驱动代码
#include <linux/init.h>
#include <linux/module.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
#include "head.h"
dev_t devno;//存放申请的到的设备号的空间首地址
unsigned baseminor;//次设备号的起始值
unsigned count;//申请的设备资源数量
struct cdev *cdev;//申请的字符设备驱动对象指针
char kbuf[128] = {0};//内核空间首地址
unsigned int major=0;
unsigned int minor=0;
struct class *cls;
struct device *dev;
module_param(major,uint,0664);
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
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://控制LED1
switch (cmd)
{
case LED_ON:
//开灯
vir_led1->ODR |= 1 << 10;
break;
case LED_OFF:
//关灯
vir_led1->ODR &= (~(1 << 10));
break;
}
break;
case 1://控制LED2
switch (cmd)
{
case LED_ON:
//开灯
vir_led2->ODR |= 1 << 10;
break;
case LED_OFF:
//关灯
vir_led2->ODR &= (~(1 << 10));
break;
}
break;
case 2://控制LED3
switch (cmd)
{
case LED_ON:
//开灯
vir_led3->ODR |= 1 << 8;
break;
case LED_OFF:
//关灯
vir_led3->ODR &= (~(1 << 8));
break;
}
break;
}
return 0;
}
ssize_t mycdev_read(struct file *file,char *ubuf,size_t size,loff_t *lof)
{
int ret;
ret=copy_to_user(ubuf,kbuf,size);
if (ret)
{
printk("copy_to_user err\n");
return -EIO;
}
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)
{
int ret;
//从用户拷贝
ret=copy_from_user(kbuf,ubuf,size);
if (ret)
{
printk("copy_from_user err\n");
return -EIO;
}
return 0;
}
int mycdev_close(struct inode *inode,struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
//定义一个操作方法结构体对象并且初始化
struct file_operations fops = {
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.release=mycdev_close,
.unlocked_ioctl = mycdev_ioctl,
};
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) |= (0X3 << 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;
//申请一个字符设备驱动对象空间
cdev = cdev_alloc();
if (cdev == NULL)
{
printk("申请字符设备对象驱动空间失败\n");
ret = -EFAULT;
goto out1;
}
printk("字符设备驱动对象成功\n");
//字符设备设备驱动对象初始化
cdev_init(cdev,&fops);
//申请设备号
if (major > 0)//静态指定设备号
{
ret=register_chrdev_region(MKDEV(major,minor),3,"myled");
if (ret)
{
printk("静态申请设备号失败\n");
goto out2;
}
}else if(major == 0)
{
int ret= alloc_chrdev_region(&devno,minor,3,"myled");
if (ret!=0)
{
//释放申请的字符设备对象空间
printk("动态申请设备号失败\n");
goto out2;
}
major=MAJOR(devno);//获取主设备号
minor=MINOR(devno);//获取次设备号
}
printk("申请设备号成功\n");
//根据申请到的设备号和驱动对象注册驱动
ret=cdev_add(cdev,MKDEV(major,minor),3);
if (ret != 0)
{
printk("驱动对象注册失败\n");
goto out3;
}
printk("字符设备驱动对象注册成功\n");
// 寄存器映射以及初始化
all_led_init();
//向上提交目录信息
cls=class_create(THIS_MODULE,"myled");
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");
//向上提交设备节点信息
int i;
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");
return 0;
out5:
//释放前一次提交成功的设备信息
for(--i;i>=0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
class_destroy(cls);//释放目录
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),3);
out2:
kfree(cdev);
out1:
return ret;
}
static void __exit mycdev_exit(void)
{
//释放节点信息
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
//销毁目录
class_destroy(cls);
// 取消地址映射
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
//注销驱动对象
cdev_del(cdev);
//释放设备号
unregister_chrdev_region(MKDEV(major,minor),3);
//释放设备空间
kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");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
//构建LED开关的功能码，添加ioctl第三个参数int
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif 应用代码
#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[])
{
int a,b;
int c;
char buf[128] = {0};
int fd,fd1,fd2;
while (1)
{
// 从终端读取
printf("请输入要控制的灯：0(LED1) 1(LED2) 2(LED3)>");
scanf("%d",&a);
switch (a)
{
case 0:
fd = open("/dev/myled0", O_RDWR);
printf("请输入开灯(1) 关灯(0)>");
scanf("%d",&b);
switch (b)
{
case 1:
ioctl(fd, LED_ON,c); // 开灯
close(fd);
break;
case 0:
ioctl(fd, LED_OFF,c); // 关灯
break;
close(fd);
}
break;
case 1:
fd1 = open("/dev/myled1", O_RDWR);
printf("请输入开灯(1) 关灯(0)>");
scanf("%d",&b);
switch(b)
{
case 1:
ioctl(fd1, LED_ON,c); // 开灯
close(fd1);
break;
case 0:
ioctl(fd1, LED_OFF,c); // 关灯
close(fd1);
break;
}
break;
case 2:
fd2 = open("/dev/myled2", O_RDWR);
printf("请输入开灯(1) 关灯(0)>");
scanf("%d",&b);
switch(b)
{
case 1:
ioctl(fd2, LED_ON,c); // 开灯
close(fd2);
break;
case 0:
ioctl(fd2, LED_OFF,c); // 关灯
close(fd2);
break;
}
break;
}
}
return 0;
}