zynq: Add new ddrc driver for ECC support

The first 1MB is not initialized by first stage bootloader.
Check if memory is setup to 16bit mode and ECC is enabled.
If it is, clear the first 1MB.
Also u-boot should report only the half size of memory.

Acked-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/cpu/armv7/zynq/Makefile

@@ -14,6 +14,7 @@ LIB	= $(obj)lib$(SOC).o
 
 COBJS-y	:= timer.o
 COBJS-y	+= cpu.o
+COBJS-y	+= ddrc.o
 COBJS-y	+= slcr.o
 
 COBJS	:= $(COBJS-y)

arch/arm/cpu/armv7/zynq/ddrc.c

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2012 - 2013 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2012 - 2013 Xilinx, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/hardware.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Control regsiter bitfield definitions */
+#define ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK		0xC
+#define ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT	2
+#define ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT	1
+
+/* ECC scrub regsiter definitions */
+#define ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK	0x7
+#define ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED	0x4
+
+void zynq_ddrc_init(void)
+{
+	u32 width, ecctype;
+
+	width = readl(&ddrc_base->ddrc_ctrl);
+	width = (width & ZYNQ_DDRC_CTRLREG_BUSWIDTH_MASK) >>
+					ZYNQ_DDRC_CTRLREG_BUSWIDTH_SHIFT;
+	ecctype = (readl(&ddrc_base->ecc_scrub) &
+		ZYNQ_DDRC_ECC_SCRUBREG_ECC_MODE_MASK);
+
+	/* ECC is enabled when memory is in 16bit mode and it is enabled */
+	if ((ecctype == ZYNQ_DDRC_ECC_SCRUBREG_ECCMODE_SECDED) &&
+	    (width == ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT)) {
+		puts("Memory: ECC enabled\n");
+		/*
+		 * Clear the first 1MB because it is not initialized from
+		 * first stage bootloader. To get ECC to work all memory has
+		 * been initialized by writing any value.
+		 */
+		memset(0, 0, 1 * 1024 * 1024);
+	} else {
+		puts("Memory: ECC disabled\n");
+	}
+
+	if (width == ZYNQ_DDRC_CTRLREG_BUSWIDTH_16BIT)
+		gd->ram_size /= 2;
+}

arch/arm/include/asm/arch-zynq/hardware.h

@@ -17,6 +17,7 @@
 #define ZYNQ_SDHCI_BASEADDR1		0xE0101000
 #define ZYNQ_I2C_BASEADDR0		0xE0004000
 #define ZYNQ_I2C_BASEADDR1		0xE0005000
+#define ZYNQ_DDRC_BASEADDR		0xF8006000
 
 /* Reflect slcr offsets */
 struct slcr_regs {
@@ -84,4 +85,11 @@ struct scu_regs {
 
 #define scu_base ((struct scu_regs *)ZYNQ_SCU_BASEADDR)
 
+struct ddrc_regs {
+	u32 ddrc_ctrl; /* 0x0 */
+	u32 reserved[60];
+	u32 ecc_scrub; /* 0xF4 */
+};
+#define ddrc_base ((struct ddrc_regs *)ZYNQ_DDRC_BASEADDR)
+
 #endif /* _ASM_ARCH_HARDWARE_H */

arch/arm/include/asm/arch-zynq/sys_proto.h

@@ -14,6 +14,7 @@ extern void zynq_slcr_gem_clk_setup(u32 gem_id, u32 rclk, u32 clk);
 extern void zynq_slcr_devcfg_disable(void);
 extern void zynq_slcr_devcfg_enable(void);
 extern u32 zynq_slcr_get_idcode(void);
+extern void zynq_ddrc_init(void);
 
 /* Driver extern functions */
 extern int zynq_sdhci_init(u32 regbase);

board/xilinx/zynq/board.c

@@ -96,5 +96,7 @@ int dram_init(void)
 {
 	gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
 
+	zynq_ddrc_init();
+
 	return 0;
 }