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authorAaron Durbin <adurbin@chromium.org>2017-03-31 14:51:40 -0500
committerAaron Durbin <adurbin@chromium.org>2017-04-05 18:03:35 +0200
commit2fb5ca81d9b15d956949907c83e61c97d958992e (patch)
tree4feb20cb4d227ebaa834425424b3e1dc531f6923
parent66386d24974e158e7be0c7fed50da654275474e3 (diff)
mainboard/google/reef: increase trackpad data hold time
Even though the i2c spec has no minimum data hold time in fast mode the trackpad vendor indicates 300ns is their minimum. However, the topology of the board uses FET isolation to cross voltage domains. Therefore, the default 300ns which should work isn't reflected on the device side of the voltage isolation circuit. Therefore, increase the data hold time to show an observed data hold time of more than 300ns on the device side. BUG=b:36469182 Change-Id: I1b70f2f53c5a29cc7cfd5035a71ca5811b3bcba0 Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/19065 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Furquan Shaikh <furquan@google.com>
-rw-r--r--src/mainboard/google/reef/variants/baseboard/devicetree.cb1
1 files changed, 1 insertions, 0 deletions
diff --git a/src/mainboard/google/reef/variants/baseboard/devicetree.cb b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
index 443918e037..d5f546c99b 100644
--- a/src/mainboard/google/reef/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
@@ -103,6 +103,7 @@ chip soc/intel/apollolake
.speed = I2C_SPEED_FAST,
.rise_time_ns = 114,
.fall_time_ns = 164,
+ .data_hold_time_ns = 350,
}"
# digitizer at 400kHz