Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
54f69b92 JK |
2 | /* |
3 | * Dummy IRQ handler driver. | |
4 | * | |
5 | * This module only registers itself as a handler that is specified to it | |
6 | * by the 'irq' parameter. | |
7 | * | |
8 | * The sole purpose of this module is to help with debugging of systems on | |
9 | * which spurious IRQs would happen on disabled IRQ vector. | |
10 | * | |
11 | * Copyright (C) 2013 Jiri Kosina | |
12 | */ | |
13 | ||
54f69b92 JK |
14 | #include <linux/module.h> |
15 | #include <linux/irq.h> | |
16 | #include <linux/interrupt.h> | |
17 | ||
a7b594b4 | 18 | static int irq = -1; |
54f69b92 JK |
19 | |
20 | static irqreturn_t dummy_interrupt(int irq, void *dev_id) | |
21 | { | |
22 | static int count = 0; | |
23 | ||
24 | if (count == 0) { | |
8b513d0c | 25 | printk(KERN_INFO "dummy-irq: interrupt occurred on IRQ %d\n", |
54f69b92 JK |
26 | irq); |
27 | count++; | |
28 | } | |
29 | ||
30 | return IRQ_NONE; | |
31 | } | |
32 | ||
33 | static int __init dummy_irq_init(void) | |
34 | { | |
a7b594b4 JC |
35 | if (irq < 0) { |
36 | printk(KERN_ERR "dummy-irq: no IRQ given. Use irq=N\n"); | |
37 | return -EIO; | |
38 | } | |
54f69b92 JK |
39 | if (request_irq(irq, &dummy_interrupt, IRQF_SHARED, "dummy_irq", &irq)) { |
40 | printk(KERN_ERR "dummy-irq: cannot register IRQ %d\n", irq); | |
41 | return -EIO; | |
42 | } | |
43 | printk(KERN_INFO "dummy-irq: registered for IRQ %d\n", irq); | |
44 | return 0; | |
45 | } | |
46 | ||
47 | static void __exit dummy_irq_exit(void) | |
48 | { | |
49 | printk(KERN_INFO "dummy-irq unloaded\n"); | |
50 | free_irq(irq, &irq); | |
51 | } | |
52 | ||
53 | module_init(dummy_irq_init); | |
54 | module_exit(dummy_irq_exit); | |
55 | ||
56 | MODULE_LICENSE("GPL"); | |
57 | MODULE_AUTHOR("Jiri Kosina"); | |
4f1927dc | 58 | module_param_hw(irq, uint, irq, 0444); |
54f69b92 | 59 | MODULE_PARM_DESC(irq, "The IRQ to register for"); |
da86920f | 60 | MODULE_DESCRIPTION("Dummy IRQ handler driver"); |