path: root/ports/beagleboneblack/am335x_mmc.c

/*
 * Copyright (c) 2015 Jarielle Catbagan <jcatbagan93@gmail.com>
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.apache.org/licenses/LICENSE-2.0
 */

#include "genlib.h"
#include "cli.h"
#include "stddefs.h"
#include "am335x.h"
#include "am335x_mmc.h"

uint16_t mmcrca;
int mmcInum;

char *mmcHelp[] = {
	"MultiMediaCard Interface",
	"[options] {operation} [args]...",
#if INCLUDE_VERBOSEHELP
	"",
	"Options:",
	" -i ##	interface # (default is 0)",
	" -v 	additive verbosity",
	"",
	"Operations:",
	" init",
	" read {dest} {blk} {blktot}",
	" write {source} {blk} {blktot}",
#endif /* INCLUDE_VERBOSEHELP */
	0
};

int
mmccmd(uint32_t cmd, uint32_t arg, uint32_t resp[4])
{
	/* Clear the SD_STAT register for proper update of status bits after CMD invocation */
	MMC1_REG(SD_STAT) = 0xFFFFFFFF;

	MMC1_REG(SD_ARG) = arg;
	MMC1_REG(SD_CMD) = cmd;

	/* CMDx complete? */
	while (!(MMC1_REG(SD_STAT) & (SD_STAT_CC | SD_STAT_ERRI)));

	resp[0] = MMC1_REG(SD_RSP10);
	resp[1] = MMC1_REG(SD_RSP32);
	resp[2] = MMC1_REG(SD_RSP54);
	resp[3] = MMC1_REG(SD_RSP76);

	/* CMDx error? */
	if (MMC1_REG(SD_STAT) & SD_STAT_ERRI)
		return(-1);
	else
		return(0);
}

int
mmc(int argc, char *argv[])
{
	char *cmd, *buf;
	int opt, verbose, mmcret, blknum, blkcnt;

	verbose = 0;

	while ((opt = getopt(argc, argv, "i:v")) != -1) {
		switch (opt) {
			case 'i':
				mmcInum = atoi(optarg);
				break;
			case 'v':
				verbose++;
				break;
			default:
				return(CMD_PARAM_ERROR);
		}
	}

	if (argc < optind + 1)
		return(CMD_PARAM_ERROR);

	cmd = argv[optind];

	if (mmcInstalled(mmcInum) == 0) {
		printf("MMC not installed\n");
		return(CMD_FAILURE);
	}

	if (strcmp(cmd, "init") == 0) {
		mmcret = mmcInit(mmcInum, verbose);
		if(mmcret < 0) {
			printf("mmcInit returned %d\n", mmcret);
			return(CMD_FAILURE);
		}
	}
	else if (strcmp(cmd, "read") == 0) {
		if (argc != (optind + 4))
			return(CMD_PARAM_ERROR);

		buf = (char *)strtoul(argv[optind + 1], 0, 0);
		blknum = strtoul(argv[optind + 2], 0, 0);
		blkcnt = strtoul(argv[optind + 3], 0, 0);

		mmcret = mmcRead(mmcInum, buf, blknum, blkcnt);
		if (mmcret < 0) {
			printf("mmcRead returned %d\n", mmcret);
			return(CMD_FAILURE);
		}
	}
	else if (strcmp(cmd, "write") == 0) {
		if (argc != (optind + 4))
			return(CMD_PARAM_ERROR);

		buf = (char *)strtoul(argv[optind + 1], 0, 0);
		blknum = strtoul(argv[optind + 2], 0, 0);
		blkcnt = strtoul(argv[optind + 3], 0, 0);

		mmcret = mmcWrite(mmcInum, buf, blknum, blkcnt);
		if (mmcret < 0) {
			printf("mmcWrite returned %d\n", mmcret);
			return(CMD_FAILURE);
		}
	}
	else {
		printf("mmc op <%s> not found\n", cmd);
		return(CMD_FAILURE);
	}

	return(CMD_SUCCESS);
}

int
mmcInit(int interface, int verbose)
{
	uint32_t cmd, arg, resp[4];

	/* Enable MMC1 clocks */
	CM_PER_REG(CM_PER_MMC1_CLKCTRL) |= CM_PER_MMC1_CLKCTRL_MODULEMODE_ENABLE;
	while (CM_PER_REG(CM_PER_MMC1_CLKCTRL) & CM_PER_MMC0_CLKCTRL_IDLEST);

	/* Reset the MMC1 Controller */
	MMC1_REG(SD_SYSCONFIG) = SD_SYSCONFIG_SOFTRESET;
	while (!(MMC1_REG(SD_SYSSTATUS) & SD_SYSSTATUS_RESETDONE));

	/* Reset the command and data lines */
	MMC1_REG(SD_SYSCTL) |= SD_SYSCTL_SRA;
	while (MMC1_REG(SD_SYSCTL) & SD_SYSCTL_SRA);

	/* Configure the MMC1 controller capabilities to enable 3.0 V operating voltage */
	MMC1_REG(SD_CAPA) |= SD_CAPA_VS30;

	/* Configure SD_IE register to update certain status bits in SD_STAT */
	MMC1_REG(SD_IE) = SD_IE_BADA_ENABLE | SD_IE_CERR_ENABLE | SD_IE_ACE_ENABLE |
		SD_IE_DEB_ENABLE | SD_IE_DCRC_ENABLE | SD_IE_DTO_ENABLE | SD_IE_CIE_ENABLE |
		SD_IE_CEB_ENABLE | SD_IE_CCRC_ENABLE | SD_IE_CIRQ_ENABLE | SD_IE_CREM_ENABLE |
		SD_IE_CINS_ENABLE | SD_IE_BRR_ENABLE | SD_IE_BWR_ENABLE |
		SD_IE_TC_ENABLE | SD_IE_CC_ENABLE;

	/* Configure the operating voltage to 3.0 V */
	MMC1_REG(SD_HCTL) &= ~(SD_HCTL_SDVS);
	MMC1_REG(SD_HCTL) |= SD_HCTL_SDVS_VS30;

	/* Turn on the bus */
	MMC1_REG(SD_HCTL) |= SD_HCTL_SDBP;
	while (!(MMC1_REG(SD_HCTL) & SD_HCTL_SDBP));

	/* Enable the internal clock */
	MMC1_REG(SD_SYSCTL) |= SD_SYSCTL_ICE;

	/* Configure Clock Frequency Select to 100 KHz */
	MMC1_REG(SD_SYSCTL) = (MMC1_REG(SD_SYSCTL) & ~SD_SYSCTL_CLKD) | (960 << 6);

	/* Wait for clock to stabilize */
	while (!(MMC1_REG(SD_SYSCTL) & SD_SYSCTL_ICS));

	/* Configure SD_SYSCONFIG */
	MMC1_REG(SD_SYSCONFIG) &= ~(SD_SYSCONFIG_CLOCKACTIVITY | SD_SYSCONFIG_SIDLEMODE);
	MMC1_REG(SD_SYSCONFIG) |= SD_SYSCONFIG_SIDLEMODE_WKUP | SD_SYSCONFIG_ENAWAKEUP_ENABLE |
		SD_SYSCONFIG_AUTOIDLE_AUTOGATE;

	/* Enable the clock to the eMMC */
	MMC1_REG(SD_SYSCTL) |= SD_SYSCTL_CEN;

	/* Perform the Initialization Stream as specified in the AM335x TRM, Section 18.3.3.2
	   "Card Detection, Identification, and Selection" */
	MMC1_REG(SD_CON) |= SD_CON_INIT;
	/* Clear the SD_STAT register */
	MMC1_REG(SD_STAT) = 0xFFFFFFFF;
	MMC1_REG(SD_ARG) = 0x00000000;
	MMC1_REG(SD_CMD) = 0x00000000;
	while (!(MMC1_REG(SD_STAT) & SD_STAT_CC));
	/* Clear CC flag in SD_STAT */
	MMC1_REG(SD_STAT) |= SD_STAT_CC;
	MMC1_REG(SD_CON) &= ~SD_CON_INIT;

	/* Clear the SD_STAT register */
	MMC1_REG(SD_STAT) = 0xFFFFFFFF;

	/* Enable open-drain mode until we enter Stand-by State as illustrated in the
	   JEDEC JESD84-A43 Embedded MultiMediaCard Product Standard specification, Table 5 */
	MMC1_REG(SD_CON) |= SD_CON_OD;

	/* Send CMD0/GO_IDLE_STATE to reset the eMMC on MMC1 interface */
	arg = 0x00000000;
	cmd = SD_CMD_CMD0_GO_IDLE_STATE | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_DISABLE | SD_CMD_CCCE_DISABLE | SD_CMD_RSP_TYPE_NO_RESPONSE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Send CMD1 and poll busy bit in response */
	do {
		arg = 0x40FF8000;
		cmd = SD_CMD_CMD1_SEND_OP_COND | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_DISABLE | SD_CMD_CCCE_DISABLE | SD_CMD_RSP_TYPE_R3;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while (!(MMC1_REG(SD_RSP10) & 0x80000000));

	/* Send CMD2, i.e. ALL_SEND_CID */
	arg = 0x00000000;
	cmd = SD_CMD_CMD2_ALL_SEND_CID | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_DISABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R2;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Set RCA of eMMC */
	mmcrca = 0x3A3A;

	/* Send CMD3 to set the relative card address (RCA) of the eMMC */
	arg = (mmcrca << 16) & 0xFFFF0000;
	cmd = SD_CMD_CMD3_SET_RELATIVE_ADDR | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Wait for the eMMC to enter Stand-by State */
	do {
		/* Send CMD13 to get the status of the MMC */
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_STANDBY);

	/* Disable open-drain mode */
	MMC1_REG(SD_CON) &= ~SD_CON_OD;

	/* Send CMD7 to put the eMMC into Transfer State */
	arg = (mmcrca << 16) & 0xFFFF0000;
	cmd = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Wait for eMMC to enter Transfer State */
	do {
		/* Send CMD13 to get the status of the eMMC */
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER);

	/* Send CMD6 to change bus-width to 8-bits */
	arg = (3 << 24) | (183 << 16) | (2 << 8);
	cmd = SD_CMD_CMD6_SWITCH | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1B;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);
	while (!(MMC1_REG(SD_STAT) & SD_STAT_TC));

	/* Wait while CMD6 is still in effect, i.e. while eMMC is not in Transfer State */
	do {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER);

	/* Configure the MMC1 controller to use an 8-bit data width */
	MMC1_REG(SD_CON) |= SD_CON_DW8_8BIT;

	/* Send CMD6 to change to high-speed mode */
	arg = 0x03B90100;
	cmd = SD_CMD_CMD6_SWITCH | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1B;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);
	while (!(MMC1_REG(SD_STAT) & SD_STAT_TC));

	/* Wait while CMD6 is still in effect, i.e. while eMMC is not in Transfer State */
	do {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER);

	/* Change the clock frequency to 48 MHz and set the DTO to the maximum value setting */
	MMC1_REG(SD_SYSCTL) &= ~SD_SYSCTL_DTO;
	MMC1_REG(SD_SYSCTL) |= SD_SYSCTL_DTO_TCF_2_27;
	MMC1_REG(SD_SYSCTL) = (MMC1_REG(SD_SYSCTL) & ~SD_SYSCTL_CLKD) | (2 << 6);

	/* Wait for clock to stabilize */
	while ((MMC1_REG(SD_SYSCTL) & SD_SYSCTL_ICS) != SD_SYSCTL_ICS);

	/* Put the eMMC into Stand-by State */
	arg = 0x00000000;
	cmd = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_DISABLE | SD_CMD_CCCE_DISABLE | SD_CMD_RSP_TYPE_NO_RESPONSE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Wait for the eMMC to enter Stand-by State */
	do {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_STANDBY);

	return(0);
}

int
mmcRead(int interface, char *buf, int blknum, int blkcnt)
{
	uint32_t cmd, arg, resp[4];
	uint32_t *wordptr = (uint32_t *) buf;
	int byteindex;

	/* Get the SD card's status via CMD13 */
	arg = (mmcrca << 16) & 0xFFFF0000;
	cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Ensure that the card is in Transfer State before proceeding */
	if ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER) {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL |
			SD_CMD_DP_NO_DATA_PRESENT | SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE |
			SD_CMD_RSP_TYPE_R1B;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);

		/* Wait for the SD card to enter Transfer State */
		do {
			arg = (mmcrca << 16) & 0xFFFF0000;
			cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL |
				SD_CMD_DP_NO_DATA_PRESENT | SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE |
				SD_CMD_RSP_TYPE_R1;
			if (mmccmd(cmd, arg, resp) == -1)
				return(-1);
		} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER);
	}

	/* Set the block length and the number of blocks to read */
	MMC1_REG(SD_BLK) = 0x200 | (blkcnt << 16);
	/* Read multiple blocks via CMD18 */
	arg = blknum;
	cmd = SD_CMD_CMD18_READ_MULTIPLE_BLOCK | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1 | SD_CMD_MSBS_MULTIPLE |
		SD_CMD_DDIR_READ | SD_CMD_ACEN_CMD12_ENABLE | SD_CMD_BCE_ENABLE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Check the data buffer to see if there is data to be read */
	do {
		while (!(MMC1_REG(SD_STAT) & SD_STAT_BRR));

		/* Clear the BRR status bit in SD_STAT */
		MMC1_REG(SD_STAT) |= SD_STAT_BRR;

		for (byteindex = 0; byteindex < (0x200 / 4); byteindex++) {
			*wordptr = MMC1_REG(SD_DATA);
			wordptr++;
		}
	} while (!(MMC1_REG(SD_STAT) & SD_STAT_TC));

	/* Put the eMMC into Stand-by State */
	arg = 0;
	cmd = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_DISABLE | SD_CMD_CCCE_DISABLE | SD_CMD_RSP_TYPE_NO_RESPONSE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Wait for the eMMC to enter Stand-by State */
	do {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_STANDBY);

	return(0);
}

int
mmcWrite(int interface, char *buf, int blknum, int blkcnt)
{
	uint32_t cmd, arg, resp[4];
	uint32_t *wordptr = (uint32_t *) buf;
	int byteindex;

	/* Get the eMMC status by sending CMD13 */
	arg = (mmcrca << 16) & 0xFFFF0000;
	cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Ensure that the eMMC is in the Transfer State before proceeding */
	if ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER) {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd  = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL |
			SD_CMD_DP_NO_DATA_PRESENT | SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE |
			SD_CMD_RSP_TYPE_R1B;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);

		/* Wait for eMMC to enter Transfer State */
		do {
			arg = (mmcrca << 16) & 0xFFFF0000;
			cmd = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL |
				SD_CMD_DP_NO_DATA_PRESENT | SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE |
				SD_CMD_RSP_TYPE_R1;
			if (mmccmd(cmd, arg, resp) == -1)
				return(-1);
		} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_TRANSFER);
	}

	/* Set the block length in bytes and the number of blocks to write to the SD card */
	MMC1_REG(SD_BLK) = 0x200 | (blkcnt << 16);
	/* Send CMD25, that is write the number of blocks specified in 'blkcount' from 'buf' to the
	 * location that is 512 byte aligned in the SD card specified by the block number 'blknum'
	 */
	arg = blknum;
	cmd = SD_CMD_CMD25_WRITE_MULTIPLE_BLOCK | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1 | SD_CMD_MSBS_MULTIPLE |
		SD_CMD_DDIR_WRITE | SD_CMD_ACEN_CMD12_ENABLE | SD_CMD_BCE_ENABLE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Write the data */
	do {
		/* Wait until data is ready to be written */
		while (!(MMC1_REG(SD_STAT) & (SD_STAT_BWR | SD_STAT_TC)));

		if (MMC1_REG(SD_STAT) & SD_STAT_TC)
			break;

		/* Clear the BWR status bit in SD_STAT */
		MMC1_REG(SD_STAT) |= SD_STAT_BWR;

		for (byteindex = 0; byteindex < (0x200 / 4); byteindex++)
			MMC1_REG(SD_DATA) = *wordptr++;
	} while (!(MMC1_REG(SD_STAT) & SD_STAT_TC));

	/* Put the eMMC into Stand-by State */
	arg = 0x00000000;
	cmd = SD_CMD_CMD7_SELECT_DESELECT_CARD | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
		SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_NO_RESPONSE;
	if (mmccmd(cmd, arg, resp) == -1)
		return(-1);

	/* Wait for eMMC to enter Stand-by State */
	do {
		arg = (mmcrca << 16) & 0xFFFF0000;
		cmd  = SD_CMD_CMD13_SEND_STATUS | SD_CMD_CMD_TYPE_NORMAL | SD_CMD_DP_NO_DATA_PRESENT |
			SD_CMD_CICE_ENABLE | SD_CMD_CCCE_ENABLE | SD_CMD_RSP_TYPE_R1;
		if (mmccmd(cmd, arg, resp) == -1)
			return(-1);
	} while ((resp[0] & SD_RSP10_R1_CURRENT_STATE) != SD_RSP10_R1_CURRENT_STATE_STANDBY);

	return(0);
}

int
mmcInstalled(int interface)
{
	return(1);
}