Re: [RFC PATCH v3 3/5] pinctrl: imx: add pinctrl imx driver

[Richard Zhao <richard.zhao@freescale.com>]

On Mon, Jan 09, 2012 at 02:32:12PM +0800, Shawn Guo wrote:
> On Mon, Jan 09, 2012 at 10:17:03AM +0800, Richard Zhao wrote:
> > On Mon, Jan 09, 2012 at 10:08:51AM +0800, Shawn Guo wrote:
> > > On Sun, Jan 08, 2012 at 09:05:44PM +0800, Richard Zhao wrote:
> > > > > +enum imx_imx53_pinctrl_pads {
> > > > > +	MX53_GPIO_19 = 0,
> > > > > +	MX53_KEY_COL0 = 1,
> > > > > +	MX53_KEY_ROW0 = 2,
> > > > > +	MX53_KEY_COL1 = 3,
> > > > > +	MX53_KEY_ROW1 = 4,
> > > > > +	MX53_KEY_COL2 = 5,
> > > > > +	MX53_KEY_ROW2 = 6,
> > > > ...
> > > > Why not describe it in dts and make this file generic for imx?
> > > > One node for one pad,
> > > 
> > > Doing this will bloat the device tree dramatically.  Actually I had
> > > a patch doing so before the pinctrl subsystem was born, but it
> > > concerned Grant a lot for that reason and thus died.
> > are you against describing pad in dts or one node per pad?
> > one node per pad is just a tip to extend pad property, to support
> > other features (pinconf in your word).
> 
> I definitely want to describe pinconf in device tree, though what's
> the best interface for pinctrl client driver to talk to pinconf is
> still vague to me.
> 
> > > 
> > > > it'll be easy to extend pad properties. You know
> > > > the pad may set pull up/down, open drain, drive strenth, daisy chain etc.
> > > > The features have to be supported, to make your model usefull.
> > > > 
> > > As Aisheng mentioned, the pinconf support will be added later.
> > I expect pinconf come together, and get a ready-to-use patch series.
> > 
> As I was educated by Linus.W, we can not drink ocean and we need to
> split big chunk of work into pieces and achieve it step by step.
Sure, we can not drink out the ocean :). But if people can not use it
in real case, how do we verify the driver? How do we know the driver
goes in the right way?

Thanks
Richard
> 
> -- 
> Regards,
> Shawn
>