mb/google/zork/berknip: Increase eMMC initial clock frequency
This will reduce boot time by 7ms. Some of the initial designs
don't have a pull-up resistor on the CMD line. These designs still boot
at 400 kHz despite not having the pull-up.
BUG=b:158766134
TEST=Boot Berknip w/ eMMC to OS.
BRANCH=zork
Change-Id: I5d55f55b8208b4dc3fbdc9d1ec6333f9e211e3fd
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45931
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/zork/variants/berknip/overridetree.cb b/src/mainboard/google/zork/variants/berknip/overridetree.cb
index 9562939..674d557 100644
--- a/src/mainboard/google/zork/variants/berknip/overridetree.cb
+++ b/src/mainboard/google/zork/variants/berknip/overridetree.cb
@@ -38,6 +38,12 @@
.early_init = true,
}"
+ register "emmc_config" = "{
+ .timing = SD_EMMC_EMMC_HS400,
+ .sdr104_hs400_driver_strength = SD_EMMC_DRIVE_STRENGTH_A,
+ .init_khz_preset = 400,
+ }"
+
# See AMD 55570-B1 Table 13: PCI Device ID Assignments.
device domain 0 on
subsystemid 0x1022 0x1510 inherit