3月22号作用-优快云博客

本文链接：https://blog.youkuaiyun.com/xiaocaiji0/article/details/129718318

该代码示例展示了如何在Linux内核中编写一个字符设备驱动，通过ioctl系统调用来实现对6个LED灯的开关操作。驱动程序包含了设备的打开、读取、写入和关闭函数，以及ioctl处理函数，用于接收用户空间的控制命令。用户空间的应用程序通过打开设备文件并发送ioctl命令来控制LED的状态。

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题目：通过字符设备驱动分布操作进行6个灯的操作（ioctl）(优快云)

代码：

mycdev.h

#ifndef __MYLED_H__
#define __MYLED_H__

typedef struct {
    volatile unsigned int MODER;   // 0x00
    volatile unsigned int OTYPER;  // 0x04
    volatile unsigned int OSPEEDR; // 0x08
    volatile unsigned int PUPDR;   // 0x0C
    volatile unsigned int IDR;     // 0x10
    volatile unsigned int ODR;     // 0x14
    volatile unsigned int BSRR;    // 0x18
    volatile unsigned int LCKR;    // 0x1C 
    volatile unsigned int AFRL;    // 0x20 
    volatile unsigned int AFRH;    // 0x24
    volatile unsigned int BRR;     // 0x28
    volatile unsigned int res;
    volatile unsigned int SECCFGR; // 0x30
}gpio_t;

enum{
    LED1,
    LED2,
    LED3,
    LED4,
    LED5,
    LED6
};
typedef struct 
{
    int width;
    int high;
}image_t;
//GPIOE基地址
#define PHY_GPIOE_ADDR 0x50006000
#define PHY_GPIOF_ADDR 0x50007000
#define PHY_GPIOZ_ADDR 0x54004000
//RCC基地址：0x50000A28
#define PHY_RCC_LED_123 0x50000A28
#define PHY_RCC_LED_456 0x54000210

#define LED_ON _IOW('a',1,int)
#define LED_OFF _IOW('a',0,int)
#define UACCESS_BUF _IOW('a',1,char[128])
#define UACCESS_STRUCT _IOW('a',1,image_t)



#endif

mycdev.c

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

//#define CNAME "myled"


struct class *cls;
struct device *dev;
char kbuf[128] = {0};

gpio_t *virt_gpioe = NULL;
gpio_t *virt_gpiof = NULL;
gpio_t *virt_gpioz = NULL;
unsigned int *virt_rcc_123 = NULL;
unsigned int *virt_rcc_456 = NULL;

#define LED1_ON (virt_gpioe->ODR |= (0x1 << 10))
#define LED1_OFF (virt_gpioe->ODR &= (~(0x1 << 10)))
#define LED2_ON (virt_gpiof->ODR |= (0x1 << 10))
#define LED2_OFF (virt_gpiof->ODR &= (~(0x1 << 10)))
#define LED3_ON (virt_gpioe->ODR |= (0x1 << 8))
#define LED3_OFF (virt_gpioe->ODR &= (~(0x1 << 8)))
#define LED4_ON (virt_gpioz->ODR |= (0x1 << 5))
#define LED4_OFF (virt_gpioz->ODR &= (~(0x1 << 5)))
#define LED5_ON (virt_gpioz->ODR |= (0x1 << 6))
#define LED5_OFF (virt_gpioz->ODR &= (~(0x1 << 6)))
#define LED6_ON (virt_gpioz->ODR |= (0x1 << 7))
#define LED6_OFF (virt_gpioz->ODR &= (~(0x1 << 7)))

struct cdev *cdev;
dev_t devno;
unsigned int minor=0;

#if 0
    unsigned int majour=0;
#else
    unsigned int major=500;
#endif

int myled_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}
ssize_t myled_read(struct file *file, char __user *ubuf, size_t size, loff_t *loff)
{
    int ret;
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    
    if (size > sizeof(kbuf))
        size = sizeof(kbuf);// 1.校验传输数据的大小，如果用户空间写的数据比内核空间数据大小大，需要更正大小
    
    ret = copy_to_user(ubuf, kbuf, size);// 2.将数据从用户空间拷贝到内核空间
    if (ret) // 3.判断是否错误
    {
        printk("copy to user is error\n");
        return -EIO;
    }
    return size; // 5.返回拷贝数据大小
}
ssize_t myled_write(struct file *file, const char __user *ubuf, size_t size, loff_t *loff)
{
    int ret;
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    
    if (size > sizeof(kbuf))
        size = sizeof(kbuf);// 1.校验传输数据的大小，如果用户空间写的数据比内核空间数据大小大，需要更正大小
    
    ret = copy_from_user(kbuf, ubuf, size);// 2.将数据从用户空间拷贝到内核空间
    if (ret) // 3.判断是否错误
    {
        printk("copy from user is error\n");
        return -EIO;
    }

    return size; // 5.返回拷贝数据大小
}
int myled_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
    return 0;
}
long myled_ioctl(struct file *file, unsigned int cmd, unsigned long args)
{
    int whitch;
    int ret;
    char buf[128];
    image_t image;
    switch (cmd)
    {
    case LED_ON:
        ret = copy_from_user(&whitch, (void *)args, sizeof(int));
        if (ret)
        {
            printk("copy from user is error\n");
            return -EIO;
        }
        switch (whitch)
        {
        case LED1:
            LED1_ON;
            break;
        case LED2:
            LED2_ON;
            break;
        case LED3:
            LED3_ON;
            break;
        case LED4:
            LED4_ON;
            break;
        case LED5:
            LED5_ON;
            break;
        case LED6:
            LED6_ON;
            break;
        }
        break;
    case LED_OFF:
        ret = copy_from_user(&whitch, (void *)args, sizeof(int));
        if (ret)
        {
            printk("copy from user is error\n");
            return -EIO;
        }
        switch (whitch)
        {
        case LED1:
            LED1_OFF;
            break;
        case LED2:
            LED2_OFF;
            break;
        case LED3:
            LED3_OFF;
            break;
        case LED4:
            LED4_OFF;
            break;
        case LED5:
            LED5_OFF;
            break;
        case LED6:
            LED6_OFF;
            break;
        }
        break;
    }
    return 0;
}
const struct file_operations fops = {
    .open = myled_open,
    .read = myled_read,
    .write = myled_write,
    .unlocked_ioctl = myled_ioctl,
    .release = myled_close,
};




static int __init mycdev_init(void)
{
    int ret,i;
    cdev=cdev_alloc();
    if(cdev==NULL)
    {
        printk("分配对象空间失败\n");
        ret=-ENOMEM;
        goto ERR1;
    }
    printk("分配对象空间成功\n");
    cdev_init(cdev,&fops);
    if(major==0)
    {
        ret=alloc_chrdev_region(&devno,minor,1,"mycdev");
        if(ret)
        {
            printk("动态申请设备号失败\n");
            goto ERR2;
        }
        major=MAJOR(devno);
        minor=MINOR(devno);
    }
    else if(major>0)
    {
        ret=register_chrdev_region(MKDEV(major,minor),1,"mycdev");
        if(ret)
        {
            printk("静态设备号失败\n");
            goto ERR2;
        }
    }

    ret=cdev_add(cdev,MKDEV(major,minor),1);
    if(ret)
    {
        printk("驱动对象注册内核失败\n");
        goto ERR3;
    }
    printk("驱动对象注册进内核失败\n");
    cls=class_create(THIS_MODULE,"mycdev");
    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");
    dev=device_create(cls,NULL,MKDEV(major,0),NULL,"mycdev");
    if(IS_ERR(dev)) 
    {
        printk("向上提交节点信息失败\n");
        goto ERR5;
    }

    printk("向上提交设备节点成功\n");

    virt_rcc_123 = ioremap(PHY_RCC_LED_123, 4);
    if (virt_rcc_123 == NULL)
    {
        printk("rcc ioremap is error\n");
        return -ENOMEM;
    }

    virt_rcc_456 = ioremap(PHY_RCC_LED_456, 4);
    if (virt_rcc_456 == NULL)
    {
        printk("rcc ioremap is error\n");
        return -ENOMEM;
    }

    virt_gpioe = ioremap(PHY_GPIOE_ADDR, sizeof(gpio_t));
    if (virt_gpioe == NULL)
    {
        printk("virt_gpioe ioremap is error\n");
        return -ENOMEM;
    }

    virt_gpiof = ioremap(PHY_GPIOF_ADDR, sizeof(gpio_t));
    if (virt_gpiof == NULL)
    {
        printk("virt_gpiof ioremap is error\n");
        return -ENOMEM;
    }

    virt_gpioz = ioremap(PHY_GPIOZ_ADDR, sizeof(gpio_t));
    if (virt_gpioz == NULL)
    {
        printk("virt_gpiof ioremap is error\n");
        return -ENOMEM;
    }

    // 5.对led1---->PE10引脚初始化  对led3---->PE8引脚初始化
    *virt_rcc_123 |= (0x1 << 4);             // 5.1 使能GPIOE组时钟[4]=1
    virt_gpioe->MODER &= (~(0x3 << 20)); // 5.2 设置PE10引脚为输出模式 [21:20] = 01
    virt_gpioe->MODER |= (0x1 << 20);
    virt_gpioe->ODR &= (~(0x1 << 10)); // 5.3 设置PE10引脚输出低电平

    // 6. 对led2---->PF10引脚初始化
    *virt_rcc_123 |= (0x1 << 5);             // 5.1 使能GPIOF组时钟[5]=1
    virt_gpiof->MODER &= (~(0x3 << 20)); // 5.2 设置PF10引脚为输出模式 [21:20] = 01
    virt_gpiof->MODER |= (0x1 << 20);
    virt_gpiof->ODR &= (~(0x1 << 10)); // 5.3 设置PF10引脚输出低电平

    // 7.对led3---->PE8引脚初始化
    virt_gpioe->MODER &= (~(0x3 << 16)); // 5.2 设置PE8引脚为输出模式 [17:16] = 01
    virt_gpioe->MODER |= (0x1 << 16);
    virt_gpioe->ODR &= (~(0x1 << 8)); // 5.3 设置PE8引脚输出低电平

    // 6. 对led4---->PZ5引脚初始化
    *virt_rcc_456 |= (0x1 << 0);             // 5.1 使能GPIOF组时钟[5]=1
    virt_gpioz->MODER &= (~(0x3 << 10)); // 5.2 设置PF10引脚为输出模式 [21:20] = 01
    virt_gpioz->MODER |= (0x1 << 10);
    virt_gpioz->ODR &= (~(0x1 << 5)); // 5.3 设置PF10引脚输出低电平

    // 6. 对led5---->PZ6引脚初始化
    virt_gpioz->MODER &= (~(0x3 << 12)); // 5.2 设置PF10引脚为输出模式 [21:20] = 01
    virt_gpioz->MODER |= (0x1 << 12);
    virt_gpioz->ODR &= (~(0x1 << 6)); // 5.3 设置PF10引脚输出低电平
    
    // 6. 对led6---->PZ7引脚初始化
    virt_gpioz->MODER &= (~(0x3 << 14)); // 5.2 设置PF10引脚为输出模式 [21:20] = 01
    virt_gpioz->MODER |= (0x1 << 14);
    virt_gpioz->ODR &= (~(0x1 << 7)); // 5.3 设置PF10引脚输出低电平

    return 0;
ERR5:
    device_destroy(cls,MKDEV(major,0));
ERR4:
    cdev_del(cdev);
ERR3:
    unregister_chrdev_region(MKDEV(major,minor),1);
ERR2:
    kfree(cdev);
ERR1:
    return ret;
}

static void __exit mycdev_exit(void)
{
    device_destroy(cls,MKDEV(major,0));
    class_destroy(cls);
    cdev_del(cdev);
    unregister_chrdev_region(MKDEV(major,minor),1);
    kfree(cdev);

    // 2.取消地址映射
    iounmap(virt_rcc_123);
    iounmap(virt_rcc_456);
    iounmap(virt_gpioe);
    iounmap(virt_gpiof);
    iounmap(virt_gpioz);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

text.c

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

/// @brief 
/// @param argc 
/// @param argv 
/// @return 
int main(int argc, const char *argv[])
{
    int whitch;
    char buf[128] = {0};
    image_t image;
    image.high=200;
    image.width=10;
    int fd = -1;

    fd = open("/dev/mycdev", O_RDWR);
    if (fd == -1)
    {
        perror("open is error\n");
        return -1;
    }
    /*
    ioctl(fd,UACCESS_STRUCT,&image);
    printf("用户空间: width=%d  high=%d\n",image.width,image.high);

    printf("please input------>");
    fgets(buf,sizeof(buf),stdin);
    buf[strlen(buf)-1]=0;
    ioctl(fd,UACCESS_BUF,buf);
    */
    
    while (1)
    {
        
        whitch = LED1;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);

        whitch = LED2;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);

        whitch = LED3;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);

        whitch = LED4;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);

        whitch = LED5;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);

        whitch = LED6;
        ioctl(fd, LED_ON, &whitch);
        sleep(1);
        ioctl(fd, LED_OFF, &whitch);
        sleep(1);
        
    }
    close(fd);
    return 0;
}