diff options
Diffstat (limited to 'drivers/mtd/nand/raw/nand_micron.c')
| -rw-r--r-- | drivers/mtd/nand/raw/nand_micron.c | 557 |
1 files changed, 557 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/nand_micron.c b/drivers/mtd/nand/raw/nand_micron.c new file mode 100644 index 000000000..fb401c257 --- /dev/null +++ b/drivers/mtd/nand/raw/nand_micron.c @@ -0,0 +1,557 @@ +/* + * 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> +#include <linux/slab.h> + +/* + * Special Micron status bit 3 indicates that the block has been + * corrected by on-die ECC and should be rewritten. + */ +#define NAND_ECC_STATUS_WRITE_RECOMMENDED BIT(3) + +/* + * On chips with 8-bit ECC and additional bit can be used to distinguish + * cases where a errors were corrected without needing a rewrite + * + * Bit 4 Bit 3 Bit 0 Description + * ----- ----- ----- ----------- + * 0 0 0 No Errors + * 0 0 1 Multiple uncorrected errors + * 0 1 0 4 - 6 errors corrected, recommend rewrite + * 0 1 1 Reserved + * 1 0 0 1 - 3 errors corrected + * 1 0 1 Reserved + * 1 1 0 7 - 8 errors corrected, recommend rewrite + */ +#define NAND_ECC_STATUS_MASK (BIT(4) | BIT(3) | BIT(0)) +#define NAND_ECC_STATUS_UNCORRECTABLE BIT(0) +#define NAND_ECC_STATUS_4_6_CORRECTED BIT(3) +#define NAND_ECC_STATUS_1_3_CORRECTED BIT(4) +#define NAND_ECC_STATUS_7_8_CORRECTED (BIT(4) | 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; + +struct micron_on_die_ecc { + bool forced; + bool enabled; + void *rawbuf; +}; + +struct micron_nand { + struct micron_on_die_ecc ecc; +}; + +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 nand_set_features(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_parameters *p = &chip->parameters; + + if (p->onfi) { + struct nand_onfi_vendor_micron *micron = (void *)p->onfi->vendor; + + chip->read_retries = micron->read_retry_options; + chip->setup_read_retry = micron_nand_setup_read_retry; + } + + if (p->supports_set_get_features) { + set_bit(ONFI_FEATURE_ADDR_READ_RETRY, p->set_feature_list); + set_bit(ONFI_FEATURE_ON_DIE_ECC, p->set_feature_list); + set_bit(ONFI_FEATURE_ADDR_READ_RETRY, p->get_feature_list); + set_bit(ONFI_FEATURE_ON_DIE_ECC, p->get_feature_list); + } + + return 0; +} + +static int micron_nand_on_die_4_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_4_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_4_ooblayout_ops = { + .ecc = micron_nand_on_die_4_ooblayout_ecc, + .free = micron_nand_on_die_4_ooblayout_free, +}; + +static int micron_nand_on_die_8_ooblayout_ecc(struct mtd_info *mtd, + int section, + struct mtd_oob_region *oobregion) +{ + struct nand_chip *chip = mtd_to_nand(mtd); + + if (section) + return -ERANGE; + + oobregion->offset = mtd->oobsize - chip->ecc.total; + oobregion->length = chip->ecc.total; + + return 0; +} + +static int micron_nand_on_die_8_ooblayout_free(struct mtd_info *mtd, + int section, + struct mtd_oob_region *oobregion) +{ + struct nand_chip *chip = mtd_to_nand(mtd); + + if (section) + return -ERANGE; + + oobregion->offset = 2; + oobregion->length = mtd->oobsize - chip->ecc.total - 2; + + return 0; +} + +static const struct mtd_ooblayout_ops micron_nand_on_die_8_ooblayout_ops = { + .ecc = micron_nand_on_die_8_ooblayout_ecc, + .free = micron_nand_on_die_8_ooblayout_free, +}; + +static int micron_nand_on_die_ecc_setup(struct nand_chip *chip, bool enable) +{ + struct micron_nand *micron = nand_get_manufacturer_data(chip); + u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = { 0, }; + int ret; + + if (micron->ecc.forced) + return 0; + + if (micron->ecc.enabled == enable) + return 0; + + if (enable) + feature[0] |= ONFI_FEATURE_ON_DIE_ECC_EN; + + ret = nand_set_features(chip, ONFI_FEATURE_ON_DIE_ECC, feature); + if (!ret) + micron->ecc.enabled = enable; + + return ret; +} + +static int micron_nand_on_die_ecc_status_4(struct nand_chip *chip, u8 status, + void *buf, int page, + int oob_required) +{ + struct micron_nand *micron = nand_get_manufacturer_data(chip); + struct mtd_info *mtd = nand_to_mtd(chip); + unsigned int step, max_bitflips = 0; + int ret; + + if (!(status & NAND_ECC_STATUS_WRITE_RECOMMENDED)) { + if (status & NAND_STATUS_FAIL) + mtd->ecc_stats.failed++; + + return 0; + } + + /* + * 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, we need to read the page in raw mode and compare + * its content to the corrected version to extract the actual number of + * bitflips. + * But before we do that, we must make sure we have all OOB bytes read + * in non-raw mode, even if the user did not request those bytes. + */ + if (!oob_required) { + ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, + false); + if (ret) + return ret; + } + + micron_nand_on_die_ecc_setup(chip, false); + + ret = nand_read_page_op(chip, page, 0, micron->ecc.rawbuf, + mtd->writesize + mtd->oobsize); + if (ret) + return ret; + + for (step = 0; step < chip->ecc.steps; step++) { + unsigned int offs, i, nbitflips = 0; + u8 *rawbuf, *corrbuf; + + offs = step * chip->ecc.size; + rawbuf = micron->ecc.rawbuf + offs; + corrbuf = buf + offs; + + for (i = 0; i < chip->ecc.size; i++) + nbitflips += hweight8(corrbuf[i] ^ rawbuf[i]); + + offs = (step * 16) + 4; + rawbuf = micron->ecc.rawbuf + mtd->writesize + offs; + corrbuf = chip->oob_poi + offs; + + for (i = 0; i < chip->ecc.bytes + 4; i++) + nbitflips += hweight8(corrbuf[i] ^ rawbuf[i]); + + if (WARN_ON(nbitflips > chip->ecc.strength)) + return -EINVAL; + + max_bitflips = max(nbitflips, max_bitflips); + mtd->ecc_stats.corrected += nbitflips; + } + + return max_bitflips; +} + +static int micron_nand_on_die_ecc_status_8(struct nand_chip *chip, u8 status) +{ + struct mtd_info *mtd = nand_to_mtd(chip); + + /* + * With 8/512 we have more information but still don't know precisely + * how many bit-flips were seen. + */ + switch (status & NAND_ECC_STATUS_MASK) { + case NAND_ECC_STATUS_UNCORRECTABLE: + mtd->ecc_stats.failed++; + return 0; + case NAND_ECC_STATUS_1_3_CORRECTED: + mtd->ecc_stats.corrected += 3; + return 3; + case NAND_ECC_STATUS_4_6_CORRECTED: + mtd->ecc_stats.corrected += 6; + /* rewrite recommended */ + return 6; + case NAND_ECC_STATUS_7_8_CORRECTED: + mtd->ecc_stats.corrected += 8; + /* rewrite recommended */ + return 8; + default: + return 0; + } +} + +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; + + 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); + + if (chip->ecc.strength == 4) + max_bitflips = micron_nand_on_die_ecc_status_4(chip, status, + buf, page, + oob_required); + else + max_bitflips = micron_nand_on_die_ecc_status_8(chip, status); + +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, +}; + +#define MICRON_ID_INTERNAL_ECC_MASK GENMASK(1, 0) +#define MICRON_ID_ECC_ENABLED BIT(7) + +/* + * 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 id[5]; + int ret; + + if (!chip->parameters.onfi) + return MICRON_ON_DIE_UNSUPPORTED; + + if (chip->bits_per_cell != 1) + return MICRON_ON_DIE_UNSUPPORTED; + + /* + * We only support on-die ECC of 4/512 or 8/512 + */ + if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8) + return MICRON_ON_DIE_UNSUPPORTED; + + /* 0x2 means on-die ECC is available. */ + if (chip->id.len != 5 || + (chip->id.data[4] & MICRON_ID_INTERNAL_ECC_MASK) != 0x2) + return MICRON_ON_DIE_UNSUPPORTED; + + /* + * It seems that there are devices which do not support ECC officially. + * At least the MT29F2G08ABAGA / MT29F2G08ABBGA devices supports + * enabling the ECC feature but don't reflect that to the READ_ID table. + * So we have to guarantee that we disable the ECC feature directly + * after we did the READ_ID table command. Later we can evaluate the + * ECC_ENABLE support. + */ + ret = micron_nand_on_die_ecc_setup(chip, true); + if (ret) + return MICRON_ON_DIE_UNSUPPORTED; + + ret = nand_readid_op(chip, 0, id, sizeof(id)); + if (ret) + return MICRON_ON_DIE_UNSUPPORTED; + + ret = micron_nand_on_die_ecc_setup(chip, false); + if (ret) + return MICRON_ON_DIE_UNSUPPORTED; + + if (!(id[4] & MICRON_ID_ECC_ENABLED)) + return MICRON_ON_DIE_UNSUPPORTED; + + ret = nand_readid_op(chip, 0, id, sizeof(id)); + if (ret) + return MICRON_ON_DIE_UNSUPPORTED; + + if (id[4] & MICRON_ID_ECC_ENABLED) + return MICRON_ON_DIE_MANDATORY; + + /* + * We only support on-die ECC of 4/512 or 8/512 + */ + if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8) + 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); + struct micron_nand *micron; + int ondie; + int ret; + + micron = kzalloc(sizeof(*micron), GFP_KERNEL); + if (!micron) + return -ENOMEM; + + nand_set_manufacturer_data(chip, micron); + + ret = micron_nand_onfi_init(chip); + if (ret) + goto err_free_manuf_data; + + if (mtd->writesize == 2048) + chip->bbt_options |= NAND_BBT_SCAN2NDPAGE; + + ondie = micron_supports_on_die_ecc(chip); + + if (ondie == MICRON_ON_DIE_MANDATORY && + chip->ecc.mode != NAND_ECC_ON_DIE) { + pr_err("On-die ECC forcefully enabled, not supported\n"); + ret = -EINVAL; + goto err_free_manuf_data; + } + + if (chip->ecc.mode == NAND_ECC_ON_DIE) { + if (ondie == MICRON_ON_DIE_UNSUPPORTED) { + pr_err("On-die ECC selected but not supported\n"); + ret = -EINVAL; + goto err_free_manuf_data; + } + + if (ondie == MICRON_ON_DIE_MANDATORY) { + micron->ecc.forced = true; + micron->ecc.enabled = true; + } + + /* + * In case of 4bit on-die ECC, we need a buffer to store a + * page dumped in raw mode so that we can compare its content + * to the same page after ECC correction happened and extract + * the real number of bitflips from this comparison. + * That's not needed for 8-bit ECC, because the status expose + * a better approximation of the number of bitflips in a page. + */ + if (chip->ecc_strength_ds == 4) { + micron->ecc.rawbuf = kmalloc(mtd->writesize + + mtd->oobsize, + GFP_KERNEL); + if (!micron->ecc.rawbuf) { + ret = -ENOMEM; + goto err_free_manuf_data; + } + } + + if (chip->ecc_strength_ds == 4) + mtd_set_ooblayout(mtd, + µn_nand_on_die_4_ooblayout_ops); + else + mtd_set_ooblayout(mtd, + µn_nand_on_die_8_ooblayout_ops); + + chip->ecc.bytes = chip->ecc_strength_ds * 2; + chip->ecc.size = 512; + chip->ecc.strength = chip->ecc_strength_ds; + 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; + + if (ondie == MICRON_ON_DIE_MANDATORY) { + chip->ecc.read_page_raw = nand_read_page_raw_notsupp; + chip->ecc.write_page_raw = nand_write_page_raw_notsupp; + } else { + chip->ecc.read_page_raw = nand_read_page_raw; + chip->ecc.write_page_raw = nand_write_page_raw; + } + } + + return 0; + +err_free_manuf_data: + kfree(micron->ecc.rawbuf); + kfree(micron); + + return ret; +} + +static void micron_nand_cleanup(struct nand_chip *chip) +{ + struct micron_nand *micron = nand_get_manufacturer_data(chip); + + kfree(micron->ecc.rawbuf); + kfree(micron); +} + +static void micron_fixup_onfi_param_page(struct nand_chip *chip, + struct nand_onfi_params *p) +{ + /* + * MT29F1G08ABAFAWP-ITE:F and possibly others report 00 00 for the + * revision number field of the ONFI parameter page. Assume ONFI + * version 1.0 if the revision number is 00 00. + */ + if (le16_to_cpu(p->revision) == 0) + p->revision = cpu_to_le16(ONFI_VERSION_1_0); +} + +const struct nand_manufacturer_ops micron_nand_manuf_ops = { + .init = micron_nand_init, + .cleanup = micron_nand_cleanup, + .fixup_onfi_param_page = micron_fixup_onfi_param_page, +}; |