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 
19 static const char default_time[] = "00:00:00";
20 
21 int 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