Initial Arduino IDE based on Processing.

build/shared/lib/avrlib/mmc.c

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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.
+//
+// This code is distributed under the GNU Public License
+//		which can be found at http://www.gnu.org/licenses/gpl.txt
+//
+//*****************************************************************************
+
+//----- Include Files ---------------------------------------------------------
+#include <avr/io.h>			// include I/O definitions (port names, pin names, etc)
+#include <avr/signal.h>		// include "signal" names (interrupt names)
+#include <avr/interrupt.h>	// include interrupt support
+
+#include "global.h"		// include our global settings
+#include "spi.h"		// include spi bus support
+
+#include "rprintf.h"
+
+#include "mmc.h"
+
+// include project-specific hardware configuration
+#include "mmcconf.h"
+
+// Global variables
+
+// Functions
+
+void mmcInit(void)
+{
+	// initialize SPI interface
+	spiInit();
+	// release chip select
+	sbi(MMC_CS_DDR, MMC_CS_PIN);
+	sbi(MMC_CS_PORT,MMC_CS_PIN);
+}
+
+u08 mmcReset(void)
+{
+	u08 retry;
+	u08 r1=0;
+
+	retry = 0;
+	do
+	{
+		// send dummy bytes with CS high before accessing
+		spiTransferByte(0xFF);
+		spiTransferByte(0xFF);
+		spiTransferByte(0xFF);
+		spiTransferByte(0xFF);
+		// resetting card, go to SPI mode
+		r1 = mmcSendCommand(MMC_GO_IDLE_STATE, 0);
+		#ifdef MMC_DEBUG
+		rprintf("MMC_GO_IDLE_STATE: R1=0x%x\r\n", r1);
+		#endif
+		// do retry counter
+		retry++;
+		if(retry>10) return -1;
+	} while(r1 != 0x01);
+
+	// TODO: check card parameters for voltage compliance
+	// before issuing initialize command
+
+	retry = 0;
+	do
+	{
+		// initializing card for operation
+		r1 = mmcSendCommand(MMC_SEND_OP_COND, 0);
+		#ifdef MMC_DEBUG
+		rprintf("MMC_SEND_OP_COND: R1=0x%x\r\n", r1);
+		#endif
+		// do retry counter
+		retry++;
+		if(retry>100) return -1;
+	} while(r1);
+		
+	// turn off CRC checking to simplify communication
+	r1 = mmcSendCommand(MMC_CRC_ON_OFF, 0);
+	#ifdef MMC_DEBUG
+	rprintf("MMC_CRC_ON_OFF: R1=0x%x\r\n", r1);
+	#endif
+
+	// set block length to 512 bytes
+	r1 = mmcSendCommand(MMC_SET_BLOCKLEN, 512);
+	#ifdef MMC_DEBUG
+	rprintf("MMC_SET_BLOCKLEN: R1=0x%x\r\n", r1);
+	#endif
+
+	// return success
+	return 0;
+}
+
+u08 mmcSendCommand(u08 cmd, u32 arg)
+{
+	u08 r1;
+
+	// assert chip select
+	cbi(MMC_CS_PORT,MMC_CS_PIN);
+	// issue the command
+	r1 = mmcCommand(cmd, arg);
+	// release chip select
+	sbi(MMC_CS_PORT,MMC_CS_PIN);
+
+	return r1;
+}
+
+u08 mmcRead(u32 sector, u08* buffer)
+{
+	u08 r1;
+	u16 i;
+
+	// assert chip select
+	cbi(MMC_CS_PORT,MMC_CS_PIN);
+	// issue command
+	r1 = mmcCommand(MMC_READ_SINGLE_BLOCK, sector<<9);
+	#ifdef MMC_DEBUG
+	rprintf("MMC Read Block R1=0x%x\r\n", r1);
+	#endif
+	// check for valid response
+	if(r1 != 0x00)
+		return r1;
+	// wait for block start
+	while(spiTransferByte(0xFF) != MMC_STARTBLOCK_READ);
+	// read in data
+	for(i=0; i<0x200; i++)
+	{
+		*buffer++ = spiTransferByte(0xFF);
+	}
+	// read 16-bit CRC
+	spiTransferByte(0xFF);
+	spiTransferByte(0xFF);
+	// release chip select
+	sbi(MMC_CS_PORT,MMC_CS_PIN);
+	// return success
+	return 0;
+}
+
+u08 mmcWrite(u32 sector, u08* buffer)
+{
+	u08 r1;
+	u16 i;
+
+	// assert chip select
+	cbi(MMC_CS_PORT,MMC_CS_PIN);
+	// issue command
+	r1 = mmcCommand(MMC_WRITE_BLOCK, sector<<9);
+	#ifdef MMC_DEBUG
+	rprintf("MMC Write Block R1=0x%x\r\n", r1);
+	#endif
+	// check for valid response
+	if(r1 != 0x00)
+		return r1;
+	// send dummy
+	spiTransferByte(0xFF);
+	// send data start token
+	spiTransferByte(MMC_STARTBLOCK_WRITE);
+	// write data
+	for(i=0; i<0x200; i++)
+	{
+		spiTransferByte(*buffer++);
+	}
+	// write 16-bit CRC (dummy values)
+	spiTransferByte(0xFF);
+	spiTransferByte(0xFF);
+	// read data response token
+	r1 = spiTransferByte(0xFF);
+	if( (r1&MMC_DR_MASK) != MMC_DR_ACCEPT)
+		return r1;
+	#ifdef MMC_DEBUG
+	rprintf("Data Response Token=0x%x\r\n", r1);
+	#endif
+	// wait until card not busy
+	while(!spiTransferByte(0xFF));
+	// release chip select
+	sbi(MMC_CS_PORT,MMC_CS_PIN);
+	// return success
+	return 0;
+}
+
+u08 mmcCommand(u08 cmd, u32 arg)
+{
+	u08 r1;
+	u08 retry=0;
+	// send command
+	spiTransferByte(cmd | 0x40);
+	spiTransferByte(arg>>24);
+	spiTransferByte(arg>>16);
+	spiTransferByte(arg>>8);
+	spiTransferByte(arg);
+	spiTransferByte(0x95);	// crc valid only for MMC_GO_IDLE_STATE
+	// end command
+	// wait for response
+	// if more than 8 retries, card has timed-out
+	// return the received 0xFF
+	while((r1 = spiTransferByte(0xFF)) == 0xFF)
+		if(retry++ > 8) break;
+	// return response
+	return r1;
+}