1 /*
2 * Real Time Clock Driver Test/Example Program
3 *
4 * Compile with:
5 * gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
6 *
7 * Copyright (C) 1996, Paul Gortmaker.
8 *
9 * Released under the GNU General Public License, version 2,
10 * included herein by reference.
11 *
12 */
13
14 #include <stdio.h>
15 #include <linux/rtc.h>
16 #include <sys/ioctl.h>
17 #include <sys/time.h>
18 #include <sys/types.h>
19 #include <fcntl.h>
20 #include <unistd.h>
21 #include <stdlib.h>
22 #include <errno.h>
23
24
25 /*
26 * This expects the new RTC class driver framework, working with
27 * clocks that will often not be clones of what the PC-AT had.
28 * Use the command line to specify another RTC if you need one.
29 */
30 static const char default_rtc[] = "/dev/rtc0";
31
32
main(int argc,char ** argv)33 int main(int argc, char **argv)
34 {
35 int i, fd, retval, irqcount = 0;
36 unsigned long tmp, data;
37 struct rtc_time rtc_tm;
38 const char *rtc = default_rtc;
39 struct timeval start, end, diff;
40
41 switch (argc) {
42 case 2:
43 rtc = argv[1];
44 /* FALLTHROUGH */
45 case 1:
46 break;
47 default:
48 fprintf(stderr, "usage: rtctest [rtcdev]\n");
49 return 1;
50 }
51
52 fd = open(rtc, O_RDONLY);
53
54 if (fd == -1) {
55 perror(rtc);
56 exit(errno);
57 }
58
59 fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
60
61 /* Turn on update interrupts (one per second) */
62 retval = ioctl(fd, RTC_UIE_ON, 0);
63 if (retval == -1) {
64 if (errno == EINVAL) {
65 fprintf(stderr,
66 "\n...Update IRQs not supported.\n");
67 goto test_READ;
68 }
69 perror("RTC_UIE_ON ioctl");
70 exit(errno);
71 }
72
73 fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
74 rtc);
75 fflush(stderr);
76 for (i=1; i<6; i++) {
77 /* This read will block */
78 retval = read(fd, &data, sizeof(unsigned long));
79 if (retval == -1) {
80 perror("read");
81 exit(errno);
82 }
83 fprintf(stderr, " %d",i);
84 fflush(stderr);
85 irqcount++;
86 }
87
88 fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
89 fflush(stderr);
90 for (i=1; i<6; i++) {
91 struct timeval tv = {5, 0}; /* 5 second timeout on select */
92 fd_set readfds;
93
94 FD_ZERO(&readfds);
95 FD_SET(fd, &readfds);
96 /* The select will wait until an RTC interrupt happens. */
97 retval = select(fd+1, &readfds, NULL, NULL, &tv);
98 if (retval == -1) {
99 perror("select");
100 exit(errno);
101 }
102 /* This read won't block unlike the select-less case above. */
103 retval = read(fd, &data, sizeof(unsigned long));
104 if (retval == -1) {
105 perror("read");
106 exit(errno);
107 }
108 fprintf(stderr, " %d",i);
109 fflush(stderr);
110 irqcount++;
111 }
112
113 /* Turn off update interrupts */
114 retval = ioctl(fd, RTC_UIE_OFF, 0);
115 if (retval == -1) {
116 perror("RTC_UIE_OFF ioctl");
117 exit(errno);
118 }
119
120 test_READ:
121 /* Read the RTC time/date */
122 retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
123 if (retval == -1) {
124 perror("RTC_RD_TIME ioctl");
125 exit(errno);
126 }
127
128 fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
129 rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
130 rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
131
132 /* Set the alarm to 5 sec in the future, and check for rollover */
133 rtc_tm.tm_sec += 5;
134 if (rtc_tm.tm_sec >= 60) {
135 rtc_tm.tm_sec %= 60;
136 rtc_tm.tm_min++;
137 }
138 if (rtc_tm.tm_min == 60) {
139 rtc_tm.tm_min = 0;
140 rtc_tm.tm_hour++;
141 }
142 if (rtc_tm.tm_hour == 24)
143 rtc_tm.tm_hour = 0;
144
145 retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
146 if (retval == -1) {
147 if (errno == ENOTTY) {
148 fprintf(stderr,
149 "\n...Alarm IRQs not supported.\n");
150 goto test_PIE;
151 }
152 perror("RTC_ALM_SET ioctl");
153 exit(errno);
154 }
155
156 /* Read the current alarm settings */
157 retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
158 if (retval == -1) {
159 perror("RTC_ALM_READ ioctl");
160 exit(errno);
161 }
162
163 fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
164 rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
165
166 /* Enable alarm interrupts */
167 retval = ioctl(fd, RTC_AIE_ON, 0);
168 if (retval == -1) {
169 perror("RTC_AIE_ON ioctl");
170 exit(errno);
171 }
172
173 fprintf(stderr, "Waiting 5 seconds for alarm...");
174 fflush(stderr);
175 /* This blocks until the alarm ring causes an interrupt */
176 retval = read(fd, &data, sizeof(unsigned long));
177 if (retval == -1) {
178 perror("read");
179 exit(errno);
180 }
181 irqcount++;
182 fprintf(stderr, " okay. Alarm rang.\n");
183
184 /* Disable alarm interrupts */
185 retval = ioctl(fd, RTC_AIE_OFF, 0);
186 if (retval == -1) {
187 perror("RTC_AIE_OFF ioctl");
188 exit(errno);
189 }
190
191 test_PIE:
192 /* Read periodic IRQ rate */
193 retval = ioctl(fd, RTC_IRQP_READ, &tmp);
194 if (retval == -1) {
195 /* not all RTCs support periodic IRQs */
196 if (errno == ENOTTY) {
197 fprintf(stderr, "\nNo periodic IRQ support\n");
198 goto done;
199 }
200 perror("RTC_IRQP_READ ioctl");
201 exit(errno);
202 }
203 fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
204
205 fprintf(stderr, "Counting 20 interrupts at:");
206 fflush(stderr);
207
208 /* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
209 for (tmp=2; tmp<=64; tmp*=2) {
210
211 retval = ioctl(fd, RTC_IRQP_SET, tmp);
212 if (retval == -1) {
213 /* not all RTCs can change their periodic IRQ rate */
214 if (errno == ENOTTY) {
215 fprintf(stderr,
216 "\n...Periodic IRQ rate is fixed\n");
217 goto done;
218 }
219 perror("RTC_IRQP_SET ioctl");
220 exit(errno);
221 }
222
223 fprintf(stderr, "\n%ldHz:\t", tmp);
224 fflush(stderr);
225
226 /* Enable periodic interrupts */
227 retval = ioctl(fd, RTC_PIE_ON, 0);
228 if (retval == -1) {
229 perror("RTC_PIE_ON ioctl");
230 exit(errno);
231 }
232
233 for (i=1; i<21; i++) {
234 gettimeofday(&start, NULL);
235 /* This blocks */
236 retval = read(fd, &data, sizeof(unsigned long));
237 if (retval == -1) {
238 perror("read");
239 exit(errno);
240 }
241 gettimeofday(&end, NULL);
242 timersub(&end, &start, &diff);
243 if (diff.tv_sec > 0 ||
244 diff.tv_usec > ((1000000L / tmp) * 1.10)) {
245 fprintf(stderr, "\nPIE delta error: %ld.%06ld should be close to 0.%06ld\n",
246 diff.tv_sec, diff.tv_usec,
247 (1000000L / tmp));
248 fflush(stdout);
249 exit(-1);
250 }
251
252 fprintf(stderr, " %d",i);
253 fflush(stderr);
254 irqcount++;
255 }
256
257 /* Disable periodic interrupts */
258 retval = ioctl(fd, RTC_PIE_OFF, 0);
259 if (retval == -1) {
260 perror("RTC_PIE_OFF ioctl");
261 exit(errno);
262 }
263 }
264
265 done:
266 fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
267
268 close(fd);
269
270 return 0;
271 }
272