mmc.c

我改写的在TFT上显示SD卡中BMP文件的程序

/*-----------------------------------------------------------------------*/
/* MMC/SDSC/SDHC (in SPI mode) control module  (C)ChaN, 2007             */
/*-----------------------------------------------------------------------*/
/* Only rcvr_spi(), xmit_spi(), disk_timerproc() and some macros         */
/* are platform dependent.                                               */
/*-----------------------------------------------------------------------*/


#include <avr/io.h>
#include "diskio.h"


/* Definitions for MMC/SDC command */
#define CMD0	(0x40+0)	/* GO_IDLE_STATE */
#define CMD1	(0x40+1)	/* SEND_OP_COND (MMC) */
#define	ACMD41	(0xC0+41)	/* SEND_OP_COND (SDC) */
#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 ACMD13	(0xC0+13)	/* SD_STATUS (SDC) */
#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 (MMC) */
#define	ACMD23	(0xC0+23)	/* SET_WR_BLK_ERASE_COUNT (SDC) */
#define CMD24	(0x40+24)	/* WRITE_BLOCK */
#define CMD25	(0x40+25)	/* WRITE_MULTIPLE_BLOCK */
#define CMD55	(0x40+55)	/* APP_CMD */
#define CMD58	(0x40+58)	/* READ_OCR */



//引脚定义
#define MMC_SD_PORT		PORTB                    
#define MMC_SD_DDR		DDRB
#define MMC_SD_CS		2                        //mega16
#define MMC_SD_MOSI		3
#define MMC_SD_MISO		4
#define MMC_SD_SCK		5

/* Port Controls  (Platform dependent) */
#define SELECT()	MMC_SD_PORT &= ~(1 << MMC_SD_CS)		/* MMC CS = L */
#define	DESELECT()	MMC_SD_PORT |= (1 << MMC_SD_CS)		/* MMC CS = H */


#define configure_pin_mosi()	MMC_SD_DDR |= (1 << MMC_SD_MOSI)
#define configure_pin_sck()		MMC_SD_DDR |= (1 << MMC_SD_SCK)
#define configure_pin_ss()		MMC_SD_DDR |= (1 << MMC_SD_CS)
#define configure_pin_miso()	MMC_SD_DDR &= ~(1 << MMC_SD_MISO)

#define select_card()	MMC_SD_PORT &= ~(1 << MMC_SD_CS)
#define unselect_card()	MMC_SD_PORT |= (1 << MMC_SD_CS)

#define SOCKPORT	PINB			/* Socket contact port */
#define SOCKWP		0x01			/* Write protect switch  */
#define SOCKINS		0x00			/* Card detect switch  */



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

   Module Private Functions

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

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

static volatile
BYTE Timer1, Timer2;	/* 100Hz decrement timer */

static
BYTE CardType;			/* b0:MMC, b1:SDv1, b2:SDv2, b3:Block addressing */



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

#define xmit_spi(dat) 	SPDR=(dat); loop_until_bit_is_set(SPSR,SPIF);



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

static
BYTE rcvr_spi (void)
{
	SPDR = 0xFF;
	loop_until_bit_is_set(SPSR, SPIF);
	return SPDR;
}

/* Alternative macro to receive data fast */
#define rcvr_spi_m(dst)	SPDR=0xFF; loop_until_bit_is_set(SPSR,SPIF);  *(dst)=SPDR



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

static
BYTE wait_ready (void)
{
	BYTE res;


	Timer2 = 50;	/* Wait for ready in timeout of 500ms */
	rcvr_spi();
	do
		res = rcvr_spi();
	while ((res != 0xFF) && Timer2);

	return res;
}



/*-----------------------------------------------------------------------*/
/* Deselect the card and release SPI bus                                 */
/*-----------------------------------------------------------------------*/

static
void release_spi (void)
{
	DESELECT();
	rcvr_spi();
}



/*-----------------------------------------------------------------------*/
/* 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)
{
//	PORTE &= ~0x80;				/* Socket power ON */
	for (Timer1 = 3; Timer1; );	/* Wait for 30ms */

    /* enable outputs for MOSI, SCK, SS, input for MISO */
    configure_pin_mosi();
    configure_pin_sck();
    configure_pin_ss();
    configure_pin_miso();

	  
    unselect_card();


    /* initialize SPI with lowest frequency; max. 400kHz during identification mode of card */
    SPCR = (0 << SPIE) | /* SPI Interrupt Enable */
           (1 << SPE)  | /* SPI Enable */
           (0 << DORD) | /* Data Order: MSB first */
           (1 << MSTR) | /* Master mode */
           (0 << CPOL) | /* Clock Polarity: SCK low when idle */
           (0 << CPHA) | /* Clock Phase: sample on rising SCK edge */
           (1 << SPR1) | /* Clock Frequency: f_OSC / 128 */
           (1 << SPR0);
    SPSR &= ~(1 << SPI2X); /* No doubled clock frequency */



   
}

static
void power_off (void)
{

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

static
int chk_power(void)		/* Socket power state: 0=off, 1=on */
{
	///return (PORTE & 0x80) ? 0 : 1;
	return 1;
}



/*-----------------------------------------------------------------------*/
/* 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 = 10;
	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 */

	do {							/* Receive the data block into buffer */
		rcvr_spi_m(buff++);
		rcvr_spi_m(buff++);
	} while (btr -= 2);
	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;


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

	xmit_spi(token);					/* Xmit data token */
	if (token != 0xFD) {	/* Is data token */
		wc = 0;
		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 (cmd & 0x80) {	/* ACMD<n> is the command sequense of CMD55-CMD<n> */
		cmd &= 0x7F;
		res = send_cmd(CMD55, 0);
		if (res > 1) return res;
	}

	/* Select the card and wait for ready */
	DESELECT();
	SELECT();
	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 = 0xFF;							/* CRC */
	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

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


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

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