#include <avr/io.h>
#include <stdint.h>
#include <avr/interrupt.h>

#include "spi.h"
#include "dataflash.h"

// Prevent Double Initialization
unsigned short dataflash_flag = 0;

void dataflash_opcode_and_address(unsigned char opcode, unsigned int page, unsigned int offset)
{
  SPI_MasterTransfer(opcode);
  SPI_MasterTransfer((unsigned char)(page >> 7) & 0x1f);
  SPI_MasterTransfer(((unsigned char)(offset >> 8) & 0x01) | ((unsigned char)(page) << 1));
  SPI_MasterTransfer((unsigned char)(offset));
}

void dataflash_wait(void)
{
  DATAFLASH_Chip_Select;
  SPI_MasterTransfer(DATAFLASH_STATUS_REGISTER_READ);

  while (!(SPI_MasterTransferRead(0x00) & 0x80))
    ;

  DATAFLASH_Chip_Unselect;
}

void dataflash_init(void)
{
  // Check if already initialized
  if (!(dataflash_flag & 1))
  {
    // Backup Status Register and disable Interrupts
    uint8_t sreg = SREG;
    cli();
    // AT45DB081 doesn't actually need an intialization,
    // only the ChipSelect should be configured as an output.
    DDRB |= (1 << PB4);
    DATAFLASH_Chip_Unselect;
    SPI_MasterInit();

    // Restore Status Register
    SREG = sreg;

    // Set dataflash Init Flag
    dataflash_flag = 1;
  }
}

void dataflash_buffer_to_page(unsigned int page, unsigned char buffer)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;

  switch (buffer)
  {
  default:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_1_TO_MAIN_MEMORY_PAGE_PROGRAM_WITH_BUILT_IN_ERASE,
                                 page, 0x00);
    break;

  case 2:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_2_TO_MAIN_MEMORY_PAGE_PROGRAM_WITH_BUILT_IN_ERASE,
                                 page, 0x00);
    break;
  }
  DATAFLASH_Chip_Unselect;
}

void dataflash_page_to_buffer(unsigned int page, unsigned char buffer)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;

  switch (buffer)
  {
  default:
    dataflash_opcode_and_address(DATAFLASH_MAIN_MEMORY_PAGE_TO_BUFFER_1_TRANSFER,
                                 page, 0x00);
    break;

  case 2:
    dataflash_opcode_and_address(DATAFLASH_MAIN_MEMORY_PAGE_TO_BUFFER_2_TRANSFER,
                                 page, 0x00);
    break;
  }
  DATAFLASH_Chip_Unselect;
}

void dataflash_buffer_read(unsigned char buffer, unsigned int offset,
                           unsigned int length, unsigned char *array)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;

  switch (buffer)
  {
  default:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_1_READ_LF,
                                 0x00, offset);
    break;

  case 2:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_2_READ_LF,
                                 0x00, offset);
    break;
  }

  offset = 0x00;

  while (length--)
  {
    array[offset++] = SPI_MasterTransferRead(0x00);
  }

  DATAFLASH_Chip_Unselect;
}

void dataflash_buffer_write(unsigned char buffer, unsigned int offset,
                            unsigned int length, unsigned char *array)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;

  switch (buffer)
  {
  default:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_1_WRITE,
                                 0x00, offset);
    break;

  case 2:
    dataflash_opcode_and_address(DATAFLASH_BUFFER_2_WRITE,
                                 0x00, offset);
    break;
  }

  offset = 0x00;

  while (length--)
  {
    SPI_MasterTransfer(array[offset++]);
  }

  DATAFLASH_Chip_Unselect;
}

void dataflash_read(unsigned int page, unsigned int offset,
                    unsigned int length, unsigned char *array)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;

  dataflash_opcode_and_address(DATAFLASH_CONTINUOUS_ARRAY_READ_LF, page, offset);

  offset = 0x00;

  while (length--)
  {
    array[offset++] = SPI_MasterTransferRead(0x00);
  }

  DATAFLASH_Chip_Unselect;
}

void dataflash_chip_erase(void)
{
  dataflash_wait();
  DATAFLASH_Chip_Select;
  SPI_MasterTransfer(DATAFLASH_CHIP_ERASE_1);
  SPI_MasterTransfer(DATAFLASH_CHIP_ERASE_2);
  SPI_MasterTransfer(DATAFLASH_CHIP_ERASE_3);
  SPI_MasterTransfer(DATAFLASH_CHIP_ERASE_4);
  DATAFLASH_Chip_Unselect;
}