// 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;
}
