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Linux驱动开发之点亮三盏小灯

news 2025/9/12 13:39:05

头文件

#ifndef __HEAD_H__
#define __HEAD_H__//LED1和LED3的硬件地址
#define PHY_LED1_MODER 0x50006000
#define PHY_LED1_ODR 0x50006014
#define PHY_LED1_RCC 0x50000A28
//LED2的硬件地址
#define PHY_LED2_MODER 0x50007000
#define PHY_LED2_ODR 0x50007014
#define PHY_LED2_RCC 0x50000A28#endif

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 <linux/device.h>
#include "head.h"
int major;
char kbuf[128]={0}; 
//定义指针接收映射成功的虚拟内存首地址
unsigned int *vir_moder1;
unsigned int *vir_odr1;
unsigned int *vir_rcc1;unsigned int *vir_moder2;
unsigned int *vir_odr2;
unsigned int *vir_rcc2;//定义一个指针用来接收创建类
struct class *cls;//定义一个指针用来接收接收创建设备信息
struct device *dev;
// 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)
{printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);int ret;ret=copy_to_user(ubuf,kbuf,size);if(ret){printk("copy_to_user filad\n");return ret;}return 0;
}
ssize_t mycdev_write(struct file *file, const char  *ubuf, size_t size, loff_t *lof)
{int ret;ret=copy_from_user(kbuf,ubuf,size);if(ret){printk("copy_from_user filed\n");return ret;}if(kbuf[0]=='1' && kbuf[1] == '1')//LED1开灯{//开灯逻辑(*vir_odr1) |= (0X1<<10);}else if(kbuf[0]=='1' && kbuf[1] == '0')//LED1关灯{//关灯逻辑(*vir_odr1) &= (~(0X1<<10));}else if(kbuf[0]=='2' && kbuf[1] == '1')//LED2开灯{//开灯逻辑(*vir_odr2) |= (0X1<<10);}else if(kbuf[0]=='2' && kbuf[1] == '0')//LED1关灯{//关灯逻辑(*vir_odr2) &= (~(0X1<<10));}else if(kbuf[0]=='3' && kbuf[1] == '1')//LED#开灯{//开灯逻辑(*vir_odr1) |= (0X1<<8);}else if(kbuf[0]=='3' && kbuf[1] == '0')//LED3关灯{//关灯逻辑(*vir_odr1) &= (~(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遍历并且初始化
struct file_operations fops = {.open=mycdev_open,.read=mycdev_read,.write=mycdev_write,.release=mycdev_close,
};static int __init mycdev_init(void)
{int i;// 注册字符设备驱动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);//向上提交目录信息cls = class_create(THIS_MODULE,"mycdev");if(IS_ERR(cls)){printk("向上提交目录信息失败\n");return -PTR_ERR(cls);}printk("向上提交目录信息成功\n");//向上提交设备信息for(i=0;i<3;i++){dev=device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);if(IS_ERR(cls)){printk("向上提交设备信息信息失败\n");return -PTR_ERR(cls);}}printk("向上提交设备信息成功\n");//完成硬件寄存器物理内存的映射vir_moder1=ioremap(PHY_LED1_MODER,4);if(vir_moder1==NULL){printk("LED1物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_odr1=ioremap(PHY_LED1_ODR,4);if(vir_odr1==NULL){printk("LED1物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_rcc1=ioremap(PHY_LED1_RCC,4);if(vir_rcc1==NULL){printk("LED1物理内存映射失败%d\n",__LINE__);return -EFAULT;}printk("LED1物理内存映射成功\n");//LED2物理内存映射vir_moder2=ioremap(PHY_LED2_MODER,4);if(vir_moder2==NULL){printk("LED2物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_odr2=ioremap(PHY_LED2_ODR,4);if(vir_odr2==NULL){printk("LED2物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_rcc2=ioremap(PHY_LED2_RCC,4);if(vir_rcc2==NULL){printk("LED2物理内存映射失败%d\n",__LINE__);return -EFAULT;}printk("LED2物理内存映射成功\n");//LED3物理内存映射vir_moder1=ioremap(PHY_LED1_MODER,4);if(vir_moder1==NULL){printk("LED3物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_odr1=ioremap(PHY_LED1_ODR,4);if(vir_odr1==NULL){printk("LED3物理内存映射失败%d\n",__LINE__);return -EFAULT;}vir_rcc1=ioremap(PHY_LED1_RCC,4);if(vir_rcc1==NULL){printk("LED3物理内存映射失败%d\n",__LINE__);return -EFAULT;}printk("LED3物理内存映射成功\n");//硬件寄存器的初始化//LED1硬件初始化(*vir_moder1) &= (~(0X3<<20));//设置为输出(*vir_moder1) |= (0X1<<20);//LED2硬件初始化(*vir_moder2) &= (~(0X3<<20));//设置为输出(*vir_moder2) |= (0X1<<20);//LED3硬件初始化(*vir_moder1) &= (~(0X3<<16));//设置为输出(*vir_moder1) |= (0X1<<16);//rcc使能(*vir_rcc1) |= (0X1<<4);(*vir_rcc2) |= (0X1<<5);//默认关灯(*vir_odr1) &= (~(0X1<<10));(*vir_odr2) &= (~(0X1<<10));(*vir_odr1) &= (~(0X1<<8));return 0;
}
static void __exit mycdev_exit(void)
{//取消物理内存的映射iounmap(vir_moder1);iounmap(vir_odr1);iounmap(vir_rcc1);iounmap(vir_moder2);iounmap(vir_odr2);iounmap(vir_rcc2);//销毁设备信息int i;for(i=0;i<3;i++){device_destroy(cls,MKDEV(major,i));}//销毁目录信息class_destroy(cls);//字符设备驱动的注销unregister_chrdev(major,"mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

测试文件

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
int main(int argc, const char *argv[])
{char buf[128] = {};int fd0 = open("/dev/mycdev0", O_RDWR);int fd1 = open("/dev/mycdev1", O_RDWR);int fd2 = open("/dev/mycdev2", O_RDWR);if (fd0 < 0){printf("打开设备文件失败\n");exit(-1);}printf("成功打开设备文件\n");while (1){printf("逻辑关系：例如11表示LED1亮 10表示LED1灭...\n");fgets(buf, sizeof(buf), stdin); // 从终端读一个字符串存放在bufbuf[strlen(buf) - 1] = '\0';if(buf[0] == '1'){write(fd0, buf, sizeof(buf)); // 将从终端得到的字符串传递到驱动}else if(buf[0] == '2'){write(fd1, buf, sizeof(buf));}else if(buf[0] == '3'){write(fd2, buf, sizeof(buf));}}close(fd0);return 0;
}

结果