dummy-irq.c
1.46 KB
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
/*
* Dummy IRQ handler driver.
*
* This module only registers itself as a handler that is specified to it
* by the 'irq' parameter.
*
* The sole purpose of this module is to help with debugging of systems on
* which spurious IRQs would happen on disabled IRQ vector.
*
* Copyright (C) 2013 Jiri Kosina
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
static int irq = -1;
static irqreturn_t dummy_interrupt(int irq, void *dev_id)
{
static int count = 0;
if (count == 0) {
printk(KERN_INFO "dummy-irq: interrupt occurred on IRQ %d\n",
irq);
count++;
}
return IRQ_NONE;
}
static int __init dummy_irq_init(void)
{
if (irq < 0) {
printk(KERN_ERR "dummy-irq: no IRQ given. Use irq=N\n");
return -EIO;
}
if (request_irq(irq, &dummy_interrupt, IRQF_SHARED, "dummy_irq", &irq)) {
printk(KERN_ERR "dummy-irq: cannot register IRQ %d\n", irq);
return -EIO;
}
printk(KERN_INFO "dummy-irq: registered for IRQ %d\n", irq);
return 0;
}
static void __exit dummy_irq_exit(void)
{
printk(KERN_INFO "dummy-irq unloaded\n");
free_irq(irq, &irq);
}
module_init(dummy_irq_init);
module_exit(dummy_irq_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jiri Kosina");
module_param(irq, uint, 0444);
MODULE_PARM_DESC(irq, "The IRQ to register for");