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

 /*
  * Freescale i.MX28 SSP MMC driver
  *
  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
  * on behalf of DENX Software Engineering GmbH
  *
  * Based on code from LTIB:
  * (C) Copyright 2008-2010 Freescale Semiconductor, Inc.
  * Terry Lv
  *
  * Copyright 2007, Freescale Semiconductor, Inc
  * Andy Fleming
  *
  * Based vaguely on the pxa mmc code:
  * (C) Copyright 2003
  * Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 #include <common.h>
 #include <malloc.h>
 #include <mmc.h>
 #include <asm/errno.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/imx-common/dma.h>
 #include <bouncebuf.h>

 struct mxsmmc_priv {
 	int			id;
 	struct mxs_ssp_regs	*regs;
 	uint32_t		buswidth;
 	int			(*mmc_is_wp)(int);
 	int			(*mmc_cd)(int);
 	struct mxs_dma_desc	*desc;
 };

 #define	MXSMMC_MAX_TIMEOUT	10000
 #define MXSMMC_SMALL_TRANSFER	512

 static int mxsmmc_cd(struct mxsmmc_priv *priv)
 {
 	struct mxs_ssp_regs *ssp_regs = priv->regs;

 	if (priv->mmc_cd)
 		return priv->mmc_cd(priv->id);

 	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
 }

 static int mxsmmc_send_cmd_pio(struct mxsmmc_priv *priv, struct mmc_data *data)
 {
 	struct mxs_ssp_regs *ssp_regs = priv->regs;
 	uint32_t *data_ptr;
 	int timeout = MXSMMC_MAX_TIMEOUT;
 	uint32_t reg;
 	uint32_t data_count = data->blocksize * data->blocks;

 	if (data->flags & MMC_DATA_READ) {
 		data_ptr = (uint32_t *)data->dest;
 		while (data_count && --timeout) {
 			reg = readl(&ssp_regs->hw_ssp_status);
 			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
 				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
 				data_count -= 4;
 				timeout = MXSMMC_MAX_TIMEOUT;
 			} else
 				udelay(1000);
 		}
 	} else {
 		data_ptr = (uint32_t *)data->src;
 		timeout *= 100;
 		while (data_count && --timeout) {
 			reg = readl(&ssp_regs->hw_ssp_status);
 			if (!(reg & SSP_STATUS_FIFO_FULL)) {
 				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
 				data_count -= 4;
 				timeout = MXSMMC_MAX_TIMEOUT;
 			} else
 				udelay(1000);
 		}
 	}

 	return timeout ? 0 : COMM_ERR;
 }

 static int mxsmmc_send_cmd_dma(struct mxsmmc_priv *priv, struct mmc_data *data)
 {
 	uint32_t data_count = data->blocksize * data->blocks;
 	int dmach;
 	struct mxs_dma_desc *desc = priv->desc;
 	void *addr;
 	unsigned int flags;
 	struct bounce_buffer bbstate;

 	memset(desc, 0, sizeof(struct mxs_dma_desc));
 	desc->address = (dma_addr_t)desc;

 	if (data->flags & MMC_DATA_READ) {
 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
 		addr = data->dest;
 		flags = GEN_BB_WRITE;
 	} else {
 		priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
 		addr = (void *)data->src;
 		flags = GEN_BB_READ;
 	}

 	bounce_buffer_start(&bbstate, addr, data_count, flags);

 	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;

 	priv->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
 				(data_count << MXS_DMA_DESC_BYTES_OFFSET);

 	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id;
 	mxs_dma_desc_append(dmach, priv->desc);
 	if (mxs_dma_go(dmach)) {
 		bounce_buffer_stop(&bbstate);
 		return COMM_ERR;
 	}

 	bounce_buffer_stop(&bbstate);

 	return 0;
 }

 /*
  * Sends a command out on the bus.  Takes the mmc pointer,
  * a command pointer, and an optional data pointer.
  */
 static int
 mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
 {
 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
 	struct mxs_ssp_regs *ssp_regs = priv->regs;
 	uint32_t reg;
 	int timeout;
 	uint32_t ctrl0;
 	int ret;

 	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);

 	/* Check bus busy */
 	timeout = MXSMMC_MAX_TIMEOUT;
 	while (--timeout) {
 		udelay(1000);
 		reg = readl(&ssp_regs->hw_ssp_status);
 		if (!(reg &
 			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
 			SSP_STATUS_CMD_BUSY))) {
 			break;
 		}
 	}

 	if (!timeout) {
 		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
 		return TIMEOUT;
 	}

 	/* See if card is present */
 	if (!mxsmmc_cd(priv)) {
 		printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
 		return NO_CARD_ERR;
 	}

 	/* Start building CTRL0 contents */
 	ctrl0 = priv->buswidth;

 	/* Set up command */
 	if (!(cmd->resp_type & MMC_RSP_CRC))
 		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
 	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
 		ctrl0 |= SSP_CTRL0_GET_RESP;
 	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
 		ctrl0 |= SSP_CTRL0_LONG_RESP;

 	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
 	else
 		writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);

 	/* Command index */
 	reg = readl(&ssp_regs->hw_ssp_cmd0);
 	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
 	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
 	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
 		reg |= SSP_CMD0_APPEND_8CYC;
 	writel(reg, &ssp_regs->hw_ssp_cmd0);

 	/* Command argument */
 	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);

 	/* Set up data */
 	if (data) {
 		/* READ or WRITE */
 		if (data->flags & MMC_DATA_READ) {
 			ctrl0 |= SSP_CTRL0_READ;
 		} else if (priv->mmc_is_wp &&
 			priv->mmc_is_wp(mmc->block_dev.dev)) {
 			printf("MMC%d: Can not write a locked card!\n",
 				mmc->block_dev.dev);
 			return UNUSABLE_ERR;
 		}

 		ctrl0 |= SSP_CTRL0_DATA_XFER;

 		reg = data->blocksize * data->blocks;
 #if defined(CONFIG_MX23)
 		ctrl0 |= reg & SSP_CTRL0_XFER_COUNT_MASK;

 		clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
 			SSP_CMD0_BLOCK_SIZE_MASK | SSP_CMD0_BLOCK_COUNT_MASK,
 			((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) |
 			((ffs(data->blocksize) - 1) <<
 				SSP_CMD0_BLOCK_SIZE_OFFSET));
 #elif defined(CONFIG_MX28)
 		writel(reg, &ssp_regs->hw_ssp_xfer_size);

 		reg = ((data->blocks - 1) <<
 			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
 			((ffs(data->blocksize) - 1) <<
 			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
 		writel(reg, &ssp_regs->hw_ssp_block_size);
 #endif
 	}

 	/* Kick off the command */
 	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
 	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);

 	/* Wait for the command to complete */
 	timeout = MXSMMC_MAX_TIMEOUT;
 	while (--timeout) {
 		udelay(1000);
 		reg = readl(&ssp_regs->hw_ssp_status);
 		if (!(reg & SSP_STATUS_CMD_BUSY))
 			break;
 	}

 	if (!timeout) {
 		printf("MMC%d: Command %d busy\n",
 			mmc->block_dev.dev, cmd->cmdidx);
 		return TIMEOUT;
 	}

 	/* Check command timeout */
 	if (reg & SSP_STATUS_RESP_TIMEOUT) {
 		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
 			mmc->block_dev.dev, cmd->cmdidx, reg);
 		return TIMEOUT;
 	}

 	/* Check command errors */
 	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
 		printf("MMC%d: Command %d error (status 0x%08x)!\n",
 			mmc->block_dev.dev, cmd->cmdidx, reg);
 		return COMM_ERR;
 	}

 	/* Copy response to response buffer */
 	if (cmd->resp_type & MMC_RSP_136) {
 		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
 		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
 		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
 	} else
 		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);

 	/* Return if no data to process */
 	if (!data)
 		return 0;

 	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
 		ret = mxsmmc_send_cmd_pio(priv, data);
 		if (ret) {
 			printf("MMC%d: Data timeout with command %d "
 				"(status 0x%08x)!\n",
 				mmc->block_dev.dev, cmd->cmdidx, reg);
 			return ret;
 		}
 	} else {
 		ret = mxsmmc_send_cmd_dma(priv, data);
 		if (ret) {
 			printf("MMC%d: DMA transfer failed\n",
 				mmc->block_dev.dev);
 			return ret;
 		}
 	}

 	/* Check data errors */
 	reg = readl(&ssp_regs->hw_ssp_status);
 	if (reg &
 		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
 		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
 		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
 			mmc->block_dev.dev, cmd->cmdidx, reg);
 		return COMM_ERR;
 	}

 	return 0;
 }

 static void mxsmmc_set_ios(struct mmc *mmc)
 {
 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
 	struct mxs_ssp_regs *ssp_regs = priv->regs;

 	/* Set the clock speed */
 	if (mmc->clock)
 		mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);

 	switch (mmc->bus_width) {
 	case 1:
 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
 		break;
 	case 4:
 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
 		break;
 	case 8:
 		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
 		break;
 	}

 	/* Set the bus width */
 	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
 			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);

 	debug("MMC%d: Set %d bits bus width\n",
 		mmc->block_dev.dev, mmc->bus_width);
 }

 static int mxsmmc_init(struct mmc *mmc)
 {
 	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
 	struct mxs_ssp_regs *ssp_regs = priv->regs;

 	/* Reset SSP */
 	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);

 	/* Reconfigure the SSP block for MMC operation */
 	writel(SSP_CTRL1_SSP_MODE_SD_MMC |
 		SSP_CTRL1_WORD_LENGTH_EIGHT_BITS |
 		SSP_CTRL1_DMA_ENABLE |
 		SSP_CTRL1_POLARITY |
 		SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
 		SSP_CTRL1_DATA_CRC_IRQ_EN |
 		SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
 		SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
 		SSP_CTRL1_RESP_ERR_IRQ_EN,
 		&ssp_regs->hw_ssp_ctrl1_set);

 	/* Set initial bit clock 400 KHz */
 	mxs_set_ssp_busclock(priv->id, 400);

 	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
 	udelay(200);
 	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);

 	return 0;
 }

 int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int), int (*cd)(int))
 {
 	struct mmc *mmc = NULL;
 	struct mxsmmc_priv *priv = NULL;
 	int ret;
 	const unsigned int mxsmmc_clk_id = mxs_ssp_clock_by_bus(id);

 	if (!mxs_ssp_bus_id_valid(id))
 		return -ENODEV;

 	mmc = malloc(sizeof(struct mmc));
 	if (!mmc)
 		return -ENOMEM;

 	priv = malloc(sizeof(struct mxsmmc_priv));
 	if (!priv) {
 		free(mmc);
 		return -ENOMEM;
 	}

 	priv->desc = mxs_dma_desc_alloc();
 	if (!priv->desc) {
 		free(priv);
 		free(mmc);
 		return -ENOMEM;
 	}

 	ret = mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + id);
 	if (ret)
 		return ret;

 	priv->mmc_is_wp = wp;
 	priv->mmc_cd = cd;
 	priv->id = id;
 	priv->regs = mxs_ssp_regs_by_bus(id);

 	sprintf(mmc->name, "MXS MMC");
 	mmc->send_cmd = mxsmmc_send_cmd;
 	mmc->set_ios = mxsmmc_set_ios;
 	mmc->init = mxsmmc_init;
 	mmc->getcd = NULL;
 	mmc->getwp = NULL;
 	mmc->priv = priv;

 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;

 	mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
 			 MMC_MODE_HS_52MHz | MMC_MODE_HS;

 	/*
 	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
 	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
 	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
 	 * CLOCK_RATE could be any integer from 0 to 255.
 	 */
 	mmc->f_min = 400000;
 	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
 	mmc->b_max = 0x20;

 	mmc_register(mmc);
 	return 0;
 }
	/*
	* Freescale i.MX28 SSP MMC driver
	*
	* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
	* on behalf of DENX Software Engineering GmbH
	*
	* Based on code from LTIB:
	* (C) Copyright 2008-2010 Freescale Semiconductor, Inc.
	* Terry Lv
	*
	* Copyright 2007, Freescale Semiconductor, Inc
	* Andy Fleming
	*
	* Based vaguely on the pxa mmc code:
	* (C) Copyright 2003
	* Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/
	#include <common.h>
	#include <malloc.h>
	#include <mmc.h>
	#include <asm/errno.h>
	#include <asm/io.h>
	#include <asm/arch/clock.h>
	#include <asm/arch/imx-regs.h>
	#include <asm/arch/sys_proto.h>
	#include <asm/imx-common/dma.h>
	#include <bouncebuf.h>

	struct mxsmmc_priv {
	int id;
	struct mxs_ssp_regs *regs;
	uint32_t buswidth;
	int (*mmc_is_wp)(int);
	int (*mmc_cd)(int);
	struct mxs_dma_desc *desc;
	};

	#define MXSMMC_MAX_TIMEOUT 10000
	#define MXSMMC_SMALL_TRANSFER 512

	static int mxsmmc_cd(struct mxsmmc_priv *priv)
	{
	struct mxs_ssp_regs *ssp_regs = priv->regs;

	if (priv->mmc_cd)
	return priv->mmc_cd(priv->id);

	return !(readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT);
	}

	static int mxsmmc_send_cmd_pio(struct mxsmmc_priv priv, struct mmc_data data)
	{
	struct mxs_ssp_regs *ssp_regs = priv->regs;
	uint32_t *data_ptr;
	int timeout = MXSMMC_MAX_TIMEOUT;
	uint32_t reg;
	uint32_t data_count = data->blocksize * data->blocks;

	if (data->flags & MMC_DATA_READ) {
	data_ptr = (uint32_t *)data->dest;
	while (data_count && --timeout) {
	reg = readl(&ssp_regs->hw_ssp_status);
	if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
	*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
	data_count -= 4;
	timeout = MXSMMC_MAX_TIMEOUT;
	} else
	udelay(1000);
	}
	} else {
	data_ptr = (uint32_t *)data->src;
	timeout *= 100;
	while (data_count && --timeout) {
	reg = readl(&ssp_regs->hw_ssp_status);
	if (!(reg & SSP_STATUS_FIFO_FULL)) {
	writel(*data_ptr++, &ssp_regs->hw_ssp_data);
	data_count -= 4;
	timeout = MXSMMC_MAX_TIMEOUT;
	} else
	udelay(1000);
	}
	}

	return timeout ? 0 : COMM_ERR;
	}

	static int mxsmmc_send_cmd_dma(struct mxsmmc_priv priv, struct mmc_data data)
	{
	uint32_t data_count = data->blocksize * data->blocks;
	int dmach;
	struct mxs_dma_desc *desc = priv->desc;
	void *addr;
	unsigned int flags;
	struct bounce_buffer bbstate;

	memset(desc, 0, sizeof(struct mxs_dma_desc));
	desc->address = (dma_addr_t)desc;

	if (data->flags & MMC_DATA_READ) {
	priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
	addr = data->dest;
	flags = GEN_BB_WRITE;
	} else {
	priv->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
	addr = (void *)data->src;
	flags = GEN_BB_READ;
	}

	bounce_buffer_start(&bbstate, addr, data_count, flags);

	priv->desc->cmd.address = (dma_addr_t)bbstate.bounce_buffer;

	priv->desc->cmd.data \|= MXS_DMA_DESC_IRQ \| MXS_DMA_DESC_DEC_SEM \|
	(data_count << MXS_DMA_DESC_BYTES_OFFSET);

	dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + priv->id;
	mxs_dma_desc_append(dmach, priv->desc);
	if (mxs_dma_go(dmach)) {
	bounce_buffer_stop(&bbstate);
	return COMM_ERR;
	}

	bounce_buffer_stop(&bbstate);

	return 0;
	}

	/*
	* Sends a command out on the bus. Takes the mmc pointer,
	* a command pointer, and an optional data pointer.
	*/
	static int
	mxsmmc_send_cmd(struct mmc mmc, struct mmc_cmd cmd, struct mmc_data *data)
	{
	struct mxsmmc_priv priv = (struct mxsmmc_priv )mmc->priv;
	struct mxs_ssp_regs *ssp_regs = priv->regs;
	uint32_t reg;
	int timeout;
	uint32_t ctrl0;
	int ret;

	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);

	/* Check bus busy */
	timeout = MXSMMC_MAX_TIMEOUT;
	while (--timeout) {
	udelay(1000);
	reg = readl(&ssp_regs->hw_ssp_status);
	if (!(reg &
	(SSP_STATUS_BUSY \| SSP_STATUS_DATA_BUSY \|
	SSP_STATUS_CMD_BUSY))) {
	break;
	}
	}

	if (!timeout) {
	printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
	return TIMEOUT;
	}

	/* See if card is present */
	if (!mxsmmc_cd(priv)) {
	printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
	return NO_CARD_ERR;
	}

	/* Start building CTRL0 contents */
	ctrl0 = priv->buswidth;

	/* Set up command */
	if (!(cmd->resp_type & MMC_RSP_CRC))
	ctrl0 \|= SSP_CTRL0_IGNORE_CRC;
	if (cmd->resp_type & MMC_RSP_PRESENT) /* Need to get response */
	ctrl0 \|= SSP_CTRL0_GET_RESP;
	if (cmd->resp_type & MMC_RSP_136) /* It's a 136 bits response */
	ctrl0 \|= SSP_CTRL0_LONG_RESP;

	if (data && (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER))
	writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
	else
	writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);

	/* Command index */
	reg = readl(&ssp_regs->hw_ssp_cmd0);
	reg &= ~(SSP_CMD0_CMD_MASK \| SSP_CMD0_APPEND_8CYC);
	reg \|= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
	reg \|= SSP_CMD0_APPEND_8CYC;
	writel(reg, &ssp_regs->hw_ssp_cmd0);

	/* Command argument */
	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);

	/* Set up data */
	if (data) {
	/* READ or WRITE */
	if (data->flags & MMC_DATA_READ) {
	ctrl0 \|= SSP_CTRL0_READ;
	} else if (priv->mmc_is_wp &&
	priv->mmc_is_wp(mmc->block_dev.dev)) {
	printf("MMC%d: Can not write a locked card!\n",
	mmc->block_dev.dev);
	return UNUSABLE_ERR;
	}

	ctrl0 \|= SSP_CTRL0_DATA_XFER;

	reg = data->blocksize * data->blocks;
	#if defined(CONFIG_MX23)
	ctrl0 \|= reg & SSP_CTRL0_XFER_COUNT_MASK;

	clrsetbits_le32(&ssp_regs->hw_ssp_cmd0,
	SSP_CMD0_BLOCK_SIZE_MASK \| SSP_CMD0_BLOCK_COUNT_MASK,
	((data->blocks - 1) << SSP_CMD0_BLOCK_COUNT_OFFSET) \|
	((ffs(data->blocksize) - 1) <<
	SSP_CMD0_BLOCK_SIZE_OFFSET));
	#elif defined(CONFIG_MX28)
	writel(reg, &ssp_regs->hw_ssp_xfer_size);

	reg = ((data->blocks - 1) <<
	SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) \|
	((ffs(data->blocksize) - 1) <<
	SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
	writel(reg, &ssp_regs->hw_ssp_block_size);
	#endif
	}

	/* Kick off the command */
	ctrl0 \|= SSP_CTRL0_WAIT_FOR_IRQ \| SSP_CTRL0_ENABLE \| SSP_CTRL0_RUN;
	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);

	/* Wait for the command to complete */
	timeout = MXSMMC_MAX_TIMEOUT;
	while (--timeout) {
	udelay(1000);
	reg = readl(&ssp_regs->hw_ssp_status);
	if (!(reg & SSP_STATUS_CMD_BUSY))
	break;
	}

	if (!timeout) {
	printf("MMC%d: Command %d busy\n",
	mmc->block_dev.dev, cmd->cmdidx);
	return TIMEOUT;
	}

	/* Check command timeout */
	if (reg & SSP_STATUS_RESP_TIMEOUT) {
	printf("MMC%d: Command %d timeout (status 0x%08x)\n",
	mmc->block_dev.dev, cmd->cmdidx, reg);
	return TIMEOUT;
	}

	/* Check command errors */
	if (reg & (SSP_STATUS_RESP_CRC_ERR \| SSP_STATUS_RESP_ERR)) {
	printf("MMC%d: Command %d error (status 0x%08x)!\n",
	mmc->block_dev.dev, cmd->cmdidx, reg);
	return COMM_ERR;
	}

	/* Copy response to response buffer */
	if (cmd->resp_type & MMC_RSP_136) {
	cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
	cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
	cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
	cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
	} else
	cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);

	/* Return if no data to process */
	if (!data)
	return 0;

	if (data->blocksize * data->blocks < MXSMMC_SMALL_TRANSFER) {
	ret = mxsmmc_send_cmd_pio(priv, data);
	if (ret) {
	printf("MMC%d: Data timeout with command %d "
	"(status 0x%08x)!\n",
	mmc->block_dev.dev, cmd->cmdidx, reg);
	return ret;
	}
	} else {
	ret = mxsmmc_send_cmd_dma(priv, data);
	if (ret) {
	printf("MMC%d: DMA transfer failed\n",
	mmc->block_dev.dev);
	return ret;
	}
	}

	/* Check data errors */
	reg = readl(&ssp_regs->hw_ssp_status);
	if (reg &
	(SSP_STATUS_TIMEOUT \| SSP_STATUS_DATA_CRC_ERR \|
	SSP_STATUS_FIFO_OVRFLW \| SSP_STATUS_FIFO_UNDRFLW)) {
	printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
	mmc->block_dev.dev, cmd->cmdidx, reg);
	return COMM_ERR;
	}

	return 0;
	}

	static void mxsmmc_set_ios(struct mmc *mmc)
	{
	struct mxsmmc_priv priv = (struct mxsmmc_priv )mmc->priv;
	struct mxs_ssp_regs *ssp_regs = priv->regs;

	/* Set the clock speed */
	if (mmc->clock)
	mxs_set_ssp_busclock(priv->id, mmc->clock / 1000);

	switch (mmc->bus_width) {
	case 1:
	priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
	break;
	case 4:
	priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
	break;
	case 8:
	priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
	break;
	}

	/* Set the bus width */
	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
	SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);

	debug("MMC%d: Set %d bits bus width\n",
	mmc->block_dev.dev, mmc->bus_width);
	}

	static int mxsmmc_init(struct mmc *mmc)
	{
	struct mxsmmc_priv priv = (struct mxsmmc_priv )mmc->priv;
	struct mxs_ssp_regs *ssp_regs = priv->regs;

	/* Reset SSP */
	mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);

	/* Reconfigure the SSP block for MMC operation */
	writel(SSP_CTRL1_SSP_MODE_SD_MMC \|
	SSP_CTRL1_WORD_LENGTH_EIGHT_BITS \|
	SSP_CTRL1_DMA_ENABLE \|
	SSP_CTRL1_POLARITY \|
	SSP_CTRL1_RECV_TIMEOUT_IRQ_EN \|
	SSP_CTRL1_DATA_CRC_IRQ_EN \|
	SSP_CTRL1_DATA_TIMEOUT_IRQ_EN \|
	SSP_CTRL1_RESP_TIMEOUT_IRQ_EN \|
	SSP_CTRL1_RESP_ERR_IRQ_EN,
	&ssp_regs->hw_ssp_ctrl1_set);

	/* Set initial bit clock 400 KHz */
	mxs_set_ssp_busclock(priv->id, 400);

	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
	udelay(200);
	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);

	return 0;
	}

	int mxsmmc_initialize(bd_t bis, int id, int (wp)(int), int (*cd)(int))
	{
	struct mmc *mmc = NULL;
	struct mxsmmc_priv *priv = NULL;
	int ret;
	const unsigned int mxsmmc_clk_id = mxs_ssp_clock_by_bus(id);

	if (!mxs_ssp_bus_id_valid(id))
	return -ENODEV;

	mmc = malloc(sizeof(struct mmc));
	if (!mmc)
	return -ENOMEM;

	priv = malloc(sizeof(struct mxsmmc_priv));
	if (!priv) {
	free(mmc);
	return -ENOMEM;
	}

	priv->desc = mxs_dma_desc_alloc();
	if (!priv->desc) {
	free(priv);
	free(mmc);
	return -ENOMEM;
	}

	ret = mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + id);
	if (ret)
	return ret;

	priv->mmc_is_wp = wp;
	priv->mmc_cd = cd;
	priv->id = id;
	priv->regs = mxs_ssp_regs_by_bus(id);

	sprintf(mmc->name, "MXS MMC");
	mmc->send_cmd = mxsmmc_send_cmd;
	mmc->set_ios = mxsmmc_set_ios;
	mmc->init = mxsmmc_init;
	mmc->getcd = NULL;
	mmc->getwp = NULL;
	mmc->priv = priv;

	mmc->voltages = MMC_VDD_32_33 \| MMC_VDD_33_34;

	mmc->host_caps = MMC_MODE_4BIT \| MMC_MODE_8BIT \|
	MMC_MODE_HS_52MHz \| MMC_MODE_HS;

	/*
	* SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
	* SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
	* CLOCK_DIVIDE has to be an even value from 2 to 254, and
	* CLOCK_RATE could be any integer from 0 to 255.
	*/
	mmc->f_min = 400000;
	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + mxsmmc_clk_id) * 1000 / 2;
	mmc->b_max = 0x20;

	mmc_register(mmc);
	return 0;
	}