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    SubjectRe: [PATCH v3 1/1] pinctrl: add Intel BayTrail GPIO/pinctrl support
    On 04/15/2014 05:01 AM, Mathias Nyman wrote:
    >>
    >> This device will only be used on an ACPI system, right? And isn't ACPI
    >> supposed to hide all the pinctrl programming from the OS? I thought
    >> that was the whole point behind ACPI and the reason why ARM64 isn't
    >> going to use device trees.
    >>
    >
    > This was my starting point as well, and the driver was initially
    > submitted as a GPIO driver. But Linus W. suggested pinctrl instead, and
    > as he's the maintainer of both those subsystem I trust his judgment.

    Do you think, for an ACPI pinctrl driver, that we will need to specify
    any function groups? When I look at the ASL that configures GPIOs, I
    see only lines like this:

    GpioIo (Exclusive, PullDefault, , , , "\\GIO0") {0x1D, 0x1E}

    This tells me that ACPI will never use any of the names that are
    defined. I see that .get_function_name is called on my ACPI system, but
    I don't see where it is used.

    The reason I ask is because I would like to make a "generic" ACPI
    pinctrl/gpio driver that doesn't specify any pin groups. So if we use
    the same pinctrl/gpio hardware on multiple SOCs, the only thing that the
    driver needs from ACPI is the number of pins.

    --
    Sent by an employee of the Qualcomm Innovation Center, Inc.
    The Qualcomm Innovation Center, Inc. is a member of the
    Code Aurora Forum, hosted by the Linux Foundation.


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