imx6ul gpio中断接收（代码）-蒲公英云

imx6ul gpio中断接收（代码）

gpio这里的调试要注意的是管脚的功能配置，需要更改设备树文件；

更改设备树文件：https://blog.csdn.net/cao849861802/article/details/111604277

然后注意gpio的计算比如gpio2_8

（2-1）*32 + 8 = 40

这个计算公式可以算出操作的gpio管脚是哪个。

#include "fcntl.h"
#include "stdio.h"
#include "poll.h"
#include "string.h"
#include "stdlib.h"
#include "unistd.h"
#define GPIO_EXPORT_BASE 118
#define GPIO_KEY_NUMBER   6
void edgfdinit()
{
    char buf[64];
    int i = 0;
    int edgfd;
    int len = 0;
    int ret ;
    for(i = 0; i < GPIO_KEY_NUMBER; i++)
    {
        memset(buf,0,sizeof(buf));
        sprintf(buf,"echo %d > /sys/class/gpio/export",GPIO_EXPORT_BASE + i);
        ret = system(buf);
        if(ret < 0)
        {
            printf("system %s failed\r\n",buf);
            continue;
        }
        memset(buf,0,sizeof(buf));
        sprintf(buf,"/sys/class/gpio/gpio%d/edge",GPIO_EXPORT_BASE + i);
        edgfd = open(buf,O_RDWR);
        if(edgfd < 0)
        {
            printf("open %s failed\r\n",buf);
            continue;
        }
        len = write(edgfd,"falling",strlen("falling"));
        if(len < strlen("falling"))
        {
            printf("write edgfd falling failed GPIO = %d\r\n",i + GPIO_EXPORT_BASE);
            close(edgfd);
            continue;
        }
    }
}
void main()
{
    int i = 0;
    char buf[64];
    int ret ;
    struct pollfd fds[GPIO_KEY_NUMBER];
    printf("gpio task start\r\n");
    edgfdinit();
    for(i = 0; i < GPIO_KEY_NUMBER; i++)
    {
        memset(buf,0,sizeof(buf));
        sprintf(buf,"/sys/class/gpio/gpio%d/value",GPIO_EXPORT_BASE + i);
        fds[i].fd = open(buf,O_RDONLY);
        if(fds[i].fd < 0)
        {
            printf("open fd %s failed\r\n",buf);
            continue;
        }
        fds[i].events = POLLPRI;
    }
    while(1)
    {
        ret = poll(fds,GPIO_KEY_NUMBER,-1);
        if(ret < 0)
        {
            printf("poll fds failed \r\n");
            return ;
        }
        for(i = 0; i < GPIO_KEY_NUMBER; i++)
        {    
            if(fds[i].revents & POLLPRI)
            {
                printf("get fd is %d\r\n",fds[i].fd);
                ret = lseek(fds[i].fd,0,SEEK_SET);
                if(ret < 0)
                {
                    printf("lseek seek_set failed i = %d\r\n",i);
                    return ;
                }
                memset(buf,0,sizeof(buf));
                ret = read(fds[i].fd,buf,1);
                if(ret < 0)
                {
                    printf("read fds.fd failed\r\n");
                    return ;
                }
                printf("the key %d is %s",i,buf);
            }            
        }
    }
}