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authorDuncan Laurie <dlaurie@google.com>2018-12-05 15:41:03 -0800
committerPatrick Georgi <pgeorgi@google.com>2018-12-07 11:19:16 +0000
commitd2226060aac315c4420dc57569d90af5b0bf32c0 (patch)
treeb2a30420080a13dac5cf2d3f7762c32a6507856e
parent4afefd648b28d4ebabd6d07790037e3e00c9ff03 (diff)
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 <dlaurie@google.com> Reviewed-on: https://review.coreboot.org/c/30069 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
-rw-r--r--src/mainboard/google/sarien/variants/arcada/devicetree.cb4
-rw-r--r--src/mainboard/google/sarien/variants/sarien/devicetree.cb4
2 files changed, 8 insertions, 0 deletions
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,
},
}"