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    SubjectRe: [PATCH 1/2] drivers: create a pinmux subsystem v3
    On Sat, Jul 9, 2011 at 12:23 PM, Mark Brown
    <> wrote:
    > On Mon, Jun 13, 2011 at 01:57:36PM -0600, Grant Likely wrote:
    >> On Mon, Jun 13, 2011 at 10:58 AM, Linus Walleij
    >> I would *strongly* recommend against individual device drivers
    >> accessing the pinmux api.  This is system level configuration code,
    >> and should be handled at the system level.
    > There can also be advantages to putting the pin into the designed mode
    > without the driver being loaded from the electrical point of view.  For
    > example, selecting appropriate pull values for pads can cut down on
    > power consumption.

    Since the pin control subsystem is reference counting wrt
    mux settings, one does not exclude the other. So for
    example a driver may or may not grab a certain set-up of pins
    and the core platform may do the same, but when they start to
    request different conflicting things the subsystem will complain,
    as is apropriate.

    So this is a very pure driver framework, without policy, it just
    does what it's told, and will prevent undefined and impossible
    settings. Atleast that's the idea.

    Linus Walleij
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