root/drivers/mtd/nand/spi/skyhigh.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2024 SkyHigh Memory Limited
 *
 * Author: Takahiro Kuwano <takahiro.kuwano@infineon.com>
 * Co-Author: KR Kim <kr.kim@skyhighmemory.com>
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mtd/spinand.h>

#define SPINAND_MFR_SKYHIGH                     0x01
#define SKYHIGH_STATUS_ECC_1TO2_BITFLIPS        (1 << 4)
#define SKYHIGH_STATUS_ECC_3TO6_BITFLIPS        (2 << 4)
#define SKYHIGH_STATUS_ECC_UNCOR_ERROR          (3 << 4)
#define SKYHIGH_CONFIG_PROTECT_EN               BIT(1)

static SPINAND_OP_VARIANTS(read_cache_variants,
                SPINAND_PAGE_READ_FROM_CACHE_1S_4S_4S_OP(0, 4, NULL, 0, 0),
                SPINAND_PAGE_READ_FROM_CACHE_1S_1S_4S_OP(0, 1, NULL, 0, 0),
                SPINAND_PAGE_READ_FROM_CACHE_1S_2S_2S_OP(0, 2, NULL, 0, 0),
                SPINAND_PAGE_READ_FROM_CACHE_1S_1S_2S_OP(0, 1, NULL, 0, 0),
                SPINAND_PAGE_READ_FROM_CACHE_FAST_1S_1S_1S_OP(0, 1, NULL, 0, 0),
                SPINAND_PAGE_READ_FROM_CACHE_1S_1S_1S_OP(0, 1, NULL, 0, 0));

static SPINAND_OP_VARIANTS(write_cache_variants,
                SPINAND_PROG_LOAD_1S_1S_4S_OP(true, 0, NULL, 0),
                SPINAND_PROG_LOAD_1S_1S_1S_OP(true, 0, NULL, 0));

static SPINAND_OP_VARIANTS(update_cache_variants,
                SPINAND_PROG_LOAD_1S_1S_4S_OP(false, 0, NULL, 0),
                SPINAND_PROG_LOAD_1S_1S_1S_OP(false, 0, NULL, 0));

static int skyhigh_spinand_ooblayout_ecc(struct mtd_info *mtd, int section,
                                         struct mtd_oob_region *region)
{
        /* ECC bytes are stored in hidden area. */
        return -ERANGE;
}

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

        /* ECC bytes are stored in hidden area. Reserve 2 bytes for the BBM. */
        region->offset = 2;
        region->length = mtd->oobsize - 2;

        return 0;
}

static const struct mtd_ooblayout_ops skyhigh_spinand_ooblayout = {
        .ecc = skyhigh_spinand_ooblayout_ecc,
        .free = skyhigh_spinand_ooblayout_free,
};

static int skyhigh_spinand_ecc_get_status(struct spinand_device *spinand,
                                          u8 status)
{
        switch (status & STATUS_ECC_MASK) {
        case STATUS_ECC_NO_BITFLIPS:
                return 0;

        case SKYHIGH_STATUS_ECC_UNCOR_ERROR:
                return -EBADMSG;

        case SKYHIGH_STATUS_ECC_1TO2_BITFLIPS:
                return 2;

        case SKYHIGH_STATUS_ECC_3TO6_BITFLIPS:
                return 6;

        default:
                break;
        }

        return -EINVAL;
}

static const struct spinand_info skyhigh_spinand_table[] = {
        SPINAND_INFO("S35ML01G301",
                     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x15),
                     NAND_MEMORG(1, 2048, 64, 64, 1024, 20, 1, 1, 1),
                     NAND_ECCREQ(6, 32),
                     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
                                              &write_cache_variants,
                                              &update_cache_variants),
                     SPINAND_NO_RAW_ACCESS,
                     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
                                     skyhigh_spinand_ecc_get_status)),
        SPINAND_INFO("S35ML01G300",
                     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x14),
                     NAND_MEMORG(1, 2048, 128, 64, 1024, 20, 1, 1, 1),
                     NAND_ECCREQ(6, 32),
                     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
                                              &write_cache_variants,
                                              &update_cache_variants),
                     SPINAND_NO_RAW_ACCESS,
                     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
                                     skyhigh_spinand_ecc_get_status)),
        SPINAND_INFO("S35ML02G300",
                     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x25),
                     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 2, 1, 1),
                     NAND_ECCREQ(6, 32),
                     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
                                              &write_cache_variants,
                                              &update_cache_variants),
                     SPINAND_NO_RAW_ACCESS,
                     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
                                     skyhigh_spinand_ecc_get_status)),
        SPINAND_INFO("S35ML04G300",
                     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_DUMMY, 0x35),
                     NAND_MEMORG(1, 2048, 128, 64, 4096, 80, 2, 1, 1),
                     NAND_ECCREQ(6, 32),
                     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
                                              &write_cache_variants,
                                              &update_cache_variants),
                     SPINAND_NO_RAW_ACCESS,
                     SPINAND_ECCINFO(&skyhigh_spinand_ooblayout,
                                     skyhigh_spinand_ecc_get_status)),
};

static int skyhigh_spinand_init(struct spinand_device *spinand)
{
        /*
         * Config_Protect_En (bit 1 in Block Lock register) must be set to 1
         * before writing other bits. Do it here before core unlocks all blocks
         * by writing block protection bits.
         */
        return spinand_write_reg_op(spinand, REG_BLOCK_LOCK,
                                    SKYHIGH_CONFIG_PROTECT_EN);
}

static const struct spinand_manufacturer_ops skyhigh_spinand_manuf_ops = {
        .init = skyhigh_spinand_init,
};

const struct spinand_manufacturer skyhigh_spinand_manufacturer = {
        .id = SPINAND_MFR_SKYHIGH,
        .name = "SkyHigh",
        .chips = skyhigh_spinand_table,
        .nchips = ARRAY_SIZE(skyhigh_spinand_table),
        .ops = &skyhigh_spinand_manuf_ops,
};