【这里使用的核心是4.14版本的】
1.创建驱动程序源文件Driver.c
1 #include "linux/kernel.h"
2 #include "linux/module.h"
3 #include "linux/fs.h"
4 #include "linux/init.h"
5 #include "linux/types.h"
6 #include "linux/errno.h"
7 #include "linux/uaccess.h"
8 #include "linux/kdev_t.h"
9
10 #define MAX_SIZE 1024
11
12 int my_open(struct inode *inode, struct file *file);
13 int my_release(struct inode *inode, struct file *file);
14 ssize_t my_read(struct file *file, char __user *user, size_t t, loff_t *f);
15 ssize_t my_write(struct file *file, const char __user *user, size_t t, loff_t *f);
16
17 char message[MAX_SIZE] = "this is arafat(very shuai boy)'s Drive"; //打开设备时会显示的消息
18 int device_num;//设备号
19 char* devName = "Driver";//设备名
20
21 struct file_operations pStruct =
22 {
23 open:my_open,
24 release:my_release,
25 read:my_read,
26 write:my_write,
27 };
28
29 /* 注册 */
30 int init_module()
31 {
32 int ret;
33
34 ret = register_chrdev(0, devName, &pStruct);
35 if (ret < 0)
36 {
37 printk("failed to register_chrdev.\n");
38 return -1;
39 }
40 else
41 {
42 printk("the lgsDrive has been registered!\n");
43 printk("id: %d\n", ret);
44 device_num = ret;
45
46 return 0;
47 }
48 }
49
50 //注销
51 void cleanup_module()
52 {
53 unregister_chrdev(device_num, devName);
54 printk("unregister successful.\n");
55 }
56
57
58 //打开
59 int my_open(struct inode *inode, struct file *file)
60 {
61 printk("open lgsDrive OK!\n");
62 try_module_get(THIS_MODULE);
63 return 0;
64 }
65
66 //关闭
67 int my_release(struct inode *inode, struct file *file)
68 {
69 printk("Device released!\n");
70 module_put(THIS_MODULE);
71
72 return 0;
73 }
74
75
76 //读设备里的信息
77 ssize_t my_read(struct file *file, char __user *user, size_t t, loff_t *f)
78 {
79 if(copy_to_user(user,message,sizeof(message)))
80 {
81 return -2;
82 }
83 return sizeof(message);
84 }
85
86 //向设备里写信息
87 ssize_t my_write(struct file *file, const char __user *user, size_t t, loff_t *f)
88 {
89 if(copy_from_user(message,user,sizeof(message)))
90 {
91 return -3;
92 }
93 return sizeof(message);
94 }
1 #include "
