驱动day2：LED灯实现三盏灯的亮灭

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head.h

#ifndef __HEAD_H__
#define __HEAD_H__
#define PHY_PE_MODER 0x50006000
#define PHY_PF_MODER 0x50007000
#define PHY_PE_ODR 0x50006014
#define PHY_PF_ODR 0x50007014
#define PHY_RCC 0x50000A28#endif

应用程序

#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);   //在终端读一个字符串buf[strlen(buf) - 1] = '\0';write(fd,buf,sizeof(buf));//将数据传递给内核}
/*fgets(buf,sizeof(buf),stdin);   //在终端读一个字符串buf[strlen(buf) - 1] = '\0';write(fd,buf,sizeof(buf));//将数据传递给内核memset(buf, 0, sizeof(buf));   //清空数组read(fd,buf,sizeof(buf));    //将内核数据传递给用户printf("buf: %s\n", buf);
*/close(fd);return 0;
}

驱动程序

#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;   //主设备号
char kbuf[128] = {};   //内核空间buf
//定义五个指针指向映射后的虚拟内存
unsigned int *vir_pe_moder;
unsigned int *vir_pf_moder;
unsigned int *vir_pe_odr;
unsigned int *vir_pf_odr;
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)
{//mycdev_read()函数中的ubuf和size分别是指向应用程序中read()函数中的buf, 和sizeof(buf)的值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 failed\n");return -EIO;}if(kbuf[0] == '0')//关灯{   //关灯逻辑(*vir_pe_odr) &= (~(0x1 << 10));     //默认关灯(*vir_pf_odr) &= (~(0x1 << 10));(*vir_pe_odr) &= (~(0x1 << 8));}else if(kbuf[0] == '1'){//开灯逻辑(*vir_pe_odr) |= (0x1 << 10); (*vir_pf_odr) |= (0x1 << 10); (*vir_pe_odr) |= (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,
};static int __init mycdev_init(void)
{//注册字符设备驱动major= register_chrdev(0,"mycdev",&fops);if(major < 0){printk("字符设备驱动注册失败\n");return major;}printk("注册字符设备成功major=%d\n",major);//进行寄存器的地址映射vir_pe_moder = ioremap(PHY_PE_MODER, 4);if(vir_pe_moder == NULL){printk("物理地址内存映射失败%d\n",__LINE__);return -EFAULT;}vir_pf_moder = ioremap(PHY_PF_MODER,4);if(vir_pf_moder == NULL){printk("物理地址内存映射失败%d\n",__LINE__);return -EFAULT;}vir_pe_odr = ioremap(PHY_PE_ODR, 4);if(vir_pe_odr == NULL){printk("物理地址内存映射失败%d\n",__LINE__);return -EFAULT;}vir_pf_odr = ioremap(PHY_PF_ODR, 4);if(vir_pf_odr == NULL){printk("物理地址内存映射失败%d\n",__LINE__);return -EFAULT;}vir_rcc = ioremap(PHY_RCC, 4);if(vir_rcc == NULL){printk("物理地址内存映射失败%d\n",__LINE__);return -EFAULT;}printk("寄存器内存映射成功\n");//LED寄存器初始化(*vir_rcc) |= (0x3 << 4);   //GPIOE和GPIOF控制器时钟使能//PE10(*vir_pe_moder) &= (~(0x3 << 20));   //MODER[21:20]－＞00(*vir_pe_moder) |= (0x1 << 20);  //MODER[21"20]->01(*vir_pe_odr) &= (~(0x1 << 10));   //默认关灯//PF10(*vir_pf_moder) &= (~(0x3 << 20));(*vir_pf_moder) |= (0x1 << 20);(*vir_pf_odr) &= (~(0x1 << 10));   //默认关灯//PE8(*vir_pe_moder) &= (~(0x3 << 16));(*vir_pe_moder) |= (0x1 << 16); (*vir_pe_odr) &= (~(0x1 << 8));   //默认关灯return 0;
}static void __exit mycdev_exit(void)
{//取消内存映射iounmap(vir_pe_moder);iounmap(vir_pf_moder);iounmap(vir_pe_odr);iounmap(vir_pf_odr);iounmap(vir_rcc);//注销字符设备驱动unregister_chrdev(major,"mychrdev");
}module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

实现效果

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