led.c
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.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("请输入选择哪一个灯泡 1 2 3\n");
fgets(buf,sizeof(buf),stdin);
printf("请输入亮灭 0 灭 1 亮\n");
fgets(buf+1,sizeof(buf),stdin);
buf[strlen(buf)-1]='\0';
write(fd,buf,sizeof(buf));
}
close(fd);
return 0;
}
mychrdev.c文章来源:https://www.toymoban.com/news/detail-603148.html
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include "led.h"
unsigned int major;
char kbuf[128] = {0};
unsigned int *vir_led1_moder;
unsigned int *vir_led1_odr;
unsigned int *vir_rcc;
unsigned int *vir_led2_moder;
unsigned int *vir_led2_odr;
unsigned int *vir_led3_moder;
unsigned int *vir_led3_odr;
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__);
long ret;
ret=copy_to_user(ubuf,kbuf,size);
if(ret)
{
printk("copy_to_user failed\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__);
long ret;
ret=copy_from_user(kbuf,ubuf,size);
if(ret)
{
printk("copy_from_user failed\n");
return -EIO;
}
switch(kbuf[0])
{
case '1':
if(kbuf[1] == '0')
{
(*vir_led1_odr) &= (~(0x1 << 10));
}
else if(kbuf[1] == '1')
{
(*vir_led1_odr) |= (0x1 << 10);
}
break;
case '2':
if(kbuf[1] == '0')
{
(*vir_led2_odr) &= (~(0x1 << 10));
}
else if(kbuf[1] == '1')
{
(*vir_led2_odr) |= (0x1 << 10);
}
break;
case '3':
if(kbuf[1] == '0')
{
(*vir_led1_odr) &= (~(0x1 << 8));
}
else if(kbuf[1] == '1')
{
(*vir_led1_odr) |= (0x1 << 8);
}
break;
}
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
struct file_operations fops={
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.release=mycdev_close,
};
//入口函数,里面主要进行资源的申请和注册
static int __init mycdev_init(void)
{
printk(KERN_ERR "入口函数\n");
major=register_chrdev(0,"mychrdev",&fops);
if(major<0)
{
printk("注册字符设备驱动失败\n");
return major;
}
printk("字符设备注册成功\n");
//地址映射
vir_led1_moder=ioremap(PHY_LED1_MODER,4);
if(vir_led1_moder==NULL)
{
printk("映射物理地址失败%d\n",__LINE__);
return -EFAULT;
}
vir_led2_moder=ioremap(PHY_LED2_MODER,4);
if(vir_led2_moder==NULL)
{
printk("映射物理地址失败%d\n",__LINE__);
return -EFAULT;
}
vir_led1_odr=ioremap(PHY_LED1_ODR,4);
if(vir_led1_odr==NULL)
{
printk("映射物理地址失败%d\n",__LINE__);
return -EFAULT;
}
vir_led2_odr=ioremap(PHY_LED2_ODR,4);
if(vir_led2_odr==NULL)
{
printk("映射物理地址失败%d\n",__LINE__);
return -EFAULT;
}
vir_led3_moder = vir_led1_moder;
vir_led3_odr = vir_led1_odr;
vir_rcc=ioremap(PHY_RCC,4);
if(vir_rcc==NULL)
{
printk("映射物理地址失败%d\n",__LINE__);
return -EFAULT;
}
//硬件初始化
(*vir_rcc)|=(0x3 << 4);
(*vir_led1_moder) &= (~(0x3 << 20));
(*vir_led1_moder) |= (0x1 << 20);
(*vir_led3_moder) &= (~(0x3 << 16));
(*vir_led3_moder) |= (0x1 << 16);
(*vir_led2_moder) &= (~(0x3 << 20));
(*vir_led2_moder) |= (0x1 << 20);
(*vir_led1_odr) &= (~(0x1 << 10));
(*vir_led3_odr) &= (~(0x1 << 8));
(*vir_led2_odr) &= (~(0x1 << 10));
printk("映射物理地址成功");
return 0;//返回值一定要加,除非函数类型是void
}
//出口函数,主要进行资源的释放和注销
static void __exit mycdev_exit(void)
{
printk("出口函数\n");
unregister_chrdev(major,"mychrdev");
//__exit __section(".exit.text")
//用于声明mycdev_exit在.exit.text段
}
//用于向内核报备当前内核模块入口函数的地址
module_init(mycdev_init);
//用于向内核报备当前内核模块出口函数的地址
module_exit(mycdev_exit);
//声明当前内核模块遵循GPL协议
MODULE_LICENSE("GPL");
led.h文章来源地址https://www.toymoban.com/news/detail-603148.html
#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
#endif
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