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    Subject[RFC 00/17] Remove GENERIC_GPIO from architecture code
    This series makes sure the GENERIC_GPIO option can only be set through GPIOLIB 
    (and not by individual architectures), as a first step towards its removal.

    It is targeted at getting feedback from architecture maintainers (and complains
    if this is deemed too bold a move - however, I hope the rationale behind this
    will be convincing).

    AFAICT every GPIO driver that implement the generic GPIO API support gpiolib at
    least optionally, and the overwhelming majority actually requires it. Using the
    generic GPIO API alone has become a marginal practice, and the benefit of
    retaining this option is rather uncertain when compared to the confusion and
    complexity it induces:
    * More and more GPIO features are built around gpiolib. The sysfs interface is
    one of them ; the future gpiod API is another one. Platforms that only implement
    the generic GPIO API cannot benefit from these and the split between those who
    only implement the generic GPIO API and full-fledge users of gpiolib is becoming
    wider and wider.
    * Having two layers of GPIO support is confusing to both GPIO users and
    providers, and it is easy to e.g. only depend on GENERIC_GPIO when one actually
    needs gpiolib. This series actually fixes a few of these cases.
    * Simplicity and consistency is always a good thing - features in the kernel are
    typically implemented through well-defined frameworks, and similarly GPIO
    support could be consolidated around gpiolib.

    Arguments against using gpiolib:
    * Memory footprint of gpiolib. According to my tests a gpiolib with 256 GPIOs
    induces an overhead of ~15KB, which sounds rather reasonable.
    * Performance. gpiolib introduces another layer of indirection compared to
    drivers that only implement the generic GPIO API. However, a fast path is
    available to platforms for which GPIO performance matters through the
    implementation of custom gpio_set_value() and gpio_get_value() functions which
    test for a given GPIO range and shortcut gpiolib.

    For most platforms, this change should be a no-op. However I would like to make
    sure that everyone is ok with it and that nothing gets broken, as the effect of
    changing configuration options are sometimes difficult to predict.

    Alexandre Courbot (17):
    arm: remove unneeded select GENERIC_GPIO
    arm: remove redundant GENERIC_GPIO selection
    arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB
    mips: remove redundant GENERIC_GPIO select
    mips: loongson: use GPIO driver on CONFIG_GPIOLIB
    mips: txx9: change GENERIC_GPIO to GPIOLIB
    unicore32: remove unneeded select GENERIC_GPIO
    powerpc: remove redundant GENERIC_GPIO selection
    xtensa: remove explicit selection of GENERIC_GPIO
    mips: alchemy: require gpiolib
    mips: pnx833x: remove requirement for GENERIC_GPIO
    avr32: default GENERIC_GPIO to false
    m68k: coldfire: use gpiolib
    avr32: default GENERIC_GPIO to false
    openrisc: default GENERIC_GPIO to false
    unicore32: default GENERIC_GPIO to false

    arch/arm/Kconfig | 2 --
    arch/arm/plat-orion/Makefile | 2 +-
    arch/avr32/Kconfig | 2 +-
    arch/blackfin/Kconfig | 2 +-
    arch/m68k/Kconfig.cpu | 3 +--
    arch/mips/Kconfig | 7 +------
    arch/mips/loongson/common/Makefile | 2 +-
    arch/mips/txx9/generic/setup.c | 2 +-
    arch/openrisc/Kconfig | 2 +-
    arch/powerpc/platforms/40x/Kconfig | 1 -
    arch/powerpc/platforms/44x/Kconfig | 1 -
    arch/powerpc/platforms/85xx/Kconfig | 1 -
    arch/powerpc/platforms/86xx/Kconfig | 3 ---
    arch/powerpc/platforms/8xx/Kconfig | 1 -
    arch/powerpc/platforms/Kconfig | 4 ----
    arch/sh/boards/mach-sdk7786/Makefile | 2 +-
    arch/sh/boards/mach-x3proto/Makefile | 2 +-
    arch/sh/kernel/cpu/sh2a/Makefile | 2 +-
    arch/sh/kernel/cpu/sh3/Makefile | 2 +-
    arch/sh/kernel/cpu/sh4a/Makefile | 2 +-
    arch/unicore32/Kconfig | 3 +--
    arch/xtensa/configs/iss_defconfig | 1 -
    arch/xtensa/configs/s6105_defconfig | 1 -
    23 files changed, 14 insertions(+), 36 deletions(-)


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