ARM Linux实时时钟RTC示例程序
ARM Linux实时时钟RTC示例程序，如下：/********************************************************************
* copyright (C) 2014 all rights reserved
* @file: rtc_test.c
* @Created: 2014-8-7 10:30
* @Author: conway chen
* @Description: read and write rtc time
* @Modify Date: 2014-8-7 10:30
*********************************************************************/
#include <stdio.h>
#include <linux/rtc.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <string.h>
static const char default_rtc[] = "/dev/rtc0";
static char *program_name;
/**
* @brief: print help message
*/
static void help(void)
{
fprintf(stderr,
"\tUsage: %s ...\n"
"\t-h,--help help\n"
"\t-s,--set set date/time given with you.\n\tinput format:./rtc_test \n"
"\t-r,--show read hardware clock and print result\n"
"\n", program_name);
}
/**
* @brief: read RTC date and time
* @Param: fd: the file descriptor of rtc device
*/
void rtc_read_time(int fd)
{
int retval;
struct rtc_time rtc_tm;
/*read the RTC time/date*/
retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
if (retval == -1) {
perror("RTC_RD_TIME ioctl");
exit(errno);
}
fprintf(stderr, "\n\tCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n\n",
rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
}
/**
* @brief: set rtc date and time
* @Param: fd: the file descriptor of rtc device
* @Param: hour: the hour to set
* @Param: minute: the minute to set
* @Param: second: the hour to set
* @Param: year: the year to set
* @Param: month: the month to set
* @Param: day: the day to set
*/
void rtc_set_time(int fd, int hour, int minute, int second, int year, int month, int day)
{
int retval;
struct rtc_time rtc_tm;
rtc_tm.tm_mday = day;
rtc_tm.tm_mon = month - 1;
rtc_tm.tm_year = year - 1900;
rtc_tm.tm_hour = hour;
rtc_tm.tm_min = minute;
rtc_tm.tm_wday = rtc_tm.tm_yday = rtc_tm.tm_isdst = 0;
rtc_tm.tm_sec = second;
/*set the RTC time/date*/
retval = ioctl(fd, RTC_SET_TIME, &rtc_tm);
if (retval == -1) {
perror("RTC_SET_TIME ioctl");
exit(errno);
}
fprintf(stderr, "\n\t\tdate/time is updated to:%d-%d-%d, %02d:%02d:%02d.\n\n",
rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
}
/**
* @brief: main function
* @Param: argc: number of parameters
* @Param: argv: parameters list
*/
int main(int argc, char *argv[])
{
int fd, retval, c;
int set_flag = 0, read_flag = 0;
struct rtc_time rtc_tm;
const char *rtc = default_rtc;
struct option long_option[] =
{
{"help", 0, NULL, 'h'},
{"set", 1, NULL, 's'},
{"show", 0, NULL, 'r'},
{NULL, 0, NULL, 0},
};
program_name = argv;
while (1) {
if ((c = getopt_long(argc, argv, "hs:r", long_option, NULL)) < 0)
break;
switch (c) {
case 'h':
help();
break;
case 's':
if (argc < 8) {
fprintf(stderr, "\n\t\ttime format error!\n\n");
exit(errno);
}
set_flag = 1;
break;
case 'r':
read_flag = 1;
break;
case '?':
help();
break;
default:
abort ();
}
}
/* open rtc device */
fd = open(rtc, O_RDWR);
if (fd ==-1) {
perror(rtc);
exit(errno);
}
if (argc == 1) {
rtc_read_time(fd);
}
if (set_flag)
rtc_set_time(fd, atoi(argv), atoi(argv), atoi(argv), atoi(argv), atoi(argv), atoi(argv));
if (read_flag)
rtc_read_time(fd);
close(fd);
return 0;
}
最后，附上Makefile文件下载：
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