1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Real Time Clock Driver Test
3 * by: Benjamin Gaignard (benjamin.gaignard@linaro.org)
4 *
5 * To build
6 * gcc rtctest_setdate.c -o rtctest_setdate
7 */
8
9#include <stdio.h>
10#include <linux/rtc.h>
11#include <sys/ioctl.h>
12#include <sys/time.h>
13#include <sys/types.h>
14#include <fcntl.h>
15#include <unistd.h>
16#include <stdlib.h>
17#include <errno.h>
18
19static const char default_time[] = "00:00:00";
20
21int main(int argc, char **argv)
22{
23 int fd, retval;
24 struct rtc_time new, current;
25 const char *rtc, *date;
26 const char *time = default_time;
27
28 switch (argc) {
29 case 4:
30 time = argv[3];
31 /* FALLTHROUGH */
32 case 3:
33 date = argv[2];
34 rtc = argv[1];
35 break;
36 default:
37 fprintf(stderr, "usage: rtctest_setdate <rtcdev> <DD-MM-YYYY> [HH:MM:SS]\n");
38 return 1;
39 }
40
41 fd = open(rtc, O_RDONLY);
42 if (fd == -1) {
43 perror(rtc);
44 exit(errno);
45 }
46
47 sscanf(date, "%d-%d-%d", &new.tm_mday, &new.tm_mon, &new.tm_year);
48 new.tm_mon -= 1;
49 new.tm_year -= 1900;
50 sscanf(time, "%d:%d:%d", &new.tm_hour, &new.tm_min, &new.tm_sec);
51
52 fprintf(stderr, "Test will set RTC date/time to %d-%d-%d, %02d:%02d:%02d.\n",
53 new.tm_mday, new.tm_mon + 1, new.tm_year + 1900,
54 new.tm_hour, new.tm_min, new.tm_sec);
55
56 /* Write the new date in RTC */
57 retval = ioctl(fd, RTC_SET_TIME, &new);
58 if (retval == -1) {
59 perror("RTC_SET_TIME ioctl");
60 close(fd);
61 exit(errno);
62 }
63
64 /* Read back */
65 retval = ioctl(fd, RTC_RD_TIME, &current);
66 if (retval == -1) {
67 perror("RTC_RD_TIME ioctl");
68 exit(errno);
69 }
70
71 fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
72 current.tm_mday, current.tm_mon + 1, current.tm_year + 1900,
73 current.tm_hour, current.tm_min, current.tm_sec);
74
75 close(fd);
76 return 0;
77}
78

source code of linux/tools/testing/selftests/rtc/setdate.c