//**********************************************************
//
//  file cf_io.c
//
//  8 bits i/o for Compact Flash card by Teunis van Beelen
//
//  teuniz@gmail.com
//
//  LBA-mode, 512 bytes per sector
//
//  last revision  03-02-2005
//
//**********************************************************

#include "cf_io.h"


void activate_powersave(void)
{
  access_card(0x02, 64);           // powersave after 64 * 5 mSec.
  access_card(0x06, 0);
  access_card(0x07, 0xe3);         // idle mode
}

unsigned short cf_read_word(void)
{
  unsigned short cf_read_word_int;

  unsigned char cf_read_word_byte;

  clear_bit(portc,3);              //  strobe _OE
  nop();
  while(!(portc&32));              //  RDY/_BSY
  cf_read_word_byte = portd;       //  read byte
  set_bit(portc,3);
  nop();
  while(!(portc&32));              //  RDY/_BSY
  nop();
  clear_bit(portc,3);              //  strobe _OE
  nop();
  while(!(portc&32));              //  RDY/_BSY
  cf_read_word_int = portd;
  set_bit(portc,3);
  cf_read_word_int = (cf_read_word_int << 8) + cf_read_word_byte;
  return(cf_read_word_int);
}

void read_write_sector(unsigned long lba, unsigned char write, unsigned char n)
{
  access_card(0x02, n);                //  sector count
  access_card(0x03, lba);
  lba >>= 8;
  access_card(0x04, lba);
  lba >>= 8;
  access_card(0x05, lba);
  lba >>= 8;
  lba = lba | 11100000b;               //  zie pagina 60 CF specification rev. 1.4
  access_card(0x06, lba);
  if(write)  access_card(0x07,0x30);   //  write sector
  else access_card(0x07, 0x20);        //  read sector
}

unsigned long get_drive_param(void)
{
  unsigned char k;
 
  unsigned short s;

  unsigned long sectors;

  access_card(0x07,0xec);       //  STATUS/COMMAND,  identify drive command
  k = cf_read_byte();
  if(k!=0x8a)   return(0);
  k = cf_read_byte();
  if(k!=0x84)	return(0);
  for(k=0; k<12; k++)   cf_read_byte();
  sectors = cf_read_word();
  sectors <<= 16;
  s = cf_read_word();
  sectors += s;
  return(sectors);
}


void access_card(unsigned char a_c_command, unsigned char a_c_data)
{                               //  for details see tabel 35, chapter 6.1.3 of CF-spec.
  trisd = 0x00;                 //  set port D as output
  porte = a_c_command;          //  STATUS/COMMAND
  portd = a_c_data;             //  identify drive command
  while(!(portc&32));           //  RDY/_BSY
  clear_bit(portc,4);           //  strobe _WE
  nop();
  set_bit(portc,4);
  nop();
  while(!(portc&32));           //  RDY/_BSY
  porte = 0x00;                 //  read data command
  trisd = 0xff;                 //  set port D as input
}

void cf_write_word(unsigned short cf_write_word_temp)
{
  trisd = 0x00;                 //  set port D as output
  porte = 0x00;                 //  even write data
  portd = cf_write_word_temp;   //  data
  while(!(portc&32));           //  RDY/_BSY
  clear_bit(portc,4);           //  strobe _WE
  nop();
  set_bit(portc,4);
  portd = cf_write_word_temp >> 8;   //  data
  while(!(portc&32));           //  RDY/_BSY
  clear_bit(portc,4);           //  strobe _WE
  nop();
  set_bit(portc,4);
  nop();
  while(!(portc&32));           //  RDY/_BSY
  trisd = 0xff;                 //  set port D as input
}

void cf_write_byte(unsigned char cf_write_byte_temp)
{
  trisd = 0x00;                 //  set port D as output
  porte = 0x00;                 //  even write data
  portd = cf_write_byte_temp;   //  data
  while(!(portc&32));           //  RDY/_BSY
  clear_bit(portc,4);           //  strobe _WE
  nop();
  set_bit(portc,4);
  nop();
  while(!(portc&32));           //  RDY/_BSY
  trisd = 0xff;                 //  set port D as input
}

void cf_write_null(unsigned short write_cnt)
{
  trisd = 0x00;                 //  set port D as output
  porte = 0x00;                 //  even write data
  portd = 0x00;                 //  data
  while(write_cnt--)
  {
    clear_bit(portc,4);         //  strobe _WE
    nop();
    set_bit(portc,4);
    while(!(portc&32));         //  RDY/_BSY
  }
  trisd = 0xff;                 //  set port D as input
}


unsigned char cf_read_byte(void)
{
  unsigned char cf_read_byte_temp;
  clear_bit(portc,3);           //  strobe _OE
  nop();
  while(!(portc&32));           //  RDY/_BSY
  cf_read_byte_temp = portd;    //  read byte
  set_bit(portc,3);
  return(cf_read_byte_temp);
}

void reset_card(void)
{
  while(!(portc&32));      //  RDY/_BSY
  delay_ms(50);
  set_bit(portc,2);        //  reset line
  delay_ms(100);
  clear_bit(portc,2);
  delay_ms(50);
  while(!(portc&32));      //  RDY/_BSY
  delay_ms(10);
}