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

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@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); }

On Wednesday 27 March 2013 09:55 AM, Lokesh Vutla wrote:
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:
- Keep EMIF in self refresh mode.
- Reset PHY to bring back the PHY to a known state.
- Start Levelling procedure.
Doing the same. And also enabling DLL lock and code output after warm reset.
Should the $subject be something like Fix DDR3 initialisation after warm reset ?
Tested on OMAP5432 ES2.0
Signed-off-by: Lokesh Vutla lokeshvutla@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);
- }
Why do we need !in_sdram check here ?. Otherwise, good..
Reviewed-by: R Sricharan r.sricharan@ti.com
Regards, Sricharan

On Wednesday 27 March 2013 10:41 AM, Sricharan R wrote:
On Wednesday 27 March 2013 09:55 AM, Lokesh Vutla wrote:
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:
- Keep EMIF in self refresh mode.
- Reset PHY to bring back the PHY to a known state.
- Start Levelling procedure.
Doing the same. And also enabling DLL lock and code output after warm reset.
Should the $subject be something like Fix DDR3 initialisation after warm reset ?
Ok I ll change it.
Tested on OMAP5432 ES2.0
Signed-off-by: Lokesh Vutla lokeshvutla@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);
- }
Why do we need !in_sdram check here ?. Otherwise, good..
DDR3 leveling cannot happen from SDRAM. So I kept a check here.
Thanks and Regards, Lokesh
Reviewed-by: R Sricharan <r.sricharan@ti.com>
Regards, Sricharan
participants (2)
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Lokesh Vutla
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Sricharan R