头文件代码

#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 

 应用层代码

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include "head.h"int main(int argc, char const *argv[])
{char buf[128] = {0};int a, b;int fd;while (1){// 从终端读取printf("请输入要打开哪个设备>");printf("0:LED1 1:LED2 2:LED3\n");printf("请输入>");scanf("%d", &b);if (b == 0){fd = open("/dev/mycdev0", O_RDWR);}else if (b == 1){fd = open("/dev/mycdev1", O_RDWR);}else if (b == 2){fd = open("/dev/mycdev2", O_RDWR);}if (fd < 0){printf("打开设备文件失败\n");exit(-1);}printf("请输入指令\n");printf("0(关灯) 1(开灯)\n");printf("请输入>");scanf("%d", &a);switch (a){case 1:ioctl(fd, LED_ON); // 开灯break;case 0:ioctl(fd, LED_OFF);break;}close(fd);}return 0;
}

 驱动代码

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include<linux/slab.h>
#include<linux/cdev.h>
#include "head.h"dev_t devid;
struct cdev *cdev;
unsigned int major = 500;
unsigned int minor = 0;
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{//获取当前设备文件对应的设备号int which_dev = inode->i_rdev;//将次设备号保存到当前文件的file结构中file->private_data = (void *)MINOR(which_dev);printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{unsigned int which_dev = (unsigned int)file->private_data; switch(which_dev){case 0://LED1控制逻辑；if(cmd == LED_ON){vir_led1->ODR |= (0x1 << 10); // LED1开灯}else if(cmd == LED_OFF){vir_led1->ODR &= (~(0X1 << 10));}break;   case 1://LED2控制逻辑；if(cmd == LED_ON){vir_led2->ODR |= (0x1 << 10); // LED2开灯}else if(cmd == LED_OFF){vir_led2->ODR &= (~(0X1 << 10));}break; case 2://LED3控制逻辑；if(cmd == LED_ON){vir_led3->ODR |= (0x1 << 8); // LED3开灯}else if(cmd == LED_OFF){vir_led3->ODR &= (~(0X1 << 8));}break;                          }return 0;
}ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{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)
{printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}int mycdev_close(struct inode *inode, struct file *file)
{printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);return 0;
}// 定义操作方法风扇结构体变量并赋值
struct file_operations fops = {.open = mycdev_open,.unlocked_ioctl = mycdev_ioctl,.release = mycdev_close,.read = mycdev_read,.write = mycdev_write,
};// 灯的寄存器映射以及初始化
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);// led1vir_led1->MODER &= (~(3 << 20));vir_led1->MODER |= (1 << 20);vir_led1->ODR &= (~(1 << 10));// led2vir_led2->MODER &= (~(3 << 20));vir_led2->MODER |= (1 << 20);vir_led2->ODR &= (~(1 << 10));// led3vir_led3->MODER &= (~(3 << 16));vir_led1->MODER |= (1 << 16);vir_led1->ODR &= (~(1 << 8));printk("灯的寄存器初始化成功\n");return 0;
}static int __init mycdev_init(void)
{int ret;// 1.申请对象空间 cdev_alloccdev = cdev_alloc();if (cdev == NULL){printk("申请驱动对象空间失败\n");ret = -EFAULT;goto OUT1;}printk("申请驱动对象空间成功\n");// 2.初始化对象  cdev_initcdev_init(cdev, &fops);// 3.申请设备号  register_chrdev_region()/alloc_chrdev_region()// 动态申请if (major == 0){ret = alloc_chrdev_region(&devid, minor, 3, "mycdev");if (ret != 0){printk("动态申请设备号失败\n");goto OUT2;}//统一后面的操作major = MAJOR(devid); //根据设备号获取主设备号minor = MINOR(devid);}//静态指定申请else{ret = register_chrdev_region(MKDEV(major,minor),3,"mycdev");if(ret != 0){printk("静态指定设备号失败\n");goto OUT2;}}printk("申请设备号成功\n");// 4.注册驱动对象 cdev_add()ret = cdev_add(cdev, MKDEV(major,minor), 3);if (ret != 0){printk("注册设备驱动对象失败\n");goto OUT3;}printk("注册设备驱动对象成功\n");// 5.向上提交目录  class_create()cls = class_create(THIS_MODULE, "mycdev");if (IS_ERR(cls)){printk("向上提交目录失败\n");goto OUT4;}printk("向上提交目录成功\n");// 6.向上提交设备信息 device_create()int i;for (i = 0; i < 3; i++){dev = device_create(cls, NULL, MKDEV(major, i), NULL, "mycdev%d",i);}if (IS_ERR(dev)){printk("向上提交设备节点信息失败\n");goto OUT5;}printk("向上提交设备节点信息成功\n");// 灯的寄存器映射以及初始化all_led_init();return 0;
OUT5:
//将提交成功的设备信息销毁
for(--i;i>=0;i--)
{device_destroy(cls,MKDEV(major,i));
}
OUT4:class_destroy(cls);
OUT3:unregister_chrdev_region(MKDEV(major,minor), 3);
OUT2:kfree(cdev);
OUT1:return ret;
}static void __exit mycdev_exit(void)
{// 取消地址映射iounmap(vir_led1);iounmap(vir_led2);iounmap(vir_rcc);// 1.销毁设备信息  device_destroyint i;for(i=0;i<3;i++){device_destroy(cls,MKDEV(major,i));}// 2.销毁目录    class_destroyclass_destroy(cls);// 3.注销驱动对象  cdev_delcdev_del(cdev);// 4.释放设备号   unregister_chrdev_region()unregister_chrdev_region(MKDEV(major,minor),3);// 5.释放对象空间   kfree()kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");