/******************************************************************************
 *
 * msr_jitter.c
 *
 * Autor: Wilhelm Hagemeister
 *
 * (C) Copyright IgH 2002
 * Ingenieurgemeinschaft IgH
 * Heinz-B�äcker Str. 34
 * D-45356 Essen
 * Tel.: +49 201/61 99 31
 * Fax.: +49 201/61 98 36
 * E-mail: hm@igh-essen.com
 *
 * $Id$
 *
 *****************************************************************************/

#ifndef __KERNEL__
#  define __KERNEL__
#endif
#ifndef MODULE
#  define MODULE
#endif

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <asm/msr.h> /* maschine-specific registers */
#include <linux/param.h> /* fuer HZ */

#include <msr_reg.h>
#include "msr_jitter.h"

/*--includes-----------------------------------------------------------------*/

/*--external functions-------------------------------------------------------*/

/*--external data------------------------------------------------------------*/

/*--public data--------------------------------------------------------------*/

/*--local data---------------------------------------------------------------*/

#define NUMCLASSES 16

static int jittime[NUMCLASSES]={0,1,2,5,10,20,50,100,200,500,
                                1000,2000,5000,10000,20000,50000}; //in usec
static int jitcount[NUMCLASSES];
static double jitpercent[NUMCLASSES];
static unsigned int tcount = 1;

static void msr_jit_read(void)
{
    int i;
    for(i=0;i<NUMCLASSES;i++) {
	if(tcount >100) {
	    jitpercent[i] = jitcount[i]*100.0/tcount;
	}
    }
}

void msr_jitter_init(void)
{
    msr_reg_int_list("/Taskinfo/Jitter/Classes","usec",
                     &jittime[0],MSR_R,NUMCLASSES,NULL,NULL,NULL);
    msr_reg_int_list("/Taskinfo/Jitter/Count","",
                     &jitcount[0],MSR_R,NUMCLASSES,NULL,NULL,NULL);
    msr_reg_dbl_list("/Taskinfo/Jitter/percent","%",
                     &jitpercent[0],MSR_R,NUMCLASSES,NULL,NULL,&msr_jit_read);
}

/******************************************************************************
 *
 * Function: msr_jitter_run
 *
 * Beschreibung:
 *
 *
 * Parameter: Zeiger auf msr_data
 *
 * R�ückgabe:
 *
 * Status: exp
 *
 *****************************************************************************/

void msr_jitter_run(unsigned int hz) {

    int i,hit;
    static int firstrun = 1;
    static unsigned long k,j = 0;
    unsigned int dt,jitter;


    rdtscl(k);

    tcount++;

    //Zeitabstand zwischen zwei Interrupts in usec

    dt = ((unsigned long)(100000/HZ)*((unsigned long)(k-j)))
        /(current_cpu_data.loops_per_jiffy/10);

    jitter = (unsigned int)abs((int)dt-(int)1000000/hz);
    //jitter errechnet zum Sollabtastrate

    //in die Klassen einsortieren
    if(!firstrun) { //das erste mal nicht einsortieren
	hit = 0;
	for(i=0;i<NUMCLASSES-1;i++) {
	    if(jitter>=jittime[i] && jitter<jittime[i+1]) {
		jitcount[i]++;
		hit = 1;
		break;
	    }
	}
	if(hit == 0) //grŽöŽßer als der letzte
	    jitcount[NUMCLASSES-1]++;

    }
    else
	firstrun = 0;

    j = k;


}