1
0
mirror of https://github.com/mist-devel/mist-board.git synced 2026-01-13 23:26:27 +00:00
2016-01-15 10:14:19 +01:00

318 lines
9.3 KiB
C

/*------------------------------------------------------------------------/
/ Bitbanging MMCv3/SDv1/SDv2 (in SPI mode) control module for PFF
/ Modified to support the Z80 SoC hardware spi interface
/-------------------------------------------------------------------------/
/
/ Copyright (C) 2014, ChaN, all right reserved.
/
/ * This software is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/ personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/--------------------------------------------------------------------------/
*/
#include "diskio.h"
static unsigned char buffer[512];
static DWORD buffer_sector = 0xffffffff;
// SPI data is read and written via port 0. Writing to the port starts a spi transfer,
// reading the port returns the last byte received during a transfer but doesn't start
// a transfer by itself
__sfr __at 0x00 DataPort;
// SPI control port is a single write only port bit used for spi select (ss)
__sfr __at 0x01 ControlPort;
void dly_us(unsigned int n) {
while(n--) {};
}
void forward(BYTE n) {
}
/*-------------------------------------------------------------------------*/
/* Platform dependent macros and functions needed to be modified */
/*-------------------------------------------------------------------------*/
#define INIT_PORT() init_port() /* Initialize MMC control port (CS/CLK/DI:output, DO:input) */
#define DLY_US(n) dly_us(n) /* Delay n microseconds */
#define FORWARD(d) forward(d) /* Data in-time processing function (depends on the project) */
#define CS_H() ControlPort=1 /* Set MMC CS "high" */
#define CS_L() ControlPort=0 /* Set MMC CS "low" */
/*--------------------------------------------------------------------------
Module Private Functions
---------------------------------------------------------------------------*/
/* 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 CMD16 (0x40+16) /* SET_BLOCKLEN */
#define CMD17 (0x40+17) /* READ_SINGLE_BLOCK */
#define CMD24 (0x40+24) /* WRITE_BLOCK */
#define CMD55 (0x40+55) /* APP_CMD */
#define CMD58 (0x40+58) /* READ_OCR */
/* Card type flags (CardType) */
#define CT_MMC 0x01 /* MMC ver 3 */
#define CT_SD1 0x02 /* SD ver 1 */
#define CT_SD2 0x04 /* SD ver 2 */
#define CT_SDC (CT_SD1|CT_SD2) /* SD */
#define CT_BLOCK 0x08 /* Block addressing */
static
BYTE CardType; /* b0:MMC, b1:SDv1, b2:SDv2, b3:Block addressing */
/*-----------------------------------------------------------------------*/
/* Transmit a byte to the MMC via SPI */
/*-----------------------------------------------------------------------*/
#define XMIT_MMC(a) DataPort=a
/*-----------------------------------------------------------------------*/
/* Receive a byte from the MMC (bitbanging) */
/*-----------------------------------------------------------------------*/
static
BYTE rcvr_mmc (void)
{
DataPort = 0xff;
// some additional delay to give spi transmitter some
// time to finish
__asm
nop
nop
__endasm;
return DataPort;
}
/*-----------------------------------------------------------------------*/
/* Skip bytes on the MMC (bitbanging) */
/*-----------------------------------------------------------------------*/
static
void skip_mmc (
UINT n /* Number of bytes to skip */
)
{
do {
DataPort = 0xff;
} while (--n);
}
/*-----------------------------------------------------------------------*/
/* Deselect the card and release SPI bus */
/*-----------------------------------------------------------------------*/
static
void release_spi (void)
{
CS_H();
rcvr_mmc();
}
/*-----------------------------------------------------------------------*/
/* 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 */
CS_H(); rcvr_mmc();
CS_L(); rcvr_mmc();
/* Send a command packet */
XMIT_MMC(cmd); /* Start + Command index */
XMIT_MMC((BYTE)(arg >> 24)); /* Argument[31..24] */
XMIT_MMC((BYTE)(arg >> 16)); /* Argument[23..16] */
XMIT_MMC((BYTE)(arg >> 8)); /* Argument[15..8] */
XMIT_MMC((BYTE)arg); /* Argument[7..0] */
n = 0x01; /* Dummy CRC + Stop */
if (cmd == CMD0) n = 0x95; /* Valid CRC for CMD0(0) */
if (cmd == CMD8) n = 0x87; /* Valid CRC for CMD8(0x1AA) */
XMIT_MMC(n);
/* Receive a command response */
n = 10; /* Wait for a valid response in timeout of 10 attempts */
do {
res = rcvr_mmc();
} while ((res & 0x80) && --n);
return res; /* Return with the response value */
}
/*--------------------------------------------------------------------------
Public Functions
---------------------------------------------------------------------------*/
/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive */
/*-----------------------------------------------------------------------*/
DSTATUS disk_initialize (void)
{
BYTE n, cmd, ty, buf[4];
UINT tmr;
CS_H();
skip_mmc(10); /* Dummy clocks */
ty = 0;
if (send_cmd(CMD0, 0) == 1) { /* Enter Idle state */
if (send_cmd(CMD8, 0x1AA) == 1) { /* SDv2 */
for (n = 0; n < 4; n++) buf[n] = rcvr_mmc(); /* Get trailing return value of R7 resp */
if (buf[2] == 0x01 && buf[3] == 0xAA) { /* The card can work at vdd range of 2.7-3.6V */
for (tmr = 1000; tmr; tmr--) { /* Wait for leaving idle state (ACMD41 with HCS bit) */
if (send_cmd(ACMD41, 1UL << 30) == 0) break;
DLY_US(1000);
}
if (tmr && send_cmd(CMD58, 0) == 0) { /* Check CCS bit in the OCR */
for (n = 0; n < 4; n++) buf[n] = rcvr_mmc();
ty = (buf[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2; /* SDv2 (HC or SC) */
}
}
} else { /* SDv1 or MMCv3 */
if (send_cmd(ACMD41, 0) <= 1) {
ty = CT_SD1; cmd = ACMD41; /* SDv1 */
} else {
ty = CT_MMC; cmd = CMD1; /* MMCv3 */
}
for (tmr = 1000; tmr; tmr--) { /* Wait for leaving idle state */
if (send_cmd(cmd, 0) == 0) break;
DLY_US(1000);
}
if (!tmr || send_cmd(CMD16, 512) != 0) /* Set R/W block length to 512 */
ty = 0;
}
}
CardType = ty;
release_spi();
return ty ? 0 : STA_NOINIT;
}
/*-----------------------------------------------------------------------*/
/* Read partial sector */
/*-----------------------------------------------------------------------*/
DRESULT disk_readp (
BYTE *buff, /* Pointer to the read buffer (NULL:Read bytes are forwarded to the stream) */
DWORD sector, /* Sector number (LBA) */
UINT offset, /* Byte offset to read from (0..511) */
UINT count /* Number of bytes to read (ofs + cnt mus be <= 512) */
)
{
BYTE *buff_sec = buffer;
DRESULT res;
BYTE d;
UINT bc, tmr;
if (!(CardType & CT_BLOCK)) sector *= 512; /* Convert to byte address if needed */
// check if sector is already in sector buffer
if(buffer_sector == sector) {
buff_sec += offset; // skip to requested bytes
while(count--)
*buff++ = *buff_sec++;
return RES_OK;
}
res = RES_ERROR;
if (send_cmd(CMD17, sector) == 0) { /* READ_SINGLE_BLOCK */
tmr = 1000;
do { /* Wait for data packet in timeout of 100ms */
DLY_US(100);
d = rcvr_mmc();
} while (d == 0xFF && --tmr);
if (d == 0xFE) { /* A data packet arrived */
// if the whole sector is being read we assume that it
// will not be needed again and we won't cache it
if((!offset) && (count == 512)) {
BYTE c;
for(c=0;c<64;c++) {
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
*buff++ = rcvr_mmc();
}
skip_mmc(2);
} else {
bc = 512 - offset - count;
/* Skip leading bytes (store in buffer only) */
while(offset--)
*buff_sec++ = rcvr_mmc();
/* Receive a part of the sector */
if (buff) { /* Store data to the memory */
do
*buff_sec++ = *buff++ = rcvr_mmc();
while (--count);
} else { /* Forward data to the outgoing stream */
do {
*buff_sec++ = d = rcvr_mmc();
FORWARD(d);
} while (--count);
}
/* Skip trailing bytes (store in buffer only) */
while(bc--)
*buff_sec++ = rcvr_mmc();
/* and skip crc */
skip_mmc(2);
buffer_sector = sector;
}
res = RES_OK;
}
}
release_spi();
return res;
}