head.h
#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
驱动文件
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include"head.h"
unsigned int major=0;//主设备号
unsigned int minor=0;//次设备号
dev_t devno;
struct cdev *cdev;
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
char kbuf[128]={0};
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
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__);
unsigned long ret;
//向用户空间读取拷贝
if(size>sizeof(kbuf))//用户空间期待读取的大小内核满足不了，那就给内核支持的最大大小
size=sizeof(kbuf);
ret=copy_to_user(ubuf,kbuf,size);
if(ret)//拷贝失败
{
printk("copy_to_user filed\n");
return ret;
}
return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
unsigned long ret;
// 从用户空间读取数据
if (size > sizeof(kbuf)) // 用户空间期待读取的大小内核满足不了，那就给内核支持的最大大小
size = sizeof(kbuf);
ret = copy_from_user(kbuf, ubuf, size);
if (ret) // 拷贝失败
{
printk("copy_to_user filed\n");
return ret;
}
return 0;
}
long mycdev_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
{
int ar;
int ret;
ret=copy_from_user(&ar,(void*)arg,4);
if(ret)//拷贝失败
{
printk("copy_to_user filed\n");
return ret;
}
switch(cmd)
{
case LED_ON:
switch(ar)
{
case 0:
vir_led1->ODR |= 1<<10;
break;
case 1:
vir_led2->ODR |= 1<<10;
break;
case 2:
vir_led3->ODR |= 1<<8;
break;
}
break;
case LED_OFF:
switch(ar)
{
case 0:
vir_led1->ODR &= (~(1<<10));
break;
case 1:
vir_led2->ODR &= (~(1<<10));
break;
case 2:
vir_led3->ODR &= (~(1<<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={
.unlocked_ioctl=mycdev_ioctl,
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.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)
{
int ret;
//1.创建驱动对象
cdev=cdev_alloc();
if(cdev==NULL)
{
return -ENOMEM;
}
printk("驱动对象创建成功\n");
//2.驱动对象初始化
cdev_init(cdev, &fops);
//3.申请设备号
ret=alloc_chrdev_region(&devno, 0 ,3,"myled");
if(ret)
{
printk("设备号申请失败\n");
goto out;
}
major=MAJOR(devno);
minor=MINOR(devno);
printk("设备号申请成功\n");
//4.驱动注册
ret=cdev_add(cdev,devno,3);
if(ret)
{
printk("驱动注册失败\n");
goto out1;
}
printk("驱动注册成功\n");
//5.向上提交目录
cls=class_create(THIS_MODULE,"led");
if(IS_ERR(cls))
{
printk("向上提交目录失败\n");
ret=-PTR_ERR(cls);
goto out2;
}
printk("向上提交目录成功\n");
//6.向上提交节点
int i;
//向上提交三次设备节点信息
for(i=0;i<3;i++)
{
dev=device_create(cls,NULL,MKDEV(major,i),NULL,"myled%d",i);
if(IS_ERR(dev))
{
printk("向上提交设备节点失败\n");
ret=-PTR_ERR(dev);
goto out3;
}
}
printk("向上提交设备节点成功\n");
//寄存器映射以及初始化
all_led_init();
return 0;
out3:
for(--i;i>=0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
class_destroy(cls);
out2:
cdev_del(cdev);
out1:
unregister_chrdev_region(devno,3);
out:
kfree(cdev);
return ret;
}
static void __exit mycdev_exit(void)
{
//取消地址映射
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
//销毁节点
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
//销毁目录
class_destroy(cls);
//销毁驱动对象
cdev_del(cdev);
//销毁驱动号
unregister_chrdev_region(MKDEV(major,minor), 3);
//释放驱动对象
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
应用文件
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
int main(int argc, char const *argv[])
{
int a,b;
char buf[128]={0};
int fd=open("/dev/myled0",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("请输入功能选择\n");
printf("0(关灯) 1(开灯)\n");
printf("请输入>");
scanf("%d",&a);
printf("请输入灯选择\n");
printf("0(led0) 1(led1) 2(led2)\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;
}
现象实现
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