/* * Copyright (C) 2017 Free Electrons * Copyright (C) 2017 NextThing Co * * Author: Boris Brezillon * * 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 /* * 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) { u8 status; int ret, max_bitflips = 0; ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return ret; ret = nand_read_page_op(chip, page, 0, NULL, 0); if (ret) goto out; ret = nand_status_op(chip, &status); if (ret) goto out; ret = nand_exit_status_op(chip); if (ret) goto out; 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; ret = nand_read_data_op(chip, buf, mtd->writesize, false); if (!ret && oob_required) ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, false); out: micron_nand_on_die_ecc_setup(chip, false); return ret ? ret : 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 ret; ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return ret; ret = nand_write_page_raw(mtd, chip, buf, oob_required, page); micron_nand_on_die_ecc_setup(chip, false); return ret; } 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.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 = nand_read_page_raw; chip->ecc.write_page_raw = nand_write_page_raw; mtd_set_ooblayout(mtd, µn_nand_on_die_ooblayout_ops); } return 0; } const struct nand_manufacturer_ops micron_nand_manuf_ops = { .init = micron_nand_init, };