main.i

this program for sd mmc card in fat file system

static
BYTE send_cmd (
	BYTE cmd,		/* Command byte */
	DWORD arg		/* Argument */
)
{
	BYTE n, res;


	if (cmd & 0x80) {	/* ACMD<n> is the command sequense of CMD55-CMD<n> */
		cmd &= 0x7F;
		res = send_cmd((0x40+55)	, 0);
		if (res > 1) return res;
	}

	/* Select the card and wait for ready */
	PORTB	|= (1<<3		); ;
	PORTB	&=~(1<<3		); ;
	if (wait_ready() != 0xFF) return 0xFF;

	/* Send command packet */
	SPDR=(cmd); while(!(SPSR & (1<<7)));						/* Command */
	SPDR=((BYTE)(arg >> 24)); while(!(SPSR & (1<<7)));		/* Argument[31..24] */
	SPDR=((BYTE)(arg >> 16)); while(!(SPSR & (1<<7)));		/* Argument[23..16] */
	SPDR=((BYTE)(arg >> 8)); while(!(SPSR & (1<<7)));			/* Argument[15..8] */
	SPDR=((BYTE)arg); while(!(SPSR & (1<<7)));				/* Argument[7..0] */
	n = 0xFF;							/* CRC */
	if (cmd == (0x40+0)	) n = 0x95;			/* CRC for CMD0(0) */
	if (cmd == (0x40+8)	) n = 0x87;			/* CRC for CMD8(0x1AA) */
	SPDR=(n); while(!(SPSR & (1<<7)));

	/* Receive command response */
	if (cmd == (0x40+12)	) rcvr_spi();		/* Skip a stuff byte when stop reading */
	n = 10;								/* Wait for a valid response in timeout of 10 attempts */
	do
		res = rcvr_spi();
	while ((res & 0x80) && --n);

	return res;			/* Return with the response value */
}



/*--------------------------------------------------------------------------

   Public Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive                                                 */
/*-----------------------------------------------------------------------*/

DSTATUS disk_initialize (
	BYTE drv		/* Physical drive nmuber (0) */
)
{
	BYTE n, cmd, ty, ocr[4];


	if (drv) return 0x01	;			/* Supports only single drive */
	if (Stat & 0x02	) return Stat;	/* No card in the socket */

	power_on();							/* Force socket power on */
	for (n = 10; n; n--) rcvr_spi();	/* 80 dummy clocks */

	ty = 0;
	if (send_cmd((0x40+0)	, 0) == 1) {			/* Enter Idle state */
		Timer1 = 100;						/* Initialization timeout of 1000 msec */
		if (send_cmd((0x40+8)	, 0x1AA) == 1) {	/* SDHC */
			for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();		/* Get trailing return value of R7 resp */
			if (ocr[2] == 0x01 && ocr[3] == 0xAA) {				/* The card can work at vdd range of 2.7-3.6V */
				while (Timer1 && send_cmd((0xC0+41)	, 1UL << 30));	/* Wait for leaving idle state (ACMD41 with HCS bit) */
				if (Timer1 && send_cmd((0x40+58)	, 0) == 0) {		/* Check CCS bit in the OCR */
					for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();
					ty = (ocr[0] & 0x40) ? 12 : 4;
				}
			}
		} else {							/* SDSC or MMC */
			if (send_cmd((0xC0+41)	, 0) <= 1) 	{
				ty = 2; cmd = (0xC0+41)	;	/* SDSC */
			} else {
				ty = 1; cmd = (0x40+1)	;		/* MMC */
			}
			while (Timer1 && send_cmd(cmd, 0));			/* Wait for leaving idle state */
			if (!Timer1 || send_cmd((0x40+16)	, 512) != 0)	/* Set R/W block length to 512 */
				ty = 0;
		}
	}
	CardType = ty;
	release_spi();

	if (ty) {			/* Initialization succeded */
		Stat &= ~0x01	;		/* Clear STA_NOINIT */
	} else {			/* Initialization failed */
		power_off();
	}

	return Stat;
}



/*-----------------------------------------------------------------------*/
/* Get Disk Status                                                       */
/*-----------------------------------------------------------------------*/

DSTATUS disk_status (
	BYTE drv		/* Physical drive nmuber (0) */
)
{
	if (drv) return 0x01	;		/* Supports only single drive */
	return Stat;
}



/*-----------------------------------------------------------------------*/
/* Read Sector(s)                                                        */
/*-----------------------------------------------------------------------*/

DRESULT disk_read (
	BYTE drv,			/* Physical drive nmuber (0) */
	BYTE *buff,			/* Pointer to the data buffer to store read data */
	DWORD sector,		/* Start sector number (LBA) */
	BYTE count			/* Sector count (1..255) */
)
{
	if (drv || !count) return RES_PARERR;
	if (Stat & 0x01	) return RES_NOTRDY;

	if (!(CardType & 8)) sector *= 512;	/* Convert to byte address if needed */

	if (count == 1) {	/* Single block read */
		if ((send_cmd((0x40+17)	, sector) == 0)	/* READ_SINGLE_BLOCK */
			&& rcvr_datablock(buff, 512))
			count = 0;
	}
	else {				/* Multiple block read */
		if (send_cmd((0x40+18)	, sector) == 0) {	/* READ_MULTIPLE_BLOCK */
			do {
				if (!rcvr_datablock(buff, 512)) break;
				buff += 512;
			} while (--count);
			send_cmd((0x40+12)	, 0);				/* STOP_TRANSMISSION */
		}
	}
	release_spi();

	return count ? RES_ERROR : RES_OK;
}



/*-----------------------------------------------------------------------*/
/* Write Sector(s)                                                       */
/*-----------------------------------------------------------------------*/

DRESULT disk_write (
	BYTE drv,			/* Physical drive nmuber (0) */
	const BYTE *buff,	/* Pointer to the data to be written */
	DWORD sector,		/* Start sector number (LBA) */
	BYTE count			/* Sector count (1..255) */
)
{
	if (drv || !count) return RES_PARERR;
	if (Stat & 0x01	) return RES_NOTRDY;
	if (Stat & 0x04	) return RES_WRPRT;

	if (!(CardType & 8)) sector *= 512;	/* Convert to byte address if needed */

	if (count == 1) {	/* Single block write */
		if ((send_cmd((0x40+24)	, sector) == 0)	/* WRITE_BLOCK */
			&& xmit_datablock(buff, 0xFE))
			count = 0;
	}
	else {				/* Multiple block write */
		if (CardType & 6) send_cmd((0xC0+23)	, count);
		if (send_cmd((0x40+25)	, sector) == 0) {	/* WRITE_MULTIPLE_BLOCK */
			do {
				if (!xmit_datablock(buff, 0xFC)) break;
				buff += 512;
			} while (--count);
			if (!xmit_datablock(0, 0xFD))	/* STOP_TRAN token */
				count = 1;
		}
	}
	release_spi();

	return count ? RES_ERROR : RES_OK;
}



/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions                                               */
/*-----------------------------------------------------------------------*/

DRESULT disk_ioctl (
	BYTE drv,		/* Physical drive nmuber (0) */
	BYTE ctrl,		/* Control code */
	void *buff		/* Buffer to send/receive control data */
)
{
	DRESULT res;
	BYTE n, csd[16], *ptr = buff;
	WORD csize;


	if (drv) return RES_PARERR;

	res = RES_ERROR;

	if (ctrl == 4) {
		switch (*ptr) {
		case 0:		/* Sub control code == 0 (POWER_OFF) */
			if (chk_power())
				power_off();		/* Power off */
			res = RES_OK;
			break;
		case 1:		/* Sub control code == 1 (POWER_ON) */
			power_on();				/* Power on */
			res = RES_OK;
			break;
		case 2:		/* Sub control code == 2 (POWER_GET) */
			*(ptr+1) = (BYTE)chk_power();
			res = RES_OK;
			break;
		default :
			res = RES_PARERR;
		}
	}
	else {
		if (Stat & 0x01	) return RES_NOTRDY;

		switch (ctrl) {
		case 0	 :		/* Make sure that no pending write process */
			PORTB	&=~(1<<3		); ;
			if (wait_ready() == 0xFF)
				res = RES_OK;
			break;

		case 1	 :	/* Get number of sectors on the disk (DWORD) */
			if ((send_cmd((0x40+9)	, 0) == 0) && rcvr_datablock(csd, 16)) {
				if ((csd[0] >> 6) == 1) {	/* SDC ver 2.00 */
					csize = csd[9] + ((WORD)csd[8] << 8) + 1;
					*(DWORD*)buff = (DWORD)csize << 10;
				} else {					/* SDC ver 1.XX or MMC*/
					n = (csd[5] & 15) + ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
					csize = (csd[8] >> 6) + ((WORD)csd[7] << 2) + ((WORD)(csd[6] & 3) << 10) + 1;
					*(DWORD*)buff = (DWORD)csize << (n - 9);
				}
				res = RES_OK;
			}
			break;

		case 2 :	/* Get R/W sector size (WORD) */
			*(WORD*)buff = 512;
			res = RES_OK;
			break;

		case 3	 :	/* Get erase block size in unit of sector (DWORD) */
			if (CardType & 4) {			/* SDC ver 2.00 */
				if (send_cmd((0xC0+13)	, 0) == 0) {		/* Read SD status */
					rcvr_spi();
					if (rcvr_datablock(csd, 16)) {				/* Read partial block */
						for (n = 64 - 16; n; n--) rcvr_spi();	/* Purge trailing data */
						*(DWORD*)buff = 16UL << (csd[10] >> 4);
						res = RES_OK;
					}
				}
			} else {					/* SDC ver 1.XX or MMC */
				if ((send_cmd((0x40+9)	, 0) == 0) && rcvr_datablock(csd, 16)) {	/* Read CSD */
					if (CardType & 2) {			/* SDC ver 1.XX */
#pragma warn-
						*(DWORD*)buff = (((csd[10] & 63) << 1) + ((WORD)(csd[11] & 128) >> 7) + 1) << ((csd[13] >> 6) - 1);
					} else {					/* MMC */
						*(DWORD*)buff = ((WORD)((csd[10] & 124) >> 2) + 1) * (((csd[11] & 3) << 3) + ((csd[11] & 224) >> 5) + 1);
#pragma warn+
					}
					res = RES_OK;
				}
			}
			break;

		case 10 :		/* Get card type flags (1 byte) */
			*ptr = CardType;
			res = RES_OK;
			break;

		case 11 :		/* Receive CSD as a data block (16 bytes) */
			if (send_cmd((0x40+9)	, 0) == 0		/* READ_CSD */
				&& rcvr_datablock(ptr, 16))
				res = RES_OK;
			break;

		case 12 :		/* Receive CID as a data block (16 bytes) */
			if (send_cmd((0x40+10)	, 0) == 0		/* READ_CID */
				&& rcvr_datablock(ptr, 16))
				res = RES_OK;
			break;

		case 13 :		/* Receive OCR as an R3 resp (4 bytes) */
			if (send_cmd((0x40+58)	, 0) == 0) {	/* READ_OCR */
				for (n = 4; n; n--) *ptr++ = rcvr_spi();
				res = RES_OK;
			}
			break;

		case 14 :	/* Receive SD statsu as a data block (64 bytes) */
			if (send_cmd((0xC0+13)	, 0) == 0) {	/* SD_STATUS */
				rcvr_spi();
				if (rcvr_datablock(ptr, 64))
					res = RES_OK;
			}
			break;

		default:
			res = RES_PARERR;
		}

		release_spi();
	}

	return res;
}


/*-----------------------------------------------------------------------*/
/* Device Timer Interrupt Procedure  (Platform dependent)                */
/*-----------------------------------------------------------------------*/
/* This function must be called in period of 10ms                        */

void disk_timerproc (void)
{
	static BYTE pv;
	BYTE n, s;


	n = Timer1;						/* 100Hz decrement timer */
	if (n) Timer1 = --n;
	n = Timer2;
	if (n) Timer2 = --n;

	n = pv;
	pv = PINB			 & (0 			 | 0 			);	/* Sample socket switch */

	if (n == pv) {					/* Have contacts stabled? */
		s = Stat;

		if (pv & 0 			)			/* WP is H (write protected) */
			s |= 0x04	;
		else						/* WP is L (write enabled) */
			s &= ~0x04	;

		if (pv & 0 			)			/* INS = H (Socket empty) */
			s |= (0x02	 | 0x01	);
		else						/* INS = L (Card inserted) */
			s &= ~0x02	;

		Stat = s;
	}
}

/*--------------------------------------------------------------------------/
/  FatFs - Tiny FAT file system module  R0.05                 (C)ChaN, 2007
/
/  Ported To CodevisionAVR By Behzad Khazama www.khazama.com Sabzevar-IRAN 2007
/  tff.c current Port ver:1.0
/
/---------------------------------------------------------------------------/
/ The FatFs module is an experimenal project to implement FAT file system to
/ cheap microcontrollers. This is a free software and is opened for education,
/ research and development under license policy of following trems.
/
/  Copyright (C) 2007, ChaN, all right reserved.
/