作業(yè)：
編寫LED驅(qū)動，創(chuàng)建三個設(shè)備文件，每一個設(shè)備文件和一個LED燈綁定，當(dāng)操作這個設(shè)備文件時只能控制對應(yīng)的這盞燈。
1.將GPIO的相關(guān)寄存器封裝成結(jié)構(gòu)體 --------> head.h
2.LED相關(guān)驅(qū)動文件 --------> led.c
led0 ------> LED1
led1 ------> LED2
led2 ------> LED3
3.應(yīng)用層測試文件 --------> test.c文章來源：http://www.zghlxwxcb.cn/news/detail-528974.html
head.h
#ifndef __HEAD_H__
#define __HEAD_H__
//定義寄存器組織結(jié)構(gòu)體
typedef struct{
unsigned int moder;
unsigned int otyper;
unsigned int ospeedr;
unsigned int pupdr;
unsigned int idr;
unsigned int odr;
}gpio_t;
//定義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("打開LED1設(shè)備文件失敗\n");
exit(-1);
}
int fd_led2 = open("/dev/led1", O_RDWR);
if (fd_led2 < 0)
{
printf("打開LED2設(shè)備文件失敗\n");
exit(-1);
}
int fd_led3 = open("/dev/led2", O_RDWR);
if (fd_led3 < 0)
{
printf("打開LED3設(shè)備文件失敗\n");
exit(-1);
}
while (1)
{
// 從終端讀取
printf("請選擇LED1燈功能\n");
printf("0(關(guān)) 1(開)>");
scanf("%d", &a);
printf("請輸入要控制的燈\n");
printf("0(LED1) 1(LED2) 2(LED3)>");
scanf("%d", &b);
if (a == 1) // 開燈
{
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) // 關(guān)燈
{
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; //字符設(shè)備空間首地址
unsigned int major=500; //靜態(tài)申請設(shè)備號
unsigned int minor=0;//次設(shè)備號的起始值
dev_t devno; //動態(tài)申請設(shè)備號
struct class *cls; //接收注冊結(jié)構(gòu)體的地址
struct device *dev; //設(shè)備號
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); //得到次設(shè)備號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; //次設(shè)備號
// 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;
}
// 定義操作方法結(jié)構(gòu)體變量并賦值
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返回錯誤碼
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失敗\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符設(shè)備驅(qū)動對象空間 cdev_alloc
cdev=cdev_alloc(); //字符設(shè)備空間首地址
if(cdev==NULL)
{
printk("申請字符設(shè)備驅(qū)動對象空間失敗\n");
ret=-EFAULT;
goto out1;
}
printk("字符設(shè)備驅(qū)動對象申請成功\n");
//2.字符設(shè)備驅(qū)動對象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申請設(shè)備號 register_chrdev_region/alloc_chrdev_region
if(major>0)//靜態(tài)申請設(shè)備號
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led0"); //設(shè)備號需要是組合出來的,次設(shè)備數(shù)量，設(shè)備文件名
if(ret)
{
printk("靜態(tài)指定設(shè)備號失敗\n");
goto out2;
}
}
else//動態(tài)申請設(shè)備號
{
ret=alloc_chrdev_region(&devno,minor,1,"led0"); //動態(tài)申請設(shè)備號，次設(shè)備號，設(shè)備數(shù)量，文件名
if(ret)
{
printk("動態(tài)申請設(shè)備號失敗\n");
goto out2;
}
major=MAJOR(devno); //根據(jù)設(shè)備號得到主設(shè)備號
minor=MINOR(devno); //根據(jù)設(shè)備號得到次設(shè)備號
}
printk("申請設(shè)備號成功\n");
//4.注冊字符設(shè)備驅(qū)動對象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符設(shè)備，設(shè)備號，設(shè)備數(shù)量
if(ret)
{
printk("注冊字符設(shè)備驅(qū)動對象失敗\n");
goto out3;
}
printk("注冊字符設(shè)備驅(qū)動對象成功\n");
//5.向上提交目錄
cls=class_create(THIS_MODULE,"led0"); //指向自身的指針，文件名
if(IS_ERR(cls))
{
printk("向上提交目錄失敗\n");
ret=-PTR_ERR(cls);
goto out4;
}
printk("向上提交目錄成功\n");
//6.向上提交設(shè)備節(jié)點
dev=device_create(cls,NULL,MKDEV(major,0),NULL,"led0"); //創(chuàng)建設(shè)備節(jié)點
if(IS_ERR(dev))
{
printk("向上提交節(jié)點信息失敗\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交設(shè)備節(jié)點信息成功\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:
//銷毀上面提交的設(shè)備信息
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.銷毀設(shè)備信息 device_destroy
device_destroy(cls,MKDEV(major,0));
//2.銷毀目錄 class_destroy
class_destroy(cls);
//3.注銷對象 cdev_del()
cdev_del(cdev);
//4.釋放設(shè)備號 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.釋放對象空間 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 銷毀設(shè)備節(jié)點信息
device_destroy(cls, MKDEV(major, 0));
// 銷毀字符設(shè)備驅(qū)動
class_destroy(cls);
// 字符設(shè)備驅(qū)動的注銷
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; //字符設(shè)備空間首地址
unsigned int major=500; //靜態(tài)申請設(shè)備號
unsigned int minor=1;//次設(shè)備號的起始值
dev_t devno; //動態(tài)申請設(shè)備號
struct class *cls; //接收注冊結(jié)構(gòu)體的地址
struct device *dev; //設(shè)備號
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); //得到次設(shè)備號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; //次設(shè)備號
// 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;
}
// 定義操作方法結(jié)構(gòu)體變量并賦值
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返回錯誤碼
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失敗\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符設(shè)備驅(qū)動對象空間 cdev_alloc
cdev=cdev_alloc(); //字符設(shè)備空間首地址
if(cdev==NULL)
{
printk("申請字符設(shè)備驅(qū)動對象空間失敗\n");
ret=-EFAULT;
goto out1;
}
printk("字符設(shè)備驅(qū)動對象申請成功\n");
//2.字符設(shè)備驅(qū)動對象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申請設(shè)備號 register_chrdev_region/alloc_chrdev_region
if(major>0)//靜態(tài)申請設(shè)備號
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led1"); //設(shè)備號需要是組合出來的,次設(shè)備數(shù)量，設(shè)備文件名
if(ret)
{
printk("靜態(tài)指定設(shè)備號失敗\n");
goto out2;
}
}
else//動態(tài)申請設(shè)備號
{
ret=alloc_chrdev_region(&devno,minor,1,"led1"); //動態(tài)申請設(shè)備號，次設(shè)備號，設(shè)備數(shù)量，文件名
if(ret)
{
printk("動態(tài)申請設(shè)備號失敗\n");
goto out2;
}
major=MAJOR(devno); //根據(jù)設(shè)備號得到主設(shè)備號
minor=MINOR(devno); //根據(jù)設(shè)備號得到次設(shè)備號
}
printk("申請設(shè)備號成功\n");
//4.注冊字符設(shè)備驅(qū)動對象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符設(shè)備，設(shè)備號，設(shè)備數(shù)量
if(ret)
{
printk("注冊字符設(shè)備驅(qū)動對象失敗\n");
goto out3;
}
printk("注冊字符設(shè)備驅(qū)動對象成功\n");
//5.向上提交目錄
cls=class_create(THIS_MODULE,"led1"); //指向自身的指針，文件名
if(IS_ERR(cls))
{
printk("向上提交目錄失敗\n");
ret=-PTR_ERR(cls);
goto out4;
}
printk("向上提交目錄成功\n");
//6.向上提交設(shè)備節(jié)點
dev=device_create(cls,NULL,MKDEV(major,1),NULL,"led1"); //創(chuàng)建設(shè)備節(jié)點
if(IS_ERR(dev))
{
printk("向上提交節(jié)點信息失敗\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交設(shè)備節(jié)點信息成功\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:
//銷毀上面提交的設(shè)備信息
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.銷毀設(shè)備信息 device_destroy
device_destroy(cls,MKDEV(major,1));
//2.銷毀目錄 class_destroy
class_destroy(cls);
//3.注銷對象 cdev_del()
cdev_del(cdev);
//4.釋放設(shè)備號 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.釋放對象空間 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 銷毀設(shè)備節(jié)點信息
device_destroy(cls, MKDEV(major, 1));
// 銷毀字符設(shè)備驅(qū)動
class_destroy(cls);
// 字符設(shè)備驅(qū)動的注銷
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; //字符設(shè)備空間首地址
unsigned int major=500; //靜態(tài)申請設(shè)備號
unsigned int minor=2;//次設(shè)備號的起始值
dev_t devno; //動態(tài)申請設(shè)備號
struct class *cls; //接收注冊結(jié)構(gòu)體的地址
struct device *dev; //設(shè)備號
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); //得到次設(shè)備號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; //次設(shè)備號
// 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;
}
// 定義操作方法結(jié)構(gòu)體變量并賦值
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返回錯誤碼
// 映射物理地址
vir_gpioe = ioremap(GPIOE, sizeof(gpio_t));
if (vir_gpioe == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
vir_rcc = ioremap(RCC, 4);
if (vir_rcc == NULL)
{
printk("RCC寄存器映射失敗\n");
return -EFAULT;
}
vir_gpiof = ioremap(GPIOF, sizeof(gpio_t));
if (vir_gpiof == NULL)
{
printk("MODER寄存器映射失敗\n");
return -EFAULT;
}
printk("寄存器映射成功\n");
//1.分配字符設(shè)備驅(qū)動對象空間 cdev_alloc
cdev=cdev_alloc(); //字符設(shè)備空間首地址
if(cdev==NULL)
{
printk("申請字符設(shè)備驅(qū)動對象空間失敗\n");
ret=-EFAULT;
goto out1;
}
printk("字符設(shè)備驅(qū)動對象申請成功\n");
//2.字符設(shè)備驅(qū)動對象部分初始化 cdev_init
cdev_init(cdev,&fops);
//3.申請設(shè)備號 register_chrdev_region/alloc_chrdev_region
if(major>0)//靜態(tài)申請設(shè)備號
{
ret=register_chrdev_region(MKDEV(major,minor),1,"led2"); //設(shè)備號需要是組合出來的,次設(shè)備數(shù)量，設(shè)備文件名
if(ret)
{
printk("靜態(tài)指定設(shè)備號失敗\n");
goto out2;
}
}
else//動態(tài)申請設(shè)備號
{
ret=alloc_chrdev_region(&devno,minor,1,"led2"); //動態(tài)申請設(shè)備號，次設(shè)備號，設(shè)備數(shù)量，文件名
if(ret)
{
printk("動態(tài)申請設(shè)備號失敗\n");
goto out2;
}
major=MAJOR(devno); //根據(jù)設(shè)備號得到主設(shè)備號
minor=MINOR(devno); //根據(jù)設(shè)備號得到次設(shè)備號
}
printk("申請設(shè)備號成功\n");
//4.注冊字符設(shè)備驅(qū)動對象 cdev_add()
ret=cdev_add(cdev,MKDEV(major,minor),1); //字符設(shè)備，設(shè)備號，設(shè)備數(shù)量
if(ret)
{
printk("注冊字符設(shè)備驅(qū)動對象失敗\n");
goto out3;
}
printk("注冊字符設(shè)備驅(qū)動對象成功\n");
//5.向上提交目錄
cls=class_create(THIS_MODULE,"led2"); //指向自身的指針，文件名
if(IS_ERR(cls))
{
printk("向上提交目錄失敗\n");
ret=-PTR_ERR(cls);
goto out4;
}
printk("向上提交目錄成功\n");
//6.向上提交設(shè)備節(jié)點
dev=device_create(cls,NULL,MKDEV(major,2),NULL,"led2"); //創(chuàng)建設(shè)備節(jié)點
if(IS_ERR(dev))
{
printk("向上提交節(jié)點信息失敗\n");
ret=-PTR_ERR(dev);
goto out5;
}
printk("向上提交設(shè)備節(jié)點信息成功\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:
//銷毀上面提交的設(shè)備信息
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.銷毀設(shè)備信息 device_destroy
device_destroy(cls,MKDEV(major,2));
//2.銷毀目錄 class_destroy
class_destroy(cls);
//3.注銷對象 cdev_del()
cdev_del(cdev);
//4.釋放設(shè)備號 unregister_chrdev_region()
unregister_chrdev_region(MKDEV(major,minor),1);
//5.釋放對象空間 kfree()
kfree(cdev);
// 取消寄存器地址映射
iounmap(vir_gpioe);
iounmap(vir_rcc);
iounmap(vir_gpiof);
// 銷毀設(shè)備節(jié)點信息
device_destroy(cls, MKDEV(major, 2));
// 銷毀字符設(shè)備驅(qū)動
class_destroy(cls);
// 字符設(shè)備驅(qū)動的注銷
unregister_chrdev(major, "led2");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
實驗結(jié)果
文章來源地址http://www.zghlxwxcb.cn/news/detail-528974.html
到了這里，關(guān)于【編寫LED驅(qū)動，創(chuàng)建三個設(shè)備文件，每一個設(shè)備文件和一個LED燈綁定，當(dāng)操作這個設(shè)備文件時只能控制對應(yīng)的這盞燈】的文章就介紹完了。如果您還想了解更多內(nèi)容，請在右上角搜索TOY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！
