驱动开发--day2（内核不同模块的相互访问、字符设备驱动、led控制实验代码及现象）

实现三盏灯的控制，编写应用程序测试

head.h

cs 复制代码

#ifndef __HEAD_H__
#define __HEAD_H__

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

#define LED2_MODER 0X50007000
#define LED2_ODR 0X50007014


#endif

mychrdev.c

cs 复制代码

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"

//保存主设备号
unsigned int major;

char kbuf[128]={0};

unsigned int* vir_moder;
unsigned int* vir_odr;
unsigned int* vir_rcc;

unsigned int* vir_moder_F;
unsigned int* vir_odr_F;
//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)
{
    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)
{
    int ret;
    ret=copy_from_user(kbuf,ubuf,size);
    if(ret)
    {
        printk("copy_from_user err\n");
        return -EIO;
    }
    if(kbuf[0]=='1')
    {
        //开灯逻辑
        if(kbuf[1]=='1')
        {
            (*vir_odr) |= (0x1<<10);
        }
        else if(kbuf[1]=='2')
        {
            (*vir_odr_F) |= (0x1<<10);
        }
        else if(kbuf[1]=='3')
        {
            (*vir_odr) |= (0x1<<8);
        }
    }
    else if(kbuf[0]=='0')
    {
        //关灯逻辑
        if(kbuf[1]=='1')
        {
            (*vir_odr) &= (~(0x1<<10));
        }
        else if(kbuf[1]=='2')
        {
            (*vir_odr_F) &= (~(0x1<<10));
        }
        else if(kbuf[1]=='3')
        {
            (*vir_odr) &= (~(0x1<<8));
        }
    }
    return 0;
}
int mycdev_close(struct inode* inode,struct file* file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
//定义一个操作方式结构体对象并初始化
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_odr=ioremap(LED1_ODR,4);
    if(vir_odr==NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_rcc=ioremap(LED1_RCC,4);
    if(vir_rcc==NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_moder=ioremap(LED1_MODER,4);
    if(vir_moder==NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("寄存器内存映射成功\n");

    vir_moder_F=ioremap(LED2_MODER,4);
    if(vir_moder_F==NULL)
    {
        printk("物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("寄存器内存映射成功\n");
    vir_odr_F=ioremap(LED2_ODR,4);
    if(vir_odr_F==NULL)
    {
        printk("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) |= (0x1<<4);
    (*vir_rcc) |= (0x1<<5);
    //设置PE10为输出
    (*vir_moder) &= (~(0x3<<20));
    (*vir_moder) |= (0x1<<20);
    //设置PF8为输出
    (*vir_moder_F) &= (~(0x3<<20));
    (*vir_moder_F) |= (0x1<<20);
    //设置PE8为输出
    (*vir_moder) &= (~(0x3<<16));
    (*vir_moder) |= (0x1<<16);
    //默认关灯
    (*vir_odr) &= (~(0X1<<10));
    (*vir_odr_F) &= (~(0X1<<10));
    (*vir_odr) &= (~(0X1<<8));

    return 0;
}
static void __exit mycdev_exit(void)
{
    //取消物理内存映射
    iounmap(vir_moder);
    iounmap(vir_odr);
    iounmap(vir_rcc);
    iounmap(vir_moder_F);
    iounmap(vir_odr_F);
    //字符设备驱动的注销
    unregister_chrdev(major,"mychrdev");
}

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

test.c

cs 复制代码

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
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)
    {
        memset(buf,0,sizeof(buf));
        printf("请输入对LED1的控制命令11(开灯) 01(关灯)>>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1]='\0';
        write(fd,buf,sizeof(buf));

        memset(buf,0,sizeof(buf));
        printf("请输入对LED2的控制命令12(开灯) 02(关灯)>>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1]='\0';
        write(fd,buf,sizeof(buf));

        memset(buf,0,sizeof(buf));
        printf("请输入对LED3的控制命令13(开灯) 03(关灯)>>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1]='\0';
        write(fd,buf,sizeof(buf));
    }
    
    close(fd);
}

测试过程及现象：

1.编译>>>

2.测试>>>

3.现象>>>