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

// MMC Lib
#ifndef _MMCLIB_C
#define _MMCLIB_C
//---------------------------------------------------------------------

#include "mmc.h"
#include "stm32f10x_lib.h"
#include "bits.h"
#include <string.h>

// macro defines
#define CS_LOW()  GPIOB->BRR   |= BIT12	// Card Select
#define CS_HIGH() GPIOB->BSRR  |= BIT12  // Card Deselect

#define DUMMY 0xff

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


// Buffer for mmc i/o for data and registers
char mmc_buffer[512] = { 0 };	

// setup usart1 in spi mode
void initSPI (void)
{

  SPI_InitTypeDef  SPI_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;

  // Enable SPI2 and GPIOB, GPIOC clocks
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC, ENABLE);

  // Configure SPI1 pins: SCK, MISO and MOSI
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // Configure PB12 as Output push-pull, used as CE
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  // CE high
  GPIO_WriteBit(GPIOB, GPIO_Pin_12, Bit_SET);


  // SPI1 configuration
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI2, &SPI_InitStructure);

  // Enable SPI2
  SPI_Cmd(SPI2, ENABLE);

}


// 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;

  // Start iniMMC......
  initSPI();
  //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)
  {
   CS_HIGH();
   spiSendByte(0xff);
   CS_LOW();
   mmcSendCmd(0x01,0x00,0xff);
   response=mmcGetResponse();
  }
  CS_HIGH();
  spiSendByte(0xff);

  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;
}				// block_length

//TI added substitution routine for spi_read and spi_write
unsigned char spiSendByte(const unsigned char data)
{

  // Loop while DR register in not emplty
  while(SPI_GetFlagStatus(SPI2, SPI_FLAG_TXE) == RESET);

  // Send byte through the SPI1 peripheral
  SPI_SendData(SPI2, data);	

  // Wait to receive a byte
  while(SPI_GetFlagStatus(SPI2, SPI_FLAG_RXNE) == RESET);

  // Return the byte read from the SPI bus
  return SPI_ReceiveData(SPI2);

}


// 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 */