[U-Boot] [PATCH] arm: omap: emif: Support for ddr3 after warm reset

[Lokesh Vutla]

EMIF supports a global warm reset mode, during which the
EMIF keeps the SDRAM content. But if leveling is enabled
at the time of warm reset for DDR3, the following steps
needs to be done after warm reset:
1) Keep EMIF in self refresh mode.
2) Reset PHY to bring back the PHY to a known state.
3) Start Levelling procedure.
Doing the same.
And also enabling DLL lock and code output after warm reset.

Tested on OMAP5432 ES2.0

Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
---
 arch/arm/cpu/armv7/omap-common/emif-common.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap-common/emif-common.c b/arch/arm/cpu/armv7/omap-common/emif-common.c
index 9eb1279..8811958 100644
--- a/arch/arm/cpu/armv7/omap-common/emif-common.c
+++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
@@ -1072,6 +1072,12 @@ static void do_sdram_init(u32 base)
 		else
 			ddr3_init(base, regs);
 	}
+	if (!in_sdram && warm_reset() &&
+	    (emif_sdram_type() == EMIF_SDRAM_TYPE_DDR3)) {
+		set_lpmode_selfrefresh(base);
+		emif_reset_phy(base);
+		ddr3_leveling(base, regs);
+	}
 
 	/* Write to the shadow registers */
 	emif_update_timings(base, regs);
@@ -1259,10 +1265,10 @@ void sdram_init(void)
 	in_sdram = running_from_sdram();
 	debug("in_sdram = %d\n", in_sdram);
 
-	if (!(in_sdram || warm_reset())) {
-		if (sdram_type == EMIF_SDRAM_TYPE_LPDDR2)
+	if (!in_sdram) {
+		if ((sdram_type == EMIF_SDRAM_TYPE_LPDDR2) && !warm_reset())
 			bypass_dpll((*prcm)->cm_clkmode_dpll_core);
-		else
+		else if (sdram_type == EMIF_SDRAM_TYPE_DDR3)
 			writel(CM_DLL_CTRL_NO_OVERRIDE, (*prcm)->cm_dll_ctrl);
 	}
 
-- 
1.7.9.5