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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;
void InitMMC(void) {
chEvtInit(&MMCInsertEventSource);
}
/*
* 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(0, 0) == 0x01)
break;
if (++i >= CMD0_RETRY)
return TRUE;
chThdSleep(10);
}
/*
* Initialization.
*/
i = 0;
while (TRUE) {
BYTE8 b = mmcSendCommand(1, 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;
}
static void sendhdr(BYTE8 cmd, ULONG32 arg) {
BYTE8 buf[8];
buf[0] = 0xFF;
buf[1] = 0x40 | cmd;
buf[2] = arg >> 24;
buf[3] = arg >> 16;
buf[4] = arg >> 8;
buf[5] = arg;
buf[6] = 0x95; /* Valid for CMD0 ingnored by other commands. */
buf[7] = 0xFF;
sspRW(NULL, buf, 8);
}
static BYTE8 recvr1(void) {
int i;
BYTE8 r1[1];
for (i = 0; i < 8; i++) {
sspRW(r1, NULL, 1);
if (r1[0] != 0xFF)
return r1[0];
}
return 0xFF;
}
/*
* 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;
}
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