10月10日 驱动开发作业

终端输入1亮LED1

2-》LED2

3->LED3

0->关灯

.h

#ifndef __YONGHU__
#define __YONGHU__

#define led1_mode 0x50006000
#define led1_odr 0x50006014
#define led1_rcc 0x50000A28

#define led2_mode 0x50007000
#define led2_odr 0x50007014
#define led2_rcc 0x50000A28

#define led3_mode 0x50006000
#define led3_odr 0x50006014
#define led3_rcc 0x50000A28


#endif

驱动文件 

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include"yonghu.h"
#define CNAME  "myled"

int major;
char kbuf[128] = "";
unsigned int *vir1_moder;
unsigned int *vir1_odr;
unsigned int *vir1_rcc;

unsigned int *vir2_moder;
unsigned int *vir2_odr;
unsigned int *vir2_rcc;

unsigned int *vir3_moder;
unsigned int *vir3_odr;
unsigned int *vir3_rcc;
int myled_open(struct inode *inode, struct file *file)
{

    return 0;
}

ssize_t myled_read(struct file *file, char __user *ubuf, size_t size,loff_t *loff)
{
    int ret;
    if(size > sizeof(kbuf))
    size = sizeof(kbuf);
    ret = copy_to_user(ubuf, kbuf, size);
    if(ret)
    {
        printk("数据从内核向用户拷贝失败\n");
        return -EIO;
    }
    return 0;
}

ssize_t myled_write(struct file *file, const char __user *ubuf, size_t size, loff_t *loff)
{
    int ret;
    if(size > sizeof(kbuf))
    size = sizeof(kbuf);
    ret = copy_from_user(kbuf, ubuf, size);
    if(ret)
    {
        printk("数据从内核向用户拷贝失败\n");
        return -EIO;   
    }
    if(kbuf[0] == '1')
        (*vir1_odr) |= (1 << 10);
    else if(kbuf[0] == '2')
        (*vir2_odr) |= (1 << 10);
    else if(kbuf[0] == '3')
        (*vir3_odr) |= (1 << 8);
    else
    {
        (*vir1_odr) &= ~(1<<10);
        (*vir2_odr) &= ~(1<<10);
        (*vir3_odr) &= ~(1<<8);
    }
     return 0;
}

int myled_close(struct inode *inode, struct file *file)
{
       return 0;
}

struct file_operations fops=
{
    .open = myled_open,
    .read = myled_read,
    .write=myled_write,
    .release=myled_close,
};
static int __init mycdev_init(void)
{
    major = register_chrdev(0, CNAME, &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);
    vir1_moder = ioremap(led1_mode, 4);
    if(vir1_moder==NULL)
    {
        printk("vir1_moder 映射失败\n");
        return -ENOMEM;
    }
    printk("vir1_moder 映射成功\n");

    vir1_odr=ioremap(led1_odr,4);
    if(vir1_odr==NULL)
    {
        printk("vir1_odr 映射失败\n");
        return -ENOMEM;
    }
    printk("vir1_odr 映射成功\n");
    vir1_rcc=ioremap(led1_rcc,4);
    if(vir1_rcc==NULL)
    {
        printk("vir1_rcc 映射失败\n");
        return -ENOMEM;
    }
    printk("vir1_rcc 映射成功\n");

    vir2_moder = ioremap(led2_mode, 4);
    if(vir2_moder==NULL)
    {
        printk("vir2_moder 映射失败\n");
        return -ENOMEM;
    }
    printk("vir2_moder 映射成功\n");

    vir2_odr=ioremap(led2_odr,4);
    if(vir2_odr==NULL)
    {
        printk("vir2_odr 映射失败\n");
        return -ENOMEM;
    }
    printk("vir2_odr 映射成功\n");
    vir2_rcc=ioremap(led2_rcc,4);
    if(vir2_rcc==NULL)
    {
        printk("vir2_rcc 映射失败\n");
        return -ENOMEM;
    }
    printk("vir2_rcc 映射成功\n");


    vir3_moder = ioremap(led3_mode, 4);
    if(vir3_moder==NULL)
    {
        printk("vir3_moder 映射失败\n");
        return -ENOMEM;
    }
    printk("vir3_moder 映射成功\n");

    vir3_odr=ioremap(led3_odr,4);
    if(vir3_odr==NULL)
    {
        printk("vir3_odr 映射失败\n");
        return -ENOMEM;
    }
    printk("vir3_odr 映射成功\n");
    vir3_rcc=ioremap(led3_rcc,4);
    if(vir3_rcc==NULL)
    {
        printk("vir3_rcc 映射失败\n");
        return -ENOMEM;
    }
    printk("vir3_rcc 映射成功\n");

    (*vir1_moder) &= ~(3<<20);
    (*vir1_moder) |= (1<<20);
    (*vir1_odr) &= ~(1<<10);
    (*vir1_rcc) |= (1<<4);

    (*vir2_moder) &= ~(3<<20);
    (*vir2_moder) |= (1<<20);
    (*vir2_odr) &= ~(1<<10);
    (*vir2_rcc) |= (1<<5);

    (*vir3_moder) &= ~(3<<16);
    (*vir3_moder) |= (1<<16);
    (*vir3_odr) &= ~(1<<8);
    (*vir3_rcc) |= (1<<4);
    return 0;
}
static void __exit mycdev_exit(void)
{

    //注销字符设备驱动
   unregister_chrdev(major,CNAME);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

 

应用层 

#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]={};
    int fd=open("/dev/myled",O_RDWR);
    if(fd<0)
    {

        printf("打开设备文件失败\n");
        exit(-1);
    }
    printf("设备文件打开成功\n");
    //在终端输入
    while(1)
    {
    printf("请输入控制命令 1:开灯1 2:开灯2 3:开灯3 0:关闭所有灯\n");
    fgets(buf,sizeof(buf),stdin);
    //吃掉换行符
    buf[strlen(buf)-1]='\0';
    write(fd,buf,sizeof(buf));
    }
    close(fd);
    return 0;
}