/* * 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");