drivers/mtd/nand/raw/nand_amd.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Free Electrons
 * Copyright (C) 2017 NextThing Co
 *
 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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/mtd/rawnand.h>

static void amd_nand_decode_id(struct nand_chip *chip)
{
	struct mtd_info *mtd = nand_to_mtd(chip);

	nand_decode_ext_id(chip);

	/*
	 * Check for Spansion/AMD ID + repeating 5th, 6th byte since
	 * some Spansion chips have erasesize that conflicts with size
	 * listed in nand_ids table.
	 * Data sheet (5 byte ID): Spansion S30ML-P ORNAND (p.39)
	 */
	if (chip->id.data[4] != 0x00 && chip->id.data[5] == 0x00 &&
	    chip->id.data[6] == 0x00 && chip->id.data[7] == 0x00 &&
	    mtd->writesize == 512) {
		mtd->erasesize = 128 * 1024;
		mtd->erasesize <<= ((chip->id.data[3] & 0x03) << 1);
	}
}

static int amd_nand_init(struct nand_chip *chip)
{
	if (nand_is_slc(chip))
		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;

	return 0;
}

const struct nand_manufacturer_ops amd_nand_manuf_ops = {
	.detect = amd_nand_decode_id,
	.init = amd_nand_init,
};