sample-mmc.c

非常好用的嵌入式系统用的fat文件系统,支持fat12 fat16 fat32

                    if (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 1UL << 30) == 0)    break;    /* ACMD41 with HCS bit */
                } while (Timer1);
                if (Timer1 && send_cmd(CMD58, 0) == 0) {    /* Check CCS bit */
                    for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();
                    ty = (ocr[0] & 0x40) ? 6 : 2;
                }
            }
        } else {                            /* SDC Ver1 or MMC */
            ty = (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 0) <= 1) ? 2 : 1;    /* SDC : MMC */
            do {
                if (ty == 2) {
                    if (send_cmd(CMD55, 0) <= 1 && send_cmd(CMD41, 0) == 0) break;    /* ACMD41 */
                } else {
                    if (send_cmd(CMD1, 0) == 0) break;                                /* CMD1 */
                }
            } while (Timer1);
            if (!Timer1 || send_cmd(CMD16, 512) != 0)    /* Select R/W block length */
                ty = 0;
        }
    }
    CardType = ty;
    DESELECT();            /* CS = H */
    rcvr_spi();            /* Idle (Release DO) */

    if (ty) {            /* Initialization succeded */
        Stat &= ~STA_NOINIT;        /* 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 STA_NOINIT;        /* 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 & STA_NOINIT) return RES_NOTRDY;

    if (!(CardType & 4)) sector *= 512;    /* Convert to byte address if needed */

    SELECT();            /* CS = L */

    if (count == 1) {    /* Single block read */
        if ((send_cmd(CMD17, sector) == 0)    /* READ_SINGLE_BLOCK */
            && rcvr_datablock(buff, 512))
            count = 0;
    }
    else {                /* Multiple block read */
        if (send_cmd(CMD18, sector) == 0) {    /* READ_MULTIPLE_BLOCK */
            do {
                if (!rcvr_datablock(buff, 512)) 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,    /* 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 & STA_NOINIT) return RES_NOTRDY;
    if (Stat & STA_PROTECT) return RES_WRPRT;

    if (!(CardType & 4)) sector *= 512;    /* Convert to byte address if needed */

    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 (CardType & 2) {
            send_cmd(CMD55, 0); send_cmd(CMD23, count);    /* ACMD23 */
        }
        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 control data */
)
{
    DRESULT res;
    BYTE n, csd[16], *ptr = buff;
    WORD csize;


    if (drv) return RES_PARERR;

    res = RES_ERROR;

    if (ctrl == CTRL_POWER) {
        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 & STA_NOINIT) return RES_NOTRDY;

        SELECT();        /* CS = L */

        switch (ctrl) {
        case GET_SECTOR_COUNT :    /* Get number of sectors on the disk (DWORD) */
            if ((send_cmd(CMD9, 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 {                    /* MMC or SDC ver 1.XX */
                    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 GET_SECTOR_SIZE :    /* Get sectors on the disk (WORD) */
            *(WORD*)buff = 512;
            res = RES_OK;
            break;

        case CTRL_SYNC :    /* Make sure that data has been written */
            if (wait_ready() == 0xFF)
                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(ptr, 16))
                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(ptr, 16))
                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++)
                    *ptr++ = rcvr_spi();
                res = RES_OK;
            }

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

        default:
            res = RES_PARERR;
        }

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

    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 = SOCKPORT & (SOCKWP | SOCKINS);    /* Sample 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;
    }
}