UPSTREAM: 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: Ibf33401c55f4e3b34b7f236f26eda7dcf5fa3bf3
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 2fb5ca81d9
Original-Change-Id: I1b70f2f53c5a29cc7cfd5035a71ca5811b3bcba0
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://review.coreboot.org/19065
Original-Tested-by: build bot (Jenkins)
Original-Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Original-Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/471453
This commit is contained in:
Aaron Durbin 2017-03-31 14:51:40 -05:00 committed by chrome-bot
parent 194c3a7785
commit bbda19b27e

View file

@ -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