• Johan Hovold's avatar
    gpio: remove gpiod_sysfs_set_active_low · 166a85e4
    Johan Hovold authored
    Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
    allowed code to change the polarity of a gpio line even after it had
    been exported through sysfs.
    
    Drivers should not care, and generally does not know, about gpio-line
    polarity which is a hardware feature that needs to be described by
    firmware.
    
    It is currently possible to define gpio-line polarity in device-tree and
    acpi firmware or using platform data. Userspace can also change the
    polarity through sysfs.
    
    Note that drivers using the legacy gpio interface could still use
    GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.
    
    There are no in-kernel users of this interface.
    
    Cc: Jonathan Corbet <corbet@lwn.net>
    Cc: Harry Wei <harryxiyou@gmail.com>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: linux-doc@vger.kernel.org
    Cc: linux-kernel@zh-kernel.org
    Cc: linux-arch@vger.kernel.org
    Signed-off-by: 's avatarJohan Hovold <johan@kernel.org>
    Reviewed-by: 's avatarAlexandre Courbot <acourbot@nvidia.com>
    Signed-off-by: 's avatarLinus Walleij <linus.walleij@linaro.org>
    166a85e4
gpio.h 5.63 KB