From b491da7233d5dc1a24d46ca1ad0209900329c5d0 Mon Sep 17 00:00:00 2001 From: Pekon Gupta Date: Thu, 24 Oct 2013 18:20:22 +0530 Subject: mtd: nand: omap: clean-up ecc layout for BCH ecc schemes In current implementation omap3_init_bch_tail() is a common function to define ecc layout for different BCHx ecc schemes.This patch: (1) removes omap3_init_bch_tail() and defines ecc layout for individual ecc-schemes along with populating their nand_chip->ecc data in omap_nand_probe(). This improves the readability and scalability of code for add new ecc schemes in future. (2) removes 'struct nand_bbt_descr bb_descrip_flashbased' because default nand_bbt_descr in nand_bbt.c matches the same (.len=1 for x8 devices). (3) add the check to see if NAND device has enough OOB/Spare bytes to store ECC signature of whole page, as defined by ecc-scheme. Signed-off-by: Pekon Gupta Tested-by: Ezequiel Garcia Signed-off-by: Brian Norris diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 86ce48b..b6a08b2 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -139,6 +139,7 @@ #define BCH_ECC_SIZE0 0x0 /* ecc_size0 = 0, no oob protection */ #define BCH_ECC_SIZE1 0x20 /* ecc_size1 = 32 */ +#define BADBLOCK_MARKER_LENGTH 2 #define OMAP_ECC_BCH8_POLYNOMIAL 0x201b #ifdef CONFIG_MTD_NAND_OMAP_BCH @@ -149,17 +150,6 @@ static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10}; /* 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 - * while scanning a device for factory marked good / bad blocks - */ -static uint8_t scan_ff_pattern[] = { 0xff }; -static struct nand_bbt_descr bb_descrip_flashbased = { - .options = NAND_BBT_SCANALLPAGES, - .offs = 0, - .len = 1, - .pattern = scan_ff_pattern, -}; - struct omap_nand_info { struct nand_hw_control controller; @@ -184,7 +174,6 @@ struct omap_nand_info { struct gpmc_nand_regs reg; /* fields specific for BCHx_HW ECC scheme */ struct bch_control *bch; - struct nand_ecclayout ecclayout; bool is_elm_used; struct device *elm_dev; struct device_node *of_node; @@ -1686,65 +1675,8 @@ static void omap3_free_bch(struct mtd_info *mtd) } } -/** - * omap3_init_bch_tail - Build an oob layout for BCH ECC correction. - * @mtd: MTD device structure - */ -static int omap3_init_bch_tail(struct mtd_info *mtd) -{ - int i, steps, offset; - struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, - mtd); - struct nand_ecclayout *layout = &info->ecclayout; - - /* build oob layout */ - steps = mtd->writesize/info->nand.ecc.size; - layout->eccbytes = steps*info->nand.ecc.bytes; - - /* do not bother creating special oob layouts for small page devices */ - if (mtd->oobsize < 64) { - pr_err("BCH ecc is not supported on small page devices\n"); - goto fail; - } - - /* reserve 2 bytes for bad block marker */ - if (layout->eccbytes+2 > mtd->oobsize) { - pr_err("no oob layout available for oobsize %d eccbytes %u\n", - mtd->oobsize, layout->eccbytes); - 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] = 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].length = mtd->oobsize-2-layout->eccbytes; - info->nand.ecc.layout = layout; - - if (!(info->nand.options & NAND_BUSWIDTH_16)) - info->nand.badblock_pattern = &bb_descrip_flashbased; - return 0; -fail: - omap3_free_bch(mtd); - return -1; -} - #else -static int omap3_init_bch_tail(struct mtd_info *mtd) -{ - return -1; -} + static void omap3_free_bch(struct mtd_info *mtd) { } @@ -1756,8 +1688,9 @@ static int omap_nand_probe(struct platform_device *pdev) struct omap_nand_platform_data *pdata; struct mtd_info *mtd; struct nand_chip *nand_chip; + struct nand_ecclayout *ecclayout; int err; - int i, offset; + int i; dma_cap_mask_t mask; unsigned sig; struct resource *res; @@ -1840,6 +1773,13 @@ static int omap_nand_probe(struct platform_device *pdev) goto out_release_mem_region; } + /* check for small page devices */ + if ((mtd->oobsize < 64) && (pdata->ecc_opt != OMAP_ECC_HAM1_CODE_HW)) { + pr_err("small page devices are not supported\n"); + err = -EINVAL; + goto out_release_mem_region; + } + /* re-populate low-level callbacks based on xfer modes */ switch (pdata->xfer_type) { case NAND_OMAP_PREFETCH_POLLED: @@ -1931,6 +1871,8 @@ static int omap_nand_probe(struct platform_device *pdev) } /* populate MTD interface based on ECC scheme */ + nand_chip->ecc.layout = &omap_oobinfo; + ecclayout = &omap_oobinfo; switch (pdata->ecc_opt) { case OMAP_ECC_HAM1_CODE_HW: pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n"); @@ -1941,6 +1883,16 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.calculate = omap_calculate_ecc; nand_chip->ecc.hwctl = omap_enable_hwecc; nand_chip->ecc.correct = omap_correct_data; + /* define ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + if (nand_chip->options & NAND_BUSWIDTH_16) + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + else + ecclayout->eccpos[0] = 1; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; break; case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW: @@ -1953,6 +1905,13 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; nand_chip->ecc.correct = omap3_correct_data_bch; nand_chip->ecc.calculate = omap3_calculate_ecc_bch4; + /* define ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; /* software bch library is used for locating errors */ info->bch = init_bch(nand_chip->ecc.bytes, nand_chip->ecc.strength, @@ -1981,6 +1940,13 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.calculate = omap3_calculate_ecc_bch; nand_chip->ecc.read_page = omap_read_page_bch; nand_chip->ecc.write_page = omap_write_page_bch; + /* define ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; /* This ECC scheme requires ELM H/W block */ if (is_elm_present(info, pdata->elm_of_node, BCH4_ECC) < 0) { pr_err("nand: error: could not initialize ELM\n"); @@ -2004,6 +1970,13 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; nand_chip->ecc.correct = omap3_correct_data_bch; nand_chip->ecc.calculate = omap3_calculate_ecc_bch8; + /* define ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; /* software bch library is used for locating errors */ info->bch = init_bch(nand_chip->ecc.bytes, nand_chip->ecc.strength, @@ -2038,6 +2011,13 @@ static int omap_nand_probe(struct platform_device *pdev) pr_err("nand: error: could not initialize ELM\n"); goto out_release_mem_region; } + /* define ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; break; #else pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n"); @@ -2051,34 +2031,17 @@ static int omap_nand_probe(struct platform_device *pdev) goto out_release_mem_region; } - /* rom code layout */ - if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { - - if (nand_chip->options & NAND_BUSWIDTH_16) { - offset = 2; - } else { - offset = 1; - nand_chip->badblock_pattern = &bb_descrip_flashbased; - } - omap_oobinfo.eccbytes = 3 * (mtd->writesize / 512); - for (i = 0; i < omap_oobinfo.eccbytes; i++) - omap_oobinfo.eccpos[i] = i+offset; - - omap_oobinfo.oobfree->offset = offset + omap_oobinfo.eccbytes; - omap_oobinfo.oobfree->length = mtd->oobsize - - (offset + omap_oobinfo.eccbytes); - - nand_chip->ecc.layout = &omap_oobinfo; - } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) || - (pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW_DETECTION_SW) || - (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW_DETECTION_SW) || - (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) { - /* build OOB layout for BCH ECC correction */ - err = omap3_init_bch_tail(mtd); - if (err) { - err = -EINVAL; - goto out_release_mem_region; - } + /* populate remaining ECC layout data */ + ecclayout->oobfree->length = mtd->oobsize - (BADBLOCK_MARKER_LENGTH + + ecclayout->eccbytes); + for (i = 1; i < ecclayout->eccbytes; i++) + ecclayout->eccpos[i] = ecclayout->eccpos[0] + i; + /* check if NAND device's OOB is enough to store ECC signatures */ + if (mtd->oobsize < (ecclayout->eccbytes + BADBLOCK_MARKER_LENGTH)) { + pr_err("not enough OOB bytes required = %d, available=%d\n", + ecclayout->eccbytes, mtd->oobsize); + err = -EINVAL; + goto out_release_mem_region; } /* second phase scan */ -- cgit v0.10.2