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驱动开发day4（实现通过字符设备驱动的分布实现编写LED驱动，实现设备文件的绑定）

news 2025/9/15 14:55:35

头文件（head.h）

#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_LED1_MODER 0x50006000
#define PHY_LED2_MODER 0x50007000
#define PHY_LED3_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED2_ODR 0x50007014
#define PHY_LED3_ODR 0x50006014
#define PHY_RCC 0x50000A28
//构建开灯关灯的功能码
#define LED_ON _IO('l',1)
#define LED_OFF _IO('l',0)
#endif

c文件：

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include "head.h"
int main(int argc, char const *argv[])
{char buf[128] = "";int a;int fd = open("/dev/mycdev1", O_RDWR);if (fd < 0){printf("打开设备文件失败\n");return -1;}printf("打开设备文件成功\n");while (1){printf("请输入要进行的操作,0(关灯),1(开灯) >");scanf("%d", &a);switch (a){case 1:ioctl(fd, LED_ON);break;case 0:ioctl(fd, LED_OFF);break;}}close(fd);return 0;
}

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include "head.h"
struct cdev *cdev;
unsigned int major = 0;
unsigned int minor = 0;
dev_t devno;
// 定义RCC控制器指针指向映射后的虚拟内存
unsigned int *vir_rcc;
// LED1定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led1;
unsigned int *vir_odr_led1;
// LED2定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led2;
unsigned int *vir_odr_led2;
// LED3定义两个指针指向映射后的虚拟内存
unsigned int *vir_moder_led3;
unsigned int *vir_odr_led3;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{// 获取打开的文件的次设备号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 args)
{// 获取文件的次设备号int min = (int)file->private_data;switch (min){case 0://操作LED1switch(cmd){case LED_ON:(*vir_odr_led1) |= (0x1 << 10); // LED1开灯break;case LED_OFF:(*vir_odr_led1) &= (~(0x1 << 10)); // LED1关灯break;}break;case 1://操作LED2switch(cmd){case LED_ON:(*vir_odr_led2) |= (0x1 << 10); // LED2开灯break;case LED_OFF:(*vir_odr_led2) &= (~(0x1 << 10)); // LED2关灯break;}break;case 2://操作LED3switch(cmd){case LED_ON:(*vir_odr_led3) |= (0x1 << 10); // LED3开灯break;case LED_OFF:(*vir_odr_led3) &= (~(0x1 << 10)); // LED3关灯break;}break;}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变量赋值
struct file_operations fops = {.open = mycdev_open,.unlocked_ioctl = mycdev_ioctl,.release = mycdev_close,};
static int __init mycdev_init(void)
{int ret;// 1.申请一个对象空间 cdev_alloccdev = cdev_alloc();if (cdev == NULL){printk("申请字符设备驱动对象失败");ret = -EFAULT;goto cont1;}printk("字符设备驱动对象申请成功\n");// 2.初始化对象 cdev_initcdev_init(cdev, &fops);// 3.申请设备号 register_chrdev_region()/alloc_chrdev_region()if (major == 0) // 动态申请模拟{ret = alloc_chrdev_region(&devno, minor, 3, "mychrdev");if (ret){printk("动态申请设备号失败\n");goto cont2;}major = MAJOR(devno); // 根据设备号获取主设备号minor = MINOR(devno); // 根据设备号获取次设备号}else // 静态申请模拟{ret = register_chrdev_region(MKDEV(major, minor), 3, "mychrdev");if (ret){printk("静态指定设备号失败\n");goto cont2;}}printk("设备号申请成功\n");// 4.注册驱动对象 cdev_addret = cdev_add(cdev, MKDEV(major, minor), 3);if (ret){printk("注册驱动对象失败\n");goto cont3;}printk("注册字符设备驱动对象成功\n");// 5.向上提交目录 class_createcls = class_create(THIS_MODULE, "mychrdev");if (IS_ERR(cls)){printk("向上提交目录失败\n");goto cont4;}printk("向上提交目录成功\n");// 6.向上提交设备节点信息 device_createint i;for (i = 0; i < 3; i++){dev = device_create(cls, NULL, MKDEV(major, i), NULL, "mycdev%d", i);if (IS_ERR(dev)){printk("向上提交设备节点失败\n");goto cont5;}}printk("向上提交设备节点信息成功\n");// RCC控制器地址映射vir_rcc = ioremap(PHY_RCC, 4);if (vir_rcc == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}// LED1进行寄存器的地址映射vir_moder_led1 = ioremap(PHY_LED1_MODER, 4);if (vir_moder_led1 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}vir_odr_led1 = ioremap(PHY_LED1_ODR, 4);if (vir_odr_led1 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}printk("LED1寄存器内存映射成功\n");// LED2进行寄存器的地址映射vir_moder_led2 = ioremap(PHY_LED2_MODER, 4);if (vir_moder_led2 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}vir_odr_led2 = ioremap(PHY_LED2_ODR, 4);if (vir_odr_led2 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}printk("LED2寄存器内存映射成功\n");// LED3进行寄存器的地址映射vir_moder_led3 = vir_moder_led1;if (vir_moder_led3 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}vir_odr_led3 = vir_odr_led1;if (vir_odr_led3 == NULL){printk("物理内存地址映射失败%d\n", __LINE__);return -1;}printk("LED3寄存器内存映射成功\n");// RCC寄存器初始化(*vir_rcc) |= (0x3 << 4); // GPIOE/GPIOF控制器时钟使能// LED1寄存器初始化(*vir_moder_led1) &= (~(0x3 << 20)); // MODER[21:20]->00(*vir_moder_led1) |= (0x1 << 20);    // MODER[21:20]->01(*vir_odr_led1) &= (~(0x1 << 10));   // 默认关灯// LED2寄存器初始化(*vir_moder_led2) &= (~(0x3 << 20)); // MODER[21:20]->00(*vir_moder_led2) |= (0x1 << 20);    // MODER[21:20]->01(*vir_odr_led2) &= (~(0x1 << 10));   // 默认关灯// LED3寄存器初始化(*vir_moder_led3) &= (~(0x3 << 16)); // MODER[17:16]->00(*vir_moder_led3) |= (0x1 << 16);    // MODER[17:16]->01(*vir_odr_led3) &= (~(0x1 << 8));    // 默认关灯return 0;
cont5:// 将提交成功的节点信息释放for (--i; i > 0; i--){device_destroy(cls, MKDEV(major, i));}// 销毁目录class_destroy(cls);
cont4:cdev_del(cdev);
cont3:unregister_chrdev_region(MKDEV(major, minor), 3);
cont2:kfree(cdev);
cont1:return ret;
}
static void __exit mycdev_exit(void)
{// 取消RCC控制器内存映射iounmap(vir_rcc);// 取消LED1内存映射iounmap(vir_moder_led1);iounmap(vir_odr_led1);// 取消LED2内存映射iounmap(vir_moder_led2);iounmap(vir_odr_led2);// 1.销毁设备节点信息int i;for (i = 0; i < 3; i++){device_destroy(cls, MKDEV(major, i));}// 2.销毁目录class_destroy(cls);// 3.注销字符设备驱动对象cdev_del(cdev);// 4.释放设备号unregister_chrdev_region(MKDEV(major, minor), 3);// 5.释放申请到的字符设备驱动对象空间kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");