驱动开发LED灯绑定设备文件

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LED1switch (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LED2switch (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LED3switch (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);//led1vir_led1->MODER &= (~(3<<20));vir_led1->MODER |= (1<<20);vir_led1->ODR &= (~(1<<10));//led2vir_led2->MODER &= (~(3<<20));vir_led2->MODER |= (1<<20);vir_led2->ODR &= (~(1<<10));//led3vir_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_allocint 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_initcdev_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_addret=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_createcls=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_createint 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");