From: Ezequiel García Date: Sat, 20 Sep 2014 16:53:14 +0000 (+0100) Subject: mtd: nand: Move ELM driver and rename as omap_elm X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6d178ef2fd5e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git mtd: nand: Move ELM driver and rename as omap_elm The ELM driver is only used by the OMAP NAND driver, so let's move it to the nand/ directory. Additionally, let's rename it to a less confusing name, so the module is built with a meaningful name, instead of the previous 'elm.ko'. Acked-by: Roger Quadros Signed-off-by: Ezequiel Garcia Signed-off-by: Brian Norris --- diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile index c68868f60588..f0b0e611d1d6 100644 --- a/drivers/mtd/devices/Makefile +++ b/drivers/mtd/devices/Makefile @@ -12,7 +12,6 @@ obj-$(CONFIG_MTD_LART) += lart.o obj-$(CONFIG_MTD_BLOCK2MTD) += block2mtd.o obj-$(CONFIG_MTD_DATAFLASH) += mtd_dataflash.o obj-$(CONFIG_MTD_M25P80) += m25p80.o -obj-$(CONFIG_MTD_NAND_OMAP_BCH) += elm.o obj-$(CONFIG_MTD_SPEAR_SMI) += spear_smi.o obj-$(CONFIG_MTD_SST25L) += sst25l.o obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o diff --git a/drivers/mtd/devices/elm.c b/drivers/mtd/devices/elm.c deleted file mode 100644 index b4f61c7fc161..000000000000 --- a/drivers/mtd/devices/elm.c +++ /dev/null @@ -1,579 +0,0 @@ -/* - * Error Location Module - * - * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - */ - -#define DRIVER_NAME "omap-elm" - -#include -#include -#include -#include -#include -#include -#include -#include - -#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 *dev; - void __iomem *elm_base; - struct completion elm_completion; - struct list_head list; - enum bch_ecc bch_type; - struct elm_registers elm_regs; - int ecc_steps; - int ecc_syndrome_size; -}; - -static LIST_HEAD(elm_devices); - -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(struct device *dev, enum bch_ecc bch_type, - int ecc_steps, int ecc_step_size, int ecc_syndrome_size) -{ - u32 reg_val; - struct elm_info *info = dev_get_drvdata(dev); - - if (!info) { - dev_err(dev, "Unable to configure elm - device not probed?\n"); - return -ENODEV; - } - /* ELM cannot detect ECC errors for chunks > 1KB */ - if (ecc_step_size > ((ELM_ECC_SIZE + 1) / 2)) { - dev_err(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(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; -} -EXPORT_SYMBOL(elm_config); - -/** - * 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); - } - } -} - -/** - * 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 - */ -void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, - struct elm_errorvec *err_vec) -{ - struct elm_info *info = dev_get_drvdata(dev); - u32 reg_val; - - /* 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 */ - wait_for_completion(&info->elm_completion); - - /* 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); -} -EXPORT_SYMBOL(elm_decode_bch_error_page); - -static irqreturn_t elm_isr(int this_irq, void *dev_id) -{ - u32 reg_val; - struct elm_info *info = dev_id; - - 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); - complete(&info->elm_completion); - return IRQ_HANDLED; - } - - return IRQ_NONE; -} - -static int elm_probe(struct platform_device *pdev) -{ - int ret = 0; - struct resource *res, *irq; - struct elm_info *info; - - info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); - if (!info) - return -ENOMEM; - - info->dev = &pdev->dev; - - irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); - if (!irq) { - dev_err(&pdev->dev, "no irq resource defined\n"); - return -ENODEV; - } - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - info->elm_base = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(info->elm_base)) - return PTR_ERR(info->elm_base); - - ret = devm_request_irq(&pdev->dev, irq->start, elm_isr, 0, - pdev->name, info); - if (ret) { - dev_err(&pdev->dev, "failure requesting irq %i\n", irq->start); - return ret; - } - - pm_runtime_enable(&pdev->dev); - if (pm_runtime_get_sync(&pdev->dev) < 0) { - ret = -EINVAL; - pm_runtime_disable(&pdev->dev); - dev_err(&pdev->dev, "can't enable clock\n"); - return ret; - } - - init_completion(&info->elm_completion); - INIT_LIST_HEAD(&info->list); - list_add(&info->list, &elm_devices); - platform_set_drvdata(pdev, info); - return ret; -} - -static int elm_remove(struct platform_device *pdev) -{ - pm_runtime_put_sync(&pdev->dev); - pm_runtime_disable(&pdev->dev); - return 0; -} - -#ifdef CONFIG_PM_SLEEP -/** - * elm_context_save - * saves ELM configurations to preserve them across Hardware powered-down - */ -static int elm_context_save(struct elm_info *info) -{ - struct elm_registers *regs = &info->elm_regs; - enum bch_ecc bch_type = info->bch_type; - u32 offset = 0, i; - - regs->elm_irqenable = elm_read_reg(info, ELM_IRQENABLE); - regs->elm_sysconfig = elm_read_reg(info, ELM_SYSCONFIG); - regs->elm_location_config = elm_read_reg(info, ELM_LOCATION_CONFIG); - regs->elm_page_ctrl = elm_read_reg(info, ELM_PAGE_CTRL); - for (i = 0; i < ERROR_VECTOR_MAX; i++) { - offset = i * SYNDROME_FRAGMENT_REG_SIZE; - switch (bch_type) { - case BCH16_ECC: - regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_6 + offset); - regs->elm_syndrome_fragment_5[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_5 + offset); - regs->elm_syndrome_fragment_4[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_4 + offset); - case BCH8_ECC: - regs->elm_syndrome_fragment_3[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_3 + offset); - regs->elm_syndrome_fragment_2[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_2 + offset); - case BCH4_ECC: - regs->elm_syndrome_fragment_1[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_1 + offset); - regs->elm_syndrome_fragment_0[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_0 + offset); - break; - default: - return -EINVAL; - } - /* ELM SYNDROME_VALID bit in SYNDROME_FRAGMENT_6[] needs - * to be saved for all BCH schemes*/ - regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, - ELM_SYNDROME_FRAGMENT_6 + offset); - } - return 0; -} - -/** - * elm_context_restore - * writes configurations saved duing power-down back into ELM registers - */ -static int elm_context_restore(struct elm_info *info) -{ - struct elm_registers *regs = &info->elm_regs; - enum bch_ecc bch_type = info->bch_type; - u32 offset = 0, i; - - elm_write_reg(info, ELM_IRQENABLE, regs->elm_irqenable); - elm_write_reg(info, ELM_SYSCONFIG, regs->elm_sysconfig); - elm_write_reg(info, ELM_LOCATION_CONFIG, regs->elm_location_config); - elm_write_reg(info, ELM_PAGE_CTRL, regs->elm_page_ctrl); - for (i = 0; i < ERROR_VECTOR_MAX; i++) { - offset = i * SYNDROME_FRAGMENT_REG_SIZE; - switch (bch_type) { - case BCH16_ECC: - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, - regs->elm_syndrome_fragment_6[i]); - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_5 + offset, - regs->elm_syndrome_fragment_5[i]); - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_4 + offset, - regs->elm_syndrome_fragment_4[i]); - case BCH8_ECC: - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_3 + offset, - regs->elm_syndrome_fragment_3[i]); - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_2 + offset, - regs->elm_syndrome_fragment_2[i]); - case BCH4_ECC: - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_1 + offset, - regs->elm_syndrome_fragment_1[i]); - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_0 + offset, - regs->elm_syndrome_fragment_0[i]); - break; - default: - return -EINVAL; - } - /* ELM_SYNDROME_VALID bit to be set in last to trigger FSM */ - elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, - regs->elm_syndrome_fragment_6[i] & - ELM_SYNDROME_VALID); - } - return 0; -} - -static int elm_suspend(struct device *dev) -{ - struct elm_info *info = dev_get_drvdata(dev); - elm_context_save(info); - pm_runtime_put_sync(dev); - return 0; -} - -static int elm_resume(struct device *dev) -{ - struct elm_info *info = dev_get_drvdata(dev); - pm_runtime_get_sync(dev); - elm_context_restore(info); - return 0; -} -#endif - -static SIMPLE_DEV_PM_OPS(elm_pm_ops, elm_suspend, elm_resume); - -#ifdef CONFIG_OF -static const struct of_device_id elm_of_match[] = { - { .compatible = "ti,am3352-elm" }, - {}, -}; -MODULE_DEVICE_TABLE(of, elm_of_match); -#endif - -static struct platform_driver elm_driver = { - .driver = { - .name = DRIVER_NAME, - .owner = THIS_MODULE, - .of_match_table = of_match_ptr(elm_of_match), - .pm = &elm_pm_ops, - }, - .probe = elm_probe, - .remove = elm_remove, -}; - -module_platform_driver(elm_driver); - -MODULE_DESCRIPTION("ELM driver for BCH error correction"); -MODULE_AUTHOR("Texas Instruments"); -MODULE_ALIAS("platform: elm"); -MODULE_LICENSE("GPL v2"); diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile index a035e7cc6d46..b3237b742eb5 100644 --- a/drivers/mtd/nand/Makefile +++ b/drivers/mtd/nand/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_MTD_NAND_NDFC) += ndfc.o obj-$(CONFIG_MTD_NAND_ATMEL) += atmel_nand.o obj-$(CONFIG_MTD_NAND_GPIO) += gpio.o obj-$(CONFIG_MTD_NAND_OMAP2) += omap2.o +obj-$(CONFIG_MTD_NAND_OMAP_BCH) += omap_elm.o obj-$(CONFIG_MTD_NAND_CM_X270) += cmx270_nand.o obj-$(CONFIG_MTD_NAND_PXA3xx) += pxa3xx_nand.o obj-$(CONFIG_MTD_NAND_TMIO) += tmio_nand.o diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c new file mode 100644 index 000000000000..b4f61c7fc161 --- /dev/null +++ b/drivers/mtd/nand/omap_elm.c @@ -0,0 +1,579 @@ +/* + * Error Location Module + * + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#define DRIVER_NAME "omap-elm" + +#include +#include +#include +#include +#include +#include +#include +#include + +#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 *dev; + void __iomem *elm_base; + struct completion elm_completion; + struct list_head list; + enum bch_ecc bch_type; + struct elm_registers elm_regs; + int ecc_steps; + int ecc_syndrome_size; +}; + +static LIST_HEAD(elm_devices); + +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(struct device *dev, enum bch_ecc bch_type, + int ecc_steps, int ecc_step_size, int ecc_syndrome_size) +{ + u32 reg_val; + struct elm_info *info = dev_get_drvdata(dev); + + if (!info) { + dev_err(dev, "Unable to configure elm - device not probed?\n"); + return -ENODEV; + } + /* ELM cannot detect ECC errors for chunks > 1KB */ + if (ecc_step_size > ((ELM_ECC_SIZE + 1) / 2)) { + dev_err(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(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; +} +EXPORT_SYMBOL(elm_config); + +/** + * 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); + } + } +} + +/** + * 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 + */ +void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc, + struct elm_errorvec *err_vec) +{ + struct elm_info *info = dev_get_drvdata(dev); + u32 reg_val; + + /* 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 */ + wait_for_completion(&info->elm_completion); + + /* 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); +} +EXPORT_SYMBOL(elm_decode_bch_error_page); + +static irqreturn_t elm_isr(int this_irq, void *dev_id) +{ + u32 reg_val; + struct elm_info *info = dev_id; + + 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); + complete(&info->elm_completion); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int elm_probe(struct platform_device *pdev) +{ + int ret = 0; + struct resource *res, *irq; + struct elm_info *info; + + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->dev = &pdev->dev; + + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!irq) { + dev_err(&pdev->dev, "no irq resource defined\n"); + return -ENODEV; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + info->elm_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(info->elm_base)) + return PTR_ERR(info->elm_base); + + ret = devm_request_irq(&pdev->dev, irq->start, elm_isr, 0, + pdev->name, info); + if (ret) { + dev_err(&pdev->dev, "failure requesting irq %i\n", irq->start); + return ret; + } + + pm_runtime_enable(&pdev->dev); + if (pm_runtime_get_sync(&pdev->dev) < 0) { + ret = -EINVAL; + pm_runtime_disable(&pdev->dev); + dev_err(&pdev->dev, "can't enable clock\n"); + return ret; + } + + init_completion(&info->elm_completion); + INIT_LIST_HEAD(&info->list); + list_add(&info->list, &elm_devices); + platform_set_drvdata(pdev, info); + return ret; +} + +static int elm_remove(struct platform_device *pdev) +{ + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +/** + * elm_context_save + * saves ELM configurations to preserve them across Hardware powered-down + */ +static int elm_context_save(struct elm_info *info) +{ + struct elm_registers *regs = &info->elm_regs; + enum bch_ecc bch_type = info->bch_type; + u32 offset = 0, i; + + regs->elm_irqenable = elm_read_reg(info, ELM_IRQENABLE); + regs->elm_sysconfig = elm_read_reg(info, ELM_SYSCONFIG); + regs->elm_location_config = elm_read_reg(info, ELM_LOCATION_CONFIG); + regs->elm_page_ctrl = elm_read_reg(info, ELM_PAGE_CTRL); + for (i = 0; i < ERROR_VECTOR_MAX; i++) { + offset = i * SYNDROME_FRAGMENT_REG_SIZE; + switch (bch_type) { + case BCH16_ECC: + regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_6 + offset); + regs->elm_syndrome_fragment_5[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_5 + offset); + regs->elm_syndrome_fragment_4[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_4 + offset); + case BCH8_ECC: + regs->elm_syndrome_fragment_3[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_3 + offset); + regs->elm_syndrome_fragment_2[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_2 + offset); + case BCH4_ECC: + regs->elm_syndrome_fragment_1[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_1 + offset); + regs->elm_syndrome_fragment_0[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_0 + offset); + break; + default: + return -EINVAL; + } + /* ELM SYNDROME_VALID bit in SYNDROME_FRAGMENT_6[] needs + * to be saved for all BCH schemes*/ + regs->elm_syndrome_fragment_6[i] = elm_read_reg(info, + ELM_SYNDROME_FRAGMENT_6 + offset); + } + return 0; +} + +/** + * elm_context_restore + * writes configurations saved duing power-down back into ELM registers + */ +static int elm_context_restore(struct elm_info *info) +{ + struct elm_registers *regs = &info->elm_regs; + enum bch_ecc bch_type = info->bch_type; + u32 offset = 0, i; + + elm_write_reg(info, ELM_IRQENABLE, regs->elm_irqenable); + elm_write_reg(info, ELM_SYSCONFIG, regs->elm_sysconfig); + elm_write_reg(info, ELM_LOCATION_CONFIG, regs->elm_location_config); + elm_write_reg(info, ELM_PAGE_CTRL, regs->elm_page_ctrl); + for (i = 0; i < ERROR_VECTOR_MAX; i++) { + offset = i * SYNDROME_FRAGMENT_REG_SIZE; + switch (bch_type) { + case BCH16_ECC: + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, + regs->elm_syndrome_fragment_6[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_5 + offset, + regs->elm_syndrome_fragment_5[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_4 + offset, + regs->elm_syndrome_fragment_4[i]); + case BCH8_ECC: + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_3 + offset, + regs->elm_syndrome_fragment_3[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_2 + offset, + regs->elm_syndrome_fragment_2[i]); + case BCH4_ECC: + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_1 + offset, + regs->elm_syndrome_fragment_1[i]); + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_0 + offset, + regs->elm_syndrome_fragment_0[i]); + break; + default: + return -EINVAL; + } + /* ELM_SYNDROME_VALID bit to be set in last to trigger FSM */ + elm_write_reg(info, ELM_SYNDROME_FRAGMENT_6 + offset, + regs->elm_syndrome_fragment_6[i] & + ELM_SYNDROME_VALID); + } + return 0; +} + +static int elm_suspend(struct device *dev) +{ + struct elm_info *info = dev_get_drvdata(dev); + elm_context_save(info); + pm_runtime_put_sync(dev); + return 0; +} + +static int elm_resume(struct device *dev) +{ + struct elm_info *info = dev_get_drvdata(dev); + pm_runtime_get_sync(dev); + elm_context_restore(info); + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(elm_pm_ops, elm_suspend, elm_resume); + +#ifdef CONFIG_OF +static const struct of_device_id elm_of_match[] = { + { .compatible = "ti,am3352-elm" }, + {}, +}; +MODULE_DEVICE_TABLE(of, elm_of_match); +#endif + +static struct platform_driver elm_driver = { + .driver = { + .name = DRIVER_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(elm_of_match), + .pm = &elm_pm_ops, + }, + .probe = elm_probe, + .remove = elm_remove, +}; + +module_platform_driver(elm_driver); + +MODULE_DESCRIPTION("ELM driver for BCH error correction"); +MODULE_AUTHOR("Texas Instruments"); +MODULE_ALIAS("platform: elm"); +MODULE_LICENSE("GPL v2");