drivers/mtd/nand/nand_micron.c - arm/linux - Git at Google

 /*
  * 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>

 /*
  * 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,
 };
	/*
	* 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>

	/*
	* 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,
	};