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repo2/firmware/sd_direct/mmc.c @ 57

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/*! \file mmc.c \brief MultiMedia and SD Flash Card Interface. */
//*****************************************************************************
//
// File Name : 'mmc.c'
// Title : MultiMedia and SD Flash Card Interface
// Author : Pascal Stang - Copyright (C) 2004
// Created : 2004.09.22
// Revised : 2004.09.22
// Version : 0.1
// Target MCU : Atmel AVR Series
// Editor Tabs : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested. Nonetheless, you can expect most functions to work.
//
// ----------------------------------------------------------------------------
// 17.8.2008
// Bob!k & Raster, C.P.U.
// Original code was modified especially for the SDrive device.
// Some parts of code have been added, removed, rewrited or optimized due to
// lack of MCU AVR Atmega8 memory.
// ----------------------------------------------------------------------------
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

//----- Include Files ---------------------------------------------------------
#include "spi.h" // include spi bus support


//#define spiTransferTwoFF() { spiTransferFF(); spiTransferFF(); }


#include "mmc.h"

// include project-specific hardware configuration
#include "mmcconf.h"
#include "debug.h"

void mmcInit(void)
{
// initialize SPI interface
spiInit();
// release chip select
mmcChipSelect(0);
}

u08 mmcReset(void)
{
u16 retry;
u08 r1;
u08 i;
u08 sdcard;

//
i=0xff; //255x
do { spiTransferFF(); i--; } while(i); //255x

//
r1 = mmcSendCommand(MMC_GO_IDLE_STATE, 0);
if (r1!=1) return -1;

retry=0xffff; //65535x
do
{
r1 = mmcSendCommand(55, 0);
if (r1!=1) break; //MMC
//if (r1==5) break; //MMC <--- kontrolovat takhle rekl Bob 27.6.2008
//Strana 120 ve specifikaci.
//bit 0 - in idle state, bit 2 - illegal command

r1 = mmcSendCommand(41, 0);
if (r1==0) break; //SD

retry--;
}
while(retry);

// initializing card for operation
r1 = mmcSendCommand(MMC_SEND_OP_COND, 0);
// SDkarty vraceji 0
// MMCkarta vraci 1
//if (r1>=2) return -1; //problem (MMC taky nefunguje)
if (r1!=0) return -1;

//kdyz jsem to tady nechal jit s MMC kartou dal (s r1=1)
//tak to na nekterem z dalsich povelu zustalo zasekle
//a po vytazeni MMC a vlozeni jine SD se muset mackat Reset :-(

/*
if( r1!=0 && r1!=5)
{
u08 v;
v=inb(PINC)&0xf0;
v|=(0x0f ^ (r1 & 0x0f) );
PORTC=v;
while(1); //nekonecna smycka
return -1;
}
*/

// turn off CRC checking to simplify communication
//r1 =
mmcSendCommand(MMC_CRC_ON_OFF, 0);

// set block length to 512 bytes
//r1 =
mmcSendCommand(MMC_SET_BLOCKLEN, 512);

// return success
return 0;
}

u08 mmcSendCommand(u08 cmd, u32 arg)
{
u08 r1;

// assert chip select
mmcChipSelect(1);
//
//spiTransferFF(); //pribude 34 bajtu kodu (!)
// issue the command
r1 = mmcCommand(cmd, arg);
//
//spiTransferFF();
// release chip select
mmcChipSelect(0);

return r1;
}

unsigned char mmc_sector_buffer[512];

void mmcReadLoop()
{
u16 i;
u08 *buffer=mmc_sector_buffer; //natvrdo!

i=0x80; //512
do { *buffer++ = spiTransferFF(); i--; } while(i);

//spiDisplay(1);
i=0x80; //512
do { *buffer++ = spiTransferFF(); i--; } while(i);

i=0x80; //512
do { *buffer++ = spiTransferFF(); i--; } while(i);

i=0x80; //512
do { *buffer++ = spiTransferFF(); i--; } while(i);

//spiDisplay(0);

}

u08 mmcRead(u32 sector)
{
u08 r1;

// assert chip select
mmcChipSelect(1);
// issue command
r1 = mmcCommand(MMC_READ_SINGLE_BLOCK, sector<<9);

// check for valid response
if(r1 != 0x00) return r1;

// wait for block start
while(spiTransferFF() != MMC_STARTBLOCK_READ);

//zacatek bloku

//nacti 512 bytu
mmcReadLoop();

// read 16-bit CRC
//2x FF:
spiTransferFF();
spiTransferFF();
//// + 1x FF navic pred releasnutim chip selectu
//spiTransferFF();
//
// release chip select
mmcChipSelect(0);

//debug("Hexdump\n");
//hexdump(mmc_sector_buffer,80);

//
return 0; //success
}

u08 mmcWrite(u32 sector)
{
u08 r1;
u16 i;
u08 *buffer=mmc_sector_buffer; //natvrdo!

// assert chip select
mmcChipSelect(1);
// issue command
r1 = mmcCommand(MMC_WRITE_BLOCK, sector<<9);
// check for valid response
if(r1 != 0x00)
return r1;
// send dummy
spiTransferFF();
// send data start token
spiTransferByte(MMC_STARTBLOCK_WRITE);

// write data (512 bytes)
i=0x200;
do { spiTransferByte(*buffer++); i--; } while(i);

// write 16-bit CRC (dummy values)
//2x FF:
spiTransferFF();
spiTransferFF();
// read data response token
r1 = spiTransferFF();
if( (r1&MMC_DR_MASK) != MMC_DR_ACCEPT)
return r1;
// wait until card not busy
while(!spiTransferFF());
// release chip select
mmcChipSelect(0);
// return success
return 0;
}

u08 mmcCommand(u08 cmd, u32 arg)
{
u08 r1;
u08 retry=0xff; //255x
//

spiTransferFF();

spiTransferFF(); //pridano navic! 27.6.2008 doporucil Bob!k
spiTransferFF(); //pridano navic! 27.6.2008 doporucil Bob!k
spiTransferFF(); //pridano navic! 27.6.2008 doporucil Bob!k

// send command
spiTransferByte(cmd | 0x40);
//
spiTransferByte(arg>>24);
spiTransferByte(arg>>16);
spiTransferByte(arg>>8);
spiTransferByte(arg);
//Alternativni zpusob pres ((u08*)&arg)[] je delsi.

spiTransferByte(0x95); // crc valid only for MMC_GO_IDLE_STATE
// end command
// wait for response
// if more than 255 retries, card has timed-out
// return the received 0xFF
do
{
r1 = spiTransferFF();
retry--;
}
while(retry && (r1 == 0xFF) );

// return response
return r1;
}