When attempting to setup up a gpio hog, device probing will repeatedly
fail with -EPROBE_DEFERED errors. It is caused by a circular dependency
between the gpio and pinctrl frameworks. If the gpio-ranges property is
present in device tree, then the gpio framework will handle the gpio pin
registration and eliminate the circular dependency.
See Christian Lamparter's commit a86caa9ba5 ("pinctrl: msm: fix
gpio-hog related boot issues") for a detailed commit message that
explains the issue in much more detail. The code comment in this commit
came from Christian's commit.
I did not test this change against any hardware supported by this
particular driver, however I was able to validate this same fix works
for pinctrl-spmi-gpio.c using a LG Nexus 5 (hammerhead) phone.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>