path: root/src/flash/nand/mx3.c

/***************************************************************************
 *   Copyright (C) 2009 by Alexei Babich                                   *
 *   Rezonans plc., Chelyabinsk, Russia                                    *
 *   impatt@mail.ru                                                        *
 *                                                                         *
 *   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.             *
 ***************************************************************************/

/*
 * Freescale iMX3* OpenOCD NAND Flash controller support.
 *
 * Many thanks to Ben Dooks for writing s3c24xx driver.
 */

/*
driver tested with STMicro NAND512W3A @imx31
tested "nand probe #", "nand erase # 0 #", "nand dump # file 0 #", "nand write # file 0"
get_next_halfword_from_sram_buffer() not tested
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "imp.h"
#include "mx3.h"
#include <target/target.h>

static const char target_not_halted_err_msg[] =
	"target must be halted to use mx3 NAND flash controller";
static const char data_block_size_err_msg[] =
	"minimal granularity is one half-word, %" PRId32 " is incorrect";
static const char sram_buffer_bounds_err_msg[] =
	"trying to access out of SRAM buffer bound (addr=0x%" PRIx32 ")";
static const char get_status_register_err_msg[] = "can't get NAND status";
static uint32_t in_sram_address;
static unsigned char sign_of_sequental_byte_read;

static int test_iomux_settings (struct target * target, uint32_t value,
				uint32_t mask, const char *text);
static int initialize_nf_controller (struct nand_device *nand);
static int get_next_byte_from_sram_buffer (struct target * target, uint8_t * value);
static int get_next_halfword_from_sram_buffer (struct target * target,
					       uint16_t * value);
static int poll_for_complete_op (struct target * target, const char *text);
static int validate_target_state (struct nand_device *nand);
static int do_data_output (struct nand_device *nand);

static int imx31_command (struct nand_device *nand, uint8_t command);
static int imx31_address (struct nand_device *nand, uint8_t address);

NAND_DEVICE_COMMAND_HANDLER(imx31_nand_device_command)
{
	struct mx3_nf_controller *mx3_nf_info;
	mx3_nf_info = malloc (sizeof (struct mx3_nf_controller));
	if (mx3_nf_info == NULL)
	{
	    LOG_ERROR ("no memory for nand controller");
	    return ERROR_FAIL;
	}

	nand->controller_priv = mx3_nf_info;

	if (CMD_ARGC < 3)
	{
	    LOG_ERROR ("use \"nand device imx31 target noecc|hwecc\"");
	    return ERROR_FAIL;
	}
	/*
	* check hwecc requirements
	*/
	{
	int hwecc_needed;
	hwecc_needed = strcmp (CMD_ARGV[2], "hwecc");
	if (hwecc_needed == 0)
	    {
		mx3_nf_info->flags.hw_ecc_enabled = 1;
	    }
	else
	    {
		mx3_nf_info->flags.hw_ecc_enabled = 0;
	    }
	}

	mx3_nf_info->optype = MX3_NF_DATAOUT_PAGE;
	mx3_nf_info->fin = MX3_NF_FIN_NONE;
	mx3_nf_info->flags.target_little_endian =
	(nand->target->endianness == TARGET_LITTLE_ENDIAN);
	/*
	* testing host endianness
	*/
	{
	int x = 1;
	if (*(char *) &x == 1)
	    {
		mx3_nf_info->flags.host_little_endian = 1;
	    }
	else
	    {
		mx3_nf_info->flags.host_little_endian = 0;
	    }
	}
	return ERROR_OK;
}

static int imx31_init (struct nand_device *nand)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;

	{
	/*
	 * validate target state
	 */
	int validate_target_result;
	validate_target_result = validate_target_state(nand);
	if (validate_target_result != ERROR_OK)
	    {
		return validate_target_result;
	    }
	}

	{
	uint16_t buffsize_register_content;
	target_read_u16 (target, MX3_NF_BUFSIZ, &buffsize_register_content);
	mx3_nf_info->flags.one_kb_sram = !(buffsize_register_content & 0x000f);
	}

	{
	uint32_t pcsr_register_content;
	target_read_u32 (target, MX3_PCSR, &pcsr_register_content);
	if (!nand->bus_width)
	    {
		nand->bus_width =
		    (pcsr_register_content & 0x80000000) ? 16 : 8;
	    }
	else
	    {
		pcsr_register_content |=
		    ((nand->bus_width == 16) ? 0x80000000 : 0x00000000);
		target_write_u32 (target, MX3_PCSR, pcsr_register_content);
	    }

	if (!nand->page_size)
	    {
		nand->page_size =
		    (pcsr_register_content & 0x40000000) ? 2048 : 512;
	    }
	else
	    {
		pcsr_register_content |=
		    ((nand->page_size == 2048) ? 0x40000000 : 0x00000000);
		target_write_u32 (target, MX3_PCSR, pcsr_register_content);
	    }
	if (mx3_nf_info->flags.one_kb_sram && (nand->page_size == 2048))
	    {
		LOG_ERROR
		    ("NAND controller have only 1 kb SRAM, so pagesize 2048 is incompatible with it");
	    }
	}

	{
	uint32_t cgr_register_content;
	target_read_u32 (target, MX3_CCM_CGR2, &cgr_register_content);
	if (!(cgr_register_content & 0x00000300))
	    {
		LOG_ERROR ("clock gating to EMI disabled");
		return ERROR_FAIL;
	    }
	}

	{
	uint32_t gpr_register_content;
	target_read_u32 (target, MX3_GPR, &gpr_register_content);
	if (gpr_register_content & 0x00000060)
	    {
		LOG_ERROR ("pins mode overrided by GPR");
		return ERROR_FAIL;
	    }
	}

	{
	/*
	 * testing IOMUX settings; must be in "functional-mode output and
	 * functional-mode input" mode
	 */
	int test_iomux;
	test_iomux = ERROR_OK;
	test_iomux |=
	    test_iomux_settings (target, 0x43fac0c0, 0x7f7f7f00, "d0,d1,d2");
	test_iomux |=
	    test_iomux_settings (target, 0x43fac0c4, 0x7f7f7f7f, "d3,d4,d5,d6");
	test_iomux |=
	    test_iomux_settings (target, 0x43fac0c8, 0x0000007f, "d7");
	if (nand->bus_width == 16)
	    {
		test_iomux |=
		    test_iomux_settings (target, 0x43fac0c8, 0x7f7f7f00,
					 "d8,d9,d10");
		test_iomux |=
		    test_iomux_settings (target, 0x43fac0cc, 0x7f7f7f7f,
					 "d11,d12,d13,d14");
		test_iomux |=
		    test_iomux_settings (target, 0x43fac0d0, 0x0000007f, "d15");
	    }
	test_iomux |=
	    test_iomux_settings (target, 0x43fac0d0, 0x7f7f7f00,
				 "nfwp,nfce,nfrb");
	test_iomux |=
	    test_iomux_settings (target, 0x43fac0d4, 0x7f7f7f7f,
				 "nfwe,nfre,nfale,nfcle");
	if (test_iomux != ERROR_OK)
	    {
		return ERROR_FAIL;
	    }
	}

	initialize_nf_controller (nand);

	{
	int retval;
	uint16_t nand_status_content;
	retval = ERROR_OK;
	retval |= imx31_command (nand, NAND_CMD_STATUS);
	retval |= imx31_address (nand, 0x00);
	retval |= do_data_output (nand);
	if (retval != ERROR_OK)
	    {
		LOG_ERROR (get_status_register_err_msg);
		return ERROR_FAIL;
	    }
	target_read_u16 (target, MX3_NF_MAIN_BUFFER0, &nand_status_content);
	if (!(nand_status_content & 0x0080))
	    {
		/*
		 * is host-big-endian correctly ??
		 */
		LOG_INFO ("NAND read-only");
		mx3_nf_info->flags.nand_readonly = 1;
	    }
	else
	    {
		mx3_nf_info->flags.nand_readonly = 0;
	    }
	}
	return ERROR_OK;
}

static int imx31_read_data (struct nand_device *nand, void *data)
{
	struct target *target = nand->target;
	{
	/*
	 * validate target state
	 */
	int validate_target_result;
	validate_target_result = validate_target_state (nand);
	if (validate_target_result != ERROR_OK)
	    {
		return validate_target_result;
	    }
	}

	{
	/*
	 * get data from nand chip
	 */
	int try_data_output_from_nand_chip;
	try_data_output_from_nand_chip = do_data_output (nand);
	if (try_data_output_from_nand_chip != ERROR_OK)
	    {
		return try_data_output_from_nand_chip;
	    }
	}

	if (nand->bus_width == 16)
	{
	    get_next_halfword_from_sram_buffer (target, data);
	}
	else
	{
	    get_next_byte_from_sram_buffer (target, data);
	}

	return ERROR_OK;
}

static int imx31_write_data (struct nand_device *nand, uint16_t data)
{
	LOG_ERROR ("write_data() not implemented");
	return ERROR_NAND_OPERATION_FAILED;
}

static int imx31_reset (struct nand_device *nand)
{
	/*
	* validate target state
	*/
	int validate_target_result;
	validate_target_result = validate_target_state (nand);
	if (validate_target_result != ERROR_OK)
	{
	    return validate_target_result;
	}
	initialize_nf_controller (nand);
	return ERROR_OK;
}

static int imx31_command (struct nand_device *nand, uint8_t command)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;
	{
	/*
	 * validate target state
	 */
	int validate_target_result;
	validate_target_result = validate_target_state (nand);
	if (validate_target_result != ERROR_OK)
	    {
		return validate_target_result;
	    }
	}

	switch (command)
	{
	    case NAND_CMD_READOOB:
		command = NAND_CMD_READ0;
		in_sram_address = MX3_NF_SPARE_BUFFER0;	/* set read point for
							 * data_read() and
							 * read_block_data() to
							 * spare area in SRAM
							 * buffer */
		break;
	    case NAND_CMD_READ1:
		command = NAND_CMD_READ0;
		/*
		 * offset == one half of page size
		 */
		in_sram_address =
		    MX3_NF_MAIN_BUFFER0 + (nand->page_size >> 1);
	    default:
		in_sram_address = MX3_NF_MAIN_BUFFER0;
	}

	target_write_u16 (target, MX3_NF_FCMD, command);
	/*
	* start command input operation (set MX3_NF_BIT_OP_DONE==0)
	*/
	target_write_u16 (target, MX3_NF_CFG2, MX3_NF_BIT_OP_FCI);
	{
	int poll_result;
	poll_result = poll_for_complete_op (target, "command");
	if (poll_result != ERROR_OK)
	    {
		return poll_result;
	    }
	}
	/*
	* reset cursor to begin of the buffer
	*/
	sign_of_sequental_byte_read = 0;
	switch (command)
	{
	    case NAND_CMD_READID:
		mx3_nf_info->optype = MX3_NF_DATAOUT_NANDID;
		mx3_nf_info->fin = MX3_NF_FIN_DATAOUT;
		break;
	    case NAND_CMD_STATUS:
		mx3_nf_info->optype = MX3_NF_DATAOUT_NANDSTATUS;
		mx3_nf_info->fin = MX3_NF_FIN_DATAOUT;
		break;
	    case NAND_CMD_READ0:
		mx3_nf_info->fin = MX3_NF_FIN_DATAOUT;
		mx3_nf_info->optype = MX3_NF_DATAOUT_PAGE;
		break;
	    default:
		mx3_nf_info->optype = MX3_NF_DATAOUT_PAGE;
	}
	return ERROR_OK;
}

static int imx31_address (struct nand_device *nand, uint8_t address)
{
	struct target *target = nand->target;
	{
	/*
	 * validate target state
	 */
	int validate_target_result;
	validate_target_result = validate_target_state (nand);
	if (validate_target_result != ERROR_OK)
	    {
		return validate_target_result;
	    }
	}

	target_write_u16 (target, MX3_NF_FADDR, address);
	/*
	* start address input operation (set MX3_NF_BIT_OP_DONE==0)
	*/
	target_write_u16 (target, MX3_NF_CFG2, MX3_NF_BIT_OP_FAI);
	{
	int poll_result;
	poll_result = poll_for_complete_op (target, "address");
	if (poll_result != ERROR_OK)
	    {
		return poll_result;
	    }
	}
	return ERROR_OK;
}

static int imx31_nand_ready (struct nand_device *nand, int tout)
{
	uint16_t poll_complete_status;
	struct target *target = nand->target;

	{
	/*
	 * validate target state
	 */
	int validate_target_result;
	validate_target_result = validate_target_state (nand);
	if (validate_target_result != ERROR_OK)
	    {
		return validate_target_result;
	    }
	}

	do
	{
	    target_read_u16 (target, MX3_NF_CFG2, &poll_complete_status);
	    if (poll_complete_status & MX3_NF_BIT_OP_DONE)
		{
		    return tout;
		}
	    alive_sleep (1);
	}
	while (tout-- > 0);
	return tout;
}

static int imx31_write_page (struct nand_device *nand, uint32_t page,
			     uint8_t * data, uint32_t data_size, uint8_t * oob,
			     uint32_t oob_size)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;

	if (data_size % 2)
	{
	    LOG_ERROR (data_block_size_err_msg, data_size);
	    return ERROR_NAND_OPERATION_FAILED;
	}
	if (oob_size % 2)
	{
	    LOG_ERROR (data_block_size_err_msg, oob_size);
	    return ERROR_NAND_OPERATION_FAILED;
	}
	if (!data)
	{
	    LOG_ERROR ("nothing to program");
	    return ERROR_NAND_OPERATION_FAILED;
	}
	{
	/*
	 * validate target state
	 */
	int retval;
	retval = validate_target_state (nand);
	if (retval != ERROR_OK)
	    {
		return retval;
	    }
	}
	{
	int retval = ERROR_OK;
	retval |= imx31_command(nand, NAND_CMD_SEQIN);
	retval |= imx31_address(nand, 0x00);
	retval |= imx31_address(nand, page & 0xff);
	retval |= imx31_address(nand, (page >> 8) & 0xff);
	if (nand->address_cycles >= 4)
	    {
		retval |= imx31_address (nand, (page >> 16) & 0xff);
		if (nand->address_cycles >= 5)
		    {
			retval |= imx31_address (nand, (page >> 24) & 0xff);
		    }
	    }
	target_write_buffer (target, MX3_NF_MAIN_BUFFER0, data_size, data);
	if (oob)
	    {
		if (mx3_nf_info->flags.hw_ecc_enabled)
		    {
			/*
			 * part of spare block will be overrided by hardware
			 * ECC generator
			 */
			LOG_DEBUG
			    ("part of spare block will be overrided by hardware ECC generator");
		    }
		target_write_buffer (target, MX3_NF_SPARE_BUFFER0, oob_size,
				     oob);
	    }
	/*
	 * start data input operation (set MX3_NF_BIT_OP_DONE==0)
	 */
	target_write_u16 (target, MX3_NF_CFG2, MX3_NF_BIT_OP_FDI);
	{
	    int poll_result;
	    poll_result = poll_for_complete_op (target, "data input");
	    if (poll_result != ERROR_OK)
		{
		    return poll_result;
		}
	}
	retval |= imx31_command (nand, NAND_CMD_PAGEPROG);
	if (retval != ERROR_OK)
	    {
		return retval;
	    }

	/*
	 * check status register
	 */
	{
	    uint16_t nand_status_content;
	    retval = ERROR_OK;
	    retval |= imx31_command(nand, NAND_CMD_STATUS);
	    retval |= imx31_address(nand, 0x00);
	    retval |= do_data_output(nand);
	    if (retval != ERROR_OK)
		{
		    LOG_ERROR (get_status_register_err_msg);
		    return retval;
		}
	    target_read_u16 (target, MX3_NF_MAIN_BUFFER0, &nand_status_content);
	    if (nand_status_content & 0x0001)
		{
		    /*
		     * is host-big-endian correctly ??
		     */
		    return ERROR_NAND_OPERATION_FAILED;
		}
	}
	}
	return ERROR_OK;
}

static int imx31_read_page (struct nand_device *nand, uint32_t page,
			    uint8_t * data, uint32_t data_size, uint8_t * oob,
			    uint32_t oob_size)
{
	struct target *target = nand->target;

	if (data_size % 2)
	{
	    LOG_ERROR (data_block_size_err_msg, data_size);
	    return ERROR_NAND_OPERATION_FAILED;
	}
	if (oob_size % 2)
	{
	    LOG_ERROR (data_block_size_err_msg, oob_size);
	    return ERROR_NAND_OPERATION_FAILED;
	}

	{
	/*
	 * validate target state
	 */
	int retval;
	retval = validate_target_state(nand);
	if (retval != ERROR_OK)
	    {
		return retval;
	    }
	}
	{
	int retval = ERROR_OK;
	retval |= imx31_command(nand, NAND_CMD_READ0);
	retval |= imx31_address(nand, 0x00);
	retval |= imx31_address(nand, page & 0xff);
	retval |= imx31_address(nand, (page >> 8) & 0xff);
	if (nand->address_cycles >= 4)
	    {
		retval |= imx31_address(nand, (page >> 16) & 0xff);
		if (nand->address_cycles >= 5)
		    {
			retval |= imx31_address(nand, (page >> 24) & 0xff);
			retval |= imx31_command(nand, NAND_CMD_READSTART);
		    }
	    }
	retval |= do_data_output (nand);
	if (retval != ERROR_OK)
	    {
		return retval;
	    }

	if (data)
	    {
		target_read_buffer (target, MX3_NF_MAIN_BUFFER0, data_size,
				    data);
	    }
	if (oob)
	    {
		target_read_buffer (target, MX3_NF_SPARE_BUFFER0, oob_size,
				    oob);
	    }
	}
	return ERROR_OK;
}

static int test_iomux_settings (struct target * target, uint32_t address,
				uint32_t mask, const char *text)
{
	uint32_t register_content;
	target_read_u32 (target, address, &register_content);
	if ((register_content & mask) != (0x12121212 & mask))
	{
	    LOG_ERROR ("IOMUX for {%s} is bad", text);
	    return ERROR_FAIL;
	}
	return ERROR_OK;
}

static int initialize_nf_controller (struct nand_device *nand)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;
	/*
	* resets NAND flash controller in zero time ? I dont know.
	*/
	target_write_u16 (target, MX3_NF_CFG1, MX3_NF_BIT_RESET_EN);
	{
	uint16_t work_mode;
	work_mode = MX3_NF_BIT_INT_DIS;	/* disable interrupt */
	if (target->endianness == TARGET_BIG_ENDIAN)
	    {
		work_mode |= MX3_NF_BIT_BE_EN;
	    }
	if (mx3_nf_info->flags.hw_ecc_enabled)
	    {
		work_mode |= MX3_NF_BIT_ECC_EN;
	    }
	target_write_u16 (target, MX3_NF_CFG1, work_mode);
	}
	/*
	* unlock SRAM buffer for write; 2 mean "Unlock", other values means "Lock"
	*/
	target_write_u16 (target, MX3_NF_BUFCFG, 2);
	{
	uint16_t temp;
	target_read_u16 (target, MX3_NF_FWP, &temp);
	if ((temp & 0x0007) == 1)
	    {
		LOG_ERROR ("NAND flash is tight-locked, reset needed");
		return ERROR_FAIL;
	    }

	}
	/*
	* unlock NAND flash for write
	*/
	target_write_u16 (target, MX3_NF_FWP, 4);
	target_write_u16 (target, MX3_NF_LOCKSTART, 0x0000);
	target_write_u16 (target, MX3_NF_LOCKEND, 0xFFFF);
	/*
	* 0x0000 means that first SRAM buffer @0xB800_0000 will be used
	*/
	target_write_u16 (target, MX3_NF_BUFADDR, 0x0000);
	/*
	* address of SRAM buffer
	*/
	in_sram_address = MX3_NF_MAIN_BUFFER0;
	sign_of_sequental_byte_read = 0;
	return ERROR_OK;
}

static int get_next_byte_from_sram_buffer (struct target * target, uint8_t * value)
{
	static uint8_t even_byte = 0;
	/*
	* host-big_endian ??
	*/
	if (sign_of_sequental_byte_read == 0)
	{
	    even_byte = 0;
	}
	if (in_sram_address > MX3_NF_LAST_BUFFER_ADDR)
	{
	    LOG_ERROR (sram_buffer_bounds_err_msg, in_sram_address);
	    *value = 0;
	    sign_of_sequental_byte_read = 0;
	    even_byte = 0;
	    return ERROR_NAND_OPERATION_FAILED;
	}
	else
	{
	    uint16_t temp;
	    target_read_u16 (target, in_sram_address, &temp);
	    if (even_byte)
		{
		    *value = temp >> 8;
		    even_byte = 0;
		    in_sram_address += 2;
		}
	    else
		{
		    *value = temp & 0xff;
		    even_byte = 1;
		}
	}
	sign_of_sequental_byte_read = 1;
	return ERROR_OK;
}

static int get_next_halfword_from_sram_buffer (struct target * target,
					       uint16_t * value)
{
	if (in_sram_address > MX3_NF_LAST_BUFFER_ADDR)
	{
	    LOG_ERROR (sram_buffer_bounds_err_msg, in_sram_address);
	    *value = 0;
	    return ERROR_NAND_OPERATION_FAILED;
	}
	else
	{
	    target_read_u16 (target, in_sram_address, value);
	    in_sram_address += 2;
	}
	return ERROR_OK;
}

static int poll_for_complete_op (struct target * target, const char *text)
{
	uint16_t poll_complete_status;
	for (int poll_cycle_count = 0; poll_cycle_count < 100; poll_cycle_count++)
	{
	    usleep (25);
	    target_read_u16 (target, MX3_NF_CFG2, &poll_complete_status);
	    if (poll_complete_status & MX3_NF_BIT_OP_DONE)
		{
		    break;
		}
	}
	if (!(poll_complete_status & MX3_NF_BIT_OP_DONE))
	{
	    LOG_ERROR ("%s sending timeout", text);
	    return ERROR_NAND_OPERATION_FAILED;
	}
	return ERROR_OK;
}

static int validate_target_state (struct nand_device *nand)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;

	if (target->state != TARGET_HALTED)
	{
	    LOG_ERROR (target_not_halted_err_msg);
	    return ERROR_NAND_OPERATION_FAILED;
	}

	if (mx3_nf_info->flags.target_little_endian !=
	(target->endianness == TARGET_LITTLE_ENDIAN))
	{
	    /*
	     * endianness changed after NAND controller probed
	     */
	    return ERROR_NAND_OPERATION_FAILED;
	}
	return ERROR_OK;
}

static int do_data_output (struct nand_device *nand)
{
	struct mx3_nf_controller *mx3_nf_info = nand->controller_priv;
	struct target *target = nand->target;
	switch (mx3_nf_info->fin)
	{
	    case MX3_NF_FIN_DATAOUT:
		/*
		 * start data output operation (set MX3_NF_BIT_OP_DONE==0)
		 */
		target_write_u16 (target, MX3_NF_CFG2,
				  MX3_NF_BIT_DATAOUT_TYPE (mx3_nf_info->
							   optype));
		{
		    int poll_result;
		    poll_result = poll_for_complete_op (target, "data output");
		    if (poll_result != ERROR_OK)
			{
			    return poll_result;
			}
		}
		mx3_nf_info->fin = MX3_NF_FIN_NONE;
		/*
		 * ECC stuff
		 */
		if ((mx3_nf_info->optype == MX3_NF_DATAOUT_PAGE)
		    && mx3_nf_info->flags.hw_ecc_enabled)
		    {
			uint16_t ecc_status;
			target_read_u16 (target, MX3_NF_ECCSTATUS, &ecc_status);
			switch (ecc_status & 0x000c)
			    {
				case 1 << 2:
				    LOG_DEBUG
					("main area readed with 1 (correctable) error");
				    break;
				case 2 << 2:
				    LOG_DEBUG
					("main area readed with more than 1 (incorrectable) error");
				    return ERROR_NAND_OPERATION_FAILED;
				    break;
			    }
			switch (ecc_status & 0x0003)
			    {
				case 1:
				    LOG_DEBUG
					("spare area readed with 1 (correctable) error");
				    break;
				case 2:
				    LOG_DEBUG
					("main area readed with more than 1 (incorrectable) error");
				    return ERROR_NAND_OPERATION_FAILED;
				    break;
			    }
		    }
		break;
	    case MX3_NF_FIN_NONE:
		break;
	}
	return ERROR_OK;
}

struct nand_flash_controller imx31_nand_flash_controller = {
		.name = "imx31",
		.nand_device_command = &imx31_nand_device_command,
		.init = &imx31_init,
		.reset = &imx31_reset,
		.command = &imx31_command,
		.address = &imx31_address,
		.write_data = &imx31_write_data,
		.read_data = &imx31_read_data,
		.write_page = &imx31_write_page,
		.read_page = &imx31_read_page,
		.nand_ready = &imx31_nand_ready,
	};