题目：实现开发板点灯操作

程序要求：

        1）分部实现注册字符设备驱动

        2）自动创建设备节点

        3）通过结构体对led灯地址进行映射

        4）次设备号完成私有数据传参

        5）在open函数中获取到次设备号，用私有数据传参，传递给write函数

        6）在write函数，判断次设备号，就知道操作的是哪盏灯

操作方法：

在串口工具进行输入：

        echo 1 > /dev/myled0 ---->led1灯点亮

        echo 0 > /dev/myled0 ---->led1灯熄灭

        echo 1 > /dev/myled1 ---->led1灯点亮

        echo 0 > /dev/myled1 ---->led1灯熄灭

程序：

#ifndef __LED_H__
#define __LED_H__typedef struct{volatile unsigned int MODER;volatile unsigned int OPTYPER;volatile unsigned int OSPEEDR;volatile unsigned int PUPDR;volatile unsigned int IDR;volatile unsigned int ODR;
}gpio_t;
typedef enum{LED1,LED2,LED3
}led_t;
#define GPIOE 0x50006000
#define GPIOF 0x50007000
#define PHY_RCC 0x50000A28#endif

​​​​​​​

#include 
#include 
#include 
#include 
#include 
#include 
#include "led.h"
#include 
#include 
#define CNAME "myled"
struct class *cls;
struct device *dev;
struct cdev *mycdev;
#if 1
unsigned int major = 0;
#else
unsigned int major = 500;
#endif
int minor =0;
const int count = 3;
volatile unsigned int* virt_rcc;
gpio_t *virt_gpioe;
gpio_t *virt_gpiof;
int mycdev_open(struct inode *inode,struct file *file)
{int pos = MINOR(inode->i_rdev);printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);file->private_data = (void*)pos;return 0;
}
ssize_t mycdev_read(struct file* file,char __user *ubuf,size_t size,loff_t *loffs)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return 0;
}
ssize_t mycdev_write(struct file* file,const char __user *ubuf,size_t size,loff_t *loffs)
{int pos;int ret = 0;char kbuf[5]={0};if(size > 5) size=5;ret = copy_from_user(kbuf,ubuf,size);if(ret){printk("copy from user error\n");return -EIO;}//判断是点灯还是熄灭pos =(int)file->private_data;if('1' == kbuf[0]){//通过次设备号判断是哪个灯需要亮switch (pos){case 0:virt_gpioe->ODR |= (0x1 << 10); //led1输出高电平break;case 1:virt_gpiof->ODR |= (0x1 << 10); //led2输出高电平break;case 2:virt_gpioe->ODR |= (0x1 << 8); //led3输出高电平break;} }if('0' == kbuf[0]){//通过次设备号判断是哪个灯需要灭switch (pos){case 0:virt_gpioe->ODR &= ~(0x1 << 10); //led1输出低电平break;case 1:virt_gpiof->ODR &= ~(0x1 << 10); //led2输出低电平break;case 2:virt_gpioe->ODR &= ~(0x1 << 8); //led3输出低电平break;} }printk("kbuf=%s\n",kbuf);printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return size;
}
int mycdev_close(struct inode *inode,struct file *file)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return 0;
}
const struct file_operations fops ={.open = mycdev_open,.read = mycdev_read,.write = mycdev_write,.release = mycdev_close,
};
static int __init demo_init(void)
{int ret = 0;dev_t devno;int i;//分配cdev结构体空间mycdev = cdev_alloc();if(NULL == mycdev){printk("cdev alloc error\n");ret = -EIO;goto ERR1;}//初始化结构体cdev_init(mycdev,&fops);//申请设备号if(major >0){//静态申请设备号ret = register_chrdev_region(MKDEV(major,minor),count,CNAME);if(ret){printk("register chrdev regin error\n");ret = -ENOMEM;goto ERR2;}}else {//动态申请设备号ret = alloc_chrdev_region(&devno,0,count,CNAME);if(ret){printk("alloc_chrdev error\n");ret = -ENOMEM; goto ERR2;}major = MAJOR(devno);minor = MINOR(devno);}//驱动注册ret = cdev_add(mycdev,MKDEV(major,minor),count);if(ret){printk("cdev add error\n");ret = -EIO;goto ERR3;}//自动创建设备节点//提交目录信息cls = class_create(THIS_MODULE,CNAME);if(IS_ERR(cls)){printk("class create error\n");ret = PTR_ERR(cls);goto ERR4;}//提交设备节点信息for(i=0;iMODER &= (~(0x3<<20));virt_gpioe->MODER |= 0x1<<20;virt_gpioe->ODR &= (~(0x1<<10));//PE8初始化virt_gpioe->MODER &= (~(0x3<<16));virt_gpioe->MODER |= 0x1<<16;virt_gpioe->ODR &= (~(0x1<<8));//PF10初始化virt_gpiof->MODER &= (~(0x3<<20));virt_gpiof->MODER |= 0x1<<20;virt_gpiof->ODR &= (~(0x1<<10));return 0;
ERR5:for(--i;i>=0;i--){device_destroy(cls,MKDEV(major,i));}class_destroy(cls);ERR4:cdev_del(mycdev);
ERR3:unregister_chrdev_region(MKDEV(major,minor),count);
ERR2:kfree(mycdev);
ERR1:return -EIO;
}
static void __exit demo_exit(void)
{int i = 0;//销毁设备节点信息for(i=0;i