xref: /linux/kernel/irq/dummychip.c (revision 1c4b5ecb7ea190fa3e9f9d6891e6c90b60e04f24)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
5  *
6  * This file contains the dummy interrupt chip implementation
7  */
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/export.h>
11 
12 #include "internals.h"
13 
14 /*
15  * What should we do if we get a hw irq event on an illegal vector?
16  * Each architecture has to answer this themselves.
17  */
18 static void ack_bad(struct irq_data *data)
19 {
20 	struct irq_desc *desc = irq_data_to_desc(data);
21 
22 	print_irq_desc(data->irq, desc);
23 	ack_bad_irq(data->irq);
24 }
25 
26 /*
27  * NOP functions
28  */
29 static void noop(struct irq_data *data) { }
30 
31 static unsigned int noop_ret(struct irq_data *data)
32 {
33 	return 0;
34 }
35 
36 /*
37  * Generic no controller implementation
38  */
39 struct irq_chip no_irq_chip = {
40 	.name		= "none",
41 	.irq_startup	= noop_ret,
42 	.irq_shutdown	= noop,
43 	.irq_enable	= noop,
44 	.irq_disable	= noop,
45 	.irq_ack	= ack_bad,
46 	.flags		= IRQCHIP_SKIP_SET_WAKE,
47 };
48 
49 /*
50  * Generic dummy implementation which can be used for
51  * real dumb interrupt sources
52  */
53 struct irq_chip dummy_irq_chip = {
54 	.name		= "dummy",
55 	.irq_startup	= noop_ret,
56 	.irq_shutdown	= noop,
57 	.irq_enable	= noop,
58 	.irq_disable	= noop,
59 	.irq_ack	= noop,
60 	.irq_mask	= noop,
61 	.irq_unmask	= noop,
62 	.flags		= IRQCHIP_SKIP_SET_WAKE,
63 };
64 EXPORT_SYMBOL_GPL(dummy_irq_chip);
65