[PATCH V1 05/11] ARM: dts: imx6qdl-sabrelite: specify pad settings

[Shawn Guo]

On Fri, Dec 13, 2013 at 10:50:29PM +0100, Marek Vasut wrote:
> On Friday, December 13, 2013 at 07:42:25 PM, Troy Kisky wrote:
> > On 12/13/2013 4:48 AM, Marek Vasut wrote:
> > > On Friday, December 13, 2013 at 02:49:09 AM, Troy Kisky wrote:
> > >> Don't use 0x80000000 to get default pad settings.
> > > 
> > > What is the rationale behind this change please? Can you explain more in
> > > detail?
> > 
> > No real need, but I thought relying on what the boot loader did or did
> > not do
> > was discouraged?
> 
> Full ACK on this, we do not rely on bootloader configuration (though these two 
> should be in-line).
> 
> > What is the value in not explicitly setting the pad registers?
> 
> My question was in the direction of "why do you need to change the pin 
> configuration values from the current ones?". This is what I want to understand.
> 
> > Btw, I need to rebase series on your patch anyway so omitting this patch
> > would be easy.
> 
> I am not saying to omit it, please do not misunderstand me. I am just wondering 
> why the change from 0x80000000 to 0x1b0b0 .

Per Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt,

 Bits used for CONFIG:
 NO_PAD_CTL(1 << 31): indicate this pin does not need config.

0x80000000 tells pinctrl driver to not touch pad config register at all.
In that case, the configuration of the pad will be what boot loader
configures or just the reset value.

Explicitly putting a proper pad config value instead of 0x80000000
should be something we encourage.

Shawn