ardupilot/libraries/DataFlash/DataFlash_APM1.cpp

/*
	DataFlash_APM1.cpp - DataFlash log library for AT45DB161
	Code by Jordi Munoz and Jose Julio. DIYDrones.com
	This code works with boards based on ATMega168/328 and ATMega1280/2560 using SPI port

	This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

	Dataflash library for AT45DB161D flash memory
	Memory organization : 4096 pages of 512 bytes or 528 bytes

	Maximun write bandwidth : 512 bytes in 14ms
	This code is written so the master never has to wait to write the data on the eeprom

	Methods:
		Init() : Library initialization (SPI initialization)
		StartWrite(page) : Start a write session. page=start page.
		WriteByte(data) : Write a byte
		WriteInt(data) :  Write an integer (2 bytes)
		WriteLong(data) : Write a long (4 bytes)
		StartRead(page) : Start a read on (page)
		GetWritePage() : Returns the last page written to
		GetPage() : Returns the last page read
		ReadByte()
		ReadInt()
		ReadLong()

	Properties:

*/

#include <stdint.h>
#include "DataFlash.h"
#include <SPI.h>

#define OVERWRITE_DATA 1 // 0: When reach the end page stop, 1: Start overwriting from page 1

// *** INTERNAL FUNCTIONS ***

void dataflash_CS_inactive()
{
  digitalWrite(DF_SLAVESELECT,HIGH); //disable device
}

void dataflash_CS_active()
{
  digitalWrite(DF_SLAVESELECT,LOW); //enable device
}

// Constructors ////////////////////////////////////////////////////////////////
DataFlash_APM1::DataFlash_APM1()
{
}

// Public Methods //////////////////////////////////////////////////////////////
void DataFlash_APM1::Init(void)
{
  pinMode(DF_DATAOUT, OUTPUT);
  pinMode(DF_DATAIN, INPUT);
  pinMode(DF_SPICLOCK,OUTPUT);
  pinMode(DF_SLAVESELECT,OUTPUT);
  #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
	pinMode(DF_RESET,OUTPUT);
	// Reset the chip
	digitalWrite(DF_RESET,LOW);
	delay(1);
	digitalWrite(DF_RESET,HIGH);
  #endif

  df_Read_END=false;

  dataflash_CS_inactive();     //disable device

  // Setup SPI  Master, Mode 3, fosc/4 = 4MHz
  SPI.begin();
  SPI.setBitOrder(MSBFIRST);
  SPI.setDataMode(SPI_MODE3);
  SPI.setClockDivider(SPI_CLOCK_DIV2);

  // get page size: 512 or 528
  df_PageSize=PageSize();
}

// This function is mainly to test the device
void DataFlash_APM1::ReadManufacturerID()
{
  dataflash_CS_active();     // activate dataflash command decoder

  // Read manufacturer and ID command...
  SPI.transfer(DF_READ_MANUFACTURER_AND_DEVICE_ID);

  df_manufacturer = SPI.transfer(0xff);
  df_device_0 = SPI.transfer(0xff);
  df_device_1 = SPI.transfer(0xff);
  SPI.transfer(0xff);

  dataflash_CS_inactive();    // Reset dataflash command decoder
}

// Read the status register
byte DataFlash_APM1::ReadStatusReg()
{
  byte tmp;

  dataflash_CS_active();     // activate dataflash command decoder

  // Read status command
  SPI.transfer(DF_STATUS_REGISTER_READ);
  tmp = SPI.transfer(0x00);  // We only want to extract the READY/BUSY bit

  dataflash_CS_inactive();    // Reset dataflash command decoder

  return tmp;
}

// Read the status of the DataFlash
inline
byte DataFlash_APM1::ReadStatus()
{
  return(ReadStatusReg()&0x80);  // We only want to extract the READY/BUSY bit
}


inline
unsigned int DataFlash_APM1::PageSize()
{
  return(528-((ReadStatusReg()&0x01)<<4));  // if first bit 1 trhen 512 else 528 bytes
}


// Wait until DataFlash is in ready state...
void DataFlash_APM1::WaitReady()
{
  while(!ReadStatus());
}

void DataFlash_APM1::PageToBuffer(unsigned char BufferNum, unsigned int PageAdr)
{
  dataflash_CS_active();     // activate dataflash command decoder

  if (BufferNum==1)
    SPI.transfer(DF_TRANSFER_PAGE_TO_BUFFER_1);
  else
    SPI.transfer(DF_TRANSFER_PAGE_TO_BUFFER_2);

  if(df_PageSize==512){
    SPI.transfer((unsigned char)(PageAdr >> 7));
    SPI.transfer((unsigned char)(PageAdr << 1));
  }else{
    SPI.transfer((unsigned char)(PageAdr >> 6));
    SPI.transfer((unsigned char)(PageAdr << 2));
  }
  SPI.transfer(0x00);	// don´t care bytes

  dataflash_CS_inactive();	//initiate the transfer
  dataflash_CS_active();

  while(!ReadStatus());  //monitor the status register, wait until busy-flag is high

  dataflash_CS_inactive();

}

void DataFlash_APM1::BufferToPage (unsigned char BufferNum, unsigned int PageAdr, unsigned char wait)
{
  dataflash_CS_active();     // activate dataflash command decoder

  if (BufferNum==1)
    SPI.transfer(DF_BUFFER_1_TO_PAGE_WITH_ERASE);
  else
    SPI.transfer(DF_BUFFER_2_TO_PAGE_WITH_ERASE);

  if(df_PageSize==512){
    SPI.transfer((unsigned char)(PageAdr >> 7));
    SPI.transfer((unsigned char)(PageAdr << 1));
  }else{
    SPI.transfer((unsigned char)(PageAdr >> 6));
    SPI.transfer((unsigned char)(PageAdr << 2));
  }
  SPI.transfer(0x00);	// don´t care bytes

  dataflash_CS_inactive();	//initiate the transfer
  dataflash_CS_active();

  // Check if we need to wait to write the buffer to memory or we can continue...
  if (wait)
	while(!ReadStatus());  //monitor the status register, wait until busy-flag is high

  dataflash_CS_inactive();	//deactivate dataflash command decoder
}

void DataFlash_APM1::BufferWrite (unsigned char BufferNum, unsigned int IntPageAdr, unsigned char Data)
{
  dataflash_CS_active();     // activate dataflash command decoder

  if (BufferNum==1)
    SPI.transfer(DF_BUFFER_1_WRITE);
  else
    SPI.transfer(DF_BUFFER_2_WRITE);
  SPI.transfer(0x00);				 //don't cares
  SPI.transfer((unsigned char)(IntPageAdr>>8));  //upper part of internal buffer address
  SPI.transfer((unsigned char)(IntPageAdr));	 //lower part of internal buffer address
  SPI.transfer(Data);				 //write data byte

  dataflash_CS_inactive();   // disable dataflash command decoder
}

unsigned char DataFlash_APM1::BufferRead (unsigned char BufferNum, unsigned int IntPageAdr)
{
  byte tmp;

  dataflash_CS_active();     // activate dataflash command decoder

  if (BufferNum==1)
    SPI.transfer(DF_BUFFER_1_READ);
  else
    SPI.transfer(DF_BUFFER_2_READ);
  SPI.transfer(0x00);				 //don't cares
  SPI.transfer((unsigned char)(IntPageAdr>>8));  //upper part of internal buffer address
  SPI.transfer((unsigned char)(IntPageAdr));	 //lower part of internal buffer address
  SPI.transfer(0x00);                            //don't cares
  tmp = SPI.transfer(0x00);		         //read data byte

  dataflash_CS_inactive();   // deactivate dataflash command decoder

  return (tmp);
}
// *** END OF INTERNAL FUNCTIONS ***

void DataFlash_APM1::PageErase (unsigned int PageAdr)
{
  dataflash_CS_active();     // activate dataflash command decoder
  SPI.transfer(DF_PAGE_ERASE);   // Command

  if(df_PageSize==512){
    SPI.transfer((unsigned char)(PageAdr >> 7));
    SPI.transfer((unsigned char)(PageAdr << 1));
  }else{
    SPI.transfer((unsigned char)(PageAdr >> 6));
    SPI.transfer((unsigned char)(PageAdr << 2));
  }

  SPI.transfer(0x00);	           // "dont cares"
  dataflash_CS_inactive();               //initiate flash page erase
  dataflash_CS_active();
  while(!ReadStatus());

  dataflash_CS_inactive();   // deactivate dataflash command decoder
}


void DataFlash_APM1::ChipErase ()
{

  dataflash_CS_active();     // activate dataflash command decoder
  // opcodes for chip erase
  SPI.transfer(DF_CHIP_ERASE_0);
  SPI.transfer(DF_CHIP_ERASE_1);
  SPI.transfer(DF_CHIP_ERASE_2);
  SPI.transfer(DF_CHIP_ERASE_3);

  dataflash_CS_inactive();               //initiate flash page erase
  dataflash_CS_active();
  while(!ReadStatus());

  dataflash_CS_inactive();   // deactivate dataflash command decoder
}

// *** DATAFLASH PUBLIC FUNCTIONS ***
void DataFlash_APM1::StartWrite(int PageAdr)
{
  df_BufferNum=1;
  df_BufferIdx=4;
  df_PageAdr=PageAdr;
  df_Stop_Write=0;
  WaitReady();
      // We are starting a new page - write FileNumber and FilePage
		BufferWrite(df_BufferNum,0,df_FileNumber>>8);   // High byte
		BufferWrite(df_BufferNum,1,df_FileNumber&0xFF); // Low byte
		BufferWrite(df_BufferNum,2,df_FilePage>>8);   // High byte
		BufferWrite(df_BufferNum,3,df_FilePage&0xFF); // Low byte
}

void DataFlash_APM1::FinishWrite(void)
{
	df_BufferIdx=0;
	BufferToPage(df_BufferNum,df_PageAdr,0);  // Write Buffer to memory, NO WAIT
	df_PageAdr++;
	if (OVERWRITE_DATA==1)
	    {
        if (df_PageAdr>DF_LAST_PAGE)  // If we reach the end of the memory, start from the begining
		  df_PageAdr = 1;
	    }
	else
	    {
        if (df_PageAdr>DF_LAST_PAGE)  // If we reach the end of the memory, stop here
		  df_Stop_Write=1;
	    }

	if (df_BufferNum==1)  // Change buffer to continue writing...
        df_BufferNum=2;
	else
        df_BufferNum=1;
}


void DataFlash_APM1::WriteByte(byte data)
{
  if (!df_Stop_Write)
    {
    BufferWrite(df_BufferNum,df_BufferIdx,data);
    df_BufferIdx++;
    if (df_BufferIdx >= df_PageSize)  // End of buffer?
      {
      df_BufferIdx=4;		//(4 bytes for FileNumber, FilePage)
	  BufferToPage(df_BufferNum,df_PageAdr,0);  // Write Buffer to memory, NO WAIT
      df_PageAdr++;
	  if (OVERWRITE_DATA==1)
	    {
        if (df_PageAdr>DF_LAST_PAGE)  // If we reach the end of the memory, start from the begining
		  df_PageAdr = 1;
	    }
      else
	    {
        if (df_PageAdr>DF_LAST_PAGE)  // If we reach the end of the memory, stop here
		  df_Stop_Write=1;
	    }

      if (df_BufferNum==1)  // Change buffer to continue writing...
        df_BufferNum=2;
      else
        df_BufferNum=1;
      // We are starting a new page - write FileNumber and FilePage
		BufferWrite(df_BufferNum,0,df_FileNumber>>8);   // High byte
		BufferWrite(df_BufferNum,1,df_FileNumber&0xFF); // Low byte
		df_FilePage++;
		BufferWrite(df_BufferNum,2,df_FilePage>>8);   // High byte
		BufferWrite(df_BufferNum,3,df_FilePage&0xFF); // Low byte
      }
    }
}

void DataFlash_APM1::WriteInt(int data)
{
  WriteByte(data>>8);   // High byte
  WriteByte(data&0xFF); // Low byte
}

void DataFlash_APM1::WriteLong(long data)
{
  WriteByte(data>>24);   // First byte
  WriteByte(data>>16);
  WriteByte(data>>8);
  WriteByte(data&0xFF);  // Last byte
}

// Get the last page written to
int DataFlash_APM1::GetWritePage()
{
  return(df_PageAdr);
}

// Get the last page read
int DataFlash_APM1::GetPage()
{
  return(df_Read_PageAdr-1);
}

void DataFlash_APM1::StartRead(int PageAdr)
{
  df_Read_BufferNum=1;
  df_Read_BufferIdx=4;
  df_Read_PageAdr=PageAdr;
  WaitReady();
  PageToBuffer(df_Read_BufferNum,df_Read_PageAdr);  // Write Memory page to buffer
//Serial.print(df_Read_PageAdr, DEC);	Serial.print("\t");
  df_Read_PageAdr++;
      // We are starting a new page - read FileNumber and FilePage
		df_FileNumber = BufferRead(df_Read_BufferNum,0);   // High byte
//Serial.print(df_FileNumber, DEC);	Serial.print("\t");
		df_FileNumber = (df_FileNumber<<8) | BufferRead(df_Read_BufferNum,1); // Low byte
//Serial.println(df_FileNumber, DEC);	Serial.print("\t");
		df_FilePage = BufferRead(df_Read_BufferNum,2);   // High byte
		df_FilePage = (df_FilePage<<8) | BufferRead(df_Read_BufferNum,3); // Low byte
}

byte DataFlash_APM1::ReadByte()
{
  byte result;

  WaitReady();
  result = BufferRead(df_Read_BufferNum,df_Read_BufferIdx);
  df_Read_BufferIdx++;
  if (df_Read_BufferIdx >= df_PageSize)  // End of buffer?
    {
    df_Read_BufferIdx=4;		//(4 bytes for FileNumber, FilePage)
    PageToBuffer(df_Read_BufferNum,df_Read_PageAdr);  // Write memory page to Buffer
    df_Read_PageAdr++;
    if (df_Read_PageAdr>DF_LAST_PAGE)  // If we reach the end of the memory, start from the begining
      {
      df_Read_PageAdr = 0;
      df_Read_END = true;
      }
      // We are starting a new page - read FileNumber and FilePage
		df_FileNumber = BufferRead(df_Read_BufferNum,0);   // High byte
		df_FileNumber = (df_FileNumber<<8) | BufferRead(df_Read_BufferNum,1); // Low byte
		df_FilePage = BufferRead(df_Read_BufferNum,2);   // High byte
		df_FilePage = (df_FilePage<<8) | BufferRead(df_Read_BufferNum,3); // Low byte
    }
  return result;
}

int DataFlash_APM1::ReadInt()
{
  int result;

  result = ReadByte();               // High byte
  result = (result<<8) | ReadByte(); // Low byte
  return result;
}

long DataFlash_APM1::ReadLong()
{
  long result;

  result = ReadByte();               // First byte
  result = (result<<8) | ReadByte();
  result = (result<<8) | ReadByte();
  result = (result<<8) | ReadByte(); // Last byte
  return result;
}

void DataFlash_APM1::SetFileNumber(uint16_t FileNumber)
{
	df_FileNumber = FileNumber;
	df_FilePage = 1;
}

uint16_t DataFlash_APM1::GetFileNumber()
{
	return df_FileNumber;
}

uint16_t DataFlash_APM1::GetFilePage()
{
	return df_FilePage;
}



// make one instance for the user to use
DataFlash_APM1 DataFlash;