/* * Written by Der Herr Hofrat, der.herr@hofr.at * (C) 2002 FSMLabs * License: GPL Version 2 */#include <rtl.h>#include <time.h>#include <pthread.h>#include <asm/io.h>#include "common.h"/* set the paralell port address */int lpt_port=0x378;/* compiled in addresses are unpractical so lsets define a module parameter  * that permits setting the parport address at module insertion time  * insmod sched_toggle.o lpt_port=0x3bc would override 0x378 . */MODULE_PARM(lpt_port,"i");pthread_t thread;void * toggle(void *arg){	int nibl;        hrtime_t now;	struct sched_param p;	p . sched_priority = 1;        /* set the attributes for the thread , this          * defines the scheduling policy and priority         */	pthread_setschedparam (pthread_self(), SCHED_FIFO, &p);        now = gethrtime(); /* get the current time in nano-seconds */        /* make the thread periodic          * starting now , with a period of 500000000 nano-seconds         */ 	pthread_make_periodic_np (pthread_self(), now, 500000000);        nibl = 0x0f;	while (1) {                outb(nibl,lpt_port); /* write it out to the parport*/                nibl = ~nibl;        /* two's complement of nibl*/		pthread_wait_np ();  /* put the thread on the wait queue */	}	return 0;}/* init_module is called when the module is inserted it will do  * the basic setup and register the module with the kernel */int init_module(void){	rtl_printf("RTL thread starts on CPU%d : using LPT at 0x%x\n",		rtl_getcpuid(),lpt_port);        /* create the thread                                                * attributes are "initialized" to NULL and set in toggle          *         *                      thread, attributes, function , ARG         */	return pthread_create (&thread, NULL      , toggle   , 0  );}/* when the module is removed with  rmmod sched_toggle  this is called * to cleanup any kernels trace of this module */void cleanup_module(void){        /* send a request for cancelation*/	pthread_delete_np (thread);}