root/drivers/edac/highbank_mc_edac.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2011-2012 Calxeda, Inc.
 */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/edac.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>

#include "edac_module.h"

/* DDR Ctrlr Error Registers */

#define HB_DDR_ECC_ERR_BASE             0x128
#define MW_DDR_ECC_ERR_BASE             0x1b4

#define HB_DDR_ECC_OPT                  0x00
#define HB_DDR_ECC_U_ERR_ADDR           0x08
#define HB_DDR_ECC_U_ERR_STAT           0x0c
#define HB_DDR_ECC_U_ERR_DATAL          0x10
#define HB_DDR_ECC_U_ERR_DATAH          0x14
#define HB_DDR_ECC_C_ERR_ADDR           0x18
#define HB_DDR_ECC_C_ERR_STAT           0x1c
#define HB_DDR_ECC_C_ERR_DATAL          0x20
#define HB_DDR_ECC_C_ERR_DATAH          0x24

#define HB_DDR_ECC_OPT_MODE_MASK        0x3
#define HB_DDR_ECC_OPT_FWC              0x100
#define HB_DDR_ECC_OPT_XOR_SHIFT        16

/* DDR Ctrlr Interrupt Registers */

#define HB_DDR_ECC_INT_BASE             0x180
#define MW_DDR_ECC_INT_BASE             0x218

#define HB_DDR_ECC_INT_STATUS           0x00
#define HB_DDR_ECC_INT_ACK              0x04

#define HB_DDR_ECC_INT_STAT_CE          0x8
#define HB_DDR_ECC_INT_STAT_DOUBLE_CE   0x10
#define HB_DDR_ECC_INT_STAT_UE          0x20
#define HB_DDR_ECC_INT_STAT_DOUBLE_UE   0x40

struct hb_mc_drvdata {
        void __iomem *mc_err_base;
        void __iomem *mc_int_base;
};

static irqreturn_t highbank_mc_err_handler(int irq, void *dev_id)
{
        struct mem_ctl_info *mci = dev_id;
        struct hb_mc_drvdata *drvdata = mci->pvt_info;
        u32 status, err_addr;

        /* Read the interrupt status register */
        status = readl(drvdata->mc_int_base + HB_DDR_ECC_INT_STATUS);

        if (status & HB_DDR_ECC_INT_STAT_UE) {
                err_addr = readl(drvdata->mc_err_base + HB_DDR_ECC_U_ERR_ADDR);
                edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
                                     err_addr >> PAGE_SHIFT,
                                     err_addr & ~PAGE_MASK, 0,
                                     0, 0, -1,
                                     mci->ctl_name, "");
        }
        if (status & HB_DDR_ECC_INT_STAT_CE) {
                u32 syndrome = readl(drvdata->mc_err_base + HB_DDR_ECC_C_ERR_STAT);
                syndrome = (syndrome >> 8) & 0xff;
                err_addr = readl(drvdata->mc_err_base + HB_DDR_ECC_C_ERR_ADDR);
                edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
                                     err_addr >> PAGE_SHIFT,
                                     err_addr & ~PAGE_MASK, syndrome,
                                     0, 0, -1,
                                     mci->ctl_name, "");
        }

        /* clear the error, clears the interrupt */
        writel(status, drvdata->mc_int_base + HB_DDR_ECC_INT_ACK);
        return IRQ_HANDLED;
}

static void highbank_mc_err_inject(struct mem_ctl_info *mci, u8 synd)
{
        struct hb_mc_drvdata *pdata = mci->pvt_info;
        u32 reg;

        reg = readl(pdata->mc_err_base + HB_DDR_ECC_OPT);
        reg &= HB_DDR_ECC_OPT_MODE_MASK;
        reg |= (synd << HB_DDR_ECC_OPT_XOR_SHIFT) | HB_DDR_ECC_OPT_FWC;
        writel(reg, pdata->mc_err_base + HB_DDR_ECC_OPT);
}

#define to_mci(k) container_of(k, struct mem_ctl_info, dev)

static ssize_t highbank_mc_inject_ctrl(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
        struct mem_ctl_info *mci = to_mci(dev);
        u8 synd;

        if (kstrtou8(buf, 16, &synd))
                return -EINVAL;

        highbank_mc_err_inject(mci, synd);

        return count;
}

static DEVICE_ATTR(inject_ctrl, S_IWUSR, NULL, highbank_mc_inject_ctrl);

static struct attribute *highbank_dev_attrs[] = {
        &dev_attr_inject_ctrl.attr,
        NULL
};

ATTRIBUTE_GROUPS(highbank_dev);

struct hb_mc_settings {
        int     err_offset;
        int     int_offset;
};

static struct hb_mc_settings hb_settings = {
        .err_offset = HB_DDR_ECC_ERR_BASE,
        .int_offset = HB_DDR_ECC_INT_BASE,
};

static struct hb_mc_settings mw_settings = {
        .err_offset = MW_DDR_ECC_ERR_BASE,
        .int_offset = MW_DDR_ECC_INT_BASE,
};

static const struct of_device_id hb_ddr_ctrl_of_match[] = {
        { .compatible = "calxeda,hb-ddr-ctrl",          .data = &hb_settings },
        { .compatible = "calxeda,ecx-2000-ddr-ctrl",    .data = &mw_settings },
        {},
};
MODULE_DEVICE_TABLE(of, hb_ddr_ctrl_of_match);

static int highbank_mc_probe(struct platform_device *pdev)
{
        const struct of_device_id *id;
        const struct hb_mc_settings *settings;
        struct edac_mc_layer layers[2];
        struct mem_ctl_info *mci;
        struct hb_mc_drvdata *drvdata;
        struct dimm_info *dimm;
        struct resource *r;
        void __iomem *base;
        u32 control;
        int irq;
        int res = 0;

        id = of_match_device(hb_ddr_ctrl_of_match, &pdev->dev);
        if (!id)
                return -ENODEV;

        layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
        layers[0].size = 1;
        layers[0].is_virt_csrow = true;
        layers[1].type = EDAC_MC_LAYER_CHANNEL;
        layers[1].size = 1;
        layers[1].is_virt_csrow = false;
        mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
                            sizeof(struct hb_mc_drvdata));
        if (!mci)
                return -ENOMEM;

        mci->pdev = &pdev->dev;
        drvdata = mci->pvt_info;
        platform_set_drvdata(pdev, mci);

        if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
                res = -ENOMEM;
                goto free;
        }

        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!r) {
                dev_err(&pdev->dev, "Unable to get mem resource\n");
                res = -ENODEV;
                goto err;
        }

        if (!devm_request_mem_region(&pdev->dev, r->start,
                                     resource_size(r), dev_name(&pdev->dev))) {
                dev_err(&pdev->dev, "Error while requesting mem region\n");
                res = -EBUSY;
                goto err;
        }

        base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
        if (!base) {
                dev_err(&pdev->dev, "Unable to map regs\n");
                res = -ENOMEM;
                goto err;
        }

        settings = id->data;
        drvdata->mc_err_base = base + settings->err_offset;
        drvdata->mc_int_base = base + settings->int_offset;

        control = readl(drvdata->mc_err_base + HB_DDR_ECC_OPT) & 0x3;
        if (!control || (control == 0x2)) {
                dev_err(&pdev->dev, "No ECC present, or ECC disabled\n");
                res = -ENODEV;
                goto err;
        }

        mci->mtype_cap = MEM_FLAG_DDR3;
        mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
        mci->edac_cap = EDAC_FLAG_SECDED;
        mci->mod_name = pdev->dev.driver->name;
        mci->ctl_name = id->compatible;
        mci->dev_name = dev_name(&pdev->dev);
        mci->scrub_mode = SCRUB_SW_SRC;

        /* Only a single 4GB DIMM is supported */
        dimm = *mci->dimms;
        dimm->nr_pages = (~0UL >> PAGE_SHIFT) + 1;
        dimm->grain = 8;
        dimm->dtype = DEV_X8;
        dimm->mtype = MEM_DDR3;
        dimm->edac_mode = EDAC_SECDED;

        res = edac_mc_add_mc_with_groups(mci, highbank_dev_groups);
        if (res < 0)
                goto err;

        irq = platform_get_irq(pdev, 0);
        res = devm_request_irq(&pdev->dev, irq, highbank_mc_err_handler,
                               0, dev_name(&pdev->dev), mci);
        if (res < 0) {
                dev_err(&pdev->dev, "Unable to request irq %d\n", irq);
                goto err2;
        }

        devres_close_group(&pdev->dev, NULL);
        return 0;
err2:
        edac_mc_del_mc(&pdev->dev);
err:
        devres_release_group(&pdev->dev, NULL);
free:
        edac_mc_free(mci);
        return res;
}

static void highbank_mc_remove(struct platform_device *pdev)
{
        struct mem_ctl_info *mci = platform_get_drvdata(pdev);

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

static struct platform_driver highbank_mc_edac_driver = {
        .probe = highbank_mc_probe,
        .remove = highbank_mc_remove,
        .driver = {
                .name = "hb_mc_edac",
                .of_match_table = hb_ddr_ctrl_of_match,
        },
};

module_platform_driver(highbank_mc_edac_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Calxeda, Inc.");
MODULE_DESCRIPTION("EDAC Driver for Calxeda Highbank");