| /* |
| * 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_hw(irq, uint, irq, 0444); |
| MODULE_PARM_DESC(irq, "The IRQ to register for"); |
| MODULE_DESCRIPTION("Dummy IRQ handler driver"); |