linux/drivers/mtd/nand/nand_samsung.c

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/*
* 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/nand.h>
static void samsung_nand_decode_id(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
/* 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 */
mtd->writesize = 2048 << (extid & 0x03);
extid >>= 2;
/* Get oobsize */
switch (((extid >> 2) & 0x4) | (extid & 0x3)) {
case 1:
mtd->oobsize = 128;
break;
case 2:
mtd->oobsize = 218;
break;
case 3:
mtd->oobsize = 400;
break;
case 4:
mtd->oobsize = 436;
break;
case 5:
mtd->oobsize = 512;
break;
case 6:
mtd->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;
}
/* Get blocksize */
extid >>= 2;
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) {
chip->ecc_step_ds = 512;
chip->ecc_strength_ds = 1 << extid;
} else {
chip->ecc_step_ds = 1024;
switch (extid) {
case 5:
chip->ecc_strength_ds = 24;
break;
case 6:
chip->ecc_strength_ds = 40;
break;
case 7:
chip->ecc_strength_ds = 60;
break;
}
}
} else {
nand_decode_ext_id(chip);
}
}
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->bbt_options |= NAND_BBT_SCANLASTPAGE;
else
chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
return 0;
}
const struct nand_manufacturer_ops samsung_nand_manuf_ops = {
.detect = samsung_nand_decode_id,
.init = samsung_nand_init,
};