[PATCHv4 5/7] EDAC, altera: Add Arria10 ECC memory init functions

[tthayer@opensource.altera.com (tthayer at opensource.altera.com)]

From: Thor Thayer <tthayer@opensource.altera.com>

In preparation for additional memory module ECCs, add the
memory initialization functions and helper functions used
for memory initialization.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
---
v2: Specify INTMODE selection -> IRQ on each ECC error.
    Insert functions above memory-specific functions so that function
    declarations are not required.
    Use ERRINTENS & ERRINTENR registers instead of read/modify/write.
v3: Changes for common compatibility string:
    - Pass node instead of compatibility string.
    - New altr_init_a10_ecc_device_type() for peripherals.
    - Add __init to altr_init_a10_ecc_block().
    - Add a10_get_irq_mask().
v4  Replace ifdefs with __maybe_unused macro
    Improve if,else statement in altr_init_memory_port()
    Remove confusing comment about shared function.
---
 drivers/edac/altera_edac.c |  192 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/edac/altera_edac.h |    8 ++
 2 files changed, 200 insertions(+)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 5f01974..d97f22e 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -19,6 +19,7 @@
 
 #include <asm/cacheflush.h>
 #include <linux/ctype.h>
+#include <linux/delay.h>
 #include <linux/edac.h>
 #include <linux/genalloc.h>
 #include <linux/interrupt.h>
@@ -874,6 +875,197 @@ static irqreturn_t __maybe_unused altr_edac_a10_ecc_irq(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
+/******************* Arria10 Memory Buffer Functions *********************/
+
+static inline int a10_get_irq_mask(struct device_node *np)
+{
+	int irq;
+	const u32 *handle = of_get_property(np, "interrupts", NULL);
+
+	if (!handle)
+		return -ENODEV;
+	irq = be32_to_cpup(handle);
+	return irq;
+}
+
+static inline void ecc_set_bits(u32 bit_mask, void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr);
+
+	value |= bit_mask;
+	writel(value, ioaddr);
+}
+
+static inline void ecc_clear_bits(u32 bit_mask, void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr);
+
+	value &= ~bit_mask;
+	writel(value, ioaddr);
+}
+
+static inline int ecc_test_bits(u32 bit_mask, void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr);
+
+	return (value & bit_mask) ? 1 : 0;
+}
+
+/*
+ * This function uses the memory initialization block in the Arria10 ECC
+ * controller to initialize/clear the entire memory data and ECC data.
+ */
+static int __maybe_unused altr_init_memory_port(void __iomem *ioaddr, int port)
+{
+	int limit = ALTR_A10_ECC_INIT_WATCHDOG_10US;
+	u32 init_mask, stat_mask, clear_mask;
+	int ret = 0;
+
+	if (port) {
+		init_mask = ALTR_A10_ECC_INITB;
+		stat_mask = ALTR_A10_ECC_INITCOMPLETEB;
+		clear_mask = ALTR_A10_ECC_ERRPENB_MASK;
+	} else {
+		init_mask = ALTR_A10_ECC_INITA;
+		stat_mask = ALTR_A10_ECC_INITCOMPLETEA;
+		clear_mask = ALTR_A10_ECC_ERRPENA_MASK;
+	}
+
+	ecc_set_bits(init_mask, (ioaddr + ALTR_A10_ECC_CTRL_OFST));
+	while (limit--) {
+		if (ecc_test_bits(stat_mask,
+				  (ioaddr + ALTR_A10_ECC_INITSTAT_OFST)))
+			break;
+		udelay(1);
+	}
+	if (limit < 0)
+		ret = -EBUSY;
+
+	/* Clear any pending ECC interrupts */
+	writel(clear_mask, (ioaddr + ALTR_A10_ECC_INTSTAT_OFST));
+
+	return ret;
+}
+
+static __init int __maybe_unused
+altr_init_a10_ecc_block(struct device_node *np, u32 irq_mask,
+			u32 ecc_ctrl_en_mask, bool dual_port)
+{
+	int ret = 0;
+	void __iomem *ecc_block_base;
+	struct regmap *ecc_mgr_map;
+	char *ecc_name;
+	struct device_node *np_eccmgr;
+
+	ecc_name = (char *)np->name;
+
+	/* Get the ECC Manager - parent of the device EDACs */
+	np_eccmgr = of_get_parent(np);
+	ecc_mgr_map = syscon_regmap_lookup_by_phandle(np_eccmgr,
+						      "altr,sysmgr-syscon");
+	of_node_put(np_eccmgr);
+	if (IS_ERR(ecc_mgr_map)) {
+		edac_printk(KERN_ERR, EDAC_DEVICE,
+			    "Unable to get syscon altr,sysmgr-syscon\n");
+		return -ENODEV;
+	}
+
+	/* Map the ECC Block */
+	ecc_block_base = of_iomap(np, 0);
+	if (!ecc_block_base) {
+		edac_printk(KERN_ERR, EDAC_DEVICE,
+			    "Unable to map %s ECC block\n", ecc_name);
+		return -ENODEV;
+	}
+
+	/* Disable ECC */
+	regmap_write(ecc_mgr_map, A10_SYSMGR_ECC_INTMASK_SET_OFST, irq_mask);
+	writel(ALTR_A10_ECC_SERRINTEN,
+	       (ecc_block_base + ALTR_A10_ECC_ERRINTENR_OFST));
+	ecc_clear_bits(ecc_ctrl_en_mask,
+		       (ecc_block_base + ALTR_A10_ECC_CTRL_OFST));
+	/* Ensure all writes complete */
+	wmb();
+	/* Use HW initialization block to initialize memory for ECC */
+	ret = altr_init_memory_port(ecc_block_base, 0);
+	if (ret) {
+		edac_printk(KERN_ERR, EDAC_DEVICE,
+			    "ECC: cannot init %s PORTA memory\n", ecc_name);
+		goto out;
+	}
+
+	if (dual_port) {
+		ret = altr_init_memory_port(ecc_block_base, 1);
+		if (ret) {
+			edac_printk(KERN_ERR, EDAC_DEVICE,
+				    "ECC: cannot init %s PORTB memory\n",
+				    ecc_name);
+			goto out;
+		}
+	}
+
+	/* Interrupt mode set to every SBERR */
+	regmap_write(ecc_mgr_map, ALTR_A10_ECC_INTMODE_OFST,
+		     ALTR_A10_ECC_INTMODE);
+	/* Enable ECC */
+	ecc_set_bits(ecc_ctrl_en_mask, (ecc_block_base +
+					ALTR_A10_ECC_CTRL_OFST));
+	writel(ALTR_A10_ECC_SERRINTEN,
+	       (ecc_block_base + ALTR_A10_ECC_ERRINTENS_OFST));
+	regmap_write(ecc_mgr_map, A10_SYSMGR_ECC_INTMASK_CLR_OFST, irq_mask);
+	/* Ensure all writes complete */
+	wmb();
+out:
+	iounmap(ecc_block_base);
+	return ret;
+}
+
+static int validate_parent_available(struct device_node *np);
+static const struct of_device_id altr_edac_a10_device_of_match[];
+static int __init __maybe_unused altr_init_a10_ecc_device_type(char *compat)
+{
+	int irq;
+	struct device_node *child, *np = of_find_compatible_node(NULL, NULL,
+					"altr,socfpga-a10-ecc-manager");
+	if (!np) {
+		edac_printk(KERN_ERR, EDAC_DEVICE, "ECC Manager not found\n");
+		return -ENODEV;
+	}
+
+	for_each_child_of_node(np, child) {
+		const struct of_device_id *pdev_id;
+		const struct edac_device_prv_data *prv;
+
+		if (!of_device_is_available(child))
+			continue;
+		if (!of_device_is_compatible(child, compat))
+			continue;
+
+		if (validate_parent_available(child))
+			continue;
+
+		irq = a10_get_irq_mask(child);
+		if (irq < 0)
+			continue;
+
+		/* Get matching node and check for valid result */
+		pdev_id = of_match_node(altr_edac_a10_device_of_match, child);
+		if (IS_ERR_OR_NULL(pdev_id))
+			continue;
+
+		/* Validate private data pointer before dereferencing */
+		prv = pdev_id->data;
+		if (!prv)
+			continue;
+
+		altr_init_a10_ecc_block(child, BIT(irq),
+					prv->ecc_enable_mask, 0);
+	}
+
+	of_node_put(np);
+	return 0;
+}
+
 /*********************** OCRAM EDAC Device Functions *********************/
 
 #ifdef CONFIG_EDAC_ALTERA_OCRAM
diff --git a/drivers/edac/altera_edac.h b/drivers/edac/altera_edac.h
index cf4e8cb..aa7c690 100644
--- a/drivers/edac/altera_edac.h
+++ b/drivers/edac/altera_edac.h
@@ -230,8 +230,13 @@ struct altr_sdram_mc_data {
 #define ALTR_A10_ECC_INITCOMPLETEB      BIT(8)
 
 #define ALTR_A10_ECC_ERRINTEN_OFST      0x10
+#define ALTR_A10_ECC_ERRINTENS_OFST     0x14
+#define ALTR_A10_ECC_ERRINTENR_OFST     0x18
 #define ALTR_A10_ECC_SERRINTEN          BIT(0)
 
+#define ALTR_A10_ECC_INTMODE_OFST       0x1C
+#define ALTR_A10_ECC_INTMODE            BIT(0)
+
 #define ALTR_A10_ECC_INTSTAT_OFST       0x20
 #define ALTR_A10_ECC_SERRPENA           BIT(0)
 #define ALTR_A10_ECC_DERRPENA           BIT(8)
@@ -280,6 +285,9 @@ struct altr_sdram_mc_data {
 /* Arria 10 OCRAM ECC Management Group Defines */
 #define ALTR_A10_OCRAM_ECC_EN_CTL       (BIT(1) | BIT(0))
 
+/* A10 ECC Controller memory initialization timeout */
+#define ALTR_A10_ECC_INIT_WATCHDOG_10US      10000
+
 struct altr_edac_device_dev;
 
 struct edac_device_prv_data {
-- 
1.7.9.5