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@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, }, }"