mmc.c

Firmware for lpc2148, including mmc, uart, rtc, lcd, interrupts

// mmc.c : MultiMediaCard functions: init, read, write ...
//
// Rolf Freitag 5/2003
//



// MMC Lib
#ifndef _MMCLIB_C
#define _MMCLIB_C
//---------------------------------------------------------------------
#include "mmc.h"


#include <iolpc2138.h>
#include  "math.h"
#include  "string.h"

char mmcGetResponse(void);
char mmcGetXXResponse(const char resp);
char mmcCheckBusy(void);

void initSSP (void);

char mmc_buffer[512] = { 0 };	// Buffer for mmc i/o for data and registers
extern char card_state;		// 0 for no card found, 1 for card found (init successfull)


//---------------------------------------------------------------------
void Delays (unsigned long a) { while (--a!=0); }

unsigned long SSPSetBaudRate(unsigned long baudrate, unsigned long systemfreq)
{
    //Compute the new value for SPICK
    //baudrate = systemfreq / (2 * (SPICK + 1))
    unsigned long spick = ((systemfreq / baudrate) >> 1);

    //Only divide ratios between 1 & 256 are supported
    spick &= 0x0FF;

    //Set the SPICK register
    SSPCPSR = (spick & 0x0FF);
    //SSPCR0_bit.SCR = (spick & 0x0FF);
    //CPSDVSR = (spick & 0x0FF);

    //Return the actual value achieved
    return (systemfreq / ((spick + 1) << 1));
}

// setup usart1 in spi mode
void initSSP (void)
{
  //set functionalite to pins:
  //port0.17 -> SCK1
  //port0.18 -> MISO0
  //port0.19 -> MOSI0
  //port0.20 -> SSEL1
  PINSEL1_bit.P0_17 = 0x2;
  PINSEL1_bit.P0_18 = 0x2;
  PINSEL1_bit.P0_19 = 0x2;
  PINSEL1_bit.P0_20 = 0x2;


  SSPCR0_bit.CPHA   = 0;      //ClockPhase (active)
  SSPCR0_bit.CPOL   = 0;      //ClockPlarity
  SSPCR0_bit.FRF    = 0;      //Select SPI mode
  SSPCR0_bit.DSS    = 0x7;    //8 bits data size

  SSPCR1_bit.MS     = 0;      //Master mode (0) or Slave mode (1)
  SSPCR1_bit.SSE    = 1;      //Enable SPI


  //SSPSR_bit.TNF = 0;
  //SSPSR_bit.RNE = 0;

  //Char lenght (8 bite)
  //SPICF_bit.CHR     = 0;

  //Set Baund Rate
  //1st operand - data rate - must be max 1/8 from System frequency
  //2nd operand - system freguency
  SSPSetBaudRate(9600, 12000000);

}


// Initialisieren
char initMMC (void)
{

   //raise SS and MOSI for 80 clock cycles
  //SendByte(0xff) 10 times with SS high
  //RAISE SS
  int i;
  char response=0x01;


 // debug_printf("Start iniMMC......");
  initSSP();
  //initialization sequence on PowerUp
  ///CS_HIGH();
  for(i=0;i<=9;i++)
    spiSendByte(0xff);
  ///CS_LOW();
  //Send Command 0 to put MMC in SPI mode
  mmcSendCmd(0x00,0,0x95);
  //Now wait for READY RESPONSE
  if(mmcGetResponse()!=0x01);
//       debug_printf("no responce");

  while(response==0x01)
  {
 //  debug_printf("Sending Command 1");
   //CS_HIGH();
   spiSendByte(0xff);
   //CS_LOW();
   mmcSendCmd(0x01,0x00,0xff);
   response=mmcGetResponse();
  }
  //CS_HIGH();
  spiSendByte(0xff);
 // debug_printf("MMC INITIALIZED AND SET TO SPI MODE PROPERLY.");
  return MMC_SUCCESS;
}



// Ti added mmc Get Responce
char mmcGetResponse(void)
{
  //Response comes 1-8bytes after command
  //the first bit will be a 0
  //followed by an error code
  //data will be 0xff until response
  int i=0;

  char response;

  while(i<=64)
  {
   response=spiSendByte(0xff);
   if(response==0x00)break;
   if(response==0x01)break;
   i++;
  }
  return response;
}

char mmcGetXXResponse(const char resp)
{
  //Response comes 1-8bytes after command
  //the first bit will be a 0
  //followed by an error code
  //data will be 0xff until response
  int i=0;

  char response;

  while(i<=500)
  {
   response=spiSendByte(0xff);
   if(response==resp)break;
   i++;
  }
  return response;
}
char mmcCheckBusy(void)
{
  //Response comes 1-8bytes after command
  //the first bit will be a 0
  //followed by an error code
  //data will be 0xff until response
  int i=0;

  char response;
  char rvalue;
  while(i<=64)
  {
   response=spiSendByte(0xff);
   response &= 0x1f;
   switch(response)
    {
     case 0x05: rvalue=MMC_SUCCESS;break;
     case 0x0b: return(MMC_CRC_ERROR);
     case 0x0d: return(MMC_WRITE_ERROR);
     default:
	      rvalue = MMC_OTHER_ERROR;
	      break;
    }
   if(rvalue==MMC_SUCCESS)break;
    i++;
  }
  i=0;
  do
  {
   response=spiSendByte(0xff);
   i++;
  }while(response==0);
  return response;
}
// The card will respond with a standard response token followed by a data
// block suffixed with a 16 bit CRC.

// Ti Modification: long int -> long ; int -> long
char mmcReadBlock(const unsigned long address, const unsigned long count)
{
  unsigned long i = 0;
  char rvalue = MMC_RESPONSE_ERROR;

  // Set the block length to read
  if (mmcSetBlockLength (count) == MMC_SUCCESS)	// block length could be set
    {
      // SS = LOW (on)
      //CS_LOW ();
      // send read command MMC_READ_SINGLE_BLOCK=CMD17
      mmcSendCmd (17,address, 0xFF);
      // Send 8 Clock pulses of delay, check if the MMC acknowledged the read block command
      // it will do this by sending an affirmative response
      // in the R1 format (0x00 is no errors)
      if (mmcGetResponse() == 0x00)
	{
	  // now look for the data token to signify the start of
	  // the data
	  if (mmcGetXXResponse(MMC_START_DATA_BLOCK_TOKEN) == MMC_START_DATA_BLOCK_TOKEN)
	    {
	      // clock the actual data transfer and receive the bytes; spi_read automatically finds the Data Block
	      for (i = 0; i < 512; i++)
		mmc_buffer[i] = spiSendByte(0xff);	// is executed with card inserted

	      // get CRC bytes (not really needed by us, but required by MMC)
	      spiSendByte(0xff);
	      spiSendByte(0xff);
	      rvalue = MMC_SUCCESS;
	    }
	  else
	    {
	      // the data token was never received
	      rvalue = MMC_DATA_TOKEN_ERROR;	// 3
	    }
	}
      else
	{
	  // the MMC never acknowledge the read command
	  rvalue = MMC_RESPONSE_ERROR;	// 2
	}
    }
  else
    {
      rvalue = MMC_BLOCK_SET_ERROR;	// 1
    }
  //CS_HIGH ();
  spiSendByte(0xff);
  return rvalue;
}				// mmc_read_block



//---------------------------------------------------------------------
// Ti Modification: long int -> long
char mmcWriteBlock (const unsigned long address)
{
  unsigned long i = 0;
  char rvalue = MMC_RESPONSE_ERROR;	// MMC_SUCCESS;
  //char c = 0x00;

  // Set the block length to read
  if (mmcSetBlockLength (512) == MMC_SUCCESS)	// block length could be set
    {
      // SS = LOW (on)
      //CS_LOW ();
      // send write command
      mmcSendCmd (24,address, 0xFF);

      // check if the MMC acknowledged the write block command
      // it will do this by sending an affirmative response
      // in the R1 format (0x00 is no errors)
      if (mmcGetXXResponse(MMC_R1_RESPONSE) == MMC_R1_RESPONSE)
	{
	  spiSendByte(0xff);
	  // send the data token to signify the start of the data
	  spiSendByte(0xfe);
	  // clock the actual data transfer and transmitt the bytes
	  for (i = 0; i < 512; i++)
	    spiSendByte(mmc_buffer[i]);	// mmc_buffer[i];       Test: i & 0xff
	  // put CRC bytes (not really needed by us, but required by MMC)
	  spiSendByte(0xff);
	  spiSendByte(0xff);
	  // read the data response xxx0<status>1 : status 010: Data accected, status 101: Data
	  //   rejected due to a crc error, status 110: Data rejected due to a Write error.
          mmcCheckBusy();
	}
      else
	{
	  // the MMC never acknowledge the write command
	  rvalue = MMC_RESPONSE_ERROR;	// 2
	}
    }
  else
    {
      rvalue = MMC_BLOCK_SET_ERROR;	// 1
    }
  //give the MMC the required clocks to finish up what ever it needs to do
  //for (i = 0; i < 9; ++i)
  //spiSendByte(0xff);

  //CS_HIGH ();
  // Send 8 Clock pulses of delay.
  spiSendByte(0xff);
  return rvalue;
}// mmc_write_block


//---------------------------------------------------------------------
void mmcSendCmd (const char cmd, unsigned long data, const char crc)
{
  char frame[6];
  char temp;
  int i;

  frame[0]=(cmd|0x40);
  for(i=3;i>=0;i--){
    temp=(char)(data>>(8*i));
    frame[4-i]=(temp);
  }
  frame[5]=(crc);
  for(i=0;i<6;i++)
    spiSendByte(frame[i]);
}


//--------------- set blocklength 2^n ------------------------------------------------------
// Ti Modification: long int-> long
char mmcSetBlockLength (const unsigned long blocklength)
{
  //char rValue = MMC_TIMEOUT_ERROR;
  //char i = 0;

  // SS = LOW (on)
  //CS_LOW ();

  // Set the block length to read
  //MMC_SET_BLOCKLEN =CMD16
  mmcSendCmd(16, blocklength, 0xFF);

  // get response from MMC - make sure that its 0x00 (R1 ok response format)
  if(mmcGetResponse()!=0x00);

  //CS_HIGH ();

  // Send 8 Clock pulses of delay.
  spiSendByte(0xff);

  return MMC_SUCCESS;
}				


unsigned char spiSendByte(const unsigned char data)
{
    /*
    unsigned char spib;

    //while(SSIOST_bit.BUSY != 0);    // Wait until the character can be sent
    SSIOINT_bit.TXCMP = 1;            //clear interrupt register
    SSIOBUF = data;                   // Send the data

    while((SSIOINT & 0x02) != 0x02);   // Wait for the transfer to complete
    spib = SSIOBUF;                   // Get the data received
    SSIOINT_bit.RXCMP = 1;            //clear interrupt register
    return spib;                      //return transmited character
    */

    //NOTE!!! This function send character to SPI bus when mode is MASTER
    //NOTE!!! This function receive character from SPI when mode is SLAVE
    unsigned int spib;

    //while(SSPSR_bit.BSY);      // Wait until the character can be sent
    while(SSPSR_bit.TNF == 0);
    SSPDR = data;              // Send the data

    //while(!SPSR0_bit.SPIF);     // Wait for the transfer to complete
    while(SSPSR_bit.RNE == 0);    // Wait until the character can be sent
    spib = SSPDR;                 // Get the data received
    return spib;
    //return 0;
}

void spiWriteByte(const unsigned char data)
{
  //while(SSIOST_bit.BUSY != 0);      // Wait until the character can be sent
  //SSIOINT_bit.TXCMP = 1;            // clear interrupt register
  //SSIOBUF = data;
}

unsigned char spiReadByte()
{
  //unsigned char spib;
  //while(SSIOINT_bit.RXCMP == 0);
  //spib = SSIOBUF;                   // Get the data received
  //SSIOINT_bit.RXCMP = 1;            //clear interrupt register
  //return spib;
  return 0;
}

// Reading the contents of the CSD and CID registers in SPI mode is a simple
// read-block transaction.

char mmcReadRegister (const char cmd_register, const unsigned char length)
{
  char uc = 0;
  char rvalue = MMC_TIMEOUT_ERROR;
//  char i = 0;

  if (mmcSetBlockLength (length) == MMC_SUCCESS)
    {
      //CS_LOW ();
      // CRC not used: 0xff as last byte
      mmcSendCmd(cmd_register, 0x000000, 0xff);

      // wait for response
      // in the R1 format (0x00 is no errors)
      if (mmcGetResponse() == 0x00)
	{
	 if (mmcGetXXResponse(0xfe)== 0xfe)
	    for (uc = 0; uc < length; uc++)
	      mmc_buffer[uc] = spiSendByte(0xff);
	  // get CRC bytes (not really needed by us, but required by MMC)
	  spiSendByte(0xff);
	  spiSendByte(0xff);
	}
      else
	rvalue = MMC_RESPONSE_ERROR;
      // CS = HIGH (off)
      //CS_HIGH ();

      // Send 8 Clock pulses of delay.
      spiSendByte(0xff);
    }
  //CS_HIGH ();
  return rvalue;
}// mmc_read_register

//---------------------------------------------------------------------
#endif /* _MMCLIB_C */