[PATCHv6 2/5] arm: socfpga: Enable OCRAM ECC on startup.

[tthayer at opensource.altera.com]

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

This patch enables the ECC for On-Chip RAM on machine
startup.  The ECC has to be enabled before data is
is stored in memory otherwise the ECC will fail on
reads.

Signed-off-by: Thor Thayer <tthayer at opensource.altera.com>
---
v2: Split OCRAM ECC portion separately. Addition of iounmap()
    and reorganization of gen_pool_free. Remove defconfig from patch.

v3/4: No change

v5: Remove ocram.h, use io.h instead of clk-provider.h
    Check prop in correct place. Add ECC EN defines.

v6: Implement OCRAM discovery changes from community. Add
    of_node_put(). Remove be32_to_cpup(). Use __init() which
    allows removal of .init_machine(). Update year in header.
---
 arch/arm/mach-socfpga/Makefile |    1 +
 arch/arm/mach-socfpga/ocram.c  |   97 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+)
 create mode 100644 arch/arm/mach-socfpga/ocram.c

diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
index 142609e..1552ca5 100644
--- a/arch/arm/mach-socfpga/Makefile
+++ b/arch/arm/mach-socfpga/Makefile
@@ -5,3 +5,4 @@
 obj-y					:= socfpga.o
 obj-$(CONFIG_SMP)	+= headsmp.o platsmp.o
 obj-$(CONFIG_EDAC_ALTERA_L2C) += l2_cache.o
+obj-$(CONFIG_EDAC_ALTERA_OCRAM) += ocram.o
diff --git a/arch/arm/mach-socfpga/ocram.c b/arch/arm/mach-socfpga/ocram.c
new file mode 100644
index 0000000..1f12a38
--- /dev/null
+++ b/arch/arm/mach-socfpga/ocram.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright Altera Corporation (C) 2015. All rights reserved.
+ *
+ * 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/io.h>
+#include <linux/genalloc.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+#define ALTR_OCRAM_CLEAR_ECC          0x00000018
+#define ALTR_OCRAM_ECC_EN             0x00000019
+
+static int __init socfpga_init_ocram_ecc(void)
+{
+	struct device_node *np;
+	struct resource    res;
+	u32                iram_addr;
+	void __iomem       *mapped_ocr_edac_addr;
+	resource_size_t    size;
+	struct gen_pool    *gp;
+	int                ret;
+
+	/* Get the size of the on-chip RAM */
+	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
+	if (!np) {
+		pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
+		return -ENODEV;
+	}
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		of_node_put(np);
+		pr_err("%s: Problem getting SRAM address in dtb\n", __func__);
+		return -ENODEV;
+	}
+	size = resource_size(&res);
+	of_node_put(np);
+
+	/* Find the OCRAM EDAC device tree node */
+	np = of_find_compatible_node(NULL, NULL, "altr,ocram-edac");
+	if (!np) {
+		pr_err("%s: Unable to find altr,ocram-edac\n", __func__);
+		return -ENODEV;
+	}
+
+	mapped_ocr_edac_addr = of_iomap(np, 0);
+	if (!mapped_ocr_edac_addr) {
+		of_node_put(np);
+		pr_err("%s: Unable to map OCRAM ecc regs.\n", __func__);
+		return -ENODEV;
+	}
+
+	gp = of_get_named_gen_pool(np, "iram", 0);
+	if (!gp) {
+		of_node_put(np);
+		pr_err("%s: OCRAM cannot find gen pool\n", __func__);
+		return -ENODEV;
+	}
+	of_node_put(np);
+
+	iram_addr = gen_pool_alloc(gp, size / sizeof(size_t));
+	if (iram_addr == 0) {
+		pr_err("%s: cannot alloc from gen pool\n", __func__);
+		return -ENODEV;
+	}
+
+	/* Clear any pending OCRAM ECC interrupts, then enable ECC */
+	writel(ALTR_OCRAM_CLEAR_ECC, mapped_ocr_edac_addr);
+	writel(ALTR_OCRAM_ECC_EN, mapped_ocr_edac_addr);
+
+	memset((void *)iram_addr, 0, size);
+
+	gen_pool_free(gp, iram_addr, size / sizeof(size_t));
+
+	iounmap(mapped_ocr_edac_addr);
+
+	return 0;
+}
+
+static void __exit socfpga_exit_ocram_ecc(void)
+{
+}
+
+module_init(socfpga_init_ocram_ecc);
+module_exit(socfpga_exit_ocram_ecc);
-- 
1.7.9.5