drivers/mtd/nand/txx9ndfmc.c - kernel/msm-5.4 - Gitiles

 /*
  * TXx9 NAND flash memory controller driver
  * Based on RBTX49xx patch from CELF patch archive.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * (C) Copyright TOSHIBA CORPORATION 2004-2007
  * All Rights Reserved.
  */
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
 #include <linux/mtd/nand_ecc.h>
 #include <linux/mtd/partitions.h>
 #include <linux/io.h>
 #include <asm/txx9/ndfmc.h>

 /* TXX9 NDFMC Registers */
 #define TXX9_NDFDTR	0x00
 #define TXX9_NDFMCR	0x04
 #define TXX9_NDFSR	0x08
 #define TXX9_NDFISR	0x0c
 #define TXX9_NDFIMR	0x10
 #define TXX9_NDFSPR	0x14
 #define TXX9_NDFRSTR	0x18	/* not TX4939 */

 /* NDFMCR : NDFMC Mode Control */
 #define TXX9_NDFMCR_WE	0x80
 #define TXX9_NDFMCR_ECC_ALL	0x60
 #define TXX9_NDFMCR_ECC_RESET	0x60
 #define TXX9_NDFMCR_ECC_READ	0x40
 #define TXX9_NDFMCR_ECC_ON	0x20
 #define TXX9_NDFMCR_ECC_OFF	0x00
 #define TXX9_NDFMCR_CE	0x10
 #define TXX9_NDFMCR_BSPRT	0x04	/* TX4925/TX4926 only */
 #define TXX9_NDFMCR_ALE	0x02
 #define TXX9_NDFMCR_CLE	0x01
 /* TX4939 only */
 #define TXX9_NDFMCR_X16	0x0400
 #define TXX9_NDFMCR_DMAREQ_MASK	0x0300
 #define TXX9_NDFMCR_DMAREQ_NODMA	0x0000
 #define TXX9_NDFMCR_DMAREQ_128	0x0100
 #define TXX9_NDFMCR_DMAREQ_256	0x0200
 #define TXX9_NDFMCR_DMAREQ_512	0x0300
 #define TXX9_NDFMCR_CS_MASK	0x0c
 #define TXX9_NDFMCR_CS(ch)	((ch) << 2)

 /* NDFMCR : NDFMC Status */
 #define TXX9_NDFSR_BUSY	0x80
 /* TX4939 only */
 #define TXX9_NDFSR_DMARUN	0x40

 /* NDFMCR : NDFMC Reset */
 #define TXX9_NDFRSTR_RST	0x01

 struct txx9ndfmc_priv {
 	struct platform_device *dev;
 	struct nand_chip chip;
 	struct mtd_info mtd;
 	int cs;
 	const char *mtdname;
 };

 #define MAX_TXX9NDFMC_DEV	4
 struct txx9ndfmc_drvdata {
 	struct mtd_info *mtds[MAX_TXX9NDFMC_DEV];
 	void __iomem *base;
 	unsigned char hold;	/* in gbusclock */
 	unsigned char spw;	/* in gbusclock */
 	struct nand_hw_control hw_control;
 };

 static struct platform_device *mtd_to_platdev(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd->priv;
 	struct txx9ndfmc_priv *txx9_priv = chip->priv;
 	return txx9_priv->dev;
 }

 static void __iomem *ndregaddr(struct platform_device *dev, unsigned int reg)
 {
 	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
 	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;

 	return drvdata->base + (reg << plat->shift);
 }

 static u32 txx9ndfmc_read(struct platform_device *dev, unsigned int reg)
 {
 	return __raw_readl(ndregaddr(dev, reg));
 }

 static void txx9ndfmc_write(struct platform_device *dev,
 			    u32 val, unsigned int reg)
 {
 	__raw_writel(val, ndregaddr(dev, reg));
 }

 static uint8_t txx9ndfmc_read_byte(struct mtd_info *mtd)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);

 	return txx9ndfmc_read(dev, TXX9_NDFDTR);
 }

 static void txx9ndfmc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
 				int len)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);
 	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);
 	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_WE, TXX9_NDFMCR);
 	while (len--)
 		__raw_writel(*buf++, ndfdtr);
 	txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
 }

 static void txx9ndfmc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);
 	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);

 	while (len--)
 		*buf++ = __raw_readl(ndfdtr);
 }

 static int txx9ndfmc_verify_buf(struct mtd_info *mtd, const uint8_t *buf,
 				int len)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);
 	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);

 	while (len--)
 		if (*buf++ != (uint8_t)__raw_readl(ndfdtr))
 			return -EFAULT;
 	return 0;
 }

 static void txx9ndfmc_cmd_ctrl(struct mtd_info *mtd, int cmd,
 			       unsigned int ctrl)
 {
 	struct nand_chip *chip = mtd->priv;
 	struct txx9ndfmc_priv *txx9_priv = chip->priv;
 	struct platform_device *dev = txx9_priv->dev;
 	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;

 	if (ctrl & NAND_CTRL_CHANGE) {
 		u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

 		mcr &= ~(TXX9_NDFMCR_CLE | TXX9_NDFMCR_ALE | TXX9_NDFMCR_CE);
 		mcr |= ctrl & NAND_CLE ? TXX9_NDFMCR_CLE : 0;
 		mcr |= ctrl & NAND_ALE ? TXX9_NDFMCR_ALE : 0;
 		/* TXX9_NDFMCR_CE bit is 0:high 1:low */
 		mcr |= ctrl & NAND_NCE ? TXX9_NDFMCR_CE : 0;
 		if (txx9_priv->cs >= 0 && (ctrl & NAND_NCE)) {
 			mcr &= ~TXX9_NDFMCR_CS_MASK;
 			mcr |= TXX9_NDFMCR_CS(txx9_priv->cs);
 		}
 		txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
 	}
 	if (cmd != NAND_CMD_NONE)
 		txx9ndfmc_write(dev, cmd & 0xff, TXX9_NDFDTR);
 	if (plat->flags & NDFMC_PLAT_FLAG_DUMMYWRITE) {
 		/* dummy write to update external latch */
 		if ((ctrl & NAND_CTRL_CHANGE) && cmd == NAND_CMD_NONE)
 			txx9ndfmc_write(dev, 0, TXX9_NDFDTR);
 	}
 	mmiowb();
 }

 static int txx9ndfmc_dev_ready(struct mtd_info *mtd)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);

 	return !(txx9ndfmc_read(dev, TXX9_NDFSR) & TXX9_NDFSR_BUSY);
 }

 static int txx9ndfmc_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
 				   uint8_t *ecc_code)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);
 	struct nand_chip *chip = mtd->priv;
 	int eccbytes;
 	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

 	mcr &= ~TXX9_NDFMCR_ECC_ALL;
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_READ, TXX9_NDFMCR);
 	for (eccbytes = chip->ecc.bytes; eccbytes > 0; eccbytes -= 3) {
 		ecc_code[1] = txx9ndfmc_read(dev, TXX9_NDFDTR);
 		ecc_code[0] = txx9ndfmc_read(dev, TXX9_NDFDTR);
 		ecc_code[2] = txx9ndfmc_read(dev, TXX9_NDFDTR);
 		ecc_code += 3;
 	}
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
 	return 0;
 }

 static int txx9ndfmc_correct_data(struct mtd_info *mtd, unsigned char *buf,
 		unsigned char *read_ecc, unsigned char *calc_ecc)
 {
 	struct nand_chip *chip = mtd->priv;
 	int eccsize;
 	int corrected = 0;
 	int stat;

 	for (eccsize = chip->ecc.size; eccsize > 0; eccsize -= 256) {
 		stat = __nand_correct_data(buf, read_ecc, calc_ecc, 256);
 		if (stat < 0)
 			return stat;
 		corrected += stat;
 		buf += 256;
 		read_ecc += 3;
 		calc_ecc += 3;
 	}
 	return corrected;
 }

 static void txx9ndfmc_enable_hwecc(struct mtd_info *mtd, int mode)
 {
 	struct platform_device *dev = mtd_to_platdev(mtd);
 	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

 	mcr &= ~TXX9_NDFMCR_ECC_ALL;
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_RESET, TXX9_NDFMCR);
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
 	txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_ON, TXX9_NDFMCR);
 }

 static void txx9ndfmc_initialize(struct platform_device *dev)
 {
 	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
 	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
 	int tmout = 100;

 	if (plat->flags & NDFMC_PLAT_FLAG_NO_RSTR)
 		; /* no NDFRSTR.  Write to NDFSPR resets the NDFMC. */
 	else {
 		/* reset NDFMC */
 		txx9ndfmc_write(dev,
 				txx9ndfmc_read(dev, TXX9_NDFRSTR) |
 				TXX9_NDFRSTR_RST,
 				TXX9_NDFRSTR);
 		while (txx9ndfmc_read(dev, TXX9_NDFRSTR) & TXX9_NDFRSTR_RST) {
 			if (--tmout == 0) {
 				dev_err(&dev->dev, "reset failed.\n");
 				break;
 			}
 			udelay(1);
 		}
 	}
 	/* setup Hold Time, Strobe Pulse Width */
 	txx9ndfmc_write(dev, (drvdata->hold << 4) | drvdata->spw, TXX9_NDFSPR);
 	txx9ndfmc_write(dev,
 			(plat->flags & NDFMC_PLAT_FLAG_USE_BSPRT) ?
 			TXX9_NDFMCR_BSPRT : 0, TXX9_NDFMCR);
 }

 #define TXX9NDFMC_NS_TO_CYC(gbusclk, ns) \
 	DIV_ROUND_UP((ns) * DIV_ROUND_UP(gbusclk, 1000), 1000000)

 static int txx9ndfmc_nand_scan(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd->priv;
 	int ret;

 	ret = nand_scan_ident(mtd, 1, NULL);
 	if (!ret) {
 		if (mtd->writesize >= 512) {
 			/* Hardware ECC 6 byte ECC per 512 Byte data */
 			chip->ecc.size = 512;
 			chip->ecc.bytes = 6;
 		}
 		ret = nand_scan_tail(mtd);
 	}
 	return ret;
 }

 static int __init txx9ndfmc_probe(struct platform_device *dev)
 {
 	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
 	int hold, spw;
 	int i;
 	struct txx9ndfmc_drvdata *drvdata;
 	unsigned long gbusclk = plat->gbus_clock;
 	struct resource *res;

 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;
 	drvdata = devm_kzalloc(&dev->dev, sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata)
 		return -ENOMEM;
 	drvdata->base = devm_request_and_ioremap(&dev->dev, res);
 	if (!drvdata->base)
 		return -EBUSY;

 	hold = plat->hold ?: 20; /* tDH */
 	spw = plat->spw ?: 90; /* max(tREADID, tWP, tRP) */

 	hold = TXX9NDFMC_NS_TO_CYC(gbusclk, hold);
 	spw = TXX9NDFMC_NS_TO_CYC(gbusclk, spw);
 	if (plat->flags & NDFMC_PLAT_FLAG_HOLDADD)
 		hold -= 2;	/* actual hold time : (HOLD + 2) BUSCLK */
 	spw -= 1;	/* actual wait time : (SPW + 1) BUSCLK */
 	hold = clamp(hold, 1, 15);
 	drvdata->hold = hold;
 	spw = clamp(spw, 1, 15);
 	drvdata->spw = spw;
 	dev_info(&dev->dev, "CLK:%ldMHz HOLD:%d SPW:%d\n",
 		 (gbusclk + 500000) / 1000000, hold, spw);

 	spin_lock_init(&drvdata->hw_control.lock);
 	init_waitqueue_head(&drvdata->hw_control.wq);

 	platform_set_drvdata(dev, drvdata);
 	txx9ndfmc_initialize(dev);

 	for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
 		struct txx9ndfmc_priv *txx9_priv;
 		struct nand_chip *chip;
 		struct mtd_info *mtd;

 		if (!(plat->ch_mask & (1 << i)))
 			continue;
 		txx9_priv = kzalloc(sizeof(struct txx9ndfmc_priv),
 				    GFP_KERNEL);
 		if (!txx9_priv) {
 			dev_err(&dev->dev, "Unable to allocate "
 				"TXx9 NDFMC MTD device structure.\n");
 			continue;
 		}
 		chip = &txx9_priv->chip;
 		mtd = &txx9_priv->mtd;
 		mtd->owner = THIS_MODULE;

 		mtd->priv = chip;

 		chip->read_byte = txx9ndfmc_read_byte;
 		chip->read_buf = txx9ndfmc_read_buf;
 		chip->write_buf = txx9ndfmc_write_buf;
 		chip->verify_buf = txx9ndfmc_verify_buf;
 		chip->cmd_ctrl = txx9ndfmc_cmd_ctrl;
 		chip->dev_ready = txx9ndfmc_dev_ready;
 		chip->ecc.calculate = txx9ndfmc_calculate_ecc;
 		chip->ecc.correct = txx9ndfmc_correct_data;
 		chip->ecc.hwctl = txx9ndfmc_enable_hwecc;
 		chip->ecc.mode = NAND_ECC_HW;
 		/* txx9ndfmc_nand_scan will overwrite ecc.size and ecc.bytes */
 		chip->ecc.size = 256;
 		chip->ecc.bytes = 3;
 		chip->chip_delay = 100;
 		chip->controller = &drvdata->hw_control;

 		chip->priv = txx9_priv;
 		txx9_priv->dev = dev;

 		if (plat->ch_mask != 1) {
 			txx9_priv->cs = i;
 			txx9_priv->mtdname = kasprintf(GFP_KERNEL, "%s.%u",
 						       dev_name(&dev->dev), i);
 		} else {
 			txx9_priv->cs = -1;
 			txx9_priv->mtdname = kstrdup(dev_name(&dev->dev),
 						     GFP_KERNEL);
 		}
 		if (!txx9_priv->mtdname) {
 			kfree(txx9_priv);
 			dev_err(&dev->dev, "Unable to allocate MTD name.\n");
 			continue;
 		}
 		if (plat->wide_mask & (1 << i))
 			chip->options |= NAND_BUSWIDTH_16;

 		if (txx9ndfmc_nand_scan(mtd)) {
 			kfree(txx9_priv->mtdname);
 			kfree(txx9_priv);
 			continue;
 		}
 		mtd->name = txx9_priv->mtdname;

 		mtd_device_parse_register(mtd, NULL, 0, NULL, 0);
 		drvdata->mtds[i] = mtd;
 	}

 	return 0;
 }

 static int __exit txx9ndfmc_remove(struct platform_device *dev)
 {
 	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
 	int i;

 	platform_set_drvdata(dev, NULL);
 	if (!drvdata)
 		return 0;
 	for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
 		struct mtd_info *mtd = drvdata->mtds[i];
 		struct nand_chip *chip;
 		struct txx9ndfmc_priv *txx9_priv;

 		if (!mtd)
 			continue;
 		chip = mtd->priv;
 		txx9_priv = chip->priv;

 		nand_release(mtd);
 		kfree(txx9_priv->mtdname);
 		kfree(txx9_priv);
 	}
 	return 0;
 }

 #ifdef CONFIG_PM
 static int txx9ndfmc_resume(struct platform_device *dev)
 {
 	if (platform_get_drvdata(dev))
 		txx9ndfmc_initialize(dev);
 	return 0;
 }
 #else
 #define txx9ndfmc_resume NULL
 #endif

 static struct platform_driver txx9ndfmc_driver = {
 	.remove		= __exit_p(txx9ndfmc_remove),
 	.resume		= txx9ndfmc_resume,
 	.driver		= {
 		.name	= "txx9ndfmc",
 		.owner	= THIS_MODULE,
 	},
 };

 static int __init txx9ndfmc_init(void)
 {
 	return platform_driver_probe(&txx9ndfmc_driver, txx9ndfmc_probe);
 }

 static void __exit txx9ndfmc_exit(void)
 {
 	platform_driver_unregister(&txx9ndfmc_driver);
 }

 module_init(txx9ndfmc_init);
 module_exit(txx9ndfmc_exit);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("TXx9 SoC NAND flash controller driver");
 MODULE_ALIAS("platform:txx9ndfmc");
	/*
	* TXx9 NAND flash memory controller driver
	* Based on RBTX49xx patch from CELF patch archive.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* (C) Copyright TOSHIBA CORPORATION 2004-2007
	* All Rights Reserved.
	*/
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/delay.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/nand.h>
	#include <linux/mtd/nand_ecc.h>
	#include <linux/mtd/partitions.h>
	#include <linux/io.h>
	#include <asm/txx9/ndfmc.h>

	/* TXX9 NDFMC Registers */
	#define TXX9_NDFDTR 0x00
	#define TXX9_NDFMCR 0x04
	#define TXX9_NDFSR 0x08
	#define TXX9_NDFISR 0x0c
	#define TXX9_NDFIMR 0x10
	#define TXX9_NDFSPR 0x14
	#define TXX9_NDFRSTR 0x18 /* not TX4939 */

	/* NDFMCR : NDFMC Mode Control */
	#define TXX9_NDFMCR_WE 0x80
	#define TXX9_NDFMCR_ECC_ALL 0x60
	#define TXX9_NDFMCR_ECC_RESET 0x60
	#define TXX9_NDFMCR_ECC_READ 0x40
	#define TXX9_NDFMCR_ECC_ON 0x20
	#define TXX9_NDFMCR_ECC_OFF 0x00
	#define TXX9_NDFMCR_CE 0x10
	#define TXX9_NDFMCR_BSPRT 0x04 /* TX4925/TX4926 only */
	#define TXX9_NDFMCR_ALE 0x02
	#define TXX9_NDFMCR_CLE 0x01
	/* TX4939 only */
	#define TXX9_NDFMCR_X16 0x0400
	#define TXX9_NDFMCR_DMAREQ_MASK 0x0300
	#define TXX9_NDFMCR_DMAREQ_NODMA 0x0000
	#define TXX9_NDFMCR_DMAREQ_128 0x0100
	#define TXX9_NDFMCR_DMAREQ_256 0x0200
	#define TXX9_NDFMCR_DMAREQ_512 0x0300
	#define TXX9_NDFMCR_CS_MASK 0x0c
	#define TXX9_NDFMCR_CS(ch) ((ch) << 2)

	/* NDFMCR : NDFMC Status */
	#define TXX9_NDFSR_BUSY 0x80
	/* TX4939 only */
	#define TXX9_NDFSR_DMARUN 0x40

	/* NDFMCR : NDFMC Reset */
	#define TXX9_NDFRSTR_RST 0x01

	struct txx9ndfmc_priv {
	struct platform_device *dev;
	struct nand_chip chip;
	struct mtd_info mtd;
	int cs;
	const char *mtdname;
	};

	#define MAX_TXX9NDFMC_DEV 4
	struct txx9ndfmc_drvdata {
	struct mtd_info *mtds[MAX_TXX9NDFMC_DEV];
	void __iomem *base;
	unsigned char hold; /* in gbusclock */
	unsigned char spw; /* in gbusclock */
	struct nand_hw_control hw_control;
	};

	static struct platform_device mtd_to_platdev(struct mtd_info mtd)
	{
	struct nand_chip *chip = mtd->priv;
	struct txx9ndfmc_priv *txx9_priv = chip->priv;
	return txx9_priv->dev;
	}

	static void __iomem ndregaddr(struct platform_device dev, unsigned int reg)
	{
	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;

	return drvdata->base + (reg << plat->shift);
	}

	static u32 txx9ndfmc_read(struct platform_device *dev, unsigned int reg)
	{
	return __raw_readl(ndregaddr(dev, reg));
	}

	static void txx9ndfmc_write(struct platform_device *dev,
	u32 val, unsigned int reg)
	{
	__raw_writel(val, ndregaddr(dev, reg));
	}

	static uint8_t txx9ndfmc_read_byte(struct mtd_info *mtd)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);

	return txx9ndfmc_read(dev, TXX9_NDFDTR);
	}

	static void txx9ndfmc_write_buf(struct mtd_info mtd, const uint8_t buf,
	int len)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);
	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);
	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_WE, TXX9_NDFMCR);
	while (len--)
	__raw_writel(*buf++, ndfdtr);
	txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
	}

	static void txx9ndfmc_read_buf(struct mtd_info mtd, uint8_t buf, int len)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);
	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);

	while (len--)
	*buf++ = __raw_readl(ndfdtr);
	}

	static int txx9ndfmc_verify_buf(struct mtd_info mtd, const uint8_t buf,
	int len)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);
	void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);

	while (len--)
	if (*buf++ != (uint8_t)__raw_readl(ndfdtr))
	return -EFAULT;
	return 0;
	}

	static void txx9ndfmc_cmd_ctrl(struct mtd_info *mtd, int cmd,
	unsigned int ctrl)
	{
	struct nand_chip *chip = mtd->priv;
	struct txx9ndfmc_priv *txx9_priv = chip->priv;
	struct platform_device *dev = txx9_priv->dev;
	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;

	if (ctrl & NAND_CTRL_CHANGE) {
	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

	mcr &= ~(TXX9_NDFMCR_CLE \| TXX9_NDFMCR_ALE \| TXX9_NDFMCR_CE);
	mcr \|= ctrl & NAND_CLE ? TXX9_NDFMCR_CLE : 0;
	mcr \|= ctrl & NAND_ALE ? TXX9_NDFMCR_ALE : 0;
	/* TXX9_NDFMCR_CE bit is 0:high 1:low */
	mcr \|= ctrl & NAND_NCE ? TXX9_NDFMCR_CE : 0;
	if (txx9_priv->cs >= 0 && (ctrl & NAND_NCE)) {
	mcr &= ~TXX9_NDFMCR_CS_MASK;
	mcr \|= TXX9_NDFMCR_CS(txx9_priv->cs);
	}
	txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
	}
	if (cmd != NAND_CMD_NONE)
	txx9ndfmc_write(dev, cmd & 0xff, TXX9_NDFDTR);
	if (plat->flags & NDFMC_PLAT_FLAG_DUMMYWRITE) {
	/* dummy write to update external latch */
	if ((ctrl & NAND_CTRL_CHANGE) && cmd == NAND_CMD_NONE)
	txx9ndfmc_write(dev, 0, TXX9_NDFDTR);
	}
	mmiowb();
	}

	static int txx9ndfmc_dev_ready(struct mtd_info *mtd)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);

	return !(txx9ndfmc_read(dev, TXX9_NDFSR) & TXX9_NDFSR_BUSY);
	}

	static int txx9ndfmc_calculate_ecc(struct mtd_info mtd, const uint8_t dat,
	uint8_t *ecc_code)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);
	struct nand_chip *chip = mtd->priv;
	int eccbytes;
	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

	mcr &= ~TXX9_NDFMCR_ECC_ALL;
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_READ, TXX9_NDFMCR);
	for (eccbytes = chip->ecc.bytes; eccbytes > 0; eccbytes -= 3) {
	ecc_code[1] = txx9ndfmc_read(dev, TXX9_NDFDTR);
	ecc_code[0] = txx9ndfmc_read(dev, TXX9_NDFDTR);
	ecc_code[2] = txx9ndfmc_read(dev, TXX9_NDFDTR);
	ecc_code += 3;
	}
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
	return 0;
	}

	static int txx9ndfmc_correct_data(struct mtd_info mtd, unsigned char buf,
	unsigned char read_ecc, unsigned char calc_ecc)
	{
	struct nand_chip *chip = mtd->priv;
	int eccsize;
	int corrected = 0;
	int stat;

	for (eccsize = chip->ecc.size; eccsize > 0; eccsize -= 256) {
	stat = __nand_correct_data(buf, read_ecc, calc_ecc, 256);
	if (stat < 0)
	return stat;
	corrected += stat;
	buf += 256;
	read_ecc += 3;
	calc_ecc += 3;
	}
	return corrected;
	}

	static void txx9ndfmc_enable_hwecc(struct mtd_info *mtd, int mode)
	{
	struct platform_device *dev = mtd_to_platdev(mtd);
	u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);

	mcr &= ~TXX9_NDFMCR_ECC_ALL;
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_RESET, TXX9_NDFMCR);
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
	txx9ndfmc_write(dev, mcr \| TXX9_NDFMCR_ECC_ON, TXX9_NDFMCR);
	}

	static void txx9ndfmc_initialize(struct platform_device *dev)
	{
	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
	int tmout = 100;

	if (plat->flags & NDFMC_PLAT_FLAG_NO_RSTR)
	; /* no NDFRSTR. Write to NDFSPR resets the NDFMC. */
	else {
	/* reset NDFMC */
	txx9ndfmc_write(dev,
	txx9ndfmc_read(dev, TXX9_NDFRSTR) \|
	TXX9_NDFRSTR_RST,
	TXX9_NDFRSTR);
	while (txx9ndfmc_read(dev, TXX9_NDFRSTR) & TXX9_NDFRSTR_RST) {
	if (--tmout == 0) {
	dev_err(&dev->dev, "reset failed.\n");
	break;
	}
	udelay(1);
	}
	}
	/* setup Hold Time, Strobe Pulse Width */
	txx9ndfmc_write(dev, (drvdata->hold << 4) \| drvdata->spw, TXX9_NDFSPR);
	txx9ndfmc_write(dev,
	(plat->flags & NDFMC_PLAT_FLAG_USE_BSPRT) ?
	TXX9_NDFMCR_BSPRT : 0, TXX9_NDFMCR);
	}

	#define TXX9NDFMC_NS_TO_CYC(gbusclk, ns) \
	DIV_ROUND_UP((ns) * DIV_ROUND_UP(gbusclk, 1000), 1000000)

	static int txx9ndfmc_nand_scan(struct mtd_info *mtd)
	{
	struct nand_chip *chip = mtd->priv;
	int ret;

	ret = nand_scan_ident(mtd, 1, NULL);
	if (!ret) {
	if (mtd->writesize >= 512) {
	/* Hardware ECC 6 byte ECC per 512 Byte data */
	chip->ecc.size = 512;
	chip->ecc.bytes = 6;
	}
	ret = nand_scan_tail(mtd);
	}
	return ret;
	}

	static int __init txx9ndfmc_probe(struct platform_device *dev)
	{
	struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
	int hold, spw;
	int i;
	struct txx9ndfmc_drvdata *drvdata;
	unsigned long gbusclk = plat->gbus_clock;
	struct resource *res;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
	return -ENODEV;
	drvdata = devm_kzalloc(&dev->dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata)
	return -ENOMEM;
	drvdata->base = devm_request_and_ioremap(&dev->dev, res);
	if (!drvdata->base)
	return -EBUSY;

	hold = plat->hold ?: 20; /* tDH */
	spw = plat->spw ?: 90; /* max(tREADID, tWP, tRP) */

	hold = TXX9NDFMC_NS_TO_CYC(gbusclk, hold);
	spw = TXX9NDFMC_NS_TO_CYC(gbusclk, spw);
	if (plat->flags & NDFMC_PLAT_FLAG_HOLDADD)
	hold -= 2; /* actual hold time : (HOLD + 2) BUSCLK */
	spw -= 1; /* actual wait time : (SPW + 1) BUSCLK */
	hold = clamp(hold, 1, 15);
	drvdata->hold = hold;
	spw = clamp(spw, 1, 15);
	drvdata->spw = spw;
	dev_info(&dev->dev, "CLK:%ldMHz HOLD:%d SPW:%d\n",
	(gbusclk + 500000) / 1000000, hold, spw);

	spin_lock_init(&drvdata->hw_control.lock);
	init_waitqueue_head(&drvdata->hw_control.wq);

	platform_set_drvdata(dev, drvdata);
	txx9ndfmc_initialize(dev);

	for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
	struct txx9ndfmc_priv *txx9_priv;
	struct nand_chip *chip;
	struct mtd_info *mtd;

	if (!(plat->ch_mask & (1 << i)))
	continue;
	txx9_priv = kzalloc(sizeof(struct txx9ndfmc_priv),
	GFP_KERNEL);
	if (!txx9_priv) {
	dev_err(&dev->dev, "Unable to allocate "
	"TXx9 NDFMC MTD device structure.\n");
	continue;
	}
	chip = &txx9_priv->chip;
	mtd = &txx9_priv->mtd;
	mtd->owner = THIS_MODULE;

	mtd->priv = chip;

	chip->read_byte = txx9ndfmc_read_byte;
	chip->read_buf = txx9ndfmc_read_buf;
	chip->write_buf = txx9ndfmc_write_buf;
	chip->verify_buf = txx9ndfmc_verify_buf;
	chip->cmd_ctrl = txx9ndfmc_cmd_ctrl;
	chip->dev_ready = txx9ndfmc_dev_ready;
	chip->ecc.calculate = txx9ndfmc_calculate_ecc;
	chip->ecc.correct = txx9ndfmc_correct_data;
	chip->ecc.hwctl = txx9ndfmc_enable_hwecc;
	chip->ecc.mode = NAND_ECC_HW;
	/* txx9ndfmc_nand_scan will overwrite ecc.size and ecc.bytes */
	chip->ecc.size = 256;
	chip->ecc.bytes = 3;
	chip->chip_delay = 100;
	chip->controller = &drvdata->hw_control;

	chip->priv = txx9_priv;
	txx9_priv->dev = dev;

	if (plat->ch_mask != 1) {
	txx9_priv->cs = i;
	txx9_priv->mtdname = kasprintf(GFP_KERNEL, "%s.%u",
	dev_name(&dev->dev), i);
	} else {
	txx9_priv->cs = -1;
	txx9_priv->mtdname = kstrdup(dev_name(&dev->dev),
	GFP_KERNEL);
	}
	if (!txx9_priv->mtdname) {
	kfree(txx9_priv);
	dev_err(&dev->dev, "Unable to allocate MTD name.\n");
	continue;
	}
	if (plat->wide_mask & (1 << i))
	chip->options \|= NAND_BUSWIDTH_16;

	if (txx9ndfmc_nand_scan(mtd)) {
	kfree(txx9_priv->mtdname);
	kfree(txx9_priv);
	continue;
	}
	mtd->name = txx9_priv->mtdname;

	mtd_device_parse_register(mtd, NULL, 0, NULL, 0);
	drvdata->mtds[i] = mtd;
	}

	return 0;
	}

	static int __exit txx9ndfmc_remove(struct platform_device *dev)
	{
	struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
	int i;

	platform_set_drvdata(dev, NULL);
	if (!drvdata)
	return 0;
	for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
	struct mtd_info *mtd = drvdata->mtds[i];
	struct nand_chip *chip;
	struct txx9ndfmc_priv *txx9_priv;

	if (!mtd)
	continue;
	chip = mtd->priv;
	txx9_priv = chip->priv;

	nand_release(mtd);
	kfree(txx9_priv->mtdname);
	kfree(txx9_priv);
	}
	return 0;
	}

	#ifdef CONFIG_PM
	static int txx9ndfmc_resume(struct platform_device *dev)
	{
	if (platform_get_drvdata(dev))
	txx9ndfmc_initialize(dev);
	return 0;
	}
	#else
	#define txx9ndfmc_resume NULL
	#endif

	static struct platform_driver txx9ndfmc_driver = {
	.remove = __exit_p(txx9ndfmc_remove),
	.resume = txx9ndfmc_resume,
	.driver = {
	.name = "txx9ndfmc",
	.owner = THIS_MODULE,
	},
	};

	static int __init txx9ndfmc_init(void)
	{
	return platform_driver_probe(&txx9ndfmc_driver, txx9ndfmc_probe);
	}

	static void __exit txx9ndfmc_exit(void)
	{
	platform_driver_unregister(&txx9ndfmc_driver);
	}

	module_init(txx9ndfmc_init);
	module_exit(txx9ndfmc_exit);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("TXx9 SoC NAND flash controller driver");
	MODULE_ALIAS("platform:txx9ndfmc");