From d9105d98b7cf98bec64f53ee1fb786599279b336 Mon Sep 17 00:00:00 2001 From: Seunghwan Kim Date: Thu, 28 Nov 2019 16:35:02 +0900 Subject: mb/google/kohaku: Adjust I2C clock frequency All serial I2C bus frequencies should not be over 400KHz in kohaku, but the measurement showed frequencies of I2C1 and I2C4 were over 400KHz. (b:144885961) This change adjusts I2C speed settings to limit that frequencies to 400KHz. The new setting values have been from other projects using same I2C components, and verified I2C1 and I2C4 frequencies < 400MHz internally. BUG=b:144885961 BRANCH=firmware-hatch-12672.B TEST=Verified I2C1 and I2C4 frequency not over 400KHz Change-Id: I9614fb39b6e55cb2ce1b0879a9f5204e55002f8d Signed-off-by: Seunghwan Kim Reviewed-on: https://review.coreboot.org/c/coreboot/+/37313 Tested-by: build bot (Jenkins) Reviewed-by: Tim Wawrzynczak --- src/mainboard/google/hatch/variants/kohaku/overridetree.cb | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb index 55ac071be5..d515ecc44d 100644 --- a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb +++ b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb @@ -60,6 +60,8 @@ chip soc/intel/cannonlake }, .i2c[1] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 60, + .fall_time_ns = 25, }, .i2c[2] = { .speed = I2C_SPEED_FAST, @@ -68,8 +70,8 @@ chip soc/intel/cannonlake }, .i2c[4] = { .speed = I2C_SPEED_FAST, - .rise_time_ns = 100, - .fall_time_ns = 20, + .rise_time_ns = 104, + .fall_time_ns = 52, }, .gspi[0] = { .speed_mhz = 1, -- cgit v1.2.3