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u-boot/drivers/mtd/nand/atmel_nand.c
Wu, Josh bdfd59aa0f at91: atmel_nand: Update driver to support Programmable Multibit ECC controller 
The Programmable Multibit ECC (PMECC) controller is a programmable binary
BCH(Bose, Chaudhuri and Hocquenghem) encoder and decoder. This controller
can be used to support both SLC and MLC NAND Flash devices. It supports to
generate ECC to correct 2, 4, 8, 12 or 24 bits of error per sector of data.

To use PMECC in this driver, the user needs to set the PMECC correction
capability, the sector size and ROM lookup table offsets in board config file.

This driver is ported from Linux kernel atmel_nand PMECC patch. The main difference
is in this version it uses registers structure access hardware instead of using macros.
It is tested in 9x5 serial boards.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
[rebase]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
2012-09-01 17:06:14 +02:00

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/*
* (C) Copyright 2007-2008
* Stelian Pop <stelian@popies.net>
* Lead Tech Design <www.leadtechdesign.com>
*
* (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
*
* Add Programmable Multibit ECC support for various AT91 SoC
* (C) Copyright 2012 ATMEL, Hong Xu
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/arch/hardware.h>
#include <asm/arch/gpio.h>
#include <asm/arch/at91_pio.h>
#include <nand.h>
#include <watchdog.h>
#ifdef CONFIG_ATMEL_NAND_HWECC
/* Register access macros */
#define ecc_readl(add, reg) \
readl(AT91_BASE_SYS + add + ATMEL_ECC_##reg)
#define ecc_writel(add, reg, value) \
writel((value), AT91_BASE_SYS + add + ATMEL_ECC_##reg)
#include "atmel_nand_ecc.h" /* Hardware ECC registers */
#ifdef CONFIG_ATMEL_NAND_HW_PMECC
struct atmel_nand_host {
struct pmecc_regs __iomem *pmecc;
struct pmecc_errloc_regs __iomem *pmerrloc;
void __iomem *pmecc_rom_base;
u8 pmecc_corr_cap;
u16 pmecc_sector_size;
u32 pmecc_index_table_offset;
int pmecc_bytes_per_sector;
int pmecc_sector_number;
int pmecc_degree; /* Degree of remainders */
int pmecc_cw_len; /* Length of codeword */
/* lookup table for alpha_to and index_of */
void __iomem *pmecc_alpha_to;
void __iomem *pmecc_index_of;
/* data for pmecc computation */
int16_t pmecc_smu[(CONFIG_PMECC_CAP + 2) * (2 * CONFIG_PMECC_CAP + 1)];
int16_t pmecc_partial_syn[2 * CONFIG_PMECC_CAP + 1];
int16_t pmecc_si[2 * CONFIG_PMECC_CAP + 1];
int16_t pmecc_lmu[CONFIG_PMECC_CAP + 1]; /* polynomal order */
int pmecc_mu[CONFIG_PMECC_CAP + 1];
int pmecc_dmu[CONFIG_PMECC_CAP + 1];
int pmecc_delta[CONFIG_PMECC_CAP + 1];
};
static struct atmel_nand_host pmecc_host;
static struct nand_ecclayout atmel_pmecc_oobinfo;
/*
* Return number of ecc bytes per sector according to sector size and
* correction capability
*
* Following table shows what at91 PMECC supported:
* Correction Capability Sector_512_bytes Sector_1024_bytes
* ===================== ================ =================
* 2-bits 4-bytes 4-bytes
* 4-bits 7-bytes 7-bytes
* 8-bits 13-bytes 14-bytes
* 12-bits 20-bytes 21-bytes
* 24-bits 39-bytes 42-bytes
*/
static int pmecc_get_ecc_bytes(int cap, int sector_size)
{
int m = 12 + sector_size / 512;
return (m * cap + 7) / 8;
}
static void pmecc_config_ecc_layout(struct nand_ecclayout *layout,
int oobsize, int ecc_len)
{
int i;
layout->eccbytes = ecc_len;
/* ECC will occupy the last ecc_len bytes continuously */
for (i = 0; i < ecc_len; i++)
layout->eccpos[i] = oobsize - ecc_len + i;
layout->oobfree[0].offset = 2;
layout->oobfree[0].length =
oobsize - ecc_len - layout->oobfree[0].offset;
}
static void __iomem *pmecc_get_alpha_to(struct atmel_nand_host *host)
{
int table_size;
table_size = host->pmecc_sector_size == 512 ?
PMECC_INDEX_TABLE_SIZE_512 : PMECC_INDEX_TABLE_SIZE_1024;
/* the ALPHA lookup table is right behind the INDEX lookup table. */
return host->pmecc_rom_base + host->pmecc_index_table_offset +
table_size * sizeof(int16_t);
}
static void pmecc_gen_syndrome(struct mtd_info *mtd, int sector)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
int i;
uint32_t value;
/* Fill odd syndromes */
for (i = 0; i < host->pmecc_corr_cap; i++) {
value = readl(&host->pmecc->rem_port[sector].rem[i / 2]);
if (i & 1)
value >>= 16;
value &= 0xffff;
host->pmecc_partial_syn[(2 * i) + 1] = (int16_t)value;
}
}
static void pmecc_substitute(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
int16_t __iomem *alpha_to = host->pmecc_alpha_to;
int16_t __iomem *index_of = host->pmecc_index_of;
int16_t *partial_syn = host->pmecc_partial_syn;
const int cap = host->pmecc_corr_cap;
int16_t *si;
int i, j;
/* si[] is a table that holds the current syndrome value,
* an element of that table belongs to the field
*/
si = host->pmecc_si;
memset(&si[1], 0, sizeof(int16_t) * (2 * cap - 1));
/* Computation 2t syndromes based on S(x) */
/* Odd syndromes */
for (i = 1; i < 2 * cap; i += 2) {
for (j = 0; j < host->pmecc_degree; j++) {
if (partial_syn[i] & (0x1 << j))
si[i] = readw(alpha_to + i * j) ^ si[i];
}
}
/* Even syndrome = (Odd syndrome) ** 2 */
for (i = 2, j = 1; j <= cap; i = ++j << 1) {
if (si[j] == 0) {
si[i] = 0;
} else {
int16_t tmp;
tmp = readw(index_of + si[j]);
tmp = (tmp * 2) % host->pmecc_cw_len;
si[i] = readw(alpha_to + tmp);
}
}
}
/*
* This function defines a Berlekamp iterative procedure for
* finding the value of the error location polynomial.
* The input is si[], initialize by pmecc_substitute().
* The output is smu[][].
*
* This function is written according to chip datasheet Chapter:
* Find the Error Location Polynomial Sigma(x) of Section:
* Programmable Multibit ECC Control (PMECC).
*/
static void pmecc_get_sigma(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
int16_t *lmu = host->pmecc_lmu;
int16_t *si = host->pmecc_si;
int *mu = host->pmecc_mu;
int *dmu = host->pmecc_dmu; /* Discrepancy */
int *delta = host->pmecc_delta; /* Delta order */
int cw_len = host->pmecc_cw_len;
const int16_t cap = host->pmecc_corr_cap;
const int num = 2 * cap + 1;
int16_t __iomem *index_of = host->pmecc_index_of;
int16_t __iomem *alpha_to = host->pmecc_alpha_to;
int i, j, k;
uint32_t dmu_0_count, tmp;
int16_t *smu = host->pmecc_smu;
/* index of largest delta */
int ro;
int largest;
int diff;
/* Init the Sigma(x) */
memset(smu, 0, sizeof(int16_t) * ARRAY_SIZE(smu));
dmu_0_count = 0;
/* First Row */
/* Mu */
mu[0] = -1;
smu[0] = 1;
/* discrepancy set to 1 */
dmu[0] = 1;
/* polynom order set to 0 */
lmu[0] = 0;
/* delta[0] = (mu[0] * 2 - lmu[0]) >> 1; */
delta[0] = -1;
/* Second Row */
/* Mu */
mu[1] = 0;
/* Sigma(x) set to 1 */
smu[num] = 1;
/* discrepancy set to S1 */
dmu[1] = si[1];
/* polynom order set to 0 */
lmu[1] = 0;
/* delta[1] = (mu[1] * 2 - lmu[1]) >> 1; */
delta[1] = 0;
for (i = 1; i <= cap; i++) {
mu[i + 1] = i << 1;
/* Begin Computing Sigma (Mu+1) and L(mu) */
/* check if discrepancy is set to 0 */
if (dmu[i] == 0) {
dmu_0_count++;
tmp = ((cap - (lmu[i] >> 1) - 1) / 2);
if ((cap - (lmu[i] >> 1) - 1) & 0x1)
tmp += 2;
else
tmp += 1;
if (dmu_0_count == tmp) {
for (j = 0; j <= (lmu[i] >> 1) + 1; j++)
smu[(cap + 1) * num + j] =
smu[i * num + j];
lmu[cap + 1] = lmu[i];
return;
}
/* copy polynom */
for (j = 0; j <= lmu[i] >> 1; j++)
smu[(i + 1) * num + j] = smu[i * num + j];
/* copy previous polynom order to the next */
lmu[i + 1] = lmu[i];
} else {
ro = 0;
largest = -1;
/* find largest delta with dmu != 0 */
for (j = 0; j < i; j++) {
if ((dmu[j]) && (delta[j] > largest)) {
largest = delta[j];
ro = j;
}
}
/* compute difference */
diff = (mu[i] - mu[ro]);
/* Compute degree of the new smu polynomial */
if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff))
lmu[i + 1] = lmu[i];
else
lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2;
/* Init smu[i+1] with 0 */
for (k = 0; k < num; k++)
smu[(i + 1) * num + k] = 0;
/* Compute smu[i+1] */
for (k = 0; k <= lmu[ro] >> 1; k++) {
int16_t a, b, c;
if (!(smu[ro * num + k] && dmu[i]))
continue;
a = readw(index_of + dmu[i]);
b = readw(index_of + dmu[ro]);
c = readw(index_of + smu[ro * num + k]);
tmp = a + (cw_len - b) + c;
a = readw(alpha_to + tmp % cw_len);
smu[(i + 1) * num + (k + diff)] = a;
}
for (k = 0; k <= lmu[i] >> 1; k++)
smu[(i + 1) * num + k] ^= smu[i * num + k];
}
/* End Computing Sigma (Mu+1) and L(mu) */
/* In either case compute delta */
delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1;
/* Do not compute discrepancy for the last iteration */
if (i >= cap)
continue;
for (k = 0; k <= (lmu[i + 1] >> 1); k++) {
tmp = 2 * (i - 1);
if (k == 0) {
dmu[i + 1] = si[tmp + 3];
} else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) {
int16_t a, b, c;
a = readw(index_of +
smu[(i + 1) * num + k]);
b = si[2 * (i - 1) + 3 - k];
c = readw(index_of + b);
tmp = a + c;
tmp %= cw_len;
dmu[i + 1] = readw(alpha_to + tmp) ^
dmu[i + 1];
}
}
}
}
static int pmecc_err_location(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
const int cap = host->pmecc_corr_cap;
const int num = 2 * cap + 1;
int sector_size = host->pmecc_sector_size;
int err_nbr = 0; /* number of error */
int roots_nbr; /* number of roots */
int i;
uint32_t val;
int16_t *smu = host->pmecc_smu;
int timeout = PMECC_MAX_TIMEOUT_US;
writel(PMERRLOC_DISABLE, &host->pmerrloc->eldis);
for (i = 0; i <= host->pmecc_lmu[cap + 1] >> 1; i++) {
writel(smu[(cap + 1) * num + i], &host->pmerrloc->sigma[i]);
err_nbr++;
}
val = PMERRLOC_ELCFG_NUM_ERRORS(err_nbr - 1);
if (sector_size == 1024)
val |= PMERRLOC_ELCFG_SECTOR_1024;
writel(val, &host->pmerrloc->elcfg);
writel(sector_size * 8 + host->pmecc_degree * cap,
&host->pmerrloc->elen);
while (--timeout) {
if (readl(&host->pmerrloc->elisr) & PMERRLOC_CALC_DONE)
break;
WATCHDOG_RESET();
udelay(1);
}
if (!timeout) {
printk(KERN_ERR "atmel_nand : Timeout to calculate PMECC error location\n");
return -1;
}
roots_nbr = (readl(&host->pmerrloc->elisr) & PMERRLOC_ERR_NUM_MASK)
>> 8;
/* Number of roots == degree of smu hence <= cap */
if (roots_nbr == host->pmecc_lmu[cap + 1] >> 1)
return err_nbr - 1;
/* Number of roots does not match the degree of smu
* unable to correct error */
return -1;
}
static void pmecc_correct_data(struct mtd_info *mtd, uint8_t *buf, uint8_t *ecc,
int sector_num, int extra_bytes, int err_nbr)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
int i = 0;
int byte_pos, bit_pos, sector_size, pos;
uint32_t tmp;
uint8_t err_byte;
sector_size = host->pmecc_sector_size;
while (err_nbr) {
tmp = readl(&host->pmerrloc->el[i]) - 1;
byte_pos = tmp / 8;
bit_pos = tmp % 8;
if (byte_pos >= (sector_size + extra_bytes))
BUG(); /* should never happen */
if (byte_pos < sector_size) {
err_byte = *(buf + byte_pos);
*(buf + byte_pos) ^= (1 << bit_pos);
pos = sector_num * host->pmecc_sector_size + byte_pos;
printk(KERN_INFO "Bit flip in data area, byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
pos, bit_pos, err_byte, *(buf + byte_pos));
} else {
/* Bit flip in OOB area */
tmp = sector_num * host->pmecc_bytes_per_sector
+ (byte_pos - sector_size);
err_byte = ecc[tmp];
ecc[tmp] ^= (1 << bit_pos);
pos = tmp + nand_chip->ecc.layout->eccpos[0];
printk(KERN_INFO "Bit flip in OOB, oob_byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
pos, bit_pos, err_byte, ecc[tmp]);
}
i++;
err_nbr--;
}
return;
}
static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
u8 *ecc)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
int i, err_nbr, eccbytes;
uint8_t *buf_pos;
eccbytes = nand_chip->ecc.bytes;
for (i = 0; i < eccbytes; i++)
if (ecc[i] != 0xff)
goto normal_check;
/* Erased page, return OK */
return 0;
normal_check:
for (i = 0; i < host->pmecc_sector_number; i++) {
err_nbr = 0;
if (pmecc_stat & 0x1) {
buf_pos = buf + i * host->pmecc_sector_size;
pmecc_gen_syndrome(mtd, i);
pmecc_substitute(mtd);
pmecc_get_sigma(mtd);
err_nbr = pmecc_err_location(mtd);
if (err_nbr == -1) {
printk(KERN_ERR "PMECC: Too many errors\n");
mtd->ecc_stats.failed++;
return -EIO;
} else {
pmecc_correct_data(mtd, buf_pos, ecc, i,
host->pmecc_bytes_per_sector, err_nbr);
mtd->ecc_stats.corrected += err_nbr;
}
}
pmecc_stat >>= 1;
}
return 0;
}
static int atmel_nand_pmecc_read_page(struct mtd_info *mtd,
struct nand_chip *chip, uint8_t *buf, int page)
{
struct atmel_nand_host *host = chip->priv;
int eccsize = chip->ecc.size;
uint8_t *oob = chip->oob_poi;
uint32_t *eccpos = chip->ecc.layout->eccpos;
uint32_t stat;
int timeout = PMECC_MAX_TIMEOUT_US;
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);
pmecc_writel(host->pmecc, cfg, ((pmecc_readl(host->pmecc, cfg))
& ~PMECC_CFG_WRITE_OP) | PMECC_CFG_AUTO_ENABLE);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DATA);
chip->read_buf(mtd, buf, eccsize);
chip->read_buf(mtd, oob, mtd->oobsize);
while (--timeout) {
if (!(pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
break;
WATCHDOG_RESET();
udelay(1);
}
if (!timeout) {
printk(KERN_ERR "atmel_nand : Timeout to read PMECC page\n");
return -1;
}
stat = pmecc_readl(host->pmecc, isr);
if (stat != 0)
if (pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]) != 0)
return -EIO;
return 0;
}
static void atmel_nand_pmecc_write_page(struct mtd_info *mtd,
struct nand_chip *chip, const uint8_t *buf)
{
struct atmel_nand_host *host = chip->priv;
uint32_t *eccpos = chip->ecc.layout->eccpos;
int i, j;
int timeout = PMECC_MAX_TIMEOUT_US;
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);
pmecc_writel(host->pmecc, cfg, (pmecc_readl(host->pmecc, cfg) |
PMECC_CFG_WRITE_OP) & ~PMECC_CFG_AUTO_ENABLE);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DATA);
chip->write_buf(mtd, (u8 *)buf, mtd->writesize);
while (--timeout) {
if (!(pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
break;
WATCHDOG_RESET();
udelay(1);
}
if (!timeout) {
printk(KERN_ERR "atmel_nand : Timeout to read PMECC status, fail to write PMECC in oob\n");
return;
}
for (i = 0; i < host->pmecc_sector_number; i++) {
for (j = 0; j < host->pmecc_bytes_per_sector; j++) {
int pos;
pos = i * host->pmecc_bytes_per_sector + j;
chip->oob_poi[eccpos[pos]] =
readb(&host->pmecc->ecc_port[i].ecc[j]);
}
}
chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
}
static void atmel_pmecc_core_init(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
uint32_t val = 0;
struct nand_ecclayout *ecc_layout;
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);
switch (host->pmecc_corr_cap) {
case 2:
val = PMECC_CFG_BCH_ERR2;
break;
case 4:
val = PMECC_CFG_BCH_ERR4;
break;
case 8:
val = PMECC_CFG_BCH_ERR8;
break;
case 12:
val = PMECC_CFG_BCH_ERR12;
break;
case 24:
val = PMECC_CFG_BCH_ERR24;
break;
}
if (host->pmecc_sector_size == 512)
val |= PMECC_CFG_SECTOR512;
else if (host->pmecc_sector_size == 1024)
val |= PMECC_CFG_SECTOR1024;
switch (host->pmecc_sector_number) {
case 1:
val |= PMECC_CFG_PAGE_1SECTOR;
break;
case 2:
val |= PMECC_CFG_PAGE_2SECTORS;
break;
case 4:
val |= PMECC_CFG_PAGE_4SECTORS;
break;
case 8:
val |= PMECC_CFG_PAGE_8SECTORS;
break;
}
val |= (PMECC_CFG_READ_OP | PMECC_CFG_SPARE_DISABLE
| PMECC_CFG_AUTO_DISABLE);
pmecc_writel(host->pmecc, cfg, val);
ecc_layout = nand_chip->ecc.layout;
pmecc_writel(host->pmecc, sarea, mtd->oobsize - 1);
pmecc_writel(host->pmecc, saddr, ecc_layout->eccpos[0]);
pmecc_writel(host->pmecc, eaddr,
ecc_layout->eccpos[ecc_layout->eccbytes - 1]);
/* See datasheet about PMECC Clock Control Register */
pmecc_writel(host->pmecc, clk, PMECC_CLK_133MHZ);
pmecc_writel(host->pmecc, idr, 0xff);
pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
}
static int atmel_pmecc_nand_init_params(struct nand_chip *nand,
struct mtd_info *mtd)
{
struct atmel_nand_host *host;
int cap, sector_size;
host = nand->priv = &pmecc_host;
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.calculate = NULL;
nand->ecc.correct = NULL;
nand->ecc.hwctl = NULL;
cap = host->pmecc_corr_cap = CONFIG_PMECC_CAP;
sector_size = host->pmecc_sector_size = CONFIG_PMECC_SECTOR_SIZE;
host->pmecc_index_table_offset = CONFIG_PMECC_INDEX_TABLE_OFFSET;
printk(KERN_INFO "Initialize PMECC params, cap: %d, sector: %d\n",
cap, sector_size);
host->pmecc = (struct pmecc_regs __iomem *) ATMEL_BASE_PMECC;
host->pmerrloc = (struct pmecc_errloc_regs __iomem *)
ATMEL_BASE_PMERRLOC;
host->pmecc_rom_base = (void __iomem *) ATMEL_BASE_ROM;
/* ECC is calculated for the whole page (1 step) */
nand->ecc.size = mtd->writesize;
/* set ECC page size and oob layout */
switch (mtd->writesize) {
case 2048:
case 4096:
host->pmecc_degree = PMECC_GF_DIMENSION_13;
host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
host->pmecc_sector_number = mtd->writesize / sector_size;
host->pmecc_bytes_per_sector = pmecc_get_ecc_bytes(
cap, sector_size);
host->pmecc_alpha_to = pmecc_get_alpha_to(host);
host->pmecc_index_of = host->pmecc_rom_base +
host->pmecc_index_table_offset;
nand->ecc.steps = 1;
nand->ecc.bytes = host->pmecc_bytes_per_sector *
host->pmecc_sector_number;
if (nand->ecc.bytes > mtd->oobsize - 2) {
printk(KERN_ERR "No room for ECC bytes\n");
return -EINVAL;
}
pmecc_config_ecc_layout(&atmel_pmecc_oobinfo,
mtd->oobsize,
nand->ecc.bytes);
nand->ecc.layout = &atmel_pmecc_oobinfo;
break;
case 512:
case 1024:
/* TODO */
printk(KERN_ERR "Unsupported page size for PMECC, use Software ECC\n");
default:
/* page size not handled by HW ECC */
/* switching back to soft ECC */
nand->ecc.mode = NAND_ECC_SOFT;
nand->ecc.read_page = NULL;
nand->ecc.postpad = 0;
nand->ecc.prepad = 0;
nand->ecc.bytes = 0;
return 0;
}
nand->ecc.read_page = atmel_nand_pmecc_read_page;
nand->ecc.write_page = atmel_nand_pmecc_write_page;
atmel_pmecc_core_init(mtd);
return 0;
}
#else
/* oob layout for large page size
* bad block info is on bytes 0 and 1
* the bytes have to be consecutives to avoid
* several NAND_CMD_RNDOUT during read
*/
static struct nand_ecclayout atmel_oobinfo_large = {
.eccbytes = 4,
.eccpos = {60, 61, 62, 63},
.oobfree = {
{2, 58}
},
};
/* oob layout for small page size
* bad block info is on bytes 4 and 5
* the bytes have to be consecutives to avoid
* several NAND_CMD_RNDOUT during read
*/
static struct nand_ecclayout atmel_oobinfo_small = {
.eccbytes = 4,
.eccpos = {0, 1, 2, 3},
.oobfree = {
{6, 10}
},
};
/*
* Calculate HW ECC
*
* function called after a write
*
* mtd: MTD block structure
* dat: raw data (unused)
* ecc_code: buffer for ECC
*/
static int atmel_nand_calculate(struct mtd_info *mtd,
const u_char *dat, unsigned char *ecc_code)
{
unsigned int ecc_value;
/* get the first 2 ECC bytes */
ecc_value = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR);
ecc_code[0] = ecc_value & 0xFF;
ecc_code[1] = (ecc_value >> 8) & 0xFF;
/* get the last 2 ECC bytes */
ecc_value = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, NPR) & ATMEL_ECC_NPARITY;
ecc_code[2] = ecc_value & 0xFF;
ecc_code[3] = (ecc_value >> 8) & 0xFF;
return 0;
}
/*
* HW ECC read page function
*
* mtd: mtd info structure
* chip: nand chip info structure
* buf: buffer to store read data
*/
static int atmel_nand_read_page(struct mtd_info *mtd,
struct nand_chip *chip, uint8_t *buf, int page)
{
int eccsize = chip->ecc.size;
int eccbytes = chip->ecc.bytes;
uint32_t *eccpos = chip->ecc.layout->eccpos;
uint8_t *p = buf;
uint8_t *oob = chip->oob_poi;
uint8_t *ecc_pos;
int stat;
/* read the page */
chip->read_buf(mtd, p, eccsize);
/* move to ECC position if needed */
if (eccpos[0] != 0) {
/* This only works on large pages
* because the ECC controller waits for
* NAND_CMD_RNDOUTSTART after the
* NAND_CMD_RNDOUT.
* anyway, for small pages, the eccpos[0] == 0
*/
chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
mtd->writesize + eccpos[0], -1);
}
/* the ECC controller needs to read the ECC just after the data */
ecc_pos = oob + eccpos[0];
chip->read_buf(mtd, ecc_pos, eccbytes);
/* check if there's an error */
stat = chip->ecc.correct(mtd, p, oob, NULL);
if (stat < 0)
mtd->ecc_stats.failed++;
else
mtd->ecc_stats.corrected += stat;
/* get back to oob start (end of page) */
chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
/* read the oob */
chip->read_buf(mtd, oob, mtd->oobsize);
return 0;
}
/*
* HW ECC Correction
*
* function called after a read
*
* mtd: MTD block structure
* dat: raw data read from the chip
* read_ecc: ECC from the chip (unused)
* isnull: unused
*
* Detect and correct a 1 bit error for a page
*/
static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *isnull)
{
struct nand_chip *nand_chip = mtd->priv;
unsigned int ecc_status;
unsigned int ecc_word, ecc_bit;
/* get the status from the Status Register */
ecc_status = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, SR);
/* if there's no error */
if (likely(!(ecc_status & ATMEL_ECC_RECERR)))
return 0;
/* get error bit offset (4 bits) */
ecc_bit = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR) & ATMEL_ECC_BITADDR;
/* get word address (12 bits) */
ecc_word = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR) & ATMEL_ECC_WORDADDR;
ecc_word >>= 4;
/* if there are multiple errors */
if (ecc_status & ATMEL_ECC_MULERR) {
/* check if it is a freshly erased block
* (filled with 0xff) */
if ((ecc_bit == ATMEL_ECC_BITADDR)
&& (ecc_word == (ATMEL_ECC_WORDADDR >> 4))) {
/* the block has just been erased, return OK */
return 0;
}
/* it doesn't seems to be a freshly
* erased block.
* We can't correct so many errors */
printk(KERN_WARNING "atmel_nand : multiple errors detected."
" Unable to correct.\n");
return -EIO;
}
/* if there's a single bit error : we can correct it */
if (ecc_status & ATMEL_ECC_ECCERR) {
/* there's nothing much to do here.
* the bit error is on the ECC itself.
*/
printk(KERN_WARNING "atmel_nand : one bit error on ECC code."
" Nothing to correct\n");
return 0;
}
printk(KERN_WARNING "atmel_nand : one bit error on data."
" (word offset in the page :"
" 0x%x bit offset : 0x%x)\n",
ecc_word, ecc_bit);
/* correct the error */
if (nand_chip->options & NAND_BUSWIDTH_16) {
/* 16 bits words */
((unsigned short *) dat)[ecc_word] ^= (1 << ecc_bit);
} else {
/* 8 bits words */
dat[ecc_word] ^= (1 << ecc_bit);
}
printk(KERN_WARNING "atmel_nand : error corrected\n");
return 1;
}
/*
* Enable HW ECC : unused on most chips
*/
static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
{
}
int atmel_hwecc_nand_init_param(struct nand_chip *nand, struct mtd_info *mtd)
{
nand->ecc.mode = NAND_ECC_HW;
nand->ecc.calculate = atmel_nand_calculate;
nand->ecc.correct = atmel_nand_correct;
nand->ecc.hwctl = atmel_nand_hwctl;
nand->ecc.read_page = atmel_nand_read_page;
nand->ecc.bytes = 4;
if (nand->ecc.mode == NAND_ECC_HW) {
/* ECC is calculated for the whole page (1 step) */
nand->ecc.size = mtd->writesize;
/* set ECC page size and oob layout */
switch (mtd->writesize) {
case 512:
nand->ecc.layout = &atmel_oobinfo_small;
ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
ATMEL_ECC_PAGESIZE_528);
break;
case 1024:
nand->ecc.layout = &atmel_oobinfo_large;
ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
ATMEL_ECC_PAGESIZE_1056);
break;
case 2048:
nand->ecc.layout = &atmel_oobinfo_large;
ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
ATMEL_ECC_PAGESIZE_2112);
break;
case 4096:
nand->ecc.layout = &atmel_oobinfo_large;
ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
ATMEL_ECC_PAGESIZE_4224);
break;
default:
/* page size not handled by HW ECC */
/* switching back to soft ECC */
nand->ecc.mode = NAND_ECC_SOFT;
nand->ecc.calculate = NULL;
nand->ecc.correct = NULL;
nand->ecc.hwctl = NULL;
nand->ecc.read_page = NULL;
nand->ecc.postpad = 0;
nand->ecc.prepad = 0;
nand->ecc.bytes = 0;
break;
}
}
return 0;
}
#endif /* CONFIG_ATMEL_NAND_HW_PMECC */
#endif /* CONFIG_ATMEL_NAND_HWECC */
static void at91_nand_hwcontrol(struct mtd_info *mtd,
int cmd, unsigned int ctrl)
{
struct nand_chip *this = mtd->priv;
if (ctrl & NAND_CTRL_CHANGE) {
ulong IO_ADDR_W = (ulong) this->IO_ADDR_W;
IO_ADDR_W &= ~(CONFIG_SYS_NAND_MASK_ALE
| CONFIG_SYS_NAND_MASK_CLE);
if (ctrl & NAND_CLE)
IO_ADDR_W |= CONFIG_SYS_NAND_MASK_CLE;
if (ctrl & NAND_ALE)
IO_ADDR_W |= CONFIG_SYS_NAND_MASK_ALE;
#ifdef CONFIG_SYS_NAND_ENABLE_PIN
at91_set_gpio_value(CONFIG_SYS_NAND_ENABLE_PIN,
!(ctrl & NAND_NCE));
#endif
this->IO_ADDR_W = (void *) IO_ADDR_W;
}
if (cmd != NAND_CMD_NONE)
writeb(cmd, this->IO_ADDR_W);
}
#ifdef CONFIG_SYS_NAND_READY_PIN
static int at91_nand_ready(struct mtd_info *mtd)
{
return at91_get_gpio_value(CONFIG_SYS_NAND_READY_PIN);
}
#endif
#ifndef CONFIG_SYS_NAND_BASE_LIST
#define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
#endif
static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE];
static ulong base_addr[CONFIG_SYS_MAX_NAND_DEVICE] = CONFIG_SYS_NAND_BASE_LIST;
int atmel_nand_chip_init(int devnum, ulong base_addr)
{
int ret;
struct mtd_info *mtd = &nand_info[devnum];
struct nand_chip *nand = &nand_chip[devnum];
mtd->priv = nand;
nand->IO_ADDR_R = nand->IO_ADDR_W = (void __iomem *)base_addr;
nand->ecc.mode = NAND_ECC_SOFT;
#ifdef CONFIG_SYS_NAND_DBW_16
nand->options = NAND_BUSWIDTH_16;
#endif
nand->cmd_ctrl = at91_nand_hwcontrol;
#ifdef CONFIG_SYS_NAND_READY_PIN
nand->dev_ready = at91_nand_ready;
#endif
nand->chip_delay = 20;
ret = nand_scan_ident(mtd, CONFIG_SYS_NAND_MAX_CHIPS, NULL);
if (ret)
return ret;
#ifdef CONFIG_ATMEL_NAND_HWECC
#ifdef CONFIG_ATMEL_NAND_HW_PMECC
ret = atmel_pmecc_nand_init_params(nand, mtd);
#else
ret = atmel_hwecc_nand_init_param(nand, mtd);
#endif
if (ret)
return ret;
#endif
ret = nand_scan_tail(mtd);
if (!ret)
nand_register(devnum);
return ret;
}
void board_nand_init(void)
{
int i;
for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
if (atmel_nand_chip_init(i, base_addr[i]))
printk(KERN_ERR "atmel_nand: Fail to initialize #%d chip",
i);
}
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