chip->ecc.calculate() is used for calculating and fetching of ECC syndrome by processing the data passed during Read/Write accesses.
All H/W based ECC schemes use GPMC controller to calculate ECC syndrome. But each BCHx_ECC scheme has its own implemetation of post-processing and fetching ECC syndrome from GPMC controller.
This patch updates OMAP_ECC_BCH8_CODE_HW ECC scheme in following way: - merges multiple chip->calculate API for different ECC schemes omap_calculate_ecc() + omap_calculate_ecc_bch() + omap_calculate_ecc_bch_sw() ==> omap_calculate_ecc() - removes omap_ecc_disable() and instead uses it as inline.
Signed-off-by: Pekon Gupta pekon@ti.com --- drivers/mtd/nand/omap_gpmc.c | 226 ++++++++++++------------------------------- 1 file changed, 63 insertions(+), 163 deletions(-)
diff --git a/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c index 035b1f7..ea1054b 100644 --- a/drivers/mtd/nand/omap_gpmc.c +++ b/drivers/mtd/nand/omap_gpmc.c @@ -21,7 +21,10 @@ #define SECTOR_BYTES 512 #define ECCCLEAR (0x1 << 8) #define ECCRESULTREG1 (0x1 << 0) - +#ifdef CONFIG_BCH +static u8 bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2, + 0x97, 0x79, 0xe5, 0x24, 0xb5}; +#endif static uint8_t cs; static __maybe_unused struct nand_ecclayout omap_ecclayout;
@@ -143,42 +146,6 @@ static int __maybe_unused omap_correct_data(struct mtd_info *mtd, uint8_t *dat, }
/* - * omap_calculate_ecc - Generate non-inverted ECC bytes. - * - * Using noninverted ECC can be considered ugly since writing a blank - * page ie. padding will clear the ECC bytes. This is no problem as - * long nobody is trying to write data on the seemingly unused page. - * Reading an erased page will produce an ECC mismatch between - * generated and read ECC bytes that has to be dealt with separately. - * E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC - * is used, the result of read will be 0x0 while the ECC offsets of the - * spare area will be 0xFF which will result in an ECC mismatch. - * @mtd: MTD structure - * @dat: unused - * @ecc_code: ecc_code buffer - */ -static int __maybe_unused omap_calculate_ecc(struct mtd_info *mtd, - const uint8_t *dat, uint8_t *ecc_code) -{ - u_int32_t val; - - /* Start Reading from HW ECC1_Result = 0x200 */ - val = readl(&gpmc_cfg->ecc1_result); - - ecc_code[0] = val & 0xFF; - ecc_code[1] = (val >> 16) & 0xFF; - ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0); - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - writel(0x000, &gpmc_cfg->ecc_config); - - return 0; -} - -/* * Generic BCH interface */ struct nand_bch_priv { @@ -194,12 +161,7 @@ struct nand_bch_priv { #define ECC_BCH8 1 #define ECC_BCH16 2
-/* GPMC ecc engine settings */ -#define BCH_WRAPMODE_1 1 /* BCH wrap mode 1 */ -#define BCH_WRAPMODE_6 6 /* BCH wrap mode 6 */ - /* BCH nibbles for diff bch levels */ -#define NAND_ECC_HW_BCH ((uint8_t)(NAND_ECC_HW_OOB_FIRST) + 1) #define ECC_BCH4_NIBBLES 13 #define ECC_BCH8_NIBBLES 26 #define ECC_BCH16_NIBBLES 52 @@ -211,7 +173,6 @@ struct nand_bch_priv { * When some users with other BCH strength will exists this have to change! */ static __maybe_unused struct nand_bch_priv bch_priv = { - .mode = NAND_ECC_HW_BCH, .type = ECC_BCH8, .nibbles = ECC_BCH8_NIBBLES, .control = NULL @@ -280,57 +241,76 @@ static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode) }
/* - * omap_ecc_disable - Disable H/W ECC calculation - * - * @mtd: MTD device structure - */ -static void __maybe_unused omap_ecc_disable(struct mtd_info *mtd) -{ - writel((readl(&gpmc_cfg->ecc_config) & ~0x1), &gpmc_cfg->ecc_config); -} - -/* - * BCH support using ELM module - */ -#ifdef CONFIG_NAND_OMAP_ELM -/* - * omap_read_bch8_result - Read BCH result for BCH8 level - * - * @mtd: MTD device structure - * @big_endian: When set read register 3 first - * @ecc_code: Read syndrome from BCH result registers + * omap_calculate_ecc - Read ECC result + * @mtd: MTD structure + * @dat: unused + * @ecc_code: ecc_code buffer + * Using noninverted ECC can be considered ugly since writing a blank + * page ie. padding will clear the ECC bytes. This is no problem as + * long nobody is trying to write data on the seemingly unused page. + * Reading an erased page will produce an ECC mismatch between + * generated and read ECC bytes that has to be dealt with separately. + * E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC + * is used, the result of read will be 0x0 while the ECC offsets of the + * spare area will be 0xFF which will result in an ECC mismatch. */ -static void omap_read_bch8_result(struct mtd_info *mtd, uint8_t big_endian, +static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat, uint8_t *ecc_code) { - uint32_t *ptr; + struct nand_chip *chip = mtd->priv; + struct nand_bch_priv *bch = chip->priv; + uint32_t *ptr, val = 0; int8_t i = 0, j;
- if (big_endian) { + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_HW: + val = readl(&gpmc_cfg->ecc1_result); + ecc_code[0] = val & 0xFF; + ecc_code[1] = (val >> 16) & 0xFF; + ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0); + break; +#ifdef CONFIG_BCH + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: +#endif + case OMAP_ECC_BCH8_CODE_HW: ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[3]; - ecc_code[i++] = readl(ptr) & 0xFF; + val = readl(ptr); + ecc_code[i++] = (val >> 0) & 0xFF; ptr--; for (j = 0; j < 3; j++) { - ecc_code[i++] = (readl(ptr) >> 24) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 16) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 8) & 0xFF; - ecc_code[i++] = readl(ptr) & 0xFF; + val = readl(ptr); + ecc_code[i++] = (val >> 24) & 0xFF; + ecc_code[i++] = (val >> 16) & 0xFF; + ecc_code[i++] = (val >> 8) & 0xFF; + ecc_code[i++] = (val >> 0) & 0xFF; ptr--; } - } else { - ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[0]; - for (j = 0; j < 3; j++) { - ecc_code[i++] = readl(ptr) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 8) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 16) & 0xFF; - ecc_code[i++] = (readl(ptr) >> 24) & 0xFF; - ptr++; - } - ecc_code[i++] = readl(ptr) & 0xFF; - ecc_code[i++] = 0; /* 14th byte is always zero */ + break; + default: + return -EINVAL; + } + /* ECC scheme specific syndrome customizations */ + switch (bch->ecc_scheme) { + case OMAP_ECC_HAM1_CODE_HW: + break; +#ifdef CONFIG_BCH + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: + + for (i = 0; i < chip->ecc.bytes; i++) + *(ecc_code + i) = *(ecc_code + i) ^ + bch8_polynomial[i]; + break; +#endif + case OMAP_ECC_BCH8_CODE_HW: + ecc_code[chip->ecc.bytes - 1] = 0x00; + break; + default: + return -EINVAL; } + return 0; }
+#ifdef CONFIG_NAND_OMAP_ELM /* * omap_rotate_ecc_bch - Rotate the syndrome bytes * @@ -367,35 +347,6 @@ static void omap_rotate_ecc_bch(struct mtd_info *mtd, uint8_t *calc_ecc, }
/* - * omap_calculate_ecc_bch - Read BCH ECC result - * - * @mtd: MTD structure - * @dat: unused - * @ecc_code: ecc_code buffer - */ -static int omap_calculate_ecc_bch(struct mtd_info *mtd, const uint8_t *dat, - uint8_t *ecc_code) -{ - struct nand_chip *chip = mtd->priv; - struct nand_bch_priv *bch = chip->priv; - uint8_t big_endian = 1; - int8_t ret = 0; - - if (bch->type == ECC_BCH8) - omap_read_bch8_result(mtd, big_endian, ecc_code); - else /* BCH4 and BCH16 currently not supported */ - ret = -1; - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - omap_ecc_disable(mtd); - - return ret; -} - -/* * omap_fix_errors_bch - Correct bch error in the data * * @mtd: MTD device structure @@ -551,57 +502,6 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, * OMAP3 BCH8 support (with BCH library) */ #ifdef CONFIG_BCH -/* - * 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_sw(struct mtd_info *mtd, const uint8_t *dat, - uint8_t *ecc) -{ - int ret = 0; - size_t i; - unsigned long nsectors, val1, val2, val3, val4; - - nsectors = ((readl(&gpmc_cfg->ecc_config) >> 4) & 0x7) + 1; - - for (i = 0; i < nsectors; i++) { - /* Read hw-computed remainder */ - val1 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[0]); - val2 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[1]); - val3 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[2]); - val4 = readl(&gpmc_cfg->bch_result_0_3[i].bch_result_x[3]); - - /* - * Add constant polynomial to remainder, in order to get an ecc - * sequence of 0xFFs for a buffer filled with 0xFFs. - */ - *ecc++ = 0xef ^ (val4 & 0xFF); - *ecc++ = 0x51 ^ ((val3 >> 24) & 0xFF); - *ecc++ = 0x2e ^ ((val3 >> 16) & 0xFF); - *ecc++ = 0x09 ^ ((val3 >> 8) & 0xFF); - *ecc++ = 0xed ^ (val3 & 0xFF); - *ecc++ = 0x93 ^ ((val2 >> 24) & 0xFF); - *ecc++ = 0x9a ^ ((val2 >> 16) & 0xFF); - *ecc++ = 0xc2 ^ ((val2 >> 8) & 0xFF); - *ecc++ = 0x97 ^ (val2 & 0xFF); - *ecc++ = 0x79 ^ ((val1 >> 24) & 0xFF); - *ecc++ = 0xe5 ^ ((val1 >> 16) & 0xFF); - *ecc++ = 0x24 ^ ((val1 >> 8) & 0xFF); - *ecc++ = 0xb5 ^ (val1 & 0xFF); - } - - /* - * Stop reading anymore ECC vals and clear old results - * enable will be called if more reads are required - */ - omap_ecc_disable(mtd); - - return ret; -} - /** * omap_correct_data_bch_sw - Decode received data and correct errors * @mtd: MTD device structure @@ -746,7 +646,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.bytes = 13; nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch_sw; - nand->ecc.calculate = omap_calculate_ecc_bch_sw; + nand->ecc.calculate = omap_calculate_ecc; /* define ecc-layout */ ecclayout->eccbytes = nand->ecc.bytes * eccsteps; ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; @@ -787,7 +687,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand, nand->ecc.bytes = 14; nand->ecc.hwctl = omap_enable_hwecc; nand->ecc.correct = omap_correct_data_bch; - nand->ecc.calculate = omap_calculate_ecc_bch; + nand->ecc.calculate = omap_calculate_ecc; nand->ecc.read_page = omap_read_page_bch; /* define ecc-layout */ ecclayout->eccbytes = nand->ecc.bytes * eccsteps;