// SPDX-License-Identifier: GPL-2.0

/*
 * EDAC driver for DMC-520 memory controller.
 *
 * The driver supports 10 interrupt lines,
 * though only dram_ecc_errc and dram_ecc_errd are currently handled.
 *
 * Authors:     Rui Zhao <ruizhao@microsoft.com>
 *              Lei Wang <lewan@microsoft.com>
 *              Shiping Ji <shji@microsoft.com>
 */

#include <linux/bitfield.h>
#include <linux/edac.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "edac_mc.h"

/* DMC-520 registers */
#define REG_OFFSET_FEATURE_CONFIG                       0x130
#define REG_OFFSET_ECC_ERRC_COUNT_31_00         0x158
#define REG_OFFSET_ECC_ERRC_COUNT_63_32         0x15C
#define REG_OFFSET_ECC_ERRD_COUNT_31_00         0x160
#define REG_OFFSET_ECC_ERRD_COUNT_63_32         0x164
#define REG_OFFSET_INTERRUPT_CONTROL                    0x500
#define REG_OFFSET_INTERRUPT_CLR                        0x508
#define REG_OFFSET_INTERRUPT_STATUS                     0x510
#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 0x528
#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 0x52C
#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00 0x530
#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32 0x534
#define REG_OFFSET_ADDRESS_CONTROL_NOW                  0x1010
#define REG_OFFSET_MEMORY_TYPE_NOW                      0x1128
#define REG_OFFSET_SCRUB_CONTROL0_NOW                   0x1170
#define REG_OFFSET_FORMAT_CONTROL                       0x18

/* DMC-520 types, masks and bitfields */
#define RAM_ECC_INT_CE_BIT                      BIT(0)
#define RAM_ECC_INT_UE_BIT                      BIT(1)
#define DRAM_ECC_INT_CE_BIT                     BIT(2)
#define DRAM_ECC_INT_UE_BIT                     BIT(3)
#define FAILED_ACCESS_INT_BIT                   BIT(4)
#define FAILED_PROG_INT_BIT                     BIT(5)
#define LINK_ERR_INT_BIT                        BIT(6)
#define TEMPERATURE_EVENT_INT_BIT               BIT(7)
#define ARCH_FSM_INT_BIT                        BIT(8)
#define PHY_REQUEST_INT_BIT                     BIT(9)
#define MEMORY_WIDTH_MASK                       GENMASK(1, 0)
#define SCRUB_TRIGGER0_NEXT_MASK                GENMASK(1, 0)
#define REG_FIELD_DRAM_ECC_ENABLED              GENMASK(1, 0)
#define REG_FIELD_MEMORY_TYPE                   GENMASK(2, 0)
#define REG_FIELD_DEVICE_WIDTH                  GENMASK(9, 8)
#define REG_FIELD_ADDRESS_CONTROL_COL           GENMASK(2,  0)
#define REG_FIELD_ADDRESS_CONTROL_ROW           GENMASK(10, 8)
#define REG_FIELD_ADDRESS_CONTROL_BANK          GENMASK(18, 16)
#define REG_FIELD_ADDRESS_CONTROL_RANK          GENMASK(25, 24)
#define REG_FIELD_ERR_INFO_LOW_VALID            BIT(0)
#define REG_FIELD_ERR_INFO_LOW_COL              GENMASK(10, 1)
#define REG_FIELD_ERR_INFO_LOW_ROW              GENMASK(28, 11)
#define REG_FIELD_ERR_INFO_LOW_RANK             GENMASK(31, 29)
#define REG_FIELD_ERR_INFO_HIGH_BANK            GENMASK(3, 0)
#define REG_FIELD_ERR_INFO_HIGH_VALID           BIT(31)

#define DRAM_ADDRESS_CONTROL_MIN_COL_BITS       8
#define DRAM_ADDRESS_CONTROL_MIN_ROW_BITS       11

#define DMC520_SCRUB_TRIGGER_ERR_DETECT 2
#define DMC520_SCRUB_TRIGGER_IDLE               3

/* Driver settings */
/*
 * The max-length message would be: "rank:7 bank:15 row:262143 col:1023".
 * Max length is 34. Using a 40-size buffer is enough.
 */
#define DMC520_MSG_BUF_SIZE                     40
#define EDAC_MOD_NAME                           "dmc520-edac"
#define EDAC_CTL_NAME                           "dmc520"

/* the data bus width for the attached memory chips. */
enum dmc520_mem_width {
        MEM_WIDTH_X32 = 2,
        MEM_WIDTH_X64 = 3
};

/* memory type */
enum dmc520_mem_type {
        MEM_TYPE_DDR3 = 1,
        MEM_TYPE_DDR4 = 2
};

/* memory device width */
enum dmc520_dev_width {
        DEV_WIDTH_X4 = 0,
        DEV_WIDTH_X8 = 1,
        DEV_WIDTH_X16 = 2
};

struct ecc_error_info {
        u32 col;
        u32 row;
        u32 bank;
        u32 rank;
};

/* The interrupt config */
struct dmc520_irq_config {
        char *name;
        int mask;
};

/* The interrupt mappings */
static struct dmc520_irq_config dmc520_irq_configs[] = {
        {
                .name = "ram_ecc_errc",
                .mask = RAM_ECC_INT_CE_BIT
        },
        {
                .name = "ram_ecc_errd",
                .mask = RAM_ECC_INT_UE_BIT
        },
        {
                .name = "dram_ecc_errc",
                .mask = DRAM_ECC_INT_CE_BIT
        },
        {
                .name = "dram_ecc_errd",
                .mask = DRAM_ECC_INT_UE_BIT
        },
        {
                .name = "failed_access",
                .mask = FAILED_ACCESS_INT_BIT
        },
        {
                .name = "failed_prog",
                .mask = FAILED_PROG_INT_BIT
        },
        {
                .name = "link_err",
                .mask = LINK_ERR_INT_BIT
        },
        {
                .name = "temperature_event",
                .mask = TEMPERATURE_EVENT_INT_BIT
        },
        {
                .name = "arch_fsm",
                .mask = ARCH_FSM_INT_BIT
        },
        {
                .name = "phy_request",
                .mask = PHY_REQUEST_INT_BIT
        }
};

#define NUMBER_OF_IRQS                          ARRAY_SIZE(dmc520_irq_configs)

/*
 * The EDAC driver private data.
 * error_lock is to protect concurrent writes to the mci->error_desc through
 * edac_mc_handle_error().
 */
struct dmc520_edac {
        void __iomem *reg_base;
        spinlock_t error_lock;
        u32 mem_width_in_bytes;
        int irqs[NUMBER_OF_IRQS];
        int masks[NUMBER_OF_IRQS];
};

static int dmc520_mc_idx;

static u32 dmc520_read_reg(struct dmc520_edac *pvt, u32 offset)
{
        return readl(pvt->reg_base + offset);
}

static void dmc520_write_reg(struct dmc520_edac *pvt, u32 val, u32 offset)
{
        writel(val, pvt->reg_base + offset);
}

static u32 dmc520_calc_dram_ecc_error(u32 value)
{
        u32 total = 0;

        /* Each rank's error counter takes one byte. */
        while (value > 0) {
                total += (value & 0xFF);
                value >>= 8;
        }
        return total;
}

static u32 dmc520_get_dram_ecc_error_count(struct dmc520_edac *pvt,
                                            bool is_ce)
{
        u32 reg_offset_low, reg_offset_high;
        u32 err_low, err_high;
        u32 err_count;

        reg_offset_low = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_31_00 :
                                 REG_OFFSET_ECC_ERRD_COUNT_31_00;
        reg_offset_high = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_63_32 :
                                  REG_OFFSET_ECC_ERRD_COUNT_63_32;

        err_low = dmc520_read_reg(pvt, reg_offset_low);
        err_high = dmc520_read_reg(pvt, reg_offset_high);
        /* Reset error counters */
        dmc520_write_reg(pvt, 0, reg_offset_low);
        dmc520_write_reg(pvt, 0, reg_offset_high);

        err_count = dmc520_calc_dram_ecc_error(err_low) +
                   dmc520_calc_dram_ecc_error(err_high);

        return err_count;
}

static void dmc520_get_dram_ecc_error_info(struct dmc520_edac *pvt,
                                            bool is_ce,
                                            struct ecc_error_info *info)
{
        u32 reg_offset_low, reg_offset_high;
        u32 reg_val_low, reg_val_high;
        bool valid;

        reg_offset_low = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 :
                                 REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00;
        reg_offset_high = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 :
                                  REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32;

        reg_val_low = dmc520_read_reg(pvt, reg_offset_low);
        reg_val_high = dmc520_read_reg(pvt, reg_offset_high);

        valid = (FIELD_GET(REG_FIELD_ERR_INFO_LOW_VALID, reg_val_low) != 0) &&
                (FIELD_GET(REG_FIELD_ERR_INFO_HIGH_VALID, reg_val_high) != 0);

        if (valid) {
                info->col = FIELD_GET(REG_FIELD_ERR_INFO_LOW_COL, reg_val_low);
                info->row = FIELD_GET(REG_FIELD_ERR_INFO_LOW_ROW, reg_val_low);
                info->rank = FIELD_GET(REG_FIELD_ERR_INFO_LOW_RANK, reg_val_low);
                info->bank = FIELD_GET(REG_FIELD_ERR_INFO_HIGH_BANK, reg_val_high);
        } else {
                memset(info, 0, sizeof(*info));
        }
}

static bool dmc520_is_ecc_enabled(void __iomem *reg_base)
{
        u32 reg_val = readl(reg_base + REG_OFFSET_FEATURE_CONFIG);

        return FIELD_GET(REG_FIELD_DRAM_ECC_ENABLED, reg_val);
}

static enum scrub_type dmc520_get_scrub_type(struct dmc520_edac *pvt)
{
        enum scrub_type type = SCRUB_NONE;
        u32 reg_val, scrub_cfg;

        reg_val = dmc520_read_reg(pvt, REG_OFFSET_SCRUB_CONTROL0_NOW);
        scrub_cfg = FIELD_GET(SCRUB_TRIGGER0_NEXT_MASK, reg_val);

        if (scrub_cfg == DMC520_SCRUB_TRIGGER_ERR_DETECT ||
            scrub_cfg == DMC520_SCRUB_TRIGGER_IDLE)
                type = SCRUB_HW_PROG;

        return type;
}

/* Get the memory data bus width, in number of bytes. */
static u32 dmc520_get_memory_width(struct dmc520_edac *pvt)
{
        enum dmc520_mem_width mem_width_field;
        u32 mem_width_in_bytes = 0;
        u32 reg_val;

        reg_val = dmc520_read_reg(pvt, REG_OFFSET_FORMAT_CONTROL);
        mem_width_field = FIELD_GET(MEMORY_WIDTH_MASK, reg_val);

        if (mem_width_field == MEM_WIDTH_X32)
                mem_width_in_bytes = 4;
        else if (mem_width_field == MEM_WIDTH_X64)
                mem_width_in_bytes = 8;
        return mem_width_in_bytes;
}

static enum mem_type dmc520_get_mtype(struct dmc520_edac *pvt)
{
        enum mem_type mt = MEM_UNKNOWN;
        enum dmc520_mem_type type;
        u32 reg_val;

        reg_val = dmc520_read_reg(pvt, REG_OFFSET_MEMORY_TYPE_NOW);
        type = FIELD_GET(REG_FIELD_MEMORY_TYPE, reg_val);

        switch (type) {
        case MEM_TYPE_DDR3:
                mt = MEM_DDR3;
                break;

        case MEM_TYPE_DDR4:
                mt = MEM_DDR4;
                break;
        }

        return mt;
}

static enum dev_type dmc520_get_dtype(struct dmc520_edac *pvt)
{
        enum dmc520_dev_width device_width;
        enum dev_type dt = DEV_UNKNOWN;
        u32 reg_val;

        reg_val = dmc520_read_reg(pvt, REG_OFFSET_MEMORY_TYPE_NOW);
        device_width = FIELD_GET(REG_FIELD_DEVICE_WIDTH, reg_val);

        switch (device_width) {
        case DEV_WIDTH_X4:
                dt = DEV_X4;
                break;

        case DEV_WIDTH_X8:
                dt = DEV_X8;
                break;

        case DEV_WIDTH_X16:
                dt = DEV_X16;
                break;
        }

        return dt;
}

static u32 dmc520_get_rank_count(void __iomem *reg_base)
{
        u32 reg_val, rank_bits;

        reg_val = readl(reg_base + REG_OFFSET_ADDRESS_CONTROL_NOW);
        rank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_RANK, reg_val);

        return BIT(rank_bits);
}

static u64 dmc520_get_rank_size(struct dmc520_edac *pvt)
{
        u32 reg_val, col_bits, row_bits, bank_bits;

        reg_val = dmc520_read_reg(pvt, REG_OFFSET_ADDRESS_CONTROL_NOW);

        col_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_COL, reg_val) +
                   DRAM_ADDRESS_CONTROL_MIN_COL_BITS;
        row_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_ROW, reg_val) +
                   DRAM_ADDRESS_CONTROL_MIN_ROW_BITS;
        bank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_BANK, reg_val);

        return (u64)pvt->mem_width_in_bytes << (col_bits + row_bits + bank_bits);
}

static void dmc520_handle_dram_ecc_errors(struct mem_ctl_info *mci,
                                           bool is_ce)
{
        struct dmc520_edac *pvt = mci->pvt_info;
        char message[DMC520_MSG_BUF_SIZE];
        struct ecc_error_info info;
        u32 cnt;

        dmc520_get_dram_ecc_error_info(pvt, is_ce, &info);

        cnt = dmc520_get_dram_ecc_error_count(pvt, is_ce);
        if (!cnt)
                return;

        snprintf(message, ARRAY_SIZE(message),
                 "rank:%d bank:%d row:%d col:%d",
                 info.rank, info.bank,
                 info.row, info.col);

        spin_lock(&pvt->error_lock);
        edac_mc_handle_error((is_ce ? HW_EVENT_ERR_CORRECTED :
                             HW_EVENT_ERR_UNCORRECTED),
                             mci, cnt, 0, 0, 0, info.rank, -1, -1,
                             message, "");
        spin_unlock(&pvt->error_lock);
}

static irqreturn_t dmc520_edac_dram_ecc_isr(int irq, struct mem_ctl_info *mci,
                                             bool is_ce)
{
        struct dmc520_edac *pvt = mci->pvt_info;
        u32 i_mask;

        i_mask = is_ce ? DRAM_ECC_INT_CE_BIT : DRAM_ECC_INT_UE_BIT;

        dmc520_handle_dram_ecc_errors(mci, is_ce);

        dmc520_write_reg(pvt, i_mask, REG_OFFSET_INTERRUPT_CLR);

        return IRQ_HANDLED;
}

static irqreturn_t dmc520_edac_dram_all_isr(int irq, struct mem_ctl_info *mci,
                                             u32 irq_mask)
{
        struct dmc520_edac *pvt = mci->pvt_info;
        irqreturn_t irq_ret = IRQ_NONE;
        u32 status;

        status = dmc520_read_reg(pvt, REG_OFFSET_INTERRUPT_STATUS);

        if ((irq_mask & DRAM_ECC_INT_CE_BIT) &&
                (status & DRAM_ECC_INT_CE_BIT))
                irq_ret = dmc520_edac_dram_ecc_isr(irq, mci, true);

        if ((irq_mask & DRAM_ECC_INT_UE_BIT) &&
                (status & DRAM_ECC_INT_UE_BIT))
                irq_ret = dmc520_edac_dram_ecc_isr(irq, mci, false);

        return irq_ret;
}

static irqreturn_t dmc520_isr(int irq, void *data)
{
        struct mem_ctl_info *mci = data;
        struct dmc520_edac *pvt = mci->pvt_info;
        u32 mask = 0;
        int idx;

        for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
                if (pvt->irqs[idx] == irq) {
                        mask = pvt->masks[idx];
                        break;
                }
        }
        return dmc520_edac_dram_all_isr(irq, mci, mask);
}

static void dmc520_init_csrow(struct mem_ctl_info *mci)
{
        struct dmc520_edac *pvt = mci->pvt_info;
        struct csrow_info *csi;
        struct dimm_info *dimm;
        u32 pages_per_rank;
        enum dev_type dt;
        enum mem_type mt;
        int row, ch;
        u64 rs;

        dt = dmc520_get_dtype(pvt);
        mt = dmc520_get_mtype(pvt);
        rs = dmc520_get_rank_size(pvt);
        pages_per_rank = rs >> PAGE_SHIFT;

        for (row = 0; row < mci->nr_csrows; row++) {
                csi = mci->csrows[row];

                for (ch = 0; ch < csi->nr_channels; ch++) {
                        dimm            = csi->channels[ch]->dimm;
                        dimm->grain     = pvt->mem_width_in_bytes;
                        dimm->dtype     = dt;
                        dimm->mtype     = mt;
                        dimm->edac_mode = EDAC_SECDED;
                        dimm->nr_pages  = pages_per_rank / csi->nr_channels;
                }
        }
}

static int dmc520_edac_probe(struct platform_device *pdev)
{
        bool registered[NUMBER_OF_IRQS] = { false };
        int irqs[NUMBER_OF_IRQS] = { -ENXIO };
        int masks[NUMBER_OF_IRQS] = { 0 };
        struct edac_mc_layer layers[1];
        struct dmc520_edac *pvt = NULL;
        struct mem_ctl_info *mci;
        void __iomem *reg_base;
        u32 irq_mask_all = 0;
        struct device *dev;
        int ret, idx, irq;
        u32 reg_val;

        /* Parse the device node */
        dev = &pdev->dev;

        for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
                irq = platform_get_irq_byname_optional(pdev, dmc520_irq_configs[idx].name);
                irqs[idx] = irq;
                masks[idx] = dmc520_irq_configs[idx].mask;
                if (irq >= 0) {
                        irq_mask_all |= dmc520_irq_configs[idx].mask;
                        edac_dbg(0, "Discovered %s, irq: %d.\n", dmc520_irq_configs[idx].name, irq);
                }
        }

        if (!irq_mask_all) {
                edac_printk(KERN_ERR, EDAC_MOD_NAME,
                            "At least one valid interrupt line is expected.\n");
                return -EINVAL;
        }

        /* Initialize dmc520 edac */
        reg_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(reg_base))
                return PTR_ERR(reg_base);

        if (!dmc520_is_ecc_enabled(reg_base))
                return -ENXIO;

        layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
        layers[0].size = dmc520_get_rank_count(reg_base);
        layers[0].is_virt_csrow = true;

        mci = edac_mc_alloc(dmc520_mc_idx++, ARRAY_SIZE(layers), layers, sizeof(*pvt));
        if (!mci) {
                edac_printk(KERN_ERR, EDAC_MOD_NAME,
                            "Failed to allocate memory for mc instance\n");
                ret = -ENOMEM;
                goto err;
        }

        pvt = mci->pvt_info;

        pvt->reg_base = reg_base;
        spin_lock_init(&pvt->error_lock);
        memcpy(pvt->irqs, irqs, sizeof(irqs));
        memcpy(pvt->masks, masks, sizeof(masks));

        platform_set_drvdata(pdev, mci);

        mci->pdev = dev;
        mci->mtype_cap          = MEM_FLAG_DDR3 | MEM_FLAG_DDR4;
        mci->edac_ctl_cap       = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
        mci->edac_cap           = EDAC_FLAG_SECDED;
        mci->scrub_cap          = SCRUB_FLAG_HW_SRC;
        mci->scrub_mode         = dmc520_get_scrub_type(pvt);
        mci->ctl_name           = EDAC_CTL_NAME;
        mci->dev_name           = dev_name(mci->pdev);
        mci->mod_name           = EDAC_MOD_NAME;

        edac_op_state = EDAC_OPSTATE_INT;

        pvt->mem_width_in_bytes = dmc520_get_memory_width(pvt);

        dmc520_init_csrow(mci);

        /* Clear interrupts, not affecting other unrelated interrupts */
        reg_val = dmc520_read_reg(pvt, REG_OFFSET_INTERRUPT_CONTROL);
        dmc520_write_reg(pvt, reg_val & (~irq_mask_all),
                         REG_OFFSET_INTERRUPT_CONTROL);
        dmc520_write_reg(pvt, irq_mask_all, REG_OFFSET_INTERRUPT_CLR);

        for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
                irq = irqs[idx];
                if (irq >= 0) {
                        ret = devm_request_irq(&pdev->dev, irq,
                                               dmc520_isr, IRQF_SHARED,
                                               dev_name(&pdev->dev), mci);
                        if (ret < 0) {
                                edac_printk(KERN_ERR, EDAC_MC,
                                            "Failed to request irq %d\n", irq);
                                goto err;
                        }
                        registered[idx] = true;
                }
        }

        /* Reset DRAM CE/UE counters */
        if (irq_mask_all & DRAM_ECC_INT_CE_BIT)
                dmc520_get_dram_ecc_error_count(pvt, true);

        if (irq_mask_all & DRAM_ECC_INT_UE_BIT)
                dmc520_get_dram_ecc_error_count(pvt, false);

        ret = edac_mc_add_mc(mci);
        if (ret) {
                edac_printk(KERN_ERR, EDAC_MOD_NAME,
                            "Failed to register with EDAC core\n");
                goto err;
        }

        /* Enable interrupts, not affecting other unrelated interrupts */
        dmc520_write_reg(pvt, reg_val | irq_mask_all,
                         REG_OFFSET_INTERRUPT_CONTROL);

        return 0;

err:
        for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
                if (registered[idx])
                        devm_free_irq(&pdev->dev, pvt->irqs[idx], mci);
        }
        if (mci)
                edac_mc_free(mci);

        return ret;
}

static void dmc520_edac_remove(struct platform_device *pdev)
{
        u32 reg_val, idx, irq_mask_all = 0;
        struct mem_ctl_info *mci;
        struct dmc520_edac *pvt;

        mci = platform_get_drvdata(pdev);
        pvt = mci->pvt_info;

        /* Disable interrupts */
        reg_val = dmc520_read_reg(pvt, REG_OFFSET_INTERRUPT_CONTROL);
        dmc520_write_reg(pvt, reg_val & (~irq_mask_all),
                         REG_OFFSET_INTERRUPT_CONTROL);

        /* free irq's */
        for (idx = 0; idx < NUMBER_OF_IRQS; idx++) {
                if (pvt->irqs[idx] >= 0) {
                        irq_mask_all |= pvt->masks[idx];
                        devm_free_irq(&pdev->dev, pvt->irqs[idx], mci);
                }
        }

        edac_mc_del_mc(&pdev->dev);
        edac_mc_free(mci);
}

static const struct of_device_id dmc520_edac_driver_id[] = {
        { .compatible = "arm,dmc-520", },
        { /* end of table */ }
};

MODULE_DEVICE_TABLE(of, dmc520_edac_driver_id);

static struct platform_driver dmc520_edac_driver = {
        .driver = {
                .name = "dmc520",
                .of_match_table = dmc520_edac_driver_id,
        },

        .probe = dmc520_edac_probe,
        .remove = dmc520_edac_remove
};

module_platform_driver(dmc520_edac_driver);

MODULE_AUTHOR("Rui Zhao <ruizhao@microsoft.com>");
MODULE_AUTHOR("Lei Wang <lewan@microsoft.com>");
MODULE_AUTHOR("Shiping Ji <shji@microsoft.com>");
MODULE_DESCRIPTION("DMC-520 ECC driver");
MODULE_LICENSE("GPL v2");