驱动开发day2
通过物理内存映射为虚拟内存 实现三盏LED灯亮灯灭
head.h
#ifndef __HEAD_H__
#define __HEAD_H__#define PHY_LED1_MODER 0X50006000
#define PHY_LED1_ODR 0X50006014
#define PHY_RCC 0x50000A28#define PHY_LED2_MODER 0X50007000
#define PHY_LED2_ODR 0X50007014#define PHY_LED3_MODER 0X50006000
#define PHY_LED3_ODR 0X50006014#endiftest.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
int main(int argc,char const *argv[])
{char buf[128] = {0};int fd = open("/dev/mychrdev",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){printf("请输入要进行的操作：0(关灯)1(开灯)>");fgets(buf,sizeof(buf),stdin);//在终端第一个字符串buf[strlen(buf)-1]='\0';write(fd,buf,sizeof(buf));//将数据传递给内核}close(fd);return 0;
}demo.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"unsigned int major;
char kbuf[128]={};
//LED1定义三个指针指向映射后的虚拟内存
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_rcc;
//LED2定义三个指针指向映射后的虚拟内存
unsigned int *vir_moder2;
unsigned int *vir_odr2;//LED3定义三个指针指向映射后的虚拟内存
unsigned int *vir_moder3;
unsigned int *vir_odr3;//封装操作方法
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__);int ret;ret=copy_to_user(ubuf,kbuf,size);if(ret){printk("copy_to_user filed\n");return -EIO;}return 0;
}
ssize_t mycdev_write(struct file *file,const char *ubuf,size_t size,loff_t *lof)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);int ret;ret=copy_from_user(kbuf,ubuf,size);if(ret){printk("copy_from_user filed\n");return -EIO;}if(kbuf[0] == '0')//关灯{//关灯逻辑(*vir_odr1) &= (~(0x1 << 10));(*vir_odr2) &= (~(0x1 << 10));(*vir_odr3) &= (~(0x1 << 8));}else if(kbuf[0]=='1'){//开灯逻辑(*vir_odr1) |= (0x1 << 10); (*vir_odr2) |= (0x1 << 10); (*vir_odr3) |= (0x1 << 8); }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对象
struct file_operations fops = {.open=mycdev_open,.read=mycdev_read,.write=mycdev_write,.release=mycdev_close,
};//入口函数，安装内核模块时执行
static int __init mycdev_init(void)
{//注册字符设备major = register_chrdev(0,"mychrdev",&fops);if(major < 0){printk("字符设备驱动注册失败\n");return major;}printk("注册字符设备驱动成功major=%d\n",major);vir_rcc = ioremap(PHY_RCC,4);if(vir_rcc ==NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}//----------LED1进行寄存器的地址映射------------------//vir_moder1 = ioremap(PHY_LED1_MODER,4);if(vir_moder1 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}vir_odr1 = ioremap(PHY_LED1_ODR,4);if(vir_odr1 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}printk("LED1寄存器内存映射成功\n");//----------LED2进行寄存器的地址映射------------------//vir_moder2 = ioremap(PHY_LED2_MODER,4);if(vir_moder2 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}vir_odr2 = ioremap(PHY_LED2_ODR,4);if(vir_odr2 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}printk("LED2寄存器内存映射成功\n");//----------LED3进行寄存器的地址映射------------------//vir_moder3 = ioremap(PHY_LED3_MODER,4);if(vir_moder3 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}vir_odr3 = ioremap(PHY_LED3_ODR,4);if(vir_odr3 == NULL){printk("物理内存地址映射失败%d\n",__LINE__);return -EFAULT;}printk("LED3寄存器内存映射成功\n");//LED1寄存器初始化(*vir_rcc) |= (0x3 << 4);//GPIOE/GPIOF控制器时钟使能(*vir_moder1) &= (~(0x3 << 20));//MODER[21:20]->00(*vir_moder1) |= (0x1 << 20);//MODER[21:20]->01(*vir_odr1) &= (~(0x1 << 10));//默认关灯//LED2寄存器初始化 (*vir_moder2) &= (~(0x3 << 20));//MODER[21:20]->00(*vir_moder2) |= (0x1 << 20);//MODER[21:20]->01(*vir_odr2) &= (~(0x1 << 10));//默认关灯//LED3寄存器初始化(*vir_moder3) &= (~(0x3 << 16));//MODER[17:16]->00(*vir_moder3) |= (0x1 << 16);//MODER[17:16]->01(*vir_odr3) &= (~(0x1 << 8));//默认关灯return 0;
}//出口函数，卸载内核模块时执行
static void __exit mycdev_exit(void)
{//取消内存映射iounmap(vir_rcc);//LED1取消内存映射iounmap(vir_moder1);iounmap(vir_odr1);//LED2取消内存映射iounmap(vir_moder2);iounmap(vir_odr2);//LED3取消内存映射iounmap(vir_moder3);iounmap(vir_odr3);//注销字符设备驱动unregister_chrdev(major,"mychrdev");
}//用于声明入口函数
module_init(mycdev_init);
//用于声明出口函数
module_exit(mycdev_exit);
//声明当前内核模块遵循GPL协议
MODULE_LICENSE("GPL");
