int nand_onfi_detect()

in nand/raw/nand_onfi.c [144:337]


int nand_onfi_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_onfi_params *p = NULL, *pbuf;
	struct onfi_params *onfi;
	bool use_datain = false;
	int onfi_version = 0;
	char id[4];
	int i, ret, val;
	u16 crc;

	memorg = nanddev_get_memorg(&chip->base);

	/* Try ONFI for unknown chip or LP */
	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
	if (ret || strncmp(id, "ONFI", 4))
		return 0;

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

	if (!nand_has_exec_op(chip) ||
	    !nand_read_data_op(chip, &pbuf[0], sizeof(*pbuf), true, true))
		use_datain = true;

	for (i = 0; i < ONFI_PARAM_PAGES; i++) {
		if (!i)
			ret = nand_read_param_page_op(chip, 0, &pbuf[i],
						      sizeof(*pbuf));
		else if (use_datain)
			ret = nand_read_data_op(chip, &pbuf[i], sizeof(*pbuf),
						true, false);
		else
			ret = nand_change_read_column_op(chip, sizeof(*pbuf) * i,
							 &pbuf[i], sizeof(*pbuf),
							 true);
		if (ret) {
			ret = 0;
			goto free_onfi_param_page;
		}

		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)&pbuf[i], 254);
		if (crc == le16_to_cpu(pbuf[i].crc)) {
			p = &pbuf[i];
			break;
		}
	}

	if (i == ONFI_PARAM_PAGES) {
		const void *srcbufs[ONFI_PARAM_PAGES];
		unsigned int j;

		for (j = 0; j < ONFI_PARAM_PAGES; j++)
			srcbufs[j] = pbuf + j;

		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
		nand_bit_wise_majority(srcbufs, ONFI_PARAM_PAGES, pbuf,
				       sizeof(*pbuf));

		crc = onfi_crc16(ONFI_CRC_BASE, (u8 *)pbuf, 254);
		if (crc != le16_to_cpu(pbuf->crc)) {
			pr_err("ONFI parameter recovery failed, aborting\n");
			goto free_onfi_param_page;
		}
		p = pbuf;
	}

	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
	    chip->manufacturer.desc->ops->fixup_onfi_param_page)
		chip->manufacturer.desc->ops->fixup_onfi_param_page(chip, p);

	/* Check version */
	val = le16_to_cpu(p->revision);
	if (val & ONFI_VERSION_2_3)
		onfi_version = 23;
	else if (val & ONFI_VERSION_2_2)
		onfi_version = 22;
	else if (val & ONFI_VERSION_2_1)
		onfi_version = 21;
	else if (val & ONFI_VERSION_2_0)
		onfi_version = 20;
	else if (val & ONFI_VERSION_1_0)
		onfi_version = 10;

	if (!onfi_version) {
		pr_info("unsupported ONFI version: %d\n", val);
		goto free_onfi_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_onfi_param_page;
	}

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

	/*
	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
	 * (don't ask me who thought of this...). MTD assumes that these
	 * dimensions will be power-of-2, so just truncate the remaining area.
	 */
	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->interleaved_bits;

	/* See erasesize comment */
	memorg->eraseblocks_per_lun =
		1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
	memorg->max_bad_eraseblocks_per_lun = le32_to_cpu(p->blocks_per_lun);
	memorg->bits_per_cell = p->bits_per_cell;

	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
		chip->options |= NAND_BUSWIDTH_16;

	if (p->ecc_bits != 0xff) {
		struct nand_ecc_props requirements = {
			.strength = p->ecc_bits,
			.step_size = 512,
		};

		nanddev_set_ecc_requirements(base, &requirements);
	} else if (onfi_version >= 21 &&
		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {

		/*
		 * The nand_flash_detect_ext_param_page() uses the
		 * Change Read Column command which maybe not supported
		 * by the chip->legacy.cmdfunc. So try to update the
		 * chip->legacy.cmdfunc now. We do not replace user supplied
		 * command function.
		 */
		nand_legacy_adjust_cmdfunc(chip);

		/* The Extended Parameter Page is supported since ONFI 2.1. */
		if (nand_flash_detect_ext_param_page(chip, p))
			pr_warn("Failed to detect ONFI extended param page\n");
	} else {
		pr_warn("Could not retrieve ONFI ECC requirements\n");
	}

	/* Save some parameters from the parameter page for future use */
	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
		chip->parameters.supports_set_get_features = true;
		bitmap_set(chip->parameters.get_feature_list,
			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
		bitmap_set(chip->parameters.set_feature_list,
			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
	}

	onfi = kzalloc(sizeof(*onfi), GFP_KERNEL);
	if (!onfi) {
		ret = -ENOMEM;
		goto free_model;
	}

	onfi->version = onfi_version;
	onfi->tPROG = le16_to_cpu(p->t_prog);
	onfi->tBERS = le16_to_cpu(p->t_bers);
	onfi->tR = le16_to_cpu(p->t_r);
	onfi->tCCS = le16_to_cpu(p->t_ccs);
	onfi->fast_tCAD = le16_to_cpu(p->nvddr_nvddr2_features) & BIT(0);
	onfi->sdr_timing_modes = le16_to_cpu(p->sdr_timing_modes);
	if (le16_to_cpu(p->features) & ONFI_FEATURE_NV_DDR)
		onfi->nvddr_timing_modes = le16_to_cpu(p->nvddr_timing_modes);
	onfi->vendor_revision = le16_to_cpu(p->vendor_revision);
	memcpy(onfi->vendor, p->vendor, sizeof(p->vendor));
	chip->parameters.onfi = onfi;

	/* Identification done, free the full ONFI parameter page and exit */
	kfree(pbuf);

	return 1;

free_model:
	kfree(chip->parameters.model);
free_onfi_param_page:
	kfree(pbuf);

	return ret;
}