78 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/* Real Time Clock Driver Test3 * by: Benjamin Gaignard (benjamin.gaignard@linaro.org)4 *5 * To build6 * gcc rtctest_setdate.c -o rtctest_setdate7 */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, ¤t);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