edac: add support for Calxeda highbank memory controller

Add support for memory controller on Calxeda Highbank platforms. Highbank
platforms support a single 4GB mini-DIMM with 1-bit correction and 2-bit
detection.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 274 insertions, 1 deletions

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 3b3f84ff351f..f7efa8b282f1 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -7,7 +7,7 @@
 menuconfig EDAC
         bool "EDAC (Error Detection And Correction) reporting"
         depends on HAS_IOMEM
-        depends on X86 || PPC || TILE
+        depends on X86 || PPC || TILE || ARM
         help
           EDAC is designed to report errors in the core system.
           These are low-level errors that are reported in the CPU or
@@ -302,4 +302,11 @@ config EDAC_TILE
           Support for error detection and correction on the
           Tilera memory controller.
 
+config EDAC_HIGHBANK_MC
+        tristate "Highbank Memory Controller"
+        depends on EDAC_MM_EDAC && ARCH_HIGHBANK
+        help
+          Support for error detection and correction on the
+          Calxeda Highbank memory controller.
+
 endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 196a63dd37c5..44f2044d4079 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -55,3 +55,5 @@ obj-$(CONFIG_EDAC_AMD8111)		+= amd8111_edac.o
 obj-$(CONFIG_EDAC_AMD8131)              += amd8131_edac.o
 
 obj-$(CONFIG_EDAC_TILE)                 += tile_edac.o
+
+obj-$(CONFIG_EDAC_HIGHBANK_MC)  += highbank_mc_edac.o
diff --git a/drivers/edac/highbank_mc_edac.c b/drivers/edac/highbank_mc_edac.c
new file mode 100644
index 000000000000..c769f477fd22
--- /dev/null
+++ b/drivers/edac/highbank_mc_edac.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright 2011-2012 Calxeda, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/edac.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/uaccess.h>
+
+#include "edac_core.h"
+#include "edac_module.h"
+
+/* DDR Ctrlr Error Registers */
+#define HB_DDR_ECC_OPT                  0x128
+#define HB_DDR_ECC_U_ERR_ADDR           0x130
+#define HB_DDR_ECC_U_ERR_STAT           0x134
+#define HB_DDR_ECC_U_ERR_DATAL          0x138
+#define HB_DDR_ECC_U_ERR_DATAH          0x13c
+#define HB_DDR_ECC_C_ERR_ADDR           0x140
+#define HB_DDR_ECC_C_ERR_STAT           0x144
+#define HB_DDR_ECC_C_ERR_DATAL          0x148
+#define HB_DDR_ECC_C_ERR_DATAH          0x14c
+#define HB_DDR_ECC_INT_STATUS           0x180
+#define HB_DDR_ECC_INT_ACK              0x184
+#define HB_DDR_ECC_U_ERR_ID             0x424
+#define HB_DDR_ECC_C_ERR_ID             0x428
+
+#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
+
+#define HB_DDR_ECC_OPT_MODE_MASK        0x3
+#define HB_DDR_ECC_OPT_FWC              0x100
+#define HB_DDR_ECC_OPT_XOR_SHIFT        16
+
+struct hb_mc_drvdata {
+        void __iomem *mc_vbase;
+};
+
+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_vbase + HB_DDR_ECC_INT_STATUS);
+
+        if (status & HB_DDR_ECC_INT_STAT_UE) {
+                err_addr = readl(drvdata->mc_vbase + 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_vbase + HB_DDR_ECC_C_ERR_STAT);
+                syndrome = (syndrome >> 8) & 0xff;
+                err_addr = readl(drvdata->mc_vbase + 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_vbase + HB_DDR_ECC_INT_ACK);
+        return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_EDAC_DEBUG
+static ssize_t highbank_mc_err_inject_write(struct file *file,
+                                      const char __user *data,
+                                      size_t count, loff_t *ppos)
+{
+        struct mem_ctl_info *mci = file->private_data;
+        struct hb_mc_drvdata *pdata = mci->pvt_info;
+        char buf[32];
+        size_t buf_size;
+        u32 reg;
+        u8 synd;
+
+        buf_size = min(count, (sizeof(buf)-1));
+        if (copy_from_user(buf, data, buf_size))
+                return -EFAULT;
+        buf[buf_size] = 0;
+
+        if (!kstrtou8(buf, 16, &synd)) {
+                reg = readl(pdata->mc_vbase + 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_vbase + HB_DDR_ECC_OPT);
+        }
+
+        return count;
+}
+
+static int debugfs_open(struct inode *inode, struct file *file)
+{
+        file->private_data = inode->i_private;
+        return 0;
+}
+
+static const struct file_operations highbank_mc_debug_inject_fops = {
+        .open = debugfs_open,
+        .write = highbank_mc_err_inject_write,
+        .llseek = generic_file_llseek,
+};
+
+static void __devinit highbank_mc_create_debugfs_nodes(struct mem_ctl_info *mci)
+{
+        if (mci->debugfs)
+                debugfs_create_file("inject_ctrl", S_IWUSR, mci->debugfs, mci,
+                                    &highbank_mc_debug_inject_fops);
+;
+}
+#else
+static void __devinit highbank_mc_create_debugfs_nodes(struct mem_ctl_info *mci)
+{}
+#endif
+
+static int __devinit highbank_mc_probe(struct platform_device *pdev)
+{
+        struct edac_mc_layer layers[2];
+        struct mem_ctl_info *mci;
+        struct hb_mc_drvdata *drvdata;
+        struct dimm_info *dimm;
+        struct resource *r;
+        u32 control;
+        int irq;
+        int res = 0;
+
+        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))
+                return -ENOMEM;
+
+        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;
+        }
+
+        drvdata->mc_vbase = devm_ioremap(&pdev->dev,
+                                          r->start, resource_size(r));
+        if (!drvdata->mc_vbase) {
+                dev_err(&pdev->dev, "Unable to map regs\n");
+                res = -ENOMEM;
+                goto err;
+        }
+
+        control = readl(drvdata->mc_vbase + HB_DDR_ECC_OPT) & 0x3;
+        if (!control || (control == 0x2)) {
+                dev_err(&pdev->dev, "No ECC present, or ECC disabled\n");
+                res = -ENODEV;
+                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 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 = dev_name(&pdev->dev);
+        mci->mod_ver = "1";
+        mci->ctl_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(mci);
+        if (res < 0)
+                goto err;
+
+        highbank_mc_create_debugfs_nodes(mci);
+
+        devres_close_group(&pdev->dev, NULL);
+        return 0;
+err:
+        devres_release_group(&pdev->dev, NULL);
+        edac_mc_free(mci);
+        return res;
+}
+
+static int 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);
+        return 0;
+}
+
+static const struct of_device_id hb_ddr_ctrl_of_match[] = {
+        { .compatible = "calxeda,hb-ddr-ctrl", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, hb_ddr_ctrl_of_match);
+
+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");