From 9b87645a3d4a36fc5fa45b020991381d324b85eb Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Fri, 13 Jun 2025 10:50:29 +0100
Subject: [PATCH] interrupt added and working

---
 driver/counter.c   | 85 +++++++++++++++++++++++++++++++++++++++++++++-
 driver/counter.dts |  4 +++
 2 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/driver/counter.c b/driver/counter.c
index ff2ea69..68b6b4f 100644
--- a/driver/counter.c
+++ b/driver/counter.c
@@ -6,6 +6,8 @@
 #include <linux/of_device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
 
 #include "ls7366r.h"
 
@@ -207,11 +209,82 @@ static void dt_ls7366r_remove(struct spi_device *client) {
 }
 
 
+/* interrupt stuff */
+static int dt_interrupt_probe(struct platform_device *pdev);
+static void dt_interrupt_remove(struct platform_device *pdev);
+
+static struct of_device_id interrupt_driver_ids[] = {
+  {
+    .compatible = "hottis,intr",
+  }, 
+  {},
+};
+MODULE_DEVICE_TABLE(of, interrupt_driver_ids);
+
+static struct platform_driver interrupt_driver = {
+  .probe = dt_interrupt_probe,
+  .remove = dt_interrupt_remove,
+  .driver = {
+    .name = "interrupt_device_driver",
+    .of_match_table = interrupt_driver_ids,
+  },
+};
+
+static struct gpio_desc *counter_interrupt;
+static int irq_number;
+
+// ISR
+static irqreturn_t counter_isr(int irq, void *dev_id) {
+  printk("counter - interrupt received\n");
+  return IRQ_HANDLED;
+}
+
+static int dt_interrupt_probe(struct platform_device *pdev) {
+  struct device *dev = &pdev->dev;
+
+  printk("counter - interrupt probing\n");
+
+  counter_interrupt = gpiod_get(dev, "intr", GPIOD_IN);
+  if (IS_ERR(counter_interrupt)) {
+    printk("counter - Error! Could not setup the GPIO intr\n");
+    return -1 * IS_ERR(counter_interrupt);
+  }
+
+  irq_number = gpiod_to_irq(counter_interrupt);
+  if (irq_number < 0) {
+    printk("counter - Error! Could not map GPIO to IRQ\n");
+    gpiod_put(counter_interrupt);
+    return irq_number;
+  }
+  printk("counter - Info! IRQ %d assigned\n", irq_number);
+
+  int ret = request_irq(irq_number, counter_isr,
+      IRQF_TRIGGER_RISING, "gpio19_irq", dev);
+  if (ret) {
+    printk("counter - Error! Could not request IRQ\n");
+    gpiod_put(counter_interrupt);
+    return ret;
+  }
+
+  printk("counter - Info! Interrupt assigned\n");
+
+  return 0;
+}
+
+static void dt_interrupt_remove(struct platform_device *pdev) {
+  printk("counter - interrupt removing\n");
+  struct device *dev = &pdev->dev;
+  free_irq(irq_number, dev);
+  gpiod_put(counter_interrupt);
+}
+
+
+
 /* module loading and unloading */
 static int __init my_init(void) {
   printk("counter - Loading the leds driver...\n");
   if(platform_driver_register(&leds_driver)) {
-    printk("dt_gpio - Error! Could not load driver\n");
+    printk("dt_gpio - Error! Could not load leds driver\n");
     return -1;
   }
 
@@ -221,6 +294,13 @@ static int __init my_init(void) {
     return -1;
   }
 
+  printk("counter - Loading the interrupt driver...\n");
+  if(platform_driver_register(&interrupt_driver)) {
+    printk("dt_gpio - Error! Could not load interrupt driver\n");
+    return -1;
+  }
+
+
   printk("counter - red led on\n");
   gpiod_set_value(red_led, 1);
 
@@ -236,6 +316,9 @@ static void __exit my_exit(void) {
 
   printk("counter - Unloading the ls7366r driver...\n");
   spi_unregister_driver(&ls7366r_driver);
+
+  printk("counter - Unloading the interrupt driver...\n");
+  platform_driver_unregister(&interrupt_driver);
 }
 
 module_init(my_init);
diff --git a/driver/counter.dts b/driver/counter.dts
index 289f687..615b71e 100644
--- a/driver/counter.dts
+++ b/driver/counter.dts
@@ -11,6 +11,10 @@
         red-led-gpio = <&gpio 26 0>; 
         blue-led-gpio = <&gpio 21 0>; 
       };
+      intr {
+        compatible = "hottis,intr";
+        intr-gpio = <&gpio 19 0>;
+      };
     };
   };