xref: /linux/tools/testing/selftests/alsa/global-timer.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This tool is used by the utimer test, and it allows us to
4  * count the ticks of a global timer in a certain time frame
5  * (which is set by `timeout` parameter).
6  *
7  * Author: Ivan Orlov <ivan.orlov0322@gmail.com>
8  */
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <alsa/asoundlib.h>
12 #include <time.h>
13 
14 static int ticked;
15 static void async_callback(snd_async_handler_t *ahandler)
16 {
17 	ticked++;
18 }
19 
20 static char timer_name[64];
21 static void bind_to_timer(int device, int subdevice, int timeout)
22 {
23 	snd_timer_t *handle;
24 	snd_timer_params_t *params;
25 	snd_async_handler_t *ahandler;
26 
27 	time_t end;
28 
29 	sprintf(timer_name, "hw:CLASS=%d,SCLASS=%d,DEV=%d,SUBDEV=%d",
30 		SND_TIMER_CLASS_GLOBAL, SND_TIMER_SCLASS_NONE,
31 		device, subdevice);
32 
33 	snd_timer_params_alloca(&params);
34 
35 	if (snd_timer_open(&handle, timer_name, SND_TIMER_OPEN_NONBLOCK) < 0) {
36 		perror("Can't open the timer");
37 		exit(EXIT_FAILURE);
38 	}
39 
40 	snd_timer_params_set_auto_start(params, 1);
41 	snd_timer_params_set_ticks(params, 1);
42 	if (snd_timer_params(handle, params) < 0) {
43 		perror("Can't set timer params");
44 		exit(EXIT_FAILURE);
45 	}
46 
47 	if (snd_async_add_timer_handler(&ahandler, handle, async_callback, NULL) < 0) {
48 		perror("Can't create a handler");
49 		exit(EXIT_FAILURE);
50 	}
51 	end = time(NULL) + timeout;
52 	if (snd_timer_start(handle) < 0) {
53 		perror("Failed to start the timer");
54 		exit(EXIT_FAILURE);
55 	}
56 	printf("Timer has started\n");
57 	while (time(NULL) <= end) {
58 		/*
59 		 * Waiting for the timeout to elapse. Can't use sleep here, as it gets
60 		 * constantly interrupted by the signal from the timer (SIGIO)
61 		 */
62 	}
63 	snd_timer_stop(handle);
64 	snd_timer_close(handle);
65 }
66 
67 int main(int argc, char *argv[])
68 {
69 	int device, subdevice, timeout;
70 
71 	if (argc < 4) {
72 		perror("Usage: %s <device> <subdevice> <timeout>");
73 		return EXIT_FAILURE;
74 	}
75 
76 	setlinebuf(stdout);
77 
78 	device = atoi(argv[1]);
79 	subdevice = atoi(argv[2]);
80 	timeout = atoi(argv[3]);
81 
82 	bind_to_timer(device, subdevice, timeout);
83 
84 	printf("Total ticks count: %d\n", ticked);
85 
86 	return EXIT_SUCCESS;
87 }
88