#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>   /* Needed for the macros */
/* The character device definitions are here */
#include <linux/fs.h>

#define MAGICNUM 0x14000000
#define CRIME_MAJOR_NUM 300

static int crime_open(struct inode*, struct file*);
static int crime_close(struct inode*, struct file*);
static ssize_t crime_write(struct file*, const char __user*, size_t, loff_t*);
static ssize_t crime_read(struct file*, char*, size_t, loff_t*);
static int crime_ioctl(struct inode*, struct file*, unsigned int, unsigned long);

struct file_operations crime_fops = {
    .owner = THIS_MODULE,
    .open = crime_open,
    .release = crime_close,
    .read = crime_read,
    .write = crime_write
};
int port;

static int __init crime_init(void) {
    int result;

    pr_debug("crime_init called\n");

    if ((result = register_chrdev(CRIME_MAJOR_NUM, "crime", &crime_fops)) < 0)
        printk(KERN_ERR, "register_chrdev %d\n", result);
    return result;
}

static void __exit crime_exit(void) {
    printk("crime_exit called, unloading module\n");
}

static ssize_t
crime_read(struct file* flip, char* ubuf, size_t count, loff_t* f_pos) {
    ssize_t len, ret;
    const char* works = "It works!\n";

    len = min(count, strlen(works));
    if (copy_to_user(ubuf, works, len)) {
        ret = -EFAULT;
        goto free_page;
    }

    *f_pos += len;
    ret = len;

free_page:
    return ret;
}

static int crime_open(struct inode* inode, struct file* flip) {
    return 0;
}

static int crime_close(struct inode* inode, struct file* flip) {
    return 0;
}

static ssize_t
crime_write(struct file* flip, const char* __user ubuf, size_t count, loff_t* f_pos) {
    /* per stampare in debug ubuf bisognerebbe copiarlo prima o quantomeno
    fare dei controlli se si tratta di dati grezzi etc */
    printk("crime_write was called with parameter %d\n", count);
    return 0;
}

static int crime_ioctl(struct inode* inode, struct file* file, unsigned int cmd, unsigned long data) {
    printk("crime_ioctl called with parameters %d %d\n", cmd, data);
    return 0;
}

module_init(crime_init);
module_exit(crime_exit);

MODULE_AUTHOR("author");
MODULE_DESCRIPTION("description");
MODULE_LICENSE("license");