#include "myi2c.h"
#include "keyboard.h"

#include "delay.h"

#define DRIVER 0x70
#define SCANNER 0x72

unsigned char keyboard_read_hardware(unsigned char scancode)
{
	unsigned char ack,read;

	ack = StartI2C(DRIVER);
	WriteI2CByte( scancode );
	StopI2C();
	Delay10us(1); //I2C spec's siger min 4.7 uSec mellem stop og nęste start
	

	ack = ReStartI2C(SCANNER | 0x01); //read-mode
	read = ReadI2CByte(0); //Lastbyte
	StopI2C();
	Delay10us(1);
	
	read &= 0x0F; //clear upper 4 bit
	if (ack)
		return read;
	else
		return 0;
}

unsigned char keyboard_read(void)
{
	unsigned char read;

	read = keyboard_read_hardware(0x0E);
	
	switch(read)
	{
		case 0x0e:
			return 'C';
		case 0x0D:
			return 'D';
		case 0x0B:
			return 'E';
		case 0x07:
			return 'F';
	}

	read = keyboard_read_hardware(0x0D);
	switch(read)
	{
		case 0x0e:
			return 'B';
		case 0x0d:
			return '9';
		case 0x0B:
			return '6';
		case 0x07:
			return '3';
	}
	
	read = keyboard_read_hardware(0x0b);
	switch(read)
	{
		case 0x0e:
			return '0';
		case 0x0d:
			return '8';
		case 0x0B:
			return '5';
		case 0x07:
			return '2';
	}	

	read = keyboard_read_hardware(0x07);
	switch(read)
	{
		case 0x0e:
			return 'A';
		case 0x0d:
			return '7';
		case 0x0B:
			return '4';
		case 0x07:
			return '1';
	}		
	
	return 0;
}

unsigned char keyboard_read_safe(void)
{
	static unsigned char last_read;
	unsigned char key,returnkey;
	
	returnkey = 0;
	key = keyboard_read();
	
	if (last_read == 0 && key != 0)
	{
		returnkey = key;		
	}
	
	last_read = key;
	
	return returnkey;
}