This adds support for the ELM (Error Location Module) found on not-too-old OMAP SoCs. The driver has been taken from Linux-5.3-rc6 with interrupt support removed. Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> --- drivers/mtd/nand/Kconfig | 10 + drivers/mtd/nand/Makefile | 1 + drivers/mtd/nand/omap_elm.c | 413 ++++++++++++++++++++++++++++++++++++ include/platform_data/elm.h | 53 +++++ 4 files changed, 477 insertions(+) create mode 100644 drivers/mtd/nand/omap_elm.c create mode 100644 include/platform_data/elm.h diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 2b4a478a03..fadfe1f99b 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig @@ -90,6 +90,16 @@ config NAND_OMAP_GPMC Support for NAND flash using GPMC. GPMC is a common memory interface found on Texas Instrument's OMAP platforms +config MTD_NAND_OMAP_ELM + bool "Support for ELM (Error Location Module) on OMAP platforms" + depends on NAND_OMAP_GPMC + help + This config enables the ELM hardware engine, which can be used to + locate and correct errors when using BCH ECC scheme. This offloads + the cpu from doing ECC error searching and correction. However some + legacy OMAP families like OMAP2xxx, OMAP3xxx do not have ELM engine + so this is optional for them. + config NAND_ORION bool prompt "Marvell Orion NAND driver" diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile index 6088512745..a4066ba778 100644 --- a/drivers/mtd/nand/Makefile +++ b/drivers/mtd/nand/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_MTD_NAND_NOMADIK) += nomadik_nand.o obj-$(CONFIG_NAND_IMX) += nand_imx.o obj-$(CONFIG_NAND_IMX_BBM) += nand_imx_bbm.o obj-$(CONFIG_NAND_OMAP_GPMC) += nand_omap_gpmc.o nand_omap_bch_decoder.o +obj-$(CONFIG_MTD_NAND_OMAP_ELM) += omap_elm.o obj-$(CONFIG_NAND_ORION) += nand_orion.o obj-$(CONFIG_NAND_MRVL_NFC) += nand_mrvl_nfc.o obj-$(CONFIG_NAND_ATMEL) += atmel_nand.o diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c new file mode 100644 index 0000000000..583235fc78 --- /dev/null +++ b/drivers/mtd/nand/omap_elm.c @@ -0,0 +1,413 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Error Location Module + * + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ + */ + +#define DRIVER_NAME "omap-elm" + +#include <common.h> +#include <driver.h> +#include <init.h> +#include <platform_data/elm.h> + +#define ELM_SYSCONFIG 0x010 +#define ELM_IRQSTATUS 0x018 +#define ELM_IRQENABLE 0x01c +#define ELM_LOCATION_CONFIG 0x020 +#define ELM_PAGE_CTRL 0x080 +#define ELM_SYNDROME_FRAGMENT_0 0x400 +#define ELM_SYNDROME_FRAGMENT_1 0x404 +#define ELM_SYNDROME_FRAGMENT_2 0x408 +#define ELM_SYNDROME_FRAGMENT_3 0x40c +#define ELM_SYNDROME_FRAGMENT_4 0x410 +#define ELM_SYNDROME_FRAGMENT_5 0x414 +#define ELM_SYNDROME_FRAGMENT_6 0x418 +#define ELM_LOCATION_STATUS 0x800 +#define ELM_ERROR_LOCATION_0 0x880 + +/* ELM Interrupt Status Register */ +#define INTR_STATUS_PAGE_VALID BIT(8) + +/* ELM Interrupt Enable Register */ +#define INTR_EN_PAGE_MASK BIT(8) + +/* ELM Location Configuration Register */ +#define ECC_BCH_LEVEL_MASK 0x3 + +/* ELM syndrome */ +#define ELM_SYNDROME_VALID BIT(16) + +/* ELM_LOCATION_STATUS Register */ +#define ECC_CORRECTABLE_MASK BIT(8) +#define ECC_NB_ERRORS_MASK 0x1f + +/* ELM_ERROR_LOCATION_0-15 Registers */ +#define ECC_ERROR_LOCATION_MASK 0x1fff + +#define ELM_ECC_SIZE 0x7ff + +#define SYNDROME_FRAGMENT_REG_SIZE 0x40 +#define ERROR_LOCATION_SIZE 0x100 + +struct elm_registers { + u32 elm_irqenable; + u32 elm_sysconfig; + u32 elm_location_config; + u32 elm_page_ctrl; + u32 elm_syndrome_fragment_6[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_5[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_4[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_3[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_2[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_1[ERROR_VECTOR_MAX]; + u32 elm_syndrome_fragment_0[ERROR_VECTOR_MAX]; +}; + +struct elm_info { + struct device_d *dev; + void __iomem *elm_base; + struct list_head list; + enum bch_ecc bch_type; + struct elm_registers elm_regs; + int ecc_steps; + int ecc_syndrome_size; +}; + +static struct elm_info *ginfo; + +static void elm_write_reg(struct elm_info *info, int offset, u32 val) +{ + writel(val, info->elm_base + offset); +} + +static u32 elm_read_reg(struct elm_info *info, int offset) +{ + return readl(info->elm_base + offset); +} + +/** + * elm_config - Configure ELM module + * @dev: ELM device + * @bch_type: Type of BCH ecc + */ +int elm_config(enum bch_ecc bch_type, int ecc_steps, int ecc_step_size, + int ecc_syndrome_size) +{ + struct elm_info *info = ginfo; + u32 reg_val; + + if (!info) + return -ENODEV; + /* ELM cannot detect ECC errors for chunks > 1KB */ + if (ecc_step_size > ((ELM_ECC_SIZE + 1) / 2)) { + dev_err(info->dev, "unsupported config ecc-size=%d\n", ecc_step_size); + return -EINVAL; + } + /* ELM support 8 error syndrome process */ + if (ecc_steps > ERROR_VECTOR_MAX) { + dev_err(info->dev, "unsupported config ecc-step=%d\n", ecc_steps); + return -EINVAL; + } + + 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; + info->ecc_steps = ecc_steps; + info->ecc_syndrome_size = ecc_syndrome_size; + + return 0; +} + +/** + * elm_configure_page_mode - Enable/Disable page mode + * @info: elm info + * @index: index number of syndrome fragment vector + * @enable: enable/disable flag for page mode + * + * Enable page mode for syndrome fragment index + */ +static void elm_configure_page_mode(struct elm_info *info, int index, + bool enable) +{ + u32 reg_val; + + reg_val = elm_read_reg(info, ELM_PAGE_CTRL); + if (enable) + reg_val |= BIT(index); /* enable page mode */ + else + reg_val &= ~BIT(index); /* disable page mode */ + + elm_write_reg(info, ELM_PAGE_CTRL, reg_val); +} + +/** + * elm_load_syndrome - Load ELM syndrome reg + * @info: elm info + * @err_vec: elm error vectors + * @ecc: buffer with calculated ecc + * + * 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) +{ + int i, offset; + u32 val; + + for (i = 0; i < info->ecc_steps; 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; + switch (info->bch_type) { + case BCH8_ECC: + /* 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); + break; + case BCH4_ECC: + /* 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); + break; + case BCH16_ECC: + val = cpu_to_be32(*(u32 *) &ecc[22]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[18]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[14]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[10]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[6]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[2]); + elm_write_reg(info, offset, val); + offset += 4; + val = cpu_to_be32(*(u32 *) &ecc[0]) >> 16; + elm_write_reg(info, offset, val); + break; + default: + pr_err("invalid config bch_type\n"); + } + } + + /* Update ecc pointer with ecc byte size */ + ecc += info->ecc_syndrome_size; + } +} + +/** + * elm_start_processing - start elm syndrome processing + * @info: elm info + * @err_vec: elm error vectors + * + * Set syndrome valid bit for syndrome fragment registers for which + * elm syndrome fragment registers are loaded. This enables elm module + * to start processing syndrome vectors. + */ +static void elm_start_processing(struct elm_info *info, + struct elm_errorvec *err_vec) +{ + int i, offset; + u32 reg_val; + + /* + * Set syndrome vector valid, so that ELM module + * will process it for vectors error is reported + */ + for (i = 0; i < info->ecc_steps; i++) { + if (err_vec[i].error_reported) { + offset = ELM_SYNDROME_FRAGMENT_6 + + SYNDROME_FRAGMENT_REG_SIZE * i; + reg_val = elm_read_reg(info, offset); + reg_val |= ELM_SYNDROME_VALID; + elm_write_reg(info, offset, reg_val); + } + } +} + +/** + * elm_error_correction - locate correctable error position + * @info: elm info + * @err_vec: elm error vectors + * + * On completion of processing by elm module, error location status + * register updated with correctable/uncorrectable error information. + * In case of correctable errors, number of errors located from + * elm location status register & read the positions from + * elm error location register. + */ +static void elm_error_correction(struct elm_info *info, + struct elm_errorvec *err_vec) +{ + int i, j, errors = 0; + int offset; + u32 reg_val; + + for (i = 0; i < info->ecc_steps; i++) { + + /* Check error reported */ + if (err_vec[i].error_reported) { + offset = ELM_LOCATION_STATUS + ERROR_LOCATION_SIZE * i; + reg_val = elm_read_reg(info, offset); + + /* Check correctable error or not */ + if (reg_val & ECC_CORRECTABLE_MASK) { + offset = ELM_ERROR_LOCATION_0 + + ERROR_LOCATION_SIZE * i; + + /* Read count of correctable errors */ + err_vec[i].error_count = reg_val & + ECC_NB_ERRORS_MASK; + + /* Update the error locations in error vector */ + for (j = 0; j < err_vec[i].error_count; j++) { + + reg_val = elm_read_reg(info, offset); + err_vec[i].error_loc[j] = reg_val & + ECC_ERROR_LOCATION_MASK; + + /* Update error location register */ + offset += 4; + } + + errors += err_vec[i].error_count; + } else { + err_vec[i].error_uncorrectable = true; + } + + /* Clearing interrupts for processed error vectors */ + elm_write_reg(info, ELM_IRQSTATUS, BIT(i)); + + /* Disable page mode */ + elm_configure_page_mode(info, i, false); + } + } +} + +static int elm_poll(struct elm_info *info) +{ + u32 reg_val; + + reg_val = elm_read_reg(info, ELM_IRQSTATUS); + + /* All error vectors processed */ + if (reg_val & INTR_STATUS_PAGE_VALID) { + elm_write_reg(info, ELM_IRQSTATUS, + reg_val & INTR_STATUS_PAGE_VALID); + return 0; + } + + return -EINPROGRESS; +} + +/** + * elm_decode_bch_error_page - Locate error position + * @dev: device pointer + * @ecc_calc: calculated ECC bytes from GPMC + * @err_vec: elm error vectors + * + * Called with one or more error reported vectors & vectors with + * error reported is updated in err_vec[].error_reported + */ +int elm_decode_bch_error_page(u8 *ecc_calc, struct elm_errorvec *err_vec) +{ + struct elm_info *info = ginfo; + u32 reg_val; + uint64_t start; + + if (!info) + return -ENODEV; + + /* Enable page mode interrupt */ + reg_val = elm_read_reg(info, ELM_IRQSTATUS); + elm_write_reg(info, ELM_IRQSTATUS, reg_val & INTR_STATUS_PAGE_VALID); + elm_write_reg(info, ELM_IRQENABLE, INTR_EN_PAGE_MASK); + + /* Load valid ecc byte to syndrome fragment register */ + elm_load_syndrome(info, err_vec, ecc_calc); + + /* Enable syndrome processing for which syndrome fragment is updated */ + elm_start_processing(info, err_vec); + + /* Wait for ELM module to finish locating error correction */ + start = get_time_ns(); + while (elm_poll(info) < 0) { + if (is_timeout(start, SECOND)) + return -ETIMEDOUT; + } + + /* Disable page mode interrupt */ + reg_val = elm_read_reg(info, ELM_IRQENABLE); + elm_write_reg(info, ELM_IRQENABLE, reg_val & ~INTR_EN_PAGE_MASK); + elm_error_correction(info, err_vec); + + return 0; +} + +static int elm_probe(struct device_d *dev) +{ + struct resource *res; + struct elm_info *info; + + info = xzalloc(sizeof(*info)); + + info->dev = dev; + + res = dev_request_mem_resource(dev, 0); + if (IS_ERR(res)) + return PTR_ERR(res); + info->elm_base = IOMEM(res->start); + + dev->priv = info; + + ginfo = info; + + return 0; +} + +static struct of_device_id elm_compatible[] = { + { + .compatible = "ti,am3352-elm", + }, { + /* sentinel */ + } +}; + +static struct driver_d omap_elm_driver = { + .name = "omap-elm", + .probe = elm_probe, + .of_compatible = DRV_OF_COMPAT(elm_compatible) +}; +coredevice_platform_driver(omap_elm_driver); diff --git a/include/platform_data/elm.h b/include/platform_data/elm.h new file mode 100644 index 0000000000..bc5d2edb1d --- /dev/null +++ b/include/platform_data/elm.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * BCH Error Location Module + * + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ + */ + +#ifndef __ELM_H +#define __ELM_H + +enum bch_ecc { + BCH4_ECC = 0, + BCH8_ECC, + BCH16_ECC, +}; + +/* ELM support 8 error syndrome process */ +#define ERROR_VECTOR_MAX 8 + +/** + * struct elm_errorvec - error vector for elm + * @error_reported: set true for vectors error is reported + * @error_uncorrectable: number of uncorrectable errors + * @error_count: number of correctable errors in the sector + * @error_loc: buffer for error location + * + */ +struct elm_errorvec { + bool error_reported; + bool error_uncorrectable; + int error_count; + int error_loc[16]; +}; + +#if IS_ENABLED(CONFIG_MTD_NAND_OMAP_ELM) +int elm_decode_bch_error_page(u8 *ecc_calc, struct elm_errorvec *err_vec); +int elm_config(enum bch_ecc bch_type, int ecc_steps, int ecc_step_size, + int ecc_syndrome_size); +#else +static inline int +elm_decode_bch_error_page(u8 *ecc_calc, struct elm_errorvec *err_vec) +{ + return -ENODEV; +} + +static inline int elm_config(enum bch_ecc bch_type, int ecc_steps, + int ecc_step_size, int ecc_syndrome_size) +{ + return -ENOSYS; +} +#endif /* CONFIG_MTD_NAND_OMAP_ELM */ + +#endif /* __ELM_H */ -- 2.23.0 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
