• Charles Keepax's avatar
    pinctrl: samsung: Register pinctrl before GPIO · 1abd18d1
    Charles Keepax authored
    If we request a GPIO hog, then gpiochip_add_data will attempt
    to request some of its own GPIOs. The driver also uses
    gpiochip_generic_request which means that for any GPIO request to
    succeed the pinctrl needs to be registered. Currently however the
    driver registers the GPIO and then the pinctrl meaning all GPIO hog
    requests will fail, which then in turn causes the whole driver to fail
    probe.
    
    Fix this up by ensuring we register the pinctrl first. This
    does require us to manually set the GPIO base for the
    pinctrl. Fortunately the driver already assigns a fixed GPIO base, in
    samsung_gpiolib_register, and uses the same calculation it does for
    the pin_base. Meaning the two will always be the same and allowing us
    to reuse the pinbase and avoid the issue.
    
    Although currently there are no users of GPIO hogs in mainline
    there are plenty of Samsung based boards that are widely used for
    development purposes of other hardware. Indeed we hit this issue
    whilst attaching some additional hardware to an Arndale system.
    Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
    Signed-off-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
    1abd18d1
pinctrl-samsung.c 33.2 KB