[coreboot-gerrit] Change in coreboot[master]: mb/google/kukui: fix damu touchscreen reset sequence

[Magf - (Code Review)]

Hello Hung-Te Lin, build bot (Jenkins), Chen-Tsung Hsieh,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/43319

to look at the new patch set (#4).

Change subject: mb/google/kukui: fix damu touchscreen reset sequence
......................................................................

mb/google/kukui: fix damu touchscreen reset sequence

Damu touchscreen is a typical hid-over-i2c device and its reset pin
has a sequence requirement (T5) > 500us. Kernel hid-over-i2c driver
has no interface to support a reset pin, so current implementation
will be using a default pull down pin and rely on kernel to pull
it to high to make it exit reset. In warm boot, in order to get a
valid reset, we have to pull it low then high in firmware stage
to construct a valid reset.

BUG=b:159688118
BRANCH=kukui
TEST=build and boot damu device, when warm reboot, we can get a
     valid reset sequence which is greater than 500us.

Change-Id: I069f5ef3e9477410d5349e5a702a4fbc14c201ed
Signed-off-by: Paul Ma 
---
M src/mainboard/google/kukui/gpio.h
M src/mainboard/google/kukui/mainboard.c
2 files changed, 12 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/19/43319/4