summaryrefslogtreecommitdiff
path: root/kernel-devel/char-device/example/kernel/huhu.c
blob: 99eafe7eda6a210f047676d8228559f66699cd06 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>

static int major;

static int huhu_open(struct inode *node, struct file *f)
{
	printk(KERN_INFO "huhu_open: done\n");
	return 0;
}

static int huhu_release(struct inode *node, struct file *f)
{
	printk(KERN_INFO "huhu_release: done\n");
	return 0;
}

static ssize_t huhu_read(struct file *f, char __user *u, size_t s, loff_t *l)
{
	printk(KERN_INFO "huhu_read\n");
	return 0;
}

static ssize_t huhu_write (struct file *f, const char __user *u, size_t s,
	loff_t *l)
{
	printk(KERN_INFO "huhu_write\n");
	return 0;
}

static const struct file_operations huhu_fops = {
	.owner		= THIS_MODULE,
	.open		= huhu_open,
	.release 	= huhu_release,
	.read		= huhu_read,
	.write		= huhu_write,
};

static int huhu_init(void)
{
	major = register_chrdev (0, "huhu", &huhu_fops);
	if (major < 0)
	{
		printk(KERN_ERR "huhu_init: register_chrdev failed\n");
		return major;
	}
	printk(KERN_INFO "mknod /dev/huhu c %d 0", major);
	return 0;
}

static void huhu_exit(void)
{
	unregister_chrdev (major, "huhu");
	printk(KERN_INFO "huhu_exit: done\n");
}

module_init(huhu_init);
module_exit(huhu_exit);

MODULE_AUTHOR("Manuel Traut <manut@linutronix.de>");
MODULE_DESCRIPTION("a more or less useless module using char");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0815");