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
}
close(fd);
return 0;
}
头文件
#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;
char kbuf[128] = {};
// 定义三个指针指向映射后的虚拟内存
unsigned int *vir_moder;
unsigned int *vir_odr;
unsigned int *vir_moder2;
unsigned int *vir_odr2;
unsigned int *vir_moder3;
unsigned int *vir_odr3;
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)
{
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 filed\n");
return -EIO;
}
if (kbuf[0] == '0') // 关灯
{
// 关灯逻辑
(*vir_odr) &= (~(0X1<<10));//默认关灯
(*vir_odr2) &= (~(0X1<<10));
(*vir_odr3) &= (~(0X1<<8));
}
else if (kbuf[0] == '1')
{
// 开灯逻辑
(*vir_odr) |= (0X1<<10);
(*vir_odr2) |= (0X1<<10);
(*vir_odr3) |= (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, "mychrdev", &fops);
if (major < 0)
{
printk("字符设备驱动注册失败\n");
return major;
}
printk("注册字符设备驱动成功major=%d\n", major);
// 进行寄存器的地址映射
vir_moder = ioremap(PHY_LED1_MODER, 4);
if (vir_moder == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_moder2 = ioremap(PHY_LED2_MODER, 4);
if (vir_moder2 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_moder3 = ioremap(PHY_LED3_MODER, 4);
if (vir_moder3 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_odr = ioremap(PHY_LED1_ODR, 4);
if (vir_odr == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_odr2 = ioremap(PHY_LED2_ODR, 4);
if (vir_odr2 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_odr3 = ioremap(PHY_LED3_ODR, 4);
if (vir_odr3 == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
vir_rcc = ioremap(PHY_RCC, 4);
if (vir_rcc == NULL)
{
printk("物理内存地址映射失败%d\n", __LINE__);
return -EFAULT;
}
printk("寄存器内存映射成功\n");
//LED1寄存器初始化
(*vir_rcc) |= (0X1<<4);//GPIOE控制器时钟使能
(*vir_moder) &= (~(0X3<<20));//MODER[21:20]->00
(*vir_moder) |= (0X1<<20);//MODER[21:20]->01
(*vir_odr) &= (~(0X1<<10));//默认关灯
//LED2寄存器初始化
(*vir_rcc) |= (0X1<<5);//GPIOF控制器时钟使能
(*vir_moder2) &= (~(0X3<<20));//MODER[21:20]->00
(*vir_moder2) |= (0X1<<20);//MODER[21:20]->01
(*vir_odr2) &= (~(0X1<<10));//默认关灯
//LED3寄存器初始化
(*vir_rcc) |= (0X1<<4);//GPIOE控制器时钟使能
(*vir_moder3) &= (~(0X3<<16));//MODER[17:16]->00
(*vir_moder3) |= (0X1<<16);//MODER[17:16]->01
(*vir_odr3) &= (~(0X1<<8));//默认关灯
return 0;
}
static void __exit mycdev_exit(void)
{
//取消内存映射
iounmap(vir_moder);
iounmap(vir_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");
