Change in coreboot[master]: mb/google/dedede/var/sasuke: Configure I2C times for touchpad/audio

[Karthik Ramasubramanian (Code Review)]

Karthik Ramasubramanian has submitted this change. ( https://review.coreboot.org/c/coreboot/+/51335 )

Change subject: mb/google/dedede/var/sasuke: Configure I2C times for touchpad/audio
......................................................................

mb/google/dedede/var/sasuke: Configure I2C times for touchpad/audio

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

Measured I2C frequency just as below after tuning:
I2C0(touchpad): 385 kHz
I2C4(audio): 380 kHz

BUG=b:180335053
BRANCH=dedede
TEST=Build and check after tuning I2C clock is under 400kHz

Change-Id: Ic92ee0379456e80260a8026bc38ee41325dad6d2
Signed-off-by: Seunghwan Kim 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51335
Tested-by: build bot (Jenkins) 
Reviewed-by: Karthik Ramasubramanian 
---
M src/mainboard/google/dedede/variants/sasuke/overridetree.cb
1 file changed, 4 insertions(+), 9 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Karthik Ramasubramanian: Looks good to me, approved

diff --git a/src/mainboard/google/dedede/variants/sasuke/overridetree.cb b/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
index 2fb1d61..bcc4b49 100644
--- a/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
+++ b/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
@@ -61,9 +61,8 @@
    	},
    	.i2c[0] = {
    		.speed = I2C_SPEED_FAST,
-			.rise_time_ns = 66,
-			.fall_time_ns = 90,
-			.data_hold_time_ns = 350,
+			.rise_time_ns = 209,
+			.fall_time_ns = 12,
    	},
    	.i2c[1] = {
    		.speed = I2C_SPEED_FAST,
@@ -76,12 +75,8 @@
    	},
    	.i2c[4] = {
    		.speed = I2C_SPEED_FAST,
-			.speed_config[0] = {
-				.speed = I2C_SPEED_FAST,
-				.scl_lcnt = 176,
-				.scl_hcnt = 95,
-				.sda_hold = 36,
-			}
+			.rise_time_ns = 175,
+			.fall_time_ns = 8,
    	},
    }"
    device domain 0 on