ralink: add mt7620 nand driver

This is a minor rework of the SDK driver. This driver needs a full rewrite.

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 38846

2 files changed, 2418 insertions, 0 deletions

diff --git a/target/linux/ramips/mt7620a/config-3.10 b/target/linux/ramips/mt7620a/config-3.10
index 62195bd198..21d5be1d52 100644
--- a/target/linux/ramips/mt7620a/config-3.10
+++ b/target/linux/ramips/mt7620a/config-3.10
@@ -96,6 +96,7 @@ CONFIG_MODULES_USE_ELF_REL=y
 # CONFIG_MTD_CFI_INTELEXT is not set
 CONFIG_MTD_CMDLINE_PARTS=y
 CONFIG_MTD_M25P80=y
+CONFIG_MTD_NAND_MT7620=y
 CONFIG_MTD_OF_PARTS=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_PHYSMAP_OF=y
diff --git a/target/linux/ramips/patches-3.10/0250-nand-7620.patch b/target/linux/ramips/patches-3.10/0250-nand-7620.patch
new file mode 100644
index 0000000000..c9a845d44d
--- /dev/null
+++ b/target/linux/ramips/patches-3.10/0250-nand-7620.patch
@@ -0,0 +1,2417 @@
+From a5fc495c8dc199ffa997d43331693a5b7ee07270 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Sun, 17 Nov 2013 17:41:46 +0100
+Subject: [PATCH] ralink: add mt7620 nand driver
+
+Signed-off-by: John Crispin <blogic@openwrt.org>
+---
+ drivers/mtd/maps/Kconfig       |    4 +
+ drivers/mtd/maps/Makefile      |    2 +
+ drivers/mtd/maps/ralink_nand.c | 2136 ++++++++++++++++++++++++++++++++++++++++
+ drivers/mtd/maps/ralink_nand.h |  232 +++++
+ drivers/mtd/nand/Makefile      |    2 +-
+ 5 files changed, 2375 insertions(+), 1 deletion(-)
+ create mode 100644 drivers/mtd/maps/ralink_nand.c
+ create mode 100644 drivers/mtd/maps/ralink_nand.h
+
+Index: linux-3.10.18/drivers/mtd/maps/Kconfig
+===================================================================
+--- linux-3.10.18.orig/drivers/mtd/maps/Kconfig	2013-11-17 17:50:02.049020043 +0100
++++ linux-3.10.18/drivers/mtd/maps/Kconfig	2013-11-17 17:51:50.545024547 +0100
+@@ -424,4 +424,8 @@
+ 
+           If compiled as a module, it will be called latch-addr-flash.
+ 
++config MTD_NAND_MT7620
++	tristate "Support for NAND on Mediatek MT7620"
++	depends on RALINK && SOC_MT7620
++
+ endmenu
+Index: linux-3.10.18/drivers/mtd/maps/Makefile
+===================================================================
+--- linux-3.10.18.orig/drivers/mtd/maps/Makefile	2013-11-17 17:50:02.049020043 +0100
++++ linux-3.10.18/drivers/mtd/maps/Makefile	2013-11-17 17:51:50.545024547 +0100
+@@ -46,3 +46,5 @@
+ obj-$(CONFIG_MTD_GPIO_ADDR)	+= gpio-addr-flash.o
+ obj-$(CONFIG_MTD_LATCH_ADDR)	+= latch-addr-flash.o
+ obj-$(CONFIG_MTD_LANTIQ)	+= lantiq-flash.o
++obj-$(CONFIG_MTD_NAND_MT7620)	+= ralink_nand.o
++
+Index: linux-3.10.18/drivers/mtd/maps/ralink_nand.c
+===================================================================
+--- /dev/null	1970-01-01 00:00:00.000000000 +0000
++++ linux-3.10.18/drivers/mtd/maps/ralink_nand.c	2013-11-17 17:51:50.549024547 +0100
+@@ -0,0 +1,2136 @@
++#define DEBUG
++#include <linux/device.h>
++#undef DEBUG
++#include <linux/slab.h>
++#include <linux/mtd/mtd.h>
++#include <linux/delay.h>
++#include <linux/module.h>
++#include <linux/interrupt.h>
++#include <linux/dma-mapping.h>
++#include <linux/mtd/partitions.h>
++#include <asm/io.h>
++#include <linux/delay.h>
++#include <linux/sched.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++
++#include "ralink_nand.h"
++#ifdef RANDOM_GEN_BAD_BLOCK
++#include <linux/random.h>
++#endif
++
++#define LARGE_MTD_BOOT_PART_SIZE       (CFG_BLOCKSIZE<<2)
++#define LARGE_MTD_CONFIG_PART_SIZE     (CFG_BLOCKSIZE<<2)
++#define LARGE_MTD_FACTORY_PART_SIZE    (CFG_BLOCKSIZE<<1)
++
++
++#define BLOCK_ALIGNED(a) ((a) & (CFG_BLOCKSIZE - 1))
++
++#define READ_STATUS_RETRY	1000
++
++struct mtd_info *ranfc_mtd = NULL;
++
++int skipbbt = 0;
++int ranfc_debug = 1;
++static int ranfc_bbt = 1;
++#if defined (WORKAROUND_RX_BUF_OV)
++static int ranfc_verify = 1;
++#endif
++static u32 nand_addrlen;
++
++#if 0
++module_param(ranfc_debug, int, 0644);
++module_param(ranfc_bbt, int, 0644);
++module_param(ranfc_verify, int, 0644);
++#endif
++
++#if 0
++#define ra_dbg(args...) do { if (ranfc_debug) printk(args); } while(0)
++#else
++#define ra_dbg(args...)
++#endif
++
++#define CLEAR_INT_STATUS()	ra_outl(NFC_INT_ST, ra_inl(NFC_INT_ST))
++#define NFC_TRANS_DONE()	(ra_inl(NFC_INT_ST) & INT_ST_ND_DONE)
++
++int is_nand_page_2048 = 0;
++const unsigned int nand_size_map[2][3] = {{25, 30, 30}, {20, 27, 30}};
++
++static int nfc_wait_ready(int snooze_ms);
++
++static const char * const mtk_probe_types[] = { "cmdlinepart", "ofpart", NULL };
++
++/**
++ * reset nand chip
++ */
++static int nfc_chip_reset(void)
++{
++	int status;
++
++	//ra_dbg("%s:\n", __func__);
++
++	// reset nand flash
++	ra_outl(NFC_CMD1, 0x0);
++	ra_outl(NFC_CMD2, 0xff);
++	ra_outl(NFC_ADDR, 0x0);
++	ra_outl(NFC_CONF, 0x0411);
++
++	status = nfc_wait_ready(5);  //erase wait 5us
++	if (status & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++	}
++	
++	return (int)(status & NAND_STATUS_FAIL);
++
++}
++
++
++
++/** 
++ * clear NFC and flash chip.
++ */
++static int nfc_all_reset(void)
++{
++	int retry;
++
++	ra_dbg("%s: \n", __func__);
++
++	// reset controller
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) | 0x02); //clear data buffer
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) & ~0x02); //clear data buffer
++
++	CLEAR_INT_STATUS();
++
++	retry = READ_STATUS_RETRY;
++	while ((ra_inl(NFC_INT_ST) & 0x02) != 0x02 && retry--);
++	if (retry <= 0) {
++		printk("nfc_all_reset: clean buffer fail \n");
++		return -1;
++	}
++
++	retry = READ_STATUS_RETRY;
++	while ((ra_inl(NFC_STATUS) & 0x1) != 0x0 && retry--) { //fixme, controller is busy ?
++		udelay(1);
++	}
++
++	nfc_chip_reset();
++
++	return 0;
++}
++
++/** NOTICE: only called by nfc_wait_ready().
++ * @return -1, nfc can not get transction done 
++ * @return 0, ok.
++ */
++static int _nfc_read_status(char *status)
++{
++	unsigned long cmd1, conf;
++	int int_st, nfc_st;
++	int retry;
++
++	cmd1 = 0x70;
++	conf = 0x000101 | (1 << 20);
++
++	//fixme, should we check nfc status?
++	CLEAR_INT_STATUS();
++
++	ra_outl(NFC_CMD1, cmd1); 	
++	ra_outl(NFC_CONF, conf); 
++
++	/* FIXME, 
++	 * 1. since we have no wired ready signal, directly 
++	 * calling this function is not gurantee to read right status under ready state.
++	 * 2. the other side, we can not determine how long to become ready, this timeout retry is nonsense.
++	 * 3. SUGGESTION: call nfc_read_status() from nfc_wait_ready(),
++	 * that is aware about caller (in sementics) and has snooze plused nfc ND_DONE.
++	 */
++	retry = READ_STATUS_RETRY; 
++	do {
++		nfc_st = ra_inl(NFC_STATUS);
++		int_st = ra_inl(NFC_INT_ST);
++		
++		ndelay(10);
++	} while (!(int_st & INT_ST_RX_BUF_RDY) && retry--);
++
++	if (!(int_st & INT_ST_RX_BUF_RDY)) {
++		printk("nfc_read_status: NFC fail, int_st(%x), retry:%x. nfc:%x, reset nfc and flash. \n", 
++		       int_st, retry, nfc_st);
++		nfc_all_reset();
++		*status = NAND_STATUS_FAIL;
++		return -1;
++	}
++
++	*status = (char)(le32_to_cpu(ra_inl(NFC_DATA)) & 0x0ff);
++	return 0;
++}
++
++/**
++ * @return !0, chip protect.
++ * @return 0, chip not protected.
++ */
++static int nfc_check_wp(void)
++{
++	/* Check the WP bit */
++#if !defined CONFIG_NOT_SUPPORT_WP
++	return !!(ra_inl(NFC_CTRL) & 0x01);
++#else
++	char result = 0;
++	int ret;
++
++	ret = _nfc_read_status(&result);
++	//FIXME, if ret < 0
++
++	return !(result & NAND_STATUS_WP);
++#endif
++}
++
++#if !defined CONFIG_NOT_SUPPORT_RB
++/*
++ * @return !0, chip ready.
++ * @return 0, chip busy.
++ */
++static int nfc_device_ready(void)
++{
++	/* Check the ready  */
++	return !!(ra_inl(NFC_STATUS) & 0x04);
++}
++#endif
++
++
++/**
++ * generic function to get data from flash.
++ * @return data length reading from flash.
++ */
++static int _ra_nand_pull_data(char *buf, int len, int use_gdma)
++{
++#ifdef RW_DATA_BY_BYTE
++	char *p = buf;
++#else
++	__u32 *p = (__u32 *)buf;
++#endif
++	int retry, int_st;
++	unsigned int ret_data;
++	int ret_size;
++
++	// receive data by use_gdma 
++	if (use_gdma) { 
++		//if (_ra_nand_dma_pull((unsigned long)p, len)) {
++		if (1) {
++			printk("%s: fail \n", __func__);
++			len = -1; //return error
++		}
++
++		return len;
++	}
++
++	//fixme: retry count size?
++	retry = READ_STATUS_RETRY;
++	// no gdma
++	while (len > 0) {
++		int_st = ra_inl(NFC_INT_ST);
++		if (int_st & INT_ST_RX_BUF_RDY) {
++
++			ret_data = ra_inl(NFC_DATA);
++			ra_outl(NFC_INT_ST, INT_ST_RX_BUF_RDY); 
++#ifdef RW_DATA_BY_BYTE
++			ret_size = sizeof(unsigned int);
++			ret_size = min(ret_size, len);
++			len -= ret_size;
++			while (ret_size-- > 0) {
++				//nfc is little endian 
++				*p++ = ret_data & 0x0ff;
++				ret_data >>= 8; 
++			}
++#else
++			ret_size = min(len, 4);
++			len -= ret_size;
++			if (ret_size == 4)
++				*p++ = ret_data;
++			else {
++				__u8 *q = (__u8 *)p;
++				while (ret_size-- > 0) {
++					*q++ = ret_data & 0x0ff;
++					ret_data >>= 8; 
++				}
++				p = (__u32 *)q;
++			}
++#endif
++			retry = READ_STATUS_RETRY;
++		}
++		else if (int_st & INT_ST_ND_DONE) {
++			break;
++		}
++		else {
++			udelay(1);
++			if (retry-- < 0) 
++				break;
++		}
++	}
++
++#ifdef RW_DATA_BY_BYTE
++	return (int)(p - buf);
++#else
++	return ((int)p - (int)buf);
++#endif
++}
++
++/**
++ * generic function to put data into flash.
++ * @return data length writing into flash.
++ */
++static int _ra_nand_push_data(char *buf, int len, int use_gdma)
++{
++#ifdef RW_DATA_BY_BYTE
++	char *p = buf;
++#else
++	__u32 *p = (__u32 *)buf;
++#endif
++	int retry, int_st;
++	unsigned int tx_data = 0;
++	int tx_size, iter = 0;
++
++	// receive data by use_gdma 
++	if (use_gdma) { 
++		//if (_ra_nand_dma_push((unsigned long)p, len))
++		if (1)
++			len = 0;		
++		printk("%s: fail \n", __func__);
++		return len;
++	}
++
++	// no gdma
++	retry = READ_STATUS_RETRY;
++	while (len > 0) {
++		int_st = ra_inl(NFC_INT_ST);
++		if (int_st & INT_ST_TX_BUF_RDY) {
++#ifdef RW_DATA_BY_BYTE
++			tx_size = min(len, (int)sizeof(unsigned long));
++			for (iter = 0; iter < tx_size; iter++) {
++				tx_data |= (*p++ << (8*iter));
++			}
++#else
++			tx_size = min(len, 4);
++			if (tx_size == 4)
++				tx_data = (*p++);
++			else {
++				__u8 *q = (__u8 *)p;
++				for (iter = 0; iter < tx_size; iter++)
++					tx_data |= (*q++ << (8*iter));
++				p = (__u32 *)q;
++			}
++#endif
++			ra_outl(NFC_INT_ST, INT_ST_TX_BUF_RDY);
++			ra_outl(NFC_DATA, tx_data);
++			len -= tx_size;
++			retry = READ_STATUS_RETRY;
++		}
++		else if (int_st & INT_ST_ND_DONE) {
++			break;
++		}
++		else {
++			udelay(1);
++			if (retry-- < 0) {
++				ra_dbg("%s p:%p buf:%p \n", __func__, p, buf);
++				break;
++			}
++		}
++	}
++
++	
++#ifdef RW_DATA_BY_BYTE
++	return (int)(p - buf);
++#else
++	return ((int)p - (int)buf);
++#endif
++
++}
++
++static int nfc_select_chip(struct ra_nand_chip *ra, int chipnr)
++{
++#if (CONFIG_NUMCHIPS == 1)
++	if (!(chipnr < CONFIG_NUMCHIPS))
++		return -1;
++	return 0;
++#else
++	BUG();
++#endif
++}
++
++/** @return -1: chip_select fail
++ *	    0 : both CE and WP==0 are OK
++ * 	    1 : CE OK and WP==1
++ */
++static int nfc_enable_chip(struct ra_nand_chip *ra, unsigned int offs, int read_only)
++{
++	int chipnr = offs >> ra->chip_shift;
++
++	ra_dbg("%s: offs:%x read_only:%x \n", __func__, offs, read_only);
++
++	chipnr = nfc_select_chip(ra, chipnr);
++	if (chipnr < 0) {
++		printk("%s: chip select error, offs(%x)\n", __func__, offs);
++		return -1;
++	}
++
++	if (!read_only)
++		return nfc_check_wp();
++	
++	return 0;
++}
++
++/** wait nand chip becomeing ready and return queried status.
++ * @param snooze: sleep time in ms unit before polling device ready.
++ * @return status of nand chip
++ * @return NAN_STATUS_FAIL if something unexpected.
++ */
++static int nfc_wait_ready(int snooze_ms)
++{
++	int retry;
++	char status;
++
++	// wait nfc idle,
++	if (snooze_ms == 0)
++		snooze_ms = 1;
++	else
++		schedule_timeout(snooze_ms * HZ / 1000);
++	
++	snooze_ms = retry = snooze_ms *1000000 / 100 ;  // ndelay(100)
++
++	while (!NFC_TRANS_DONE() && retry--) {
++		if (!cond_resched())
++			ndelay(100);
++	}
++	
++	if (!NFC_TRANS_DONE()) {
++		printk("nfc_wait_ready: no transaction done \n");
++		return NAND_STATUS_FAIL;
++	}
++
++#if !defined (CONFIG_NOT_SUPPORT_RB)
++	//fixme
++	while(!(status = nfc_device_ready()) && retry--) {
++		ndelay(100);
++	}
++
++	if (status == 0) {
++		printk("nfc_wait_ready: no device ready. \n");	
++		return NAND_STATUS_FAIL;
++	}
++
++	_nfc_read_status(&status);
++	return status;
++#else
++
++	while(retry--) {
++		_nfc_read_status(&status);
++		if (status & NAND_STATUS_READY)
++			break;
++		ndelay(100);
++	}
++	if (retry<0)
++		printk("nfc_wait_ready 2: no device ready, status(%x). \n", status);	
++
++	return status;
++#endif
++}
++
++/**
++ * return 0: erase OK
++ * return -EIO: fail 
++ */
++int nfc_erase_block(struct ra_nand_chip *ra, int row_addr)
++{
++	unsigned long cmd1, cmd2, bus_addr, conf;
++	char status;
++
++	cmd1 = 0x60;
++	cmd2 = 0xd0;
++	bus_addr = row_addr;
++	conf = 0x00511 | ((CFG_ROW_ADDR_CYCLE)<<16);
++
++	// set NFC
++	ra_dbg("%s: cmd1: %lx, cmd2:%lx bus_addr: %lx, conf: %lx \n", 
++	       __func__, cmd1, cmd2, bus_addr, conf);
++
++	//fixme, should we check nfc status?
++	CLEAR_INT_STATUS();
++
++	ra_outl(NFC_CMD1, cmd1); 	
++	ra_outl(NFC_CMD2, cmd2);
++	ra_outl(NFC_ADDR, bus_addr);
++	ra_outl(NFC_CONF, conf); 
++
++	status = nfc_wait_ready(3);  //erase wait 3ms 
++	if (status & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++		return -EIO;
++	}
++	
++	return 0;
++
++}
++
++static inline int _nfc_read_raw_data(int cmd1, int cmd2, int bus_addr, int bus_addr2, int conf, char *buf, int len, int flags)
++{
++	int ret;
++
++	CLEAR_INT_STATUS();
++	ra_outl(NFC_CMD1, cmd1); 	
++	ra_outl(NFC_CMD2, cmd2);
++	ra_outl(NFC_ADDR, bus_addr);
++#if defined (CONFIG_RALINK_RT6855) || defined (CONFIG_RALINK_RT6855A) || \
++    defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_MT7621)	
++	ra_outl(NFC_ADDR2, bus_addr2);
++#endif	
++	ra_outl(NFC_CONF, conf); 
++
++	ret = _ra_nand_pull_data(buf, len, 0);
++	if (ret != len) {
++		ra_dbg("%s: ret:%x (%x) \n", __func__, ret, len);
++		return NAND_STATUS_FAIL;
++	}
++
++	//FIXME, this section is not necessary
++	ret = nfc_wait_ready(0); //wait ready 
++	/* to prevent the DATA FIFO 's old data from next operation */
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) | 0x02); //clear data buffer
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) & ~0x02); //clear data buffer
++
++	if (ret & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++		return NAND_STATUS_FAIL;
++	}
++
++	return 0;
++}
++
++static inline int _nfc_write_raw_data(int cmd1, int cmd3, int bus_addr, int bus_addr2, int conf, char *buf, int len, int flags)
++{
++	int ret;
++
++	CLEAR_INT_STATUS();
++	ra_outl(NFC_CMD1, cmd1); 	
++	ra_outl(NFC_CMD3, cmd3); 	
++	ra_outl(NFC_ADDR, bus_addr);
++#if defined (CONFIG_RALINK_RT6855) || defined (CONFIG_RALINK_RT6855A) || \
++    defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_MT7621)	
++	ra_outl(NFC_ADDR2, bus_addr2);
++#endif	
++	ra_outl(NFC_CONF, conf); 
++
++	ret = _ra_nand_push_data(buf, len, 0);
++	if (ret != len) {
++		ra_dbg("%s: ret:%x (%x) \n", __func__, ret, len);
++		return NAND_STATUS_FAIL;
++	}
++
++	ret = nfc_wait_ready(1); //write wait 1ms
++	/* to prevent the DATA FIFO 's old data from next operation */
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) | 0x02); //clear data buffer
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) & ~0x02); //clear data buffer
++
++	if (ret & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++		return NAND_STATUS_FAIL;
++	}
++
++	return 0;
++}
++
++/**
++ * @return !0: fail
++ * @return 0: OK
++ */
++int nfc_read_oob(struct ra_nand_chip *ra, int page, unsigned int offs, char *buf, int len, int flags)
++{
++	unsigned int cmd1 = 0, cmd2 = 0, conf = 0;
++	unsigned int bus_addr = 0, bus_addr2 = 0;
++	unsigned int ecc_en;
++	int use_gdma;
++	int status;
++
++	int pages_perblock = 1<<(ra->erase_shift - ra->page_shift);
++	// constrain of nfc read function 
++
++#if defined (WORKAROUND_RX_BUF_OV)
++	BUG_ON (len > 60); 	//problem of rx-buffer overrun 
++#endif
++	BUG_ON (offs >> ra->oob_shift); //page boundry
++	BUG_ON ((unsigned int)(((offs + len) >> ra->oob_shift) + page) >
++		((page + pages_perblock) & ~(pages_perblock-1))); //block boundry
++
++	use_gdma = flags & FLAG_USE_GDMA;
++	ecc_en = flags & FLAG_ECC_EN;
++	bus_addr = (page << (CFG_COLUMN_ADDR_CYCLE*8)) | (offs & ((1<<CFG_COLUMN_ADDR_CYCLE*8) - 1));
++
++	if (is_nand_page_2048) {
++		bus_addr += CFG_PAGESIZE;
++		bus_addr2 = page >> (CFG_COLUMN_ADDR_CYCLE*8);
++		cmd1 = 0x0;
++		cmd2 = 0x30;
++		conf = 0x000511| ((CFG_ADDR_CYCLE)<<16) | (len << 20); 
++	}
++	else {
++		cmd1 = 0x50;
++		conf = 0x000141| ((CFG_ADDR_CYCLE)<<16) | (len << 20); 
++	}
++	if (ecc_en) 
++		conf |= (1<<3); 
++	if (use_gdma)
++		conf |= (1<<2);
++
++	ra_dbg("%s: cmd1:%x, bus_addr:%x, conf:%x, len:%x, flag:%x\n",
++	       __func__, cmd1, bus_addr, conf, len, flags);
++
++	status = _nfc_read_raw_data(cmd1, cmd2, bus_addr, bus_addr2, conf, buf, len, flags);
++	if (status & NAND_STATUS_FAIL) {
++		printk("%s: fail\n", __func__);
++		return -EIO;
++	}
++
++	return 0; 
++}
++
++/**
++ * @return !0: fail
++ * @return 0: OK
++ */
++int nfc_write_oob(struct ra_nand_chip *ra, int page, unsigned int offs, char *buf, int len, int flags)
++{
++	unsigned int cmd1 = 0, cmd3=0, conf = 0;
++	unsigned int bus_addr = 0, bus_addr2 = 0;
++	int use_gdma;
++	int status;
++
++	int pages_perblock = 1<<(ra->erase_shift - ra->page_shift);
++	// constrain of nfc read function 
++
++	BUG_ON (offs >> ra->oob_shift); //page boundry
++	BUG_ON ((unsigned int)(((offs + len) >> ra->oob_shift) + page) >
++		((page + pages_perblock) & ~(pages_perblock-1))); //block boundry 
++
++	use_gdma = flags & FLAG_USE_GDMA;
++	bus_addr = (page << (CFG_COLUMN_ADDR_CYCLE*8)) | (offs & ((1<<CFG_COLUMN_ADDR_CYCLE*8) - 1));
++
++	if (is_nand_page_2048) {
++		cmd1 = 0x80;
++		cmd3 = 0x10;
++		bus_addr += CFG_PAGESIZE;
++		bus_addr2 = page >> (CFG_COLUMN_ADDR_CYCLE*8);
++		conf = 0x001123 | ((CFG_ADDR_CYCLE)<<16) | ((len) << 20);
++	}
++	else {
++		cmd1 = 0x08050;
++		cmd3 = 0x10;
++		conf = 0x001223 | ((CFG_ADDR_CYCLE)<<16) | ((len) << 20); 
++	}
++	if (use_gdma)
++		conf |= (1<<2);
++
++	// set NFC
++	ra_dbg("%s: cmd1: %x, cmd3: %x bus_addr: %x, conf: %x, len:%x\n", 
++	       __func__, cmd1, cmd3, bus_addr, conf, len);
++
++	status = _nfc_write_raw_data(cmd1, cmd3, bus_addr, bus_addr2, conf, buf, len, flags);
++	if (status & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++		return -EIO;
++	}
++
++	return 0; 
++}
++
++
++int nfc_read_page(struct ra_nand_chip *ra, char *buf, int page, int flags);
++int nfc_write_page(struct ra_nand_chip *ra, char *buf, int page, int flags);
++
++
++#if !defined (WORKAROUND_RX_BUF_OV)	
++static int one_bit_correction(char *ecc, char *expected, int *bytes, int *bits);
++int nfc_ecc_verify(struct ra_nand_chip *ra, char *buf, int page, int mode)
++{
++	int ret, i;
++	char *p, *e;
++	int ecc;
++	
++	//ra_dbg("%s, page:%x mode:%d\n", __func__, page, mode);
++
++	if (mode == FL_WRITING) {
++		int len = CFG_PAGESIZE + CFG_PAGE_OOBSIZE;
++		int conf = 0x000141| ((CFG_ADDR_CYCLE)<<16) | (len << 20); 
++		conf |= (1<<3); //(ecc_en) 
++		//conf |= (1<<2); // (use_gdma)
++
++		p = ra->readback_buffers;
++		ret = nfc_read_page(ra, ra->readback_buffers, page, FLAG_ECC_EN); 
++		if (ret == 0) 
++			goto ecc_check;
++		
++		//FIXME, double comfirm
++		printk("%s: read back fail, try again \n",__func__);
++		ret = nfc_read_page(ra, ra->readback_buffers, page, FLAG_ECC_EN); 
++		if (ret != 0) {
++			printk("\t%s: read back fail agian \n",__func__);
++			goto bad_block;
++		}
++	}
++	else if (mode == FL_READING) {
++		p = buf;
++	}	
++	else
++		return -2;
++
++ecc_check:
++	p += CFG_PAGESIZE;
++	if (!is_nand_page_2048) {
++		ecc = ra_inl(NFC_ECC); 
++		if (ecc == 0) //clean page.
++			return 0;
++		e = (char*)&ecc;
++		for (i=0; i<CONFIG_ECC_BYTES; i++) {
++			int eccpos = CONFIG_ECC_OFFSET + i;
++			if (*(p + eccpos) != (char)0xff)
++				break;
++			if (i == CONFIG_ECC_BYTES - 1) {
++				printk("skip ecc 0xff at page %x\n", page);
++				return 0;
++			}
++		}
++		for (i=0; i<CONFIG_ECC_BYTES; i++) {
++			int eccpos = CONFIG_ECC_OFFSET + i;
++			if (*(p + eccpos) != *(e + i)) {
++				printk("%s mode:%s, invalid ecc, page: %x read:%x %x %x, ecc:%x \n",
++						__func__, (mode == FL_READING)?"read":"write", page,	
++						*(p+ CONFIG_ECC_OFFSET), *(p+ CONFIG_ECC_OFFSET+1), *(p+ CONFIG_ECC_OFFSET +2), ecc);
++				return -1;
++			}
++		}
++	}
++#if defined (CONFIG_RALINK_RT6855) || defined (CONFIG_RALINK_RT6855A) || \
++    defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_MT7621)	
++	else {
++		int ecc2, ecc3, ecc4, qsz;
++		char *e2, *e3, *e4;
++		int correction_flag = 0;
++		ecc = ra_inl(NFC_ECC_P1);
++		ecc2 = ra_inl(NFC_ECC_P2);
++		ecc3 = ra_inl(NFC_ECC_P3);
++		ecc4 = ra_inl(NFC_ECC_P4);
++		e = (char*)&ecc;
++		e2 = (char*)&ecc2;
++		e3 = (char*)&ecc3;
++		e4 = (char*)&ecc4;
++		qsz = CFG_PAGE_OOBSIZE / 4;
++		if (ecc == 0 && ecc2 == 0 && ecc3 == 0 && ecc4 == 0)
++			return 0;
++		for (i=0; i<CONFIG_ECC_BYTES; i++) {
++			int eccpos = CONFIG_ECC_OFFSET + i;
++			if (*(p + eccpos) != (char)0xff)
++				break;
++			else if (*(p + eccpos + qsz) != (char)0xff)
++				break;
++			else if (*(p + eccpos + qsz*2) != (char)0xff)
++				break;
++			else if (*(p + eccpos + qsz*3) != (char)0xff)
++				break;
++			if (i == CONFIG_ECC_BYTES - 1) {
++				printk("skip ecc 0xff at page %x\n", page);
++				return 0;
++			}
++		}
++		for (i=0; i<CONFIG_ECC_BYTES; i++) {
++			int eccpos = CONFIG_ECC_OFFSET + i;
++			if (*(p + eccpos) != *(e + i)) {
++				printk("%s mode:%s, invalid ecc, page: %x read:%x %x %x, ecc:%x \n",
++						__func__, (mode == FL_READING)?"read":"write", page,
++						*(p+ CONFIG_ECC_OFFSET), *(p+ CONFIG_ECC_OFFSET+1), *(p+ CONFIG_ECC_OFFSET +2), ecc);
++				correction_flag |= 0x1;
++			}
++			if (*(p + eccpos + qsz) != *(e2 + i)) {
++				printk("%s mode:%s, invalid ecc2, page: %x read:%x %x %x, ecc2:%x \n",
++						__func__, (mode == FL_READING)?"read":"write", page,
++						*(p+CONFIG_ECC_OFFSET+qsz), *(p+ CONFIG_ECC_OFFSET+1+qsz), *(p+ CONFIG_ECC_OFFSET+2+qsz), ecc2);
++				correction_flag |= 0x2;
++			}
++			if (*(p + eccpos + qsz*2) != *(e3 + i)) {
++				printk("%s mode:%s, invalid ecc3, page: %x read:%x %x %x, ecc3:%x \n",
++						__func__, (mode == FL_READING)?"read":"write", page,
++						*(p+CONFIG_ECC_OFFSET+qsz*2), *(p+ CONFIG_ECC_OFFSET+1+qsz*2), *(p+ CONFIG_ECC_OFFSET+2+qsz*2), ecc3);
++				correction_flag |= 0x4;
++			}
++			if (*(p + eccpos + qsz*3) != *(e4 + i)) {
++				printk("%s mode:%s, invalid ecc4, page: %x read:%x %x %x, ecc4:%x \n",
++						__func__, (mode == FL_READING)?"read":"write", page,
++						*(p+CONFIG_ECC_OFFSET+qsz*3), *(p+ CONFIG_ECC_OFFSET+1+qsz*3), *(p+ CONFIG_ECC_OFFSET+2+qsz*3), ecc4);
++				correction_flag |= 0x8;
++			}
++		}
++
++		if (correction_flag)
++		{
++			printk("trying to do correction!\n");
++			if (correction_flag & 0x1)
++			{
++				int bytes, bits;
++				char *pBuf = p - CFG_PAGESIZE;
++			
++				if (one_bit_correction(p + CONFIG_ECC_OFFSET, e, &bytes, &bits) == 0)
++				{
++					pBuf[bytes] = pBuf[bytes] ^ (1 << bits);
++					printk("1. correct byte %d, bit %d!\n", bytes, bits);
++				}
++				else
++				{
++					printk("failed to correct!\n");
++					return -1;
++				}
++			}
++
++			if (correction_flag & 0x2)
++			{
++				int bytes, bits;
++				char *pBuf = (p - CFG_PAGESIZE) + CFG_PAGESIZE/4;
++			
++				if (one_bit_correction((p + CONFIG_ECC_OFFSET + qsz), e2, &bytes, &bits) == 0)
++				{
++					pBuf[bytes] = pBuf[bytes] ^ (1 << bits);
++					printk("2. correct byte %d, bit %d!\n", bytes, bits);
++				}
++				else
++				{
++					printk("failed to correct!\n");
++					return -1;
++				}
++			}
++			if (correction_flag & 0x4)
++			{
++				int bytes, bits;
++				char *pBuf = (p - CFG_PAGESIZE) + CFG_PAGESIZE/2;
++			
++				if (one_bit_correction((p + CONFIG_ECC_OFFSET + qsz * 2), e3, &bytes, &bits) == 0)
++				{
++					pBuf[bytes] = pBuf[bytes] ^ (1 << bits);
++					printk("3. correct byte %d, bit %d!\n", bytes, bits);
++				}
++				else
++				{
++					printk("failed to correct!\n");
++					return -1;
++				}
++			}
++			if (correction_flag & 0x8)
++			{
++				int bytes, bits;
++				char *pBuf = (p - CFG_PAGESIZE) + CFG_PAGESIZE*3/4;
++			
++				if (one_bit_correction((p + CONFIG_ECC_OFFSET + qsz * 3), e4, &bytes, &bits) == 0)
++				{
++					pBuf[bytes] = pBuf[bytes] ^ (1 << bits);
++					printk("4. correct byte %d, bit %d!\n", bytes, bits);
++				}
++				else
++				{
++					printk("failed to correct!\n");
++					return -1;
++				}
++			}
++		}
++
++	}
++#endif	
++	return 0;
++
++bad_block:
++	return -1;
++}
++
++#else
++
++void ranfc_dump(void) 
++{	
++	int i;
++	for (i=0; i<11; i++) {
++		if (i==6) 
++			continue;
++		printk("%x: %x \n", NFC_BASE + i*4, ra_inl(NFC_BASE + i*4));
++	}
++}
++
++/**
++ * @return 0, ecc OK or corrected.
++ * @return NAND_STATUS_FAIL, ecc fail.   
++ */
++
++int nfc_ecc_verify(struct ra_nand_chip *ra, char *buf, int page, int mode)
++{
++	int ret, i;
++	char *p, *e;
++	int ecc;
++	
++	if (ranfc_verify == 0)
++		return 0;
++
++	ra_dbg("%s, page:%x mode:%d\n", __func__, page, mode);
++
++	if (mode == FL_WRITING) { // read back and memcmp
++		ret = nfc_read_page(ra, ra->readback_buffers, page, FLAG_NONE); 
++		if (ret != 0) //double comfirm
++			ret = nfc_read_page(ra, ra->readback_buffers, page, FLAG_NONE); 
++
++		if (ret != 0) {
++			printk("%s: mode:%x read back fail \n", __func__, mode);
++			return -1;
++		}
++		return memcmp(buf, ra->readback_buffers, 1<<ra->page_shift);
++	}
++	
++	if (mode == FL_READING) { 
++#if 0
++		if (ra->sandbox_page == 0)
++			return 0;
++
++		ret = nfc_write_page(ra, buf, ra->sandbox_page, FLAG_USE_GDMA | FLAG_ECC_EN);
++		if (ret != 0) {
++			printk("%s, fail write sandbox_page \n", __func__);
++			return -1;
++		}
++#else
++		/** @note: 
++		 * The following command is actually not 'write' command to drive NFC to write flash.
++		 * However, it can make NFC to calculate ECC, that will be used to compare with original ones.
++		 * --YT
++		 */
++		unsigned int conf = 0x001223| (CFG_ADDR_CYCLE<<16) | (0x200 << 20) | (1<<3) | (1<<2); 
++		_nfc_write_raw_data(0xff, 0xff, ra->sandbox_page<<ra->page_shift, conf, buf, 0x200, FLAG_USE_GDMA);
++#endif
++
++		ecc = ra_inl(NFC_ECC); 
++		if (ecc == 0) //clean page.
++			return 0;
++		e = (char*)&ecc;
++		p = buf + (1<<ra->page_shift);
++		for (i=0; i<CONFIG_ECC_BYTES; i++) {
++			int eccpos = CONFIG_ECC_OFFSET + i;
++			if (*(p + eccpos) != *(e + i)) {
++				printk("%s mode:%s, invalid ecc, page: %x read:%x %x %x, write:%x \n",
++				       __func__, (mode == FL_READING)?"read":"write", page,	
++				       *(p+ CONFIG_ECC_OFFSET), *(p+ CONFIG_ECC_OFFSET+1), *(p+ CONFIG_ECC_OFFSET +2), ecc);
++
++				for (i=0; i<528; i++)
++					printk("%-2x \n", *(buf + i));
++				return -1;
++			}
++		}
++		return 0;
++	}
++
++	return -1;
++
++}
++
++#endif
++
++
++/**
++ * @return -EIO, writing size is less than a page 
++ * @return 0, OK
++ */
++int nfc_read_page(struct ra_nand_chip *ra, char *buf, int page, int flags)
++{
++	unsigned int cmd1 = 0, cmd2 = 0, conf = 0;
++	unsigned int bus_addr = 0, bus_addr2 = 0;
++	unsigned int ecc_en;
++	int use_gdma;
++	int size, offs;
++	int status = 0;
++
++	use_gdma = flags & FLAG_USE_GDMA;
++	ecc_en = flags & FLAG_ECC_EN;
++
++	page = page & (CFG_CHIPSIZE - 1); // chip boundary
++	size = CFG_PAGESIZE + CFG_PAGE_OOBSIZE; //add oobsize
++	offs = 0;
++
++	while (size > 0) {
++		int len;
++#if defined (WORKAROUND_RX_BUF_OV)
++		len = min(60, size);
++#else
++		len = size;
++#endif		
++		bus_addr = (page << (CFG_COLUMN_ADDR_CYCLE*8)) | (offs & ((1<<CFG_COLUMN_ADDR_CYCLE*8)-1)); 
++		if (is_nand_page_2048) {
++			bus_addr2 = page >> (CFG_COLUMN_ADDR_CYCLE*8);
++			cmd1 = 0x0;
++			cmd2 = 0x30;
++			conf = 0x000511| ((CFG_ADDR_CYCLE)<<16) | (len << 20); 
++		}
++		else {
++			if (offs & ~(CFG_PAGESIZE-1))
++				cmd1 = 0x50;
++			else if (offs & ~((1<<CFG_COLUMN_ADDR_CYCLE*8)-1))
++				cmd1 = 0x01;
++			else
++				cmd1 = 0;
++
++			conf = 0x000141| ((CFG_ADDR_CYCLE)<<16) | (len << 20); 
++		}
++#if !defined (WORKAROUND_RX_BUF_OV)
++		if (ecc_en) 
++			conf |= (1<<3); 
++#endif
++		if (use_gdma)
++			conf |= (1<<2);
++
++		status = _nfc_read_raw_data(cmd1, cmd2, bus_addr, bus_addr2, conf, buf+offs, len, flags);
++		if (status & NAND_STATUS_FAIL) {
++			printk("%s: fail \n", __func__);
++			return -EIO;
++		}
++
++		offs += len;
++		size -= len;
++	}
++
++	// verify and correct ecc
++	if ((flags & (FLAG_VERIFY | FLAG_ECC_EN)) == (FLAG_VERIFY | FLAG_ECC_EN)) {
++		status = nfc_ecc_verify(ra, buf, page, FL_READING);	
++		if (status != 0) {
++			printk("%s: fail, buf:%x, page:%x, flag:%x\n", 
++			       __func__, (unsigned int)buf, page, flags);
++			return -EBADMSG;
++		}
++	}
++	else {
++		// fix,e not yet support
++		ra->buffers_page = -1; //cached
++	}
++
++	return 0;
++}
++
++
++/** 
++ * @return -EIO, fail to write
++ * @return 0, OK
++ */
++int nfc_write_page(struct ra_nand_chip *ra, char *buf, int page, int flags)
++{
++	unsigned int cmd1 = 0, cmd3, conf = 0;
++	unsigned int bus_addr = 0, bus_addr2 = 0;
++	unsigned int ecc_en;
++	int use_gdma;
++	int size;
++	char status;
++	uint8_t *oob = buf + (1<<ra->page_shift);
++
++	use_gdma = flags & FLAG_USE_GDMA;
++	ecc_en = flags & FLAG_ECC_EN;
++
++	oob[ra->badblockpos] = 0xff;	//tag as good block.
++	ra->buffers_page = -1; //cached
++
++	page = page & (CFG_CHIPSIZE-1); //chip boundary
++	size = CFG_PAGESIZE + CFG_PAGE_OOBSIZE; //add oobsize
++	bus_addr = (page << (CFG_COLUMN_ADDR_CYCLE*8)); //write_page always write from offset 0.
++
++	if (is_nand_page_2048) {
++	bus_addr2 = page >> (CFG_COLUMN_ADDR_CYCLE*8);
++		cmd1 = 0x80;
++		cmd3 = 0x10;
++		conf = 0x001123| ((CFG_ADDR_CYCLE)<<16) | (size << 20); 
++	}
++	else {
++	cmd1 = 0x8000;
++	cmd3 = 0x10;
++	conf = 0x001223| ((CFG_ADDR_CYCLE)<<16) | (size << 20); 
++}
++	if (ecc_en) 
++		conf |= (1<<3); //enable ecc
++	if (use_gdma)
++		conf |= (1<<2);
++
++	// set NFC
++	ra_dbg("nfc_write_page: cmd1: %x, cmd3: %x bus_addr: %x, conf: %x, len:%x\n", 
++	       cmd1, cmd3, bus_addr, conf, size);
++
++	status = _nfc_write_raw_data(cmd1, cmd3, bus_addr, bus_addr2, conf, buf, size, flags);
++	if (status & NAND_STATUS_FAIL) {
++		printk("%s: fail \n", __func__);
++		return -EIO;
++	}
++	
++
++	if (flags & FLAG_VERIFY) { // verify and correct ecc
++		status = nfc_ecc_verify(ra, buf, page, FL_WRITING);
++
++#ifdef RANDOM_GEN_BAD_BLOCK
++		if (((random32() & 0x1ff) == 0x0) && (page >= 0x100)) // randomly create bad block
++		{
++			printk("hmm... create a bad block at page %x\n", (bus_addr >> 16));
++			status = -1;
++		}
++#endif
++
++		if (status != 0) {
++			printk("%s: ecc_verify fail: ret:%x \n", __func__, status);
++			oob[ra->badblockpos] = 0x33; 
++			page -= page % (CFG_BLOCKSIZE/CFG_PAGESIZE);
++			printk("create a bad block at page %x\n", page);
++			if (!is_nand_page_2048)
++				status = nfc_write_oob(ra, page, ra->badblockpos, oob+ra->badblockpos, 1, flags);
++			else
++			{
++				status = _nfc_write_raw_data(cmd1, cmd3, bus_addr, bus_addr2, conf, buf, size, flags);
++				nfc_write_oob(ra, page, 0, oob, 16, FLAG_NONE);
++			}
++			return -EBADMSG;
++		}
++	}
++
++
++	ra->buffers_page = page; //cached
++	return 0;
++}
++
++
++
++/*************************************************************
++ * nand internal process 
++ *************************************************************/
++
++/**
++ * nand_release_device - [GENERIC] release chip
++ * @mtd:	MTD device structure
++ *
++ * Deselect, release chip lock and wake up anyone waiting on the device
++ */
++static void nand_release_device(struct ra_nand_chip *ra)
++{
++	/* De-select the NAND device */
++	nfc_select_chip(ra, -1);
++
++	/* Release the controller and the chip */
++	ra->state = FL_READY;
++
++	mutex_unlock(ra->controller);
++}
++
++/**
++ * nand_get_device - [GENERIC] Get chip for selected access
++ * @chip:	the nand chip descriptor
++ * @mtd:	MTD device structure
++ * @new_state:	the state which is requested
++ *
++ * Get the device and lock it for exclusive access
++ */
++static int
++nand_get_device(struct ra_nand_chip *ra, int new_state)
++{
++	int ret = 0;
++
++	ret = mutex_lock_interruptible(ra->controller);
++	if (!ret) 
++		ra->state = new_state;
++
++	return ret;
++
++}
++
++
++
++/*************************************************************
++ * nand internal process 
++ *************************************************************/
++
++int nand_bbt_get(struct ra_nand_chip *ra, int block)
++{
++	int byte, bits;
++	bits = block * BBTTAG_BITS;
++
++	byte = bits / 8;
++	bits = bits % 8;
++	
++	return (ra->bbt[byte] >> bits) & BBTTAG_BITS_MASK;
++}
++
++int nand_bbt_set(struct ra_nand_chip *ra, int block, int tag)
++{
++	int byte, bits;
++	bits = block * BBTTAG_BITS;
++
++	byte = bits / 8;
++	bits = bits % 8;
++
++	// If previous tag is bad, dont overwrite it	
++	if (((ra->bbt[byte] >> bits) & BBTTAG_BITS_MASK) == BBT_TAG_BAD)
++	{
++		return BBT_TAG_BAD;
++	}
++
++	ra->bbt[byte] = (ra->bbt[byte] & ~(BBTTAG_BITS_MASK << bits)) | ((tag & BBTTAG_BITS_MASK) << bits);
++		
++	return tag;
++}
++
++/**
++ * nand_block_checkbad - [GENERIC] Check if a block is marked bad
++ * @mtd:	MTD device structure
++ * @ofs:	offset from device start
++ *
++ * Check, if the block is bad. Either by reading the bad block table or
++ * calling of the scan function.
++ */
++int nand_block_checkbad(struct ra_nand_chip *ra, loff_t offs)
++{
++	int page, block;
++	int ret = 4;
++	unsigned int tag;
++	char *str[]= {"UNK", "RES", "BAD", "GOOD"};
++
++	if (ranfc_bbt == 0)
++		return 0;
++
++	{
++		// align with chip
++
++		offs = offs & ((1<<ra->chip_shift) -1);
++
++		page = offs >> ra->page_shift;
++		block = offs >> ra->erase_shift;
++	}
++
++	tag = nand_bbt_get(ra, block);
++
++	if (tag == BBT_TAG_UNKNOWN) {
++		ret = nfc_read_oob(ra, page, ra->badblockpos, (char*)&tag, 1, FLAG_NONE);
++		if (ret == 0)
++			tag = ((le32_to_cpu(tag) & 0x0ff) == 0x0ff) ? BBT_TAG_GOOD : BBT_TAG_BAD;
++		else
++			tag = BBT_TAG_BAD;
++
++		nand_bbt_set(ra, block, tag);
++	}
++
++	if (tag != BBT_TAG_GOOD) {
++		printk("%s: offs:%x tag: %s \n", __func__, (unsigned int)offs, str[tag]);
++		return 1;
++	}
++	else 
++		return 0;
++	
++}
++
++
++
++/**
++ * nand_block_markbad -
++ */
++int nand_block_markbad(struct ra_nand_chip *ra, loff_t offs)
++{
++	int page, block;
++	int ret = 4;
++	unsigned int tag;
++	char *ecc;
++
++	// align with chip
++	ra_dbg("%s offs: %x \n", __func__, (int)offs);
++
++	offs = offs & ((1<<ra->chip_shift) -1);
++
++	page = offs >> ra->page_shift;
++	block = offs >> ra->erase_shift;
++
++	tag = nand_bbt_get(ra, block);
++
++	if (tag == BBT_TAG_BAD) {
++		printk("%s: mark repeatedly \n", __func__);
++		return 0;
++	}
++
++	// new tag as bad
++	tag =BBT_TAG_BAD;
++	ret = nfc_read_page(ra, ra->buffers, page, FLAG_NONE);
++	if (ret != 0) {
++		printk("%s: fail to read bad block tag \n", __func__);
++		goto tag_bbt;
++	}
++
++	ecc = &ra->buffers[(1<<ra->page_shift)+ra->badblockpos];
++	if (*ecc == (char)0x0ff) {
++		//tag into flash
++		*ecc = (char)tag;
++		ret = nfc_write_page(ra, ra->buffers, page, FLAG_USE_GDMA);
++		if (ret)
++			printk("%s: fail to write bad block tag \n", __func__);
++		
++	}	
++
++tag_bbt:
++	//update bbt
++	nand_bbt_set(ra, block, tag);
++
++	return 0;
++}
++
++
++#if defined (WORKAROUND_RX_BUF_OV)
++/**
++ * to find a bad block for ecc verify of read_page
++ */
++unsigned int nand_bbt_find_sandbox(struct ra_nand_chip *ra)
++{
++	loff_t offs = 0;
++	int chipsize = 1 << ra->chip_shift;
++	int blocksize = 1 << ra->erase_shift;
++
++	
++	while (offs < chipsize) {
++		if (nand_block_checkbad(ra, offs)) //scan and verify the unknown tag
++			break;
++		offs += blocksize;
++	}
++
++	if (offs >= chipsize) {
++		offs = chipsize - blocksize;
++	}
++
++	nand_bbt_set(ra, (unsigned int)offs>>ra->erase_shift, BBT_TAG_RES);	 // tag bbt only, instead of update badblockpos of flash.
++	return (offs >> ra->page_shift);
++}
++#endif
++
++
++
++/**
++ * nand_erase_nand - [Internal] erase block(s)
++ * @mtd:	MTD device structure
++ * @instr:	erase instruction
++ * @allowbbt:	allow erasing the bbt area
++ *
++ * Erase one ore more blocks
++ */
++int _nand_erase_nand(struct ra_nand_chip *ra, struct erase_info *instr)
++{
++	int page, len, status, ret;
++	unsigned int addr, blocksize = 1<<ra->erase_shift;
++
++	ra_dbg("%s: start:%x, len:%x \n", __func__, 
++	       (unsigned int)instr->addr, (unsigned int)instr->len);
++
++//#define BLOCK_ALIGNED(a) ((a) & (blocksize - 1)) // already defined
++
++	if (BLOCK_ALIGNED(instr->addr) || BLOCK_ALIGNED(instr->len)) {
++		ra_dbg("%s: erase block not aligned, addr:%x len:%x\n", __func__, instr->addr, instr->len);
++		return -EINVAL;
++	}
++
++	instr->fail_addr = 0xffffffff;
++
++	len = instr->len;
++	addr = instr->addr;
++	instr->state = MTD_ERASING;
++
++	while (len) {
++
++		page = (int)(addr >> ra->page_shift);
++
++		/* select device and check wp */
++		if (nfc_enable_chip(ra, addr, 0)) {
++			printk("%s: nand is write protected \n", __func__);
++			instr->state = MTD_ERASE_FAILED;
++			goto erase_exit;
++		}
++
++		/* if we have a bad block, we do not erase bad blocks */
++		if (nand_block_checkbad(ra, addr)) {
++			printk(KERN_WARNING "nand_erase: attempt to erase a "
++			       "bad block at 0x%08x\n", addr);
++			instr->state = MTD_ERASE_FAILED;
++			goto erase_exit;
++		}
++
++		/*
++		 * Invalidate the page cache, if we erase the block which
++		 * contains the current cached page
++		 */
++		if (BLOCK_ALIGNED(addr) == BLOCK_ALIGNED(ra->buffers_page << ra->page_shift))
++			ra->buffers_page = -1;
++
++		status = nfc_erase_block(ra, page);
++		/* See if block erase succeeded */
++		if (status) {
++			printk("%s: failed erase, page 0x%08x\n", __func__, page);
++			instr->state = MTD_ERASE_FAILED;
++			instr->fail_addr = (page << ra->page_shift);
++			goto erase_exit;
++		}
++
++
++		/* Increment page address and decrement length */
++		len -= blocksize;
++		addr += blocksize;
++
++	}
++	instr->state = MTD_ERASE_DONE;
++
++erase_exit:
++
++	ret = ((instr->state == MTD_ERASE_DONE) ? 0 : -EIO);
++	/* Do call back function */
++	if (!ret)
++		mtd_erase_callback(instr);
++
++	if (ret) {
++		nand_bbt_set(ra, addr >> ra->erase_shift, BBT_TAG_BAD);
++	}
++
++	/* Return more or less happy */
++	return ret;
++}
++
++static int
++nand_write_oob_buf(struct ra_nand_chip *ra, uint8_t *buf, uint8_t *oob, size_t size,
++		   int mode, int ooboffs)
++{
++	size_t oobsize = 1<<ra->oob_shift;
++	struct nand_oobfree *free;
++	uint32_t woffs = ooboffs;
++	int retsize = 0;
++
++	ra_dbg("%s: size:%x, mode:%x, offs:%x  \n", __func__, size, mode, ooboffs);
++
++	switch(mode) {
++	case MTD_OPS_PLACE_OOB:
++	case MTD_OPS_RAW:
++		if (ooboffs > oobsize)
++			return -1;
++
++		size = min(size, oobsize - ooboffs);
++		memcpy(buf + ooboffs, oob, size);
++		retsize = size;
++		break;
++
++	case MTD_OPS_AUTO_OOB:
++		if (ooboffs > ra->oob->oobavail)
++			return -1;
++
++		while (size) {
++			for(free = ra->oob->oobfree; free->length && size; free++) {
++				int wlen = free->length - woffs;
++				int bytes = 0;
++
++				/* Write request not from offset 0 ? */
++				if (wlen <= 0) {
++					woffs = -wlen;
++					continue;
++				}
++
++				bytes = min_t(size_t, size, wlen);
++				memcpy (buf + free->offset + woffs, oob, bytes);
++				woffs = 0;
++				oob += bytes;
++				size -= bytes;
++				retsize += bytes;
++			}
++			buf += oobsize;
++		}
++		break;
++
++	default:
++		BUG();
++	}
++
++	return retsize;
++}
++
++static int nand_read_oob_buf(struct ra_nand_chip *ra, uint8_t *oob, size_t size, 
++			     int mode, int ooboffs) 
++{
++	size_t oobsize = 1<<ra->oob_shift;
++	uint8_t *buf = ra->buffers + (1<<ra->page_shift);
++	int retsize=0;
++
++	ra_dbg("%s: size:%x, mode:%x, offs:%x  \n", __func__, size, mode, ooboffs);
++
++	switch(mode) {
++	case MTD_OPS_PLACE_OOB:
++	case MTD_OPS_RAW:
++		if (ooboffs > oobsize)
++			return -1;
++
++		size = min(size, oobsize - ooboffs);
++		memcpy(oob, buf + ooboffs, size);
++		return size;
++
++	case MTD_OPS_AUTO_OOB: {
++		struct nand_oobfree *free;
++		uint32_t woffs = ooboffs;
++
++		if (ooboffs > ra->oob->oobavail) 
++			return -1;
++		
++		size = min(size, ra->oob->oobavail - ooboffs);
++		for(free = ra->oob->oobfree; free->length && size; free++) {
++			int wlen = free->length - woffs;
++			int bytes = 0;
++
++			/* Write request not from offset 0 ? */
++			if (wlen <= 0) {
++				woffs = -wlen;
++				continue;
++			}
++			
++			bytes = min_t(size_t, size, wlen);
++			memcpy (oob, buf + free->offset + woffs, bytes);
++			woffs = 0;
++			oob += bytes;
++			size -= bytes;
++			retsize += bytes;
++		}
++		return retsize;
++	}
++	default:
++		BUG();
++	}
++	
++	return -1;
++}
++
++/**
++ * nand_do_write_ops - [Internal] NAND write with ECC
++ * @mtd:	MTD device structure
++ * @to:		offset to write to
++ * @ops:	oob operations description structure
++ *
++ * NAND write with ECC
++ */
++static int nand_do_write_ops(struct ra_nand_chip *ra, loff_t to,
++			     struct mtd_oob_ops *ops)
++{
++	int page;
++	uint32_t datalen = ops->len;
++	uint32_t ooblen = ops->ooblen;
++	uint8_t *oob = ops->oobbuf;
++	uint8_t *data = ops->datbuf;
++	int pagesize = (1<<ra->page_shift);
++	int pagemask = (pagesize -1);
++	int oobsize = 1<<ra->oob_shift;
++	loff_t addr = to;
++	//int i = 0; //for ra_dbg only
++
++	ra_dbg("%s: to:%x, ops data:%p, oob:%p datalen:%x ooblen:%x, ooboffs:%x oobmode:%x \n", 
++	       __func__, (unsigned int)to, data, oob, datalen, ooblen, ops->ooboffs, ops->mode);
++
++	ops->retlen = 0;
++	ops->oobretlen = 0;
++
++
++	/* Invalidate the page cache, when we write to the cached page */
++	ra->buffers_page = -1;
++
++	
++	if (data ==0)
++		datalen = 0;
++	
++	// oob sequential (burst) write
++	if (datalen == 0 && ooblen) {
++		int len = ((ooblen + ops->ooboffs) + (ra->oob->oobavail - 1)) / ra->oob->oobavail * oobsize;
++
++		/* select chip, and check if it is write protected */
++		if (nfc_enable_chip(ra, addr, 0))
++			return -EIO;
++
++		//FIXME, need sanity check of block boundary
++		page = (int)((to & ((1<<ra->chip_shift)-1)) >> ra->page_shift); //chip boundary
++		memset(ra->buffers, 0x0ff, pagesize);
++		//fixme, should we reserve the original content?
++		if (ops->mode == MTD_OPS_AUTO_OOB) {
++			nfc_read_oob(ra, page, 0, ra->buffers, len, FLAG_NONE);
++		}
++		//prepare buffers
++		if (ooblen != 8)
++		{
++			nand_write_oob_buf(ra, ra->buffers, oob, ooblen, ops->mode, ops->ooboffs);
++			// write out buffer to chip
++			nfc_write_oob(ra, page, 0, ra->buffers, len, FLAG_USE_GDMA);
++		}
++
++		ops->oobretlen = ooblen;
++		ooblen = 0;
++	}
++
++	// data sequential (burst) write
++	if (datalen && ooblen == 0) {
++		// ranfc can not support write_data_burst, since hw-ecc and fifo constraints..
++	}
++
++	// page write
++	while(datalen || ooblen) {
++		int len;
++		int ret;
++		int offs;
++		int ecc_en = 0;
++
++		ra_dbg("%s (%d): addr:%x, ops data:%p, oob:%p datalen:%x ooblen:%x, ooboffs:%x \n", 
++		       __func__, i++, (unsigned int)addr, data, oob, datalen, ooblen, ops->ooboffs);
++
++		page = (int)((addr & ((1<<ra->chip_shift)-1)) >> ra->page_shift); //chip boundary
++		
++		/* select chip, and check if it is write protected */
++		if (nfc_enable_chip(ra, addr, 0))
++			return -EIO;
++
++		// oob write
++		if (ops->mode == MTD_OPS_AUTO_OOB) {
++			//fixme, this path is not yet varified 
++			nfc_read_oob(ra, page, 0, ra->buffers + pagesize, oobsize, FLAG_NONE);
++		}
++		if (oob && ooblen > 0) {
++			len = nand_write_oob_buf(ra, ra->buffers + pagesize, oob, ooblen, ops->mode, ops->ooboffs);
++			if (len < 0) 
++				return -EINVAL;
++			
++			oob += len;
++			ops->oobretlen += len;
++			ooblen -= len;
++		}
++
++		// data write
++		offs = addr & pagemask;
++		len = min_t(size_t, datalen, pagesize - offs);
++		if (data && len > 0) {
++			memcpy(ra->buffers + offs, data, len);	// we can not sure ops->buf wether is DMA-able.
++
++			data += len;
++			datalen -= len;
++			ops->retlen += len;
++
++			ecc_en = FLAG_ECC_EN;
++		}
++		ret = nfc_write_page(ra, ra->buffers, page, FLAG_USE_GDMA | FLAG_VERIFY |
++				     ((ops->mode == MTD_OPS_RAW || ops->mode == MTD_OPS_PLACE_OOB) ? 0 : ecc_en ));
++		if (ret) {
++			nand_bbt_set(ra, addr >> ra->erase_shift, BBT_TAG_BAD);
++			return ret;
++		}
++
++		nand_bbt_set(ra, addr >> ra->erase_shift, BBT_TAG_GOOD);
++
++		addr = (page+1) << ra->page_shift;
++
++	}
++	return 0;
++}
++
++/**
++ * nand_do_read_ops - [Internal] Read data with ECC
++ *
++ * @mtd:	MTD device structure
++ * @from:	offset to read from
++ * @ops:	oob ops structure
++ *
++ * Internal function. Called with chip held.
++ */
++static int nand_do_read_ops(struct ra_nand_chip *ra, loff_t from,
++			    struct mtd_oob_ops *ops)
++{
++	int page;
++	uint32_t datalen = ops->len;
++	uint32_t ooblen = ops->ooblen;
++	uint8_t *oob = ops->oobbuf;
++	uint8_t *data = ops->datbuf;
++	int pagesize = (1<<ra->page_shift);
++	int pagemask = (pagesize -1);
++	loff_t addr = from;
++	//int i = 0; //for ra_dbg only
++
++	ra_dbg("%s: addr:%x, ops data:%p, oob:%p datalen:%x ooblen:%x, ooboffs:%x \n", 
++	       __func__, (unsigned int)addr, data, oob, datalen, ooblen, ops->ooboffs);
++
++	ops->retlen = 0;
++	ops->oobretlen = 0;
++	if (data == 0)
++		datalen = 0;
++
++
++	while(datalen || ooblen) {
++		int len;
++		int ret;
++		int offs;
++
++		ra_dbg("%s (%d): addr:%x, ops data:%p, oob:%p datalen:%x ooblen:%x, ooboffs:%x \n", 
++		       __func__, i++, (unsigned int)addr, data, oob, datalen, ooblen, ops->ooboffs);
++		/* select chip */
++		if (nfc_enable_chip(ra, addr, 1) < 0)
++			return -EIO;
++
++		page = (int)((addr & ((1<<ra->chip_shift)-1)) >> ra->page_shift); 
++
++		ret = nfc_read_page(ra, ra->buffers, page, FLAG_VERIFY | 
++				    ((ops->mode == MTD_OPS_RAW || ops->mode == MTD_OPS_PLACE_OOB) ? 0: FLAG_ECC_EN ));
++		//FIXME, something strange here, some page needs 2 more tries to guarantee read success.
++		if (ret) {
++			printk("read again:\n");
++			ret = nfc_read_page(ra, ra->buffers, page, FLAG_VERIFY | 
++					    ((ops->mode == MTD_OPS_RAW || ops->mode == MTD_OPS_PLACE_OOB) ? 0: FLAG_ECC_EN ));
++
++			if (ret) {
++				printk("read again fail \n");
++				nand_bbt_set(ra, addr >> ra->erase_shift, BBT_TAG_BAD);
++				if ((ret != -EUCLEAN) && (ret != -EBADMSG)) {
++					return ret;
++				}
++				else {
++					/* ecc verification fail, but data need to be returned. */
++				}
++			}
++			else {
++				printk(" read agian susccess \n");
++			}
++		}
++
++		// oob read
++		if (oob && ooblen > 0) {
++			len = nand_read_oob_buf(ra, oob, ooblen, ops->mode, ops->ooboffs);
++			if (len < 0) {
++				printk("nand_read_oob_buf: fail return %x \n", len);
++				return -EINVAL;
++			}
++
++			oob += len;
++			ops->oobretlen += len;
++			ooblen -= len;
++		}
++
++		// data read
++		offs = addr & pagemask;
++		len = min_t(size_t, datalen, pagesize - offs);
++		if (data && len > 0) {
++			memcpy(data, ra->buffers + offs, len);	// we can not sure ops->buf wether is DMA-able.
++
++			data += len;
++			datalen -= len;
++			ops->retlen += len;
++			if (ret)
++				return ret;
++		}
++
++
++		nand_bbt_set(ra, addr >> ra->erase_shift, BBT_TAG_GOOD);
++		// address go further to next page, instead of increasing of length of write. This avoids some special cases wrong.
++		addr = (page+1) << ra->page_shift;
++	}
++	return 0;
++}
++
++static int
++ramtd_nand_erase(struct mtd_info *mtd, struct erase_info *instr)
++{
++	struct ra_nand_chip *ra = (struct ra_nand_chip *)mtd->priv;
++	int ret;
++
++	ra_dbg("%s: start:%x, len:%x \n", __func__,
++		(unsigned int)instr->addr, (unsigned int)instr->len);
++
++	nand_get_device(ra, FL_ERASING);
++	ret = _nand_erase_nand((struct ra_nand_chip *)mtd->priv, instr);
++	nand_release_device(ra);
++
++	return ret;
++}
++
++static int
++ramtd_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
++		size_t *retlen, const uint8_t *buf)
++{
++	struct ra_nand_chip *ra = mtd->priv;
++	struct mtd_oob_ops ops;
++	int ret;
++
++	ra_dbg("%s: to 0x%x len=0x%x\n", __func__, to, len);
++
++	if ((to + len) > mtd->size)
++		return -EINVAL;
++
++	if (!len)
++		return 0;
++
++	nand_get_device(ra, FL_WRITING);
++
++	memset(&ops, 0, sizeof(ops));
++	ops.len = len;
++	ops.datbuf = (uint8_t *)buf;
++	ops.oobbuf = NULL;
++	ops.mode =  MTD_OPS_AUTO_OOB;
++
++	ret = nand_do_write_ops(ra, to, &ops);
++
++	*retlen = ops.retlen;
++
++	nand_release_device(ra);
++
++	return ret;
++}
++
++static int
++ramtd_nand_read(struct mtd_info *mtd, loff_t from, size_t len,
++		size_t *retlen, uint8_t *buf)
++{
++
++	struct ra_nand_chip *ra = mtd->priv;
++	int ret;
++	struct mtd_oob_ops ops;
++
++	ra_dbg("%s: mtd:%p from:%x, len:%x, buf:%p \n", __func__, mtd, (unsigned int)from, len, buf);
++
++	/* Do not allow reads past end of device */
++	if ((from + len) > mtd->size)
++		return -EINVAL;
++	if (!len)
++		return 0;
++
++	nand_get_device(ra, FL_READING);
++
++	memset(&ops, 0, sizeof(ops));
++	ops.len = len;
++	ops.datbuf = buf;
++	ops.oobbuf = NULL;
++	ops.mode = MTD_OPS_AUTO_OOB;
++
++	ret = nand_do_read_ops(ra, from, &ops);
++
++	*retlen = ops.retlen;
++
++	nand_release_device(ra);
++
++	return ret;
++
++}
++
++static int
++ramtd_nand_readoob(struct mtd_info *mtd, loff_t from,
++			struct mtd_oob_ops *ops)
++{
++	struct ra_nand_chip *ra = mtd->priv;
++	int ret;
++
++	ra_dbg("%s: \n", __func__);
++
++	nand_get_device(ra, FL_READING);
++
++	ret = nand_do_read_ops(ra, from, ops);
++
++	nand_release_device(ra);
++
++	return ret;
++}
++
++static int
++ramtd_nand_writeoob(struct mtd_info *mtd, loff_t to,
++			struct mtd_oob_ops *ops)
++{
++	struct ra_nand_chip *ra = mtd->priv;
++	int ret;
++
++	nand_get_device(ra, FL_READING);
++	ret = nand_do_write_ops(ra, to, ops);
++	nand_release_device(ra);
++
++	return ret;
++}
++
++static int
++ramtd_nand_block_isbad(struct mtd_info *mtd, loff_t offs)
++{
++	if (offs > mtd->size)
++		return -EINVAL;
++
++	return nand_block_checkbad((struct ra_nand_chip *)mtd->priv, offs);
++}
++
++static int
++ramtd_nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
++{
++	struct ra_nand_chip *ra = mtd->priv;
++	int ret;
++
++	ra_dbg("%s: \n", __func__);
++	nand_get_device(ra, FL_WRITING);
++	ret = nand_block_markbad(ra, ofs);
++	nand_release_device(ra);
++
++	return ret;
++}
++
++// 1-bit error detection
++static int one_bit_correction(char *ecc1, char *ecc2, int *bytes, int *bits)
++{
++	// check if ecc and expected are all valid
++	char *p, nibble, crumb;
++	int i, xor, iecc1 = 0, iecc2 = 0;
++
++	printk("correction : %x %x %x\n", ecc1[0], ecc1[1], ecc1[2]);
++	printk("correction : %x %x %x\n", ecc2[0], ecc2[1], ecc2[2]);
++
++	p = (char *)ecc1;
++	for (i = 0; i < CONFIG_ECC_BYTES; i++)
++	{
++		nibble = *(p+i) & 0xf;
++		if ((nibble != 0x0) && (nibble != 0xf) && (nibble != 0x3) && (nibble != 0xc) &&
++			(nibble != 0x5) && (nibble != 0xa) && (nibble != 0x6) && (nibble != 0x9))
++			return -1;
++		nibble = ((*(p+i)) >> 4) & 0xf;
++		if ((nibble != 0x0) && (nibble != 0xf) && (nibble != 0x3) && (nibble != 0xc) &&
++			(nibble != 0x5) && (nibble != 0xa) && (nibble != 0x6) && (nibble != 0x9))
++			return -1;
++	}
++
++	p = (char *)ecc2;
++	for (i = 0; i < CONFIG_ECC_BYTES; i++)
++	{
++		nibble = *(p+i) & 0xf;
++		if ((nibble != 0x0) && (nibble != 0xf) && (nibble != 0x3) && (nibble != 0xc) &&
++			(nibble != 0x5) && (nibble != 0xa) && (nibble != 0x6) && (nibble != 0x9))
++			return -1;
++		nibble = ((*(p+i)) >> 4) & 0xf;
++		if ((nibble != 0x0) && (nibble != 0xf) && (nibble != 0x3) && (nibble != 0xc) &&
++			(nibble != 0x5) && (nibble != 0xa) && (nibble != 0x6) && (nibble != 0x9))
++			return -1;
++	}
++
++	memcpy(&iecc1, ecc1, 3);
++	memcpy(&iecc2, ecc2, 3);
++
++	xor = iecc1 ^ iecc2;
++	printk("xor = %x (%x %x)\n", xor, iecc1, iecc2);
++
++	*bytes = 0;
++	for (i = 0; i < 9; i++)
++	{
++		crumb = (xor >> (2*i)) & 0x3;
++		if ((crumb == 0x0) || (crumb == 0x3))
++			return -1;
++		if (crumb == 0x2)
++			*bytes += (1 << i);
++	}
++
++	*bits = 0;
++	for (i = 0; i < 3; i++)
++	{
++		crumb = (xor >> (18 + 2*i)) & 0x3;
++		if ((crumb == 0x0) || (crumb == 0x3))
++			return -1;
++		if (crumb == 0x2)
++			*bits += (1 << i);
++	}
++
++	return 0;
++}
++
++
++
++/************************************************************
++ * the init/exit section.
++ */
++
++static struct nand_ecclayout ra_oob_layout = {
++	.eccbytes = CONFIG_ECC_BYTES,
++	.eccpos = {5, 6, 7},
++	.oobfree = {
++		 {.offset = 0, .length = 4},
++		 {.offset = 8, .length = 8},
++		 {.offset = 0, .length = 0}
++	 },
++#define RA_CHIP_OOB_AVAIL (4+8)
++	.oobavail = RA_CHIP_OOB_AVAIL,
++	// 5th byte is bad-block flag.
++};
++
++static int
++mtk_nand_probe(struct platform_device *pdev)
++{
++        struct mtd_part_parser_data ppdata;
++	struct ra_nand_chip *ra;
++	int alloc_size, bbt_size, buffers_size, reg, err;
++	unsigned char chip_mode = 12;
++
++/*	if(ra_check_flash_type()!=BOOT_FROM_NAND) {
++		return 0;
++	}*/
++
++	//FIXME: config 512 or 2048-byte page according to HWCONF
++#if defined (CONFIG_RALINK_RT6855A)
++	reg = ra_inl(RALINK_SYSCTL_BASE+0x8c);
++	chip_mode = ((reg>>28) & 0x3)|(((reg>>22) & 0x3)<<2);
++	if (chip_mode == 1) {
++		printk("! nand 2048\n");
++		ra_or(NFC_CONF1, 1);
++		is_nand_page_2048 = 1;
++		nand_addrlen = 5;
++	}
++	else {
++		printk("! nand 512\n");
++		ra_and(NFC_CONF1, ~1);
++		is_nand_page_2048 = 0;
++		nand_addrlen = 4;
++	}	
++#elif (defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_RT6855))
++	ra_outl(RALINK_SYSCTL_BASE+0x60, ra_inl(RALINK_SYSCTL_BASE+0x60) & ~(0x3<<18));
++	reg = ra_inl(RALINK_SYSCTL_BASE+0x10);
++	chip_mode = (reg & 0x0F);
++	if((chip_mode==1)||(chip_mode==11)) {
++		ra_or(NFC_CONF1, 1);
++		is_nand_page_2048 = 1;
++		nand_addrlen = ((chip_mode!=11) ? 4 : 5);
++		printk("!!! nand page size = 2048, addr len=%d\n", nand_addrlen);
++	}
++	else {
++		ra_and(NFC_CONF1, ~1);
++		is_nand_page_2048 = 0;
++		nand_addrlen = ((chip_mode!=10) ? 3 : 4);
++		printk("!!! nand page size = 512, addr len=%d\n", nand_addrlen);
++	}			
++#else
++	is_nand_page_2048 = 0;
++	nand_addrlen = 3;
++	printk("!!! nand page size = 512, addr len=%d\n", nand_addrlen);
++#endif			
++
++#if defined (CONFIG_RALINK_RT6855A) || defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_RT6855) 
++	//config ECC location
++    ra_and(NFC_CONF1, 0xfff000ff);
++	ra_or(NFC_CONF1, ((CONFIG_ECC_OFFSET + 2) << 16) +
++						((CONFIG_ECC_OFFSET + 1) << 12) +
++						(CONFIG_ECC_OFFSET << 8));
++#endif
++
++#define ALIGNE_16(a) (((unsigned long)(a)+15) & ~15)
++	buffers_size = ALIGNE_16((1<<CONFIG_PAGE_SIZE_BIT) + (1<<CONFIG_OOBSIZE_PER_PAGE_BIT)); //ra->buffers
++	bbt_size = BBTTAG_BITS * (1<<(CONFIG_CHIP_SIZE_BIT - (CONFIG_PAGE_SIZE_BIT + CONFIG_NUMPAGE_PER_BLOCK_BIT))) / 8; //ra->bbt
++	bbt_size = ALIGNE_16(bbt_size);
++
++	alloc_size = buffers_size + bbt_size;
++	alloc_size += buffers_size; //for ra->readback_buffers
++	alloc_size += sizeof(*ra); 
++	alloc_size += sizeof(*ranfc_mtd);
++
++	//make sure gpio-0 is input
++	ra_outl(RALINK_PIO_BASE+0x24, ra_inl(RALINK_PIO_BASE+0x24) & ~0x01);
++
++	ra = (struct ra_nand_chip *)kzalloc(alloc_size, GFP_KERNEL | GFP_DMA);
++	if (!ra) {
++		printk("%s: mem alloc fail \n", __func__);
++		return -ENOMEM;
++	}
++	memset(ra, 0, alloc_size);
++
++	//dynamic
++	ra->buffers = (char *)((char *)ra + sizeof(*ra));
++	ra->readback_buffers = ra->buffers + buffers_size; 
++	ra->bbt = ra->readback_buffers + buffers_size; 
++	ranfc_mtd = (struct mtd_info *)(ra->bbt + bbt_size);
++
++	//static 
++	ra->numchips		= CONFIG_NUMCHIPS;
++	ra->chip_shift		= CONFIG_CHIP_SIZE_BIT;
++	ra->page_shift		= CONFIG_PAGE_SIZE_BIT;
++	ra->oob_shift		= CONFIG_OOBSIZE_PER_PAGE_BIT;
++	ra->erase_shift		= (CONFIG_PAGE_SIZE_BIT + CONFIG_NUMPAGE_PER_BLOCK_BIT);
++	ra->badblockpos		= CONFIG_BAD_BLOCK_POS;
++	ra_oob_layout.eccpos[0] = CONFIG_ECC_OFFSET;
++	ra_oob_layout.eccpos[1] = CONFIG_ECC_OFFSET + 1;
++	ra_oob_layout.eccpos[2] = CONFIG_ECC_OFFSET + 2;
++	ra->oob			= &ra_oob_layout;
++	ra->buffers_page	= -1;
++
++#if defined (WORKAROUND_RX_BUF_OV)
++	if (ranfc_verify) {
++		ra->sandbox_page = nand_bbt_find_sandbox(ra);
++	}
++#endif
++	ra_outl(NFC_CTRL, ra_inl(NFC_CTRL) | 0x01); //set wp to high
++	nfc_all_reset();
++
++	ranfc_mtd->type		= MTD_NANDFLASH;
++	ranfc_mtd->flags	= MTD_CAP_NANDFLASH;
++	ranfc_mtd->size		= CONFIG_NUMCHIPS * CFG_CHIPSIZE;
++	ranfc_mtd->erasesize	= CFG_BLOCKSIZE;
++	ranfc_mtd->writesize	= CFG_PAGESIZE;
++	ranfc_mtd->oobsize 	= CFG_PAGE_OOBSIZE;
++	ranfc_mtd->oobavail	= RA_CHIP_OOB_AVAIL;
++	ranfc_mtd->name		= "ra_nfc";
++	//ranfc_mtd->index
++	ranfc_mtd->ecclayout	= &ra_oob_layout;
++	//ranfc_mtd->numberaseregions
++	//ranfc_mtd->eraseregions
++	//ranfc_mtd->bansize
++	ranfc_mtd->_erase 	= ramtd_nand_erase;
++	//ranfc_mtd->point
++	//ranfc_mtd->unpoint
++	ranfc_mtd->_read		= ramtd_nand_read;
++	ranfc_mtd->_write	= ramtd_nand_write;
++	ranfc_mtd->_read_oob	= ramtd_nand_readoob;
++	ranfc_mtd->_write_oob	= ramtd_nand_writeoob;
++	//ranfc_mtd->get_fact_prot_info; ranfc_mtd->read_fact_prot_reg; 
++	//ranfc_mtd->get_user_prot_info; ranfc_mtd->read_user_prot_reg;
++	//ranfc_mtd->write_user_prot_reg; ranfc_mtd->lock_user_prot_reg;
++	//ranfc_mtd->writev; ranfc_mtd->sync; ranfc_mtd->lock; ranfc_mtd->unlock; ranfc_mtd->suspend; ranfc_mtd->resume;
++	ranfc_mtd->_block_isbad		= ramtd_nand_block_isbad;
++	ranfc_mtd->_block_markbad	= ramtd_nand_block_markbad;
++	//ranfc_mtd->reboot_notifier
++	//ranfc_mtd->ecc_stats;
++	// subpage_sht;
++
++	//ranfc_mtd->get_device; ranfc_mtd->put_device
++	ranfc_mtd->priv = ra;
++
++	ranfc_mtd->owner = THIS_MODULE;
++	ra->controller = &ra->hwcontrol;
++	mutex_init(ra->controller);
++
++	printk("%s: alloc %x, at %p , btt(%p, %x), ranfc_mtd:%p\n", 
++	       __func__ , alloc_size, ra, ra->bbt, bbt_size, ranfc_mtd);
++
++	ppdata.of_node = pdev->dev.of_node;
++	err = mtd_device_parse_register(ranfc_mtd, mtk_probe_types,
++			&ppdata, NULL, 0);
++
++	return err;
++}
++
++static int
++mtk_nand_remove(struct platform_device *pdev)
++{
++	struct ra_nand_chip *ra;
++
++	if (ranfc_mtd) {
++		ra = (struct ra_nand_chip  *)ranfc_mtd->priv;
++
++		/* Deregister partitions */
++		//del_mtd_partitions(ranfc_mtd);
++		kfree(ra);
++	}
++	return 0;
++}
++
++static const struct of_device_id mtk_nand_match[] = {
++	{ .compatible = "mtk,mt7620-nand" },
++	{},
++};
++MODULE_DEVICE_TABLE(of, mtk_nand_match);
++
++static struct platform_driver mtk_nand_driver = {
++	.probe = mtk_nand_probe,
++	.remove = mtk_nand_remove,
++	.driver = {
++		.name = "mt7620_nand",
++		.owner = THIS_MODULE,
++		.of_match_table = mtk_nand_match,
++	},
++};
++
++module_platform_driver(mtk_nand_driver);
++
++
++MODULE_LICENSE("GPL");
+Index: linux-3.10.18/drivers/mtd/maps/ralink_nand.h
+===================================================================
+--- /dev/null	1970-01-01 00:00:00.000000000 +0000
++++ linux-3.10.18/drivers/mtd/maps/ralink_nand.h	2013-11-17 17:51:50.549024547 +0100
+@@ -0,0 +1,232 @@
++#ifndef RT2880_NAND_H
++#define RT2880_NAND_H
++
++#include <linux/mtd/mtd.h>
++
++//#include "gdma.h"
++
++#define RALINK_SYSCTL_BASE		0xB0000000
++#define RALINK_PIO_BASE			0xB0000600
++#define RALINK_NAND_CTRL_BASE		0xB0000810
++#define CONFIG_RALINK_MT7620
++
++#define SKIP_BAD_BLOCK
++//#define RANDOM_GEN_BAD_BLOCK
++
++#define ra_inl(addr)  (*(volatile unsigned int *)(addr))
++#define ra_outl(addr, value)  (*(volatile unsigned int *)(addr) = (value))
++#define ra_aor(addr, a_mask, o_value)  ra_outl(addr, (ra_inl(addr) & (a_mask)) | (o_value))
++#define ra_and(addr, a_mask)  ra_aor(addr, a_mask, 0)
++#define ra_or(addr, o_value)  ra_aor(addr, -1, o_value)
++
++
++#define CONFIG_NUMCHIPS 1
++#define CONFIG_NOT_SUPPORT_WP //rt3052 has no WP signal for chip.
++//#define CONFIG_NOT_SUPPORT_RB
++
++extern int is_nand_page_2048;
++extern const unsigned int nand_size_map[2][3];
++
++//chip
++// chip geometry: SAMSUNG small size 32MB.
++#define CONFIG_CHIP_SIZE_BIT (nand_size_map[is_nand_page_2048][nand_addrlen-3]) //! (1<<NAND_SIZE_BYTE) MB
++//#define CONFIG_CHIP_SIZE_BIT (is_nand_page_2048? 29 : 25)	//! (1<<NAND_SIZE_BYTE) MB
++#define CONFIG_PAGE_SIZE_BIT (is_nand_page_2048? 11 : 9)	//! (1<<PAGE_SIZE) MB
++//#define CONFIG_SUBPAGE_BIT 1		//! these bits will be compensate by command cycle
++#define CONFIG_NUMPAGE_PER_BLOCK_BIT (is_nand_page_2048? 6 : 5)	//! order of number of pages a block. 
++#define CONFIG_OOBSIZE_PER_PAGE_BIT (is_nand_page_2048? 6 : 4)	//! byte number of oob a page.
++#define CONFIG_BAD_BLOCK_POS (is_nand_page_2048? 0 : 4)     //! offset of byte to denote bad block.
++#define CONFIG_ECC_BYTES 3      //! ecc has 3 bytes
++#define CONFIG_ECC_OFFSET (is_nand_page_2048? 6 : 5)        //! ecc starts from offset 5.
++
++//this section should not be modified.
++//#define CFG_COLUMN_ADDR_MASK ((1 << (CONFIG_PAGE_SIZE_BIT - CONFIG_SUBPAGE_BIT)) - 1)
++//#define CFG_COLUMN_ADDR_CYCLE (((CONFIG_PAGE_SIZE_BIT - CONFIG_SUBPAGE_BIT) + 7)/8) 
++//#define CFG_ROW_ADDR_CYCLE ((CONFIG_CHIP_SIZE_BIT - CONFIG_PAGE_SIZE_BIT + 7)/8) 
++//#define CFG_ADDR_CYCLE (CFG_COLUMN_ADDR_CYCLE + CFG_ROW_ADDR_CYCLE)
++
++#define CFG_COLUMN_ADDR_CYCLE   (is_nand_page_2048? 2 : 1)
++#define CFG_ROW_ADDR_CYCLE      (nand_addrlen - CFG_COLUMN_ADDR_CYCLE)
++#define CFG_ADDR_CYCLE (CFG_COLUMN_ADDR_CYCLE + CFG_ROW_ADDR_CYCLE)
++
++#define CFG_CHIPSIZE    (1 << ((CONFIG_CHIP_SIZE_BIT>=32)? 31 : CONFIG_CHIP_SIZE_BIT))
++//#define CFG_CHIPSIZE  	(1 << CONFIG_CHIP_SIZE_BIT)
++#define CFG_PAGESIZE	(1 << CONFIG_PAGE_SIZE_BIT)
++#define CFG_BLOCKSIZE 	(CFG_PAGESIZE << CONFIG_NUMPAGE_PER_BLOCK_BIT)
++#define CFG_NUMPAGE	(1 << (CONFIG_CHIP_SIZE_BIT - CONFIG_PAGE_SIZE_BIT))
++#define CFG_NUMBLOCK	(CFG_NUMPAGE >> CONFIG_NUMPAGE_PER_BLOCK_BIT)
++#define CFG_BLOCK_OOBSIZE	(1 << (CONFIG_OOBSIZE_PER_PAGE_BIT + CONFIG_NUMPAGE_PER_BLOCK_BIT))	
++#define CFG_PAGE_OOBSIZE	(1 << CONFIG_OOBSIZE_PER_PAGE_BIT)	
++
++#define NAND_BLOCK_ALIGN(addr) ((addr) & (CFG_BLOCKSIZE-1))
++#define NAND_PAGE_ALIGN(addr) ((addr) & (CFG_PAGESIZE-1))
++
++
++#define NFC_BASE 	RALINK_NAND_CTRL_BASE
++#define NFC_CTRL	(NFC_BASE + 0x0)
++#define NFC_CONF	(NFC_BASE + 0x4)
++#define NFC_CMD1	(NFC_BASE + 0x8)
++#define NFC_CMD2	(NFC_BASE + 0xc)
++#define NFC_CMD3	(NFC_BASE + 0x10)
++#define NFC_ADDR	(NFC_BASE + 0x14)
++#define NFC_DATA	(NFC_BASE + 0x18)
++#if defined (CONFIG_RALINK_RT6855) || defined (CONFIG_RALINK_RT6855A) || \
++	defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_MT7621)
++#define NFC_ECC		(NFC_BASE + 0x30)
++#else
++#define NFC_ECC		(NFC_BASE + 0x1c)
++#endif
++#define NFC_STATUS	(NFC_BASE + 0x20)
++#define NFC_INT_EN	(NFC_BASE + 0x24)
++#define NFC_INT_ST	(NFC_BASE + 0x28)
++#if defined (CONFIG_RALINK_RT6855) || defined (CONFIG_RALINK_RT6855A) || \
++	defined (CONFIG_RALINK_MT7620) || defined (CONFIG_RALINK_MT7621)
++#define NFC_CONF1	(NFC_BASE + 0x2c)
++#define NFC_ECC_P1	(NFC_BASE + 0x30)
++#define NFC_ECC_P2	(NFC_BASE + 0x34)
++#define NFC_ECC_P3	(NFC_BASE + 0x38)
++#define NFC_ECC_P4	(NFC_BASE + 0x3c)
++#define NFC_ECC_ERR1	(NFC_BASE + 0x40)
++#define NFC_ECC_ERR2	(NFC_BASE + 0x44)
++#define NFC_ECC_ERR3	(NFC_BASE + 0x48)
++#define NFC_ECC_ERR4	(NFC_BASE + 0x4c)
++#define NFC_ADDR2	(NFC_BASE + 0x50)
++#endif
++
++enum _int_stat {
++	INT_ST_ND_DONE 	= 1<<0,
++	INT_ST_TX_BUF_RDY       = 1<<1,
++	INT_ST_RX_BUF_RDY	= 1<<2,
++	INT_ST_ECC_ERR		= 1<<3,
++	INT_ST_TX_TRAS_ERR	= 1<<4,
++	INT_ST_RX_TRAS_ERR	= 1<<5,
++	INT_ST_TX_KICK_ERR	= 1<<6,
++	INT_ST_RX_KICK_ERR      = 1<<7
++};
++
++
++//#define WORKAROUND_RX_BUF_OV 1
++
++
++/*************************************************************
++ * stolen from nand.h
++ *************************************************************/
++
++/*
++ * Standard NAND flash commands
++ */
++#define NAND_CMD_READ0		0
++#define NAND_CMD_READ1		1
++#define NAND_CMD_RNDOUT		5
++#define NAND_CMD_PAGEPROG	0x10
++#define NAND_CMD_READOOB	0x50
++#define NAND_CMD_ERASE1		0x60
++#define NAND_CMD_STATUS		0x70
++#define NAND_CMD_STATUS_MULTI	0x71
++#define NAND_CMD_SEQIN		0x80
++#define NAND_CMD_RNDIN		0x85
++#define NAND_CMD_READID		0x90
++#define NAND_CMD_ERASE2		0xd0
++#define NAND_CMD_RESET		0xff
++
++/* Extended commands for large page devices */
++#define NAND_CMD_READSTART	0x30
++#define NAND_CMD_RNDOUTSTART	0xE0
++#define NAND_CMD_CACHEDPROG	0x15
++
++/* Extended commands for AG-AND device */
++/*
++ * Note: the command for NAND_CMD_DEPLETE1 is really 0x00 but
++ *       there is no way to distinguish that from NAND_CMD_READ0
++ *       until the remaining sequence of commands has been completed
++ *       so add a high order bit and mask it off in the command.
++ */
++#define NAND_CMD_DEPLETE1	0x100
++#define NAND_CMD_DEPLETE2	0x38
++#define NAND_CMD_STATUS_MULTI	0x71
++#define NAND_CMD_STATUS_ERROR	0x72
++/* multi-bank error status (banks 0-3) */
++#define NAND_CMD_STATUS_ERROR0	0x73
++#define NAND_CMD_STATUS_ERROR1	0x74
++#define NAND_CMD_STATUS_ERROR2	0x75
++#define NAND_CMD_STATUS_ERROR3	0x76
++#define NAND_CMD_STATUS_RESET	0x7f
++#define NAND_CMD_STATUS_CLEAR	0xff
++
++#define NAND_CMD_NONE		-1
++
++/* Status bits */
++#define NAND_STATUS_FAIL	0x01
++#define NAND_STATUS_FAIL_N1	0x02
++#define NAND_STATUS_TRUE_READY	0x20
++#define NAND_STATUS_READY	0x40
++#define NAND_STATUS_WP		0x80
++
++typedef enum {
++	FL_READY,
++	FL_READING,
++	FL_WRITING,
++	FL_ERASING,
++	FL_SYNCING,
++	FL_CACHEDPRG,
++	FL_PM_SUSPENDED,
++} nand_state_t;
++
++/*************************************************************/
++
++
++
++typedef enum _ra_flags {
++	FLAG_NONE	= 0,
++	FLAG_ECC_EN 	= (1<<0),
++	FLAG_USE_GDMA 	= (1<<1),
++	FLAG_VERIFY 	= (1<<2),
++} RA_FLAGS;
++
++
++#define BBTTAG_BITS		2
++#define BBTTAG_BITS_MASK	((1<<BBTTAG_BITS) -1)
++enum BBT_TAG {
++	BBT_TAG_UNKNOWN = 0, //2'b01
++	BBT_TAG_GOOD	= 3, //2'b11
++	BBT_TAG_BAD	= 2, //2'b10
++	BBT_TAG_RES	= 1, //2'b01
++};
++
++struct ra_nand_chip {
++	int	numchips;
++	int 	chip_shift;
++	int	page_shift;
++	int 	erase_shift;
++	int 	oob_shift;
++	int	badblockpos;
++#if !defined (__UBOOT__)
++	struct mutex hwcontrol;
++	struct mutex *controller;
++#endif
++	struct nand_ecclayout	*oob;
++	int 	state;
++	unsigned int 	buffers_page;
++	char	*buffers; //[CFG_PAGESIZE + CFG_PAGE_OOBSIZE];
++	char 	*readback_buffers;
++	unsigned char 	*bbt;
++#if defined (WORKAROUND_RX_BUF_OV)
++	unsigned int	 sandbox_page;	// steal a page (block) for read ECC verification
++#endif
++
++};
++
++
++
++//fixme, gdma api 
++int nand_dma_sync(void);
++void release_dma_buf(void);
++int set_gdma_ch(unsigned long dst, 
++		unsigned long src, unsigned int len, int burst_size,
++		int soft_mode, int src_req_type, int dst_req_type,
++		int src_burst_mode, int dst_burst_mode);
++
++
++
++
++#endif