1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/nand_onfi.c b/drivers/mtd/nand/raw/nand_onfi.c
new file mode 100644
index 000000000000..d8184cf591ad
--- /dev/null
+++ b/drivers/mtd/nand/raw/nand_onfi.c
@@ -0,0 +1,305 @@
+// 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"
+
+u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 8;
+		for (i = 0; i < 8; i++)
+			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
+	}
+
+	return crc;
+}
+
+/* Parse the Extended Parameter Page. */
+static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
+					    struct nand_onfi_params *p)
+{
+	struct onfi_ext_param_page *ep;
+	struct onfi_ext_section *s;
+	struct onfi_ext_ecc_info *ecc;
+	uint8_t *cursor;
+	int ret;
+	int len;
+	int i;
+
+	len = le16_to_cpu(p->ext_param_page_length) * 16;
+	ep = kmalloc(len, GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+
+	/* Send our own NAND_CMD_PARAM. */
+	ret = nand_read_param_page_op(chip, 0, NULL, 0);
+	if (ret)
+		goto ext_out;
+
+	/* Use the Change Read Column command to skip the ONFI param pages. */
+	ret = nand_change_read_column_op(chip,
+					 sizeof(*p) * p->num_of_param_pages,
+					 ep, len, true);
+	if (ret)
+		goto ext_out;
+
+	ret = -EINVAL;
+	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
+		!= le16_to_cpu(ep->crc))) {
+		pr_debug("fail in the CRC.\n");
+		goto ext_out;
+	}
+
+	/*
+	 * Check the signature.
+	 * Do not strictly follow the ONFI spec, maybe changed in future.
+	 */
+	if (strncmp(ep->sig, "EPPS", 4)) {
+		pr_debug("The signature is invalid.\n");
+		goto ext_out;
+	}
+
+	/* find the ECC section. */
+	cursor = (uint8_t *)(ep + 1);
+	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
+		s = ep->sections + i;
+		if (s->type == ONFI_SECTION_TYPE_2)
+			break;
+		cursor += s->length * 16;
+	}
+	if (i == ONFI_EXT_SECTION_MAX) {
+		pr_debug("We can not find the ECC section.\n");
+		goto ext_out;
+	}
+
+	/* get the info we want. */
+	ecc = (struct onfi_ext_ecc_info *)cursor;
+
+	if (!ecc->codeword_size) {
+		pr_debug("Invalid codeword size\n");
+		goto ext_out;
+	}
+
+	chip->ecc_strength_ds = ecc->ecc_bits;
+	chip->ecc_step_ds = 1 << ecc->codeword_size;
+	ret = 0;
+
+ext_out:
+	kfree(ep);
+	return ret;
+}
+
+/*
+ * Recover data with bit-wise majority
+ */
+static void nand_bit_wise_majority(const void **srcbufs,
+				   unsigned int nsrcbufs,
+				   void *dstbuf,
+				   unsigned int bufsize)
+{
+	int i, j, k;
+
+	for (i = 0; i < bufsize; i++) {
+		u8 val = 0;
+
+		for (j = 0; j < 8; j++) {
+			unsigned int cnt = 0;
+
+			for (k = 0; k < nsrcbufs; k++) {
+				const u8 *srcbuf = srcbufs[k];
+
+				if (srcbuf[i] & BIT(j))
+					cnt++;
+			}
+
+			if (cnt > nsrcbufs / 2)
+				val |= BIT(j);
+		}
+
+		((u8 *)dstbuf)[i] = val;
+	}
+}
+
+/*
+ * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
+ */
+int nand_onfi_detect(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_onfi_params *p;
+	struct onfi_params *onfi;
+	int onfi_version = 0;
+	char id[4];
+	int i, ret, val;
+
+	/* 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 */
+	p = kzalloc((sizeof(*p) * 3), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	ret = nand_read_param_page_op(chip, 0, NULL, 0);
+	if (ret) {
+		ret = 0;
+		goto free_onfi_param_page;
+	}
+
+	for (i = 0; i < 3; i++) {
+		ret = nand_read_data_op(chip, &p[i], sizeof(*p), true);
+		if (ret) {
+			ret = 0;
+			goto free_onfi_param_page;
+		}
+
+		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)&p[i], 254) ==
+				le16_to_cpu(p->crc)) {
+			if (i)
+				memcpy(p, &p[i], sizeof(*p));
+			break;
+		}
+	}
+
+	if (i == 3) {
+		const void *srcbufs[3] = {p, p + 1, p + 2};
+
+		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
+		nand_bit_wise_majority(srcbufs, ARRAY_SIZE(srcbufs), p,
+				       sizeof(*p));
+
+		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 254) !=
+				le16_to_cpu(p->crc)) {
+			pr_err("ONFI parameter recovery failed, aborting\n");
+			goto free_onfi_param_page;
+		}
+	}
+
+	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;
+	}
+
+	mtd->writesize = le32_to_cpu(p->byte_per_page);
+
+	/*
+	 * 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.
+	 */
+	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
+	mtd->erasesize *= mtd->writesize;
+
+	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+
+	/* See erasesize comment */
+	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
+	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
+	chip->bits_per_cell = p->bits_per_cell;
+
+	chip->max_bb_per_die = le16_to_cpu(p->bb_per_lun);
+	chip->blocks_per_die = le32_to_cpu(p->blocks_per_lun);
+
+	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
+		chip->options |= NAND_BUSWIDTH_16;
+
+	if (p->ecc_bits != 0xff) {
+		chip->ecc_strength_ds = p->ecc_bits;
+		chip->ecc_step_ds = 512;
+	} 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->async_timing_mode = le16_to_cpu(p->async_timing_mode);
+	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(p);
+
+	return 1;
+
+free_model:
+	kfree(chip->parameters.model);
+free_onfi_param_page:
+	kfree(p);
+
+	return ret;
+}