RK3399 watch dog

内核选中红框部分，确保有/dev/watchdog

#include
#include
#include
#include
#include
#include "stdio.h"
#include         /* System V */
#include     /* BSD and Linux */
#include     /* XSI STREAMS */

#include

 

#define DEV_NAME "/dev/watchdog"

int fd;

/*
 * @brief  初始化看门狗
 * @param  interval     喂狗时间
 * @param  margin  喂狗间隔保留时间
 * @return  int
 * @create at 2019.09.04 by Eric.Xi
 */
int watch_dog_init(int interval,int margin)
{

     printf("started (interval %d, margin %d)!\n", interval, margin);

    fd = open(DEV_NAME, O_RDWR|O_CLOEXEC);
    if (fd == -1) {
        printf("Failed to open %s: %s\n", DEV_NAME, strerror(errno));
        return 1;
    }

    int timeout = interval + margin;
    int ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
    if (ret) {
        printf("Failed to set timeout to %d: %s\n", timeout, strerror(errno));
        ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
        if (ret) {
            printf("Failed to get timeout: %s\n", strerror(errno));
        } else {
            if (timeout > margin) {
                interval = timeout - margin;
            } else {
                interval = 1;
            }
            printf("Adjusted interval to timeout returned by driver:"
                    " timeout %d, interval %d, margin %d\n",
                    timeout, interval, margin);
        }
    }
    return 0;
}

/*
 * @brief  喂看门狗
 * @param  interval     喂狗时间
 * @param  fd  看门狗句柄
 * @return  int
 * @create at 2019.09.04 by Eric.Xi
 */
int watch_dog_feed(int fd, int interval)
{
    write(fd, "", 1);
    sleep(interval);
    return 0;
}

/*
 * @brief  看门狗使用ｄｅｍｏ
 * @return  int
 * @create at 2019.09.04 by Eric.Xi
 */
int main(int argc, char **argv)
{
    int interval = 1;
    int margin =2;
    int ret;
    ret = watch_dog_init(interval,margin);
    if(ret<0){
        return -1;
    }
   

        while (true) {
            watch_dog_feed(fd ,interval);
         printf("------feed--------\n");
        
        }
}