[PATCH v9 3/3] MTD: at91: atmel_nand: Update driver to support Programmable Multibit ECC controller
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Mon May 28 02:58:22 EDT 2012
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
> + /* 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
> +{
> + 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;
> + 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
> +
> + /* 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
> + 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 {
}
> + si[i] = 0;
> + else {
> + int16_t tmp;
missing blank line
> + 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
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?
Best Regards,
J.
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