exynos5420: ddr3: Alter init sequence as per recommendation
As per hardware recommendation, CKE PAD retention release must
happen just before gate leveling enable and only in case of resume.
Hence, this patch moves pad retention release from dmc_common.c to
dmc_init_ddr3_exynos5420.c. In addition to this we are providing
125 (+3 extra being safe) times auto refresh to DRAM by sending
REFA direct command. This is required because when CKE PAD retention
release happens, self refresh mode of DDR3 is disabled.
Hence, auto refresh 125 times.
BRANCH=pit
BUG=chrome-os-partner:20775
TEST=Tested suspend_stress_test on four boards with this change in
U-Boot. All four boards completed 5000 cycles successfully.
[dianders: split change, adjusted commit tags]
Change-Id: I4bb5e4d08993cbdeaa8c7d62ef91a3e641702e8c
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/65573
3 files changed
