控制三盏灯亮灭
代码：
//head.h#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_RCC 0x50000A28
#define PHY_GPIOE_MODER 0x50006000
#define PHY_GPIOF_MODER 0x50007000
#define PHY_GPIOE_ODR 0x50006014
#define PHY_GPIOF_ODR 0x50007014#endif//demo.c#include<linux/init.h>
#include<linux/module.h>
#include<linux/fs.h>
#include<linux/uaccess.h>
#include<linux/io.h>
#include"include/head.h"
char kbuf[128] = {0};
int a = 10;
unsigned int major;unsigned int *vir_led1_odr;
unsigned int *vir_led1_moder;
unsigned int *vir_rcc;
unsigned int *vir_led2_odr;
unsigned int *vir_led2_moder;int mycdev_open(struct inode *inode,struct file *file)
{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)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);int ret = copy_from_user(kbuf,ubuf,size);if(ret){printk("failed\n");return -EIO;}switch(kbuf[0]) //kbuf的第0位为led灯，第2位为led灯的状态{case '1':if(kbuf[2] == '0'){//关灯(*vir_led1_odr) &= (~(0x1 << 10));}else if(kbuf[2] == '1'){//开灯(*vir_led1_odr) |= (0x1 << 10);}break;case '2':if(kbuf[2] == '0'){//关灯(*vir_led2_odr) &= (~(0x1 << 10));}else if(kbuf[2] == '1'){//开灯(*vir_led2_odr) |= (0x1 << 10);}break;case '3':if(kbuf[2] == '0'){//关灯(*vir_led1_odr) &= (~(0x1 << 8));}else if(kbuf[2] == '1'){//开灯(*vir_led1_odr) |= (0x1 << 8);}break;default:break;}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 = copy_to_user(ubuf,kbuf,size);if(ret){printk("failed\n");return -EIO;}return 0;
}int mycdev_close(struct inode *inode,struct file *file)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);return 0;
}struct file_operations fops = {.open = mycdev_open,.read = mycdev_read,.write = mycdev_write,.release = mycdev_close,
};module_param(a,int,0664);
static int __init mycdev_init(void)
{printk("a = %d\n",a);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);vir_led1_moder = ioremap(PHY_GPIOE_MODER,4); if(NULL == vir_led1_moder){printk("物理内存地址映射失败\n");return -EFAULT;} vir_led1_odr = ioremap(PHY_GPIOE_ODR,4);if(NULL == vir_led1_odr){printk("物理内存地址映射失败\n");return -EFAULT;} vir_rcc = ioremap(PHY_RCC,4);if(NULL == vir_rcc){printk("物理内存地址映射失败\n");return -EFAULT;}vir_led2_moder = ioremap(PHY_GPIOF_MODER,4); if(NULL == vir_led2_moder){printk("物理内存地址映射失败\n");return -EFAULT;} vir_led2_odr = ioremap(PHY_GPIOF_ODR,4);if(NULL == vir_led2_odr){printk("物理内存地址映射失败\n");return -EFAULT;} printk("寄存器内存映射成功\n");(*vir_rcc) |= (0x1 << 4);(*vir_rcc) |= (0x1 << 5);(*vir_led1_moder) &= (~(0x3 << 20)); //led1_moder(*vir_led1_moder) |= (0x1 << 20);(*vir_led1_moder) &= (~(0x3 << 16)); //led3_moder(*vir_led1_moder) |= (0x1 << 16);(*vir_led1_odr) &= (~(0x1 << 10)); //led1_odr(*vir_led1_odr) &= (~(0x1 << 8)); //led3_odr(*vir_led2_moder) &= (~(0x3 << 20)); //led2_moder(*vir_led2_moder) |= (0x1 << 20);(*vir_led2_odr) &= (~(0X1 << 10)); //led2_odrreturn 0;
}static void __exit mycdev_exit(void)
{unregister_chrdev(major,"mychrdev");}module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");//test.c
#include<unistd.h>
#include<fcntl.h>
#include<sys/stat.h>
#include<sys/types.h>
#include<stdio.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){fgets(buf,sizeof(buf),stdin);buf[strlen(buf) - 1] = 0;write(fd,buf,sizeof(buf));}//read(fd,buf,sizeof(buf));memset(buf,0,sizeof(buf));read(fd,buf,sizeof(buf));printf("buf:%s\n",buf);close(fd);return 0;
}
实验现象：
