/*
* RaspberryPi system shutdown
* By Boguslaw Kempny kempny@stanpol.com.pl
*
* LCD display procedures based on i2clcd.txt
* by Lewis Loflin www.bristolwatch.com lewis@bvu.net
* http://www.bristolwatch.com/rpi/i2clcd.htm
* Using wiringPi by Gordon Henderson
*
* There is no warrenty of any kind use at your own risk.
*
*/

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <wait.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <wiringPi.h>
#include <wiringPiI2C.h>
#include <lcd.h>



#define WEWY 25 // connect reset switch to this pin and GND
#define I2C_ADDR   0x27 // I2C device address
#define LCD_CHR  1 // Mode - Sending data
#define LCD_CMD  0 // Mode - Sending command

#define ENABLE  0b00000100 // Enable bit

static sigset_t   signal_mask;  /* signals to block         */

struct timespec tim;
int fdlcd;  
int sleep_time;
int konvline[4]={0x80, 0xC0, 0x94, 0xd4}; //addr. of 1, 2, 3 and 4 line on LCD 
int lcd_backlight = 0x08;
void Delay_ms(int microsec);
void lcd_init(void);
void lcd_byte(int bits, int mode);
void lcd_toggle_enable(int bits);
void lcdLoc(int col, int line); //move cursor
void typeln(const char *s);
void typeChar(char val);






/* S T A R T */
void main (argc, argv)
int argc;
char *argv[];

{

// check wiringPi setup
if (wiringPiSetup() == -1)
  {
	printf("wiringPi-Error\n");
    exit(1);
  }

// set reset pin to input, activate pull-up resistor
pinMode (WEWY , INPUT) ;
pullUpDnControl(WEWY, PUD_UP);


int state;
int count;


while (TRUE)
  {
   state=digitalRead(WEWY); 

   if (state == 0) // WEWY pin connected to GND
    {
     for(count=30;count>0;count--)  //WEWY pin connected to GND for 5 seconds
      {
       state=digitalRead(WEWY);
       if(state == 1) break;
       Delay_ms(200);
      }
     if (state == 0)
      {
       system("killall pomiar");  // terminate a process
       sleep(1);
//**** initiate LCD Display 
    fdlcd = wiringPiI2CSetup(I2C_ADDR);
    lcd_init(); // setup LCD

    lcdLoc (0, 0) ; // set cursor at line 0, column 0
    typeln ("Closing the system") ; // display some info on display

//*****  mask signals to avoid premature closure of our process

    sigemptyset (&signal_mask);
    sigaddset (&signal_mask, SIGINT);
    sigaddset (&signal_mask, SIGTERM);
    sigaddset (&signal_mask, SIGHUP);
    sigprocmask(SIG_BLOCK, &signal_mask, NULL);
    Delay_ms(900);
    system("shutdown -h now"); // begin shutdown procedure
//**** wait 5 seconds 
    sleep_time = 10;
    while (sleep_time > 0)
      sleep_time = sleep (sleep_time);

// *** turn off LCD backlight
    lcd_backlight = 0x00;  
    typeln (" ") ;
    exit(0);
      }
    }
  }                               
}                               


//*****************************************
void Delay_ms(int milisec)
{
 tim.tv_sec = 0;
 tim.tv_nsec = milisec * 1000000;
     while(nanosleep(&tim,&tim)==-1)
          continue;
}

//*************************************
// go to location on LCD
void lcdLoc(int col, int line)   {
  lcd_byte(konvline[line] + col, LCD_CMD);
}

//*************************************
// out char to LCD at current position
void typeChar(char val)   {

  lcd_byte(val, LCD_CHR);
}


// this allows use of any size string
//*************************************
void typeln(const char *s)   {

  while ( *s ) lcd_byte(*(s++), LCD_CHR);

}

//*************************************
void lcd_byte(int bits, int mode)   {

  //Send byte to data pins
  // bits = the data
  // mode = 1 for data, 0 for command
  int bits_high;
  int bits_low;
  // uses the two half byte writes to LCD
  bits_high = mode | (bits & 0xF0) | lcd_backlight ;
  bits_low = mode | ((bits << 4) & 0xF0) | lcd_backlight ;

  // High bits
  wiringPiI2CReadReg8(fdlcd, bits_high);
  lcd_toggle_enable(bits_high);

  // Low bits
  wiringPiI2CReadReg8(fdlcd, bits_low);
  lcd_toggle_enable(bits_low);
}


//*************************************
void lcd_toggle_enable(int bits)   {
  // Toggle enable pin on LCD display
  delayMicroseconds(1);
  wiringPiI2CReadReg8(fdlcd, (bits | ENABLE));
  delayMicroseconds(1);
  wiringPiI2CReadReg8(fdlcd, (bits & ~ENABLE));
  delayMicroseconds(1);
}

//*************************************
void lcd_init()   {
  // Initialise display
  lcd_byte(0x33, LCD_CMD); // Initialise
  lcd_byte(0x32, LCD_CMD); // Initialise
  lcd_byte(0x06, LCD_CMD); // Cursor move direction
  lcd_byte(0x0C, LCD_CMD); // 0x0F On, Blink Off
  lcd_byte(0x28, LCD_CMD); // Data length, number of lines, font size
  lcd_byte(0x01, LCD_CMD); // Clear display
  delayMicroseconds(500);
}