mtd: nand: add sunxi NAND flash controller support

Add support for the sunxi NAND Flash Controller (NFC).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Brian: tweaked to fix ecc->steps issue]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

3 files changed, 1439 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index dd10646982ae..4c51d2c9acc1 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -516,4 +516,10 @@ config MTD_NAND_XWAY
 	  Enables support for NAND Flash chips on Lantiq XWAY SoCs. NAND is attached
 	  to the External Bus Unit (EBU).
 
+config MTD_NAND_SUNXI
+	tristate "Support for NAND on Allwinner SoCs"
+	depends on ARCH_SUNXI
+	help
+	  Enables support for NAND Flash chips on Allwinner SoCs.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 9c847e469ca7..bd38f21d2e28 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -50,5 +50,6 @@ obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
 obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
 obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
+obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
new file mode 100644
index 000000000000..ccaa8e283388
--- /dev/null
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -0,0 +1,1432 @@
+/*
+ * Copyright (C) 2013 Boris BREZILLON <b.brezillon.dev@gmail.com>
+ *
+ * Derived from:
+ *	https://github.com/yuq/sunxi-nfc-mtd
+ *	Copyright (C) 2013 Qiang Yu <yuq825@gmail.com>
+ *
+ *	https://github.com/hno/Allwinner-Info
+ *	Copyright (C) 2013 Henrik Nordström <Henrik Nordström>
+ *
+ *	Copyright (C) 2013 Dmitriy B. <rzk333@gmail.com>
+ *	Copyright (C) 2013 Sergey Lapin <slapin@ossfans.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_mtd.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#define NFC_REG_CTL		0x0000
+#define NFC_REG_ST		0x0004
+#define NFC_REG_INT		0x0008
+#define NFC_REG_TIMING_CTL	0x000C
+#define NFC_REG_TIMING_CFG	0x0010
+#define NFC_REG_ADDR_LOW	0x0014
+#define NFC_REG_ADDR_HIGH	0x0018
+#define NFC_REG_SECTOR_NUM	0x001C
+#define NFC_REG_CNT		0x0020
+#define NFC_REG_CMD		0x0024
+#define NFC_REG_RCMD_SET	0x0028
+#define NFC_REG_WCMD_SET	0x002C
+#define NFC_REG_IO_DATA		0x0030
+#define NFC_REG_ECC_CTL		0x0034
+#define NFC_REG_ECC_ST		0x0038
+#define NFC_REG_DEBUG		0x003C
+#define NFC_REG_ECC_CNT0	0x0040
+#define NFC_REG_ECC_CNT1	0x0044
+#define NFC_REG_ECC_CNT2	0x0048
+#define NFC_REG_ECC_CNT3	0x004c
+#define NFC_REG_USER_DATA_BASE	0x0050
+#define NFC_REG_SPARE_AREA	0x00A0
+#define NFC_RAM0_BASE		0x0400
+#define NFC_RAM1_BASE		0x0800
+
+/* define bit use in NFC_CTL */
+#define NFC_EN			BIT(0)
+#define NFC_RESET		BIT(1)
+#define NFC_BUS_WIDYH		BIT(2)
+#define NFC_RB_SEL		BIT(3)
+#define NFC_CE_SEL		GENMASK(26, 24)
+#define NFC_CE_CTL		BIT(6)
+#define NFC_CE_CTL1		BIT(7)
+#define NFC_PAGE_SIZE		GENMASK(11, 8)
+#define NFC_SAM			BIT(12)
+#define NFC_RAM_METHOD		BIT(14)
+#define NFC_DEBUG_CTL		BIT(31)
+
+/* define bit use in NFC_ST */
+#define NFC_RB_B2R		BIT(0)
+#define NFC_CMD_INT_FLAG	BIT(1)
+#define NFC_DMA_INT_FLAG	BIT(2)
+#define NFC_CMD_FIFO_STATUS	BIT(3)
+#define NFC_STA			BIT(4)
+#define NFC_NATCH_INT_FLAG	BIT(5)
+#define NFC_RB_STATE0		BIT(8)
+#define NFC_RB_STATE1		BIT(9)
+#define NFC_RB_STATE2		BIT(10)
+#define NFC_RB_STATE3		BIT(11)
+
+/* define bit use in NFC_INT */
+#define NFC_B2R_INT_ENABLE	BIT(0)
+#define NFC_CMD_INT_ENABLE	BIT(1)
+#define NFC_DMA_INT_ENABLE	BIT(2)
+#define NFC_INT_MASK		(NFC_B2R_INT_ENABLE | \
+				 NFC_CMD_INT_ENABLE | \
+				 NFC_DMA_INT_ENABLE)
+
+/* define bit use in NFC_CMD */
+#define NFC_CMD_LOW_BYTE	GENMASK(7, 0)
+#define NFC_CMD_HIGH_BYTE	GENMASK(15, 8)
+#define NFC_ADR_NUM		GENMASK(18, 16)
+#define NFC_SEND_ADR		BIT(19)
+#define NFC_ACCESS_DIR		BIT(20)
+#define NFC_DATA_TRANS		BIT(21)
+#define NFC_SEND_CMD1		BIT(22)
+#define NFC_WAIT_FLAG		BIT(23)
+#define NFC_SEND_CMD2		BIT(24)
+#define NFC_SEQ			BIT(25)
+#define NFC_DATA_SWAP_METHOD	BIT(26)
+#define NFC_ROW_AUTO_INC	BIT(27)
+#define NFC_SEND_CMD3		BIT(28)
+#define NFC_SEND_CMD4		BIT(29)
+#define NFC_CMD_TYPE		GENMASK(31, 30)
+
+/* define bit use in NFC_RCMD_SET */
+#define NFC_READ_CMD		GENMASK(7, 0)
+#define NFC_RANDOM_READ_CMD0	GENMASK(15, 8)
+#define NFC_RANDOM_READ_CMD1	GENMASK(23, 16)
+
+/* define bit use in NFC_WCMD_SET */
+#define NFC_PROGRAM_CMD		GENMASK(7, 0)
+#define NFC_RANDOM_WRITE_CMD	GENMASK(15, 8)
+#define NFC_READ_CMD0		GENMASK(23, 16)
+#define NFC_READ_CMD1		GENMASK(31, 24)
+
+/* define bit use in NFC_ECC_CTL */
+#define NFC_ECC_EN		BIT(0)
+#define NFC_ECC_PIPELINE	BIT(3)
+#define NFC_ECC_EXCEPTION	BIT(4)
+#define NFC_ECC_BLOCK_SIZE	BIT(5)
+#define NFC_RANDOM_EN		BIT(9)
+#define NFC_RANDOM_DIRECTION	BIT(10)
+#define NFC_ECC_MODE_SHIFT	12
+#define NFC_ECC_MODE		GENMASK(15, 12)
+#define NFC_RANDOM_SEED		GENMASK(30, 16)
+
+#define NFC_DEFAULT_TIMEOUT_MS	1000
+
+#define NFC_SRAM_SIZE		1024
+
+#define NFC_MAX_CS		7
+
+/*
+ * Ready/Busy detection type: describes the Ready/Busy detection modes
+ *
+ * @RB_NONE:	no external detection available, rely on STATUS command
+ *		and software timeouts
+ * @RB_NATIVE:	use sunxi NAND controller Ready/Busy support. The Ready/Busy
+ *		pin of the NAND flash chip must be connected to one of the
+ *		native NAND R/B pins (those which can be muxed to the NAND
+ *		Controller)
+ * @RB_GPIO:	use a simple GPIO to handle Ready/Busy status. The Ready/Busy
+ *		pin of the NAND flash chip must be connected to a GPIO capable
+ *		pin.
+ */
+enum sunxi_nand_rb_type {
+	RB_NONE,
+	RB_NATIVE,
+	RB_GPIO,
+};
+
+/*
+ * Ready/Busy structure: stores information related to Ready/Busy detection
+ *
+ * @type:	the Ready/Busy detection mode
+ * @info:	information related to the R/B detection mode. Either a gpio
+ *		id or a native R/B id (those supported by the NAND controller).
+ */
+struct sunxi_nand_rb {
+	enum sunxi_nand_rb_type type;
+	union {
+		int gpio;
+		int nativeid;
+	} info;
+};
+
+/*
+ * Chip Select structure: stores information related to NAND Chip Select
+ *
+ * @cs:		the NAND CS id used to communicate with a NAND Chip
+ * @rb:		the Ready/Busy description
+ */
+struct sunxi_nand_chip_sel {
+	u8 cs;
+	struct sunxi_nand_rb rb;
+};
+
+/*
+ * sunxi HW ECC infos: stores information related to HW ECC support
+ *
+ * @mode:	the sunxi ECC mode field deduced from ECC requirements
+ * @layout:	the OOB layout depending on the ECC requirements and the
+ *		selected ECC mode
+ */
+struct sunxi_nand_hw_ecc {
+	int mode;
+	struct nand_ecclayout layout;
+};
+
+/*
+ * NAND chip structure: stores NAND chip device related information
+ *
+ * @node:		used to store NAND chips into a list
+ * @nand:		base NAND chip structure
+ * @mtd:		base MTD structure
+ * @clk_rate:		clk_rate required for this NAND chip
+ * @selected:		current active CS
+ * @nsels:		number of CS lines required by the NAND chip
+ * @sels:		array of CS lines descriptions
+ */
+struct sunxi_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+	struct mtd_info mtd;
+	unsigned long clk_rate;
+	int selected;
+	int nsels;
+	struct sunxi_nand_chip_sel sels[0];
+};
+
+static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct sunxi_nand_chip, nand);
+}
+
+/*
+ * NAND Controller structure: stores sunxi NAND controller information
+ *
+ * @controller:		base controller structure
+ * @dev:		parent device (used to print error messages)
+ * @regs:		NAND controller registers
+ * @ahb_clk:		NAND Controller AHB clock
+ * @mod_clk:		NAND Controller mod clock
+ * @assigned_cs:	bitmask describing already assigned CS lines
+ * @clk_rate:		NAND controller current clock rate
+ * @chips:		a list containing all the NAND chips attached to
+ *			this NAND controller
+ * @complete:		a completion object used to wait for NAND
+ *			controller events
+ */
+struct sunxi_nfc {
+	struct nand_hw_control controller;
+	struct device *dev;
+	void __iomem *regs;
+	struct clk *ahb_clk;
+	struct clk *mod_clk;
+	unsigned long assigned_cs;
+	unsigned long clk_rate;
+	struct list_head chips;
+	struct completion complete;
+};
+
+static inline struct sunxi_nfc *to_sunxi_nfc(struct nand_hw_control *ctrl)
+{
+	return container_of(ctrl, struct sunxi_nfc, controller);
+}
+
+static irqreturn_t sunxi_nfc_interrupt(int irq, void *dev_id)
+{
+	struct sunxi_nfc *nfc = dev_id;
+	u32 st = readl(nfc->regs + NFC_REG_ST);
+	u32 ien = readl(nfc->regs + NFC_REG_INT);
+
+	if (!(ien & st))
+		return IRQ_NONE;
+
+	if ((ien & st) == ien)
+		complete(&nfc->complete);
+
+	writel(st & NFC_INT_MASK, nfc->regs + NFC_REG_ST);
+	writel(~st & ien & NFC_INT_MASK, nfc->regs + NFC_REG_INT);
+
+	return IRQ_HANDLED;
+}
+
+static int sunxi_nfc_wait_int(struct sunxi_nfc *nfc, u32 flags,
+			      unsigned int timeout_ms)
+{
+	init_completion(&nfc->complete);
+
+	writel(flags, nfc->regs + NFC_REG_INT);
+
+	if (!timeout_ms)
+		timeout_ms = NFC_DEFAULT_TIMEOUT_MS;
+
+	if (!wait_for_completion_timeout(&nfc->complete,
+					 msecs_to_jiffies(timeout_ms))) {
+		dev_err(nfc->dev, "wait interrupt timedout\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int sunxi_nfc_wait_cmd_fifo_empty(struct sunxi_nfc *nfc)
+{
+	unsigned long timeout = jiffies +
+				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
+
+	do {
+		if (!(readl(nfc->regs + NFC_REG_ST) & NFC_CMD_FIFO_STATUS))
+			return 0;
+	} while (time_before(jiffies, timeout));
+
+	dev_err(nfc->dev, "wait for empty cmd FIFO timedout\n");
+	return -ETIMEDOUT;
+}
+
+static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
+{
+	unsigned long timeout = jiffies +
+				msecs_to_jiffies(NFC_DEFAULT_TIMEOUT_MS);
+
+	writel(0, nfc->regs + NFC_REG_ECC_CTL);
+	writel(NFC_RESET, nfc->regs + NFC_REG_CTL);
+
+	do {
+		if (!(readl(nfc->regs + NFC_REG_CTL) & NFC_RESET))
+			return 0;
+	} while (time_before(jiffies, timeout));
+
+	dev_err(nfc->dev, "wait for NAND controller reset timedout\n");
+	return -ETIMEDOUT;
+}
+
+static int sunxi_nfc_dev_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	struct sunxi_nand_rb *rb;
+	unsigned long timeo = (sunxi_nand->nand.state == FL_ERASING ? 400 : 20);
+	int ret;
+
+	if (sunxi_nand->selected < 0)
+		return 0;
+
+	rb = &sunxi_nand->sels[sunxi_nand->selected].rb;
+
+	switch (rb->type) {
+	case RB_NATIVE:
+		ret = !!(readl(nfc->regs + NFC_REG_ST) &
+			 (NFC_RB_STATE0 << rb->info.nativeid));
+		if (ret)
+			break;
+
+		sunxi_nfc_wait_int(nfc, NFC_RB_B2R, timeo);
+		ret = !!(readl(nfc->regs + NFC_REG_ST) &
+			 (NFC_RB_STATE0 << rb->info.nativeid));
+		break;
+	case RB_GPIO:
+		ret = gpio_get_value(rb->info.gpio);
+		break;
+	case RB_NONE:
+	default:
+		ret = 0;
+		dev_err(nfc->dev, "cannot check R/B NAND status!\n");
+		break;
+	}
+
+	return ret;
+}
+
+static void sunxi_nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	struct sunxi_nand_chip_sel *sel;
+	u32 ctl;
+
+	if (chip > 0 && chip >= sunxi_nand->nsels)
+		return;
+
+	if (chip == sunxi_nand->selected)
+		return;
+
+	ctl = readl(nfc->regs + NFC_REG_CTL) &
+	      ~(NFC_CE_SEL | NFC_RB_SEL | NFC_EN);
+
+	if (chip >= 0) {
+		sel = &sunxi_nand->sels[chip];
+
+		ctl |= (sel->cs << 24) | NFC_EN |
+		       (((nand->page_shift - 10) & 0xf) << 8);
+		if (sel->rb.type == RB_NONE) {
+			nand->dev_ready = NULL;
+		} else {
+			nand->dev_ready = sunxi_nfc_dev_ready;
+			if (sel->rb.type == RB_NATIVE)
+				ctl |= (sel->rb.info.nativeid << 3);
+		}
+
+		writel(mtd->writesize, nfc->regs + NFC_REG_SPARE_AREA);
+
+		if (nfc->clk_rate != sunxi_nand->clk_rate) {
+			clk_set_rate(nfc->mod_clk, sunxi_nand->clk_rate);
+			nfc->clk_rate = sunxi_nand->clk_rate;
+		}
+	}
+
+	writel(ctl, nfc->regs + NFC_REG_CTL);
+
+	sunxi_nand->selected = chip;
+}
+
+static void sunxi_nfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	int ret;
+	int cnt;
+	int offs = 0;
+	u32 tmp;
+
+	while (len > offs) {
+		cnt = min(len - offs, NFC_SRAM_SIZE);
+
+		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+		if (ret)
+			break;
+
+		writel(cnt, nfc->regs + NFC_REG_CNT);
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD;
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			break;
+
+		if (buf)
+			memcpy_fromio(buf + offs, nfc->regs + NFC_RAM0_BASE,
+				      cnt);
+		offs += cnt;
+	}
+}
+
+static void sunxi_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
+				int len)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	int ret;
+	int cnt;
+	int offs = 0;
+	u32 tmp;
+
+	while (len > offs) {
+		cnt = min(len - offs, NFC_SRAM_SIZE);
+
+		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+		if (ret)
+			break;
+
+		writel(cnt, nfc->regs + NFC_REG_CNT);
+		memcpy_toio(nfc->regs + NFC_RAM0_BASE, buf + offs, cnt);
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD |
+		      NFC_ACCESS_DIR;
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			break;
+
+		offs += cnt;
+	}
+}
+
+static uint8_t sunxi_nfc_read_byte(struct mtd_info *mtd)
+{
+	uint8_t ret;
+
+	sunxi_nfc_read_buf(mtd, &ret, 1);
+
+	return ret;
+}
+
+static void sunxi_nfc_cmd_ctrl(struct mtd_info *mtd, int dat,
+			       unsigned int ctrl)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	int ret;
+	u32 tmp;
+
+	ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+	if (ret)
+		return;
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		tmp = readl(nfc->regs + NFC_REG_CTL);
+		if (ctrl & NAND_NCE)
+			tmp |= NFC_CE_CTL;
+		else
+			tmp &= ~NFC_CE_CTL;
+		writel(tmp, nfc->regs + NFC_REG_CTL);
+	}
+
+	if (dat == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_CLE) {
+		writel(NFC_SEND_CMD1 | dat, nfc->regs + NFC_REG_CMD);
+	} else {
+		writel(dat, nfc->regs + NFC_REG_ADDR_LOW);
+		writel(NFC_SEND_ADR, nfc->regs + NFC_REG_CMD);
+	}
+
+	sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+}
+
+static int sunxi_nfc_hw_ecc_read_page(struct mtd_info *mtd,
+				      struct nand_chip *chip, uint8_t *buf,
+				      int oob_required, int page)
+{
+	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	struct nand_ecclayout *layout = ecc->layout;
+	struct sunxi_nand_hw_ecc *data = ecc->priv;
+	unsigned int max_bitflips = 0;
+	int offset;
+	int ret;
+	u32 tmp;
+	int i;
+	int cnt;
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
+	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
+	       NFC_ECC_EXCEPTION;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	for (i = 0; i < ecc->steps; i++) {
+		if (i)
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, i * ecc->size, -1);
+
+		offset = mtd->writesize + layout->eccpos[i * ecc->bytes] - 4;
+
+		chip->read_buf(mtd, NULL, ecc->size);
+
+		chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
+
+		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+		if (ret)
+			return ret;
+
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | (1 << 30);
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			return ret;
+
+		memcpy_fromio(buf + (i * ecc->size),
+			      nfc->regs + NFC_RAM0_BASE, ecc->size);
+
+		if (readl(nfc->regs + NFC_REG_ECC_ST) & 0x1) {
+			mtd->ecc_stats.failed++;
+		} else {
+			tmp = readl(nfc->regs + NFC_REG_ECC_CNT0) & 0xff;
+			mtd->ecc_stats.corrected += tmp;
+			max_bitflips = max_t(unsigned int, max_bitflips, tmp);
+		}
+
+		if (oob_required) {
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
+
+			ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+			if (ret)
+				return ret;
+
+			offset -= mtd->writesize;
+			chip->read_buf(mtd, chip->oob_poi + offset,
+				      ecc->bytes + 4);
+		}
+	}
+
+	if (oob_required) {
+		cnt = ecc->layout->oobfree[ecc->steps].length;
+		if (cnt > 0) {
+			offset = mtd->writesize +
+				 ecc->layout->oobfree[ecc->steps].offset;
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
+			offset -= mtd->writesize;
+			chip->read_buf(mtd, chip->oob_poi + offset, cnt);
+		}
+	}
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~NFC_ECC_EN;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	return max_bitflips;
+}
+
+static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
+				       struct nand_chip *chip,
+				       const uint8_t *buf, int oob_required)
+{
+	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	struct nand_ecclayout *layout = ecc->layout;
+	struct sunxi_nand_hw_ecc *data = ecc->priv;
+	int offset;
+	int ret;
+	u32 tmp;
+	int i;
+	int cnt;
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
+	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
+	       NFC_ECC_EXCEPTION;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	for (i = 0; i < ecc->steps; i++) {
+		if (i)
+			chip->cmdfunc(mtd, NAND_CMD_RNDIN, i * ecc->size, -1);
+
+		chip->write_buf(mtd, buf + (i * ecc->size), ecc->size);
+
+		offset = layout->eccpos[i * ecc->bytes] - 4 + mtd->writesize;
+
+		/* Fill OOB data in */
+		if (oob_required) {
+			tmp = 0xffffffff;
+			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
+				    4);
+		} else {
+			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE,
+				    chip->oob_poi + offset - mtd->writesize,
+				    4);
+		}
+
+		chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
+
+		ret = sunxi_nfc_wait_cmd_fifo_empty(nfc);
+		if (ret)
+			return ret;
+
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
+		      (1 << 30);
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			return ret;
+	}
+
+	if (oob_required) {
+		cnt = ecc->layout->oobfree[i].length;
+		if (cnt > 0) {
+			offset = mtd->writesize +
+				 ecc->layout->oobfree[i].offset;
+			chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
+			offset -= mtd->writesize;
+			chip->write_buf(mtd, chip->oob_poi + offset, cnt);
+		}
+	}
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~NFC_ECC_EN;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	return 0;
+}
+
+static int sunxi_nfc_hw_syndrome_ecc_read_page(struct mtd_info *mtd,
+					       struct nand_chip *chip,
+					       uint8_t *buf, int oob_required,
+					       int page)
+{
+	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	struct sunxi_nand_hw_ecc *data = ecc->priv;
+	unsigned int max_bitflips = 0;
+	uint8_t *oob = chip->oob_poi;
+	int offset = 0;
+	int ret;
+	int cnt;
+	u32 tmp;
+	int i;
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
+	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
+	       NFC_ECC_EXCEPTION;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	for (i = 0; i < ecc->steps; i++) {
+		chip->read_buf(mtd, NULL, ecc->size);
+
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | (1 << 30);
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			return ret;
+
+		memcpy_fromio(buf, nfc->regs + NFC_RAM0_BASE, ecc->size);
+		buf += ecc->size;
+		offset += ecc->size;
+
+		if (readl(nfc->regs + NFC_REG_ECC_ST) & 0x1) {
+			mtd->ecc_stats.failed++;
+		} else {
+			tmp = readl(nfc->regs + NFC_REG_ECC_CNT0) & 0xff;
+			mtd->ecc_stats.corrected += tmp;
+			max_bitflips = max_t(unsigned int, max_bitflips, tmp);
+		}
+
+		if (oob_required) {
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
+			chip->read_buf(mtd, oob, ecc->bytes + ecc->prepad);
+			oob += ecc->bytes + ecc->prepad;
+		}
+
+		offset += ecc->bytes + ecc->prepad;
+	}
+
+	if (oob_required) {
+		cnt = mtd->oobsize - (oob - chip->oob_poi);
+		if (cnt > 0) {
+			chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset, -1);
+			chip->read_buf(mtd, oob, cnt);
+		}
+	}
+
+	writel(readl(nfc->regs + NFC_REG_ECC_CTL) & ~NFC_ECC_EN,
+	       nfc->regs + NFC_REG_ECC_CTL);
+
+	return max_bitflips;
+}
+
+static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd,
+						struct nand_chip *chip,
+						const uint8_t *buf,
+						int oob_required)
+{
+	struct sunxi_nfc *nfc = to_sunxi_nfc(chip->controller);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	struct sunxi_nand_hw_ecc *data = ecc->priv;
+	uint8_t *oob = chip->oob_poi;
+	int offset = 0;
+	int ret;
+	int cnt;
+	u32 tmp;
+	int i;
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~(NFC_ECC_MODE | NFC_ECC_PIPELINE | NFC_ECC_BLOCK_SIZE);
+	tmp |= NFC_ECC_EN | (data->mode << NFC_ECC_MODE_SHIFT) |
+	       NFC_ECC_EXCEPTION;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	for (i = 0; i < ecc->steps; i++) {
+		chip->write_buf(mtd, buf + (i * ecc->size), ecc->size);
+		offset += ecc->size;
+
+		/* Fill OOB data in */
+		if (oob_required) {
+			tmp = 0xffffffff;
+			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
+				    4);
+		} else {
+			memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, oob,
+				    4);
+		}
+
+		tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
+		      (1 << 30);
+		writel(tmp, nfc->regs + NFC_REG_CMD);
+
+		ret = sunxi_nfc_wait_int(nfc, NFC_CMD_INT_FLAG, 0);
+		if (ret)
+			return ret;
+
+		offset += ecc->bytes + ecc->prepad;
+		oob += ecc->bytes + ecc->prepad;
+	}
+
+	if (oob_required) {
+		cnt = mtd->oobsize - (oob - chip->oob_poi);
+		if (cnt > 0) {
+			chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);
+			chip->write_buf(mtd, oob, cnt);
+		}
+	}
+
+	tmp = readl(nfc->regs + NFC_REG_ECC_CTL);
+	tmp &= ~NFC_ECC_EN;
+
+	writel(tmp, nfc->regs + NFC_REG_ECC_CTL);
+
+	return 0;
+}
+
+static int sunxi_nand_chip_set_timings(struct sunxi_nand_chip *chip,
+				       const struct nand_sdr_timings *timings)
+{
+	u32 min_clk_period = 0;
+
+	/* T1 <=> tCLS */
+	if (timings->tCLS_min > min_clk_period)
+		min_clk_period = timings->tCLS_min;
+
+	/* T2 <=> tCLH */
+	if (timings->tCLH_min > min_clk_period)
+		min_clk_period = timings->tCLH_min;
+
+	/* T3 <=> tCS */
+	if (timings->tCS_min > min_clk_period)
+		min_clk_period = timings->tCS_min;
+
+	/* T4 <=> tCH */
+	if (timings->tCH_min > min_clk_period)
+		min_clk_period = timings->tCH_min;
+
+	/* T5 <=> tWP */
+	if (timings->tWP_min > min_clk_period)
+		min_clk_period = timings->tWP_min;
+
+	/* T6 <=> tWH */
+	if (timings->tWH_min > min_clk_period)
+		min_clk_period = timings->tWH_min;
+
+	/* T7 <=> tALS */
+	if (timings->tALS_min > min_clk_period)
+		min_clk_period = timings->tALS_min;
+
+	/* T8 <=> tDS */
+	if (timings->tDS_min > min_clk_period)
+		min_clk_period = timings->tDS_min;
+
+	/* T9 <=> tDH */
+	if (timings->tDH_min > min_clk_period)
+		min_clk_period = timings->tDH_min;
+
+	/* T10 <=> tRR */
+	if (timings->tRR_min > (min_clk_period * 3))
+		min_clk_period = DIV_ROUND_UP(timings->tRR_min, 3);
+
+	/* T11 <=> tALH */
+	if (timings->tALH_min > min_clk_period)
+		min_clk_period = timings->tALH_min;
+
+	/* T12 <=> tRP */
+	if (timings->tRP_min > min_clk_period)
+		min_clk_period = timings->tRP_min;
+
+	/* T13 <=> tREH */
+	if (timings->tREH_min > min_clk_period)
+		min_clk_period = timings->tREH_min;
+
+	/* T14 <=> tRC */
+	if (timings->tRC_min > (min_clk_period * 2))
+		min_clk_period = DIV_ROUND_UP(timings->tRC_min, 2);
+
+	/* T15 <=> tWC */
+	if (timings->tWC_min > (min_clk_period * 2))
+		min_clk_period = DIV_ROUND_UP(timings->tWC_min, 2);
+
+
+	/* Convert min_clk_period from picoseconds to nanoseconds */
+	min_clk_period = DIV_ROUND_UP(min_clk_period, 1000);
+
+	/*
+	 * Convert min_clk_period into a clk frequency, then get the
+	 * appropriate rate for the NAND controller IP given this formula
+	 * (specified in the datasheet):
+	 * nand clk_rate = 2 * min_clk_rate
+	 */
+	chip->clk_rate = (2 * NSEC_PER_SEC) / min_clk_period;
+
+	/* TODO: configure T16-T19 */
+
+	return 0;
+}
+
+static int sunxi_nand_chip_init_timings(struct sunxi_nand_chip *chip,
+					struct device_node *np)
+{
+	const struct nand_sdr_timings *timings;
+	int ret;
+	int mode;
+
+	mode = onfi_get_async_timing_mode(&chip->nand);
+	if (mode == ONFI_TIMING_MODE_UNKNOWN) {
+		mode = chip->nand.onfi_timing_mode_default;
+	} else {
+		uint8_t feature[ONFI_SUBFEATURE_PARAM_LEN] = {};
+
+		mode = fls(mode) - 1;
+		if (mode < 0)
+			mode = 0;
+
+		feature[0] = mode;
+		ret = chip->nand.onfi_set_features(&chip->mtd, &chip->nand,
+						ONFI_FEATURE_ADDR_TIMING_MODE,
+						feature);
+		if (ret)
+			return ret;
+	}
+
+	timings = onfi_async_timing_mode_to_sdr_timings(mode);
+	if (IS_ERR(timings))
+		return PTR_ERR(timings);
+
+	return sunxi_nand_chip_set_timings(chip, timings);
+}
+
+static int sunxi_nand_hw_common_ecc_ctrl_init(struct mtd_info *mtd,
+					      struct nand_ecc_ctrl *ecc,
+					      struct device_node *np)
+{
+	static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
+	struct nand_chip *nand = mtd->priv;
+	struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand);
+	struct sunxi_nfc *nfc = to_sunxi_nfc(sunxi_nand->nand.controller);
+	struct sunxi_nand_hw_ecc *data;
+	struct nand_ecclayout *layout;
+	int nsectors;
+	int ret;
+	int i;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* Add ECC info retrieval from DT */
+	for (i = 0; i < ARRAY_SIZE(strengths); i++) {
+		if (ecc->strength <= strengths[i])
+			break;
+	}
+
+	if (i >= ARRAY_SIZE(strengths)) {
+		dev_err(nfc->dev, "unsupported strength\n");
+		ret = -ENOTSUPP;
+		goto err;
+	}
+
+	data->mode = i;
+
+	/* HW ECC always request ECC bytes for 1024 bytes blocks */
+	ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * 1024), 8);
+
+	/* HW ECC always work with even numbers of ECC bytes */
+	ecc->bytes = ALIGN(ecc->bytes, 2);
+
+	layout = &data->layout;
+	nsectors = mtd->writesize / ecc->size;
+
+	if (mtd->oobsize < ((ecc->bytes + 4) * nsectors)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	layout->eccbytes = (ecc->bytes * nsectors);
+
+	ecc->layout = layout;
+	ecc->priv = data;
+
+	return 0;
+
+err:
+	kfree(data);
+
+	return ret;
+}
+
+static void sunxi_nand_hw_common_ecc_ctrl_cleanup(struct nand_ecc_ctrl *ecc)
+{
+	kfree(ecc->priv);
+}
+
+static int sunxi_nand_hw_ecc_ctrl_init(struct mtd_info *mtd,
+				       struct nand_ecc_ctrl *ecc,
+				       struct device_node *np)
+{
+	struct nand_ecclayout *layout;
+	int nsectors;
+	int i, j;
+	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;
+	layout = ecc->layout;
+	nsectors = mtd->writesize / ecc->size;
+
+	for (i = 0; i < nsectors; i++) {
+		if (i) {
+			layout->oobfree[i].offset =
+				layout->oobfree[i - 1].offset +
+				layout->oobfree[i - 1].length +
+				ecc->bytes;
+			layout->oobfree[i].length = 4;
+		} else {
+			/*
+			 * The first 2 bytes are used for BB markers, hence we
+			 * only have 2 bytes available in the first user data
+			 * section.
+			 */
+			layout->oobfree[i].length = 2;
+			layout->oobfree[i].offset = 2;
+		}
+
+		for (j = 0; j < ecc->bytes; j++)
+			layout->eccpos[(ecc->bytes * i) + j] =
+					layout->oobfree[i].offset +
+					layout->oobfree[i].length + j;
+	}
+
+	if (mtd->oobsize > (ecc->bytes + 4) * nsectors) {
+		layout->oobfree[nsectors].offset =
+				layout->oobfree[nsectors - 1].offset +
+				layout->oobfree[nsectors - 1].length +
+				ecc->bytes;
+		layout->oobfree[nsectors].length = mtd->oobsize -
+				((ecc->bytes + 4) * nsectors);
+	}
+
+	return 0;
+}
+
+static int sunxi_nand_hw_syndrome_ecc_ctrl_init(struct mtd_info *mtd,
+						struct nand_ecc_ctrl *ecc,
+						struct device_node *np)
+{
+	struct nand_ecclayout *layout;
+	int nsectors;
+	int i;
+	int ret;
+
+	ret = sunxi_nand_hw_common_ecc_ctrl_init(mtd, ecc, np);
+	if (ret)
+		return ret;
+
+	ecc->prepad = 4;
+	ecc->read_page = sunxi_nfc_hw_syndrome_ecc_read_page;
+	ecc->write_page = sunxi_nfc_hw_syndrome_ecc_write_page;
+
+	layout = ecc->layout;
+	nsectors = mtd->writesize / ecc->size;
+
+	for (i = 0; i < (ecc->bytes * nsectors); i++)
+		layout->eccpos[i] = i;
+
+	layout->oobfree[0].length = mtd->oobsize - i;
+	layout->oobfree[0].offset = i;
+
+	return 0;
+}
+
+static void sunxi_nand_ecc_cleanup(struct nand_ecc_ctrl *ecc)
+{
+	switch (ecc->mode) {
+	case NAND_ECC_HW:
+	case NAND_ECC_HW_SYNDROME:
+		sunxi_nand_hw_common_ecc_ctrl_cleanup(ecc);
+		break;
+	case NAND_ECC_NONE:
+		kfree(ecc->layout);
+	default:
+		break;
+	}
+}
+
+static int sunxi_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
+			       struct device_node *np)
+{
+	struct nand_chip *nand = mtd->priv;
+	int strength;
+	int blk_size;
+	int ret;
+
+	blk_size = of_get_nand_ecc_step_size(np);
+	strength = of_get_nand_ecc_strength(np);
+	if (blk_size > 0 && strength > 0) {
+		ecc->size = blk_size;
+		ecc->strength = strength;
+	} else {
+		ecc->size = nand->ecc_step_ds;
+		ecc->strength = nand->ecc_strength_ds;
+	}
+
+	if (!ecc->size || !ecc->strength)
+		return -EINVAL;
+
+	ecc->mode = NAND_ECC_HW;
+
+	ret = of_get_nand_ecc_mode(np);
+	if (ret >= 0)
+		ecc->mode = ret;
+
+	switch (ecc->mode) {
+	case NAND_ECC_SOFT_BCH:
+		ecc->bytes = DIV_ROUND_UP(ecc->strength * fls(8 * ecc->size),
+					  8);
+		break;
+	case NAND_ECC_HW:
+		ret = sunxi_nand_hw_ecc_ctrl_init(mtd, ecc, np);
+		if (ret)
+			return ret;
+		break;
+	case NAND_ECC_HW_SYNDROME:
+		ret = sunxi_nand_hw_syndrome_ecc_ctrl_init(mtd, ecc, np);
+		if (ret)
+			return ret;
+		break;
+	case NAND_ECC_NONE:
+		ecc->layout = kzalloc(sizeof(*ecc->layout), GFP_KERNEL);
+		if (!ecc->layout)
+			return -ENOMEM;
+		ecc->layout->oobfree[0].length = mtd->oobsize;
+	case NAND_ECC_SOFT:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc,
+				struct device_node *np)
+{
+	const struct nand_sdr_timings *timings;
+	struct sunxi_nand_chip *chip;
+	struct mtd_part_parser_data ppdata;
+	struct mtd_info *mtd;
+	struct nand_chip *nand;
+	int nsels;
+	int ret;
+	int i;
+	u32 tmp;
+
+	if (!of_get_property(np, "reg", &nsels))
+		return -EINVAL;
+
+	nsels /= sizeof(u32);
+	if (!nsels) {
+		dev_err(dev, "invalid reg property size\n");
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(dev,
+			    sizeof(*chip) +
+			    (nsels * sizeof(struct sunxi_nand_chip_sel)),
+			    GFP_KERNEL);
+	if (!chip) {
+		dev_err(dev, "could not allocate chip\n");
+		return -ENOMEM;
+	}
+
+	chip->nsels = nsels;
+	chip->selected = -1;
+
+	for (i = 0; i < nsels; i++) {
+		ret = of_property_read_u32_index(np, "reg", i, &tmp);
+		if (ret) {
+			dev_err(dev, "could not retrieve reg property: %d\n",
+				ret);
+			return ret;
+		}
+
+		if (tmp > NFC_MAX_CS) {
+			dev_err(dev,
+				"invalid reg value: %u (max CS = 7)\n",
+				tmp);
+			return -EINVAL;
+		}
+
+		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
+			dev_err(dev, "CS %d already assigned\n", tmp);
+			return -EINVAL;
+		}
+
+		chip->sels[i].cs = tmp;
+
+		if (!of_property_read_u32_index(np, "allwinner,rb", i, &tmp) &&
+		    tmp < 2) {
+			chip->sels[i].rb.type = RB_NATIVE;
+			chip->sels[i].rb.info.nativeid = tmp;
+		} else {
+			ret = of_get_named_gpio(np, "rb-gpios", i);
+			if (ret >= 0) {
+				tmp = ret;
+				chip->sels[i].rb.type = RB_GPIO;
+				chip->sels[i].rb.info.gpio = tmp;
+				ret = devm_gpio_request(dev, tmp, "nand-rb");
+				if (ret)
+					return ret;
+
+				ret = gpio_direction_input(tmp);
+				if (ret)
+					return ret;
+			} else {
+				chip->sels[i].rb.type = RB_NONE;
+			}
+		}
+	}
+
+	timings = onfi_async_timing_mode_to_sdr_timings(0);
+	if (IS_ERR(timings)) {
+		ret = PTR_ERR(timings);
+		dev_err(dev,
+			"could not retrieve timings for ONFI mode 0: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = sunxi_nand_chip_set_timings(chip, timings);
+	if (ret) {
+		dev_err(dev, "could not configure chip timings: %d\n", ret);
+		return ret;
+	}
+
+	nand = &chip->nand;
+	/* Default tR value specified in the ONFI spec (chapter 4.15.1) */
+	nand->chip_delay = 200;
+	nand->controller = &nfc->controller;
+	nand->select_chip = sunxi_nfc_select_chip;
+	nand->cmd_ctrl = sunxi_nfc_cmd_ctrl;
+	nand->read_buf = sunxi_nfc_read_buf;
+	nand->write_buf = sunxi_nfc_write_buf;
+	nand->read_byte = sunxi_nfc_read_byte;
+
+	if (of_get_nand_on_flash_bbt(np))
+		nand->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
+
+	mtd = &chip->mtd;
+	mtd->dev.parent = dev;
+	mtd->priv = nand;
+	mtd->owner = THIS_MODULE;
+
+	ret = nand_scan_ident(mtd, nsels, NULL);
+	if (ret)
+		return ret;
+
+	ret = sunxi_nand_chip_init_timings(chip, np);
+	if (ret) {
+		dev_err(dev, "could not configure chip timings: %d\n", ret);
+		return ret;
+	}
+
+	ret = sunxi_nand_ecc_init(mtd, &nand->ecc, np);
+	if (ret) {
+		dev_err(dev, "ECC init failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = nand_scan_tail(mtd);
+	if (ret) {
+		dev_err(dev, "nand_scan_tail failed: %d\n", ret);
+		return ret;
+	}
+
+	ppdata.of_node = np;
+	ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
+	if (ret) {
+		dev_err(dev, "failed to register mtd device: %d\n", ret);
+		nand_release(mtd);
+		return ret;
+	}
+
+	list_add_tail(&chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int sunxi_nand_chips_init(struct device *dev, struct sunxi_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int nchips = of_get_child_count(np);
+	int ret;
+
+	if (nchips > 8) {
+		dev_err(dev, "too many NAND chips: %d (max = 8)\n", nchips);
+		return -EINVAL;
+	}
+
+	for_each_child_of_node(np, nand_np) {
+		ret = sunxi_nand_chip_init(dev, nfc, nand_np);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void sunxi_nand_chips_cleanup(struct sunxi_nfc *nfc)
+{
+	struct sunxi_nand_chip *chip;
+
+	while (!list_empty(&nfc->chips)) {
+		chip = list_first_entry(&nfc->chips, struct sunxi_nand_chip,
+					node);
+		nand_release(&chip->mtd);
+		sunxi_nand_ecc_cleanup(&chip->nand.ecc);
+	}
+}
+
+static int sunxi_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *r;
+	struct sunxi_nfc *nfc;
+	int irq;
+	int ret;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	nfc->dev = dev;
+	spin_lock_init(&nfc->controller.lock);
+	init_waitqueue_head(&nfc->controller.wq);
+	INIT_LIST_HEAD(&nfc->chips);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->regs = devm_ioremap_resource(dev, r);
+	if (IS_ERR(nfc->regs))
+		return PTR_ERR(nfc->regs);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to retrieve irq\n");
+		return irq;
+	}
+
+	nfc->ahb_clk = devm_clk_get(dev, "ahb");
+	if (IS_ERR(nfc->ahb_clk)) {
+		dev_err(dev, "failed to retrieve ahb clk\n");
+		return PTR_ERR(nfc->ahb_clk);
+	}
+
+	ret = clk_prepare_enable(nfc->ahb_clk);
+	if (ret)
+		return ret;
+
+	nfc->mod_clk = devm_clk_get(dev, "mod");
+	if (IS_ERR(nfc->mod_clk)) {
+		dev_err(dev, "failed to retrieve mod clk\n");
+		ret = PTR_ERR(nfc->mod_clk);
+		goto out_ahb_clk_unprepare;
+	}
+
+	ret = clk_prepare_enable(nfc->mod_clk);
+	if (ret)
+		goto out_ahb_clk_unprepare;
+
+	ret = sunxi_nfc_rst(nfc);
+	if (ret)
+		goto out_mod_clk_unprepare;
+
+	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;
+
+	platform_set_drvdata(pdev, nfc);
+
+	/*
+	 * TODO: replace these magic values with proper flags as soon as we
+	 * know what they are encoding.
+	 */
+	writel(0x100, nfc->regs + NFC_REG_TIMING_CTL);
+	writel(0x7ff, nfc->regs + NFC_REG_TIMING_CFG);
+
+	ret = sunxi_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init nand chips\n");
+		goto out_mod_clk_unprepare;
+	}
+
+	return 0;
+
+out_mod_clk_unprepare:
+	clk_disable_unprepare(nfc->mod_clk);
+out_ahb_clk_unprepare:
+	clk_disable_unprepare(nfc->ahb_clk);
+
+	return ret;
+}
+
+static int sunxi_nfc_remove(struct platform_device *pdev)
+{
+	struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
+
+	sunxi_nand_chips_cleanup(nfc);
+
+	return 0;
+}
+
+static const struct of_device_id sunxi_nfc_ids[] = {
+	{ .compatible = "allwinner,sun4i-a10-nand" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sunxi_nfc_ids);
+
+static struct platform_driver sunxi_nfc_driver = {
+	.driver = {
+		.name = "sunxi_nand",
+		.of_match_table = sunxi_nfc_ids,
+	},
+	.probe = sunxi_nfc_probe,
+	.remove = sunxi_nfc_remove,
+};
+module_platform_driver(sunxi_nfc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Boris BREZILLON");
+MODULE_DESCRIPTION("Allwinner NAND Flash Controller driver");
+MODULE_ALIAS("platform:sunxi_nand");