作业：
编写LED驱动，创建三个设备文件，每一个设备文件和一个LED灯绑定，当操作这个设备文件时只能控制对应的这盏灯。
1.将GPIO的相关寄存器封装成结构体 --------> head.h
2.LED相关驱动文件 --------> led.c
led0 ------> LED1
led1 ------> LED2
led2 ------> LED3
3.应用层测试文件 --------> test.c文章来源：https://www.toymoban.com/news/detail-528974.html
head.h
#ifndef __HEAD_H__
#define __HEAD_H__
//定义寄存器组织结构体
typedef struct{
unsigned int moder;
unsigned int otyper;
unsigned int ospeedr;
unsigned int pupdr;
unsigned int idr;
unsigned int odr;
}gpio_t;
//定义GPIOE和GPIOF
#define GPIOE 0X50006000 //LED1 PE10 LED3 PE8
#define GPIOF 0X50007000 //LED2 PF10
//#define GPIOB 0X50003000
#define RCC 0X50000A28
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif
test.c
#include <stdio.h>
#include <stdlib.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[])
{
int a, b;
char buf[128] = {0};
int fd_led1 = open("/dev/led0", O_RDWR);
if (fd_led1 < 0)
{
printf("打开LED1设备文件失败\n");
exit(-1);
}
int fd_led2 = open("/dev/led1", O_RDWR);
if (fd_led2 < 0)
{
printf("打开LED2设备文件失败\n");
exit(-1);
}
int fd_led3 = open("/dev/led2", O_RDWR);
if (fd_led3 < 0)
{
printf("打开LED3设备文件失败\n");
exit(-1);
}
while (1)
{
// 从终端读取
printf("请选择LED1灯功能\n");
printf("0(关) 1(开)>");
scanf("%d", &a);
printf("请输入要控制的灯\n");
printf("0(LED1) 1(LED2) 2(LED3)>");
scanf("%d", &b);
if (a == 1) // 开灯
{
switch (b)
{
case 0:
ioctl(fd_led1, LED_ON, b);
break;
case 1:
ioctl(fd_led2, LED_ON, b);
break;
case 2:
ioctl(fd_led3, LED_ON, b);
break;
}
}
else if (a == 0) // 关灯
{
switch (b)
{
case 0:
ioctl(fd_led1, LED_OFF, b);
break;
case 1:
ioctl(fd_led2, LED_OFF, b);
break;
case 2:
ioctl(fd_led3, LED_OFF, b);
break;
}
}
}
close(fd_led1);
close(fd_led2);
close(fd_led3);
return 0;
}
led0.c
#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 "head.h"
struct cdev *cdev; //字符设备空间首地址
unsigned int major=500; //静态申请设备号
unsigned int minor=0;//次设备号的起始值
dev_t devno; //动态申请设备号
struct class *cls; //接收注册结构体的地址
struct device *dev; //设备号
gpio_t *vir_gpioe;
gpio_t *vir_gpiof;
unsigned int *vir_rcc;
int mycdev_open(struct inode *inode, struct file *file)
{
unsigned int aaa = MINOR(inode->i_rdev); //得到次设备号aaa
file->private_data = (void *)aaa;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int aaa = (int)file->private_data; //次设备号
// 功能控制
switch (cmd)
{
case LED_ON:
switch (aaa)
{
case 0:
vir_gpioe->odr |= (0x1 << 10);
break;
}
break;
case LED_OFF:
switch (aaa)
{
case 0:
vir_gpioe->odr &= (~(0x1 << 10));
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并赋值
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void) //寄存器地址映射和初始化
{
int ret; //ret返回错误码
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失败\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符设备驱动对象空间 cdev_alloc
cdev=cdev_alloc(); //字符设备空间首地址
if(cdev==NULL)
{
printk("申请字符设备驱动对象空间失败\n");
ret=-EFAULT;
goto out1;
}
printk("字符设备驱动对象申请成功\n");
//2.字符设备驱动对象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申请设备号 register_chrdev_region/alloc_chrdev_region
if(major>0)//静态申请设备号
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led0"); //设备号需要是组合出来的,次设备数量，设备文件名
if(ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
}
else//动态申请设备号
{
ret=alloc_chrdev_region(&devno,minor,1,"led0"); //动态申请设备号，次设备号，设备数量，文件名
if(ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
major=MAJOR(devno); //根据设备号得到主设备号
minor=MINOR(devno); //根据设备号得到次设备号
}
printk("申请设备号成功\n");
//4.注册字符设备驱动对象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符设备，设备号，设备数量
if(ret)
{
printk("注册字符设备驱动对象失败\n");
goto out3;
}
printk("注册字符设备驱动对象成功\n");
//5.向上提交目录
cls=class_create(THIS_MODULE,"led0"); //指向自身的指针，文件名
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");
//6.向上提交设备节点
dev=device_create(cls,NULL,MKDEV(major,0),NULL,"led0"); //创建设备节点
if(IS_ERR(dev))
{
printk("向上提交节点信息失败\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交设备节点信息成功\n");
(*vir_rcc) |= (0x3 << 4);
// 寄存器初始化led1
vir_gpioe->moder &= (~(0x3 << 20));
vir_gpioe->moder |= (0x1 << 20);
vir_gpioe->odr &= (~(0x1 << 10));
printk("LED1硬件寄存器初始化成功\n");
return 0;
out5:
//销毁上面提交的设备信息
device_destroy(cls,MKDEV(major,0));
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),1);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
//1.销毁设备信息 device_destroy
device_destroy(cls,MKDEV(major,0));
//2.销毁目录 class_destroy
class_destroy(cls);
//3.注销对象 cdev_del()
cdev_del(cdev);
//4.释放设备号 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.释放对象空间 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 销毁设备节点信息
device_destroy(cls, MKDEV(major, 0));
// 销毁字符设备驱动
class_destroy(cls);
// 字符设备驱动的注销
unregister_chrdev(major, "led0");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
led1.c
#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 "head.h"
struct cdev *cdev; //字符设备空间首地址
unsigned int major=500; //静态申请设备号
unsigned int minor=1;//次设备号的起始值
dev_t devno; //动态申请设备号
struct class *cls; //接收注册结构体的地址
struct device *dev; //设备号
gpio_t *vir_gpioe;
gpio_t *vir_gpiof;
unsigned int *vir_rcc;
int mycdev_open(struct inode *inode, struct file *file)
{
unsigned int aaa = MINOR(inode->i_rdev); //得到次设备号aaa
file->private_data = (void *)aaa;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int aaa = (int)file->private_data; //次设备号
// 功能控制
switch (cmd)
{
case LED_ON:
switch (aaa)
{
case 1:
vir_gpiof->odr |= (0x1 << 10);
break;
}
break;
case LED_OFF:
switch (aaa)
{
case 1:
vir_gpiof->odr &= (~(0x1 << 10));
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并赋值
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void) //寄存器地址映射和初始化
{
int ret; //ret返回错误码
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失败\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符设备驱动对象空间 cdev_alloc
cdev=cdev_alloc(); //字符设备空间首地址
if(cdev==NULL)
{
printk("申请字符设备驱动对象空间失败\n");
ret=-EFAULT;
goto out1;
}
printk("字符设备驱动对象申请成功\n");
//2.字符设备驱动对象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申请设备号 register_chrdev_region/alloc_chrdev_region
if(major>0)//静态申请设备号
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led1"); //设备号需要是组合出来的,次设备数量，设备文件名
if(ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
}
else//动态申请设备号
{
ret=alloc_chrdev_region(&devno,minor,1,"led1"); //动态申请设备号，次设备号，设备数量，文件名
if(ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
major=MAJOR(devno); //根据设备号得到主设备号
minor=MINOR(devno); //根据设备号得到次设备号
}
printk("申请设备号成功\n");
//4.注册字符设备驱动对象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符设备，设备号，设备数量
if(ret)
{
printk("注册字符设备驱动对象失败\n");
goto out3;
}
printk("注册字符设备驱动对象成功\n");
//5.向上提交目录
cls=class_create(THIS_MODULE,"led1"); //指向自身的指针，文件名
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");
//6.向上提交设备节点
dev=device_create(cls,NULL,MKDEV(major,1),NULL,"led1"); //创建设备节点
if(IS_ERR(dev))
{
printk("向上提交节点信息失败\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交设备节点信息成功\n");
(*vir_rcc) |= (0x3 << 4);
// 寄存器初始化led1
vir_gpiof->moder &= (~(0x3 << 20));
vir_gpiof->moder |= (0x1 << 20);
vir_gpiof->odr &= (~(0x1 << 10));
printk("LED2硬件寄存器初始化成功\n");
return 0;
out5:
//销毁上面提交的设备信息
device_destroy(cls,MKDEV(major,1));
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),1);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
//1.销毁设备信息 device_destroy
device_destroy(cls,MKDEV(major,1));
//2.销毁目录 class_destroy
class_destroy(cls);
//3.注销对象 cdev_del()
cdev_del(cdev);
//4.释放设备号 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.释放对象空间 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 销毁设备节点信息
device_destroy(cls, MKDEV(major, 1));
// 销毁字符设备驱动
class_destroy(cls);
// 字符设备驱动的注销
unregister_chrdev(major, "led1");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
led2.c
#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 "head.h"
struct cdev *cdev; //字符设备空间首地址
unsigned int major=500; //静态申请设备号
unsigned int minor=2;//次设备号的起始值
dev_t devno; //动态申请设备号
struct class *cls; //接收注册结构体的地址
struct device *dev; //设备号
gpio_t *vir_gpioe;
gpio_t *vir_gpiof;
unsigned int *vir_rcc;
int mycdev_open(struct inode *inode, struct file *file)
{
unsigned int aaa = MINOR(inode->i_rdev); //得到次设备号aaa
file->private_data = (void *)aaa;
printk("%s:%s:%d\n", __FILE__, __func__, __LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int aaa = (int)file->private_data; //次设备号
// 功能控制
switch (cmd)
{
case LED_ON:
switch (aaa)
{
case 2:
vir_gpioe->odr |= (0x1 << 8);
break;
}
break;
case LED_OFF:
switch (aaa)
{
case 2:
vir_gpioe->odr &= (~(0x1 << 8));
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并赋值
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void) //寄存器地址映射和初始化
{
int ret; //ret返回错误码
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失败\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失败\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符设备驱动对象空间 cdev_alloc
cdev=cdev_alloc(); //字符设备空间首地址
if(cdev==NULL)
{
printk("申请字符设备驱动对象空间失败\n");
ret=-EFAULT;
goto out1;
}
printk("字符设备驱动对象申请成功\n");
//2.字符设备驱动对象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申请设备号 register_chrdev_region/alloc_chrdev_region
if(major>0)//静态申请设备号
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led2"); //设备号需要是组合出来的,次设备数量，设备文件名
if(ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
}
else//动态申请设备号
{
ret=alloc_chrdev_region(&devno,minor,1,"led2"); //动态申请设备号，次设备号，设备数量，文件名
if(ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
major=MAJOR(devno); //根据设备号得到主设备号
minor=MINOR(devno); //根据设备号得到次设备号
}
printk("申请设备号成功\n");
//4.注册字符设备驱动对象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符设备，设备号，设备数量
if(ret)
{
printk("注册字符设备驱动对象失败\n");
goto out3;
}
printk("注册字符设备驱动对象成功\n");
//5.向上提交目录
cls=class_create(THIS_MODULE,"led2"); //指向自身的指针，文件名
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");
//6.向上提交设备节点
dev=device_create(cls,NULL,MKDEV(major,2),NULL,"led2"); //创建设备节点
if(IS_ERR(dev))
{
printk("向上提交节点信息失败\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交设备节点信息成功\n");
(*vir_rcc) |= (0x3 << 4);
// 寄存器初始化led1
vir_gpioe->moder &= (~(0x3 << 16));
vir_gpioe->moder |= (0x1 << 16);
vir_gpioe->odr &= (~(0x1 << 8));
printk("LED1硬件寄存器初始化成功\n");
return 0;
out5:
//销毁上面提交的设备信息
device_destroy(cls,MKDEV(major,2));
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),1);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
//1.销毁设备信息 device_destroy
device_destroy(cls,MKDEV(major,2));
//2.销毁目录 class_destroy
class_destroy(cls);
//3.注销对象 cdev_del()
cdev_del(cdev);
//4.释放设备号 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.释放对象空间 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 销毁设备节点信息
device_destroy(cls, MKDEV(major, 2));
// 销毁字符设备驱动
class_destroy(cls);
// 字符设备驱动的注销
unregister_chrdev(major, "led2");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
实验结果
文章来源地址https://www.toymoban.com/news/detail-528974.html
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