From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bear.ext.ti.com ([192.94.94.41]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vkt6w-0001Fj-N8 for linux-mtd@lists.infradead.org; Mon, 25 Nov 2013 10:09:53 +0000 From: Pekon Gupta To: Brain Norris , Artem Bityutskiy Subject: [PATCH v4 4/4] mtd: devices: elm: add checks ELM H/W constrains, driver code cleanup Date: Mon, 25 Nov 2013 15:39:01 +0530 Message-ID: <1385374141-10934-5-git-send-email-pekon@ti.com> In-Reply-To: <1385374141-10934-1-git-send-email-pekon@ti.com> References: <1385374141-10934-1-git-send-email-pekon@ti.com> MIME-Version: 1.0 Content-Type: text/plain Cc: linux-mtd , Pekon Gupta , ezequiel.garcia@free-electrons.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ELM H/W engine is used by BCHx_ECC schemes for detecting and locating bit-flips. However, ELM H/W engine has some constrains like: - ELM can decode errors in chunks of 512 data bytes only - ELM can operate max upto 8 such buffers in parallel This patch - add checks for above constrains - fixes ELM register configs based on number of info->eccsteps - cleans-up elm_load_syndrome() Signed-off-by: Pekon Gupta Tested-by: Ezequiel Garcia --- drivers/mtd/devices/elm.c | 127 +++++++++++++++++++++++--------------- drivers/mtd/nand/omap2.c | 2 +- include/linux/platform_data/elm.h | 6 +- 3 files changed, 83 insertions(+), 52 deletions(-) diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c index d1dd6a3..10026ef 100644 --- a/drivers/mtd/devices/elm.c +++ b/drivers/mtd/devices/elm.c @@ -15,6 +15,9 @@ * */ +#define DRIVER_NAME "omap-elm" +#define pr_fmt(fmt) DRIVER_NAME ": " fmt + #include #include #include @@ -22,6 +25,8 @@ #include #include #include +#include +#include #include #define ELM_SYSCONFIG 0x010 @@ -82,6 +87,7 @@ struct elm_info { void __iomem *elm_base; struct completion elm_completion; struct list_head list; + struct mtd_info *mtd; enum bch_ecc bch_type; struct elm_registers elm_regs; }; @@ -103,19 +109,41 @@ static u32 elm_read_reg(struct elm_info *info, int offset) * @dev: ELM device * @bch_type: Type of BCH ecc */ -int elm_config(struct device *dev, enum bch_ecc bch_type) +int elm_config(struct device *dev, struct mtd_info *mtd, + enum bch_ecc bch_type) { u32 reg_val; - struct elm_info *info = dev_get_drvdata(dev); - + struct elm_info *info; + struct nand_chip *nand_chip; + if (!dev) { + pr_err("ELM device not found\n"); + return -ENODEV; + } + info = dev_get_drvdata(dev); if (!info) { - dev_err(dev, "Unable to configure elm - device not probed?\n"); + pr_err("ELM device data not found\n"); return -ENODEV; } - + if (!mtd) { + pr_err("MTD device not found\n"); + return -ENODEV; + } + nand_chip = mtd->priv; + /* ELM supports error correction in chunks of 512bytes of data only + * where each 512bytes of data has its own ECC syndrome */ + if (nand_chip->ecc.size != 512) { + pr_err("invalid config ecc-size=%d", nand_chip->ecc.size); + return -EINVAL; + } + if (mtd->writesize > 4096) { + pr_err("unsupported page-size=%d > 4096", mtd->writesize); + return -EINVAL; + } + /* populate ELM driver configurations from MTD device data */ + info->mtd = mtd; + info->bch_type = bch_type; reg_val = (bch_type & ECC_BCH_LEVEL_MASK) | (ELM_ECC_SIZE << 16); elm_write_reg(info, ELM_LOCATION_CONFIG, reg_val); - info->bch_type = bch_type; return 0; } @@ -152,55 +180,52 @@ static void elm_configure_page_mode(struct elm_info *info, int index, * Load syndrome fragment registers with calculated ecc in reverse order. */ static void elm_load_syndrome(struct elm_info *info, - struct elm_errorvec *err_vec, u8 *ecc) + struct elm_errorvec *err_vec, u8 *ecc_calc) { + struct nand_chip *nand_chip = info->mtd->priv; + unsigned int eccbytes = nand_chip->ecc.bytes; + unsigned int eccsteps = nand_chip->ecc.steps; + u8 *ecc = ecc_calc; int i, offset; u32 val; - for (i = 0; i < ERROR_VECTOR_MAX; i++) { - + for (i = 0; i < eccsteps; i++) { /* Check error reported */ if (err_vec[i].error_reported) { elm_configure_page_mode(info, i, true); - offset = ELM_SYNDROME_FRAGMENT_0 + - SYNDROME_FRAGMENT_REG_SIZE * i; - - /* BCH8 */ - if (info->bch_type) { - - /* syndrome fragment 0 = ecc[9-12B] */ - val = cpu_to_be32(*(u32 *) &ecc[9]); - elm_write_reg(info, offset, val); - - /* syndrome fragment 1 = ecc[5-8B] */ - offset += 4; - val = cpu_to_be32(*(u32 *) &ecc[5]); - elm_write_reg(info, offset, val); - - /* syndrome fragment 2 = ecc[1-4B] */ - offset += 4; - val = cpu_to_be32(*(u32 *) &ecc[1]); - elm_write_reg(info, offset, val); - - /* syndrome fragment 3 = ecc[0B] */ - offset += 4; - val = ecc[0]; - elm_write_reg(info, offset, val); - } else { - /* syndrome fragment 0 = ecc[20-52b] bits */ - val = (cpu_to_be32(*(u32 *) &ecc[3]) >> 4) | - ((ecc[2] & 0xf) << 28); - elm_write_reg(info, offset, val); - - /* syndrome fragment 1 = ecc[0-20b] bits */ - offset += 4; - val = cpu_to_be32(*(u32 *) &ecc[0]) >> 12; - elm_write_reg(info, offset, val); + offset = SYNDROME_FRAGMENT_REG_SIZE * i; + ecc = ecc_calc + (i * eccbytes); + switch (info->bch_type) { + case BCH4_ECC: + val = ((*(ecc + 6) >> 4) & 0x0F) | + *(ecc + 5) << 4 | *(ecc + 4) << 12 | + *(ecc + 3) << 20 | *(ecc + 2) << 28; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_0 + + offset), cpu_to_le32(val)); + val = ((*(ecc + 2) >> 4) & 0x0F) | + *(ecc + 1) << 4 | *(ecc + 0) << 12; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_1 + + offset), cpu_to_le32(val)); + break; + case BCH8_ECC: + val = *(ecc + 12) << 0 | *(ecc + 11) << 8 | + *(ecc + 10) << 16 | *(ecc + 9) << 24; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_0 + + offset), cpu_to_le32(val)); + val = *(ecc + 8) << 0 | *(ecc + 7) << 8 | + *(ecc + 6) << 16 | *(ecc + 5) << 24; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_1 + + offset), cpu_to_le32(val)); + val = *(ecc + 4) << 0 | *(ecc + 3) << 8 | + *(ecc + 2) << 16 | *(ecc + 1) << 24; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_2 + + offset), cpu_to_le32(val)); + val = *(ecc + 0) << 0 & 0x000000FF; + elm_write_reg(info, (ELM_SYNDROME_FRAGMENT_3 + + offset), cpu_to_le32(val)); + break; } } - - /* Update ecc pointer with ecc byte size */ - ecc += info->bch_type ? BCH8_SIZE : BCH4_SIZE; } } @@ -216,6 +241,8 @@ static void elm_load_syndrome(struct elm_info *info, static void elm_start_processing(struct elm_info *info, struct elm_errorvec *err_vec) { + struct nand_chip *nand_chip = info->mtd->priv; + unsigned int eccsteps = nand_chip->ecc.steps; int i, offset; u32 reg_val; @@ -223,7 +250,7 @@ static void elm_start_processing(struct elm_info *info, * Set syndrome vector valid, so that ELM module * will process it for vectors error is reported */ - for (i = 0; i < ERROR_VECTOR_MAX; i++) { + for (i = 0; i < eccsteps; i++) { if (err_vec[i].error_reported) { offset = ELM_SYNDROME_FRAGMENT_6 + SYNDROME_FRAGMENT_REG_SIZE * i; @@ -248,11 +275,13 @@ static void elm_start_processing(struct elm_info *info, static void elm_error_correction(struct elm_info *info, struct elm_errorvec *err_vec) { + struct nand_chip *nand_chip = info->mtd->priv; + unsigned int eccsteps = nand_chip->ecc.steps; int i, j, errors = 0; int offset; u32 reg_val; - for (i = 0; i < ERROR_VECTOR_MAX; i++) { + for (i = 0; i < eccsteps; i++) { /* Check error reported */ if (err_vec[i].error_reported) { @@ -505,7 +534,7 @@ MODULE_DEVICE_TABLE(of, elm_of_match); static struct platform_driver elm_driver = { .driver = { - .name = "elm", + .name = DRIVER_NAME, .owner = THIS_MODULE, .of_match_table = of_match_ptr(elm_of_match), .pm = &elm_pm_ops, diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index f34b99c..37852cda5 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1389,7 +1389,7 @@ static int is_elm_present(struct omap_nand_info *info, } /* ELM module available, now configure it */ info->elm_dev = &pdev->dev; - if (elm_config(info->elm_dev, bch_type)) + if (elm_config(info->elm_dev, &info->mtd, bch_type)) return -ENODEV; return 0; } diff --git a/include/linux/platform_data/elm.h b/include/linux/platform_data/elm.h index bf0a83b..d16465b 100644 --- a/include/linux/platform_data/elm.h +++ b/include/linux/platform_data/elm.h @@ -25,6 +25,7 @@ enum bch_ecc { /* ELM support 8 error syndrome process */ #define ERROR_VECTOR_MAX 8 +#define ELM_MAX_DETECTABLE_ERRORS 16 #define BCH8_ECC_OOB_BYTES 13 #define BCH4_ECC_OOB_BYTES 7 @@ -45,10 +46,11 @@ struct elm_errorvec { bool error_reported; bool error_uncorrectable; int error_count; - int error_loc[ERROR_VECTOR_MAX]; + int error_loc[ELM_MAX_DETECTABLE_ERRORS]; }; void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, struct elm_errorvec *err_vec); -int elm_config(struct device *dev, enum bch_ecc bch_type); +int elm_config(struct device *dev, struct mtd_info *mtd, + enum bch_ecc bch_type); #endif /* __ELM_H */ -- 1.8.1