It is not necessary to enable Bank B, as we do not use it.
Also, we have seen a race between enabling the banks and writing
the brightness register to 0xFF, where the chip would reset the
value after it has been set by EC. Adding a short 100us sleep
fixes the issue.
BRANCH=none
BUG=b:69379749
TEST=Flash whiskers, pwm 0 50 works, even after a cold reset.
Change-Id: Ic523a2475c3874c8433eb1b39e927793dd893e8f
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/906165
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Edward Hill <ecgh@chromium.org>
Reviewed-by: Benjamin Gordon <bmgordon@chromium.org>