u-boot/drivers/mtd/nand/raw/nand_samsung.c
Michael Trimarchi 007f1d1473 mtd: nand: samsung: Retrieve ECC requirements from extended
Upstream linux commit 8fc82d456e40a0.

On some nand controllers with hw-ecc the controller code wants to know
the ecc strength and size and having these as 0, 0 is not accepted.

Specifying these in devicetree is possible but undesirable as the nand
may be different in different production runs of the same board, so it
is better to get this info from the nand id where possible.

This commit adds code to read the ecc strength and size from the nand
for Samsung extended-id nands. This code is based on the info for the 5th
id byte in the datasheets for the following Samsung nands: K9GAG08U0E,
K9GAG08U0F, K9GAG08X0D, K9GBG08U0A, K9GBG08U0B. These all use these bits
in the exact same way.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
2022-08-22 11:15:24 +02:00

110 lines
2.5 KiB
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/bug.h>
#include <linux/mtd/rawnand.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;
case 7:
default: /* Other cases are "reserved" (unknown) */
WARN(1, "Invalid OOB size value");
mtd->oobsize = 1024;
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,
};