Linux驱动开发之点亮三盏小灯

 

头文件

#ifndef __HEAD_H__
#define __HEAD_H__

//LED1和LED3的硬件地址
#define PHY_LED1_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED1_RCC 0x50000A28
//LED2的硬件地址
#define PHY_LED2_MODER 0x50007000
#define PHY_LED2_ODR 0x50007014
#define PHY_LED2_RCC 0x50000A28

#endif

驱动代码

#include 
#include 
#include 
#include 
#include 
#include 
#include "head.h"
int major;
char kbuf[128]={0}; 
//定义指针接收映射成功的虚拟内存首地址
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_rcc1;

unsigned int *vir_moder2;
unsigned int *vir_odr2;
unsigned int *vir_rcc2;


//定义一个指针用来接收创建类
struct class *cls;

//定义一个指针用来接收接收创建设备信息
struct device *dev;
// 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 filad\n");
        return ret;
    }
    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 filed\n");
        return ret;
    }
    if(kbuf[0]=='1' && kbuf[1] == '1')//LED1开灯
    {
        //开灯逻辑
        (*vir_odr1) |= (0X1<<10);
            }
    else if(kbuf[0]=='1' && kbuf[1] == '0')//LED1关灯
    {
        //关灯逻辑
        (*vir_odr1) &= (~(0X1<<10));
    }
    else if(kbuf[0]=='2' && kbuf[1] == '1')//LED2开灯
    {
        //开灯逻辑
        (*vir_odr2) |= (0X1<<10);
    }
    else if(kbuf[0]=='2' && kbuf[1] == '0')//LED1关灯
    {
        //关灯逻辑
        (*vir_odr2) &= (~(0X1<<10));
    }
    else if(kbuf[0]=='3' && kbuf[1] == '1')//LED#开灯
    {
        //开灯逻辑
        (*vir_odr1) |= (0X1<<8);
    }
    else if(kbuf[0]=='3' && kbuf[1] == '0')//LED3关灯
    {
        //关灯逻辑
        (*vir_odr1) &= (~(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遍历并且初始化
struct file_operations fops = {
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
};
 
static int __init mycdev_init(void)
{
    int i;

    // 注册字符设备驱动
    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);
    //向上提交目录信息
    cls = class_create(THIS_MODULE,"mycdev");
    if(IS_ERR(cls))
    {
        printk("向上提交目录信息失败\n");
        return -PTR_ERR(cls);
    }
    printk("向上提交目录信息成功\n");

    //向上提交设备信息
    for(i=0;i<3;i++)
    {
        dev=device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);
        if(IS_ERR(cls))
        {
            printk("向上提交设备信息信息失败\n");
            return -PTR_ERR(cls);
        }
    }
    printk("向上提交设备信息成功\n");
    
    //完成硬件寄存器物理内存的映射
    vir_moder1=ioremap(PHY_LED1_MODER,4);
    if(vir_moder1==NULL)
    {
        printk("LED1物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_odr1=ioremap(PHY_LED1_ODR,4);
    if(vir_odr1==NULL)
    {
        printk("LED1物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_rcc1=ioremap(PHY_LED1_RCC,4);
    if(vir_rcc1==NULL)
    {
        printk("LED1物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("LED1物理内存映射成功\n");

    //LED2物理内存映射
    vir_moder2=ioremap(PHY_LED2_MODER,4);
    if(vir_moder2==NULL)
    {
        printk("LED2物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_odr2=ioremap(PHY_LED2_ODR,4);
    if(vir_odr2==NULL)
    {
        printk("LED2物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_rcc2=ioremap(PHY_LED2_RCC,4);
    if(vir_rcc2==NULL)
    {
        printk("LED2物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("LED2物理内存映射成功\n");

    //LED3物理内存映射
    vir_moder1=ioremap(PHY_LED1_MODER,4);
    if(vir_moder1==NULL)
    {
        printk("LED3物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_odr1=ioremap(PHY_LED1_ODR,4);
    if(vir_odr1==NULL)
    {
        printk("LED3物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
     vir_rcc1=ioremap(PHY_LED1_RCC,4);
    if(vir_rcc1==NULL)
    {
        printk("LED3物理内存映射失败%d\n",__LINE__);
        return -EFAULT;
    }
    printk("LED3物理内存映射成功\n");

    //硬件寄存器的初始化

    //LED1硬件初始化
    (*vir_moder1) &= (~(0X3<<20));//设置为输出
    (*vir_moder1) |= (0X1<<20);

    //LED2硬件初始化
    (*vir_moder2) &= (~(0X3<<20));//设置为输出
    (*vir_moder2) |= (0X1<<20);

    //LED3硬件初始化
    (*vir_moder1) &= (~(0X3<<16));//设置为输出
    (*vir_moder1) |= (0X1<<16);
    //rcc使能
    (*vir_rcc1) |= (0X1<<4);
    (*vir_rcc2) |= (0X1<<5);

    //默认关灯
    (*vir_odr1) &= (~(0X1<<10));
    (*vir_odr2) &= (~(0X1<<10));
    (*vir_odr1) &= (~(0X1<<8));
    return 0;
}
static void __exit mycdev_exit(void)
{
    //取消物理内存的映射
    iounmap(vir_moder1);
    iounmap(vir_odr1);
    iounmap(vir_rcc1);

    iounmap(vir_moder2);
    iounmap(vir_odr2);
    iounmap(vir_rcc2);
    //销毁设备信息
    int i;
    for(i=0;i<3;i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }

    //销毁目录信息
    class_destroy(cls);

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

测试文件

#include 
#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, const char *argv[])
{
    char buf[128] = {};

    int fd0 = open("/dev/mycdev0", O_RDWR);
    int fd1 = open("/dev/mycdev1", O_RDWR);
    int fd2 = open("/dev/mycdev2", O_RDWR);

    if (fd0 < 0)
    {
        printf("打开设备文件失败\n");
        exit(-1);
    }
    printf("成功打开设备文件\n");
    while (1)
    {
        printf("逻辑关系：例如11表示LED1亮 10表示LED1灭...\n");
        fgets(buf, sizeof(buf), stdin); // 从终端读一个字符串存放在buf
        buf[strlen(buf) - 1] = '\0';

        if(buf[0] == '1')
        {
            write(fd0, buf, sizeof(buf)); // 将从终端得到的字符串传递到驱动
        }
        else if(buf[0] == '2')
        {
            write(fd1, buf, sizeof(buf));
        }
        else if(buf[0] == '3')
        {
            write(fd2, buf, sizeof(buf));
        }
    }
    close(fd0);

    return 0;
}

结果

 实现效果如上