lkml.org 
[lkml]   [2012]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 1/2] pinctrl: add pinctrl_provide_dummies interface for platforms to use
    On Wed, Apr 25, 2012 at 11:22:11PM +0800, Stephen Warren wrote:
    > On 04/25/2012 05:49 AM, Dong Aisheng wrote:
    > > On Wed, Apr 25, 2012 at 07:19:43PM +0800, Linus Walleij wrote:
    > >> On Wed, Apr 25, 2012 at 11:49 AM, Dong Aisheng
    > >> <aisheng.dong@freescale.com> wrote:
    > >>> On Wed, Apr 25, 2012 at 03:00:23AM +0800, Stephen Warren wrote:
    > >>
    > >>>> The only thing that should be calling pinctrl_request_gpio() is a GPIO
    > >>>> driver. It should only be calling it for the GPIOs it manages. I'd
    > >>>> expect that if a platform's pinctrl driver was not yet written to
    > >>>> support the GPIO functionality, then the GPIO driver would not be
    > >>>> calling this function.
    > >>>>
    > >>> Hmm, pinctrl gpio is in the same situation as pinctrl state that gpio
    > >>> driver may be shared between several platforms, with pinctrl support
    > >>> or not.
    > >>
    > >> I think it's mostly safe to assume that either:
    > >>
    > > I just saw your reply after i sent out the revised patch...
    > >
    > >> - pinctrl calls from GPIO drivers gets stubbed out totally due to
    > >> CONFIG_PINCTRL not being selected
    > >>
    > > Yes, we already have that in include/linux/pinctrl/consumer.h
    > >
    > >> or:
    > >>
    > >> - You need to pass a token through platform data to the
    > >> GPIO driver telling it whether it needs to request pins for
    > >> it's GPIOs or not. Just a bool should work fine?
    > >>
    > > Yes, this is an alternative way.
    > > I'm using a similar way, but pass the data to pinctrl core
    > > rather than gpio driver. Then it is be handled together with
    > > dummy state in platform code.
    > >
    > > Do you think if the current way i used is ok?
    > > Or i need to change to your proposed way?
    >
    > I think Linus was suggesting a flag in platform data for each GPIO
    > driver rather than a global flag for the entire pinctrl subsystem.
    >
    > That way, if one of the pinctrl drivers did fully support all the GPIO
    > functionality and the other didn't, you'd be able to have just one of
    > the GPIO drivers not call into pinctrl (or ignore certain errors) yet
    > the other GPIO driver could still fully interact with pinctrl as desired.
    >
    Yes, it's true.
    I will drop the dummy gpio support in pinctrl subsystem and let gpio
    driver to decide whether it wants to use pinctrl gpio mux function.

    Regards
    Dong Aisheng



    \
     
     \ /
      Last update: 2012-04-26 09:43    [W:0.034 / U:0.708 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site