#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>

/* Module information */
MODULE_AUTHOR( "Gul-uc3m" );
MODULE_DESCRIPTION( "Modulo de ejemplo" );
MODULE_LICENSE("GPL");


int entero=0;
int major=250;
char * cadena;
module_param(major,int,S_IRUGO);

struct cdev *my_cdev;
ssize_t midispositivo_write (struct file *fichero, const char __user * datos, size_t tamano, loff_t * offset){
	printk(KERN_INFO "Estoy escribiendo\n");
	return tamano;
}

ssize_t midispositivo_read (struct file *fichero , char __user * destino, size_t tamano, loff_t * offset){
	printk(KERN_INFO "Estoy leyendo\n");
	return 0;
}

struct file_operations fops = {
	.owner = THIS_MODULE,
	.read = midispositivo_read,
	.write = midispositivo_write
};
int hola(void){
	entero=4;
	cadena=kmalloc(entero+1,GFP_KERNEL);
	memcpy(cadena,"hola",entero);
	cadena[entero]=0x00;
	my_cdev = cdev_alloc();
	my_cdev->owner = THIS_MODULE;
	my_cdev->ops = &fops;
	if(cdev_add(my_cdev, MKDEV(major,0), 1)){
		printk(KERN_INFO "ERROR CARGANDO\n");
		return -1;
	}
	printk(KERN_INFO "Hola Mundo.entero=%d y cadena=%s.\n",entero, cadena);
	return 0;
}
void adios(void){
	cdev_del(my_cdev);
	printk(KERN_INFO "Adios mundo cruel.entero=%d y cadena=%s.\n",entero, cadena);
	kfree(cadena);
}

module_init(hola);
module_exit(adios);