#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/list.h>
#include <linux/kthread.h>
#include <linux/init_task.h>
#include <linux/sched.h>
#include <linux/rtmutex.h>
#include <linux/hrtimer.h>
#include <linux/delay.h>
#include <linux/gpio.h>

MODULE_LICENSE( "GPL" );
MODULE_AUTHOR( "Anon <[email protected]>" );

static struct task_struct *thread_10ms;

static int bus_rt_timer_thread(void *arg) {
    bool led_state = false;
    if (gpio_request(62, "LED"))
    {
        printk( "+ error requesting LED GPIO" );
        return -1;
    }
    gpio_direction_output(62, 0);
    ktime_t timeout = ktime_get();
    while(!kthread_should_stop()) {
        led_state = !led_state;
        gpio_set_value(62, led_state);

        timeout = ktime_add_us(timeout, 250000);
        __set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_hrtimeout_range(&timeout, 100, HRTIMER_MODE_ABS);
    }
    gpio_direction_output(62, 0);
    gpio_free(62);
    return 0;
}

int __init bus_timer_interrupt_init(void) {
    struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };

    thread_10ms = kthread_create(bus_rt_timer_thread, NULL, "bus_10ms");
    if (IS_ERR(thread_10ms)) {
        printk(KERN_ERR "RT Failed to create RT thread\n");
        return -ESRCH;
    }
    sched_setscheduler(thread_10ms, SCHED_FIFO, &param);
    wake_up_process(thread_10ms);
    return 0;
}

void __exit bus_timer_interrupt_exit(void) {
    kthread_stop(thread_10ms);
    printk(KERN_INFO "RT Thread removed.\n");
}

module_init( bus_timer_interrupt_init );
module_exit( bus_timer_interrupt_exit );