mmc.c

基于AVR UC/OS-II的FAT32文件系统。

/*-----------------------------------------------------------------------*/
/* MMC/SD (in SPI mode) control module  (C)ChaN, 2006                    */
/*-----------------------------------------------------------------------*/
/* Only rcvr_spi(), xmit_spi(), disk_timerproc(), disk_initialize () and */
/* some macros are platform dependent.                                   */
/*-----------------------------------------------------------------------*/


#include "io86fm29.h"
#include "integer.h"
#include "diskio.h"


/* MMC/SD command (in SPI) */
#define CMD0	(0x40+0)	/* GO_IDLE_STATE */
#define CMD1	(0x40+1)	/* SEND_OP_COND */
#define CMD9	(0x40+9)	/* SEND_CSD */
#define CMD10	(0x40+10)	/* SEND_CID */
#define CMD12	(0x40+12)	/* STOP_TRANSMISSION */
#define CMD17	(0x40+17)	/* READ_SINGLE_BLOCK */
#define CMD18	(0x40+18)	/* READ_MULTIPLE_BLOCK */
#define CMD24	(0x40+24)	/* WRITE_BLOCK */
#define CMD25	(0x40+25)	/* WRITE_MULTIPLE_BLOCK */
#define CMD58	(0x40+58)	/* READ_OCR */


/* Control signals (Platform dependent) */
#define MMPORT		P3DR
#define MMPIN		P3PRD
#define MMCTRL		P3OUTCR
#define MMCLK		0x01	/* MMC SCLK */
#define MMDO		0x02	/* MMC DO */
#define MMDI		0x04	/* MMC DI */
#define	MMCS		0x08	/* MMC CS */
#define SELECT()	MMPORT &= ~MMCS	/* MMC CS = L */
#define	DESELECT()	MMPORT |= MMCS	/* MMC CS = H */

#define SOCKPORT	P5DR		/* Socket control port output */
#define SOCKPIN		P5PRD		/* Socket control port input */
#define SOCKINS		0x01		/* Card detect switch (P50) */
#define SOCKWP		0x02		/* Write protect switch (P51) */
#define CARDPWR		0x04		/* Card power (P52) */


static volatile
DSTATUS Stat = STA_NOINIT;	/* Disk status */

static volatile
BYTE Timer;			/* 100Hz decrement timer */



/*-----------------------------------------------------------------------*/
/* Module Private Functions                                              */


/*--------------------------------*/
/* Transmit a byte to MMC via SPI */
/* (Platform dependent)           */

static
void xmit_spi (BYTE dat)
{
	BYTE n = 8;


	do {
		if (dat & 0x80)
			MMPORT |= MMDI;
		else
			MMPORT &= ~MMDI;
		dat <<= 1;
		MMPORT |= MMCLK;
		MMPORT &= ~MMCLK;
	} while (--n);
}



/*---------------------------------*/
/* Receive a byte from MMC via SPI */
/* (Platform dependent)            */

static
BYTE rcvr_spi()
{
	BYTE r = 0, n = 8;


	MMPORT |= MMDI;
	do {
		r <<= 1;
		if (MMPIN & MMDO) r++;
		MMPORT |= MMCLK;
		MMPORT &= ~MMCLK;
	} while (--n);
	return r;
}



/*---------------------*/
/* Wait for card ready */

static
BYTE wait_ready ()
{
	BYTE res;


	Timer = 50;			/* Wait for ready in timeout of 500ms */
	rcvr_spi();
	do
		res = rcvr_spi();
	while ((res != 0xFF) && Timer);
	return res;
}



/*--------------------------------*/
/* Receive a data packet from MMC */

static
BOOL rcvr_datablock (
	BYTE *buff,			/* Data buffer to store received data */
	BYTE wc				/* Word count (0 means 256 words) */
)
{
	BYTE token;


	Timer = 10;
	do {							/* Wait for data packet in timeout of 100ms */
		token = rcvr_spi();
	} while ((token == 0xFF) && Timer);
	if(token != 0xFE) return FALSE;	/* If not valid data token, retutn with error */

	do {							/* Receive the data block into buffer */
		*buff++ = rcvr_spi();
		*buff++ = rcvr_spi();
	} while (--wc);
	rcvr_spi();						/* Discard CRC */
	rcvr_spi();

	return TRUE;					/* Return with success */
}



/*---------------------------*/
/* Send a data packet to MMC */

#if _READONLY == 0
static
BOOL xmit_datablock (
	const BYTE *buff,	/* 512 byte data block to be transmitted */
	BYTE token			/* Data/Stop token */
)
{
	BYTE resp, wc = 0;


	if (wait_ready() != 0xFF) return FALSE;

	xmit_spi(token);					/* Xmit data token */
	if (token != 0xFD) {	/* Is data token */
		do {							/* Xmit the 512 byte data block to MMC */
			xmit_spi(*buff++);
			xmit_spi(*buff++);
		} while (--wc);
		xmit_spi(0xFF);					/* CRC (Dummy) */
		xmit_spi(0xFF);
		resp = rcvr_spi();				/* Reveive data response */
		if ((resp & 0x1F) != 0x05)		/* If not accepted, return with error */
			return FALSE;
	}

	return TRUE;
}
#endif /* _READONLY */


/*------------------------------*/
/* Send a command packet to MMC */

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


	if (wait_ready() != 0xFF) return 0xFF;

	/* Send command packet */
	xmit_spi(cmd);						/* Command */
	xmit_spi((BYTE)(arg >> 24));		/* Argument[31..24] */
	xmit_spi((BYTE)(arg >> 16));		/* Argument[23..16] */
	xmit_spi((BYTE)(arg >> 8));			/* Argument[15..8] */
	xmit_spi((BYTE)arg);				/* Argument[7..0] */
	xmit_spi(0x95);						/* CRC (valid for only CMD0) */

	/* Receive command response */
	if (cmd == CMD12) 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 */
/* (Platform dependent)  */

DSTATUS disk_initialize (
	BYTE drv		/* Physical drive nmuber (0) */
)
{
	BYTE n;


	if (drv) return STA_NOINIT;		/* Supports only single drive */

	SOCKPORT = 0x03;			/* Power ON */
	for (Timer = 2; Timer; );	/* Wait for 20ms */
	MMPORT = 0x0E;				/* Enable Driver */
	MMCTRL = 0x0D;
	for (Timer = 1; Timer; );	/* Wait for 10ms */

	Stat |= STA_NOINIT;
	if (!(Stat & STA_NODISK)) {

		n = 10;					/* Dummy clock */
		do
			rcvr_spi();
		while (--n);

		SELECT();				/* CS = L */
		if (send_cmd(CMD0, 0) == 1) {			/* Enter Idle state */
			Timer = 100;						/* Wait for card ready in timeout of 1 sec */
			while (Timer && send_cmd(CMD1, 0));
			if (Timer) Stat &= ~STA_NOINIT;		/* When device goes ready, clear STA_NOINIT */
		}
		DESELECT();				/* CS = H */
		rcvr_spi();				/* Idle (Release DO) */
	}

	if (Stat & STA_NOINIT) {	/* Wnen initialization failed, shutdown card power */
		MMCTRL = 0x00;		/* Disable driver */
		SOCKPORT = 0x07;	/* Power OFF */
	}

	return Stat;
}



/*--------------------*/
/* Return Disk Status */

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



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

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

	sector *= 512;		/* LBA --> byte address */

	SELECT();			/* CS = L */

	if (count == 1) {	/* Single block read */
		if ((send_cmd(CMD17, sector) == 0)	/* READ_SINGLE_BLOCK */
			&& rcvr_datablock(buff, (BYTE)(512/2)))
			count = 0;
	}
	else {				/* Multiple block read */
		if (send_cmd(CMD18, sector) == 0) {	/* READ_MULTIPLE_BLOCK */
			do {
				if (!rcvr_datablock(buff, (BYTE)(512/2))) break;
				buff += 512;
			} while (--count);
			send_cmd(CMD12, 0);				/* STOP_TRANSMISSION */
		}
	}

	DESELECT();			/* CS = H */
	rcvr_spi();			/* Idle (Release DO) */

	return count ? RES_ERROR : RES_OK;
}



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

#if _READONLY == 0
DRESULT disk_write (
	BYTE drv,			/* Physical drive nmuber (0) */
	const BYTE *buff,	/* Data to be written */
	DWORD sector,		/* Sector number (LBA) */
	BYTE count			/* Sector count (1..255) */
)
{
	if (drv || !count) return RES_PARERR;
	if (Stat & STA_NOINIT) return RES_NOTRDY;
	if (Stat & STA_PROTECT) return RES_WRPRT;
	sector *= 512;		/* LBA --> byte address */

	SELECT();			/* CS = L */

	if (count == 1) {	/* Single block write */
		if ((send_cmd(CMD24, sector) == 0)	/* WRITE_BLOCK */
			&& xmit_datablock(buff, 0xFE))
			count = 0;
	}
	else {				/* Multiple block write */
		if (send_cmd(CMD25, 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;
		}
	}

	DESELECT();			/* CS = H */
	rcvr_spi();			/* Idle (Release DO) */

	return count ? RES_ERROR : RES_OK;
}
#endif /* _READONLY */



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

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


	if (drv) return RES_PARERR;
	if (Stat & STA_NOINIT) return RES_NOTRDY;

	SELECT();		/* CS = L */

	res = RES_ERROR;
	switch (ctrl) {
		case GET_SECTORS :	/* Get number of sectors on the disk (unsigned long) */
			if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16/2)) {
				csm = ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
				csize = ((csd[8] & 0xC0) >> 6) + ((WORD)csd[7] << 2) + ((WORD)(csd[6] & 3) << 10) + 1;
				*(DWORD*)buff = (DWORD)csize << csm;
				res = RES_OK;
			}
			break;

		case MMC_GET_CSD :	/* Receive CSD as a data block (16 bytes) */
			if ((send_cmd(CMD9, 0) == 0)	/* READ_CSD */
				&& rcvr_datablock(buff, 16/2))
				res = RES_OK;
			break;

		case MMC_GET_CID :	/* Receive CID as a data block (16 bytes) */
			if ((send_cmd(CMD10, 0) == 0)	/* READ_CID */
				&& rcvr_datablock(buff, 16/2))
				res = RES_OK;
			break;

		case MMC_GET_OCR :	/* Receive OCR as an R3 resp (4 bytes) */
			if (send_cmd(CMD58, 0) == 0) {	/* READ_OCR */
				for (n = 0; n < 4; n++)
					*((BYTE*)buff+n) = rcvr_spi();
				res = RES_OK;
			}
			break;

		default:
			res = RES_PARERR;
	}

	DESELECT();			/* CS = H */
	rcvr_spi();			/* Idle (Release DO) */

	return res;
}



/*---------------------------------------*/
/* Device timer interrupt procedure      */
/* This must be called in period of 10ms */
/* (Platform dependent)                  */

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


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

	n = pv;
	pv = SOCKPIN & (SOCKWP | SOCKINS);	/* Sapmle socket switch */

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

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

		if (pv & SOCKINS)			/* INS = H (Socket empty) */
			s |= (STA_NODISK | STA_NOINIT);
		else						/* INS = L (Card inserted) */
			s &= ~STA_NODISK;

		Stat = s;
	}
}