• Masahiro Yamada's avatar
    gpio: of: fix GPIO drivers with multiple gpio_chip for a single node · c7e9d398
    Masahiro Yamada authored
    Sylvain Lemieux reports the LPC32xx GPIO driver is broken since
    commit 762c2e46 ("gpio: of: remove of_gpiochip_and_xlate() and
    struct gg_data").  Probably, gpio-etraxfs.c and gpio-davinci.c are
    broken too.
    
    Those drivers register multiple gpio_chip that are associated to a
    single OF node, and their own .of_xlate() checks if the passed
    gpio_chip is valid.
    
    Now, the problem is of_find_gpiochip_by_node() returns the first
    gpio_chip found to match the given node.  So, .of_xlate() fails,
    except for the first GPIO bank.
    
    Reverting the commit could be a solution, but I do not want to go
    back to the mess of struct gg_data.  Another solution here is to
    take the match by a node pointer and the success of .of_xlate().
    It is a bit clumsy to call .of_xlate twice; for gpio_chip matching
    and for really getting the gpio_desc index.  Perhaps, our long-term
    goal might be to convert the drivers to single chip registration,
    but this commit will solve the problem until then.
    
    Fixes: 762c2e46 ("gpio: of: remove of_gpiochip_and_xlate() and struct gg_data")
    Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
    Reported-by: default avatarSylvain Lemieux <slemieux.tyco@gmail.com>
    Tested-by: default avatarDavid Lechner <david@lechnology.com>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    c7e9d398
gpiolib-of.c 13 KB