BCH8_ECC scheme implemented in omap_gpmc.c driver has following favours +-----------------------------------+-----------------+-----------------+ |ECC Scheme | ECC Calculation | Error Detection | +-----------------------------------+-----------------+-----------------+ |OMAP_ECC_BCH8_CODE_HW |GPMC |ELM H/W engine | |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |GPMC |S/W BCH library | +-----------------------------------+-----------------+-----------------+

Current implementation limits the BCH8_CODE_HW only for AM33xx device family. (using CONFIG_AM33XX). However, other SoC families (like TI81xx) also have ELM hardware module, and can support ECC error detection using ELM.

This patch - removes CONFIG_AM33xx Thus this driver can be reused by all devices having ELM h/w engine. - adds omap_select_ecc_scheme() A common function to handle ecc-scheme related configurations. This can be used both during device-probe and via user-space u-boot commads to change ecc-scheme. - adds CONFIG_BCH S/W library (lib/bch.c) required by OMAP_ECC_BCH8_CODE_HW_DETECTION_SW is enabled by CONFIG_BCH. - adds CONFIG_SYS_NAND_ECCSCHEME (new) user specified CONFIG to determine ecc-scheme used during boot - adds CONFIG_SYS_NAND_ONFI_DETECTION enable auto-detection of ONFI compliant devices

Signed-off-by: Pekon Gupta pekon@ti.com --- arch/arm/include/asm/arch-am33xx/omap_gpmc.h | 48 +---- doc/README.nand | 13 ++ drivers/mtd/nand/omap_gpmc.c | 291 ++++++++++++++++----------- include/configs/am335x_evm.h | 2 + 4 files changed, 195 insertions(+), 159 deletions(-)

diff --git a/arch/arm/include/asm/arch-am33xx/omap_gpmc.h b/arch/arm/include/asm/arch-am33xx/omap_gpmc.h index 00ad1d0..69982c1 100644 --- a/arch/arm/include/asm/arch-am33xx/omap_gpmc.h +++ b/arch/arm/include/asm/arch-am33xx/omap_gpmc.h @@ -7,42 +7,16 @@ #ifndef __ASM_ARCH_OMAP_GPMC_H #define __ASM_ARCH_OMAP_GPMC_H

-/* These GPMC_NAND_HW_BCHx_ECC_LAYOUT defines are based on AM33xx ELM */ -#define GPMC_NAND_HW_BCH4_ECC_LAYOUT {\ - .eccbytes = 32,\ - .eccpos = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,\ - 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,\ - 28, 29, 30, 31, 32, 33},\ - .oobfree = {\ - {.offset = 34,\ - .length = 30 } } \ -} +enum omap_ecc { + /* 1-bit ECC calculation by Software, Error detection by Software */ + OMAP_ECC_HAM1_CODE_SW = 0, + /* 1-bit ECC calculation by GPMC, Error detection by Software */ + /* ECC layout compatible to legacy ROMCODE. */ + OMAP_ECC_HAM1_CODE_HW_ROMCODE, + /* 8-bit ECC calculation by GPMC, Error detection by Software */ + OMAP_ECC_BCH8_CODE_HW_DETECTION_SW, + /* 8-bit ECC calculation by GPMC, Error detection by ELM */ + OMAP_ECC_BCH8_CODE_HW +};

-#define GPMC_NAND_HW_BCH8_ECC_LAYOUT {\ - .eccbytes = 56,\ - .eccpos = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,\ - 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,\ - 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,\ - 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,\ - 52, 53, 54, 55, 56, 57},\ - .oobfree = {\ - {.offset = 58,\ - .length = 6 } } \ -} - -#define GPMC_NAND_HW_BCH16_ECC_LAYOUT {\ - .eccbytes = 104,\ - .eccpos = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,\ - 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,\ - 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,\ - 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,\ - 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,\ - 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75,\ - 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87,\ - 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99,\ - 100, 101, 102, 103, 104, 105},\ - .oobfree = {\ - {.offset = 106,\ - .length = 8 } } \ -} #endif /* __ASM_ARCH_OMAP_GPMC_H */ diff --git a/doc/README.nand b/doc/README.nand index 913e9b5..f72f618 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -169,6 +169,19 @@ Configuration Options: Please convert your driver even if you don't need the extra flexibility, so that one day we can eliminate the old mechanism.

+ CONFIG_SYS_NAND_ONFI_DETECTION + Enables detection of ONFI compliant devices during probe. + And fetching device parameters flashed on device, by parsing + ONFI parameter page. + + CONFIG_BCH + Enables software based BCH ECC algorithm present in lib/bch.c + This is used by SoC platforms which do not have in-build hardware + engine to calculate and correct BCH ECC. + + CONFIG_SYS_NAND_ECCSCHEME + specifies which ECC scheme to use. + NOTE: =====

diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index ec1787f..f97e862 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -15,15 +15,13 @@ #include <linux/bch.h> #include <linux/compiler.h> #include <nand.h> -#ifdef CONFIG_AM33XX #include <asm/arch/elm.h> -#endif + +#define BADBLOCK_MARKER_LENGTH 0x2 +#define SECTOR_BYTES 512

static uint8_t cs; -static __maybe_unused struct nand_ecclayout hw_nand_oob = - GPMC_NAND_HW_ECC_LAYOUT; -static __maybe_unused struct nand_ecclayout hw_bch8_nand_oob = - GPMC_NAND_HW_BCH8_ECC_LAYOUT; +static __maybe_unused struct nand_ecclayout omap_ecclayout;

/* * omap_nand_hwcontrol - Set the address pointers corretly for the @@ -233,6 +231,7 @@ struct nand_bch_priv { uint8_t type; uint8_t nibbles; struct bch_control *control; + enum omap_ecc ecc_scheme; };

/* bch types */ @@ -274,17 +273,15 @@ static void omap_hwecc_init_bch(struct nand_chip *chip, int32_t mode) { uint32_t val; uint32_t dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1; -#ifdef CONFIG_AM33XX uint32_t unused_length = 0; -#endif uint32_t wr_mode = BCH_WRAPMODE_6; struct nand_bch_priv *bch = chip->priv;

/* Clear the ecc result registers, select ecc reg as 1 */ writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control);

-#ifdef CONFIG_AM33XX - wr_mode = BCH_WRAPMODE_1; + if (bch->ecc_scheme == OMAP_ECC_BCH8_CODE_HW) { + wr_mode = BCH_WRAPMODE_1;

switch (bch->nibbles) { case ECC_BCH4_NIBBLES: @@ -320,7 +317,7 @@ static void omap_hwecc_init_bch(struct nand_chip *chip, int32_t mode) val |= (unused_length << 22); break; } -#else + } else { /* * This ecc_size_config setting is for BCH sw library. * @@ -333,7 +330,7 @@ static void omap_hwecc_init_bch(struct nand_chip *chip, int32_t mode) * size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area) */ val = (32 << 22) | (0 << 12); -#endif + } /* ecc size configuration */ writel(val, &gpmc_cfg->ecc_size_config);

@@ -376,9 +373,8 @@ static void __maybe_unused omap_ecc_disable(struct mtd_info *mtd) }

/* - * BCH8 support (needs ELM and thus AM33xx-only) + * BCH support using ELM module */ -#ifdef CONFIG_AM33XX /* * omap_read_bch8_result - Read BCH result for BCH8 level * @@ -631,20 +627,19 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, } return 0; } -#endif /* CONFIG_AM33XX */

/* * OMAP3 BCH8 support (with BCH library) */ -#ifdef CONFIG_NAND_OMAP_BCH8 +#ifdef CONFIG_BCH /* - * omap_calculate_ecc_bch - Read BCH ECC result + * omap_calculate_ecc_bch_sw - Read BCH ECC result * * @mtd: MTD device structure * @dat: The pointer to data on which ecc is computed (unused here) * @ecc: The ECC output buffer */ -static int omap_calculate_ecc_bch(struct mtd_info *mtd, const uint8_t *dat, +static int omap_calculate_ecc_bch_sw(struct mtd_info *mtd, const uint8_t *dat, uint8_t *ecc) { int ret = 0; @@ -689,13 +684,13 @@ static int omap_calculate_ecc_bch(struct mtd_info *mtd, const uint8_t *dat, }

/** - * omap_correct_data_bch - Decode received data and correct errors + * omap_correct_data_bch_sw - Decode received data and correct errors * @mtd: MTD device structure * @data: page data * @read_ecc: ecc read from nand flash * @calc_ecc: ecc read from HW ECC registers */ -static int omap_correct_data_bch(struct mtd_info *mtd, u_char *data, +static int omap_correct_data_bch_sw(struct mtd_info *mtd, u_char *data, u_char *read_ecc, u_char *calc_ecc) { int i, count; @@ -752,7 +747,120 @@ static void __maybe_unused omap_free_bch(struct mtd_info *mtd) chip_priv->control = NULL; } } -#endif /* CONFIG_NAND_OMAP_BCH8 */ +#endif /* CONFIG_BCH */ + +/** + * omap_select_ecc_scheme - configures driver for particular ecc-scheme + * @nand: NAND chip device structure + * @ecc_scheme: ecc scheme to configure + * @pagesize: number of main-area bytes per page of NAND device + * @oobsize: number of OOB/spare bytes per page of NAND device + */ +static int omap_select_ecc_scheme(struct nand_chip *nand, int ecc_scheme, + unsigned int pagesize, unsigned int oobsize) { + struct nand_bch_priv *bch = nand->priv; + struct nand_ecclayout *ecclayout = nand->ecc.layout; + int i; + + /* Reset ecc interface */ + nand->ecc.mode = NAND_ECC_NONE; + nand->ecc.read_page = NULL; + nand->ecc.write_page = NULL; + nand->ecc.read_oob = NULL; + nand->ecc.write_oob = NULL; + nand->ecc.hwctl = NULL; + nand->ecc.correct = NULL; + nand->ecc.calculate = NULL; + + switch (ecc_scheme) { + case OMAP_ECC_HAM1_CODE_SW: + printf("nand: selected OMAP_ECC_HAM1_CODE_SW\n"); + nand->ecc.mode = NAND_ECC_SOFT; + nand->ecc.layout = NULL; + nand->ecc.size = 0; + nand->ecc.strength = 1; + bch->ecc_scheme = OMAP_ECC_HAM1_CODE_SW; + break; + case OMAP_ECC_HAM1_CODE_HW_ROMCODE: + printf("nand: selected OMAP_ECC_HAM1_CODE_HW_ROMCODE\n"); + nand->ecc.mode = NAND_ECC_HW; + nand->ecc.strength = 1; + nand->ecc.size = 512; + nand->ecc.bytes = 3; + nand->ecc.hwctl = omap_enable_hwecc; + nand->ecc.correct = omap_correct_data; + nand->ecc.calculate = omap_calculate_ecc; + /* define ecc-layout */ + ecclayout->eccbytes = nand->ecc.bytes * + (pagesize / SECTOR_BYTES); + for (i = 0; i < ecclayout->eccbytes; i++) + ecclayout->eccpos[i] = i + + BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree[0].offset = i + + BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes - + BADBLOCK_MARKER_LENGTH; + bch->ecc_scheme = OMAP_ECC_HAM1_CODE_HW_ROMCODE; + break; +#ifdef CONFIG_BCH + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: + printf("nand: selected OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n"); + nand->ecc.mode = NAND_ECC_HW; + nand->ecc.strength = 8; + nand->ecc.size = 512; + nand->ecc.bytes = 13; + nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.correct = omap_correct_data_bch_sw; + nand->ecc.calculate = omap_calculate_ecc_bch_sw; + /* BCH SW library is used for error detection */ + bch_priv.control = init_bch(13, 8, 0x201b); + if (!bch_priv.control) { + printf("nand: err: could not init_bch()\n"); + return -ENODEV; + } + /* define ecc-layout */ + ecclayout->eccbytes = nand->ecc.bytes * + (pagesize / SECTOR_BYTES); + for (i = 0; i < ecclayout->eccbytes; i++) + ecclayout->eccpos[i] = i + (oobsize - + ecclayout->eccbytes); + ecclayout->oobfree[0].offset = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes - + BADBLOCK_MARKER_LENGTH; + omap_hwecc_init_bch(nand, NAND_ECC_READ); + bch->ecc_scheme = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW; + break; +#endif + case OMAP_ECC_BCH8_CODE_HW: + printf("nand: selected OMAP_ECC_BCH8_CODE_HW\n"); + nand->ecc.mode = NAND_ECC_HW; + nand->ecc.strength = 8; + nand->ecc.size = 512; + nand->ecc.bytes = 14; + nand->ecc.read_page = omap_read_page_bch; + nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.correct = omap_correct_data_bch; + nand->ecc.calculate = omap_calculate_ecc_bch; + /* ELM is used for ECC error detection */ + elm_init(); + /* define ecc-layout */ + ecclayout->eccbytes = nand->ecc.bytes * + (pagesize / SECTOR_BYTES); + for (i = 0; i < ecclayout->eccbytes; i++) + ecclayout->eccpos[i] = i + + BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree[0].offset = i + + BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes - + BADBLOCK_MARKER_LENGTH; + bch->ecc_scheme = OMAP_ECC_BCH8_CODE_HW; + break; + default: + printf("nand: error: ecc scheme not enabled or supported\n"); + return -EINVAL; + } + return 0; +}

#ifndef CONFIG_SPL_BUILD /* @@ -767,67 +875,41 @@ void omap_nand_switch_ecc(uint32_t hardware, uint32_t eccstrength) { struct nand_chip *nand; struct mtd_info *mtd; + struct nand_bch_priv *bch; + int err = 0;

if (nand_curr_device < 0 || nand_curr_device >= CONFIG_SYS_MAX_NAND_DEVICE || !nand_info[nand_curr_device].name) { - printf("Error: Can't switch ecc, no devices available\n"); + printf("nand: error: no devices available\n"); return; }

mtd = &nand_info[nand_curr_device]; nand = mtd->priv; - + bch = nand->priv; nand->options |= NAND_OWN_BUFFERS; - - /* Reset ecc interface */ - nand->ecc.mode = NAND_ECC_NONE; - nand->ecc.read_page = NULL; - nand->ecc.write_page = NULL; - nand->ecc.read_oob = NULL; - nand->ecc.write_oob = NULL; - nand->ecc.hwctl = NULL; - nand->ecc.correct = NULL; - nand->ecc.calculate = NULL; - nand->ecc.strength = eccstrength; - /* Setup the ecc configurations again */ - if (hardware) { + if (hardware) if (eccstrength == 1) { - nand->ecc.mode = NAND_ECC_HW; - nand->ecc.layout = &hw_nand_oob; - nand->ecc.size = 512; - nand->ecc.bytes = 3; - nand->ecc.hwctl = omap_enable_hwecc; - nand->ecc.correct = omap_correct_data; - nand->ecc.calculate = omap_calculate_ecc; - omap_hwecc_init(nand); - printf("1-bit hamming HW ECC selected\n"); - } -#if defined(CONFIG_AM33XX) || defined(CONFIG_NAND_OMAP_BCH8) - else if (eccstrength == 8) { - nand->ecc.mode = NAND_ECC_HW; - nand->ecc.layout = &hw_bch8_nand_oob; - nand->ecc.size = 512; -#ifdef CONFIG_AM33XX - nand->ecc.bytes = 14; - nand->ecc.read_page = omap_read_page_bch; -#else - nand->ecc.bytes = 13; -#endif - nand->ecc.hwctl = omap_enable_ecc_bch; - nand->ecc.correct = omap_correct_data_bch; - nand->ecc.calculate = omap_calculate_ecc_bch; - omap_hwecc_init_bch(nand, NAND_ECC_READ); - printf("8-bit BCH HW ECC selected\n"); + err = omap_select_ecc_scheme(nand, + OMAP_ECC_HAM1_CODE_HW_ROMCODE, + mtd->writesize, mtd->oobsize); + } else if (eccstrength == 8) { + err = omap_select_ecc_scheme(nand, + OMAP_ECC_BCH8_CODE_HW, + mtd->writesize, mtd->oobsize); + } else { + printf("nand: error: unsupported ECC scheme\n"); + err = -EINVAL; } -#endif - } else { - nand->ecc.mode = NAND_ECC_SOFT; - /* Use mtd default settings */ - nand->ecc.layout = NULL; - nand->ecc.size = 0; - printf("SW ECC selected\n"); + else + err = omap_select_ecc_scheme(nand, OMAP_ECC_HAM1_CODE_SW, + mtd->writesize, mtd->oobsize); + if (err) { + printf("nand: error: could not switch ecc, reverting\n"); + omap_select_ecc_scheme(nand, bch->ecc_scheme, + mtd->writesize, mtd->oobsize); }

/* Update NAND handling after ECC mode switch */ @@ -854,6 +936,10 @@ void omap_nand_switch_ecc(uint32_t hardware, uint32_t eccstrength) */ int board_nand_init(struct nand_chip *nand) { + struct mtd_info *mtd; +#ifdef CONFIG_SPL_BUILD + struct mtd_info nand_info[CONFIG_SYS_MAX_NAND_DEVICE]; +#endif int32_t gpmc_config = 0; cs = 0;

@@ -873,7 +959,7 @@ int board_nand_init(struct nand_chip *nand) cs++; } if (cs >= GPMC_MAX_CS) { - printf("NAND: Unable to find NAND settings in " + printf("nand: error: Unable to find NAND settings in " "GPMC Configuration - quitting\n"); return -ENODEV; } @@ -883,66 +969,27 @@ int board_nand_init(struct nand_chip *nand) gpmc_config |= 0x10; writel(gpmc_config, &gpmc_cfg->config);

+ mtd = &nand_info[0]; + mtd->priv = nand; nand->IO_ADDR_R = (void __iomem *)&gpmc_cfg->cs[cs].nand_dat; nand->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_cmd; - - nand->cmd_ctrl = omap_nand_hwcontrol; - nand->options = NAND_NO_PADDING | NAND_CACHEPRG; + nand->priv = &bch_priv; + nand->cmd_ctrl = omap_nand_hwcontrol; + nand->options = NAND_NO_PADDING | NAND_CACHEPRG; /* If we are 16 bit dev, our gpmc config tells us that */ if ((readl(&gpmc_cfg->cs[cs].config1) & 0x3000) == 0x1000) nand->options |= NAND_BUSWIDTH_16;

nand->chip_delay = 100; - -#if defined(CONFIG_AM33XX) || defined(CONFIG_NAND_OMAP_BCH8) -#ifdef CONFIG_AM33XX - /* AM33xx uses the ELM */ - /* required in case of BCH */ - elm_init(); -#else - /* - * Whereas other OMAP based SoC do not have the ELM, they use the BCH - * SW library. - */ - bch_priv.control = init_bch(13, 8, 0x201b /* hw polynominal */); - if (!bch_priv.control) { - puts("Could not init_bch()\n"); - return -ENODEV; + nand->ecc.layout = &omap_ecclayout; + + /* select ECC scheme */ + if (omap_select_ecc_scheme(nand, CONFIG_SYS_NAND_ECCSCHEME, + CONFIG_SYS_NAND_PAGE_SIZE, + CONFIG_SYS_NAND_OOBSIZE)) { + printf("nand: error: cannot select ecc scheme\n"); + return -EINVAL; } -#endif - /* BCH info that will be correct for SPL or overridden otherwise. */ - nand->priv = &bch_priv; -#endif - - /* Default ECC mode */ -#if defined(CONFIG_AM33XX) || defined(CONFIG_NAND_OMAP_BCH8) - nand->ecc.mode = NAND_ECC_HW; - nand->ecc.layout = &hw_bch8_nand_oob; - nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE; - nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES; - nand->ecc.strength = 8; - nand->ecc.hwctl = omap_enable_ecc_bch; - nand->ecc.correct = omap_correct_data_bch; - nand->ecc.calculate = omap_calculate_ecc_bch; -#ifdef CONFIG_AM33XX - nand->ecc.read_page = omap_read_page_bch; -#endif - omap_hwecc_init_bch(nand, NAND_ECC_READ); -#else -#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_NAND_SOFTECC) - nand->ecc.mode = NAND_ECC_SOFT; -#else - nand->ecc.mode = NAND_ECC_HW; - nand->ecc.layout = &hw_nand_oob; - nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE; - nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES; - nand->ecc.hwctl = omap_enable_hwecc; - nand->ecc.correct = omap_correct_data; - nand->ecc.calculate = omap_calculate_ecc; - nand->ecc.strength = 1; - omap_hwecc_init(nand); -#endif -#endif

#ifdef CONFIG_SPL_BUILD if (nand->options & NAND_BUSWIDTH_16) diff --git a/include/configs/am335x_evm.h b/include/configs/am335x_evm.h index e0a87f8..db0cbdb 100644 --- a/include/configs/am335x_evm.h +++ b/include/configs/am335x_evm.h @@ -259,6 +259,7 @@

#define CONFIG_SYS_NAND_ECCSIZE 512 #define CONFIG_SYS_NAND_ECCBYTES 14 +#define CONFIG_SYS_NAND_ECCSCHEME 3

#define CONFIG_SYS_NAND_U_BOOT_START CONFIG_SYS_TEXT_BASE #define CONFIG_SYS_NAND_U_BOOT_OFFS 0x80000 @@ -351,6 +352,7 @@

/* NAND support */ #ifdef CONFIG_NAND +#define CONFIG_SYS_NAND_ONFI_DETECTION #define CONFIG_CMD_NAND #define GPMC_NAND_ECC_LP_x16_LAYOUT 1 #if !defined(CONFIG_SPI_BOOT) && !defined(CONFIG_NOR_BOOT)

chip->ecc.hwctl() is used for preparing the H/W controller before read/write NAND accesses (like assigning data-buf, enabling ECC scheme configs, etc.)

Though all ECC schemes in OMAP NAND driver use GPMC controller for generating ECC syndrome (for both Read/Write accesses). But but in current code HAM1_ECC and BCHx_ECC schemes implement individual function to achieve this. This patch (1) removes omap_hwecc_init() and omap_hwecc_init_bch() as chip->ecc.hwctl will re-initializeGPMC before every read/write call. omap_hwecc_init_bch() -> omap_enable_ecc_bch()

(2) merges the GPMC configuration code for all ECC schemes into single omap_enable_hwecc(), thus adding scalability for future ECC schemes. omap_enable_hwecc() + omap_enable_ecc_bch() -> omap_enable_hwecc()

Signed-off-by: Pekon Gupta pekon@ti.com --- arch/arm/include/asm/omap_gpmc.h | 7 -- drivers/mtd/nand/omap_gpmc.c | 193 +++++++++++---------------------------- 2 files changed, 55 insertions(+), 145 deletions(-)

diff --git a/arch/arm/include/asm/omap_gpmc.h b/arch/arm/include/asm/omap_gpmc.h index dd40cb6..9660842 100644 --- a/arch/arm/include/asm/omap_gpmc.h +++ b/arch/arm/include/asm/omap_gpmc.h @@ -14,13 +14,6 @@ #define GPMC_BUF_EMPTY 0 #define GPMC_BUF_FULL 1

-#define ECCCLEAR (0x1 << 8) -#define ECCRESULTREG1 (0x1 << 0) -#define ECCSIZE512BYTE 0xFF -#define ECCSIZE1 (ECCSIZE512BYTE << 22) -#define ECCSIZE0 (ECCSIZE512BYTE << 12) -#define ECCSIZE0SEL (0x000 << 0) - /* Generic ECC Layouts */ /* Large Page x8 NAND device Layout */ #ifdef GPMC_NAND_ECC_LP_x8_LAYOUT diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index f97e862..0af4fa4 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -19,6 +19,8 @@

#define BADBLOCK_MARKER_LENGTH 0x2 #define SECTOR_BYTES 512 +#define ECCCLEAR (0x1 << 8) +#define ECCRESULTREG1 (0x1 << 0)

static uint8_t cs; static __maybe_unused struct nand_ecclayout omap_ecclayout; @@ -60,21 +62,6 @@ int omap_spl_dev_ready(struct mtd_info *mtd) } #endif

-/* - * omap_hwecc_init - Initialize the Hardware ECC for NAND flash in - * GPMC controller - * @mtd: MTD device structure - * - */ -static void __maybe_unused omap_hwecc_init(struct nand_chip *chip) -{ - /* - * Init ECC Control Register - * Clear all ECC | Enable Reg1 - */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - writel(ECCSIZE1 | ECCSIZE0 | ECCSIZE0SEL, &gpmc_cfg->ecc_size_config); -}

/* * gen_true_ecc - This function will generate true ECC value, which @@ -192,38 +179,6 @@ static int __maybe_unused omap_calculate_ecc(struct mtd_info *mtd, }

/* - * omap_enable_ecc - This function enables the hardware ecc functionality - * @mtd: MTD device structure - * @mode: Read/Write mode - */ -static void __maybe_unused omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) -{ - struct nand_chip *chip = mtd->priv; - uint32_t val, dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1; - - switch (mode) { - case NAND_ECC_READ: - case NAND_ECC_WRITE: - /* Clear the ecc result registers, select ecc reg as 1 */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - - /* - * Size 0 = 0xFF, Size1 is 0xFF - both are 512 bytes - * tell all regs to generate size0 sized regs - * we just have a single ECC engine for all CS - */ - writel(ECCSIZE1 | ECCSIZE0 | ECCSIZE0SEL, - &gpmc_cfg->ecc_size_config); - val = (dev_width << 7) | (cs << 1) | (0x1); - writel(val, &gpmc_cfg->ecc_config); - break; - default: - printf("Error: Unrecognized Mode[%d]!\n", mode); - break; - } -} - -/* * Generic BCH interface */ struct nand_bch_priv { @@ -263,103 +218,66 @@ static __maybe_unused struct nand_bch_priv bch_priv = { };

/* - * omap_hwecc_init_bch - Initialize the BCH Hardware ECC for NAND flash in - * GPMC controller + * omap_enable_hwecc - configures GPMC as per ECC scheme before read/write * @mtd: MTD device structure * @mode: Read/Write mode */ __maybe_unused -static void omap_hwecc_init_bch(struct nand_chip *chip, int32_t mode) +static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) { - uint32_t val; - uint32_t dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1; - uint32_t unused_length = 0; - uint32_t wr_mode = BCH_WRAPMODE_6; - struct nand_bch_priv *bch = chip->priv; - - /* Clear the ecc result registers, select ecc reg as 1 */ - writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); - - if (bch->ecc_scheme == OMAP_ECC_BCH8_CODE_HW) { - wr_mode = BCH_WRAPMODE_1; - - switch (bch->nibbles) { - case ECC_BCH4_NIBBLES: - unused_length = 3; - break; - case ECC_BCH8_NIBBLES: - unused_length = 2; - break; - case ECC_BCH16_NIBBLES: - unused_length = 0; + struct nand_chip *nand = mtd->priv; + struct nand_bch_priv *bch = nand->priv; + unsigned int dev_width = (nand->options & NAND_BUSWIDTH_16) ? 1 : 0; + unsigned int ecc_algo = 0; + unsigned int bch_type = 0; + unsigned int eccsize1 = 0x00, eccsize0 = 0x00, bch_wrapmode = 0x00; + u32 ecc_size_config_val = 0; + u32 ecc_config_val = 0; + + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_SW: + case OMAP_ECC_HAM1_CODE_HW_ROMCODE: + ecc_algo = 0x0; + bch_type = 0x0; + bch_wrapmode = 0x00; + eccsize0 = 0xFF; + eccsize1 = 0xFF; break; - } - - /* - * This is ecc_size_config for ELM mode. - * Here we are using different settings for read and write access and - * also depending on BCH strength. - */ - switch (mode) { - case NAND_ECC_WRITE: - /* write access only setup eccsize1 config */ - val = ((unused_length + bch->nibbles) << 22); + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: + case OMAP_ECC_BCH8_CODE_HW: + ecc_algo = 0x1; + bch_type = 0x1; + if (mode == NAND_ECC_WRITE) { + bch_wrapmode = 0x01; + eccsize0 = 0; /* extra bits in nibbles per sector */ + eccsize1 = 28; /* OOB bits in nibbles per sector */ + } else { + bch_wrapmode = 0x01; + eccsize0 = 26; /* ECC bits in nibbles per sector */ + eccsize1 = 2; /* non-ECC bits in nibbles per sector */ + } break; - - case NAND_ECC_READ: default: - /* - * by default eccsize0 selected for ecc1resultsize - * eccsize0 config. - */ - val = (bch->nibbles << 12); - /* eccsize1 config */ - val |= (unused_length << 22); - break; - } - } else { - /* - * This ecc_size_config setting is for BCH sw library. - * - * Note: we only support BCH8 currently with BCH sw library! - * Should be really easy to adobt to BCH4, however some omap3 have - * flaws with BCH4. - * - * 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 << 22) | (0 << 12); + printf("nand: error: invalid driver configuration\n"); + return; } - /* ecc size configuration */ - writel(val, &gpmc_cfg->ecc_size_config); - - /* - * Configure the ecc engine in gpmc - * We assume 512 Byte sector pages for access to NAND. - */ - val = (1 << 16); /* enable BCH mode */ - val |= (bch->type << 12); /* setup BCH type */ - val |= (wr_mode << 8); /* setup wrapping mode */ - val |= (dev_width << 7); /* setup device width (16 or 8 bit) */ - val |= (cs << 1); /* setup chip select to work on */ - debug("set ECC_CONFIG=0x%08x\n", val); - writel(val, &gpmc_cfg->ecc_config); -} - -/* - * omap_enable_ecc_bch - This function enables the bch h/w ecc functionality - * @mtd: MTD device structure - * @mode: Read/Write mode - */ -__maybe_unused -static void omap_enable_ecc_bch(struct mtd_info *mtd, int32_t mode) -{ - struct nand_chip *chip = mtd->priv; - - omap_hwecc_init_bch(chip, mode); - /* enable ecc */ - writel((readl(&gpmc_cfg->ecc_config) | 0x1), &gpmc_cfg->ecc_config); + /* Clear ecc and enable bits */ + writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control); + /* Configure ecc size for BCH */ + ecc_size_config_val = (eccsize1 << 22) | (eccsize0 << 12); + writel(ecc_size_config_val, &gpmc_cfg->ecc_size_config); + + /* Configure device details for BCH engine */ + ecc_config_val = ((ecc_algo << 16) | /* HAM1 | BCHx */ + (bch_type << 12) | /* BCH4/BCH8/BCH16 */ + (bch_wrapmode << 8) | /* wrap mode */ + (dev_width << 7) | /* bus width */ + (0x0 << 4) | /* number of sectors */ + (cs << 1) | /* ECC CS */ + (0x0)); /* disable ECC */ + writel(ecc_config_val, &gpmc_cfg->ecc_config); + /* enable ECC engine */ + writel(ecc_config_val | 0x1, &gpmc_cfg->ecc_config); }

/* @@ -809,7 +727,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, int ecc_scheme, nand->ecc.strength = 8; nand->ecc.size = 512; nand->ecc.bytes = 13; - nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch_sw; nand->ecc.calculate = omap_calculate_ecc_bch_sw; /* BCH SW library is used for error detection */ @@ -827,7 +745,6 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, int ecc_scheme, ecclayout->oobfree[0].offset = BADBLOCK_MARKER_LENGTH; ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes - BADBLOCK_MARKER_LENGTH; - omap_hwecc_init_bch(nand, NAND_ECC_READ); bch->ecc_scheme = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW; break; #endif @@ -838,7 +755,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, int ecc_scheme, nand->ecc.size = 512; nand->ecc.bytes = 14; nand->ecc.read_page = omap_read_page_bch; - nand->ecc.hwctl = omap_enable_ecc_bch; + nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch; nand->ecc.calculate = omap_calculate_ecc_bch; /* ELM is used for ECC error detection */

chip->ecc.correct() is used for detecting and correcting bit-flips during read operations. In omap-nand driver it implemented as: (a) omap_correct_data(): for h/w based ECC_HAM1 scheme (b) omap_correct_data_bch() + CONFIG_NAND_OMAP_ECC_BCH8_CODE_HW_DETECTION_SW for ECC_BCH8 scheme using GPMC and software lib/bch.c (c) omap_correct_data_bch() + CONFIG_NAND_OMAP_ECC_BCH8_CODE_HW for ECC_BCH8 scheme using GPMC and ELM

This patch updates (c) - checks for calc_ecc[]==0x00 so that error_correction is not required for known good pages. - adds scalability for other ECC_BCHx scheme by merging following omap_rotate_ecc_bch() + omap_fix_errors_bch() => omap_correct_data_bch() - fixing logic for bit-flip correction based on error_loc[count]

Signed-off-by: Pekon Gupta pekon@ti.com --- drivers/mtd/nand/omap_gpmc.c | 125 +++++++++++++++---------------------------- 1 file changed, 44 insertions(+), 81 deletions(-)

diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index e914c73..9e94e9e 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -21,6 +21,8 @@ #define SECTOR_BYTES 512 #define ECCCLEAR (0x1 << 8) #define ECCRESULTREG1 (0x1 << 0) +/* 4 bit padding to make byte aligned, 56 = 52 + 4 */ +#define BCH4_BIT_PAD 4

static uint8_t cs; static __maybe_unused struct nand_ecclayout omap_ecclayout; @@ -319,77 +321,6 @@ static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat, }

/* - * omap_rotate_ecc_bch - Rotate the syndrome bytes - * - * @mtd: MTD device structure - * @calc_ecc: ECC read from ECC registers - * @syndrome: Rotated syndrome will be retuned in this array - * - */ -static void omap_rotate_ecc_bch(struct mtd_info *mtd, uint8_t *calc_ecc, - uint8_t *syndrome) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t n_bytes = 0; - int8_t i, j; - - switch (bch->type) { - case ECC_BCH4: - n_bytes = 8; - break; - - case ECC_BCH16: - n_bytes = 28; - break; - - case ECC_BCH8: - default: - n_bytes = 13; - break; - } - - for (i = 0, j = (n_bytes-1); i < n_bytes; i++, j--) - syndrome[i] = calc_ecc[j]; -} - -/* - * omap_fix_errors_bch - Correct bch error in the data - * - * @mtd: MTD device structure - * @data: Data read from flash - * @error_count:Number of errors in data - * @error_loc: Locations of errors in the data - * - */ -static void omap_fix_errors_bch(struct mtd_info *mtd, uint8_t *data, - uint32_t error_count, uint32_t *error_loc) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t count = 0; - uint32_t error_byte_pos; - uint32_t error_bit_mask; - uint32_t last_bit = (bch->nibbles * 4) - 1; - - /* Flip all bits as specified by the error location array. */ - /* FOR( each found error location flip the bit ) */ - for (count = 0; count < error_count; count++) { - if (error_loc[count] > last_bit) { - /* Remove the ECC spare bits from correction. */ - error_loc[count] -= (last_bit + 1); - /* Offset bit in data region */ - error_byte_pos = ((512 * 8) - - (error_loc[count]) - 1) / 8; - /* Error Bit mask */ - error_bit_mask = 0x1 << (error_loc[count] % 8); - /* Toggle the error bit to make the correction. */ - data[error_byte_pos] ^= error_bit_mask; - } - } -} - -/* * omap_correct_data_bch - Compares the ecc read from nand spare area * with ECC registers values and corrects one bit error if it has occured * @@ -405,16 +336,26 @@ static int omap_correct_data_bch(struct mtd_info *mtd, uint8_t *dat, { struct nand_chip *chip = mtd->priv; struct nand_bch_priv *bch = chip->priv; + uint32_t eccbytes = chip->ecc.bytes; uint8_t syndrome[28]; - uint32_t error_count = 0; + uint32_t error_count = 0, error_max; uint32_t error_loc[8]; - uint32_t i, ecc_flag; + uint32_t i, j, ecc_flag = 0; + uint8_t count, err = 0; + uint32_t byte_pos, bit_pos; + + /* check calculated ecc */ + for (i = 0; i < chip->ecc.bytes && !ecc_flag; i++) + if (calc_ecc[i] != 0x00) + ecc_flag = 1; + if (!ecc_flag) + return 0;

+ /* check for whether its a erased-page */ ecc_flag = 0; - for (i = 0; i < chip->ecc.bytes; i++) + for (i = 0; i < chip->ecc.bytes && !ecc_flag; i++) if (read_ecc[i] != 0xff) ecc_flag = 1; - if (!ecc_flag) return 0;

@@ -425,20 +366,42 @@ static int omap_correct_data_bch(struct mtd_info *mtd, uint8_t *dat, * while reading ECC result we read it in big endian. * Hence while loading to ELM we have rotate to get the right endian. */ - omap_rotate_ecc_bch(mtd, calc_ecc, syndrome); + for (i = 0, j = (eccbytes-1); i < eccbytes; i++, j--) + syndrome[i] = calc_ecc[j];

/* use elm module to check for errors */ if (elm_check_error(syndrome, bch->nibbles, &error_count, error_loc) != 0) { - printf("ECC: uncorrectable.\n"); - return -1; + printf("nand: error: uncorrectable ECC errors\n"); + return -EINVAL; }

/* correct bch error */ - if (error_count > 0) - omap_fix_errors_bch(mtd, dat, error_count, error_loc); + for (count = 0; count < error_count; count++) { + switch (bch->type) { + case ECC_BCH4: + error_max = SECTOR_BYTES + (eccbytes - 1); + /* add 4 to take care 4 bit padding */ + error_loc[count] += BCH4_BIT_PAD; + break; + case ECC_BCH8: + /* 14th byte in ECC is reserved to match ROM layout */ + error_max = SECTOR_BYTES + (eccbytes - 1); + break; + default: + return -EINVAL; + } + byte_pos = error_max - ((error_loc[count] - 1) / 8); + bit_pos = error_loc[count] % 8;

- return 0; + if (byte_pos < SECTOR_BYTES) + dat[byte_pos] ^= 1 << bit_pos; + else if (byte_pos < error_max) + read_ecc[byte_pos - SECTOR_BYTES] = 1 << bit_pos; + else + err = -EBADMSG; + } + return (err) ? err : error_count; }

/**