From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Cooper <jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org>
Subject: Re: [PATCH v4 03/10] pinctrl: mvebu: kirkwood pinctrl driver
Date: Sun, 16 Sep 2012 08:40:15 -0400
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To: Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>
Cc: Thomas Petazzoni <thomas.petazzoni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>, Lior Amsalem <alior-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>, Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>, Ben Dooks <ben.dooks-4yDnlxn2s6sWdaTGBSpHTA@public.gmane.org>, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Sebastian Hesselbarth <sebastian.hesselbarth-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
List-Id: devicetree@vger.kernel.org

On Sun, Sep 16, 2012 at 09:46:52AM +0200, Andrew Lunn wrote:
> > +++ b/Documentation/devicetree/bindings/pinctrl/marvell,kirkwood-pinctrl.txt
> > @@ -0,0 +1,279 @@
> > +* Marvell Kirkwood SoC pinctrl driver for mpp
> > +
> > +Please refer to marvell,mvebu-pinctrl.txt in this directory for common binding
> > +part and usage.
> > +
> > +Required properties:
> > +- compatible: "marvell,88f6180-pinctrl",
> > +              "marvell,88f6190-pinctrl", "marvell,88f6192-pinctrl",
> > +              "marvell,88f6281-pinctrl", "marvell,88f6282-pinctrl"
> > +
> > +This driver supports all kirkwood variants, i.e. 88f6180, 88f619x, and 88f628
> 
> Hi Sebastian 
> 
> The current MPP code determines for itself what chip it is running on.
> It can then check if a pin configuration is valid for the current
> run time environment.
> 
> Here you are suggesting we have to put into the DT what chip we expect
> to be on.
> 
> What is the advantage of this, over getting the information from the
> device itself?

The DT should describe the hardware as accurately as possible.  We can't
always assume Linux will be the only thing the DT is handed off to.

> If i wanted to mass convert all existing kirkwood DT boards over to
> use pinctrl, im stuck at the very first step. I've no idea what chip
> they use, it was not relevant before.

Let's try to do the DT correctly, and create a migration path for
kirkwood to work first, then migrate to using the DT fully.

thx,

Jason.