n1sdp: fix DMC ECC enablement sequence in N1SDP platform

The DMC-620 memory controllers in N1SDP platform has to be put
into CONFIG state before writing to ERR0CTLR0 register to enable
ECC.

This patch fixes the sequence so that DMCs are set to CONFIG
state before writing to ERR0CTLR0 register and moved back to
READY state after writing.

Change-Id: I1252f3ae0991603bb29234029cddb5fbf869c1b2
Signed-off-by: Manoj Kumar <manoj.kumar3@arm.com>

plat/arm/board/n1sdp/n1sdp_bl31_setup.c

@@ -80,8 +80,17 @@ void dmc_ecc_setup(uint32_t ddr_size_gb)
 	flush_dcache_range(ARM_DRAM2_BASE, dram2_size);
 
 	INFO("Enabling ECC on DMCs\n");
+	/* Set DMCs to CONFIG state before writing ERR0CTLR0 register */
+	mmio_write_32(N1SDP_DMC0_MEMC_CMD_REG, N1SDP_DMC_MEMC_CMD_CONFIG);
+	mmio_write_32(N1SDP_DMC1_MEMC_CMD_REG, N1SDP_DMC_MEMC_CMD_CONFIG);
+
+	/* Enable ECC in DMCs */
 	mmio_setbits_32(N1SDP_DMC0_ERR0CTLR0_REG, N1SDP_DMC_ERR0CTLR0_ECC_EN);
 	mmio_setbits_32(N1SDP_DMC1_ERR0CTLR0_REG, N1SDP_DMC_ERR0CTLR0_ECC_EN);
+
+	/* Set DMCs to READY state */
+	mmio_write_32(N1SDP_DMC0_MEMC_CMD_REG, N1SDP_DMC_MEMC_CMD_READY);
+	mmio_write_32(N1SDP_DMC1_MEMC_CMD_REG, N1SDP_DMC_MEMC_CMD_READY);
 }
 
 void copy_bl33(uint32_t src, uint32_t dst, uint32_t size)

plat/arm/board/n1sdp/n1sdp_def.h

@@ -25,10 +25,18 @@
 #define N1SDP_SDS_BL33_INFO_OFFSET		0
 #define N1SDP_SDS_BL33_INFO_SIZE		12
 
+/* DMC memory command registers */
+#define N1SDP_DMC0_MEMC_CMD_REG			0x4E000008
+#define N1SDP_DMC1_MEMC_CMD_REG			0x4E100008
+
 /* DMC ERR0CTLR0 registers */
 #define N1SDP_DMC0_ERR0CTLR0_REG		0x4E000708
 #define N1SDP_DMC1_ERR0CTLR0_REG		0x4E100708
 
+/* DMC memory commands */
+#define N1SDP_DMC_MEMC_CMD_CONFIG		0
+#define N1SDP_DMC_MEMC_CMD_READY		3
+
 /* DMC ECC enable bit in ERR0CTLR0 register */
 #define N1SDP_DMC_ERR0CTLR0_ECC_EN		0x1