xref: /openbmc/linux/samples/timers/hpet_example.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 #include <fcntl.h>
6 #include <string.h>
7 #include <memory.h>
8 #include <malloc.h>
9 #include <time.h>
10 #include <ctype.h>
11 #include <sys/types.h>
12 #include <sys/wait.h>
13 #include <signal.h>
14 #include <errno.h>
15 #include <sys/time.h>
16 #include <linux/hpet.h>
17 
18 
19 extern void hpet_open_close(int, const char **);
20 extern void hpet_info(int, const char **);
21 extern void hpet_poll(int, const char **);
22 extern void hpet_fasync(int, const char **);
23 extern void hpet_read(int, const char **);
24 
25 #include <sys/poll.h>
26 #include <sys/ioctl.h>
27 
28 struct hpet_command {
29 	char		*command;
30 	void		(*func)(int argc, const char ** argv);
31 } hpet_command[] = {
32 	{
33 		"open-close",
34 		hpet_open_close
35 	},
36 	{
37 		"info",
38 		hpet_info
39 	},
40 	{
41 		"poll",
42 		hpet_poll
43 	},
44 	{
45 		"fasync",
46 		hpet_fasync
47 	},
48 };
49 
50 int
51 main(int argc, const char ** argv)
52 {
53 	unsigned int	i;
54 
55 	argc--;
56 	argv++;
57 
58 	if (!argc) {
59 		fprintf(stderr, "-hpet: requires command\n");
60 		return -1;
61 	}
62 
63 
64 	for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++)
65 		if (!strcmp(argv[0], hpet_command[i].command)) {
66 			argc--;
67 			argv++;
68 			fprintf(stderr, "-hpet: executing %s\n",
69 				hpet_command[i].command);
70 			hpet_command[i].func(argc, argv);
71 			return 0;
72 		}
73 
74 	fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]);
75 
76 	return -1;
77 }
78 
79 void
80 hpet_open_close(int argc, const char **argv)
81 {
82 	int	fd;
83 
84 	if (argc != 1) {
85 		fprintf(stderr, "hpet_open_close: device-name\n");
86 		return;
87 	}
88 
89 	fd = open(argv[0], O_RDONLY);
90 	if (fd < 0)
91 		fprintf(stderr, "hpet_open_close: open failed\n");
92 	else
93 		close(fd);
94 
95 	return;
96 }
97 
98 void
99 hpet_info(int argc, const char **argv)
100 {
101 	struct hpet_info	info;
102 	int			fd;
103 
104 	if (argc != 1) {
105 		fprintf(stderr, "hpet_info: device-name\n");
106 		return;
107 	}
108 
109 	fd = open(argv[0], O_RDONLY);
110 	if (fd < 0) {
111 		fprintf(stderr, "hpet_info: open of %s failed\n", argv[0]);
112 		return;
113 	}
114 
115 	if (ioctl(fd, HPET_INFO, &info) < 0) {
116 		fprintf(stderr, "hpet_info: failed to get info\n");
117 		goto out;
118 	}
119 
120 	fprintf(stderr, "hpet_info: hi_irqfreq 0x%lx hi_flags 0x%lx ",
121 		info.hi_ireqfreq, info.hi_flags);
122 	fprintf(stderr, "hi_hpet %d hi_timer %d\n",
123 		info.hi_hpet, info.hi_timer);
124 
125 out:
126 	close(fd);
127 	return;
128 }
129 
130 void
131 hpet_poll(int argc, const char **argv)
132 {
133 	unsigned long		freq;
134 	int			iterations, i, fd;
135 	struct pollfd		pfd;
136 	struct hpet_info	info;
137 	struct timeval		stv, etv;
138 	struct timezone		tz;
139 	long			usec;
140 
141 	if (argc != 3) {
142 		fprintf(stderr, "hpet_poll: device-name freq iterations\n");
143 		return;
144 	}
145 
146 	freq = atoi(argv[1]);
147 	iterations = atoi(argv[2]);
148 
149 	fd = open(argv[0], O_RDONLY);
150 
151 	if (fd < 0) {
152 		fprintf(stderr, "hpet_poll: open of %s failed\n", argv[0]);
153 		return;
154 	}
155 
156 	if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
157 		fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n");
158 		goto out;
159 	}
160 
161 	if (ioctl(fd, HPET_INFO, &info) < 0) {
162 		fprintf(stderr, "hpet_poll: failed to get info\n");
163 		goto out;
164 	}
165 
166 	fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags);
167 
168 	if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
169 		fprintf(stderr, "hpet_poll: HPET_EPI failed\n");
170 		goto out;
171 	}
172 
173 	if (ioctl(fd, HPET_IE_ON, 0) < 0) {
174 		fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n");
175 		goto out;
176 	}
177 
178 	pfd.fd = fd;
179 	pfd.events = POLLIN;
180 
181 	for (i = 0; i < iterations; i++) {
182 		pfd.revents = 0;
183 		gettimeofday(&stv, &tz);
184 		if (poll(&pfd, 1, -1) < 0)
185 			fprintf(stderr, "hpet_poll: poll failed\n");
186 		else {
187 			long 	data;
188 
189 			gettimeofday(&etv, &tz);
190 			usec = stv.tv_sec * 1000000 + stv.tv_usec;
191 			usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec;
192 
193 			fprintf(stderr,
194 				"hpet_poll: expired time = 0x%lx\n", usec);
195 
196 			fprintf(stderr, "hpet_poll: revents = 0x%x\n",
197 				pfd.revents);
198 
199 			if (read(fd, &data, sizeof(data)) != sizeof(data)) {
200 				fprintf(stderr, "hpet_poll: read failed\n");
201 			}
202 			else
203 				fprintf(stderr, "hpet_poll: data 0x%lx\n",
204 					data);
205 		}
206 	}
207 
208 out:
209 	close(fd);
210 	return;
211 }
212 
213 static int hpet_sigio_count;
214 
215 static void
216 hpet_sigio(int val)
217 {
218 	fprintf(stderr, "hpet_sigio: called\n");
219 	hpet_sigio_count++;
220 }
221 
222 void
223 hpet_fasync(int argc, const char **argv)
224 {
225 	unsigned long		freq;
226 	int			iterations, i, fd, value;
227 	sig_t			oldsig;
228 	struct hpet_info	info;
229 
230 	hpet_sigio_count = 0;
231 	fd = -1;
232 
233 	if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) {
234 		fprintf(stderr, "hpet_fasync: failed to set signal handler\n");
235 		return;
236 	}
237 
238 	if (argc != 3) {
239 		fprintf(stderr, "hpet_fasync: device-name freq iterations\n");
240 		goto out;
241 	}
242 
243 	fd = open(argv[0], O_RDONLY);
244 
245 	if (fd < 0) {
246 		fprintf(stderr, "hpet_fasync: failed to open %s\n", argv[0]);
247 		return;
248 	}
249 
250 
251 	if ((fcntl(fd, F_SETOWN, getpid()) == 1) ||
252 		((value = fcntl(fd, F_GETFL)) == 1) ||
253 		(fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) {
254 		fprintf(stderr, "hpet_fasync: fcntl failed\n");
255 		goto out;
256 	}
257 
258 	freq = atoi(argv[1]);
259 	iterations = atoi(argv[2]);
260 
261 	if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
262 		fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n");
263 		goto out;
264 	}
265 
266 	if (ioctl(fd, HPET_INFO, &info) < 0) {
267 		fprintf(stderr, "hpet_fasync: failed to get info\n");
268 		goto out;
269 	}
270 
271 	fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags);
272 
273 	if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
274 		fprintf(stderr, "hpet_fasync: HPET_EPI failed\n");
275 		goto out;
276 	}
277 
278 	if (ioctl(fd, HPET_IE_ON, 0) < 0) {
279 		fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n");
280 		goto out;
281 	}
282 
283 	for (i = 0; i < iterations; i++) {
284 		(void) pause();
285 		fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count);
286 	}
287 
288 out:
289 	signal(SIGIO, oldsig);
290 
291 	if (fd >= 0)
292 		close(fd);
293 
294 	return;
295 }
296