mmc.c

这是一个很精巧的FAT文件系统的,它实现数据文件存储的FAT方式访问

/*-----------------------------------------------------------------------*/
/* MMC/SDC (in SPI mode) control module  (C)ChaN, 2007                   */
/*-----------------------------------------------------------------------*/


#include "v850es.h"
#include "diskio.h"

#define USE_DMA3


/* MMC/SD command (in SPI) */
#define CMD0	(0x40+0)	/* GO_IDLE_STATE */
#define CMD1	(0x40+1)	/* SEND_OP_COND */
#define CMD8	(0x40+8)	/* SEND_IF_COND */
#define CMD9	(0x40+9)	/* SEND_CSD */
#define CMD10	(0x40+10)	/* SEND_CID */
#define CMD12	(0x40+12)	/* STOP_TRANSMISSION */
#define CMD16	(0x40+16)	/* SET_BLOCKLEN */
#define CMD17	(0x40+17)	/* READ_SINGLE_BLOCK */
#define CMD18	(0x40+18)	/* READ_MULTIPLE_BLOCK */
#define CMD23	(0x40+23)	/* SET_BLOCK_COUNT */
#define CMD24	(0x40+24)	/* WRITE_BLOCK */
#define CMD25	(0x40+25)	/* WRITE_MULTIPLE_BLOCK */
#define CMD41	(0x40+41)	/* SEND_OP_COND (ACMD) */
#define CMD55	(0x40+55)	/* APP_CMD */
#define CMD58	(0x40+58)	/* READ_OCR */


/* Control signals (Platform dependent) */
#define SELECT()	P0 &= ~(1<<6)	/* MMC CS = L */
#define	DESELECT()	P0 |= (1<<6)	/* MMC CS = H */

#define SOCKPORT	P3L			/* Socket contact port */
#define SOCKWP		0x04		/* Write protect switch (bit2) */
#define SOCKINS		0x08		/* Card detect switch (bit3) */



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

   Module Private Functions

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

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

static volatile
UINT Timer1, Timer2;	/* 1000Hz decrement timer */

static
UINT CardType;			/* b0:MMC, b1:SDC, b2:Block addressing */



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

#define xmit_spi(dat) 	CB0TXL=(dat); do; while(CB0TSF)



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

static
BYTE rcvr_spi (void)
{
	CB0TXL = 0xFF;
	do; while (CB0TSF);
	return CB0RXL;
}

/* Alternative macro to receive data fast */
#define rcvr_spi_m(dst)	CB0TXL=0xFF; do; while(CB0TSF); *(dst)=CB0RXL



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

static
BYTE wait_ready (void)
{
	BYTE res;


	Timer2 = 500;	/* Wait for ready in timeout of 500ms */
	rcvr_spi();
	do
		res = rcvr_spi();
	while ((res != 0xFF) && Timer2);

	return res;
}



/*-----------------------------------------------------------------------*/
/* Power Control  (Platform dependent)                                   */
/*-----------------------------------------------------------------------*/
/* When the target system does not support socket power control, there   */
/* is nothing to do in these functions and chk_power always returns 1.   */

static
void power_on (void)
{
	P4 = 0x03;					/* Attach CSIB0 unit to I/O pin */
	PM4 = 0x02;
	PF4 = 0x00;
	PMC4 = 0x07;
	PFC4 = 0x00;

	CB0CTL0 = 0;				/* Disable CSIB0 */
	CB0CTL1 = 0x18;				/* Select fclk=fxx/2, SPI-0 */
	CB0CTL2 = 0;				/* Select 8 bit mode */
	CB0CTL0 = 0xE0;				/* Enable CSIB0 with single R/W, MSB first */
}

static
void power_off (void)
{
	SELECT();				/* Wait for card ready */
	wait_ready();
	DESELECT();
	rcvr_spi();

	CB1CTL0 = 0;				/* Disable CSIB1 */

	Stat |= STA_NOINIT;		/* Set STA_NOINIT */
}



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

static
BOOL rcvr_datablock (
	BYTE *buff,			/* Data buffer to store received data */
	UINT btr			/* Byte count (must be even number) */
)
{
	BYTE token;


	Timer1 = 100;
	do {								/* Wait for data packet in timeout of 100ms */
		token = rcvr_spi();
	} while ((token == 0xFF) && Timer1);

	if(token != 0xFE) return FALSE;		/* If not valid data token, retutn with error */

#ifdef USE_DMA3		/* (Platform dependent in DMA mode) */
	PMC4.1 = 0;								/* Initialize CSIB0 to R/O mode */
	CB0CTL0 = 0;
	CB0CTL0 = 0xA1;

	DDA3H = (((DWORD)buff >> 16) | 0x8000) & 0x83FF;/* Destination address (data buffer) */
	DDA3L = (WORD)buff;
	DSA3H = 0x03FF; DSA3L = 0xFD04;			/* Source address (CB0RXL) */
	DADC3 = 0x0080;							/* Src fixed, Dst increment */
	DBC3 = btr - 1;							/* DMA count */
	DTFR3 = 0x1E;							/* Triggered by INTCB0R */
	DCHC3 = 0x01;							/* Enable DMA */
	token = CB0RXL;							/* Start DMA xfer */
	do; while (!TC3);						/* Wait for end of xfer */
	do; while (CB0TSF);

	CB0CTL0 = 0;							/* Re-initialize CSIB0 to R/W mode */
	CB0CTL0 = 0xE0;
	PMC4.1 = 1;
#else
	do {								/* Receive the data block into buffer */
		rcvr_spi_m(buff++);
		rcvr_spi_m(buff++);
	} while (btr -= 2);
#endif
	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;
	UINT bc = 512;


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

	xmit_spi(token);			/* Xmit data token */
	if (token != 0xFD) {	/* Is data token */
#ifdef USE_DMA3		/* (Platform dependent in DMA mode) */
		DSA3H = (((DWORD)(buff+1) >> 16) | 0x8000) & 0x83FF;/* Source address (data buffer + 1) */
		DSA3L = (WORD)(buff+1);
		DDA3H = 0x03FF; DDA3L = 0xFD06;		/* Destination address (CB0TXL) */
		DADC3 = 0x0020;						/* Src increment, Dst fixed */
		DBC3 = bc - 2;						/* DMA count */
		DTFR3 = 0x1E;						/* Triggered by INTCB0R */
		DCHC3 = 0x01;						/* Enable DMA */
		CB0TXL = *buff;						/* Start DMA xfer */
		do; while (!TC3);					/* Wait for end of xfer */
		do; while (CB0TSF);
#else
		do {						/* Xmit the 512 byte data block to MMC */
			xmit_spi(*buff++);
			xmit_spi(*buff++);
		} while (bc -= 2);
#endif
		xmit_spi(0xFF);				/* CRC (Dummy) */
		xmit_spi(0xFF);
		resp = rcvr_spi();			/* Receive 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] */
	n = 0;
	if (cmd == CMD0) n = 0x95;			/* CRC for CMD0(0) */
	if (cmd == CMD8) n = 0x87;			/* CRC for CMD8(0x1AA) */
	xmit_spi(n);

	/* 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

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