📄 mmc.c
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/*-----------------------------------------------------------------------*/
/* MMC/SDC (in SPI mode) control module (C)ChaN, 2006 */
/*-----------------------------------------------------------------------*/
/* Only rcvr_spi(), xmit_spi(), disk_timerproc(), disk_initialize () 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 */
#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() PORTB &= ~_BV(PB2) /* MMC CS = L */
#define DESELECT() PORTB |= _BV(PB2) /* MMC CS = H */
#define SOCKPORT PINB /* Socket contact port */
#define SOCKINS 0x01 /* Card detect switch (PB0) */
/*--------------------------------------------------------------------------
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:SDC, b2: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;
}
/*-----------------------------------------------------------------------*/
/* 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 (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
---------------------------------------------------------------------------*/
/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive */
/*-----------------------------------------------------------------------*/
DSTATUS disk_initialize (
BYTE drv /* Physical drive nmuber (0) */
)
{
BYTE n, ty, ocr[4];
if (drv) return STA_NOINIT; /* Supports only single drive */
if (Stat & STA_NODISK) return Stat; /* No card in the socket */
for (n = 10; n; n--) rcvr_spi(); /* 80 dummy clocks */
SELECT(); /* CS = L */
ty = 0;
if (send_cmd(CMD0, 0) == 1) { /* Enter Idle state */
Timer1 = 100; /* Initialization timeout of 1000 msec */
if (send_cmd(CMD8, 0x1AA) == 1) { /* SDC Ver2+ */
for (n = 0; n < 4; n++) ocr[n] = rcvr_spi();
if (ocr[2] == 0x01 && ocr[3] == 0xAA) { /* The card can work at vdd range of 2.7-3.6V */
do {
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 */
Stat |= STA_NOINIT; /* Set STA_NOINIT */
}
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 data block */
)
{
DRESULT res;
BYTE n, csd[16], *ptr = buff;
WORD csize;
if (drv) return RES_PARERR;
SELECT(); /* CS = L */
res = RES_ERROR;
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 (Stat & STA_NOINIT) return RES_NOTRDY;
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 (Stat & STA_NOINIT) return RES_NOTRDY;
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 (Stat & STA_NOINIT) return RES_NOTRDY;
if (send_cmd(CMD58, 0) == 0) { /* READ_OCR */
for (n = 0; n < 4; n++)
*ptr++ = 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 (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 & (SOCKINS); /* Sample socket switch */
if (n == pv) { /* Have contacts stabled? */
s = Stat;
if (pv & SOCKINS) /* INS = H (Socket empty) */
s |= (STA_NODISK | STA_NOINIT);
else /* INS = L (Card inserted) */
s &= ~STA_NODISK;
Stat = s;
}
}
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