• Janusz Krzysztofik's avatar
    gpiolib: Identify arrays matching GPIO hardware · bf9346f5
    Janusz Krzysztofik authored
    Certain GPIO array lookup results may map directly to GPIO pins of a
    single GPIO chip in hardware order.  If that condition is recognized
    and handled efficiently, significant performance gain of get/set array
    functions may be possible.
    
    While processing a request for an array of GPIO descriptors, identify
    those which represent corresponding pins of a single GPIO chip.  Skip
    over pins which require open source or open drain special processing.
    Moreover, identify pins which require inversion.  Pass a pointer to
    that information with the array to the caller so it can benefit from
    enhanced performance as soon as get/set array functions can accept and
    make efficient use of it.
    
    Cc: Jonathan Corbet <corbet@lwn.net>
    Signed-off-by: default avatarJanusz Krzysztofik <jmkrzyszt@gmail.com>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    bf9346f5
gpiolib.c 119 KB