[coreboot-gerrit] Change in coreboot[master]: mb/google/hatch: Fine-tune Kohaku I2C CLK frequency

[Philip Chen (Code Review)]

Philip Chen has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/34559 )

Change subject: mb/google/hatch: Fine-tune Kohaku I2C CLK frequency
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mb/google/hatch: Fine-tune Kohaku I2C CLK frequency

Add rise time / fall time to I2C config in device tree
to ensure I2C CLK runs accurately at I2C_SPEED_FAST (400 kHz).

BUG=b:138258384
BRANCH=none
TEST=probe I2C0/I2C2/I2C3 SCL on Kohaku board,
verify all of them run at 395-399 kHz.

Change-Id: Id98079e717f0db3fdcb88f85e45693925d11d7fd
Signed-off-by: Philip Chen 
---
M src/mainboard/google/hatch/variants/kohaku/overridetree.cb
1 file changed, 6 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/59/34559/1

diff --git a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb
index e463b8b..6fdc0a0 100644
--- a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb
+++ b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb
@@ -29,15 +29,21 @@
    register "common_soc_config" = "{
    	.i2c[0] = {
    		.speed = I2C_SPEED_FAST,
+			.rise_time_ns = 135,
+			.fall_time_ns = 45,
    	},
    	.i2c[1] = {
    		.speed = I2C_SPEED_FAST,
    	},
    	.i2c[2] = {
    		.speed = I2C_SPEED_FAST,
+			.rise_time_ns = 95,
+			.fall_time_ns = 55,
    	},
    	.i2c[4] = {
    		.speed = I2C_SPEED_FAST,
+			.rise_time_ns = 100,
+			.fall_time_ns = 20,
    	},
    	.gspi[0] = {
    	       .speed_mhz = 1,