[coreboot-gerrit] New patch to review for coreboot: google/eve: Add rise/fall times for I2C buses

[Duncan Laurie (dlaurie@chromium.org)]

Duncan Laurie (dlaurie at chromium.org) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/18487

-gerrit

commit e8858c0fe99fa2323b484f283ddcab459939a372
Author: Duncan Laurie <dlaurie at chromium.org>
Date:   Fri Feb 24 12:28:12 2017 -0800

    google/eve: Add rise/fall times for I2C buses
    
    Apply tuning for the PCH I2C buses on Eve based on rise/fall time
    measurements that were done with a scope.
    
    BUG=chrome-os-partner:59686
    BRANCH=none
    TEST=Manual testing on Eve P1 to verify that all devices on I2C
    buses are still functional.  Post-tuning measurement will be done
    once a new firmware is released.
    
    Change-Id: I3d70ff455a20ecda374d7e7fa6cd3ab15e7f2621
    Signed-off-by: Duncan Laurie <dlaurie at chromium.org>
---
 src/mainboard/google/eve/devicetree.cb | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/mainboard/google/eve/devicetree.cb b/src/mainboard/google/eve/devicetree.cb
index e5ac17f..0de7a26 100644
--- a/src/mainboard/google/eve/devicetree.cb
+++ b/src/mainboard/google/eve/devicetree.cb
@@ -162,12 +162,16 @@ chip soc/intel/skylake
 	register "usb3_ports[2]" = "USB3_PORT_EMPTY"		# Empty
 	register "usb3_ports[3]" = "USB3_PORT_EMPTY"		# Empty
 
-	register "i2c_voltage[0]" = "I2C_VOLTAGE_3V3"	# Touchscreen
-	register "i2c_voltage[1]" = "I2C_VOLTAGE_3V3"	# TPM
-	register "i2c_voltage[2]" = "I2C_VOLTAGE_1V8"	# Touchpad
-	register "i2c_voltage[4]" = "I2C_VOLTAGE_1V8"	# Audio
+	# Touchscreen
+	register "i2c_voltage[0]" = "I2C_VOLTAGE_3V3"
+	register "i2c[0]" = "{
+		.speed = I2C_SPEED_FAST_PLUS,
+		.rise_time_ns = 17,
+		.fall_time_ns = 38,
+	}"
 
 	# Enable I2C1 bus early for TPM access
+	register "i2c_voltage[1]" = "I2C_VOLTAGE_3V3"
 	register "i2c[1]" = "{
 		.early_init = 1,
 		.speed = I2C_SPEED_FAST,
@@ -175,6 +179,22 @@ chip soc/intel/skylake
 		.fall_time_ns = 32,
 	}"
 
+	# Touchpad
+	register "i2c_voltage[2]" = "I2C_VOLTAGE_1V8"
+	register "i2c[2]" = "{
+		.speed = I2C_SPEED_FAST,
+		.rise_time_ns = 247,
+		.fall_time_ns = 17,
+	}"
+
+	# Audio
+	register "i2c_voltage[4]" = "I2C_VOLTAGE_1V8"
+	register "i2c[4]" = "{
+		.speed = I2C_SPEED_FAST,
+		.rise_time_ns = 240,
+		.fall_time_ns = 30,
+	}"
+
 	# Must leave UART0 enabled or SD/eMMC will not work as PCI
 	register "SerialIoDevMode" = "{
 		[PchSerialIoIndexI2C0]  = PchSerialIoPci,