#include "sd.h"
#include "uart.h"
#include <util/delay.h>

#define CS  2 // Chip select
#define DI  1 // master to slave
#define CLK 0 // Clock
#define DO  3 // slave to master

#define SD_PORT PORTC
#define SD_READ PINC




//#################################################################
// Init SD Karte
char init_SD(void)
//#################################################################
{ 
  
	DDRC &=~(1<<DO);		
	DDRC |= (1<<CLK);	
	DDRC |= (1<<DI);		
	DDRC |= (1<<CS);	
	SD_PORT |= (1<<CS);	

  unsigned int Timeout = 0;

  for(unsigned char i = 0; i<200; i++)
  {
      asm volatile ("nop");
  }
  for (unsigned char b = 0;b<0x0f;b++)
  {
	  write_char(0xff);
	  _delay_us(10);
  }

	unsigned char CMD[] = {0x40,0x00,0x00,0x00,0x00,0x95};

	while(write_command (CMD) !=1)
	{
		if (Timeout++ > 200)
			{
			SD_PORT |= (1<<CS);
			uart_putc(write_command (CMD)); // test!
			return(1); 
			}
	}
  	Timeout = 0;
	CMD[0] = 0x41;
	CMD[5] = 0xFF;
	while( write_command (CMD) !=0)
	{
		if (Timeout++ > 400)
			{
			SD_PORT |= (1<<CS);
			return(2); 
			}
	}

	SD_PORT |= (1<<CS);
    return 0;
} 

//#################################################################
//Byte senden
void write_char(unsigned char data) 
//#################################################################
{ 
 
  for(char bits = 8; bits > 0;bits--){ 

	if (bit_is_set(data,(bits-1))>0)
	{
    	SD_PORT |= (1<<DI);
	}
	else
	{
	    SD_PORT &=~(1<<DI);
	}

	SD_PORT &=~(1<< CLK);
	_delay_us(10);	 
	SD_PORT |= (1<< CLK);
	

  }
  SD_PORT |= (1<<DI);
}
//#################################################################
// Byte empfangen
unsigned char read_char(void)
//#################################################################
{
  unsigned char byte = 0;

  for(unsigned char bits = 8; bits > 0; bits--)
  {
   SD_PORT &=~(1<<CLK);

    if (bit_is_set(SD_READ,DO) > 0)
	 {
    	byte |= (1<<(bits-1));
	 }
	else
	 {
	    byte &=~(1<<(bits-1));
	 }
	SD_PORT |=(1<<CLK);	 
  }
  return (byte);
}
//#################################################################
// command senden
unsigned char write_command (unsigned char *cmd)
//#################################################################
{ 
   unsigned char tmp    = 0xFF;
   SD_PORT |= (1<<CS);
   write_char(0xFF);
   SD_PORT &=~(1<<CS);
   for(unsigned char a = 0; a< 0x06 ;a++)
   {
     write_char(*cmd++);
	 
   }
   while(tmp == 0xFF)
   {
     tmp = read_char();
	 if(tmp != 0xFF){ break;} 
   }
   return(tmp);
}