TASK08: Implemented IRQ handling task

08_irq_handling/Makefile

@@ -0,0 +1,12 @@
+ORANGEKERN ?= ~/Orange/buildroot-2021.11.1/output/build/linux-5.12.2/ #relative path
+LOCALKERN ?= /lib/modules/$(shell uname -r)/build
+
+obj-m := irq_module.o
+
+all: clean build
+
+build:
+	$(MAKE) -C $(ORANGEKERN) M=$(PWD) modules
+
+clean:
+	$(MAKE) -C $(ORANGEKERN) M=$(PWD) clean

08_irq_handling/irq_module.c

@@ -0,0 +1,65 @@
+#define pr_fmt(fmt) "%s: " fmt, KBUILD_MODNAME
+#define MOD_AUTHOR "Artem Shyshko"
+#define MOD_LICENSE "GPL"
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+
+#define GPIO_NUMBER(port, bit) (32 * (port) + (bit))
+#define LED_RED GPIO_NUMBER(0, 17)
+
+static int irq, dev_id = 1;
+static int ledr_gpio = -1;
+static bool irq_count = false;
+
+module_param(irq, int, S_IRUGO);
+
+static irqreturn_t timer_interrupt(int irq, void* dev_id)
+{
+	irq_count = !irq_count;
+	gpio_set_value(ledr_gpio, irq_count);
+	return IRQ_NONE;
+}
+
+static int led_gpio_init(int gpio, int *led_gpio)
+{
+	int res;
+
+	res = gpio_direction_output(gpio, 0);
+	if (res != 0)
+		return res;
+
+	*led_gpio = gpio;
+	return 0;
+}
+
+static int proc_init(void)
+{
+	int res = 0;
+	if (request_irq(irq, timer_interrupt, IRQF_SHARED, "interrupt", &dev_id)) {
+		res = -1;
+		pr_info("Error while loading\n");
+	} else {
+		pr_info("Module loaded, %d\n", irq);
+		res = led_gpio_init(LED_RED, &ledr_gpio);
+		if (res != 0)
+			pr_err("Can't set GPIO%d for output\n", LED_RED);
+	}
+	return res;
+}
+
+static void proc_exit(void)
+{
+	synchronize_irq(irq);
+	free_irq(irq, &dev_id);
+	gpio_set_value(ledr_gpio, 0);
+	pr_info("Module exited\n");
+}
+
+module_init(proc_init);
+module_exit(proc_exit);
+
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_LICENSE(MOD_LICENSE);