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
14static int ticked;
15static void async_callback(snd_async_handler_t *ahandler)
16{
17 ticked++;
18}
19
20static char timer_name[64];
21static 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
67int 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

source code of linux/tools/testing/selftests/alsa/global-timer.c