// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016-2017 Micron Technology, Inc.
 *
 * Authors:
 *      Peter Pan <peterpandong@micron.com>
 *      Boris Brezillon <boris.brezillon@bootlin.com>
 */

#define pr_fmt(fmt)     "spi-nand: " fmt

#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/spinand.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>

static void spinand_cache_op_adjust_colum(struct spinand_device *spinand,
                                          const struct nand_page_io_req *req,
                                          u16 *column)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int shift;

        if (nand->memorg.planes_per_lun < 2)
                return;

        /* The plane number is passed in MSB just above the column address */
        shift = fls(nand->memorg.pagesize);
        *column |= req->pos.plane << shift;
}

static int spinand_read_reg_op(struct spinand_device *spinand, u8 reg, u8 *val)
{
        struct spi_mem_op op = SPINAND_GET_FEATURE_OP(reg,
                                                      spinand->scratchbuf);
        int ret;

        ret = spi_mem_exec_op(spinand->spimem, &op);
        if (ret)
                return ret;

        *val = *spinand->scratchbuf;
        return 0;
}

static int spinand_write_reg_op(struct spinand_device *spinand, u8 reg, u8 val)
{
        struct spi_mem_op op = SPINAND_SET_FEATURE_OP(reg,
                                                      spinand->scratchbuf);

        *spinand->scratchbuf = val;
        return spi_mem_exec_op(spinand->spimem, &op);
}

static int spinand_read_status(struct spinand_device *spinand, u8 *status)
{
        return spinand_read_reg_op(spinand, REG_STATUS, status);
}

static int spinand_get_cfg(struct spinand_device *spinand, u8 *cfg)
{
        struct nand_device *nand = spinand_to_nand(spinand);

        if (WARN_ON(spinand->cur_target < 0 ||
                    spinand->cur_target >= nand->memorg.ntargets))
                return -EINVAL;

        *cfg = spinand->cfg_cache[spinand->cur_target];
        return 0;
}

static int spinand_set_cfg(struct spinand_device *spinand, u8 cfg)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        int ret;

        if (WARN_ON(spinand->cur_target < 0 ||
                    spinand->cur_target >= nand->memorg.ntargets))
                return -EINVAL;

        if (spinand->cfg_cache[spinand->cur_target] == cfg)
                return 0;

        ret = spinand_write_reg_op(spinand, REG_CFG, cfg);
        if (ret)
                return ret;

        spinand->cfg_cache[spinand->cur_target] = cfg;
        return 0;
}

/**
 * spinand_upd_cfg() - Update the configuration register
 * @spinand: the spinand device
 * @mask: the mask encoding the bits to update in the config reg
 * @val: the new value to apply
 *
 * Update the configuration register.
 *
 * Return: 0 on success, a negative error code otherwise.
 */
int spinand_upd_cfg(struct spinand_device *spinand, u8 mask, u8 val)
{
        int ret;
        u8 cfg;

        ret = spinand_get_cfg(spinand, &cfg);
        if (ret)
                return ret;

        cfg &= ~mask;
        cfg |= val;

        return spinand_set_cfg(spinand, cfg);
}

/**
 * spinand_select_target() - Select a specific NAND target/die
 * @spinand: the spinand device
 * @target: the target/die to select
 *
 * Select a new target/die. If chip only has one die, this function is a NOOP.
 *
 * Return: 0 on success, a negative error code otherwise.
 */
int spinand_select_target(struct spinand_device *spinand, unsigned int target)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        int ret;

        if (WARN_ON(target >= nand->memorg.ntargets))
                return -EINVAL;

        if (spinand->cur_target == target)
                return 0;

        if (nand->memorg.ntargets == 1) {
                spinand->cur_target = target;
                return 0;
        }

        ret = spinand->select_target(spinand, target);
        if (ret)
                return ret;

        spinand->cur_target = target;
        return 0;
}

static int spinand_init_cfg_cache(struct spinand_device *spinand)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        struct device *dev = &spinand->spimem->spi->dev;
        unsigned int target;
        int ret;

        spinand->cfg_cache = devm_kcalloc(dev,
                                          nand->memorg.ntargets,
                                          sizeof(*spinand->cfg_cache),
                                          GFP_KERNEL);
        if (!spinand->cfg_cache)
                return -ENOMEM;

        for (target = 0; target < nand->memorg.ntargets; target++) {
                ret = spinand_select_target(spinand, target);
                if (ret)
                        return ret;

                /*
                 * We use spinand_read_reg_op() instead of spinand_get_cfg()
                 * here to bypass the config cache.
                 */
                ret = spinand_read_reg_op(spinand, REG_CFG,
                                          &spinand->cfg_cache[target]);
                if (ret)
                        return ret;
        }

        return 0;
}

static int spinand_init_quad_enable(struct spinand_device *spinand)
{
        bool enable = false;

        if (!(spinand->flags & SPINAND_HAS_QE_BIT))
                return 0;

        if (spinand->op_templates.read_cache->data.buswidth == 4 ||
            spinand->op_templates.write_cache->data.buswidth == 4 ||
            spinand->op_templates.update_cache->data.buswidth == 4)
                enable = true;

        return spinand_upd_cfg(spinand, CFG_QUAD_ENABLE,
                               enable ? CFG_QUAD_ENABLE : 0);
}

static int spinand_ecc_enable(struct spinand_device *spinand,
                              bool enable)
{
        return spinand_upd_cfg(spinand, CFG_ECC_ENABLE,
                               enable ? CFG_ECC_ENABLE : 0);
}

static int spinand_write_enable_op(struct spinand_device *spinand)
{
        struct spi_mem_op op = SPINAND_WR_EN_DIS_OP(true);

        return spi_mem_exec_op(spinand->spimem, &op);
}

static int spinand_load_page_op(struct spinand_device *spinand,
                                const struct nand_page_io_req *req)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int row = nanddev_pos_to_row(nand, &req->pos);
        struct spi_mem_op op = SPINAND_PAGE_READ_OP(row);

        return spi_mem_exec_op(spinand->spimem, &op);
}

static int spinand_read_from_cache_op(struct spinand_device *spinand,
                                      const struct nand_page_io_req *req)
{
        struct spi_mem_op op = *spinand->op_templates.read_cache;
        struct nand_device *nand = spinand_to_nand(spinand);
        struct mtd_info *mtd = nanddev_to_mtd(nand);
        struct nand_page_io_req adjreq = *req;
        unsigned int nbytes = 0;
        void *buf = NULL;
        u16 column = 0;
        int ret;

        if (req->datalen) {
                adjreq.datalen = nanddev_page_size(nand);
                adjreq.dataoffs = 0;
                adjreq.databuf.in = spinand->databuf;
                buf = spinand->databuf;
                nbytes = adjreq.datalen;
        }

        if (req->ooblen) {
                adjreq.ooblen = nanddev_per_page_oobsize(nand);
                adjreq.ooboffs = 0;
                adjreq.oobbuf.in = spinand->oobbuf;
                nbytes += nanddev_per_page_oobsize(nand);
                if (!buf) {
                        buf = spinand->oobbuf;
                        column = nanddev_page_size(nand);
                }
        }

        spinand_cache_op_adjust_colum(spinand, &adjreq, &column);
        op.addr.val = column;

        /*
         * Some controllers are limited in term of max RX data size. In this
         * case, just repeat the READ_CACHE operation after updating the
         * column.
         */
        while (nbytes) {
                op.data.buf.in = buf;
                op.data.nbytes = nbytes;
                ret = spi_mem_adjust_op_size(spinand->spimem, &op);
                if (ret)
                        return ret;

                ret = spi_mem_exec_op(spinand->spimem, &op);
                if (ret)
                        return ret;

                buf += op.data.nbytes;
                nbytes -= op.data.nbytes;
                op.addr.val += op.data.nbytes;
        }

        if (req->datalen)
                memcpy(req->databuf.in, spinand->databuf + req->dataoffs,
                       req->datalen);

        if (req->ooblen) {
                if (req->mode == MTD_OPS_AUTO_OOB)
                        mtd_ooblayout_get_databytes(mtd, req->oobbuf.in,
                                                    spinand->oobbuf,
                                                    req->ooboffs,
                                                    req->ooblen);
                else
                        memcpy(req->oobbuf.in, spinand->oobbuf + req->ooboffs,
                               req->ooblen);
        }

        return 0;
}

static int spinand_write_to_cache_op(struct spinand_device *spinand,
                                     const struct nand_page_io_req *req)
{
        struct spi_mem_op op = *spinand->op_templates.write_cache;
        struct nand_device *nand = spinand_to_nand(spinand);
        struct mtd_info *mtd = nanddev_to_mtd(nand);
        struct nand_page_io_req adjreq = *req;
        unsigned int nbytes = 0;
        void *buf = NULL;
        u16 column = 0;
        int ret;

        memset(spinand->databuf, 0xff,
               nanddev_page_size(nand) +
               nanddev_per_page_oobsize(nand));

        if (req->datalen) {
                memcpy(spinand->databuf + req->dataoffs, req->databuf.out,
                       req->datalen);
                adjreq.dataoffs = 0;
                adjreq.datalen = nanddev_page_size(nand);
                adjreq.databuf.out = spinand->databuf;
                nbytes = adjreq.datalen;
                buf = spinand->databuf;
        }

        if (req->ooblen) {
                if (req->mode == MTD_OPS_AUTO_OOB)
                        mtd_ooblayout_set_databytes(mtd, req->oobbuf.out,
                                                    spinand->oobbuf,
                                                    req->ooboffs,
                                                    req->ooblen);
                else
                        memcpy(spinand->oobbuf + req->ooboffs, req->oobbuf.out,
                               req->ooblen);

                adjreq.ooblen = nanddev_per_page_oobsize(nand);
                adjreq.ooboffs = 0;
                nbytes += nanddev_per_page_oobsize(nand);
                if (!buf) {
                        buf = spinand->oobbuf;
                        column = nanddev_page_size(nand);
                }
        }

        spinand_cache_op_adjust_colum(spinand, &adjreq, &column);

        op = *spinand->op_templates.write_cache;
        op.addr.val = column;

        /*
         * Some controllers are limited in term of max TX data size. In this
         * case, split the operation into one LOAD CACHE and one or more
         * LOAD RANDOM CACHE.
         */
        while (nbytes) {
                op.data.buf.out = buf;
                op.data.nbytes = nbytes;

                ret = spi_mem_adjust_op_size(spinand->spimem, &op);
                if (ret)
                        return ret;

                ret = spi_mem_exec_op(spinand->spimem, &op);
                if (ret)
                        return ret;

                buf += op.data.nbytes;
                nbytes -= op.data.nbytes;
                op.addr.val += op.data.nbytes;

                /*
                 * We need to use the RANDOM LOAD CACHE operation if there's
                 * more than one iteration, because the LOAD operation resets
                 * the cache to 0xff.
                 */
                if (nbytes) {
                        column = op.addr.val;
                        op = *spinand->op_templates.update_cache;
                        op.addr.val = column;
                }
        }

        return 0;
}

static int spinand_program_op(struct spinand_device *spinand,
                              const struct nand_page_io_req *req)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int row = nanddev_pos_to_row(nand, &req->pos);
        struct spi_mem_op op = SPINAND_PROG_EXEC_OP(row);

        return spi_mem_exec_op(spinand->spimem, &op);
}

static int spinand_erase_op(struct spinand_device *spinand,
                            const struct nand_pos *pos)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int row = nanddev_pos_to_row(nand, pos);
        struct spi_mem_op op = SPINAND_BLK_ERASE_OP(row);

        return spi_mem_exec_op(spinand->spimem, &op);
}

static int spinand_wait(struct spinand_device *spinand, u8 *s)
{
        unsigned long timeo =  jiffies + msecs_to_jiffies(400);
        u8 status;
        int ret;

        do {
                ret = spinand_read_status(spinand, &status);
                if (ret)
                        return ret;

                if (!(status & STATUS_BUSY))
                        goto out;
        } while (time_before(jiffies, timeo));

        /*
         * Extra read, just in case the STATUS_READY bit has changed
         * since our last check
         */
        ret = spinand_read_status(spinand, &status);
        if (ret)
                return ret;

out:
        if (s)
                *s = status;

        return status & STATUS_BUSY ? -ETIMEDOUT : 0;
}

static int spinand_read_id_op(struct spinand_device *spinand, u8 *buf)
{
        struct spi_mem_op op = SPINAND_READID_OP(0, spinand->scratchbuf,
                                                 SPINAND_MAX_ID_LEN);
        int ret;

        ret = spi_mem_exec_op(spinand->spimem, &op);
        if (!ret)
                memcpy(buf, spinand->scratchbuf, SPINAND_MAX_ID_LEN);

        return ret;
}

static int spinand_reset_op(struct spinand_device *spinand)
{
        struct spi_mem_op op = SPINAND_RESET_OP;
        int ret;

        ret = spi_mem_exec_op(spinand->spimem, &op);
        if (ret)
                return ret;

        return spinand_wait(spinand, NULL);
}

static int spinand_lock_block(struct spinand_device *spinand, u8 lock)
{
        return spinand_write_reg_op(spinand, REG_BLOCK_LOCK, lock);
}

static int spinand_check_ecc_status(struct spinand_device *spinand, u8 status)
{
        struct nand_device *nand = spinand_to_nand(spinand);

        if (spinand->eccinfo.get_status)
                return spinand->eccinfo.get_status(spinand, status);

        switch (status & STATUS_ECC_MASK) {
        case STATUS_ECC_NO_BITFLIPS:
                return 0;

        case STATUS_ECC_HAS_BITFLIPS:
                /*
                 * We have no way to know exactly how many bitflips have been
                 * fixed, so let's return the maximum possible value so that
                 * wear-leveling layers move the data immediately.
                 */
                return nand->eccreq.strength;

        case STATUS_ECC_UNCOR_ERROR:
                return -EBADMSG;

        default:
                break;
        }

        return -EINVAL;
}

static int spinand_read_page(struct spinand_device *spinand,
                             const struct nand_page_io_req *req,
                             bool ecc_enabled)
{
        u8 status;
        int ret;

        ret = spinand_load_page_op(spinand, req);
        if (ret)
                return ret;

        ret = spinand_wait(spinand, &status);
        if (ret < 0)
                return ret;

        ret = spinand_read_from_cache_op(spinand, req);
        if (ret)
                return ret;

        if (!ecc_enabled)
                return 0;

        return spinand_check_ecc_status(spinand, status);
}

static int spinand_write_page(struct spinand_device *spinand,
                              const struct nand_page_io_req *req)
{
        u8 status;
        int ret;

        ret = spinand_write_enable_op(spinand);
        if (ret)
                return ret;

        ret = spinand_write_to_cache_op(spinand, req);
        if (ret)
                return ret;

        ret = spinand_program_op(spinand, req);
        if (ret)
                return ret;

        ret = spinand_wait(spinand, &status);
        if (!ret && (status & STATUS_PROG_FAILED))
                ret = -EIO;

        return ret;
}

static int spinand_mtd_read(struct mtd_info *mtd, loff_t from,
                            struct mtd_oob_ops *ops)
{
        struct spinand_device *spinand = mtd_to_spinand(mtd);
        struct nand_device *nand = mtd_to_nanddev(mtd);
        unsigned int max_bitflips = 0;
        struct nand_io_iter iter;
        bool enable_ecc = false;
        bool ecc_failed = false;
        int ret = 0;

        if (ops->mode != MTD_OPS_RAW && spinand->eccinfo.ooblayout)
                enable_ecc = true;

        mutex_lock(&spinand->lock);

        nanddev_io_for_each_page(nand, from, ops, &iter) {
                ret = spinand_select_target(spinand, iter.req.pos.target);
                if (ret)
                        break;

                ret = spinand_ecc_enable(spinand, enable_ecc);
                if (ret)
                        break;

                ret = spinand_read_page(spinand, &iter.req, enable_ecc);
                if (ret < 0 && ret != -EBADMSG)
                        break;

                if (ret == -EBADMSG) {
                        ecc_failed = true;
                        mtd->ecc_stats.failed++;
                        ret = 0;
                } else {
                        mtd->ecc_stats.corrected += ret;
                        max_bitflips = max_t(unsigned int, max_bitflips, ret);
                }

                ops->retlen += iter.req.datalen;
                ops->oobretlen += iter.req.ooblen;
        }

        mutex_unlock(&spinand->lock);

        if (ecc_failed && !ret)
                ret = -EBADMSG;

        return ret ? ret : max_bitflips;
}

static int spinand_mtd_write(struct mtd_info *mtd, loff_t to,
                             struct mtd_oob_ops *ops)
{
        struct spinand_device *spinand = mtd_to_spinand(mtd);
        struct nand_device *nand = mtd_to_nanddev(mtd);
        struct nand_io_iter iter;
        bool enable_ecc = false;
        int ret = 0;

        if (ops->mode != MTD_OPS_RAW && mtd->ooblayout)
                enable_ecc = true;

        mutex_lock(&spinand->lock);

        nanddev_io_for_each_page(nand, to, ops, &iter) {
                ret = spinand_select_target(spinand, iter.req.pos.target);
                if (ret)
                        break;

                ret = spinand_ecc_enable(spinand, enable_ecc);
                if (ret)
                        break;

                ret = spinand_write_page(spinand, &iter.req);
                if (ret)
                        break;

                ops->retlen += iter.req.datalen;
                ops->oobretlen += iter.req.ooblen;
        }

        mutex_unlock(&spinand->lock);

        return ret;
}

static bool spinand_isbad(struct nand_device *nand, const struct nand_pos *pos)
{
        struct spinand_device *spinand = nand_to_spinand(nand);
        struct nand_page_io_req req = {
                .pos = *pos,
                .ooblen = 2,
                .ooboffs = 0,
                .oobbuf.in = spinand->oobbuf,
                .mode = MTD_OPS_RAW,
        };

        memset(spinand->oobbuf, 0, 2);
        spinand_select_target(spinand, pos->target);
        spinand_read_page(spinand, &req, false);
        if (spinand->oobbuf[0] != 0xff || spinand->oobbuf[1] != 0xff)
                return true;

        return false;
}

static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs)
{
        struct nand_device *nand = mtd_to_nanddev(mtd);
        struct spinand_device *spinand = nand_to_spinand(nand);
        struct nand_pos pos;
        int ret;

        nanddev_offs_to_pos(nand, offs, &pos);
        mutex_lock(&spinand->lock);
        ret = nanddev_isbad(nand, &pos);
        mutex_unlock(&spinand->lock);

        return ret;
}

static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos)
{
        struct spinand_device *spinand = nand_to_spinand(nand);
        struct nand_page_io_req req = {
                .pos = *pos,
                .ooboffs = 0,
                .ooblen = 2,
                .oobbuf.out = spinand->oobbuf,
        };
        int ret;

        /* Erase block before marking it bad. */
        ret = spinand_select_target(spinand, pos->target);
        if (ret)
                return ret;

        ret = spinand_write_enable_op(spinand);
        if (ret)
                return ret;

        spinand_erase_op(spinand, pos);

        memset(spinand->oobbuf, 0, 2);
        return spinand_write_page(spinand, &req);
}

static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs)
{
        struct nand_device *nand = mtd_to_nanddev(mtd);
        struct spinand_device *spinand = nand_to_spinand(nand);
        struct nand_pos pos;
        int ret;

        nanddev_offs_to_pos(nand, offs, &pos);
        mutex_lock(&spinand->lock);
        ret = nanddev_markbad(nand, &pos);
        mutex_unlock(&spinand->lock);

        return ret;
}

static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos)
{
        struct spinand_device *spinand = nand_to_spinand(nand);
        u8 status;
        int ret;

        ret = spinand_select_target(spinand, pos->target);
        if (ret)
                return ret;

        ret = spinand_write_enable_op(spinand);
        if (ret)
                return ret;

        ret = spinand_erase_op(spinand, pos);
        if (ret)
                return ret;

        ret = spinand_wait(spinand, &status);
        if (!ret && (status & STATUS_ERASE_FAILED))
                ret = -EIO;

        return ret;
}

static int spinand_mtd_erase(struct mtd_info *mtd,
                             struct erase_info *einfo)
{
        struct spinand_device *spinand = mtd_to_spinand(mtd);
        int ret;

        mutex_lock(&spinand->lock);
        ret = nanddev_mtd_erase(mtd, einfo);
        mutex_unlock(&spinand->lock);

        return ret;
}

static int spinand_mtd_block_isreserved(struct mtd_info *mtd, loff_t offs)
{
        struct spinand_device *spinand = mtd_to_spinand(mtd);
        struct nand_device *nand = mtd_to_nanddev(mtd);
        struct nand_pos pos;
        int ret;

        nanddev_offs_to_pos(nand, offs, &pos);
        mutex_lock(&spinand->lock);
        ret = nanddev_isreserved(nand, &pos);
        mutex_unlock(&spinand->lock);

        return ret;
}

static const struct nand_ops spinand_ops = {
        .erase = spinand_erase,
        .markbad = spinand_markbad,
        .isbad = spinand_isbad,
};

static const struct spinand_manufacturer *spinand_manufacturers[] = {
        &macronix_spinand_manufacturer,
        &micron_spinand_manufacturer,
        &winbond_spinand_manufacturer,
};

static int spinand_manufacturer_detect(struct spinand_device *spinand)
{
        unsigned int i;
        int ret;

        for (i = 0; i < ARRAY_SIZE(spinand_manufacturers); i++) {
                ret = spinand_manufacturers[i]->ops->detect(spinand);
                if (ret > 0) {
                        spinand->manufacturer = spinand_manufacturers[i];
                        return 0;
                } else if (ret < 0) {
                        return ret;
                }
        }

        return -ENOTSUPP;
}

static int spinand_manufacturer_init(struct spinand_device *spinand)
{
        if (spinand->manufacturer->ops->init)
                return spinand->manufacturer->ops->init(spinand);

        return 0;
}

static void spinand_manufacturer_cleanup(struct spinand_device *spinand)
{
        /* Release manufacturer private data */
        if (spinand->manufacturer->ops->cleanup)
                return spinand->manufacturer->ops->cleanup(spinand);
}

static const struct spi_mem_op *
spinand_select_op_variant(struct spinand_device *spinand,
                          const struct spinand_op_variants *variants)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int i;

        for (i = 0; i < variants->nops; i++) {
                struct spi_mem_op op = variants->ops[i];
                unsigned int nbytes;
                int ret;

                nbytes = nanddev_per_page_oobsize(nand) +
                         nanddev_page_size(nand);

                while (nbytes) {
                        op.data.nbytes = nbytes;
                        ret = spi_mem_adjust_op_size(spinand->spimem, &op);
                        if (ret)
                                break;

                        if (!spi_mem_supports_op(spinand->spimem, &op))
                                break;

                        nbytes -= op.data.nbytes;
                }

                if (!nbytes)
                        return &variants->ops[i];
        }

        return NULL;
}

/**
 * spinand_match_and_init() - Try to find a match between a device ID and an
 *                            entry in a spinand_info table
 * @spinand: SPI NAND object
 * @table: SPI NAND device description table
 * @table_size: size of the device description table
 *
 * Should be used by SPI NAND manufacturer drivers when they want to find a
 * match between a device ID retrieved through the READ_ID command and an
 * entry in the SPI NAND description table. If a match is found, the spinand
 * object will be initialized with information provided by the matching
 * spinand_info entry.
 *
 * Return: 0 on success, a negative error code otherwise.
 */
int spinand_match_and_init(struct spinand_device *spinand,
                           const struct spinand_info *table,
                           unsigned int table_size, u8 devid)
{
        struct nand_device *nand = spinand_to_nand(spinand);
        unsigned int i;

        for (i = 0; i < table_size; i++) {
                const struct spinand_info *info = &table[i];
                const struct spi_mem_op *op;

                if (devid != info->devid)
                        continue;

                nand->memorg = table[i].memorg;
                nand->eccreq = table[i].eccreq;
                spinand->eccinfo = table[i].eccinfo;
                spinand->flags = table[i].flags;
                spinand->select_target = table[i].select_target;

                op = spinand_select_op_variant(spinand,
                                               info->op_variants.read_cache);
                if (!op)
                        return -ENOTSUPP;

                spinand->op_templates.read_cache = op;

                op = spinand_select_op_variant(spinand,
                                               info->op_variants.write_cache);
                if (!op)
                        return -ENOTSUPP;

                spinand->op_templates.write_cache = op;

                op = spinand_select_op_variant(spinand,
                                               info->op_variants.update_cache);
                spinand->op_templates.update_cache = op;

                return 0;
        }

        return -ENOTSUPP;
}

static int spinand_detect(struct spinand_device *spinand)
{
        struct device *dev = &spinand->spimem->spi->dev;
        struct nand_device *nand = spinand_to_nand(spinand);
        int ret;

        ret = spinand_reset_op(spinand);
        if (ret)
                return ret;

        ret = spinand_read_id_op(spinand, spinand->id.data);
        if (ret)
                return ret;

        spinand->id.len = SPINAND_MAX_ID_LEN;

        ret = spinand_manufacturer_detect(spinand);
        if (ret) {
                dev_err(dev, "unknown raw ID %*phN\n", SPINAND_MAX_ID_LEN,
                        spinand->id.data);
                return ret;
        }

        if (nand->memorg.ntargets > 1 && !spinand->select_target) {
                dev_err(dev,
                        "SPI NANDs with more than one die must implement ->select_target()\n");
                return -EINVAL;
        }

        dev_info(&spinand->spimem->spi->dev,
                 "%s SPI NAND was found.\n", spinand->manufacturer->name);
        dev_info(&spinand->spimem->spi->dev,
                 "%llu MiB, block size: %zu KiB, page size: %zu, OOB size: %u\n",
                 nanddev_size(nand) >> 20, nanddev_eraseblock_size(nand) >> 10,
                 nanddev_page_size(nand), nanddev_per_page_oobsize(nand));

        return 0;
}

static int spinand_noecc_ooblayout_ecc(struct mtd_info *mtd, int section,
                                       struct mtd_oob_region *region)
{
        return -ERANGE;
}

static int spinand_noecc_ooblayout_free(struct mtd_info *mtd, int section,
                                        struct mtd_oob_region *region)
{
        if (section)
                return -ERANGE;

        /* Reserve 2 bytes for the BBM. */
        region->offset = 2;
        region->length = 62;

        return 0;
}

static const struct mtd_ooblayout_ops spinand_noecc_ooblayout = {
        .ecc = spinand_noecc_ooblayout_ecc,
        .free = spinand_noecc_ooblayout_free,
};

static int spinand_init(struct spinand_device *spinand)
{
        struct device *dev = &spinand->spimem->spi->dev;
        struct mtd_info *mtd = spinand_to_mtd(spinand);
        struct nand_device *nand = mtd_to_nanddev(mtd);
        int ret, i;

        /*
         * We need a scratch buffer because the spi_mem interface requires that
         * buf passed in spi_mem_op->data.buf be DMA-able.
         */
        spinand->scratchbuf = kzalloc(SPINAND_MAX_ID_LEN, GFP_KERNEL);
        if (!spinand->scratchbuf)
                return -ENOMEM;

        ret = spinand_detect(spinand);
        if (ret)
                goto err_free_bufs;

        /*
         * Use kzalloc() instead of devm_kzalloc() here, because some drivers
         * may use this buffer for DMA access.
         * Memory allocated by devm_ does not guarantee DMA-safe alignment.
         */
        spinand->databuf = kzalloc(nanddev_page_size(nand) +
                               nanddev_per_page_oobsize(nand),
                               GFP_KERNEL);
        if (!spinand->databuf) {
                ret = -ENOMEM;
                goto err_free_bufs;
        }

        spinand->oobbuf = spinand->databuf + nanddev_page_size(nand);

        ret = spinand_init_cfg_cache(spinand);
        if (ret)
                goto err_free_bufs;

        ret = spinand_init_quad_enable(spinand);
        if (ret)

                goto err_free_bufs;

        ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
        if (ret)
                goto err_free_bufs;

        ret = spinand_manufacturer_init(spinand);
        if (ret) {
                dev_err(dev,
                        "Failed to initialize the SPI NAND chip (err = %d)\n",
                        ret);
                goto err_free_bufs;
        }

        /* After power up, all blocks are locked, so unlock them here. */
        for (i = 0; i < nand->memorg.ntargets; i++) {
                ret = spinand_select_target(spinand, i);
                if (ret)
                        goto err_free_bufs;

                ret = spinand_lock_block(spinand, BL_ALL_UNLOCKED);
                if (ret)
                        goto err_free_bufs;
        }

        ret = nanddev_init(nand, &spinand_ops, THIS_MODULE);
        if (ret)
                goto err_manuf_cleanup;

        /*
         * Right now, we don't support ECC, so let the whole oob
         * area is available for user.
         */
        mtd->_read_oob = spinand_mtd_read;
        mtd->_write_oob = spinand_mtd_write;
        mtd->_block_isbad = spinand_mtd_block_isbad;
        mtd->_block_markbad = spinand_mtd_block_markbad;
        mtd->_block_isreserved = spinand_mtd_block_isreserved;
        mtd->_erase = spinand_mtd_erase;

        if (spinand->eccinfo.ooblayout)
                mtd_set_ooblayout(mtd, spinand->eccinfo.ooblayout);
        else
                mtd_set_ooblayout(mtd, &spinand_noecc_ooblayout);

        ret = mtd_ooblayout_count_freebytes(mtd);
        if (ret < 0)
                goto err_cleanup_nanddev;

        mtd->oobavail = ret;

        return 0;

err_cleanup_nanddev:
        nanddev_cleanup(nand);

err_manuf_cleanup:
        spinand_manufacturer_cleanup(spinand);

err_free_bufs:
        kfree(spinand->databuf);
        kfree(spinand->scratchbuf);
        return ret;
}

static void spinand_cleanup(struct spinand_device *spinand)
{
        struct nand_device *nand = spinand_to_nand(spinand);

        nanddev_cleanup(nand);
        spinand_manufacturer_cleanup(spinand);
        kfree(spinand->databuf);
        kfree(spinand->scratchbuf);
}

static int spinand_probe(struct spi_mem *mem)
{
        struct spinand_device *spinand;
        struct mtd_info *mtd;
        int ret;

        spinand = devm_kzalloc(&mem->spi->dev, sizeof(*spinand),
                               GFP_KERNEL);
        if (!spinand)
                return -ENOMEM;

        spinand->spimem = mem;
        spi_mem_set_drvdata(mem, spinand);
        spinand_set_of_node(spinand, mem->spi->dev.of_node);
        mutex_init(&spinand->lock);
        mtd = spinand_to_mtd(spinand);
        mtd->dev.parent = &mem->spi->dev;

        ret = spinand_init(spinand);
        if (ret)
                return ret;

        ret = mtd_device_register(mtd, NULL, 0);
        if (ret)
                goto err_spinand_cleanup;

        return 0;

err_spinand_cleanup:
        spinand_cleanup(spinand);

        return ret;
}

static int spinand_remove(struct spi_mem *mem)
{
        struct spinand_device *spinand;
        struct mtd_info *mtd;
        int ret;

        spinand = spi_mem_get_drvdata(mem);
        mtd = spinand_to_mtd(spinand);

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

        spinand_cleanup(spinand);

        return 0;
}

static const struct spi_device_id spinand_ids[] = {
        { .name = "spi-nand" },
        { /* sentinel */ },
};

#ifdef CONFIG_OF
static const struct of_device_id spinand_of_ids[] = {
        { .compatible = "spi-nand" },
        { /* sentinel */ },
};
#endif

static struct spi_mem_driver spinand_drv = {
        .spidrv = {
                .id_table = spinand_ids,
                .driver = {
                        .name = "spi-nand",
                        .of_match_table = of_match_ptr(spinand_of_ids),
                },
        },
        .probe = spinand_probe,
        .remove = spinand_remove,
};
module_spi_mem_driver(spinand_drv);

MODULE_DESCRIPTION("SPI NAND framework");
MODULE_AUTHOR("Peter Pan<peterpandong@micron.com>");
MODULE_LICENSE("GPL v2");