[U-Boot] [PATCH v2 3/5] at91: atmel_nand: Update driver to support Programmable Multibit ECC controller
Andreas Bießmann
andreas.devel at googlemail.com
Fri Aug 17 11:24:20 CEST 2012
Dear Josh Wu,
On 16.08.2012 07:05, 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 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 at atmel.com>
> ---
> Changes since v1:
> Change 'ecc' array's type from u32 to u8 in structure pmecc_regs (u32 ecc[11] -> u8 ecc[44]). That will make PMECC write correctly.
> enable 4k-page nand flash pmecc support.
> fix coding style errors and warnings.
> changed lookup table variable name which sounds correct.
>
> drivers/mtd/nand/atmel_nand.c | 654 ++++++++++++++++++++++++++++++++++++-
> drivers/mtd/nand/atmel_nand_ecc.h | 111 +++++++
> 2 files changed, 763 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 9dc003e..784370c 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -5,6 +5,9 @@
> *
> * (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.
> *
> @@ -41,6 +44,648 @@
>
> #include "atmel_nand_ecc.h" /* Hardware ECC registers */
>
> +static int chip_nr;
> +
> +#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];
can you please add some README entry describing these new config parameters?
Namely CONFIG_ATMEL_NAND_HW_PMECC, CONFIG_PMECC_CAP,
CONFIG_PMECC_SECTOR_SIZE (can't this be derived from some already
available NAND information?) and CONFIG_PMECC_INDEX_TABLE_OFFSET.
> +};
> +
> +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] & ((unsigned short)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);
> + }
> + }
> +
> + 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;
> +
> + 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;
> +
> + dmu_0_count = 0;
> +
> + /* First Row */
> +
> + /* Mu */
> + mu[0] = -1;
> +
> + memset(smu, 0, sizeof(int16_t) * num);
> + 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;
---------------------^
isn't mu[0] -1 here
> +
> + /* Second Row */
> +
> + /* Mu */
> + mu[1] = 0;
> + /* Sigma(x) set to 1 */
> + memset(&smu[num], 0, sizeof(int16_t) * num);
> + 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;
----------------------^
isn't mu[1] 0 here?
I see, this algorithm is just copied from the processors datasheet.
> +
> + /* Init the Sigma(x) last row */
> + memset(&smu[(cap + 1) * num], 0, sizeof(int16_t) * num);
Isn't the whole smu zeroed here at this stage? why not just call
memset(smu, 0, sizeof(int16) * ARRAY_SIZE(smu))?
> +
> + 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];
Horrible to read, this was written first by an electrical engineer
(insider joke)? Can you please add a comment at top of pmecc_get_sigma
and add a warning about extremely complicated to read algorithm ;) But
it must be right cause it is written down in the datasheet ...
> + } 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];
> + }
> + }
> + }
> +
> + return;
> +}
> +
> +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;
> +
> + 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 (!(readl(&host->pmerrloc->elisr) & PMERRLOC_CALC_DONE))
> + udelay(10);
Can you please add some timeout here. Maybe a WATCHDOG_RESET is also
required?
> +
> + 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;
> +
> + 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 ((pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
> + udelay(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;
> +
> + 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 ((pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
> + udelay(1);
> +
> + 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;
> +
> + mtd = &nand_info[chip_nr++];
NAK
> + mtd->priv = nand;
> + host = nand->priv = &pmecc_host;
> +
> + /* Detect NAND chips */
> + if (nand_scan_ident(mtd, 1, NULL)) {
please change that, read later on.
> + printk(KERN_WARNING "NAND Flash not found !\n");
> + return -ENXIO;
> + }
> +
> + 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;
Can't we use some information from the nand chip here? Do we need to
hard code this paramater?
> + 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
> @@ -234,7 +879,6 @@ static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
>
> int atmel_hw_nand_init_param(struct nand_chip *nand)
> {
> - static int chip_nr = 0;
> struct mtd_info *mtd;
>
> nand->ecc.mode = NAND_ECC_HW;
> @@ -293,7 +937,9 @@ int atmel_hw_nand_init_param(struct nand_chip *nand)
> return 0;
> }
>
> -#endif
> +#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)
> @@ -343,8 +989,12 @@ int board_nand_init(struct nand_chip *nand)
> nand->chip_delay = 20;
>
> #ifdef CONFIG_ATMEL_NAND_HWECC
> +#ifdef CONFIG_ATMEL_NAND_HW_PMECC
> + res = atmel_pmecc_nand_init_params(nand);
> +#else
> res = atmel_hw_nand_init_param(nand);
> #endif
> +#endif
>
> return res;
> }
> diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h
> index 1ee7f99..8f06b14 100644
> --- a/drivers/mtd/nand/atmel_nand_ecc.h
> +++ b/drivers/mtd/nand/atmel_nand_ecc.h
> @@ -33,4 +33,115 @@
> #define ATMEL_ECC_NPR 0x10 /* NParity register */
> #define ATMEL_ECC_NPARITY (0xffff << 0) /* NParity */
>
> +/* Register access macros for PMECC */
> +#define pmecc_readl(addr, reg) \
> + readl(&addr->reg)
> +
> +#define pmecc_writel(addr, reg, value) \
> + writel((value), &addr->reg)
> +
> +/* PMECC Register Definitions */
> +#define PMECC_MAX_SECTOR_NUM 8
> +struct pmecc_regs {
> + u32 cfg; /* 0x00 PMECC Configuration Register */
> + u32 sarea; /* 0x04 PMECC Spare Area Size Register */
> + u32 saddr; /* 0x08 PMECC Start Address Register */
> + u32 eaddr; /* 0x0C PMECC End Address Register */
> + u32 clk; /* 0x10 PMECC Clock Control Register */
> + u32 ctrl; /* 0x14 PMECC Control Register */
> + u32 sr; /* 0x18 PMECC Status Register */
> + u32 ier; /* 0x1C PMECC Interrupt Enable Register */
> + u32 idr; /* 0x20 PMECC Interrupt Disable Register */
> + u32 imr; /* 0x24 PMECC Interrupt Mask Register */
> + u32 isr; /* 0x28 PMECC Interrupt Status Register */
> + u32 reserved0[5]; /* 0x2C-0x3C Reserved */
> +
> + /* 0x40 + sector_num * (0x40), Redundancy Registers */
> + struct {
> + u8 ecc[44]; /* PMECC Generated Redundancy Byte Per Sector */
> + u32 reserved1[5];
> + } ecc_port[PMECC_MAX_SECTOR_NUM];
> +
> + /* 0x240 + sector_num * (0x40) Remainder Registers */
> + struct {
> + u32 rem[12];
> + u32 reserved2[4];
> + } rem_port[PMECC_MAX_SECTOR_NUM];
> + u32 reserved3[16]; /* 0x440-0x47C Reserved */
> +};
> +
> +/* For PMECC Configuration Register */
> +#define PMECC_CFG_BCH_ERR2 (0 << 0)
> +#define PMECC_CFG_BCH_ERR4 (1 << 0)
> +#define PMECC_CFG_BCH_ERR8 (2 << 0)
> +#define PMECC_CFG_BCH_ERR12 (3 << 0)
> +#define PMECC_CFG_BCH_ERR24 (4 << 0)
> +
> +#define PMECC_CFG_SECTOR512 (0 << 4)
> +#define PMECC_CFG_SECTOR1024 (1 << 4)
> +
> +#define PMECC_CFG_PAGE_1SECTOR (0 << 8)
> +#define PMECC_CFG_PAGE_2SECTORS (1 << 8)
> +#define PMECC_CFG_PAGE_4SECTORS (2 << 8)
> +#define PMECC_CFG_PAGE_8SECTORS (3 << 8)
> +
> +#define PMECC_CFG_READ_OP (0 << 12)
> +#define PMECC_CFG_WRITE_OP (1 << 12)
> +
> +#define PMECC_CFG_SPARE_ENABLE (1 << 16)
> +#define PMECC_CFG_SPARE_DISABLE (0 << 16)
> +
> +#define PMECC_CFG_AUTO_ENABLE (1 << 20)
> +#define PMECC_CFG_AUTO_DISABLE (0 << 20)
> +
> +/* For PMECC Clock Control Register */
> +#define PMECC_CLK_133MHZ (2 << 0)
> +
> +/* For PMECC Control Register */
> +#define PMECC_CTRL_RST (1 << 0)
> +#define PMECC_CTRL_DATA (1 << 1)
> +#define PMECC_CTRL_USER (1 << 2)
> +#define PMECC_CTRL_ENABLE (1 << 4)
> +#define PMECC_CTRL_DISABLE (1 << 5)
> +
> +/* For PMECC Status Register */
> +#define PMECC_SR_BUSY (1 << 0)
> +#define PMECC_SR_ENABLE (1 << 4)
> +
> +/* PMERRLOC Register Definitions */
> +struct pmecc_errloc_regs {
> + u32 elcfg; /* 0x00 Error Location Configuration Register */
> + u32 elprim; /* 0x04 Error Location Primitive Register */
> + u32 elen; /* 0x08 Error Location Enable Register */
> + u32 eldis; /* 0x0C Error Location Disable Register */
> + u32 elsr; /* 0x10 Error Location Status Register */
> + u32 elier; /* 0x14 Error Location Interrupt Enable Register */
> + u32 elidr; /* 0x08 Error Location Interrupt Disable Register */
> + u32 elimr; /* 0x0C Error Location Interrupt Mask Register */
> + u32 elisr; /* 0x20 Error Location Interrupt Status Register */
> + u32 reserved0; /* 0x24 Reserved */
> + u32 sigma[25]; /* 0x28-0x88 Error Location Sigma Registers */
> + u32 el[24]; /* 0x8C-0xE8 Error Location Registers */
> + u32 reserved1[5]; /* 0xEC-0xFC Reserved */
> +};
> +
> +/* For Error Location Configuration Register */
> +#define PMERRLOC_ELCFG_SECTOR_512 (0 << 0)
> +#define PMERRLOC_ELCFG_SECTOR_1024 (1 << 0)
> +#define PMERRLOC_ELCFG_NUM_ERRORS(n) ((n) << 16)
> +
> +/* For Error Location Disable Register */
> +#define PMERRLOC_DISABLE (1 << 0)
> +
> +/* For Error Location Interrupt Status Register */
> +#define PMERRLOC_ERR_NUM_MASK (0x1f << 8)
> +#define PMERRLOC_CALC_DONE (1 << 0)
> +
> +/* Galois field dimension */
> +#define PMECC_GF_DIMENSION_13 13
> +#define PMECC_GF_DIMENSION_14 14
> +
> +#define PMECC_INDEX_TABLE_SIZE_512 0x2000
> +#define PMECC_INDEX_TABLE_SIZE_1024 0x4000
> +
> #endif
>
Not really nice code but it seems the kernel guys accepted it the same
way. So I will _not_ NAK it. But please add at least a README entry
describing the new config parameters, think about the sector size (ore
explain me why you need another config) and please change the driver
initialization to the SELF_INIT as mentioned in another mail. You use
again the nand_scan_indent() inside your xx_nand_init_params().
Please rewrite the board_nand_init() as shown in doc/README.nand, maybe
copy the stub from mtd/nand.c's nand_init() and nand_init_chip(). Call
in your own atmel_nand_init_chip() nand_scan_ident() and after that
setup the parameters for eighter ECC or PMECC. Always hand over the
struct nand_chip and do not work with the nand_chip array in the
xx_init_param() functions.
Best regards
Andreas Bießmann
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