/*------------------- ADC_driver -----------------------------------

  PURPOSE - Gives one sensor reading
  

  COMPILE to binary st as below-
            gcc -o run_ADC ADC_driver_rev4.c

  RUN       ./lp_tty_start ./ADC_driver_rev4
*/

//#include <asm/io.h>
#include <sys/io.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>

//------- Parallel port data.
static short lp_base_addr;
#define status_offset  1
#define control_offset 2
#define high 1
#define low  0

//-------Parallel port pins-------------------------
#define CS         0x02 //pin 3
#define CLK        0x01 //pin 2
#define all_low    0x00

static char save_data ;    // save of original values.
static char save_control ;
static char image_data ;   // use image as master record of port.
static char image_control ;
int DOUT = 0;
short cycle = 0;

// init du port parallèle
void lp_init()
 { 
   printf("lp_init()\n");
   lp_base_addr = 0x378 ;
   image_data    = save_data    = inb( lp_base_addr) ;
   image_control = save_control = inb( lp_base_addr+2) ;
   outb( (image_control &= 0xEF),  lp_base_addr + control_offset) ;
 }

// restore du port parallèle
void lp_restore()
{
   printf("lp_restore()\n");
   outb( save_data,    lp_base_addr) ;
   outb( save_control, lp_base_addr + control_offset);
}

int horloge(char lecture)
{
	printf("horloge()\n");
	short clk = 0;
	outb(all_low, lp_base_addr); // tout à 0

	if(lecture == 0);
	{
		for(clk=1; clk<=8; clk++)
		{
			outb(0, lp_base_addr);
			outb(CLK, lp_base_addr);
		//	printf("clk %d\n", clk);
		}
	}
	else if(lecture == 1);
	{
		for(clk=1; clk<=8; clk++)
		{
			outb(0, lp_base_addr);
			outb(CLK, lp_base_addr);
		//	printf("clk %d\n", clk);
		}
	}
	else
	{
		return(0);
	}
	outb(CS, lp_base_addr); // CS à 1
	usleep(500000); // attente de 500000µs (500ms)
	outb(0, lp_base_addr); //CS à 0
}

/*void horloge_lecture()
{
	printf("horloge()\n");
	short clk = 0;
	outb(all_low, lp_base_addr); // tout à 0
	for(cycle=1; cycle <=2; cycle++)
	{
		outb(CS, lp_base_addr); // CS à 1
	//	sleep(1); //attente de 1s
		usleep(500000); // attente de 500000µs (500ms)
		outb(0, lp_base_addr); //CS à 0

		for(clk=1; clk<=8; clk++)
		{
		  outb(0, lp_base_addr);
		  outb(CLK, lp_base_addr);
	//	  printf("clk %d\n", clk);
		}
	printf("fin du cycle d\'horloge %d\n", cycle);
	
	outb(CS, lp_base_addr); // CS à 1
	usleep(500000); // attente de 500000µs (500ms)
	outb(0, lp_base_addr); //CS à 0
	
	horloge_clk(0); // cycle d'horloge
	horloge_clk(1); // horloge + lecture
	}
}
*/

/*int lecture()
{
	printf("lecture()\n");
	ordre[8] ={6,5,4,3,2,1,0,7};
	
	return(DOUT);
}
*/
void affichage()
{
	printf("affichage()\n");
	if(DOUT != 4095)
	{
	  printf("Tension: %d\n", DOUT);
	}
	else
	printf("Lecture impossible\n");
	usleep(500000);
}

int main()
{
	lp_init(); //init du port parallèle
	short i = 0;
	for(i=0; i<1; i++)
	{
		//horloge_lecture();
		horloge_clk(0); // cycle d'horloge
		horloge_clk(1); // horloge + lecture
	}
	affichage();//
	lp_restore(); // restauration du port parallèle
	return(0);
}