kernel_samsung_a34x-permissive/drivers/mtd/nand/raw/nand_toshiba.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/rawnand.h>
static void toshiba_nand_decode_id(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
nand_decode_ext_id(chip);
/*
* Toshiba 24nm raw SLC (i.e., not BENAND) have 32B OOB per
* 512B page. For Toshiba SLC, we decode the 5th/6th byte as
* follows:
* - ID byte 6, bits[2:0]: 100b -> 43nm, 101b -> 32nm,
* 110b -> 24nm
* - ID byte 5, bit[7]: 1 -> BENAND, 0 -> raw SLC
*/
if (chip->id.len >= 6 && nand_is_slc(chip) &&
(chip->id.data[5] & 0x7) == 0x6 /* 24nm */ &&
!(chip->id.data[4] & 0x80) /* !BENAND */)
mtd->oobsize = 32 * mtd->writesize >> 9;
/*
* Extract ECC requirements from 6th id byte.
* For Toshiba SLC, ecc requrements are as follows:
* - 43nm: 1 bit ECC for each 512Byte is required.
* - 32nm: 4 bit ECC for each 512Byte is required.
* - 24nm: 8 bit ECC for each 512Byte is required.
*/
if (chip->id.len >= 6 && nand_is_slc(chip)) {
chip->ecc_step_ds = 512;
switch (chip->id.data[5] & 0x7) {
case 0x4:
chip->ecc_strength_ds = 1;
break;
case 0x5:
chip->ecc_strength_ds = 4;
break;
case 0x6:
chip->ecc_strength_ds = 8;
break;
default:
WARN(1, "Could not get ECC info");
chip->ecc_step_ds = 0;
break;
}
}
}
static int toshiba_nand_init(struct nand_chip *chip)
{
if (nand_is_slc(chip))
chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
return 0;
}
const struct nand_manufacturer_ops toshiba_nand_manuf_ops = {
.detect = toshiba_nand_decode_id,
.init = toshiba_nand_init,
};