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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2013-07-02 20:01:31 +0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2013-07-02 20:01:31 +0400
commit27eb2c4b3d3e13f376a359e293c212a2e9407af5 (patch)
tree556aa7b5cd6eeb4214dec129c789515157187010 /drivers/misc/dummy-irq.c
parent5705b8aca5a80141de5637ff0e23b31b26f2c5bf (diff)
parent67bf12ca50d524f9e225347fe63533562e2004de (diff)
downloadlinux-27eb2c4b3d3e13f376a359e293c212a2e9407af5.tar.xz
Merge branch 'next' into for-linus
Prepare first set of updates for 3.11 merge window.
Diffstat (limited to 'drivers/misc/dummy-irq.c')
-rw-r--r--drivers/misc/dummy-irq.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/misc/dummy-irq.c b/drivers/misc/dummy-irq.c
new file mode 100644
index 000000000000..c37eeedfe215
--- /dev/null
+++ b/drivers/misc/dummy-irq.c
@@ -0,0 +1,63 @@
+/*
+ * 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 occured 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");