Re: [PATCH 2/3] ARM: dts: imx: replace magic number with pin function name

[Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

On Fri, Feb 22, 2013 at 03:36:32PM +0800, Shawn Guo wrote:
> On Fri, Feb 22, 2013 at 08:27:43AM +0100, Sascha Hauer wrote:
> > On Fri, Feb 22, 2013 at 01:52:04PM +0800, Shawn Guo wrote:
> > > On Thu, Feb 21, 2013 at 11:36:36AM -0600, Matt Sealey wrote:
> > > > On Wed, Feb 20, 2013 at 11:02 PM, Shawn Guo <shawn.guo@linaro.org> wrote:
> > > > > On Wed, Feb 20, 2013 at 06:03:39PM -0600, Matt Sealey wrote:
> > > > >> I am not sure I am getting this point across, but.. damn it.. nack nack nack :D
> > > > >>
> > > > > Do you see any downgrade side that the series introduces over the
> > > > > existing implementation?
> > > > 
> > > > Because it replaces the horribly stupid existing implementation with
> > > > something that doesn't solve the fundamental logical problems caused
> > > > by the existing implementation.
> > > 
> > > When did I say that the series is targeting to solve those "fundamental
> > > logical problems" in *your* view?
> > > 
> > > ...
> > > 
> > > > What you've fixed it to do, as I read this patch, is this;
> > > > 
> > > > <arbitrary_pin_name pad_mode>
> > > > 
> > > No, it's not arbitrary_pin_name.  It's pin function name which comes
> > > from hardware manual.  It may not exactly match the public reference
> > > manual, but they are obvious to be identified.  For imx6q pad SD2_DAT1
> > > example, the manual says:
> > > 
> > > Select 1 of 6 iomux modes to be used for pad: SD2_DAT1.
> > >   000 ALT0 — Select signal SD2_DATA1.
> > >   001 ALT1 — Select signal ECSPI5_SS0.
> > >   010 ALT2 — Select signal EIM_CS2.
> > >   011 ALT3 — Select signal AUD4_TXFS.
> > >   100 ALT4 — Select signal KEY_COL7.
> > >   101 ALT5 — Select signal GPIO1_IO14.
> > 
> > What makes them arbitrary is the fact that 110 and 111 are not encoded,
> > so there is no way to calculate the register number from the pin number.
> > 
> > Also
> > 
> > commit 4a5f7eff8b0b34354e5c63272835e5e2dfe1c933
> > Author: Dong Aisheng <dong.aisheng@linaro.org>
> > Date:   Fri Jul 6 17:09:23 2012 +0800
> > 
> >     pinctrl: pinctrl-imx6q: add missed mux function for USBOTG_ID
> > 
> > Shows that they are indeed arbitrary.
> > 
> > I'm really with Matt here when he says that this number doesn't have to
> > be in the binding.
> 
> I think you are still talking about that arbitrary index in the old
> binding, while I'm arguing against Matt's the comment on the new one,
> saying the macro/pin name is arbitrary.

Sorry, I haven't read the above carefully enough. We are talking about
the names here, not the numbers I referred to.

Sascha

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