feat(MP/kernel): add blink part

Closes: #4

src/06-mini-project/kernel/blink/blink.c

@@ -0,0 +1,64 @@
+#include "blink.h"
+
+static struct task_struct* blink_thread;
+atomic_t blink_period_ms;
+
+int thread_blinkThread(void* data);
+
+void blink_init(void) {
+    int ret = 0;
+    pr_info("Initialize blink thread\n");
+
+    atomic_set(&blink_period_ms, DEFAULT_PERIOD_MS);
+
+    ret = gpio_request(GPIO_PIN, "blink-led");
+    if(ret) {
+        pr_err("Failed to request GPIO pin %d, error %d\n", GPIO_PIN, ret);
+        return;
+    }
+
+    ret = gpio_direction_output(GPIO_PIN, 0);
+    if(ret) {
+        pr_err("Failed to set GPIO pin %d direction, error %d\n", GPIO_PIN, ret);
+        gpio_free(GPIO_PIN);
+        return;
+    }
+
+    blink_thread = kthread_run(thread_blinkThread, NULL, "blink_thread");
+    if (IS_ERR(blink_thread)) {
+        pr_err("Failed to create blink thread\n");
+        gpio_free(GPIO_PIN);
+        return;
+    }
+
+    pr_info("Blink thread initialized\n");
+}
+
+void blink_exit(void) {
+    pr_info("Exiting blink thread\n");
+    kthread_stop(blink_thread);
+    gpio_free(GPIO_PIN);
+    pr_info("Blink thread exited\n");
+}
+
+int thread_blinkThread(void* data) {
+
+    bool state = false;
+    int period = 0;
+    
+    pr_info("Blink started\n");
+
+    while (!kthread_should_stop()) {
+        gpio_set_value(GPIO_PIN, state);
+        state = !state;
+        period = atomic_read(&blink_period_ms);
+        msleep(period >> 1);
+    }
+
+    return 0;
+}
+
+void adjust_frequency(int new_period_ms) {
+    pr_info("Adjusting blink period to %d ms\n", new_period_ms);
+    atomic_set(&blink_period_ms, new_period_ms);
+}

src/06-mini-project/kernel/blink/blink.h

@@ -0,0 +1,24 @@
+#include <linux/module.h>	// needed by all modules
+#include <linux/init.h>		// needed for macros
+#include <linux/kernel.h>	// needed for debugging
+
+
+#include <linux/kthread.h>
+#include <linux/delay.h>
+
+#include <linux/gpio.h>
+
+#include <linux/atomic.h>
+
+
+#define GPIO_PIN 10
+#define DEFAULT_PERIOD_MS 1000
+
+/**
+ * Allow to set a new frequency for the blinky led
+ * @param new_period_ms The new period in ms for the blinky led
+ */
+void adjust_frequency(int new_period_ms);
+
+void blink_init(void);
+void blink_exit(void);

src/06-mini-project/kernel/main.c

@@ -2,13 +2,11 @@
 #include <linux/module.h>	// needed by all modules
 #include <linux/init.h>		// needed for macros
 #include <linux/kernel.h>	// needed for debugging
-#include <linux/kthread.h>
-#include <linux/delay.h>
-#include <linux/err.h>
 
 #include "linux/printk.h"
 
 #include "temperature/temp.h"
+#include "blink/blink.h"
 
 static int __init temp_regulator_init(void) {
     pr_info("Linux module temp_regulator loading...\n");
@@ -27,6 +25,12 @@ static int __init temp_regulator_init(void) {
             temp / 1000,
             temp % 1000);
 
+    blink_init();
+    ssleep(5);
+    adjust_frequency(500);
+    ssleep(5);
+    adjust_frequency(5000);
+
     pr_info("Linux module temp_regulator loaded\n");
     return 0;
 }
@@ -37,6 +41,7 @@ static void __exit temp_regulator_exit(void) {
 
     /* Release sensor resources */
     temp_exit();
+    blink_exit();
 
     pr_info("Linux module temp_regulator unloaded\n");
 }