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/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <ch.h>
#include "lpc214x.h"
#include "lpc214x_ssp.h"
#include "mmcsd.h"
static EventSource MMCInsertEventSource;
/*
* Subsystem initialization.
*/
void InitMMC(void) {
chEvtInit(&MMCInsertEventSource);
}
static void sendhdr(BYTE8 cmd, ULONG32 arg) {
BYTE8 buf[6];
/*
* Wait for the bus to become idle if a write operation was in progress.
*/
while (TRUE) {
sspRW(buf, NULL, 1);
if (buf[0] == 0xFF)
break;
#ifdef NICE_WAITING
chThdSleep(1); /* Trying to be nice with the other threads.*/
#endif
}
buf[0] = 0x40 | cmd;
buf[1] = arg >> 24;
buf[2] = arg >> 16;
buf[3] = arg >> 8;
buf[4] = arg;
buf[5] = 0x95; /* Valid for CMD0 ingnored by other commands. */
sspRW(NULL, buf, 6);
}
static BYTE8 recvr1(void) {
int i;
BYTE8 r1[1];
for (i = 0; i < 9; i++) {
sspRW(r1, NULL, 1);
if (r1[0] != 0xFF)
return r1[0];
}
return 0xFF; /* Timeout.*/
}
static BOOL getdata(BYTE8 *buf, ULONG32 n) {
int i;
for (i = 0; i < MMC_WAIT_DATA; i++) {
sspRW(buf, NULL, 1);
if (buf[0] == 0xFE) {
sspRW(buf, NULL, n);
sspRW(NULL, NULL, 2); /* CRC ignored.*/
return FALSE;
}
}
return TRUE; /* Timeout.*/
}
/*
* Initializes a card after the power up by selecting the SPI mode.
*/
BOOL mmcInit(void) {
/*
* Starting initialization with slow clock mode.
*/
SetSSP(254, CR0_DSS8BIT | CR0_FRFSPI | CR0_CLOCKRATE(0), 0);
/*
* SPI mode selection.
*/
sspRW(NULL, NULL, 16); /* 128 clock pulses without ~CS asserted. */
int i = 0;
while (TRUE) {
if (mmcSendCommand(CMDGOIDLE, 0) == 0x01)
break;
if (++i >= CMD0_RETRY)
return TRUE;
chThdSleep(10);
}
/*
* Initialization.
*/
i = 0;
while (TRUE) {
BYTE8 b = mmcSendCommand(CMDINIT, 0);
if (b == 0x00)
break;
if (b != 0x01)
return TRUE;
if (++i >= CMD1_RETRY)
return TRUE;
chThdSleep(10);
}
/*
* Full speed.
*/
SetSSP(2, CR0_DSS8BIT | CR0_FRFSPI | CR0_CLOCKRATE(0), 0);
return FALSE;
}
/*
* Sends a simple command and returns a R1-type response.
*/
BYTE8 mmcSendCommand(BYTE8 cmd, ULONG32 arg) {
BYTE8 r1;
sspAcquireBus();
sendhdr(cmd, arg);
r1 = recvr1();
sspReleaseBus();
return r1;
}
/*
* Reads the card info record.
* @param data the pointer to a \p MMCCSD structure
* @return \p TRUE if an error happened
*/
BOOL mmcGetSize(MMCCSD *data) {
BYTE8 buf[16];
sspAcquireBus();
sendhdr(CMDREADCSD, 0);
if (recvr1() != 0x00) {
sspReleaseBus();
return TRUE;
}
if (getdata(buf, 16)) {
sspReleaseBus();
return TRUE;
}
sspReleaseBus();
/* csize * multiplier */
data->csize = (((buf[6] & 3) << 10) | (buf[7] << 2) | (buf[8] >> 6)) *
(1 << (2 + (((buf[9] & 3) << 1) | (buf[10] >> 7))));
data->rdblklen = 1 << (buf[5] & 15);
return FALSE;
}
/*
* Reads a block.
* @param blknum the block number
* @param buf the pointer to the read buffer
* @return \p TRUE if an error happened
*/
BOOL mmcBlockRead(ULONG32 blknum, BYTE8 *buf) {
sspAcquireBus();
sendhdr(CMDREAD, blknum << 8);
if (recvr1() != 0x00) {
sspReleaseBus();
return TRUE;
}
if (getdata(buf, 512)) {
sspReleaseBus();
return TRUE;
}
sspReleaseBus();
return FALSE;
}
/*
* Writes a block.
* @param blknum the block number
* @param buf the pointer to the write buffer
* @return \p TRUE if an error happened
* @note The function DOES NOT wait for the SPI bus to become free after
* sending the data, the bus check is done before sending commands to
* the card, this allows to not make useless busy waiting. The invoking
* thread can do other things while the data is being written.
*/
BOOL mmcBlockWrite(ULONG32 blknum, BYTE8 *buf) {
static BYTE8 start[] = {0xFF, 0xFE};
BYTE8 b[4];
sspAcquireBus();
sendhdr(CMDWRITE, blknum << 8);
if (recvr1() != 0x00) {
sspReleaseBus();
return TRUE;
}
sspRW(NULL, start, 2); /* Data prologue.*/
sspRW(NULL, buf, 512); /* Data.*/
sspRW(NULL, NULL, 2); /* CRC ignored in this version.*/
sspRW(b, NULL, 1);
sspReleaseBus();
if ((b[0] & 0x1E) != 0x05)
return TRUE;
return FALSE;
}
/*
* Makes sure that pending operations are completed before returning.
*/
void mmcSynch(void) {
BYTE8 buf[4];
sspAcquireBus();
while (TRUE) {
sspRW(buf, NULL, 1);
if (buf[0] == 0xFF)
break;
#ifdef NICE_WAITING
chThdSleep(1); /* Trying to be nice with the other threads.*/
#endif
}
sspReleaseBus();
}
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