Linux 4.8.3
[linux/fpc-iii.git] / Documentation / timers / hpet_example.c
blob3ab4993d85e0f79ee7c9a22790315028d3af7d52
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <unistd.h>
4 #include <fcntl.h>
5 #include <string.h>
6 #include <memory.h>
7 #include <malloc.h>
8 #include <time.h>
9 #include <ctype.h>
10 #include <sys/types.h>
11 #include <sys/wait.h>
12 #include <signal.h>
13 #include <errno.h>
14 #include <sys/time.h>
15 #include <linux/hpet.h>
18 extern void hpet_open_close(int, const char **);
19 extern void hpet_info(int, const char **);
20 extern void hpet_poll(int, const char **);
21 extern void hpet_fasync(int, const char **);
22 extern void hpet_read(int, const char **);
24 #include <sys/poll.h>
25 #include <sys/ioctl.h>
27 struct hpet_command {
28 char *command;
29 void (*func)(int argc, const char ** argv);
30 } hpet_command[] = {
32 "open-close",
33 hpet_open_close
36 "info",
37 hpet_info
40 "poll",
41 hpet_poll
44 "fasync",
45 hpet_fasync
49 int
50 main(int argc, const char ** argv)
52 unsigned int i;
54 argc--;
55 argv++;
57 if (!argc) {
58 fprintf(stderr, "-hpet: requires command\n");
59 return -1;
63 for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++)
64 if (!strcmp(argv[0], hpet_command[i].command)) {
65 argc--;
66 argv++;
67 fprintf(stderr, "-hpet: executing %s\n",
68 hpet_command[i].command);
69 hpet_command[i].func(argc, argv);
70 return 0;
73 fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]);
75 return -1;
78 void
79 hpet_open_close(int argc, const char **argv)
81 int fd;
83 if (argc != 1) {
84 fprintf(stderr, "hpet_open_close: device-name\n");
85 return;
88 fd = open(argv[0], O_RDONLY);
89 if (fd < 0)
90 fprintf(stderr, "hpet_open_close: open failed\n");
91 else
92 close(fd);
94 return;
97 void
98 hpet_info(int argc, const char **argv)
100 struct hpet_info info;
101 int fd;
103 if (argc != 1) {
104 fprintf(stderr, "hpet_info: device-name\n");
105 return;
108 fd = open(argv[0], O_RDONLY);
109 if (fd < 0) {
110 fprintf(stderr, "hpet_info: open of %s failed\n", argv[0]);
111 return;
114 if (ioctl(fd, HPET_INFO, &info) < 0) {
115 fprintf(stderr, "hpet_info: failed to get info\n");
116 goto out;
119 fprintf(stderr, "hpet_info: hi_irqfreq 0x%lx hi_flags 0x%lx ",
120 info.hi_ireqfreq, info.hi_flags);
121 fprintf(stderr, "hi_hpet %d hi_timer %d\n",
122 info.hi_hpet, info.hi_timer);
124 out:
125 close(fd);
126 return;
129 void
130 hpet_poll(int argc, const char **argv)
132 unsigned long freq;
133 int iterations, i, fd;
134 struct pollfd pfd;
135 struct hpet_info info;
136 struct timeval stv, etv;
137 struct timezone tz;
138 long usec;
140 if (argc != 3) {
141 fprintf(stderr, "hpet_poll: device-name freq iterations\n");
142 return;
145 freq = atoi(argv[1]);
146 iterations = atoi(argv[2]);
148 fd = open(argv[0], O_RDONLY);
150 if (fd < 0) {
151 fprintf(stderr, "hpet_poll: open of %s failed\n", argv[0]);
152 return;
155 if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
156 fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n");
157 goto out;
160 if (ioctl(fd, HPET_INFO, &info) < 0) {
161 fprintf(stderr, "hpet_poll: failed to get info\n");
162 goto out;
165 fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags);
167 if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
168 fprintf(stderr, "hpet_poll: HPET_EPI failed\n");
169 goto out;
172 if (ioctl(fd, HPET_IE_ON, 0) < 0) {
173 fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n");
174 goto out;
177 pfd.fd = fd;
178 pfd.events = POLLIN;
180 for (i = 0; i < iterations; i++) {
181 pfd.revents = 0;
182 gettimeofday(&stv, &tz);
183 if (poll(&pfd, 1, -1) < 0)
184 fprintf(stderr, "hpet_poll: poll failed\n");
185 else {
186 long data;
188 gettimeofday(&etv, &tz);
189 usec = stv.tv_sec * 1000000 + stv.tv_usec;
190 usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec;
192 fprintf(stderr,
193 "hpet_poll: expired time = 0x%lx\n", usec);
195 fprintf(stderr, "hpet_poll: revents = 0x%x\n",
196 pfd.revents);
198 if (read(fd, &data, sizeof(data)) != sizeof(data)) {
199 fprintf(stderr, "hpet_poll: read failed\n");
201 else
202 fprintf(stderr, "hpet_poll: data 0x%lx\n",
203 data);
207 out:
208 close(fd);
209 return;
212 static int hpet_sigio_count;
214 static void
215 hpet_sigio(int val)
217 fprintf(stderr, "hpet_sigio: called\n");
218 hpet_sigio_count++;
221 void
222 hpet_fasync(int argc, const char **argv)
224 unsigned long freq;
225 int iterations, i, fd, value;
226 sig_t oldsig;
227 struct hpet_info info;
229 hpet_sigio_count = 0;
230 fd = -1;
232 if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) {
233 fprintf(stderr, "hpet_fasync: failed to set signal handler\n");
234 return;
237 if (argc != 3) {
238 fprintf(stderr, "hpet_fasync: device-name freq iterations\n");
239 goto out;
242 fd = open(argv[0], O_RDONLY);
244 if (fd < 0) {
245 fprintf(stderr, "hpet_fasync: failed to open %s\n", argv[0]);
246 return;
250 if ((fcntl(fd, F_SETOWN, getpid()) == 1) ||
251 ((value = fcntl(fd, F_GETFL)) == 1) ||
252 (fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) {
253 fprintf(stderr, "hpet_fasync: fcntl failed\n");
254 goto out;
257 freq = atoi(argv[1]);
258 iterations = atoi(argv[2]);
260 if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
261 fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n");
262 goto out;
265 if (ioctl(fd, HPET_INFO, &info) < 0) {
266 fprintf(stderr, "hpet_fasync: failed to get info\n");
267 goto out;
270 fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags);
272 if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
273 fprintf(stderr, "hpet_fasync: HPET_EPI failed\n");
274 goto out;
277 if (ioctl(fd, HPET_IE_ON, 0) < 0) {
278 fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n");
279 goto out;
282 for (i = 0; i < iterations; i++) {
283 (void) pause();
284 fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count);
287 out:
288 signal(SIGIO, oldsig);
290 if (fd >= 0)
291 close(fd);
293 return;