From d2226060aac315c4420dc57569d90af5b0bf32c0 Mon Sep 17 00:00:00 2001 From: Duncan Laurie Date: Wed, 5 Dec 2018 15:41:03 -0800 Subject: mb/google/sarien: Set initial I2C bus rise/fall times Provide rise/fall times as measured on existing boards. This will need adjusted for new boards but provides a starting point that makes I2C clocks look reasonable. Tested by measuring I2C bus speed and rise/fall times with a scope. Change-Id: Ic18010f5efc41dcee8925d696767ba2c44e3df4b Signed-off-by: Duncan Laurie Reviewed-on: https://review.coreboot.org/c/30069 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin Reviewed-by: Lijian Zhao --- src/mainboard/google/sarien/variants/arcada/devicetree.cb | 4 ++++ src/mainboard/google/sarien/variants/sarien/devicetree.cb | 4 ++++ 2 files changed, 8 insertions(+) (limited to 'src/mainboard/google') diff --git a/src/mainboard/google/sarien/variants/arcada/devicetree.cb b/src/mainboard/google/sarien/variants/arcada/devicetree.cb index f4879792de..54308e1852 100644 --- a/src/mainboard/google/sarien/variants/arcada/devicetree.cb +++ b/src/mainboard/google/sarien/variants/arcada/devicetree.cb @@ -67,10 +67,14 @@ chip soc/intel/cannonlake }, .i2c[1] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 216, + .fall_time_ns = 28, }, .i2c[4] = { .early_init = 1, .speed = I2C_SPEED_FAST, + .rise_time_ns = 452, + .fall_time_ns = 110, }, }" diff --git a/src/mainboard/google/sarien/variants/sarien/devicetree.cb b/src/mainboard/google/sarien/variants/sarien/devicetree.cb index 5004abf1b8..6afc13c694 100644 --- a/src/mainboard/google/sarien/variants/sarien/devicetree.cb +++ b/src/mainboard/google/sarien/variants/sarien/devicetree.cb @@ -67,10 +67,14 @@ chip soc/intel/cannonlake }, .i2c[1] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 290, + .fall_time_ns = 110, }, .i2c[4] = { .early_init = 1, .speed = I2C_SPEED_FAST, + .rise_time_ns = 280, + .fall_time_ns = 90, }, }" -- cgit v1.2.3