Lux base detection is a little trickier than previous bases,
as the detection levels switch around when GPIO_EC_COMM_PD gets
enabled:
- When disconnected, low levels (~550mV) mean base got connected,
and high levels (~3300mV) mean base is still disconnected.
- When connected, low levels (~43mV) mean base got disconnected,
and high levels (~2346mV) mean base is still connected.
On reset, when base_status is unknown, we enable GPIO_EC_COMM_PD,
to be able to differentiate between connected and disconnected.
BRANCH=none
BUG=b:67029560
TEST=Connect lux/wand, check that base gets detected correctly.
TEST=Type reboot in EC console, base gets detected as well.
Change-Id: I742def8e378a93c08e2dcc155b06cbca814e7fd8
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/845543
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
ecfa696638