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-rw-r--r--drivers/mtd/nand/omap2.c573
-rw-r--r--include/linux/platform_data/elm.h3
2 files changed, 536 insertions, 40 deletions
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index ec20f67e8949..1a88bd062ac1 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>
@@ -120,6 +123,30 @@
#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
@@ -159,6 +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
};
@@ -1034,6 +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)
{
@@ -1042,32 +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.strength;
- 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 */
@@ -1075,7 +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);
}
@@ -1165,6 +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
@@ -1197,6 +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
*/
@@ -1225,6 +1665,11 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
#else
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) ?
@@ -1235,30 +1680,67 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
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);
@@ -1274,7 +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;
@@ -1296,11 +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;
@@ -1363,6 +1855,9 @@ 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) {
diff --git a/include/linux/platform_data/elm.h b/include/linux/platform_data/elm.h
index 11ab6aaf2431..1bd5244d1dcd 100644
--- a/include/linux/platform_data/elm.h
+++ b/include/linux/platform_data/elm.h
@@ -30,7 +30,8 @@ enum bch_ecc {
#define BCH4_ECC_OOB_BYTES 7
/* RBL requires 14 byte even though BCH8 uses only 13 byte */
#define BCH8_SIZE (BCH8_ECC_OOB_BYTES + 1)
-#define BCH4_SIZE (BCH4_ECC_OOB_BYTES)
+/* Uses 1 extra byte to handle erased pages */
+#define BCH4_SIZE (BCH4_ECC_OOB_BYTES + 1)
/**
* struct elm_errorvec - error vector for elm