驱动开发（10/12—林雪阵）-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_47348012/article/details/127288311

创建3个设备节点，分别控制3个LED灯

/dev/led1      /dev/led1        /dev/led1

=============================

                   myled(驱动)

=============================

LED1    LED2                LED3

mycdev.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include "myled.h"
#include <linux/io.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/uaccess.h>
#include <linux/device.h>
#include <linux/poison.h>
#include <linux/slab.h>
#include <linux/cdev.h>

#define CNAME "mycdev"

struct cdev *cdev;

struct class* cls;
struct device* dev;

dev_t dev1;

unsigned int major;
unsigned int minor;


char kbuf[128]={};  //定义数组用于存放和用户之间拷贝的数据
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;

//定义自选锁
spinlock_t lock;
//定义信号量
struct semaphore sem;

//read()
ssize_t mycdev_read (struct file *file, char __user *ubuf, size_t size, loff_t *loff)
{
    
    //size是用户期待读到的字节长度
    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 size;
}
//write()
ssize_t mycdev_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("数据从用户向内核拷贝失败\n");
        return -EIO;
    }
/*
    if(kbuf[0] == '1')
    {
        vir_led1->ODR |= (1<<10);
    }else if(kbuf[0]== '2')
    {
        vir_led2->ODR |= (1<<10);
    }
    else if(kbuf[0] == '3')
    {
        vir_led3->ODR |= (1<<8);
    }
    else
    {
        vir_led1->ODR &= ~(1<<10);
        vir_led2->ODR &= ~(1<<10);
        vir_led3->ODR &= ~(1<<8);
    }
    */
    return size;
}
int flags=0;
//open()
int mycdev_open (struct inode *inode, struct file *file)
{
    //down(&sem);
    //down_trylock(&sem);    //尝试获取锁
    
    //上锁
    /*
    spin_lock(&lock);
    if(flags !=0)
    {
        spin_unlock(&lock);
        return -EBUSY;
    }
    flags=1;
    spin_unlock(&lock);
    */
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
     return 0;
}
//close()
int mycdev_release (struct inode *inode, struct file *file)
{
    //up(&sem);
    //解锁
    //flags=0;

     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
     return 0;
}
//ioctl()
long ioctl (struct file *file,unsigned int cmd,unsigned long arg)
{
    int ret,which;
    switch(cmd)
    {
        case LEDON:
        {
            ret=copy_from_user(&which,(void *)arg,sizeof(int));
            if(ret)
            {
                printk("用户向内核拷贝数据失败");
                return -EIO;
            }
            switch(which)
            {
                case LED1:
                vir_led1->ODR |= (1<<10);
                break;
                case LED2:
                vir_led2->ODR |= (1<<10);
                break;
                case LED3:
                vir_led3->ODR |= (1<<8);
                break;
            }
        }
            break;
        case LEDOFF:
        {
            ret=copy_from_user(&which,(void *)arg,sizeof(int));
            if(ret)
            {
                printk("用户向内核拷贝数据失败");
                return -EIO;
            }
            switch(which)
            {
                case LED1:
                vir_led1->ODR &= ~(1<<10);
                break;
                case LED2:
                vir_led2->ODR &= ~(1<<10);
                break;
                case LED3:
                vir_led3->ODR &= ~(1<<8);
                break;
            }
        }
            break;
        default:
            printk("功能码错误\n");
            break;
    }
    return 0;
}

//操作方法结构体的初始化
struct file_operations fops=
{
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_release,
    .unlocked_ioctl=ioctl
};

//led物理地址映射和初始化
static int all_led_init(void)
{
    //moder 地址映射
    //GPIOE
    vir_led1=ioremap(PHY_LED1_ADDR,sizeof(gpio_t));
    if(vir_led1 ==NULL)
    {
        printk("vir_led1 映射失败\n");
        return -ENOMEM;
    }
    printk("vir_led1 映射成功\n");

    vir_led2=ioremap(PHY_LED2_ADDR,sizeof(gpio_t));
    if(vir_led2 ==NULL)
    {
        printk("vir_led2 映射失败\n");
        return -ENOMEM;
    }
    printk("vir_led2 映射成功\n");

    vir_led3=ioremap(PHY_LED3_ADDR,sizeof(gpio_t));
    if(vir_led3 ==NULL)
    {
        printk("vir_led3 映射失败\n");
        return -ENOMEM;
    }
    printk("vir_led3 映射成功\n");

    //rcc 地址映射
    vir_rcc=ioremap(PHY_RCC_ADDR,4);
    if(vir_rcc ==NULL)
    {
        printk("vir_rcc 映射失败\n");
        return -ENOMEM;
    }
    printk("vir_rcc 映射成功\n");
    
    //LED1 init
    vir_led1->MODER &= (~(3<<20));
    vir_led1->MODER |= (1<<20);
    vir_led1->ODR &= (~(1<<10));
    
    //LED2 init
    vir_led2->MODER &= (~(3<<20));
    vir_led2->MODER |= (1<<20);
    vir_led2->ODR &= (~(1<<10));

    //LED3 init
    vir_led3->MODER &= (~(3<<16));
    vir_led3->MODER |= (1<<16);
    vir_led3->ODR &= (~(1<<8));
    
    //rcc
    *vir_rcc |= (3<<4);

    return 0;
}

static int __init mycdev_init(void)
{
    int ret1,ret2,i;
    //1,分配设备驱动对象
    cdev=cdev_alloc();
    if(NULL==cdev)
    {
        printk("申请驱动对象空间失败\n");
        ret1 = -ENOMEM;
        goto ERR1;
        //return -ENOMEM;
    }
    //2，初始化对象
    cdev_init(cdev,&fops);
    //3，设备号的申请
    // register_chrdev_region();
    ret1=alloc_chrdev_region(&dev1,0,3,"LED");
    if(ret1 != 0)
    {
        printk("申请设备号失败\n");
        goto ERR2;
    }
    major = MAJOR(dev1);
    minor = MINOR(dev1);
    printk("动态设备号申请成功\n");
    //4，注册字符设备驱动
    ret2=cdev_add(cdev,dev1,3);
    if(ret2 !=0)
    {
        printk("注册设备驱动失败\n");
        goto ERR3;
    }
    printk("注册字符设备驱动成功：%d\n",dev1);

    //5，自动创建设备节点
    //创建目录
    cls=class_create(THIS_MODULE,"LED");
    if(IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        goto ERR4;
    }
    printk("向上提交目录成功\n");
    //创建设备节点  3次
    for(i=0;i<3;i++)
    {
        dev=device_create(cls,NULL,MKDEV(major,i),NULL,"myled%d",i);
        if(IS_ERR(dev))
        {
            printk("向上提交节点失败\n");
            ret2 = PTR_ERR(dev);
            goto ERR5;
        }
    }
    printk("向上提交节点成功\n");
    
    all_led_init();
    
    //初始化自旋锁
    //spin_lock_init(&lock);

    //初始化信号量
    //sema_init(&sem,1);

    return 0;
ERR5:
    for(--i;i>=0;i--)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    class_destroy(cls);
ERR4:
    cdev_del(cdev);
ERR3:
    unregister_chrdev_region(dev1,3);
ERR2:
    kfree(cdev);
ERR1:
    return ret1;

}
static void __exit mycdev_exit(void)
{
    //1，销毁设备节点
    //销毁节点
    int i;
    for(i=0;i<3;i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    
    //销毁目录
    class_destroy(cls);
    //取消物理内存映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_led3);
    iounmap(vir_rcc);
    //2，注销字符设备驱动
    cdev_del(cdev);
    //3,释放设备号
    unregister_chrdev_region(dev1,3);
    //4，释放动态申请的空间
    kfree(cdev);

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

test.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include "myled.h"



int main(int argc, char const *argv[])
{
    char buf[128]={};  //定义数组储存从内存中读取的数值
    //打开驱动文件
    int n;
    int fd,which;
    while (1)
    {
        printf("请输入要打开的灯,1-LED1 2-LED2 3-LED3\n");
        scanf("%d",&n);
        switch(n)
        {
            case 1:
            {
                fd=open("/dev/myled0",O_RDWR);
                which=1;
                if(fd<0)
                {
                    printf("打开设备文件失败");
                    exit(-1);
                }
                printf("设备文件打开成功\n");

                //在终端输入
                while(1)
                {
                    ioctl(fd,LEDON,&which);
                    sleep(1);
                    ioctl(fd,LEDOFF,&which);
                    sleep(1);
                    break;
                }
            }
            break;
            case 2:
            {
                fd=open("/dev/myled1",O_RDWR);
                which=2;
                if(fd<0)
                {
                    printf("打开设备文件失败");
                    exit(-1);
                }
                printf("设备文件打开成功\n");

                //在终端输入
                while(1)
                {
                    ioctl(fd,LEDON,&which);
                    sleep(1);
                    ioctl(fd,LEDOFF,&which);
                    sleep(1);
                    break;
                }
            }
            break;
            case 3:
            {
                fd=open("/dev/myled2",O_RDWR);
                which=3;
                if(fd<0)
                {
                    printf("打开设备文件失败");
                    exit(-1);
                }
                printf("设备文件打开成功\n");

                //在终端输入
                while(1)
                {
                    ioctl(fd,LEDON,&which);
                    sleep(1);
                    ioctl(fd,LEDOFF,&which);
                    sleep(1);
                    break;
                }
            }
            break;
            default:
            printf("输入错误,请重新输入\n");
        }

                
        close(fd);
    }
    

        

    return 0;   
}

myled.h

#ifndef __MYLED_H__
#define __MYLED_H__

typedef struct{
    volatile unsigned int MODER;
    volatile unsigned int OTYPER;
    volatile unsigned int OSPEEDR;
    volatile unsigned int PUPDR;
    volatile unsigned int IDR;
    volatile unsigned int ODR;
    volatile unsigned int BSRR;
}gpio_t;


#define PHY_LED1_ADDR 0X50006000
#define PHY_LED2_ADDR 0X50007000
#define PHY_LED3_ADDR 0X50006000
#define PHY_RCC_ADDR 0x50000A28   

enum LED{
    LED1=1,
    LED2,
    LED3
};

#define LED1_ON _IO('a',1)
#define LED_OFF _IO('a',0)


#define LEDON _IOW('a',1,int)
#define LEDOFF _IOW('a',0,int)


#endif