stm32mpLED灯亮灭驱动程序

 mychrdev.c

#include 
#include 
#include 
#include 
#include 
#include "head.h"

unsigned int major; // 保存主设备号
char kbuf[128]={0};
unsigned int *vir_rcc;
unsigned int *vir_moder;
unsigned int *vir_odr;

// 封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}

ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    int ret;
    ret=copy_to_user(ubuf,kbuf,size);
    if(ret){
        printk("copy_to_user err\n");
        return -EIO;
    }
    return 0;
}

ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    int ret;
    ret=copy_from_user(kbuf,ubuf,size);
    if(ret){
        printk("copy_from_user err\n");
        return -EIO;
    }
    //拿取用户在串口输入的内容, 第0位字符. 若1, vir_odr [10] = 1 亮. 不为1, vir_odr [10] = 0 灭.
    printk("内核打印:%s",kbuf);
    if(kbuf[0]=='1'){
        //开灯逻辑
        (*vir_odr) |= (0x1 << 10);
    }else {
        //关灯逻辑
        (*vir_odr) &= (~(0x1 << 10));
    }
    return 0;
}

int mycdev_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}

// 定义一个操作方法结构体对象并且初始化
struct file_operations fops = {
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
};

static int __init mycdev_init(void)
{
    // 字符设备驱动的注册
    major = register_chrdev(0, "mychrdev", &fops);
    if (major < 0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("字符设备驱动注册成功major=%d\n",major);
    //进行相关寄存器的内存映射
    vir_rcc=ioremap(LED1_RCC,4);
    if(vir_rcc==NULL){
        printk("LED1_RCC物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_moder=ioremap(LED1_MODER,4);
    if(vir_moder==NULL){
        printk("LED1_MODER物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_odr=ioremap(LED1_ODR,4);
    if(vir_odr==NULL){
        printk("LED1_ODR物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }

    printk("寄存器内存映射成功\n");
    //硬件寄存器的初始化
    //RCC使能 vir_rcc [4]=1
    (*vir_rcc) |= (0x1 << 4);
    //设置PE10为输出模式 vir_moder [21:20]=01
    (*vir_moder) &= (~(0x3 << 20));
    (*vir_moder) |= (0x1 << 20);
    //设置默认关灯 vir_odr [10]=1
    (*vir_odr) &= (~(0x1 << 10));

    return 0;
}

static void __exit mycdev_exit(void)
{
    //取消物理内存映射
    iounmap(vir_rcc);
    iounmap(vir_moder);
    iounmap(vir_odr);
    // 字符设备驱动注销
    unregister_chrdev(major, "mychrdev");
}

module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

test.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main(int argc, char const *argv[])
{
    char buf[128] = {0};
    int fd = open("/dev/mychrdev", O_RDWR);
    if (fd < 0)
    {
        printf("设备文件打开失败\n");
        exit(-1);
    }
    while(1){
        printf("请输入对LED1的控制命令1(开灯) 0(关灯)>");
        fgets(buf,sizeof(buf),stdin);//在终端输入数据传递到buf
        buf[strlen(buf)-1]='\0';//替换末尾的'\n'
        write(fd,buf,sizeof(buf));
        memset(buf,0,sizeof(buf));//清空数组
        read(fd, buf, sizeof(buf));
        printf("buf:%s\n",buf);
    }

    close(fd);

    return 0;
}

head.h

#ifndef __HEAD_H__
#define __HEAD_H__

#define LED1_MODER   0X50006000
#define LED1_ODR     0X50006014
#define LED1_RCC     0X50000A28

#endif