EMS/drv/drv_do.c

#include "drv_do.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>



// 设置GPIO引脚为输出模式
int gpio_export(int gpio_num) {
    int fd;
    char buf[64];

    // 导出GPIO，写入对应的GPIO编号
    fd = open(GPIO_PATH "/export", O_WRONLY);
    if (fd == -1) {
        perror("Failed to open export file");
        return -1;
    }

    snprintf(buf, sizeof(buf), "%d", gpio_num);
    if (write(fd, buf, strlen(buf)) == -1) {
        perror("Failed to export GPIO");
        close(fd);
        return -1;
    }

    close(fd);
    return 0;
}

// 设置GPIO引脚方向
int gpio_set_direction(int gpio_num, const char *direction) {
    int fd;
    char buf[64];

    // 设置GPIO方向
    snprintf(buf, sizeof(buf), GPIO_PATH "/gpio%d/direction", gpio_num);
    fd = open(buf, O_WRONLY);
    if (fd == -1) {
        perror("Failed to open GPIO direction file");
        return -1;
    }

    if (write(fd, direction, strlen(direction)) == -1) {
        perror("Failed to set GPIO direction");
        close(fd);
        return -1;
    }

    close(fd);
    return 0;
}

// 读取GPIO引脚值
int gpio_read_value(int gpio_num) {
    int fd;
    char buf[64];
    char value;

    // 打开GPIO值文件
    snprintf(buf, sizeof(buf), GPIO_PATH "/gpio%d/value", gpio_num);
    fd = open(buf, O_RDONLY);
    if (fd == -1) {
        perror("Failed to open GPIO value file");
        return -1;
    }

    // 读取GPIO值
    if (read(fd, &value, 1) == -1) {
        perror("Failed to read GPIO value");
        close(fd);
        return -1;
    }

    close(fd);
    return (value == '1') ? 1 : 0;
}

// 设置GPIO引脚值
int gpio_write_value(int gpio_num, int value) {
    int fd;
    char buf[64];

    // 打开GPIO值文件
    snprintf(buf, sizeof(buf), GPIO_PATH "/gpio%d/value", gpio_num);
    fd = open(buf, O_WRONLY);
    if (fd == -1) {
        perror("Failed to open GPIO value file");
        return -1;
    }

    // 写入GPIO值
    if (write(fd, (value ? "1" : "0"), 1) == -1) {
        perror("Failed to write GPIO value");
        close(fd);
        return -1;
    }

    close(fd);
    return 0;
}

// 取消导出GPIO
int gpio_unexport(int gpio_num) {
    int fd;
    char buf[64];

    // 取消导出GPIO
    fd = open(GPIO_PATH "/unexport", O_WRONLY);
    if (fd == -1) {
        perror("Failed to open unexport file");
        return -1;
    }

    snprintf(buf, sizeof(buf), "%d", gpio_num);
    if (write(fd, buf, strlen(buf)) == -1) {
        perror("Failed to unexport GPIO");
        close(fd);
        return -1;
    }

    close(fd);
    return 0;
}


void do_open()
{
       int gpio_num = 24; // 需要操作的GPIO引脚编号

    // 导出GPIO
    if (gpio_export(gpio_num) == -1) {
        return -1;
    }

    // 设置GPIO为输出模式
    if (gpio_set_direction(gpio_num, "out") == -1) {
        gpio_unexport(gpio_num);
        return -1;
    }

    // 设置GPIO值为1 (高电平)
    if (gpio_write_value(gpio_num, 1) == -1) {
        gpio_unexport(gpio_num);
        return -1;
    }

    // 读取GPIO值
    int value = gpio_read_value(gpio_num);
    if (value != -1) {
        printf("GPIO %d value: %d\n", gpio_num, value);
    }

    // 设置GPIO值为0 (低电平)
    if (gpio_write_value(gpio_num, 0) == -1) {
        gpio_unexport(gpio_num);
        return -1;
    }
}