Merge tag 'nand/for-4.8' of github.com:linux-nand/linux into mtd

Pull NAND changes from Boris Brezillon:
"""
This pull request contains only one notable change:
* Addition of the MTK NAND controller driver

And a bunch of specific NAND driver improvements/fixes. Here are the
changes that are worth mentioning:
* A few fixes/improvements for the xway NAND controller driver
* A few fixes for the sunxi NAND controller driver
* Support for DMA in the sunxi NAND driver
* Support for the sunxi NAND controller IP embedded in A23/A33 SoCs
* Addition for bitflips detection in erased pages to the brcmnand driver
* Support for new brcmnand IPs
* Update of the OMAP-GPMC binding to support DMA channel description
"""

Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt

···
 			0 maps to GPMC_WAIT0 pin.
  - gpio-cells:		Must be set to 2
 
+Required properties when using NAND prefetch dma:
+ - dmas			GPMC NAND prefetch dma channel
+ - dma-names		Must be set to "rxtx"
+
 Timing properties for child nodes. All are optional and default to 0.
 
  - gpmc,sync-clk-ps:	Minimum clock period for synchronous mode, in picoseconds
···
 		ti,hwmods = "gpmc";
 		reg = <0x50000000 0x2000>;
 		interrupts = <100>;
-
+		dmas = <&edma 52 0>;
+		dma-names = "rxtx";
 		gpmc,num-cs = <8>;
 		gpmc,num-waitpins = <2>;
 		#address-cells = <2>;

Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt

···
                          brcm,brcmnand-v6.2
                          brcm,brcmnand-v7.0
                          brcm,brcmnand-v7.1
+                         brcm,brcmnand-v7.2
                          brcm,brcmnand
 - reg              : the register start and length for NAND register region.
                      (optional) Flash DMA register range (if present)

Documentation/devicetree/bindings/mtd/gpmc-nand.txt

···
 
 		"prefetch-polled"	Prefetch polled mode (default)
 		"polled"		Polled mode, without prefetch
-		"prefetch-dma"		Prefetch enabled sDMA mode
+		"prefetch-dma"		Prefetch enabled DMA mode
 		"prefetch-irq"		Prefetch enabled irq mode
 
  - elm_id:	<deprecated> use "ti,elm-id" instead

Documentation/devicetree/bindings/mtd/mtk-nand.txt

···
+MTK SoCs NAND FLASH controller (NFC) DT binding
+
+This file documents the device tree bindings for MTK SoCs NAND controllers.
+The functional split of the controller requires two drivers to operate:
+the nand controller interface driver and the ECC engine driver.
+
+The hardware description for both devices must be captured as device
+tree nodes.
+
+1) NFC NAND Controller Interface (NFI):
+=======================================
+
+The first part of NFC is NAND Controller Interface (NFI) HW.
+Required NFI properties:
+- compatible:			Should be "mediatek,mtxxxx-nfc".
+- reg:				Base physical address and size of NFI.
+- interrupts:			Interrupts of NFI.
+- clocks:			NFI required clocks.
+- clock-names:			NFI clocks internal name.
+- status:			Disabled default. Then set "okay" by platform.
+- ecc-engine:			Required ECC Engine node.
+- #address-cells:		NAND chip index, should be 1.
+- #size-cells:			Should be 0.
+
+Example:
+
+	nandc: nfi@1100d000 {
+		compatible = "mediatek,mt2701-nfc";
+		reg = <0 0x1100d000 0 0x1000>;
+		interrupts = <GIC_SPI 56 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&pericfg CLK_PERI_NFI>,
+			 <&pericfg CLK_PERI_NFI_PAD>;
+		clock-names = "nfi_clk", "pad_clk";
+		status = "disabled";
+		ecc-engine = <&bch>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+        };
+
+Platform related properties, should be set in {platform_name}.dts:
+- children nodes:	NAND chips.
+
+Children nodes properties:
+- reg:			Chip Select Signal, default 0.
+			Set as reg = <0>, <1> when need 2 CS.
+Optional:
+- nand-on-flash-bbt:	Store BBT on NAND Flash.
+- nand-ecc-mode:	the NAND ecc mode (check driver for supported modes)
+- nand-ecc-step-size:	Number of data bytes covered by a single ECC step.
+			valid values: 512 and 1024.
+			1024 is recommended for large page NANDs.
+- nand-ecc-strength:	Number of bits to correct per ECC step.
+			The valid values that the controller supports are: 4, 6,
+			8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 40, 44,
+			48, 52, 56, 60.
+			The strength should be calculated as follows:
+			E = (S - F) * 8 / 14
+			S = O / (P / Q)
+				E :	nand-ecc-strength.
+				S :	spare size per sector.
+				F :	FDM size, should be in the range [1,8].
+					It is used to store free oob data.
+				O :	oob size.
+				P :	page size.
+				Q :	nand-ecc-step-size.
+			If the result does not match any one of the listed
+			choices above, please select the smaller valid value from
+			the list.
+			(otherwise the driver will do the adjustment at runtime)
+- pinctrl-names:	Default NAND pin GPIO setting name.
+- pinctrl-0:		GPIO setting node.
+
+Example:
+	&pio {
+		nand_pins_default: nanddefault {
+			pins_dat {
+				pinmux = <MT2701_PIN_111_MSDC0_DAT7__FUNC_NLD7>,
+					 <MT2701_PIN_112_MSDC0_DAT6__FUNC_NLD6>,
+					 <MT2701_PIN_114_MSDC0_DAT4__FUNC_NLD4>,
+					 <MT2701_PIN_118_MSDC0_DAT3__FUNC_NLD3>,
+					 <MT2701_PIN_121_MSDC0_DAT0__FUNC_NLD0>,
+					 <MT2701_PIN_120_MSDC0_DAT1__FUNC_NLD1>,
+					 <MT2701_PIN_113_MSDC0_DAT5__FUNC_NLD5>,
+					 <MT2701_PIN_115_MSDC0_RSTB__FUNC_NLD8>,
+					 <MT2701_PIN_119_MSDC0_DAT2__FUNC_NLD2>;
+				input-enable;
+				drive-strength = <MTK_DRIVE_8mA>;
+				bias-pull-up;
+			};
+
+			pins_we {
+				pinmux = <MT2701_PIN_117_MSDC0_CLK__FUNC_NWEB>;
+				drive-strength = <MTK_DRIVE_8mA>;
+				bias-pull-up = <MTK_PUPD_SET_R1R0_10>;
+			};
+
+			pins_ale {
+				pinmux = <MT2701_PIN_116_MSDC0_CMD__FUNC_NALE>;
+				drive-strength = <MTK_DRIVE_8mA>;
+				bias-pull-down = <MTK_PUPD_SET_R1R0_10>;
+			};
+		};
+	};
+
+	&nandc {
+		status = "okay";
+		pinctrl-names = "default";
+		pinctrl-0 = <&nand_pins_default>;
+		nand@0 {
+			reg = <0>;
+			nand-on-flash-bbt;
+			nand-ecc-mode = "hw";
+			nand-ecc-strength = <24>;
+			nand-ecc-step-size = <1024>;
+		};
+	};
+
+NAND chip optional subnodes:
+- Partitions, see Documentation/devicetree/bindings/mtd/partition.txt
+
+Example:
+	nand@0 {
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			preloader@0 {
+				label = "pl";
+				read-only;
+				reg = <0x00000000 0x00400000>;
+			};
+			android@0x00400000 {
+				label = "android";
+				reg = <0x00400000 0x12c00000>;
+			};
+		};
+	};
+
+2) ECC Engine:
+==============
+
+Required BCH properties:
+- compatible:	Should be "mediatek,mtxxxx-ecc".
+- reg:		Base physical address and size of ECC.
+- interrupts:	Interrupts of ECC.
+- clocks:	ECC required clocks.
+- clock-names:	ECC clocks internal name.
+- status:	Disabled default. Then set "okay" by platform.
+
+Example:
+
+	bch: ecc@1100e000 {
+		compatible = "mediatek,mt2701-ecc";
+		reg = <0 0x1100e000 0 0x1000>;
+		interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&pericfg CLK_PERI_NFI_ECC>;
+		clock-names = "nfiecc_clk";
+		status = "disabled";
+	};

Documentation/devicetree/bindings/mtd/sunxi-nand.txt

···
     * "ahb" : AHB gating clock
     * "mod" : nand controller clock
 
+Optional properties:
+- dmas : shall reference DMA channel associated to the NAND controller.
+- dma-names : shall be "rxtx".
+
 Optional children nodes:
 Children nodes represent the available nand chips.
 
 Optional properties:
+- reset : phandle + reset specifier pair
+- reset-names : must contain "ahb"
 - allwinner,rb : shall contain the native Ready/Busy ids.
  or
 - rb-gpios : shall contain the gpios used as R/B pins.

drivers/mtd/nand/Kconfig

···
 config MTD_NAND_XWAY
 	tristate "Support for NAND on Lantiq XWAY SoC"
 	depends on LANTIQ && SOC_TYPE_XWAY
-	select MTD_NAND_PLATFORM
 	help
 	  Enables support for NAND Flash chips on Lantiq XWAY SoCs. NAND is attached
 	  to the External Bus Unit (EBU).
···
 	help
 	  Enables support for NAND flash chips on SoCs containing the EBI2 NAND
 	  controller. This controller is found on IPQ806x SoC.
+
+config MTD_NAND_MTK
+	tristate "Support for NAND controller on MTK SoCs"
+	depends on HAS_DMA
+	help
+	  Enables support for NAND controller on MTK SoCs.
+	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
 
 endif # MTD_NAND

drivers/mtd/nand/Makefile

···
 obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
+obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_nand.o mtk_ecc.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o

drivers/mtd/nand/brcmnand/brcmnand.c

···
 	[BRCMNAND_FC_BASE]		= 0x400,
 };
 
+/* BRCMNAND v7.2 */
+static const u16 brcmnand_regs_v72[] = {
+	[BRCMNAND_CMD_START]		=  0x04,
+	[BRCMNAND_CMD_EXT_ADDRESS]	=  0x08,
+	[BRCMNAND_CMD_ADDRESS]		=  0x0c,
+	[BRCMNAND_INTFC_STATUS]		=  0x14,
+	[BRCMNAND_CS_SELECT]		=  0x18,
+	[BRCMNAND_CS_XOR]		=  0x1c,
+	[BRCMNAND_LL_OP]		=  0x20,
+	[BRCMNAND_CS0_BASE]		=  0x50,
+	[BRCMNAND_CS1_BASE]		=     0,
+	[BRCMNAND_CORR_THRESHOLD]	=  0xdc,
+	[BRCMNAND_CORR_THRESHOLD_EXT]	=  0xe0,
+	[BRCMNAND_UNCORR_COUNT]		=  0xfc,
+	[BRCMNAND_CORR_COUNT]		= 0x100,
+	[BRCMNAND_CORR_EXT_ADDR]	= 0x10c,
+	[BRCMNAND_CORR_ADDR]		= 0x110,
+	[BRCMNAND_UNCORR_EXT_ADDR]	= 0x114,
+	[BRCMNAND_UNCORR_ADDR]		= 0x118,
+	[BRCMNAND_SEMAPHORE]		= 0x150,
+	[BRCMNAND_ID]			= 0x194,
+	[BRCMNAND_ID_EXT]		= 0x198,
+	[BRCMNAND_LL_RDATA]		= 0x19c,
+	[BRCMNAND_OOB_READ_BASE]	= 0x200,
+	[BRCMNAND_OOB_READ_10_BASE]	=     0,
+	[BRCMNAND_OOB_WRITE_BASE]	= 0x400,
+	[BRCMNAND_OOB_WRITE_10_BASE]	=     0,
+	[BRCMNAND_FC_BASE]		= 0x600,
+};
+
 enum brcmnand_cs_reg {
 	BRCMNAND_CS_CFG_EXT = 0,
 	BRCMNAND_CS_CFG,
···
 	}
 
 	/* Register offsets */
-	if (ctrl->nand_version >= 0x0701)
+	if (ctrl->nand_version >= 0x0702)
+		ctrl->reg_offsets = brcmnand_regs_v72;
+	else if (ctrl->nand_version >= 0x0701)
 		ctrl->reg_offsets = brcmnand_regs_v71;
 	else if (ctrl->nand_version >= 0x0600)
 		ctrl->reg_offsets = brcmnand_regs_v60;
···
 	}
 
 	/* Maximum spare area sector size (per 512B) */
-	if (ctrl->nand_version >= 0x0600)
+	if (ctrl->nand_version >= 0x0702)
+		ctrl->max_oob = 128;
+	else if (ctrl->nand_version >= 0x0600)
 		ctrl->max_oob = 64;
 	else if (ctrl->nand_version >= 0x0500)
 		ctrl->max_oob = 32;
···
 	enum brcmnand_reg reg = BRCMNAND_CORR_THRESHOLD;
 	int cs = host->cs;
 
-	if (ctrl->nand_version >= 0x0600)
+	if (ctrl->nand_version >= 0x0702)
+		bits = 7;
+	else if (ctrl->nand_version >= 0x0600)
 		bits = 6;
 	else if (ctrl->nand_version >= 0x0500)
 		bits = 5;
 	else
 		bits = 4;
 
-	if (ctrl->nand_version >= 0x0600) {
+	if (ctrl->nand_version >= 0x0702) {
+		if (cs >= 4)
+			reg = BRCMNAND_CORR_THRESHOLD_EXT;
+		shift = (cs % 4) * bits;
+	} else if (ctrl->nand_version >= 0x0600) {
 		if (cs >= 5)
 			reg = BRCMNAND_CORR_THRESHOLD_EXT;
 		shift = (cs % 5) * bits;
···
 
 static inline u32 brcmnand_spare_area_mask(struct brcmnand_controller *ctrl)
 {
-	if (ctrl->nand_version >= 0x0600)
+	if (ctrl->nand_version >= 0x0702)
+		return GENMASK(7, 0);
+	else if (ctrl->nand_version >= 0x0600)
 		return GENMASK(6, 0);
 	else
 		return GENMASK(5, 0);
 }
 
 #define NAND_ACC_CONTROL_ECC_SHIFT	16
+#define NAND_ACC_CONTROL_ECC_EXT_SHIFT	13
 
 static inline u32 brcmnand_ecc_level_mask(struct brcmnand_controller *ctrl)
 {
 	u32 mask = (ctrl->nand_version >= 0x0600) ? 0x1f : 0x0f;
 
-	return mask << NAND_ACC_CONTROL_ECC_SHIFT;
+	mask <<= NAND_ACC_CONTROL_ECC_SHIFT;
+
+	/* v7.2 includes additional ECC levels */
+	if (ctrl->nand_version >= 0x0702)
+		mask |= 0x7 << NAND_ACC_CONTROL_ECC_EXT_SHIFT;
+
+	return mask;
 }
 
 static void brcmnand_set_ecc_enabled(struct brcmnand_host *host, int en)
···
 
 static inline int brcmnand_sector_1k_shift(struct brcmnand_controller *ctrl)
 {
-	if (ctrl->nand_version >= 0x0600)
+	if (ctrl->nand_version >= 0x0702)
+		return 9;
+	else if (ctrl->nand_version >= 0x0600)
 		return 7;
 	else if (ctrl->nand_version >= 0x0500)
 		return 6;
···
  * Internal support functions
  ***********************************************************************/
 
-static inline bool is_hamming_ecc(struct brcmnand_cfg *cfg)
+static inline bool is_hamming_ecc(struct brcmnand_controller *ctrl,
+				  struct brcmnand_cfg *cfg)
 {
-	return cfg->sector_size_1k == 0 && cfg->spare_area_size == 16 &&
-		cfg->ecc_level == 15;
+	if (ctrl->nand_version <= 0x0701)
+		return cfg->sector_size_1k == 0 && cfg->spare_area_size == 16 &&
+			cfg->ecc_level == 15;
+	else
+		return cfg->sector_size_1k == 0 && ((cfg->spare_area_size == 16 &&
+			cfg->ecc_level == 15) ||
+			(cfg->spare_area_size == 28 && cfg->ecc_level == 16));
 }
 
 /*
···
 	if (p->sector_size_1k)
 		ecc_level <<= 1;
 
-	if (is_hamming_ecc(p)) {
+	if (is_hamming_ecc(host->ctrl, p)) {
 		ecc->bytes = 3 * sectors;
 		mtd_set_ooblayout(mtd, &brcmnand_hamming_ooblayout_ops);
 		return 0;
···
 	return ret;
 }
 
+/*
+ * Check a page to see if it is erased (w/ bitflips) after an uncorrectable ECC
+ * error
+ *
+ * Because the HW ECC signals an ECC error if an erase paged has even a single
+ * bitflip, we must check each ECC error to see if it is actually an erased
+ * page with bitflips, not a truly corrupted page.
+ *
+ * On a real error, return a negative error code (-EBADMSG for ECC error), and
+ * buf will contain raw data.
+ * Otherwise, buf gets filled with 0xffs and return the maximum number of
+ * bitflips-per-ECC-sector to the caller.
+ *
+ */
+static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd,
+		  struct nand_chip *chip, void *buf, u64 addr)
+{
+	int i, sas;
+	void *oob = chip->oob_poi;
+	int bitflips = 0;
+	int page = addr >> chip->page_shift;
+	int ret;
+
+	if (!buf) {
+		buf = chip->buffers->databuf;
+		/* Invalidate page cache */
+		chip->pagebuf = -1;
+	}
+
+	sas = mtd->oobsize / chip->ecc.steps;
+
+	/* read without ecc for verification */
+	chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
+	ret = chip->ecc.read_page_raw(mtd, chip, buf, true, page);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < chip->ecc.steps; i++, oob += sas) {
+		ret = nand_check_erased_ecc_chunk(buf, chip->ecc.size,
+						  oob, sas, NULL, 0,
+						  chip->ecc.strength);
+		if (ret < 0)
+			return ret;
+
+		bitflips = max(bitflips, ret);
+	}
+
+	return bitflips;
+}
+
 static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
 			 u64 addr, unsigned int trans, u32 *buf, u8 *oob)
 {
···
 	struct brcmnand_controller *ctrl = host->ctrl;
 	u64 err_addr = 0;
 	int err;
+	bool retry = true;
 
 	dev_dbg(ctrl->dev, "read %llx -> %p\n", (unsigned long long)addr, buf);
 
+try_dmaread:
 	brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_COUNT, 0);
 
 	if (has_flash_dma(ctrl) && !oob && flash_dma_buf_ok(buf)) {
···
 	}
 
 	if (mtd_is_eccerr(err)) {
+		/*
+		 * On controller version and 7.0, 7.1 , DMA read after a
+		 * prior PIO read that reported uncorrectable error,
+		 * the DMA engine captures this error following DMA read
+		 * cleared only on subsequent DMA read, so just retry once
+		 * to clear a possible false error reported for current DMA
+		 * read
+		 */
+		if ((ctrl->nand_version == 0x0700) ||
+		    (ctrl->nand_version == 0x0701)) {
+			if (retry) {
+				retry = false;
+				goto try_dmaread;
+			}
+		}
+
+		/*
+		 * Controller version 7.2 has hw encoder to detect erased page
+		 * bitflips, apply sw verification for older controllers only
+		 */
+		if (ctrl->nand_version < 0x0702) {
+			err = brcmstb_nand_verify_erased_page(mtd, chip, buf,
+							      addr);
+			/* erased page bitflips corrected */
+			if (err > 0)
+				return err;
+		}
+
 		dev_dbg(ctrl->dev, "uncorrectable error at 0x%llx\n",
 			(unsigned long long)err_addr);
 		mtd->ecc_stats.failed++;
···
 	return 0;
 }
 
-static void brcmnand_print_cfg(char *buf, struct brcmnand_cfg *cfg)
+static void brcmnand_print_cfg(struct brcmnand_host *host,
+			       char *buf, struct brcmnand_cfg *cfg)
 {
 	buf += sprintf(buf,
 		"%lluMiB total, %uKiB blocks, %u%s pages, %uB OOB, %u-bit",
···
 		cfg->spare_area_size, cfg->device_width);
 
 	/* Account for Hamming ECC and for BCH 512B vs 1KiB sectors */
-	if (is_hamming_ecc(cfg))
+	if (is_hamming_ecc(host->ctrl, cfg))
 		sprintf(buf, ", Hamming ECC");
 	else if (cfg->sector_size_1k)
 		sprintf(buf, ", BCH-%u (1KiB sector)", cfg->ecc_level << 1);
···
 
 	brcmnand_set_ecc_enabled(host, 1);
 
-	brcmnand_print_cfg(msg, cfg);
+	brcmnand_print_cfg(host, msg, cfg);
 	dev_info(ctrl->dev, "detected %s\n", msg);
 
 	/* Configure ACC_CONTROL */
···
 	tmp = nand_readreg(ctrl, offs);
 	tmp &= ~ACC_CONTROL_PARTIAL_PAGE;
 	tmp &= ~ACC_CONTROL_RD_ERASED;
+
+	/* We need to turn on Read from erased paged protected by ECC */
+	if (ctrl->nand_version >= 0x0702)
+		tmp |= ACC_CONTROL_RD_ERASED;
 	tmp &= ~ACC_CONTROL_FAST_PGM_RDIN;
 	if (ctrl->features & BRCMNAND_HAS_PREFETCH) {
 		/*
···
 	{ .compatible = "brcm,brcmnand-v6.2" },
 	{ .compatible = "brcm,brcmnand-v7.0" },
 	{ .compatible = "brcm,brcmnand-v7.1" },
+	{ .compatible = "brcm,brcmnand-v7.2" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, brcmnand_of_match);

drivers/mtd/nand/jz4780_bch.c

···
 module_platform_driver(jz4780_bch_driver);
 
 MODULE_AUTHOR("Alex Smith <[e-mail]>");
-MODULE_AUTHOR("Harvey Hunt <[e-mail]>");
+MODULE_AUTHOR("Harvey Hunt <[e-mail]>");
 MODULE_DESCRIPTION("Ingenic JZ4780 BCH error correction driver");
 MODULE_LICENSE("GPL v2");

drivers/mtd/nand/jz4780_nand.c

···
 module_platform_driver(jz4780_nand_driver);
 
 MODULE_AUTHOR("Alex Smith <[e-mail]>");
-MODULE_AUTHOR("Harvey Hunt <[e-mail]>");
+MODULE_AUTHOR("Harvey Hunt <[e-mail]>");
 MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
 MODULE_LICENSE("GPL v2");

drivers/mtd/nand/mtk_ecc.c

···
+/*
+ * MTK ECC controller driver.
+ * Copyright (C) 2016  MediaTek Inc.
+ * Authors:	Xiaolei Li		<[e-mail]>
+ *		Jorge Ramirez-Ortiz	<[e-mail]>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/mutex.h>
+
+#include "mtk_ecc.h"
+
+#define ECC_IDLE_MASK		BIT(0)
+#define ECC_IRQ_EN		BIT(0)
+#define ECC_OP_ENABLE		(1)
+#define ECC_OP_DISABLE		(0)
+
+#define ECC_ENCCON		(0x00)
+#define ECC_ENCCNFG		(0x04)
+#define		ECC_CNFG_4BIT		(0)
+#define		ECC_CNFG_6BIT		(1)
+#define		ECC_CNFG_8BIT		(2)
+#define		ECC_CNFG_10BIT		(3)
+#define		ECC_CNFG_12BIT		(4)
+#define		ECC_CNFG_14BIT		(5)
+#define		ECC_CNFG_16BIT		(6)
+#define		ECC_CNFG_18BIT		(7)
+#define		ECC_CNFG_20BIT		(8)
+#define		ECC_CNFG_22BIT		(9)
+#define		ECC_CNFG_24BIT		(0xa)
+#define		ECC_CNFG_28BIT		(0xb)
+#define		ECC_CNFG_32BIT		(0xc)
+#define		ECC_CNFG_36BIT		(0xd)
+#define		ECC_CNFG_40BIT		(0xe)
+#define		ECC_CNFG_44BIT		(0xf)
+#define		ECC_CNFG_48BIT		(0x10)
+#define		ECC_CNFG_52BIT		(0x11)
+#define		ECC_CNFG_56BIT		(0x12)
+#define		ECC_CNFG_60BIT		(0x13)
+#define		ECC_MODE_SHIFT		(5)
+#define		ECC_MS_SHIFT		(16)
+#define ECC_ENCDIADDR		(0x08)
+#define ECC_ENCIDLE		(0x0C)
+#define ECC_ENCPAR(x)		(0x10 + (x) * sizeof(u32))
+#define ECC_ENCIRQ_EN		(0x80)
+#define ECC_ENCIRQ_STA		(0x84)
+#define ECC_DECCON		(0x100)
+#define ECC_DECCNFG		(0x104)
+#define		DEC_EMPTY_EN		BIT(31)
+#define		DEC_CNFG_CORRECT	(0x3 << 12)
+#define ECC_DECIDLE		(0x10C)
+#define ECC_DECENUM0		(0x114)
+#define		ERR_MASK		(0x3f)
+#define ECC_DECDONE		(0x124)
+#define ECC_DECIRQ_EN		(0x200)
+#define ECC_DECIRQ_STA		(0x204)
+
+#define ECC_TIMEOUT		(500000)
+
+#define ECC_IDLE_REG(op)	((op) == ECC_ENCODE ? ECC_ENCIDLE : ECC_DECIDLE)
+#define ECC_CTL_REG(op)		((op) == ECC_ENCODE ? ECC_ENCCON : ECC_DECCON)
+#define ECC_IRQ_REG(op)		((op) == ECC_ENCODE ? \
+					ECC_ENCIRQ_EN : ECC_DECIRQ_EN)
+
+struct mtk_ecc {
+	struct device *dev;
+	void __iomem *regs;
+	struct clk *clk;
+
+	struct completion done;
+	struct mutex lock;
+	u32 sectors;
+};
+
+static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc,
+				     enum mtk_ecc_operation op)
+{
+	struct device *dev = ecc->dev;
+	u32 val;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(op), val,
+					val & ECC_IDLE_MASK,
+					10, ECC_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "%s NOT idle\n",
+			 op == ECC_ENCODE ? "encoder" : "decoder");
+}
+
+static irqreturn_t mtk_ecc_irq(int irq, void *id)
+{
+	struct mtk_ecc *ecc = id;
+	enum mtk_ecc_operation op;
+	u32 dec, enc;
+
+	dec = readw(ecc->regs + ECC_DECIRQ_STA) & ECC_IRQ_EN;
+	if (dec) {
+		op = ECC_DECODE;
+		dec = readw(ecc->regs + ECC_DECDONE);
+		if (dec & ecc->sectors) {
+			ecc->sectors = 0;
+			complete(&ecc->done);
+		} else {
+			return IRQ_HANDLED;
+		}
+	} else {
+		enc = readl(ecc->regs + ECC_ENCIRQ_STA) & ECC_IRQ_EN;
+		if (enc) {
+			op = ECC_ENCODE;
+			complete(&ecc->done);
+		} else {
+			return IRQ_NONE;
+		}
+	}
+
+	writel(0, ecc->regs + ECC_IRQ_REG(op));
+
+	return IRQ_HANDLED;
+}
+
+static void mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	u32 ecc_bit = ECC_CNFG_4BIT, dec_sz, enc_sz;
+	u32 reg;
+
+	switch (config->strength) {
+	case 4:
+		ecc_bit = ECC_CNFG_4BIT;
+		break;
+	case 6:
+		ecc_bit = ECC_CNFG_6BIT;
+		break;
+	case 8:
+		ecc_bit = ECC_CNFG_8BIT;
+		break;
+	case 10:
+		ecc_bit = ECC_CNFG_10BIT;
+		break;
+	case 12:
+		ecc_bit = ECC_CNFG_12BIT;
+		break;
+	case 14:
+		ecc_bit = ECC_CNFG_14BIT;
+		break;
+	case 16:
+		ecc_bit = ECC_CNFG_16BIT;
+		break;
+	case 18:
+		ecc_bit = ECC_CNFG_18BIT;
+		break;
+	case 20:
+		ecc_bit = ECC_CNFG_20BIT;
+		break;
+	case 22:
+		ecc_bit = ECC_CNFG_22BIT;
+		break;
+	case 24:
+		ecc_bit = ECC_CNFG_24BIT;
+		break;
+	case 28:
+		ecc_bit = ECC_CNFG_28BIT;
+		break;
+	case 32:
+		ecc_bit = ECC_CNFG_32BIT;
+		break;
+	case 36:
+		ecc_bit = ECC_CNFG_36BIT;
+		break;
+	case 40:
+		ecc_bit = ECC_CNFG_40BIT;
+		break;
+	case 44:
+		ecc_bit = ECC_CNFG_44BIT;
+		break;
+	case 48:
+		ecc_bit = ECC_CNFG_48BIT;
+		break;
+	case 52:
+		ecc_bit = ECC_CNFG_52BIT;
+		break;
+	case 56:
+		ecc_bit = ECC_CNFG_56BIT;
+		break;
+	case 60:
+		ecc_bit = ECC_CNFG_60BIT;
+		break;
+	default:
+		dev_err(ecc->dev, "invalid strength %d, default to 4 bits\n",
+			config->strength);
+	}
+
+	if (config->op == ECC_ENCODE) {
+		/* configure ECC encoder (in bits) */
+		enc_sz = config->len << 3;
+
+		reg = ecc_bit | (config->mode << ECC_MODE_SHIFT);
+		reg |= (enc_sz << ECC_MS_SHIFT);
+		writel(reg, ecc->regs + ECC_ENCCNFG);
+
+		if (config->mode != ECC_NFI_MODE)
+			writel(lower_32_bits(config->addr),
+			       ecc->regs + ECC_ENCDIADDR);
+
+	} else {
+		/* configure ECC decoder (in bits) */
+		dec_sz = (config->len << 3) +
+					config->strength * ECC_PARITY_BITS;
+
+		reg = ecc_bit | (config->mode << ECC_MODE_SHIFT);
+		reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
+		reg |= DEC_EMPTY_EN;
+		writel(reg, ecc->regs + ECC_DECCNFG);
+
+		if (config->sectors)
+			ecc->sectors = 1 << (config->sectors - 1);
+	}
+}
+
+void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
+		       int sectors)
+{
+	u32 offset, i, err;
+	u32 bitflips = 0;
+
+	stats->corrected = 0;
+	stats->failed = 0;
+
+	for (i = 0; i < sectors; i++) {
+		offset = (i >> 2) << 2;
+		err = readl(ecc->regs + ECC_DECENUM0 + offset);
+		err = err >> ((i % 4) * 8);
+		err &= ERR_MASK;
+		if (err == ERR_MASK) {
+			/* uncorrectable errors */
+			stats->failed++;
+			continue;
+		}
+
+		stats->corrected += err;
+		bitflips = max_t(u32, bitflips, err);
+	}
+
+	stats->bitflips = bitflips;
+}
+EXPORT_SYMBOL(mtk_ecc_get_stats);
+
+void mtk_ecc_release(struct mtk_ecc *ecc)
+{
+	clk_disable_unprepare(ecc->clk);
+	put_device(ecc->dev);
+}
+EXPORT_SYMBOL(mtk_ecc_release);
+
+static void mtk_ecc_hw_init(struct mtk_ecc *ecc)
+{
+	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
+	writew(ECC_OP_DISABLE, ecc->regs + ECC_ENCCON);
+
+	mtk_ecc_wait_idle(ecc, ECC_DECODE);
+	writel(ECC_OP_DISABLE, ecc->regs + ECC_DECCON);
+}
+
+static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
+{
+	struct platform_device *pdev;
+	struct mtk_ecc *ecc;
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev || !platform_get_drvdata(pdev))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&pdev->dev);
+	ecc = platform_get_drvdata(pdev);
+	clk_prepare_enable(ecc->clk);
+	mtk_ecc_hw_init(ecc);
+
+	return ecc;
+}
+
+struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
+{
+	struct mtk_ecc *ecc = NULL;
+	struct device_node *np;
+
+	np = of_parse_phandle(of_node, "ecc-engine", 0);
+	if (np) {
+		ecc = mtk_ecc_get(np);
+		of_node_put(np);
+	}
+
+	return ecc;
+}
+EXPORT_SYMBOL(of_mtk_ecc_get);
+
+int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
+{
+	enum mtk_ecc_operation op = config->op;
+	int ret;
+
+	ret = mutex_lock_interruptible(&ecc->lock);
+	if (ret) {
+		dev_err(ecc->dev, "interrupted when attempting to lock\n");
+		return ret;
+	}
+
+	mtk_ecc_wait_idle(ecc, op);
+	mtk_ecc_config(ecc, config);
+	writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));
+
+	init_completion(&ecc->done);
+	writew(ECC_IRQ_EN, ecc->regs + ECC_IRQ_REG(op));
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_enable);
+
+void mtk_ecc_disable(struct mtk_ecc *ecc)
+{
+	enum mtk_ecc_operation op = ECC_ENCODE;
+
+	/* find out the running operation */
+	if (readw(ecc->regs + ECC_CTL_REG(op)) != ECC_OP_ENABLE)
+		op = ECC_DECODE;
+
+	/* disable it */
+	mtk_ecc_wait_idle(ecc, op);
+	writew(0, ecc->regs + ECC_IRQ_REG(op));
+	writew(ECC_OP_DISABLE, ecc->regs + ECC_CTL_REG(op));
+
+	mutex_unlock(&ecc->lock);
+}
+EXPORT_SYMBOL(mtk_ecc_disable);
+
+int mtk_ecc_wait_done(struct mtk_ecc *ecc, enum mtk_ecc_operation op)
+{
+	int ret;
+
+	ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
+			(op == ECC_ENCODE) ? "encoder" : "decoder");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_ecc_wait_done);
+
+int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
+		   u8 *data, u32 bytes)
+{
+	dma_addr_t addr;
+	u32 *p, len, i;
+	int ret = 0;
+
+	addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
+	ret = dma_mapping_error(ecc->dev, addr);
+	if (ret) {
+		dev_err(ecc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	config->op = ECC_ENCODE;
+	config->addr = addr;
+	ret = mtk_ecc_enable(ecc, config);
+	if (ret) {
+		dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+		return ret;
+	}
+
+	ret = mtk_ecc_wait_done(ecc, ECC_ENCODE);
+	if (ret)
+		goto timeout;
+
+	mtk_ecc_wait_idle(ecc, ECC_ENCODE);
+
+	/* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
+	len = (config->strength * ECC_PARITY_BITS + 7) >> 3;
+	p = (u32 *)(data + bytes);
+
+	/* write the parity bytes generated by the ECC back to the OOB region */
+	for (i = 0; i < len; i++)
+		p[i] = readl(ecc->regs + ECC_ENCPAR(i));
+timeout:
+
+	dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
+	mtk_ecc_disable(ecc);
+
+	return ret;
+}
+EXPORT_SYMBOL(mtk_ecc_encode);
+
+void mtk_ecc_adjust_strength(u32 *p)
+{
+	u32 ecc[] = {4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
+			40, 44, 48, 52, 56, 60};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ecc); i++) {
+		if (*p <= ecc[i]) {
+			if (!i)
+				*p = ecc[i];
+			else if (*p != ecc[i])
+				*p = ecc[i - 1];
+			return;
+		}
+	}
+
+	*p = ecc[ARRAY_SIZE(ecc) - 1];
+}
+EXPORT_SYMBOL(mtk_ecc_adjust_strength);
+
+static int mtk_ecc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_ecc *ecc;
+	struct resource *res;
+	int irq, ret;
+
+	ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
+	if (!ecc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ecc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ecc->regs)) {
+		dev_err(dev, "failed to map regs: %ld\n", PTR_ERR(ecc->regs));
+		return PTR_ERR(ecc->regs);
+	}
+
+	ecc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ecc->clk)) {
+		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
+		return PTR_ERR(ecc->clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get irq\n");
+		return -EINVAL;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return -EINVAL;
+	}
+
+	ecc->dev = dev;
+	mutex_init(&ecc->lock);
+	platform_set_drvdata(pdev, ecc);
+	dev_info(dev, "probed\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_ecc_suspend(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(ecc->clk);
+
+	return 0;
+}
+
+static int mtk_ecc_resume(struct device *dev)
+{
+	struct mtk_ecc *ecc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(ecc->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clk\n");
+		return ret;
+	}
+
+	mtk_ecc_hw_init(ecc);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
+#endif
+
+static const struct of_device_id mtk_ecc_dt_match[] = {
+	{ .compatible = "mediatek,mt2701-ecc" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);
+
+static struct platform_driver mtk_ecc_driver = {
+	.probe  = mtk_ecc_probe,
+	.driver = {
+		.name  = "mtk-ecc",
+		.of_match_table = of_match_ptr(mtk_ecc_dt_match),
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_ecc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_ecc_driver);
+
+MODULE_AUTHOR("Xiaolei Li <[e-mail]>");
+MODULE_DESCRIPTION("MTK Nand ECC Driver");
+MODULE_LICENSE("GPL");

drivers/mtd/nand/mtk_ecc.h

···
+/*
+ * MTK SDG1 ECC controller
+ *
+ * Copyright (c) 2016 Mediatek
+ * Authors:	Xiaolei Li		<[e-mail]>
+ *		Jorge Ramirez-Ortiz	<[e-mail]>
+ * 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.
+ */
+
+#ifndef __DRIVERS_MTD_NAND_MTK_ECC_H__
+#define __DRIVERS_MTD_NAND_MTK_ECC_H__
+
+#include <linux/types.h>
+
+#define ECC_PARITY_BITS		(14)
+
+enum mtk_ecc_mode {ECC_DMA_MODE = 0, ECC_NFI_MODE = 1};
+enum mtk_ecc_operation {ECC_ENCODE, ECC_DECODE};
+
+struct device_node;
+struct mtk_ecc;
+
+struct mtk_ecc_stats {
+	u32 corrected;
+	u32 bitflips;
+	u32 failed;
+};
+
+struct mtk_ecc_config {
+	enum mtk_ecc_operation op;
+	enum mtk_ecc_mode mode;
+	dma_addr_t addr;
+	u32 strength;
+	u32 sectors;
+	u32 len;
+};
+
+int mtk_ecc_encode(struct mtk_ecc *, struct mtk_ecc_config *, u8 *, u32);
+void mtk_ecc_get_stats(struct mtk_ecc *, struct mtk_ecc_stats *, int);
+int mtk_ecc_wait_done(struct mtk_ecc *, enum mtk_ecc_operation);
+int mtk_ecc_enable(struct mtk_ecc *, struct mtk_ecc_config *);
+void mtk_ecc_disable(struct mtk_ecc *);
+void mtk_ecc_adjust_strength(u32 *);
+
+struct mtk_ecc *of_mtk_ecc_get(struct device_node *);
+void mtk_ecc_release(struct mtk_ecc *);
+
+#endif

drivers/mtd/nand/mtk_nand.c

···
+/*
+ * MTK NAND Flash controller driver.
+ * Copyright (C) 2016 MediaTek Inc.
+ * Authors:	Xiaolei Li		<[e-mail]>
+ *		Jorge Ramirez-Ortiz	<[e-mail]>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/mtd.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include "mtk_ecc.h"
+
+/* NAND controller register definition */
+#define NFI_CNFG		(0x00)
+#define		CNFG_AHB		BIT(0)
+#define		CNFG_READ_EN		BIT(1)
+#define		CNFG_DMA_BURST_EN	BIT(2)
+#define		CNFG_BYTE_RW		BIT(6)
+#define		CNFG_HW_ECC_EN		BIT(8)
+#define		CNFG_AUTO_FMT_EN	BIT(9)
+#define		CNFG_OP_CUST		(6 << 12)
+#define NFI_PAGEFMT		(0x04)
+#define		PAGEFMT_FDM_ECC_SHIFT	(12)
+#define		PAGEFMT_FDM_SHIFT	(8)
+#define		PAGEFMT_SPARE_16	(0)
+#define		PAGEFMT_SPARE_26	(1)
+#define		PAGEFMT_SPARE_27	(2)
+#define		PAGEFMT_SPARE_28	(3)
+#define		PAGEFMT_SPARE_32	(4)
+#define		PAGEFMT_SPARE_36	(5)
+#define		PAGEFMT_SPARE_40	(6)
+#define		PAGEFMT_SPARE_44	(7)
+#define		PAGEFMT_SPARE_48	(8)
+#define		PAGEFMT_SPARE_49	(9)
+#define		PAGEFMT_SPARE_50	(0xa)
+#define		PAGEFMT_SPARE_51	(0xb)
+#define		PAGEFMT_SPARE_52	(0xc)
+#define		PAGEFMT_SPARE_62	(0xd)
+#define		PAGEFMT_SPARE_63	(0xe)
+#define		PAGEFMT_SPARE_64	(0xf)
+#define		PAGEFMT_SPARE_SHIFT	(4)
+#define		PAGEFMT_SEC_SEL_512	BIT(2)
+#define		PAGEFMT_512_2K		(0)
+#define		PAGEFMT_2K_4K		(1)
+#define		PAGEFMT_4K_8K		(2)
+#define		PAGEFMT_8K_16K		(3)
+/* NFI control */
+#define NFI_CON			(0x08)
+#define		CON_FIFO_FLUSH		BIT(0)
+#define		CON_NFI_RST		BIT(1)
+#define		CON_BRD			BIT(8)  /* burst  read */
+#define		CON_BWR			BIT(9)	/* burst  write */
+#define		CON_SEC_SHIFT		(12)
+/* Timming control register */
+#define NFI_ACCCON		(0x0C)
+#define NFI_INTR_EN		(0x10)
+#define		INTR_AHB_DONE_EN	BIT(6)
+#define NFI_INTR_STA		(0x14)
+#define NFI_CMD			(0x20)
+#define NFI_ADDRNOB		(0x30)
+#define NFI_COLADDR		(0x34)
+#define NFI_ROWADDR		(0x38)
+#define NFI_STRDATA		(0x40)
+#define		STAR_EN			(1)
+#define		STAR_DE			(0)
+#define NFI_CNRNB		(0x44)
+#define NFI_DATAW		(0x50)
+#define NFI_DATAR		(0x54)
+#define NFI_PIO_DIRDY		(0x58)
+#define		PIO_DI_RDY		(0x01)
+#define NFI_STA			(0x60)
+#define		STA_CMD			BIT(0)
+#define		STA_ADDR		BIT(1)
+#define		STA_BUSY		BIT(8)
+#define		STA_EMP_PAGE		BIT(12)
+#define		NFI_FSM_CUSTDATA	(0xe << 16)
+#define		NFI_FSM_MASK		(0xf << 16)
+#define NFI_ADDRCNTR		(0x70)
+#define		CNTR_MASK		GENMASK(16, 12)
+#define NFI_STRADDR		(0x80)
+#define NFI_BYTELEN		(0x84)
+#define NFI_CSEL		(0x90)
+#define NFI_FDML(x)		(0xA0 + (x) * sizeof(u32) * 2)
+#define NFI_FDMM(x)		(0xA4 + (x) * sizeof(u32) * 2)
+#define NFI_FDM_MAX_SIZE	(8)
+#define NFI_FDM_MIN_SIZE	(1)
+#define NFI_MASTER_STA		(0x224)
+#define		MASTER_STA_MASK		(0x0FFF)
+#define NFI_EMPTY_THRESH	(0x23C)
+
+#define MTK_NAME		"mtk-nand"
+#define KB(x)			((x) * 1024UL)
+#define MB(x)			(KB(x) * 1024UL)
+
+#define MTK_TIMEOUT		(500000)
+#define MTK_RESET_TIMEOUT	(1000000)
+#define MTK_MAX_SECTOR		(16)
+#define MTK_NAND_MAX_NSELS	(2)
+
+struct mtk_nfc_bad_mark_ctl {
+	void (*bm_swap)(struct mtd_info *, u8 *buf, int raw);
+	u32 sec;
+	u32 pos;
+};
+
+/*
+ * FDM: region used to store free OOB data
+ */
+struct mtk_nfc_fdm {
+	u32 reg_size;
+	u32 ecc_size;
+};
+
+struct mtk_nfc_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+
+	struct mtk_nfc_bad_mark_ctl bad_mark;
+	struct mtk_nfc_fdm fdm;
+	u32 spare_per_sector;
+
+	int nsels;
+	u8 sels[0];
+	/* nothing after this field */
+};
+
+struct mtk_nfc_clk {
+	struct clk *nfi_clk;
+	struct clk *pad_clk;
+};
+
+struct mtk_nfc {
+	struct nand_hw_control controller;
+	struct mtk_ecc_config ecc_cfg;
+	struct mtk_nfc_clk clk;
+	struct mtk_ecc *ecc;
+
+	struct device *dev;
+	void __iomem *regs;
+
+	struct completion done;
+	struct list_head chips;
+
+	u8 *buffer;
+};
+
+static inline struct mtk_nfc_nand_chip *to_mtk_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct mtk_nfc_nand_chip, nand);
+}
+
+static inline u8 *data_ptr(struct nand_chip *chip, const u8 *p, int i)
+{
+	return (u8 *)p + i * chip->ecc.size;
+}
+
+static inline u8 *oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u8 *poi;
+
+	/* map the sector's FDM data to free oob:
+	 * the beginning of the oob area stores the FDM data of bad mark sectors
+	 */
+
+	if (i < mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi + (i + 1) * mtk_nand->fdm.reg_size;
+	else if (i == mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi;
+	else
+		poi = chip->oob_poi + i * mtk_nand->fdm.reg_size;
+
+	return poi;
+}
+
+static inline int mtk_data_len(struct nand_chip *chip)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+
+	return chip->ecc.size + mtk_nand->spare_per_sector;
+}
+
+static inline u8 *mtk_data_ptr(struct nand_chip *chip,  int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip);
+}
+
+static inline u8 *mtk_oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip) + chip->ecc.size;
+}
+
+static inline void nfi_writel(struct mtk_nfc *nfc, u32 val, u32 reg)
+{
+	writel(val, nfc->regs + reg);
+}
+
+static inline void nfi_writew(struct mtk_nfc *nfc, u16 val, u32 reg)
+{
+	writew(val, nfc->regs + reg);
+}
+
+static inline void nfi_writeb(struct mtk_nfc *nfc, u8 val, u32 reg)
+{
+	writeb(val, nfc->regs + reg);
+}
+
+static inline u32 nfi_readl(struct mtk_nfc *nfc, u32 reg)
+{
+	return readl_relaxed(nfc->regs + reg);
+}
+
+static inline u16 nfi_readw(struct mtk_nfc *nfc, u32 reg)
+{
+	return readw_relaxed(nfc->regs + reg);
+}
+
+static inline u8 nfi_readb(struct mtk_nfc *nfc, u32 reg)
+{
+	return readb_relaxed(nfc->regs + reg);
+}
+
+static void mtk_nfc_hw_reset(struct mtk_nfc *nfc)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	/* reset all registers and force the NFI master to terminate */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+
+	/* wait for the master to finish the last transaction */
+	ret = readl_poll_timeout(nfc->regs + NFI_MASTER_STA, val,
+				 !(val & MASTER_STA_MASK), 50,
+				 MTK_RESET_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "master active in reset [0x%x] = 0x%x\n",
+			 NFI_MASTER_STA, val);
+
+	/* ensure any status register affected by the NFI master is reset */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+	nfi_writew(nfc, STAR_DE, NFI_STRDATA);
+}
+
+static int mtk_nfc_send_command(struct mtk_nfc *nfc, u8 command)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, command, NFI_CMD);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_CMD), 10,  MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering command mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_send_address(struct mtk_nfc *nfc, int addr)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, addr, NFI_COLADDR);
+	nfi_writel(nfc, 0, NFI_ROWADDR);
+	nfi_writew(nfc, 1, NFI_ADDRNOB);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_ADDR), 10, MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering address mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_hw_runtime_config(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 fmt, spare;
+
+	if (!mtd->writesize)
+		return 0;
+
+	spare = mtk_nand->spare_per_sector;
+
+	switch (mtd->writesize) {
+	case 512:
+		fmt = PAGEFMT_512_2K | PAGEFMT_SEC_SEL_512;
+		break;
+	case KB(2):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_2K_4K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_512_2K;
+		break;
+	case KB(4):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_4K_8K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_2K_4K;
+		break;
+	case KB(8):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_8K_16K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_4K_8K;
+		break;
+	case KB(16):
+		fmt = PAGEFMT_8K_16K;
+		break;
+	default:
+		dev_err(nfc->dev, "invalid page len: %d\n", mtd->writesize);
+		return -EINVAL;
+	}
+
+	/*
+	 * the hardware will double the value for this eccsize, so we need to
+	 * halve it
+	 */
+	if (chip->ecc.size == 1024)
+		spare >>= 1;
+
+	switch (spare) {
+	case 16:
+		fmt |= (PAGEFMT_SPARE_16 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 26:
+		fmt |= (PAGEFMT_SPARE_26 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 27:
+		fmt |= (PAGEFMT_SPARE_27 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 28:
+		fmt |= (PAGEFMT_SPARE_28 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 32:
+		fmt |= (PAGEFMT_SPARE_32 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 36:
+		fmt |= (PAGEFMT_SPARE_36 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 40:
+		fmt |= (PAGEFMT_SPARE_40 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 44:
+		fmt |= (PAGEFMT_SPARE_44 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 48:
+		fmt |= (PAGEFMT_SPARE_48 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 49:
+		fmt |= (PAGEFMT_SPARE_49 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 50:
+		fmt |= (PAGEFMT_SPARE_50 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 51:
+		fmt |= (PAGEFMT_SPARE_51 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 52:
+		fmt |= (PAGEFMT_SPARE_52 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 62:
+		fmt |= (PAGEFMT_SPARE_62 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 63:
+		fmt |= (PAGEFMT_SPARE_63 << PAGEFMT_SPARE_SHIFT);
+		break;
+	case 64:
+		fmt |= (PAGEFMT_SPARE_64 << PAGEFMT_SPARE_SHIFT);
+		break;
+	default:
+		dev_err(nfc->dev, "invalid spare per sector %d\n", spare);
+		return -EINVAL;
+	}
+
+	fmt |= mtk_nand->fdm.reg_size << PAGEFMT_FDM_SHIFT;
+	fmt |= mtk_nand->fdm.ecc_size << PAGEFMT_FDM_ECC_SHIFT;
+	nfi_writew(nfc, fmt, NFI_PAGEFMT);
+
+	nfc->ecc_cfg.strength = chip->ecc.strength;
+	nfc->ecc_cfg.len = chip->ecc.size + mtk_nand->fdm.ecc_size;
+
+	return 0;
+}
+
+static void mtk_nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(nand);
+
+	if (chip < 0)
+		return;
+
+	mtk_nfc_hw_runtime_config(mtd);
+
+	nfi_writel(nfc, mtk_nand->sels[chip], NFI_CSEL);
+}
+
+static int mtk_nfc_dev_ready(struct mtd_info *mtd)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+
+	if (nfi_readl(nfc, NFI_STA) & STA_BUSY)
+		return 0;
+
+	return 1;
+}
+
+static void mtk_nfc_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+
+	if (ctrl & NAND_ALE) {
+		mtk_nfc_send_address(nfc, dat);
+	} else if (ctrl & NAND_CLE) {
+		mtk_nfc_hw_reset(nfc);
+
+		nfi_writew(nfc, CNFG_OP_CUST, NFI_CNFG);
+		mtk_nfc_send_command(nfc, dat);
+	}
+}
+
+static inline void mtk_nfc_wait_ioready(struct mtk_nfc *nfc)
+{
+	int rc;
+	u8 val;
+
+	rc = readb_poll_timeout_atomic(nfc->regs + NFI_PIO_DIRDY, val,
+				       val & PIO_DI_RDY, 10, MTK_TIMEOUT);
+	if (rc < 0)
+		dev_err(nfc->dev, "data not ready\n");
+}
+
+static inline u8 mtk_nfc_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 reg;
+
+	/* after each byte read, the NFI_STA reg is reset by the hardware */
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG);
+		reg |= CNFG_BYTE_RW | CNFG_READ_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		/*
+		 * set to max sector to allow the HW to continue reading over
+		 * unaligned accesses
+		 */
+		reg = (MTK_MAX_SECTOR << CON_SEC_SHIFT) | CON_BRD;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		/* trigger to fetch data */
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+
+	return nfi_readb(nfc, NFI_DATAR);
+}
+
+static void mtk_nfc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = mtk_nfc_read_byte(mtd);
+}
+
+static void mtk_nfc_write_byte(struct mtd_info *mtd, u8 byte)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+	u32 reg;
+
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_BYTE_RW;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		reg = MTK_MAX_SECTOR << CON_SEC_SHIFT | CON_BWR;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+	nfi_writeb(nfc, byte, NFI_DATAW);
+}
+
+static void mtk_nfc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		mtk_nfc_write_byte(mtd, buf[i]);
+}
+
+static int mtk_nfc_sector_encode(struct nand_chip *chip, u8 *data)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	int size = chip->ecc.size + mtk_nand->fdm.reg_size;
+
+	nfc->ecc_cfg.mode = ECC_DMA_MODE;
+	nfc->ecc_cfg.op = ECC_ENCODE;
+
+	return mtk_ecc_encode(nfc->ecc, &nfc->ecc_cfg, data, size);
+}
+
+static void mtk_nfc_no_bad_mark_swap(struct mtd_info *a, u8 *b, int c)
+{
+	/* nop */
+}
+
+static void mtk_nfc_bad_mark_swap(struct mtd_info *mtd, u8 *buf, int raw)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *nand = to_mtk_nand(chip);
+	u32 bad_pos = nand->bad_mark.pos;
+
+	if (raw)
+		bad_pos += nand->bad_mark.sec * mtk_data_len(chip);
+	else
+		bad_pos += nand->bad_mark.sec * chip->ecc.size;
+
+	swap(chip->oob_poi[0], buf[bad_pos]);
+}
+
+static int mtk_nfc_format_subpage(struct mtd_info *mtd, u32 offset,
+				  u32 len, const u8 *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 start, end;
+	int i, ret;
+
+	start = offset / chip->ecc.size;
+	end = DIV_ROUND_UP(offset + len, chip->ecc.size);
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+		       chip->ecc.size);
+
+		if (start > i || i >= end)
+			continue;
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+
+		/* program the CRC back to the OOB */
+		ret = mtk_nfc_sector_encode(chip, mtk_data_ptr(chip, i));
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_format_page(struct mtd_info *mtd, const u8 *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 i;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		if (buf)
+			memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+			       chip->ecc.size);
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+	}
+}
+
+static inline void mtk_nfc_read_fdm(struct nand_chip *chip, u32 start,
+				    u32 sectors)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i, j;
+
+	for (i = 0; i < sectors; i++) {
+		oobptr = oob_ptr(chip, start + i);
+		vall = nfi_readl(nfc, NFI_FDML(i));
+		valm = nfi_readl(nfc, NFI_FDMM(i));
+
+		for (j = 0; j < fdm->reg_size; j++)
+			oobptr[j] = (j >= 4 ? valm : vall) >> ((j % 4) * 8);
+	}
+}
+
+static inline void mtk_nfc_write_fdm(struct nand_chip *chip)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i, j;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		oobptr = oob_ptr(chip, i);
+		vall = 0;
+		valm = 0;
+		for (j = 0; j < 8; j++) {
+			if (j < 4)
+				vall |= (j < fdm->reg_size ? oobptr[j] : 0xff)
+						<< (j * 8);
+			else
+				valm |= (j < fdm->reg_size ? oobptr[j] : 0xff)
+						<< ((j - 4) * 8);
+		}
+		nfi_writel(nfc, vall, NFI_FDML(i));
+		nfi_writel(nfc, valm, NFI_FDMM(i));
+	}
+}
+
+static int mtk_nfc_do_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				 const u8 *buf, int page, int len)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct device *dev = nfc->dev;
+	dma_addr_t addr;
+	u32 reg;
+	int ret;
+
+	addr = dma_map_single(dev, (void *)buf, len, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nfc->dev, addr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AHB | CNFG_DMA_BURST_EN;
+	nfi_writew(nfc, reg, NFI_CNFG);
+
+	nfi_writel(nfc, chip->ecc.steps << CON_SEC_SHIFT, NFI_CON);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+
+	init_completion(&nfc->done);
+
+	reg = nfi_readl(nfc, NFI_CON) | CON_BWR;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	ret = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(dev, "program ahb done timeout\n");
+		nfi_writew(nfc, 0, NFI_INTR_EN);
+		ret = -ETIMEDOUT;
+		goto timeout;
+	}
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_ADDRCNTR, reg,
+					(reg & CNTR_MASK) >= chip->ecc.steps,
+					10, MTK_TIMEOUT);
+	if (ret)
+		dev_err(dev, "hwecc write timeout\n");
+
+timeout:
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_TO_DEVICE);
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return ret;
+}
+
+static int mtk_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+			      const u8 *buf, int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	size_t len;
+	const u8 *bufpoi;
+	u32 reg;
+	int ret;
+
+	if (!raw) {
+		/* OOB => FDM: from register,  ECC: from HW */
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AUTO_FMT_EN;
+		nfi_writew(nfc, reg | CNFG_HW_ECC_EN, NFI_CNFG);
+
+		nfc->ecc_cfg.op = ECC_ENCODE;
+		nfc->ecc_cfg.mode = ECC_NFI_MODE;
+		ret = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (ret) {
+			/* clear NFI config */
+			reg = nfi_readw(nfc, NFI_CNFG);
+			reg &= ~(CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+
+			return ret;
+		}
+
+		memcpy(nfc->buffer, buf, mtd->writesize);
+		mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, raw);
+		bufpoi = nfc->buffer;
+
+		/* write OOB into the FDM registers (OOB area in MTK NAND) */
+		mtk_nfc_write_fdm(chip);
+	} else {
+		bufpoi = buf;
+	}
+
+	len = mtd->writesize + (raw ? mtd->oobsize : 0);
+	ret = mtk_nfc_do_write_page(mtd, chip, bufpoi, page, len);
+
+	if (!raw)
+		mtk_ecc_disable(nfc->ecc);
+
+	return ret;
+}
+
+static int mtk_nfc_write_page_hwecc(struct mtd_info *mtd,
+				    struct nand_chip *chip, const u8 *buf,
+				    int oob_on, int page)
+{
+	return mtk_nfc_write_page(mtd, chip, buf, page, 0);
+}
+
+static int mtk_nfc_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				  const u8 *buf, int oob_on, int pg)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	mtk_nfc_format_page(mtd, buf);
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, pg, 1);
+}
+
+static int mtk_nfc_write_subpage_hwecc(struct mtd_info *mtd,
+				       struct nand_chip *chip, u32 offset,
+				       u32 data_len, const u8 *buf,
+				       int oob_on, int page)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	int ret;
+
+	ret = mtk_nfc_format_subpage(mtd, offset, data_len, buf);
+	if (ret < 0)
+		return ret;
+
+	/* use the data in the private buffer (now with FDM and CRC) */
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, page, 1);
+}
+
+static int mtk_nfc_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+				 int page)
+{
+	int ret;
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+
+	ret = mtk_nfc_write_page_raw(mtd, chip, NULL, 1, page);
+	if (ret < 0)
+		return -EIO;
+
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	ret = chip->waitfunc(mtd, chip);
+
+	return ret & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+static int mtk_nfc_update_ecc_stats(struct mtd_info *mtd, u8 *buf, u32 sectors)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_ecc_stats stats;
+	int rc, i;
+
+	rc = nfi_readl(nfc, NFI_STA) & STA_EMP_PAGE;
+	if (rc) {
+		memset(buf, 0xff, sectors * chip->ecc.size);
+		for (i = 0; i < sectors; i++)
+			memset(oob_ptr(chip, i), 0xff, mtk_nand->fdm.reg_size);
+		return 0;
+	}
+
+	mtk_ecc_get_stats(nfc->ecc, &stats, sectors);
+	mtd->ecc_stats.corrected += stats.corrected;
+	mtd->ecc_stats.failed += stats.failed;
+
+	return stats.bitflips;
+}
+
+static int mtk_nfc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+				u32 data_offs, u32 readlen,
+				u8 *bufpoi, int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 spare = mtk_nand->spare_per_sector;
+	u32 column, sectors, start, end, reg;
+	dma_addr_t addr;
+	int bitflips;
+	size_t len;
+	u8 *buf;
+	int rc;
+
+	start = data_offs / chip->ecc.size;
+	end = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
+
+	sectors = end - start;
+	column = start * (chip->ecc.size + spare);
+
+	len = sectors * chip->ecc.size + (raw ? sectors * spare : 0);
+	buf = bufpoi + start * chip->ecc.size;
+
+	if (column != 0)
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, column, -1);
+
+	addr = dma_map_single(nfc->dev, buf, len, DMA_FROM_DEVICE);
+	rc = dma_mapping_error(nfc->dev, addr);
+	if (rc) {
+		dev_err(nfc->dev, "dma mapping error\n");
+
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG);
+	reg |= CNFG_READ_EN | CNFG_DMA_BURST_EN | CNFG_AHB;
+	if (!raw) {
+		reg |= CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		nfc->ecc_cfg.mode = ECC_NFI_MODE;
+		nfc->ecc_cfg.sectors = sectors;
+		nfc->ecc_cfg.op = ECC_DECODE;
+		rc = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (rc) {
+			dev_err(nfc->dev, "ecc enable\n");
+			/* clear NFI_CNFG */
+			reg &= ~(CNFG_DMA_BURST_EN | CNFG_AHB | CNFG_READ_EN |
+				CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+			dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+			return rc;
+		}
+	} else {
+		nfi_writew(nfc, reg, NFI_CNFG);
+	}
+
+	nfi_writel(nfc, sectors << CON_SEC_SHIFT, NFI_CON);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+
+	init_completion(&nfc->done);
+	reg = nfi_readl(nfc, NFI_CON) | CON_BRD;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	rc = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!rc)
+		dev_warn(nfc->dev, "read ahb/dma done timeout\n");
+
+	rc = readl_poll_timeout_atomic(nfc->regs + NFI_BYTELEN, reg,
+				       (reg & CNTR_MASK) >= sectors, 10,
+				       MTK_TIMEOUT);
+	if (rc < 0) {
+		dev_err(nfc->dev, "subpage done timeout\n");
+		bitflips = -EIO;
+	} else {
+		bitflips = 0;
+		if (!raw) {
+			rc = mtk_ecc_wait_done(nfc->ecc, ECC_DECODE);
+			bitflips = rc < 0 ? -ETIMEDOUT :
+				mtk_nfc_update_ecc_stats(mtd, buf, sectors);
+			mtk_nfc_read_fdm(chip, start, sectors);
+		}
+	}
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+	if (raw)
+		goto done;
+
+	mtk_ecc_disable(nfc->ecc);
+
+	if (clamp(mtk_nand->bad_mark.sec, start, end) == mtk_nand->bad_mark.sec)
+		mtk_nand->bad_mark.bm_swap(mtd, bufpoi, raw);
+done:
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return bitflips;
+}
+
+static int mtk_nfc_read_subpage_hwecc(struct mtd_info *mtd,
+				      struct nand_chip *chip, u32 off,
+				      u32 len, u8 *p, int pg)
+{
+	return mtk_nfc_read_subpage(mtd, chip, off, len, p, pg, 0);
+}
+
+static int mtk_nfc_read_page_hwecc(struct mtd_info *mtd,
+				   struct nand_chip *chip, u8 *p,
+				   int oob_on, int pg)
+{
+	return mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, p, pg, 0);
+}
+
+static int mtk_nfc_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				 u8 *buf, int oob_on, int page)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	int i, ret;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	ret = mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, nfc->buffer,
+				   page, 1);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		memcpy(oob_ptr(chip, i), mtk_oob_ptr(chip, i), fdm->reg_size);
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		if (buf)
+			memcpy(data_ptr(chip, buf, i), mtk_data_ptr(chip, i),
+			       chip->ecc.size);
+	}
+
+	return ret;
+}
+
+static int mtk_nfc_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip,
+				int page)
+{
+	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+	return mtk_nfc_read_page_raw(mtd, chip, NULL, 1, page);
+}
+
+static inline void mtk_nfc_hw_init(struct mtk_nfc *nfc)
+{
+	/*
+	 * ACCON: access timing control register
+	 * -------------------------------------
+	 * 31:28: minimum required time for CS post pulling down after accessing
+	 *	the device
+	 * 27:22: minimum required time for CS pre pulling down before accessing
+	 *	the device
+	 * 21:16: minimum required time from NCEB low to NREB low
+	 * 15:12: minimum required time from NWEB high to NREB low.
+	 * 11:08: write enable hold time
+	 * 07:04: write wait states
+	 * 03:00: read wait states
+	 */
+	nfi_writel(nfc, 0x10804211, NFI_ACCCON);
+
+	/*
+	 * CNRNB: nand ready/busy register
+	 * -------------------------------
+	 * 7:4: timeout register for polling the NAND busy/ready signal
+	 * 0  : poll the status of the busy/ready signal after [7:4]*16 cycles.
+	 */
+	nfi_writew(nfc, 0xf1, NFI_CNRNB);
+	nfi_writew(nfc, PAGEFMT_8K_16K, NFI_PAGEFMT);
+
+	mtk_nfc_hw_reset(nfc);
+
+	nfi_readl(nfc, NFI_INTR_STA);
+	nfi_writel(nfc, 0, NFI_INTR_EN);
+}
+
+static irqreturn_t mtk_nfc_irq(int irq, void *id)
+{
+	struct mtk_nfc *nfc = id;
+	u16 sta, ien;
+
+	sta = nfi_readw(nfc, NFI_INTR_STA);
+	ien = nfi_readw(nfc, NFI_INTR_EN);
+
+	if (!(sta & ien))
+		return IRQ_NONE;
+
+	nfi_writew(nfc, ~sta & ien, NFI_INTR_EN);
+	complete(&nfc->done);
+
+	return IRQ_HANDLED;
+}
+
+static int mtk_nfc_enable_clk(struct device *dev, struct mtk_nfc_clk *clk)
+{
+	int ret;
+
+	ret = clk_prepare_enable(clk->nfi_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable nfi clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(clk->pad_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable pad clk\n");
+		clk_disable_unprepare(clk->nfi_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_disable_clk(struct mtk_nfc_clk *clk)
+{
+	clk_disable_unprepare(clk->nfi_clk);
+	clk_disable_unprepare(clk->pad_clk);
+}
+
+static int mtk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 eccsteps;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+
+	if (section >= eccsteps)
+		return -ERANGE;
+
+	oob_region->length = fdm->reg_size - fdm->ecc_size;
+	oob_region->offset = section * fdm->reg_size + fdm->ecc_size;
+
+	return 0;
+}
+
+static int mtk_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 eccsteps;
+
+	if (section)
+		return -ERANGE;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+	oob_region->offset = mtk_nand->fdm.reg_size * eccsteps;
+	oob_region->length = mtd->oobsize - oob_region->offset;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops mtk_nfc_ooblayout_ops = {
+	.free = mtk_nfc_ooblayout_free,
+	.ecc = mtk_nfc_ooblayout_ecc,
+};
+
+static void mtk_nfc_set_fdm(struct mtk_nfc_fdm *fdm, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *chip = to_mtk_nand(nand);
+	u32 ecc_bytes;
+
+	ecc_bytes = DIV_ROUND_UP(nand->ecc.strength * ECC_PARITY_BITS, 8);
+
+	fdm->reg_size = chip->spare_per_sector - ecc_bytes;
+	if (fdm->reg_size > NFI_FDM_MAX_SIZE)
+		fdm->reg_size = NFI_FDM_MAX_SIZE;
+
+	/* bad block mark storage */
+	fdm->ecc_size = 1;
+}
+
+static void mtk_nfc_set_bad_mark_ctl(struct mtk_nfc_bad_mark_ctl *bm_ctl,
+				     struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (mtd->writesize == 512) {
+		bm_ctl->bm_swap = mtk_nfc_no_bad_mark_swap;
+	} else {
+		bm_ctl->bm_swap = mtk_nfc_bad_mark_swap;
+		bm_ctl->sec = mtd->writesize / mtk_data_len(nand);
+		bm_ctl->pos = mtd->writesize % mtk_data_len(nand);
+	}
+}
+
+static void mtk_nfc_set_spare_per_sector(u32 *sps, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	u32 spare[] = {16, 26, 27, 28, 32, 36, 40, 44,
+			48, 49, 50, 51, 52, 62, 63, 64};
+	u32 eccsteps, i;
+
+	eccsteps = mtd->writesize / nand->ecc.size;
+	*sps = mtd->oobsize / eccsteps;
+
+	if (nand->ecc.size == 1024)
+		*sps >>= 1;
+
+	for (i = 0; i < ARRAY_SIZE(spare); i++) {
+		if (*sps <= spare[i]) {
+			if (!i)
+				*sps = spare[i];
+			else if (*sps != spare[i])
+				*sps = spare[i - 1];
+			break;
+		}
+	}
+
+	if (i >= ARRAY_SIZE(spare))
+		*sps = spare[ARRAY_SIZE(spare) - 1];
+
+	if (nand->ecc.size == 1024)
+		*sps <<= 1;
+}
+
+static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	u32 spare;
+	int free;
+
+	/* support only ecc hw mode */
+	if (nand->ecc.mode != NAND_ECC_HW) {
+		dev_err(dev, "ecc.mode not supported\n");
+		return -EINVAL;
+	}
+
+	/* if optional dt settings not present */
+	if (!nand->ecc.size || !nand->ecc.strength) {
+		/* use datasheet requirements */
+		nand->ecc.strength = nand->ecc_strength_ds;
+		nand->ecc.size = nand->ecc_step_ds;
+
+		/*
+		 * align eccstrength and eccsize
+		 * this controller only supports 512 and 1024 sizes
+		 */
+		if (nand->ecc.size < 1024) {
+			if (mtd->writesize > 512) {
+				nand->ecc.size = 1024;
+				nand->ecc.strength <<= 1;
+			} else {
+				nand->ecc.size = 512;
+			}
+		} else {
+			nand->ecc.size = 1024;
+		}
+
+		mtk_nfc_set_spare_per_sector(&spare, mtd);
+
+		/* calculate oob bytes except ecc parity data */
+		free = ((nand->ecc.strength * ECC_PARITY_BITS) + 7) >> 3;
+		free = spare - free;
+
+		/*
+		 * enhance ecc strength if oob left is bigger than max FDM size
+		 * or reduce ecc strength if oob size is not enough for ecc
+		 * parity data.
+		 */
+		if (free > NFI_FDM_MAX_SIZE) {
+			spare -= NFI_FDM_MAX_SIZE;
+			nand->ecc.strength = (spare << 3) / ECC_PARITY_BITS;
+		} else if (free < 0) {
+			spare -= NFI_FDM_MIN_SIZE;
+			nand->ecc.strength = (spare << 3) / ECC_PARITY_BITS;
+		}
+	}
+
+	mtk_ecc_adjust_strength(&nand->ecc.strength);
+
+	dev_info(dev, "eccsize %d eccstrength %d\n",
+		 nand->ecc.size, nand->ecc.strength);
+
+	return 0;
+}
+
+static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
+				  struct device_node *np)
+{
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int nsels, len;
+	u32 tmp;
+	int ret;
+	int i;
+
+	if (!of_get_property(np, "reg", &nsels))
+		return -ENODEV;
+
+	nsels /= sizeof(u32);
+	if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
+		dev_err(dev, "invalid reg property size %d\n", nsels);
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(dev, sizeof(*chip) + nsels * sizeof(u8),
+			    GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->nsels = nsels;
+	for (i = 0; i < nsels; i++) {
+		ret = of_property_read_u32_index(np, "reg", i, &tmp);
+		if (ret) {
+			dev_err(dev, "reg property failure : %d\n", ret);
+			return ret;
+		}
+		chip->sels[i] = tmp;
+	}
+
+	nand = &chip->nand;
+	nand->controller = &nfc->controller;
+
+	nand_set_flash_node(nand, np);
+	nand_set_controller_data(nand, nfc);
+
+	nand->options |= NAND_USE_BOUNCE_BUFFER | NAND_SUBPAGE_READ;
+	nand->dev_ready = mtk_nfc_dev_ready;
+	nand->select_chip = mtk_nfc_select_chip;
+	nand->write_byte = mtk_nfc_write_byte;
+	nand->write_buf = mtk_nfc_write_buf;
+	nand->read_byte = mtk_nfc_read_byte;
+	nand->read_buf = mtk_nfc_read_buf;
+	nand->cmd_ctrl = mtk_nfc_cmd_ctrl;
+
+	/* set default mode in case dt entry is missing */
+	nand->ecc.mode = NAND_ECC_HW;
+
+	nand->ecc.write_subpage = mtk_nfc_write_subpage_hwecc;
+	nand->ecc.write_page_raw = mtk_nfc_write_page_raw;
+	nand->ecc.write_page = mtk_nfc_write_page_hwecc;
+	nand->ecc.write_oob_raw = mtk_nfc_write_oob_std;
+	nand->ecc.write_oob = mtk_nfc_write_oob_std;
+
+	nand->ecc.read_subpage = mtk_nfc_read_subpage_hwecc;
+	nand->ecc.read_page_raw = mtk_nfc_read_page_raw;
+	nand->ecc.read_page = mtk_nfc_read_page_hwecc;
+	nand->ecc.read_oob_raw = mtk_nfc_read_oob_std;
+	nand->ecc.read_oob = mtk_nfc_read_oob_std;
+
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = dev;
+	mtd->name = MTK_NAME;
+	mtd_set_ooblayout(mtd, &mtk_nfc_ooblayout_ops);
+
+	mtk_nfc_hw_init(nfc);
+
+	ret = nand_scan_ident(mtd, nsels, NULL);
+	if (ret)
+		return -ENODEV;
+
+	/* store bbt magic in page, cause OOB is not protected */
+	if (nand->bbt_options & NAND_BBT_USE_FLASH)
+		nand->bbt_options |= NAND_BBT_NO_OOB;
+
+	ret = mtk_nfc_ecc_init(dev, mtd);
+	if (ret)
+		return -EINVAL;
+
+	if (nand->options & NAND_BUSWIDTH_16) {
+		dev_err(dev, "16bits buswidth not supported");
+		return -EINVAL;
+	}
+
+	mtk_nfc_set_spare_per_sector(&chip->spare_per_sector, mtd);
+	mtk_nfc_set_fdm(&chip->fdm, mtd);
+	mtk_nfc_set_bad_mark_ctl(&chip->bad_mark, mtd);
+
+	len = mtd->writesize + mtd->oobsize;
+	nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL);
+	if (!nfc->buffer)
+		return  -ENOMEM;
+
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return -ENODEV;
+
+	ret = mtd_device_parse_register(mtd, NULL, NULL, NULL, 0);
+	if (ret) {
+		dev_err(dev, "mtd parse partition error\n");
+		nand_release(mtd);
+		return ret;
+	}
+
+	list_add_tail(&chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int mtk_nfc_nand_chips_init(struct device *dev, struct mtk_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int ret;
+
+	for_each_child_of_node(np, nand_np) {
+		ret = mtk_nfc_nand_chip_init(dev, nfc, nand_np);
+		if (ret) {
+			of_node_put(nand_np);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mtk_nfc *nfc;
+	struct resource *res;
+	int ret, irq;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	spin_lock_init(&nfc->controller.lock);
+	init_waitqueue_head(&nfc->controller.wq);
+	INIT_LIST_HEAD(&nfc->chips);
+
+	/* probe defer if not ready */
+	nfc->ecc = of_mtk_ecc_get(np);
+	if (IS_ERR(nfc->ecc))
+		return PTR_ERR(nfc->ecc);
+	else if (!nfc->ecc)
+		return -ENODEV;
+
+	nfc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->regs)) {
+		ret = PTR_ERR(nfc->regs);
+		dev_err(dev, "no nfi base\n");
+		goto release_ecc;
+	}
+
+	nfc->clk.nfi_clk = devm_clk_get(dev, "nfi_clk");
+	if (IS_ERR(nfc->clk.nfi_clk)) {
+		dev_err(dev, "no clk\n");
+		ret = PTR_ERR(nfc->clk.nfi_clk);
+		goto release_ecc;
+	}
+
+	nfc->clk.pad_clk = devm_clk_get(dev, "pad_clk");
+	if (IS_ERR(nfc->clk.pad_clk)) {
+		dev_err(dev, "no pad clk\n");
+		ret = PTR_ERR(nfc->clk.pad_clk);
+		goto release_ecc;
+	}
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		goto release_ecc;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no nfi irq resource\n");
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_nfc_irq, 0x0, "mtk-nand", nfc);
+	if (ret) {
+		dev_err(dev, "failed to request nfi irq\n");
+		goto clk_disable;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set dma mask\n");
+		goto clk_disable;
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = mtk_nfc_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init nand chips\n");
+		goto clk_disable;
+	}
+
+	return 0;
+
+clk_disable:
+	mtk_nfc_disable_clk(&nfc->clk);
+
+release_ecc:
+	mtk_ecc_release(nfc->ecc);
+
+	return ret;
+}
+
+static int mtk_nfc_remove(struct platform_device *pdev)
+{
+	struct mtk_nfc *nfc = platform_get_drvdata(pdev);
+	struct mtk_nfc_nand_chip *chip;
+
+	while (!list_empty(&nfc->chips)) {
+		chip = list_first_entry(&nfc->chips, struct mtk_nfc_nand_chip,
+					node);
+		nand_release(nand_to_mtd(&chip->nand));
+		list_del(&chip->node);
+	}
+
+	mtk_ecc_release(nfc->ecc);
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_nfc_suspend(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+static int mtk_nfc_resume(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int ret;
+	u32 i;
+
+	udelay(200);
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		return ret;
+
+	mtk_nfc_hw_init(nfc);
+
+	/* reset NAND chip if VCC was powered off */
+	list_for_each_entry(chip, &nfc->chips, node) {
+		nand = &chip->nand;
+		mtd = nand_to_mtd(nand);
+		for (i = 0; i < chip->nsels; i++) {
+			nand->select_chip(mtd, i);
+			nand->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+		}
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_nfc_pm_ops, mtk_nfc_suspend, mtk_nfc_resume);
+#endif
+
+static const struct of_device_id mtk_nfc_id_table[] = {
+	{ .compatible = "mediatek,mt2701-nfc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mtk_nfc_id_table);
+
+static struct platform_driver mtk_nfc_driver = {
+	.probe  = mtk_nfc_probe,
+	.remove = mtk_nfc_remove,
+	.driver = {
+		.name  = MTK_NAME,
+		.of_match_table = mtk_nfc_id_table,
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_nfc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_nfc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Xiaolei Li <[e-mail]>");
+MODULE_DESCRIPTION("MTK Nand Flash Controller Driver");

drivers/mtd/nand/nand_ids.c

···
 /* Manufacturer IDs */
 struct nand_manufacturers nand_manuf_ids[] = {
 	{NAND_MFR_TOSHIBA, "Toshiba"},
+	{NAND_MFR_ESMT, "ESMT"},
 	{NAND_MFR_SAMSUNG, "Samsung"},
 	{NAND_MFR_FUJITSU, "Fujitsu"},
 	{NAND_MFR_NATIONAL, "National"},

drivers/mtd/nand/omap2.c

···
 #define	PREFETCH_STATUS_FIFO_CNT(val)	((val >> 24) & 0x7F)
 #define	STATUS_BUFF_EMPTY		0x00000001
 
-#define OMAP24XX_DMA_GPMC		4
-
 #define SECTOR_BYTES		512
 /* 4 bit padding to make byte aligned, 56 = 52 + 4 */
 #define BCH4_BIT_PAD		4
···
 	struct nand_chip		*nand_chip;
 	int				err;
 	dma_cap_mask_t			mask;
-	unsigned			sig;
 	struct resource			*res;
 	struct device			*dev = &pdev->dev;
 	int				min_oobbytes = BADBLOCK_MARKER_LENGTH;
···
 	case NAND_OMAP_PREFETCH_DMA:
 		dma_cap_zero(mask);
 		dma_cap_set(DMA_SLAVE, mask);
-		sig = OMAP24XX_DMA_GPMC;
-		info->dma = dma_request_channel(mask, omap_dma_filter_fn, &sig);
+		info->dma = dma_request_chan(pdev->dev.parent, "rxtx");
+
 		if (!info->dma) {
 			dev_err(&pdev->dev, "DMA engine request failed\n");
 			err = -ENXIO;

drivers/mtd/nand/sunxi_nand.c

···
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/reset.h>
 
 #define NFC_REG_CTL		0x0000
 #define NFC_REG_ST		0x0004
···
 
 /* define bit use in NFC_ECC_ST */
 #define NFC_ECC_ERR(x)		BIT(x)
+#define NFC_ECC_ERR_MSK		GENMASK(15, 0)
 #define NFC_ECC_PAT_FOUND(x)	BIT(x + 16)
 #define NFC_ECC_ERR_CNT(b, x)	(((x) >> (((b) % 4) * 8)) & 0xff)
 
···
 	void __iomem *regs;
 	struct clk *ahb_clk;
 	struct clk *mod_clk;
+	struct reset_control *reset;
 	unsigned long assigned_cs;
 	unsigned long clk_rate;
 	struct list_head chips;
 	struct completion complete;
+	struct dma_chan *dmac;
 };
 
 static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)
···
 		dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
 
 	return ret;
+}
+
+static int sunxi_nfc_dma_op_prepare(struct mtd_info *mtd, const void *buf,
+				    int chunksize, int nchunks,
+				    enum dma_data_direction ddir,
+				    struct scatterlist *sg)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct dma_async_tx_descriptor *dmad;
+	enum dma_transfer_direction tdir;
+	dma_cookie_t dmat;
+	int ret;
+
+	if (ddir == DMA_FROM_DEVICE)
+		tdir = DMA_DEV_TO_MEM;
+	else
+		tdir = DMA_MEM_TO_DEV;
+
+	sg_init_one(sg, buf, nchunks * chunksize);
+	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
+	if (!ret)
+		return -ENOMEM;
+
+	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
+	if (!dmad) {
+		ret = -EINVAL;
+		goto err_unmap_buf;
+	}
+
+	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
+	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
+	writel(chunksize, nfc->regs + NFC_REG_CNT);
+	dmat = dmaengine_submit(dmad);
+
+	ret = dma_submit_error(dmat);
+	if (ret)
+		goto err_clr_dma_flag;
+
+	return 0;
+
+err_clr_dma_flag:
+	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
+
+err_unmap_buf:
+	dma_unmap_sg(nfc->dev, sg, 1, ddir);
+	return ret;
+}
+
+static void sunxi_nfc_dma_op_cleanup(struct mtd_info *mtd,
+				     enum dma_data_direction ddir,
+				     struct scatterlist *sg)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+
+	dma_unmap_sg(nfc->dev, sg, 1, ddir);
+	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
+	       nfc->regs + NFC_REG_CTL);
 }
 
 static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
···
 }
 
 static int sunxi_nfc_hw_ecc_correct(struct mtd_info *mtd, u8 *data, u8 *oob,
-				    int step, bool *erased)
+				    int step, u32 status, bool *erased)
 {
 	struct nand_chip *nand = mtd_to_nand(mtd);
 	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
 	struct nand_ecc_ctrl *ecc = &nand->ecc;
-	u32 status, tmp;
+	u32 tmp;
 
 	*erased = false;
-
-	status = readl(nfc->regs + NFC_REG_ECC_ST);
 
 	if (status & NFC_ECC_ERR(step))
 		return -EBADMSG;
···
 	*cur_off = oob_off + ecc->bytes + 4;
 
 	ret = sunxi_nfc_hw_ecc_correct(mtd, data, oob_required ? oob : NULL, 0,
+				       readl(nfc->regs + NFC_REG_ECC_ST),
 				       &erased);
 	if (erased)
 		return 1;
···
 
 	if (cur_off)
 		*cur_off = mtd->oobsize + mtd->writesize;
+}
+
+static int sunxi_nfc_hw_ecc_read_chunks_dma(struct mtd_info *mtd, uint8_t *buf,
+					    int oob_required, int page,
+					    int nchunks)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	bool randomized = nand->options & NAND_NEED_SCRAMBLING;
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	unsigned int max_bitflips = 0;
+	int ret, i, raw_mode = 0;
+	struct scatterlist sg;
+	u32 status;
+
+	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+	if (ret)
+		return ret;
+
+	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, nchunks,
+				       DMA_FROM_DEVICE, &sg);
+	if (ret)
+		return ret;
+
+	sunxi_nfc_hw_ecc_enable(mtd);
+	sunxi_nfc_randomizer_config(mtd, page, false);
+	sunxi_nfc_randomizer_enable(mtd);
+
+	writel((NAND_CMD_RNDOUTSTART << 16) | (NAND_CMD_RNDOUT << 8) |
+	       NAND_CMD_READSTART, nfc->regs + NFC_REG_RCMD_SET);
+
+	dma_async_issue_pending(nfc->dmac);
+
+	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD | NFC_DATA_TRANS,
+	       nfc->regs + NFC_REG_CMD);
+
+	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, true, 0);
+	if (ret)
+		dmaengine_terminate_all(nfc->dmac);
+
+	sunxi_nfc_randomizer_disable(mtd);
+	sunxi_nfc_hw_ecc_disable(mtd);
+
+	sunxi_nfc_dma_op_cleanup(mtd, DMA_FROM_DEVICE, &sg);
+
+	if (ret)
+		return ret;
+
+	status = readl(nfc->regs + NFC_REG_ECC_ST);
+
+	for (i = 0; i < nchunks; i++) {
+		int data_off = i * ecc->size;
+		int oob_off = i * (ecc->bytes + 4);
+		u8 *data = buf + data_off;
+		u8 *oob = nand->oob_poi + oob_off;
+		bool erased;
+
+		ret = sunxi_nfc_hw_ecc_correct(mtd, randomized ? data : NULL,
+					       oob_required ? oob : NULL,
+					       i, status, &erased);
+
+		/* ECC errors are handled in the second loop. */
+		if (ret < 0)
+			continue;
+
+		if (oob_required && !erased) {
+			/* TODO: use DMA to retrieve OOB */
+			nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
+				      mtd->writesize + oob_off, -1);
+			nand->read_buf(mtd, oob, ecc->bytes + 4);
+
+			sunxi_nfc_hw_ecc_get_prot_oob_bytes(mtd, oob, i,
+							    !i, page);
+		}
+
+		if (erased)
+			raw_mode = 1;
+
+		sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
+	}
+
+	if (status & NFC_ECC_ERR_MSK) {
+		for (i = 0; i < nchunks; i++) {
+			int data_off = i * ecc->size;
+			int oob_off = i * (ecc->bytes + 4);
+			u8 *data = buf + data_off;
+			u8 *oob = nand->oob_poi + oob_off;
+
+			if (!(status & NFC_ECC_ERR(i)))
+				continue;
+
+			/*
+			 * Re-read the data with the randomizer disabled to
+			 * identify bitflips in erased pages.
+			 */
+			if (randomized) {
+				/* TODO: use DMA to read page in raw mode */
+				nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
+					      data_off, -1);
+				nand->read_buf(mtd, data, ecc->size);
+			}
+
+			/* TODO: use DMA to retrieve OOB */
+			nand->cmdfunc(mtd, NAND_CMD_RNDOUT,
+				      mtd->writesize + oob_off, -1);
+			nand->read_buf(mtd, oob, ecc->bytes + 4);
+
+			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
+							  oob, ecc->bytes + 4,
+							  NULL, 0,
+							  ecc->strength);
+			if (ret >= 0)
+				raw_mode = 1;
+
+			sunxi_nfc_hw_ecc_update_stats(mtd, &max_bitflips, ret);
+		}
+	}
+
+	if (oob_required)
+		sunxi_nfc_hw_ecc_read_extra_oob(mtd, nand->oob_poi,
+						NULL, !raw_mode,
+						page);
+
+	return max_bitflips;
 }
 
 static int sunxi_nfc_hw_ecc_write_chunk(struct mtd_info *mtd,
···
 	return max_bitflips;
 }
 
+static int sunxi_nfc_hw_ecc_read_page_dma(struct mtd_info *mtd,
+					  struct nand_chip *chip, u8 *buf,
+					  int oob_required, int page)
+{
+	int ret;
+
+	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, oob_required, page,
+					       chip->ecc.steps);
+	if (ret >= 0)
+		return ret;
+
+	/* Fallback to PIO mode */
+	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1);
+
+	return sunxi_nfc_hw_ecc_read_page(mtd, chip, buf, oob_required, page);
+}
+
 static int sunxi_nfc_hw_ecc_read_subpage(struct mtd_info *mtd,
 					 struct nand_chip *chip,
 					 u32 data_offs, u32 readlen,
···
 	return max_bitflips;
 }
 
+static int sunxi_nfc_hw_ecc_read_subpage_dma(struct mtd_info *mtd,
+					     struct nand_chip *chip,
+					     u32 data_offs, u32 readlen,
+					     u8 *buf, int page)
+{
+	int nchunks = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
+	int ret;
+
+	ret = sunxi_nfc_hw_ecc_read_chunks_dma(mtd, buf, false, page, nchunks);
+	if (ret >= 0)
+		return ret;
+
+	/* Fallback to PIO mode */
+	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1);
+
+	return sunxi_nfc_hw_ecc_read_subpage(mtd, chip, data_offs, readlen,
+					     buf, page);
+}
+
 static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
 				       struct nand_chip *chip,
 				       const uint8_t *buf, int oob_required,
···
 	sunxi_nfc_hw_ecc_disable(mtd);
 
 	return 0;
+}
+
+static int sunxi_nfc_hw_ecc_write_subpage(struct mtd_info *mtd,
+					  struct nand_chip *chip,
+					  u32 data_offs, u32 data_len,
+					  const u8 *buf, int oob_required,
+					  int page)
+{
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int ret, i, cur_off = 0;
+
+	sunxi_nfc_hw_ecc_enable(mtd);
+
+	for (i = data_offs / ecc->size;
+	     i < DIV_ROUND_UP(data_offs + data_len, ecc->size); i++) {
+		int data_off = i * ecc->size;
+		int oob_off = i * (ecc->bytes + 4);
+		const u8 *data = buf + data_off;
+		const u8 *oob = chip->oob_poi + oob_off;
+
+		ret = sunxi_nfc_hw_ecc_write_chunk(mtd, data, data_off, oob,
+						   oob_off + mtd->writesize,
+						   &cur_off, !i, page);
+		if (ret)
+			return ret;
+	}
+
+	sunxi_nfc_hw_ecc_disable(mtd);
+
+	return 0;
+}
+
+static int sunxi_nfc_hw_ecc_write_page_dma(struct mtd_info *mtd,
+					   struct nand_chip *chip,
+					   const u8 *buf,
+					   int oob_required,
+					   int page)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	struct scatterlist sg;
+	int ret, i;
+
+	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+	if (ret)
+		return ret;
+
+	ret = sunxi_nfc_dma_op_prepare(mtd, buf, ecc->size, ecc->steps,
+				       DMA_TO_DEVICE, &sg);
+	if (ret)
+		goto pio_fallback;
+
+	for (i = 0; i < ecc->steps; i++) {
+		const u8 *oob = nand->oob_poi + (i * (ecc->bytes + 4));
+
+		sunxi_nfc_hw_ecc_set_prot_oob_bytes(mtd, oob, i, !i, page);
+	}
+
+	sunxi_nfc_hw_ecc_enable(mtd);
+	sunxi_nfc_randomizer_config(mtd, page, false);
+	sunxi_nfc_randomizer_enable(mtd);
+
+	writel((NAND_CMD_RNDIN << 8) | NAND_CMD_PAGEPROG,
+	       nfc->regs + NFC_REG_RCMD_SET);
+
+	dma_async_issue_pending(nfc->dmac);
+
+	writel(NFC_PAGE_OP | NFC_DATA_SWAP_METHOD |
+	       NFC_DATA_TRANS | NFC_ACCESS_DIR,
+	       nfc->regs + NFC_REG_CMD);
+
+	ret = sunxi_nfc_wait_events(nfc, NFC_CMD_INT_FLAG, true, 0);
+	if (ret)
+		dmaengine_terminate_all(nfc->dmac);
+
+	sunxi_nfc_randomizer_disable(mtd);
+	sunxi_nfc_hw_ecc_disable(mtd);
+
+	sunxi_nfc_dma_op_cleanup(mtd, DMA_TO_DEVICE, &sg);
+
+	if (ret)
+		return ret;
+
+	if (oob_required || (chip->options & NAND_NEED_SCRAMBLING))
+		/* TODO: use DMA to transfer extra OOB bytes ? */
+		sunxi_nfc_hw_ecc_write_extra_oob(mtd, chip->oob_poi,
+						 NULL, page);
+
+	return 0;
+
+pio_fallback:
+	return sunxi_nfc_hw_ecc_write_page(mtd, chip, buf, oob_required, page);
 }
 
 static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
···
 	int ret;
 	int i;
 
+	if (ecc->size != 512 && ecc->size != 1024)
+		return -EINVAL;
+
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
+
+	/* Prefer 1k ECC chunk over 512 ones */
+	if (ecc->size == 512 && mtd->writesize > 512) {
+		ecc->size = 1024;
+		ecc->strength *= 2;
+	}
 
 	/* Add ECC info retrieval from DT */
 	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
···
 				       struct nand_ecc_ctrl *ecc,
 				       struct device_node *np)
 {
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
 	int ret;
 
 	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
 	if (ret)
 		return ret;
 
-	ecc->read_page = sunxi_nfc_hw_ecc_read_page;
-	ecc->write_page = sunxi_nfc_hw_ecc_write_page;
+	if (nfc->dmac) {
+		ecc->read_page = sunxi_nfc_hw_ecc_read_page_dma;
+		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage_dma;
+		ecc->write_page = sunxi_nfc_hw_ecc_write_page_dma;
+		nand->options |= NAND_USE_BOUNCE_BUFFER;
+	} else {
+		ecc->read_page = sunxi_nfc_hw_ecc_read_page;
+		ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
+		ecc->write_page = sunxi_nfc_hw_ecc_write_page;
+	}
+
+	/* TODO: support DMA for raw accesses and subpage write */
+	ecc->write_subpage = sunxi_nfc_hw_ecc_write_subpage;
 	ecc->read_oob_raw = nand_read_oob_std;
 	ecc->write_oob_raw = nand_write_oob_std;
 	ecc->read_subpage = sunxi_nfc_hw_ecc_read_subpage;
···
 	if (ret)
 		goto out_ahb_clk_unprepare;
 
+	nfc->reset = devm_reset_control_get_optional(dev, "ahb");
+	if (!IS_ERR(nfc->reset)) {
+		ret = reset_control_deassert(nfc->reset);
+		if (ret) {
+			dev_err(dev, "reset err %d\n", ret);
+			goto out_mod_clk_unprepare;
+		}
+	} else if (PTR_ERR(nfc->reset) != -ENOENT) {
+		ret = PTR_ERR(nfc->reset);
+		goto out_mod_clk_unprepare;
+	}
+
 	ret = sunxi_nfc_rst(nfc);
 	if (ret)
-		goto out_mod_clk_unprepare;
+		goto out_ahb_reset_reassert;
 
 	writel(0, nfc->regs + NFC_REG_INT);
 	ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
 			       0, "sunxi-nand", nfc);
 	if (ret)
-		goto out_mod_clk_unprepare;
+		goto out_ahb_reset_reassert;
+
+	nfc->dmac = dma_request_slave_channel(dev, "rxtx");
+	if (nfc->dmac) {
+		struct dma_slave_config dmac_cfg = { };
+
+		dmac_cfg.src_addr = r->start + NFC_REG_IO_DATA;
+		dmac_cfg.dst_addr = dmac_cfg.src_addr;
+		dmac_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		dmac_cfg.dst_addr_width = dmac_cfg.src_addr_width;
+		dmac_cfg.src_maxburst = 4;
+		dmac_cfg.dst_maxburst = 4;
+		dmaengine_slave_config(nfc->dmac, &dmac_cfg);
+	} else {
+		dev_warn(dev, "failed to request rxtx DMA channel\n");
+	}
 
 	platform_set_drvdata(pdev, nfc);
 
 	ret = sunxi_nand_chips_init(dev, nfc);
 	if (ret) {
 		dev_err(dev, "failed to init nand chips\n");
-		goto out_mod_clk_unprepare;
+		goto out_release_dmac;
 	}
 
 	return 0;
 
+out_release_dmac:
+	if (nfc->dmac)
+		dma_release_channel(nfc->dmac);
+out_ahb_reset_reassert:
+	if (!IS_ERR(nfc->reset))
+		reset_control_assert(nfc->reset);
 out_mod_clk_unprepare:
 	clk_disable_unprepare(nfc->mod_clk);
 out_ahb_clk_unprepare:
···
 	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
 
 	sunxi_nand_chips_cleanup(nfc);
+
+	if (!IS_ERR(nfc->reset))
+		reset_control_assert(nfc->reset);
+
+	if (nfc->dmac)
+		dma_release_channel(nfc->dmac);
 	clk_disable_unprepare(nfc->mod_clk);
 	clk_disable_unprepare(nfc->ahb_clk);
 

drivers/mtd/nand/xway_nand.c

···
  *  by the Free Software Foundation.
  *
  *  Copyright © 2012 John Crispin <[e-mail]>
+ *  Copyright © 2016 Hauke Mehrtens <[e-mail]>
  */
 
 #include <linux/mtd/nand.h>
···
 #define EBU_ADDSEL1		0x24
 #define EBU_NAND_CON		0xB0
 #define EBU_NAND_WAIT		0xB4
+#define  NAND_WAIT_RD		BIT(0) /* NAND flash status output */
+#define  NAND_WAIT_WR_C		BIT(3) /* NAND Write/Read complete */
 #define EBU_NAND_ECC0		0xB8
 #define EBU_NAND_ECC_AC		0xBC
 
-/* nand commands */
-#define NAND_CMD_ALE		(1 << 2)
-#define NAND_CMD_CLE		(1 << 3)
-#define NAND_CMD_CS		(1 << 4)
-#define NAND_WRITE_CMD_RESET	0xff
+/*
+ * nand commands
+ * The pins of the NAND chip are selected based on the address bits of the
+ * "register" read and write. There are no special registers, but an
+ * address range and the lower address bits are used to activate the
+ * correct line. For example when the bit (1 << 2) is set in the address
+ * the ALE pin will be activated.
+ */
+#define NAND_CMD_ALE		BIT(2) /* address latch enable */
+#define NAND_CMD_CLE		BIT(3) /* command latch enable */
+#define NAND_CMD_CS		BIT(4) /* chip select */
+#define NAND_CMD_SE		BIT(5) /* spare area access latch */
+#define NAND_CMD_WP		BIT(6) /* write protect */
 #define NAND_WRITE_CMD		(NAND_CMD_CS | NAND_CMD_CLE)
 #define NAND_WRITE_ADDR		(NAND_CMD_CS | NAND_CMD_ALE)
 #define NAND_WRITE_DATA		(NAND_CMD_CS)
 #define NAND_READ_DATA		(NAND_CMD_CS)
-#define NAND_WAIT_WR_C		(1 << 3)
-#define NAND_WAIT_RD		(0x1)
 
 /* we need to tel the ebu which addr we mapped the nand to */
 #define ADDSEL1_MASK(x)		(x << 4)
···
 #define NAND_CON_CSMUX		(1 << 1)
 #define NAND_CON_NANDM		1
 
-static void xway_reset_chip(struct nand_chip *chip)
+struct xway_nand_data {
+	struct nand_chip	chip;
+	unsigned long		csflags;
+	void __iomem		*nandaddr;
+};
+
+static u8 xway_readb(struct mtd_info *mtd, int op)
 {
-	unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
-	unsigned long flags;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct xway_nand_data *data = nand_get_controller_data(chip);
 
-	nandaddr &= ~NAND_WRITE_ADDR;
-	nandaddr |= NAND_WRITE_CMD;
-
-	/* finish with a reset */
-	spin_lock_irqsave(&ebu_lock, flags);
-	writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
-	while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
-		;
-	spin_unlock_irqrestore(&ebu_lock, flags);
+	return readb(data->nandaddr + op);
 }
 
-static void xway_select_chip(struct mtd_info *mtd, int chip)
+static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
 {
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct xway_nand_data *data = nand_get_controller_data(chip);
 
-	switch (chip) {
+	writeb(value, data->nandaddr + op);
+}
+
+static void xway_select_chip(struct mtd_info *mtd, int select)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct xway_nand_data *data = nand_get_controller_data(chip);
+
+	switch (select) {
 	case -1:
 		ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
 		ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
+		spin_unlock_irqrestore(&ebu_lock, data->csflags);
 		break;
 	case 0:
+		spin_lock_irqsave(&ebu_lock, data->csflags);
 		ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
 		ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
 		break;
···
 
 static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 {
-	struct nand_chip *this = mtd_to_nand(mtd);
-	unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
-	unsigned long flags;
+	if (cmd == NAND_CMD_NONE)
+		return;
 
-	if (ctrl & NAND_CTRL_CHANGE) {
-		nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR);
-		if (ctrl & NAND_CLE)
-			nandaddr |= NAND_WRITE_CMD;
-		else
-			nandaddr |= NAND_WRITE_ADDR;
-		this->IO_ADDR_W = (void __iomem *) nandaddr;
-	}
+	if (ctrl & NAND_CLE)
+		xway_writeb(mtd, NAND_WRITE_CMD, cmd);
+	else if (ctrl & NAND_ALE)
+		xway_writeb(mtd, NAND_WRITE_ADDR, cmd);
 
-	if (cmd != NAND_CMD_NONE) {
-		spin_lock_irqsave(&ebu_lock, flags);
-		writeb(cmd, this->IO_ADDR_W);
-		while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
-			;
-		spin_unlock_irqrestore(&ebu_lock, flags);
-	}
+	while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+		;
 }
 
 static int xway_dev_ready(struct mtd_info *mtd)
···
 
 static unsigned char xway_read_byte(struct mtd_info *mtd)
 {
-	struct nand_chip *this = mtd_to_nand(mtd);
-	unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
-	unsigned long flags;
-	int ret;
-
-	spin_lock_irqsave(&ebu_lock, flags);
-	ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
-	spin_unlock_irqrestore(&ebu_lock, flags);
-
-	return ret;
+	return xway_readb(mtd, NAND_READ_DATA);
 }
 
+static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
+}
+
+static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
+}
+
+/*
+ * Probe for the NAND device.
+ */
 static int xway_nand_probe(struct platform_device *pdev)
 {
-	struct nand_chip *this = platform_get_drvdata(pdev);
-	unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
-	const __be32 *cs = of_get_property(pdev->dev.of_node,
-					"lantiq,cs", NULL);
+	struct xway_nand_data *data;
+	struct mtd_info *mtd;
+	struct resource *res;
+	int err;
+	u32 cs;
 	u32 cs_flag = 0;
 
+	/* Allocate memory for the device structure (and zero it) */
+	data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->nandaddr))
+		return PTR_ERR(data->nandaddr);
+
+	nand_set_flash_node(&data->chip, pdev->dev.of_node);
+	mtd = nand_to_mtd(&data->chip);
+	mtd->dev.parent = &pdev->dev;
+
+	data->chip.cmd_ctrl = xway_cmd_ctrl;
+	data->chip.dev_ready = xway_dev_ready;
+	data->chip.select_chip = xway_select_chip;
+	data->chip.write_buf = xway_write_buf;
+	data->chip.read_buf = xway_read_buf;
+	data->chip.read_byte = xway_read_byte;
+	data->chip.chip_delay = 30;
+
+	data->chip.ecc.mode = NAND_ECC_SOFT;
+	data->chip.ecc.algo = NAND_ECC_HAMMING;
+
+	platform_set_drvdata(pdev, data);
+	nand_set_controller_data(&data->chip, data);
+
 	/* load our CS from the DT. Either we find a valid 1 or default to 0 */
-	if (cs && (*cs == 1))
+	err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
+	if (!err && cs == 1)
 		cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
 
 	/* setup the EBU to run in NAND mode on our base addr */
-	ltq_ebu_w32(CPHYSADDR(nandaddr)
-		| ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
+	ltq_ebu_w32(CPHYSADDR(data->nandaddr)
+		    | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
 
 	ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
-		| BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
-		| BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
+		    | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
+		    | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
 
 	ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
-		| NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
-		| cs_flag, EBU_NAND_CON);
+		    | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
+		    | cs_flag, EBU_NAND_CON);
 
-	/* finish with a reset */
-	xway_reset_chip(this);
+	/* Scan to find existence of the device */
+	err = nand_scan(mtd, 1);
+	if (err)
+		return err;
 
-	return 0;
+	err = mtd_device_register(mtd, NULL, 0);
+	if (err)
+		nand_release(mtd);
+
+	return err;
 }
-
-static struct platform_nand_data xway_nand_data = {
-	.chip = {
-		.nr_chips		= 1,
-		.chip_delay		= 30,
-	},
-	.ctrl = {
-		.probe		= xway_nand_probe,
-		.cmd_ctrl	= xway_cmd_ctrl,
-		.dev_ready	= xway_dev_ready,
-		.select_chip	= xway_select_chip,
-		.read_byte	= xway_read_byte,
-	}
-};
 
 /*
- * Try to find the node inside the DT. If it is available attach out
- * platform_nand_data
+ * Remove a NAND device.
  */
-static int __init xway_register_nand(void)
+static int xway_nand_remove(struct platform_device *pdev)
 {
-	struct device_node *node;
-	struct platform_device *pdev;
+	struct xway_nand_data *data = platform_get_drvdata(pdev);
 
-	node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway");
-	if (!node)
-		return -ENOENT;
-	pdev = of_find_device_by_node(node);
-	if (!pdev)
-		return -EINVAL;
-	pdev->dev.platform_data = &xway_nand_data;
-	of_node_put(node);
+	nand_release(nand_to_mtd(&data->chip));
+
 	return 0;
 }
 
-subsys_initcall(xway_register_nand);
+static const struct of_device_id xway_nand_match[] = {
+	{ .compatible = "lantiq,nand-xway" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xway_nand_match);
+
+static struct platform_driver xway_nand_driver = {
+	.probe	= xway_nand_probe,
+	.remove	= xway_nand_remove,
+	.driver	= {
+		.name		= "lantiq,nand-xway",
+		.of_match_table = xway_nand_match,
+	},
+};
+
+module_platform_driver(xway_nand_driver);
+
+MODULE_LICENSE("GPL");

drivers/mtd/tests/nandbiterrs.c

···
 
 	while (opno < max_overwrite) {
 
-		err = rewrite_page(0);
+		err = write_page(0);
 		if (err)
 			break;
 

include/linux/mtd/nand.h

···
  * NAND Flash Manufacturer ID Codes
  */
 #define NAND_MFR_TOSHIBA	0x98
+#define NAND_MFR_ESMT		0xc8
 #define NAND_MFR_SAMSUNG	0xec
 #define NAND_MFR_FUJITSU	0x04
 #define NAND_MFR_NATIONAL	0x8f