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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-02 16:33:54 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-02 16:33:54 -0800 |
commit | 48476df99894492a0f7239f2f3c9a2dde4ff38e2 (patch) | |
tree | 5a1b80f20449968f0de6e5bfbcda5e360e31ba1f /drivers/mtd/nand/omap2.c | |
parent | 37cae6ad4c484030fa972241533c32730ec79b7d (diff) | |
parent | 24dea0c9feccf699749f860fa2f4ccd84d30390d (diff) | |
download | linux-48476df99894492a0f7239f2f3c9a2dde4ff38e2.tar.bz2 |
Merge tag 'for-linus-20130301' of git://git.infradead.org/linux-mtd
Pull MTD update from David Woodhouse:
"Fairly unexciting MTD merge for 3.9:
- misc clean-ups in the MTD command-line partitioning parser
(cmdlinepart)
- add flash locking support for STmicro chips serial flash chips, as
well as for CFI command set 2 chips.
- new driver for the ELM error correction HW module found in various
TI chips, enable the OMAP NAND driver to use the ELM HW error
correction
- added number of new serial flash IDs
- various fixes and improvements in the gpmi NAND driver
- bcm47xx NAND driver improvements
- make the mtdpart module actually removable"
* tag 'for-linus-20130301' of git://git.infradead.org/linux-mtd: (45 commits)
mtd: map: BUG() in non handled cases
mtd: bcm47xxnflash: use pr_fmt for module prefix in messages
mtd: davinci_nand: Use managed resources
mtd: mtd_torturetest can cause stack overflows
mtd: physmap_of: Convert device allocation to managed devm_kzalloc()
mtd: at91: atmel_nand: for PMECC, add code to check the ONFI parameter ECC requirement.
mtd: atmel_nand: make pmecc-cap, pmecc-sector-size in dts is optional.
mtd: atmel_nand: avoid to report an error when lookup table offset is 0.
mtd: bcm47xxsflash: adjust names of bus-specific functions
mtd: bcm47xxpart: improve probing of nvram partition
mtd: bcm47xxpart: add support for other erase sizes
mtd: bcm47xxnflash: register this as normal driver
mtd: bcm47xxnflash: fix message
mtd: bcm47xxsflash: register this as normal driver
mtd: bcm47xxsflash: write number of written bytes
mtd: gpmi: add sanity check for the ECC
mtd: gpmi: set the Golois Field bit for mx6q's BCH
mtd: devices: elm: Removes <xx> literals in elm DT node
mtd: gpmi: fix a dereferencing freed memory error
mtd: fix the wrong timeo for panic_nand_wait()
...
Diffstat (limited to 'drivers/mtd/nand/omap2.c')
-rw-r--r-- | drivers/mtd/nand/omap2.c | 583 |
1 files changed, 541 insertions, 42 deletions
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 1d333497cfcb..8e820ddf4e08 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -22,9 +22,12 @@ #include <linux/omap-dma.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_device.h> #ifdef CONFIG_MTD_NAND_OMAP_BCH #include <linux/bch.h> +#include <linux/platform_data/elm.h> #endif #include <linux/platform_data/mtd-nand-omap2.h> @@ -117,6 +120,33 @@ #define OMAP24XX_DMA_GPMC 4 +#define BCH8_MAX_ERROR 8 /* upto 8 bit correctable */ +#define BCH4_MAX_ERROR 4 /* upto 4 bit correctable */ + +#define SECTOR_BYTES 512 +/* 4 bit padding to make byte aligned, 56 = 52 + 4 */ +#define BCH4_BIT_PAD 4 +#define BCH8_ECC_MAX ((SECTOR_BYTES + BCH8_ECC_OOB_BYTES) * 8) +#define BCH4_ECC_MAX ((SECTOR_BYTES + BCH4_ECC_OOB_BYTES) * 8) + +/* GPMC ecc engine settings for read */ +#define BCH_WRAPMODE_1 1 /* BCH wrap mode 1 */ +#define BCH8R_ECC_SIZE0 0x1a /* ecc_size0 = 26 */ +#define BCH8R_ECC_SIZE1 0x2 /* ecc_size1 = 2 */ +#define BCH4R_ECC_SIZE0 0xd /* ecc_size0 = 13 */ +#define BCH4R_ECC_SIZE1 0x3 /* ecc_size1 = 3 */ + +/* GPMC ecc engine settings for write */ +#define BCH_WRAPMODE_6 6 /* BCH wrap mode 6 */ +#define BCH_ECC_SIZE0 0x0 /* ecc_size0 = 0, no oob protection */ +#define BCH_ECC_SIZE1 0x20 /* ecc_size1 = 32 */ + +#ifdef CONFIG_MTD_NAND_OMAP_BCH +static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc, + 0xac, 0x6b, 0xff, 0x99, 0x7b}; +static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10}; +#endif + /* oob info generated runtime depending on ecc algorithm and layout selected */ static struct nand_ecclayout omap_oobinfo; /* Define some generic bad / good block scan pattern which are used @@ -156,6 +186,9 @@ struct omap_nand_info { #ifdef CONFIG_MTD_NAND_OMAP_BCH struct bch_control *bch; struct nand_ecclayout ecclayout; + bool is_elm_used; + struct device *elm_dev; + struct device_node *of_node; #endif }; @@ -1031,6 +1064,13 @@ static int omap_dev_ready(struct mtd_info *mtd) * omap3_enable_hwecc_bch - Program OMAP3 GPMC to perform BCH ECC correction * @mtd: MTD device structure * @mode: Read/Write mode + * + * When using BCH, sector size is hardcoded to 512 bytes. + * Using wrapping mode 6 both for reading and writing if ELM module not uses + * for error correction. + * On writing, + * eccsize0 = 0 (no additional protected byte in spare area) + * eccsize1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) */ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) { @@ -1039,32 +1079,57 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); struct nand_chip *chip = mtd->priv; - u32 val; + u32 val, wr_mode; + unsigned int ecc_size1, ecc_size0; + + /* Using wrapping mode 6 for writing */ + wr_mode = BCH_WRAPMODE_6; - nerrors = (info->nand.ecc.bytes == 13) ? 8 : 4; - dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0; - nsectors = 1; /* - * Program GPMC to perform correction on one 512-byte sector at a time. - * Using 4 sectors at a time (i.e. ecc.size = 2048) is also possible and - * gives a slight (5%) performance gain (but requires additional code). + * ECC engine enabled for valid ecc_size0 nibbles + * and disabled for ecc_size1 nibbles. */ + ecc_size0 = BCH_ECC_SIZE0; + ecc_size1 = BCH_ECC_SIZE1; + + /* Perform ecc calculation on 512-byte sector */ + nsectors = 1; + + /* Update number of error correction */ + nerrors = info->nand.ecc.strength; + + /* Multi sector reading/writing for NAND flash with page size < 4096 */ + if (info->is_elm_used && (mtd->writesize <= 4096)) { + if (mode == NAND_ECC_READ) { + /* Using wrapping mode 1 for reading */ + wr_mode = BCH_WRAPMODE_1; + + /* + * ECC engine enabled for ecc_size0 nibbles + * and disabled for ecc_size1 nibbles. + */ + ecc_size0 = (nerrors == 8) ? + BCH8R_ECC_SIZE0 : BCH4R_ECC_SIZE0; + ecc_size1 = (nerrors == 8) ? + BCH8R_ECC_SIZE1 : BCH4R_ECC_SIZE1; + } + + /* Perform ecc calculation for one page (< 4096) */ + nsectors = info->nand.ecc.steps; + } writel(ECC1, info->reg.gpmc_ecc_control); - /* - * When using BCH, sector size is hardcoded to 512 bytes. - * Here we are using wrapping mode 6 both for reading and writing, with: - * size0 = 0 (no additional protected byte in spare area) - * size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) - */ - val = (32 << ECCSIZE1_SHIFT) | (0 << ECCSIZE0_SHIFT); + /* Configure ecc size for BCH */ + val = (ecc_size1 << ECCSIZE1_SHIFT) | (ecc_size0 << ECCSIZE0_SHIFT); writel(val, info->reg.gpmc_ecc_size_config); + dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0; + /* BCH configuration */ val = ((1 << 16) | /* enable BCH */ (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */ - (0x06 << 8) | /* wrap mode = 6 */ + (wr_mode << 8) | /* wrap mode */ (dev_width << 7) | /* bus width */ (((nsectors-1) & 0x7) << 4) | /* number of sectors */ (info->gpmc_cs << 1) | /* ECC CS */ @@ -1072,7 +1137,7 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) writel(val, info->reg.gpmc_ecc_config); - /* clear ecc and enable bits */ + /* Clear ecc and enable bits */ writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control); } @@ -1162,6 +1227,298 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat, } /** + * omap3_calculate_ecc_bch - Generate bytes of ECC bytes + * @mtd: MTD device structure + * @dat: The pointer to data on which ecc is computed + * @ecc_code: The ecc_code buffer + * + * Support calculating of BCH4/8 ecc vectors for the page + */ +static int omap3_calculate_ecc_bch(struct mtd_info *mtd, const u_char *dat, + u_char *ecc_code) +{ + struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, + mtd); + unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4; + int i, eccbchtsel; + + nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1; + /* + * find BCH scheme used + * 0 -> BCH4 + * 1 -> BCH8 + */ + eccbchtsel = ((readl(info->reg.gpmc_ecc_config) >> 12) & 0x3); + + for (i = 0; i < nsectors; i++) { + + /* Read hw-computed remainder */ + bch_val1 = readl(info->reg.gpmc_bch_result0[i]); + bch_val2 = readl(info->reg.gpmc_bch_result1[i]); + if (eccbchtsel) { + bch_val3 = readl(info->reg.gpmc_bch_result2[i]); + bch_val4 = readl(info->reg.gpmc_bch_result3[i]); + } + + if (eccbchtsel) { + /* BCH8 ecc scheme */ + *ecc_code++ = (bch_val4 & 0xFF); + *ecc_code++ = ((bch_val3 >> 24) & 0xFF); + *ecc_code++ = ((bch_val3 >> 16) & 0xFF); + *ecc_code++ = ((bch_val3 >> 8) & 0xFF); + *ecc_code++ = (bch_val3 & 0xFF); + *ecc_code++ = ((bch_val2 >> 24) & 0xFF); + *ecc_code++ = ((bch_val2 >> 16) & 0xFF); + *ecc_code++ = ((bch_val2 >> 8) & 0xFF); + *ecc_code++ = (bch_val2 & 0xFF); + *ecc_code++ = ((bch_val1 >> 24) & 0xFF); + *ecc_code++ = ((bch_val1 >> 16) & 0xFF); + *ecc_code++ = ((bch_val1 >> 8) & 0xFF); + *ecc_code++ = (bch_val1 & 0xFF); + /* + * Setting 14th byte to zero to handle + * erased page & maintain compatibility + * with RBL + */ + *ecc_code++ = 0x0; + } else { + /* BCH4 ecc scheme */ + *ecc_code++ = ((bch_val2 >> 12) & 0xFF); + *ecc_code++ = ((bch_val2 >> 4) & 0xFF); + *ecc_code++ = ((bch_val2 & 0xF) << 4) | + ((bch_val1 >> 28) & 0xF); + *ecc_code++ = ((bch_val1 >> 20) & 0xFF); + *ecc_code++ = ((bch_val1 >> 12) & 0xFF); + *ecc_code++ = ((bch_val1 >> 4) & 0xFF); + *ecc_code++ = ((bch_val1 & 0xF) << 4); + /* + * Setting 8th byte to zero to handle + * erased page + */ + *ecc_code++ = 0x0; + } + } + + return 0; +} + +/** + * erased_sector_bitflips - count bit flips + * @data: data sector buffer + * @oob: oob buffer + * @info: omap_nand_info + * + * Check the bit flips in erased page falls below correctable level. + * If falls below, report the page as erased with correctable bit + * flip, else report as uncorrectable page. + */ +static int erased_sector_bitflips(u_char *data, u_char *oob, + struct omap_nand_info *info) +{ + int flip_bits = 0, i; + + for (i = 0; i < info->nand.ecc.size; i++) { + flip_bits += hweight8(~data[i]); + if (flip_bits > info->nand.ecc.strength) + return 0; + } + + for (i = 0; i < info->nand.ecc.bytes - 1; i++) { + flip_bits += hweight8(~oob[i]); + if (flip_bits > info->nand.ecc.strength) + return 0; + } + + /* + * Bit flips falls in correctable level. + * Fill data area with 0xFF + */ + if (flip_bits) { + memset(data, 0xFF, info->nand.ecc.size); + memset(oob, 0xFF, info->nand.ecc.bytes); + } + + return flip_bits; +} + +/** + * omap_elm_correct_data - corrects page data area in case error reported + * @mtd: MTD device structure + * @data: page data + * @read_ecc: ecc read from nand flash + * @calc_ecc: ecc read from HW ECC registers + * + * Calculated ecc vector reported as zero in case of non-error pages. + * In case of error/erased pages non-zero error vector is reported. + * In case of non-zero ecc vector, check read_ecc at fixed offset + * (x = 13/7 in case of BCH8/4 == 0) to find page programmed or not. + * To handle bit flips in this data, count the number of 0's in + * read_ecc[x] and check if it greater than 4. If it is less, it is + * programmed page, else erased page. + * + * 1. If page is erased, check with standard ecc vector (ecc vector + * for erased page to find any bit flip). If check fails, bit flip + * is present in erased page. Count the bit flips in erased page and + * if it falls under correctable level, report page with 0xFF and + * update the correctable bit information. + * 2. If error is reported on programmed page, update elm error + * vector and correct the page with ELM error correction routine. + * + */ +static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, + u_char *read_ecc, u_char *calc_ecc) +{ + struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, + mtd); + int eccsteps = info->nand.ecc.steps; + int i , j, stat = 0; + int eccsize, eccflag, ecc_vector_size; + struct elm_errorvec err_vec[ERROR_VECTOR_MAX]; + u_char *ecc_vec = calc_ecc; + u_char *spare_ecc = read_ecc; + u_char *erased_ecc_vec; + enum bch_ecc type; + bool is_error_reported = false; + + /* Initialize elm error vector to zero */ + memset(err_vec, 0, sizeof(err_vec)); + + if (info->nand.ecc.strength == BCH8_MAX_ERROR) { + type = BCH8_ECC; + erased_ecc_vec = bch8_vector; + } else { + type = BCH4_ECC; + erased_ecc_vec = bch4_vector; + } + + ecc_vector_size = info->nand.ecc.bytes; + + /* + * Remove extra byte padding for BCH8 RBL + * compatibility and erased page handling + */ + eccsize = ecc_vector_size - 1; + + for (i = 0; i < eccsteps ; i++) { + eccflag = 0; /* initialize eccflag */ + + /* + * Check any error reported, + * In case of error, non zero ecc reported. + */ + + for (j = 0; (j < eccsize); j++) { + if (calc_ecc[j] != 0) { + eccflag = 1; /* non zero ecc, error present */ + break; + } + } + + if (eccflag == 1) { + /* + * Set threshold to minimum of 4, half of ecc.strength/2 + * to allow max bit flip in byte to 4 + */ + unsigned int threshold = min_t(unsigned int, 4, + info->nand.ecc.strength / 2); + + /* + * Check data area is programmed by counting + * number of 0's at fixed offset in spare area. + * Checking count of 0's against threshold. + * In case programmed page expects at least threshold + * zeros in byte. + * If zeros are less than threshold for programmed page/ + * zeros are more than threshold erased page, either + * case page reported as uncorrectable. + */ + if (hweight8(~read_ecc[eccsize]) >= threshold) { + /* + * Update elm error vector as + * data area is programmed + */ + err_vec[i].error_reported = true; + is_error_reported = true; + } else { + /* Error reported in erased page */ + int bitflip_count; + u_char *buf = &data[info->nand.ecc.size * i]; + + if (memcmp(calc_ecc, erased_ecc_vec, eccsize)) { + bitflip_count = erased_sector_bitflips( + buf, read_ecc, info); + + if (bitflip_count) + stat += bitflip_count; + else + return -EINVAL; + } + } + } + + /* Update the ecc vector */ + calc_ecc += ecc_vector_size; + read_ecc += ecc_vector_size; + } + + /* Check if any error reported */ + if (!is_error_reported) + return 0; + + /* Decode BCH error using ELM module */ + elm_decode_bch_error_page(info->elm_dev, ecc_vec, err_vec); + + for (i = 0; i < eccsteps; i++) { + if (err_vec[i].error_reported) { + for (j = 0; j < err_vec[i].error_count; j++) { + u32 bit_pos, byte_pos, error_max, pos; + + if (type == BCH8_ECC) + error_max = BCH8_ECC_MAX; + else + error_max = BCH4_ECC_MAX; + + if (info->nand.ecc.strength == BCH8_MAX_ERROR) + pos = err_vec[i].error_loc[j]; + else + /* Add 4 to take care 4 bit padding */ + pos = err_vec[i].error_loc[j] + + BCH4_BIT_PAD; + + /* Calculate bit position of error */ + bit_pos = pos % 8; + + /* Calculate byte position of error */ + byte_pos = (error_max - pos - 1) / 8; + + if (pos < error_max) { + if (byte_pos < 512) + data[byte_pos] ^= 1 << bit_pos; + else + spare_ecc[byte_pos - 512] ^= + 1 << bit_pos; + } + /* else, not interested to correct ecc */ + } + } + + /* Update number of correctable errors */ + stat += err_vec[i].error_count; + + /* Update page data with sector size */ + data += info->nand.ecc.size; + spare_ecc += ecc_vector_size; + } + + for (i = 0; i < eccsteps; i++) + /* Return error if uncorrectable error present */ + if (err_vec[i].error_uncorrectable) + return -EINVAL; + + return stat; +} + +/** * omap3_correct_data_bch - Decode received data and correct errors * @mtd: MTD device structure * @data: page data @@ -1194,6 +1551,92 @@ static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data, } /** + * omap_write_page_bch - BCH ecc based write page function for entire page + * @mtd: mtd info structure + * @chip: nand chip info structure + * @buf: data buffer + * @oob_required: must write chip->oob_poi to OOB + * + * Custom write page method evolved to support multi sector writing in one shot + */ +static int omap_write_page_bch(struct mtd_info *mtd, struct nand_chip *chip, + const uint8_t *buf, int oob_required) +{ + int i; + uint8_t *ecc_calc = chip->buffers->ecccalc; + uint32_t *eccpos = chip->ecc.layout->eccpos; + + /* Enable GPMC ecc engine */ + chip->ecc.hwctl(mtd, NAND_ECC_WRITE); + + /* Write data */ + chip->write_buf(mtd, buf, mtd->writesize); + + /* Update ecc vector from GPMC result registers */ + chip->ecc.calculate(mtd, buf, &ecc_calc[0]); + + for (i = 0; i < chip->ecc.total; i++) + chip->oob_poi[eccpos[i]] = ecc_calc[i]; + + /* Write ecc vector to OOB area */ + chip->write_buf(mtd, chip->oob_poi, mtd->oobsize); + return 0; +} + +/** + * omap_read_page_bch - BCH ecc based page read function for entire page + * @mtd: mtd info structure + * @chip: nand chip info structure + * @buf: buffer to store read data + * @oob_required: caller requires OOB data read to chip->oob_poi + * @page: page number to read + * + * For BCH ecc scheme, GPMC used for syndrome calculation and ELM module + * used for error correction. + * Custom method evolved to support ELM error correction & multi sector + * reading. On reading page data area is read along with OOB data with + * ecc engine enabled. ecc vector updated after read of OOB data. + * For non error pages ecc vector reported as zero. + */ +static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, + uint8_t *buf, int oob_required, int page) +{ + uint8_t *ecc_calc = chip->buffers->ecccalc; + uint8_t *ecc_code = chip->buffers->ecccode; + uint32_t *eccpos = chip->ecc.layout->eccpos; + uint8_t *oob = &chip->oob_poi[eccpos[0]]; + uint32_t oob_pos = mtd->writesize + chip->ecc.layout->eccpos[0]; + int stat; + unsigned int max_bitflips = 0; + + /* Enable GPMC ecc engine */ + chip->ecc.hwctl(mtd, NAND_ECC_READ); + + /* Read data */ + chip->read_buf(mtd, buf, mtd->writesize); + + /* Read oob bytes */ + chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1); + chip->read_buf(mtd, oob, chip->ecc.total); + + /* Calculate ecc bytes */ + chip->ecc.calculate(mtd, buf, ecc_calc); + + memcpy(ecc_code, &chip->oob_poi[eccpos[0]], chip->ecc.total); + + stat = chip->ecc.correct(mtd, buf, ecc_code, ecc_calc); + + if (stat < 0) { + mtd->ecc_stats.failed++; + } else { + mtd->ecc_stats.corrected += stat; + max_bitflips = max_t(unsigned int, max_bitflips, stat); + } + + return max_bitflips; +} + +/** * omap3_free_bch - Release BCH ecc resources * @mtd: MTD device structure */ @@ -1218,43 +1661,86 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt) struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); #ifdef CONFIG_MTD_NAND_OMAP_BCH8 - const int hw_errors = 8; + const int hw_errors = BCH8_MAX_ERROR; #else - const int hw_errors = 4; + const int hw_errors = BCH4_MAX_ERROR; #endif + enum bch_ecc bch_type; + const __be32 *parp; + int lenp; + struct device_node *elm_node; + info->bch = NULL; - max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ? 8 : 4; + max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ? + BCH8_MAX_ERROR : BCH4_MAX_ERROR; if (max_errors != hw_errors) { pr_err("cannot configure %d-bit BCH ecc, only %d-bit supported", max_errors, hw_errors); goto fail; } - /* software bch library is only used to detect and locate errors */ - info->bch = init_bch(13, max_errors, 0x201b /* hw polynomial */); - if (!info->bch) - goto fail; + info->nand.ecc.size = 512; + info->nand.ecc.hwctl = omap3_enable_hwecc_bch; + info->nand.ecc.mode = NAND_ECC_HW; + info->nand.ecc.strength = max_errors; - info->nand.ecc.size = 512; - info->nand.ecc.hwctl = omap3_enable_hwecc_bch; - info->nand.ecc.correct = omap3_correct_data_bch; - info->nand.ecc.mode = NAND_ECC_HW; + if (hw_errors == BCH8_MAX_ERROR) + bch_type = BCH8_ECC; + else + bch_type = BCH4_ECC; - /* - * The number of corrected errors in an ecc block that will trigger - * block scrubbing defaults to the ecc strength (4 or 8). - * Set mtd->bitflip_threshold here to define a custom threshold. - */ + /* Detect availability of ELM module */ + parp = of_get_property(info->of_node, "elm_id", &lenp); + if ((parp == NULL) && (lenp != (sizeof(void *) * 2))) { + pr_err("Missing elm_id property, fall back to Software BCH\n"); + info->is_elm_used = false; + } else { + struct platform_device *pdev; - if (max_errors == 8) { - info->nand.ecc.strength = 8; - info->nand.ecc.bytes = 13; - info->nand.ecc.calculate = omap3_calculate_ecc_bch8; + elm_node = of_find_node_by_phandle(be32_to_cpup(parp)); + pdev = of_find_device_by_node(elm_node); + info->elm_dev = &pdev->dev; + elm_config(info->elm_dev, bch_type); + info->is_elm_used = true; + } + + if (info->is_elm_used && (mtd->writesize <= 4096)) { + + if (hw_errors == BCH8_MAX_ERROR) + info->nand.ecc.bytes = BCH8_SIZE; + else + info->nand.ecc.bytes = BCH4_SIZE; + + info->nand.ecc.correct = omap_elm_correct_data; + info->nand.ecc.calculate = omap3_calculate_ecc_bch; + info->nand.ecc.read_page = omap_read_page_bch; + info->nand.ecc.write_page = omap_write_page_bch; } else { - info->nand.ecc.strength = 4; - info->nand.ecc.bytes = 7; - info->nand.ecc.calculate = omap3_calculate_ecc_bch4; + /* + * software bch library is only used to detect and + * locate errors + */ + info->bch = init_bch(13, max_errors, + 0x201b /* hw polynomial */); + if (!info->bch) + goto fail; + + info->nand.ecc.correct = omap3_correct_data_bch; + + /* + * The number of corrected errors in an ecc block that will + * trigger block scrubbing defaults to the ecc strength (4 or 8) + * Set mtd->bitflip_threshold here to define a custom threshold. + */ + + if (max_errors == 8) { + info->nand.ecc.bytes = 13; + info->nand.ecc.calculate = omap3_calculate_ecc_bch8; + } else { + info->nand.ecc.bytes = 7; + info->nand.ecc.calculate = omap3_calculate_ecc_bch4; + } } pr_info("enabling NAND BCH ecc with %d-bit correction\n", max_errors); @@ -1270,7 +1756,7 @@ fail: */ static int omap3_init_bch_tail(struct mtd_info *mtd) { - int i, steps; + int i, steps, offset; struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); struct nand_ecclayout *layout = &info->ecclayout; @@ -1292,11 +1778,21 @@ static int omap3_init_bch_tail(struct mtd_info *mtd) goto fail; } + /* ECC layout compatible with RBL for BCH8 */ + if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE)) + offset = 2; + else + offset = mtd->oobsize - layout->eccbytes; + /* put ecc bytes at oob tail */ for (i = 0; i < layout->eccbytes; i++) - layout->eccpos[i] = mtd->oobsize-layout->eccbytes+i; + layout->eccpos[i] = offset + i; + + if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE)) + layout->oobfree[0].offset = 2 + layout->eccbytes * steps; + else + layout->oobfree[0].offset = 2; - layout->oobfree[0].offset = 2; layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes; info->nand.ecc.layout = layout; @@ -1360,6 +1856,9 @@ static int omap_nand_probe(struct platform_device *pdev) info->nand.options = pdata->devsize; info->nand.options |= NAND_SKIP_BBTSCAN; +#ifdef CONFIG_MTD_NAND_OMAP_BCH + info->of_node = pdata->of_node; +#endif res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (res == NULL) { |