分布注册设备，实现文件和设备的绑定
代码：
//head.h
#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_RCC 0x50000A28
#define PHY_GPIOE_MODER 0x50006000
#define PHY_GPIOF_MODER 0x50007000
#define PHY_GPIOE_ODR 0x50006014
#define PHY_GPIOF_ODR 0x50007014
typedef struct
{
unsigned int MODER;
unsigned int OTYPER;
unsigned int OSPEEDR;
unsigned int PUPDR;
unsigned int IDR;
unsigned int ODR;
}gpio_t;
#define GPIOE 0x50006000
#define GPIOF 0x50007000
#define PHY_RCC_ADDR 0x50000A28
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif
//mycdev.c
#include<linux/init.h>
#include<linux/module.h>
#include<linux/io.h>
#include<linux/device.h>
#include<linux/fs.h>
#include<linux/cdev.h>
#include<linux/uaccess.h>
#include<linux/slab.h>
#include"include/head.h"
unsigned int major = 0,minor = 0;
dev_t devno;
struct class *cls;
struct cdev* cdev;
struct device *dev;
gpio_t *vir_led1;
gpio_t *vir_led2;
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:
switch(cmd)
{
case LED_OFF:
vir_led1->ODR &= (~(0x1 << 10));
break;
case LED_ON:
vir_led1->ODR |= (0x1 << 10);
break;
}
break;
case 1:
switch(cmd)
{
case LED_OFF:
vir_led2->ODR &= (~(0x1 << 10));
break;
case LED_ON:
vir_led2->ODR |= (0x1 << 10);
break;
}
break;
case 2:
switch(cmd)
{
case LED_OFF:
vir_led1->ODR &= (~(0x1 << 8));
break;
case LED_ON:
vir_led1->ODR |= (0x1 << 8);
break;
}
break;
default:
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;
}
int all_led_init(void)
{
vir_led1 = ioremap(GPIOE,sizeof(gpio_t));
if(NULL == vir_led1)
{
printk("ioremap failed : %d\n",__LINE__);
return -ENOMEM;
}
vir_led2 = ioremap(GPIOF,sizeof(gpio_t));
if(NULL == vir_led2)
{
printk("ioremap failed : %d\n",__LINE__);
return -ENOMEM;
}
vir_rcc = ioremap(PHY_RCC,4);
if(NULL == vir_rcc)
{
printk("ioremap failed : %d\n",__LINE__);
return -ENOMEM;
}
printk("寄存器内存映射成功\n");
(*vir_rcc) |= (0x1 << 4);
(*vir_rcc) |= (0x1 << 5);
(vir_led1->MODER) &= (~(0x3 << 20)); //led1_moder
(vir_led1->MODER) |= (0x1 << 20);
(vir_led1->MODER) &= (~(0x3 << 16)); //led3_moder
(vir_led1->MODER) |= (0x1 << 16);
(vir_led1->ODR) &= (~(0x1 << 10)); //led1_odr
(vir_led1->ODR) &= (~(0x1 << 8)); //led3_odr
(vir_led2->MODER) &= (~(0x3 << 20)); //led2_moder
(vir_led2->MODER) |= (0x1 << 20);
(vir_led2->ODR) &= (~(0X1 << 10)); //led2_odr
return 0;
}
struct file_operations fops = {
.open = mycdev_open,
.unlocked_ioctl = mycdev_ioctl,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
int ret;
all_led_init();
//申请对象空间
cdev = cdev_alloc();
if(NULL == cdev)
{
printk("申请字符设备驱动对象空间失败\n");
ret = -EFAULT;
goto out;
}
printk("申请字符设备驱动对象空间成功\n");
//初始化对象
cdev_init(cdev,&fops);
//申请设备号
if(0 == major)
{
ret = alloc_chrdev_region(&devno,0,3,"mychrdev");
if(0 != ret)
{
printk("动态申请设备号失败\n");
goto out2;
}
major = MAJOR(devno);
minor = MINOR(devno);
}
else
{
ret = register_chrdev_region(MKDEV(major,minor),3,"mychrdev");
if(0 != ret)
{
printk("静态申请设备号失败\n");
goto out2;
}
}
printk("申请设备号成功\n");
//注册驱动对象
int ret2 = cdev_add(cdev,devno,3);
if(0 != ret2)
{
printk("注册驱动对象失败\n");
goto out3;
}
printk("注册字符设备驱动对象成功\n");
//向上提交目录
cls = class_create(THIS_MODULE,"mychrdev");
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");
//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,"mychrdev%d",i);
if(IS_ERR(dev))
{
printk("向上提交设备节点失败\n");
goto out5;
}
}
printk("向上提交设备节点成功\n");
return 0;
out5:
for(--i;i >= 0;i--)
{
device_destroy(cls,MKDEV(major,i));
}
class_destroy(cls);
out4:
cdev_del(cdev);
out3:
unregister_chrdev_region(MKDEV(major,minor),3);
out2:
kfree(cdev);
out:
return ret;
}
static void __exit mycdev_exit(void)
{
//销毁设备节点信息
int i;
for(i = 0;i < 3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
//销毁设备目录
class_destroy(cls);
//销毁字符设备驱动对象
cdev_del(cdev);
//释放设备号
unregister_chrdev_region(MKDEV(major,minor),3);
kfree(cdev);
return;
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");
//test.c
#include<unistd.h>
#include<fcntl.h>
#include<sys/stat.h>
#include<sys/types.h>
#include<sys/ioctl.h>
#include<stdio.h>
#include<string.h>
#include"include/head.h"
int main(int argc, char const *argv[])
{
char buf[128] = {0};
int led_id,led_state;
fgets(buf,sizeof(buf),stdin);
buf[strlen(buf) - 1] = 0;
int fd = open(buf,O_RDWR);
if(fd < 0)
{
printf("打开设备文件失败\n");
return -1;
}
printf("打开设备文件成功\n");
while(1)
{
// fgets(buf,sizeof(buf),stdin);
// buf[strlen(buf) - 1] = 0;
// write(fd,buf,sizeof(buf));
// scanf("%d",&led_id);
scanf("%d",&led_state);
switch(led_state)
{
case 1:
ioctl(fd,LED_ON);
break;
case 0:
ioctl(fd,LED_OFF);
break;
default:
break;
}
}
//read(fd,buf,sizeof(buf));
// memset(buf,0,sizeof(buf));
// read(fd,buf,sizeof(buf));
// printf("buf:%s\n",buf);
close(fd);
return 0;
}
实现效果：
