[coreboot-gerrit] New patch to review for coreboot: mainboard/google/reef: Tune i2c frequency to under 400 Khz
Tim Chen (Tim-Chen@quantatw.com)
gerrit at coreboot.org
Fri Feb 3 10:42:24 CET 2017
Tim Chen (Tim-Chen at quantatw.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/18284
-gerrit
commit 8fca0ab3999413daeadb990aca4cb5fcad41b366
Author: Tim Chen <Tim-Chen at quantatw.com>
Date: Fri Feb 3 16:57:39 2017 +0800
mainboard/google/reef: Tune i2c frequency to under 400 Khz
tune i2c devices clk for reef:
I2C0: audio
I2C2: TPM H1
I2C4: elan touchpad
BUG=chrome-os-partner:62593
BRANCH=master
TEST=emerge-reef coreboot chromeos-bootimage, and measured on EVT.
audio:
Freq. 393.1kHz
TPM H1:
Freq. 369.5kHz
elan touchpad:
Freq. 397.0kHz
Change-Id: If27b7a1333d5f1e14c850a0dfb3c6eb90f0072fc
---
src/mainboard/google/reef/variants/baseboard/devicetree.cb | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/mainboard/google/reef/variants/baseboard/devicetree.cb b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
index 2ccf277..e40bfee 100644
--- a/src/mainboard/google/reef/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
@@ -76,16 +76,16 @@ chip soc/intel/apollolake
# Enable I2C0 for audio codec at 400kHz
register "i2c[0]" = "{
.speed = I2C_SPEED_FAST,
- .rise_time_ns = 104,
- .fall_time_ns = 52,
+ .rise_time_ns = 44,
+ .fall_time_ns = 22,
}"
# Enable I2C2 bus early for TPM at 400kHz
register "i2c[2]" = "{
.early_init = 1,
.speed = I2C_SPEED_FAST,
- .rise_time_ns = 57,
- .fall_time_ns = 28,
+ .rise_time_ns = 30,
+ .fall_time_ns = 15,
}"
# touchscreen at 400kHz
@@ -98,8 +98,8 @@ chip soc/intel/apollolake
# trackpad at 400kHz
register "i2c[4]" = "{
.speed = I2C_SPEED_FAST,
- .rise_time_ns = 114,
- .fall_time_ns = 164,
+ .rise_time_ns = 57,
+ .fall_time_ns = 82,
}"
# digitizer at 400kHz
More information about the coreboot-gerrit
mailing list