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

 /*
  * Davinci MMC Controller Driver
  *
  * Copyright (C) 2010 Texas Instruments Incorporated
  *
  * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include <config.h>
 #include <common.h>
 #include <command.h>
 #include <mmc.h>
 #include <part.h>
 #include <malloc.h>
 #include <asm/io.h>
 #include <asm/arch/sdmmc_defs.h>

 #define DAVINCI_MAX_BLOCKS	(32)
 #define WATCHDOG_COUNT		(100000)

 #define get_val(addr)		REG(addr)
 #define set_val(addr, val)	REG(addr) = (val)
 #define set_bit(addr, val)	set_val((addr), (get_val(addr) | (val)))
 #define clear_bit(addr, val)	set_val((addr), (get_val(addr) & ~(val)))

 /* Set davinci clock prescalar value based on the required clock in HZ */
 static void dmmc_set_clock(struct mmc *mmc, uint clock)
 {
 	struct davinci_mmc *host = mmc->priv;
 	struct davinci_mmc_regs *regs = host->reg_base;
 	uint clkrt, sysclk2, act_clock;

 	if (clock < mmc->f_min)
 		clock = mmc->f_min;
 	if (clock > mmc->f_max)
 		clock = mmc->f_max;

 	set_val(&regs->mmcclk, 0);
 	sysclk2 = host->input_clk;
 	clkrt = (sysclk2 / (2 * clock)) - 1;

 	/* Calculate the actual clock for the divider used */
 	act_clock = (sysclk2 / (2 * (clkrt + 1)));

 	/* Adjust divider if actual clock exceeds the required clock */
 	if (act_clock > clock)
 		clkrt++;

 	/* check clock divider boundary and correct it */
 	if (clkrt > 0xFF)
 		clkrt = 0xFF;

 	set_val(&regs->mmcclk, (clkrt | MMCCLK_CLKEN));
 }

 /* Status bit wait loop for MMCST1 */
 static int
 dmmc_wait_fifo_status(volatile struct davinci_mmc_regs *regs, uint status)
 {
 	uint mmcstatus1, wdog = WATCHDOG_COUNT;
 	mmcstatus1 = get_val(&regs->mmcst1);
 	while (--wdog && ((get_val(&regs->mmcst1) & status) != status))
 		udelay(10);

 	if (!(get_val(&regs->mmcctl) & MMCCTL_WIDTH_4_BIT))
 		udelay(100);

 	if (wdog == 0)
 		return COMM_ERR;

 	return 0;
 }

 /* Busy bit wait loop for MMCST1 */
 static int dmmc_busy_wait(volatile struct davinci_mmc_regs *regs)
 {
 	uint mmcstatus1, wdog = WATCHDOG_COUNT;

 	mmcstatus1 = get_val(&regs->mmcst1);
 	while (--wdog && (get_val(&regs->mmcst1) & MMCST1_BUSY))
 		udelay(10);

 	if (wdog == 0)
 		return COMM_ERR;

 	return 0;
 }

 /* Status bit wait loop for MMCST0 - Checks for error bits as well */
 static int dmmc_check_status(volatile struct davinci_mmc_regs *regs,
 		uint *cur_st, uint st_ready, uint st_error)
 {
 	uint wdog = WATCHDOG_COUNT;
 	uint mmcstatus = *cur_st;

 	while (wdog--) {
 		if (mmcstatus & st_ready) {
 			*cur_st = mmcstatus;
 			mmcstatus = get_val(&regs->mmcst1);
 			return 0;
 		} else if (mmcstatus & st_error) {
 			if (mmcstatus & MMCST0_TOUTRS)
 				return TIMEOUT;
 			printf("[ ST0 ERROR %x]\n", mmcstatus);
 			/*
 			 * Ignore CRC errors as some MMC cards fail to
 			 * initialize on DM365-EVM on the SD1 slot
 			 */
 			if (mmcstatus & MMCST0_CRCRS)
 				return 0;
 			return COMM_ERR;
 		}
 		udelay(10);

 		mmcstatus = get_val(&regs->mmcst0);
 	}

 	printf("Status %x Timeout ST0:%x ST1:%x\n", st_ready, mmcstatus,
 			get_val(&regs->mmcst1));
 	return COMM_ERR;
 }

 /*
  * Sends a command out on the bus.  Takes the mmc pointer,
  * a command pointer, and an optional data pointer.
  */
 static int
 dmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
 {
 	struct davinci_mmc *host = mmc->priv;
 	volatile struct davinci_mmc_regs *regs = host->reg_base;
 	uint mmcstatus, status_rdy, status_err;
 	uint i, cmddata, bytes_left = 0;
 	int fifo_words, fifo_bytes, err;
 	char *data_buf = NULL;

 	/* Clear status registers */
 	mmcstatus = get_val(&regs->mmcst0);
 	fifo_words = (host->version == MMC_CTLR_VERSION_2) ? 16 : 8;
 	fifo_bytes = fifo_words << 2;

 	/* Wait for any previous busy signal to be cleared */
 	dmmc_busy_wait(regs);

 	cmddata = cmd->cmdidx;
 	cmddata |= MMCCMD_PPLEN;

 	/* Send init clock for CMD0 */
 	if (cmd->cmdidx == MMC_CMD_GO_IDLE_STATE)
 		cmddata |= MMCCMD_INITCK;

 	switch (cmd->resp_type) {
 	case MMC_RSP_R1b:
 		cmddata |= MMCCMD_BSYEXP;
 		/* Fall-through */
 	case MMC_RSP_R1:    /* R1, R1b, R5, R6, R7 */
 		cmddata |= MMCCMD_RSPFMT_R1567;
 		break;
 	case MMC_RSP_R2:
 		cmddata |= MMCCMD_RSPFMT_R2;
 		break;
 	case MMC_RSP_R3: /* R3, R4 */
 		cmddata |= MMCCMD_RSPFMT_R3;
 		break;
 	}

 	set_val(&regs->mmcim, 0);

 	if (data) {
 		/* clear previous data transfer if any and set new one */
 		bytes_left = (data->blocksize * data->blocks);

 		/* Reset FIFO - Always use 32 byte fifo threshold */
 		set_val(&regs->mmcfifoctl,
 				(MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));

 		if (host->version == MMC_CTLR_VERSION_2)
 			cmddata |= MMCCMD_DMATRIG;

 		cmddata |= MMCCMD_WDATX;
 		if (data->flags == MMC_DATA_READ) {
 			set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
 		} else if (data->flags == MMC_DATA_WRITE) {
 			set_val(&regs->mmcfifoctl,
 					(MMCFIFOCTL_FIFOLEV |
 					 MMCFIFOCTL_FIFODIR));
 			cmddata |= MMCCMD_DTRW;
 		}

 		set_val(&regs->mmctod, 0xFFFF);
 		set_val(&regs->mmcnblk, (data->blocks & MMCNBLK_NBLK_MASK));
 		set_val(&regs->mmcblen, (data->blocksize & MMCBLEN_BLEN_MASK));

 		if (data->flags == MMC_DATA_WRITE) {
 			uint val;
 			data_buf = (char *)data->src;
 			/* For write, fill FIFO with data before issue of CMD */
 			for (i = 0; (i < fifo_words) && bytes_left; i++) {
 				memcpy((char *)&val, data_buf, 4);
 				set_val(&regs->mmcdxr, val);
 				data_buf += 4;
 				bytes_left -= 4;
 			}
 		}
 	} else {
 		set_val(&regs->mmcblen, 0);
 		set_val(&regs->mmcnblk, 0);
 	}

 	set_val(&regs->mmctor, 0x1FFF);

 	/* Send the command */
 	set_val(&regs->mmcarghl, cmd->cmdarg);
 	set_val(&regs->mmccmd, cmddata);

 	status_rdy = MMCST0_RSPDNE;
 	status_err = (MMCST0_TOUTRS | MMCST0_TOUTRD |
 			MMCST0_CRCWR | MMCST0_CRCRD);
 	if (cmd->resp_type & MMC_RSP_CRC)
 		status_err |= MMCST0_CRCRS;

 	mmcstatus = get_val(&regs->mmcst0);
 	err = dmmc_check_status(regs, &mmcstatus, status_rdy, status_err);
 	if (err)
 		return err;

 	/* For R1b wait for busy done */
 	if (cmd->resp_type == MMC_RSP_R1b)
 		dmmc_busy_wait(regs);

 	/* Collect response from controller for specific commands */
 	if (mmcstatus & MMCST0_RSPDNE) {
 		/* Copy the response to the response buffer */
 		if (cmd->resp_type & MMC_RSP_136) {
 			cmd->response[0] = get_val(&regs->mmcrsp67);
 			cmd->response[1] = get_val(&regs->mmcrsp45);
 			cmd->response[2] = get_val(&regs->mmcrsp23);
 			cmd->response[3] = get_val(&regs->mmcrsp01);
 		} else if (cmd->resp_type & MMC_RSP_PRESENT) {
 			cmd->response[0] = get_val(&regs->mmcrsp67);
 		}
 	}

 	if (data == NULL)
 		return 0;

 	if (data->flags == MMC_DATA_READ) {
 		/* check for DATDNE along with DRRDY as the controller might
 		 * set the DATDNE without DRRDY for smaller transfers with
 		 * less than FIFO threshold bytes
 		 */
 		status_rdy = MMCST0_DRRDY | MMCST0_DATDNE;
 		status_err = MMCST0_TOUTRD | MMCST0_CRCRD;
 		data_buf = data->dest;
 	} else {
 		status_rdy = MMCST0_DXRDY | MMCST0_DATDNE;
 		status_err = MMCST0_CRCWR;
 	}

 	/* Wait until all of the blocks are transferred */
 	while (bytes_left) {
 		err = dmmc_check_status(regs, &mmcstatus, status_rdy,
 				status_err);
 		if (err)
 			return err;

 		if (data->flags == MMC_DATA_READ) {
 			/*
 			 * MMC controller sets the Data receive ready bit
 			 * (DRRDY) in MMCST0 even before the entire FIFO is
 			 * full. This results in erratic behavior if we start
 			 * reading the FIFO soon after DRRDY.  Wait for the
 			 * FIFO full bit in MMCST1 for proper FIFO clearing.
 			 */
 			if (bytes_left > fifo_bytes)
 				dmmc_wait_fifo_status(regs, 0x4a);
 			else if (bytes_left == fifo_bytes)
 				dmmc_wait_fifo_status(regs, 0x40);

 			for (i = 0; bytes_left && (i < fifo_words); i++) {
 				cmddata = get_val(&regs->mmcdrr);
 				memcpy(data_buf, (char *)&cmddata, 4);
 				data_buf += 4;
 				bytes_left -= 4;
 			}
 		} else {
 			/*
 			 * MMC controller sets the Data transmit ready bit
 			 * (DXRDY) in MMCST0 even before the entire FIFO is
 			 * empty. This results in erratic behavior if we start
 			 * writing the FIFO soon after DXRDY.  Wait for the
 			 * FIFO empty bit in MMCST1 for proper FIFO clearing.
 			 */
 			dmmc_wait_fifo_status(regs, MMCST1_FIFOEMP);
 			for (i = 0; bytes_left && (i < fifo_words); i++) {
 				memcpy((char *)&cmddata, data_buf, 4);
 				set_val(&regs->mmcdxr, cmddata);
 				data_buf += 4;
 				bytes_left -= 4;
 			}
 			dmmc_busy_wait(regs);
 		}
 	}

 	err = dmmc_check_status(regs, &mmcstatus, MMCST0_DATDNE, status_err);
 	if (err)
 		return err;

 	return 0;
 }

 /* Initialize Davinci MMC controller */
 static int dmmc_init(struct mmc *mmc)
 {
 	struct davinci_mmc *host = mmc->priv;
 	struct davinci_mmc_regs *regs = host->reg_base;

 	/* Clear status registers explicitly - soft reset doesn't clear it
 	 * If Uboot is invoked from UBL with SDMMC Support, the status
 	 * registers can have uncleared bits
 	 */
 	get_val(&regs->mmcst0);
 	get_val(&regs->mmcst1);

 	/* Hold software reset */
 	set_bit(&regs->mmcctl, MMCCTL_DATRST);
 	set_bit(&regs->mmcctl, MMCCTL_CMDRST);
 	udelay(10);

 	set_val(&regs->mmcclk, 0x0);
 	set_val(&regs->mmctor, 0x1FFF);
 	set_val(&regs->mmctod, 0xFFFF);

 	/* Clear software reset */
 	clear_bit(&regs->mmcctl, MMCCTL_DATRST);
 	clear_bit(&regs->mmcctl, MMCCTL_CMDRST);

 	udelay(10);

 	/* Reset FIFO - Always use the maximum fifo threshold */
 	set_val(&regs->mmcfifoctl, (MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));
 	set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);

 	return 0;
 }

 /* Set buswidth or clock as indicated by the GENERIC_MMC framework */
 static void dmmc_set_ios(struct mmc *mmc)
 {
 	struct davinci_mmc *host = mmc->priv;
 	struct davinci_mmc_regs *regs = host->reg_base;

 	/* Set the bus width */
 	if (mmc->bus_width == 4)
 		set_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
 	else
 		clear_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);

 	/* Set clock speed */
 	if (mmc->clock)
 		dmmc_set_clock(mmc, mmc->clock);
 }

 /* Called from board_mmc_init during startup. Can be called multiple times
  * depending on the number of slots available on board and controller
  */
 int davinci_mmc_init(bd_t *bis, struct davinci_mmc *host)
 {
 	struct mmc *mmc;

 	mmc = malloc(sizeof(struct mmc));
 	memset(mmc, 0, sizeof(struct mmc));

 	sprintf(mmc->name, "davinci");
 	mmc->priv = host;
 	mmc->send_cmd = dmmc_send_cmd;
 	mmc->set_ios = dmmc_set_ios;
 	mmc->init = dmmc_init;

 	mmc->f_min = 200000;
 	mmc->f_max = 25000000;
 	mmc->voltages = host->voltages;
 	mmc->host_caps = host->host_caps;

 	mmc->b_max = DAVINCI_MAX_BLOCKS;

 	mmc_register(mmc);

 	return 0;
 }
	/*
	* Davinci MMC Controller Driver
	*
	* Copyright (C) 2010 Texas Instruments Incorporated
	*
	* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include <config.h>
	#include <common.h>
	#include <command.h>
	#include <mmc.h>
	#include <part.h>
	#include <malloc.h>
	#include <asm/io.h>
	#include <asm/arch/sdmmc_defs.h>

	#define DAVINCI_MAX_BLOCKS (32)
	#define WATCHDOG_COUNT (100000)

	#define get_val(addr) REG(addr)
	#define set_val(addr, val) REG(addr) = (val)
	#define set_bit(addr, val) set_val((addr), (get_val(addr) \| (val)))
	#define clear_bit(addr, val) set_val((addr), (get_val(addr) & ~(val)))

	/* Set davinci clock prescalar value based on the required clock in HZ */
	static void dmmc_set_clock(struct mmc *mmc, uint clock)
	{
	struct davinci_mmc *host = mmc->priv;
	struct davinci_mmc_regs *regs = host->reg_base;
	uint clkrt, sysclk2, act_clock;

	if (clock < mmc->f_min)
	clock = mmc->f_min;
	if (clock > mmc->f_max)
	clock = mmc->f_max;

	set_val(&regs->mmcclk, 0);
	sysclk2 = host->input_clk;
	clkrt = (sysclk2 / (2 * clock)) - 1;

	/* Calculate the actual clock for the divider used */
	act_clock = (sysclk2 / (2 * (clkrt + 1)));

	/* Adjust divider if actual clock exceeds the required clock */
	if (act_clock > clock)
	clkrt++;

	/* check clock divider boundary and correct it */
	if (clkrt > 0xFF)
	clkrt = 0xFF;

	set_val(&regs->mmcclk, (clkrt \| MMCCLK_CLKEN));
	}

	/* Status bit wait loop for MMCST1 */
	static int
	dmmc_wait_fifo_status(volatile struct davinci_mmc_regs *regs, uint status)
	{
	uint mmcstatus1, wdog = WATCHDOG_COUNT;
	mmcstatus1 = get_val(&regs->mmcst1);
	while (--wdog && ((get_val(&regs->mmcst1) & status) != status))
	udelay(10);

	if (!(get_val(&regs->mmcctl) & MMCCTL_WIDTH_4_BIT))
	udelay(100);

	if (wdog == 0)
	return COMM_ERR;

	return 0;
	}

	/* Busy bit wait loop for MMCST1 */
	static int dmmc_busy_wait(volatile struct davinci_mmc_regs *regs)
	{
	uint mmcstatus1, wdog = WATCHDOG_COUNT;

	mmcstatus1 = get_val(&regs->mmcst1);
	while (--wdog && (get_val(&regs->mmcst1) & MMCST1_BUSY))
	udelay(10);

	if (wdog == 0)
	return COMM_ERR;

	return 0;
	}

	/* Status bit wait loop for MMCST0 - Checks for error bits as well */
	static int dmmc_check_status(volatile struct davinci_mmc_regs *regs,
	uint *cur_st, uint st_ready, uint st_error)
	{
	uint wdog = WATCHDOG_COUNT;
	uint mmcstatus = *cur_st;

	while (wdog--) {
	if (mmcstatus & st_ready) {
	*cur_st = mmcstatus;
	mmcstatus = get_val(&regs->mmcst1);
	return 0;
	} else if (mmcstatus & st_error) {
	if (mmcstatus & MMCST0_TOUTRS)
	return TIMEOUT;
	printf("[ ST0 ERROR %x]\n", mmcstatus);
	/*
	* Ignore CRC errors as some MMC cards fail to
	* initialize on DM365-EVM on the SD1 slot
	*/
	if (mmcstatus & MMCST0_CRCRS)
	return 0;
	return COMM_ERR;
	}
	udelay(10);

	mmcstatus = get_val(&regs->mmcst0);
	}

	printf("Status %x Timeout ST0:%x ST1:%x\n", st_ready, mmcstatus,
	get_val(&regs->mmcst1));
	return COMM_ERR;
	}

	/*
	* Sends a command out on the bus. Takes the mmc pointer,
	* a command pointer, and an optional data pointer.
	*/
	static int
	dmmc_send_cmd(struct mmc mmc, struct mmc_cmd cmd, struct mmc_data *data)
	{
	struct davinci_mmc *host = mmc->priv;
	volatile struct davinci_mmc_regs *regs = host->reg_base;
	uint mmcstatus, status_rdy, status_err;
	uint i, cmddata, bytes_left = 0;
	int fifo_words, fifo_bytes, err;
	char *data_buf = NULL;

	/* Clear status registers */
	mmcstatus = get_val(&regs->mmcst0);
	fifo_words = (host->version == MMC_CTLR_VERSION_2) ? 16 : 8;
	fifo_bytes = fifo_words << 2;

	/* Wait for any previous busy signal to be cleared */
	dmmc_busy_wait(regs);

	cmddata = cmd->cmdidx;
	cmddata \|= MMCCMD_PPLEN;

	/* Send init clock for CMD0 */
	if (cmd->cmdidx == MMC_CMD_GO_IDLE_STATE)
	cmddata \|= MMCCMD_INITCK;

	switch (cmd->resp_type) {
	case MMC_RSP_R1b:
	cmddata \|= MMCCMD_BSYEXP;
	/* Fall-through */
	case MMC_RSP_R1: /* R1, R1b, R5, R6, R7 */
	cmddata \|= MMCCMD_RSPFMT_R1567;
	break;
	case MMC_RSP_R2:
	cmddata \|= MMCCMD_RSPFMT_R2;
	break;
	case MMC_RSP_R3: /* R3, R4 */
	cmddata \|= MMCCMD_RSPFMT_R3;
	break;
	}

	set_val(&regs->mmcim, 0);

	if (data) {
	/* clear previous data transfer if any and set new one */
	bytes_left = (data->blocksize * data->blocks);

	/* Reset FIFO - Always use 32 byte fifo threshold */
	set_val(&regs->mmcfifoctl,
	(MMCFIFOCTL_FIFOLEV \| MMCFIFOCTL_FIFORST));

	if (host->version == MMC_CTLR_VERSION_2)
	cmddata \|= MMCCMD_DMATRIG;

	cmddata \|= MMCCMD_WDATX;
	if (data->flags == MMC_DATA_READ) {
	set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
	} else if (data->flags == MMC_DATA_WRITE) {
	set_val(&regs->mmcfifoctl,
	(MMCFIFOCTL_FIFOLEV \|
	MMCFIFOCTL_FIFODIR));
	cmddata \|= MMCCMD_DTRW;
	}

	set_val(&regs->mmctod, 0xFFFF);
	set_val(&regs->mmcnblk, (data->blocks & MMCNBLK_NBLK_MASK));
	set_val(&regs->mmcblen, (data->blocksize & MMCBLEN_BLEN_MASK));

	if (data->flags == MMC_DATA_WRITE) {
	uint val;
	data_buf = (char *)data->src;
	/* For write, fill FIFO with data before issue of CMD */
	for (i = 0; (i < fifo_words) && bytes_left; i++) {
	memcpy((char *)&val, data_buf, 4);
	set_val(&regs->mmcdxr, val);
	data_buf += 4;
	bytes_left -= 4;
	}
	}
	} else {
	set_val(&regs->mmcblen, 0);
	set_val(&regs->mmcnblk, 0);
	}

	set_val(&regs->mmctor, 0x1FFF);

	/* Send the command */
	set_val(&regs->mmcarghl, cmd->cmdarg);
	set_val(&regs->mmccmd, cmddata);

	status_rdy = MMCST0_RSPDNE;
	status_err = (MMCST0_TOUTRS \| MMCST0_TOUTRD \|
	MMCST0_CRCWR \| MMCST0_CRCRD);
	if (cmd->resp_type & MMC_RSP_CRC)
	status_err \|= MMCST0_CRCRS;

	mmcstatus = get_val(&regs->mmcst0);
	err = dmmc_check_status(regs, &mmcstatus, status_rdy, status_err);
	if (err)
	return err;

	/* For R1b wait for busy done */
	if (cmd->resp_type == MMC_RSP_R1b)
	dmmc_busy_wait(regs);

	/* Collect response from controller for specific commands */
	if (mmcstatus & MMCST0_RSPDNE) {
	/* Copy the response to the response buffer */
	if (cmd->resp_type & MMC_RSP_136) {
	cmd->response[0] = get_val(&regs->mmcrsp67);
	cmd->response[1] = get_val(&regs->mmcrsp45);
	cmd->response[2] = get_val(&regs->mmcrsp23);
	cmd->response[3] = get_val(&regs->mmcrsp01);
	} else if (cmd->resp_type & MMC_RSP_PRESENT) {
	cmd->response[0] = get_val(&regs->mmcrsp67);
	}
	}

	if (data == NULL)
	return 0;

	if (data->flags == MMC_DATA_READ) {
	/* check for DATDNE along with DRRDY as the controller might
	* set the DATDNE without DRRDY for smaller transfers with
	* less than FIFO threshold bytes
	*/
	status_rdy = MMCST0_DRRDY \| MMCST0_DATDNE;
	status_err = MMCST0_TOUTRD \| MMCST0_CRCRD;
	data_buf = data->dest;
	} else {
	status_rdy = MMCST0_DXRDY \| MMCST0_DATDNE;
	status_err = MMCST0_CRCWR;
	}

	/* Wait until all of the blocks are transferred */
	while (bytes_left) {
	err = dmmc_check_status(regs, &mmcstatus, status_rdy,
	status_err);
	if (err)
	return err;

	if (data->flags == MMC_DATA_READ) {
	/*
	* MMC controller sets the Data receive ready bit
	* (DRRDY) in MMCST0 even before the entire FIFO is
	* full. This results in erratic behavior if we start
	* reading the FIFO soon after DRRDY. Wait for the
	* FIFO full bit in MMCST1 for proper FIFO clearing.
	*/
	if (bytes_left > fifo_bytes)
	dmmc_wait_fifo_status(regs, 0x4a);
	else if (bytes_left == fifo_bytes)
	dmmc_wait_fifo_status(regs, 0x40);

	for (i = 0; bytes_left && (i < fifo_words); i++) {
	cmddata = get_val(&regs->mmcdrr);
	memcpy(data_buf, (char *)&cmddata, 4);
	data_buf += 4;
	bytes_left -= 4;
	}
	} else {
	/*
	* MMC controller sets the Data transmit ready bit
	* (DXRDY) in MMCST0 even before the entire FIFO is
	* empty. This results in erratic behavior if we start
	* writing the FIFO soon after DXRDY. Wait for the
	* FIFO empty bit in MMCST1 for proper FIFO clearing.
	*/
	dmmc_wait_fifo_status(regs, MMCST1_FIFOEMP);
	for (i = 0; bytes_left && (i < fifo_words); i++) {
	memcpy((char *)&cmddata, data_buf, 4);
	set_val(&regs->mmcdxr, cmddata);
	data_buf += 4;
	bytes_left -= 4;
	}
	dmmc_busy_wait(regs);
	}
	}

	err = dmmc_check_status(regs, &mmcstatus, MMCST0_DATDNE, status_err);
	if (err)
	return err;

	return 0;
	}

	/* Initialize Davinci MMC controller */
	static int dmmc_init(struct mmc *mmc)
	{
	struct davinci_mmc *host = mmc->priv;
	struct davinci_mmc_regs *regs = host->reg_base;

	/* Clear status registers explicitly - soft reset doesn't clear it
	* If Uboot is invoked from UBL with SDMMC Support, the status
	* registers can have uncleared bits
	*/
	get_val(&regs->mmcst0);
	get_val(&regs->mmcst1);

	/* Hold software reset */
	set_bit(&regs->mmcctl, MMCCTL_DATRST);
	set_bit(&regs->mmcctl, MMCCTL_CMDRST);
	udelay(10);

	set_val(&regs->mmcclk, 0x0);
	set_val(&regs->mmctor, 0x1FFF);
	set_val(&regs->mmctod, 0xFFFF);

	/* Clear software reset */
	clear_bit(&regs->mmcctl, MMCCTL_DATRST);
	clear_bit(&regs->mmcctl, MMCCTL_CMDRST);

	udelay(10);

	/* Reset FIFO - Always use the maximum fifo threshold */
	set_val(&regs->mmcfifoctl, (MMCFIFOCTL_FIFOLEV \| MMCFIFOCTL_FIFORST));
	set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);

	return 0;
	}

	/* Set buswidth or clock as indicated by the GENERIC_MMC framework */
	static void dmmc_set_ios(struct mmc *mmc)
	{
	struct davinci_mmc *host = mmc->priv;
	struct davinci_mmc_regs *regs = host->reg_base;

	/* Set the bus width */
	if (mmc->bus_width == 4)
	set_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
	else
	clear_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);

	/* Set clock speed */
	if (mmc->clock)
	dmmc_set_clock(mmc, mmc->clock);
	}

	/* Called from board_mmc_init during startup. Can be called multiple times
	* depending on the number of slots available on board and controller
	*/
	int davinci_mmc_init(bd_t bis, struct davinci_mmc host)
	{
	struct mmc *mmc;

	mmc = malloc(sizeof(struct mmc));
	memset(mmc, 0, sizeof(struct mmc));

	sprintf(mmc->name, "davinci");
	mmc->priv = host;
	mmc->send_cmd = dmmc_send_cmd;
	mmc->set_ios = dmmc_set_ios;
	mmc->init = dmmc_init;

	mmc->f_min = 200000;
	mmc->f_max = 25000000;
	mmc->voltages = host->voltages;
	mmc->host_caps = host->host_caps;

	mmc->b_max = DAVINCI_MAX_BLOCKS;

	mmc_register(mmc);

	return 0;
	}