Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block

[linux/fpc-iii.git] / drivers / mtd / nand / raw / cadence-nand-controller.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Cadence NAND flash controller driver
 *
 * Copyright (C) 2019 Cadence
 *
 * Author: Piotr Sroka <piotrs@cadence.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/of_device.h>
#include <linux/iopoll.h>
#include <linux/slab.h>

/*
 * HPNFC can work in 3 modes:
 * -  PIO - can work in master or slave DMA
 * -  CDMA - needs Master DMA for accessing command descriptors.
 * -  Generic mode - can use only slave DMA.
 * CDMA and PIO modes can be used to execute only base commands.
 * Generic mode can be used to execute any command
 * on NAND flash memory. Driver uses CDMA mode for
 * block erasing, page reading, page programing.
 * Generic mode is used for executing rest of commands.
 */

#define MAX_ADDRESS_CYC         6
#define MAX_ERASE_ADDRESS_CYC   3
#define MAX_DATA_SIZE           0xFFFC
#define DMA_DATA_SIZE_ALIGN     8

/* Register definition. */
/*
 * Command register 0.
 * Writing data to this register will initiate a new transaction
 * of the NF controller.
 */
#define CMD_REG0                        0x0000
/* Command type field mask. */
#define         CMD_REG0_CT             GENMASK(31, 30)
/* Command type CDMA. */
#define         CMD_REG0_CT_CDMA        0uL
/* Command type generic. */
#define         CMD_REG0_CT_GEN         3uL
/* Command thread number field mask. */
#define         CMD_REG0_TN             GENMASK(27, 24)

/* Command register 2. */
#define CMD_REG2                        0x0008
/* Command register 3. */
#define CMD_REG3                        0x000C
/* Pointer register to select which thread status will be selected. */
#define CMD_STATUS_PTR                  0x0010
/* Command status register for selected thread. */
#define CMD_STATUS                      0x0014

/* Interrupt status register. */
#define INTR_STATUS                     0x0110
#define         INTR_STATUS_SDMA_ERR    BIT(22)
#define         INTR_STATUS_SDMA_TRIGG  BIT(21)
#define         INTR_STATUS_UNSUPP_CMD  BIT(19)
#define         INTR_STATUS_DDMA_TERR   BIT(18)
#define         INTR_STATUS_CDMA_TERR   BIT(17)
#define         INTR_STATUS_CDMA_IDL    BIT(16)

/* Interrupt enable register. */
#define INTR_ENABLE                             0x0114
#define         INTR_ENABLE_INTR_EN             BIT(31)
#define         INTR_ENABLE_SDMA_ERR_EN         BIT(22)
#define         INTR_ENABLE_SDMA_TRIGG_EN       BIT(21)
#define         INTR_ENABLE_UNSUPP_CMD_EN       BIT(19)
#define         INTR_ENABLE_DDMA_TERR_EN        BIT(18)
#define         INTR_ENABLE_CDMA_TERR_EN        BIT(17)
#define         INTR_ENABLE_CDMA_IDLE_EN        BIT(16)

/* Controller internal state. */
#define CTRL_STATUS                             0x0118
#define         CTRL_STATUS_INIT_COMP           BIT(9)
#define         CTRL_STATUS_CTRL_BUSY           BIT(8)

/* Command Engine threads state. */
#define TRD_STATUS                              0x0120

/* Command Engine interrupt thread error status. */
#define TRD_ERR_INT_STATUS                      0x0128
/* Command Engine interrupt thread error enable. */
#define TRD_ERR_INT_STATUS_EN                   0x0130
/* Command Engine interrupt thread complete status. */
#define TRD_COMP_INT_STATUS                     0x0138

/*
 * Transfer config 0 register.
 * Configures data transfer parameters.
 */
#define TRAN_CFG_0                              0x0400
/* Offset value from the beginning of the page. */
#define         TRAN_CFG_0_OFFSET               GENMASK(31, 16)
/* Numbers of sectors to transfer within singlNF device's page. */
#define         TRAN_CFG_0_SEC_CNT              GENMASK(7, 0)

/*
 * Transfer config 1 register.
 * Configures data transfer parameters.
 */
#define TRAN_CFG_1                              0x0404
/* Size of last data sector. */
#define         TRAN_CFG_1_LAST_SEC_SIZE        GENMASK(31, 16)
/* Size of not-last data sector. */
#define         TRAN_CFG_1_SECTOR_SIZE          GENMASK(15, 0)

/* ECC engine configuration register 0. */
#define ECC_CONFIG_0                            0x0428
/* Correction strength. */
#define         ECC_CONFIG_0_CORR_STR           GENMASK(10, 8)
/* Enable erased pages detection mechanism. */
#define         ECC_CONFIG_0_ERASE_DET_EN       BIT(1)
/* Enable controller ECC check bits generation and correction. */
#define         ECC_CONFIG_0_ECC_EN             BIT(0)

/* ECC engine configuration register 1. */
#define ECC_CONFIG_1                            0x042C

/* Multiplane settings register. */
#define MULTIPLANE_CFG                          0x0434
/* Cache operation settings. */
#define CACHE_CFG                               0x0438

/* DMA settings register. */
#define DMA_SETINGS                             0x043C
/* Enable SDMA error report on access unprepared slave DMA interface. */
#define         DMA_SETINGS_SDMA_ERR_RSP        BIT(17)

/* Transferred data block size for the slave DMA module. */
#define SDMA_SIZE                               0x0440

/* Thread number associated with transferred data block
 * for the slave DMA module.
 */
#define SDMA_TRD_NUM                            0x0444
/* Thread number mask. */
#define         SDMA_TRD_NUM_SDMA_TRD           GENMASK(2, 0)

#define CONTROL_DATA_CTRL                       0x0494
/* Thread number mask. */
#define         CONTROL_DATA_CTRL_SIZE          GENMASK(15, 0)

#define CTRL_VERSION                            0x800
#define         CTRL_VERSION_REV                GENMASK(7, 0)

/* Available hardware features of the controller. */
#define CTRL_FEATURES                           0x804
/* Support for NV-DDR2/3 work mode. */
#define         CTRL_FEATURES_NVDDR_2_3         BIT(28)
/* Support for NV-DDR work mode. */
#define         CTRL_FEATURES_NVDDR             BIT(27)
/* Support for asynchronous work mode. */
#define         CTRL_FEATURES_ASYNC             BIT(26)
/* Support for asynchronous work mode. */
#define         CTRL_FEATURES_N_BANKS           GENMASK(25, 24)
/* Slave and Master DMA data width. */
#define         CTRL_FEATURES_DMA_DWITH64       BIT(21)
/* Availability of Control Data feature.*/
#define         CTRL_FEATURES_CONTROL_DATA      BIT(10)

/* BCH Engine identification register 0 - correction strengths. */
#define BCH_CFG_0                               0x838
#define         BCH_CFG_0_CORR_CAP_0            GENMASK(7, 0)
#define         BCH_CFG_0_CORR_CAP_1            GENMASK(15, 8)
#define         BCH_CFG_0_CORR_CAP_2            GENMASK(23, 16)
#define         BCH_CFG_0_CORR_CAP_3            GENMASK(31, 24)

/* BCH Engine identification register 1 - correction strengths. */
#define BCH_CFG_1                               0x83C
#define         BCH_CFG_1_CORR_CAP_4            GENMASK(7, 0)
#define         BCH_CFG_1_CORR_CAP_5            GENMASK(15, 8)
#define         BCH_CFG_1_CORR_CAP_6            GENMASK(23, 16)
#define         BCH_CFG_1_CORR_CAP_7            GENMASK(31, 24)

/* BCH Engine identification register 2 - sector sizes. */
#define BCH_CFG_2                               0x840
#define         BCH_CFG_2_SECT_0                GENMASK(15, 0)
#define         BCH_CFG_2_SECT_1                GENMASK(31, 16)

/* BCH Engine identification register 3. */
#define BCH_CFG_3                               0x844
#define         BCH_CFG_3_METADATA_SIZE         GENMASK(23, 16)

/* Ready/Busy# line status. */
#define RBN_SETINGS                             0x1004

/* Common settings. */
#define COMMON_SET                              0x1008
/* 16 bit device connected to the NAND Flash interface. */
#define         COMMON_SET_DEVICE_16BIT         BIT(8)

/* Skip_bytes registers. */
#define SKIP_BYTES_CONF                         0x100C
#define         SKIP_BYTES_MARKER_VALUE         GENMASK(31, 16)
#define         SKIP_BYTES_NUM_OF_BYTES         GENMASK(7, 0)

#define SKIP_BYTES_OFFSET                       0x1010
#define          SKIP_BYTES_OFFSET_VALUE        GENMASK(23, 0)

/* Timings configuration. */
#define ASYNC_TOGGLE_TIMINGS                    0x101c
#define         ASYNC_TOGGLE_TIMINGS_TRH        GENMASK(28, 24)
#define         ASYNC_TOGGLE_TIMINGS_TRP        GENMASK(20, 16)
#define         ASYNC_TOGGLE_TIMINGS_TWH        GENMASK(12, 8)
#define         ASYNC_TOGGLE_TIMINGS_TWP        GENMASK(4, 0)

#define TIMINGS0                                0x1024
#define         TIMINGS0_TADL                   GENMASK(31, 24)
#define         TIMINGS0_TCCS                   GENMASK(23, 16)
#define         TIMINGS0_TWHR                   GENMASK(15, 8)
#define         TIMINGS0_TRHW                   GENMASK(7, 0)

#define TIMINGS1                                0x1028
#define         TIMINGS1_TRHZ                   GENMASK(31, 24)
#define         TIMINGS1_TWB                    GENMASK(23, 16)
#define         TIMINGS1_TVDLY                  GENMASK(7, 0)

#define TIMINGS2                                0x102c
#define         TIMINGS2_TFEAT                  GENMASK(25, 16)
#define         TIMINGS2_CS_HOLD_TIME           GENMASK(13, 8)
#define         TIMINGS2_CS_SETUP_TIME          GENMASK(5, 0)

/* Configuration of the resynchronization of slave DLL of PHY. */
#define DLL_PHY_CTRL                            0x1034
#define         DLL_PHY_CTRL_DLL_RST_N          BIT(24)
#define         DLL_PHY_CTRL_EXTENDED_WR_MODE   BIT(17)
#define         DLL_PHY_CTRL_EXTENDED_RD_MODE   BIT(16)
#define         DLL_PHY_CTRL_RS_HIGH_WAIT_CNT   GENMASK(11, 8)
#define         DLL_PHY_CTRL_RS_IDLE_CNT        GENMASK(7, 0)

/* Register controlling DQ related timing. */
#define PHY_DQ_TIMING                           0x2000
/* Register controlling DSQ related timing.  */
#define PHY_DQS_TIMING                          0x2004
#define         PHY_DQS_TIMING_DQS_SEL_OE_END   GENMASK(3, 0)
#define         PHY_DQS_TIMING_PHONY_DQS_SEL    BIT(16)
#define         PHY_DQS_TIMING_USE_PHONY_DQS    BIT(20)

/* Register controlling the gate and loopback control related timing. */
#define PHY_GATE_LPBK_CTRL                      0x2008
#define         PHY_GATE_LPBK_CTRL_RDS          GENMASK(24, 19)

/* Register holds the control for the master DLL logic. */
#define PHY_DLL_MASTER_CTRL                     0x200C
#define         PHY_DLL_MASTER_CTRL_BYPASS_MODE BIT(23)

/* Register holds the control for the slave DLL logic. */
#define PHY_DLL_SLAVE_CTRL                      0x2010

/* This register handles the global control settings for the PHY. */
#define PHY_CTRL                                0x2080
#define         PHY_CTRL_SDR_DQS                BIT(14)
#define         PHY_CTRL_PHONY_DQS              GENMASK(9, 4)

/*
 * This register handles the global control settings
 * for the termination selects for reads.
 */
#define PHY_TSEL                                0x2084

/* Generic command layout. */
#define GCMD_LAY_CS                     GENMASK_ULL(11, 8)
/*
 * This bit informs the minicotroller if it has to wait for tWB
 * after sending the last CMD/ADDR/DATA in the sequence.
 */
#define GCMD_LAY_TWB                    BIT_ULL(6)
/* Type of generic instruction. */
#define GCMD_LAY_INSTR                  GENMASK_ULL(5, 0)

/* Generic CMD sequence type. */
#define         GCMD_LAY_INSTR_CMD      0
/* Generic ADDR sequence type. */
#define         GCMD_LAY_INSTR_ADDR     1
/* Generic data transfer sequence type. */
#define         GCMD_LAY_INSTR_DATA     2

/* Input part of generic command type of input is command. */
#define GCMD_LAY_INPUT_CMD              GENMASK_ULL(23, 16)

/* Generic command address sequence - address fields. */
#define GCMD_LAY_INPUT_ADDR             GENMASK_ULL(63, 16)
/* Generic command address sequence - address size. */
#define GCMD_LAY_INPUT_ADDR_SIZE        GENMASK_ULL(13, 11)

/* Transfer direction field of generic command data sequence. */
#define GCMD_DIR                        BIT_ULL(11)
/* Read transfer direction of generic command data sequence. */
#define         GCMD_DIR_READ           0
/* Write transfer direction of generic command data sequence. */
#define         GCMD_DIR_WRITE          1

/* ECC enabled flag of generic command data sequence - ECC enabled. */
#define GCMD_ECC_EN                     BIT_ULL(12)
/* Generic command data sequence - sector size. */
#define GCMD_SECT_SIZE                  GENMASK_ULL(31, 16)
/* Generic command data sequence - sector count. */
#define GCMD_SECT_CNT                   GENMASK_ULL(39, 32)
/* Generic command data sequence - last sector size. */
#define GCMD_LAST_SIZE                  GENMASK_ULL(55, 40)

/* CDMA descriptor fields. */
/* Erase command type of CDMA descriptor. */
#define CDMA_CT_ERASE           0x1000
/* Program page command type of CDMA descriptor. */
#define CDMA_CT_WR              0x2100
/* Read page command type of CDMA descriptor. */
#define CDMA_CT_RD              0x2200

/* Flash pointer memory shift. */
#define CDMA_CFPTR_MEM_SHIFT    24
/* Flash pointer memory mask. */
#define CDMA_CFPTR_MEM          GENMASK(26, 24)

/*
 * Command DMA descriptor flags. If set causes issue interrupt after
 * the completion of descriptor processing.
 */
#define CDMA_CF_INT             BIT(8)
/*
 * Command DMA descriptor flags - the next descriptor
 * address field is valid and descriptor processing should continue.
 */
#define CDMA_CF_CONT            BIT(9)
/* DMA master flag of command DMA descriptor. */
#define CDMA_CF_DMA_MASTER      BIT(10)

/* Operation complete status of command descriptor. */
#define CDMA_CS_COMP            BIT(15)
/* Operation complete status of command descriptor. */
/* Command descriptor status - operation fail. */
#define CDMA_CS_FAIL            BIT(14)
/* Command descriptor status - page erased. */
#define CDMA_CS_ERP             BIT(11)
/* Command descriptor status - timeout occurred. */
#define CDMA_CS_TOUT            BIT(10)
/*
 * Maximum amount of correction applied to one ECC sector.
 * It is part of command descriptor status.
 */
#define CDMA_CS_MAXERR          GENMASK(9, 2)
/* Command descriptor status - uncorrectable ECC error. */
#define CDMA_CS_UNCE            BIT(1)
/* Command descriptor status - descriptor error. */
#define CDMA_CS_ERR             BIT(0)

/* Status of operation - OK. */
#define STAT_OK                 0
/* Status of operation - FAIL. */
#define STAT_FAIL               2
/* Status of operation - uncorrectable ECC error. */
#define STAT_ECC_UNCORR         3
/* Status of operation - page erased. */
#define STAT_ERASED             5
/* Status of operation - correctable ECC error. */
#define STAT_ECC_CORR           6
/* Status of operation - unsuspected state. */
#define STAT_UNKNOWN            7
/* Status of operation - operation is not completed yet. */
#define STAT_BUSY               0xFF

#define BCH_MAX_NUM_CORR_CAPS           8
#define BCH_MAX_NUM_SECTOR_SIZES        2

struct cadence_nand_timings {
        u32 async_toggle_timings;
        u32 timings0;
        u32 timings1;
        u32 timings2;
        u32 dll_phy_ctrl;
        u32 phy_ctrl;
        u32 phy_dqs_timing;
        u32 phy_gate_lpbk_ctrl;
};

/* Command DMA descriptor. */
struct cadence_nand_cdma_desc {
        /* Next descriptor address. */
        u64 next_pointer;

        /* Flash address is a 32-bit address comprising of BANK and ROW ADDR. */
        u32 flash_pointer;
        /*field appears in HPNFC version 13*/
        u16 bank;
        u16 rsvd0;

        /* Operation the controller needs to perform. */
        u16 command_type;
        u16 rsvd1;
        /* Flags for operation of this command. */
        u16 command_flags;
        u16 rsvd2;

        /* System/host memory address required for data DMA commands. */
        u64 memory_pointer;

        /* Status of operation. */
        u32 status;
        u32 rsvd3;

        /* Address pointer to sync buffer location. */
        u64 sync_flag_pointer;

        /* Controls the buffer sync mechanism. */
        u32 sync_arguments;
        u32 rsvd4;

        /* Control data pointer. */
        u64 ctrl_data_ptr;
};

/* Interrupt status. */
struct cadence_nand_irq_status {
        /* Thread operation complete status. */
        u32 trd_status;
        /* Thread operation error. */
        u32 trd_error;
        /* Controller status. */
        u32 status;
};

/* Cadence NAND flash controller capabilities get from driver data. */
struct cadence_nand_dt_devdata {
        /* Skew value of the output signals of the NAND Flash interface. */
        u32 if_skew;
        /* It informs if slave DMA interface is connected to DMA engine. */
        unsigned int has_dma:1;
};

/* Cadence NAND flash controller capabilities read from registers. */
struct cdns_nand_caps {
        /* Maximum number of banks supported by hardware. */
        u8 max_banks;
        /* Slave and Master DMA data width in bytes (4 or 8). */
        u8 data_dma_width;
        /* Control Data feature supported. */
        bool data_control_supp;
        /* Is PHY type DLL. */
        bool is_phy_type_dll;
};

struct cdns_nand_ctrl {
        struct device *dev;
        struct nand_controller controller;
        struct cadence_nand_cdma_desc *cdma_desc;
        /* IP capability. */
        const struct cadence_nand_dt_devdata *caps1;
        struct cdns_nand_caps caps2;
        u8 ctrl_rev;
        dma_addr_t dma_cdma_desc;
        u8 *buf;
        u32 buf_size;
        u8 curr_corr_str_idx;

        /* Register interface. */
        void __iomem *reg;

        struct {
                void __iomem *virt;
                dma_addr_t dma;
        } io;

        int irq;
        /* Interrupts that have happened. */
        struct cadence_nand_irq_status irq_status;
        /* Interrupts we are waiting for. */
        struct cadence_nand_irq_status irq_mask;
        struct completion complete;
        /* Protect irq_mask and irq_status. */
        spinlock_t irq_lock;

        int ecc_strengths[BCH_MAX_NUM_CORR_CAPS];
        struct nand_ecc_step_info ecc_stepinfos[BCH_MAX_NUM_SECTOR_SIZES];
        struct nand_ecc_caps ecc_caps;

        int curr_trans_type;

        struct dma_chan *dmac;

        u32 nf_clk_rate;
        /*
         * Estimated Board delay. The value includes the total
         * round trip delay for the signals and is used for deciding on values
         * associated with data read capture.
         */
        u32 board_delay;

        struct nand_chip *selected_chip;

        unsigned long assigned_cs;
        struct list_head chips;
        u8 bch_metadata_size;
};

struct cdns_nand_chip {
        struct cadence_nand_timings timings;
        struct nand_chip chip;
        u8 nsels;
        struct list_head node;

        /*
         * part of oob area of NAND flash memory page.
         * This part is available for user to read or write.
         */
        u32 avail_oob_size;

        /* Sector size. There are few sectors per mtd->writesize */
        u32 sector_size;
        u32 sector_count;

        /* Offset of BBM. */
        u8 bbm_offs;
        /* Number of bytes reserved for BBM. */
        u8 bbm_len;
        /* ECC strength index. */
        u8 corr_str_idx;

        u8 cs[];
};

struct ecc_info {
        int (*calc_ecc_bytes)(int step_size, int strength);
        int max_step_size;
};

static inline struct
cdns_nand_chip *to_cdns_nand_chip(struct nand_chip *chip)
{
        return container_of(chip, struct cdns_nand_chip, chip);
}

static inline struct
cdns_nand_ctrl *to_cdns_nand_ctrl(struct nand_controller *controller)
{
        return container_of(controller, struct cdns_nand_ctrl, controller);
}

static bool
cadence_nand_dma_buf_ok(struct cdns_nand_ctrl *cdns_ctrl, const void *buf,
                        u32 buf_len)
{
        u8 data_dma_width = cdns_ctrl->caps2.data_dma_width;

        return buf && virt_addr_valid(buf) &&
                likely(IS_ALIGNED((uintptr_t)buf, data_dma_width)) &&
                likely(IS_ALIGNED(buf_len, DMA_DATA_SIZE_ALIGN));
}

static int cadence_nand_wait_for_value(struct cdns_nand_ctrl *cdns_ctrl,
                                       u32 reg_offset, u32 timeout_us,
                                       u32 mask, bool is_clear)
{
        u32 val;
        int ret;

        ret = readl_relaxed_poll_timeout(cdns_ctrl->reg + reg_offset,
                                         val, !(val & mask) == is_clear,
                                         10, timeout_us);

        if (ret < 0) {
                dev_err(cdns_ctrl->dev,
                        "Timeout while waiting for reg %x with mask %x is clear %d\n",
                        reg_offset, mask, is_clear);
        }

        return ret;
}

static int cadence_nand_set_ecc_enable(struct cdns_nand_ctrl *cdns_ctrl,
                                       bool enable)
{
        u32 reg;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);

        if (enable)
                reg |= ECC_CONFIG_0_ECC_EN;
        else
                reg &= ~ECC_CONFIG_0_ECC_EN;

        writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);

        return 0;
}

static void cadence_nand_set_ecc_strength(struct cdns_nand_ctrl *cdns_ctrl,
                                          u8 corr_str_idx)
{
        u32 reg;

        if (cdns_ctrl->curr_corr_str_idx == corr_str_idx)
                return;

        reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);
        reg &= ~ECC_CONFIG_0_CORR_STR;
        reg |= FIELD_PREP(ECC_CONFIG_0_CORR_STR, corr_str_idx);
        writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);

        cdns_ctrl->curr_corr_str_idx = corr_str_idx;
}

static int cadence_nand_get_ecc_strength_idx(struct cdns_nand_ctrl *cdns_ctrl,
                                             u8 strength)
{
        int i, corr_str_idx = -1;

        for (i = 0; i < BCH_MAX_NUM_CORR_CAPS; i++) {
                if (cdns_ctrl->ecc_strengths[i] == strength) {
                        corr_str_idx = i;
                        break;
                }
        }

        return corr_str_idx;
}

static int cadence_nand_set_skip_marker_val(struct cdns_nand_ctrl *cdns_ctrl,
                                            u16 marker_value)
{
        u32 reg;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        reg = readl_relaxed(cdns_ctrl->reg + SKIP_BYTES_CONF);
        reg &= ~SKIP_BYTES_MARKER_VALUE;
        reg |= FIELD_PREP(SKIP_BYTES_MARKER_VALUE,
                          marker_value);

        writel_relaxed(reg, cdns_ctrl->reg + SKIP_BYTES_CONF);

        return 0;
}

static int cadence_nand_set_skip_bytes_conf(struct cdns_nand_ctrl *cdns_ctrl,
                                            u8 num_of_bytes,
                                            u32 offset_value,
                                            int enable)
{
        u32 reg, skip_bytes_offset;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        if (!enable) {
                num_of_bytes = 0;
                offset_value = 0;
        }

        reg = readl_relaxed(cdns_ctrl->reg + SKIP_BYTES_CONF);
        reg &= ~SKIP_BYTES_NUM_OF_BYTES;
        reg |= FIELD_PREP(SKIP_BYTES_NUM_OF_BYTES,
                          num_of_bytes);
        skip_bytes_offset = FIELD_PREP(SKIP_BYTES_OFFSET_VALUE,
                                       offset_value);

        writel_relaxed(reg, cdns_ctrl->reg + SKIP_BYTES_CONF);
        writel_relaxed(skip_bytes_offset, cdns_ctrl->reg + SKIP_BYTES_OFFSET);

        return 0;
}

/* Functions enables/disables hardware detection of erased data */
static void cadence_nand_set_erase_detection(struct cdns_nand_ctrl *cdns_ctrl,
                                             bool enable,
                                             u8 bitflips_threshold)
{
        u32 reg;

        reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);

        if (enable)
                reg |= ECC_CONFIG_0_ERASE_DET_EN;
        else
                reg &= ~ECC_CONFIG_0_ERASE_DET_EN;

        writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);
        writel_relaxed(bitflips_threshold, cdns_ctrl->reg + ECC_CONFIG_1);
}

static int cadence_nand_set_access_width16(struct cdns_nand_ctrl *cdns_ctrl,
                                           bool bit_bus16)
{
        u32 reg;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        reg = readl_relaxed(cdns_ctrl->reg + COMMON_SET);

        if (!bit_bus16)
                reg &= ~COMMON_SET_DEVICE_16BIT;
        else
                reg |= COMMON_SET_DEVICE_16BIT;
        writel_relaxed(reg, cdns_ctrl->reg + COMMON_SET);

        return 0;
}

static void
cadence_nand_clear_interrupt(struct cdns_nand_ctrl *cdns_ctrl,
                             struct cadence_nand_irq_status *irq_status)
{
        writel_relaxed(irq_status->status, cdns_ctrl->reg + INTR_STATUS);
        writel_relaxed(irq_status->trd_status,
                       cdns_ctrl->reg + TRD_COMP_INT_STATUS);
        writel_relaxed(irq_status->trd_error,
                       cdns_ctrl->reg + TRD_ERR_INT_STATUS);
}

static void
cadence_nand_read_int_status(struct cdns_nand_ctrl *cdns_ctrl,
                             struct cadence_nand_irq_status *irq_status)
{
        irq_status->status = readl_relaxed(cdns_ctrl->reg + INTR_STATUS);
        irq_status->trd_status = readl_relaxed(cdns_ctrl->reg
                                               + TRD_COMP_INT_STATUS);
        irq_status->trd_error = readl_relaxed(cdns_ctrl->reg
                                              + TRD_ERR_INT_STATUS);
}

static u32 irq_detected(struct cdns_nand_ctrl *cdns_ctrl,
                        struct cadence_nand_irq_status *irq_status)
{
        cadence_nand_read_int_status(cdns_ctrl, irq_status);

        return irq_status->status || irq_status->trd_status ||
                irq_status->trd_error;
}

static void cadence_nand_reset_irq(struct cdns_nand_ctrl *cdns_ctrl)
{
        unsigned long flags;

        spin_lock_irqsave(&cdns_ctrl->irq_lock, flags);
        memset(&cdns_ctrl->irq_status, 0, sizeof(cdns_ctrl->irq_status));
        memset(&cdns_ctrl->irq_mask, 0, sizeof(cdns_ctrl->irq_mask));
        spin_unlock_irqrestore(&cdns_ctrl->irq_lock, flags);
}

/*
 * This is the interrupt service routine. It handles all interrupts
 * sent to this device.
 */
static irqreturn_t cadence_nand_isr(int irq, void *dev_id)
{
        struct cdns_nand_ctrl *cdns_ctrl = dev_id;
        struct cadence_nand_irq_status irq_status;
        irqreturn_t result = IRQ_NONE;

        spin_lock(&cdns_ctrl->irq_lock);

        if (irq_detected(cdns_ctrl, &irq_status)) {
                /* Handle interrupt. */
                /* First acknowledge it. */
                cadence_nand_clear_interrupt(cdns_ctrl, &irq_status);
                /* Status in the device context for someone to read. */
                cdns_ctrl->irq_status.status |= irq_status.status;
                cdns_ctrl->irq_status.trd_status |= irq_status.trd_status;
                cdns_ctrl->irq_status.trd_error |= irq_status.trd_error;
                /* Notify anyone who cares that it happened. */
                complete(&cdns_ctrl->complete);
                /* Tell the OS that we've handled this. */
                result = IRQ_HANDLED;
        }
        spin_unlock(&cdns_ctrl->irq_lock);

        return result;
}

static void cadence_nand_set_irq_mask(struct cdns_nand_ctrl *cdns_ctrl,
                                      struct cadence_nand_irq_status *irq_mask)
{
        writel_relaxed(INTR_ENABLE_INTR_EN | irq_mask->status,
                       cdns_ctrl->reg + INTR_ENABLE);

        writel_relaxed(irq_mask->trd_error,
                       cdns_ctrl->reg + TRD_ERR_INT_STATUS_EN);
}

static void
cadence_nand_wait_for_irq(struct cdns_nand_ctrl *cdns_ctrl,
                          struct cadence_nand_irq_status *irq_mask,
                          struct cadence_nand_irq_status *irq_status)
{
        unsigned long timeout = msecs_to_jiffies(10000);
        unsigned long time_left;

        time_left = wait_for_completion_timeout(&cdns_ctrl->complete,
                                                timeout);

        *irq_status = cdns_ctrl->irq_status;
        if (time_left == 0) {
                /* Timeout error. */
                dev_err(cdns_ctrl->dev, "timeout occurred:\n");
                dev_err(cdns_ctrl->dev, "\tstatus = 0x%x, mask = 0x%x\n",
                        irq_status->status, irq_mask->status);
                dev_err(cdns_ctrl->dev,
                        "\ttrd_status = 0x%x, trd_status mask = 0x%x\n",
                        irq_status->trd_status, irq_mask->trd_status);
                dev_err(cdns_ctrl->dev,
                        "\t trd_error = 0x%x, trd_error mask = 0x%x\n",
                        irq_status->trd_error, irq_mask->trd_error);
        }
}

/* Execute generic command on NAND controller. */
static int cadence_nand_generic_cmd_send(struct cdns_nand_ctrl *cdns_ctrl,
                                         u8 chip_nr,
                                         u64 mini_ctrl_cmd)
{
        u32 mini_ctrl_cmd_l, mini_ctrl_cmd_h, reg;

        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_CS, chip_nr);
        mini_ctrl_cmd_l = mini_ctrl_cmd & 0xFFFFFFFF;
        mini_ctrl_cmd_h = mini_ctrl_cmd >> 32;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        cadence_nand_reset_irq(cdns_ctrl);

        writel_relaxed(mini_ctrl_cmd_l, cdns_ctrl->reg + CMD_REG2);
        writel_relaxed(mini_ctrl_cmd_h, cdns_ctrl->reg + CMD_REG3);

        /* Select generic command. */
        reg = FIELD_PREP(CMD_REG0_CT, CMD_REG0_CT_GEN);
        /* Thread number. */
        reg |= FIELD_PREP(CMD_REG0_TN, 0);

        /* Issue command. */
        writel_relaxed(reg, cdns_ctrl->reg + CMD_REG0);

        return 0;
}

/* Wait for data on slave DMA interface. */
static int cadence_nand_wait_on_sdma(struct cdns_nand_ctrl *cdns_ctrl,
                                     u8 *out_sdma_trd,
                                     u32 *out_sdma_size)
{
        struct cadence_nand_irq_status irq_mask, irq_status;

        irq_mask.trd_status = 0;
        irq_mask.trd_error = 0;
        irq_mask.status = INTR_STATUS_SDMA_TRIGG
                | INTR_STATUS_SDMA_ERR
                | INTR_STATUS_UNSUPP_CMD;

        cadence_nand_set_irq_mask(cdns_ctrl, &irq_mask);
        cadence_nand_wait_for_irq(cdns_ctrl, &irq_mask, &irq_status);
        if (irq_status.status == 0) {
                dev_err(cdns_ctrl->dev, "Timeout while waiting for SDMA\n");
                return -ETIMEDOUT;
        }

        if (irq_status.status & INTR_STATUS_SDMA_TRIGG) {
                *out_sdma_size = readl_relaxed(cdns_ctrl->reg + SDMA_SIZE);
                *out_sdma_trd  = readl_relaxed(cdns_ctrl->reg + SDMA_TRD_NUM);
                *out_sdma_trd =
                        FIELD_GET(SDMA_TRD_NUM_SDMA_TRD, *out_sdma_trd);
        } else {
                dev_err(cdns_ctrl->dev, "SDMA error - irq_status %x\n",
                        irq_status.status);
                return -EIO;
        }

        return 0;
}

static void cadence_nand_get_caps(struct cdns_nand_ctrl *cdns_ctrl)
{
        u32  reg;

        reg = readl_relaxed(cdns_ctrl->reg + CTRL_FEATURES);

        cdns_ctrl->caps2.max_banks = 1 << FIELD_GET(CTRL_FEATURES_N_BANKS, reg);

        if (FIELD_GET(CTRL_FEATURES_DMA_DWITH64, reg))
                cdns_ctrl->caps2.data_dma_width = 8;
        else
                cdns_ctrl->caps2.data_dma_width = 4;

        if (reg & CTRL_FEATURES_CONTROL_DATA)
                cdns_ctrl->caps2.data_control_supp = true;

        if (reg & (CTRL_FEATURES_NVDDR_2_3
                   | CTRL_FEATURES_NVDDR))
                cdns_ctrl->caps2.is_phy_type_dll = true;
}

/* Prepare CDMA descriptor. */
static void
cadence_nand_cdma_desc_prepare(struct cdns_nand_ctrl *cdns_ctrl,
                               char nf_mem, u32 flash_ptr, dma_addr_t mem_ptr,
                                   dma_addr_t ctrl_data_ptr, u16 ctype)
{
        struct cadence_nand_cdma_desc *cdma_desc = cdns_ctrl->cdma_desc;

        memset(cdma_desc, 0, sizeof(struct cadence_nand_cdma_desc));

        /* Set fields for one descriptor. */
        cdma_desc->flash_pointer = flash_ptr;
        if (cdns_ctrl->ctrl_rev >= 13)
                cdma_desc->bank = nf_mem;
        else
                cdma_desc->flash_pointer |= (nf_mem << CDMA_CFPTR_MEM_SHIFT);

        cdma_desc->command_flags |= CDMA_CF_DMA_MASTER;
        cdma_desc->command_flags  |= CDMA_CF_INT;

        cdma_desc->memory_pointer = mem_ptr;
        cdma_desc->status = 0;
        cdma_desc->sync_flag_pointer = 0;
        cdma_desc->sync_arguments = 0;

        cdma_desc->command_type = ctype;
        cdma_desc->ctrl_data_ptr = ctrl_data_ptr;
}

static u8 cadence_nand_check_desc_error(struct cdns_nand_ctrl *cdns_ctrl,
                                        u32 desc_status)
{
        if (desc_status & CDMA_CS_ERP)
                return STAT_ERASED;

        if (desc_status & CDMA_CS_UNCE)
                return STAT_ECC_UNCORR;

        if (desc_status & CDMA_CS_ERR) {
                dev_err(cdns_ctrl->dev, ":CDMA desc error flag detected.\n");
                return STAT_FAIL;
        }

        if (FIELD_GET(CDMA_CS_MAXERR, desc_status))
                return STAT_ECC_CORR;

        return STAT_FAIL;
}

static int cadence_nand_cdma_finish(struct cdns_nand_ctrl *cdns_ctrl)
{
        struct cadence_nand_cdma_desc *desc_ptr = cdns_ctrl->cdma_desc;
        u8 status = STAT_BUSY;

        if (desc_ptr->status & CDMA_CS_FAIL) {
                status = cadence_nand_check_desc_error(cdns_ctrl,
                                                       desc_ptr->status);
                dev_err(cdns_ctrl->dev, ":CDMA error %x\n", desc_ptr->status);
        } else if (desc_ptr->status & CDMA_CS_COMP) {
                /* Descriptor finished with no errors. */
                if (desc_ptr->command_flags & CDMA_CF_CONT) {
                        dev_info(cdns_ctrl->dev, "DMA unsupported flag is set");
                        status = STAT_UNKNOWN;
                } else {
                        /* Last descriptor.  */
                        status = STAT_OK;
                }
        }

        return status;
}

static int cadence_nand_cdma_send(struct cdns_nand_ctrl *cdns_ctrl,
                                  u8 thread)
{
        u32 reg;
        int status;

        /* Wait for thread ready. */
        status = cadence_nand_wait_for_value(cdns_ctrl, TRD_STATUS,
                                             1000000,
                                             BIT(thread), true);
        if (status)
                return status;

        cadence_nand_reset_irq(cdns_ctrl);
        reinit_completion(&cdns_ctrl->complete);

        writel_relaxed((u32)cdns_ctrl->dma_cdma_desc,
                       cdns_ctrl->reg + CMD_REG2);
        writel_relaxed(0, cdns_ctrl->reg + CMD_REG3);

        /* Select CDMA mode. */
        reg = FIELD_PREP(CMD_REG0_CT, CMD_REG0_CT_CDMA);
        /* Thread number. */
        reg |= FIELD_PREP(CMD_REG0_TN, thread);
        /* Issue command. */
        writel_relaxed(reg, cdns_ctrl->reg + CMD_REG0);

        return 0;
}

/* Send SDMA command and wait for finish. */
static u32
cadence_nand_cdma_send_and_wait(struct cdns_nand_ctrl *cdns_ctrl,
                                u8 thread)
{
        struct cadence_nand_irq_status irq_mask, irq_status = {0};
        int status;

        irq_mask.trd_status = BIT(thread);
        irq_mask.trd_error = BIT(thread);
        irq_mask.status = INTR_STATUS_CDMA_TERR;

        cadence_nand_set_irq_mask(cdns_ctrl, &irq_mask);

        status = cadence_nand_cdma_send(cdns_ctrl, thread);
        if (status)
                return status;

        cadence_nand_wait_for_irq(cdns_ctrl, &irq_mask, &irq_status);

        if (irq_status.status == 0 && irq_status.trd_status == 0 &&
            irq_status.trd_error == 0) {
                dev_err(cdns_ctrl->dev, "CDMA command timeout\n");
                return -ETIMEDOUT;
        }
        if (irq_status.status & irq_mask.status) {
                dev_err(cdns_ctrl->dev, "CDMA command failed\n");
                return -EIO;
        }

        return 0;
}

/*
 * ECC size depends on configured ECC strength and on maximum supported
 * ECC step size.
 */
static int cadence_nand_calc_ecc_bytes(int max_step_size, int strength)
{
        int nbytes = DIV_ROUND_UP(fls(8 * max_step_size) * strength, 8);

        return ALIGN(nbytes, 2);
}

#define CADENCE_NAND_CALC_ECC_BYTES(max_step_size) \
        static int \
        cadence_nand_calc_ecc_bytes_##max_step_size(int step_size, \
                                                    int strength)\
        {\
                return cadence_nand_calc_ecc_bytes(max_step_size, strength);\
        }

CADENCE_NAND_CALC_ECC_BYTES(256)
CADENCE_NAND_CALC_ECC_BYTES(512)
CADENCE_NAND_CALC_ECC_BYTES(1024)
CADENCE_NAND_CALC_ECC_BYTES(2048)
CADENCE_NAND_CALC_ECC_BYTES(4096)

/* Function reads BCH capabilities. */
static int cadence_nand_read_bch_caps(struct cdns_nand_ctrl *cdns_ctrl)
{
        struct nand_ecc_caps *ecc_caps = &cdns_ctrl->ecc_caps;
        int max_step_size = 0, nstrengths, i;
        u32 reg;

        reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_3);
        cdns_ctrl->bch_metadata_size = FIELD_GET(BCH_CFG_3_METADATA_SIZE, reg);
        if (cdns_ctrl->bch_metadata_size < 4) {
                dev_err(cdns_ctrl->dev,
                        "Driver needs at least 4 bytes of BCH meta data\n");
                return -EIO;
        }

        reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_0);
        cdns_ctrl->ecc_strengths[0] = FIELD_GET(BCH_CFG_0_CORR_CAP_0, reg);
        cdns_ctrl->ecc_strengths[1] = FIELD_GET(BCH_CFG_0_CORR_CAP_1, reg);
        cdns_ctrl->ecc_strengths[2] = FIELD_GET(BCH_CFG_0_CORR_CAP_2, reg);
        cdns_ctrl->ecc_strengths[3] = FIELD_GET(BCH_CFG_0_CORR_CAP_3, reg);

        reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_1);
        cdns_ctrl->ecc_strengths[4] = FIELD_GET(BCH_CFG_1_CORR_CAP_4, reg);
        cdns_ctrl->ecc_strengths[5] = FIELD_GET(BCH_CFG_1_CORR_CAP_5, reg);
        cdns_ctrl->ecc_strengths[6] = FIELD_GET(BCH_CFG_1_CORR_CAP_6, reg);
        cdns_ctrl->ecc_strengths[7] = FIELD_GET(BCH_CFG_1_CORR_CAP_7, reg);

        reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_2);
        cdns_ctrl->ecc_stepinfos[0].stepsize =
                FIELD_GET(BCH_CFG_2_SECT_0, reg);

        cdns_ctrl->ecc_stepinfos[1].stepsize =
                FIELD_GET(BCH_CFG_2_SECT_1, reg);

        nstrengths = 0;
        for (i = 0; i < BCH_MAX_NUM_CORR_CAPS; i++) {
                if (cdns_ctrl->ecc_strengths[i] != 0)
                        nstrengths++;
        }

        ecc_caps->nstepinfos = 0;
        for (i = 0; i < BCH_MAX_NUM_SECTOR_SIZES; i++) {
                /* ECC strengths are common for all step infos. */
                cdns_ctrl->ecc_stepinfos[i].nstrengths = nstrengths;
                cdns_ctrl->ecc_stepinfos[i].strengths =
                        cdns_ctrl->ecc_strengths;

                if (cdns_ctrl->ecc_stepinfos[i].stepsize != 0)
                        ecc_caps->nstepinfos++;

                if (cdns_ctrl->ecc_stepinfos[i].stepsize > max_step_size)
                        max_step_size = cdns_ctrl->ecc_stepinfos[i].stepsize;
        }
        ecc_caps->stepinfos = &cdns_ctrl->ecc_stepinfos[0];

        switch (max_step_size) {
        case 256:
                ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_256;
                break;
        case 512:
                ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_512;
                break;
        case 1024:
                ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_1024;
                break;
        case 2048:
                ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_2048;
                break;
        case 4096:
                ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_4096;
                break;
        default:
                dev_err(cdns_ctrl->dev,
                        "Unsupported sector size(ecc step size) %d\n",
                        max_step_size);
                return -EIO;
        }

        return 0;
}

/* Hardware initialization. */
static int cadence_nand_hw_init(struct cdns_nand_ctrl *cdns_ctrl)
{
        int status;
        u32 reg;

        status = cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                             1000000,
                                             CTRL_STATUS_INIT_COMP, false);
        if (status)
                return status;

        reg = readl_relaxed(cdns_ctrl->reg + CTRL_VERSION);
        cdns_ctrl->ctrl_rev = FIELD_GET(CTRL_VERSION_REV, reg);

        dev_info(cdns_ctrl->dev,
                 "%s: cadence nand controller version reg %x\n",
                 __func__, reg);

        /* Disable cache and multiplane. */
        writel_relaxed(0, cdns_ctrl->reg + MULTIPLANE_CFG);
        writel_relaxed(0, cdns_ctrl->reg + CACHE_CFG);

        /* Clear all interrupts. */
        writel_relaxed(0xFFFFFFFF, cdns_ctrl->reg + INTR_STATUS);

        cadence_nand_get_caps(cdns_ctrl);
        if (cadence_nand_read_bch_caps(cdns_ctrl))
                return -EIO;

        /*
         * Set IO width access to 8.
         * It is because during SW device discovering width access
         * is expected to be 8.
         */
        status = cadence_nand_set_access_width16(cdns_ctrl, false);

        return status;
}

#define TT_MAIN_OOB_AREAS       2
#define TT_RAW_PAGE             3
#define TT_BBM                  4
#define TT_MAIN_OOB_AREA_EXT    5

/* Prepare size of data to transfer. */
static void
cadence_nand_prepare_data_size(struct nand_chip *chip,
                               int transfer_type)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);
        u32 sec_size = 0, offset = 0, sec_cnt = 1;
        u32 last_sec_size = cdns_chip->sector_size;
        u32 data_ctrl_size = 0;
        u32 reg = 0;

        if (cdns_ctrl->curr_trans_type == transfer_type)
                return;

        switch (transfer_type) {
        case TT_MAIN_OOB_AREA_EXT:
                sec_cnt = cdns_chip->sector_count;
                sec_size = cdns_chip->sector_size;
                data_ctrl_size = cdns_chip->avail_oob_size;
                break;
        case TT_MAIN_OOB_AREAS:
                sec_cnt = cdns_chip->sector_count;
                last_sec_size = cdns_chip->sector_size
                        + cdns_chip->avail_oob_size;
                sec_size = cdns_chip->sector_size;
                break;
        case TT_RAW_PAGE:
                last_sec_size = mtd->writesize + mtd->oobsize;
                break;
        case TT_BBM:
                offset = mtd->writesize + cdns_chip->bbm_offs;
                last_sec_size = 8;
                break;
        }

        reg = 0;
        reg |= FIELD_PREP(TRAN_CFG_0_OFFSET, offset);
        reg |= FIELD_PREP(TRAN_CFG_0_SEC_CNT, sec_cnt);
        writel_relaxed(reg, cdns_ctrl->reg + TRAN_CFG_0);

        reg = 0;
        reg |= FIELD_PREP(TRAN_CFG_1_LAST_SEC_SIZE, last_sec_size);
        reg |= FIELD_PREP(TRAN_CFG_1_SECTOR_SIZE, sec_size);
        writel_relaxed(reg, cdns_ctrl->reg + TRAN_CFG_1);

        if (cdns_ctrl->caps2.data_control_supp) {
                reg = readl_relaxed(cdns_ctrl->reg + CONTROL_DATA_CTRL);
                reg &= ~CONTROL_DATA_CTRL_SIZE;
                reg |= FIELD_PREP(CONTROL_DATA_CTRL_SIZE, data_ctrl_size);
                writel_relaxed(reg, cdns_ctrl->reg + CONTROL_DATA_CTRL);
        }

        cdns_ctrl->curr_trans_type = transfer_type;
}

static int
cadence_nand_cdma_transfer(struct cdns_nand_ctrl *cdns_ctrl, u8 chip_nr,
                           int page, void *buf, void *ctrl_dat, u32 buf_size,
                           u32 ctrl_dat_size, enum dma_data_direction dir,
                           bool with_ecc)
{
        dma_addr_t dma_buf, dma_ctrl_dat = 0;
        u8 thread_nr = chip_nr;
        int status;
        u16 ctype;

        if (dir == DMA_FROM_DEVICE)
                ctype = CDMA_CT_RD;
        else
                ctype = CDMA_CT_WR;

        cadence_nand_set_ecc_enable(cdns_ctrl, with_ecc);

        dma_buf = dma_map_single(cdns_ctrl->dev, buf, buf_size, dir);
        if (dma_mapping_error(cdns_ctrl->dev, dma_buf)) {
                dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
                return -EIO;
        }

        if (ctrl_dat && ctrl_dat_size) {
                dma_ctrl_dat = dma_map_single(cdns_ctrl->dev, ctrl_dat,
                                              ctrl_dat_size, dir);
                if (dma_mapping_error(cdns_ctrl->dev, dma_ctrl_dat)) {
                        dma_unmap_single(cdns_ctrl->dev, dma_buf,
                                         buf_size, dir);
                        dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
                        return -EIO;
                }
        }

        cadence_nand_cdma_desc_prepare(cdns_ctrl, chip_nr, page,
                                       dma_buf, dma_ctrl_dat, ctype);

        status = cadence_nand_cdma_send_and_wait(cdns_ctrl, thread_nr);

        dma_unmap_single(cdns_ctrl->dev, dma_buf,
                         buf_size, dir);

        if (ctrl_dat && ctrl_dat_size)
                dma_unmap_single(cdns_ctrl->dev, dma_ctrl_dat,
                                 ctrl_dat_size, dir);
        if (status)
                return status;

        return cadence_nand_cdma_finish(cdns_ctrl);
}

static void cadence_nand_set_timings(struct cdns_nand_ctrl *cdns_ctrl,
                                     struct cadence_nand_timings *t)
{
        writel_relaxed(t->async_toggle_timings,
                       cdns_ctrl->reg + ASYNC_TOGGLE_TIMINGS);
        writel_relaxed(t->timings0, cdns_ctrl->reg + TIMINGS0);
        writel_relaxed(t->timings1, cdns_ctrl->reg + TIMINGS1);
        writel_relaxed(t->timings2, cdns_ctrl->reg + TIMINGS2);

        if (cdns_ctrl->caps2.is_phy_type_dll)
                writel_relaxed(t->dll_phy_ctrl, cdns_ctrl->reg + DLL_PHY_CTRL);

        writel_relaxed(t->phy_ctrl, cdns_ctrl->reg + PHY_CTRL);

        if (cdns_ctrl->caps2.is_phy_type_dll) {
                writel_relaxed(0, cdns_ctrl->reg + PHY_TSEL);
                writel_relaxed(2, cdns_ctrl->reg + PHY_DQ_TIMING);
                writel_relaxed(t->phy_dqs_timing,
                               cdns_ctrl->reg + PHY_DQS_TIMING);
                writel_relaxed(t->phy_gate_lpbk_ctrl,
                               cdns_ctrl->reg + PHY_GATE_LPBK_CTRL);
                writel_relaxed(PHY_DLL_MASTER_CTRL_BYPASS_MODE,
                               cdns_ctrl->reg + PHY_DLL_MASTER_CTRL);
                writel_relaxed(0, cdns_ctrl->reg + PHY_DLL_SLAVE_CTRL);
        }
}

static int cadence_nand_select_target(struct nand_chip *chip)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);

        if (chip == cdns_ctrl->selected_chip)
                return 0;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        cadence_nand_set_timings(cdns_ctrl, &cdns_chip->timings);

        cadence_nand_set_ecc_strength(cdns_ctrl,
                                      cdns_chip->corr_str_idx);

        cadence_nand_set_erase_detection(cdns_ctrl, true,
                                         chip->ecc.strength);

        cdns_ctrl->curr_trans_type = -1;
        cdns_ctrl->selected_chip = chip;

        return 0;
}

static int cadence_nand_erase(struct nand_chip *chip, u32 page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        int status;
        u8 thread_nr = cdns_chip->cs[chip->cur_cs];

        cadence_nand_cdma_desc_prepare(cdns_ctrl,
                                       cdns_chip->cs[chip->cur_cs],
                                       page, 0, 0,
                                       CDMA_CT_ERASE);
        status = cadence_nand_cdma_send_and_wait(cdns_ctrl, thread_nr);
        if (status) {
                dev_err(cdns_ctrl->dev, "erase operation failed\n");
                return -EIO;
        }

        status = cadence_nand_cdma_finish(cdns_ctrl);
        if (status)
                return status;

        return 0;
}

static int cadence_nand_read_bbm(struct nand_chip *chip, int page, u8 *buf)
{
        int status;
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);

        cadence_nand_prepare_data_size(chip, TT_BBM);

        cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);

        /*
         * Read only bad block marker from offset
         * defined by a memory manufacturer.
         */
        status = cadence_nand_cdma_transfer(cdns_ctrl,
                                            cdns_chip->cs[chip->cur_cs],
                                            page, cdns_ctrl->buf, NULL,
                                            mtd->oobsize,
                                            0, DMA_FROM_DEVICE, false);
        if (status) {
                dev_err(cdns_ctrl->dev, "read BBM failed\n");
                return -EIO;
        }

        memcpy(buf + cdns_chip->bbm_offs, cdns_ctrl->buf, cdns_chip->bbm_len);

        return 0;
}

static int cadence_nand_write_page(struct nand_chip *chip,
                                   const u8 *buf, int oob_required,
                                   int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);
        int status;
        u16 marker_val = 0xFFFF;

        status = cadence_nand_select_target(chip);
        if (status)
                return status;

        cadence_nand_set_skip_bytes_conf(cdns_ctrl, cdns_chip->bbm_len,
                                         mtd->writesize
                                         + cdns_chip->bbm_offs,
                                         1);

        if (oob_required) {
                marker_val = *(u16 *)(chip->oob_poi
                                      + cdns_chip->bbm_offs);
        } else {
                /* Set oob data to 0xFF. */
                memset(cdns_ctrl->buf + mtd->writesize, 0xFF,
                       cdns_chip->avail_oob_size);
        }

        cadence_nand_set_skip_marker_val(cdns_ctrl, marker_val);

        cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREA_EXT);

        if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, mtd->writesize) &&
            cdns_ctrl->caps2.data_control_supp) {
                u8 *oob;

                if (oob_required)
                        oob = chip->oob_poi;
                else
                        oob = cdns_ctrl->buf + mtd->writesize;

                status = cadence_nand_cdma_transfer(cdns_ctrl,
                                                    cdns_chip->cs[chip->cur_cs],
                                                    page, (void *)buf, oob,
                                                    mtd->writesize,
                                                    cdns_chip->avail_oob_size,
                                                    DMA_TO_DEVICE, true);
                if (status) {
                        dev_err(cdns_ctrl->dev, "write page failed\n");
                        return -EIO;
                }

                return 0;
        }

        if (oob_required) {
                /* Transfer the data to the oob area. */
                memcpy(cdns_ctrl->buf + mtd->writesize, chip->oob_poi,
                       cdns_chip->avail_oob_size);
        }

        memcpy(cdns_ctrl->buf, buf, mtd->writesize);

        cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREAS);

        return cadence_nand_cdma_transfer(cdns_ctrl,
                                          cdns_chip->cs[chip->cur_cs],
                                          page, cdns_ctrl->buf, NULL,
                                          mtd->writesize
                                          + cdns_chip->avail_oob_size,
                                          0, DMA_TO_DEVICE, true);
}

static int cadence_nand_write_oob(struct nand_chip *chip, int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct mtd_info *mtd = nand_to_mtd(chip);

        memset(cdns_ctrl->buf, 0xFF, mtd->writesize);

        return cadence_nand_write_page(chip, cdns_ctrl->buf, 1, page);
}

static int cadence_nand_write_page_raw(struct nand_chip *chip,
                                       const u8 *buf, int oob_required,
                                       int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);
        int writesize = mtd->writesize;
        int oobsize = mtd->oobsize;
        int ecc_steps = chip->ecc.steps;
        int ecc_size = chip->ecc.size;
        int ecc_bytes = chip->ecc.bytes;
        void *tmp_buf = cdns_ctrl->buf;
        int oob_skip = cdns_chip->bbm_len;
        size_t size = writesize + oobsize;
        int i, pos, len;
        int status = 0;

        status = cadence_nand_select_target(chip);
        if (status)
                return status;

        /*
         * Fill the buffer with 0xff first except the full page transfer.
         * This simplifies the logic.
         */
        if (!buf || !oob_required)
                memset(tmp_buf, 0xff, size);

        cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);

        /* Arrange the buffer for syndrome payload/ecc layout. */
        if (buf) {
                for (i = 0; i < ecc_steps; i++) {
                        pos = i * (ecc_size + ecc_bytes);
                        len = ecc_size;

                        if (pos >= writesize)
                                pos += oob_skip;
                        else if (pos + len > writesize)
                                len = writesize - pos;

                        memcpy(tmp_buf + pos, buf, len);
                        buf += len;
                        if (len < ecc_size) {
                                len = ecc_size - len;
                                memcpy(tmp_buf + writesize + oob_skip, buf,
                                       len);
                                buf += len;
                        }
                }
        }

        if (oob_required) {
                const u8 *oob = chip->oob_poi;
                u32 oob_data_offset = (cdns_chip->sector_count - 1) *
                        (cdns_chip->sector_size + chip->ecc.bytes)
                        + cdns_chip->sector_size + oob_skip;

                /* BBM at the beginning of the OOB area. */
                memcpy(tmp_buf + writesize, oob, oob_skip);

                /* OOB free. */
                memcpy(tmp_buf + oob_data_offset, oob,
                       cdns_chip->avail_oob_size);
                oob += cdns_chip->avail_oob_size;

                /* OOB ECC. */
                for (i = 0; i < ecc_steps; i++) {
                        pos = ecc_size + i * (ecc_size + ecc_bytes);
                        if (i == (ecc_steps - 1))
                                pos += cdns_chip->avail_oob_size;

                        len = ecc_bytes;

                        if (pos >= writesize)
                                pos += oob_skip;
                        else if (pos + len > writesize)
                                len = writesize - pos;

                        memcpy(tmp_buf + pos, oob, len);
                        oob += len;
                        if (len < ecc_bytes) {
                                len = ecc_bytes - len;
                                memcpy(tmp_buf + writesize + oob_skip, oob,
                                       len);
                                oob += len;
                        }
                }
        }

        cadence_nand_prepare_data_size(chip, TT_RAW_PAGE);

        return cadence_nand_cdma_transfer(cdns_ctrl,
                                          cdns_chip->cs[chip->cur_cs],
                                          page, cdns_ctrl->buf, NULL,
                                          mtd->writesize +
                                          mtd->oobsize,
                                          0, DMA_TO_DEVICE, false);
}

static int cadence_nand_write_oob_raw(struct nand_chip *chip,
                                      int page)
{
        return cadence_nand_write_page_raw(chip, NULL, true, page);
}

static int cadence_nand_read_page(struct nand_chip *chip,
                                  u8 *buf, int oob_required, int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);
        int status = 0;
        int ecc_err_count = 0;

        status = cadence_nand_select_target(chip);
        if (status)
                return status;

        cadence_nand_set_skip_bytes_conf(cdns_ctrl, cdns_chip->bbm_len,
                                         mtd->writesize
                                         + cdns_chip->bbm_offs, 1);

        /*
         * If data buffer can be accessed by DMA and data_control feature
         * is supported then transfer data and oob directly.
         */
        if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, mtd->writesize) &&
            cdns_ctrl->caps2.data_control_supp) {
                u8 *oob;

                if (oob_required)
                        oob = chip->oob_poi;
                else
                        oob = cdns_ctrl->buf + mtd->writesize;

                cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREA_EXT);
                status = cadence_nand_cdma_transfer(cdns_ctrl,
                                                    cdns_chip->cs[chip->cur_cs],
                                                    page, buf, oob,
                                                    mtd->writesize,
                                                    cdns_chip->avail_oob_size,
                                                    DMA_FROM_DEVICE, true);
        /* Otherwise use bounce buffer. */
        } else {
                cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREAS);
                status = cadence_nand_cdma_transfer(cdns_ctrl,
                                                    cdns_chip->cs[chip->cur_cs],
                                                    page, cdns_ctrl->buf,
                                                    NULL, mtd->writesize
                                                    + cdns_chip->avail_oob_size,
                                                    0, DMA_FROM_DEVICE, true);

                memcpy(buf, cdns_ctrl->buf, mtd->writesize);
                if (oob_required)
                        memcpy(chip->oob_poi,
                               cdns_ctrl->buf + mtd->writesize,
                               mtd->oobsize);
        }

        switch (status) {
        case STAT_ECC_UNCORR:
                mtd->ecc_stats.failed++;
                ecc_err_count++;
                break;
        case STAT_ECC_CORR:
                ecc_err_count = FIELD_GET(CDMA_CS_MAXERR,
                                          cdns_ctrl->cdma_desc->status);
                mtd->ecc_stats.corrected += ecc_err_count;
                break;
        case STAT_ERASED:
        case STAT_OK:
                break;
        default:
                dev_err(cdns_ctrl->dev, "read page failed\n");
                return -EIO;
        }

        if (oob_required)
                if (cadence_nand_read_bbm(chip, page, chip->oob_poi))
                        return -EIO;

        return ecc_err_count;
}

/* Reads OOB data from the device. */
static int cadence_nand_read_oob(struct nand_chip *chip, int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);

        return cadence_nand_read_page(chip, cdns_ctrl->buf, 1, page);
}

static int cadence_nand_read_page_raw(struct nand_chip *chip,
                                      u8 *buf, int oob_required, int page)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct mtd_info *mtd = nand_to_mtd(chip);
        int oob_skip = cdns_chip->bbm_len;
        int writesize = mtd->writesize;
        int ecc_steps = chip->ecc.steps;
        int ecc_size = chip->ecc.size;
        int ecc_bytes = chip->ecc.bytes;
        void *tmp_buf = cdns_ctrl->buf;
        int i, pos, len;
        int status = 0;

        status = cadence_nand_select_target(chip);
        if (status)
                return status;

        cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);

        cadence_nand_prepare_data_size(chip, TT_RAW_PAGE);
        status = cadence_nand_cdma_transfer(cdns_ctrl,
                                            cdns_chip->cs[chip->cur_cs],
                                            page, cdns_ctrl->buf, NULL,
                                            mtd->writesize
                                            + mtd->oobsize,
                                            0, DMA_FROM_DEVICE, false);

        switch (status) {
        case STAT_ERASED:
        case STAT_OK:
                break;
        default:
                dev_err(cdns_ctrl->dev, "read raw page failed\n");
                return -EIO;
        }

        /* Arrange the buffer for syndrome payload/ecc layout. */
        if (buf) {
                for (i = 0; i < ecc_steps; i++) {
                        pos = i * (ecc_size + ecc_bytes);
                        len = ecc_size;

                        if (pos >= writesize)
                                pos += oob_skip;
                        else if (pos + len > writesize)
                                len = writesize - pos;

                        memcpy(buf, tmp_buf + pos, len);
                        buf += len;
                        if (len < ecc_size) {
                                len = ecc_size - len;
                                memcpy(buf, tmp_buf + writesize + oob_skip,
                                       len);
                                buf += len;
                        }
                }
        }

        if (oob_required) {
                u8 *oob = chip->oob_poi;
                u32 oob_data_offset = (cdns_chip->sector_count - 1) *
                        (cdns_chip->sector_size + chip->ecc.bytes)
                        + cdns_chip->sector_size + oob_skip;

                /* OOB free. */
                memcpy(oob, tmp_buf + oob_data_offset,
                       cdns_chip->avail_oob_size);

                /* BBM at the beginning of the OOB area. */
                memcpy(oob, tmp_buf + writesize, oob_skip);

                oob += cdns_chip->avail_oob_size;

                /* OOB ECC */
                for (i = 0; i < ecc_steps; i++) {
                        pos = ecc_size + i * (ecc_size + ecc_bytes);
                        len = ecc_bytes;

                        if (i == (ecc_steps - 1))
                                pos += cdns_chip->avail_oob_size;

                        if (pos >= writesize)
                                pos += oob_skip;
                        else if (pos + len > writesize)
                                len = writesize - pos;

                        memcpy(oob, tmp_buf + pos, len);
                        oob += len;
                        if (len < ecc_bytes) {
                                len = ecc_bytes - len;
                                memcpy(oob, tmp_buf + writesize + oob_skip,
                                       len);
                                oob += len;
                        }
                }
        }

        return 0;
}

static int cadence_nand_read_oob_raw(struct nand_chip *chip,
                                     int page)
{
        return cadence_nand_read_page_raw(chip, NULL, true, page);
}

static void cadence_nand_slave_dma_transfer_finished(void *data)
{
        struct completion *finished = data;

        complete(finished);
}

static int cadence_nand_slave_dma_transfer(struct cdns_nand_ctrl *cdns_ctrl,
                                           void *buf,
                                           dma_addr_t dev_dma, size_t len,
                                           enum dma_data_direction dir)
{
        DECLARE_COMPLETION_ONSTACK(finished);
        struct dma_chan *chan;
        struct dma_device *dma_dev;
        dma_addr_t src_dma, dst_dma, buf_dma;
        struct dma_async_tx_descriptor *tx;
        dma_cookie_t cookie;

        chan = cdns_ctrl->dmac;
        dma_dev = chan->device;

        buf_dma = dma_map_single(dma_dev->dev, buf, len, dir);
        if (dma_mapping_error(dma_dev->dev, buf_dma)) {
                dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
                goto err;
        }

        if (dir == DMA_FROM_DEVICE) {
                src_dma = cdns_ctrl->io.dma;
                dst_dma = buf_dma;
        } else {
                src_dma = buf_dma;
                dst_dma = cdns_ctrl->io.dma;
        }

        tx = dmaengine_prep_dma_memcpy(cdns_ctrl->dmac, dst_dma, src_dma, len,
                                       DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
        if (!tx) {
                dev_err(cdns_ctrl->dev, "Failed to prepare DMA memcpy\n");
                goto err_unmap;
        }

        tx->callback = cadence_nand_slave_dma_transfer_finished;
        tx->callback_param = &finished;

        cookie = dmaengine_submit(tx);
        if (dma_submit_error(cookie)) {
                dev_err(cdns_ctrl->dev, "Failed to do DMA tx_submit\n");
                goto err_unmap;
        }

        dma_async_issue_pending(cdns_ctrl->dmac);
        wait_for_completion(&finished);

        dma_unmap_single(cdns_ctrl->dev, buf_dma, len, dir);

        return 0;

err_unmap:
        dma_unmap_single(cdns_ctrl->dev, buf_dma, len, dir);

err:
        dev_dbg(cdns_ctrl->dev, "Fall back to CPU I/O\n");

        return -EIO;
}

static int cadence_nand_read_buf(struct cdns_nand_ctrl *cdns_ctrl,
                                 u8 *buf, int len)
{
        u8 thread_nr = 0;
        u32 sdma_size;
        int status;

        /* Wait until slave DMA interface is ready to data transfer. */
        status = cadence_nand_wait_on_sdma(cdns_ctrl, &thread_nr, &sdma_size);
        if (status)
                return status;

        if (!cdns_ctrl->caps1->has_dma) {
                int len_in_words = len >> 2;

                /* read alingment data */
                ioread32_rep(cdns_ctrl->io.virt, buf, len_in_words);
                if (sdma_size > len) {
                        /* read rest data from slave DMA interface if any */
                        ioread32_rep(cdns_ctrl->io.virt, cdns_ctrl->buf,
                                     sdma_size / 4 - len_in_words);
                        /* copy rest of data */
                        memcpy(buf + (len_in_words << 2), cdns_ctrl->buf,
                               len - (len_in_words << 2));
                }
                return 0;
        }

        if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, len)) {
                status = cadence_nand_slave_dma_transfer(cdns_ctrl, buf,
                                                         cdns_ctrl->io.dma,
                                                         len, DMA_FROM_DEVICE);
                if (status == 0)
                        return 0;

                dev_warn(cdns_ctrl->dev,
                         "Slave DMA transfer failed. Try again using bounce buffer.");
        }

        /* If DMA transfer is not possible or failed then use bounce buffer. */
        status = cadence_nand_slave_dma_transfer(cdns_ctrl, cdns_ctrl->buf,
                                                 cdns_ctrl->io.dma,
                                                 sdma_size, DMA_FROM_DEVICE);

        if (status) {
                dev_err(cdns_ctrl->dev, "Slave DMA transfer failed");
                return status;
        }

        memcpy(buf, cdns_ctrl->buf, len);

        return 0;
}

static int cadence_nand_write_buf(struct cdns_nand_ctrl *cdns_ctrl,
                                  const u8 *buf, int len)
{
        u8 thread_nr = 0;
        u32 sdma_size;
        int status;

        /* Wait until slave DMA interface is ready to data transfer. */
        status = cadence_nand_wait_on_sdma(cdns_ctrl, &thread_nr, &sdma_size);
        if (status)
                return status;

        if (!cdns_ctrl->caps1->has_dma) {
                int len_in_words = len >> 2;

                iowrite32_rep(cdns_ctrl->io.virt, buf, len_in_words);
                if (sdma_size > len) {
                        /* copy rest of data */
                        memcpy(cdns_ctrl->buf, buf + (len_in_words << 2),
                               len - (len_in_words << 2));
                        /* write all expected by nand controller data */
                        iowrite32_rep(cdns_ctrl->io.virt, cdns_ctrl->buf,
                                      sdma_size / 4 - len_in_words);
                }

                return 0;
        }

        if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, len)) {
                status = cadence_nand_slave_dma_transfer(cdns_ctrl, (void *)buf,
                                                         cdns_ctrl->io.dma,
                                                         len, DMA_TO_DEVICE);
                if (status == 0)
                        return 0;

                dev_warn(cdns_ctrl->dev,
                         "Slave DMA transfer failed. Try again using bounce buffer.");
        }

        /* If DMA transfer is not possible or failed then use bounce buffer. */
        memcpy(cdns_ctrl->buf, buf, len);

        status = cadence_nand_slave_dma_transfer(cdns_ctrl, cdns_ctrl->buf,
                                                 cdns_ctrl->io.dma,
                                                 sdma_size, DMA_TO_DEVICE);

        if (status)
                dev_err(cdns_ctrl->dev, "Slave DMA transfer failed");

        return status;
}

static int cadence_nand_force_byte_access(struct nand_chip *chip,
                                          bool force_8bit)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        int status;

        /*
         * Callers of this function do not verify if the NAND is using a 16-bit
         * an 8-bit bus for normal operations, so we need to take care of that
         * here by leaving the configuration unchanged if the NAND does not have
         * the NAND_BUSWIDTH_16 flag set.
         */
        if (!(chip->options & NAND_BUSWIDTH_16))
                return 0;

        status = cadence_nand_set_access_width16(cdns_ctrl, !force_8bit);

        return status;
}

static int cadence_nand_cmd_opcode(struct nand_chip *chip,
                                   const struct nand_subop *subop)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        const struct nand_op_instr *instr;
        unsigned int op_id = 0;
        u64 mini_ctrl_cmd = 0;
        int ret;

        instr = &subop->instrs[op_id];

        if (instr->delay_ns > 0)
                mini_ctrl_cmd |= GCMD_LAY_TWB;

        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
                                    GCMD_LAY_INSTR_CMD);
        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_CMD,
                                    instr->ctx.cmd.opcode);

        ret = cadence_nand_generic_cmd_send(cdns_ctrl,
                                            cdns_chip->cs[chip->cur_cs],
                                            mini_ctrl_cmd);
        if (ret)
                dev_err(cdns_ctrl->dev, "send cmd %x failed\n",
                        instr->ctx.cmd.opcode);

        return ret;
}

static int cadence_nand_cmd_address(struct nand_chip *chip,
                                    const struct nand_subop *subop)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        const struct nand_op_instr *instr;
        unsigned int op_id = 0;
        u64 mini_ctrl_cmd = 0;
        unsigned int offset, naddrs;
        u64 address = 0;
        const u8 *addrs;
        int ret;
        int i;

        instr = &subop->instrs[op_id];

        if (instr->delay_ns > 0)
                mini_ctrl_cmd |= GCMD_LAY_TWB;

        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
                                    GCMD_LAY_INSTR_ADDR);

        offset = nand_subop_get_addr_start_off(subop, op_id);
        naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
        addrs = &instr->ctx.addr.addrs[offset];

        for (i = 0; i < naddrs; i++)
                address |= (u64)addrs[i] << (8 * i);

        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_ADDR,
                                    address);
        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_ADDR_SIZE,
                                    naddrs - 1);

        ret = cadence_nand_generic_cmd_send(cdns_ctrl,
                                            cdns_chip->cs[chip->cur_cs],
                                            mini_ctrl_cmd);
        if (ret)
                dev_err(cdns_ctrl->dev, "send address %llx failed\n", address);

        return ret;
}

static int cadence_nand_cmd_erase(struct nand_chip *chip,
                                  const struct nand_subop *subop)
{
        unsigned int op_id;

        if (subop->instrs[0].ctx.cmd.opcode == NAND_CMD_ERASE1) {
                int i;
                const struct nand_op_instr *instr = NULL;
                unsigned int offset, naddrs;
                const u8 *addrs;
                u32 page = 0;

                instr = &subop->instrs[1];
                offset = nand_subop_get_addr_start_off(subop, 1);
                naddrs = nand_subop_get_num_addr_cyc(subop, 1);
                addrs = &instr->ctx.addr.addrs[offset];

                for (i = 0; i < naddrs; i++)
                        page |= (u32)addrs[i] << (8 * i);

                return cadence_nand_erase(chip, page);
        }

        /*
         * If it is not an erase operation then handle operation
         * by calling exec_op function.
         */
        for (op_id = 0; op_id < subop->ninstrs; op_id++) {
                int ret;
                const struct nand_operation nand_op = {
                        .cs = chip->cur_cs,
                        .instrs =  &subop->instrs[op_id],
                        .ninstrs = 1};
                ret = chip->controller->ops->exec_op(chip, &nand_op, false);
                if (ret)
                        return ret;
        }

        return 0;
}

static int cadence_nand_cmd_data(struct nand_chip *chip,
                                 const struct nand_subop *subop)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        const struct nand_op_instr *instr;
        unsigned int offset, op_id = 0;
        u64 mini_ctrl_cmd = 0;
        int len = 0;
        int ret;

        instr = &subop->instrs[op_id];

        if (instr->delay_ns > 0)
                mini_ctrl_cmd |= GCMD_LAY_TWB;

        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
                                    GCMD_LAY_INSTR_DATA);

        if (instr->type == NAND_OP_DATA_OUT_INSTR)
                mini_ctrl_cmd |= FIELD_PREP(GCMD_DIR,
                                            GCMD_DIR_WRITE);

        len = nand_subop_get_data_len(subop, op_id);
        offset = nand_subop_get_data_start_off(subop, op_id);
        mini_ctrl_cmd |= FIELD_PREP(GCMD_SECT_CNT, 1);
        mini_ctrl_cmd |= FIELD_PREP(GCMD_LAST_SIZE, len);
        if (instr->ctx.data.force_8bit) {
                ret = cadence_nand_force_byte_access(chip, true);
                if (ret) {
                        dev_err(cdns_ctrl->dev,
                                "cannot change byte access generic data cmd failed\n");
                        return ret;
                }
        }

        ret = cadence_nand_generic_cmd_send(cdns_ctrl,
                                            cdns_chip->cs[chip->cur_cs],
                                            mini_ctrl_cmd);
        if (ret) {
                dev_err(cdns_ctrl->dev, "send generic data cmd failed\n");
                return ret;
        }

        if (instr->type == NAND_OP_DATA_IN_INSTR) {
                void *buf = instr->ctx.data.buf.in + offset;

                ret = cadence_nand_read_buf(cdns_ctrl, buf, len);
        } else {
                const void *buf = instr->ctx.data.buf.out + offset;

                ret = cadence_nand_write_buf(cdns_ctrl, buf, len);
        }

        if (ret) {
                dev_err(cdns_ctrl->dev, "data transfer failed for generic command\n");
                return ret;
        }

        if (instr->ctx.data.force_8bit) {
                ret = cadence_nand_force_byte_access(chip, false);
                if (ret) {
                        dev_err(cdns_ctrl->dev,
                                "cannot change byte access generic data cmd failed\n");
                }
        }

        return ret;
}

static int cadence_nand_cmd_waitrdy(struct nand_chip *chip,
                                    const struct nand_subop *subop)
{
        int status;
        unsigned int op_id = 0;
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        const struct nand_op_instr *instr = &subop->instrs[op_id];
        u32 timeout_us = instr->ctx.waitrdy.timeout_ms * 1000;

        status = cadence_nand_wait_for_value(cdns_ctrl, RBN_SETINGS,
                                             timeout_us,
                                             BIT(cdns_chip->cs[chip->cur_cs]),
                                             false);
        return status;
}

static const struct nand_op_parser cadence_nand_op_parser = NAND_OP_PARSER(
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_erase,
                NAND_OP_PARSER_PAT_CMD_ELEM(false),
                NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ERASE_ADDRESS_CYC),
                NAND_OP_PARSER_PAT_CMD_ELEM(false),
                NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_opcode,
                NAND_OP_PARSER_PAT_CMD_ELEM(false)),
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_address,
                NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYC)),
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_data,
                NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, MAX_DATA_SIZE)),
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_data,
                NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, MAX_DATA_SIZE)),
        NAND_OP_PARSER_PATTERN(
                cadence_nand_cmd_waitrdy,
                NAND_OP_PARSER_PAT_WAITRDY_ELEM(false))
        );

static int cadence_nand_exec_op(struct nand_chip *chip,
                                const struct nand_operation *op,
                                bool check_only)
{
        if (!check_only) {
                int status = cadence_nand_select_target(chip);

                if (status)
                        return status;
        }

        return nand_op_parser_exec_op(chip, &cadence_nand_op_parser, op,
                                      check_only);
}

static int cadence_nand_ooblayout_free(struct mtd_info *mtd, int section,
                                       struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);

        if (section)
                return -ERANGE;

        oobregion->offset = cdns_chip->bbm_len;
        oobregion->length = cdns_chip->avail_oob_size
                - cdns_chip->bbm_len;

        return 0;
}

static int cadence_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
                                      struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);

        if (section)
                return -ERANGE;

        oobregion->offset = cdns_chip->avail_oob_size;
        oobregion->length = chip->ecc.total;

        return 0;
}

static const struct mtd_ooblayout_ops cadence_nand_ooblayout_ops = {
        .free = cadence_nand_ooblayout_free,
        .ecc = cadence_nand_ooblayout_ecc,
};

static int calc_cycl(u32 timing, u32 clock)
{
        if (timing == 0 || clock == 0)
                return 0;

        if ((timing % clock) > 0)
                return timing / clock;
        else
                return timing / clock - 1;
}

/* Calculate max data valid window. */
static inline u32 calc_tdvw_max(u32 trp_cnt, u32 clk_period, u32 trhoh_min,
                                u32 board_delay_skew_min, u32 ext_mode)
{
        if (ext_mode == 0)
                clk_period /= 2;

        return (trp_cnt + 1) * clk_period + trhoh_min +
                board_delay_skew_min;
}

/* Calculate data valid window. */
static inline u32 calc_tdvw(u32 trp_cnt, u32 clk_period, u32 trhoh_min,
                            u32 trea_max, u32 ext_mode)
{
        if (ext_mode == 0)
                clk_period /= 2;

        return (trp_cnt + 1) * clk_period + trhoh_min - trea_max;
}

static int
cadence_nand_setup_interface(struct nand_chip *chip, int chipnr,
                             const struct nand_interface_config *conf)
{
        const struct nand_sdr_timings *sdr;
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        struct cadence_nand_timings *t = &cdns_chip->timings;
        u32 reg;
        u32 board_delay = cdns_ctrl->board_delay;
        u32 clk_period = DIV_ROUND_DOWN_ULL(1000000000000ULL,
                                            cdns_ctrl->nf_clk_rate);
        u32 tceh_cnt, tcs_cnt, tadl_cnt, tccs_cnt;
        u32 tfeat_cnt, trhz_cnt, tvdly_cnt;
        u32 trhw_cnt, twb_cnt, twh_cnt = 0, twhr_cnt;
        u32 twp_cnt = 0, trp_cnt = 0, trh_cnt = 0;
        u32 if_skew = cdns_ctrl->caps1->if_skew;
        u32 board_delay_skew_min = board_delay - if_skew;
        u32 board_delay_skew_max = board_delay + if_skew;
        u32 dqs_sampl_res, phony_dqs_mod;
        u32 tdvw, tdvw_min, tdvw_max;
        u32 ext_rd_mode, ext_wr_mode;
        u32 dll_phy_dqs_timing = 0, phony_dqs_timing = 0, rd_del_sel = 0;
        u32 sampling_point;

        sdr = nand_get_sdr_timings(conf);
        if (IS_ERR(sdr))
                return PTR_ERR(sdr);

        memset(t, 0, sizeof(*t));
        /* Sampling point calculation. */

        if (cdns_ctrl->caps2.is_phy_type_dll)
                phony_dqs_mod = 2;
        else
                phony_dqs_mod = 1;

        dqs_sampl_res = clk_period / phony_dqs_mod;

        tdvw_min = sdr->tREA_max + board_delay_skew_max;
        /*
         * The idea of those calculation is to get the optimum value
         * for tRP and tRH timings. If it is NOT possible to sample data
         * with optimal tRP/tRH settings, the parameters will be extended.
         * If clk_period is 50ns (the lowest value) this condition is met
         * for asynchronous timing modes 1, 2, 3, 4 and 5.
         * If clk_period is 20ns the condition is met only
         * for asynchronous timing mode 5.
         */
        if (sdr->tRC_min <= clk_period &&
            sdr->tRP_min <= (clk_period / 2) &&
            sdr->tREH_min <= (clk_period / 2)) {
                /* Performance mode. */
                ext_rd_mode = 0;
                tdvw = calc_tdvw(trp_cnt, clk_period, sdr->tRHOH_min,
                                 sdr->tREA_max, ext_rd_mode);
                tdvw_max = calc_tdvw_max(trp_cnt, clk_period, sdr->tRHOH_min,
                                         board_delay_skew_min,
                                         ext_rd_mode);
                /*
                 * Check if data valid window and sampling point can be found
                 * and is not on the edge (ie. we have hold margin).
                 * If not extend the tRP timings.
                 */
                if (tdvw > 0) {
                        if (tdvw_max <= tdvw_min ||
                            (tdvw_max % dqs_sampl_res) == 0) {
                                /*
                                 * No valid sampling point so the RE pulse need
                                 * to be widen widening by half clock cycle.
                                 */
                                ext_rd_mode = 1;
                        }
                } else {
                        /*
                         * There is no valid window
                         * to be able to sample data the tRP need to be widen.
                         * Very safe calculations are performed here.
                         */
                        trp_cnt = (sdr->tREA_max + board_delay_skew_max
                                   + dqs_sampl_res) / clk_period;
                        ext_rd_mode = 1;
                }

        } else {
                /* Extended read mode. */
                u32 trh;

                ext_rd_mode = 1;
                trp_cnt = calc_cycl(sdr->tRP_min, clk_period);
                trh = sdr->tRC_min - ((trp_cnt + 1) * clk_period);
                if (sdr->tREH_min >= trh)
                        trh_cnt = calc_cycl(sdr->tREH_min, clk_period);
                else
                        trh_cnt = calc_cycl(trh, clk_period);

                tdvw = calc_tdvw(trp_cnt, clk_period, sdr->tRHOH_min,
                                 sdr->tREA_max, ext_rd_mode);
                /*
                 * Check if data valid window and sampling point can be found
                 * or if it is at the edge check if previous is valid
                 * - if not extend the tRP timings.
                 */
                if (tdvw > 0) {
                        tdvw_max = calc_tdvw_max(trp_cnt, clk_period,
                                                 sdr->tRHOH_min,
                                                 board_delay_skew_min,
                                                 ext_rd_mode);

                        if ((((tdvw_max / dqs_sampl_res)
                              * dqs_sampl_res) <= tdvw_min) ||
                            (((tdvw_max % dqs_sampl_res) == 0) &&
                             (((tdvw_max / dqs_sampl_res - 1)
                               * dqs_sampl_res) <= tdvw_min))) {
                                /*
                                 * Data valid window width is lower than
                                 * sampling resolution and do not hit any
                                 * sampling point to be sure the sampling point
                                 * will be found the RE low pulse width will be
                                 *  extended by one clock cycle.
                                 */
                                trp_cnt = trp_cnt + 1;
                        }
                } else {
                        /*
                         * There is no valid window to be able to sample data.
                         * The tRP need to be widen.
                         * Very safe calculations are performed here.
                         */
                        trp_cnt = (sdr->tREA_max + board_delay_skew_max
                                   + dqs_sampl_res) / clk_period;
                }
        }

        tdvw_max = calc_tdvw_max(trp_cnt, clk_period,
                                 sdr->tRHOH_min,
                                 board_delay_skew_min, ext_rd_mode);

        if (sdr->tWC_min <= clk_period &&
            (sdr->tWP_min + if_skew) <= (clk_period / 2) &&
            (sdr->tWH_min + if_skew) <= (clk_period / 2)) {
                ext_wr_mode = 0;
        } else {
                u32 twh;

                ext_wr_mode = 1;
                twp_cnt = calc_cycl(sdr->tWP_min + if_skew, clk_period);
                if ((twp_cnt + 1) * clk_period < (sdr->tALS_min + if_skew))
                        twp_cnt = calc_cycl(sdr->tALS_min + if_skew,
                                            clk_period);

                twh = (sdr->tWC_min - (twp_cnt + 1) * clk_period);
                if (sdr->tWH_min >= twh)
                        twh = sdr->tWH_min;

                twh_cnt = calc_cycl(twh + if_skew, clk_period);
        }

        reg = FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TRH, trh_cnt);
        reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TRP, trp_cnt);
        reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TWH, twh_cnt);
        reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TWP, twp_cnt);
        t->async_toggle_timings = reg;
        dev_dbg(cdns_ctrl->dev, "ASYNC_TOGGLE_TIMINGS_SDR\t%x\n", reg);

        tadl_cnt = calc_cycl((sdr->tADL_min + if_skew), clk_period);
        tccs_cnt = calc_cycl((sdr->tCCS_min + if_skew), clk_period);
        twhr_cnt = calc_cycl((sdr->tWHR_min + if_skew), clk_period);
        trhw_cnt = calc_cycl((sdr->tRHW_min + if_skew), clk_period);
        reg = FIELD_PREP(TIMINGS0_TADL, tadl_cnt);

        /*
         * If timing exceeds delay field in timing register
         * then use maximum value.
         */
        if (FIELD_FIT(TIMINGS0_TCCS, tccs_cnt))
                reg |= FIELD_PREP(TIMINGS0_TCCS, tccs_cnt);
        else
                reg |= TIMINGS0_TCCS;

        reg |= FIELD_PREP(TIMINGS0_TWHR, twhr_cnt);
        reg |= FIELD_PREP(TIMINGS0_TRHW, trhw_cnt);
        t->timings0 = reg;
        dev_dbg(cdns_ctrl->dev, "TIMINGS0_SDR\t%x\n", reg);

        /* The following is related to single signal so skew is not needed. */
        trhz_cnt = calc_cycl(sdr->tRHZ_max, clk_period);
        trhz_cnt = trhz_cnt + 1;
        twb_cnt = calc_cycl((sdr->tWB_max + board_delay), clk_period);
        /*
         * Because of the two stage syncflop the value must be increased by 3
         * first value is related with sync, second value is related
         * with output if delay.
         */
        twb_cnt = twb_cnt + 3 + 5;
        /*
         * The following is related to the we edge of the random data input
         * sequence so skew is not needed.
         */
        tvdly_cnt = calc_cycl(500000 + if_skew, clk_period);
        reg = FIELD_PREP(TIMINGS1_TRHZ, trhz_cnt);
        reg |= FIELD_PREP(TIMINGS1_TWB, twb_cnt);
        reg |= FIELD_PREP(TIMINGS1_TVDLY, tvdly_cnt);
        t->timings1 = reg;
        dev_dbg(cdns_ctrl->dev, "TIMINGS1_SDR\t%x\n", reg);

        tfeat_cnt = calc_cycl(sdr->tFEAT_max, clk_period);
        if (tfeat_cnt < twb_cnt)
                tfeat_cnt = twb_cnt;

        tceh_cnt = calc_cycl(sdr->tCEH_min, clk_period);
        tcs_cnt = calc_cycl((sdr->tCS_min + if_skew), clk_period);

        reg = FIELD_PREP(TIMINGS2_TFEAT, tfeat_cnt);
        reg |= FIELD_PREP(TIMINGS2_CS_HOLD_TIME, tceh_cnt);
        reg |= FIELD_PREP(TIMINGS2_CS_SETUP_TIME, tcs_cnt);
        t->timings2 = reg;
        dev_dbg(cdns_ctrl->dev, "TIMINGS2_SDR\t%x\n", reg);

        if (cdns_ctrl->caps2.is_phy_type_dll) {
                reg = DLL_PHY_CTRL_DLL_RST_N;
                if (ext_wr_mode)
                        reg |= DLL_PHY_CTRL_EXTENDED_WR_MODE;
                if (ext_rd_mode)
                        reg |= DLL_PHY_CTRL_EXTENDED_RD_MODE;

                reg |= FIELD_PREP(DLL_PHY_CTRL_RS_HIGH_WAIT_CNT, 7);
                reg |= FIELD_PREP(DLL_PHY_CTRL_RS_IDLE_CNT, 7);
                t->dll_phy_ctrl = reg;
                dev_dbg(cdns_ctrl->dev, "DLL_PHY_CTRL_SDR\t%x\n", reg);
        }

        /* Sampling point calculation. */
        if ((tdvw_max % dqs_sampl_res) > 0)
                sampling_point = tdvw_max / dqs_sampl_res;
        else
                sampling_point = (tdvw_max / dqs_sampl_res - 1);

        if (sampling_point * dqs_sampl_res > tdvw_min) {
                dll_phy_dqs_timing =
                        FIELD_PREP(PHY_DQS_TIMING_DQS_SEL_OE_END, 4);
                dll_phy_dqs_timing |= PHY_DQS_TIMING_USE_PHONY_DQS;
                phony_dqs_timing = sampling_point / phony_dqs_mod;

                if ((sampling_point % 2) > 0) {
                        dll_phy_dqs_timing |= PHY_DQS_TIMING_PHONY_DQS_SEL;
                        if ((tdvw_max % dqs_sampl_res) == 0)
                                /*
                                 * Calculation for sampling point at the edge
                                 * of data and being odd number.
                                 */
                                phony_dqs_timing = (tdvw_max / dqs_sampl_res)
                                        / phony_dqs_mod - 1;

                        if (!cdns_ctrl->caps2.is_phy_type_dll)
                                phony_dqs_timing--;

                } else {
                        phony_dqs_timing--;
                }
                rd_del_sel = phony_dqs_timing + 3;
        } else {
                dev_warn(cdns_ctrl->dev,
                         "ERROR : cannot find valid sampling point\n");
        }

        reg = FIELD_PREP(PHY_CTRL_PHONY_DQS, phony_dqs_timing);
        if (cdns_ctrl->caps2.is_phy_type_dll)
                reg  |= PHY_CTRL_SDR_DQS;
        t->phy_ctrl = reg;
        dev_dbg(cdns_ctrl->dev, "PHY_CTRL_REG_SDR\t%x\n", reg);

        if (cdns_ctrl->caps2.is_phy_type_dll) {
                dev_dbg(cdns_ctrl->dev, "PHY_TSEL_REG_SDR\t%x\n", 0);
                dev_dbg(cdns_ctrl->dev, "PHY_DQ_TIMING_REG_SDR\t%x\n", 2);
                dev_dbg(cdns_ctrl->dev, "PHY_DQS_TIMING_REG_SDR\t%x\n",
                        dll_phy_dqs_timing);
                t->phy_dqs_timing = dll_phy_dqs_timing;

                reg = FIELD_PREP(PHY_GATE_LPBK_CTRL_RDS, rd_del_sel);
                dev_dbg(cdns_ctrl->dev, "PHY_GATE_LPBK_CTRL_REG_SDR\t%x\n",
                        reg);
                t->phy_gate_lpbk_ctrl = reg;

                dev_dbg(cdns_ctrl->dev, "PHY_DLL_MASTER_CTRL_REG_SDR\t%lx\n",
                        PHY_DLL_MASTER_CTRL_BYPASS_MODE);
                dev_dbg(cdns_ctrl->dev, "PHY_DLL_SLAVE_CTRL_REG_SDR\t%x\n", 0);
        }

        return 0;
}

static int cadence_nand_attach_chip(struct nand_chip *chip)
{
        struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
        struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
        u32 ecc_size;
        struct mtd_info *mtd = nand_to_mtd(chip);
        int ret;

        if (chip->options & NAND_BUSWIDTH_16) {
                ret = cadence_nand_set_access_width16(cdns_ctrl, true);
                if (ret)
                        return ret;
        }

        chip->bbt_options |= NAND_BBT_USE_FLASH;
        chip->bbt_options |= NAND_BBT_NO_OOB;
        chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;

        chip->options |= NAND_NO_SUBPAGE_WRITE;

        cdns_chip->bbm_offs = chip->badblockpos;
        cdns_chip->bbm_offs &= ~0x01;
        /* this value should be even number */
        cdns_chip->bbm_len = 2;

        ret = nand_ecc_choose_conf(chip,
                                   &cdns_ctrl->ecc_caps,
                                   mtd->oobsize - cdns_chip->bbm_len);
        if (ret) {
                dev_err(cdns_ctrl->dev, "ECC configuration failed\n");
                return ret;
        }

        dev_dbg(cdns_ctrl->dev,
                "chosen ECC settings: step=%d, strength=%d, bytes=%d\n",
                chip->ecc.size, chip->ecc.strength, chip->ecc.bytes);

        /* Error correction configuration. */
        cdns_chip->sector_size = chip->ecc.size;
        cdns_chip->sector_count = mtd->writesize / cdns_chip->sector_size;
        ecc_size = cdns_chip->sector_count * chip->ecc.bytes;

        cdns_chip->avail_oob_size = mtd->oobsize - ecc_size;

        if (cdns_chip->avail_oob_size > cdns_ctrl->bch_metadata_size)
                cdns_chip->avail_oob_size = cdns_ctrl->bch_metadata_size;

        if ((cdns_chip->avail_oob_size + cdns_chip->bbm_len + ecc_size)
            > mtd->oobsize)
                cdns_chip->avail_oob_size -= 4;

        ret = cadence_nand_get_ecc_strength_idx(cdns_ctrl, chip->ecc.strength);
        if (ret < 0)
                return -EINVAL;

        cdns_chip->corr_str_idx = (u8)ret;

        if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
                                        1000000,
                                        CTRL_STATUS_CTRL_BUSY, true))
                return -ETIMEDOUT;

        cadence_nand_set_ecc_strength(cdns_ctrl,
                                      cdns_chip->corr_str_idx);

        cadence_nand_set_erase_detection(cdns_ctrl, true,
                                         chip->ecc.strength);

        /* Override the default read operations. */
        chip->ecc.read_page = cadence_nand_read_page;
        chip->ecc.read_page_raw = cadence_nand_read_page_raw;
        chip->ecc.write_page = cadence_nand_write_page;
        chip->ecc.write_page_raw = cadence_nand_write_page_raw;
        chip->ecc.read_oob = cadence_nand_read_oob;
        chip->ecc.write_oob = cadence_nand_write_oob;
        chip->ecc.read_oob_raw = cadence_nand_read_oob_raw;
        chip->ecc.write_oob_raw = cadence_nand_write_oob_raw;

        if ((mtd->writesize + mtd->oobsize) > cdns_ctrl->buf_size)
                cdns_ctrl->buf_size = mtd->writesize + mtd->oobsize;

        /* Is 32-bit DMA supported? */
        ret = dma_set_mask(cdns_ctrl->dev, DMA_BIT_MASK(32));
        if (ret) {
                dev_err(cdns_ctrl->dev, "no usable DMA configuration\n");
                return ret;
        }

        mtd_set_ooblayout(mtd, &cadence_nand_ooblayout_ops);

        return 0;
}

static const struct nand_controller_ops cadence_nand_controller_ops = {
        .attach_chip = cadence_nand_attach_chip,
        .exec_op = cadence_nand_exec_op,
        .setup_interface = cadence_nand_setup_interface,
};

static int cadence_nand_chip_init(struct cdns_nand_ctrl *cdns_ctrl,
                                  struct device_node *np)
{
        struct cdns_nand_chip *cdns_chip;
        struct mtd_info *mtd;
        struct nand_chip *chip;
        int nsels, ret, i;
        u32 cs;

        nsels = of_property_count_elems_of_size(np, "reg", sizeof(u32));
        if (nsels <= 0) {
                dev_err(cdns_ctrl->dev, "missing/invalid reg property\n");
                return -EINVAL;
        }

        /* Allocate the nand chip structure. */
        cdns_chip = devm_kzalloc(cdns_ctrl->dev, sizeof(*cdns_chip) +
                                 (nsels * sizeof(u8)),
                                 GFP_KERNEL);
        if (!cdns_chip) {
                dev_err(cdns_ctrl->dev, "could not allocate chip structure\n");
                return -ENOMEM;
        }

        cdns_chip->nsels = nsels;

        for (i = 0; i < nsels; i++) {
                /* Retrieve CS id. */
                ret = of_property_read_u32_index(np, "reg", i, &cs);
                if (ret) {
                        dev_err(cdns_ctrl->dev,
                                "could not retrieve reg property: %d\n",
                                ret);
                        return ret;
                }

                if (cs >= cdns_ctrl->caps2.max_banks) {
                        dev_err(cdns_ctrl->dev,
                                "invalid reg value: %u (max CS = %d)\n",
                                cs, cdns_ctrl->caps2.max_banks);
                        return -EINVAL;
                }

                if (test_and_set_bit(cs, &cdns_ctrl->assigned_cs)) {
                        dev_err(cdns_ctrl->dev,
                                "CS %d already assigned\n", cs);
                        return -EINVAL;
                }

                cdns_chip->cs[i] = cs;
        }

        chip = &cdns_chip->chip;
        chip->controller = &cdns_ctrl->controller;
        nand_set_flash_node(chip, np);

        mtd = nand_to_mtd(chip);
        mtd->dev.parent = cdns_ctrl->dev;

        /*
         * Default to HW ECC engine mode. If the nand-ecc-mode property is given
         * in the DT node, this entry will be overwritten in nand_scan_ident().
         */
        chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;

        ret = nand_scan(chip, cdns_chip->nsels);
        if (ret) {
                dev_err(cdns_ctrl->dev, "could not scan the nand chip\n");
                return ret;
        }

        ret = mtd_device_register(mtd, NULL, 0);
        if (ret) {
                dev_err(cdns_ctrl->dev,
                        "failed to register mtd device: %d\n", ret);
                nand_cleanup(chip);
                return ret;
        }

        list_add_tail(&cdns_chip->node, &cdns_ctrl->chips);

        return 0;
}

static void cadence_nand_chips_cleanup(struct cdns_nand_ctrl *cdns_ctrl)
{
        struct cdns_nand_chip *entry, *temp;
        struct nand_chip *chip;
        int ret;

        list_for_each_entry_safe(entry, temp, &cdns_ctrl->chips, node) {
                chip = &entry->chip;
                ret = mtd_device_unregister(nand_to_mtd(chip));
                WARN_ON(ret);
                nand_cleanup(chip);
                list_del(&entry->node);
        }
}

static int cadence_nand_chips_init(struct cdns_nand_ctrl *cdns_ctrl)
{
        struct device_node *np = cdns_ctrl->dev->of_node;
        struct device_node *nand_np;
        int max_cs = cdns_ctrl->caps2.max_banks;
        int nchips, ret;

        nchips = of_get_child_count(np);

        if (nchips > max_cs) {
                dev_err(cdns_ctrl->dev,
                        "too many NAND chips: %d (max = %d CS)\n",
                        nchips, max_cs);
                return -EINVAL;
        }

        for_each_child_of_node(np, nand_np) {
                ret = cadence_nand_chip_init(cdns_ctrl, nand_np);
                if (ret) {
                        of_node_put(nand_np);
                        cadence_nand_chips_cleanup(cdns_ctrl);
                        return ret;
                }
        }

        return 0;
}

static void
cadence_nand_irq_cleanup(int irqnum, struct cdns_nand_ctrl *cdns_ctrl)
{
        /* Disable interrupts. */
        writel_relaxed(INTR_ENABLE_INTR_EN, cdns_ctrl->reg + INTR_ENABLE);
}

static int cadence_nand_init(struct cdns_nand_ctrl *cdns_ctrl)
{
        dma_cap_mask_t mask;
        int ret;

        cdns_ctrl->cdma_desc = dma_alloc_coherent(cdns_ctrl->dev,
                                                  sizeof(*cdns_ctrl->cdma_desc),
                                                  &cdns_ctrl->dma_cdma_desc,
                                                  GFP_KERNEL);
        if (!cdns_ctrl->dma_cdma_desc)
                return -ENOMEM;

        cdns_ctrl->buf_size = SZ_16K;
        cdns_ctrl->buf = kmalloc(cdns_ctrl->buf_size, GFP_KERNEL);
        if (!cdns_ctrl->buf) {
                ret = -ENOMEM;
                goto free_buf_desc;
        }

        if (devm_request_irq(cdns_ctrl->dev, cdns_ctrl->irq, cadence_nand_isr,
                             IRQF_SHARED, "cadence-nand-controller",
                             cdns_ctrl)) {
                dev_err(cdns_ctrl->dev, "Unable to allocate IRQ\n");
                ret = -ENODEV;
                goto free_buf;
        }

        spin_lock_init(&cdns_ctrl->irq_lock);
        init_completion(&cdns_ctrl->complete);

        ret = cadence_nand_hw_init(cdns_ctrl);
        if (ret)
                goto disable_irq;

        dma_cap_zero(mask);
        dma_cap_set(DMA_MEMCPY, mask);

        if (cdns_ctrl->caps1->has_dma) {
                cdns_ctrl->dmac = dma_request_channel(mask, NULL, NULL);
                if (!cdns_ctrl->dmac) {
                        dev_err(cdns_ctrl->dev,
                                "Unable to get a DMA channel\n");
                        ret = -EBUSY;
                        goto disable_irq;
                }
        }

        nand_controller_init(&cdns_ctrl->controller);
        INIT_LIST_HEAD(&cdns_ctrl->chips);

        cdns_ctrl->controller.ops = &cadence_nand_controller_ops;
        cdns_ctrl->curr_corr_str_idx = 0xFF;

        ret = cadence_nand_chips_init(cdns_ctrl);
        if (ret) {
                dev_err(cdns_ctrl->dev, "Failed to register MTD: %d\n",
                        ret);
                goto dma_release_chnl;
        }

        kfree(cdns_ctrl->buf);
        cdns_ctrl->buf = kzalloc(cdns_ctrl->buf_size, GFP_KERNEL);
        if (!cdns_ctrl->buf) {
                ret = -ENOMEM;
                goto dma_release_chnl;
        }

        return 0;

dma_release_chnl:
        if (cdns_ctrl->dmac)
                dma_release_channel(cdns_ctrl->dmac);

disable_irq:
        cadence_nand_irq_cleanup(cdns_ctrl->irq, cdns_ctrl);

free_buf:
        kfree(cdns_ctrl->buf);

free_buf_desc:
        dma_free_coherent(cdns_ctrl->dev, sizeof(struct cadence_nand_cdma_desc),
                          cdns_ctrl->cdma_desc, cdns_ctrl->dma_cdma_desc);

        return ret;
}

/* Driver exit point. */
static void cadence_nand_remove(struct cdns_nand_ctrl *cdns_ctrl)
{
        cadence_nand_chips_cleanup(cdns_ctrl);
        cadence_nand_irq_cleanup(cdns_ctrl->irq, cdns_ctrl);
        kfree(cdns_ctrl->buf);
        dma_free_coherent(cdns_ctrl->dev, sizeof(struct cadence_nand_cdma_desc),
                          cdns_ctrl->cdma_desc, cdns_ctrl->dma_cdma_desc);

        if (cdns_ctrl->dmac)
                dma_release_channel(cdns_ctrl->dmac);
}

struct cadence_nand_dt {
        struct cdns_nand_ctrl cdns_ctrl;
        struct clk *clk;
};

static const struct cadence_nand_dt_devdata cadence_nand_default = {
        .if_skew = 0,
        .has_dma = 1,
};

static const struct of_device_id cadence_nand_dt_ids[] = {
        {
                .compatible = "cdns,hp-nfc",
                .data = &cadence_nand_default
        }, {}
};

MODULE_DEVICE_TABLE(of, cadence_nand_dt_ids);

static int cadence_nand_dt_probe(struct platform_device *ofdev)
{
        struct resource *res;
        struct cadence_nand_dt *dt;
        struct cdns_nand_ctrl *cdns_ctrl;
        int ret;
        const struct of_device_id *of_id;
        const struct cadence_nand_dt_devdata *devdata;
        u32 val;

        of_id = of_match_device(cadence_nand_dt_ids, &ofdev->dev);
        if (of_id) {
                ofdev->id_entry = of_id->data;
                devdata = of_id->data;
        } else {
                pr_err("Failed to find the right device id.\n");
                return -ENOMEM;
        }

        dt = devm_kzalloc(&ofdev->dev, sizeof(*dt), GFP_KERNEL);
        if (!dt)
                return -ENOMEM;

        cdns_ctrl = &dt->cdns_ctrl;
        cdns_ctrl->caps1 = devdata;

        cdns_ctrl->dev = &ofdev->dev;
        cdns_ctrl->irq = platform_get_irq(ofdev, 0);
        if (cdns_ctrl->irq < 0)
                return cdns_ctrl->irq;

        dev_info(cdns_ctrl->dev, "IRQ: nr %d\n", cdns_ctrl->irq);

        cdns_ctrl->reg = devm_platform_ioremap_resource(ofdev, 0);
        if (IS_ERR(cdns_ctrl->reg))
                return PTR_ERR(cdns_ctrl->reg);

        res = platform_get_resource(ofdev, IORESOURCE_MEM, 1);
        cdns_ctrl->io.dma = res->start;
        cdns_ctrl->io.virt = devm_ioremap_resource(&ofdev->dev, res);
        if (IS_ERR(cdns_ctrl->io.virt))
                return PTR_ERR(cdns_ctrl->io.virt);

        dt->clk = devm_clk_get(cdns_ctrl->dev, "nf_clk");
        if (IS_ERR(dt->clk))
                return PTR_ERR(dt->clk);

        cdns_ctrl->nf_clk_rate = clk_get_rate(dt->clk);

        ret = of_property_read_u32(ofdev->dev.of_node,
                                   "cdns,board-delay-ps", &val);
        if (ret) {
                val = 4830;
                dev_info(cdns_ctrl->dev,
                         "missing cdns,board-delay-ps property, %d was set\n",
                         val);
        }
        cdns_ctrl->board_delay = val;

        ret = cadence_nand_init(cdns_ctrl);
        if (ret)
                return ret;

        platform_set_drvdata(ofdev, dt);
        return 0;
}

static int cadence_nand_dt_remove(struct platform_device *ofdev)
{
        struct cadence_nand_dt *dt = platform_get_drvdata(ofdev);

        cadence_nand_remove(&dt->cdns_ctrl);

        return 0;
}

static struct platform_driver cadence_nand_dt_driver = {
        .probe          = cadence_nand_dt_probe,
        .remove         = cadence_nand_dt_remove,
        .driver         = {
                .name   = "cadence-nand-controller",
                .of_match_table = cadence_nand_dt_ids,
        },
};

module_platform_driver(cadence_nand_dt_driver);

MODULE_AUTHOR("Piotr Sroka <piotrs@cadence.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Driver for Cadence NAND flash controller");