/*
* Real Time Clock Driver Test/Example Program
*
* Compile with:
* gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
*
* Copyright (C) 1996, Paul Gortmaker.
*
* Released under the GNU General Public License, version 2,
* included herein by reference.
*
*/
#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>
/*
* This expects the new RTC class driver framework, working with
* clocks that will often not be clones of what the PC-AT had.
* Use the command line to specify another RTC if you need one.
*/
static const char default_rtc[] = "/dev/rtc0";
int main(int argc, char **argv)
{
int i, fd, retval, irqcount = 0;
unsigned long tmp, data;
struct rtc_time rtc_tm;
const char *rtc = default_rtc;
struct timeval start, end, diff;
switch (argc) {
case 2:
rtc = argv[1];
/* FALLTHROUGH */
case 1:
break;
default:
fprintf(stderr, "usage: rtctest [rtcdev]\n");
return 1;
}
fd = open(rtc, O_RDONLY);
if (fd == -1) {
perror(rtc);
exit(errno);
}
fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
/* Turn on update interrupts (one per second) */
retval = ioctl(fd, RTC_UIE_ON, 0);
if (retval == -1) {
if (errno == EINVAL) {
fprintf(stderr,
"\n...Update IRQs not supported.\n");
goto test_READ;
}
perror("RTC_UIE_ON ioctl");
exit(errno);
}
fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
rtc);
fflush(stderr);
for (i=1; i<6; i++) {
/* This read will block */
retval = read(fd, &data, sizeof(unsigned long));
if (retval == -1) {
perror("read");
exit(errno);
}
fprintf(stderr, " %d",i);
fflush(stderr);
irqcount++;
}
fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
fflush(stderr);
for (i=1; i<6; i++) {
struct timeval tv = {5, 0}; /* 5 second timeout on select */
fd_set readfds;
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
/* The select will wait until an RTC interrupt happens. */
retval = select(fd+1, &readfds, NULL, NULL, &tv);
if (retval == -1) {
perror("select");
exit(errno);
}
/* This read won't block unlike the select-less case above. */
retval = read(fd, &data, sizeof(unsigned long));
if (retval == -1) {
perror("read");
exit(errno);
}
fprintf(stderr, " %d",i);
fflush(stderr);
irqcount++;
}
/* Turn off update interrupts */
retval = ioctl(fd, RTC_UIE_OFF, 0);
if (retval == -1) {
perror("RTC_UIE_OFF ioctl");
exit(errno);
}
test_READ:
/* 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\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\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);
/* Set the alarm to 5 sec in the future, and check for rollover */
rtc_tm.tm_sec += 5;
if (rtc_tm.tm_sec >= 60) {
rtc_tm.tm_sec %= 60;
rtc_tm.tm_min++;
}
if (rtc_tm.tm_min == 60) {
rtc_tm.tm_min = 0;
rtc_tm.tm_hour++;
}
if (rtc_tm.tm_hour == 24)
rtc_tm.tm_hour = 0;
retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
if (retval == -1) {
if (errno == EINVAL) {
fprintf(stderr,
"\n...Alarm IRQs not supported.\n");
goto test_PIE;
}
perror("RTC_ALM_SET ioctl");
exit(errno);
}
/* Read the current alarm settings */
retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
if (retval == -1) {
perror("RTC_ALM_READ ioctl");
exit(errno);
}
fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
/* Enable alarm interrupts */
retval = ioctl(fd, RTC_AIE_ON, 0);
if (retval == -1) {
if (errno == EINVAL) {
fprintf(stderr,
"\n...Alarm IRQs not supported.\n");
goto test_PIE;
}
perror("RTC_AIE_ON ioctl");
exit(errno);
}
fprintf(stderr, "Waiting 5 seconds for alarm...");
fflush(stderr);
/* This blocks until the alarm ring causes an interrupt */
retval = read(fd, &data, sizeof(unsigned long));
if (retval == -1) {
perror("read");
exit(errno);
}
irqcount++;
fprintf(stderr, " okay. Alarm rang.\n");
/* Disable alarm interrupts */
retval = ioctl(fd, RTC_AIE_OFF, 0);
if (retval == -1) {
perror("RTC_AIE_OFF ioctl");
exit(errno);
}
test_PIE:
/* Read periodic IRQ rate */
retval = ioctl(fd, RTC_IRQP_READ, &tmp);
if (retval == -1) {
/* not all RTCs support periodic IRQs */
if (errno == EINVAL) {
fprintf(stderr, "\nNo periodic IRQ support\n");
goto done;
}
perror("RTC_IRQP_READ ioctl");
exit(errno);
}
fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
fprintf(stderr, "Counting 20 interrupts at:");
fflush(stderr);
/* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
for (tmp=2; tmp<=64; tmp*=2) {
retval = ioctl(fd, RTC_IRQP_SET, tmp);
if (retval == -1) {
/* not all RTCs can change their periodic IRQ rate */
if (errno == EINVAL) {
fprintf(stderr,
"\n...Periodic IRQ rate is fixed\n");
goto done;
}
perror("RTC_IRQP_SET ioctl");
exit(errno);
}
fprintf(stderr, "\n%ldHz:\t", tmp);
fflush(stderr);
/* Enable periodic interrupts */
retval = ioctl(fd, RTC_PIE_ON, 0);
if (retval == -1) {
perror("RTC_PIE_ON ioctl");
exit(errno);
}
for (i=1; i<21; i++) {
gettimeofday(&start, NULL);
/* This blocks */
retval = read(fd, &data, sizeof(unsigned long));
if (retval == -1) {
perror("read");
exit(errno);
}
gettimeofday(&end, NULL);
timersub(&end, &start, &diff);
if (diff.tv_sec > 0 ||
diff.tv_usec > ((1000000L / tmp) * 1.10)) {
fprintf(stderr, "\nPIE delta error: %ld.%06ld should be close to 0.%06ld\n",
diff.tv_sec, diff.tv_usec,
(1000000L / tmp));
fflush(stdout);
exit(-1);
}
fprintf(stderr, " %d",i);
fflush(stderr);
irqcount++;
}
/* Disable periodic interrupts */
retval = ioctl(fd, RTC_PIE_OFF, 0);
if (retval == -1) {
perror("RTC_PIE_OFF ioctl");
exit(errno);
}
}
done:
fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
close(fd);
return 0;
}
