From 2120c472620b6a38a9cdf48df35bca914a4aa271 Mon Sep 17 00:00:00 2001
From: Ciro Santilli <ciro.santilli@gmail.com>
Date: Thu, 15 Jun 2017 11:30:40 +0100
Subject: [PATCH] shared irqs work for keyboard and mouse input

---
 kernel_module/irq.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/kernel_module/irq.c b/kernel_module/irq.c
index 183c13f..068dbfc 100644
--- a/kernel_module/irq.c
+++ b/kernel_module/irq.c
@@ -2,13 +2,17 @@
 TODO: get handler running multiple times on some existing interrupt from /proc/interrupts.
 */
 
+#include <asm/uaccess.h> /* copy_from_user, copy_to_user */
+#include <linux/fs.h>
 #include <linux/interrupt.h>
-#include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 
+#define NAME "lkmc_character_device"
+
 MODULE_LICENSE("GPL");
 
+static int major;
 static int irq = 0;
 module_param_named(i, irq, int, S_IRUSR);
 MODULE_PARM_DESC(i, "irq line number");
@@ -23,21 +27,24 @@ MODULE_PARM_DESC(i, "irq line number");
  */
 static irqreturn_t handler(int irq, void *v)
 {
-	pr_info("handler irq = %d jiffies = %llx\n", irq, (unsigned long long)jiffies);
+	pr_info("handler irq = %d\n", irq);
 	return IRQ_HANDLED;
 }
 
+static const struct file_operations fops;
+
 static int myinit(void)
 {
 	int ret;
 
+	major = register_chrdev(0, NAME, &fops);
 	for (int i = 0; i < 128; ++i) {
 		ret = request_irq(
 			i,
 			handler,
 			IRQF_SHARED,
 			"myirqhandler0",
-			NULL
+			&major
 		);
 		pr_info("request_irq irq = %d ret = %d\n", i, ret);
 	}
@@ -47,6 +54,7 @@ static int myinit(void)
 static void myexit(void)
 {
 	free_irq(irq, NULL);
+	unregister_chrdev(major, NAME);
 }
 
 module_init(myinit)