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    SubjectRe: [PATCH] gpio: add support for ITE IT87xx Super I/O GPIO.
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    On Mon, Mar 19, 2012 at 1:54 AM, Guenter Roeck
    <guenter.roeck@ericsson.com> wrote:
    > On Sun, Mar 18, 2012 at 07:14:45PM -0400, Linus Walleij wrote:
    >> On Sat, Mar 17, 2012 at 7:53 PM, Diego Elio Pettenņ
    >> <flameeyes@flameeyes.eu> wrote:
    >>
    >> > Another reason to have a MFD driver would be to allow tweaking the few
    >> > more knobs that (at least IT8728F) expose, such as the ability to switch
    >> > a few pre-defined inputs and outputs to GPIO instead, and so on...
    >>
    >> Hm that sounds an awful lot like pin multiplexing. Is that the case?
    >>
    > Depending on the chip configuration, a physical pin may be a GPIO pin, or a UART pin,
    > or a fan control pin, or a FD pin, or something else. This does not apply to all pins,
    > but to many of the GPIO pins.

    OK that is pinmuxing, if that is to be software-controlled the place to do
    it is in drivers/pinctrl. (Documentation/pinctrl.txt gives the backrgound.)

    The rule is in that case to put the driver below drivers/pinctrl/* and also
    expose a gpiolib interface from that driver.

    As we convert drivers to the new pinctrl interfaces we tend to move them
    from drivers/gpio to drivers/pinctrl. But no biggie, if pinctrl is added later,
    it can be moved by then. I'm mainly concerned with blocking any
    extra custom interfaces to the gpio drivers.

    Yours,
    Linus Walleij
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