#include <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

#include "i2c_io.h"

#define I2C_QT_ADDR    0x1A
#define I2C_WRITE            0
#define I2C_READ             1


uint8_t get_qt_reg(uint8_t reg_addr)
{
   uint8_t ret;

   _delay_ms(1);
   ret = i2c_start(I2C_QT_ADDR+I2C_WRITE);     // set device address and write mode
   if (ret)
   {
        /* failed to issue start condition, possibly no device found */
//      uart_puts("I2C Read error 1\n\r");
      i2c_stop();
      return 0;
   }
   else
   {
      i2c_write(reg_addr);                       // write address
       i2c_stop();
      _delay_ms(1);
      ret=i2c_start(I2C_QT_ADDR+I2C_READ);      // set device address and read mode
      if (ret)
      {
           /* failed to issue start condition, possibly no device found */
//         uart_puts("I2C Read error 2\n\r");
         i2c_stop();
         return 0;
      }
        ret = i2c_readNak();
      i2c_stop();
      return ret;
   }
}

void set_qt_reg(uint8_t reg_addr, uint8_t data)
{

   uint8_t ret;
   
   _delay_ms(1);
   ret = i2c_start(I2C_QT_ADDR+I2C_WRITE);    // set device address and write mode
    if ( ret )
   {
        /* failed to issue start condition, possibly no device found */
//      uart_puts("I2C Write error\n\r");
        i2c_stop();
      return;
    }
   else
   {
        /* issuing start condition ok, device accessible */
        i2c_write(reg_addr);               // write address // ret=0 -> Ok, ret=1 -> no ACK
      _delay_ms(1);
      i2c_write(data);            // write freq lo byte
        i2c_stop();                     // set stop conditon = release bus
   }   
}


ISR(INT0_vect)
{
   uint16_t key;
   uint8_t tmphead;
   
   cli();

   get_qt_reg(2); //clear main status
   key = get_qt_reg(3)<<8;
   key |= get_qt_reg(4);
   
   if(key) //key pressed
   {         
      //put code here

   }
   sei();
}

/******************************************************************/


void kbd_init()
{
   cli();
   i2c_init();

   // init QT chip
   set_qt_reg(12, 1);
   set_qt_reg(13, 1);
   set_qt_reg(15, 20);
   set_qt_reg(16, 5);
   set_qt_reg(17, 3);
   set_qt_reg(18, 255);
   set_qt_reg(19, 25);
   set_qt_reg(20, 0);
   set_qt_reg(73, 0x1c); // GPIO set as output

   set_qt_reg(10, 1); //send calidrate

   // clear status
   get_qt_reg(2);
   get_qt_reg(3);
   get_qt_reg(4);
   get_qt_reg(5);
   get_qt_reg(6);

   MCUCR = _BV(ISC01); //Enable INT0 on falling edge
   GICR  = _BV(INT0);  //Enable external interrupt INT0
   sei();
}