linux/drivers/mtd/nand/nand_micron.c

309 lines
7.9 KiB
C

/*
* 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>
/*
* Special Micron status bit that indicates when the block has been
* corrected by on-die ECC and should be rewritten
*/
#define NAND_STATUS_WRITE_RECOMMENDED BIT(3)
struct nand_onfi_vendor_micron {
u8 two_plane_read;
u8 read_cache;
u8 read_unique_id;
u8 dq_imped;
u8 dq_imped_num_settings;
u8 dq_imped_feat_addr;
u8 rb_pulldown_strength;
u8 rb_pulldown_strength_feat_addr;
u8 rb_pulldown_strength_num_settings;
u8 otp_mode;
u8 otp_page_start;
u8 otp_data_prot_addr;
u8 otp_num_pages;
u8 otp_feat_addr;
u8 read_retry_options;
u8 reserved[72];
u8 param_revision;
} __packed;
static int micron_nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
{
struct nand_chip *chip = mtd_to_nand(mtd);
u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode};
return chip->onfi_set_features(mtd, chip, ONFI_FEATURE_ADDR_READ_RETRY,
feature);
}
/*
* Configure chip properties from Micron vendor-specific ONFI table
*/
static int micron_nand_onfi_init(struct nand_chip *chip)
{
struct nand_onfi_params *p = &chip->onfi_params;
struct nand_onfi_vendor_micron *micron = (void *)p->vendor;
if (!chip->onfi_version)
return 0;
if (le16_to_cpu(p->vendor_revision) < 1)
return 0;
chip->read_retries = micron->read_retry_options;
chip->setup_read_retry = micron_nand_setup_read_retry;
return 0;
}
static int micron_nand_on_die_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
if (section >= 4)
return -ERANGE;
oobregion->offset = (section * 16) + 8;
oobregion->length = 8;
return 0;
}
static int micron_nand_on_die_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
if (section >= 4)
return -ERANGE;
oobregion->offset = (section * 16) + 2;
oobregion->length = 6;
return 0;
}
static const struct mtd_ooblayout_ops micron_nand_on_die_ooblayout_ops = {
.ecc = micron_nand_on_die_ooblayout_ecc,
.free = micron_nand_on_die_ooblayout_free,
};
static int micron_nand_on_die_ecc_setup(struct nand_chip *chip, bool enable)
{
u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = { 0, };
if (enable)
feature[0] |= ONFI_FEATURE_ON_DIE_ECC_EN;
return chip->onfi_set_features(nand_to_mtd(chip), chip,
ONFI_FEATURE_ON_DIE_ECC, feature);
}
static int
micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip,
uint8_t *buf, int oob_required,
int page)
{
int status;
int max_bitflips = 0;
micron_nand_on_die_ecc_setup(chip, true);
chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
status = chip->read_byte(mtd);
if (status & NAND_STATUS_FAIL)
mtd->ecc_stats.failed++;
/*
* The internal ECC doesn't tell us the number of bitflips
* that have been corrected, but tells us if it recommends to
* rewrite the block. If it's the case, then we pretend we had
* a number of bitflips equal to the ECC strength, which will
* hint the NAND core to rewrite the block.
*/
else if (status & NAND_STATUS_WRITE_RECOMMENDED)
max_bitflips = chip->ecc.strength;
chip->cmdfunc(mtd, NAND_CMD_READ0, -1, -1);
nand_read_page_raw(mtd, chip, buf, oob_required, page);
micron_nand_on_die_ecc_setup(chip, false);
return max_bitflips;
}
static int
micron_nand_write_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip,
const uint8_t *buf, int oob_required,
int page)
{
int status;
micron_nand_on_die_ecc_setup(chip, true);
chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
nand_write_page_raw(mtd, chip, buf, oob_required, page);
chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
status = chip->waitfunc(mtd, chip);
micron_nand_on_die_ecc_setup(chip, false);
return status & NAND_STATUS_FAIL ? -EIO : 0;
}
static int
micron_nand_read_page_raw_on_die_ecc(struct mtd_info *mtd,
struct nand_chip *chip,
uint8_t *buf, int oob_required,
int page)
{
chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
nand_read_page_raw(mtd, chip, buf, oob_required, page);
return 0;
}
static int
micron_nand_write_page_raw_on_die_ecc(struct mtd_info *mtd,
struct nand_chip *chip,
const uint8_t *buf, int oob_required,
int page)
{
int status;
chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
nand_write_page_raw(mtd, chip, buf, oob_required, page);
chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
status = chip->waitfunc(mtd, chip);
return status & NAND_STATUS_FAIL ? -EIO : 0;
}
enum {
/* The NAND flash doesn't support on-die ECC */
MICRON_ON_DIE_UNSUPPORTED,
/*
* The NAND flash supports on-die ECC and it can be
* enabled/disabled by a set features command.
*/
MICRON_ON_DIE_SUPPORTED,
/*
* The NAND flash supports on-die ECC, and it cannot be
* disabled.
*/
MICRON_ON_DIE_MANDATORY,
};
/*
* Try to detect if the NAND support on-die ECC. To do this, we enable
* the feature, and read back if it has been enabled as expected. We
* also check if it can be disabled, because some Micron NANDs do not
* allow disabling the on-die ECC and we don't support such NANDs for
* now.
*
* This function also has the side effect of disabling on-die ECC if
* it had been left enabled by the firmware/bootloader.
*/
static int micron_supports_on_die_ecc(struct nand_chip *chip)
{
u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = { 0, };
int ret;
if (chip->onfi_version == 0)
return MICRON_ON_DIE_UNSUPPORTED;
if (chip->bits_per_cell != 1)
return MICRON_ON_DIE_UNSUPPORTED;
ret = micron_nand_on_die_ecc_setup(chip, true);
if (ret)
return MICRON_ON_DIE_UNSUPPORTED;
chip->onfi_get_features(nand_to_mtd(chip), chip,
ONFI_FEATURE_ON_DIE_ECC, feature);
if ((feature[0] & ONFI_FEATURE_ON_DIE_ECC_EN) == 0)
return MICRON_ON_DIE_UNSUPPORTED;
ret = micron_nand_on_die_ecc_setup(chip, false);
if (ret)
return MICRON_ON_DIE_UNSUPPORTED;
chip->onfi_get_features(nand_to_mtd(chip), chip,
ONFI_FEATURE_ON_DIE_ECC, feature);
if (feature[0] & ONFI_FEATURE_ON_DIE_ECC_EN)
return MICRON_ON_DIE_MANDATORY;
/*
* Some Micron NANDs have an on-die ECC of 4/512, some other
* 8/512. We only support the former.
*/
if (chip->onfi_params.ecc_bits != 4)
return MICRON_ON_DIE_UNSUPPORTED;
return MICRON_ON_DIE_SUPPORTED;
}
static int micron_nand_init(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
int ondie;
int ret;
ret = micron_nand_onfi_init(chip);
if (ret)
return ret;
if (mtd->writesize == 2048)
chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
ondie = micron_supports_on_die_ecc(chip);
if (ondie == MICRON_ON_DIE_MANDATORY) {
pr_err("On-die ECC forcefully enabled, not supported\n");
return -EINVAL;
}
if (chip->ecc.mode == NAND_ECC_ON_DIE) {
if (ondie == MICRON_ON_DIE_UNSUPPORTED) {
pr_err("On-die ECC selected but not supported\n");
return -EINVAL;
}
chip->ecc.options = NAND_ECC_CUSTOM_PAGE_ACCESS;
chip->ecc.bytes = 8;
chip->ecc.size = 512;
chip->ecc.strength = 4;
chip->ecc.algo = NAND_ECC_BCH;
chip->ecc.read_page = micron_nand_read_page_on_die_ecc;
chip->ecc.write_page = micron_nand_write_page_on_die_ecc;
chip->ecc.read_page_raw =
micron_nand_read_page_raw_on_die_ecc;
chip->ecc.write_page_raw =
micron_nand_write_page_raw_on_die_ecc;
mtd_set_ooblayout(mtd, &micron_nand_on_die_ooblayout_ops);
}
return 0;
}
const struct nand_manufacturer_ops micron_nand_manuf_ops = {
.init = micron_nand_init,
};