控制三盏灯-编程知识

控制三盏灯

驱动代码

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "head.h"unsigned int major;//保存主设备号
char kbuf[128] = {0};
unsigned int *vir1_moder;
unsigned int *vir1_odr;
unsigned int *vir1_rcc;
unsigned int *vir2_moder;
unsigned int *vir2_odr;
unsigned int *vir2_rcc;
unsigned int *vir3_moder;
unsigned int *vir3_odr;
unsigned int *vir3_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;ret = copy_to_user(ubuf,kbuf,size);if (ret){printk("copy_to_user err\n");return -EIO;}return 0;
}
ssize_t mycdev_write(struct file *file,const char *ubuf,size_t size,loff_t *lof)
{int ret = 0;ret = copy_from_user(kbuf,ubuf,size);if (ret){printk("copy_from_user err\n");return -EIO;}switch(kbuf[0]){case '1':(*vir1_odr) |= (0x1 << 10);break;case '2':   (*vir1_odr) &= (~(0x1 << 10));break;case '3':(*vir2_odr) |= (0x1 << 10);break;case '4':   (*vir2_odr) &= (~(0x1 << 10));break;case '5':(*vir3_odr) |= (0x1 << 8);break;case '6':   (*vir3_odr) &= (~(0x1 << 8));break;default:printk("输入错误\n");break;}return 0;
}
int mycdev_close(struct inode *inode,struct file *file)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return 0;
};
//定义一个操作方法结构体对象并初始化
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("字符串设备驱动注册失败\n");}printk("字符设备驱动注册成功 major = %d\n",major);//相关寄存器内存映射vir1_odr = ioremap(LED1_ODR,4);if (vir1_odr == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir1_rcc = ioremap(LED1_RCC,4);if (vir1_rcc == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir1_moder = ioremap(LED1_MODER,4);if (vir1_moder == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir2_odr = ioremap(LED2_ODR,4);if (vir2_odr == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir2_rcc = ioremap(LED2_RCC,4);if (vir2_rcc == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir2_moder = ioremap(LED2_MODER,4);if (vir2_moder == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir3_odr = ioremap(LED3_ODR,4);if (vir3_odr == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir3_rcc = ioremap(LED3_RCC,4);if (vir3_rcc == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir3_moder = ioremap(LED3_MODER,4);if (vir3_moder == NULL)  {   printk("物理内存映射失败%d\n",__LINE__);return -EFAULT;}printk("寄存器内存映射成功\n");//硬件寄存器的初始化//RCC使能(*vir1_rcc) |= (0x1 << 4);//设置PE10为输出(*vir1_moder) &= (~(0x3 << 20));(*vir1_moder) |= (0x1 << 20);//默认关灯(*vir1_odr) &= (~(0x1 << 10));//RCC使能(*vir2_rcc) |= (0x1 << 5);//设置PE10为输出(*vir2_moder) &= (~(0x3 << 20));(*vir2_moder) |= (0x1 << 20);//默认关灯(*vir1_odr) &= (~(0x1 << 10));//RCC使能(*vir1_rcc) |= (0x1 << 4);//设置PE10为输出(*vir1_moder) &= (~(0x3 << 16));(*vir1_moder) |= (0x1 << 16);//默认关灯(*vir1_odr) &= (~(0x1 << 8));return 0;
}
static void __exit mycdev_exit(void)
{//取消物理内存映射iounmap(vir1_moder);iounmap(vir1_rcc);iounmap(vir1_odr);iounmap(vir2_moder);iounmap(vir2_rcc);iounmap(vir2_odr);iounmap(vir3_moder);iounmap(vir3_rcc);iounmap(vir3_odr);//字符设备驱动注销unregister_chrdev(major,"mychrdev");}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

应用层代码

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
int main(int argc,const char * argv[])
{char buf[128] = {0};int fd = open("/dev/mychrdev",O_RDWR);if(fd < 0){printf("设备文件打开失败\n");exit(-1);}  while(1){printf("请输入对LED的控制命令1(LED1开灯)2(LED1关灯)3(LED2开灯)4(LED2关灯)5(LED3开灯)6(LED3关灯)>");fgets(buf,sizeof(buf),stdin);//在终端输入数据到bufbuf[strlen(buf)-1] = '\0';write(fd,buf,sizeof(buf));memset(buf,0,sizeof(buf));}close(fd);return 0;
}