On Wed, 30 Jan 2013, Guennadi Liakhovetski wrote:
> Hi Arnd
>
> Thanks for your input.
>
> On Wed, 30 Jan 2013, Arnd Bergmann wrote:
>
> > On Monday 28 January 2013, Chris Ball wrote:
> > > On Wed, Jan 23 2013, Guennadi Liakhovetski wrote:
> > > > +cd-inverted and wp-inverted properties are deprecated ans shouldn't be
> > > > used,
> > > > +instead pleaseuse the OF_GPIO_ACTIVE_LOW flag in respective GPIO
> > > > bindings. Note,
> > > > +that the default (as defined by the SDHCI standard) CD and WP polarity
> > > > is
> > > > +active-low, so, OF_GPIO_ACTIVE_LOW should normally be set, and only be
> > > > left
> > > > +clear, if the polarity is inverted.
> > >
> > > Please use this text for your next version, fixing typos and a newline:
> > >
> > > cd-inverted and wp-inverted properties are deprecated and shouldn't be
> > > used,
> > > instead please use the OF_GPIO_ACTIVE_LOW flag in respective GPIO
> > > bindings.
> > > Note that the default (as defined by the SDHCI standard) CD and WP
> > > polarity
> > > is active-low, so OF_GPIO_ACTIVE_LOW should normally be set, and only be
> > > left clear if the polarity is inverted.
> >
> > Hmm, I wonder if this is possible in general. A lot of the GPIO bindings
> > allow passing flags, but I think that some of them do not, for historic
> > reasons. If we want to deprecate the behavior in eMMC, we should also
> > ensure that all gpio drivers are extended to support gpio specifiers
> > with flags. It should be possible to extend all drivers in a compatible
> > way, but someone has to do that.
> >
> > When we introduced the MMC binding, the situation was already like this,
> > and it seemed easier to leave the {wp,cd}-inverted properties as optional.
>
> This means, that a multi-platform driver like, e.g. SDHCI cannot use the
> gpio "flags" cell and has to fall-back to always use "*-inverted"
> properties. Same holds for any other multi-arch driver, using GPIOs. So,
> we're stuck with this?
BTW, just verified in the current "next": all platforms, using cd-inverted
or wp-inverted in the mainline
arch/arm/boot/dts/ccu9540.dts
arch/arm/boot/dts/ea3250.dts
arch/arm/boot/dts/phy3250.dts
arch/arm/boot/dts/snowball.dts
arch/arm/boot/dts/u9540.dts
use GPIO controllers with 2 or 3 cells.
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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