RTC6900_REG_YEAR1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->year = BCD_TO_BIN(buf[0]);

	buf[0] = RTC6900_REG_CENT1;
	write(file, buf , 1);
        ret = read(file, buf, 1);
        if (ret<0){
               	perror("read error!\n");
		exit(1);
	}
        dt->cent = BCD_TO_BIN(buf[0] & 0x3f);
	DISPLAY(*dt);
        _DBGRTCTM(*dt);
        return 0;
}

static int
max6900_set_datetime(int file, struct rtc_tm *dt)
{
        int ret, len = 10;
        unsigned char buf[10];
	unsigned char cmd[30]; 	
	unsigned char * tmp;
        if (!dt)
                return -EINVAL;

        _DBGRTCTM(*dt);

	tmp = cmd;
	sprintf(tmp,"date -s ");
	tmp = tmp + strlen("date -s ");
        buf[0] = RTC6900_REG_MON;
	buf[1] = BIN_TO_BCD(dt->mon);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d",dt->mon);	

	tmp = tmp + 2;
        buf[0] = RTC6900_REG_MDAY;
	buf[1] = BIN_TO_BCD(dt->mday);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d",dt->mday);	
	tmp = tmp + 2;

        buf[0] = RTC6900_REG_HR;
	buf[1] = BIN_TO_BCD(dt->hours);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d",dt->hours);	
	tmp = tmp + 2;
      
	buf[0] = RTC6900_REG_MIN;
	buf[1] = BIN_TO_BCD(dt->mins);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d",dt->mins);	
	tmp = tmp + 2;

        buf[0] = RTC6900_REG_CENT;
	buf[1] = BIN_TO_BCD(dt->cent);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d",dt->cent);	
	tmp = tmp + 2;

        buf[0] = RTC6900_REG_YEAR;
	buf[1] = BIN_TO_BCD(dt->year);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	sprintf(tmp,"%02d.",dt->year);	
	tmp = tmp + 3;
      
	buf[0] = RTC6900_REG_SEC;
	buf[1] = BIN_TO_BCD(dt->secs);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data!\n ");
        }
	sprintf(tmp,"%02d",dt->secs);
	tmp = tmp + 2;

        buf[0] = RTC6900_REG_WDAY;
	buf[1] = BIN_TO_BCD(dt->wday);
	ret = write(file, buf, 2);
        if (ret<0) {
                printf("error writing data! \n");
        }
	system(cmd);

    return ret;
}

static int
max6900_sync_to_sys(int file, struct rtc_tm *dt)
{
	unsigned char cmd[30]; 	
	unsigned char * tmp;
        if (!dt)
                return -EINVAL;

	tmp = cmd;
	sprintf(tmp,"date -s ");
	tmp = tmp + strlen("date -s ");
	sprintf(tmp,"%02d",dt->mon);	
	tmp = tmp + 2;
	sprintf(tmp,"%02d",dt->mday);	
	tmp = tmp + 2;
	sprintf(tmp,"%02d",dt->hours);	
	tmp = tmp + 2;
	sprintf(tmp,"%02d",dt->mins);	
	tmp = tmp + 2;
	sprintf(tmp,"%02d",dt->cent);	
	tmp = tmp + 2;
	sprintf(tmp,"%02d.",dt->year);	
	tmp = tmp + 3;
	sprintf(tmp,"%02d",dt->secs);
	tmp = tmp + 2;

	system(cmd);

    return 0;
}