mtd: nand: add sunxi NAND flash controller support
authorBoris BREZILLON <boris.brezillon@free-electrons.com>
Tue, 21 Oct 2014 13:08:41 +0000 (15:08 +0200)
committerBrian Norris <computersforpeace@gmail.com>
Wed, 29 Oct 2014 17:08:00 +0000 (10:08 -0700)
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>
drivers/mtd/nand/Kconfig
drivers/mtd/nand/Makefile
drivers/mtd/nand/sunxi_nand.c [new file with mode: 0644]

index dd10646982ae26b934fd46363fa1f109cdf7b5ed..4c51d2c9acc10e031488b396baf736cd2fd72545 100644 (file)
@@ -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
index 9c847e469ca775f89df2f176d8dd712b4d7dc8b5..bd38f21d2e28e8b622ba42a1f0c0c2c6562e4bfb 100644 (file)
@@ -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 (file)
index 0000000..ccaa8e2
--- /dev/null
@@ -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");