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?
But in fact, we're not dropping support for those flags. We're just
encouraging any new mmc drivers to use GPIO flags. Maybe we should just
change the wording from "deprecated" to "discouraged" and replace the
warning with a debug message?
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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