驱动开发DAY4

驱动代码

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "head.h"
dev_t devno;//存放申请的到的设备号的空间首地址
unsigned baseminor;//次设备号的起始值
unsigned count;//申请的设备资源数量
struct cdev *cdev;//申请的字符设备驱动对象指针
char kbuf[128] = {0};//内核空间首地址
unsigned int major=0;
unsigned int minor=0;
struct class *cls;
struct device *dev;
module_param(major,uint,0664);
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;


int mycdev_open(struct inode *inode,struct file *file)
{
    int min=MINOR(inode->i_rdev);
    file->private_data=(void*)min;
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    int min=(int)file->private_data;
    switch (min)
    {
        case 0://控制LED1
            switch (cmd)
            {
                case LED_ON:
                    //开灯
                    vir_led1->ODR |= 1 << 10;
                    break;
                case LED_OFF:
                    //关灯
                    vir_led1->ODR &= (~(1 << 10));
                    break;
            }
            break;
        case 1://控制LED2
            switch (cmd)
            {
                case LED_ON:
                    //开灯
                    vir_led2->ODR |= 1 << 10;
                    break;
                case LED_OFF:
                    //关灯
                    vir_led2->ODR &= (~(1 << 10));
                    break;
            }
            break;
        case 2://控制LED3
            switch (cmd)
            {
                case LED_ON:
                    //开灯
                    vir_led3->ODR |= 1 << 8;
                    break;
                case LED_OFF:
                    //关灯
                    vir_led3->ODR &= (~(1 << 8));
                    break;
            }
            break;

    }
    
    return 0;
}
ssize_t mycdev_read(struct file *file,char *ubuf,size_t size,loff_t *lof)
{
    int ret;
    ret=copy_to_user(ubuf,kbuf,size);
    if (ret)
    {
        printk("copy_to_user err\n");
        return -EIO;
    }
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
ssize_t mycdev_write(struct file *file,const char *ubuf,size_t size,loff_t *lof)
{
    int ret;
    //从用户拷贝
    ret=copy_from_user(kbuf,ubuf,size);
    if (ret)
    {
        printk("copy_from_user err\n");
        return -EIO;
    }
    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对象并且初始化
struct file_operations fops = {
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
    .unlocked_ioctl = mycdev_ioctl,
};
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) |= (0X3 << 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 ret;
    //申请一个字符设备驱动对象空间
     cdev = cdev_alloc();
    if (cdev == NULL)
    {
        printk("申请字符设备对象驱动空间失败\n");
        ret = -EFAULT;
        goto out1;

    }
    printk("字符设备驱动对象成功\n");
    //字符设备设备驱动对象初始化
    cdev_init(cdev,&fops);
    //申请设备号
    if (major > 0)//静态指定设备号
    {
        ret=register_chrdev_region(MKDEV(major,minor),3,"myled");
        if (ret)
        {
            printk("静态申请设备号失败\n");
            goto out2;
        }
    }else if(major == 0)
    {
        int ret= alloc_chrdev_region(&devno,minor,3,"myled");
        if (ret!=0)
        {
            //释放申请的字符设备对象空间
            printk("动态申请设备号失败\n");
            goto out2;
        }
        major=MAJOR(devno);//获取主设备号
        minor=MINOR(devno);//获取次设备号

    }
    printk("申请设备号成功\n");
    //根据申请到的设备号和驱动对象注册驱动
    ret=cdev_add(cdev,MKDEV(major,minor),3);
    if (ret != 0)
    {
        printk("驱动对象注册失败\n");
        goto out3;
    }
    printk("字符设备驱动对象注册成功\n");
    // 寄存器映射以及初始化
    all_led_init();
    //向上提交目录信息
    cls=class_create(THIS_MODULE,"myled");
    if (IS_ERR(cls))
    {
        printk("向上提交目录失败\n");
        ret = -PTR_ERR(cls);
        goto out4;
    }
    printk("向上提交目录成功\n");
    //向上提交设备节点信息
    int i;
    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");
            ret=-PTR_ERR(dev);
            goto out5;
        }
    }
    printk("向上提交设备节点信息成功\n");
    return 0;
out5:
    //释放前一次提交成功的设备信息
    for(--i;i>=0;i--)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    class_destroy(cls);//释放目录



out4:
    cdev_del(cdev);
out3:
    unregister_chrdev_region(MKDEV(major,minor),3);
out2:
    kfree(cdev);
out1:
    return ret;
}
static void __exit mycdev_exit(void)
{
    //释放节点信息
    int i;
    for(i=0;i<3;i++)
    {   
        device_destroy(cls,MKDEV(major,i));

    }
    //销毁目录
    class_destroy(cls);
    // 取消地址映射
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_rcc);

    //注销驱动对象
    cdev_del(cdev);
    //释放设备号
    unregister_chrdev_region(MKDEV(major,minor),3);
    //释放设备空间
    kfree(cdev);


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

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

//构建LED开关的功能码，添加ioctl第三个参数int
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif 

应用代码

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

int main(int argc, char const *argv[])
{
    int a,b;
    int c;
    char buf[128] = {0};
    int fd,fd1,fd2;
    while (1)
    {
        // 从终端读取        
        printf("请输入要控制的灯：0(LED1) 1(LED2) 2(LED3)>");
        scanf("%d",&a);
        switch (a)
        {
        case 0:
            fd = open("/dev/myled0", O_RDWR);
            printf("请输入开灯(1) 关灯(0)>");
            scanf("%d",&b);
            switch (b)
            {
            case 1:
                ioctl(fd, LED_ON,c); // 开灯
                close(fd);
                break;
            case 0:
                ioctl(fd, LED_OFF,c); // 关灯
                break;
                close(fd);
            }
            break;
        case 1:
            fd1 = open("/dev/myled1", O_RDWR);
            printf("请输入开灯(1) 关灯(0)>");
            scanf("%d",&b);
            switch(b)
            {
            case 1:
                ioctl(fd1, LED_ON,c); // 开灯
                close(fd1);
                break;
            case 0:
                ioctl(fd1, LED_OFF,c); // 关灯
                close(fd1);
                break;
            }
            break;           
        case 2:
            fd2 = open("/dev/myled2", O_RDWR);
            printf("请输入开灯(1) 关灯(0)>");
            scanf("%d",&b);
            switch(b)
            {
            case 1:
                ioctl(fd2, LED_ON,c); // 开灯
                close(fd2);
                break;
            case 0:
                ioctl(fd2, LED_OFF,c); // 关灯
                close(fd2);
                break;
            }
            break;
        }
    }

    



    return 0;
}