/*
 * Copyright © 2010-2015 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/dma-mapping.h>
#include <linux/ioport.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/log2.h>

#include "brcmnand.h"

/*
 * This flag controls if WP stays on between erase/write commands to mitigate
 * flash corruption due to power glitches. Values:
 * 0: NAND_WP is not used or not available
 * 1: NAND_WP is set by default, cleared for erase/write operations
 * 2: NAND_WP is always cleared
 */
static int wp_on = 1;
module_param(wp_on, int, 0444);

/***********************************************************************
 * Definitions
 ***********************************************************************/

#define DRV_NAME                        "brcmnand"

#define CMD_NULL                        0x00
#define CMD_PAGE_READ                   0x01
#define CMD_SPARE_AREA_READ             0x02
#define CMD_STATUS_READ                 0x03
#define CMD_PROGRAM_PAGE                0x04
#define CMD_PROGRAM_SPARE_AREA          0x05
#define CMD_COPY_BACK                   0x06
#define CMD_DEVICE_ID_READ              0x07
#define CMD_BLOCK_ERASE                 0x08
#define CMD_FLASH_RESET                 0x09
#define CMD_BLOCKS_LOCK                 0x0a
#define CMD_BLOCKS_LOCK_DOWN            0x0b
#define CMD_BLOCKS_UNLOCK               0x0c
#define CMD_READ_BLOCKS_LOCK_STATUS     0x0d
#define CMD_PARAMETER_READ              0x0e
#define CMD_PARAMETER_CHANGE_COL        0x0f
#define CMD_LOW_LEVEL_OP                0x10

struct brcm_nand_dma_desc {
        u32 next_desc;
        u32 next_desc_ext;
        u32 cmd_irq;
        u32 dram_addr;
        u32 dram_addr_ext;
        u32 tfr_len;
        u32 total_len;
        u32 flash_addr;
        u32 flash_addr_ext;
        u32 cs;
        u32 pad2[5];
        u32 status_valid;
} __packed;

/* Bitfields for brcm_nand_dma_desc::status_valid */
#define FLASH_DMA_ECC_ERROR     (1 << 8)
#define FLASH_DMA_CORR_ERROR    (1 << 9)

/* 512B flash cache in the NAND controller HW */
#define FC_SHIFT                9U
#define FC_BYTES                512U
#define FC_WORDS                (FC_BYTES >> 2)

#define BRCMNAND_MIN_PAGESIZE   512
#define BRCMNAND_MIN_BLOCKSIZE  (8 * 1024)
#define BRCMNAND_MIN_DEVSIZE    (4ULL * 1024 * 1024)

#define NAND_CTRL_RDY                   (INTFC_CTLR_READY | INTFC_FLASH_READY)
#define NAND_POLL_STATUS_TIMEOUT_MS     100

/* Controller feature flags */
enum {
        BRCMNAND_HAS_1K_SECTORS                 = BIT(0),
        BRCMNAND_HAS_PREFETCH                   = BIT(1),
        BRCMNAND_HAS_CACHE_MODE                 = BIT(2),
        BRCMNAND_HAS_WP                         = BIT(3),
};

struct brcmnand_controller {
        struct device           *dev;
        struct nand_hw_control  controller;
        void __iomem            *nand_base;
        void __iomem            *nand_fc; /* flash cache */
        void __iomem            *flash_dma_base;
        unsigned int            irq;
        unsigned int            dma_irq;
        int                     nand_version;

        /* Some SoCs provide custom interrupt status register(s) */
        struct brcmnand_soc     *soc;

        /* Some SoCs have a gateable clock for the controller */
        struct clk              *clk;

        int                     cmd_pending;
        bool                    dma_pending;
        struct completion       done;
        struct completion       dma_done;

        /* List of NAND hosts (one for each chip-select) */
        struct list_head host_list;

        struct brcm_nand_dma_desc *dma_desc;
        dma_addr_t              dma_pa;

        /* in-memory cache of the FLASH_CACHE, used only for some commands */
        u8                      flash_cache[FC_BYTES];

        /* Controller revision details */
        const u16               *reg_offsets;
        unsigned int            reg_spacing; /* between CS1, CS2, ... regs */
        const u8                *cs_offsets; /* within each chip-select */
        const u8                *cs0_offsets; /* within CS0, if different */
        unsigned int            max_block_size;
        const unsigned int      *block_sizes;
        unsigned int            max_page_size;
        const unsigned int      *page_sizes;
        unsigned int            max_oob;
        u32                     features;

        /* for low-power standby/resume only */
        u32                     nand_cs_nand_select;
        u32                     nand_cs_nand_xor;
        u32                     corr_stat_threshold;
        u32                     flash_dma_mode;
};

struct brcmnand_cfg {
        u64                     device_size;
        unsigned int            block_size;
        unsigned int            page_size;
        unsigned int            spare_area_size;
        unsigned int            device_width;
        unsigned int            col_adr_bytes;
        unsigned int            blk_adr_bytes;
        unsigned int            ful_adr_bytes;
        unsigned int            sector_size_1k;
        unsigned int            ecc_level;
        /* use for low-power standby/resume only */
        u32                     acc_control;
        u32                     config;
        u32                     config_ext;
        u32                     timing_1;
        u32                     timing_2;
};

struct brcmnand_host {
        struct list_head        node;

        struct nand_chip        chip;
        struct platform_device  *pdev;
        int                     cs;

        unsigned int            last_cmd;
        unsigned int            last_byte;
        u64                     last_addr;
        struct brcmnand_cfg     hwcfg;
        struct brcmnand_controller *ctrl;
};

enum brcmnand_reg {
        BRCMNAND_CMD_START = 0,
        BRCMNAND_CMD_EXT_ADDRESS,
        BRCMNAND_CMD_ADDRESS,
        BRCMNAND_INTFC_STATUS,
        BRCMNAND_CS_SELECT,
        BRCMNAND_CS_XOR,
        BRCMNAND_LL_OP,
        BRCMNAND_CS0_BASE,
        BRCMNAND_CS1_BASE,              /* CS1 regs, if non-contiguous */
        BRCMNAND_CORR_THRESHOLD,
        BRCMNAND_CORR_THRESHOLD_EXT,
        BRCMNAND_UNCORR_COUNT,
        BRCMNAND_CORR_COUNT,
        BRCMNAND_CORR_EXT_ADDR,
        BRCMNAND_CORR_ADDR,
        BRCMNAND_UNCORR_EXT_ADDR,
        BRCMNAND_UNCORR_ADDR,
        BRCMNAND_SEMAPHORE,
        BRCMNAND_ID,
        BRCMNAND_ID_EXT,
        BRCMNAND_LL_RDATA,
        BRCMNAND_OOB_READ_BASE,
        BRCMNAND_OOB_READ_10_BASE,      /* offset 0x10, if non-contiguous */
        BRCMNAND_OOB_WRITE_BASE,
        BRCMNAND_OOB_WRITE_10_BASE,     /* offset 0x10, if non-contiguous */
        BRCMNAND_FC_BASE,
};

/* BRCMNAND v4.0 */
static const u16 brcmnand_regs_v40[] = {
        [BRCMNAND_CMD_START]            =  0x04,
        [BRCMNAND_CMD_EXT_ADDRESS]      =  0x08,
        [BRCMNAND_CMD_ADDRESS]          =  0x0c,
        [BRCMNAND_INTFC_STATUS]         =  0x6c,
        [BRCMNAND_CS_SELECT]            =  0x14,
        [BRCMNAND_CS_XOR]               =  0x18,
        [BRCMNAND_LL_OP]                = 0x178,
        [BRCMNAND_CS0_BASE]             =  0x40,
        [BRCMNAND_CS1_BASE]             =  0xd0,
        [BRCMNAND_CORR_THRESHOLD]       =  0x84,
        [BRCMNAND_CORR_THRESHOLD_EXT]   =     0,
        [BRCMNAND_UNCORR_COUNT]         =     0,
        [BRCMNAND_CORR_COUNT]           =     0,
        [BRCMNAND_CORR_EXT_ADDR]        =  0x70,
        [BRCMNAND_CORR_ADDR]            =  0x74,
        [BRCMNAND_UNCORR_EXT_ADDR]      =  0x78,
        [BRCMNAND_UNCORR_ADDR]          =  0x7c,
        [BRCMNAND_SEMAPHORE]            =  0x58,
        [BRCMNAND_ID]                   =  0x60,
        [BRCMNAND_ID_EXT]               =  0x64,
        [BRCMNAND_LL_RDATA]             = 0x17c,
        [BRCMNAND_OOB_READ_BASE]        =  0x20,
        [BRCMNAND_OOB_READ_10_BASE]     = 0x130,
        [BRCMNAND_OOB_WRITE_BASE]       =  0x30,
        [BRCMNAND_OOB_WRITE_10_BASE]    =     0,
        [BRCMNAND_FC_BASE]              = 0x200,
};

/* BRCMNAND v5.0 */
static const u16 brcmnand_regs_v50[] = {
        [BRCMNAND_CMD_START]            =  0x04,
        [BRCMNAND_CMD_EXT_ADDRESS]      =  0x08,
        [BRCMNAND_CMD_ADDRESS]          =  0x0c,
        [BRCMNAND_INTFC_STATUS]         =  0x6c,
        [BRCMNAND_CS_SELECT]            =  0x14,
        [BRCMNAND_CS_XOR]               =  0x18,
        [BRCMNAND_LL_OP]                = 0x178,
        [BRCMNAND_CS0_BASE]             =  0x40,
        [BRCMNAND_CS1_BASE]             =  0xd0,
        [BRCMNAND_CORR_THRESHOLD]       =  0x84,
        [BRCMNAND_CORR_THRESHOLD_EXT]   =     0,
        [BRCMNAND_UNCORR_COUNT]         =     0,
        [BRCMNAND_CORR_COUNT]           =     0,
        [BRCMNAND_CORR_EXT_ADDR]        =  0x70,
        [BRCMNAND_CORR_ADDR]            =  0x74,
        [BRCMNAND_UNCORR_EXT_ADDR]      =  0x78,
        [BRCMNAND_UNCORR_ADDR]          =  0x7c,
        [BRCMNAND_SEMAPHORE]            =  0x58,
        [BRCMNAND_ID]                   =  0x60,
        [BRCMNAND_ID_EXT]               =  0x64,
        [BRCMNAND_LL_RDATA]             = 0x17c,
        [BRCMNAND_OOB_READ_BASE]        =  0x20,
        [BRCMNAND_OOB_READ_10_BASE]     = 0x130,
        [BRCMNAND_OOB_WRITE_BASE]       =  0x30,
        [BRCMNAND_OOB_WRITE_10_BASE]    = 0x140,
        [BRCMNAND_FC_BASE]              = 0x200,
};

/* BRCMNAND v6.0 - v7.1 */
static const u16 brcmnand_regs_v60[] = {
        [BRCMNAND_CMD_START]            =  0x04,
        [BRCMNAND_CMD_EXT_ADDRESS]      =  0x08,
        [BRCMNAND_CMD_ADDRESS]          =  0x0c,
        [BRCMNAND_INTFC_STATUS]         =  0x14,
        [BRCMNAND_CS_SELECT]            =  0x18,
        [BRCMNAND_CS_XOR]               =  0x1c,
        [BRCMNAND_LL_OP]                =  0x20,
        [BRCMNAND_CS0_BASE]             =  0x50,
        [BRCMNAND_CS1_BASE]             =     0,
        [BRCMNAND_CORR_THRESHOLD]       =  0xc0,
        [BRCMNAND_CORR_THRESHOLD_EXT]   =  0xc4,
        [BRCMNAND_UNCORR_COUNT]         =  0xfc,
        [BRCMNAND_CORR_COUNT]           = 0x100,
        [BRCMNAND_CORR_EXT_ADDR]        = 0x10c,
        [BRCMNAND_CORR_ADDR]            = 0x110,
        [BRCMNAND_UNCORR_EXT_ADDR]      = 0x114,
        [BRCMNAND_UNCORR_ADDR]          = 0x118,
        [BRCMNAND_SEMAPHORE]            = 0x150,
        [BRCMNAND_ID]                   = 0x194,
        [BRCMNAND_ID_EXT]               = 0x198,
        [BRCMNAND_LL_RDATA]             = 0x19c,
        [BRCMNAND_OOB_READ_BASE]        = 0x200,
        [BRCMNAND_OOB_READ_10_BASE]     =     0,
        [BRCMNAND_OOB_WRITE_BASE]       = 0x280,
        [BRCMNAND_OOB_WRITE_10_BASE]    =     0,
        [BRCMNAND_FC_BASE]              = 0x400,
};

/* BRCMNAND v7.1 */
static const u16 brcmnand_regs_v71[] = {
        [BRCMNAND_CMD_START]            =  0x04,
        [BRCMNAND_CMD_EXT_ADDRESS]      =  0x08,
        [BRCMNAND_CMD_ADDRESS]          =  0x0c,
        [BRCMNAND_INTFC_STATUS]         =  0x14,
        [BRCMNAND_CS_SELECT]            =  0x18,
        [BRCMNAND_CS_XOR]               =  0x1c,
        [BRCMNAND_LL_OP]                =  0x20,
        [BRCMNAND_CS0_BASE]             =  0x50,
        [BRCMNAND_CS1_BASE]             =     0,
        [BRCMNAND_CORR_THRESHOLD]       =  0xdc,
        [BRCMNAND_CORR_THRESHOLD_EXT]   =  0xe0,
        [BRCMNAND_UNCORR_COUNT]         =  0xfc,
        [BRCMNAND_CORR_COUNT]           = 0x100,
        [BRCMNAND_CORR_EXT_ADDR]        = 0x10c,
        [BRCMNAND_CORR_ADDR]            = 0x110,
        [BRCMNAND_UNCORR_EXT_ADDR]      = 0x114,
        [BRCMNAND_UNCORR_ADDR]          = 0x118,
        [BRCMNAND_SEMAPHORE]            = 0x150,
        [BRCMNAND_ID]                   = 0x194,
        [BRCMNAND_ID_EXT]               = 0x198,
        [BRCMNAND_LL_RDATA]             = 0x19c,
        [BRCMNAND_OOB_READ_BASE]        = 0x200,
        [BRCMNAND_OOB_READ_10_BASE]     =     0,
        [BRCMNAND_OOB_WRITE_BASE]       = 0x280,
        [BRCMNAND_OOB_WRITE_10_BASE]    =     0,
        [BRCMNAND_FC_BASE]              = 0x400,
};

/* BRCMNAND v7.2 */
static const u16 brcmnand_regs_v72[] = {
        [BRCMNAND_CMD_START]            =  0x04,
        [BRCMNAND_CMD_EXT_ADDRESS]      =  0x08,
        [BRCMNAND_CMD_ADDRESS]          =  0x0c,
        [BRCMNAND_INTFC_STATUS]         =  0x14,
        [BRCMNAND_CS_SELECT]            =  0x18,
        [BRCMNAND_CS_XOR]               =  0x1c,
        [BRCMNAND_LL_OP]                =  0x20,
        [BRCMNAND_CS0_BASE]             =  0x50,
        [BRCMNAND_CS1_BASE]             =     0,
        [BRCMNAND_CORR_THRESHOLD]       =  0xdc,
        [BRCMNAND_CORR_THRESHOLD_EXT]   =  0xe0,
        [BRCMNAND_UNCORR_COUNT]         =  0xfc,
        [BRCMNAND_CORR_COUNT]           = 0x100,
        [BRCMNAND_CORR_EXT_ADDR]        = 0x10c,
        [BRCMNAND_CORR_ADDR]            = 0x110,
        [BRCMNAND_UNCORR_EXT_ADDR]      = 0x114,
        [BRCMNAND_UNCORR_ADDR]          = 0x118,
        [BRCMNAND_SEMAPHORE]            = 0x150,
        [BRCMNAND_ID]                   = 0x194,
        [BRCMNAND_ID_EXT]               = 0x198,
        [BRCMNAND_LL_RDATA]             = 0x19c,
        [BRCMNAND_OOB_READ_BASE]        = 0x200,
        [BRCMNAND_OOB_READ_10_BASE]     =     0,
        [BRCMNAND_OOB_WRITE_BASE]       = 0x400,
        [BRCMNAND_OOB_WRITE_10_BASE]    =     0,
        [BRCMNAND_FC_BASE]              = 0x600,
};

enum brcmnand_cs_reg {
        BRCMNAND_CS_CFG_EXT = 0,
        BRCMNAND_CS_CFG,
        BRCMNAND_CS_ACC_CONTROL,
        BRCMNAND_CS_TIMING1,
        BRCMNAND_CS_TIMING2,
};

/* Per chip-select offsets for v7.1 */
static const u8 brcmnand_cs_offsets_v71[] = {
        [BRCMNAND_CS_ACC_CONTROL]       = 0x00,
        [BRCMNAND_CS_CFG_EXT]           = 0x04,
        [BRCMNAND_CS_CFG]               = 0x08,
        [BRCMNAND_CS_TIMING1]           = 0x0c,
        [BRCMNAND_CS_TIMING2]           = 0x10,
};

/* Per chip-select offsets for pre v7.1, except CS0 on <= v5.0 */
static const u8 brcmnand_cs_offsets[] = {
        [BRCMNAND_CS_ACC_CONTROL]       = 0x00,
        [BRCMNAND_CS_CFG_EXT]           = 0x04,
        [BRCMNAND_CS_CFG]               = 0x04,
        [BRCMNAND_CS_TIMING1]           = 0x08,
        [BRCMNAND_CS_TIMING2]           = 0x0c,
};

/* Per chip-select offset for <= v5.0 on CS0 only */
static const u8 brcmnand_cs_offsets_cs0[] = {
        [BRCMNAND_CS_ACC_CONTROL]       = 0x00,
        [BRCMNAND_CS_CFG_EXT]           = 0x08,
        [BRCMNAND_CS_CFG]               = 0x08,
        [BRCMNAND_CS_TIMING1]           = 0x10,
        [BRCMNAND_CS_TIMING2]           = 0x14,
};

/*
 * Bitfields for the CFG and CFG_EXT registers. Pre-v7.1 controllers only had
 * one config register, but once the bitfields overflowed, newer controllers
 * (v7.1 and newer) added a CFG_EXT register and shuffled a few fields around.
 */
enum {
        CFG_BLK_ADR_BYTES_SHIFT         = 8,
        CFG_COL_ADR_BYTES_SHIFT         = 12,
        CFG_FUL_ADR_BYTES_SHIFT         = 16,
        CFG_BUS_WIDTH_SHIFT             = 23,
        CFG_BUS_WIDTH                   = BIT(CFG_BUS_WIDTH_SHIFT),
        CFG_DEVICE_SIZE_SHIFT           = 24,

        /* Only for pre-v7.1 (with no CFG_EXT register) */
        CFG_PAGE_SIZE_SHIFT             = 20,
        CFG_BLK_SIZE_SHIFT              = 28,

        /* Only for v7.1+ (with CFG_EXT register) */
        CFG_EXT_PAGE_SIZE_SHIFT         = 0,
        CFG_EXT_BLK_SIZE_SHIFT          = 4,
};

/* BRCMNAND_INTFC_STATUS */
enum {
        INTFC_FLASH_STATUS              = GENMASK(7, 0),

        INTFC_ERASED                    = BIT(27),
        INTFC_OOB_VALID                 = BIT(28),
        INTFC_CACHE_VALID               = BIT(29),
        INTFC_FLASH_READY               = BIT(30),
        INTFC_CTLR_READY                = BIT(31),
};

static inline u32 nand_readreg(struct brcmnand_controller *ctrl, u32 offs)
{
        return brcmnand_readl(ctrl->nand_base + offs);
}

static inline void nand_writereg(struct brcmnand_controller *ctrl, u32 offs,
                                 u32 val)
{
        brcmnand_writel(val, ctrl->nand_base + offs);
}

static int brcmnand_revision_init(struct brcmnand_controller *ctrl)
{
        static const unsigned int block_sizes_v6[] = { 8, 16, 128, 256, 512, 1024, 2048, 0 };
        static const unsigned int block_sizes_v4[] = { 16, 128, 8, 512, 256, 1024, 2048, 0 };
        static const unsigned int page_sizes[] = { 512, 2048, 4096, 8192, 0 };

        ctrl->nand_version = nand_readreg(ctrl, 0) & 0xffff;

        /* Only support v4.0+? */
        if (ctrl->nand_version < 0x0400) {
                dev_err(ctrl->dev, "version %#x not supported\n",
                        ctrl->nand_version);
                return -ENODEV;
        }

        /* Register offsets */
        if (ctrl->nand_version >= 0x0702)
                ctrl->reg_offsets = brcmnand_regs_v72;
        else if (ctrl->nand_version >= 0x0701)
                ctrl->reg_offsets = brcmnand_regs_v71;
        else if (ctrl->nand_version >= 0x0600)
                ctrl->reg_offsets = brcmnand_regs_v60;
        else if (ctrl->nand_version >= 0x0500)
                ctrl->reg_offsets = brcmnand_regs_v50;
        else if (ctrl->nand_version >= 0x0400)
                ctrl->reg_offsets = brcmnand_regs_v40;

        /* Chip-select stride */
        if (ctrl->nand_version >= 0x0701)
                ctrl->reg_spacing = 0x14;
        else
                ctrl->reg_spacing = 0x10;

        /* Per chip-select registers */
        if (ctrl->nand_version >= 0x0701) {
                ctrl->cs_offsets = brcmnand_cs_offsets_v71;
        } else {
                ctrl->cs_offsets = brcmnand_cs_offsets;

                /* v5.0 and earlier has a different CS0 offset layout */
                if (ctrl->nand_version <= 0x0500)
                        ctrl->cs0_offsets = brcmnand_cs_offsets_cs0;
        }

        /* Page / block sizes */
        if (ctrl->nand_version >= 0x0701) {
                /* >= v7.1 use nice power-of-2 values! */
                ctrl->max_page_size = 16 * 1024;
                ctrl->max_block_size = 2 * 1024 * 1024;
        } else {
                ctrl->page_sizes = page_sizes;
                if (ctrl->nand_version >= 0x0600)
                        ctrl->block_sizes = block_sizes_v6;
                else
                        ctrl->block_sizes = block_sizes_v4;

                if (ctrl->nand_version < 0x0400) {
                        ctrl->max_page_size = 4096;
                        ctrl->max_block_size = 512 * 1024;
                }
        }

        /* Maximum spare area sector size (per 512B) */
        if (ctrl->nand_version >= 0x0702)
                ctrl->max_oob = 128;
        else if (ctrl->nand_version >= 0x0600)
                ctrl->max_oob = 64;
        else if (ctrl->nand_version >= 0x0500)
                ctrl->max_oob = 32;
        else
                ctrl->max_oob = 16;

        /* v6.0 and newer (except v6.1) have prefetch support */
        if (ctrl->nand_version >= 0x0600 && ctrl->nand_version != 0x0601)
                ctrl->features |= BRCMNAND_HAS_PREFETCH;

        /*
         * v6.x has cache mode, but it's implemented differently. Ignore it for
         * now.
         */
        if (ctrl->nand_version >= 0x0700)
                ctrl->features |= BRCMNAND_HAS_CACHE_MODE;

        if (ctrl->nand_version >= 0x0500)
                ctrl->features |= BRCMNAND_HAS_1K_SECTORS;

        if (ctrl->nand_version >= 0x0700)
                ctrl->features |= BRCMNAND_HAS_WP;
        else if (of_property_read_bool(ctrl->dev->of_node, "brcm,nand-has-wp"))
                ctrl->features |= BRCMNAND_HAS_WP;

        return 0;
}

static inline u32 brcmnand_read_reg(struct brcmnand_controller *ctrl,
                enum brcmnand_reg reg)
{
        u16 offs = ctrl->reg_offsets[reg];

        if (offs)
                return nand_readreg(ctrl, offs);
        else
                return 0;
}

static inline void brcmnand_write_reg(struct brcmnand_controller *ctrl,
                                      enum brcmnand_reg reg, u32 val)
{
        u16 offs = ctrl->reg_offsets[reg];

        if (offs)
                nand_writereg(ctrl, offs, val);
}

static inline void brcmnand_rmw_reg(struct brcmnand_controller *ctrl,
                                    enum brcmnand_reg reg, u32 mask, unsigned
                                    int shift, u32 val)
{
        u32 tmp = brcmnand_read_reg(ctrl, reg);

        tmp &= ~mask;
        tmp |= val << shift;
        brcmnand_write_reg(ctrl, reg, tmp);
}

static inline u32 brcmnand_read_fc(struct brcmnand_controller *ctrl, int word)
{
        return __raw_readl(ctrl->nand_fc + word * 4);
}

static inline void brcmnand_write_fc(struct brcmnand_controller *ctrl,
                                     int word, u32 val)
{
        __raw_writel(val, ctrl->nand_fc + word * 4);
}

static inline u16 brcmnand_cs_offset(struct brcmnand_controller *ctrl, int cs,
                                     enum brcmnand_cs_reg reg)
{
        u16 offs_cs0 = ctrl->reg_offsets[BRCMNAND_CS0_BASE];
        u16 offs_cs1 = ctrl->reg_offsets[BRCMNAND_CS1_BASE];
        u8 cs_offs;

        if (cs == 0 && ctrl->cs0_offsets)
                cs_offs = ctrl->cs0_offsets[reg];
        else
                cs_offs = ctrl->cs_offsets[reg];

        if (cs && offs_cs1)
                return offs_cs1 + (cs - 1) * ctrl->reg_spacing + cs_offs;

        return offs_cs0 + cs * ctrl->reg_spacing + cs_offs;
}

static inline u32 brcmnand_count_corrected(struct brcmnand_controller *ctrl)
{
        if (ctrl->nand_version < 0x0600)
                return 1;
        return brcmnand_read_reg(ctrl, BRCMNAND_CORR_COUNT);
}

static void brcmnand_wr_corr_thresh(struct brcmnand_host *host, u8 val)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        unsigned int shift = 0, bits;
        enum brcmnand_reg reg = BRCMNAND_CORR_THRESHOLD;
        int cs = host->cs;

        if (ctrl->nand_version >= 0x0702)
                bits = 7;
        else if (ctrl->nand_version >= 0x0600)
                bits = 6;
        else if (ctrl->nand_version >= 0x0500)
                bits = 5;
        else
                bits = 4;

        if (ctrl->nand_version >= 0x0702) {
                if (cs >= 4)
                        reg = BRCMNAND_CORR_THRESHOLD_EXT;
                shift = (cs % 4) * bits;
        } else if (ctrl->nand_version >= 0x0600) {
                if (cs >= 5)
                        reg = BRCMNAND_CORR_THRESHOLD_EXT;
                shift = (cs % 5) * bits;
        }
        brcmnand_rmw_reg(ctrl, reg, (bits - 1) << shift, shift, val);
}

static inline int brcmnand_cmd_shift(struct brcmnand_controller *ctrl)
{
        if (ctrl->nand_version < 0x0602)
                return 24;
        return 0;
}

/***********************************************************************
 * NAND ACC CONTROL bitfield
 *
 * Some bits have remained constant throughout hardware revision, while
 * others have shifted around.
 ***********************************************************************/

/* Constant for all versions (where supported) */
enum {
        /* See BRCMNAND_HAS_CACHE_MODE */
        ACC_CONTROL_CACHE_MODE                          = BIT(22),

        /* See BRCMNAND_HAS_PREFETCH */
        ACC_CONTROL_PREFETCH                            = BIT(23),

        ACC_CONTROL_PAGE_HIT                            = BIT(24),
        ACC_CONTROL_WR_PREEMPT                          = BIT(25),
        ACC_CONTROL_PARTIAL_PAGE                        = BIT(26),
        ACC_CONTROL_RD_ERASED                           = BIT(27),
        ACC_CONTROL_FAST_PGM_RDIN                       = BIT(28),
        ACC_CONTROL_WR_ECC                              = BIT(30),
        ACC_CONTROL_RD_ECC                              = BIT(31),
};

static inline u32 brcmnand_spare_area_mask(struct brcmnand_controller *ctrl)
{
        if (ctrl->nand_version >= 0x0702)
                return GENMASK(7, 0);
        else if (ctrl->nand_version >= 0x0600)
                return GENMASK(6, 0);
        else
                return GENMASK(5, 0);
}

#define NAND_ACC_CONTROL_ECC_SHIFT      16
#define NAND_ACC_CONTROL_ECC_EXT_SHIFT  13

static inline u32 brcmnand_ecc_level_mask(struct brcmnand_controller *ctrl)
{
        u32 mask = (ctrl->nand_version >= 0x0600) ? 0x1f : 0x0f;

        mask <<= NAND_ACC_CONTROL_ECC_SHIFT;

        /* v7.2 includes additional ECC levels */
        if (ctrl->nand_version >= 0x0702)
                mask |= 0x7 << NAND_ACC_CONTROL_ECC_EXT_SHIFT;

        return mask;
}

static void brcmnand_set_ecc_enabled(struct brcmnand_host *host, int en)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        u16 offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_ACC_CONTROL);
        u32 acc_control = nand_readreg(ctrl, offs);
        u32 ecc_flags = ACC_CONTROL_WR_ECC | ACC_CONTROL_RD_ECC;

        if (en) {
                acc_control |= ecc_flags; /* enable RD/WR ECC */
                acc_control |= host->hwcfg.ecc_level
                               << NAND_ACC_CONTROL_ECC_SHIFT;
        } else {
                acc_control &= ~ecc_flags; /* disable RD/WR ECC */
                acc_control &= ~brcmnand_ecc_level_mask(ctrl);
        }

        nand_writereg(ctrl, offs, acc_control);
}

static inline int brcmnand_sector_1k_shift(struct brcmnand_controller *ctrl)
{
        if (ctrl->nand_version >= 0x0702)
                return 9;
        else if (ctrl->nand_version >= 0x0600)
                return 7;
        else if (ctrl->nand_version >= 0x0500)
                return 6;
        else
                return -1;
}

static int brcmnand_get_sector_size_1k(struct brcmnand_host *host)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        int shift = brcmnand_sector_1k_shift(ctrl);
        u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
                                                  BRCMNAND_CS_ACC_CONTROL);

        if (shift < 0)
                return 0;

        return (nand_readreg(ctrl, acc_control_offs) >> shift) & 0x1;
}

static void brcmnand_set_sector_size_1k(struct brcmnand_host *host, int val)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        int shift = brcmnand_sector_1k_shift(ctrl);
        u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
                                                  BRCMNAND_CS_ACC_CONTROL);
        u32 tmp;

        if (shift < 0)
                return;

        tmp = nand_readreg(ctrl, acc_control_offs);
        tmp &= ~(1 << shift);
        tmp |= (!!val) << shift;
        nand_writereg(ctrl, acc_control_offs, tmp);
}

/***********************************************************************
 * CS_NAND_SELECT
 ***********************************************************************/

enum {
        CS_SELECT_NAND_WP                       = BIT(29),
        CS_SELECT_AUTO_DEVICE_ID_CFG            = BIT(30),
};

static int bcmnand_ctrl_poll_status(struct brcmnand_controller *ctrl,
                                    u32 mask, u32 expected_val,
                                    unsigned long timeout_ms)
{
        unsigned long limit;
        u32 val;

        if (!timeout_ms)
                timeout_ms = NAND_POLL_STATUS_TIMEOUT_MS;

        limit = jiffies + msecs_to_jiffies(timeout_ms);
        do {
                val = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
                if ((val & mask) == expected_val)
                        return 0;

                cpu_relax();
        } while (time_after(limit, jiffies));

        dev_warn(ctrl->dev, "timeout on status poll (expected %x got %x)\n",
                 expected_val, val & mask);

        return -ETIMEDOUT;
}

static inline void brcmnand_set_wp(struct brcmnand_controller *ctrl, bool en)
{
        u32 val = en ? CS_SELECT_NAND_WP : 0;

        brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
}

/***********************************************************************
 * Flash DMA
 ***********************************************************************/

enum flash_dma_reg {
        FLASH_DMA_REVISION              = 0x00,
        FLASH_DMA_FIRST_DESC            = 0x04,
        FLASH_DMA_FIRST_DESC_EXT        = 0x08,
        FLASH_DMA_CTRL                  = 0x0c,
        FLASH_DMA_MODE                  = 0x10,
        FLASH_DMA_STATUS                = 0x14,
        FLASH_DMA_INTERRUPT_DESC        = 0x18,
        FLASH_DMA_INTERRUPT_DESC_EXT    = 0x1c,
        FLASH_DMA_ERROR_STATUS          = 0x20,
        FLASH_DMA_CURRENT_DESC          = 0x24,
        FLASH_DMA_CURRENT_DESC_EXT      = 0x28,
};

static inline bool has_flash_dma(struct brcmnand_controller *ctrl)
{
        return ctrl->flash_dma_base;
}

static inline bool flash_dma_buf_ok(const void *buf)
{
        return buf && !is_vmalloc_addr(buf) &&
                likely(IS_ALIGNED((uintptr_t)buf, 4));
}

static inline void flash_dma_writel(struct brcmnand_controller *ctrl, u8 offs,
                                    u32 val)
{
        brcmnand_writel(val, ctrl->flash_dma_base + offs);
}

static inline u32 flash_dma_readl(struct brcmnand_controller *ctrl, u8 offs)
{
        return brcmnand_readl(ctrl->flash_dma_base + offs);
}

/* Low-level operation types: command, address, write, or read */
enum brcmnand_llop_type {
        LL_OP_CMD,
        LL_OP_ADDR,
        LL_OP_WR,
        LL_OP_RD,
};

/***********************************************************************
 * Internal support functions
 ***********************************************************************/

static inline bool is_hamming_ecc(struct brcmnand_controller *ctrl,
                                  struct brcmnand_cfg *cfg)
{
        if (ctrl->nand_version <= 0x0701)
                return cfg->sector_size_1k == 0 && cfg->spare_area_size == 16 &&
                        cfg->ecc_level == 15;
        else
                return cfg->sector_size_1k == 0 && ((cfg->spare_area_size == 16 &&
                        cfg->ecc_level == 15) ||
                        (cfg->spare_area_size == 28 && cfg->ecc_level == 16));
}

/*
 * Set mtd->ooblayout to the appropriate mtd_ooblayout_ops given
 * the layout/configuration.
 * Returns -ERRCODE on failure.
 */
static int brcmnand_hamming_ooblayout_ecc(struct mtd_info *mtd, int section,
                                          struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_cfg *cfg = &host->hwcfg;
        int sas = cfg->spare_area_size << cfg->sector_size_1k;
        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);

        if (section >= sectors)
                return -ERANGE;

        oobregion->offset = (section * sas) + 6;
        oobregion->length = 3;

        return 0;
}

static int brcmnand_hamming_ooblayout_free(struct mtd_info *mtd, int section,
                                           struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_cfg *cfg = &host->hwcfg;
        int sas = cfg->spare_area_size << cfg->sector_size_1k;
        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);

        if (section >= sectors * 2)
                return -ERANGE;

        oobregion->offset = (section / 2) * sas;

        if (section & 1) {
                oobregion->offset += 9;
                oobregion->length = 7;
        } else {
                oobregion->length = 6;

                /* First sector of each page may have BBI */
                if (!section) {
                        /*
                         * Small-page NAND use byte 6 for BBI while large-page
                         * NAND use byte 0.
                         */
                        if (cfg->page_size > 512)
                                oobregion->offset++;
                        oobregion->length--;
                }
        }

        return 0;
}

static const struct mtd_ooblayout_ops brcmnand_hamming_ooblayout_ops = {
        .ecc = brcmnand_hamming_ooblayout_ecc,
        .free = brcmnand_hamming_ooblayout_free,
};

static int brcmnand_bch_ooblayout_ecc(struct mtd_info *mtd, int section,
                                      struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_cfg *cfg = &host->hwcfg;
        int sas = cfg->spare_area_size << cfg->sector_size_1k;
        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);

        if (section >= sectors)
                return -ERANGE;

        oobregion->offset = (section * (sas + 1)) - chip->ecc.bytes;
        oobregion->length = chip->ecc.bytes;

        return 0;
}

static int brcmnand_bch_ooblayout_free_lp(struct mtd_info *mtd, int section,
                                          struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_cfg *cfg = &host->hwcfg;
        int sas = cfg->spare_area_size << cfg->sector_size_1k;
        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);

        if (section >= sectors)
                return -ERANGE;

        if (sas <= chip->ecc.bytes)
                return 0;

        oobregion->offset = section * sas;
        oobregion->length = sas - chip->ecc.bytes;

        if (!section) {
                oobregion->offset++;
                oobregion->length--;
        }

        return 0;
}

static int brcmnand_bch_ooblayout_free_sp(struct mtd_info *mtd, int section,
                                          struct mtd_oob_region *oobregion)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_cfg *cfg = &host->hwcfg;
        int sas = cfg->spare_area_size << cfg->sector_size_1k;

        if (section > 1 || sas - chip->ecc.bytes < 6 ||
            (section && sas - chip->ecc.bytes == 6))
                return -ERANGE;

        if (!section) {
                oobregion->offset = 0;
                oobregion->length = 5;
        } else {
                oobregion->offset = 6;
                oobregion->length = sas - chip->ecc.bytes - 6;
        }

        return 0;
}

static const struct mtd_ooblayout_ops brcmnand_bch_lp_ooblayout_ops = {
        .ecc = brcmnand_bch_ooblayout_ecc,
        .free = brcmnand_bch_ooblayout_free_lp,
};

static const struct mtd_ooblayout_ops brcmnand_bch_sp_ooblayout_ops = {
        .ecc = brcmnand_bch_ooblayout_ecc,
        .free = brcmnand_bch_ooblayout_free_sp,
};

static int brcmstb_choose_ecc_layout(struct brcmnand_host *host)
{
        struct brcmnand_cfg *p = &host->hwcfg;
        struct mtd_info *mtd = nand_to_mtd(&host->chip);
        struct nand_ecc_ctrl *ecc = &host->chip.ecc;
        unsigned int ecc_level = p->ecc_level;
        int sas = p->spare_area_size << p->sector_size_1k;
        int sectors = p->page_size / (512 << p->sector_size_1k);

        if (p->sector_size_1k)
                ecc_level <<= 1;

        if (is_hamming_ecc(host->ctrl, p)) {
                ecc->bytes = 3 * sectors;
                mtd_set_ooblayout(mtd, &brcmnand_hamming_ooblayout_ops);
                return 0;
        }

        /*
         * CONTROLLER_VERSION:
         *   < v5.0: ECC_REQ = ceil(BCH_T * 13/8)
         *  >= v5.0: ECC_REQ = ceil(BCH_T * 14/8)
         * But we will just be conservative.
         */
        ecc->bytes = DIV_ROUND_UP(ecc_level * 14, 8);
        if (p->page_size == 512)
                mtd_set_ooblayout(mtd, &brcmnand_bch_sp_ooblayout_ops);
        else
                mtd_set_ooblayout(mtd, &brcmnand_bch_lp_ooblayout_ops);

        if (ecc->bytes >= sas) {
                dev_err(&host->pdev->dev,
                        "error: ECC too large for OOB (ECC bytes %d, spare sector %d)\n",
                        ecc->bytes, sas);
                return -EINVAL;
        }

        return 0;
}

static void brcmnand_wp(struct mtd_info *mtd, int wp)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;

        if ((ctrl->features & BRCMNAND_HAS_WP) && wp_on == 1) {
                static int old_wp = -1;
                int ret;

                if (old_wp != wp) {
                        dev_dbg(ctrl->dev, "WP %s\n", wp ? "on" : "off");
                        old_wp = wp;
                }

                /*
                 * make sure ctrl/flash ready before and after
                 * changing state of #WP pin
                 */
                ret = bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY |
                                               NAND_STATUS_READY,
                                               NAND_CTRL_RDY |
                                               NAND_STATUS_READY, 0);
                if (ret)
                        return;

                brcmnand_set_wp(ctrl, wp);
                chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
                /* NAND_STATUS_WP 0x00 = protected, 0x80 = not protected */
                ret = bcmnand_ctrl_poll_status(ctrl,
                                               NAND_CTRL_RDY |
                                               NAND_STATUS_READY |
                                               NAND_STATUS_WP,
                                               NAND_CTRL_RDY |
                                               NAND_STATUS_READY |
                                               (wp ? 0 : NAND_STATUS_WP), 0);

                if (ret)
                        dev_err_ratelimited(&host->pdev->dev,
                                            "nand #WP expected %s\n",
                                            wp ? "on" : "off");
        }
}

/* Helper functions for reading and writing OOB registers */
static inline u8 oob_reg_read(struct brcmnand_controller *ctrl, u32 offs)
{
        u16 offset0, offset10, reg_offs;

        offset0 = ctrl->reg_offsets[BRCMNAND_OOB_READ_BASE];
        offset10 = ctrl->reg_offsets[BRCMNAND_OOB_READ_10_BASE];

        if (offs >= ctrl->max_oob)
                return 0x77;

        if (offs >= 16 && offset10)
                reg_offs = offset10 + ((offs - 0x10) & ~0x03);
        else
                reg_offs = offset0 + (offs & ~0x03);

        return nand_readreg(ctrl, reg_offs) >> (24 - ((offs & 0x03) << 3));
}

static inline void oob_reg_write(struct brcmnand_controller *ctrl, u32 offs,
                                 u32 data)
{
        u16 offset0, offset10, reg_offs;

        offset0 = ctrl->reg_offsets[BRCMNAND_OOB_WRITE_BASE];
        offset10 = ctrl->reg_offsets[BRCMNAND_OOB_WRITE_10_BASE];

        if (offs >= ctrl->max_oob)
                return;

        if (offs >= 16 && offset10)
                reg_offs = offset10 + ((offs - 0x10) & ~0x03);
        else
                reg_offs = offset0 + (offs & ~0x03);

        nand_writereg(ctrl, reg_offs, data);
}

/*
 * read_oob_from_regs - read data from OOB registers
 * @ctrl: NAND controller
 * @i: sub-page sector index
 * @oob: buffer to read to
 * @sas: spare area sector size (i.e., OOB size per FLASH_CACHE)
 * @sector_1k: 1 for 1KiB sectors, 0 for 512B, other values are illegal
 */
static int read_oob_from_regs(struct brcmnand_controller *ctrl, int i, u8 *oob,
                              int sas, int sector_1k)
{
        int tbytes = sas << sector_1k;
        int j;

        /* Adjust OOB values for 1K sector size */
        if (sector_1k && (i & 0x01))
                tbytes = max(0, tbytes - (int)ctrl->max_oob);
        tbytes = min_t(int, tbytes, ctrl->max_oob);

        for (j = 0; j < tbytes; j++)
                oob[j] = oob_reg_read(ctrl, j);
        return tbytes;
}

/*
 * write_oob_to_regs - write data to OOB registers
 * @i: sub-page sector index
 * @oob: buffer to write from
 * @sas: spare area sector size (i.e., OOB size per FLASH_CACHE)
 * @sector_1k: 1 for 1KiB sectors, 0 for 512B, other values are illegal
 */
static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i,
                             const u8 *oob, int sas, int sector_1k)
{
        int tbytes = sas << sector_1k;
        int j;

        /* Adjust OOB values for 1K sector size */
        if (sector_1k && (i & 0x01))
                tbytes = max(0, tbytes - (int)ctrl->max_oob);
        tbytes = min_t(int, tbytes, ctrl->max_oob);

        for (j = 0; j < tbytes; j += 4)
                oob_reg_write(ctrl, j,
                                (oob[j + 0] << 24) |
                                (oob[j + 1] << 16) |
                                (oob[j + 2] <<  8) |
                                (oob[j + 3] <<  0));
        return tbytes;
}

static irqreturn_t brcmnand_ctlrdy_irq(int irq, void *data)
{
        struct brcmnand_controller *ctrl = data;

        /* Discard all NAND_CTLRDY interrupts during DMA */
        if (ctrl->dma_pending)
                return IRQ_HANDLED;

        complete(&ctrl->done);
        return IRQ_HANDLED;
}

/* Handle SoC-specific interrupt hardware */
static irqreturn_t brcmnand_irq(int irq, void *data)
{
        struct brcmnand_controller *ctrl = data;

        if (ctrl->soc->ctlrdy_ack(ctrl->soc))
                return brcmnand_ctlrdy_irq(irq, data);

        return IRQ_NONE;
}

static irqreturn_t brcmnand_dma_irq(int irq, void *data)
{
        struct brcmnand_controller *ctrl = data;

        complete(&ctrl->dma_done);

        return IRQ_HANDLED;
}

static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        int ret;

        dev_dbg(ctrl->dev, "send native cmd %d addr_lo 0x%x\n", cmd,
                brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS));
        BUG_ON(ctrl->cmd_pending != 0);
        ctrl->cmd_pending = cmd;

        ret = bcmnand_ctrl_poll_status(ctrl, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);
        WARN_ON(ret);

        mb(); /* flush previous writes */
        brcmnand_write_reg(ctrl, BRCMNAND_CMD_START,
                           cmd << brcmnand_cmd_shift(ctrl));
}

/***********************************************************************
 * NAND MTD API: read/program/erase
 ***********************************************************************/

static void brcmnand_cmd_ctrl(struct mtd_info *mtd, int dat,
        unsigned int ctrl)
{
        /* intentionally left blank */
}

static int brcmnand_waitfunc(struct mtd_info *mtd, struct nand_chip *this)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        unsigned long timeo = msecs_to_jiffies(100);

        dev_dbg(ctrl->dev, "wait on native cmd %d\n", ctrl->cmd_pending);
        if (ctrl->cmd_pending &&
                        wait_for_completion_timeout(&ctrl->done, timeo) <= 0) {
                u32 cmd = brcmnand_read_reg(ctrl, BRCMNAND_CMD_START)
                                        >> brcmnand_cmd_shift(ctrl);

                dev_err_ratelimited(ctrl->dev,
                        "timeout waiting for command %#02x\n", cmd);
                dev_err_ratelimited(ctrl->dev, "intfc status %08x\n",
                        brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS));
        }
        ctrl->cmd_pending = 0;
        return brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) &
                                 INTFC_FLASH_STATUS;
}

enum {
        LLOP_RE                         = BIT(16),
        LLOP_WE                         = BIT(17),
        LLOP_ALE                        = BIT(18),
        LLOP_CLE                        = BIT(19),
        LLOP_RETURN_IDLE                = BIT(31),

        LLOP_DATA_MASK                  = GENMASK(15, 0),
};

static int brcmnand_low_level_op(struct brcmnand_host *host,
                                 enum brcmnand_llop_type type, u32 data,
                                 bool last_op)
{
        struct mtd_info *mtd = nand_to_mtd(&host->chip);
        struct nand_chip *chip = &host->chip;
        struct brcmnand_controller *ctrl = host->ctrl;
        u32 tmp;

        tmp = data & LLOP_DATA_MASK;
        switch (type) {
        case LL_OP_CMD:
                tmp |= LLOP_WE | LLOP_CLE;
                break;
        case LL_OP_ADDR:
                /* WE | ALE */
                tmp |= LLOP_WE | LLOP_ALE;
                break;
        case LL_OP_WR:
                /* WE */
                tmp |= LLOP_WE;
                break;
        case LL_OP_RD:
                /* RE */
                tmp |= LLOP_RE;
                break;
        }
        if (last_op)
                /* RETURN_IDLE */
                tmp |= LLOP_RETURN_IDLE;

        dev_dbg(ctrl->dev, "ll_op cmd %#x\n", tmp);

        brcmnand_write_reg(ctrl, BRCMNAND_LL_OP, tmp);
        (void)brcmnand_read_reg(ctrl, BRCMNAND_LL_OP);

        brcmnand_send_cmd(host, CMD_LOW_LEVEL_OP);
        return brcmnand_waitfunc(mtd, chip);
}

static void brcmnand_cmdfunc(struct mtd_info *mtd, unsigned command,
                             int column, int page_addr)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        u64 addr = (u64)page_addr << chip->page_shift;
        int native_cmd = 0;

        if (command == NAND_CMD_READID || command == NAND_CMD_PARAM ||
                        command == NAND_CMD_RNDOUT)
                addr = (u64)column;
        /* Avoid propagating a negative, don't-care address */
        else if (page_addr < 0)
                addr = 0;

        dev_dbg(ctrl->dev, "cmd 0x%x addr 0x%llx\n", command,
                (unsigned long long)addr);

        host->last_cmd = command;
        host->last_byte = 0;
        host->last_addr = addr;

        switch (command) {
        case NAND_CMD_RESET:
                native_cmd = CMD_FLASH_RESET;
                break;
        case NAND_CMD_STATUS:
                native_cmd = CMD_STATUS_READ;
                break;
        case NAND_CMD_READID:
                native_cmd = CMD_DEVICE_ID_READ;
                break;
        case NAND_CMD_READOOB:
                native_cmd = CMD_SPARE_AREA_READ;
                break;
        case NAND_CMD_ERASE1:
                native_cmd = CMD_BLOCK_ERASE;
                brcmnand_wp(mtd, 0);
                break;
        case NAND_CMD_PARAM:
                native_cmd = CMD_PARAMETER_READ;
                break;
        case NAND_CMD_SET_FEATURES:
        case NAND_CMD_GET_FEATURES:
                brcmnand_low_level_op(host, LL_OP_CMD, command, false);
                brcmnand_low_level_op(host, LL_OP_ADDR, column, false);
                break;
        case NAND_CMD_RNDOUT:
                native_cmd = CMD_PARAMETER_CHANGE_COL;
                addr &= ~((u64)(FC_BYTES - 1));
                /*
                 * HW quirk: PARAMETER_CHANGE_COL requires SECTOR_SIZE_1K=0
                 * NB: hwcfg.sector_size_1k may not be initialized yet
                 */
                if (brcmnand_get_sector_size_1k(host)) {
                        host->hwcfg.sector_size_1k =
                                brcmnand_get_sector_size_1k(host);
                        brcmnand_set_sector_size_1k(host, 0);
                }
                break;
        }

        if (!native_cmd)
                return;

        brcmnand_write_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS,
                (host->cs << 16) | ((addr >> 32) & 0xffff));
        (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS);
        brcmnand_write_reg(ctrl, BRCMNAND_CMD_ADDRESS, lower_32_bits(addr));
        (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS);

        brcmnand_send_cmd(host, native_cmd);
        brcmnand_waitfunc(mtd, chip);

        if (native_cmd == CMD_PARAMETER_READ ||
                        native_cmd == CMD_PARAMETER_CHANGE_COL) {
                /* Copy flash cache word-wise */
                u32 *flash_cache = (u32 *)ctrl->flash_cache;
                int i;

                brcmnand_soc_data_bus_prepare(ctrl->soc, true);

                /*
                 * Must cache the FLASH_CACHE now, since changes in
                 * SECTOR_SIZE_1K may invalidate it
                 */
                for (i = 0; i < FC_WORDS; i++)
                        /*
                         * Flash cache is big endian for parameter pages, at
                         * least on STB SoCs
                         */
                        flash_cache[i] = be32_to_cpu(brcmnand_read_fc(ctrl, i));

                brcmnand_soc_data_bus_unprepare(ctrl->soc, true);

                /* Cleanup from HW quirk: restore SECTOR_SIZE_1K */
                if (host->hwcfg.sector_size_1k)
                        brcmnand_set_sector_size_1k(host,
                                                    host->hwcfg.sector_size_1k);
        }

        /* Re-enable protection is necessary only after erase */
        if (command == NAND_CMD_ERASE1)
                brcmnand_wp(mtd, 1);
}

static uint8_t brcmnand_read_byte(struct mtd_info *mtd)
{
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        uint8_t ret = 0;
        int addr, offs;

        switch (host->last_cmd) {
        case NAND_CMD_READID:
                if (host->last_byte < 4)
                        ret = brcmnand_read_reg(ctrl, BRCMNAND_ID) >>
                                (24 - (host->last_byte << 3));
                else if (host->last_byte < 8)
                        ret = brcmnand_read_reg(ctrl, BRCMNAND_ID_EXT) >>
                                (56 - (host->last_byte << 3));
                break;

        case NAND_CMD_READOOB:
                ret = oob_reg_read(ctrl, host->last_byte);
                break;

        case NAND_CMD_STATUS:
                ret = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) &
                                        INTFC_FLASH_STATUS;
                if (wp_on) /* hide WP status */
                        ret |= NAND_STATUS_WP;
                break;

        case NAND_CMD_PARAM:
        case NAND_CMD_RNDOUT:
                addr = host->last_addr + host->last_byte;
                offs = addr & (FC_BYTES - 1);

                /* At FC_BYTES boundary, switch to next column */
                if (host->last_byte > 0 && offs == 0)
                        chip->cmdfunc(mtd, NAND_CMD_RNDOUT, addr, -1);

                ret = ctrl->flash_cache[offs];
                break;
        case NAND_CMD_GET_FEATURES:
                if (host->last_byte >= ONFI_SUBFEATURE_PARAM_LEN) {
                        ret = 0;
                } else {
                        bool last = host->last_byte ==
                                ONFI_SUBFEATURE_PARAM_LEN - 1;
                        brcmnand_low_level_op(host, LL_OP_RD, 0, last);
                        ret = brcmnand_read_reg(ctrl, BRCMNAND_LL_RDATA) & 0xff;
                }
        }

        dev_dbg(ctrl->dev, "read byte = 0x%02x\n", ret);
        host->last_byte++;

        return ret;
}

static void brcmnand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
        int i;

        for (i = 0; i < len; i++, buf++)
                *buf = brcmnand_read_byte(mtd);
}

static void brcmnand_write_buf(struct mtd_info *mtd, const uint8_t *buf,
                                   int len)
{
        int i;
        struct nand_chip *chip = mtd_to_nand(mtd);
        struct brcmnand_host *host = nand_get_controller_data(chip);

        switch (host->last_cmd) {
        case NAND_CMD_SET_FEATURES:
                for (i = 0; i < len; i++)
                        brcmnand_low_level_op(host, LL_OP_WR, buf[i],
                                                  (i + 1) == len);
                break;
        default:
                BUG();
                break;
        }
}

/**
 * Construct a FLASH_DMA descriptor as part of a linked list. You must know the
 * following ahead of time:
 *  - Is this descriptor the beginning or end of a linked list?
 *  - What is the (DMA) address of the next descriptor in the linked list?
 */
static int brcmnand_fill_dma_desc(struct brcmnand_host *host,
                                  struct brcm_nand_dma_desc *desc, u64 addr,
                                  dma_addr_t buf, u32 len, u8 dma_cmd,
                                  bool begin, bool end,
                                  dma_addr_t next_desc)
{
        memset(desc, 0, sizeof(*desc));
        /* Descriptors are written in native byte order (wordwise) */
        desc->next_desc = lower_32_bits(next_desc);
        desc->next_desc_ext = upper_32_bits(next_desc);
        desc->cmd_irq = (dma_cmd << 24) |
                (end ? (0x03 << 8) : 0) | /* IRQ | STOP */
                (!!begin) | ((!!end) << 1); /* head, tail */
#ifdef CONFIG_CPU_BIG_ENDIAN
        desc->cmd_irq |= 0x01 << 12;
#endif
        desc->dram_addr = lower_32_bits(buf);
        desc->dram_addr_ext = upper_32_bits(buf);
        desc->tfr_len = len;
        desc->total_len = len;
        desc->flash_addr = lower_32_bits(addr);
        desc->flash_addr_ext = upper_32_bits(addr);
        desc->cs = host->cs;
        desc->status_valid = 0x01;
        return 0;
}

/**
 * Kick the FLASH_DMA engine, with a given DMA descriptor
 */
static void brcmnand_dma_run(struct brcmnand_host *host, dma_addr_t desc)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        unsigned long timeo = msecs_to_jiffies(100);

        flash_dma_writel(ctrl, FLASH_DMA_FIRST_DESC, lower_32_bits(desc));
        (void)flash_dma_readl(ctrl, FLASH_DMA_FIRST_DESC);
        flash_dma_writel(ctrl, FLASH_DMA_FIRST_DESC_EXT, upper_32_bits(desc));
        (void)flash_dma_readl(ctrl, FLASH_DMA_FIRST_DESC_EXT);

        /* Start FLASH_DMA engine */
        ctrl->dma_pending = true;
        mb(); /* flush previous writes */
        flash_dma_writel(ctrl, FLASH_DMA_CTRL, 0x03); /* wake | run */

        if (wait_for_completion_timeout(&ctrl->dma_done, timeo) <= 0) {
                dev_err(ctrl->dev,
                                "timeout waiting for DMA; status %#x, error status %#x\n",
                                flash_dma_readl(ctrl, FLASH_DMA_STATUS),
                                flash_dma_readl(ctrl, FLASH_DMA_ERROR_STATUS));
        }
        ctrl->dma_pending = false;
        flash_dma_writel(ctrl, FLASH_DMA_CTRL, 0); /* force stop */
}

static int brcmnand_dma_trans(struct brcmnand_host *host, u64 addr, u32 *buf,
                              u32 len, u8 dma_cmd)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        dma_addr_t buf_pa;
        int dir = dma_cmd == CMD_PAGE_READ ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

        buf_pa = dma_map_single(ctrl->dev, buf, len, dir);
        if (dma_mapping_error(ctrl->dev, buf_pa)) {
                dev_err(ctrl->dev, "unable to map buffer for DMA\n");
                return -ENOMEM;
        }

        brcmnand_fill_dma_desc(host, ctrl->dma_desc, addr, buf_pa, len,
                                   dma_cmd, true, true, 0);

        brcmnand_dma_run(host, ctrl->dma_pa);

        dma_unmap_single(ctrl->dev, buf_pa, len, dir);

        if (ctrl->dma_desc->status_valid & FLASH_DMA_ECC_ERROR)
                return -EBADMSG;
        else if (ctrl->dma_desc->status_valid & FLASH_DMA_CORR_ERROR)
                return -EUCLEAN;

        return 0;
}

/*
 * Assumes proper CS is already set
 */
static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
                                u64 addr, unsigned int trans, u32 *buf,
                                u8 *oob, u64 *err_addr)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        int i, j, ret = 0;

        /* Clear error addresses */
        brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_ADDR, 0);
        brcmnand_write_reg(ctrl, BRCMNAND_CORR_ADDR, 0);
        brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_EXT_ADDR, 0);
        brcmnand_write_reg(ctrl, BRCMNAND_CORR_EXT_ADDR, 0);

        brcmnand_write_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS,
                        (host->cs << 16) | ((addr >> 32) & 0xffff));
        (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS);

        for (i = 0; i < trans; i++, addr += FC_BYTES) {
                brcmnand_write_reg(ctrl, BRCMNAND_CMD_ADDRESS,
                                   lower_32_bits(addr));
                (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS);
                /* SPARE_AREA_READ does not use ECC, so just use PAGE_READ */
                brcmnand_send_cmd(host, CMD_PAGE_READ);
                brcmnand_waitfunc(mtd, chip);

                if (likely(buf)) {
                        brcmnand_soc_data_bus_prepare(ctrl->soc, false);

                        for (j = 0; j < FC_WORDS; j++, buf++)
                                *buf = brcmnand_read_fc(ctrl, j);

                        brcmnand_soc_data_bus_unprepare(ctrl->soc, false);
                }

                if (oob)
                        oob += read_oob_from_regs(ctrl, i, oob,
                                        mtd->oobsize / trans,
                                        host->hwcfg.sector_size_1k);

                if (!ret) {
                        *err_addr = brcmnand_read_reg(ctrl,
                                        BRCMNAND_UNCORR_ADDR) |
                                ((u64)(brcmnand_read_reg(ctrl,
                                                BRCMNAND_UNCORR_EXT_ADDR)
                                        & 0xffff) << 32);
                        if (*err_addr)
                                ret = -EBADMSG;
                }

                if (!ret) {
                        *err_addr = brcmnand_read_reg(ctrl,
                                        BRCMNAND_CORR_ADDR) |
                                ((u64)(brcmnand_read_reg(ctrl,
                                                BRCMNAND_CORR_EXT_ADDR)
                                        & 0xffff) << 32);
                        if (*err_addr)
                                ret = -EUCLEAN;
                }
        }

        return ret;
}

/*
 * Check a page to see if it is erased (w/ bitflips) after an uncorrectable ECC
 * error
 *
 * Because the HW ECC signals an ECC error if an erase paged has even a single
 * bitflip, we must check each ECC error to see if it is actually an erased
 * page with bitflips, not a truly corrupted page.
 *
 * On a real error, return a negative error code (-EBADMSG for ECC error), and
 * buf will contain raw data.
 * Otherwise, buf gets filled with 0xffs and return the maximum number of
 * bitflips-per-ECC-sector to the caller.
 *
 */
static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd,
                  struct nand_chip *chip, void *buf, u64 addr)
{
        int i, sas;
        void *oob = chip->oob_poi;
        int bitflips = 0;
        int page = addr >> chip->page_shift;
        int ret;

        if (!buf) {
                buf = chip->buffers->databuf;
                /* Invalidate page cache */
                chip->pagebuf = -1;
        }

        sas = mtd->oobsize / chip->ecc.steps;

        /* read without ecc for verification */
        chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
        ret = chip->ecc.read_page_raw(mtd, chip, buf, true, page);
        if (ret)
                return ret;

        for (i = 0; i < chip->ecc.steps; i++, oob += sas) {
                ret = nand_check_erased_ecc_chunk(buf, chip->ecc.size,
                                                  oob, sas, NULL, 0,
                                                  chip->ecc.strength);
                if (ret < 0)
                        return ret;

                bitflips = max(bitflips, ret);
        }

        return bitflips;
}

static int brcmnand_read(struct mtd_info *mtd, struct nand_chip *chip,
                         u64 addr, unsigned int trans, u32 *buf, u8 *oob)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        u64 err_addr = 0;
        int err;
        bool retry = true;

        dev_dbg(ctrl->dev, "read %llx -> %p\n", (unsigned long long)addr, buf);

try_dmaread:
        brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_COUNT, 0);

        if (has_flash_dma(ctrl) && !oob && flash_dma_buf_ok(buf)) {
                err = brcmnand_dma_trans(host, addr, buf, trans * FC_BYTES,
                                             CMD_PAGE_READ);
                if (err) {
                        if (mtd_is_bitflip_or_eccerr(err))
                                err_addr = addr;
                        else
                                return -EIO;
                }
        } else {
                if (oob)
                        memset(oob, 0x99, mtd->oobsize);

                err = brcmnand_read_by_pio(mtd, chip, addr, trans, buf,
                                               oob, &err_addr);
        }

        if (mtd_is_eccerr(err)) {
                /*
                 * On controller version and 7.0, 7.1 , DMA read after a
                 * prior PIO read that reported uncorrectable error,
                 * the DMA engine captures this error following DMA read
                 * cleared only on subsequent DMA read, so just retry once
                 * to clear a possible false error reported for current DMA
                 * read
                 */
                if ((ctrl->nand_version == 0x0700) ||
                    (ctrl->nand_version == 0x0701)) {
                        if (retry) {
                                retry = false;
                                goto try_dmaread;
                        }
                }

                /*
                 * Controller version 7.2 has hw encoder to detect erased page
                 * bitflips, apply sw verification for older controllers only
                 */
                if (ctrl->nand_version < 0x0702) {
                        err = brcmstb_nand_verify_erased_page(mtd, chip, buf,
                                                              addr);
                        /* erased page bitflips corrected */
                        if (err > 0)
                                return err;
                }

                dev_dbg(ctrl->dev, "uncorrectable error at 0x%llx\n",
                        (unsigned long long)err_addr);
                mtd->ecc_stats.failed++;
                /* NAND layer expects zero on ECC errors */
                return 0;
        }

        if (mtd_is_bitflip(err)) {
                unsigned int corrected = brcmnand_count_corrected(ctrl);

                dev_dbg(ctrl->dev, "corrected error at 0x%llx\n",
                        (unsigned long long)err_addr);
                mtd->ecc_stats.corrected += corrected;
                /* Always exceed the software-imposed threshold */
                return max(mtd->bitflip_threshold, corrected);
        }

        return 0;
}

static int brcmnand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                              uint8_t *buf, int oob_required, int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;

        return brcmnand_read(mtd, chip, host->last_addr,
                        mtd->writesize >> FC_SHIFT, (u32 *)buf, oob);
}

static int brcmnand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
                                  uint8_t *buf, int oob_required, int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;
        int ret;

        brcmnand_set_ecc_enabled(host, 0);
        ret = brcmnand_read(mtd, chip, host->last_addr,
                        mtd->writesize >> FC_SHIFT, (u32 *)buf, oob);
        brcmnand_set_ecc_enabled(host, 1);
        return ret;
}

static int brcmnand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
                             int page)
{
        return brcmnand_read(mtd, chip, (u64)page << chip->page_shift,
                        mtd->writesize >> FC_SHIFT,
                        NULL, (u8 *)chip->oob_poi);
}

static int brcmnand_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
                                 int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);

        brcmnand_set_ecc_enabled(host, 0);
        brcmnand_read(mtd, chip, (u64)page << chip->page_shift,
                mtd->writesize >> FC_SHIFT,
                NULL, (u8 *)chip->oob_poi);
        brcmnand_set_ecc_enabled(host, 1);
        return 0;
}

static int brcmnand_write(struct mtd_info *mtd, struct nand_chip *chip,
                          u64 addr, const u32 *buf, u8 *oob)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        struct brcmnand_controller *ctrl = host->ctrl;
        unsigned int i, j, trans = mtd->writesize >> FC_SHIFT;
        int status, ret = 0;

        dev_dbg(ctrl->dev, "write %llx <- %p\n", (unsigned long long)addr, buf);

        if (unlikely((unsigned long)buf & 0x03)) {
                dev_warn(ctrl->dev, "unaligned buffer: %p\n", buf);
                buf = (u32 *)((unsigned long)buf & ~0x03);
        }

        brcmnand_wp(mtd, 0);

        for (i = 0; i < ctrl->max_oob; i += 4)
                oob_reg_write(ctrl, i, 0xffffffff);

        if (has_flash_dma(ctrl) && !oob && flash_dma_buf_ok(buf)) {
                if (brcmnand_dma_trans(host, addr, (u32 *)buf,
                                        mtd->writesize, CMD_PROGRAM_PAGE))
                        ret = -EIO;
                goto out;
        }

        brcmnand_write_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS,
                        (host->cs << 16) | ((addr >> 32) & 0xffff));
        (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS);

        for (i = 0; i < trans; i++, addr += FC_BYTES) {
                /* full address MUST be set before populating FC */
                brcmnand_write_reg(ctrl, BRCMNAND_CMD_ADDRESS,
                                   lower_32_bits(addr));
                (void)brcmnand_read_reg(ctrl, BRCMNAND_CMD_ADDRESS);

                if (buf) {
                        brcmnand_soc_data_bus_prepare(ctrl->soc, false);

                        for (j = 0; j < FC_WORDS; j++, buf++)
                                brcmnand_write_fc(ctrl, j, *buf);

                        brcmnand_soc_data_bus_unprepare(ctrl->soc, false);
                } else if (oob) {
                        for (j = 0; j < FC_WORDS; j++)
                                brcmnand_write_fc(ctrl, j, 0xffffffff);
                }

                if (oob) {
                        oob += write_oob_to_regs(ctrl, i, oob,
                                        mtd->oobsize / trans,
                                        host->hwcfg.sector_size_1k);
                }

                /* we cannot use SPARE_AREA_PROGRAM when PARTIAL_PAGE_EN=0 */
                brcmnand_send_cmd(host, CMD_PROGRAM_PAGE);
                status = brcmnand_waitfunc(mtd, chip);

                if (status & NAND_STATUS_FAIL) {
                        dev_info(ctrl->dev, "program failed at %llx\n",
                                (unsigned long long)addr);
                        ret = -EIO;
                        goto out;
                }
        }
out:
        brcmnand_wp(mtd, 1);
        return ret;
}

static int brcmnand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
                               const uint8_t *buf, int oob_required, int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        void *oob = oob_required ? chip->oob_poi : NULL;

        brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
        return 0;
}

static int brcmnand_write_page_raw(struct mtd_info *mtd,
                                   struct nand_chip *chip, const uint8_t *buf,
                                   int oob_required, int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        void *oob = oob_required ? chip->oob_poi : NULL;

        brcmnand_set_ecc_enabled(host, 0);
        brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
        brcmnand_set_ecc_enabled(host, 1);
        return 0;
}

static int brcmnand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
                                  int page)
{
        return brcmnand_write(mtd, chip, (u64)page << chip->page_shift,
                                  NULL, chip->oob_poi);
}

static int brcmnand_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
                                  int page)
{
        struct brcmnand_host *host = nand_get_controller_data(chip);
        int ret;

        brcmnand_set_ecc_enabled(host, 0);
        ret = brcmnand_write(mtd, chip, (u64)page << chip->page_shift, NULL,
                                 (u8 *)chip->oob_poi);
        brcmnand_set_ecc_enabled(host, 1);

        return ret;
}

/***********************************************************************
 * Per-CS setup (1 NAND device)
 ***********************************************************************/

static int brcmnand_set_cfg(struct brcmnand_host *host,
                            struct brcmnand_cfg *cfg)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        struct nand_chip *chip = &host->chip;
        u16 cfg_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_CFG);
        u16 cfg_ext_offs = brcmnand_cs_offset(ctrl, host->cs,
                        BRCMNAND_CS_CFG_EXT);
        u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
                        BRCMNAND_CS_ACC_CONTROL);
        u8 block_size = 0, page_size = 0, device_size = 0;
        u32 tmp;

        if (ctrl->block_sizes) {
                int i, found;

                for (i = 0, found = 0; ctrl->block_sizes[i]; i++)
                        if (ctrl->block_sizes[i] * 1024 == cfg->block_size) {
                                block_size = i;
                                found = 1;
                        }
                if (!found) {
                        dev_warn(ctrl->dev, "invalid block size %u\n",
                                        cfg->block_size);
                        return -EINVAL;
                }
        } else {
                block_size = ffs(cfg->block_size) - ffs(BRCMNAND_MIN_BLOCKSIZE);
        }

        if (cfg->block_size < BRCMNAND_MIN_BLOCKSIZE || (ctrl->max_block_size &&
                                cfg->block_size > ctrl->max_block_size)) {
                dev_warn(ctrl->dev, "invalid block size %u\n",
                                cfg->block_size);
                block_size = 0;
        }

        if (ctrl->page_sizes) {
                int i, found;

                for (i = 0, found = 0; ctrl->page_sizes[i]; i++)
                        if (ctrl->page_sizes[i] == cfg->page_size) {
                                page_size = i;
                                found = 1;
                        }
                if (!found) {
                        dev_warn(ctrl->dev, "invalid page size %u\n",

                                        cfg->page_size);
                        return -EINVAL;
                }
        } else {
                page_size = ffs(cfg->page_size) - ffs(BRCMNAND_MIN_PAGESIZE);
        }

        if (cfg->page_size < BRCMNAND_MIN_PAGESIZE || (ctrl->max_page_size &&
                                cfg->page_size > ctrl->max_page_size)) {
                dev_warn(ctrl->dev, "invalid page size %u\n", cfg->page_size);
                return -EINVAL;
        }

        if (fls64(cfg->device_size) < fls64(BRCMNAND_MIN_DEVSIZE)) {
                dev_warn(ctrl->dev, "invalid device size 0x%llx\n",
                        (unsigned long long)cfg->device_size);
                return -EINVAL;
        }
        device_size = fls64(cfg->device_size) - fls64(BRCMNAND_MIN_DEVSIZE);

        tmp = (cfg->blk_adr_bytes << CFG_BLK_ADR_BYTES_SHIFT) |
                (cfg->col_adr_bytes << CFG_COL_ADR_BYTES_SHIFT) |
                (cfg->ful_adr_bytes << CFG_FUL_ADR_BYTES_SHIFT) |
                (!!(cfg->device_width == 16) << CFG_BUS_WIDTH_SHIFT) |
                (device_size << CFG_DEVICE_SIZE_SHIFT);
        if (cfg_offs == cfg_ext_offs) {
                tmp |= (page_size << CFG_PAGE_SIZE_SHIFT) |
                       (block_size << CFG_BLK_SIZE_SHIFT);
                nand_writereg(ctrl, cfg_offs, tmp);
        } else {
                nand_writereg(ctrl, cfg_offs, tmp);
                tmp = (page_size << CFG_EXT_PAGE_SIZE_SHIFT) |
                      (block_size << CFG_EXT_BLK_SIZE_SHIFT);
                nand_writereg(ctrl, cfg_ext_offs, tmp);
        }

        tmp = nand_readreg(ctrl, acc_control_offs);
        tmp &= ~brcmnand_ecc_level_mask(ctrl);
        tmp |= cfg->ecc_level << NAND_ACC_CONTROL_ECC_SHIFT;
        tmp &= ~brcmnand_spare_area_mask(ctrl);
        tmp |= cfg->spare_area_size;
        nand_writereg(ctrl, acc_control_offs, tmp);

        brcmnand_set_sector_size_1k(host, cfg->sector_size_1k);

        /* threshold = ceil(BCH-level * 0.75) */
        brcmnand_wr_corr_thresh(host, DIV_ROUND_UP(chip->ecc.strength * 3, 4));

        return 0;
}

static void brcmnand_print_cfg(struct brcmnand_host *host,
                               char *buf, struct brcmnand_cfg *cfg)
{
        buf += sprintf(buf,
                "%lluMiB total, %uKiB blocks, %u%s pages, %uB OOB, %u-bit",
                (unsigned long long)cfg->device_size >> 20,
                cfg->block_size >> 10,
                cfg->page_size >= 1024 ? cfg->page_size >> 10 : cfg->page_size,
                cfg->page_size >= 1024 ? "KiB" : "B",
                cfg->spare_area_size, cfg->device_width);

        /* Account for Hamming ECC and for BCH 512B vs 1KiB sectors */
        if (is_hamming_ecc(host->ctrl, cfg))
                sprintf(buf, ", Hamming ECC");
        else if (cfg->sector_size_1k)
                sprintf(buf, ", BCH-%u (1KiB sector)", cfg->ecc_level << 1);
        else
                sprintf(buf, ", BCH-%u", cfg->ecc_level);
}

/*
 * Minimum number of bytes to address a page. Calculated as:
 *     roundup(log2(size / page-size) / 8)
 *
 * NB: the following does not "round up" for non-power-of-2 'size'; but this is
 *     OK because many other things will break if 'size' is irregular...
 */
static inline int get_blk_adr_bytes(u64 size, u32 writesize)
{
        return ALIGN(ilog2(size) - ilog2(writesize), 8) >> 3;
}

static int brcmnand_setup_dev(struct brcmnand_host *host)
{
        struct mtd_info *mtd = nand_to_mtd(&host->chip);
        struct nand_chip *chip = &host->chip;
        struct brcmnand_controller *ctrl = host->ctrl;
        struct brcmnand_cfg *cfg = &host->hwcfg;
        char msg[128];
        u32 offs, tmp, oob_sector;
        int ret;

        memset(cfg, 0, sizeof(*cfg));

        ret = of_property_read_u32(nand_get_flash_node(chip),
                                   "brcm,nand-oob-sector-size",
                                   &oob_sector);
        if (ret) {
                /* Use detected size */
                cfg->spare_area_size = mtd->oobsize /
                                        (mtd->writesize >> FC_SHIFT);
        } else {
                cfg->spare_area_size = oob_sector;
        }
        if (cfg->spare_area_size > ctrl->max_oob)
                cfg->spare_area_size = ctrl->max_oob;
        /*
         * Set oobsize to be consistent with controller's spare_area_size, as
         * the rest is inaccessible.
         */
        mtd->oobsize = cfg->spare_area_size * (mtd->writesize >> FC_SHIFT);

        cfg->device_size = mtd->size;
        cfg->block_size = mtd->erasesize;
        cfg->page_size = mtd->writesize;
        cfg->device_width = (chip->options & NAND_BUSWIDTH_16) ? 16 : 8;
        cfg->col_adr_bytes = 2;
        cfg->blk_adr_bytes = get_blk_adr_bytes(mtd->size, mtd->writesize);

        if (chip->ecc.mode != NAND_ECC_HW) {
                dev_err(ctrl->dev, "only HW ECC supported; selected: %d\n",
                        chip->ecc.mode);
                return -EINVAL;
        }

        if (chip->ecc.algo == NAND_ECC_UNKNOWN) {
                if (chip->ecc.strength == 1 && chip->ecc.size == 512)
                        /* Default to Hamming for 1-bit ECC, if unspecified */
                        chip->ecc.algo = NAND_ECC_HAMMING;
                else
                        /* Otherwise, BCH */
                        chip->ecc.algo = NAND_ECC_BCH;
        }

        if (chip->ecc.algo == NAND_ECC_HAMMING && (chip->ecc.strength != 1 ||
                                                   chip->ecc.size != 512)) {
                dev_err(ctrl->dev, "invalid Hamming params: %d bits per %d bytes\n",
                        chip->ecc.strength, chip->ecc.size);
                return -EINVAL;
        }

        switch (chip->ecc.size) {
        case 512:
                if (chip->ecc.algo == NAND_ECC_HAMMING)
                        cfg->ecc_level = 15;
                else
                        cfg->ecc_level = chip->ecc.strength;
                cfg->sector_size_1k = 0;
                break;
        case 1024:
                if (!(ctrl->features & BRCMNAND_HAS_1K_SECTORS)) {
                        dev_err(ctrl->dev, "1KB sectors not supported\n");
                        return -EINVAL;
                }
                if (chip->ecc.strength & 0x1) {
                        dev_err(ctrl->dev,
                                "odd ECC not supported with 1KB sectors\n");
                        return -EINVAL;
                }

                cfg->ecc_level = chip->ecc.strength >> 1;
                cfg->sector_size_1k = 1;
                break;
        default:
                dev_err(ctrl->dev, "unsupported ECC size: %d\n",
                        chip->ecc.size);
                return -EINVAL;
        }

        cfg->ful_adr_bytes = cfg->blk_adr_bytes;
        if (mtd->writesize > 512)
                cfg->ful_adr_bytes += cfg->col_adr_bytes;
        else
                cfg->ful_adr_bytes += 1;

        ret = brcmnand_set_cfg(host, cfg);
        if (ret)
                return ret;

        brcmnand_set_ecc_enabled(host, 1);

        brcmnand_print_cfg(host, msg, cfg);
        dev_info(ctrl->dev, "detected %s\n", msg);

        /* Configure ACC_CONTROL */
        offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_ACC_CONTROL);
        tmp = nand_readreg(ctrl, offs);
        tmp &= ~ACC_CONTROL_PARTIAL_PAGE;
        tmp &= ~ACC_CONTROL_RD_ERASED;

        /* We need to turn on Read from erased paged protected by ECC */
        if (ctrl->nand_version >= 0x0702)
                tmp |= ACC_CONTROL_RD_ERASED;
        tmp &= ~ACC_CONTROL_FAST_PGM_RDIN;
        if (ctrl->features & BRCMNAND_HAS_PREFETCH) {
                /*
                 * FIXME: Flash DMA + prefetch may see spurious erased-page ECC
                 * errors
                 */
                if (has_flash_dma(ctrl))
                        tmp &= ~ACC_CONTROL_PREFETCH;
                else
                        tmp |= ACC_CONTROL_PREFETCH;
        }
        nand_writereg(ctrl, offs, tmp);

        return 0;
}

static int brcmnand_init_cs(struct brcmnand_host *host, struct device_node *dn)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        struct platform_device *pdev = host->pdev;
        struct mtd_info *mtd;
        struct nand_chip *chip;
        int ret;
        u16 cfg_offs;

        ret = of_property_read_u32(dn, "reg", &host->cs);
        if (ret) {
                dev_err(&pdev->dev, "can't get chip-select\n");
                return -ENXIO;
        }

        mtd = nand_to_mtd(&host->chip);
        chip = &host->chip;

        nand_set_flash_node(chip, dn);
        nand_set_controller_data(chip, host);
        mtd->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "brcmnand.%d",
                                   host->cs);
        mtd->owner = THIS_MODULE;
        mtd->dev.parent = &pdev->dev;

        chip->IO_ADDR_R = (void __iomem *)0xdeadbeef;
        chip->IO_ADDR_W = (void __iomem *)0xdeadbeef;

        chip->cmd_ctrl = brcmnand_cmd_ctrl;
        chip->cmdfunc = brcmnand_cmdfunc;
        chip->waitfunc = brcmnand_waitfunc;
        chip->read_byte = brcmnand_read_byte;
        chip->read_buf = brcmnand_read_buf;
        chip->write_buf = brcmnand_write_buf;

        chip->ecc.mode = NAND_ECC_HW;
        chip->ecc.read_page = brcmnand_read_page;
        chip->ecc.write_page = brcmnand_write_page;
        chip->ecc.read_page_raw = brcmnand_read_page_raw;
        chip->ecc.write_page_raw = brcmnand_write_page_raw;
        chip->ecc.write_oob_raw = brcmnand_write_oob_raw;
        chip->ecc.read_oob_raw = brcmnand_read_oob_raw;
        chip->ecc.read_oob = brcmnand_read_oob;
        chip->ecc.write_oob = brcmnand_write_oob;

        chip->controller = &ctrl->controller;

        /*
         * The bootloader might have configured 16bit mode but
         * NAND READID command only works in 8bit mode. We force
         * 8bit mode here to ensure that NAND READID commands works.
         */
        cfg_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_CFG);
        nand_writereg(ctrl, cfg_offs,
                      nand_readreg(ctrl, cfg_offs) & ~CFG_BUS_WIDTH);

        ret = nand_scan_ident(mtd, 1, NULL);
        if (ret)
                return ret;

        chip->options |= NAND_NO_SUBPAGE_WRITE;
        /*
         * Avoid (for instance) kmap()'d buffers from JFFS2, which we can't DMA
         * to/from, and have nand_base pass us a bounce buffer instead, as
         * needed.
         */
        chip->options |= NAND_USE_BOUNCE_BUFFER;

        if (chip->bbt_options & NAND_BBT_USE_FLASH)
                chip->bbt_options |= NAND_BBT_NO_OOB;

        if (brcmnand_setup_dev(host))
                return -ENXIO;

        chip->ecc.size = host->hwcfg.sector_size_1k ? 1024 : 512;
        /* only use our internal HW threshold */
        mtd->bitflip_threshold = 1;

        ret = brcmstb_choose_ecc_layout(host);
        if (ret)
                return ret;

        ret = nand_scan_tail(mtd);
        if (ret)
                return ret;

        return mtd_device_register(mtd, NULL, 0);
}

static void brcmnand_save_restore_cs_config(struct brcmnand_host *host,
                                            int restore)
{
        struct brcmnand_controller *ctrl = host->ctrl;
        u16 cfg_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_CFG);
        u16 cfg_ext_offs = brcmnand_cs_offset(ctrl, host->cs,
                        BRCMNAND_CS_CFG_EXT);
        u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
                        BRCMNAND_CS_ACC_CONTROL);
        u16 t1_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_TIMING1);
        u16 t2_offs = brcmnand_cs_offset(ctrl, host->cs, BRCMNAND_CS_TIMING2);

        if (restore) {
                nand_writereg(ctrl, cfg_offs, host->hwcfg.config);
                if (cfg_offs != cfg_ext_offs)
                        nand_writereg(ctrl, cfg_ext_offs,
                                      host->hwcfg.config_ext);
                nand_writereg(ctrl, acc_control_offs, host->hwcfg.acc_control);
                nand_writereg(ctrl, t1_offs, host->hwcfg.timing_1);
                nand_writereg(ctrl, t2_offs, host->hwcfg.timing_2);
        } else {
                host->hwcfg.config = nand_readreg(ctrl, cfg_offs);
                if (cfg_offs != cfg_ext_offs)
                        host->hwcfg.config_ext =
                                nand_readreg(ctrl, cfg_ext_offs);
                host->hwcfg.acc_control = nand_readreg(ctrl, acc_control_offs);
                host->hwcfg.timing_1 = nand_readreg(ctrl, t1_offs);
                host->hwcfg.timing_2 = nand_readreg(ctrl, t2_offs);
        }
}

static int brcmnand_suspend(struct device *dev)
{
        struct brcmnand_controller *ctrl = dev_get_drvdata(dev);
        struct brcmnand_host *host;

        list_for_each_entry(host, &ctrl->host_list, node)
                brcmnand_save_restore_cs_config(host, 0);

        ctrl->nand_cs_nand_select = brcmnand_read_reg(ctrl, BRCMNAND_CS_SELECT);
        ctrl->nand_cs_nand_xor = brcmnand_read_reg(ctrl, BRCMNAND_CS_XOR);
        ctrl->corr_stat_threshold =
                brcmnand_read_reg(ctrl, BRCMNAND_CORR_THRESHOLD);

        if (has_flash_dma(ctrl))
                ctrl->flash_dma_mode = flash_dma_readl(ctrl, FLASH_DMA_MODE);

        return 0;
}

static int brcmnand_resume(struct device *dev)
{
        struct brcmnand_controller *ctrl = dev_get_drvdata(dev);
        struct brcmnand_host *host;

        if (has_flash_dma(ctrl)) {
                flash_dma_writel(ctrl, FLASH_DMA_MODE, ctrl->flash_dma_mode);
                flash_dma_writel(ctrl, FLASH_DMA_ERROR_STATUS, 0);
        }

        brcmnand_write_reg(ctrl, BRCMNAND_CS_SELECT, ctrl->nand_cs_nand_select);
        brcmnand_write_reg(ctrl, BRCMNAND_CS_XOR, ctrl->nand_cs_nand_xor);
        brcmnand_write_reg(ctrl, BRCMNAND_CORR_THRESHOLD,
                        ctrl->corr_stat_threshold);
        if (ctrl->soc) {
                /* Clear/re-enable interrupt */
                ctrl->soc->ctlrdy_ack(ctrl->soc);
                ctrl->soc->ctlrdy_set_enabled(ctrl->soc, true);
        }

        list_for_each_entry(host, &ctrl->host_list, node) {
                struct nand_chip *chip = &host->chip;
                struct mtd_info *mtd = nand_to_mtd(chip);

                brcmnand_save_restore_cs_config(host, 1);

                /* Reset the chip, required by some chips after power-up */
                chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
        }

        return 0;
}

const struct dev_pm_ops brcmnand_pm_ops = {
        .suspend                = brcmnand_suspend,
        .resume                 = brcmnand_resume,
};
EXPORT_SYMBOL_GPL(brcmnand_pm_ops);

static const struct of_device_id brcmnand_of_match[] = {
        { .compatible = "brcm,brcmnand-v4.0" },
        { .compatible = "brcm,brcmnand-v5.0" },
        { .compatible = "brcm,brcmnand-v6.0" },
        { .compatible = "brcm,brcmnand-v6.1" },
        { .compatible = "brcm,brcmnand-v6.2" },
        { .compatible = "brcm,brcmnand-v7.0" },
        { .compatible = "brcm,brcmnand-v7.1" },
        { .compatible = "brcm,brcmnand-v7.2" },
        {},
};
MODULE_DEVICE_TABLE(of, brcmnand_of_match);

/***********************************************************************
 * Platform driver setup (per controller)
 ***********************************************************************/

int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
{
        struct device *dev = &pdev->dev;
        struct device_node *dn = dev->of_node, *child;
        struct brcmnand_controller *ctrl;
        struct resource *res;
        int ret;

        /* We only support device-tree instantiation */
        if (!dn)
                return -ENODEV;

        if (!of_match_node(brcmnand_of_match, dn))
                return -ENODEV;

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

        dev_set_drvdata(dev, ctrl);
        ctrl->dev = dev;

        init_completion(&ctrl->done);
        init_completion(&ctrl->dma_done);
        nand_hw_control_init(&ctrl->controller);
        INIT_LIST_HEAD(&ctrl->host_list);

        /* NAND register range */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        ctrl->nand_base = devm_ioremap_resource(dev, res);
        if (IS_ERR(ctrl->nand_base))
                return PTR_ERR(ctrl->nand_base);

        /* Enable clock before using NAND registers */
        ctrl->clk = devm_clk_get(dev, "nand");
        if (!IS_ERR(ctrl->clk)) {
                ret = clk_prepare_enable(ctrl->clk);
                if (ret)
                        return ret;
        } else {
                ret = PTR_ERR(ctrl->clk);
                if (ret == -EPROBE_DEFER)
                        return ret;

                ctrl->clk = NULL;
        }

        /* Initialize NAND revision */
        ret = brcmnand_revision_init(ctrl);
        if (ret)
                goto err;

        /*
         * Most chips have this cache at a fixed offset within 'nand' block.
         * Some must specify this region separately.
         */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand-cache");
        if (res) {
                ctrl->nand_fc = devm_ioremap_resource(dev, res);
                if (IS_ERR(ctrl->nand_fc)) {
                        ret = PTR_ERR(ctrl->nand_fc);
                        goto err;
                }
        } else {
                ctrl->nand_fc = ctrl->nand_base +
                                ctrl->reg_offsets[BRCMNAND_FC_BASE];
        }

        /* FLASH_DMA */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "flash-dma");
        if (res) {
                ctrl->flash_dma_base = devm_ioremap_resource(dev, res);
                if (IS_ERR(ctrl->flash_dma_base)) {
                        ret = PTR_ERR(ctrl->flash_dma_base);
                        goto err;
                }

                flash_dma_writel(ctrl, FLASH_DMA_MODE, 1); /* linked-list */
                flash_dma_writel(ctrl, FLASH_DMA_ERROR_STATUS, 0);

                /* Allocate descriptor(s) */
                ctrl->dma_desc = dmam_alloc_coherent(dev,
                                                     sizeof(*ctrl->dma_desc),
                                                     &ctrl->dma_pa, GFP_KERNEL);
                if (!ctrl->dma_desc) {
                        ret = -ENOMEM;
                        goto err;
                }

                ctrl->dma_irq = platform_get_irq(pdev, 1);
                if ((int)ctrl->dma_irq < 0) {
                        dev_err(dev, "missing FLASH_DMA IRQ\n");
                        ret = -ENODEV;
                        goto err;
                }

                ret = devm_request_irq(dev, ctrl->dma_irq,
                                brcmnand_dma_irq, 0, DRV_NAME,
                                ctrl);
                if (ret < 0) {
                        dev_err(dev, "can't allocate IRQ %d: error %d\n",
                                        ctrl->dma_irq, ret);
                        goto err;
                }

                dev_info(dev, "enabling FLASH_DMA\n");
        }

        /* Disable automatic device ID config, direct addressing */
        brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT,
                         CS_SELECT_AUTO_DEVICE_ID_CFG | 0xff, 0, 0);
        /* Disable XOR addressing */
        brcmnand_rmw_reg(ctrl, BRCMNAND_CS_XOR, 0xff, 0, 0);

        if (ctrl->features & BRCMNAND_HAS_WP) {
                /* Permanently disable write protection */
                if (wp_on == 2)
                        brcmnand_set_wp(ctrl, false);
        } else {
                wp_on = 0;
        }

        /* IRQ */
        ctrl->irq = platform_get_irq(pdev, 0);
        if ((int)ctrl->irq < 0) {
                dev_err(dev, "no IRQ defined\n");
                ret = -ENODEV;
                goto err;
        }

        /*
         * Some SoCs integrate this controller (e.g., its interrupt bits) in
         * interesting ways
         */
        if (soc) {
                ctrl->soc = soc;

                ret = devm_request_irq(dev, ctrl->irq, brcmnand_irq, 0,
                                       DRV_NAME, ctrl);

                /* Enable interrupt */
                ctrl->soc->ctlrdy_ack(ctrl->soc);
                ctrl->soc->ctlrdy_set_enabled(ctrl->soc, true);
        } else {
                /* Use standard interrupt infrastructure */
                ret = devm_request_irq(dev, ctrl->irq, brcmnand_ctlrdy_irq, 0,
                                       DRV_NAME, ctrl);
        }
        if (ret < 0) {
                dev_err(dev, "can't allocate IRQ %d: error %d\n",
                        ctrl->irq, ret);
                goto err;
        }

        for_each_available_child_of_node(dn, child) {
                if (of_device_is_compatible(child, "brcm,nandcs")) {
                        struct brcmnand_host *host;

                        host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
                        if (!host) {
                                of_node_put(child);
                                ret = -ENOMEM;
                                goto err;
                        }
                        host->pdev = pdev;
                        host->ctrl = ctrl;

                        ret = brcmnand_init_cs(host, child);
                        if (ret) {
                                devm_kfree(dev, host);
                                continue; /* Try all chip-selects */
                        }

                        list_add_tail(&host->node, &ctrl->host_list);
                }
        }

        /* No chip-selects could initialize properly */
        if (list_empty(&ctrl->host_list)) {
                ret = -ENODEV;
                goto err;
        }

        return 0;

err:
        clk_disable_unprepare(ctrl->clk);
        return ret;

}
EXPORT_SYMBOL_GPL(brcmnand_probe);

int brcmnand_remove(struct platform_device *pdev)
{
        struct brcmnand_controller *ctrl = dev_get_drvdata(&pdev->dev);
        struct brcmnand_host *host;

        list_for_each_entry(host, &ctrl->host_list, node)
                nand_release(nand_to_mtd(&host->chip));

        clk_disable_unprepare(ctrl->clk);

        dev_set_drvdata(&pdev->dev, NULL);

        return 0;
}
EXPORT_SYMBOL_GPL(brcmnand_remove);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Kevin Cernekee");
MODULE_AUTHOR("Brian Norris");
MODULE_DESCRIPTION("NAND driver for Broadcom chips");
MODULE_ALIAS("platform:brcmnand");