[PATCH v9 3/3] MTD: at91: atmel_nand: Update driver to support Programmable Multibit ECC controller
Josh Wu
josh.wu at atmel.com
Mon May 28 04:34:36 EDT 2012
On 5/28/2012 2:58 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 21:24 Sat 26 May , Josh Wu wrote:
>> 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 this driver, the user needs to pass in the correction capability and
>> the sector size.
>>
>> This driver has been tested on AT91SAM9X5-EK and AT91SAM9N12-EK with JFFS2,
>> YAFFS2, UBIFS and mtd-utils.
>>
>> Signed-off-by: Hong Xu<hong.xu at atmel.com>
>> Signed-off-by: Josh Wu<josh.wu at atmel.com>
>> ---
>> drivers/mtd/nand/atmel_nand.c | 761 ++++++++++++++++++++++++++++++++++++-
>> drivers/mtd/nand/atmel_nand_ecc.h | 116 ++++++
>> 2 files changed, 876 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
>> index 9a9bfbf..ddcf1ed 100644
>> --- a/drivers/mtd/nand/atmel_nand.c
>> +++ b/drivers/mtd/nand/atmel_nand.c
>> @@ -15,6 +15,8 @@
>> * (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
>> * (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
>> *
>> + * Add Programmable Multibit ECC support for various AT91 SoC
>> + * (C) Copyright 2012 ATMEL, Hong Xu
>> *
>> * This program is free software; you can redistribute it and/or modify
>> * it under the terms of the GNU General Public License version 2 as
>> @@ -77,6 +79,21 @@ static struct nand_ecclayout atmel_oobinfo_small = {
>> },
>> };
>>
>> +/* a structure includes datas for PMECC computation */
>> +struct atmel_pmecc_data {
>> + int16_t partial_syn[2 * PMECC_MAX_ERROR_NB + 1];
>> + int16_t si[2 * PMECC_MAX_ERROR_NB + 1];
>> +
>> + /* Sigma table */
>> + int16_t smu[PMECC_MAX_ERROR_NB + 2][2 * PMECC_MAX_ERROR_NB + 1];
> you still hardcode the array in the struct
>
> and if the pmecc evolve we will have to touch again
> please allocate them
ok.
>> + /* polynomal order */
>> + int16_t lmu[PMECC_MAX_ERROR_NB + 1];
>> +
>> + int mu[PMECC_MAX_ERROR_NB + 1];
>> + int dmu[PMECC_MAX_ERROR_NB + 1];
>> + int delta[PMECC_MAX_ERROR_NB + 1];
>> +};
>> +
>> struct atmel_nand_host {
>> struct nand_chip nand_chip;
>> struct mtd_info mtd;
>> @@ -92,8 +109,25 @@ struct atmel_nand_host {
>> bool has_pmecc;
>> u8 pmecc_corr_cap;
>> u16 pmecc_sector_size;
>> +
>> + int pmecc_bytes_per_sector;
>> + int pmecc_sector_number;
>> + int pmecc_degree; /* Degree of remainders */
>> + int pmecc_cw_len; /* Length of codeword */
>> +
>> + void __iomem *pmerrloc_base;
>> + void __iomem *pmecc_rom_base;
>> +
>> + /* lookup table for alpha_to and index_of */
>> + void __iomem *pmecc_alpha_to;
>> + void __iomem *pmecc_index_of;
>> +
>> + /* data for pmecc computation */
>> + struct atmel_pmecc_data *pmecc_data;
>> };
>>
>> +static struct nand_ecclayout atmel_pmecc_oobinfo;
>> +
>> static int cpu_has_dma(void)
>> {
>> return cpu_is_at91sam9rl() || cpu_is_at91sam9g45();
>> @@ -287,6 +321,708 @@ static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
>> }
>>
>> /*
>> + * 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)
>> +{
>> + void __iomem *p;
>> +
>> + switch (host->pmecc_sector_size) {
>> + case 512:
>> + p = host->pmecc_rom_base + PMECC_LOOKUP_TABLE_OFFSET_512 +
>> + PMECC_LOOKUP_TABLE_SIZE_512 * sizeof(int16_t);
>> + break;
>> + case 1024:
>> + p = host->pmecc_rom_base + PMECC_LOOKUP_TABLE_OFFSET_1024 +
>> + PMECC_LOOKUP_TABLE_SIZE_1024 * sizeof(int16_t);
>> + break;
>> + default:
>> + BUG();
>> + }
>> +
>> + return p;
>> +}
>> +
>> +static void __iomem *pmecc_get_index_of(struct atmel_nand_host *host)
> this is a __dev_init function plese check the other too
>
> btw you need to use __dev_init and not __init
Here I use pmecc_get_index_of() function to get a lookup table base
which is in ROM.
I'm not clear about how should I need __dev_init here. Can you give more
information?
>> +{
>> + void __iomem *p;
>> +
>> + switch (host->pmecc_sector_size) {
>> + case 512:
>> + p = host->pmecc_rom_base + PMECC_LOOKUP_TABLE_OFFSET_512;
>> + break;
>> + case 1024:
>> + p = host->pmecc_rom_base + PMECC_LOOKUP_TABLE_OFFSET_1024;
>> + break;
>> + default:
>> + BUG();
>> + }
>> +
>> + return p;
>> +}
>> +
>> +static void pmecc_gen_syndrome(struct mtd_info *mtd, int sector)
>> +{
>> + int i;
>> + uint32_t value;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> +
>> + /* Fill odd syndromes */
>> + for (i = 0; i< host->pmecc_corr_cap; i++) {
>> + value = pmecc_readl_rem_relaxed(host->ecc, sector, i / 2);
>> + value = (i& 1) ? (value& 0xffff0000)>> 16 : value& 0xffff;
> simplify by
> if (i& 1)
> val>>= 16;
> value&= 0xffff;
I'll fix it.
>
>> + host->pmecc_data->partial_syn[(2 * i) + 1] = (int16_t)value;
>> + }
>> +}
>> +
>> +static void pmecc_substitute(struct mtd_info *mtd)
>> +{
>> + int16_t *si;
>> + int i, j;
>> + 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_data->partial_syn;
>> +
>> + /* si[] is a table that holds the current syndrome value,
>> + * an element of that table belongs to the field
>> + */
>> + si = host->pmecc_data->si;
>> +
>> + for (i = 1; i< 2 * PMECC_MAX_ERROR_NB; i++)
>> + si[i] = 0;
> please use memset
ok
>> +
>> + /* Computation 2t syndromes based on S(x) */
>> + /* Odd syndromes */
>> + for (i = 1; i< 2 * host->pmecc_corr_cap; i += 2) {
>> + si[i] = 0;
> shy this you already init the array at 0 before
yes, I'll fix it.
>> + for (j = 0; j< host->pmecc_degree; j++) {
>> + if (partial_syn[i]& ((unsigned short)0x1<< j))
>> + si[i] = readw_relaxed(alpha_to + i * j) ^ si[i];
>> + }
>> + }
>> + /* Even syndrome = (Odd syndrome) ** 2 */
>> + for (i = 2; i<= 2 * host->pmecc_corr_cap; i += 2) {
>> + j = i / 2;
>> + if (si[j] == 0)
> here if {
> } else {
> }
ok
>> + si[i] = 0;
>> + else {
>> + int16_t tmp;
> missing blank line
ok.
>> + tmp = readw_relaxed(index_of + si[j]);
>> + tmp = (tmp * 2) % host->pmecc_cw_len;
>> + si[i] = readw_relaxed(alpha_to + tmp);
>> + }
>> + }
>> +
>> + return;
>> +}
>> +
>> +static void pmecc_get_sigma(struct mtd_info *mtd)
>> +{
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> +
>> + int i, j, k;
>> + uint32_t dmu_0_count, tmp;
>> + int16_t (*smu)[2 * PMECC_MAX_ERROR_NB + 1];
>> + int16_t *lmu = host->pmecc_data->lmu;
>> + int16_t *si = host->pmecc_data->si;
>> + int *mu = host->pmecc_data->mu;
>> + int *dmu = host->pmecc_data->dmu; /* Discrepancy */
>> + int *delta = host->pmecc_data->delta; /* Delta order */
>> + int cw_len = host->pmecc_cw_len;
>> + int16_t cap = host->pmecc_corr_cap;
>> +
>> + int16_t __iomem *index_of = host->pmecc_index_of;
>> + int16_t __iomem *alpha_to = host->pmecc_alpha_to;
>> +
>> + /* index of largest delta */
>> + int ro;
>> + int largest;
>> + int diff;
>> +
>> + dmu_0_count = 0;
>> + smu = host->pmecc_data->smu;
>> +
>> + /* First Row */
>> +
>> + /* Mu */
>> + mu[0] = -1;
>> +
>> + memset(&smu[0][0], 0,
>> + sizeof(int16_t) * (2 * PMECC_MAX_ERROR_NB + 1));
>> + smu[0][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;
>> +
>> + /* Second Row */
>> +
>> + /* Mu */
>> + mu[1] = 0;
>> + /* Sigma(x) set to 1 */
>> + memset(&smu[1][0], 0,
>> + sizeof(int16_t) * (2 * PMECC_MAX_ERROR_NB + 1));
>> + smu[1][0] = 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;
>> +
>> + /* Init the Sigma(x) last row */
>> + memset(&smu[cap + 1][0], 0,
>> + sizeof(int16_t) * (2 * PMECC_MAX_ERROR_NB + 1));
>> +
>> + 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][j] = smu[i][j];
>> + lmu[cap + 1] = lmu[i];
>> + return;
>> + }
>> +
>> + /* copy polynom */
>> + for (j = 0; j<= lmu[i]>> 1; j++)
>> + smu[i + 1][j] = smu[i][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< (2 * PMECC_MAX_ERROR_NB + 1); k++)
>> + smu[i+1][k] = 0;
>> +
>> + /* Compute smu[i+1] */
>> + for (k = 0; k<= lmu[ro]>> 1; k++) {
>> + int16_t a, b, c;
>> +
>> + if (!(smu[ro][k]&& dmu[i]))
>> + continue;
>> + a = readw_relaxed(index_of + dmu[i]);
>> + b = readw_relaxed(index_of + dmu[ro]);
>> + c = readw_relaxed(index_of + smu[ro][k]);
>> + tmp = a + (cw_len - b) + c;
>> + a = readw_relaxed(alpha_to + tmp % cw_len);
>> + smu[i + 1][k + diff] = a;
>> + }
>> +
>> + for (k = 0; k<= lmu[i]>> 1; k++)
>> + smu[i + 1][k] ^= smu[i][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][k]&& si[tmp + 3 - k]) {
>> + int16_t a, b, c;
>> + a = readw_relaxed(index_of + smu[i + 1][k]);
>> + b = si[2 * (i - 1) + 3 - k];
>> + c = readw_relaxed(index_of + b);
>> + tmp = a + c;
>> + tmp %= cw_len;
>> + dmu[i + 1] = readw_relaxed(alpha_to + tmp) ^
>> + dmu[i + 1];
>> + }
>> + }
>> + }
>> +
>> + return;
>> +}
>> +
>> +static int pmecc_err_location(struct mtd_info *mtd)
>> +{
>> + int i;
>> + int err_nbr; /* number of error */
>> + int roots_nbr; /* number of roots */
>> + int sector_size;
>> + uint32_t val;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> + int timeout_count = 0;
>> + int cap = host->pmecc_corr_cap;
>> +
>> + err_nbr = 0;
>> + sector_size = host->pmecc_sector_size;
>> +
>> + pmerrloc_writel(host->pmerrloc_base, ELDIS, PMERRLOC_DISABLE);
>> +
>> + for (i = 0; i<= host->pmecc_data->lmu[cap + 1]>> 1; i++) {
>> + pmerrloc_writel_sigma_relaxed(host->pmerrloc_base, i,
>> + host->pmecc_data->smu[cap + 1][i]);
>> + err_nbr++;
>> + }
>> +
>> + val = (err_nbr - 1)<< 16;
>> + if (sector_size == 1024)
>> + val |= 1;
>> +
>> + pmerrloc_writel(host->pmerrloc_base, ELCFG, val);
>> + pmerrloc_writel(host->pmerrloc_base, ELEN,
>> + sector_size * 8 + host->pmecc_degree * cap);
>> +
>> + while (!(pmerrloc_readl_relaxed(host->pmerrloc_base, ELISR)
>> + & PMERRLOC_CALC_DONE)) {
>> + if (unlikely(timeout_count++> PMECC_MAX_TIMEOUT_COUNT))
>> + return -1; /* Time out */
>> + cpu_relax();
>> + }
>> +
>> + roots_nbr = (pmerrloc_readl_relaxed(host->pmerrloc_base, ELISR)
>> + & PMERRLOC_ERR_NUM_MASK)>> 8;
>> + /* Number of roots == degree of smu hence<= cap */
>> + if (roots_nbr == host->pmecc_data->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,
>> + int extra_bytes, int err_nbr)
>> +{
>> + int i = 0;
>> + int byte_pos, bit_pos;
>> + int sector_size, ecc_size;
>> + uint32_t tmp;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> +
>> + sector_size = host->pmecc_sector_size;
>> + ecc_size = nand_chip->ecc.bytes;
>> +
>> + while (err_nbr) {
>> + tmp = pmerrloc_readl_el_relaxed(host->pmerrloc_base, i) - 1;
>> + byte_pos = tmp / 8;
>> + bit_pos = tmp % 8;
>> + dev_info(host->dev, "PMECC correction, byte_pos: %d bit_pos: %d\n",
>> + byte_pos, bit_pos);
>> +
>> + if (byte_pos< (sector_size + extra_bytes)) {
>> + tmp = sector_size +
>> + pmecc_readl_relaxed(host->ecc, SADDR);
>> +
>> + if (byte_pos< tmp)
>> + *(buf + byte_pos) ^= (1<< bit_pos);
>> + else
>> + *(buf + byte_pos + ecc_size) ^= (1<< bit_pos);
>> + }
>> +
>> + i++;
>> + err_nbr--;
>> + }
>> +
>> + return;
>> +}
>> +
>> +static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
>> + u8 *ecc)
>> +{
>> + int i, err_nbr;
>> + uint8_t *buf_pos;
>> + int eccbytes;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> +
>> + 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) {
>> + dev_err(host->dev, "PMECC: Too many errors\n");
>> + mtd->ecc_stats.failed++;
>> + return -EIO;
>> + } else {
>> + pmecc_correct_data(mtd, buf_pos, 0, 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)
>> +{
>> + uint32_t stat;
>> + int timeout_count = 0;
>> + int eccsize = chip->ecc.size;
>> + uint8_t *oob = chip->oob_poi;
>> + struct atmel_nand_host *host = chip->priv;
>> + uint32_t *eccpos = chip->ecc.layout->eccpos;
>> +
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST);
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
>> + pmecc_writel(host->ecc, CFG, (pmecc_readl_relaxed(host->ecc, CFG)
>> + & ~PMECC_CFG_WRITE_OP) | PMECC_CFG_AUTO_ENABLE);
>> +
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DATA);
>> +
>> + chip->read_buf(mtd, buf, eccsize);
>> + chip->read_buf(mtd, oob, mtd->oobsize);
>> +
>> + while ((pmecc_readl_relaxed(host->ecc, SR)& PMECC_SR_BUSY)) {
>> + if (unlikely(timeout_count++> PMECC_MAX_TIMEOUT_COUNT))
>> + return -EIO; /* Time out */
>> + cpu_relax();
>> + }
>> +
>> + stat = pmecc_readl_relaxed(host->ecc, 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)
>> +{
>> + int i, j;
>> + int timeout_count = 0;
>> + struct atmel_nand_host *host = chip->priv;
>> + uint32_t *eccpos = chip->ecc.layout->eccpos;
>> +
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST);
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DISABLE);
>> +
>> + pmecc_writel(host->ecc, CFG, (pmecc_readl_relaxed(host->ecc, CFG) |
>> + PMECC_CFG_WRITE_OP)& ~PMECC_CFG_AUTO_ENABLE);
>> +
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_DATA);
>> +
>> + chip->write_buf(mtd, (u8 *)buf, mtd->writesize);
>> +
>> + while ((pmecc_readl_relaxed(host->ecc, SR)& PMECC_SR_BUSY)) {
>> + if (unlikely(timeout_count++> PMECC_MAX_TIMEOUT_COUNT)) {
>> + dev_err(host->dev, "PMECC: Timeout to get ECC value.\n");
>> + return; /* Time out */
>> + }
>> + cpu_relax();
>> + }
>> +
>> + 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]] =
>> + pmecc_readb_ecc_relaxed(host->ecc, i, j);
>> + }
>> + }
>> + chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
>> +
>> + return;
>> +}
>> +
>> +static void atmel_pmecc_core_init(struct mtd_info *mtd)
>> +{
>> + uint32_t val = 0;
>> + struct nand_chip *nand_chip = mtd->priv;
>> + struct atmel_nand_host *host = nand_chip->priv;
>> + struct nand_ecclayout *ecc_layout;
>> +
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_RST);
>> + pmecc_writel(host->ecc, 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->ecc, CFG, val);
>> +
>> + ecc_layout = nand_chip->ecc.layout;
>> + pmecc_writel(host->ecc, SAREA, mtd->oobsize - 1);
>> + pmecc_writel(host->ecc, SADDR, ecc_layout->eccpos[0]);
>> + pmecc_writel(host->ecc, EADDR,
>> + ecc_layout->eccpos[ecc_layout->eccbytes - 1]);
>> + /* See datasheet about PMECC Clock Control Register */
>> + pmecc_writel(host->ecc, CLK, 2);
>> + pmecc_writel(host->ecc, IDR, 0xff);
>> + pmecc_writel(host->ecc, CTRL, PMECC_CTRL_ENABLE);
>> +}
>> +
>> +static int __init atmel_pmecc_nand_init_params(struct platform_device *pdev,
>> + struct atmel_nand_host *host)
>> +{
>> + int cap, sector_size, err_no;
>> + struct mtd_info *mtd;
>> + struct nand_chip *nand_chip;
>> + struct resource *regs;
>> + struct resource *regs_pmerr, *regs_rom;
>> +
>> + cap = host->pmecc_corr_cap;
>> + sector_size = host->pmecc_sector_size;
>> + dev_info(host->dev, "Initialize PMECC params, cap: %d, sector: %d\n",
>> + cap, sector_size);
>> +
>> + /* Sanity check */
>> + if ((sector_size != 512)&& (sector_size != 1024)) {
>> + dev_err(host->dev,
>> + "Unsupported PMECC sector size: %d; should be 512 or 1024 bytes\n",
>> + sector_size);
>> + return -EINVAL;
>> + }
>> + if ((cap != 2)&& (cap != 4)&& (cap != 8)&& (cap != 12)&&
>> + (cap != 24)) {
>> + dev_err(host->dev,
>> + "Unsupported PMECC correction capability, should be 2, 4, 8, 12 or 24\n");
>> + return -EINVAL;
>> + }
>> +
>> + nand_chip =&host->nand_chip;
>> + mtd =&host->mtd;
>> +
>> + nand_chip->ecc.mode = NAND_ECC_SOFT; /* By default */
>> +
>> + regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> + if (!regs) {
>> + dev_warn(host->dev,
>> + "Can't get I/O resource regs, rolling back on software ECC\n");
>> + return 0;
>> + }
>> +
>> + host->ecc = ioremap(regs->start, resource_size(regs));
>> + if (host->ecc == NULL) {
>> + dev_err(host->dev, "ioremap failed\n");
>> + err_no = -EIO;
>> + goto err_pmecc_ioremap;
>> + }
>> +
>> + regs_pmerr = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>> + regs_rom = platform_get_resource(pdev, IORESOURCE_MEM, 3);
>> + if (regs_pmerr&& regs_rom) {
>> + host->pmerrloc_base = ioremap(regs_pmerr->start,
>> + resource_size(regs_pmerr));
>> + host->pmecc_rom_base = ioremap(regs_rom->start,
>> + resource_size(regs_rom));
>> +
>> + if (host->pmerrloc_base&& host->pmecc_rom_base) {
>> + nand_chip->ecc.mode = NAND_ECC_HW;
>> + nand_chip->ecc.read_page =
>> + atmel_nand_pmecc_read_page;
>> + nand_chip->ecc.write_page =
>> + atmel_nand_pmecc_write_page;
>> + } else {
>> + dev_err(host->dev,
>> + "Can not get I/O resource for PMECC controller!\n");
>> + err_no = -EIO;
>> + goto err_pmloc_ioremap;
>> + }
>> + }
>> +
>> + /* ECC is calculated for the whole page (1 step) */
>> + nand_chip->ecc.size = mtd->writesize;
>> +
>> + /* set ECC page size and oob layout */
>> + switch (mtd->writesize) {
>> + case 2048:
>> + host->pmecc_degree = PMECC_GF_DIMENSION_13;
>> + host->pmecc_cw_len = (1<< host->pmecc_degree) - 1;
>> + host->pmecc_corr_cap = cap;
>> + 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 = pmecc_get_index_of(host);
>> +
>> + nand_chip->ecc.steps = 1;
>> + nand_chip->ecc.strength = cap;
>> + nand_chip->ecc.bytes = host->pmecc_bytes_per_sector *
>> + host->pmecc_sector_number;
>> + if (nand_chip->ecc.bytes> mtd->oobsize - 2) {
>> + dev_err(host->dev, "No room for ECC bytes\n");
>> + err_no = -EINVAL;
>> + goto err;
>> + }
>> + pmecc_config_ecc_layout(&atmel_pmecc_oobinfo,
>> + mtd->oobsize,
>> + nand_chip->ecc.bytes);
>> + nand_chip->ecc.layout =&atmel_pmecc_oobinfo;
>> + break;
>> + case 512:
>> + case 1024:
>> + case 4096:
>> + /* TODO */
>> + dev_warn(host->dev,
>> + "Unsupported page size for PMECC, use Software ECC\n");
>> + default:
>> + /* page size not handled by HW ECC */
>> + /* switching back to soft ECC */
>> + nand_chip->ecc.mode = NAND_ECC_SOFT;
>> + nand_chip->ecc.calculate = NULL;
>> + nand_chip->ecc.correct = NULL;
>> + nand_chip->ecc.hwctl = NULL;
>> + nand_chip->ecc.read_page = NULL;
>> + nand_chip->ecc.write_page = NULL;
>> + nand_chip->ecc.postpad = 0;
>> + nand_chip->ecc.prepad = 0;
>> + nand_chip->ecc.bytes = 0;
>> + err_no = 0;
>> + goto err;
>> + }
>> +
>> + /* Allocate data for PMECC computation */
>> + host->pmecc_data = kzalloc(sizeof(struct atmel_pmecc_data), GFP_KERNEL);
> why do you always allocate the pmecc_data?
>
> you need to allocate it only if you use it
If not using PMECC, the code will never come to here. So I think it's
right time to allocate all the computation data here.
>
> Best Regards,
> J.
>> + if (!host->pmecc_data) {
>> + dev_err(host->dev,
>> + "Cannot allocate memory for PMECC computation!\n");
>> + err_no = -ENOMEM;
>> + goto err;
>> + }
>> +
>> + atmel_pmecc_core_init(mtd);
>> +
>> + return 0;
>> +
>> +err:
>> +err_pmloc_ioremap:
>> + iounmap(host->ecc);
>> + if (host->pmerrloc_base)
>> + iounmap(host->pmerrloc_base);
>> + if (host->pmecc_rom_base)
>> + iounmap(host->pmecc_rom_base);
>> +err_pmecc_ioremap:
>> + return err_no;
>> +}
>> +
>> +/*
>> * Calculate HW ECC
>> *
>> * function called after a write
>> @@ -720,7 +1456,11 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>> }
>>
>> if (nand_chip->ecc.mode == NAND_ECC_HW) {
>> - res = atmel_hw_nand_init_params(pdev, host);
>> + if (host->has_pmecc)
>> + res = atmel_pmecc_nand_init_params(pdev, host);
>> + else
>> + res = atmel_hw_nand_init_params(pdev, host);
>> +
>> if (res != 0)
>> goto err_hw_ecc;
>> }
>> @@ -741,6 +1481,12 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>> err_scan_tail:
>> if (host->ecc)
>> iounmap(host->ecc);
>> + if (host->has_pmecc) {
> no need to check if you have teh pmecc
>
> if it's no the case pmerrloc_base will be NULLo
>
> don't you need to disable it in the error path?
right, I should disable the hardware in this error path.
>
> Best Regards,
> J.
Best Regards,
Josh Wu
More information about the linux-arm-kernel
mailing list