Files
android_kernel_xiaomi_sm8450/drivers/gpio/gpio-sch.c
Daniel Krueger 1e0d982317 gpio-sch: set output level after configuration of direction
According to the datasheet, writing to the level register has no effect
when GPIO is programmed as input. Actually the the level register is
read-only when configured as input. Thus presetting the output level
before switching to output is _NOT_ possible. Any writes are lost!
Hence we set the level after configuring the GPIO as output.
But we cannot prevent a short low pulse if direction is set to high and
an external  pull-up is connected.

Signed-off-by: Daniel Krueger <daniel.krueger@systec-electronic.com>
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-04-28 12:35:08 -07:00

7.8 KiB