[PATCH] i2c: s3c24xx: allow device core to setup default pin configuration

Heiko Stübner heiko at sntech.de
Thu Mar 21 06:50:05 EDT 2013

Am Donnerstag, 21. März 2013, 11:00:32 schrieb Wolfram Sang:
> On Mon, Mar 04, 2013 at 07:12:53PM +0530, Thomas Abraham wrote:
> > With device core now able to setup the default pin configuration,
> > the call to devm_pinctrl_get_select_default can be removed. And
> > the pin configuration code based on the deprecated Samsung specific
> > gpio bindings is also removed.
> > 
> > Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
> > ---
> > 
> > Hi Heiko, Tomasz,
> > 
> > We have to make a choice on the path forward for pinctrl support
> > on Samsung platforms. We have three cases to deal with.
> > 
> > A. Samsung platforms without DT support.
> > B. Samsung platforms with DT support using old Samsung specific
> > 
> >    gpio bindings for pin-configuration (s3c24xx and s3x64xx).
> > 
> > C. Samsung platforms with DT support using using pinctrl based
> > 
> >    pin-configurations (Exynos4 and Exynos5).
> > 
> > For [A], we just let the platform specific callbacks handle the
> > pin setup. For [B] and [C], based on Linus Walleij's pin grab
> > by device core patch and subsequent discussions with him on the
> > mailing list, would it be acceptable that we discontinue support
> > for [B] in Samsung SoC device drivers. This will impact your
> > current DT work on s3c24xx and s3c64xx platforms. Pinctrl is
> > inevitable and we have to migrate to it. Instead of workarounds
> > to maintain support for [B], it might be better that we migrate
> > s3c24xx and s3c64xx platforms to pinctrl.
> > 
> > Please do let us know your opinion on this.
> Dropping [B] sounds good, but I think it makes sense to wait with this
> patch until pinctrl support for s3c24xx is in place?

s3c24xx does not currently have dt support in mainline at all and the non-dt 
init is not touched at all. Also it seems the legacy gpio based dt init does 
not work at all currently, because the pinctrl function are no-ops and 
therefore the legacy gpio init is never reached on such systems.

So I would vote for dropping [B]. I'm already working a bit on a pinctrl 
driver for s3c24xx, so when I reintroduce s3c24xx dt support again, it should 
already have pinctrl support then.


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