使用linux的系统驱动点亮开发板的灯
**要求：**使用linux驱动点亮开发板的灯
实验现象
（LED1没亮是因为本人的开发板LED1物理损坏）
head.h代码
#ifndef __HEAD_H__
#define __HEAD_H__
typedef struct{
volatile unsigned int moder;
volatile unsigned int otyper;
volatile unsigned int ospeedr;
volatile unsigned int pupdr;
volatile unsigned int idr;
volatile unsigned int odr;
}gpio_t;
#define GPIOE ((gpio_t*)0x50006000)
#define GPIOF ((gpio_t*)0x50007000)
#define PHY_RCC 0x50000A28
#endif
test.c代码
#include <stdio.h>
#include <stdlib.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");
exit(-1);
}
while (1)
{
printf("请输入控制命令--1：开灯 0：关灯>");
fgets(buf, sizeof(buf), stdin); // 在终端读取
buf[strlen(buf) - 1] = '\0'; // 吃掉末尾的‘\n’;
write(fd, buf, sizeof(buf));
}
close(fd);
return 0;
}
mychedev.c代码
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include<linux/uaccess.h>
#include<linux/io.h>
#include"head.h"
int major; // 用于保存主设备号
char kbuf[128]={0};
gpio_t *vir_led1; //led1 pe10 ; led3 pe8
gpio_t *vir_led2; //led2 pf10
unsigned int *vir_rcc;
// 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)
{
int ret;
if(sizeof(kbuf)<size)
size=sizeof(kbuf);
ret=copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user filed\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;
if(sizeof(kbuf)<size)//判断用户空间的需求是否能被驱动满足，满足不了就给能给的最好的
size=sizeof(kbuf);
ret=copy_from_user(kbuf,ubuf,size);
if(ret)
{
printk("copy_from_user filed\n");
return -EIO;
}
if(kbuf[0]=='1')//开灯
{
//开灯逻辑
//led1开灯 pe10
(vir_led1->odr) |= (0x1<<10);
//led2开灯pf10
(vir_led2->odr) |= (0x1<<10);
//led3开灯pe8
(vir_led1->odr) |= (0x1<<8);
}
else if(kbuf[0]=='0')//关灯
{
//关灯
//led1关灯pe10
(vir_led1->odr) &= (~(0x1<<10));
//led2关灯pf10
(vir_led2->odr) &= (~(0x1<<10));
//led3关灯pe8
(vir_led1->odr) &= (~(0x1<<8));
}
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;
}
// 定义操作方法结构体变量并完成初始化
struct file_operations fops =
{
.open = mycdev_open,
.read = mycdev_read,
.write = mycdev_write,
.release = mycdev_close,
};
static int __init mycdev_init(void)
{
//字符设备驱动注册
major = register_chrdev(0, "mychrdev", &fops);
if (major < 0)
{
printk("字符设备驱动注册失败\n");
return major;
}
printk("字符设备驱动注册成功major=%d\n", major);
//映射物理寄存器
vir_led1=ioremap(GPIOE,sizeof(gpio_t));
vir_led2=ioremap(GPIOF,sizeof(gpio_t));
vir_rcc=ioremap(PHY_RCC,4);
//寄存器初始化
//led灯的控制默认为0，时钟初始化
(*vir_rcc) |= (0X3<<4);
//led1 pe10 moder,odr
(vir_led1->moder) &= (~(0x3<<20)); //清空
(vir_led1->moder) |= (0x1<<20); //赋值
(vir_led1->odr) &= (~(0x1<<10)); //默认为熄灯
//led2 pf10
(vir_led2->moder) &= (~(0x3<<20)); //清空
(vir_led2->moder) |= (0x1<<20); //赋值
(vir_led2->odr) &= (~(0x1<<10)); //默认为熄灯
//led3 pe8
(vir_led1->moder) &= (~(0x3<<16)); //清空
(vir_led1->moder) |= (0x1<<16); //赋值
(vir_led1->odr) &= (~(0x1<<8)); //默认为熄灯
if(vir_led1==NULL && vir_led2==NULL)
{
printk("MODER寄存器地址映射表失败\n");
return -EFAULT;
}
vir_led1->odr=ioremap(GPIOE,4);
if(vir_led1==NULL && vir_led2==NULL)
{
printk("ODR寄存器地址映射表失败\n");
return -EFAULT;
}
//此处是时钟寄存器的值
vir_rcc=ioremap(PHY_RCC,4);
if(vir_rcc==NULL)
{
printk("RCC寄存器地址映射表失败\n");
return -EFAULT;
}
printk("寄存器地址映射成功\n");
printk("硬件寄存器初始化成功\n");
return 0;
}
static void __exit mycdev_exit(void)
{
//取消寄存器地址映射
iounmap(vir_led1);
iounmap(vir_led2);
iounmap(vir_rcc);
//字符设备驱动的注销
unregister_chrdev(major,"mychrdev");
}
module_init(mycdev_init); //入口函数
module_exit(mycdev_exit); //出口函数
MODULE_LICENSE("GPL"); //协议许可证
