mtd: nand: Move ELM driver and rename as omap_elm
authorEzequiel García <ezequiel@vanguardiasur.com.ar>
Sat, 20 Sep 2014 16:53:14 +0000 (17:53 +0100)
committerBrian Norris <computersforpeace@gmail.com>
Mon, 22 Sep 2014 18:39:26 +0000 (11:39 -0700)
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 <rogerq@ti.com>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
drivers/mtd/devices/Makefile
drivers/mtd/devices/elm.c [deleted file]
drivers/mtd/nand/Makefile
drivers/mtd/nand/omap_elm.c [new file with mode: 0644]

index c68868f605883cab2d9507179a8fd0f340565ce9..f0b0e611d1d6a564b460af1f68c965906f629223 100644 (file)
@@ -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 (file)
index b4f61c7..0000000
+++ /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 <linux/platform_device.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/of.h>
-#include <linux/sched.h>
-#include <linux/pm_runtime.h>
-#include <linux/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 *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");
index a035e7cc6d46b7978e6b77a3fc7ebf20d9833db5..b3237b742eb5f95f957100401eac818dd98a84ba 100644 (file)
@@ -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 (file)
index 0000000..b4f61c7
--- /dev/null
@@ -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 <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/sched.h>
+#include <linux/pm_runtime.h>
+#include <linux/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 *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");