[U-Boot] [PATCH 2/2] ARM: am33xx: Always inhibit init/refresh during DDR phy init

[Russ Dill <Russ.Dill@ti.com>]

A couple of commits have modified the am33xx/am437x ddr2/ddr3
initialization path to fix certain issues, but have had the side effect
of causing L3 noc errors during initialization. The two commits are:

69b918 "am33xx,ddr3: fix ddr3 sdram configuration"
fc46ba "arm: am437x: Enable hardware leveling for EMIF"

The EMIF_REG_INITREF_DIS_MASK bit still needs to be set for all
platforms. This delays initialization and refresh until a later stage.
The 500us timer can be programmed for platforms that require it
and for platforms that don't require it. It is currently hardcoded
for 400MHz systems. For systems with a higher memory frequency
this needs to be a larger value, and for systems with a lower
memory frequency this can be a lower value. This can be
considered a separate issue and corrected in a later commit.

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
---
 arch/arm/cpu/armv7/am33xx/ddr.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/arm/cpu/armv7/am33xx/ddr.c b/arch/arm/cpu/armv7/am33xx/ddr.c
index ef1fc4d..6acf30c 100644
--- a/arch/arm/cpu/armv7/am33xx/ddr.c
+++ b/arch/arm/cpu/armv7/am33xx/ddr.c
@@ -292,19 +292,14 @@ static void ext_phy_settings_hwlvl(const struct emif_regs *regs, int nr)
 void config_ddr_phy(const struct emif_regs *regs, int nr)
 {
 	/*
-	 * Disable initialization and refreshes for now until we
-	 * finish programming EMIF regs.
-	 * Also set time between rising edge of DDR_RESET to rising
-	 * edge of DDR_CKE to > 500us per memory spec.
+	 * Disable initialization and refreshes for now until we finish
+	 * programming EMIF regs and set time between rising edge of
+	 * DDR_RESET to rising edge of DDR_CKE to > 500us per memory spec.
+	 * We currently hardcode a value based on a max expected frequency
+	 * of 400MHz.
 	 */
-#ifndef CONFIG_AM43XX
-	setbits_le32(&emif_reg[nr]->emif_sdram_ref_ctrl,
-		     EMIF_REG_INITREF_DIS_MASK);
-#endif
-	if (regs->zq_config)
-		/* Set time between rising edge of DDR_RESET to rising
-		 * edge of DDR_CKE to > 500us per memory spec. */
-		writel(0x00003100, &emif_reg[nr]->emif_sdram_ref_ctrl);
+	writel(EMIF_REG_INITREF_DIS_MASK | 0x3100,
+		&emif_reg[nr]->emif_sdram_ref_ctrl);
 
 	writel(regs->emif_ddr_phy_ctlr_1,
 		&emif_reg[nr]->emif_ddr_phy_ctrl_1);
-- 
2.8.1