驱动开发-LED驱动

创建三个设备文件，每个设备文件绑定一个设备。

头文件

#ifndef __HEAD_H__
#define __HEAD_H__ 
typedef struct{
    unsigned int MODER;
    unsigned int OTYPER;
    unsigned int OSPEEDR;
    unsigned int PUPDR;
    unsigned int IDR;
    unsigned int ODR;
}gpio_t;

#define PHY_LED1_ADDR 0X50006000
#define PHY_LED2_ADDR    0X50007000
#define PHY_LED3_ADDR 0X50006000
#define PHY_RCC_ADDR    0X50000A28

//功能码
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)

#endif 

应用程序

#include
#include
#include 
#include 
#include 
#include
#include
#include
#include"head.h"

int main(int argc, char const *argv[])
{
    char buf[128] = {0};
    int a,b;
    int fd;
    while (1)
    {
        printf("请输入要控制的灯：0(led1) 1(led2) 2(led3)\n");
        scanf("%d",&a);
        if(a == 0)
        {
            fd = open("/dev/myled0", O_RDWR);
            if (fd < 0)
            {
                printf("打开设备文件失败\n");
                exit(-1);
            }
        }

        else if(a == 1)
        {
            fd = open("/dev/myled1", O_RDWR);
            if (fd < 0)
            {
                printf("打开设备文件失败\n");
                exit(-1);
            }
        }

        else if(a == 2)
        {
            fd = open("/dev/myled2", O_RDWR);
            if (fd < 0)
            {
                printf("打开设备文件失败\n");
                exit(-1);
            }
        }
    
        printf("请输入控制命令:0(关闭) 1(开灯)>");

        scanf("%d",&b);
        switch(b)
        {
            case 1:
                ioctl(fd,LED_ON);
                break;
            case 0:
                ioctl(fd,LED_OFF);
                break;
        }
        close(fd);
    }

    return 0;
}

驱动程序

#include 
#include 
#include
#include
#include
#include"head.h"

unsigned int major;//定义一个变量保存主设备号

char kbuf[128]={0};

gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;

struct class *cls;
struct device*dev;


//封装操作方法
int mycdev_open(struct inode *inode, struct file *file)
{
    int a = inode->i_rdev;//获取当前设备文件对应的设备号
    file->private_data=(void*)MINOR(a);//将次设备号保存到当前文件的file结构中
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}


long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    unsigned int a=(unsigned int)file->private_data;
    switch(a)
    {
        case 0:
            if(cmd == LED_ON)
            vir_led1->ODR |= (0x1 << 10); // LED1开灯
            else
            vir_led1->ODR &= (~(0X1 << 10));
            break;   
        case 1:
            if(cmd == LED_ON)
            vir_led2->ODR |= (0x1 << 10); // LED2开灯
            else
            vir_led2->ODR &= (~(0X1 << 10));
            break; 
        case 2:
            if(cmd == LED_ON)
            vir_led3->ODR |= (0x1 << 8); // LED3开灯
            else
            vir_led3->ODR &= (~(0X1 << 8));
            break;                          
    }
    return 0;
}

int mycdev_close(struct inode *inode, struct file *file)
{
     printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
//定义一个操作方法结构体变量并且初始化
struct file_operations fops={
    .open=mycdev_open,
    .release=mycdev_close,
    .unlocked_ioctl = mycdev_ioctl,
};

//灯的初始化
int all_led_init(void)
{
    //寄存器地址的映射
    vir_led1=ioremap(PHY_LED1_ADDR,sizeof(gpio_t));
    if(vir_led1==NULL)
    {
        printk("ioremap filed：%d\n",__LINE__);
        return -ENOMEM;
    }
     vir_led2=ioremap(PHY_LED2_ADDR,sizeof(gpio_t));
    if(vir_led2==NULL)
    {
        printk("ioremap filed：%d\n",__LINE__);
        return -ENOMEM;
    }
     vir_led3=vir_led1;
    vir_rcc=ioremap(PHY_RCC_ADDR,4);
    if(vir_rcc==NULL)
    {
        printk("ioremap filed：%d\n",__LINE__);
        return -ENOMEM;
    }
    printk("物理地址映射成功\n");
    //寄存器的初始化
    //rcc
    (*vir_rcc) |= (3<<4);
    //led1
    vir_led1->MODER &= (~(3<<20));
    vir_led1->MODER |= (1<<20);
    vir_led1->ODR &= (~(1<<10));
    //led2
    vir_led2->MODER &= (~(3<<20));
    vir_led2->MODER |= (1<<20);
    vir_led2->ODR &= (~(1<<10));
    //led3
    vir_led3->MODER &= (~(3<<16));
    vir_led1->MODER |= (1<<16);
    vir_led1->ODR &= (~(1<<8));
    printk("寄存器初始化成功\n");

    return 0;
}

static int __init mycdev_init(void)
{
    int i;
    // 字符设备驱动注册
    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);
    // 向上提交目录
    cls = class_create(THIS_MODULE, "myled");
    if (IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        return -PTR_ERR(cls);
    }
    printk("向上提交目录信息成功\n");
    // 向上提交设备节点信息
    for (i = 0; i < 3; i++)
    {
        dev = device_create(cls, NULL, MKDEV(major, i), NULL, "myled%d", i);
        if (IS_ERR(dev))
        {
            printk("向上提交设备节点信息失败\n");
            return -PTR_ERR(dev);
        }
    }
    printk("向上提交设备节点成功\n");
    // 寄存器映射以及初始化
    all_led_init();

    return 0;
}
static void __exit mycdev_exit(void)
{
    //取消地址映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_led3);
    iounmap(vir_rcc);
    //销毁设备节点信息
    int i;
    for(i=0;i<3;i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    //销毁目录信息
    class_destroy(cls);
    //注销字符设备驱动
    unregister_chrdev(major,"mychrdev");

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