[U-Boot] [PATCH 2/3] ARM: DRA7: EMIF: Update SDRAM_REF_CTRL register value

[Lokesh Vutla]

The value in SDRAM_REF_CTRL controls the delay time between
the initial rising edge of DDR_RESETn to rising edge of DDR_CKE
(JEDEC specs this as 500us). In order to achieve this, SDRAM_REF_CTRL
should be written with a value corresponding to 500us delay before
starting DDR initialization sequence, and configure proper
value at the end of sequence.

Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
---
 arch/arm/cpu/armv7/omap-common/emif-common.c | 4 +++-
 arch/arm/cpu/armv7/omap5/sdram.c             | 9 ++++++---
 arch/arm/include/asm/emif.h                  | 1 +
 board/ti/beagle_x15/board.c                  | 6 ++++--
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap-common/emif-common.c b/arch/arm/cpu/armv7/omap-common/emif-common.c
index e601ba1..c01a98f 100644
--- a/arch/arm/cpu/armv7/omap-common/emif-common.c
+++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
@@ -252,6 +252,8 @@ static void ddr3_init(u32 base, const struct emif_regs *regs)
 {
 	struct emif_reg_struct *emif = (struct emif_reg_struct *)base;
 
+	writel(regs->ref_ctrl, &emif->emif_sdram_ref_ctrl);
+	writel(regs->sdram_config_init, &emif->emif_sdram_config);
 	/*
 	 * Set SDRAM_CONFIG and PHY control registers to locked frequency
 	 * and RL =7. As the default values of the Mode Registers are not
@@ -265,7 +267,6 @@ static void ddr3_init(u32 base, const struct emif_regs *regs)
 	writel(regs->sdram_tim2, &emif->emif_sdram_tim_2);
 	writel(regs->sdram_tim3, &emif->emif_sdram_tim_3);
 
-	writel(regs->ref_ctrl, &emif->emif_sdram_ref_ctrl);
 	writel(regs->read_idle_ctrl, &emif->emif_read_idlectrl);
 
 	/*
@@ -274,6 +275,7 @@ static void ddr3_init(u32 base, const struct emif_regs *regs)
 	 */
 	if (is_dra7xx()) {
 		do_ext_phy_settings(base, regs);
+		writel(regs->ref_ctrl_final, &emif->emif_sdram_ref_ctrl);
 		writel(regs->sdram_config2, &emif->emif_lpddr2_nvm_config);
 		writel(regs->sdram_config_init, &emif->emif_sdram_config);
 	} else {
diff --git a/arch/arm/cpu/armv7/omap5/sdram.c b/arch/arm/cpu/armv7/omap5/sdram.c
index e5456ff..61e9aef 100644
--- a/arch/arm/cpu/armv7/omap5/sdram.c
+++ b/arch/arm/cpu/armv7/omap5/sdram.c
@@ -141,7 +141,8 @@ const struct emif_regs emif_1_regs_ddr3_532_mhz_1cs_dra_es1 = {
 	.sdram_config_init              = 0x61851ab2,
 	.sdram_config                   = 0x61851ab2,
 	.sdram_config2			= 0x08000000,
-	.ref_ctrl                       = 0x00001035,
+	.ref_ctrl                       = 0x000040F1,
+	.ref_ctrl_final			= 0x00001035,
 	.sdram_tim1                     = 0xCCCF36B3,
 	.sdram_tim2                     = 0x308F7FDA,
 	.sdram_tim3                     = 0x027F88A8,
@@ -165,7 +166,8 @@ const struct emif_regs emif_2_regs_ddr3_532_mhz_1cs_dra_es1 = {
 	.sdram_config_init              = 0x61851B32,
 	.sdram_config                   = 0x61851B32,
 	.sdram_config2			= 0x08000000,
-	.ref_ctrl                       = 0x00001035,
+	.ref_ctrl                       = 0x000040F1,
+	.ref_ctrl_final			= 0x00001035,
 	.sdram_tim1                     = 0xCCCF36B3,
 	.sdram_tim2                     = 0x308F7FDA,
 	.sdram_tim3                     = 0x027F88A8,
@@ -189,7 +191,8 @@ const struct emif_regs emif_1_regs_ddr3_666_mhz_1cs_dra_es1 = {
 	.sdram_config_init              = 0x61862B32,
 	.sdram_config                   = 0x61862B32,
 	.sdram_config2			= 0x08000000,
-	.ref_ctrl                       = 0x0000144A,
+	.ref_ctrl                       = 0x0000493E,
+	.ref_ctrl_final			= 0x0000144A,
 	.sdram_tim1                     = 0xD113781C,
 	.sdram_tim2                     = 0x308F7FE3,
 	.sdram_tim3                     = 0x009F86A8,
diff --git a/arch/arm/include/asm/emif.h b/arch/arm/include/asm/emif.h
index 2fe5776..5a7a812 100644
--- a/arch/arm/include/asm/emif.h
+++ b/arch/arm/include/asm/emif.h
@@ -1122,6 +1122,7 @@ struct emif_regs {
 	u32 sdram_config;
 	u32 sdram_config2;
 	u32 ref_ctrl;
+	u32 ref_ctrl_final;
 	u32 sdram_tim1;
 	u32 sdram_tim2;
 	u32 sdram_tim3;
diff --git a/board/ti/beagle_x15/board.c b/board/ti/beagle_x15/board.c
index db96e34..3a7e04d 100644
--- a/board/ti/beagle_x15/board.c
+++ b/board/ti/beagle_x15/board.c
@@ -47,7 +47,8 @@ static const struct emif_regs beagle_x15_emif1_ddr3_532mhz_emif_regs = {
 	.sdram_config_init	= 0x61851b32,
 	.sdram_config		= 0x61851b32,
 	.sdram_config2		= 0x00000000,
-	.ref_ctrl		= 0x00001035,
+	.ref_ctrl		= 0x000040F1,
+	.ref_ctrl_final		= 0x00001035,
 	.sdram_tim1		= 0xceef266b,
 	.sdram_tim2		= 0x328f7fda,
 	.sdram_tim3		= 0x027f88a8,
@@ -103,7 +104,8 @@ static const struct emif_regs beagle_x15_emif2_ddr3_532mhz_emif_regs = {
 	.sdram_config_init	= 0x61851b32,
 	.sdram_config		= 0x61851b32,
 	.sdram_config2		= 0x00000000,
-	.ref_ctrl		= 0x00001035,
+	.ref_ctrl		= 0x000040F1,
+	.ref_ctrl_final		= 0x00001035,
 	.sdram_tim1		= 0xceef266b,
 	.sdram_tim2		= 0x328f7fda,
 	.sdram_tim3		= 0x027f88a8,
-- 
1.9.1