nand : Add Freescale iMX27 nand flash controller support

This patch add support of iMX27 nand flash controller. This is based on
driver for imx31 nand flash controller.
OOB functionality is not fully working. As in mx31 controller, mx2 NFC
has a bug that swap two bytes between SPARE and MAIN buffer.
I used this driver for several months and no problems appear.

4 files changed, 900 insertions, 0 deletions

diff --git a/src/flash/nand/Makefile.am b/src/flash/nand/Makefile.am
index a495dfdc..259a9cb6 100644
--- a/src/flash/nand/Makefile.am
+++ b/src/flash/nand/Makefile.am
@@ -18,6 +18,7 @@ NAND_DRIVERS = \
 	nonce.c \
 	davinci.c \
 	lpc3180.c \
+	mx2.c \
 	mx3.c \
 	orion.c \
 	s3c24xx.c \
@@ -35,6 +36,7 @@ noinst_HEADERS = \
 	fileio.h \
 	imp.h \
 	lpc3180.h \
+	mx2.h \
 	mx3.h \
 	s3c24xx.h \
 	s3c24xx_regs.h
diff --git a/src/flash/nand/driver.c b/src/flash/nand/driver.c
index 1c28dbc8..597d78a6 100644
--- a/src/flash/nand/driver.c
+++ b/src/flash/nand/driver.c
@@ -37,6 +37,7 @@ extern struct nand_flash_controller s3c2412_nand_controller;
 extern struct nand_flash_controller s3c2440_nand_controller;
 extern struct nand_flash_controller s3c2443_nand_controller;
 extern struct nand_flash_controller s3c6400_nand_controller;
+extern struct nand_flash_controller imx27_nand_flash_controller;
 extern struct nand_flash_controller imx31_nand_flash_controller;
 extern struct nand_flash_controller at91sam9_nand_controller;
 
@@ -53,6 +54,7 @@ static struct nand_flash_controller *nand_flash_controllers[] =
 	&s3c2440_nand_controller,
 	&s3c2443_nand_controller,
 	&s3c6400_nand_controller,
+	&imx27_nand_flash_controller,
 	&imx31_nand_flash_controller,
 	&at91sam9_nand_controller,
 /*	&boundary_scan_nand_controller, */
diff --git a/src/flash/nand/mx2.c b/src/flash/nand/mx2.c
new file mode 100644
index 00000000..83e1cb1c
--- /dev/null
+++ b/src/flash/nand/mx2.c
@@ -0,0 +1,776 @@
+/***************************************************************************
+ *   Copyright (C) 2009 by Alexei Babich                                   *
+ *   Rezonans plc., Chelyabinsk, Russia                                    *
+ *   impatt@mail.ru                                                        *
+ *                                                                         *
+ *   Copyright (C) 2010 by Gaetan CARLIER                                  *
+ *   Trump s.a., Belgium                                                   *
+ *                                                                         *
+ *   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 iMX2* OpenOCD NAND Flash controller support.
+ * based on Freescale iMX3* OpenOCD NAND Flash controller support.
+ */
+
+/*
+ * driver tested with Samsung K9F2G08UXA and Numonyx/ST NAND02G-B2D @imx27
+ * tested "nand probe #", "nand erase # 0 #", "nand dump # file 0 #", 
+ * "nand write # file 0", "nand verify"
+ *
+ * get_next_halfword_from_sram_buffer() not tested
+ * !! all function only tested with 2k page nand device; imx27_write_page
+ *    writes the 4 MAIN_BUFFER's and is not compatible with < 2k page
+ * !! oob must be be used due to NFS bug
+*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "imp.h"
+#include "mx2.h"
+#include <target/target.h>
+
+/* This permits to print (in LOG_INFO) how much bytes
+ * has been written after a page read or write.
+ * This is useful when OpenOCD is used with a graphical
+ * front-end to estimate progression of the global read/write
+ */
+#undef _MX2_PRINT_STAT
+//#define _MX2_PRINT_STAT
+
+static const char target_not_halted_err_msg[] =
+	"target must be halted to use mx2 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;
+unsigned char sign_of_sequental_byte_read;
+
+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 imx27_command(struct nand_device *nand, uint8_t command);
+static int imx27_address(struct nand_device *nand, uint8_t address);
+static int imx27_controller_ready(struct nand_device *nand, int tout);
+
+NAND_DEVICE_COMMAND_HANDLER(imx27_nand_device_command)
+{
+	struct mx2_nf_controller *mx2_nf_info;
+	int hwecc_needed;
+	int x;
+	mx2_nf_info = malloc(sizeof(struct mx2_nf_controller));
+	if (mx2_nf_info == NULL) {
+		LOG_ERROR("no memory for nand controller");
+		return ERROR_FAIL;
+	}
+
+	nand->controller_priv = mx2_nf_info;
+	mx2_nf_info->target = get_target(CMD_ARGV[1]);
+	if (mx2_nf_info->target == NULL) {
+		LOG_ERROR("target '%s' not defined", CMD_ARGV[1]);
+		return ERROR_FAIL;
+	}
+	if (CMD_ARGC < 3) {
+		LOG_ERROR("use \"nand device imx27 target noecc|hwecc\"");
+		return ERROR_FAIL;
+	}
+	/*
+	 * check hwecc requirements
+	 */
+
+	hwecc_needed = strcmp(CMD_ARGV[2], "hwecc");
+	if (hwecc_needed == 0) 
+		mx2_nf_info->flags.hw_ecc_enabled = 1;
+	else
+		mx2_nf_info->flags.hw_ecc_enabled = 0;
+
+	mx2_nf_info->optype = MX2_NF_DATAOUT_PAGE;
+	mx2_nf_info->fin = MX2_NF_FIN_NONE;
+	mx2_nf_info->flags.target_little_endian =
+	(mx2_nf_info->target->endianness == TARGET_LITTLE_ENDIAN);
+	/*
+	 * testing host endianess
+	 */
+	x = 1;
+	if (*(char *) &x == 1)
+		mx2_nf_info->flags.host_little_endian = 1;
+	else
+		mx2_nf_info->flags.host_little_endian = 0;
+	return ERROR_OK;
+}
+
+static int imx27_init(struct nand_device *nand)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+
+	int validate_target_result;
+	uint16_t buffsize_register_content;
+	uint32_t pcsr_register_content;
+	int retval;
+	uint16_t nand_status_content;
+	/*
+	 * validate target state
+	 */
+	validate_target_result = validate_target_state(nand);
+	if (validate_target_result != ERROR_OK)
+		return validate_target_result;
+
+	target_read_u16(target, MX2_NF_BUFSIZ, &buffsize_register_content);
+	mx2_nf_info->flags.one_kb_sram = !(buffsize_register_content & 0x000f);
+
+	target_read_u32(target, MX2_FMCR, &pcsr_register_content);
+	if (!nand->bus_width) {
+		/* bus_width not yet defined. Read it from MX2_FMCR */
+		nand->bus_width =
+		    (pcsr_register_content & MX2_FMCR_NF_16BIT_SEL) ? 16 : 8;
+	} else {
+		/* bus_width forced in soft. Sync it to MX2_FMCR */
+		pcsr_register_content |=
+		    ((nand->bus_width == 16) ? MX2_FMCR_NF_16BIT_SEL : 0x00000000);
+		target_write_u32(target, MX2_FMCR, pcsr_register_content);
+	}
+	if (nand->bus_width == 16)
+		LOG_DEBUG("MX2_NF : bus is 16-bit width");
+	else
+		LOG_DEBUG("MX2_NF : bus is 8-bit width");
+
+	if (!nand->page_size) {
+		nand->page_size =
+		    (pcsr_register_content & MX2_FMCR_NF_FMS) ? 2048 : 512;
+	} else {
+		pcsr_register_content |=
+		    ((nand->page_size == 2048) ? MX2_FMCR_NF_FMS : 0x00000000);
+		target_write_u32(target, MX2_FMCR, pcsr_register_content);
+	}
+	if (mx2_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");
+	} else {
+		LOG_DEBUG("MX2_NF : NAND controller can handle pagesize of 2048");
+	}
+
+	initialize_nf_controller(nand);
+
+	retval = ERROR_OK;
+	retval |= imx27_command(nand, NAND_CMD_STATUS);
+	retval |= imx27_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, MX2_NF_MAIN_BUFFER0, &nand_status_content);
+	if (!(nand_status_content & 0x0080)) {
+		LOG_INFO("NAND read-only");
+		mx2_nf_info->flags.nand_readonly = 1;
+	} else {
+		mx2_nf_info->flags.nand_readonly = 0;
+	}
+	return ERROR_OK;
+}
+
+static int imx27_read_data(struct nand_device *nand, void *data)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int validate_target_result;
+	int try_data_output_from_nand_chip;
+	/*
+	 * validate target state
+	 */
+	validate_target_result = validate_target_state(nand);
+	if (validate_target_result != ERROR_OK)
+		return validate_target_result;
+
+	/*
+	 * get data from nand chip
+	 */
+	try_data_output_from_nand_chip = do_data_output(nand);
+	if (try_data_output_from_nand_chip != ERROR_OK) {
+		LOG_ERROR("imx27_read_data : read data failed : '%x'",
+		          try_data_output_from_nand_chip);
+		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 imx27_write_data(struct nand_device *nand, uint16_t data)
+{
+	LOG_ERROR("write_data() not implemented");
+	return ERROR_NAND_OPERATION_FAILED;
+}
+
+static int imx27_nand_ready(struct nand_device *nand, int timeout)
+{
+	return imx27_controller_ready(nand, timeout);
+}
+
+static int imx27_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 imx27_command(struct nand_device *nand, uint8_t command)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int validate_target_result;
+	int poll_result;
+	/*
+	 * validate target state
+	 */
+	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;
+		/* set read point for data_read() and read_block_data() to
+		 * spare area in SRAM buffer
+		 */
+		in_sram_address = MX2_NF_SPARE_BUFFER0;	
+		break;
+	case NAND_CMD_READ1:
+		command = NAND_CMD_READ0;
+		/*
+		 * offset == one half of page size
+		 */
+		in_sram_address =
+		    MX2_NF_MAIN_BUFFER0 + (nand->page_size >> 1);
+		break;
+	default:
+		in_sram_address = MX2_NF_MAIN_BUFFER0;
+		break;
+	}
+
+	target_write_u16(target, MX2_NF_FCMD, command);
+	/*
+	 * start command input operation (set MX2_NF_BIT_OP_DONE==0)
+	 */
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FCI);
+	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;
+	/* Handle special read command and adjust NF_CFG2(FDO) */
+	switch(command) {
+	case NAND_CMD_READID:
+		mx2_nf_info->optype = MX2_NF_DATAOUT_NANDID;
+		mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+		break;
+	case NAND_CMD_STATUS:
+		mx2_nf_info->optype = MX2_NF_DATAOUT_NANDSTATUS;
+		mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+                target_write_u16 (target, MX2_NF_BUFADDR, 0);
+                in_sram_address = 0;
+		break;
+	case NAND_CMD_READ0:
+		mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+		mx2_nf_info->optype = MX2_NF_DATAOUT_PAGE;
+		break;
+	default:
+		/* Ohter command use the default 'One page data out' FDO */
+		mx2_nf_info->optype = MX2_NF_DATAOUT_PAGE;
+		break;
+	}
+	return ERROR_OK;
+}
+
+static int imx27_address(struct nand_device *nand, uint8_t address)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int validate_target_result;
+	int poll_result;
+	/*
+	 * validate target state
+	 */
+	validate_target_result = validate_target_state(nand);
+	if (validate_target_result != ERROR_OK)
+		return validate_target_result;
+
+	target_write_u16(target, MX2_NF_FADDR, address);
+	/*
+	 * start address input operation (set MX2_NF_BIT_OP_DONE==0)
+	 */
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FAI);
+	poll_result = poll_for_complete_op(target, "address");
+	if (poll_result != ERROR_OK)
+		return poll_result;
+
+	return ERROR_OK;
+}
+
+static int imx27_controller_ready(struct nand_device *nand, int tout)
+{
+	uint16_t poll_complete_status;
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int validate_target_result;
+
+	/*
+	 * validate target state
+	 */
+	validate_target_result = validate_target_state(nand);
+	if (validate_target_result != ERROR_OK)
+		return validate_target_result;
+
+	do {
+		target_read_u16(target, MX2_NF_CFG2, &poll_complete_status);
+		if (poll_complete_status & MX2_NF_BIT_OP_DONE)
+			return tout;
+
+		alive_sleep(1);
+	}
+	while (tout-- > 0);
+	return tout;
+}
+
+static int imx27_write_page(struct nand_device *nand, uint32_t page,
+			     uint8_t * data, uint32_t data_size, uint8_t * oob,
+			     uint32_t oob_size)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int retval;
+	uint16_t nand_status_content;
+	uint16_t swap1, swap2, new_swap1;
+	int poll_result;
+	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
+	 */
+	retval = validate_target_state(nand);
+	if (retval != ERROR_OK)
+		return retval;
+
+	in_sram_address = MX2_NF_MAIN_BUFFER0;
+	sign_of_sequental_byte_read = 0;
+	retval = ERROR_OK;
+	retval |= imx27_command(nand, NAND_CMD_SEQIN);
+	retval |= imx27_address(nand, 0); //col
+	retval |= imx27_address(nand, 0); //col
+	retval |= imx27_address(nand, page & 0xff); //page address
+	retval |= imx27_address(nand, (page >> 8) & 0xff); //page address
+	retval |= imx27_address(nand, (page >> 16) & 0xff); //page address
+	
+	target_write_buffer(target, MX2_NF_MAIN_BUFFER0, data_size, data);
+	if (oob) {
+		if (mx2_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, MX2_NF_SPARE_BUFFER0, oob_size,
+		                    oob);
+	}
+	//BI-swap -  work-around of imx27 NFC for NAND device with page == 2kb
+	target_read_u16(target, MX2_NF_MAIN_BUFFER3 + 464, &swap1);
+	if (oob) {
+		LOG_ERROR("Due to NFC Bug, oob is not correctly implemented "
+		          "in mx2 driver");
+		return ERROR_NAND_OPERATION_FAILED;
+	}
+	//target_read_u16 (target, MX2_NF_SPARE_BUFFER3 + 4, &swap2);
+	swap2 = 0xffff;  //Spare buffer unused forced to 0xffff
+        new_swap1 = (swap1 & 0xFF00) | (swap2 >> 8);
+        swap2 = (swap1 << 8) | (swap2 & 0xFF);
+
+	target_write_u16(target, MX2_NF_MAIN_BUFFER3 + 464, new_swap1);
+	target_write_u16(target, MX2_NF_SPARE_BUFFER3 + 4, swap2);
+	/*
+	 * start data input operation (set MX2_NF_BIT_OP_DONE==0)
+	 */
+	target_write_u16(target, MX2_NF_BUFADDR, 0);
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FDI);
+	poll_result = poll_for_complete_op(target, "data input");
+	if (poll_result != ERROR_OK)
+		return poll_result;
+	
+	target_write_u16(target, MX2_NF_BUFADDR, 1);
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FDI);
+	poll_result = poll_for_complete_op(target, "data input");
+	if (poll_result != ERROR_OK)
+		return poll_result;
+	
+	target_write_u16(target, MX2_NF_BUFADDR, 2);
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FDI);
+	poll_result = poll_for_complete_op(target, "data input");
+	if (poll_result != ERROR_OK)
+		return poll_result;
+	
+	target_write_u16(target, MX2_NF_BUFADDR, 3);
+	target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_OP_FDI);
+	poll_result = poll_for_complete_op(target, "data input");
+	if (poll_result != ERROR_OK)
+		return poll_result;
+
+	retval |= imx27_command(nand, NAND_CMD_PAGEPROG);
+	if (retval != ERROR_OK)
+		return retval;
+
+	/*
+	 * check status register
+	 */
+        retval = ERROR_OK;
+        retval |= imx27_command(nand, NAND_CMD_STATUS);
+        target_write_u16 (target, MX2_NF_BUFADDR, 0);
+        mx2_nf_info->optype = MX2_NF_DATAOUT_NANDSTATUS;
+        mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+        retval |= do_data_output(nand);
+        if (retval != ERROR_OK) {
+                LOG_ERROR (get_status_register_err_msg);
+                return retval;
+        }
+        target_read_u16 (target, MX2_NF_MAIN_BUFFER0, &nand_status_content);
+        if (nand_status_content & 0x0001) {
+                /*
+                 * page not correctly written
+                 */
+                return ERROR_NAND_OPERATION_FAILED;
+        }
+#ifdef _MX2_PRINT_STAT
+	LOG_INFO("%d bytes newly written", data_size);
+#endif
+	return ERROR_OK;
+}
+
+static int imx27_read_page(struct nand_device *nand, uint32_t page,
+			    uint8_t * data, uint32_t data_size, uint8_t * oob,
+			    uint32_t oob_size)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int retval;
+	uint16_t swap1, swap2, new_swap1;
+	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
+	 */
+	retval = validate_target_state(nand);
+	if (retval != ERROR_OK) {
+		return retval;
+	}
+	/* Reset address_cycles before imx27_command ?? */
+	retval = ERROR_OK;
+	retval |= imx27_command(nand, NAND_CMD_READ0);
+
+	retval |= imx27_address(nand, 0); //col
+	retval |= imx27_address(nand, 0); //col
+	retval |= imx27_address(nand, page & 0xff); //page address
+	retval |= imx27_address(nand, (page >> 8) & 0xff); //page address
+	retval |= imx27_address(nand, (page >> 16) & 0xff); //page address
+	retval |= imx27_command(nand, NAND_CMD_READSTART);
+
+	target_write_u16(target, MX2_NF_BUFADDR, 0);
+	mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+	retval = do_data_output(nand);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("MX2_NF : Error reading page 0");
+		return retval;
+	}
+	//Test nand page size to know how much MAIN_BUFFER must be written
+	target_write_u16(target, MX2_NF_BUFADDR, 1);
+	mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+	retval = do_data_output(nand);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("MX2_NF : Error reading page 1");
+		return retval;
+	}
+	target_write_u16(target, MX2_NF_BUFADDR, 2);
+	mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+	retval = do_data_output(nand);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("MX2_NF : Error reading page 2");
+		return retval;
+	}
+	target_write_u16(target, MX2_NF_BUFADDR, 3);
+	mx2_nf_info->fin = MX2_NF_FIN_DATAOUT;
+	retval = do_data_output(nand);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("MX2_NF : Error reading page 3");
+		return retval;
+	}
+	//BI-swap -  work-around of imx27 NFC for NAND device with page == 2k
+	target_read_u16(target, MX2_NF_MAIN_BUFFER3 + 464, &swap1);
+	target_read_u16(target, MX2_NF_SPARE_BUFFER3 + 4, &swap2);
+        new_swap1 = (swap1 & 0xFF00) | (swap2 >> 8);
+        swap2 = (swap1 << 8) | (swap2 & 0xFF);
+	target_write_u16(target, MX2_NF_MAIN_BUFFER3 + 464, new_swap1);
+	target_write_u16(target, MX2_NF_SPARE_BUFFER3 + 4, swap2);
+
+	if (data)
+		target_read_buffer(target, MX2_NF_MAIN_BUFFER0, data_size, data);
+	if (oob)
+		target_read_buffer(target, MX2_NF_SPARE_BUFFER0, oob_size,
+		                    oob);
+#ifdef _MX2_PRINT_STAT
+	if (data_size > 0) {
+		/* When Operation Status is read (when page is erased),
+		 * this function is used but data_size is null.
+		 */
+		LOG_INFO("%d bytes newly read", data_size);
+	}
+#endif
+	return ERROR_OK;
+}
+
+static int initialize_nf_controller(struct nand_device *nand)
+{
+	struct mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	uint16_t work_mode;
+	uint16_t temp;
+	/*
+	 * resets NAND flash controller in zero time ? I dont know.
+	 */
+	target_write_u16(target, MX2_NF_CFG1, MX2_NF_BIT_RESET_EN);
+	work_mode = MX2_NF_BIT_INT_DIS;	/* disable interrupt */
+	if (target->endianness == TARGET_BIG_ENDIAN) {
+		LOG_DEBUG("MX2_NF : work in Big Endian mode");
+		work_mode |= MX2_NF_BIT_BE_EN;
+	} else {
+		LOG_DEBUG("MX2_NF : work in Little Endian mode");
+	}
+	if (mx2_nf_info->flags.hw_ecc_enabled) {
+		LOG_DEBUG("MX2_NF : work with ECC mode");
+		work_mode |= MX2_NF_BIT_ECC_EN;
+	} else {
+		LOG_DEBUG("MX2_NF : work without ECC mode");
+	}
+	target_write_u16(target, MX2_NF_CFG1, work_mode);
+	/*
+	 * unlock SRAM buffer for write; 2 mean "Unlock", other values means "Lock"
+	 */
+	target_write_u16(target, MX2_NF_BUFCFG, 2);
+	target_read_u16(target, MX2_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, MX2_NF_FWP, 4);
+	target_write_u16(target, MX2_NF_LOCKSTART, 0x0000);
+	target_write_u16(target, MX2_NF_LOCKEND, 0xFFFF);
+	/*
+	 * 0x0000 means that first SRAM buffer @0xD800_0000 will be used
+	 */
+	target_write_u16(target, MX2_NF_BUFADDR, 0x0000);
+	/*
+	 * address of SRAM buffer
+	 */
+	in_sram_address = MX2_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;
+	uint16_t temp;
+	/*
+	 * host-big_endian ??
+	 */
+	if (sign_of_sequental_byte_read == 0)
+		even_byte = 0;
+	
+	if (in_sram_address > MX2_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 {
+		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 > MX2_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++) {
+		target_read_u16(target, MX2_NF_CFG2, &poll_complete_status);
+		if (poll_complete_status & MX2_NF_BIT_OP_DONE)
+			break;
+
+		usleep(10);
+	}
+	if (!(poll_complete_status & MX2_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 mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+
+	if (target->state != TARGET_HALTED) {
+		LOG_ERROR(target_not_halted_err_msg);
+		return ERROR_NAND_OPERATION_FAILED;
+	}
+
+	if (mx2_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 mx2_nf_controller *mx2_nf_info = nand->controller_priv;
+	struct target *target = mx2_nf_info->target;
+	int poll_result;
+	uint16_t ecc_status;
+	switch(mx2_nf_info->fin) {
+	case MX2_NF_FIN_DATAOUT:
+		/*
+		 * start data output operation (set MX2_NF_BIT_OP_DONE==0)
+		 */
+		target_write_u16(target, MX2_NF_CFG2, MX2_NF_BIT_DATAOUT_TYPE(mx2_nf_info->optype));
+		poll_result = poll_for_complete_op(target, "data output");
+		if (poll_result != ERROR_OK)
+			return poll_result;
+
+		mx2_nf_info->fin = MX2_NF_FIN_NONE;
+		/*
+		 * ECC stuff
+		 */
+		if ((mx2_nf_info->optype == MX2_NF_DATAOUT_PAGE) && mx2_nf_info->flags.hw_ecc_enabled) {
+			target_read_u16(target, MX2_NF_ECCSTATUS, &ecc_status);
+			switch(ecc_status & 0x000c) {
+			case 1 << 2:
+				LOG_INFO("main area readed with 1 (correctable) error");
+				break;
+			case 2 << 2:
+				LOG_INFO("main area readed with more than 1 (incorrectable) error");
+				return ERROR_NAND_OPERATION_FAILED;
+		    		break;
+			}
+			switch(ecc_status & 0x0003) {
+			case 1:
+				LOG_INFO("spare area readed with 1 (correctable) error");
+				break;
+			case 2:
+				LOG_INFO("main area readed with more than 1 (incorrectable) error");
+				return ERROR_NAND_OPERATION_FAILED;
+				break;
+			}
+		}
+		break;
+	case MX2_NF_FIN_NONE:
+		break;
+	}
+	return ERROR_OK;
+}
+
+struct nand_flash_controller imx27_nand_flash_controller = {
+	.name			= "imx27",
+	.nand_device_command 	= &imx27_nand_device_command,
+	.init			= &imx27_init,
+	.reset			= &imx27_reset,
+	.command		= &imx27_command,
+	.address		= &imx27_address,
+	.write_data		= &imx27_write_data,
+	.read_data		= &imx27_read_data,
+	.write_page		= &imx27_write_page,
+	.read_page		= &imx27_read_page,
+	.controller_ready	= &imx27_controller_ready,
+	.nand_ready		= &imx27_nand_ready,
+};
diff --git a/src/flash/nand/mx2.h b/src/flash/nand/mx2.h
new file mode 100644
index 00000000..5d0b942d
--- /dev/null
+++ b/src/flash/nand/mx2.h
@@ -0,0 +1,120 @@
+
+/***************************************************************************
+ *   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 iMX2* OpenOCD NAND Flash controller support.
+ * based on Freescale iMX3* OpenOCD NAND Flash controller support.
+ *
+ * Many thanks to Ben Dooks for writing s3c24xx driver.
+ */
+
+#define		MX2_NF_BASE_ADDR		0xd8000000
+#define		MX2_NF_BUFSIZ			(MX2_NF_BASE_ADDR + 0xe00)
+#define		MX2_NF_BUFADDR			(MX2_NF_BASE_ADDR + 0xe04)
+#define		MX2_NF_FADDR			(MX2_NF_BASE_ADDR + 0xe06)
+#define		MX2_NF_FCMD				(MX2_NF_BASE_ADDR + 0xe08)
+#define		MX2_NF_BUFCFG			(MX2_NF_BASE_ADDR + 0xe0a)
+#define		MX2_NF_ECCSTATUS			(MX2_NF_BASE_ADDR + 0xe0c)
+#define		MX2_NF_ECCMAINPOS			(MX2_NF_BASE_ADDR + 0xe0e)
+#define		MX2_NF_ECCSPAREPOS			(MX2_NF_BASE_ADDR + 0xe10)
+#define		MX2_NF_FWP			(MX2_NF_BASE_ADDR + 0xe12)
+#define		MX2_NF_LOCKSTART			(MX2_NF_BASE_ADDR + 0xe14)
+#define		MX2_NF_LOCKEND			(MX2_NF_BASE_ADDR + 0xe16)
+#define		MX2_NF_FWPSTATUS			(MX2_NF_BASE_ADDR + 0xe18)
+ /*
+  * all bits not marked as self-clearing bit
+  */
+#define		MX2_NF_CFG1			(MX2_NF_BASE_ADDR + 0xe1a)
+#define		MX2_NF_CFG2			(MX2_NF_BASE_ADDR + 0xe1c)
+
+#define		MX2_NF_MAIN_BUFFER0		(MX2_NF_BASE_ADDR + 0x0000)
+#define		MX2_NF_MAIN_BUFFER1		(MX2_NF_BASE_ADDR + 0x0200)
+#define		MX2_NF_MAIN_BUFFER2		(MX2_NF_BASE_ADDR + 0x0400)
+#define		MX2_NF_MAIN_BUFFER3		(MX2_NF_BASE_ADDR + 0x0600)
+#define		MX2_NF_SPARE_BUFFER0	(MX2_NF_BASE_ADDR + 0x0800)
+#define		MX2_NF_SPARE_BUFFER1	(MX2_NF_BASE_ADDR + 0x0810)
+#define		MX2_NF_SPARE_BUFFER2	(MX2_NF_BASE_ADDR + 0x0820)
+#define		MX2_NF_SPARE_BUFFER3	(MX2_NF_BASE_ADDR + 0x0830)
+#define		MX2_NF_MAIN_BUFFER_LEN	512
+#define		MX2_NF_SPARE_BUFFER_LEN	16
+#define		MX2_NF_LAST_BUFFER_ADDR	((MX2_NF_SPARE_BUFFER3) + MX2_NF_SPARE_BUFFER_LEN - 2)
+
+/* bits in MX2_NF_CFG1 register */
+#define		MX2_NF_BIT_SPARE_ONLY_EN	(1<<2)
+#define		MX2_NF_BIT_ECC_EN			(1<<3)
+#define		MX2_NF_BIT_INT_DIS			(1<<4)
+#define		MX2_NF_BIT_BE_EN			(1<<5)
+#define		MX2_NF_BIT_RESET_EN			(1<<6)
+#define		MX2_NF_BIT_FORCE_CE			(1<<7)
+
+/* bits in MX2_NF_CFG2 register */
+
+/*Flash Command Input*/
+#define		MX2_NF_BIT_OP_FCI			(1<<0)
+ /*
+  * Flash Address Input
+  */
+#define		MX2_NF_BIT_OP_FAI			(1<<1)
+ /*
+  * Flash Data Input
+  */
+#define		MX2_NF_BIT_OP_FDI			(1<<2)
+
+/* see "enum mx_dataout_type" below */
+#define		MX2_NF_BIT_DATAOUT_TYPE(x)	((x)<<3)
+#define		MX2_NF_BIT_OP_DONE			(1<<15)
+
+#define		MX2_CCM_CGR2		0x53f80028
+#define		MX2_GPR				0x43fac008
+//#define		MX2_PCSR			0x53f8000c
+#define		MX2_FMCR			0x10027814
+#define		MX2_FMCR_NF_16BIT_SEL		(1<<4)
+#define		MX2_FMCR_NF_FMS			(1<<5)
+
+enum mx_dataout_type
+{
+	MX2_NF_DATAOUT_PAGE = 1,
+	MX2_NF_DATAOUT_NANDID = 2,
+	MX2_NF_DATAOUT_NANDSTATUS = 4,
+};
+enum mx_nf_finalize_action
+{
+	MX2_NF_FIN_NONE,
+	MX2_NF_FIN_DATAOUT,
+};
+
+struct mx2_nf_flags
+{
+	unsigned host_little_endian:1;
+	unsigned target_little_endian:1;
+	unsigned nand_readonly:1;
+	unsigned one_kb_sram:1;
+	unsigned hw_ecc_enabled:1;
+};
+
+struct mx2_nf_controller
+{
+	struct target *target;
+	enum mx_dataout_type optype;
+	enum mx_nf_finalize_action fin;
+	struct mx2_nf_flags flags;
+};