// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017 Free Electrons
 * Copyright (C) 2017 NextThing Co
 *
 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
 */

#include "internals.h"

static void samsung_nand_decode_id(struct nand_chip *chip)
{
        struct nand_device *base = &chip->base;
        struct nand_ecc_props requirements = {};
        struct mtd_info *mtd = nand_to_mtd(chip);
        struct nand_memory_organization *memorg;

        memorg = nanddev_get_memorg(&chip->base);

        /* New Samsung (6 byte ID): Samsung K9GAG08U0F (p.44) */
        if (chip->id.len == 6 && !nand_is_slc(chip) &&
            chip->id.data[5] != 0x00) {
                u8 extid = chip->id.data[3];

                /* Get pagesize */
                memorg->pagesize = 2048 << (extid & 0x03);
                mtd->writesize = memorg->pagesize;

                extid >>= 2;

                /* Get oobsize */
                switch (((extid >> 2) & 0x4) | (extid & 0x3)) {
                case 1:
                        memorg->oobsize = 128;
                        break;
                case 2:
                        memorg->oobsize = 218;
                        break;
                case 3:
                        memorg->oobsize = 400;
                        break;
                case 4:
                        memorg->oobsize = 436;
                        break;
                case 5:
                        memorg->oobsize = 512;
                        break;
                case 6:
                        memorg->oobsize = 640;
                        break;
                default:
                        /*
                         * We should never reach this case, but if that
                         * happens, this probably means Samsung decided to use
                         * a different extended ID format, and we should find
                         * a way to support it.
                         */
                        WARN(1, "Invalid OOB size value");
                        break;
                }

                mtd->oobsize = memorg->oobsize;

                /* Get blocksize */
                extid >>= 2;
                memorg->pages_per_eraseblock = (128 * 1024) <<
                                               (((extid >> 1) & 0x04) |
                                                (extid & 0x03)) /
                                               memorg->pagesize;
                mtd->erasesize = (128 * 1024) <<
                                 (((extid >> 1) & 0x04) | (extid & 0x03));

                /* Extract ECC requirements from 5th id byte*/
                extid = (chip->id.data[4] >> 4) & 0x07;
                if (extid < 5) {
                        requirements.step_size = 512;
                        requirements.strength = 1 << extid;
                } else {
                        requirements.step_size = 1024;
                        switch (extid) {
                        case 5:
                                requirements.strength = 24;
                                break;
                        case 6:
                                requirements.strength = 40;
                                break;
                        case 7:
                                requirements.strength = 60;
                                break;
                        default:
                                WARN(1, "Could not decode ECC info");
                                requirements.step_size = 0;
                        }
                }
        } else {
                nand_decode_ext_id(chip);

                if (nand_is_slc(chip)) {
                        switch (chip->id.data[1]) {
                        /* K9F4G08U0D-S[I|C]B0(T00) */
                        case 0xDC:
                                requirements.step_size = 512;
                                requirements.strength = 1;
                                break;

                        /* K9F1G08U0E 21nm chips do not support subpage write */
                        case 0xF1:
                                if (chip->id.len > 4 &&
                                    (chip->id.data[4] & GENMASK(1, 0)) == 0x1)
                                        chip->options |= NAND_NO_SUBPAGE_WRITE;
                                break;
                        default:
                                break;
                        }
                }
        }

        nanddev_set_ecc_requirements(base, &requirements);
}

static int samsung_nand_init(struct nand_chip *chip)
{
        struct mtd_info *mtd = nand_to_mtd(chip);

        if (mtd->writesize > 512)
                chip->options |= NAND_SAMSUNG_LP_OPTIONS;

        if (!nand_is_slc(chip))
                chip->options |= NAND_BBM_LASTPAGE;
        else
                chip->options |= NAND_BBM_FIRSTPAGE | NAND_BBM_SECONDPAGE;

        return 0;
}

const struct nand_manufacturer_ops samsung_nand_manuf_ops = {
        .detect = samsung_nand_decode_id,
        .init = samsung_nand_init,
};