drivers/mmc/tegra2_mmc.c - platform/external/u-boot - Gitiles

 /*
  * (C) Copyright 2009 SAMSUNG Electronics
  * Minkyu Kang <mk7.kang@samsung.com>
  * Jaehoon Chung <jh80.chung@samsung.com>
  * Portions Copyright 2011 NVIDIA Corporation
  *
  * This program 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 2 of the License, or
  * (at your option) any later version.
  *
  * This program 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, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <common.h>
 #include <mmc.h>
 #include <asm/io.h>
 #include <asm/arch/clk_rst.h>
 #include <asm/arch/clock.h>
 #include "tegra2_mmc.h"

 /* support 4 mmc hosts */
 struct mmc mmc_dev[4];
 struct mmc_host mmc_host[4];


 /**
  * Get the host address and peripheral ID for a device. Devices are numbered
  * from 0 to 3.
  *
  * @param host		Structure to fill in (base, reg, mmc_id)
  * @param dev_index	Device index (0-3)
  */
 static void tegra2_get_setup(struct mmc_host *host, int dev_index)
 {
 	debug("tegra2_get_base_mmc: dev_index = %d\n", dev_index);

 	switch (dev_index) {
 	case 1:
 		host->base = TEGRA2_SDMMC3_BASE;
 		host->mmc_id = PERIPH_ID_SDMMC3;
 		break;
 	case 2:
 		host->base = TEGRA2_SDMMC2_BASE;
 		host->mmc_id = PERIPH_ID_SDMMC2;
 		break;
 	case 3:
 		host->base = TEGRA2_SDMMC1_BASE;
 		host->mmc_id = PERIPH_ID_SDMMC1;
 		break;
 	case 0:
 	default:
 		host->base = TEGRA2_SDMMC4_BASE;
 		host->mmc_id = PERIPH_ID_SDMMC4;
 		break;
 	}

 	host->reg = (struct tegra2_mmc *)host->base;
 }

 static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data)
 {
 	unsigned char ctrl;

 	debug("data->dest: %08X, data->blocks: %u, data->blocksize: %u\n",
 	(u32)data->dest, data->blocks, data->blocksize);

 	writel((u32)data->dest, &host->reg->sysad);
 	/*
 	 * DMASEL[4:3]
 	 * 00 = Selects SDMA
 	 * 01 = Reserved
 	 * 10 = Selects 32-bit Address ADMA2
 	 * 11 = Selects 64-bit Address ADMA2
 	 */
 	ctrl = readb(&host->reg->hostctl);
 	ctrl &= ~(3 << 3);			/* SDMA */
 	writeb(ctrl, &host->reg->hostctl);

 	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
 	writew((7 << 12) | (data->blocksize & 0xFFF), &host->reg->blksize);
 	writew(data->blocks, &host->reg->blkcnt);
 }

 static void mmc_set_transfer_mode(struct mmc_host *host, struct mmc_data *data)
 {
 	unsigned short mode;
 	debug(" mmc_set_transfer_mode called\n");
 	/*
 	 * TRNMOD
 	 * MUL1SIN0[5]	: Multi/Single Block Select
 	 * RD1WT0[4]	: Data Transfer Direction Select
 	 *	1 = read
 	 *	0 = write
 	 * ENACMD12[2]	: Auto CMD12 Enable
 	 * ENBLKCNT[1]	: Block Count Enable
 	 * ENDMA[0]	: DMA Enable
 	 */
 	mode = (1 << 1) | (1 << 0);
 	if (data->blocks > 1)
 		mode |= (1 << 5);
 	if (data->flags & MMC_DATA_READ)
 		mode |= (1 << 4);

 	writew(mode, &host->reg->trnmod);
 }

 static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 			struct mmc_data *data)
 {
 	struct mmc_host *host = (struct mmc_host *)mmc->priv;
 	int flags, i;
 	unsigned int timeout;
 	unsigned int mask;
 	unsigned int retry = 0x100000;
 	debug(" mmc_send_cmd called\n");

 	/* Wait max 10 ms */
 	timeout = 10;

 	/*
 	 * PRNSTS
 	 * CMDINHDAT[1]	: Command Inhibit (DAT)
 	 * CMDINHCMD[0]	: Command Inhibit (CMD)
 	 */
 	mask = (1 << 0);
 	if ((data != NULL) || (cmd->resp_type & MMC_RSP_BUSY))
 		mask |= (1 << 1);

 	/*
 	 * We shouldn't wait for data inhibit for stop commands, even
 	 * though they might use busy signaling
 	 */
 	if (data)
 		mask &= ~(1 << 1);

 	while (readl(&host->reg->prnsts) & mask) {
 		if (timeout == 0) {
 			printf("%s: timeout error\n", __func__);
 			return -1;
 		}
 		timeout--;
 		udelay(1000);
 	}

 	if (data)
 		mmc_prepare_data(host, data);

 	debug("cmd->arg: %08x\n", cmd->cmdarg);
 	writel(cmd->cmdarg, &host->reg->argument);

 	if (data)
 		mmc_set_transfer_mode(host, data);

 	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
 		return -1;

 	/*
 	 * CMDREG
 	 * CMDIDX[13:8]	: Command index
 	 * DATAPRNT[5]	: Data Present Select
 	 * ENCMDIDX[4]	: Command Index Check Enable
 	 * ENCMDCRC[3]	: Command CRC Check Enable
 	 * RSPTYP[1:0]
 	 *	00 = No Response
 	 *	01 = Length 136
 	 *	10 = Length 48
 	 *	11 = Length 48 Check busy after response
 	 */
 	if (!(cmd->resp_type & MMC_RSP_PRESENT))
 		flags = 0;
 	else if (cmd->resp_type & MMC_RSP_136)
 		flags = (1 << 0);
 	else if (cmd->resp_type & MMC_RSP_BUSY)
 		flags = (3 << 0);
 	else
 		flags = (2 << 0);

 	if (cmd->resp_type & MMC_RSP_CRC)
 		flags |= (1 << 3);
 	if (cmd->resp_type & MMC_RSP_OPCODE)
 		flags |= (1 << 4);
 	if (data)
 		flags |= (1 << 5);

 	debug("cmd: %d\n", cmd->cmdidx);

 	writew((cmd->cmdidx << 8) | flags, &host->reg->cmdreg);

 	for (i = 0; i < retry; i++) {
 		mask = readl(&host->reg->norintsts);
 		/* Command Complete */
 		if (mask & (1 << 0)) {
 			if (!data)
 				writel(mask, &host->reg->norintsts);
 			break;
 		}
 	}

 	if (i == retry) {
 		printf("%s: waiting for status update\n", __func__);
 		return TIMEOUT;
 	}

 	if (mask & (1 << 16)) {
 		/* Timeout Error */
 		debug("timeout: %08x cmd %d\n", mask, cmd->cmdidx);
 		return TIMEOUT;
 	} else if (mask & (1 << 15)) {
 		/* Error Interrupt */
 		debug("error: %08x cmd %d\n", mask, cmd->cmdidx);
 		return -1;
 	}

 	if (cmd->resp_type & MMC_RSP_PRESENT) {
 		if (cmd->resp_type & MMC_RSP_136) {
 			/* CRC is stripped so we need to do some shifting. */
 			for (i = 0; i < 4; i++) {
 				unsigned int offset =
 					(unsigned int)(&host->reg->rspreg3 - i);
 				cmd->response[i] = readl(offset) << 8;

 				if (i != 3) {
 					cmd->response[i] |=
 						readb(offset - 1);
 				}
 				debug("cmd->resp[%d]: %08x\n",
 						i, cmd->response[i]);
 			}
 		} else if (cmd->resp_type & MMC_RSP_BUSY) {
 			for (i = 0; i < retry; i++) {
 				/* PRNTDATA[23:20] : DAT[3:0] Line Signal */
 				if (readl(&host->reg->prnsts)
 					& (1 << 20))	/* DAT[0] */
 					break;
 			}

 			if (i == retry) {
 				printf("%s: card is still busy\n", __func__);
 				return TIMEOUT;
 			}

 			cmd->response[0] = readl(&host->reg->rspreg0);
 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
 		} else {
 			cmd->response[0] = readl(&host->reg->rspreg0);
 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
 		}
 	}

 	if (data) {
 		while (1) {
 			mask = readl(&host->reg->norintsts);

 			if (mask & (1 << 15)) {
 				/* Error Interrupt */
 				writel(mask, &host->reg->norintsts);
 				printf("%s: error during transfer: 0x%08x\n",
 						__func__, mask);
 				return -1;
 			} else if (mask & (1 << 3)) {
 				/* DMA Interrupt */
 				debug("DMA end\n");
 				break;
 			} else if (mask & (1 << 1)) {
 				/* Transfer Complete */
 				debug("r/w is done\n");
 				break;
 			}
 		}
 		writel(mask, &host->reg->norintsts);
 	}

 	udelay(1000);
 	return 0;
 }

 static void mmc_change_clock(struct mmc_host *host, uint clock)
 {
 	int div;
 	unsigned short clk;
 	unsigned long timeout;

 	debug(" mmc_change_clock called\n");

 	/*
 	 * Change Tegra2 SDMMCx clock divisor here. Source is 216MHz,
 	 * PLLP_OUT0
 	 */
 	if (clock == 0)
 		goto out;
 	clock_adjust_periph_pll_div(host->mmc_id, CLOCK_ID_PERIPH, clock,
 				    &div);
 	debug("div = %d\n", div);

 	writew(0, &host->reg->clkcon);

 	/*
 	 * CLKCON
 	 * SELFREQ[15:8]	: base clock divided by value
 	 * ENSDCLK[2]		: SD Clock Enable
 	 * STBLINTCLK[1]	: Internal Clock Stable
 	 * ENINTCLK[0]		: Internal Clock Enable
 	 */
 	div >>= 1;
 	clk = (div << 8) | (1 << 0);
 	writew(clk, &host->reg->clkcon);

 	/* Wait max 10 ms */
 	timeout = 10;
 	while (!(readw(&host->reg->clkcon) & (1 << 1))) {
 		if (timeout == 0) {
 			printf("%s: timeout error\n", __func__);
 			return;
 		}
 		timeout--;
 		udelay(1000);
 	}

 	clk |= (1 << 2);
 	writew(clk, &host->reg->clkcon);

 	debug("mmc_change_clock: clkcon = %08X\n", clk);

 out:
 	host->clock = clock;
 }

 static void mmc_set_ios(struct mmc *mmc)
 {
 	struct mmc_host *host = mmc->priv;
 	unsigned char ctrl;
 	debug(" mmc_set_ios called\n");

 	debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);

 	/* Change clock first */
 	mmc_change_clock(host, mmc->clock);

 	ctrl = readb(&host->reg->hostctl);

 	/*
 	 * WIDE8[5]
 	 * 0 = Depend on WIDE4
 	 * 1 = 8-bit mode
 	 * WIDE4[1]
 	 * 1 = 4-bit mode
 	 * 0 = 1-bit mode
 	 */
 	if (mmc->bus_width == 8)
 		ctrl |= (1 << 5);
 	else if (mmc->bus_width == 4)
 		ctrl |= (1 << 1);
 	else
 		ctrl &= ~(1 << 1);

 	writeb(ctrl, &host->reg->hostctl);
 	debug("mmc_set_ios: hostctl = %08X\n", ctrl);
 }

 static void mmc_reset(struct mmc_host *host)
 {
 	unsigned int timeout;
 	debug(" mmc_reset called\n");

 	/*
 	 * RSTALL[0] : Software reset for all
 	 * 1 = reset
 	 * 0 = work
 	 */
 	writeb((1 << 0), &host->reg->swrst);

 	host->clock = 0;

 	/* Wait max 100 ms */
 	timeout = 100;

 	/* hw clears the bit when it's done */
 	while (readb(&host->reg->swrst) & (1 << 0)) {
 		if (timeout == 0) {
 			printf("%s: timeout error\n", __func__);
 			return;
 		}
 		timeout--;
 		udelay(1000);
 	}
 }

 static int mmc_core_init(struct mmc *mmc)
 {
 	struct mmc_host *host = (struct mmc_host *)mmc->priv;
 	unsigned int mask;
 	debug(" mmc_core_init called\n");

 	mmc_reset(host);

 	host->version = readw(&host->reg->hcver);
 	debug("host version = %x\n", host->version);

 	/* mask all */
 	writel(0xffffffff, &host->reg->norintstsen);
 	writel(0xffffffff, &host->reg->norintsigen);

 	writeb(0xe, &host->reg->timeoutcon);	/* TMCLK * 2^27 */
 	/*
 	 * NORMAL Interrupt Status Enable Register init
 	 * [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
 	 * [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
 	 * [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
 	 * [0] ENSTACMDCMPLT : Command Complete Status Enable
 	*/
 	mask = readl(&host->reg->norintstsen);
 	mask &= ~(0xffff);
 	mask |= (1 << 5) | (1 << 4) | (1 << 1) | (1 << 0);
 	writel(mask, &host->reg->norintstsen);

 	/*
 	 * NORMAL Interrupt Signal Enable Register init
 	 * [1] ENSTACMDCMPLT : Transfer Complete Signal Enable
 	 */
 	mask = readl(&host->reg->norintsigen);
 	mask &= ~(0xffff);
 	mask |= (1 << 1);
 	writel(mask, &host->reg->norintsigen);

 	return 0;
 }

 static int tegra2_mmc_initialize(int dev_index, int bus_width)
 {
 	struct mmc_host *host;
 	struct mmc *mmc;

 	debug(" mmc_initialize called\n");

 	host = &mmc_host[dev_index];

 	host->clock = 0;
 	tegra2_get_setup(host, dev_index);

 	clock_start_periph_pll(host->mmc_id, CLOCK_ID_PERIPH, 20000000);

 	mmc = &mmc_dev[dev_index];

 	sprintf(mmc->name, "Tegra2 SD/MMC");
 	mmc->priv = host;
 	mmc->send_cmd = mmc_send_cmd;
 	mmc->set_ios = mmc_set_ios;
 	mmc->init = mmc_core_init;

 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
 	if (bus_width == 8)
 		mmc->host_caps = MMC_MODE_8BIT;
 	else
 		mmc->host_caps = MMC_MODE_4BIT;
 	mmc->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_HC;

 	/*
 	 * min freq is for card identification, and is the highest
 	 *  low-speed SDIO card frequency (actually 400KHz)
 	 * max freq is highest HS eMMC clock as per the SD/MMC spec
 	 *  (actually 52MHz)
 	 * Both of these are the closest equivalents w/216MHz source
 	 *  clock and Tegra2 SDMMC divisors.
 	 */
 	mmc->f_min = 375000;
 	mmc->f_max = 48000000;

 	mmc_register(mmc);

 	return 0;
 }

 int tegra2_mmc_init(int dev_index, int bus_width)
 {
 	debug(" tegra2_mmc_init: index %d, bus width %d\n",
 		dev_index, bus_width);
 	return tegra2_mmc_initialize(dev_index, bus_width);
 }
	/*
	* (C) Copyright 2009 SAMSUNG Electronics
	* Minkyu Kang <mk7.kang@samsung.com>
	* Jaehoon Chung <jh80.chung@samsung.com>
	* Portions Copyright 2011 NVIDIA Corporation
	*
	* This program 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 2 of the License, or
	* (at your option) any later version.
	*
	* This program 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <common.h>
	#include <mmc.h>
	#include <asm/io.h>
	#include <asm/arch/clk_rst.h>
	#include <asm/arch/clock.h>
	#include "tegra2_mmc.h"

	/* support 4 mmc hosts */
	struct mmc mmc_dev[4];
	struct mmc_host mmc_host[4];


	/**
	* Get the host address and peripheral ID for a device. Devices are numbered
	* from 0 to 3.
	*
	* @param host Structure to fill in (base, reg, mmc_id)
	* @param dev_index Device index (0-3)
	*/
	static void tegra2_get_setup(struct mmc_host *host, int dev_index)
	{
	debug("tegra2_get_base_mmc: dev_index = %d\n", dev_index);

	switch (dev_index) {
	case 1:
	host->base = TEGRA2_SDMMC3_BASE;
	host->mmc_id = PERIPH_ID_SDMMC3;
	break;
	case 2:
	host->base = TEGRA2_SDMMC2_BASE;
	host->mmc_id = PERIPH_ID_SDMMC2;
	break;
	case 3:
	host->base = TEGRA2_SDMMC1_BASE;
	host->mmc_id = PERIPH_ID_SDMMC1;
	break;
	case 0:
	default:
	host->base = TEGRA2_SDMMC4_BASE;
	host->mmc_id = PERIPH_ID_SDMMC4;
	break;
	}

	host->reg = (struct tegra2_mmc *)host->base;
	}

	static void mmc_prepare_data(struct mmc_host host, struct mmc_data data)
	{
	unsigned char ctrl;

	debug("data->dest: %08X, data->blocks: %u, data->blocksize: %u\n",
	(u32)data->dest, data->blocks, data->blocksize);

	writel((u32)data->dest, &host->reg->sysad);
	/*
	* DMASEL[4:3]
	* 00 = Selects SDMA
	* 01 = Reserved
	* 10 = Selects 32-bit Address ADMA2
	* 11 = Selects 64-bit Address ADMA2
	*/
	ctrl = readb(&host->reg->hostctl);
	ctrl &= ~(3 << 3); /* SDMA */
	writeb(ctrl, &host->reg->hostctl);

	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
	writew((7 << 12) \| (data->blocksize & 0xFFF), &host->reg->blksize);
	writew(data->blocks, &host->reg->blkcnt);
	}

	static void mmc_set_transfer_mode(struct mmc_host host, struct mmc_data data)
	{
	unsigned short mode;
	debug(" mmc_set_transfer_mode called\n");
	/*
	* TRNMOD
	* MUL1SIN0[5] : Multi/Single Block Select
	* RD1WT0[4] : Data Transfer Direction Select
	* 1 = read
	* 0 = write
	* ENACMD12[2] : Auto CMD12 Enable
	* ENBLKCNT[1] : Block Count Enable
	* ENDMA[0] : DMA Enable
	*/
	mode = (1 << 1) \| (1 << 0);
	if (data->blocks > 1)
	mode \|= (1 << 5);
	if (data->flags & MMC_DATA_READ)
	mode \|= (1 << 4);

	writew(mode, &host->reg->trnmod);
	}

	static int mmc_send_cmd(struct mmc mmc, struct mmc_cmd cmd,
	struct mmc_data *data)
	{
	struct mmc_host host = (struct mmc_host )mmc->priv;
	int flags, i;
	unsigned int timeout;
	unsigned int mask;
	unsigned int retry = 0x100000;
	debug(" mmc_send_cmd called\n");

	/* Wait max 10 ms */
	timeout = 10;

	/*
	* PRNSTS
	* CMDINHDAT[1] : Command Inhibit (DAT)
	* CMDINHCMD[0] : Command Inhibit (CMD)
	*/
	mask = (1 << 0);
	if ((data != NULL) \|\| (cmd->resp_type & MMC_RSP_BUSY))
	mask \|= (1 << 1);

	/*
	* We shouldn't wait for data inhibit for stop commands, even
	* though they might use busy signaling
	*/
	if (data)
	mask &= ~(1 << 1);

	while (readl(&host->reg->prnsts) & mask) {
	if (timeout == 0) {
	printf("%s: timeout error\n", __func__);
	return -1;
	}
	timeout--;
	udelay(1000);
	}

	if (data)
	mmc_prepare_data(host, data);

	debug("cmd->arg: %08x\n", cmd->cmdarg);
	writel(cmd->cmdarg, &host->reg->argument);

	if (data)
	mmc_set_transfer_mode(host, data);

	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
	return -1;

	/*
	* CMDREG
	* CMDIDX[13:8] : Command index
	* DATAPRNT[5] : Data Present Select
	* ENCMDIDX[4] : Command Index Check Enable
	* ENCMDCRC[3] : Command CRC Check Enable
	* RSPTYP[1:0]
	* 00 = No Response
	* 01 = Length 136
	* 10 = Length 48
	* 11 = Length 48 Check busy after response
	*/
	if (!(cmd->resp_type & MMC_RSP_PRESENT))
	flags = 0;
	else if (cmd->resp_type & MMC_RSP_136)
	flags = (1 << 0);
	else if (cmd->resp_type & MMC_RSP_BUSY)
	flags = (3 << 0);
	else
	flags = (2 << 0);

	if (cmd->resp_type & MMC_RSP_CRC)
	flags \|= (1 << 3);
	if (cmd->resp_type & MMC_RSP_OPCODE)
	flags \|= (1 << 4);
	if (data)
	flags \|= (1 << 5);

	debug("cmd: %d\n", cmd->cmdidx);

	writew((cmd->cmdidx << 8) \| flags, &host->reg->cmdreg);

	for (i = 0; i < retry; i++) {
	mask = readl(&host->reg->norintsts);
	/* Command Complete */
	if (mask & (1 << 0)) {
	if (!data)
	writel(mask, &host->reg->norintsts);
	break;
	}
	}

	if (i == retry) {
	printf("%s: waiting for status update\n", __func__);
	return TIMEOUT;
	}

	if (mask & (1 << 16)) {
	/* Timeout Error */
	debug("timeout: %08x cmd %d\n", mask, cmd->cmdidx);
	return TIMEOUT;
	} else if (mask & (1 << 15)) {
	/* Error Interrupt */
	debug("error: %08x cmd %d\n", mask, cmd->cmdidx);
	return -1;
	}

	if (cmd->resp_type & MMC_RSP_PRESENT) {
	if (cmd->resp_type & MMC_RSP_136) {
	/* CRC is stripped so we need to do some shifting. */
	for (i = 0; i < 4; i++) {
	unsigned int offset =
	(unsigned int)(&host->reg->rspreg3 - i);
	cmd->response[i] = readl(offset) << 8;

	if (i != 3) {
	cmd->response[i] \|=
	readb(offset - 1);
	}
	debug("cmd->resp[%d]: %08x\n",
	i, cmd->response[i]);
	}
	} else if (cmd->resp_type & MMC_RSP_BUSY) {
	for (i = 0; i < retry; i++) {
	/* PRNTDATA[23:20] : DAT[3:0] Line Signal */
	if (readl(&host->reg->prnsts)
	& (1 << 20)) /* DAT[0] */
	break;
	}

	if (i == retry) {
	printf("%s: card is still busy\n", __func__);
	return TIMEOUT;
	}

	cmd->response[0] = readl(&host->reg->rspreg0);
	debug("cmd->resp[0]: %08x\n", cmd->response[0]);
	} else {
	cmd->response[0] = readl(&host->reg->rspreg0);
	debug("cmd->resp[0]: %08x\n", cmd->response[0]);
	}
	}

	if (data) {
	while (1) {
	mask = readl(&host->reg->norintsts);

	if (mask & (1 << 15)) {
	/* Error Interrupt */
	writel(mask, &host->reg->norintsts);
	printf("%s: error during transfer: 0x%08x\n",
	__func__, mask);
	return -1;
	} else if (mask & (1 << 3)) {
	/* DMA Interrupt */
	debug("DMA end\n");
	break;
	} else if (mask & (1 << 1)) {
	/* Transfer Complete */
	debug("r/w is done\n");
	break;
	}
	}
	writel(mask, &host->reg->norintsts);
	}

	udelay(1000);
	return 0;
	}

	static void mmc_change_clock(struct mmc_host *host, uint clock)
	{
	int div;
	unsigned short clk;
	unsigned long timeout;

	debug(" mmc_change_clock called\n");

	/*
	* Change Tegra2 SDMMCx clock divisor here. Source is 216MHz,
	* PLLP_OUT0
	*/
	if (clock == 0)
	goto out;
	clock_adjust_periph_pll_div(host->mmc_id, CLOCK_ID_PERIPH, clock,
	&div);
	debug("div = %d\n", div);

	writew(0, &host->reg->clkcon);

	/*
	* CLKCON
	* SELFREQ[15:8] : base clock divided by value
	* ENSDCLK[2] : SD Clock Enable
	* STBLINTCLK[1] : Internal Clock Stable
	* ENINTCLK[0] : Internal Clock Enable
	*/
	div >>= 1;
	clk = (div << 8) \| (1 << 0);
	writew(clk, &host->reg->clkcon);

	/* Wait max 10 ms */
	timeout = 10;
	while (!(readw(&host->reg->clkcon) & (1 << 1))) {
	if (timeout == 0) {
	printf("%s: timeout error\n", __func__);
	return;
	}
	timeout--;
	udelay(1000);
	}

	clk \|= (1 << 2);
	writew(clk, &host->reg->clkcon);

	debug("mmc_change_clock: clkcon = %08X\n", clk);

	out:
	host->clock = clock;
	}

	static void mmc_set_ios(struct mmc *mmc)
	{
	struct mmc_host *host = mmc->priv;
	unsigned char ctrl;
	debug(" mmc_set_ios called\n");

	debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);

	/* Change clock first */
	mmc_change_clock(host, mmc->clock);

	ctrl = readb(&host->reg->hostctl);

	/*
	* WIDE8[5]
	* 0 = Depend on WIDE4
	* 1 = 8-bit mode
	* WIDE4[1]
	* 1 = 4-bit mode
	* 0 = 1-bit mode
	*/
	if (mmc->bus_width == 8)
	ctrl \|= (1 << 5);
	else if (mmc->bus_width == 4)
	ctrl \|= (1 << 1);
	else
	ctrl &= ~(1 << 1);

	writeb(ctrl, &host->reg->hostctl);
	debug("mmc_set_ios: hostctl = %08X\n", ctrl);
	}

	static void mmc_reset(struct mmc_host *host)
	{
	unsigned int timeout;
	debug(" mmc_reset called\n");

	/*
	* RSTALL[0] : Software reset for all
	* 1 = reset
	* 0 = work
	*/
	writeb((1 << 0), &host->reg->swrst);

	host->clock = 0;

	/* Wait max 100 ms */
	timeout = 100;

	/* hw clears the bit when it's done */
	while (readb(&host->reg->swrst) & (1 << 0)) {
	if (timeout == 0) {
	printf("%s: timeout error\n", __func__);
	return;
	}
	timeout--;
	udelay(1000);
	}
	}

	static int mmc_core_init(struct mmc *mmc)
	{
	struct mmc_host host = (struct mmc_host )mmc->priv;
	unsigned int mask;
	debug(" mmc_core_init called\n");

	mmc_reset(host);

	host->version = readw(&host->reg->hcver);
	debug("host version = %x\n", host->version);

	/* mask all */
	writel(0xffffffff, &host->reg->norintstsen);
	writel(0xffffffff, &host->reg->norintsigen);

	writeb(0xe, &host->reg->timeoutcon); /* TMCLK * 2^27 */
	/*
	* NORMAL Interrupt Status Enable Register init
	* [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
	* [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
	* [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
	* [0] ENSTACMDCMPLT : Command Complete Status Enable
	*/
	mask = readl(&host->reg->norintstsen);
	mask &= ~(0xffff);
	mask \|= (1 << 5) \| (1 << 4) \| (1 << 1) \| (1 << 0);
	writel(mask, &host->reg->norintstsen);

	/*
	* NORMAL Interrupt Signal Enable Register init
	* [1] ENSTACMDCMPLT : Transfer Complete Signal Enable
	*/
	mask = readl(&host->reg->norintsigen);
	mask &= ~(0xffff);
	mask \|= (1 << 1);
	writel(mask, &host->reg->norintsigen);

	return 0;
	}

	static int tegra2_mmc_initialize(int dev_index, int bus_width)
	{
	struct mmc_host *host;
	struct mmc *mmc;

	debug(" mmc_initialize called\n");

	host = &mmc_host[dev_index];

	host->clock = 0;
	tegra2_get_setup(host, dev_index);

	clock_start_periph_pll(host->mmc_id, CLOCK_ID_PERIPH, 20000000);

	mmc = &mmc_dev[dev_index];

	sprintf(mmc->name, "Tegra2 SD/MMC");
	mmc->priv = host;
	mmc->send_cmd = mmc_send_cmd;
	mmc->set_ios = mmc_set_ios;
	mmc->init = mmc_core_init;

	mmc->voltages = MMC_VDD_32_33 \| MMC_VDD_33_34 \| MMC_VDD_165_195;
	if (bus_width == 8)
	mmc->host_caps = MMC_MODE_8BIT;
	else
	mmc->host_caps = MMC_MODE_4BIT;
	mmc->host_caps \|= MMC_MODE_HS_52MHz \| MMC_MODE_HS \| MMC_MODE_HC;

	/*
	* min freq is for card identification, and is the highest
	* low-speed SDIO card frequency (actually 400KHz)
	* max freq is highest HS eMMC clock as per the SD/MMC spec
	* (actually 52MHz)
	* Both of these are the closest equivalents w/216MHz source
	* clock and Tegra2 SDMMC divisors.
	*/
	mmc->f_min = 375000;
	mmc->f_max = 48000000;

	mmc_register(mmc);

	return 0;
	}

	int tegra2_mmc_init(int dev_index, int bus_width)
	{
	debug(" tegra2_mmc_init: index %d, bus width %d\n",
	dev_index, bus_width);
	return tegra2_mmc_initialize(dev_index, bus_width);
	}