// SPDX-License-Identifier: GPL-2.0-or-later /* Real Time Clock Driver Test * by: Benjamin Gaignard (benjamin.gaignard@linaro.org) * * To build * gcc rtctest_setdate.c -o rtctest_setdate */ #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> static const char default_time[] = "00:00:00"; int main(int argc, char **argv) { int fd, retval; struct rtc_time new, current; const char *rtc, *date; const char *time = default_time; switch (argc) { case 4: time = argv[3]; /* FALLTHROUGH */ case 3: date = argv[2]; rtc = argv[1]; break; default: fprintf(stderr, "usage: rtctest_setdate <rtcdev> <DD-MM-YYYY> [HH:MM:SS]\n"); return 1; } fd = open(rtc, O_RDONLY); if (fd == -1) { perror(rtc); exit(errno); } sscanf(date, "%d-%d-%d", &new.tm_mday, &new.tm_mon, &new.tm_year); new.tm_mon -= 1; new.tm_year -= 1900; sscanf(time, "%d:%d:%d", &new.tm_hour, &new.tm_min, &new.tm_sec); fprintf(stderr, "Test will set RTC date/time to %d-%d-%d, %02d:%02d:%02d.\n", new.tm_mday, new.tm_mon + 1, new.tm_year + 1900, new.tm_hour, new.tm_min, new.tm_sec); /* Write the new date in RTC */ retval = ioctl(fd, RTC_SET_TIME, &new); if (retval == -1) { perror("RTC_SET_TIME ioctl"); close(fd); exit(errno); } /* Read back */ retval = ioctl(fd, RTC_RD_TIME, ¤t); if (retval == -1) { perror("RTC_RD_TIME ioctl"); exit(errno); } fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n", current.tm_mday, current.tm_mon + 1, current.tm_year + 1900, current.tm_hour, current.tm_min, current.tm_sec); close(fd); return 0; }