drivers/mtd/nand/raw/nand_jedec.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
 *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
 *
 *  Credits:
 *	David Woodhouse for adding multichip support
 *
 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
 *	rework for 2K page size chips
 *
 * This file contains all ONFI helpers.
 */

#include <linux/slab.h>

#include "internals.h"

#define JEDEC_PARAM_PAGES 3

/*
 * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
 */
int nand_jedec_detect(struct nand_chip *chip)
{
	struct nand_device *base = &chip->base;
	struct mtd_info *mtd = nand_to_mtd(chip);
	struct nand_memory_organization *memorg;
	struct nand_jedec_params *p;
	struct jedec_ecc_info *ecc;
	bool use_datain = false;
	int jedec_version = 0;
	char id[5];
	int i, val, ret;
	u16 crc;

	memorg = nanddev_get_memorg(&chip->base);

	/* Try JEDEC for unknown chip or LP */
	ret = nand_readid_op(chip, 0x40, id, sizeof(id));
	if (ret || strncmp(id, "JEDEC", sizeof(id)))
		return 0;

	/* JEDEC chip: allocate a buffer to hold its parameter page */
	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return -ENOMEM;

	if (!nand_has_exec_op(chip) || chip->controller->supported_op.data_only_read)
		use_datain = true;

	for (i = 0; i < JEDEC_PARAM_PAGES; i++) {
		if (!i)
			ret = nand_read_param_page_op(chip, 0x40, p,
						      sizeof(*p));
		else if (use_datain)
			ret = nand_read_data_op(chip, p, sizeof(*p), true,
						false);
		else
			ret = nand_change_read_column_op(chip, sizeof(*p) * i,
							 p, sizeof(*p), true);
		if (ret) {
			ret = 0;
			goto free_jedec_param_page;
		}

		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 510);
		if (crc == le16_to_cpu(p->crc))
			break;
	}

	if (i == JEDEC_PARAM_PAGES) {
		pr_err("Could not find valid JEDEC parameter page; aborting\n");
		goto free_jedec_param_page;
	}

	/* Check version */
	val = le16_to_cpu(p->revision);
	if (val & (1 << 2))
		jedec_version = 10;
	else if (val & (1 << 1))
		jedec_version = 1; /* vendor specific version */

	if (!jedec_version) {
		pr_info("unsupported JEDEC version: %d\n", val);
		goto free_jedec_param_page;
	}

	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
	sanitize_string(p->model, sizeof(p->model));
	chip->parameters.model = kstrdup(p->model, GFP_KERNEL);
	if (!chip->parameters.model) {
		ret = -ENOMEM;
		goto free_jedec_param_page;
	}

	if (p->opt_cmd[0] & JEDEC_OPT_CMD_READ_CACHE)
		chip->parameters.supports_read_cache = true;

	memorg->pagesize = le32_to_cpu(p->byte_per_page);
	mtd->writesize = memorg->pagesize;

	/* Please reference to the comment for nand_flash_detect_onfi. */
	memorg->pages_per_eraseblock =
			1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
	mtd->erasesize = memorg->pages_per_eraseblock * memorg->pagesize;

	memorg->oobsize = le16_to_cpu(p->spare_bytes_per_page);
	mtd->oobsize = memorg->oobsize;

	memorg->luns_per_target = p->lun_count;
	memorg->planes_per_lun = 1 << p->multi_plane_addr;

	/* Please reference to the comment for nand_flash_detect_onfi. */
	memorg->eraseblocks_per_lun =
		1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
	memorg->bits_per_cell = p->bits_per_cell;

	if (le16_to_cpu(p->features) & JEDEC_FEATURE_16_BIT_BUS)
		chip->options |= NAND_BUSWIDTH_16;

	/* ECC info */
	ecc = &p->ecc_info[0];

	if (ecc->codeword_size >= 9) {
		struct nand_ecc_props requirements = {
			.strength = ecc->ecc_bits,
			.step_size = 1 << ecc->codeword_size,
		};

		nanddev_set_ecc_requirements(base, &requirements);
	} else {
		pr_warn("Invalid codeword size\n");
	}

	ret = 1;

free_jedec_param_page:
	kfree(p);
	return ret;
}