[coreboot-gerrit] Change in ...coreboot[master]: mb/google/sarien: Set initial I2C bus rise/fall times

[Duncan Laurie (Code Review)]

Duncan Laurie has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/30069


Change subject: mb/google/sarien: Set initial I2C bus rise/fall times
......................................................................

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 at google.com>
---
M src/mainboard/google/sarien/variants/arcada/devicetree.cb
M src/mainboard/google/sarien/variants/sarien/devicetree.cb
2 files changed, 8 insertions(+), 0 deletions(-)



  git pull ssh://review.coreboot.org:29418/coreboot refs/changes/69/30069/1

diff --git a/src/mainboard/google/sarien/variants/arcada/devicetree.cb b/src/mainboard/google/sarien/variants/arcada/devicetree.cb
index f487979..54308e1 100644
--- a/src/mainboard/google/sarien/variants/arcada/devicetree.cb
+++ b/src/mainboard/google/sarien/variants/arcada/devicetree.cb
@@ -67,10 +67,14 @@
 		},
 		.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 991e9640..e1f2512 100644
--- a/src/mainboard/google/sarien/variants/sarien/devicetree.cb
+++ b/src/mainboard/google/sarien/variants/sarien/devicetree.cb
@@ -67,10 +67,14 @@
 		},
 		.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,
 		},
 	}"
 

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Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-Change-Id: Ic18010f5efc41dcee8925d696767ba2c44e3df4b
Gerrit-Change-Number: 30069
Gerrit-PatchSet: 1
Gerrit-Owner: Duncan Laurie <dlaurie at chromium.org>
Gerrit-MessageType: newchange
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