• H. Nikolaus Schaller's avatar
    Input: bma150 - remove support for bma150 · f069b5a0
    H. Nikolaus Schaller authored
    This essentially reverts commit baf28d91 ("Input: bma150 - avoid
    binding to bma180 if IIO bma180 driver present") and commit ef3714fd
    ("Input: bma150 - extend chip detection for bma180")
    Rationale: initially (2012) the GTA04 device using a bma180 chip simply
    referenced the bma150 platform driver in its board file [1] which happened
    to work in all scenarios that were tested.
    When conversion to DT started (2014), we needed to make the driver be still
    recognised. Hence we introduced the compatibility to the bma180 chip in
    Linux 3.15-rc5 [2] without further checks if it is really 100% compatible.
    This worked flawlessly for years with the GTA04 device.
    Recently (2016), Hans de Goede pointed out that the chips are not as
    similar as they appeared and the driver works with the bma180 for the GTA04
    only by good luck. He proposed to remove the bma180 support completely [3],
    but we still did need it until we have a replacement. Thus, a conditional
    compile was added.
    We have now developed a generic iio-input-bridge which works with any 2 or
    3 axis iio based accelerometer. It has been tested on GTA04 and Pyra and
    works as expected. Therefore we can remove the bma180 support from this
    driver completely. User-space API compatibility can be restored by using
    the iio-input-bridge.
    Maybe it is time to convert the bma150 driver to iio as well and retire the
    accelerometer input drivers completely but this is a different story and
    [1]: https://github.com/neilbrown/linux/blob/gta04/3.2.y/arch/arm/mach-omap2/board-omap3gta04.c#L976
    [2]: https://patchwork.kernel.org/patch/3961171/
    [3]: https://patchwork.kernel.org/patch/9325481/Signed-off-by: default avatarH. Nikolaus Schaller <hns@goldelico.com>
    Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
    Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>