头文件
#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
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif
应用程序
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include "head.h"
int main(int argc,char const *argv[])
{
char buf[128]={0};
int a,b;
int fd=open("/dev/demo0",O_RDWR);
if(fd<0)
{
printf("打开设备文件失败\n");
exit(-1);
}
while(1)
{
//从终端读取
printf("请输入要实现的功能 ");
printf("0(关灯) 1(开灯)\n");
printf("请输入>");
scanf("%d",&a);
printf("请选择要控制的灯：1（LED1）2(LED2) 3(LED3)\n");
printf("请输入>");
scanf("%d",&b);
switch(a)
{
case 1:
ioctl(fd,LED_ON,&b);
break;
case 0:
ioctl(fd,LED_OFF,&b);
break;
}
}
close(fd);
return 0;
}驱动程序
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include "head.h"
unsigned int major=0;
unsigned int minor=0;
char kbuf[128]={};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct cdev *cdev;
dev_t devno;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{
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 arg)
{
int min=(int)file->private_data;
switch (min)
{
case 0: // 操作LED1
switch (cmd)
{
case LED_ON: //开灯
vir_led1->ODR |= (0x1<<10);
break;
case LED_OFF://关灯
vir_led1->ODR &= (~(0x1<<10));
break;
}
break;
case 1: // 操作LED2
switch (cmd)
{
case LED_ON: //开灯
vir_led2->ODR |= (0x1<<10);
break;
case LED_OFF://关灯
vir_led2->ODR &= (~(0x1<<10));
break;
}
break;
case 2: // 操作LED3
switch (cmd)
{
case LED_ON: //开灯
vir_led3->ODR |= (0x1<<8);
break;
case LED_OFF://关灯
vir_led3->ODR &= (~(0x1<<8));
break;
}
break;
}
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;
}
struct file_operations fops =
{
.open=mycdev_open,
.unlocked_ioctl=mycdev_ioctl,
.release=mycdev_close,
};
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);
//led1
vir_led1->MODER &= (~(3<<20));
vir_led1->MODER |= (1<<20);
vir_led1->ODR &= (~(1<<10));
//led2
vir_led2->MODER &= (~(3<<20));
vir_led2->MODER |= (1<<20);
vir_led2->ODR &= (~(1<<10));
//led3
vir_led3->MODER &= (~(3<<16));
vir_led1->MODER |= (1<<16);
vir_led1->ODR &= (~(1<<8));
printk("寄存器初始化成功\n");
return 0;
}
static int __init mycdev_init(void)
{
//1.申请一个对象空间cdev_alloc
int ret;
cdev= cdev_alloc();
if(cdev==NULL)
{
printk("申请字符设备驱动对象失败\n");
ret=-EFAULT;
goto out1;
}
printk("字符设备驱动对象申请成功\n");
//2.初始化对象cdev_init
cdev_init(cdev,&fops);
//3.申请设备号 register_chrdev_region()/alloc_chrdev_region()
if(major==0)//动态申请
{
ret=alloc_chrdev_region(&devno,minor,3,"demo");
if(ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
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
{
ret=register_chrdev_region(MKDEV(major,minor),3,"demo");
if(ret)
{
printk("静态指定设备号失败\n");
goto out2;
}
}
printk("设备号申请成功\n");
//4.注册驱动对象 cdev_add
ret=cdev_add(cdev,MKDEV(major,minor),3);
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 class_create
cls=class_create(THIS_MODULE,"demo");
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.向上提交设备节点信息 device_create
int i;
for(i=0;i<3;i++)
{
dev=device_create(cls,NULL,MKDEV(major,i),NULL,"demo%d",i);
if(IS_ERR(dev))
{
printk("向上提交设备节点失败\n");
goto out5;
}
}
printk("向上提交设备节点信息成功\n");
all_led_init();
return 0;
out5:
//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);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),3);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
//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");
