[U-Boot] [PATCH V2] arm: omap: emif: Fix DDR3 init after warm reset

Lokesh Vutla lokeshvutla at ti.com
Thu Mar 28 07:24:42 CET 2013


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>
---
Changes since V1:
	- Changed $subject
	- Removed redundant in_sdram check
 arch/arm/cpu/armv7/omap-common/emif-common.c |   11 ++++++++---
 1 file changed, 8 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..3e3f3ea 100644
--- a/arch/arm/cpu/armv7/omap-common/emif-common.c
+++ b/arch/arm/cpu/armv7/omap-common/emif-common.c
@@ -1072,6 +1072,11 @@ static void do_sdram_init(u32 base)
 		else
 			ddr3_init(base, regs);
 	}
+	if (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 +1264,10 @@ 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



More information about the U-Boot mailing list