[PATCH v3 0/2] Add EDAC support for Cadence ddr controller

[PATCH v3 0/2] Add EDAC support for Cadence ddr controller

[Dhananjay Kangude]

These patches add new edac driver for Cadence ddr memory controller.
Cadence controller detects single(CE) and double(UE) bit errors during
memory operations(RMW). DDR controller raised the interrupt on detection
of the ecc error event and fill the data into registers. Driver handle
the interrupt event and notify edac subsystem about ecc errors.

Changes since v3:
=================
- Corrected YAML file location

Changes since v2:
=================
- Added minor fixes to YAML file
- Split ISR into two differnt functions
- Removed unused paramters
- Fixed indentation issues
- Improved code readabilty
- Checked return value for edac_get_dimm
- Modified quirks as a ip_features

Changes since v1:
=================
- Made predefined arrays as static
 Fixes: 201447a5db9b ("EDAC/Cadence:Add EDAC driver for cadence memory controller")
- Replace macro 'EDAC_DIMM_PTR' with newly introduce function
- Removed unused variable root

Dhananjay Kangude (2):
  dt-bindings: edac: Add cadence ddr mc support
  EDAC/Cadence:Add EDAC driver for cadence memory controller

 .../devicetree/bindings/edac/cdns,ddr-edac.yaml    |   47 ++
 drivers/edac/Kconfig                               |    8 +
 drivers/edac/cadence_edac.c                        |  641 ++++++++++++++++++++
 3 files changed, 696 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
 create mode 100644 drivers/edac/cadence_edac.c

[PATCH v3 1/2] dt-bindings: edac: Add cadence ddr mc support

[Dhananjay Kangude]

Add documentation for cadence ddr memory controller EDAC DTS bindings

Signed-off-by: Dhananjay Kangude <dkangude@cadence.com>
---
 .../devicetree/bindings/edac/cdns,ddr-edac.yaml    |   47 ++++++++++++++++++++
 1 files changed, 47 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml

diff --git a/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
new file mode 100644
index 0000000..30ea757
--- /dev/null
+++ b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/edac/cdns,ddr-edac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cadence DDR IP with ECC support (EDAC)
+
+description:
+  This binding describes the Cadence DDR/LPDDR IP with ECC feature enabled
+  to detect and correct CE/UE errors.
+
+maintainers:
+  - Dhananjay Kangdue <dkangude@cadence.com>
+
+properties:
+  compatible:
+    enum:
+      - cdns,ddr4-mc
+
+  reg:
+    minItems: 1
+    maxItems: 2
+    items:
+      - description:
+          Register block of DDR/LPDDR apb registers up to mapped area.
+          Mapped area contains the register set for memory controller,
+          phy and PI module register set doesn't part of this mapping.
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    edac: edac@fd100000 {
+        compatible = "cdns,ddr4-mc-edac";
+        reg = <0xfd100000 0x4000>;
+        interrupts = <0x00 0x01 0x04>;
+    };
+...
-- 
1.7.1

[PATCH v3 2/2] EDAC/Cadence:Add EDAC driver for cadence memory controller

[Dhananjay Kangude]

Added edac platform driver for Cadence DDR controller which
notify the ecc events based on the single or double bit errors
during memory operations.

Signed-off-by: Dhananjay Kangude <dkangude@cadence.com>
---
 drivers/edac/Kconfig        |    8 +
 drivers/edac/cadence_edac.c |  641 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 649 insertions(+), 0 deletions(-)
 create mode 100644 drivers/edac/cadence_edac.c

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index fe2eb89..d5bb399 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -530,4 +530,12 @@ config EDAC_DMC520
 	  Support for error detection and correction on the
 	  SoCs with ARM DMC-520 DRAM controller.
 
+config EDAC_CADENCE
+	tristate "Candence DDR Memory Controller ECC"
+	depends on ARM
+	help
+	  Support for error detection and correction on the Cadence DDR
+	  memory controller. The driver reports correctable and uncorrectable
+	  memory errors.
+
 endif # EDAC
diff --git a/drivers/edac/cadence_edac.c b/drivers/edac/cadence_edac.c
new file mode 100644
index 0000000..3aecc9a
--- /dev/null
+++ b/drivers/edac/cadence_edac.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence DDR4-ECC EDAC Driver.
+ *
+ * Copyright (C) 2019-2020 Cadence Design Systems.
+ *
+ * Authors: Dhananjay Kangude <dkangude@cadence.com>,
+ */
+
+#include <linux/init.h>
+#include <linux/edac.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+#include "edac_module.h"
+
+#define CDNS_EDAC_MOD_NAME "cadence-edac"
+#define FORCED_ECC_ERR_EVENT_SUPPORT	BIT(1)
+
+/* Granularity of reported error in bytes */
+#define CDNS_EDAC_ERR_GRAIN		1
+
+#define MEM_TYPE_DDR4			0xA
+/* CDNS DDR4 Controller Registers */
+#define DDR_CTL_MEM_TYPE_REG		0x000
+#define DDR_CTL_MEM_WIDTH_REG		0x00c
+#define DDR_CTL_CONTROLLER_BUSY		0x2f0
+
+/* ECC Controller Registers */
+#define ECC_CTL_CONTROL_0_REG		0x254
+#define ECC_CTL_CONTROL_1_REG		0x258
+
+#define ECC_CTL_SCRUB_CONTROL_0		0x280
+#define ECC_CTL_SCRUB_CONTROL_1		0x284
+#define ECC_CTL_SCRUB_CONTROL_2		0x288
+#define ECC_CTL_SCRUB_START_ADDR_L	0x28c
+#define ECC_CTL_SCRUB_START_ADDR_H	0x290
+#define ECC_CTL_SCRUB_END_ADDR_L	0x294
+#define ECC_CTL_SCRUB_END_ADDR_H	0x298
+
+#define ECC_SIG_ECC_C_ADDR_L		0x26c
+#define ECC_SIG_ECC_C_ADDR_H		0x270
+#define ECC_SIG_ECC_C_DATA_L		0x274
+#define ECC_SIG_ECC_C_DATA_H		0x278
+#define ECC_SIG_ECC_C_ID		0x27c
+#define ECC_SIG_ECC_C_SYND		0x270
+#define ECC_SIG_ECC_U_ADDR_L		0x25c
+#define ECC_SIG_ECC_U_ADDR_H		0x25c
+#define ECC_SIG_ECC_U_DATA_L		0x264
+#define ECC_SIG_ECC_U_DATA_H		0x268
+#define ECC_SIG_ECC_U_ID		0x27c
+#define ECC_SIG_ECC_U_SYND		0x260
+
+#define ECC_CTL_INT_STATUS		0x310
+#define ECC_CTL_INT_ACK			0x330
+#define ECC_CTL_INT_MASK		0x350
+
+/* ECC Scrub Macros */
+#define ECC_SCRUB_IN_PROGRESS		BIT(8)
+#define ECC_SCRUB_MODE			BIT(0)
+#define ECC_SCRUB_START			BIT(0)
+#define ECC_SCRUB_LEN_SHIFT		(16)
+#define ECC_SCRUB_IDLE_CNT		GENMASK(15, 0)
+#define ECC_SCRUB_LEN			GENMASK(27, 16)
+#define ECC_CTL_SCRUB_ADDR_L_MASK	GENMASK(31, 0)
+#define ECC_CTL_SCRUB_ADDR_H_MASK	GENMASK(1, 0)
+
+/* Control register width definitions */
+#define WDTH_16				(2)
+#define WDTH_32				(1)
+#define WDTH_64				(0)
+#define CTL_REG_WIDTH_SHIFT		(32)
+#define USER_WORD_SPLIT_WIDTH		(8)
+#define CTL_CONTROLLER_BUSY_FLAG	BIT(16)
+#define CTL_MEM_MAX_WIDTH_MASK		GENMASK(4, 0)
+
+/* ECC Control Macros */
+#define ECC_CTL_FORCE_WC		BIT(16)
+#define ECC_CTL_AUTO_CURRUPT_DISABLE	BIT(16)
+#define ECC_CTL_AUTO_WRITEBACK_EN	BIT(24)
+#define ECC_CTL_ECC_ENABLE		GENMASK(9, 8)
+#define ECC_CTL_MTYPE_MASK		GENMASK(11, 8)
+#define ECC_CTL_XOR_BITS_MASK		GENMASK(15, 0)
+
+/* ECC Status Macros */
+
+/* ECC IRQ Macros */
+#define ECC_INT_CE_EVENT		BIT(0)
+#define ECC_INT_SECOND_CE_EVENT		BIT(1)
+#define ECC_INT_UE_EVENT		BIT(2)
+#define ECC_INT_SECOND_UE_EVENT		BIT(3)
+#define ECC_INT_WRITEBACK_UNHANDLED	BIT(6)
+#define ECC_INT_SCRUB_DONE		BIT(7)
+#define ECC_INT_SCRUB_CE_EVENT		BIT(8)
+#define ECC_INT_MASK_ALL_H		BIT(8)
+#define ECC_INT_CE_UE_MASK		GENMASK(3, 0)
+#define ECC_CE_INTR_MASK		GENMASK(1, 0)
+#define ECC_UE_INTR_MASK		GENMASK(3, 2)
+#define ECC_CTL_INT_ENABLE_MASK		GENMASK(15, 0)
+/* ECC Signature Macros */
+#define ECC_SIG_ECC_C_ID_SHIFT		8
+#define ECC_SIG_ECC_C_SYND_SHIFT	8
+#define ECC_SIG_ECC_C_ADDR_H_MASK	GENMASK(1, 0)
+#define ECC_SIG_ECC_C_ID_MASK		GENMASK(31, 16)
+#define ECC_SIG_ECC_C_SYND_MASK		GENMASK(15, 8)
+
+#define ECC_SIG_ECC_U_ID_SHIFT		0
+#define ECC_SIG_ECC_U_SYND_SHIFT	8
+#define ECC_SIG_ECC_U_ADDR_H_MASK	GENMASK(1, 0)
+#define ECC_SIG_ECC_U_ID_MASK		GENMASK(15, 0)
+#define ECC_SIG_ECC_U_SYND_MASK		GENMASK(15, 8)
+
+/* Syndrome values */
+#define ECC_DOUBLE_MULTI_ERR_SYND	0x03
+
+static char data_synd[] = {
+			0xf4, 0xf1, 0xec, 0xea, 0xe9, 0xe6, 0xe5, 0xe3,
+			0xdc, 0xda, 0xd9, 0xd6, 0xd5, 0xd3, 0xce, 0xcb,
+			0xb5, 0xb0, 0xad, 0xab, 0xa8, 0xa7, 0xa4, 0xa2,
+			0x9d, 0x9b, 0x98, 0x97, 0x94, 0x92, 0x8f, 0x8a,
+			0x75, 0x70, 0x6d, 0x6b, 0x68, 0x67, 0x64, 0x62,
+			0x5e, 0x5b, 0x58, 0x57, 0x54, 0x52, 0x4f, 0x4a,
+			0x34, 0x31, 0x2c, 0x2a, 0x29, 0x26, 0x25, 0x23,
+			0x1c, 0x1a, 0x19, 0x16, 0x15, 0x13, 0x0e, 0x0b
+		  };
+
+static char check_synd[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
+
+/**
+ * struct cdns_platform_data -  cadence platform data structure.
+ * @ip_features:	To differentiate IP features.
+ */
+struct cdns_platform_data {
+	int ip_features;
+};
+
+/**
+ * struct priv_data - edac device private instance data.
+ * @reg:	        Base address of the DDR controller.
+ * @ce_cnt:             Correctable Error count.
+ * @ue_cnt:             Uncorrectable Error count.
+ */
+struct priv_data {
+	void __iomem *reg;
+	u32 ce_cnt;
+	u32 ue_cnt;
+#ifdef CONFIG_EDAC_DEBUG
+	struct cdns_platform_data *p;
+#endif
+};
+
+/**
+ * init_mem_layout -  Set address Map as per the mc design.
+ * @mci:   memory controller information.
+ *
+ * Set Address Map as per mc instance .
+ *
+ * Return: none.
+ */
+static void init_mem_layout(struct mem_ctl_info *mci)
+{
+	struct priv_data *priv = mci->pvt_info;
+	struct csrow_info *csi;
+	struct dimm_info *dimm;
+	struct sysinfo inf;
+	enum mem_type mtype;
+	u32 val, width;
+	u32 size, row;
+	u8 j;
+
+	dimm = edac_get_dimm(mci, 0, 0, 0);
+	if (!dimm) {
+		si_meminfo(&inf);
+		for (row = 0; row < mci->nr_csrows; row++) {
+			csi = mci->csrows[row];
+			size = inf.totalram * inf.mem_unit;
+
+			for (j = 0; j < csi->nr_channels; j++) {
+				dimm            = csi->channels[j]->dimm;
+				dimm->edac_mode = EDAC_FLAG_SECDED;
+				/* Get memory type by reading hw registers*/
+				val = readl(priv->reg + DDR_CTL_MEM_TYPE_REG);
+				mtype = val & ECC_CTL_MTYPE_MASK;
+
+				if (mtype == MEM_TYPE_DDR4)
+					dimm->mtype = MEM_DDR4;
+				else
+					dimm->mtype = MEM_EMPTY;
+
+				/*Get EDAC devtype width for the current mc*/
+				width = readl(priv->reg + DDR_CTL_MEM_WIDTH_REG)
+					      & CTL_MEM_MAX_WIDTH_MASK;
+				switch (width) {
+				case WDTH_16:
+					dimm->dtype  = DEV_X2;
+					break;
+				case WDTH_32:
+					dimm->dtype  = DEV_X4;
+					break;
+				case WDTH_64:
+					dimm->dtype  = DEV_X8;
+					break;
+				default:
+					dimm->dtype = DEV_UNKNOWN;
+				}
+
+				dimm->nr_pages  = (size >> PAGE_SHIFT) /
+					csi->nr_channels;
+				dimm->grain     = CDNS_EDAC_ERR_GRAIN;
+			}
+		}
+	}
+}
+
+/**
+ * handle_ce - Handle corrected errors and notify to
+ *             edac layer by reading appropriate hw registers
+ * @mci:   memory controller information.
+ * Return: void.
+ */
+static void handle_ce(struct mem_ctl_info *mci)
+{
+	struct priv_data *priv;
+	u64 err_c_addr = 0x0;
+	u64 err_c_data = 0x0;
+	u32 err_c_synd, err_c_id;
+	u32 sig_val_l, sig_val_h;
+
+	priv = mci->pvt_info;
+
+	sig_val_l = readl(priv->reg + ECC_SIG_ECC_C_ADDR_L);
+	sig_val_h = (readl(priv->reg + ECC_SIG_ECC_C_ADDR_H) &
+			ECC_SIG_ECC_C_ADDR_H_MASK);
+	err_c_addr = (((err_c_addr | sig_val_h) <<
+				CTL_REG_WIDTH_SHIFT) | sig_val_l);
+
+	sig_val_l = readl(priv->reg + ECC_SIG_ECC_C_DATA_L);
+	sig_val_h = readl(priv->reg + ECC_SIG_ECC_C_DATA_H);
+	err_c_data = (((err_c_data | sig_val_h) <<
+				CTL_REG_WIDTH_SHIFT) | sig_val_l);
+
+	err_c_id = ((readl(priv->reg + ECC_SIG_ECC_C_ID) &
+				ECC_SIG_ECC_C_ID_MASK) >>
+			ECC_SIG_ECC_C_ID_SHIFT);
+
+	err_c_synd = ((readl(priv->reg + ECC_SIG_ECC_C_SYND) &
+				ECC_SIG_ECC_C_SYND_MASK) >>
+			ECC_SIG_ECC_C_SYND_SHIFT);
+
+	priv->ce_cnt = priv->ce_cnt + 1;
+
+	edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci,
+			     1,
+			     err_c_addr >> PAGE_SHIFT,
+			     err_c_addr & ~PAGE_MASK,
+			     err_c_synd, 0, 0, -1,
+			     mci->ctl_name, "");
+}
+
+/**
+ * handle_ue -	Handle uncorrected errors and notify to
+ *		edac layer by reading appropriate hw registers
+ * @mci:   memory controller information.
+ * Return: void.
+ */
+static void handle_ue(struct mem_ctl_info *mci)
+{
+	struct priv_data *priv;
+	u64 err_u_addr = 0x0;
+	u64 err_u_data = 0x0;
+	u32 err_u_synd, err_u_id;
+	u32 sig_val_l, sig_val_h;
+
+	priv = mci->pvt_info;
+	sig_val_l = readl(priv->reg + ECC_SIG_ECC_U_ADDR_L);
+	sig_val_h = (readl(priv->reg + ECC_SIG_ECC_U_ADDR_H) &
+			ECC_SIG_ECC_U_ADDR_H_MASK);
+	err_u_addr = (((err_u_addr | sig_val_h) <<
+				CTL_REG_WIDTH_SHIFT) | sig_val_l);
+
+	sig_val_l = readl(priv->reg + ECC_SIG_ECC_U_DATA_L);
+	sig_val_h = readl(priv->reg + ECC_SIG_ECC_U_DATA_H);
+	err_u_data = (((err_u_data | sig_val_h) <<
+				CTL_REG_WIDTH_SHIFT) | sig_val_l);
+
+	err_u_id = ((readl(priv->reg + ECC_SIG_ECC_U_ID) &
+				ECC_SIG_ECC_U_ID_MASK) >>
+			ECC_SIG_ECC_U_ID_SHIFT);
+
+	err_u_synd = ((readl(priv->reg + ECC_SIG_ECC_U_SYND) &
+				ECC_SIG_ECC_U_SYND_MASK) >>
+			ECC_SIG_ECC_U_SYND_SHIFT);
+	priv->ue_cnt = priv->ue_cnt + 1;
+
+	edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci,
+			     1,
+			     err_u_addr >> PAGE_SHIFT,
+			     err_u_addr & ~PAGE_MASK,
+			     err_u_synd, 0, 0, -1,
+			     mci->ctl_name, "");
+}
+
+/**
+ * edac_ecc_isr - Interrupt Handler for ECC interrupts.
+ * @irq:        IRQ number.
+ * @dev_id:     Device ID.
+ *
+ * Return: IRQ_NONE, if interrupt not set or IRQ_HANDLED otherwise.
+ */
+static irqreturn_t edac_ecc_isr(int irq, void *dev_id)
+{
+	struct mem_ctl_info *mci = dev_id;
+	struct priv_data *priv;
+	u32 intr_status;
+	u32 val;
+
+	priv = mci->pvt_info;
+
+	/* Check the intr status and confirm ECC error intr */
+	intr_status = readl(priv->reg + ECC_CTL_INT_STATUS);
+
+	edac_dbg(3, "InterruptStatus : 0x%x\n", intr_status);
+	val = intr_status & (ECC_INT_CE_UE_MASK);
+	if (!((val & ECC_CE_INTR_MASK) || (val & ECC_UE_INTR_MASK)))
+		return IRQ_NONE;
+
+	if (val & ECC_CE_INTR_MASK) {
+		handle_ce(mci);
+
+		/* Clear the interrupt source */
+		if (val & ECC_INT_CE_EVENT)
+			writel(ECC_INT_CE_EVENT, priv->reg + ECC_CTL_INT_ACK);
+		else if (val & ECC_INT_SECOND_CE_EVENT)
+			writel(ECC_INT_SECOND_CE_EVENT,
+			       priv->reg + ECC_CTL_INT_ACK);
+		else
+			edac_printk(KERN_ERR, EDAC_MC, "Failed to clear IRQ\n");
+	}
+
+	if (val & ECC_UE_INTR_MASK) {
+		handle_ue(mci);
+
+		/* Clear the interrupt source */
+		if (val & ECC_INT_UE_EVENT)
+			writel(ECC_INT_UE_EVENT, priv->reg + ECC_CTL_INT_ACK);
+		else if (val & ECC_INT_SECOND_UE_EVENT)
+			writel(ECC_INT_SECOND_UE_EVENT,
+			       priv->reg + ECC_CTL_INT_ACK);
+		else
+			edac_printk(KERN_ERR, EDAC_MC, "Failed to clear IRQ\n");
+	}
+
+	edac_dbg(3, "Total error count CE %d UE %d\n",
+		 priv->ce_cnt, priv->ue_cnt);
+
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_EDAC_DEBUG
+/**
+ * forced_ecc_error_show/store - Sysfs atrribute functions.
+ * @dev: Pointer to device structure.
+ * @mattr: Pointer to device attributes.
+ * @data : Data send by User space and stored in file.
+ * Return: as SUCCESS,Total number of characters written otherwise
+ *         negative value.
+ */
+static ssize_t forced_ecc_error_show(struct device *dev,
+				     struct device_attribute *mattr,
+				     char *data)
+{
+	return sprintf(data, "CDNS-DDR4 Force Injection Help:\n"
+		       "CE/UE: Corrected/Uncorrected\n"
+		       "checkcode/data:source\n"
+		       "user_word [0-1]:subpart of data\n"
+		       "bit [0-31]:bit number\n");
+}
+
+static ssize_t forced_ecc_error_store(struct device *dev,
+				      struct device_attribute *mattr,
+				      const char *data, size_t count)
+{
+	struct mem_ctl_info *mci = to_mci(dev);
+	struct priv_data *priv = mci->pvt_info;
+	int	args_cnt;
+	int	ret;
+	char	**args;
+	u32	regval;
+	u8	user_word;
+	u8	bit_no;
+
+	/* Split string buffer into separate parameters */
+	args = argv_split(GFP_KERNEL, data, &args_cnt);
+
+	ret = kstrtou8(args[2], 0, &user_word);
+	if (ret)
+		return ret;
+
+	ret = kstrtou8(args[3], 0, &bit_no);
+	if (ret)
+		return ret;
+
+	/* Check ecc enabled */
+	if (!readl(priv->reg + ECC_CTL_CONTROL_0_REG) & ECC_CTL_ECC_ENABLE)
+		return count;
+
+	/* Check no write operation pending to controller*/
+	while (readl(priv->reg + DDR_CTL_CONTROLLER_BUSY) &
+			CTL_CONTROLLER_BUSY_FLAG) {
+		usleep_range(1000, 10000);
+	}
+
+	/* Write appropriate syndrome to xor_check_bit*/
+	if (!strcmp(args[0], "CE")) {
+		if (!strcmp(args[1], "checkcode")) {
+			regval = readl(priv->reg + ECC_CTL_CONTROL_1_REG);
+			regval = (regval & ~(ECC_CTL_XOR_BITS_MASK)) |
+				(check_synd[bit_no] <<
+				 (USER_WORD_SPLIT_WIDTH * user_word));
+			writel(regval, priv->reg + ECC_CTL_CONTROL_1_REG);
+		} else if (!strcmp(args[1], "data")) {
+			regval = readl(priv->reg + ECC_CTL_CONTROL_1_REG);
+			regval = (regval & ~(ECC_CTL_XOR_BITS_MASK)) |
+				(data_synd[bit_no] <<
+				 (USER_WORD_SPLIT_WIDTH * user_word));
+			writel(regval, priv->reg + ECC_CTL_CONTROL_1_REG);
+		}
+		/* Enable the ECC writeback_en for corrected error */
+		regval = readl(priv->reg + ECC_CTL_CONTROL_1_REG);
+		writel((regval | ECC_CTL_AUTO_WRITEBACK_EN),
+		       priv->reg + ECC_CTL_CONTROL_1_REG);
+	} else if (!strcmp(args[0], "UE")) {
+		writel(ECC_DOUBLE_MULTI_ERR_SYND,
+		       priv->reg + ECC_CTL_CONTROL_1_REG);
+	}
+
+	/* Assert fwc */
+	writel((ECC_CTL_FORCE_WC | readl(priv->reg + ECC_CTL_CONTROL_0_REG)),
+	       priv->reg + ECC_CTL_CONTROL_0_REG);
+	return count;
+}
+
+static DEVICE_ATTR_RW(forced_ecc_error);
+static int create_sysfs_attributes(struct mem_ctl_info *mci)
+{
+	int rc;
+
+	rc = device_create_file(&mci->dev, &dev_attr_forced_ecc_error);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+
+static void remove_sysfs_attributes(struct mem_ctl_info *mci)
+{
+	device_remove_file(&mci->dev, &dev_attr_forced_ecc_error);
+}
+
+#endif
+
+static const struct cdns_platform_data cdns_edac = {
+#ifdef CONFIG_EDAC_DEBUG
+	.ip_features = FORCED_ECC_ERR_EVENT_SUPPORT,
+#endif
+};
+
+static const struct of_device_id cdns_edac_of_match[] = {
+	{ .compatible = "cdns,ddr4-mc-edac", .data = &cdns_edac },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, cdns_edac_of_match);
+
+/**
+ * cdns_edac_mc_probe - bind cdns mc controller driver to framework.
+ * @pdev:  platform device.
+ *
+ * Probe a memory controller for binding with the driver.
+ *
+ * Return: 0 if binding of the controller instance is successful;
+ * otherwise, < 0 on error.
+ */
+static int cdns_edac_mc_probe(struct platform_device *pdev)
+{
+#ifdef CONFIG_EDAC_DEBUG
+	const struct cdns_platform_data *p;
+#endif
+	struct device *dev = &pdev->dev;
+	struct edac_mc_layer layers[1];
+	const struct of_device_id *id;
+	struct priv_data *priv_data;
+	struct mem_ctl_info *mci;
+	struct resource *res;
+	void __iomem *reg;
+	int ret = -ENODEV;
+	int irq;
+
+	id = of_match_device(cdns_edac_of_match, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
+#ifdef CONFIG_EDAC_DEBUG
+	p = of_device_get_match_data(&pdev->dev);
+	if (!p)
+		return -ENODEV;
+#endif
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	reg = devm_ioremap_resource(dev, res);
+	if (IS_ERR(reg)) {
+		edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+			    "cdns DDR4 mc regs are not defined\n");
+		return PTR_ERR(reg);
+	}
+
+	edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+		    "IO mapped reg addr: %p\n", reg);
+	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+	layers[0].size = 1;
+	layers[0].is_virt_csrow = true;
+
+	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
+			    sizeof(struct priv_data));
+	if (!mci) {
+		edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+			    "Failed memory allocation for mc instance\n");
+		return -ENOMEM;
+	}
+	mci->pdev = &pdev->dev;
+	priv_data = mci->pvt_info;
+	priv_data->reg = reg;
+	priv_data->ce_cnt = 0;
+	priv_data->ue_cnt = 0;
+	platform_set_drvdata(pdev, mci);
+	/* Initialize controller capabilities */
+	mci->mtype_cap = MEM_FLAG_DDR4;
+	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+	mci->scrub_cap = SCRUB_UNKNOWN;
+	mci->scrub_mode = SCRUB_HW_PROG;
+	mci->edac_cap = EDAC_FLAG_SECDED;
+	mci->ctl_name = id->compatible;
+	mci->dev_name = dev_name(&pdev->dev);
+	mci->mod_name = CDNS_EDAC_MOD_NAME;
+	mci->ctl_page_to_phys = NULL;
+
+	/* Interrupt feature is supported by cadence mc */
+	edac_op_state = EDAC_OPSTATE_INT;
+	init_mem_layout(mci);
+
+	/* Setup Interrupt handler for ECC */
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+			    "irq number not defined for ECC.\n");
+		goto err;
+	}
+	ret = devm_request_irq(dev, irq, edac_ecc_isr, 0,
+			       "cdns-edac-mc-ecc-irq", mci);
+	if (ret) {
+		edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+			    "request_irq fail for CDNS_EDAC irq\n");
+		goto err;
+	}
+	ret = edac_mc_add_mc(mci);
+	if (ret) {
+		edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+			    "Failed to register with EDAC core\n");
+		goto err;
+	}
+
+#ifdef CONFIG_EDAC_DEBUG
+	if (p->ip_features & FORCED_ECC_ERR_EVENT_SUPPORT) {
+		if (create_sysfs_attributes(mci)) {
+			edac_printk(KERN_ERR, CDNS_EDAC_MOD_NAME,
+				    "Failed to create sysfs entries\n");
+			goto err1;
+		}
+	}
+#endif
+	/* Enable & set CE/UE Interrupts for DDR4 Controller */
+	writel((unsigned int)(~(ECC_CTL_INT_ENABLE_MASK)),
+	       priv_data->reg + ECC_CTL_INT_MASK);
+
+	/* Start capturing the correctable and uncorrectable errors.
+	 * Write 1 to enable.
+	 */
+	writel(ECC_CTL_ECC_ENABLE, priv_data->reg + ECC_CTL_CONTROL_0_REG);
+	return 0;
+
+err1:
+	edac_mc_del_mc(&pdev->dev);
+
+err:
+	edac_mc_free(mci);
+	return ret;
+}
+
+/**
+ * cdns_edac_mc_remove - Unbind driver from controller.
+ * @pdev:  Platform device.
+ *
+ * Return: 0
+ */
+static int cdns_edac_mc_remove(struct platform_device *pdev)
+{
+	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+	struct priv_data *priv = mci->pvt_info;
+
+	/* Disable All ECC Interrupts for DDR4 Controller */
+	writel(ECC_CTL_INT_ENABLE_MASK, priv->reg + ECC_CTL_INT_MASK);
+
+	/* Disable ecc feature before removing driver by writing 0 */
+	writel((unsigned int)(~(ECC_CTL_ECC_ENABLE)),
+	       priv->reg + ECC_CTL_CONTROL_0_REG);
+
+#ifdef CONFIG_EDAC_DEBUG
+	remove_sysfs_attributes(mci);
+#endif
+	edac_mc_del_mc(&pdev->dev);
+	edac_mc_free(mci);
+
+	return 0;
+}
+
+static struct platform_driver cdns_edac_mc_driver = {
+	.driver = {
+		   .name = "cadence-edac",
+		   .of_match_table = cdns_edac_of_match,
+	},
+	.probe = cdns_edac_mc_probe,
+	.remove = cdns_edac_mc_remove,
+};
+
+module_platform_driver(cdns_edac_mc_driver);
+
+MODULE_AUTHOR("Cadence");
+MODULE_DESCRIPTION("Cadence DDR4 Controller ECC driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.1

Re: [PATCH v3 1/2] dt-bindings: edac: Add cadence ddr mc support

[Rob Herring]

On Mon, Apr 06, 2020 at 03:13:40PM +0200, Dhananjay Kangude wrote:
> Add documentation for cadence ddr memory controller EDAC DTS bindings
> 
> Signed-off-by: Dhananjay Kangude <dkangude@cadence.com>
> ---
>  .../devicetree/bindings/edac/cdns,ddr-edac.yaml    |   47 ++++++++++++++++++++
>  1 files changed, 47 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> 
> diff --git a/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> new file mode 100644
> index 0000000..30ea757
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/edac/cdns,ddr-edac.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Cadence DDR IP with ECC support (EDAC)
> +
> +description:
> +  This binding describes the Cadence DDR/LPDDR IP with ECC feature enabled
> +  to detect and correct CE/UE errors.
> +
> +maintainers:
> +  - Dhananjay Kangdue <dkangude@cadence.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - cdns,ddr4-mc

Surely there's more than 1 version?

> +
> +  reg:
> +    minItems: 1
> +    maxItems: 2
> +    items:
> +      - description:
> +          Register block of DDR/LPDDR apb registers up to mapped area.
> +          Mapped area contains the register set for memory controller,
> +          phy and PI module register set doesn't part of this mapping.

doesn't part of this mapping?

Need a description for the 2nd region.

> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    edac: edac@fd100000 {

memory-controller@

> +        compatible = "cdns,ddr4-mc-edac";

Doesn't match.

> +        reg = <0xfd100000 0x4000>;
> +        interrupts = <0x00 0x01 0x04>;
> +    };
> +...
> -- 
> 1.7.1
> 

RE: [PATCH v3 1/2] dt-bindings: edac: Add cadence ddr mc support

[Dhananjay Vilasrao Kangude]

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Wednesday, April 15, 2020 5:20 AM
> To: Dhananjay Vilasrao Kangude <dkangude@cadence.com>
> Cc: linux-edac@vger.kernel.org; bp@alien8.de; mchehab@kernel.org;
> tony.luck@intel.com; james.morse@arm.com; linux-kernel@vger.kernel.org;
> Milind Parab <mparab@cadence.com>; devicetree@vger.kernel.org
> Subject: Re: [PATCH v3 1/2] dt-bindings: edac: Add cadence ddr mc support
> 
> EXTERNAL MAIL
> 
> 
> On Mon, Apr 06, 2020 at 03:13:40PM +0200, Dhananjay Kangude wrote:
> > Add documentation for cadence ddr memory controller EDAC DTS bindings
> >
> > Signed-off-by: Dhananjay Kangude <dkangude@cadence.com>
> > ---
> >  .../devicetree/bindings/edac/cdns,ddr-edac.yaml    |   47
> ++++++++++++++++++++
> >  1 files changed, 47 insertions(+), 0 deletions(-)  create mode 100644
> > Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> > b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> > new file mode 100644
> > index 0000000..30ea757
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/edac/cdns,ddr-edac.yaml
> > @@ -0,0 +1,47 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id:
> > +https://urldefense.com/v3/__http://devicetree.org/schemas/edac/cdns,d
> > +dr-
> edac.yaml*__;Iw!!EHscmS1ygiU1lA!T49K56JzhGnA7nxu4mq55aDfl80QsXPj-l
> > +Egtf_PILMzq2Np6NqhLRXeTNuBLx0$
> > +$schema:
> > +https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.y
> > +aml*__;Iw!!EHscmS1ygiU1lA!T49K56JzhGnA7nxu4mq55aDfl80QsXPj-
> lEgtf_PILM
> > +zq2Np6NqhLRXe69d40qY$
> > +
> > +title: Cadence DDR IP with ECC support (EDAC)
> > +
> > +description:
> > +  This binding describes the Cadence DDR/LPDDR IP with ECC feature
> > +enabled
> > +  to detect and correct CE/UE errors.
> > +
> > +maintainers:
> > +  - Dhananjay Kangdue <dkangude@cadence.com>
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - cdns,ddr4-mc
> 
> Surely there's more than 1 version?

[Dhananjay Kangude] No, as of now we have only one version of hardware module. 
I will change the property with items instead of enum.
> 
> > +
> > +  reg:
> > +    minItems: 1
> > +    maxItems: 2
> > +    items:
> > +      - description:
> > +          Register block of DDR/LPDDR apb registers up to mapped area.
> > +          Mapped area contains the register set for memory controller,
> > +          phy and PI module register set doesn't part of this mapping.
> 
> doesn't part of this mapping?
> 
[Dhananjay Kangude] In case of combo IP, controller and phy module are together. 
But ecc doesn't have any dependencies on phy module so we can exclude phy module .
> Need a description for the 2nd region.

[Dhananjay Kangude] Removed maxItems property. We don't have another region to access.
fix will release in next version
> 
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    edac: edac@fd100000 {
> 
> memory-controller@
[Dhananjay Kangude] ] memory-controller might not the appropriate name. 
the driver module is only focused on ecc not on actual memory-controller functionality.
> 
> > +        compatible = "cdns,ddr4-mc-edac";
> 
> Doesn't match.
[Dhananjay Kangude] fixed. Changes will be part of next version.
> 
> > +        reg = <0xfd100000 0x4000>;
> > +        interrupts = <0x00 0x01 0x04>;
> > +    };
> > +...
> > --
> > 1.7.1
> >