驱动day2：LED灯实现三盏灯的亮灭

head.h

#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_PE_MODER 0x50006000
#define PHY_PF_MODER 0x50007000
#define PHY_PE_ODR 0x50006014
#define PHY_PF_ODR 0x50007014
#define PHY_RCC 0x50000A28
 
 
#endif

应用程序

#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("打开设备文件失败\n");
        return -1;
    }
    printf("打开设备文件成功\n");
    while(1)
    {
        printf("请输入要进行的操作:0(关灯) 1 (开灯)＞");
        fgets(buf,sizeof(buf),stdin);   //在终端读一个字符串
        buf[strlen(buf) - 1] = '\0';
        write(fd,buf,sizeof(buf));//将数据传递给内核
    }
/*
    fgets(buf,sizeof(buf),stdin);   //在终端读一个字符串
    buf[strlen(buf) - 1] = '\0';
   write(fd,buf,sizeof(buf));//将数据传递给内核
   memset(buf, 0, sizeof(buf));   //清空数组
    read(fd,buf,sizeof(buf));    //将内核数据传递给用户
 
    printf("buf: %s\n", buf);
*/
    close(fd);
    return 0;
}

驱动程序

#include 
#include 
#include 
#include 
#include 
#include "head.h"
 
unsigned int major;   //主设备号
char kbuf[128] = {};   //内核空间buf
//定义五个指针指向映射后的虚拟内存
unsigned int *vir_pe_moder;
unsigned int *vir_pf_moder;
unsigned int *vir_pe_odr;
unsigned int *vir_pf_odr;
unsigned int *vir_rcc;
//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)
{
    //mycdev_read()函数中的ubuf和size分别是指向应用程序中read()函数中的buf, 和sizeof(buf)的值
    printk("%s:%s:%d\n", __FILE__,__func__,__LINE__);
    int ret;
    ret = copy_to_user(ubuf, kbuf, size);
    if(ret)
    {
        printk("copy_to_user filed\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 failed\n");
        return -EIO;
    }
    if(kbuf[0] == '0')//关灯
    {   
        //关灯逻辑
        (*vir_pe_odr) &= (~(0x1 << 10));     //默认关灯
        (*vir_pf_odr) &= (~(0x1 << 10));
        (*vir_pe_odr) &= (~(0x1 << 8));
 
    }
    else if(kbuf[0] == '1')
    {
        //开灯逻辑
        (*vir_pe_odr) |= (0x1 << 10); 
        (*vir_pf_odr) |= (0x1 << 10); 
        (*vir_pe_odr) |= (0x1 << 8);
    }
 
    return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__,__func__,__LINE__);
    return 0;
}
 
//定义操作方法结构体对象
struct file_operations fops={
    .open = mycdev_open,
    .read = mycdev_read,
    .write= mycdev_write,
    .release = mycdev_close,
};
 
static int __init mycdev_init(void)
{
    //注册字符设备驱动
    major= register_chrdev(0,"mycdev",&fops);
    if(major < 0)
    {
        printk("字符设备驱动注册失败\n");
        return major;
    }
    printk("注册字符设备成功major=%d\n",major);
 
    //进行寄存器的地址映射
    vir_pe_moder = ioremap(PHY_PE_MODER, 4);
    if(vir_pe_moder == NULL)
    {
        printk("物理地址内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_pf_moder = ioremap(PHY_PF_MODER,4);
    if(vir_pf_moder == NULL)
    {
        printk("物理地址内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_pe_odr = ioremap(PHY_PE_ODR, 4);
    if(vir_pe_odr == NULL)
    {
        printk("物理地址内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_pf_odr = ioremap(PHY_PF_ODR, 4);
    if(vir_pf_odr == NULL)
    {
        printk("物理地址内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    vir_rcc = ioremap(PHY_RCC, 4);
    if(vir_rcc == NULL)
    {
        printk("物理地址内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("寄存器内存映射成功\n");
 
    //LED寄存器初始化
    (*vir_rcc) |= (0x3 << 4);   //GPIOE和GPIOF控制器时钟使能
    //PE10
    (*vir_pe_moder) &= (~(0x3 << 20));   //MODER[21:20]－＞00
    (*vir_pe_moder) |= (0x1 << 20);  //MODER[21"20]->01
    (*vir_pe_odr) &= (~(0x1 << 10));   //默认关灯
    //PF10
    (*vir_pf_moder) &= (~(0x3 << 20));
    (*vir_pf_moder) |= (0x1 << 20);
    (*vir_pf_odr) &= (~(0x1 << 10));   //默认关灯
    //PE8
     (*vir_pe_moder) &= (~(0x3 << 16));
    (*vir_pe_moder) |= (0x1 << 16); 
    (*vir_pe_odr) &= (~(0x1 << 8));   //默认关灯
    return 0;
}
 
static void __exit mycdev_exit(void)
{
    //取消内存映射
    iounmap(vir_pe_moder);
    iounmap(vir_pf_moder);
    iounmap(vir_pe_odr);
    iounmap(vir_pf_odr);
    iounmap(vir_rcc);
    //注销字符设备驱动
    unregister_chrdev(major,"mychrdev");
}
 
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

实现效果