systimer.c

来自「周立功magic2200实验箱linux增补例子。包括（GPIO zlg7290」· C语言 代码 · 共 61 行

#include "config.h"
#include <stdio.h>
#include <signal.h>
#include <sys/time.h>

#define BEEP  7
uint8 ledcon = 0;

/* signal process */
void led_info(int signo)
{
    int fd;

    printf("timeout!\n");

    ledcon = ~ledcon;
    fd = open("/dev/P0", O_RDONLY);
    if(fd == -1)
    {
        printf("\nCan't open P0!\n");
        exit(-1);
    }

    ioctl(fd, GPIO_SET_PIN_OUT, BEEP);
    if (ledcon)   ioctl(fd, GPIO_SET_PIN, BEEP);
    else ioctl(fd, GPIO_CLR_PIN, BEEP);

    close(fd);
}

/* init sigaction */
void init_sigaction(void)
{
    struct sigaction act;

    act.sa_handler = led_info;
    act.sa_flags   = 0;
    sigemptyset(&act.sa_mask);
    sigaction(SIGPROF, &act, NULL);
} 

/* init */
void init_time(void)
{
    struct itimerval val;

    val.it_value.tv_sec = 1;
    val.it_value.tv_usec = 0;
    val.it_interval = val.it_value;
    setitimer(ITIMER_PROF, &val, NULL);
}


int main(void)
{
    init_sigaction();
    init_time();
    while(1);
    exit(0);
}