root/drivers/mtd/nand/raw/mtk_nand.c
// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * MTK NAND Flash controller driver.
 * Copyright (C) 2016 MediaTek Inc.
 * Authors:     Xiaolei Li              <xiaolei.li@mediatek.com>
 *              Jorge Ramirez-Ortiz     <jorge.ramirez-ortiz@linaro.org>
 */

#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/rawnand.h>
#include <linux/mtd/mtd.h>
#include <linux/module.h>
#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/mtd/nand-ecc-mtk.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_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         ADDRCNTR_SEC_SHIFT      (12)
#define         ADDRCNTR_SEC(val) \
                (((val) & CNTR_MASK) >> ADDRCNTR_SEC_SHIFT)
#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_DEBUG_CON1          (0x220)
#define         STROBE_MASK             GENMASK(4, 3)
#define         STROBE_SHIFT            (3)
#define         MAX_STROBE_DLY          (3)
#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_NAND_MAX_NSELS      (2)
#define MTK_NFC_MIN_SPARE       (16)
#define ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt) \
        ((tpoecs) << 28 | (tprecs) << 22 | (tc2r) << 16 | \
        (tw2r) << 12 | (twh) << 8 | (twst) << 4 | (trlt))

struct mtk_nfc_caps {
        const u8 *spare_size;
        u8 num_spare_size;
        u8 pageformat_spare_shift;
        u8 nfi_clk_div;
        u8 max_sector;
        u32 max_sector_size;
};

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[] __counted_by(nsels);
        /* nothing after this field */
};

struct mtk_nfc_clk {
        struct clk *nfi_clk;
        struct clk *pad_clk;
};

struct mtk_nfc {
        struct nand_controller controller;
        struct mtk_ecc_config ecc_cfg;
        struct mtk_nfc_clk clk;
        struct mtk_ecc *ecc;

        struct device *dev;
        const struct mtk_nfc_caps *caps;
        void __iomem *regs;

        struct completion done;
        struct list_head chips;

        u8 *buffer;

        unsigned long assigned_cs;
};

/*
 * supported spare size of each IP.
 * order should be the same with the spare size bitfiled defination of
 * register NFI_PAGEFMT.
 */
static const u8 spare_size_mt2701[] = {
        16, 26, 27, 28, 32, 36, 40, 44, 48, 49, 50, 51, 52, 62, 63, 64
};

static const u8 spare_size_mt2712[] = {
        16, 26, 27, 28, 32, 36, 40, 44, 48, 49, 50, 51, 52, 62, 61, 63, 64, 67,
        74
};

static const u8 spare_size_mt7622[] = {
        16, 26, 27, 28
};

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, i;

        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;

        for (i = 0; i < nfc->caps->num_spare_size; i++) {
                if (nfc->caps->spare_size[i] == spare)
                        break;
        }

        if (i == nfc->caps->num_spare_size) {
                dev_err(nfc->dev, "invalid spare size %d\n", spare);
                return -EINVAL;
        }

        fmt |= i << nfc->caps->pageformat_spare_shift;

        fmt |= mtk_nand->fdm.reg_size << PAGEFMT_FDM_SHIFT;
        fmt |= mtk_nand->fdm.ecc_size << PAGEFMT_FDM_ECC_SHIFT;
        nfi_writel(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 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 nand_chip *chip)
{
        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 = (nfc->caps->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 nand_chip *chip, u8 *buf, int len)
{
        int i;

        for (i = 0; i < len; i++)
                buf[i] = mtk_nfc_read_byte(chip);
}

static void mtk_nfc_write_byte(struct nand_chip *chip, u8 byte)
{
        struct mtk_nfc *nfc = nand_get_controller_data(chip);
        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 = nfc->caps->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 nand_chip *chip, const u8 *buf, int len)
{
        int i;

        for (i = 0; i < len; i++)
                mtk_nfc_write_byte(chip, buf[i]);
}

static int mtk_nfc_exec_instr(struct nand_chip *chip,
                              const struct nand_op_instr *instr)
{
        struct mtk_nfc *nfc = nand_get_controller_data(chip);
        unsigned int i;
        u32 status;

        switch (instr->type) {
        case NAND_OP_CMD_INSTR:
                mtk_nfc_send_command(nfc, instr->ctx.cmd.opcode);
                return 0;
        case NAND_OP_ADDR_INSTR:
                for (i = 0; i < instr->ctx.addr.naddrs; i++)
                        mtk_nfc_send_address(nfc, instr->ctx.addr.addrs[i]);
                return 0;
        case NAND_OP_DATA_IN_INSTR:
                mtk_nfc_read_buf(chip, instr->ctx.data.buf.in,
                                 instr->ctx.data.len);
                return 0;
        case NAND_OP_DATA_OUT_INSTR:
                mtk_nfc_write_buf(chip, instr->ctx.data.buf.out,
                                  instr->ctx.data.len);
                return 0;
        case NAND_OP_WAITRDY_INSTR:
                return readl_poll_timeout(nfc->regs + NFI_STA, status,
                                          !(status & STA_BUSY), 20,
                                          instr->ctx.waitrdy.timeout_ms * 1000);
        default:
                break;
        }

        return -EINVAL;
}

static void mtk_nfc_select_target(struct nand_chip *nand, unsigned int cs)
{
        struct mtk_nfc *nfc = nand_get_controller_data(nand);
        struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(nand);

        mtk_nfc_hw_runtime_config(nand_to_mtd(nand));

        nfi_writel(nfc, mtk_nand->sels[cs], NFI_CSEL);
}

static int mtk_nfc_exec_op(struct nand_chip *chip,
                           const struct nand_operation *op,
                           bool check_only)
{
        struct mtk_nfc *nfc = nand_get_controller_data(chip);
        unsigned int i;
        int ret = 0;

        if (check_only)
                return 0;

        mtk_nfc_hw_reset(nfc);
        nfi_writew(nfc, CNFG_OP_CUST, NFI_CNFG);
        mtk_nfc_select_target(chip, op->cs);

        for (i = 0; i < op->ninstrs; i++) {
                ret = mtk_nfc_exec_instr(chip, &op->instrs[i]);
                if (ret)
                        break;
        }

        return ret;
}

static int mtk_nfc_setup_interface(struct nand_chip *chip, int csline,
                                   const struct nand_interface_config *conf)
{
        struct mtk_nfc *nfc = nand_get_controller_data(chip);
        const struct nand_sdr_timings *timings;
        u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst = 0, trlt = 0;
        u32 temp, tsel = 0;

        timings = nand_get_sdr_timings(conf);
        if (IS_ERR(timings))
                return -ENOTSUPP;

        if (csline == NAND_DATA_IFACE_CHECK_ONLY)
                return 0;

        rate = clk_get_rate(nfc->clk.nfi_clk);
        /* There is a frequency divider in some IPs */
        rate /= nfc->caps->nfi_clk_div;

        /* turn clock rate into KHZ */
        rate /= 1000;

        tpoecs = max(timings->tALH_min, timings->tCLH_min) / 1000;
        tpoecs = DIV_ROUND_UP(tpoecs * rate, 1000000);
        tpoecs &= 0xf;

        tprecs = max(timings->tCLS_min, timings->tALS_min) / 1000;
        tprecs = DIV_ROUND_UP(tprecs * rate, 1000000);
        tprecs &= 0x3f;

        /* sdr interface has no tCR which means CE# low to RE# low */
        tc2r = 0;

        tw2r = timings->tWHR_min / 1000;
        tw2r = DIV_ROUND_UP(tw2r * rate, 1000000);
        tw2r = DIV_ROUND_UP(tw2r - 1, 2);
        tw2r &= 0xf;

        twh = max(timings->tREH_min, timings->tWH_min) / 1000;
        twh = DIV_ROUND_UP(twh * rate, 1000000) - 1;
        twh &= 0xf;

        /* Calculate real WE#/RE# hold time in nanosecond */
        temp = (twh + 1) * 1000000 / rate;
        /* nanosecond to picosecond */
        temp *= 1000;

        /*
         * WE# low level time should be expaned to meet WE# pulse time
         * and WE# cycle time at the same time.
         */
        if (temp < timings->tWC_min)
                twst = timings->tWC_min - temp;
        twst = max(timings->tWP_min, twst) / 1000;
        twst = DIV_ROUND_UP(twst * rate, 1000000) - 1;
        twst &= 0xf;

        /*
         * RE# low level time should be expaned to meet RE# pulse time
         * and RE# cycle time at the same time.
         */
        if (temp < timings->tRC_min)
                trlt = timings->tRC_min - temp;
        trlt = max(trlt, timings->tRP_min) / 1000;
        trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1;
        trlt &= 0xf;

        /* Calculate RE# pulse time in nanosecond. */
        temp = (trlt + 1) * 1000000 / rate;
        /* nanosecond to picosecond */
        temp *= 1000;
        /*
         * If RE# access time is bigger than RE# pulse time,
         * delay sampling data timing.
         */
        if (temp < timings->tREA_max) {
                tsel = timings->tREA_max / 1000;
                tsel = DIV_ROUND_UP(tsel * rate, 1000000);
                tsel -= (trlt + 1);
                if (tsel > MAX_STROBE_DLY) {
                        trlt += tsel - MAX_STROBE_DLY;
                        tsel = MAX_STROBE_DLY;
                }
        }
        temp = nfi_readl(nfc, NFI_DEBUG_CON1);
        temp &= ~STROBE_MASK;
        temp |= tsel << STROBE_SHIFT;
        nfi_writel(nfc, temp, NFI_DEBUG_CON1);

        /*
         * ACCON: access timing control register
         * -------------------------------------
         * 31:28: tpoecs, minimum required time for CS post pulling down after
         *        accessing the device
         * 27:22: tprecs, minimum required time for CS pre pulling down before
         *        accessing the device
         * 21:16: tc2r, minimum required time from NCEB low to NREB low
         * 15:12: tw2r, minimum required time from NWEB high to NREB low.
         * 11:08: twh, write enable hold time
         * 07:04: twst, write wait states
         * 03:00: trlt, read wait states
         */
        trlt = ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt);
        nfi_writel(nfc, trlt, NFI_ACCCON);

        return 0;
}

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,
                                        ADDRCNTR_SEC(reg) >= 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;

        mtk_nfc_select_target(chip, chip->cur_cs);
        nand_prog_page_begin_op(chip, page, 0, NULL, 0);

        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);

        if (ret)
                return ret;

        return nand_prog_page_end_op(chip);
}

static int mtk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
                                    int oob_on, int page)
{
        return mtk_nfc_write_page(nand_to_mtd(chip), chip, buf, page, 0);
}

static int mtk_nfc_write_page_raw(struct nand_chip *chip, const u8 *buf,
                                  int oob_on, int pg)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        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 nand_chip *chip, u32 offset,
                                       u32 data_len, const u8 *buf,
                                       int oob_on, int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        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 nand_chip *chip, int page)
{
        return mtk_nfc_write_page_raw(chip, NULL, 1, page);
}

static int mtk_nfc_update_ecc_stats(struct mtd_info *mtd, u8 *buf, u32 start,
                                    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;
        u32 reg_size = mtk_nand->fdm.reg_size;
        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, start + i), 0xff, 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 = 0;
        size_t len;
        u8 *buf;
        int rc;

        mtk_nfc_select_target(chip, chip->cur_cs);
        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;

        nand_read_page_op(chip, page, column, NULL, 0);

        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,
                                       ADDRCNTR_SEC(reg) >= sectors, 10,
                                       MTK_TIMEOUT);
        if (rc < 0) {
                dev_err(nfc->dev, "subpage done timeout\n");
                bitflips = -EIO;
        } else if (!raw) {
                rc = mtk_ecc_wait_done(nfc->ecc, ECC_DECODE);
                bitflips = rc < 0 ? -ETIMEDOUT :
                        mtk_nfc_update_ecc_stats(mtd, buf, start, 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 nand_chip *chip, u32 off,
                                      u32 len, u8 *p, int pg)
{
        return mtk_nfc_read_subpage(nand_to_mtd(chip), chip, off, len, p, pg,
                                    0);
}

static int mtk_nfc_read_page_hwecc(struct nand_chip *chip, u8 *p, int oob_on,
                                   int pg)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        return mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, p, pg, 0);
}

static int mtk_nfc_read_page_raw(struct nand_chip *chip, u8 *buf, int oob_on,
                                 int page)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        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 nand_chip *chip, int page)
{
        return mtk_nfc_read_page_raw(chip, NULL, 1, page);
}

static inline void mtk_nfc_hw_init(struct mtk_nfc *nfc)
{
        /*
         * 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_writel(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_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);
        struct mtk_nfc *nfc = nand_get_controller_data(nand);
        u32 ecc_bytes;

        ecc_bytes = DIV_ROUND_UP(nand->ecc.strength *
                                 mtk_ecc_get_parity_bits(nfc->ecc), 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 int mtk_nfc_set_spare_per_sector(u32 *sps, struct mtd_info *mtd)
{
        struct nand_chip *nand = mtd_to_nand(mtd);
        struct mtk_nfc *nfc = nand_get_controller_data(nand);
        const u8 *spare = nfc->caps->spare_size;
        u32 eccsteps, i, closest_spare = 0;

        eccsteps = mtd->writesize / nand->ecc.size;
        *sps = mtd->oobsize / eccsteps;

        if (nand->ecc.size == 1024)
                *sps >>= 1;

        if (*sps < MTK_NFC_MIN_SPARE)
                return -EINVAL;

        for (i = 0; i < nfc->caps->num_spare_size; i++) {
                if (*sps >= spare[i] && spare[i] >= spare[closest_spare]) {
                        closest_spare = i;
                        if (*sps == spare[i])
                                break;
                }
        }

        *sps = spare[closest_spare];

        if (nand->ecc.size == 1024)
                *sps <<= 1;

        return 0;
}

static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
{
        struct nand_chip *nand = mtd_to_nand(mtd);
        const struct nand_ecc_props *requirements =
                nanddev_get_ecc_requirements(&nand->base);
        struct mtk_nfc *nfc = nand_get_controller_data(nand);
        u32 spare;
        int free, ret;

        /* support only ecc hw mode */
        if (nand->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) {
                dev_err(dev, "ecc.engine_type not supported\n");
                return -EINVAL;
        }

        /* if optional dt settings not present */
        if (!nand->ecc.size || !nand->ecc.strength) {
                /* use datasheet requirements */
                nand->ecc.strength = requirements->strength;
                nand->ecc.size = requirements->step_size;

                /*
                 * align eccstrength and eccsize
                 * this controller only supports 512 and 1024 sizes
                 */
                if (nand->ecc.size < 1024) {
                        if (mtd->writesize > 512 &&
                            nfc->caps->max_sector_size > 512) {
                                nand->ecc.size = 1024;
                                nand->ecc.strength <<= 1;
                        } else {
                                nand->ecc.size = 512;
                        }
                } else {
                        nand->ecc.size = 1024;
                }

                ret = mtk_nfc_set_spare_per_sector(&spare, mtd);
                if (ret)
                        return ret;

                /* calculate oob bytes except ecc parity data */
                free = (nand->ecc.strength * mtk_ecc_get_parity_bits(nfc->ecc)
                        + 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) /
                                             mtk_ecc_get_parity_bits(nfc->ecc);
                } else if (free < 0) {
                        spare -= NFI_FDM_MIN_SIZE;
                        nand->ecc.strength = (spare << 3) /
                                             mtk_ecc_get_parity_bits(nfc->ecc);
                }
        }

        mtk_ecc_adjust_strength(nfc->ecc, &nand->ecc.strength);

        dev_info(dev, "eccsize %d eccstrength %d\n",
                 nand->ecc.size, nand->ecc.strength);

        return 0;
}

static int mtk_nfc_attach_chip(struct nand_chip *chip)
{
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct device *dev = mtd->dev.parent;
        struct mtk_nfc *nfc = nand_get_controller_data(chip);
        struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
        int len;
        int ret;

        if (chip->options & NAND_BUSWIDTH_16) {
                dev_err(dev, "16bits buswidth not supported");
                return -EINVAL;
        }

        /* store bbt magic in page, cause OOB is not protected */
        if (chip->bbt_options & NAND_BBT_USE_FLASH)
                chip->bbt_options |= NAND_BBT_NO_OOB;

        ret = mtk_nfc_ecc_init(dev, mtd);
        if (ret)
                return ret;

        ret = mtk_nfc_set_spare_per_sector(&mtk_nand->spare_per_sector, mtd);
        if (ret)
                return ret;

        mtk_nfc_set_fdm(&mtk_nand->fdm, mtd);
        mtk_nfc_set_bad_mark_ctl(&mtk_nand->bad_mark, mtd);

        len = mtd->writesize + mtd->oobsize;
        nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL);
        if (!nfc->buffer)
                return  -ENOMEM;

        return 0;
}

static const struct nand_controller_ops mtk_nfc_controller_ops = {
        .attach_chip = mtk_nfc_attach_chip,
        .setup_interface = mtk_nfc_setup_interface,
        .exec_op = mtk_nfc_exec_op,
};

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;
        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, struct_size(chip, sels, nsels),
                            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;
                }

                if (tmp >= MTK_NAND_MAX_NSELS) {
                        dev_err(dev, "invalid CS: %u\n", tmp);
                        return -EINVAL;
                }

                if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
                        dev_err(dev, "CS %u already assigned\n", tmp);
                        return -EINVAL;
                }

                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_USES_DMA | NAND_SUBPAGE_READ;

        /* set default mode in case dt entry is missing */
        nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;

        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(nand, nsels);
        if (ret)
                return ret;

        ret = mtd_device_register(mtd, NULL, 0);
        if (ret) {
                dev_err(dev, "mtd parse partition error\n");
                nand_cleanup(nand);
                return ret;
        }

        list_add_tail(&chip->node, &nfc->chips);

        return 0;
}

static void mtk_nfc_nand_chips_cleanup(struct mtk_nfc *nfc)
{
        struct mtk_nfc_nand_chip *mtk_chip;
        struct nand_chip *chip;
        int ret;

        while (!list_empty(&nfc->chips)) {
                mtk_chip = list_first_entry(&nfc->chips,
                                            struct mtk_nfc_nand_chip, node);
                chip = &mtk_chip->nand;
                ret = mtd_device_unregister(nand_to_mtd(chip));
                WARN_ON(ret);
                nand_cleanup(chip);
                list_del(&mtk_chip->node);
        }
}

static int mtk_nfc_nand_chips_init(struct device *dev, struct mtk_nfc *nfc)
{
        struct device_node *np = dev->of_node;
        int ret;

        for_each_child_of_node_scoped(np, nand_np) {
                ret = mtk_nfc_nand_chip_init(dev, nfc, nand_np);
                if (ret) {
                        mtk_nfc_nand_chips_cleanup(nfc);
                        return ret;
                }
        }

        return 0;
}

static const struct mtk_nfc_caps mtk_nfc_caps_mt2701 = {
        .spare_size = spare_size_mt2701,
        .num_spare_size = 16,
        .pageformat_spare_shift = 4,
        .nfi_clk_div = 1,
        .max_sector = 16,
        .max_sector_size = 1024,
};

static const struct mtk_nfc_caps mtk_nfc_caps_mt2712 = {
        .spare_size = spare_size_mt2712,
        .num_spare_size = 19,
        .pageformat_spare_shift = 16,
        .nfi_clk_div = 2,
        .max_sector = 16,
        .max_sector_size = 1024,
};

static const struct mtk_nfc_caps mtk_nfc_caps_mt7622 = {
        .spare_size = spare_size_mt7622,
        .num_spare_size = 4,
        .pageformat_spare_shift = 4,
        .nfi_clk_div = 1,
        .max_sector = 8,
        .max_sector_size = 512,
};

static const struct of_device_id mtk_nfc_id_table[] = {
        {
                .compatible = "mediatek,mt2701-nfc",
                .data = &mtk_nfc_caps_mt2701,
        }, {
                .compatible = "mediatek,mt2712-nfc",
                .data = &mtk_nfc_caps_mt2712,
        }, {
                .compatible = "mediatek,mt7622-nfc",
                .data = &mtk_nfc_caps_mt7622,
        },
        {}
};
MODULE_DEVICE_TABLE(of, mtk_nfc_id_table);

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;
        int ret, irq;

        nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
        if (!nfc)
                return -ENOMEM;

        nand_controller_init(&nfc->controller);
        INIT_LIST_HEAD(&nfc->chips);
        nfc->controller.ops = &mtk_nfc_controller_ops;

        /* 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->caps = of_device_get_match_data(dev);
        nfc->dev = dev;

        nfc->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(nfc->regs)) {
                ret = PTR_ERR(nfc->regs);
                goto release_ecc;
        }

        nfc->clk.nfi_clk = devm_clk_get_enabled(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_enabled(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;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                ret = -EINVAL;
                goto release_ecc;
        }

        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 release_ecc;
        }

        ret = dma_set_mask(dev, DMA_BIT_MASK(32));
        if (ret) {
                dev_err(dev, "failed to set dma mask\n");
                goto release_ecc;
        }

        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 release_ecc;
        }

        return 0;

release_ecc:
        mtk_ecc_release(nfc->ecc);

        return ret;
}

static void mtk_nfc_remove(struct platform_device *pdev)
{
        struct mtk_nfc *nfc = platform_get_drvdata(pdev);

        mtk_nfc_nand_chips_cleanup(nfc);
        mtk_ecc_release(nfc->ecc);
}

#ifdef CONFIG_PM_SLEEP
static int mtk_nfc_suspend(struct device *dev)
{
        struct mtk_nfc *nfc = dev_get_drvdata(dev);

        clk_disable_unprepare(nfc->clk.nfi_clk);
        clk_disable_unprepare(nfc->clk.pad_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;
        int ret;
        u32 i;

        udelay(200);

        ret = clk_prepare_enable(nfc->clk.nfi_clk);
        if (ret) {
                dev_err(dev, "failed to enable nfi clk\n");
                return ret;
        }

        ret = clk_prepare_enable(nfc->clk.pad_clk);
        if (ret) {
                dev_err(dev, "failed to enable pad clk\n");
                clk_disable_unprepare(nfc->clk.nfi_clk);
                return ret;
        }

        /* reset NAND chip if VCC was powered off */
        list_for_each_entry(chip, &nfc->chips, node) {
                nand = &chip->nand;
                for (i = 0; i < chip->nsels; i++)
                        nand_reset(nand, i);
        }

        return 0;
}

static SIMPLE_DEV_PM_OPS(mtk_nfc_pm_ops, mtk_nfc_suspend, mtk_nfc_resume);
#endif

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("Dual MIT/GPL");
MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
MODULE_DESCRIPTION("MTK Nand Flash Controller Driver");